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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-07 08:56:33 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-07 08:56:33 -0800 |
| commit | b4a45f5fe8078bfc10837dbd5b98735058bc4698 (patch) | |
| tree | df6f13a27610a3ec7eb4a661448cd779a8f84c79 | |
| parent | 01539ba2a706ab7d35fc0667dff919ade7f87d63 (diff) | |
| parent | b3e19d924b6eaf2ca7d22cba99a517c5171007b6 (diff) | |
| download | linux-3.10-b4a45f5fe8078bfc10837dbd5b98735058bc4698.tar.gz linux-3.10-b4a45f5fe8078bfc10837dbd5b98735058bc4698.tar.bz2 linux-3.10-b4a45f5fe8078bfc10837dbd5b98735058bc4698.zip | |
Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin
* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits)
fs: scale mntget/mntput
fs: rename vfsmount counter helpers
fs: implement faster dentry memcmp
fs: prefetch inode data in dcache lookup
fs: improve scalability of pseudo filesystems
fs: dcache per-inode inode alias locking
fs: dcache per-bucket dcache hash locking
bit_spinlock: add required includes
kernel: add bl_list
xfs: provide simple rcu-walk ACL implementation
btrfs: provide simple rcu-walk ACL implementation
ext2,3,4: provide simple rcu-walk ACL implementation
fs: provide simple rcu-walk generic_check_acl implementation
fs: provide rcu-walk aware permission i_ops
fs: rcu-walk aware d_revalidate method
fs: cache optimise dentry and inode for rcu-walk
fs: dcache reduce branches in lookup path
fs: dcache remove d_mounted
fs: fs_struct use seqlock
fs: rcu-walk for path lookup
...
212 files changed, 4774 insertions, 2014 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 33fa3e5d38f..977d8919cc6 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -9,22 +9,25 @@ be able to use diff(1). --------------------------- dentry_operations -------------------------- prototypes: - int (*d_revalidate)(struct dentry *, int); - int (*d_hash) (struct dentry *, struct qstr *); - int (*d_compare) (struct dentry *, struct qstr *, struct qstr *); + int (*d_revalidate)(struct dentry *, struct nameidata *); + int (*d_hash)(const struct dentry *, const struct inode *, + struct qstr *); + int (*d_compare)(const struct dentry *, const struct inode *, + const struct dentry *, const struct inode *, + unsigned int, const char *, const struct qstr *); int (*d_delete)(struct dentry *); void (*d_release)(struct dentry *); void (*d_iput)(struct dentry *, struct inode *); char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen); locking rules: - dcache_lock rename_lock ->d_lock may block -d_revalidate: no no no yes -d_hash no no no yes -d_compare: no yes no no -d_delete: yes no yes no -d_release: no no no yes -d_iput: no no no yes + rename_lock ->d_lock may block rcu-walk +d_revalidate: no no yes (ref-walk) maybe +d_hash no no no maybe +d_compare: yes no no maybe +d_delete: no yes no no +d_release: no no yes no +d_iput: no no yes no d_dname: no no no no --------------------------- inode_operations --------------------------- @@ -44,8 +47,8 @@ ata *); void * (*follow_link) (struct dentry *, struct nameidata *); void (*put_link) (struct dentry *, struct nameidata *, void *); void (*truncate) (struct inode *); - int (*permission) (struct inode *, int, struct nameidata *); - int (*check_acl)(struct inode *, int); + int (*permission) (struct inode *, int, unsigned int); + int (*check_acl)(struct inode *, int, unsigned int); int (*setattr) (struct dentry *, struct iattr *); int (*getattr) (struct vfsmount *, struct dentry *, struct kstat *); int (*setxattr) (struct dentry *, const char *,const void *,size_t,int); @@ -73,7 +76,7 @@ follow_link: no put_link: no truncate: yes (see below) setattr: yes -permission: no +permission: no (may not block if called in rcu-walk mode) check_acl: no getattr: no setxattr: yes diff --git a/Documentation/filesystems/dentry-locking.txt b/Documentation/filesystems/dentry-locking.txt deleted file mode 100644 index 79334ed5daa..00000000000 --- a/Documentation/filesystems/dentry-locking.txt +++ /dev/null @@ -1,174 +0,0 @@ -RCU-based dcache locking model -============================== - -On many workloads, the most common operation on dcache is to look up a -dentry, given a parent dentry and the name of the child. Typically, -for every open(), stat() etc., the dentry corresponding to the -pathname will be looked up by walking the tree starting with the first -component of the pathname and using that dentry along with the next -component to look up the next level and so on. Since it is a frequent -operation for workloads like multiuser environments and web servers, -it is important to optimize this path. - -Prior to 2.5.10, dcache_lock was acquired in d_lookup and thus in -every component during path look-up. Since 2.5.10 onwards, fast-walk -algorithm changed this by holding the dcache_lock at the beginning and -walking as many cached path component dentries as possible. This -significantly decreases the number of acquisition of -dcache_lock. However it also increases the lock hold time -significantly and affects performance in large SMP machines. Since -2.5.62 kernel, dcache has been using a new locking model that uses RCU -to make dcache look-up lock-free. - -The current dcache locking model is not very different from the -existing dcache locking model. Prior to 2.5.62 kernel, dcache_lock -protected the hash chain, d_child, d_alias, d_lru lists as well as -d_inode and several other things like mount look-up. RCU-based changes -affect only the way the hash chain is protected. For everything else -the dcache_lock must be taken for both traversing as well as -updating. The hash chain updates too take the dcache_lock. The -significant change is the way d_lookup traverses the hash chain, it -doesn't acquire the dcache_lock for this and rely on RCU to ensure -that the dentry has not been *freed*. - - -Dcache locking details -====================== - -For many multi-user workloads, open() and stat() on files are very -frequently occurring operations. Both involve walking of path names to -find the dentry corresponding to the concerned file. In 2.4 kernel, -dcache_lock was held during look-up of each path component. Contention -and cache-line bouncing of this global lock caused significant -scalability problems. With the introduction of RCU in Linux kernel, -this was worked around by making the look-up of path components during -path walking lock-free. - - -Safe lock-free look-up of dcache hash table -=========================================== - -Dcache is a complex data structure with the hash table entries also -linked together in other lists. In 2.4 kernel, dcache_lock protected -all the lists. We applied RCU only on hash chain walking. The rest of -the lists are still protected by dcache_lock. Some of the important -changes are : - -1. The deletion from hash chain is done using hlist_del_rcu() macro - which doesn't initialize next pointer of the deleted dentry and - this allows us to walk safely lock-free while a deletion is - happening. - -2. Insertion of a dentry into the hash table is done using - hlist_add_head_rcu() which take care of ordering the writes - the - writes to the dentry must be visible before the dentry is - inserted. This works in conjunction with hlist_for_each_rcu(), - which has since been replaced by hlist_for_each_entry_rcu(), while - walking the hash chain. The only requirement is that all - initialization to the dentry must be done before - hlist_add_head_rcu() since we don't have dcache_lock protection - while traversing the hash chain. This isn't different from the - existing code. - -3. The dentry looked up without holding dcache_lock by cannot be - returned for walking if it is unhashed. It then may have a NULL - d_inode or other bogosity since RCU doesn't protect the other - fields in the dentry. We therefore use a flag DCACHE_UNHASHED to - indicate unhashed dentries and use this in conjunction with a - per-dentry lock (d_lock). Once looked up without the dcache_lock, - we acquire the per-dentry lock (d_lock) and check if the dentry is - unhashed. If so, the look-up is failed. If not, the reference count - of the dentry is increased and the dentry is returned. - -4. Once a dentry is looked up, it must be ensured during the path walk - for that component it doesn't go away. In pre-2.5.10 code, this was - done holding a reference to the dentry. dcache_rcu does the same. - In some sense, dcache_rcu path walking looks like the pre-2.5.10 - version. - -5. All dentry hash chain updates must take the dcache_lock as well as - the per-dentry lock in that order. dput() does this to ensure that - a dentry that has just been looked up in another CPU doesn't get - deleted before dget() can be done on it. - -6. There are several ways to do reference counting of RCU protected - objects. One such example is in ipv4 route cache where deferred - freeing (using call_rcu()) is done as soon as the reference count - goes to zero. This cannot be done in the case of dentries because - tearing down of dentries require blocking (dentry_iput()) which - isn't supported from RCU callbacks. Instead, tearing down of - dentries happen synchronously in dput(), but actual freeing happens - later when RCU grace period is over. This allows safe lock-free - walking of the hash chains, but a matched dentry may have been - partially torn down. The checking of DCACHE_UNHASHED flag with - d_lock held detects such dentries and prevents them from being - returned from look-up. - - -Maintaining POSIX rename semantics -================================== - -Since look-up of dentries is lock-free, it can race against a -concurrent rename operation. For example, during rename of file A to -B, look-up of either A or B must succeed. So, if look-up of B happens -after A has been removed from the hash chain but not added to the new -hash chain, it may fail. Also, a comparison while the name is being -written concurrently by a rename may result in false positive matches -violating rename semantics. Issues related to race with rename are -handled as described below : - -1. Look-up can be done in two ways - d_lookup() which is safe from - simultaneous renames and __d_lookup() which is not. If - __d_lookup() fails, it must be followed up by a d_lookup() to - correctly determine whether a dentry is in the hash table or - not. d_lookup() protects look-ups using a sequence lock - (rename_lock). - -2. The name associated with a dentry (d_name) may be changed if a - rename is allowed to happen simultaneously. To avoid memcmp() in - __d_lookup() go out of bounds due to a rename and false positive - comparison, the name comparison is done while holding the - per-dentry lock. This prevents concurrent renames during this - operation. - -3. Hash table walking during look-up may move to a different bucket as - the current dentry is moved to a different bucket due to rename. - But we use hlists in dcache hash table and they are - null-terminated. So, even if a dentry moves to a different bucket, - hash chain walk will terminate. [with a list_head list, it may not - since termination is when the list_head in the original bucket is - reached]. Since we redo the d_parent check and compare name while - holding d_lock, lock-free look-up will not race against d_move(). - -4. There can be a theoretical race when a dentry keeps coming back to - original bucket due to double moves. Due to this look-up may - consider that it has never moved and can end up in a infinite loop. - But this is not any worse that theoretical livelocks we already - have in the kernel. - - -Important guidelines for filesystem developers related to dcache_rcu -==================================================================== - -1. Existing dcache interfaces (pre-2.5.62) exported to filesystem - don't change. Only dcache internal implementation changes. However - filesystems *must not* delete from the dentry hash chains directly - using the list macros like allowed earlier. They must use dcache - APIs like d_drop() or __d_drop() depending on the situation. - -2. d_flags is now protected by a per-dentry lock (d_lock). All access - to d_flags must be protected by it. - -3. For a hashed dentry, checking of d_count needs to be protected by - d_lock. - - -Papers and other documentation on dcache locking -================================================ - -1. Scaling dcache with RCU (http://linuxjournal.com/article.php?sid=7124). - -2. http://lse.sourceforge.net/locking/dcache/dcache.html - - - diff --git a/Documentation/filesystems/path-lookup.txt b/Documentation/filesystems/path-lookup.txt new file mode 100644 index 00000000000..eb59c8b44be --- /dev/null +++ b/Documentation/filesystems/path-lookup.txt @@ -0,0 +1,382 @@ +Path walking and name lookup locking +==================================== + +Path resolution is the finding a dentry corresponding to a path name string, by +performing a path walk. Typically, for every open(), stat() etc., the path name +will be resolved. Paths are resolved by walking the namespace tree, starting +with the first component of the pathname (eg. root or cwd) with a known dentry, +then finding the child of that dentry, which is named the next component in the +path string. Then repeating the lookup from the child dentry and finding its +child with the next element, and so on. + +Since it is a frequent operation for workloads like multiuser environments and +web servers, it is important to optimize this code. + +Path walking synchronisation history: +Prior to 2.5.10, dcache_lock was acquired in d_lookup (dcache hash lookup) and +thus in every component during path look-up. Since 2.5.10 onwards, fast-walk +algorithm changed this by holding the dcache_lock at the beginning and walking +as many cached path component dentries as possible. This significantly +decreases the number of acquisition of dcache_lock. However it also increases +the lock hold time significantly and affects performance in large SMP machines. +Since 2.5.62 kernel, dcache has been using a new locking model that uses RCU to +make dcache look-up lock-free. + +All the above algorithms required taking a lock and reference count on the +dentry that was looked up, so that may be used as the basis for walking the +next path element. This is inefficient and unscalable. It is inefficient +because of the locks and atomic operations required for every dentry element +slows things down. It is not scalable because many parallel applications that +are path-walk intensive tend to do path lookups starting from a common dentry +(usually, the root "/" or current working directory). So contention on these +common path elements causes lock and cacheline queueing. + +Since 2.6.38, RCU is used to make a significant part of the entire path walk +(including dcache look-up) completely "store-free" (so, no locks, atomics, or +even stores into cachelines of common dentries). This is known as "rcu-walk" +path walking. + +Path walking overview +===================== + +A name string specifies a start (root directory, cwd, fd-relative) and a +sequence of elements (directory entry names), which together refer to a path in +the namespace. A path is represented as a (dentry, vfsmount) tuple. The name +elements are sub-strings, seperated by '/'. + +Name lookups will want to find a particular path that a name string refers to +(usually the final element, or parent of final element). This is done by taking +the path given by the name's starting point (which we know in advance -- eg. +current->fs->cwd or current->fs->root) as the first parent of the lookup. Then +iteratively for each subsequent name element, look up the child of the current +parent with the given name and if it is not the desired entry, make it the +parent for the next lookup. + +A parent, of course, must be a directory, and we must have appropriate +permissions on the parent inode to be able to walk into it. + +Turning the child into a parent for the next lookup requires more checks and +procedures. Symlinks essentially substitute the symlink name for the target +name in the name string, and require some recursive path walking. Mount points +must be followed into (thus changing the vfsmount that subsequent path elements +refer to), switching from the mount point path to the root of the particular +mounted vfsmount. These behaviours are variously modified depending on the +exact path walking flags. + +Path walking then must, broadly, do several particular things: +- find the start point of the walk; +- perform permissions and validity checks on inodes; +- perform dcache hash name lookups on (parent, name element) tuples; +- traverse mount points; +- traverse symlinks; +- lookup and create missing parts of the path on demand. + +Safe store-free look-up of dcache hash table +============================================ + +Dcache name lookup +------------------ +In order to lookup a dcache (parent, name) tuple, we take a hash on the tuple +and use that to select a bucket in the dcache-hash table. The list of entries +in that bucket is then walked, and we do a full comparison of each entry +against our (parent, name) tuple. + +The hash lists are RCU protected, so list walking is not serialised with +concurrent updates (insertion, deletion from the hash). This is a standard RCU +list application with the exception of renames, which will be covered below. + +Parent and name members of a dentry, as well as its membership in the dcache +hash, and its inode are protected by the per-dentry d_lock spinlock. A +reference is taken on the dentry (while the fields are verified under d_lock), +and this stabilises its d_inode pointer and actual inode. This gives a stable +point to perform the next step of our path walk against. + +These members are also protected by d_seq seqlock, although this offers +read-only protection and no durability of results, so care must be taken when +using d_seq for synchronisation (see seqcount based lookups, below). + +Renames +------- +Back to the rename case. In usual RCU protected lists, the only operations that +will happen to an object is insertion, and then eventually removal from the +list. The object will not be reused until an RCU grace period is complete. +This ensures the RCU list traversal primitives can run over the object without +problems (see RCU documentation for how this works). + +However when a dentry is renamed, its hash value can change, requiring it to be +moved to a new hash list. Allocating and inserting a new alias would be +expensive and also problematic for directory dentries. Latency would be far to +high to wait for a grace period after removing the dentry and before inserting +it in the new hash bucket. So what is done is to insert the dentry into the +new list immediately. + +However, when the dentry's list pointers are updated to point to objects in the +new list before waiting for a grace period, this can result in a concurrent RCU +lookup of the old list veering off into the new (incorrect) list and missing +the remaining dentries on the list. + +There is no fundamental problem with walking down the wrong list, because the +dentry comparisons will never match. However it is fatal to miss a matching +dentry. So a seqlock is used to detect when a rename has occurred, and so the +lookup can be retried. + + 1 2 3 + +---+ +---+ +---+ +hlist-->| N-+->| N-+->| N-+-> +head <--+-P |<-+-P |<-+-P | + +---+ +---+ +---+ + +Rename of dentry 2 may require it deleted from the above list, and inserted +into a new list. Deleting 2 gives the following list. + + 1 3 + +---+ +---+ (don't worry, the longer pointers do not +hlist-->| N-+-------->| N-+-> impose a measurable performance overhead +head <--+-P |<--------+-P | on modern CPUs) + +---+ +---+ + ^ 2 ^ + | +---+ | + | | N-+----+ + +----+-P | + +---+ + +This is a standard RCU-list deletion, which leaves the deleted object's +pointers intact, so a concurrent list walker that is currently looking at +object 2 will correctly continue to object 3 when it is time to traverse the +next object. + +However, when inserting object 2 onto a new list, we end up with this: + + 1 3 + +---+ +---+ +hlist-->| N-+-------->| N-+-> +head <--+-P |<--------+-P | + +---+ +---+ + 2 + +---+ + | N-+----> + <----+-P | + +---+ + +Because we didn't wait for a grace period, there may be a concurrent lookup +still at 2. Now when it follows 2's 'next' pointer, it will walk off into +another list without ever having checked object 3. + +A related, but distinctly different, issue is that of rename atomicity versus +lookup operations. If a file is renamed from 'A' to 'B', a lookup must only +find either 'A' or 'B'. So if a lookup of 'A' returns NULL, a subsequent lookup +of 'B' must succeed (note the reverse is not true). + +Between deleting the dentry from the old hash list, and inserting it on the new +hash list, a lookup may find neither 'A' nor 'B' matching the dentry. The same +rename seqlock is also used to cover this race in much the same way, by +retrying a negative lookup result if a rename was in progress. + +Seqcount based lookups +---------------------- +In refcount based dcache lookups, d_lock is used to serialise access to +the dentry, stabilising it while comparing its name and parent and then +taking a reference count (the reference count then gives a stable place to +start the next part of the path walk from). + +As explained above, we would like to do path walking without taking locks or +reference counts on intermediate dentries along the path. To do this, a per +dentry seqlock (d_seq) is used to take a "coherent snapshot" of what the dentry +looks like (its name, parent, and inode). That snapshot is then used to start +the next part of the path walk. When loading the coherent snapshot under d_seq, +care must be taken to load the members up-front, and use those pointers rather +than reloading from the dentry later on (otherwise we'd have interesting things +like d_inode going NULL underneath us, if the name was unlinked). + +Also important is to avoid performing any destructive operations (pretty much: +no non-atomic stores to shared data), and to recheck the seqcount when we are +"done" with the operation. Retry or abort if the seqcount does not match. +Avoiding destructive or changing operations means we can easily unwind from +failure. + +What this means is that a caller, provided they are holding RCU lock to +protect the dentry object from disappearing, can perform a seqcount based +lookup which does not increment the refcount on the dentry or write to +it in any way. This returned dentry can be used for subsequent operations, +provided that d_seq is rechecked after that operation is complete. + +Inodes are also rcu freed, so the seqcount lookup dentry's inode may also be +queried for permissions. + +With this two parts of the puzzle, we can do path lookups without taking +locks or refcounts on dentry elements. + +RCU-walk path walking design +============================ + +Path walking code now has two distinct modes, ref-walk and rcu-walk. ref-walk +is the traditional[*] way of performing dcache lookups using d_lock to +serialise concurrent modifications to the dentry and take a reference count on +it. ref-walk is simple and obvious, and may sleep, take locks, etc while path +walking is operating on each dentry. rcu-walk uses seqcount based dentry +lookups, and can perform lookup of intermediate elements without any stores to +shared data in the dentry or inode. rcu-walk can not be applied to all cases, +eg. if the filesystem must sleep or perform non trivial operations, rcu-walk +must be switched to ref-walk mode. + +[*] RCU is still used for the dentry hash lookup in ref-walk, but not the full + path walk. + +Where ref-walk uses a stable, refcounted ``parent'' to walk the remaining +path string, rcu-walk uses a d_seq protected snapshot. When looking up a +child of this parent snapshot, we open d_seq critical section on the child +before closing d_seq critical section on the parent. This gives an interlocking +ladder of snapshots to walk down. + + + proc 101 + /----------------\ + / comm: "vi" \ + / fs.root: dentry0 \ + \ fs.cwd: dentry2 / + \ / + \----------------/ + +So when vi wants to open("/home/npiggin/test.c", O_RDWR), then it will +start from current->fs->root, which is a pinned dentry. Alternatively, +"./test.c" would start from cwd; both names refer to the same path in +the context of proc101. + + dentry 0 + +---------------------+ rcu-walk begins here, we note d_seq, check the + | name: "/" | inode's permission, and then look up the next + | inode: 10 | path element which is "home"... + | children:"home", ...| + +---------------------+ + | + dentry 1 V + +---------------------+ ... which brings us here. We find dentry1 via + | name: "home" | hash lookup, then note d_seq and compare name + | inode: 678 | string and parent pointer. When we have a match, + | children:"npiggin" | we now recheck the d_seq of dentry0. Then we + +---------------------+ check inode and look up the next element. + | + dentry2 V + +---------------------+ Note: if dentry0 is now modified, lookup is + | name: "npiggin" | not necessarily invalid, so we need only keep a + | inode: 543 | parent for d_seq verification, and grandparents + | children:"a.c", ... | can be forgotten. + +---------------------+ + | + dentry3 V + +---------------------+ At this point we have our destination dentry. + | name: "a.c" | We now take its d_lock, verify d_seq of this + | inode: 14221 | dentry. If that checks out, we can increment + | children:NULL | its refcount because we're holding d_lock. + +---------------------+ + +Taking a refcount on a dentry from rcu-walk mode, by taking its d_lock, +re-checking its d_seq, and then incrementing its refcount is called +"dropping rcu" or dropping from rcu-walk into ref-walk mode. + +It is, in some sense, a bit of a house of cards. If the seqcount check of the +parent snapshot fails, the house comes down, because we had closed the d_seq +section on the grandparent, so we have nothing left to stand on. In that case, +the path walk must be fully restarted (which we do in ref-walk mode, to avoid +live locks). It is costly to have a full restart, but fortunately they are +quite rare. + +When we reach a point where sleeping is required, or a filesystem callout +requires ref-walk, then instead of restarting the walk, we attempt to drop rcu +at the last known good dentry we have. Avoiding a full restart in ref-walk in +these cases is fundamental for performance and scalability because blocking +operations such as creates and unlinks are not uncommon. + +The detailed design for rcu-walk is like this: +* LOOKUP_RCU is set in nd->flags, which distinguishes rcu-walk from ref-walk. +* Take the RCU lock for the entire path walk, starting with the acquiring + of the starting path (eg. root/cwd/fd-path). So now dentry refcounts are + not required for dentry persistence. +* synchronize_rcu is called when unregistering a filesystem, so we can + access d_ops and i_ops during rcu-walk. +* Similarly take the vfsmount lock for the entire path walk. So now mnt + refcounts are not required for persistence. Also we are free to perform mount + lookups, and to assume dentry mount points and mount roots are stable up and + down the path. +* Have a per-dentry seqlock to protect the dentry name, parent, and inode, + so we can load this tuple atomically, and also check whether any of its + members have changed. +* Dentry lookups (based on parent, candidate string tuple) recheck the parent + sequence after the child is found in case anything changed in the parent + during the path walk. +* inode is also RCU protected so we can load d_inode and use the inode for + limited things. +* i_mode, i_uid, i_gid can be tested for exec permissions during path walk. +* i_op can be loaded. +* When the destination dentry is reached, drop rcu there (ie. take d_lock, + verify d_seq, increment refcount). +* If seqlock verification fails anywhere along the path, do a full restart + of the path lookup in ref-walk mode. -ECHILD tends to be used (for want of + a better errno) to signal an rcu-walk failure. + +The cases where rcu-walk cannot continue are: +* NULL dentry (ie. any uncached path element) +* Following links + +It may be possible eventually to make following links rcu-walk aware. + +Uncached path elements will always require dropping to ref-walk mode, at the +very least because i_mutex needs to be grabbed, and objects allocated. + +Final note: +"store-free" path walking is not strictly store free. We take vfsmount lock +and refcounts (both of which can be made per-cpu), and we also store to the +stack (which is essentially CPU-local), and we also have to take locks and +refcount on final dentry. + +The point is that shared data, where practically possible, is not locked +or stored into. The result is massive improvements in performance and +scalability of path resolution. + + +Interesting statistics +====================== + +The following table gives rcu lookup statistics for a few simple workloads +(2s12c24t Westmere, debian non-graphical system). Ungraceful are attempts to +drop rcu that fail due to d_seq failure and requiring the entire path lookup +again. Other cases are successful rcu-drops that are required before the final +element, nodentry for missing dentry, revalidate for filesystem revalidate +routine requiring rcu drop, permission for permission check requiring drop, +and link for symlink traversal requiring drop. + + rcu-lookups restart nodentry link revalidate permission +bootup 47121 0 4624 1010 10283 7852 +dbench 25386793 0 6778659(26.7%) 55 549 1156 +kbuild 2696672 10 64442(2.3%) 108764(4.0%) 1 1590 +git diff 39605 0 28 2 0 106 +vfstest 24185492 4945 708725(2.9%) 1076136(4.4%) 0 2651 + +What this shows is that failed rcu-walk lookups, ie. ones that are restarted +entirely with ref-walk, are quite rare. Even the "vfstest" case which +specifically has concurrent renames/mkdir/rmdir/ creat/unlink/etc to excercise +such races is not showing a huge amount of restarts. + +Dropping from rcu-walk to ref-walk mean that we have encountered a dentry where +the reference count needs to be taken for some reason. This is either because +we have reached the target of the path walk, or because we have encountered a +condition that can't be resolved in rcu-walk mode. Ideally, we drop rcu-walk +only when we have reached the target dentry, so the other statistics show where +this does not happen. + +Note that a graceful drop from rcu-walk mode due to something such as the +dentry not existing (which can be common) is not necessarily a failure of +rcu-walk scheme, because some elements of the path may have been walked in +rcu-walk mode. The further we get from common path elements (such as cwd or +root), the less contended the dentry is likely to be. The closer we are to +common path elements, the more likely they will exist in dentry cache. + + +Papers and other documentation on dcache locking +================================================ + +1. Scaling dcache with RCU (http://linuxjournal.com/article.php?sid=7124). + +2. http://lse.sourceforge.net/locking/dcache/dcache.html + + diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index b12c8953868..07a32b42cf9 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -216,7 +216,6 @@ had ->revalidate()) add calls in ->follow_link()/->readlink(). ->d_parent changes are not protected by BKL anymore. Read access is safe if at least one of the following is true: * filesystem has no cross-directory rename() - * dcache_lock is held * we know that parent had been locked (e.g. we are looking at ->d_parent of ->lookup() argument). * we are called from ->rename(). @@ -318,3 +317,71 @@ if it's zero is not *and* *never* *had* *been* enough. Final unlink() and iput( may happen while the inode is in the middle of ->write_inode(); e.g. if you blindly free the on-disk inode, you may end up doing that while ->write_inode() is writing to it. + +--- +[mandatory] + + .d_delete() now only advises the dcache as to whether or not to cache +unreferenced dentries, and is now only called when the dentry refcount goes to +0. Even on 0 refcount transition, it must be able to tolerate being called 0, +1, or more times (eg. constant, idempotent). + +--- +[mandatory] + + .d_compare() calling convention and locking rules are significantly +changed. Read updated documentation in Documentation/filesystems/vfs.txt (and +look at examples of other filesystems) for guidance. + +--- +[mandatory] + + .d_hash() calling convention and locking rules are significantly +changed. Read updated documentation in Documentation/filesystems/vfs.txt (and +look at examples of other filesystems) for guidance. + +--- +[mandatory] + dcache_lock is gone, replaced by fine grained locks. See fs/dcache.c +for details of what locks to replace dcache_lock with in order to protect +particular things. Most of the time, a filesystem only needs ->d_lock, which +protects *all* the dcache state of a given dentry. + +-- +[mandatory] + + Filesystems must RCU-free their inodes, if they can have been accessed +via rcu-walk path walk (basically, if the file can have had a path name in the +vfs namespace). + + i_dentry and i_rcu share storage in a union, and the vfs expects +i_dentry to be reinitialized before it is freed, so an: + + INIT_LIST_HEAD(&inode->i_dentry); + +must be done in the RCU callback. + +-- +[recommended] + vfs now tries to do path walking in "rcu-walk mode", which avoids +atomic operations and scalability hazards on dentries and inodes (see +Documentation/filesystems/path-walk.txt). d_hash and d_compare changes (above) +are examples of the changes required to support this. For more complex +filesystem callbacks, the vfs drops out of rcu-walk mode before the fs call, so +no changes are required to the filesystem. However, this is costly and loses +the benefits of rcu-walk mode. We will begin to add filesystem callbacks that +are rcu-walk aware, shown below. Filesystems should take advantage of this +where possible. + +-- +[mandatory] + d_revalidate is a callback that is made on every path element (if +the filesystem provides it), which requires dropping out of rcu-walk mode. This +may now be called in rcu-walk mode (nd->flags & LOOKUP_RCU). -ECHILD should be +returned if the filesystem cannot handle rcu-walk. See +Documentation/filesystems/vfs.txt for more details. + + permission and check_acl are inode permission checks that are called +on many or all directory inodes on the way down a path walk (to check for +exec permission). These must now be rcu-walk aware (flags & IPERM_RCU). See +Documentation/filesystems/vfs.txt for more details. diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 20899e095e7..fbb324e2bd4 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -325,7 +325,8 @@ struct inode_operations { void * (*follow_link) (struct dentry *, struct nameidata *); void (*put_link) (struct dentry *, struct nameidata *, void *); void (*truncate) (struct inode *); - int (*permission) (struct inode *, int, struct nameidata *); + int (*permission) (struct inode *, int, unsigned int); + int (*check_acl)(struct inode *, int, unsigned int); int (*setattr) (struct dentry *, struct iattr *); int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *); int (*setxattr) (struct dentry *, const char *,const void *,size_t,int); @@ -414,6 +415,13 @@ otherwise noted. permission: called by the VFS to check for access rights on a POSIX-like filesystem. + May be called in rcu-walk mode (flags & IPERM_RCU). If in rcu-walk + mode, the filesystem must check the permission without blocking or + storing to the inode. + + If a situation is encountered that rcu-walk cannot handle, return + -ECHILD and it will be called again in ref-walk mode. + setattr: called by the VFS to set attributes for a file. This method is called by chmod(2) and related system calls. @@ -847,9 +855,12 @@ defined: struct dentry_operations { int (*d_revalidate)(struct dentry *, struct nameidata *); - int (*d_hash) (struct dentry *, struct qstr *); - int (*d_compare) (struct dentry *, struct qstr *, struct qstr *); - int (*d_delete)(struct dentry *); + int (*d_hash)(const struct dentry *, const struct inode *, + struct qstr *); + int (*d_compare)(const struct dentry *, const struct inode *, + const struct dentry *, const struct inode *, + unsigned int, const char *, const struct qstr *); + int (*d_delete)(const struct dentry *); void (*d_release)(struct dentry *); void (*d_iput)(struct dentry *, struct inode *); char *(*d_dname)(struct dentry *, char *, int); @@ -860,13 +871,45 @@ struct dentry_operations { dcache. Most filesystems leave this as NULL, because all their dentries in the dcache are valid - d_hash: called when the VFS adds a dentry to the hash table + d_revalidate may be called in rcu-walk mode (nd->flags & LOOKUP_RCU). + If in rcu-walk mode, the filesystem must revalidate the dentry without + blocking or storing to the dentry, d_parent and d_inode should not be + used without care (because they can go NULL), instead nd->inode should + be used. + + If a situation is encountered that rcu-walk cannot handle, return + -ECHILD and it will be called again in ref-walk mode. + + d_hash: called when the VFS adds a dentry to the hash table. The first + dentry passed to d_hash is the parent directory that the name is + to be hashed into. The inode is the dentry's inode. + + Same locking and synchronisation rules as d_compare regarding + what is safe to dereference etc. + + d_compare: called to compare a dentry name with a given name. The first + dentry is the parent of the dentry to be compared, the second is + the parent's inode, then the dentry and inode (may be NULL) of the + child dentry. len and name string are properties of the dentry to be + compared. qstr is the name to compare it with. + + Must be constant and idempotent, and should not take locks if + possible, and should not or store into the dentry or inodes. + Should not dereference pointers outside the dentry or inodes without + lots of care (eg. d_parent, d_inode, d_name should not be used). + + However, our vfsmount is pinned, and RCU held, so the dentries and + inodes won't disappear, neither will our sb or filesystem module. + ->i_sb and ->d_sb may be used. - d_compare: called when a dentry should be compared with another + It is a tricky calling convention because it needs to be called under + "rcu-walk", ie. without any locks or references on things. - d_delete: called when the last reference to a dentry is - deleted. This means no-one is using the dentry, however it is - still valid and in the dcache + d_delete: called when the last reference to a dentry is dropped and the + dcache is deciding whether or not to cache it. Return 1 to delete + immediately, or 0 to cache the dentry. Default is NULL which means to + always cache a reachable dentry. d_delete must be constant and + idempotent. d_release: called when a dentry is really deallocated @@ -910,14 +953,11 @@ manipulate dentries: the usage count) dput: close a handle for a dentry (decrements the usage count). If - the usage count drops to 0, the "d_delete" method is called - and the dentry is placed on the unused list if the dentry is - still in its parents hash list. Putting the dentry on the - unused list just means that if the system needs some RAM, it - goes through the unused list of dentries and deallocates them. - If the dentry has already been unhashed and the usage count - drops to 0, in this case the dentry is deallocated after the - "d_delete" method is called + the usage count drops to 0, and the dentry is still in its + parent's hash, the "d_delete" method is called to check whether + it should be cached. If it should not be cached, or if the dentry + is not hashed, it is deleted. Otherwise cached dentries are put + into an LRU list to be reclaimed on memory shortage. d_drop: this unhashes a dentry from its parents hash list. A subsequent call to dput() will deallocate the dentry if its diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c index 39e534f5a3b..f099b82703d 100644 --- a/arch/ia64/kernel/perfmon.c +++ b/arch/ia64/kernel/perfmon.c @@ -1542,7 +1542,7 @@ pfm_exit_smpl_buffer(pfm_buffer_fmt_t *fmt) * any operations on the root directory. However, we need a non-trivial * d_name - pfm: will go nicely and kill the special-casing in procfs. */ -static struct vfsmount *pfmfs_mnt; +static struct vfsmount *pfmfs_mnt __read_mostly; static int __init init_pfm_fs(void) @@ -2185,7 +2185,7 @@ static const struct file_operations pfm_file_ops = { }; static int -pfmfs_delete_dentry(struct dentry *dentry) +pfmfs_delete_dentry(const struct dentry *dentry) { return 1; } @@ -2233,7 +2233,7 @@ pfm_alloc_file(pfm_context_t *ctx) } path.mnt = mntget(pfmfs_mnt); - path.dentry->d_op = &pfmfs_dentry_operations; + d_set_d_op(path.dentry, &pfmfs_dentry_operations); d_add(path.dentry, inode); file = alloc_file(&path, FMODE_READ, &pfm_file_ops); diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c index 3532b92de98..856e9c39806 100644 --- a/arch/powerpc/platforms/cell/spufs/inode.c +++ b/arch/powerpc/platforms/cell/spufs/inode.c @@ -71,12 +71,18 @@ spufs_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void -spufs_destroy_inode(struct inode *inode) +static void spufs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(spufs_inode_cache, SPUFS_I(inode)); } +static void spufs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, spufs_i_callback); +} + static void spufs_init_once(void *p) { @@ -159,18 +165,18 @@ static void spufs_prune_dir(struct dentry *dir) mutex_lock(&dir->d_inode->i_mutex); list_for_each_entry_safe(dentry, tmp, &dir->d_subdirs, d_u.d_child) { - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); if (!(d_unhashed(dentry)) && dentry->d_inode) { - dget_locked(dentry); + dget_dlock(dentry); __d_drop(dentry); spin_unlock(&dentry->d_lock); simple_unlink(dir->d_inode, dentry); - spin_unlock(&dcache_lock); + /* XXX: what was dcache_lock protecting here? Other + * filesystems (IB, configfs) release dcache_lock + * before unlink */ dput(dentry); } else { spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); } } shrink_dcache_parent(dir); diff --git a/drivers/infiniband/hw/ipath/ipath_fs.c b/drivers/infiniband/hw/ipath/ipath_fs.c index 8c8afc716b9..31ae1b108ae 100644 --- a/drivers/infiniband/hw/ipath/ipath_fs.c +++ b/drivers/infiniband/hw/ipath/ipath_fs.c @@ -277,18 +277,14 @@ static int remove_file(struct dentry *parent, char *name) goto bail; } - spin_lock(&dcache_lock); spin_lock(&tmp->d_lock); if (!(d_unhashed(tmp) && tmp->d_inode)) { - dget_locked(tmp); + dget_dlock(tmp); __d_drop(tmp); spin_unlock(&tmp->d_lock); - spin_unlock(&dcache_lock); simple_unlink(parent->d_inode, tmp); - } else { + } else spin_unlock(&tmp->d_lock); - spin_unlock(&dcache_lock); - } ret = 0; bail: diff --git a/drivers/infiniband/hw/qib/qib_fs.c b/drivers/infiniband/hw/qib/qib_fs.c index f99bddc0171..df7fa251dcd 100644 --- a/drivers/infiniband/hw/qib/qib_fs.c +++ b/drivers/infiniband/hw/qib/qib_fs.c @@ -453,17 +453,14 @@ static int remove_file(struct dentry *parent, char *name) goto bail; } - spin_lock(&dcache_lock); spin_lock(&tmp->d_lock); if (!(d_unhashed(tmp) && tmp->d_inode)) { - dget_locked(tmp); + dget_dlock(tmp); __d_drop(tmp); spin_unlock(&tmp->d_lock); - spin_unlock(&dcache_lock); simple_unlink(parent->d_inode, tmp); } else { spin_unlock(&tmp->d_lock); - spin_unlock(&dcache_lock); } ret = 0; diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index 4759d827e8c..f511dd15fd3 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -1201,7 +1201,7 @@ err_unregister_chdev: static void __exit cleanup_mtdchar(void) { unregister_mtd_user(&mtdchar_notifier); - mntput(mtd_inode_mnt); + mntput_long(mtd_inode_mnt); unregister_filesystem(&mtd_inodefs_type); __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd"); } diff --git a/drivers/staging/autofs/root.c b/drivers/staging/autofs/root.c index 0fdec4befd8..bf0e9755da6 100644 --- a/drivers/staging/autofs/root.c +++ b/drivers/staging/autofs/root.c @@ -154,13 +154,16 @@ static int try_to_fill_dentry(struct dentry *dentry, struct super_block *sb, str * yet completely filled in, and revalidate has to delay such * lookups.. */ -static int autofs_revalidate(struct dentry * dentry, struct nameidata *nd) +static int autofs_revalidate(struct dentry *dentry, struct nameidata *nd) { struct inode * dir; struct autofs_sb_info *sbi; struct autofs_dir_ent *ent; int res; + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + lock_kernel(); dir = dentry->d_parent->d_inode; sbi = autofs_sbi(dir->i_sb); @@ -237,7 +240,7 @@ static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentr * * We need to do this before we release the directory semaphore. */ - dentry->d_op = &autofs_dentry_operations; + d_set_d_op(dentry, &autofs_dentry_operations); dentry->d_flags |= DCACHE_AUTOFS_PENDING; d_add(dentry, NULL); diff --git a/drivers/staging/pohmelfs/inode.c b/drivers/staging/pohmelfs/inode.c index 61685ccceda..cc8d2840f9b 100644 --- a/drivers/staging/pohmelfs/inode.c +++ b/drivers/staging/pohmelfs/inode.c @@ -826,6 +826,13 @@ const struct address_space_operations pohmelfs_aops = { .set_page_dirty = __set_page_dirty_nobuffers, }; +static void pohmelfs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(pohmelfs_inode_cache, POHMELFS_I(inode)); +} + /* * ->detroy_inode() callback. Deletes inode from the caches * and frees private data. @@ -842,8 +849,8 @@ static void pohmelfs_destroy_inode(struct inode *inode) dprintk("%s: pi: %p, inode: %p, ino: %llu.\n", __func__, pi, &pi->vfs_inode, pi->ino); - kmem_cache_free(pohmelfs_inode_cache, pi); atomic_long_dec(&psb->total_inodes); + call_rcu(&inode->i_rcu, pohmelfs_i_callback); } /* diff --git a/drivers/staging/pohmelfs/path_entry.c b/drivers/staging/pohmelfs/path_entry.c index 8ec83d2dffb..400a9fc386a 100644 --- a/drivers/staging/pohmelfs/path_entry.c +++ b/drivers/staging/pohmelfs/path_entry.c @@ -83,10 +83,11 @@ out: int pohmelfs_path_length(struct pohmelfs_inode *pi) { struct dentry *d, *root, *first; - int len = 1; /* Root slash */ + int len; + unsigned seq; - first = d = d_find_alias(&pi->vfs_inode); - if (!d) { + first = d_find_alias(&pi->vfs_inode); + if (!first) { dprintk("%s: ino: %llu, mode: %o.\n", __func__, pi->ino, pi->vfs_inode.i_mode); return -ENOENT; } @@ -95,7 +96,11 @@ int pohmelfs_path_length(struct pohmelfs_inode *pi) root = dget(current->fs->root.dentry); spin_unlock(¤t->fs->lock); - spin_lock(&dcache_lock); +rename_retry: + len = 1; /* Root slash */ + d = first; + seq = read_seqbegin(&rename_lock); + rcu_read_lock(); if (!IS_ROOT(d) && d_unhashed(d)) len += UNHASHED_OBSCURE_STRING_SIZE; /* Obscure " (deleted)" string */ @@ -104,7 +109,9 @@ int pohmelfs_path_length(struct pohmelfs_inode *pi) len += d->d_name.len + 1; /* Plus slash */ d = d->d_parent; } - spin_unlock(&dcache_lock); + rcu_read_unlock(); + if (read_seqretry(&rename_lock, seq)) + goto rename_retry; dput(root); dput(first); diff --git a/drivers/staging/smbfs/cache.c b/drivers/staging/smbfs/cache.c index dbb98658148..f2a1323ca82 100644 --- a/drivers/staging/smbfs/cache.c +++ b/drivers/staging/smbfs/cache.c @@ -62,7 +62,7 @@ smb_invalidate_dircache_entries(struct dentry *parent) struct list_head *next; struct dentry *dentry; - spin_lock(&dcache_lock); + spin_lock(&parent->d_lock); next = parent->d_subdirs.next; while (next != &parent->d_subdirs) { dentry = list_entry(next, struct dentry, d_u.d_child); @@ -70,7 +70,7 @@ smb_invalidate_dircache_entries(struct dentry *parent) smb_age_dentry(server, dentry); next = next->next; } - spin_unlock(&dcache_lock); + spin_unlock(&parent->d_lock); } /* @@ -96,13 +96,13 @@ smb_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos) } /* If a pointer is invalid, we search the dentry. */ - spin_lock(&dcache_lock); + spin_lock(&parent->d_lock); next = parent->d_subdirs.next; while (next != &parent->d_subdirs) { dent = list_entry(next, struct dentry, d_u.d_child); if ((unsigned long)dent->d_fsdata == fpos) { if (dent->d_inode) - dget_locked(dent); + dget(dent); else dent = NULL; goto out_unlock; @@ -111,7 +111,7 @@ smb_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos) } dent = NULL; out_unlock: - spin_unlock(&dcache_lock); + spin_unlock(&parent->d_lock); return dent; } @@ -134,7 +134,7 @@ smb_fill_cache(struct file *filp, void *dirent, filldir_t filldir, qname->hash = full_name_hash(qname->name, qname->len); if (dentry->d_op && dentry->d_op->d_hash) - if (dentry->d_op->d_hash(dentry, qname) != 0) + if (dentry->d_op->d_hash(dentry, inode, qname) != 0) goto end_advance; newdent = d_lookup(dentry, qname); @@ -145,8 +145,8 @@ smb_fill_cache(struct file *filp, void *dirent, filldir_t filldir, goto end_advance; } else { hashed = 1; - memcpy((char *) newdent->d_name.name, qname->name, - newdent->d_name.len); + /* dir i_mutex is locked because we're in readdir */ + dentry_update_name_case(newdent, qname); } if (!newdent->d_inode) { diff --git a/drivers/staging/smbfs/dir.c b/drivers/staging/smbfs/dir.c index f088ea2f6ac..dd612f50749 100644 --- a/drivers/staging/smbfs/dir.c +++ b/drivers/staging/smbfs/dir.c @@ -14,6 +14,7 @@ #include <linux/ctype.h> #include <linux/net.h> #include <linux/sched.h> +#include <linux/namei.h> #include "smb_fs.h" #include "smb_mount.h" @@ -274,9 +275,13 @@ smb_dir_open(struct inode *dir, struct file *file) * Dentry operations routines */ static int smb_lookup_validate(struct dentry *, struct nameidata *); -static int smb_hash_dentry(struct dentry *, struct qstr *); -static int smb_compare_dentry(struct dentry *, struct qstr *, struct qstr *); -static int smb_delete_dentry(struct dentry *); +static int smb_hash_dentry(const struct dentry *, const struct inode *, + struct qstr *); +static int smb_compare_dentry(const struct dentry *, + const struct inode *, + const struct dentry *, const struct inode *, + unsigned int, const char *, const struct qstr *); +static int smb_delete_dentry(const struct dentry *); static const struct dentry_operations smbfs_dentry_operations = { @@ -297,13 +302,20 @@ static const struct dentry_operations smbfs_dentry_operations_case = * This is the callback when the dcache has a lookup hit. */ static int -smb_lookup_validate(struct dentry * dentry, struct nameidata *nd) +smb_lookup_validate(struct dentry *dentry, struct nameidata *nd) { - struct smb_sb_info *server = server_from_dentry(dentry); - struct inode * inode = dentry->d_inode; - unsigned long age = jiffies - dentry->d_time; + struct smb_sb_info *server; + struct inode *inode; + unsigned long age; int valid; + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + + server = server_from_dentry(dentry); + inode = dentry->d_inode; + age = jiffies - dentry->d_time; + /* * The default validation is based on dentry age: * we believe in dentries for a few seconds. (But each @@ -333,7 +345,8 @@ smb_lookup_validate(struct dentry * dentry, struct nameidata *nd) } static int -smb_hash_dentry(struct dentry *dir, struct qstr *this) +smb_hash_dentry(const struct dentry *dir, const struct inode *inode, + struct qstr *this) { unsigned long hash; int i; @@ -347,14 +360,17 @@ smb_hash_dentry(struct dentry *dir, struct qstr *this) } static int -smb_compare_dentry(struct dentry *dir, struct qstr *a, struct qstr *b) +smb_compare_dentry(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { int i, result = 1; - if (a->len != b->len) + if (len != name->len) goto out; - for (i=0; i < a->len; i++) { - if (tolower(a->name[i]) != tolower(b->name[i])) + for (i=0; i < len; i++) { + if (tolower(str[i]) != tolower(name->name[i])) goto out; } result = 0; @@ -367,7 +383,7 @@ out: * We use this to unhash dentries with bad inodes. */ static int -smb_delete_dentry(struct dentry * dentry) +smb_delete_dentry(const struct dentry *dentry) { if (dentry->d_inode) { if (is_bad_inode(dentry->d_inode)) { @@ -390,9 +406,9 @@ smb_new_dentry(struct dentry *dentry) struct smb_sb_info *server = server_from_dentry(dentry); if (server->mnt->flags & SMB_MOUNT_CASE) - dentry->d_op = &smbfs_dentry_operations_case; + d_set_d_op(dentry, &smbfs_dentry_operations_case); else - dentry->d_op = &smbfs_dentry_operations; + d_set_d_op(dentry, &smbfs_dentry_operations); dentry->d_time = jiffies; } @@ -454,9 +470,9 @@ smb_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) add_entry: server = server_from_dentry(dentry); if (server->mnt->flags & SMB_MOUNT_CASE) - dentry->d_op = &smbfs_dentry_operations_case; + d_set_d_op(dentry, &smbfs_dentry_operations_case); else - dentry->d_op = &smbfs_dentry_operations; + d_set_d_op(dentry, &smbfs_dentry_operations); d_add(dentry, inode); smb_renew_times(dentry); diff --git a/drivers/staging/smbfs/file.c b/drivers/staging/smbfs/file.c index 5dcd19c60eb..31372e7b12d 100644 --- a/drivers/staging/smbfs/file.c +++ b/drivers/staging/smbfs/file.c @@ -407,11 +407,14 @@ smb_file_release(struct inode *inode, struct file * file) * privileges, so we need our own check for this. */ static int -smb_file_permission(struct inode *inode, int mask) +smb_file_permission(struct inode *inode, int mask, unsigned int flags) { int mode = inode->i_mode; int error = 0; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + VERBOSE("mode=%x, mask=%x\n", mode, mask); /* Look at user permissions */ diff --git a/drivers/staging/smbfs/inode.c b/drivers/staging/smbfs/inode.c index 540a984bb51..244319dc970 100644 --- a/drivers/staging/smbfs/inode.c +++ b/drivers/staging/smbfs/inode.c @@ -62,11 +62,18 @@ static struct inode *smb_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void smb_destroy_inode(struct inode *inode) +static void smb_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(smb_inode_cachep, SMB_I(inode)); } +static void smb_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, smb_i_callback); +} + static void init_once(void *foo) { struct smb_inode_info *ei = (struct smb_inode_info *) foo; diff --git a/drivers/usb/core/inode.c b/drivers/usb/core/inode.c index b690aa35df9..1b125c224dc 100644 --- a/drivers/usb/core/inode.c +++ b/drivers/usb/core/inode.c @@ -343,17 +343,19 @@ static int usbfs_empty (struct dentry *dentry) { struct list_head *list; - spin_lock(&dcache_lock); - + spin_lock(&dentry->d_lock); list_for_each(list, &dentry->d_subdirs) { struct dentry *de = list_entry(list, struct dentry, d_u.d_child); + + spin_lock_nested(&de->d_lock, DENTRY_D_LOCK_NESTED); if (usbfs_positive(de)) { - spin_unlock(&dcache_lock); + spin_unlock(&de->d_lock); + spin_unlock(&dentry->d_lock); return 0; } + spin_unlock(&de->d_lock); } - - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); return 1; } diff --git a/fs/9p/acl.c b/fs/9p/acl.c index 12d602351db..6e58c4ca1e6 100644 --- a/fs/9p/acl.c +++ b/fs/9p/acl.c @@ -91,11 +91,14 @@ static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type) return acl; } -int v9fs_check_acl(struct inode *inode, int mask) +int v9fs_check_acl(struct inode *inode, int mask, unsigned int flags) { struct posix_acl *acl; struct v9fs_session_info *v9ses; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + v9ses = v9fs_inode2v9ses(inode); if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) { /* diff --git a/fs/9p/acl.h b/fs/9p/acl.h index 59e18c2e8c7..7ef3ac9f6d9 100644 --- a/fs/9p/acl.h +++ b/fs/9p/acl.h @@ -16,7 +16,7 @@ #ifdef CONFIG_9P_FS_POSIX_ACL extern int v9fs_get_acl(struct inode *, struct p9_fid *); -extern int v9fs_check_acl(struct inode *inode, int mask); +extern int v9fs_check_acl(struct inode *inode, int mask, unsigned int flags); extern int v9fs_acl_chmod(struct dentry *); extern int v9fs_set_create_acl(struct dentry *, struct posix_acl *, struct posix_acl *); diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c index cbf4e50f393..466d2a4fc5c 100644 --- a/fs/9p/vfs_dentry.c +++ b/fs/9p/vfs_dentry.c @@ -51,7 +51,7 @@ * */ -static int v9fs_dentry_delete(struct dentry *dentry) +static int v9fs_dentry_delete(const struct dentry *dentry) { P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_name.name, dentry); @@ -68,7 +68,7 @@ static int v9fs_dentry_delete(struct dentry *dentry) * */ -static int v9fs_cached_dentry_delete(struct dentry *dentry) +static int v9fs_cached_dentry_delete(const struct dentry *dentry) { struct inode *inode = dentry->d_inode; P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_name.name, diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 34bf71b5654..59782981b22 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -237,10 +237,17 @@ struct inode *v9fs_alloc_inode(struct super_block *sb) * */ -void v9fs_destroy_inode(struct inode *inode) +static void v9fs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(vcookie_cache, v9fs_inode2cookie(inode)); } + +void v9fs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, v9fs_i_callback); +} #endif /** @@ -270,11 +277,11 @@ static struct dentry *v9fs_dentry_from_dir_inode(struct inode *inode) { struct dentry *dentry; - spin_lock(&dcache_lock); + spin_lock(&inode->i_lock); /* Directory should have only one entry. */ BUG_ON(S_ISDIR(inode->i_mode) && !list_is_singular(&inode->i_dentry)); dentry = list_entry(inode->i_dentry.next, struct dentry, d_alias); - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); return dentry; } @@ -628,9 +635,9 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir, } if (v9ses->cache) - dentry->d_op = &v9fs_cached_dentry_operations; + d_set_d_op(dentry, &v9fs_cached_dentry_operations); else - dentry->d_op = &v9fs_dentry_operations; + d_set_d_op(dentry, &v9fs_dentry_operations); d_instantiate(dentry, inode); err = v9fs_fid_add(dentry, fid); @@ -742,7 +749,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int omode, err); goto error; } - dentry->d_op = &v9fs_cached_dentry_operations; + d_set_d_op(dentry, &v9fs_cached_dentry_operations); d_instantiate(dentry, inode); err = v9fs_fid_add(dentry, fid); if (err < 0) @@ -760,7 +767,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int omode, err = PTR_ERR(inode); goto error; } - dentry->d_op = &v9fs_dentry_operations; + d_set_d_op(dentry, &v9fs_dentry_operations); d_instantiate(dentry, inode); } /* Now set the ACL based on the default value */ @@ -949,7 +956,7 @@ static int v9fs_vfs_mkdir_dotl(struct inode *dir, err); goto error; } - dentry->d_op = &v9fs_cached_dentry_operations; + d_set_d_op(dentry, &v9fs_cached_dentry_operations); d_instantiate(dentry, inode); err = v9fs_fid_add(dentry, fid); if (err < 0) @@ -966,7 +973,7 @@ static int v9fs_vfs_mkdir_dotl(struct inode *dir, err = PTR_ERR(inode); goto error; } - dentry->d_op = &v9fs_dentry_operations; + d_set_d_op(dentry, &v9fs_dentry_operations); d_instantiate(dentry, inode); } /* Now set the ACL based on the default value */ @@ -1034,9 +1041,9 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, inst_out: if (v9ses->cache) - dentry->d_op = &v9fs_cached_dentry_operations; + d_set_d_op(dentry, &v9fs_cached_dentry_operations); else - dentry->d_op = &v9fs_dentry_operations; + d_set_d_op(dentry, &v9fs_dentry_operations); d_add(dentry, inode); return NULL; @@ -1702,7 +1709,7 @@ v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry, err); goto error; } - dentry->d_op = &v9fs_cached_dentry_operations; + d_set_d_op(dentry, &v9fs_cached_dentry_operations); d_instantiate(dentry, inode); err = v9fs_fid_add(dentry, fid); if (err < 0) @@ -1715,7 +1722,7 @@ v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry, err = PTR_ERR(inode); goto error; } - dentry->d_op = &v9fs_dentry_operations; + d_set_d_op(dentry, &v9fs_dentry_operations); d_instantiate(dentry, inode); } @@ -1849,7 +1856,7 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir, ihold(old_dentry->d_inode); } - dentry->d_op = old_dentry->d_op; + d_set_d_op(dentry, old_dentry->d_op); d_instantiate(dentry, old_dentry->d_inode); return err; @@ -1973,7 +1980,7 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, int omode, err); goto error; } - dentry->d_op = &v9fs_cached_dentry_operations; + d_set_d_op(dentry, &v9fs_cached_dentry_operations); d_instantiate(dentry, inode); err = v9fs_fid_add(dentry, fid); if (err < 0) @@ -1989,7 +1996,7 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, int omode, err = PTR_ERR(inode); goto error; } - dentry->d_op = &v9fs_dentry_operations; + d_set_d_op(dentry, &v9fs_dentry_operations); d_instantiate(dentry, inode); } /* Now set the ACL based on the default value */ diff --git a/fs/adfs/dir.c b/fs/adfs/dir.c index f4287e4de74..bf7693c384f 100644 --- a/fs/adfs/dir.c +++ b/fs/adfs/dir.c @@ -201,7 +201,8 @@ const struct file_operations adfs_dir_operations = { }; static int -adfs_hash(struct dentry *parent, struct qstr *qstr) +adfs_hash(const struct dentry *parent, const struct inode *inode, + struct qstr *qstr) { const unsigned int name_len = ADFS_SB(parent->d_sb)->s_namelen; const unsigned char *name; @@ -237,17 +238,19 @@ adfs_hash(struct dentry *parent, struct qstr *qstr) * requirements of the underlying filesystem. */ static int -adfs_compare(struct dentry *parent, struct qstr *entry, struct qstr *name) +adfs_compare(const struct dentry *parent, const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { int i; - if (entry->len != name->len) + if (len != name->len) return 1; for (i = 0; i < name->len; i++) { char a, b; - a = entry->name[i]; + a = str[i]; b = name->name[i]; if (a >= 'A' && a <= 'Z') @@ -273,7 +276,7 @@ adfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) struct object_info obj; int error; - dentry->d_op = &adfs_dentry_operations; + d_set_d_op(dentry, &adfs_dentry_operations); lock_kernel(); error = adfs_dir_lookup_byname(dir, &dentry->d_name, &obj); if (error == 0) { diff --git a/fs/adfs/super.c b/fs/adfs/super.c index 959dbff2d42..a4041b52fbc 100644 --- a/fs/adfs/super.c +++ b/fs/adfs/super.c @@ -240,11 +240,18 @@ static struct inode *adfs_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void adfs_destroy_inode(struct inode *inode) +static void adfs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(adfs_inode_cachep, ADFS_I(inode)); } +static void adfs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, adfs_i_callback); +} + static void init_once(void *foo) { struct adfs_inode_info *ei = (struct adfs_inode_info *) foo; @@ -477,7 +484,7 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent) adfs_error(sb, "get root inode failed\n"); goto error; } else - sb->s_root->d_op = &adfs_dentry_operations; + d_set_d_op(sb->s_root, &adfs_dentry_operations); unlock_kernel(); return 0; diff --git a/fs/affs/amigaffs.c b/fs/affs/amigaffs.c index 7d0f0a30f7a..3a4557e8325 100644 --- a/fs/affs/amigaffs.c +++ b/fs/affs/amigaffs.c @@ -128,7 +128,7 @@ affs_fix_dcache(struct dentry *dentry, u32 entry_ino) void *data = dentry->d_fsdata; struct list_head *head, *next; - spin_lock(&dcache_lock); + spin_lock(&inode->i_lock); head = &inode->i_dentry; next = head->next; while (next != head) { @@ -139,7 +139,7 @@ affs_fix_dcache(struct dentry *dentry, u32 entry_ino) } next = next->next; } - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); } diff --git a/fs/affs/namei.c b/fs/affs/namei.c index 914d1c0bc07..944a4042fb6 100644 --- a/fs/affs/namei.c +++ b/fs/affs/namei.c @@ -13,11 +13,19 @@ typedef int (*toupper_t)(int); static int affs_toupper(int ch); -static int affs_hash_dentry(struct dentry *, struct qstr *); -static int affs_compare_dentry(struct dentry *, struct qstr *, struct qstr *); +static int affs_hash_dentry(const struct dentry *, + const struct inode *, struct qstr *); +static int affs_compare_dentry(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name); static int affs_intl_toupper(int ch); -static int affs_intl_hash_dentry(struct dentry *, struct qstr *); -static int affs_intl_compare_dentry(struct dentry *, struct qstr *, struct qstr *); +static int affs_intl_hash_dentry(const struct dentry *, + const struct inode *, struct qstr *); +static int affs_intl_compare_dentry(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name); const struct dentry_operations affs_dentry_operations = { .d_hash = affs_hash_dentry, @@ -58,13 +66,13 @@ affs_get_toupper(struct super_block *sb) * Note: the dentry argument is the parent dentry. */ static inline int -__affs_hash_dentry(struct dentry *dentry, struct qstr *qstr, toupper_t toupper) +__affs_hash_dentry(struct qstr *qstr, toupper_t toupper) { const u8 *name = qstr->name; unsigned long hash; int i; - i = affs_check_name(qstr->name,qstr->len); + i = affs_check_name(qstr->name, qstr->len); if (i) return i; @@ -78,39 +86,41 @@ __affs_hash_dentry(struct dentry *dentry, struct qstr *qstr, toupper_t toupper) } static int -affs_hash_dentry(struct dentry *dentry, struct qstr *qstr) +affs_hash_dentry(const struct dentry *dentry, const struct inode *inode, + struct qstr *qstr) { - return __affs_hash_dentry(dentry, qstr, affs_toupper); + return __affs_hash_dentry(qstr, affs_toupper); } static int -affs_intl_hash_dentry(struct dentry *dentry, struct qstr *qstr) +affs_intl_hash_dentry(const struct dentry *dentry, const struct inode *inode, + struct qstr *qstr) { - return __affs_hash_dentry(dentry, qstr, affs_intl_toupper); + return __affs_hash_dentry(qstr, affs_intl_toupper); } -static inline int -__affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b, toupper_t toupper) +static inline int __affs_compare_dentry(unsigned int len, + const char *str, const struct qstr *name, toupper_t toupper) { - const u8 *aname = a->name; - const u8 *bname = b->name; - int len; + const u8 *aname = str; + const u8 *bname = name->name; - /* 'a' is the qstr of an already existing dentry, so the name - * must be valid. 'b' must be validated first. + /* + * 'str' is the name of an already existing dentry, so the name + * must be valid. 'name' must be validated first. */ - if (affs_check_name(b->name,b->len)) + if (affs_check_name(name->name, name->len)) return 1; - /* If the names are longer than the allowed 30 chars, + /* + * If the names are longer than the allowed 30 chars, * the excess is ignored, so their length may differ. */ - len = a->len; if (len >= 30) { - if (b->len < 30) + if (name->len < 30) return 1; len = 30; - } else if (len != b->len) + } else if (len != name->len) return 1; for (; len > 0; len--) @@ -121,14 +131,18 @@ __affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b, tou } static int -affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b) +affs_compare_dentry(const struct dentry *parent, const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - return __affs_compare_dentry(dentry, a, b, affs_toupper); + return __affs_compare_dentry(len, str, name, affs_toupper); } static int -affs_intl_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b) +affs_intl_compare_dentry(const struct dentry *parent,const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - return __affs_compare_dentry(dentry, a, b, affs_intl_toupper); + return __affs_compare_dentry(len, str, name, affs_intl_toupper); } /* @@ -226,7 +240,7 @@ affs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) if (IS_ERR(inode)) return ERR_CAST(inode); } - dentry->d_op = AFFS_SB(sb)->s_flags & SF_INTL ? &affs_intl_dentry_operations : &affs_dentry_operations; + d_set_d_op(dentry, AFFS_SB(sb)->s_flags & SF_INTL ? &affs_intl_dentry_operations : &affs_dentry_operations); d_add(dentry, inode); return NULL; } diff --git a/fs/affs/super.c b/fs/affs/super.c index 0cf7f4384cb..d39081bbe7c 100644 --- a/fs/affs/super.c +++ b/fs/affs/super.c @@ -95,11 +95,18 @@ static struct inode *affs_alloc_inode(struct super_block *sb) return &i->vfs_inode; } -static void affs_destroy_inode(struct inode *inode) +static void affs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(affs_inode_cachep, AFFS_I(inode)); } +static void affs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, affs_i_callback); +} + static void init_once(void *foo) { struct affs_inode_info *ei = (struct affs_inode_info *) foo; @@ -475,7 +482,7 @@ got_root: printk(KERN_ERR "AFFS: Get root inode failed\n"); goto out_error; } - sb->s_root->d_op = &affs_dentry_operations; + d_set_d_op(sb->s_root, &affs_dentry_operations); pr_debug("AFFS: s_flags=%lX\n",sb->s_flags); return 0; diff --git a/fs/afs/dir.c b/fs/afs/dir.c index 5439e1bc9a8..34a3263d60a 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -13,6 +13,7 @@ #include <linux/module.h> #include <linux/init.h> #include <linux/fs.h> +#include <linux/namei.h> #include <linux/pagemap.h> #include <linux/ctype.h> #include <linux/sched.h> @@ -23,7 +24,7 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry, static int afs_dir_open(struct inode *inode, struct file *file); static int afs_readdir(struct file *file, void *dirent, filldir_t filldir); static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd); -static int afs_d_delete(struct dentry *dentry); +static int afs_d_delete(const struct dentry *dentry); static void afs_d_release(struct dentry *dentry); static int afs_lookup_filldir(void *_cookie, const char *name, int nlen, loff_t fpos, u64 ino, unsigned dtype); @@ -581,7 +582,7 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry, } success: - dentry->d_op = &afs_fs_dentry_operations; + d_set_d_op(dentry, &afs_fs_dentry_operations); d_add(dentry, inode); _leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%llu }", @@ -607,6 +608,9 @@ static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd) void *dir_version; int ret; + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + vnode = AFS_FS_I(dentry->d_inode); if (dentry->d_inode) @@ -730,7 +734,7 @@ out_bad: * - called from dput() when d_count is going to 0. * - return 1 to request dentry be unhashed, 0 otherwise */ -static int afs_d_delete(struct dentry *dentry) +static int afs_d_delete(const struct dentry *dentry) { _enter("%s", dentry->d_name.name); diff --git a/fs/afs/internal.h b/fs/afs/internal.h index cca8eef736f..6d4bc1c8ff6 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -624,7 +624,7 @@ extern void afs_clear_permits(struct afs_vnode *); extern void afs_cache_permit(struct afs_vnode *, struct key *, long); extern void afs_zap_permits(struct rcu_head *); extern struct key *afs_request_key(struct afs_cell *); -extern int afs_permission(struct inode *, int); +extern int afs_permission(struct inode *, int, unsigned int); /* * server.c diff --git a/fs/afs/security.c b/fs/afs/security.c index bb4ed144d0e..f44b9d35537 100644 --- a/fs/afs/security.c +++ b/fs/afs/security.c @@ -285,13 +285,16 @@ static int afs_check_permit(struct afs_vnode *vnode, struct key *key, * - AFS ACLs are attached to directories only, and a file is controlled by its * parent directory's ACL */ -int afs_permission(struct inode *inode, int mask) +int afs_permission(struct inode *inode, int mask, unsigned int flags) { struct afs_vnode *vnode = AFS_FS_I(inode); afs_access_t uninitialized_var(access); struct key *key; int ret; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + _enter("{{%x:%u},%lx},%x,", vnode->fid.vid, vnode->fid.vnode, vnode->flags, mask); @@ -347,7 +350,7 @@ int afs_permission(struct inode *inode, int mask) } key_put(key); - ret = generic_permission(inode, mask, NULL); + ret = generic_permission(inode, mask, flags, NULL); _leave(" = %d", ret); return ret; diff --git a/fs/afs/super.c b/fs/afs/super.c index 27201cffece..f901a9d7c11 100644 --- a/fs/afs/super.c +++ b/fs/afs/super.c @@ -498,6 +498,14 @@ static struct inode *afs_alloc_inode(struct super_block *sb) return &vnode->vfs_inode; } +static void afs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + struct afs_vnode *vnode = AFS_FS_I(inode); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(afs_inode_cachep, vnode); +} + /* * destroy an AFS inode struct */ @@ -511,7 +519,7 @@ static void afs_destroy_inode(struct inode *inode) ASSERTCMP(vnode->server, ==, NULL); - kmem_cache_free(afs_inode_cachep, vnode); + call_rcu(&inode->i_rcu, afs_i_callback); atomic_dec(&afs_count_active_inodes); } diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c index 57ce55b2564..5fd38112a6c 100644 --- a/fs/anon_inodes.c +++ b/fs/anon_inodes.c @@ -102,7 +102,7 @@ struct file *anon_inode_getfile(const char *name, this.name = name; this.len = strlen(name); this.hash = 0; - path.dentry = d_alloc(anon_inode_mnt->mnt_sb->s_root, &this); + path.dentry = d_alloc_pseudo(anon_inode_mnt->mnt_sb, &this); if (!path.dentry) goto err_module; @@ -113,7 +113,7 @@ struct file *anon_inode_getfile(const char *name, */ ihold(anon_inode_inode); - path.dentry->d_op = &anon_inodefs_dentry_operations; + d_set_d_op(path.dentry, &anon_inodefs_dentry_operations); d_instantiate(path.dentry, anon_inode_inode); error = -ENFILE; @@ -232,7 +232,7 @@ static int __init anon_inode_init(void) return 0; err_mntput: - mntput(anon_inode_mnt); + mntput_long(anon_inode_mnt); err_unregister_filesystem: unregister_filesystem(&anon_inode_fs_type); err_exit: diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h index 3d283abf67d..0fffe1c24ce 100644 --- a/fs/autofs4/autofs_i.h +++ b/fs/autofs4/autofs_i.h @@ -16,6 +16,7 @@ #include <linux/auto_fs4.h> #include <linux/auto_dev-ioctl.h> #include <linux/mutex.h> +#include <linux/spinlock.h> #include <linux/list.h> /* This is the range of ioctl() numbers we claim as ours */ @@ -60,6 +61,8 @@ do { \ current->pid, __func__, ##args); \ } while (0) +extern spinlock_t autofs4_lock; + /* Unified info structure. This is pointed to by both the dentry and inode structures. Each file in the filesystem has an instance of this structure. It holds a reference to the dentry, so dentries are never @@ -254,17 +257,15 @@ static inline int simple_positive(struct dentry *dentry) return dentry->d_inode && !d_unhashed(dentry); } -static inline int __simple_empty(struct dentry *dentry) +static inline void __autofs4_add_expiring(struct dentry *dentry) { - struct dentry *child; - int ret = 0; - - list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child) - if (simple_positive(child)) - goto out; - ret = 1; -out: - return ret; + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct autofs_info *ino = autofs4_dentry_ino(dentry); + if (ino) { + if (list_empty(&ino->expiring)) + list_add(&ino->expiring, &sbi->expiring_list); + } + return; } static inline void autofs4_add_expiring(struct dentry *dentry) diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c index a796c9417fb..cc1d0136590 100644 --- a/fs/autofs4/expire.c +++ b/fs/autofs4/expire.c @@ -91,24 +91,64 @@ done: } /* - * Calculate next entry in top down tree traversal. - * From next_mnt in namespace.c - elegant. + * Calculate and dget next entry in top down tree traversal. */ -static struct dentry *next_dentry(struct dentry *p, struct dentry *root) +static struct dentry *get_next_positive_dentry(struct dentry *prev, + struct dentry *root) { - struct list_head *next = p->d_subdirs.next; + struct list_head *next; + struct dentry *p, *ret; + + if (prev == NULL) + return dget(prev); + spin_lock(&autofs4_lock); +relock: + p = prev; + spin_lock(&p->d_lock); +again: + next = p->d_subdirs.next; if (next == &p->d_subdirs) { while (1) { - if (p == root) + struct dentry *parent; + + if (p == root) { + spin_unlock(&p->d_lock); + spin_unlock(&autofs4_lock); + dput(prev); return NULL; + } + + parent = p->d_parent; + if (!spin_trylock(&parent->d_lock)) { + spin_unlock(&p->d_lock); + cpu_relax(); + goto relock; + } + spin_unlock(&p->d_lock); next = p->d_u.d_child.next; - if (next != &p->d_parent->d_subdirs) + p = parent; + if (next != &parent->d_subdirs) break; - p = p->d_parent; } } - return list_entry(next, struct dentry, d_u.d_child); + ret = list_entry(next, struct dentry, d_u.d_child); + + spin_lock_nested(&ret->d_lock, DENTRY_D_LOCK_NESTED); + /* Negative dentry - try next */ + if (!simple_positive(ret)) { + spin_unlock(&ret->d_lock); + p = ret; + goto again; + } + dget_dlock(ret); + spin_unlock(&ret->d_lock); + spin_unlock(&p->d_lock); + spin_unlock(&autofs4_lock); + + dput(prev); + + return ret; } /* @@ -158,18 +198,11 @@ static int autofs4_tree_busy(struct vfsmount *mnt, if (!simple_positive(top)) return 1; - spin_lock(&dcache_lock); - for (p = top; p; p = next_dentry(p, top)) { - /* Negative dentry - give up */ - if (!simple_positive(p)) - continue; - + p = NULL; + while ((p = get_next_positive_dentry(p, top))) { DPRINTK("dentry %p %.*s", p, (int) p->d_name.len, p->d_name.name); - p = dget(p); - spin_unlock(&dcache_lock); - /* * Is someone visiting anywhere in the subtree ? * If there's no mount we need to check the usage @@ -198,16 +231,13 @@ static int autofs4_tree_busy(struct vfsmount *mnt, else ino_count++; - if (atomic_read(&p->d_count) > ino_count) { + if (p->d_count > ino_count) { top_ino->last_used = jiffies; dput(p); return 1; } } - dput(p); - spin_lock(&dcache_lock); } - spin_unlock(&dcache_lock); /* Timeout of a tree mount is ultimately determined by its top dentry */ if (!autofs4_can_expire(top, timeout, do_now)) @@ -226,32 +256,21 @@ static struct dentry *autofs4_check_leaves(struct vfsmount *mnt, DPRINTK("parent %p %.*s", parent, (int)parent->d_name.len, parent->d_name.name); - spin_lock(&dcache_lock); - for (p = parent; p; p = next_dentry(p, parent)) { - /* Negative dentry - give up */ - if (!simple_positive(p)) - continue; - + p = NULL; + while ((p = get_next_positive_dentry(p, parent))) { DPRINTK("dentry %p %.*s", p, (int) p->d_name.len, p->d_name.name); - p = dget(p); - spin_unlock(&dcache_lock); - if (d_mountpoint(p)) { /* Can we umount this guy */ if (autofs4_mount_busy(mnt, p)) - goto cont; + continue; /* Can we expire this guy */ if (autofs4_can_expire(p, timeout, do_now)) return p; } -cont: - dput(p); - spin_lock(&dcache_lock); } - spin_unlock(&dcache_lock); return NULL; } @@ -276,7 +295,9 @@ struct dentry *autofs4_expire_direct(struct super_block *sb, struct autofs_info *ino = autofs4_dentry_ino(root); if (d_mountpoint(root)) { ino->flags |= AUTOFS_INF_MOUNTPOINT; - root->d_mounted--; + spin_lock(&root->d_lock); + root->d_flags &= ~DCACHE_MOUNTED; + spin_unlock(&root->d_lock); } ino->flags |= AUTOFS_INF_EXPIRING; init_completion(&ino->expire_complete); @@ -302,8 +323,8 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, { unsigned long timeout; struct dentry *root = sb->s_root; + struct dentry *dentry; struct dentry *expired = NULL; - struct list_head *next; int do_now = how & AUTOFS_EXP_IMMEDIATE; int exp_leaves = how & AUTOFS_EXP_LEAVES; struct autofs_info *ino; @@ -315,23 +336,8 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, now = jiffies; timeout = sbi->exp_timeout; - spin_lock(&dcache_lock); - next = root->d_subdirs.next; - - /* On exit from the loop expire is set to a dgot dentry - * to expire or it's NULL */ - while ( next != &root->d_subdirs ) { - struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child); - - /* Negative dentry - give up */ - if (!simple_positive(dentry)) { - next = next->next; - continue; - } - - dentry = dget(dentry); - spin_unlock(&dcache_lock); - + dentry = NULL; + while ((dentry = get_next_positive_dentry(dentry, root))) { spin_lock(&sbi->fs_lock); ino = autofs4_dentry_ino(dentry); @@ -347,7 +353,7 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, /* Path walk currently on this dentry? */ ino_count = atomic_read(&ino->count) + 2; - if (atomic_read(&dentry->d_count) > ino_count) + if (dentry->d_count > ino_count) goto next; /* Can we umount this guy */ @@ -369,7 +375,7 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, if (!exp_leaves) { /* Path walk currently on this dentry? */ ino_count = atomic_read(&ino->count) + 1; - if (atomic_read(&dentry->d_count) > ino_count) + if (dentry->d_count > ino_count) goto next; if (!autofs4_tree_busy(mnt, dentry, timeout, do_now)) { @@ -383,7 +389,7 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, } else { /* Path walk currently on this dentry? */ ino_count = atomic_read(&ino->count) + 1; - if (atomic_read(&dentry->d_count) > ino_count) + if (dentry->d_count > ino_count) goto next; expired = autofs4_check_leaves(mnt, dentry, timeout, do_now); @@ -394,11 +400,7 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, } next: spin_unlock(&sbi->fs_lock); - dput(dentry); - spin_lock(&dcache_lock); - next = next->next; } - spin_unlock(&dcache_lock); return NULL; found: @@ -408,9 +410,13 @@ found: ino->flags |= AUTOFS_INF_EXPIRING; init_completion(&ino->expire_complete); spin_unlock(&sbi->fs_lock); - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); + spin_lock(&expired->d_parent->d_lock); + spin_lock_nested(&expired->d_lock, DENTRY_D_LOCK_NESTED); list_move(&expired->d_parent->d_subdirs, &expired->d_u.d_child); - spin_unlock(&dcache_lock); + spin_unlock(&expired->d_lock); + spin_unlock(&expired->d_parent->d_lock); + spin_unlock(&autofs4_lock); return expired; } @@ -499,7 +505,14 @@ int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt, spin_lock(&sbi->fs_lock); if (ino->flags & AUTOFS_INF_MOUNTPOINT) { - sb->s_root->d_mounted++; + spin_lock(&sb->s_root->d_lock); + /* + * If we haven't been expired away, then reset + * mounted status. + */ + if (mnt->mnt_parent != mnt) + sb->s_root->d_flags |= DCACHE_MOUNTED; + spin_unlock(&sb->s_root->d_lock); ino->flags &= ~AUTOFS_INF_MOUNTPOINT; } ino->flags &= ~AUTOFS_INF_EXPIRING; diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c index ac87e49fa70..a7bdb9dcac8 100644 --- a/fs/autofs4/inode.c +++ b/fs/autofs4/inode.c @@ -309,7 +309,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent) goto fail_iput; pipe = NULL; - root->d_op = &autofs4_sb_dentry_operations; + d_set_d_op(root, &autofs4_sb_dentry_operations); root->d_fsdata = ino; /* Can this call block? */ diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index d34896cfb19..651e4ef563b 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -23,6 +23,8 @@ #include "autofs_i.h" +DEFINE_SPINLOCK(autofs4_lock); + static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *); static int autofs4_dir_unlink(struct inode *,struct dentry *); static int autofs4_dir_rmdir(struct inode *,struct dentry *); @@ -142,12 +144,15 @@ static int autofs4_dir_open(struct inode *inode, struct file *file) * autofs file system so just let the libfs routines handle * it. */ - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); + spin_lock(&dentry->d_lock); if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); + spin_unlock(&autofs4_lock); return -ENOENT; } - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); + spin_unlock(&autofs4_lock); out: return dcache_dir_open(inode, file); @@ -252,9 +257,11 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) /* We trigger a mount for almost all flags */ lookup_type = autofs4_need_mount(nd->flags); spin_lock(&sbi->fs_lock); - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); + spin_lock(&dentry->d_lock); if (!(lookup_type || ino->flags & AUTOFS_INF_PENDING)) { - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); + spin_unlock(&autofs4_lock); spin_unlock(&sbi->fs_lock); goto follow; } @@ -266,7 +273,8 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) */ if (ino->flags & AUTOFS_INF_PENDING || (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) { - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); + spin_unlock(&autofs4_lock); spin_unlock(&sbi->fs_lock); status = try_to_fill_dentry(dentry, nd->flags); @@ -275,7 +283,8 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) goto follow; } - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); + spin_unlock(&autofs4_lock); spin_unlock(&sbi->fs_lock); follow: /* @@ -306,12 +315,19 @@ out_error: */ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) { - struct inode *dir = dentry->d_parent->d_inode; - struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); - int oz_mode = autofs4_oz_mode(sbi); + struct inode *dir; + struct autofs_sb_info *sbi; + int oz_mode; int flags = nd ? nd->flags : 0; int status = 1; + if (flags & LOOKUP_RCU) + return -ECHILD; + + dir = dentry->d_parent->d_inode; + sbi = autofs4_sbi(dir->i_sb); + oz_mode = autofs4_oz_mode(sbi); + /* Pending dentry */ spin_lock(&sbi->fs_lock); if (autofs4_ispending(dentry)) { @@ -346,12 +362,14 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) return 0; /* Check for a non-mountpoint directory with no contents */ - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); + spin_lock(&dentry->d_lock); if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { DPRINTK("dentry=%p %.*s, emptydir", dentry, dentry->d_name.len, dentry->d_name.name); - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); + spin_unlock(&autofs4_lock); /* The daemon never causes a mount to trigger */ if (oz_mode) @@ -367,7 +385,8 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) return status; } - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); + spin_unlock(&autofs4_lock); return 1; } @@ -422,7 +441,7 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry) const unsigned char *str = name->name; struct list_head *p, *head; - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); spin_lock(&sbi->lookup_lock); head = &sbi->active_list; list_for_each(p, head) { @@ -436,7 +455,7 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry) spin_lock(&active->d_lock); /* Already gone? */ - if (atomic_read(&active->d_count) == 0) + if (active->d_count == 0) goto next; qstr = &active->d_name; @@ -452,17 +471,17 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry) goto next; if (d_unhashed(active)) { - dget(active); + dget_dlock(active); spin_unlock(&active->d_lock); spin_unlock(&sbi->lookup_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return active; } next: spin_unlock(&active->d_lock); } spin_unlock(&sbi->lookup_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return NULL; } @@ -477,7 +496,7 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) const unsigned char *str = name->name; struct list_head *p, *head; - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); spin_lock(&sbi->lookup_lock); head = &sbi->expiring_list; list_for_each(p, head) { @@ -507,17 +526,17 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) goto next; if (d_unhashed(expiring)) { - dget(expiring); + dget_dlock(expiring); spin_unlock(&expiring->d_lock); spin_unlock(&sbi->lookup_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return expiring; } next: spin_unlock(&expiring->d_lock); } spin_unlock(&sbi->lookup_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return NULL; } @@ -559,7 +578,7 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s * we check for the hashed dentry and return the newly * hashed dentry. */ - dentry->d_op = &autofs4_root_dentry_operations; + d_set_d_op(dentry, &autofs4_root_dentry_operations); /* * And we need to ensure that the same dentry is used for @@ -698,9 +717,9 @@ static int autofs4_dir_symlink(struct inode *dir, d_add(dentry, inode); if (dir == dir->i_sb->s_root->d_inode) - dentry->d_op = &autofs4_root_dentry_operations; + d_set_d_op(dentry, &autofs4_root_dentry_operations); else - dentry->d_op = &autofs4_dentry_operations; + d_set_d_op(dentry, &autofs4_dentry_operations); dentry->d_fsdata = ino; ino->dentry = dget(dentry); @@ -753,12 +772,12 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) dir->i_mtime = CURRENT_TIME; - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); autofs4_add_expiring(dentry); spin_lock(&dentry->d_lock); __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return 0; } @@ -775,16 +794,20 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) if (!autofs4_oz_mode(sbi)) return -EACCES; - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); + spin_lock(&sbi->lookup_lock); + spin_lock(&dentry->d_lock); if (!list_empty(&dentry->d_subdirs)) { - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); + spin_unlock(&sbi->lookup_lock); + spin_unlock(&autofs4_lock); return -ENOTEMPTY; } - autofs4_add_expiring(dentry); - spin_lock(&dentry->d_lock); + __autofs4_add_expiring(dentry); + spin_unlock(&sbi->lookup_lock); __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); if (atomic_dec_and_test(&ino->count)) { p_ino = autofs4_dentry_ino(dentry->d_parent); @@ -829,9 +852,9 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) d_add(dentry, inode); if (dir == dir->i_sb->s_root->d_inode) - dentry->d_op = &autofs4_root_dentry_operations; + d_set_d_op(dentry, &autofs4_root_dentry_operations); else - dentry->d_op = &autofs4_dentry_operations; + d_set_d_op(dentry, &autofs4_dentry_operations); dentry->d_fsdata = ino; ino->dentry = dget(dentry); diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c index 2341375386f..c5f8459c905 100644 --- a/fs/autofs4/waitq.c +++ b/fs/autofs4/waitq.c @@ -186,16 +186,26 @@ static int autofs4_getpath(struct autofs_sb_info *sbi, { struct dentry *root = sbi->sb->s_root; struct dentry *tmp; - char *buf = *name; + char *buf; char *p; - int len = 0; + int len; + unsigned seq; - spin_lock(&dcache_lock); +rename_retry: + buf = *name; + len = 0; + + seq = read_seqbegin(&rename_lock); + rcu_read_lock(); + spin_lock(&autofs4_lock); for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent) len += tmp->d_name.len + 1; if (!len || --len > NAME_MAX) { - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); + rcu_read_unlock(); + if (read_seqretry(&rename_lock, seq)) + goto rename_retry; return 0; } @@ -208,7 +218,10 @@ static int autofs4_getpath(struct autofs_sb_info *sbi, p -= tmp->d_name.len; strncpy(p, tmp->d_name.name, tmp->d_name.len); } - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); + rcu_read_unlock(); + if (read_seqretry(&rename_lock, seq)) + goto rename_retry; return len; } diff --git a/fs/bad_inode.c b/fs/bad_inode.c index f024d8aadde..9ad2369d9e3 100644 --- a/fs/bad_inode.c +++ b/fs/bad_inode.c @@ -229,8 +229,11 @@ static int bad_inode_readlink(struct dentry *dentry, char __user *buffer, return -EIO; } -static int bad_inode_permission(struct inode *inode, int mask) +static int bad_inode_permission(struct inode *inode, int mask, unsigned int flags) { + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + return -EIO; } diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c index aa4e7c7ae3c..de93581b79a 100644 --- a/fs/befs/linuxvfs.c +++ b/fs/befs/linuxvfs.c @@ -284,12 +284,18 @@ befs_alloc_inode(struct super_block *sb) return &bi->vfs_inode; } -static void -befs_destroy_inode(struct inode *inode) +static void befs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(befs_inode_cachep, BEFS_I(inode)); } +static void befs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, befs_i_callback); +} + static void init_once(void *foo) { struct befs_inode_info *bi = (struct befs_inode_info *) foo; diff --git a/fs/bfs/inode.c b/fs/bfs/inode.c index 76db6d7d49b..a8e37f81d09 100644 --- a/fs/bfs/inode.c +++ b/fs/bfs/inode.c @@ -248,11 +248,18 @@ static struct inode *bfs_alloc_inode(struct super_block *sb) return &bi->vfs_inode; } -static void bfs_destroy_inode(struct inode *inode) +static void bfs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(bfs_inode_cachep, BFS_I(inode)); } +static void bfs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, bfs_i_callback); +} + static void init_once(void *foo) { struct bfs_inode_info *bi = foo; diff --git a/fs/block_dev.c b/fs/block_dev.c index 4230252fd68..771f2352701 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -409,13 +409,20 @@ static struct inode *bdev_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void bdev_destroy_inode(struct inode *inode) +static void bdev_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); struct bdev_inode *bdi = BDEV_I(inode); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(bdev_cachep, bdi); } +static void bdev_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, bdev_i_callback); +} + static void init_once(void *foo) { struct bdev_inode *ei = (struct bdev_inode *) foo; diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c index 2222d161c7b..6ae2c8cac9d 100644 --- a/fs/btrfs/acl.c +++ b/fs/btrfs/acl.c @@ -185,18 +185,23 @@ static int btrfs_xattr_acl_set(struct dentry *dentry, const char *name, return ret; } -int btrfs_check_acl(struct inode *inode, int mask) +int btrfs_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct posix_acl *acl; int error = -EAGAIN; - acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); + if (flags & IPERM_FLAG_RCU) { + if (!negative_cached_acl(inode, ACL_TYPE_ACCESS)) + error = -ECHILD; - if (IS_ERR(acl)) - return PTR_ERR(acl); - if (acl) { - error = posix_acl_permission(inode, acl, mask); - posix_acl_release(acl); + } else { + struct posix_acl *acl; + acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (acl) { + error = posix_acl_permission(inode, acl, mask); + posix_acl_release(acl); + } } return error; diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index af52f6d7a4d..a142d204b52 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2544,7 +2544,7 @@ int btrfs_sync_fs(struct super_block *sb, int wait); /* acl.c */ #ifdef CONFIG_BTRFS_FS_POSIX_ACL -int btrfs_check_acl(struct inode *inode, int mask); +int btrfs_check_acl(struct inode *inode, int mask, unsigned int flags); #else #define btrfs_check_acl NULL #endif diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c index 659f532d26a..0ccf9a8afcd 100644 --- a/fs/btrfs/export.c +++ b/fs/btrfs/export.c @@ -110,7 +110,7 @@ static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid, dentry = d_obtain_alias(inode); if (!IS_ERR(dentry)) - dentry->d_op = &btrfs_dentry_operations; + d_set_d_op(dentry, &btrfs_dentry_operations); return dentry; fail: srcu_read_unlock(&fs_info->subvol_srcu, index); @@ -225,7 +225,7 @@ static struct dentry *btrfs_get_parent(struct dentry *child) key.offset = 0; dentry = d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL)); if (!IS_ERR(dentry)) - dentry->d_op = &btrfs_dentry_operations; + d_set_d_op(dentry, &btrfs_dentry_operations); return dentry; fail: btrfs_free_path(path); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 72f31ecb5c9..a0ff46a4789 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4084,7 +4084,7 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) int index; int ret; - dentry->d_op = &btrfs_dentry_operations; + d_set_d_op(dentry, &btrfs_dentry_operations); if (dentry->d_name.len > BTRFS_NAME_LEN) return ERR_PTR(-ENAMETOOLONG); @@ -4127,7 +4127,7 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) return inode; } -static int btrfs_dentry_delete(struct dentry *dentry) +static int btrfs_dentry_delete(const struct dentry *dentry) { struct btrfs_root *root; @@ -6495,6 +6495,13 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) return inode; } +static void btrfs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); +} + void btrfs_destroy_inode(struct inode *inode) { struct btrfs_ordered_extent *ordered; @@ -6564,7 +6571,7 @@ void btrfs_destroy_inode(struct inode *inode) inode_tree_del(inode); btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); free: - kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); + call_rcu(&inode->i_rcu, btrfs_i_callback); } int btrfs_drop_inode(struct inode *inode) @@ -7204,11 +7211,11 @@ static int btrfs_set_page_dirty(struct page *page) return __set_page_dirty_nobuffers(page); } -static int btrfs_permission(struct inode *inode, int mask) +static int btrfs_permission(struct inode *inode, int mask, unsigned int flags) { if ((BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) && (mask & MAY_WRITE)) return -EACCES; - return generic_permission(inode, mask, btrfs_check_acl); + return generic_permission(inode, mask, flags, btrfs_check_acl); } static const struct inode_operations btrfs_dir_inode_operations = { diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index d902948a90d..fa7ca04ee81 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -42,11 +42,11 @@ int ceph_init_dentry(struct dentry *dentry) if (dentry->d_parent == NULL || /* nfs fh_to_dentry */ ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP) - dentry->d_op = &ceph_dentry_ops; + d_set_d_op(dentry, &ceph_dentry_ops); else if (ceph_snap(dentry->d_parent->d_inode) == CEPH_SNAPDIR) - dentry->d_op = &ceph_snapdir_dentry_ops; + d_set_d_op(dentry, &ceph_snapdir_dentry_ops); else - dentry->d_op = &ceph_snap_dentry_ops; + d_set_d_op(dentry, &ceph_snap_dentry_ops); di = kmem_cache_alloc(ceph_dentry_cachep, GFP_NOFS | __GFP_ZERO); if (!di) @@ -112,7 +112,7 @@ static int __dcache_readdir(struct file *filp, dout("__dcache_readdir %p at %llu (last %p)\n", dir, filp->f_pos, last); - spin_lock(&dcache_lock); + spin_lock(&parent->d_lock); /* start at beginning? */ if (filp->f_pos == 2 || last == NULL || @@ -136,6 +136,7 @@ more: fi->at_end = 1; goto out_unlock; } + spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); if (!d_unhashed(dentry) && dentry->d_inode && ceph_snap(dentry->d_inode) != CEPH_SNAPDIR && ceph_ino(dentry->d_inode) != CEPH_INO_CEPH && @@ -145,13 +146,15 @@ more: dentry->d_name.len, dentry->d_name.name, di->offset, filp->f_pos, d_unhashed(dentry) ? " unhashed" : "", !dentry->d_inode ? " null" : ""); + spin_unlock(&dentry->d_lock); p = p->prev; dentry = list_entry(p, struct dentry, d_u.d_child); di = ceph_dentry(dentry); } - atomic_inc(&dentry->d_count); - spin_unlock(&dcache_lock); + dget_dlock(dentry); + spin_unlock(&dentry->d_lock); + spin_unlock(&parent->d_lock); dout(" %llu (%llu) dentry %p %.*s %p\n", di->offset, filp->f_pos, dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); @@ -177,19 +180,19 @@ more: filp->f_pos++; - /* make sure a dentry wasn't dropped while we didn't have dcache_lock */ + /* make sure a dentry wasn't dropped while we didn't have parent lock */ if (!ceph_i_test(dir, CEPH_I_COMPLETE)) { dout(" lost I_COMPLETE on %p; falling back to mds\n", dir); err = -EAGAIN; goto out; } - spin_lock(&dcache_lock); + spin_lock(&parent->d_lock); p = p->prev; /* advance to next dentry */ goto more; out_unlock: - spin_unlock(&dcache_lock); + spin_unlock(&parent->d_lock); out: if (last) dput(last); @@ -987,7 +990,12 @@ static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry) */ static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd) { - struct inode *dir = dentry->d_parent->d_inode; + struct inode *dir; + + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + + dir = dentry->d_parent->d_inode; dout("d_revalidate %p '%.*s' inode %p offset %lld\n", dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode, diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index bf1286588f2..e61de4f7b99 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -368,6 +368,15 @@ struct inode *ceph_alloc_inode(struct super_block *sb) return &ci->vfs_inode; } +static void ceph_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + struct ceph_inode_info *ci = ceph_inode(inode); + + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(ceph_inode_cachep, ci); +} + void ceph_destroy_inode(struct inode *inode) { struct ceph_inode_info *ci = ceph_inode(inode); @@ -407,7 +416,7 @@ void ceph_destroy_inode(struct inode *inode) if (ci->i_xattrs.prealloc_blob) ceph_buffer_put(ci->i_xattrs.prealloc_blob); - kmem_cache_free(ceph_inode_cachep, ci); + call_rcu(&inode->i_rcu, ceph_i_callback); } @@ -841,13 +850,13 @@ static void ceph_set_dentry_offset(struct dentry *dn) di->offset = ceph_inode(inode)->i_max_offset++; spin_unlock(&inode->i_lock); - spin_lock(&dcache_lock); - spin_lock(&dn->d_lock); + spin_lock(&dir->d_lock); + spin_lock_nested(&dn->d_lock, DENTRY_D_LOCK_NESTED); list_move(&dn->d_u.d_child, &dir->d_subdirs); dout("set_dentry_offset %p %lld (%p %p)\n", dn, di->offset, dn->d_u.d_child.prev, dn->d_u.d_child.next); spin_unlock(&dn->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&dir->d_lock); } /* @@ -879,8 +888,8 @@ static struct dentry *splice_dentry(struct dentry *dn, struct inode *in, } else if (realdn) { dout("dn %p (%d) spliced with %p (%d) " "inode %p ino %llx.%llx\n", - dn, atomic_read(&dn->d_count), - realdn, atomic_read(&realdn->d_count), + dn, dn->d_count, + realdn, realdn->d_count, realdn->d_inode, ceph_vinop(realdn->d_inode)); dput(dn); dn = realdn; @@ -1231,11 +1240,11 @@ retry_lookup: goto retry_lookup; } else { /* reorder parent's d_subdirs */ - spin_lock(&dcache_lock); - spin_lock(&dn->d_lock); + spin_lock(&parent->d_lock); + spin_lock_nested(&dn->d_lock, DENTRY_D_LOCK_NESTED); list_move(&dn->d_u.d_child, &parent->d_subdirs); spin_unlock(&dn->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&parent->d_lock); } di = dn->d_fsdata; @@ -1772,12 +1781,17 @@ int ceph_do_getattr(struct inode *inode, int mask) * Check inode permissions. We verify we have a valid value for * the AUTH cap, then call the generic handler. */ -int ceph_permission(struct inode *inode, int mask) +int ceph_permission(struct inode *inode, int mask, unsigned int flags) { - int err = ceph_do_getattr(inode, CEPH_CAP_AUTH_SHARED); + int err; + + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + + err = ceph_do_getattr(inode, CEPH_CAP_AUTH_SHARED); if (!err) - err = generic_permission(inode, mask, NULL); + err = generic_permission(inode, mask, flags, NULL); return err; } diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 38800eaa81d..a50fca1e03b 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -1486,7 +1486,7 @@ retry: *base = ceph_ino(temp->d_inode); *plen = len; dout("build_path on %p %d built %llx '%.*s'\n", - dentry, atomic_read(&dentry->d_count), *base, len, path); + dentry, dentry->d_count, *base, len, path); return path; } diff --git a/fs/ceph/super.h b/fs/ceph/super.h index 7f01728a465..4553d8829ed 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -665,7 +665,7 @@ extern void ceph_queue_invalidate(struct inode *inode); extern void ceph_queue_writeback(struct inode *inode); extern int ceph_do_getattr(struct inode *inode, int mask); -extern int ceph_permission(struct inode *inode, int mask); +extern int ceph_permission(struct inode *inode, int mask, unsigned int flags); extern int ceph_setattr(struct dentry *dentry, struct iattr *attr); extern int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat); diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 3936aa7f2c2..8e21e0fe65d 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -283,10 +283,13 @@ cifs_statfs(struct dentry *dentry, struct kstatfs *buf) return 0; } -static int cifs_permission(struct inode *inode, int mask) +static int cifs_permission(struct inode *inode, int mask, unsigned int flags) { struct cifs_sb_info *cifs_sb; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + cifs_sb = CIFS_SB(inode->i_sb); if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM) { @@ -298,7 +301,7 @@ static int cifs_permission(struct inode *inode, int mask) on the client (above and beyond ACL on servers) for servers which do not support setting and viewing mode bits, so allowing client to check permissions is useful */ - return generic_permission(inode, mask, NULL); + return generic_permission(inode, mask, flags, NULL); } static struct kmem_cache *cifs_inode_cachep; @@ -334,10 +337,17 @@ cifs_alloc_inode(struct super_block *sb) return &cifs_inode->vfs_inode; } +static void cifs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(cifs_inode_cachep, CIFS_I(inode)); +} + static void cifs_destroy_inode(struct inode *inode) { - kmem_cache_free(cifs_inode_cachep, CIFS_I(inode)); + call_rcu(&inode->i_rcu, cifs_i_callback); } static void diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index 3840eddbfb7..db2a58c00f7 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -135,9 +135,9 @@ static void setup_cifs_dentry(struct cifsTconInfo *tcon, struct inode *newinode) { if (tcon->nocase) - direntry->d_op = &cifs_ci_dentry_ops; + d_set_d_op(direntry, &cifs_ci_dentry_ops); else - direntry->d_op = &cifs_dentry_ops; + d_set_d_op(direntry, &cifs_dentry_ops); d_instantiate(direntry, newinode); } @@ -421,9 +421,9 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb, xid); if (pTcon->nocase) - direntry->d_op = &cifs_ci_dentry_ops; + d_set_d_op(direntry, &cifs_ci_dentry_ops); else - direntry->d_op = &cifs_dentry_ops; + d_set_d_op(direntry, &cifs_dentry_ops); if (rc == 0) d_instantiate(direntry, newinode); @@ -604,9 +604,9 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, if ((rc == 0) && (newInode != NULL)) { if (pTcon->nocase) - direntry->d_op = &cifs_ci_dentry_ops; + d_set_d_op(direntry, &cifs_ci_dentry_ops); else - direntry->d_op = &cifs_dentry_ops; + d_set_d_op(direntry, &cifs_dentry_ops); d_add(direntry, newInode); if (posix_open) { filp = lookup_instantiate_filp(nd, direntry, @@ -634,9 +634,9 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, rc = 0; direntry->d_time = jiffies; if (pTcon->nocase) - direntry->d_op = &cifs_ci_dentry_ops; + d_set_d_op(direntry, &cifs_ci_dentry_ops); else - direntry->d_op = &cifs_dentry_ops; + d_set_d_op(direntry, &cifs_dentry_ops); d_add(direntry, NULL); /* if it was once a directory (but how can we tell?) we could do shrink_dcache_parent(direntry); */ @@ -656,22 +656,37 @@ lookup_out: static int cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd) { - int isValid = 1; + if (nd->flags & LOOKUP_RCU) + return -ECHILD; if (direntry->d_inode) { if (cifs_revalidate_dentry(direntry)) return 0; - } else { - cFYI(1, "neg dentry 0x%p name = %s", - direntry, direntry->d_name.name); - if (time_after(jiffies, direntry->d_time + HZ) || - !lookupCacheEnabled) { - d_drop(direntry); - isValid = 0; - } + else + return 1; } - return isValid; + /* + * This may be nfsd (or something), anyway, we can't see the + * intent of this. So, since this can be for creation, drop it. + */ + if (!nd) + return 0; + + /* + * Drop the negative dentry, in order to make sure to use the + * case sensitive name which is specified by user if this is + * for creation. + */ + if (!(nd->flags & (LOOKUP_CONTINUE | LOOKUP_PARENT))) { + if (nd->flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)) + return 0; + } + + if (time_after(jiffies, direntry->d_time + HZ) || !lookupCacheEnabled) + return 0; + + return 1; } /* static int cifs_d_delete(struct dentry *direntry) @@ -688,9 +703,10 @@ const struct dentry_operations cifs_dentry_ops = { /* d_delete: cifs_d_delete, */ /* not needed except for debugging */ }; -static int cifs_ci_hash(struct dentry *dentry, struct qstr *q) +static int cifs_ci_hash(const struct dentry *dentry, const struct inode *inode, + struct qstr *q) { - struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls; + struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls; unsigned long hash; int i; @@ -703,21 +719,16 @@ static int cifs_ci_hash(struct dentry *dentry, struct qstr *q) return 0; } -static int cifs_ci_compare(struct dentry *dentry, struct qstr *a, - struct qstr *b) +static int cifs_ci_compare(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls; - - if ((a->len == b->len) && - (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) { - /* - * To preserve case, don't let an existing negative dentry's - * case take precedence. If a is not a negative dentry, this - * should have no side effects - */ - memcpy((void *)a->name, b->name, a->len); + struct nls_table *codepage = CIFS_SB(pinode->i_sb)->local_nls; + + if ((name->len == len) && + (nls_strnicmp(codepage, name->name, str, len) == 0)) return 0; - } return 1; } diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index 589f3e3f6e0..a853a89857a 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -809,14 +809,14 @@ inode_has_hashed_dentries(struct inode *inode) { struct dentry *dentry; - spin_lock(&dcache_lock); + spin_lock(&inode->i_lock); list_for_each_entry(dentry, &inode->i_dentry, d_alias) { if (!d_unhashed(dentry) || IS_ROOT(dentry)) { - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); return true; } } - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); return false; } @@ -1319,9 +1319,9 @@ int cifs_mkdir(struct inode *inode, struct dentry *direntry, int mode) to set uid/gid */ inc_nlink(inode); if (pTcon->nocase) - direntry->d_op = &cifs_ci_dentry_ops; + d_set_d_op(direntry, &cifs_ci_dentry_ops); else - direntry->d_op = &cifs_dentry_ops; + d_set_d_op(direntry, &cifs_dentry_ops); cifs_unix_basic_to_fattr(&fattr, pInfo, cifs_sb); cifs_fill_uniqueid(inode->i_sb, &fattr); @@ -1363,9 +1363,9 @@ mkdir_get_info: inode->i_sb, xid, NULL); if (pTcon->nocase) - direntry->d_op = &cifs_ci_dentry_ops; + d_set_d_op(direntry, &cifs_ci_dentry_ops); else - direntry->d_op = &cifs_dentry_ops; + d_set_d_op(direntry, &cifs_dentry_ops); d_instantiate(direntry, newinode); /* setting nlink not necessary except in cases where we * failed to get it from the server or was set bogus */ diff --git a/fs/cifs/link.c b/fs/cifs/link.c index 85cdbf831e7..fe2f6a93c49 100644 --- a/fs/cifs/link.c +++ b/fs/cifs/link.c @@ -525,9 +525,9 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname) rc); } else { if (pTcon->nocase) - direntry->d_op = &cifs_ci_dentry_ops; + d_set_d_op(direntry, &cifs_ci_dentry_ops); else - direntry->d_op = &cifs_dentry_ops; + d_set_d_op(direntry, &cifs_dentry_ops); d_instantiate(direntry, newinode); } } diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c index a73eb9f4bda..ec5b68e3b92 100644 --- a/fs/cifs/readdir.c +++ b/fs/cifs/readdir.c @@ -79,7 +79,7 @@ cifs_readdir_lookup(struct dentry *parent, struct qstr *name, cFYI(1, "For %s", name->name); if (parent->d_op && parent->d_op->d_hash) - parent->d_op->d_hash(parent, name); + parent->d_op->d_hash(parent, parent->d_inode, name); else name->hash = full_name_hash(name->name, name->len); @@ -103,9 +103,9 @@ cifs_readdir_lookup(struct dentry *parent, struct qstr *name, } if (cifs_sb_master_tcon(CIFS_SB(sb))->nocase) - dentry->d_op = &cifs_ci_dentry_ops; + d_set_d_op(dentry, &cifs_ci_dentry_ops); else - dentry->d_op = &cifs_dentry_ops; + d_set_d_op(dentry, &cifs_dentry_ops); alias = d_materialise_unique(dentry, inode); if (alias != NULL) { diff --git a/fs/coda/cache.c b/fs/coda/cache.c index 9060f08e70c..5525e1c660f 100644 --- a/fs/coda/cache.c +++ b/fs/coda/cache.c @@ -93,7 +93,7 @@ static void coda_flag_children(struct dentry *parent, int flag) struct list_head *child; struct dentry *de; - spin_lock(&dcache_lock); + spin_lock(&parent->d_lock); list_for_each(child, &parent->d_subdirs) { de = list_entry(child, struct dentry, d_u.d_child); @@ -102,7 +102,7 @@ static void coda_flag_children(struct dentry *parent, int flag) continue; coda_flag_inode(de->d_inode, flag); } - spin_unlock(&dcache_lock); + spin_unlock(&parent->d_lock); return; } diff --git a/fs/coda/dir.c b/fs/coda/dir.c index 5d8b3553960..29badd91360 100644 --- a/fs/coda/dir.c +++ b/fs/coda/dir.c @@ -18,6 +18,7 @@ #include <linux/errno.h> #include <linux/string.h> #include <linux/spinlock.h> +#include <linux/namei.h> #include <asm/uaccess.h> @@ -47,7 +48,7 @@ static int coda_readdir(struct file *file, void *buf, filldir_t filldir); /* dentry ops */ static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd); -static int coda_dentry_delete(struct dentry *); +static int coda_dentry_delete(const struct dentry *); /* support routines */ static int coda_venus_readdir(struct file *coda_file, void *buf, @@ -125,7 +126,7 @@ static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, struc return ERR_PTR(error); exit: - entry->d_op = &coda_dentry_operations; + d_set_d_op(entry, &coda_dentry_operations); if (inode && (type & CODA_NOCACHE)) coda_flag_inode(inode, C_VATTR | C_PURGE); @@ -134,10 +135,13 @@ exit: } -int coda_permission(struct inode *inode, int mask) +int coda_permission(struct inode *inode, int mask, unsigned int flags) { int error; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + mask &= MAY_READ | MAY_WRITE | MAY_EXEC; if (!mask) @@ -541,9 +545,13 @@ out: /* called when a cache lookup succeeds */ static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd) { - struct inode *inode = de->d_inode; + struct inode *inode; struct coda_inode_info *cii; + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + + inode = de->d_inode; if (!inode || coda_isroot(inode)) goto out; if (is_bad_inode(inode)) @@ -559,7 +567,7 @@ static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd) if (cii->c_flags & C_FLUSH) coda_flag_inode_children(inode, C_FLUSH); - if (atomic_read(&de->d_count) > 1) + if (de->d_count > 1) /* pretend it's valid, but don't change the flags */ goto out; @@ -577,7 +585,7 @@ out: * This is the callback from dput() when d_count is going to 0. * We use this to unhash dentries with bad inodes. */ -static int coda_dentry_delete(struct dentry * dentry) +static int coda_dentry_delete(const struct dentry * dentry) { int flags; diff --git a/fs/coda/inode.c b/fs/coda/inode.c index 5ea57c8c7f9..50dc7d189f5 100644 --- a/fs/coda/inode.c +++ b/fs/coda/inode.c @@ -56,11 +56,18 @@ static struct inode *coda_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void coda_destroy_inode(struct inode *inode) +static void coda_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(coda_inode_cachep, ITOC(inode)); } +static void coda_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, coda_i_callback); +} + static void init_once(void *foo) { struct coda_inode_info *ei = (struct coda_inode_info *) foo; diff --git a/fs/coda/pioctl.c b/fs/coda/pioctl.c index 2fd89b5c5c7..741f0bd0391 100644 --- a/fs/coda/pioctl.c +++ b/fs/coda/pioctl.c @@ -24,7 +24,7 @@ #include <linux/coda_psdev.h> /* pioctl ops */ -static int coda_ioctl_permission(struct inode *inode, int mask); +static int coda_ioctl_permission(struct inode *inode, int mask, unsigned int flags); static long coda_pioctl(struct file *filp, unsigned int cmd, unsigned long user_data); @@ -41,8 +41,10 @@ const struct file_operations coda_ioctl_operations = { }; /* the coda pioctl inode ops */ -static int coda_ioctl_permission(struct inode *inode, int mask) +static int coda_ioctl_permission(struct inode *inode, int mask, unsigned int flags) { + if (flags & IPERM_FLAG_RCU) + return -ECHILD; return (mask & MAY_EXEC) ? -EACCES : 0; } diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h index da6061a6df4..026cf68553a 100644 --- a/fs/configfs/configfs_internal.h +++ b/fs/configfs/configfs_internal.h @@ -120,7 +120,7 @@ static inline struct config_item *configfs_get_config_item(struct dentry *dentry { struct config_item * item = NULL; - spin_lock(&dcache_lock); + spin_lock(&dentry->d_lock); if (!d_unhashed(dentry)) { struct configfs_dirent * sd = dentry->d_fsdata; if (sd->s_type & CONFIGFS_ITEM_LINK) { @@ -129,7 +129,7 @@ static inline struct config_item *configfs_get_config_item(struct dentry *dentry } else item = config_item_get(sd->s_element); } - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); return item; } diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index 0b502f80c69..36637a8c1ed 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -67,7 +67,7 @@ static void configfs_d_iput(struct dentry * dentry, * We _must_ delete our dentries on last dput, as the chain-to-parent * behavior is required to clear the parents of default_groups. */ -static int configfs_d_delete(struct dentry *dentry) +static int configfs_d_delete(const struct dentry *dentry) { return 1; } @@ -232,10 +232,8 @@ int configfs_make_dirent(struct configfs_dirent * parent_sd, sd->s_mode = mode; sd->s_dentry = dentry; - if (dentry) { + if (dentry) dentry->d_fsdata = configfs_get(sd); - dentry->d_op = &configfs_dentry_ops; - } return 0; } @@ -278,7 +276,6 @@ static int create_dir(struct config_item * k, struct dentry * p, error = configfs_create(d, mode, init_dir); if (!error) { inc_nlink(p->d_inode); - (d)->d_op = &configfs_dentry_ops; } else { struct configfs_dirent *sd = d->d_fsdata; if (sd) { @@ -371,9 +368,7 @@ int configfs_create_link(struct configfs_symlink *sl, CONFIGFS_ITEM_LINK); if (!err) { err = configfs_create(dentry, mode, init_symlink); - if (!err) - dentry->d_op = &configfs_dentry_ops; - else { + if (err) { struct configfs_dirent *sd = dentry->d_fsdata; if (sd) { spin_lock(&configfs_dirent_lock); @@ -399,8 +394,7 @@ static void remove_dir(struct dentry * d) if (d->d_inode) simple_rmdir(parent->d_inode,d); - pr_debug(" o %s removing done (%d)\n",d->d_name.name, - atomic_read(&d->d_count)); + pr_debug(" o %s removing done (%d)\n",d->d_name.name, d->d_count); dput(parent); } @@ -448,7 +442,7 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den return error; } - dentry->d_op = &configfs_dentry_ops; + d_set_d_op(dentry, &configfs_dentry_ops); d_rehash(dentry); return 0; @@ -493,7 +487,11 @@ static struct dentry * configfs_lookup(struct inode *dir, * If it doesn't exist and it isn't a NOT_PINNED item, * it must be negative. */ - return simple_lookup(dir, dentry, nd); + if (dentry->d_name.len > NAME_MAX) + return ERR_PTR(-ENAMETOOLONG); + d_set_d_op(dentry, &configfs_dentry_ops); + d_add(dentry, NULL); + return NULL; } out: @@ -685,6 +683,7 @@ static int create_default_group(struct config_group *parent_group, ret = -ENOMEM; child = d_alloc(parent, &name); if (child) { + d_set_d_op(child, &configfs_dentry_ops); d_add(child, NULL); ret = configfs_attach_group(&parent_group->cg_item, @@ -1682,6 +1681,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys) err = -ENOMEM; dentry = d_alloc(configfs_sb->s_root, &name); if (dentry) { + d_set_d_op(dentry, &configfs_dentry_ops); d_add(dentry, NULL); err = configfs_attach_group(sd->s_element, &group->cg_item, diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c index 253476d78ed..c83f4768eea 100644 --- a/fs/configfs/inode.c +++ b/fs/configfs/inode.c @@ -250,18 +250,14 @@ void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent) struct dentry * dentry = sd->s_dentry; if (dentry) { - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); if (!(d_unhashed(dentry) && dentry->d_inode)) { - dget_locked(dentry); + dget_dlock(dentry); __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); simple_unlink(parent->d_inode, dentry); - } else { + } else spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); - } } } diff --git a/fs/dcache.c b/fs/dcache.c index 23702a9d4e6..5699d4c027c 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -33,20 +33,58 @@ #include <linux/bootmem.h> #include <linux/fs_struct.h> #include <linux/hardirq.h> +#include <linux/bit_spinlock.h> +#include <linux/rculist_bl.h> #include "internal.h" +/* + * Usage: + * dcache->d_inode->i_lock protects: + * - i_dentry, d_alias, d_inode of aliases + * dcache_hash_bucket lock protects: + * - the dcache hash table + * s_anon bl list spinlock protects: + * - the s_anon list (see __d_drop) + * dcache_lru_lock protects: + * - the dcache lru lists and counters + * d_lock protects: + * - d_flags + * - d_name + * - d_lru + * - d_count + * - d_unhashed() + * - d_parent and d_subdirs + * - childrens' d_child and d_parent + * - d_alias, d_inode + * + * Ordering: + * dentry->d_inode->i_lock + * dentry->d_lock + * dcache_lru_lock + * dcache_hash_bucket lock + * s_anon lock + * + * If there is an ancestor relationship: + * dentry->d_parent->...->d_parent->d_lock + * ... + * dentry->d_parent->d_lock + * dentry->d_lock + * + * If no ancestor relationship: + * if (dentry1 < dentry2) + * dentry1->d_lock + * dentry2->d_lock + */ int sysctl_vfs_cache_pressure __read_mostly = 100; EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure); - __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock); +static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock); __cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock); -EXPORT_SYMBOL(dcache_lock); +EXPORT_SYMBOL(rename_lock); static struct kmem_cache *dentry_cache __read_mostly; -#define DNAME_INLINE_LEN (sizeof(struct dentry)-offsetof(struct dentry,d_iname)) - /* * This is the single most critical data structure when it comes * to the dcache: the hashtable for lookups. Somebody should try @@ -60,22 +98,51 @@ static struct kmem_cache *dentry_cache __read_mostly; static unsigned int d_hash_mask __read_mostly; static unsigned int d_hash_shift __read_mostly; -static struct hlist_head *dentry_hashtable __read_mostly; + +struct dcache_hash_bucket { + struct hlist_bl_head head; +}; +static struct dcache_hash_bucket *dentry_hashtable __read_mostly; + +static inline struct dcache_hash_bucket *d_hash(struct dentry *parent, + unsigned long hash) +{ + hash += ((unsigned long) parent ^ GOLDEN_RATIO_PRIME) / L1_CACHE_BYTES; + hash = hash ^ ((hash ^ GOLDEN_RATIO_PRIME) >> D_HASHBITS); + return dentry_hashtable + (hash & D_HASHMASK); +} + +static inline void spin_lock_bucket(struct dcache_hash_bucket *b) +{ + bit_spin_lock(0, (unsigned long *)&b->head.first); +} + +static inline void spin_unlock_bucket(struct dcache_hash_bucket *b) +{ + __bit_spin_unlock(0, (unsigned long *)&b->head.first); +} /* Statistics gathering. */ struct dentry_stat_t dentry_stat = { .age_limit = 45, }; -static struct percpu_counter nr_dentry __cacheline_aligned_in_smp; -static struct percpu_counter nr_dentry_unused __cacheline_aligned_in_smp; +static DEFINE_PER_CPU(unsigned int, nr_dentry); #if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS) +static int get_nr_dentry(void) +{ + int i; + int sum = 0; + for_each_possible_cpu(i) + sum += per_cpu(nr_dentry, i); + return sum < 0 ? 0 : sum; +} + int proc_nr_dentry(ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - dentry_stat.nr_dentry = percpu_counter_sum_positive(&nr_dentry); - dentry_stat.nr_unused = percpu_counter_sum_positive(&nr_dentry_unused); + dentry_stat.nr_dentry = get_nr_dentry(); return proc_dointvec(table, write, buffer, lenp, ppos); } #endif @@ -91,35 +158,50 @@ static void __d_free(struct rcu_head *head) } /* - * no dcache_lock, please. + * no locks, please. */ static void d_free(struct dentry *dentry) { - percpu_counter_dec(&nr_dentry); + BUG_ON(dentry->d_count); + this_cpu_dec(nr_dentry); if (dentry->d_op && dentry->d_op->d_release) dentry->d_op->d_release(dentry); /* if dentry was never inserted into hash, immediate free is OK */ - if (hlist_unhashed(&dentry->d_hash)) + if (hlist_bl_unhashed(&dentry->d_hash)) __d_free(&dentry->d_u.d_rcu); else call_rcu(&dentry->d_u.d_rcu, __d_free); } +/** + * dentry_rcuwalk_barrier - invalidate in-progress rcu-walk lookups + * After this call, in-progress rcu-walk path lookup will fail. This + * should be called after unhashing, and after changing d_inode (if + * the dentry has not already been unhashed). + */ +static inline void dentry_rcuwalk_barrier(struct dentry *dentry) +{ + assert_spin_locked(&dentry->d_lock); + /* Go through a barrier */ + write_seqcount_barrier(&dentry->d_seq); +} + /* * Release the dentry's inode, using the filesystem - * d_iput() operation if defined. + * d_iput() operation if defined. Dentry has no refcount + * and is unhashed. */ static void dentry_iput(struct dentry * dentry) __releases(dentry->d_lock) - __releases(dcache_lock) + __releases(dentry->d_inode->i_lock) { struct inode *inode = dentry->d_inode; if (inode) { dentry->d_inode = NULL; list_del_init(&dentry->d_alias); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); if (!inode->i_nlink) fsnotify_inoderemove(inode); if (dentry->d_op && dentry->d_op->d_iput) @@ -128,40 +210,72 @@ static void dentry_iput(struct dentry * dentry) iput(inode); } else { spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); } } /* - * dentry_lru_(add|del|move_tail) must be called with dcache_lock held. + * Release the dentry's inode, using the filesystem + * d_iput() operation if defined. dentry remains in-use. + */ +static void dentry_unlink_inode(struct dentry * dentry) + __releases(dentry->d_lock) + __releases(dentry->d_inode->i_lock) +{ + struct inode *inode = dentry->d_inode; + dentry->d_inode = NULL; + list_del_init(&dentry->d_alias); + dentry_rcuwalk_barrier(dentry); + spin_unlock(&dentry->d_lock); + spin_unlock(&inode->i_lock); + if (!inode->i_nlink) + fsnotify_inoderemove(inode); + if (dentry->d_op && dentry->d_op->d_iput) + dentry->d_op->d_iput(dentry, inode); + else + iput(inode); +} + +/* + * dentry_lru_(add|del|move_tail) must be called with d_lock held. */ static void dentry_lru_add(struct dentry *dentry) { if (list_empty(&dentry->d_lru)) { + spin_lock(&dcache_lru_lock); list_add(&dentry->d_lru, &dentry->d_sb->s_dentry_lru); dentry->d_sb->s_nr_dentry_unused++; - percpu_counter_inc(&nr_dentry_unused); + dentry_stat.nr_unused++; + spin_unlock(&dcache_lru_lock); } } +static void __dentry_lru_del(struct dentry *dentry) +{ + list_del_init(&dentry->d_lru); + dentry->d_sb->s_nr_dentry_unused--; + dentry_stat.nr_unused--; +} + static void dentry_lru_del(struct dentry *dentry) { if (!list_empty(&dentry->d_lru)) { - list_del_init(&dentry->d_lru); - dentry->d_sb->s_nr_dentry_unused--; - percpu_counter_dec(&nr_dentry_unused); + spin_lock(&dcache_lru_lock); + __dentry_lru_del(dentry); + spin_unlock(&dcache_lru_lock); } } static void dentry_lru_move_tail(struct dentry *dentry) { + spin_lock(&dcache_lru_lock); if (list_empty(&dentry->d_lru)) { list_add_tail(&dentry->d_lru, &dentry->d_sb->s_dentry_lru); dentry->d_sb->s_nr_dentry_unused++; - percpu_counter_inc(&nr_dentry_unused); + dentry_stat.nr_unused++; } else { list_move_tail(&dentry->d_lru, &dentry->d_sb->s_dentry_lru); } + spin_unlock(&dcache_lru_lock); } /** @@ -171,22 +285,115 @@ static void dentry_lru_move_tail(struct dentry *dentry) * The dentry must already be unhashed and removed from the LRU. * * If this is the root of the dentry tree, return NULL. + * + * dentry->d_lock and parent->d_lock must be held by caller, and are dropped by + * d_kill. */ -static struct dentry *d_kill(struct dentry *dentry) +static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent) __releases(dentry->d_lock) - __releases(dcache_lock) + __releases(parent->d_lock) + __releases(dentry->d_inode->i_lock) { - struct dentry *parent; - + dentry->d_parent = NULL; list_del(&dentry->d_u.d_child); - /*drops the locks, at that point nobody can reach this dentry */ + if (parent) + spin_unlock(&parent->d_lock); dentry_iput(dentry); + /* + * dentry_iput drops the locks, at which point nobody (except + * transient RCU lookups) can reach this dentry. + */ + d_free(dentry); + return parent; +} + +/** + * d_drop - drop a dentry + * @dentry: dentry to drop + * + * d_drop() unhashes the entry from the parent dentry hashes, so that it won't + * be found through a VFS lookup any more. Note that this is different from + * deleting the dentry - d_delete will try to mark the dentry negative if + * possible, giving a successful _negative_ lookup, while d_drop will + * just make the cache lookup fail. + * + * d_drop() is used mainly for stuff that wants to invalidate a dentry for some + * reason (NFS timeouts or autofs deletes). + * + * __d_drop requires dentry->d_lock. + */ +void __d_drop(struct dentry *dentry) +{ + if (!(dentry->d_flags & DCACHE_UNHASHED)) { + if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED)) { + bit_spin_lock(0, + (unsigned long *)&dentry->d_sb->s_anon.first); + dentry->d_flags |= DCACHE_UNHASHED; + hlist_bl_del_init(&dentry->d_hash); + __bit_spin_unlock(0, + (unsigned long *)&dentry->d_sb->s_anon.first); + } else { + struct dcache_hash_bucket *b; + b = d_hash(dentry->d_parent, dentry->d_name.hash); + spin_lock_bucket(b); + /* + * We may not actually need to put DCACHE_UNHASHED + * manipulations under the hash lock, but follow + * the principle of least surprise. + */ + dentry->d_flags |= DCACHE_UNHASHED; + hlist_bl_del_rcu(&dentry->d_hash); + spin_unlock_bucket(b); + dentry_rcuwalk_barrier(dentry); + } + } +} +EXPORT_SYMBOL(__d_drop); + +void d_drop(struct dentry *dentry) +{ + spin_lock(&dentry->d_lock); + __d_drop(dentry); + spin_unlock(&dentry->d_lock); +} +EXPORT_SYMBOL(d_drop); + +/* + * Finish off a dentry we've decided to kill. + * dentry->d_lock must be held, returns with it unlocked. + * If ref is non-zero, then decrement the refcount too. + * Returns dentry requiring refcount drop, or NULL if we're done. + */ +static inline struct dentry *dentry_kill(struct dentry *dentry, int ref) + __releases(dentry->d_lock) +{ + struct inode *inode; + struct dentry *parent; + + inode = dentry->d_inode; + if (inode && !spin_trylock(&inode->i_lock)) { +relock: + spin_unlock(&dentry->d_lock); + cpu_relax(); + return dentry; /* try again with same dentry */ + } if (IS_ROOT(dentry)) parent = NULL; else parent = dentry->d_parent; - d_free(dentry); - return parent; + if (parent && !spin_trylock(&parent->d_lock)) { + if (inode) + spin_unlock(&inode->i_lock); + goto relock; + } + + if (ref) + dentry->d_count--; + /* if dentry was on the d_lru list delete it from there */ + dentry_lru_del(dentry); + /* if it was on the hash then remove it */ + __d_drop(dentry); + return d_kill(dentry, parent); } /* @@ -214,34 +421,26 @@ static struct dentry *d_kill(struct dentry *dentry) * call the dentry unlink method as well as removing it from the queues and * releasing its resources. If the parent dentries were scheduled for release * they too may now get deleted. - * - * no dcache lock, please. */ - void dput(struct dentry *dentry) { if (!dentry) return; repeat: - if (atomic_read(&dentry->d_count) == 1) + if (dentry->d_count == 1) might_sleep(); - if (!atomic_dec_and_lock(&dentry->d_count, &dcache_lock)) - return; - spin_lock(&dentry->d_lock); - if (atomic_read(&dentry->d_count)) { + BUG_ON(!dentry->d_count); + if (dentry->d_count > 1) { + dentry->d_count--; spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); return; } - /* - * AV: ->d_delete() is _NOT_ allowed to block now. - */ - if (dentry->d_op && dentry->d_op->d_delete) { + if (dentry->d_flags & DCACHE_OP_DELETE) { if (dentry->d_op->d_delete(dentry)) - goto unhash_it; + goto kill_it; } /* Unreachable? Get rid of it */ @@ -252,16 +451,12 @@ repeat: dentry->d_flags |= DCACHE_REFERENCED; dentry_lru_add(dentry); - spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + dentry->d_count--; + spin_unlock(&dentry->d_lock); return; -unhash_it: - __d_drop(dentry); kill_it: - /* if dentry was on the d_lru list delete it from there */ - dentry_lru_del(dentry); - dentry = d_kill(dentry); + dentry = dentry_kill(dentry, 1); if (dentry) goto repeat; } @@ -284,9 +479,9 @@ int d_invalidate(struct dentry * dentry) /* * If it's already been dropped, return OK. */ - spin_lock(&dcache_lock); + spin_lock(&dentry->d_lock); if (d_unhashed(dentry)) { - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); return 0; } /* @@ -294,9 +489,9 @@ int d_invalidate(struct dentry * dentry) * to get rid of unused child entries. */ if (!list_empty(&dentry->d_subdirs)) { - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); shrink_dcache_parent(dentry); - spin_lock(&dcache_lock); + spin_lock(&dentry->d_lock); } /* @@ -309,35 +504,61 @@ int d_invalidate(struct dentry * dentry) * we might still populate it if it was a * working directory or similar). */ - spin_lock(&dentry->d_lock); - if (atomic_read(&dentry->d_count) > 1) { + if (dentry->d_count > 1) { if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)) { spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); return -EBUSY; } } __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); return 0; } EXPORT_SYMBOL(d_invalidate); -/* This should be called _only_ with dcache_lock held */ -static inline struct dentry * __dget_locked(struct dentry *dentry) +/* This must be called with d_lock held */ +static inline void __dget_dlock(struct dentry *dentry) { - atomic_inc(&dentry->d_count); - dentry_lru_del(dentry); - return dentry; + dentry->d_count++; } -struct dentry * dget_locked(struct dentry *dentry) +static inline void __dget(struct dentry *dentry) { - return __dget_locked(dentry); + spin_lock(&dentry->d_lock); + __dget_dlock(dentry); + spin_unlock(&dentry->d_lock); +} + +struct dentry *dget_parent(struct dentry *dentry) +{ + struct dentry *ret; + +repeat: + /* + * Don't need rcu_dereference because we re-check it was correct under + * the lock. + */ + rcu_read_lock(); + ret = dentry->d_parent; + if (!ret) { + rcu_read_unlock(); + goto out; + } + spin_lock(&ret->d_lock); + if (unlikely(ret != dentry->d_parent)) { + spin_unlock(&ret->d_lock); + rcu_read_unlock(); + goto repeat; + } + rcu_read_unlock(); + BUG_ON(!ret->d_count); + ret->d_count++; + spin_unlock(&ret->d_lock); +out: + return ret; } -EXPORT_SYMBOL(dget_locked); +EXPORT_SYMBOL(dget_parent); /** * d_find_alias - grab a hashed alias of inode @@ -355,42 +576,51 @@ EXPORT_SYMBOL(dget_locked); * any other hashed alias over that one unless @want_discon is set, * in which case only return an IS_ROOT, DCACHE_DISCONNECTED alias. */ - -static struct dentry * __d_find_alias(struct inode *inode, int want_discon) +static struct dentry *__d_find_alias(struct inode *inode, int want_discon) { - struct list_head *head, *next, *tmp; - struct dentry *alias, *discon_alias=NULL; + struct dentry *alias, *discon_alias; - head = &inode->i_dentry; - next = inode->i_dentry.next; - while (next != head) { - tmp = next; - next = tmp->next; - prefetch(next); - alias = list_entry(tmp, struct dentry, d_alias); +again: + discon_alias = NULL; + list_for_each_entry(alias, &inode->i_dentry, d_alias) { + spin_lock(&alias->d_lock); if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) { if (IS_ROOT(alias) && - (alias->d_flags & DCACHE_DISCONNECTED)) + (alias->d_flags & DCACHE_DISCONNECTED)) { discon_alias = alias; - else if (!want_discon) { - __dget_locked(alias); + } else if (!want_discon) { + __dget_dlock(alias); + spin_unlock(&alias->d_lock); + return alias; + } + } + spin_unlock(&alias->d_lock); + } + if (discon_alias) { + alias = discon_alias; + spin_lock(&alias->d_lock); + if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) { + if (IS_ROOT(alias) && + (alias->d_flags & DCACHE_DISCONNECTED)) { + __dget_dlock(alias); + spin_unlock(&alias->d_lock); return alias; } } + spin_unlock(&alias->d_lock); + goto again; } - if (discon_alias) - __dget_locked(discon_alias); - return discon_alias; + return NULL; } -struct dentry * d_find_alias(struct inode *inode) +struct dentry *d_find_alias(struct inode *inode) { struct dentry *de = NULL; if (!list_empty(&inode->i_dentry)) { - spin_lock(&dcache_lock); + spin_lock(&inode->i_lock); de = __d_find_alias(inode, 0); - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); } return de; } @@ -404,54 +634,61 @@ void d_prune_aliases(struct inode *inode) { struct dentry *dentry; restart: - spin_lock(&dcache_lock); + spin_lock(&inode->i_lock); list_for_each_entry(dentry, &inode->i_dentry, d_alias) { spin_lock(&dentry->d_lock); - if (!atomic_read(&dentry->d_count)) { - __dget_locked(dentry); + if (!dentry->d_count) { + __dget_dlock(dentry); __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); dput(dentry); goto restart; } spin_unlock(&dentry->d_lock); } - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); } EXPORT_SYMBOL(d_prune_aliases); /* - * Throw away a dentry - free the inode, dput the parent. This requires that - * the LRU list has already been removed. + * Try to throw away a dentry - free the inode, dput the parent. + * Requires dentry->d_lock is held, and dentry->d_count == 0. + * Releases dentry->d_lock. * - * Try to prune ancestors as well. This is necessary to prevent - * quadratic behavior of shrink_dcache_parent(), but is also expected - * to be beneficial in reducing dentry cache fragmentation. + * This may fail if locks cannot be acquired no problem, just try again. */ -static void prune_one_dentry(struct dentry * dentry) +static void try_prune_one_dentry(struct dentry *dentry) __releases(dentry->d_lock) - __releases(dcache_lock) - __acquires(dcache_lock) { - __d_drop(dentry); - dentry = d_kill(dentry); + struct dentry *parent; + parent = dentry_kill(dentry, 0); /* - * Prune ancestors. Locking is simpler than in dput(), - * because dcache_lock needs to be taken anyway. + * If dentry_kill returns NULL, we have nothing more to do. + * if it returns the same dentry, trylocks failed. In either + * case, just loop again. + * + * Otherwise, we need to prune ancestors too. This is necessary + * to prevent quadratic behavior of shrink_dcache_parent(), but + * is also expected to be beneficial in reducing dentry cache + * fragmentation. */ - spin_lock(&dcache_lock); + if (!parent) + return; + if (parent == dentry) + return; + + /* Prune ancestors. */ + dentry = parent; while (dentry) { - if (!atomic_dec_and_lock(&dentry->d_count, &dentry->d_lock)) + spin_lock(&dentry->d_lock); + if (dentry->d_count > 1) { + dentry->d_count--; + spin_unlock(&dentry->d_lock); return; - - if (dentry->d_op && dentry->d_op->d_delete) - dentry->d_op->d_delete(dentry); - dentry_lru_del(dentry); - __d_drop(dentry); - dentry = d_kill(dentry); - spin_lock(&dcache_lock); + } + dentry = dentry_kill(dentry, 1); } } @@ -459,24 +696,35 @@ static void shrink_dentry_list(struct list_head *list) { struct dentry *dentry; - while (!list_empty(list)) { - dentry = list_entry(list->prev, struct dentry, d_lru); - dentry_lru_del(dentry); + rcu_read_lock(); + for (;;) { + dentry = list_entry_rcu(list->prev, struct dentry, d_lru); + if (&dentry->d_lru == list) + break; /* empty */ + spin_lock(&dentry->d_lock); + if (dentry != list_entry(list->prev, struct dentry, d_lru)) { + spin_unlock(&dentry->d_lock); + continue; + } /* * We found an inuse dentry which was not removed from * the LRU because of laziness during lookup. Do not free * it - just keep it off the LRU list. */ - spin_lock(&dentry->d_lock); - if (atomic_read(&dentry->d_count)) { + if (dentry->d_count) { + dentry_lru_del(dentry); spin_unlock(&dentry->d_lock); continue; } - prune_one_dentry(dentry); - /* dentry->d_lock was dropped in prune_one_dentry() */ - cond_resched_lock(&dcache_lock); + + rcu_read_unlock(); + + try_prune_one_dentry(dentry); + + rcu_read_lock(); } + rcu_read_unlock(); } /** @@ -495,42 +743,44 @@ static void __shrink_dcache_sb(struct super_block *sb, int *count, int flags) LIST_HEAD(tmp); int cnt = *count; - spin_lock(&dcache_lock); +relock: + spin_lock(&dcache_lru_lock); while (!list_empty(&sb->s_dentry_lru)) { dentry = list_entry(sb->s_dentry_lru.prev, struct dentry, d_lru); BUG_ON(dentry->d_sb != sb); + if (!spin_trylock(&dentry->d_lock)) { + spin_unlock(&dcache_lru_lock); + cpu_relax(); + goto relock; + } + /* * If we are honouring the DCACHE_REFERENCED flag and the * dentry has this flag set, don't free it. Clear the flag * and put it back on the LRU. */ - if (flags & DCACHE_REFERENCED) { - spin_lock(&dentry->d_lock); - if (dentry->d_flags & DCACHE_REFERENCED) { - dentry->d_flags &= ~DCACHE_REFERENCED; - list_move(&dentry->d_lru, &referenced); - spin_unlock(&dentry->d_lock); - cond_resched_lock(&dcache_lock); - continue; - } + if (flags & DCACHE_REFERENCED && + dentry->d_flags & DCACHE_REFERENCED) { + dentry->d_flags &= ~DCACHE_REFERENCED; + list_move(&dentry->d_lru, &referenced); spin_unlock(&dentry->d_lock); + } else { + list_move_tail(&dentry->d_lru, &tmp); + spin_unlock(&dentry->d_lock); + if (!--cnt) + break; } - - list_move_tail(&dentry->d_lru, &tmp); - if (!--cnt) - break; - cond_resched_lock(&dcache_lock); + cond_resched_lock(&dcache_lru_lock); } - - *count = cnt; - shrink_dentry_list(&tmp); - if (!list_empty(&referenced)) list_splice(&referenced, &sb->s_dentry_lru); - spin_unlock(&dcache_lock); + spin_unlock(&dcache_lru_lock); + shrink_dentry_list(&tmp); + + *count = cnt; } /** @@ -546,13 +796,12 @@ static void prune_dcache(int count) { struct super_block *sb, *p = NULL; int w_count; - int unused = percpu_counter_sum_positive(&nr_dentry_unused); + int unused = dentry_stat.nr_unused; int prune_ratio; int pruned; if (unused == 0 || count == 0) return; - spin_lock(&dcache_lock); if (count >= unused) prune_ratio = 1; else @@ -589,11 +838,9 @@ static void prune_dcache(int count) if (down_read_trylock(&sb->s_umount)) { if ((sb->s_root != NULL) && (!list_empty(&sb->s_dentry_lru))) { - spin_unlock(&dcache_lock); __shrink_dcache_sb(sb, &w_count, DCACHE_REFERENCED); pruned -= w_count; - spin_lock(&dcache_lock); } up_read(&sb->s_umount); } @@ -609,7 +856,6 @@ static void prune_dcache(int count) if (p) __put_super(p); spin_unlock(&sb_lock); - spin_unlock(&dcache_lock); } /** @@ -623,12 +869,14 @@ void shrink_dcache_sb(struct super_block *sb) { LIST_HEAD(tmp); - spin_lock(&dcache_lock); + spin_lock(&dcache_lru_lock); while (!list_empty(&sb->s_dentry_lru)) { list_splice_init(&sb->s_dentry_lru, &tmp); + spin_unlock(&dcache_lru_lock); shrink_dentry_list(&tmp); + spin_lock(&dcache_lru_lock); } - spin_unlock(&dcache_lock); + spin_unlock(&dcache_lru_lock); } EXPORT_SYMBOL(shrink_dcache_sb); @@ -645,10 +893,10 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) BUG_ON(!IS_ROOT(dentry)); /* detach this root from the system */ - spin_lock(&dcache_lock); + spin_lock(&dentry->d_lock); dentry_lru_del(dentry); __d_drop(dentry); - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); for (;;) { /* descend to the first leaf in the current subtree */ @@ -657,14 +905,16 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) /* this is a branch with children - detach all of them * from the system in one go */ - spin_lock(&dcache_lock); + spin_lock(&dentry->d_lock); list_for_each_entry(loop, &dentry->d_subdirs, d_u.d_child) { + spin_lock_nested(&loop->d_lock, + DENTRY_D_LOCK_NESTED); dentry_lru_del(loop); __d_drop(loop); - cond_resched_lock(&dcache_lock); + spin_unlock(&loop->d_lock); } - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); /* move to the first child */ dentry = list_entry(dentry->d_subdirs.next, @@ -676,7 +926,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) do { struct inode *inode; - if (atomic_read(&dentry->d_count) != 0) { + if (dentry->d_count != 0) { printk(KERN_ERR "BUG: Dentry %p{i=%lx,n=%s}" " still in use (%d)" @@ -685,20 +935,23 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) dentry->d_inode ? dentry->d_inode->i_ino : 0UL, dentry->d_name.name, - atomic_read(&dentry->d_count), + dentry->d_count, dentry->d_sb->s_type->name, dentry->d_sb->s_id); BUG(); } - if (IS_ROOT(dentry)) + if (IS_ROOT(dentry)) { parent = NULL; - else { + list_del(&dentry->d_u.d_child); + } else { parent = dentry->d_parent; - atomic_dec(&parent->d_count); + spin_lock(&parent->d_lock); + parent->d_count--; + list_del(&dentry->d_u.d_child); + spin_unlock(&parent->d_lock); } - list_del(&dentry->d_u.d_child); detached++; inode = dentry->d_inode; @@ -728,8 +981,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) /* * destroy the dentries attached to a superblock on unmounting - * - we don't need to use dentry->d_lock, and only need dcache_lock when - * removing the dentry from the system lists and hashes because: + * - we don't need to use dentry->d_lock because: * - the superblock is detached from all mountings and open files, so the * dentry trees will not be rearranged by the VFS * - s_umount is write-locked, so the memory pressure shrinker will ignore @@ -746,11 +998,13 @@ void shrink_dcache_for_umount(struct super_block *sb) dentry = sb->s_root; sb->s_root = NULL; - atomic_dec(&dentry->d_count); + spin_lock(&dentry->d_lock); + dentry->d_count--; + spin_unlock(&dentry->d_lock); shrink_dcache_for_umount_subtree(dentry); - while (!hlist_empty(&sb->s_anon)) { - dentry = hlist_entry(sb->s_anon.first, struct dentry, d_hash); + while (!hlist_bl_empty(&sb->s_anon)) { + dentry = hlist_bl_entry(hlist_bl_first(&sb->s_anon), struct dentry, d_hash); shrink_dcache_for_umount_subtree(dentry); } } @@ -768,15 +1022,20 @@ void shrink_dcache_for_umount(struct super_block *sb) * Return true if the parent or its subdirectories contain * a mount point */ - int have_submounts(struct dentry *parent) { - struct dentry *this_parent = parent; + struct dentry *this_parent; struct list_head *next; + unsigned seq; + int locked = 0; + + seq = read_seqbegin(&rename_lock); +again: + this_parent = parent; - spin_lock(&dcache_lock); if (d_mountpoint(parent)) goto positive; + spin_lock(&this_parent->d_lock); repeat: next = this_parent->d_subdirs.next; resume: @@ -784,27 +1043,65 @@ resume: struct list_head *tmp = next; struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child); next = tmp->next; + + spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); /* Have we found a mount point ? */ - if (d_mountpoint(dentry)) + if (d_mountpoint(dentry)) { + spin_unlock(&dentry->d_lock); + spin_unlock(&this_parent->d_lock); goto positive; + } if (!list_empty(&dentry->d_subdirs)) { + spin_unlock(&this_parent->d_lock); + spin_release(&dentry->d_lock.dep_map, 1, _RET_IP_); this_parent = dentry; + spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_); goto repeat; } + spin_unlock(&dentry->d_lock); } /* * All done at this level ... ascend and resume the search. */ if (this_parent != parent) { - next = this_parent->d_u.d_child.next; - this_parent = this_parent->d_parent; + struct dentry *tmp; + struct dentry *child; + + tmp = this_parent->d_parent; + rcu_read_lock(); + spin_unlock(&this_parent->d_lock); + child = this_parent; + this_parent = tmp; + spin_lock(&this_parent->d_lock); + /* might go back up the wrong parent if we have had a rename + * or deletion */ + if (this_parent != child->d_parent || + (!locked && read_seqretry(&rename_lock, seq))) { + spin_unlock(&this_parent->d_lock); + rcu_read_unlock(); + goto rename_retry; + } + rcu_read_unlock(); + next = child->d_u.d_child.next; goto resume; } - spin_unlock(&dcache_lock); + spin_unlock(&this_parent->d_lock); + if (!locked && read_seqretry(&rename_lock, seq)) + goto rename_retry; + if (locked) + write_sequnlock(&rename_lock); return 0; /* No mount points found in tree */ positive: - spin_unlock(&dcache_lock); + if (!locked && read_seqretry(&rename_lock, seq)) + goto rename_retry; + if (locked) + write_sequnlock(&rename_lock); return 1; + +rename_retry: + locked = 1; + write_seqlock(&rename_lock); + goto again; } EXPORT_SYMBOL(have_submounts); @@ -824,11 +1121,16 @@ EXPORT_SYMBOL(have_submounts); */ static int select_parent(struct dentry * parent) { - struct dentry *this_parent = parent; + struct dentry *this_parent; struct list_head *next; + unsigned seq; int found = 0; + int locked = 0; - spin_lock(&dcache_lock); + seq = read_seqbegin(&rename_lock); +again: + this_parent = parent; + spin_lock(&this_parent->d_lock); repeat: next = this_parent->d_subdirs.next; resume: @@ -837,11 +1139,13 @@ resume: struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child); next = tmp->next; + spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); + /* * move only zero ref count dentries to the end * of the unused list for prune_dcache */ - if (!atomic_read(&dentry->d_count)) { + if (!dentry->d_count) { dentry_lru_move_tail(dentry); found++; } else { @@ -853,28 +1157,63 @@ resume: * ensures forward progress). We'll be coming back to find * the rest. */ - if (found && need_resched()) + if (found && need_resched()) { + spin_unlock(&dentry->d_lock); goto out; + } /* * Descend a level if the d_subdirs list is non-empty. */ if (!list_empty(&dentry->d_subdirs)) { + spin_unlock(&this_parent->d_lock); + spin_release(&dentry->d_lock.dep_map, 1, _RET_IP_); this_parent = dentry; + spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_); goto repeat; } + + spin_unlock(&dentry->d_lock); } /* * All done at this level ... ascend and resume the search. */ if (this_parent != parent) { - next = this_parent->d_u.d_child.next; - this_parent = this_parent->d_parent; + struct dentry *tmp; + struct dentry *child; + + tmp = this_parent->d_parent; + rcu_read_lock(); + spin_unlock(&this_parent->d_lock); + child = this_parent; + this_parent = tmp; + spin_lock(&this_parent->d_lock); + /* might go back up the wrong parent if we have had a rename + * or deletion */ + if (this_parent != child->d_parent || + (!locked && read_seqretry(&rename_lock, seq))) { + spin_unlock(&this_parent->d_lock); + rcu_read_unlock(); + goto rename_retry; + } + rcu_read_unlock(); + next = child->d_u.d_child.next; goto resume; } out: - spin_unlock(&dcache_lock); + spin_unlock(&this_parent->d_lock); + if (!locked && read_seqretry(&rename_lock, seq)) + goto rename_retry; + if (locked) + write_sequnlock(&rename_lock); return found; + +rename_retry: + if (found) + return found; + locked = 1; + write_seqlock(&rename_lock); + goto again; } /** @@ -908,16 +1247,13 @@ EXPORT_SYMBOL(shrink_dcache_parent); */ static int shrink_dcache_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask) { - int nr_unused; - if (nr) { if (!(gfp_mask & __GFP_FS)) return -1; prune_dcache(nr); } - nr_unused = percpu_counter_sum_positive(&nr_dentry_unused); - return (nr_unused / 100) * sysctl_vfs_cache_pressure; + return (dentry_stat.nr_unused / 100) * sysctl_vfs_cache_pressure; } static struct shrinker dcache_shrinker = { @@ -960,38 +1296,52 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name) memcpy(dname, name->name, name->len); dname[name->len] = 0; - atomic_set(&dentry->d_count, 1); + dentry->d_count = 1; dentry->d_flags = DCACHE_UNHASHED; spin_lock_init(&dentry->d_lock); + seqcount_init(&dentry->d_seq); dentry->d_inode = NULL; dentry->d_parent = NULL; dentry->d_sb = NULL; dentry->d_op = NULL; dentry->d_fsdata = NULL; - dentry->d_mounted = 0; - INIT_HLIST_NODE(&dentry->d_hash); + INIT_HLIST_BL_NODE(&dentry->d_hash); INIT_LIST_HEAD(&dentry->d_lru); INIT_LIST_HEAD(&dentry->d_subdirs); INIT_LIST_HEAD(&dentry->d_alias); + INIT_LIST_HEAD(&dentry->d_u.d_child); if (parent) { - dentry->d_parent = dget(parent); + spin_lock(&parent->d_lock); + /* + * don't need child lock because it is not subject + * to concurrency here + */ + __dget_dlock(parent); + dentry->d_parent = parent; dentry->d_sb = parent->d_sb; - } else { - INIT_LIST_HEAD(&dentry->d_u.d_child); - } - - spin_lock(&dcache_lock); - if (parent) list_add(&dentry->d_u.d_child, &parent->d_subdirs); - spin_unlock(&dcache_lock); + spin_unlock(&parent->d_lock); + } - percpu_counter_inc(&nr_dentry); + this_cpu_inc(nr_dentry); return dentry; } EXPORT_SYMBOL(d_alloc); +struct dentry *d_alloc_pseudo(struct super_block *sb, const struct qstr *name) +{ + struct dentry *dentry = d_alloc(NULL, name); + if (dentry) { + dentry->d_sb = sb; + dentry->d_parent = dentry; + dentry->d_flags |= DCACHE_DISCONNECTED; + } + return dentry; +} +EXPORT_SYMBOL(d_alloc_pseudo); + struct dentry *d_alloc_name(struct dentry *parent, const char *name) { struct qstr q; @@ -1003,12 +1353,36 @@ struct dentry *d_alloc_name(struct dentry *parent, const char *name) } EXPORT_SYMBOL(d_alloc_name); -/* the caller must hold dcache_lock */ +void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op) +{ + BUG_ON(dentry->d_op); + BUG_ON(dentry->d_flags & (DCACHE_OP_HASH | + DCACHE_OP_COMPARE | + DCACHE_OP_REVALIDATE | + DCACHE_OP_DELETE )); + dentry->d_op = op; + if (!op) + return; + if (op->d_hash) + dentry->d_flags |= DCACHE_OP_HASH; + if (op->d_compare) + dentry->d_flags |= DCACHE_OP_COMPARE; + if (op->d_revalidate) + dentry->d_flags |= DCACHE_OP_REVALIDATE; + if (op->d_delete) + dentry->d_flags |= DCACHE_OP_DELETE; + +} +EXPORT_SYMBOL(d_set_d_op); + static void __d_instantiate(struct dentry *dentry, struct inode *inode) { + spin_lock(&dentry->d_lock); if (inode) list_add(&dentry->d_alias, &inode->i_dentry); dentry->d_inode = inode; + dentry_rcuwalk_barrier(dentry); + spin_unlock(&dentry->d_lock); fsnotify_d_instantiate(dentry, inode); } @@ -1030,9 +1404,11 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode) void d_instantiate(struct dentry *entry, struct inode * inode) { BUG_ON(!list_empty(&entry->d_alias)); - spin_lock(&dcache_lock); + if (inode) + spin_lock(&inode->i_lock); __d_instantiate(entry, inode); - spin_unlock(&dcache_lock); + if (inode) + spin_unlock(&inode->i_lock); security_d_instantiate(entry, inode); } EXPORT_SYMBOL(d_instantiate); @@ -1069,15 +1445,18 @@ static struct dentry *__d_instantiate_unique(struct dentry *entry, list_for_each_entry(alias, &inode->i_dentry, d_alias) { struct qstr *qstr = &alias->d_name; + /* + * Don't need alias->d_lock here, because aliases with + * d_parent == entry->d_parent are not subject to name or + * parent changes, because the parent inode i_mutex is held. + */ if (qstr->hash != hash) continue; if (alias->d_parent != entry->d_parent) continue; - if (qstr->len != len) + if (dentry_cmp(qstr->name, qstr->len, name, len)) continue; - if (memcmp(qstr->name, name, len)) - continue; - dget_locked(alias); + __dget(alias); return alias; } @@ -1091,9 +1470,11 @@ struct dentry *d_instantiate_unique(struct dentry *entry, struct inode *inode) BUG_ON(!list_empty(&entry->d_alias)); - spin_lock(&dcache_lock); + if (inode) + spin_lock(&inode->i_lock); result = __d_instantiate_unique(entry, inode); - spin_unlock(&dcache_lock); + if (inode) + spin_unlock(&inode->i_lock); if (!result) { security_d_instantiate(entry, inode); @@ -1134,14 +1515,6 @@ struct dentry * d_alloc_root(struct inode * root_inode) } EXPORT_SYMBOL(d_alloc_root); -static inline struct hlist_head *d_hash(struct dentry *parent, - unsigned long hash) -{ - hash += ((unsigned long) parent ^ GOLDEN_RATIO_PRIME) / L1_CACHE_BYTES; - hash = hash ^ ((hash ^ GOLDEN_RATIO_PRIME) >> D_HASHBITS); - return dentry_hashtable + (hash & D_HASHMASK); -} - /** * d_obtain_alias - find or allocate a dentry for a given inode * @inode: inode to allocate the dentry for @@ -1182,10 +1555,11 @@ struct dentry *d_obtain_alias(struct inode *inode) } tmp->d_parent = tmp; /* make sure dput doesn't croak */ - spin_lock(&dcache_lock); + + spin_lock(&inode->i_lock); res = __d_find_alias(inode, 0); if (res) { - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); dput(tmp); goto out_iput; } @@ -1195,12 +1569,14 @@ struct dentry *d_obtain_alias(struct inode *inode) tmp->d_sb = inode->i_sb; tmp->d_inode = inode; tmp->d_flags |= DCACHE_DISCONNECTED; - tmp->d_flags &= ~DCACHE_UNHASHED; list_add(&tmp->d_alias, &inode->i_dentry); - hlist_add_head(&tmp->d_hash, &inode->i_sb->s_anon); + bit_spin_lock(0, (unsigned long *)&tmp->d_sb->s_anon.first); + tmp->d_flags &= ~DCACHE_UNHASHED; + hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon); + __bit_spin_unlock(0, (unsigned long *)&tmp->d_sb->s_anon.first); spin_unlock(&tmp->d_lock); + spin_unlock(&inode->i_lock); - spin_unlock(&dcache_lock); return tmp; out_iput: @@ -1230,18 +1606,18 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry) struct dentry *new = NULL; if (inode && S_ISDIR(inode->i_mode)) { - spin_lock(&dcache_lock); + spin_lock(&inode->i_lock); new = __d_find_alias(inode, 1); if (new) { BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED)); - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); security_d_instantiate(new, inode); d_move(new, dentry); iput(inode); } else { - /* already taking dcache_lock, so d_add() by hand */ + /* already taking inode->i_lock, so d_add() by hand */ __d_instantiate(dentry, inode); - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); security_d_instantiate(dentry, inode); d_rehash(dentry); } @@ -1314,10 +1690,10 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode, * Negative dentry: instantiate it unless the inode is a directory and * already has a dentry. */ - spin_lock(&dcache_lock); + spin_lock(&inode->i_lock); if (!S_ISDIR(inode->i_mode) || list_empty(&inode->i_dentry)) { __d_instantiate(found, inode); - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); security_d_instantiate(found, inode); return found; } @@ -1327,8 +1703,8 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode, * reference to it, move it in place and use it. */ new = list_entry(inode->i_dentry.next, struct dentry, d_alias); - dget_locked(new); - spin_unlock(&dcache_lock); + __dget(new); + spin_unlock(&inode->i_lock); security_d_instantiate(found, inode); d_move(new, found); iput(inode); @@ -1342,6 +1718,112 @@ err_out: EXPORT_SYMBOL(d_add_ci); /** + * __d_lookup_rcu - search for a dentry (racy, store-free) + * @parent: parent dentry + * @name: qstr of name we wish to find + * @seq: returns d_seq value at the point where the dentry was found + * @inode: returns dentry->d_inode when the inode was found valid. + * Returns: dentry, or NULL + * + * __d_lookup_rcu is the dcache lookup function for rcu-walk name + * resolution (store-free path walking) design described in + * Documentation/filesystems/path-lookup.txt. + * + * This is not to be used outside core vfs. + * + * __d_lookup_rcu must only be used in rcu-walk mode, ie. with vfsmount lock + * held, and rcu_read_lock held. The returned dentry must not be stored into + * without taking d_lock and checking d_seq sequence count against @seq + * returned here. + * + * A refcount may be taken on the found dentry with the __d_rcu_to_refcount + * function. + * + * Alternatively, __d_lookup_rcu may be called again to look up the child of + * the returned dentry, so long as its parent's seqlock is checked after the + * child is looked up. Thus, an interlocking stepping of sequence lock checks + * is formed, giving integrity down the path walk. + */ +struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name, + unsigned *seq, struct inode **inode) +{ + unsigned int len = name->len; + unsigned int hash = name->hash; + const unsigned char *str = name->name; + struct dcache_hash_bucket *b = d_hash(parent, hash); + struct hlist_bl_node *node; + struct dentry *dentry; + + /* + * Note: There is significant duplication with __d_lookup_rcu which is + * required to prevent single threaded performance regressions + * especially on architectures where smp_rmb (in seqcounts) are costly. + * Keep the two functions in sync. + */ + + /* + * The hash list is protected using RCU. + * + * Carefully use d_seq when comparing a candidate dentry, to avoid + * races with d_move(). + * + * It is possible that concurrent renames can mess up our list + * walk here and result in missing our dentry, resulting in the + * false-negative result. d_lookup() protects against concurrent + * renames using rename_lock seqlock. + * + * See Documentation/vfs/dcache-locking.txt for more details. + */ + hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) { + struct inode *i; + const char *tname; + int tlen; + + if (dentry->d_name.hash != hash) + continue; + +seqretry: + *seq = read_seqcount_begin(&dentry->d_seq); + if (dentry->d_parent != parent) + continue; + if (d_unhashed(dentry)) + continue; + tlen = dentry->d_name.len; + tname = dentry->d_name.name; + i = dentry->d_inode; + prefetch(tname); + if (i) + prefetch(i); + /* + * This seqcount check is required to ensure name and + * len are loaded atomically, so as not to walk off the + * edge of memory when walking. If we could load this + * atomically some other way, we could drop this check. + */ + if (read_seqcount_retry(&dentry->d_seq, *seq)) + goto seqretry; + if (parent->d_flags & DCACHE_OP_COMPARE) { + if (parent->d_op->d_compare(parent, *inode, + dentry, i, + tlen, tname, name)) + continue; + } else { + if (dentry_cmp(tname, tlen, str, len)) + continue; + } + /* + * No extra seqcount check is required after the name + * compare. The caller must perform a seqcount check in + * order to do anything useful with the returned dentry + * anyway. + */ + *inode = i; + return dentry; + } + return NULL; +} + +/** * d_lookup - search for a dentry * @parent: parent dentry * @name: qstr of name we wish to find @@ -1352,10 +1834,10 @@ EXPORT_SYMBOL(d_add_ci); * dentry is returned. The caller must use dput to free the entry when it has * finished using it. %NULL is returned if the dentry does not exist. */ -struct dentry * d_lookup(struct dentry * parent, struct qstr * name) +struct dentry *d_lookup(struct dentry *parent, struct qstr *name) { - struct dentry * dentry = NULL; - unsigned long seq; + struct dentry *dentry; + unsigned seq; do { seq = read_seqbegin(&rename_lock); @@ -1367,7 +1849,7 @@ struct dentry * d_lookup(struct dentry * parent, struct qstr * name) } EXPORT_SYMBOL(d_lookup); -/* +/** * __d_lookup - search for a dentry (racy) * @parent: parent dentry * @name: qstr of name we wish to find @@ -1382,17 +1864,24 @@ EXPORT_SYMBOL(d_lookup); * * __d_lookup callers must be commented. */ -struct dentry * __d_lookup(struct dentry * parent, struct qstr * name) +struct dentry *__d_lookup(struct dentry *parent, struct qstr *name) { unsigned int len = name->len; unsigned int hash = name->hash; const unsigned char *str = name->name; - struct hlist_head *head = d_hash(parent,hash); + struct dcache_hash_bucket *b = d_hash(parent, hash); + struct hlist_bl_node *node; struct dentry *found = NULL; - struct hlist_node *node; struct dentry *dentry; /* + * Note: There is significant duplication with __d_lookup_rcu which is + * required to prevent single threaded performance regressions + * especially on architectures where smp_rmb (in seqcounts) are costly. + * Keep the two functions in sync. + */ + + /* * The hash list is protected using RCU. * * Take d_lock when comparing a candidate dentry, to avoid races @@ -1407,25 +1896,16 @@ struct dentry * __d_lookup(struct dentry * parent, struct qstr * name) */ rcu_read_lock(); - hlist_for_each_entry_rcu(dentry, node, head, d_hash) { - struct qstr *qstr; + hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) { + const char *tname; + int tlen; if (dentry->d_name.hash != hash) continue; - if (dentry->d_parent != parent) - continue; spin_lock(&dentry->d_lock); - - /* - * Recheck the dentry after taking the lock - d_move may have - * changed things. Don't bother checking the hash because - * we're about to compare the whole name anyway. - */ if (dentry->d_parent != parent) goto next; - - /* non-existing due to RCU? */ if (d_unhashed(dentry)) goto next; @@ -1433,18 +1913,19 @@ struct dentry * __d_lookup(struct dentry * parent, struct qstr * name) * It is safe to compare names since d_move() cannot * change the qstr (protected by d_lock). */ - qstr = &dentry->d_name; - if (parent->d_op && parent->d_op->d_compare) { - if (parent->d_op->d_compare(parent, qstr, name)) + tlen = dentry->d_name.len; + tname = dentry->d_name.name; + if (parent->d_flags & DCACHE_OP_COMPARE) { + if (parent->d_op->d_compare(parent, parent->d_inode, + dentry, dentry->d_inode, + tlen, tname, name)) goto next; } else { - if (qstr->len != len) - goto next; - if (memcmp(qstr->name, str, len)) + if (dentry_cmp(tname, tlen, str, len)) goto next; } - atomic_inc(&dentry->d_count); + dentry->d_count++; found = dentry; spin_unlock(&dentry->d_lock); break; @@ -1473,8 +1954,8 @@ struct dentry *d_hash_and_lookup(struct dentry *dir, struct qstr *name) * routine may choose to leave the hash value unchanged. */ name->hash = full_name_hash(name->name, name->len); - if (dir->d_op && dir->d_op->d_hash) { - if (dir->d_op->d_hash(dir, name) < 0) + if (dir->d_flags & DCACHE_OP_HASH) { + if (dir->d_op->d_hash(dir, dir->d_inode, name) < 0) goto out; } dentry = d_lookup(dir, name); @@ -1483,34 +1964,32 @@ out: } /** - * d_validate - verify dentry provided from insecure source + * d_validate - verify dentry provided from insecure source (deprecated) * @dentry: The dentry alleged to be valid child of @dparent * @dparent: The parent dentry (known to be valid) * * An insecure source has sent us a dentry, here we verify it and dget() it. * This is used by ncpfs in its readdir implementation. * Zero is returned in the dentry is invalid. + * + * This function is slow for big directories, and deprecated, do not use it. */ -int d_validate(struct dentry *dentry, struct dentry *parent) +int d_validate(struct dentry *dentry, struct dentry *dparent) { - struct hlist_head *head = d_hash(parent, dentry->d_name.hash); - struct hlist_node *node; - struct dentry *d; - - /* Check whether the ptr might be valid at all.. */ - if (!kmem_ptr_validate(dentry_cache, dentry)) - return 0; - if (dentry->d_parent != parent) - return 0; + struct dentry *child; - rcu_read_lock(); - hlist_for_each_entry_rcu(d, node, head, d_hash) { - if (d == dentry) { - dget(dentry); + spin_lock(&dparent->d_lock); + list_for_each_entry(child, &dparent->d_subdirs, d_u.d_child) { + if (dentry == child) { + spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); + __dget_dlock(dentry); + spin_unlock(&dentry->d_lock); + spin_unlock(&dparent->d_lock); return 1; } } - rcu_read_unlock(); + spin_unlock(&dparent->d_lock); + return 0; } EXPORT_SYMBOL(d_validate); @@ -1538,16 +2017,23 @@ EXPORT_SYMBOL(d_validate); void d_delete(struct dentry * dentry) { + struct inode *inode; int isdir = 0; /* * Are we the only user? */ - spin_lock(&dcache_lock); +again: spin_lock(&dentry->d_lock); - isdir = S_ISDIR(dentry->d_inode->i_mode); - if (atomic_read(&dentry->d_count) == 1) { + inode = dentry->d_inode; + isdir = S_ISDIR(inode->i_mode); + if (dentry->d_count == 1) { + if (inode && !spin_trylock(&inode->i_lock)) { + spin_unlock(&dentry->d_lock); + cpu_relax(); + goto again; + } dentry->d_flags &= ~DCACHE_CANT_MOUNT; - dentry_iput(dentry); + dentry_unlink_inode(dentry); fsnotify_nameremove(dentry, isdir); return; } @@ -1556,17 +2042,18 @@ void d_delete(struct dentry * dentry) __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); fsnotify_nameremove(dentry, isdir); } EXPORT_SYMBOL(d_delete); -static void __d_rehash(struct dentry * entry, struct hlist_head *list) +static void __d_rehash(struct dentry * entry, struct dcache_hash_bucket *b) { - + BUG_ON(!d_unhashed(entry)); + spin_lock_bucket(b); entry->d_flags &= ~DCACHE_UNHASHED; - hlist_add_head_rcu(&entry->d_hash, list); + hlist_bl_add_head_rcu(&entry->d_hash, &b->head); + spin_unlock_bucket(b); } static void _d_rehash(struct dentry * entry) @@ -1583,25 +2070,39 @@ static void _d_rehash(struct dentry * entry) void d_rehash(struct dentry * entry) { - spin_lock(&dcache_lock); spin_lock(&entry->d_lock); _d_rehash(entry); spin_unlock(&entry->d_lock); - spin_unlock(&dcache_lock); } EXPORT_SYMBOL(d_rehash); -/* - * When switching names, the actual string doesn't strictly have to - * be preserved in the target - because we're dropping the target - * anyway. As such, we can just do a simple memcpy() to copy over - * the new name before we switch. +/** + * dentry_update_name_case - update case insensitive dentry with a new name + * @dentry: dentry to be updated + * @name: new name * - * Note that we have to be a lot more careful about getting the hash - * switched - we have to switch the hash value properly even if it - * then no longer matches the actual (corrupted) string of the target. - * The hash value has to match the hash queue that the dentry is on.. + * Update a case insensitive dentry with new case of name. + * + * dentry must have been returned by d_lookup with name @name. Old and new + * name lengths must match (ie. no d_compare which allows mismatched name + * lengths). + * + * Parent inode i_mutex must be held over d_lookup and into this call (to + * keep renames and concurrent inserts, and readdir(2) away). */ +void dentry_update_name_case(struct dentry *dentry, struct qstr *name) +{ + BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex)); + BUG_ON(dentry->d_name.len != name->len); /* d_lookup gives this */ + + spin_lock(&dentry->d_lock); + write_seqcount_begin(&dentry->d_seq); + memcpy((unsigned char *)dentry->d_name.name, name->name, name->len); + write_seqcount_end(&dentry->d_seq); + spin_unlock(&dentry->d_lock); +} +EXPORT_SYMBOL(dentry_update_name_case); + static void switch_names(struct dentry *dentry, struct dentry *target) { if (dname_external(target)) { @@ -1643,54 +2144,84 @@ static void switch_names(struct dentry *dentry, struct dentry *target) swap(dentry->d_name.len, target->d_name.len); } +static void dentry_lock_for_move(struct dentry *dentry, struct dentry *target) +{ + /* + * XXXX: do we really need to take target->d_lock? + */ + if (IS_ROOT(dentry) || dentry->d_parent == target->d_parent) + spin_lock(&target->d_parent->d_lock); + else { + if (d_ancestor(dentry->d_parent, target->d_parent)) { + spin_lock(&dentry->d_parent->d_lock); + spin_lock_nested(&target->d_parent->d_lock, + DENTRY_D_LOCK_NESTED); + } else { + spin_lock(&target->d_parent->d_lock); + spin_lock_nested(&dentry->d_parent->d_lock, + DENTRY_D_LOCK_NESTED); + } + } + if (target < dentry) { + spin_lock_nested(&target->d_lock, 2); + spin_lock_nested(&dentry->d_lock, 3); + } else { + spin_lock_nested(&dentry->d_lock, 2); + spin_lock_nested(&target->d_lock, 3); + } +} + +static void dentry_unlock_parents_for_move(struct dentry *dentry, + struct dentry *target) +{ + if (target->d_parent != dentry->d_parent) + spin_unlock(&dentry->d_parent->d_lock); + if (target->d_parent != target) + spin_unlock(&target->d_parent->d_lock); +} + /* - * We cannibalize "target" when moving dentry on top of it, - * because it's going to be thrown away anyway. We could be more - * polite about it, though. - * - * This forceful removal will result in ugly /proc output if - * somebody holds a file open that got deleted due to a rename. - * We could be nicer about the deleted file, and let it show - * up under the name it had before it was deleted rather than - * under the original name of the file that was moved on top of it. + * When switching names, the actual string doesn't strictly have to + * be preserved in the target - because we're dropping the target + * anyway. As such, we can just do a simple memcpy() to copy over + * the new name before we switch. + * + * Note that we have to be a lot more careful about getting the hash + * switched - we have to switch the hash value properly even if it + * then no longer matches the actual (corrupted) string of the target. + * The hash value has to match the hash queue that the dentry is on.. */ - /* - * d_move_locked - move a dentry + * d_move - move a dentry * @dentry: entry to move * @target: new dentry * * Update the dcache to reflect the move of a file name. Negative * dcache entries should not be moved in this way. */ -static void d_move_locked(struct dentry * dentry, struct dentry * target) +void d_move(struct dentry * dentry, struct dentry * target) { - struct hlist_head *list; - if (!dentry->d_inode) printk(KERN_WARNING "VFS: moving negative dcache entry\n"); + BUG_ON(d_ancestor(dentry, target)); + BUG_ON(d_ancestor(target, dentry)); + write_seqlock(&rename_lock); - /* - * XXXX: do we really need to take target->d_lock? - */ - if (target < dentry) { - spin_lock(&target->d_lock); - spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); - } else { - spin_lock(&dentry->d_lock); - spin_lock_nested(&target->d_lock, DENTRY_D_LOCK_NESTED); - } - /* Move the dentry to the target hash queue, if on different bucket */ - if (d_unhashed(dentry)) - goto already_unhashed; + dentry_lock_for_move(dentry, target); - hlist_del_rcu(&dentry->d_hash); + write_seqcount_begin(&dentry->d_seq); + write_seqcount_begin(&target->d_seq); -already_unhashed: - list = d_hash(target->d_parent, target->d_name.hash); - __d_rehash(dentry, list); + /* __d_drop does write_seqcount_barrier, but they're OK to nest. */ + + /* + * Move the dentry to the target hash queue. Don't bother checking + * for the same hash queue because of how unlikely it is. + */ + __d_drop(dentry); + __d_rehash(dentry, d_hash(target->d_parent, target->d_name.hash)); /* Unhash the target: dput() will then get rid of it */ __d_drop(target); @@ -1715,27 +2246,16 @@ already_unhashed: } list_add(&dentry->d_u.d_child, &dentry->d_parent->d_subdirs); + + write_seqcount_end(&target->d_seq); + write_seqcount_end(&dentry->d_seq); + + dentry_unlock_parents_for_move(dentry, target); spin_unlock(&target->d_lock); fsnotify_d_move(dentry); spin_unlock(&dentry->d_lock); write_sequnlock(&rename_lock); } - -/** - * d_move - move a dentry - * @dentry: entry to move - * @target: new dentry - * - * Update the dcache to reflect the move of a file name. Negative - * dcache entries should not be moved in this way. - */ - -void d_move(struct dentry * dentry, struct dentry * target) -{ - spin_lock(&dcache_lock); - d_move_locked(dentry, target); - spin_unlock(&dcache_lock); -} EXPORT_SYMBOL(d_move); /** @@ -1761,13 +2281,13 @@ struct dentry *d_ancestor(struct dentry *p1, struct dentry *p2) * This helper attempts to cope with remotely renamed directories * * It assumes that the caller is already holding - * dentry->d_parent->d_inode->i_mutex and the dcache_lock + * dentry->d_parent->d_inode->i_mutex and the inode->i_lock * * Note: If ever the locking in lock_rename() changes, then please * remember to update this too... */ -static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias) - __releases(dcache_lock) +static struct dentry *__d_unalias(struct inode *inode, + struct dentry *dentry, struct dentry *alias) { struct mutex *m1 = NULL, *m2 = NULL; struct dentry *ret; @@ -1790,10 +2310,10 @@ static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias) goto out_err; m2 = &alias->d_parent->d_inode->i_mutex; out_unalias: - d_move_locked(alias, dentry); + d_move(alias, dentry); ret = alias; out_err: - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); if (m2) mutex_unlock(m2); if (m1) @@ -1804,17 +2324,23 @@ out_err: /* * Prepare an anonymous dentry for life in the superblock's dentry tree as a * named dentry in place of the dentry to be replaced. + * returns with anon->d_lock held! */ static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon) { struct dentry *dparent, *aparent; - switch_names(dentry, anon); - swap(dentry->d_name.hash, anon->d_name.hash); + dentry_lock_for_move(anon, dentry); + + write_seqcount_begin(&dentry->d_seq); + write_seqcount_begin(&anon->d_seq); dparent = dentry->d_parent; aparent = anon->d_parent; + switch_names(dentry, anon); + swap(dentry->d_name.hash, anon->d_name.hash); + dentry->d_parent = (aparent == anon) ? dentry : aparent; list_del(&dentry->d_u.d_child); if (!IS_ROOT(dentry)) @@ -1829,6 +2355,13 @@ static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon) else INIT_LIST_HEAD(&anon->d_u.d_child); + write_seqcount_end(&dentry->d_seq); + write_seqcount_end(&anon->d_seq); + + dentry_unlock_parents_for_move(anon, dentry); + spin_unlock(&dentry->d_lock); + + /* anon->d_lock still locked, returns locked */ anon->d_flags &= ~DCACHE_DISCONNECTED; } @@ -1846,14 +2379,15 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) BUG_ON(!d_unhashed(dentry)); - spin_lock(&dcache_lock); - if (!inode) { actual = dentry; __d_instantiate(dentry, NULL); - goto found_lock; + d_rehash(actual); + goto out_nolock; } + spin_lock(&inode->i_lock); + if (S_ISDIR(inode->i_mode)) { struct dentry *alias; @@ -1864,13 +2398,12 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) /* Is this an anonymous mountpoint that we could splice * into our tree? */ if (IS_ROOT(alias)) { - spin_lock(&alias->d_lock); __d_materialise_dentry(dentry, alias); __d_drop(alias); goto found; } /* Nope, but we must(!) avoid directory aliasing */ - actual = __d_unalias(dentry, alias); + actual = __d_unalias(inode, dentry, alias); if (IS_ERR(actual)) dput(alias); goto out_nolock; @@ -1881,15 +2414,14 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) actual = __d_instantiate_unique(dentry, inode); if (!actual) actual = dentry; - else if (unlikely(!d_unhashed(actual))) - goto shouldnt_be_hashed; + else + BUG_ON(!d_unhashed(actual)); -found_lock: spin_lock(&actual->d_lock); found: _d_rehash(actual); spin_unlock(&actual->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); out_nolock: if (actual == dentry) { security_d_instantiate(dentry, inode); @@ -1898,10 +2430,6 @@ out_nolock: iput(inode); return actual; - -shouldnt_be_hashed: - spin_unlock(&dcache_lock); - BUG(); } EXPORT_SYMBOL_GPL(d_materialise_unique); @@ -1928,7 +2456,7 @@ static int prepend_name(char **buffer, int *buflen, struct qstr *name) * @buffer: pointer to the end of the buffer * @buflen: pointer to buffer length * - * Caller holds the dcache_lock. + * Caller holds the rename_lock. * * If path is not reachable from the supplied root, then the value of * root is changed (without modifying refcounts). @@ -1956,7 +2484,9 @@ static int prepend_path(const struct path *path, struct path *root, } parent = dentry->d_parent; prefetch(parent); + spin_lock(&dentry->d_lock); error = prepend_name(buffer, buflen, &dentry->d_name); + spin_unlock(&dentry->d_lock); if (!error) error = prepend(buffer, buflen, "/", 1); if (error) @@ -2012,9 +2542,9 @@ char *__d_path(const struct path *path, struct path *root, int error; prepend(&res, &buflen, "\0", 1); - spin_lock(&dcache_lock); + write_seqlock(&rename_lock); error = prepend_path(path, root, &res, &buflen); - spin_unlock(&dcache_lock); + write_sequnlock(&rename_lock); if (error) return ERR_PTR(error); @@ -2076,12 +2606,12 @@ char *d_path(const struct path *path, char *buf, int buflen) return path->dentry->d_op->d_dname(path->dentry, buf, buflen); get_fs_root(current->fs, &root); - spin_lock(&dcache_lock); + write_seqlock(&rename_lock); tmp = root; error = path_with_deleted(path, &tmp, &res, &buflen); if (error) res = ERR_PTR(error); - spin_unlock(&dcache_lock); + write_sequnlock(&rename_lock); path_put(&root); return res; } @@ -2107,12 +2637,12 @@ char *d_path_with_unreachable(const struct path *path, char *buf, int buflen) return path->dentry->d_op->d_dname(path->dentry, buf, buflen); get_fs_root(current->fs, &root); - spin_lock(&dcache_lock); + write_seqlock(&rename_lock); tmp = root; error = path_with_deleted(path, &tmp, &res, &buflen); if (!error && !path_equal(&tmp, &root)) error = prepend_unreachable(&res, &buflen); - spin_unlock(&dcache_lock); + write_sequnlock(&rename_lock); path_put(&root); if (error) res = ERR_PTR(error); @@ -2144,7 +2674,7 @@ char *dynamic_dname(struct dentry *dentry, char *buffer, int buflen, /* * Write full pathname from the root of the filesystem into the buffer. */ -char *__dentry_path(struct dentry *dentry, char *buf, int buflen) +static char *__dentry_path(struct dentry *dentry, char *buf, int buflen) { char *end = buf + buflen; char *retval; @@ -2158,10 +2688,13 @@ char *__dentry_path(struct dentry *dentry, char *buf, int buflen) while (!IS_ROOT(dentry)) { struct dentry *parent = dentry->d_parent; + int error; prefetch(parent); - if ((prepend_name(&end, &buflen, &dentry->d_name) != 0) || - (prepend(&end, &buflen, "/", 1) != 0)) + spin_lock(&dentry->d_lock); + error = prepend_name(&end, &buflen, &dentry->d_name); + spin_unlock(&dentry->d_lock); + if (error != 0 || prepend(&end, &buflen, "/", 1) != 0) goto Elong; retval = end; @@ -2171,14 +2704,25 @@ char *__dentry_path(struct dentry *dentry, char *buf, int buflen) Elong: return ERR_PTR(-ENAMETOOLONG); } -EXPORT_SYMBOL(__dentry_path); + +char *dentry_path_raw(struct dentry *dentry, char *buf, int buflen) +{ + char *retval; + + write_seqlock(&rename_lock); + retval = __dentry_path(dentry, buf, buflen); + write_sequnlock(&rename_lock); + + return retval; +} +EXPORT_SYMBOL(dentry_path_raw); char *dentry_path(struct dentry *dentry, char *buf, int buflen) { char *p = NULL; char *retval; - spin_lock(&dcache_lock); + write_seqlock(&rename_lock); if (d_unlinked(dentry)) { p = buf + buflen; if (prepend(&p, &buflen, "//deleted", 10) != 0) @@ -2186,12 +2730,11 @@ char *dentry_path(struct dentry *dentry, char *buf, int buflen) buflen++; } retval = __dentry_path(dentry, buf, buflen); - spin_unlock(&dcache_lock); + write_sequnlock(&rename_lock); if (!IS_ERR(retval) && p) *p = '/'; /* restore '/' overriden with '\0' */ return retval; Elong: - spin_unlock(&dcache_lock); return ERR_PTR(-ENAMETOOLONG); } @@ -2225,7 +2768,7 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size) get_fs_root_and_pwd(current->fs, &root, &pwd); error = -ENOENT; - spin_lock(&dcache_lock); + write_seqlock(&rename_lock); if (!d_unlinked(pwd.dentry)) { unsigned long len; struct path tmp = root; @@ -2234,7 +2777,7 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size) prepend(&cwd, &buflen, "\0", 1); error = prepend_path(&pwd, &tmp, &cwd, &buflen); - spin_unlock(&dcache_lock); + write_sequnlock(&rename_lock); if (error) goto out; @@ -2253,8 +2796,9 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size) if (copy_to_user(buf, cwd, len)) error = -EFAULT; } - } else - spin_unlock(&dcache_lock); + } else { + write_sequnlock(&rename_lock); + } out: path_put(&pwd); @@ -2282,25 +2826,25 @@ out: int is_subdir(struct dentry *new_dentry, struct dentry *old_dentry) { int result; - unsigned long seq; + unsigned seq; if (new_dentry == old_dentry) return 1; - /* - * Need rcu_readlock to protect against the d_parent trashing - * due to d_move - */ - rcu_read_lock(); do { /* for restarting inner loop in case of seq retry */ seq = read_seqbegin(&rename_lock); + /* + * Need rcu_readlock to protect against the d_parent trashing + * due to d_move + */ + rcu_read_lock(); if (d_ancestor(old_dentry, new_dentry)) result = 1; else result = 0; + rcu_read_unlock(); } while (read_seqretry(&rename_lock, seq)); - rcu_read_unlock(); return result; } @@ -2332,10 +2876,15 @@ EXPORT_SYMBOL(path_is_under); void d_genocide(struct dentry *root) { - struct dentry *this_parent = root; + struct dentry *this_parent; struct list_head *next; + unsigned seq; + int locked = 0; - spin_lock(&dcache_lock); + seq = read_seqbegin(&rename_lock); +again: + this_parent = root; + spin_lock(&this_parent->d_lock); repeat: next = this_parent->d_subdirs.next; resume: @@ -2343,21 +2892,62 @@ resume: struct list_head *tmp = next; struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child); next = tmp->next; - if (d_unhashed(dentry)||!dentry->d_inode) + + spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); + if (d_unhashed(dentry) || !dentry->d_inode) { + spin_unlock(&dentry->d_lock); continue; + } if (!list_empty(&dentry->d_subdirs)) { + spin_unlock(&this_parent->d_lock); + spin_release(&dentry->d_lock.dep_map, 1, _RET_IP_); this_parent = dentry; + spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_); goto repeat; } - atomic_dec(&dentry->d_count); + if (!(dentry->d_flags & DCACHE_GENOCIDE)) { + dentry->d_flags |= DCACHE_GENOCIDE; + dentry->d_count--; + } + spin_unlock(&dentry->d_lock); } if (this_parent != root) { - next = this_parent->d_u.d_child.next; - atomic_dec(&this_parent->d_count); - this_parent = this_parent->d_parent; + struct dentry *tmp; + struct dentry *child; + + tmp = this_parent->d_parent; + if (!(this_parent->d_flags & DCACHE_GENOCIDE)) { + this_parent->d_flags |= DCACHE_GENOCIDE; + this_parent->d_count--; + } + rcu_read_lock(); + spin_unlock(&this_parent->d_lock); + child = this_parent; + this_parent = tmp; + spin_lock(&this_parent->d_lock); + /* might go back up the wrong parent if we have had a rename + * or deletion */ + if (this_parent != child->d_parent || + (!locked && read_seqretry(&rename_lock, seq))) { + spin_unlock(&this_parent->d_lock); + rcu_read_unlock(); + goto rename_retry; + } + rcu_read_unlock(); + next = child->d_u.d_child.next; goto resume; } - spin_unlock(&dcache_lock); + spin_unlock(&this_parent->d_lock); + if (!locked && read_seqretry(&rename_lock, seq)) + goto rename_retry; + if (locked) + write_sequnlock(&rename_lock); + return; + +rename_retry: + locked = 1; + write_seqlock(&rename_lock); + goto again; } /** @@ -2411,7 +3001,7 @@ static void __init dcache_init_early(void) dentry_hashtable = alloc_large_system_hash("Dentry cache", - sizeof(struct hlist_head), + sizeof(struct dcache_hash_bucket), dhash_entries, 13, HASH_EARLY, @@ -2420,16 +3010,13 @@ static void __init dcache_init_early(void) 0); for (loop = 0; loop < (1 << d_hash_shift); loop++) - INIT_HLIST_HEAD(&dentry_hashtable[loop]); + INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head); } static void __init dcache_init(void) { int loop; - percpu_counter_init(&nr_dentry, 0); - percpu_counter_init(&nr_dentry_unused, 0); - /* * A constructor could be added for stable state like the lists, * but it is probably not worth it because of the cache nature @@ -2446,7 +3033,7 @@ static void __init dcache_init(void) dentry_hashtable = alloc_large_system_hash("Dentry cache", - sizeof(struct hlist_head), + sizeof(struct dcache_hash_bucket), dhash_entries, 13, 0, @@ -2455,7 +3042,7 @@ static void __init dcache_init(void) 0); for (loop = 0; loop < (1 << d_hash_shift); loop++) - INIT_HLIST_HEAD(&dentry_hashtable[loop]); + INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head); } /* SLAB cache for __getname() consumers */ diff --git a/fs/ecryptfs/dentry.c b/fs/ecryptfs/dentry.c index 906e803f7f7..6fc4f319b55 100644 --- a/fs/ecryptfs/dentry.c +++ b/fs/ecryptfs/dentry.c @@ -44,12 +44,17 @@ */ static int ecryptfs_d_revalidate(struct dentry *dentry, struct nameidata *nd) { - struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); - struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); + struct dentry *lower_dentry; + struct vfsmount *lower_mnt; struct dentry *dentry_save; struct vfsmount *vfsmount_save; int rc = 1; + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + + lower_dentry = ecryptfs_dentry_to_lower(dentry); + lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate) goto out; dentry_save = nd->path.dentry; diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 9d1a22d6276..337352a9475 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -260,7 +260,7 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, ecryptfs_dentry->d_parent)); lower_inode = lower_dentry->d_inode; fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode); - BUG_ON(!atomic_read(&lower_dentry->d_count)); + BUG_ON(!lower_dentry->d_count); ecryptfs_set_dentry_private(ecryptfs_dentry, kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL)); @@ -441,7 +441,7 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode, struct qstr lower_name; int rc = 0; - ecryptfs_dentry->d_op = &ecryptfs_dops; + d_set_d_op(ecryptfs_dentry, &ecryptfs_dops); if ((ecryptfs_dentry->d_name.len == 1 && !strcmp(ecryptfs_dentry->d_name.name, ".")) || (ecryptfs_dentry->d_name.len == 2 @@ -454,7 +454,7 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode, lower_name.hash = ecryptfs_dentry->d_name.hash; if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) { rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry, - &lower_name); + lower_dir_dentry->d_inode, &lower_name); if (rc < 0) goto out_d_drop; } @@ -489,7 +489,7 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode, lower_name.hash = full_name_hash(lower_name.name, lower_name.len); if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) { rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry, - &lower_name); + lower_dir_dentry->d_inode, &lower_name); if (rc < 0) goto out_d_drop; } @@ -980,8 +980,10 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) } static int -ecryptfs_permission(struct inode *inode, int mask) +ecryptfs_permission(struct inode *inode, int mask, unsigned int flags) { + if (flags & IPERM_FLAG_RCU) + return -ECHILD; return inode_permission(ecryptfs_inode_to_lower(inode), mask); } diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index a9dbd62518e..35103867537 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -189,7 +189,7 @@ int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry, if (special_file(lower_inode->i_mode)) init_special_inode(inode, lower_inode->i_mode, lower_inode->i_rdev); - dentry->d_op = &ecryptfs_dops; + d_set_d_op(dentry, &ecryptfs_dops); fsstack_copy_attr_all(inode, lower_inode); /* This size will be overwritten for real files w/ headers and * other metadata */ @@ -594,7 +594,7 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags deactivate_locked_super(s); goto out; } - s->s_root->d_op = &ecryptfs_dops; + d_set_d_op(s->s_root, &ecryptfs_dops); s->s_root->d_sb = s; s->s_root->d_parent = s->s_root; diff --git a/fs/ecryptfs/super.c b/fs/ecryptfs/super.c index 2720178b771..3042fe123a3 100644 --- a/fs/ecryptfs/super.c +++ b/fs/ecryptfs/super.c @@ -62,6 +62,16 @@ out: return inode; } +static void ecryptfs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + struct ecryptfs_inode_info *inode_info; + inode_info = ecryptfs_inode_to_private(inode); + + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(ecryptfs_inode_info_cache, inode_info); +} + /** * ecryptfs_destroy_inode * @inode: The ecryptfs inode @@ -88,7 +98,7 @@ static void ecryptfs_destroy_inode(struct inode *inode) } } ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat); - kmem_cache_free(ecryptfs_inode_info_cache, inode_info); + call_rcu(&inode->i_rcu, ecryptfs_i_callback); } /** diff --git a/fs/efs/super.c b/fs/efs/super.c index 5073a07652c..0f31acb0131 100644 --- a/fs/efs/super.c +++ b/fs/efs/super.c @@ -65,11 +65,18 @@ static struct inode *efs_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void efs_destroy_inode(struct inode *inode) +static void efs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(efs_inode_cachep, INODE_INFO(inode)); } +static void efs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, efs_i_callback); +} + static void init_once(void *foo) { struct efs_inode_info *ei = (struct efs_inode_info *) foo; diff --git a/fs/exofs/super.c b/fs/exofs/super.c index 79c3ae6e045..8c6c4669b38 100644 --- a/fs/exofs/super.c +++ b/fs/exofs/super.c @@ -150,12 +150,19 @@ static struct inode *exofs_alloc_inode(struct super_block *sb) return &oi->vfs_inode; } +static void exofs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(exofs_inode_cachep, exofs_i(inode)); +} + /* * Remove an inode from the cache */ static void exofs_destroy_inode(struct inode *inode) { - kmem_cache_free(exofs_inode_cachep, exofs_i(inode)); + call_rcu(&inode->i_rcu, exofs_i_callback); } /* diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index 51b304056f1..4b6825740dd 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -43,24 +43,26 @@ find_acceptable_alias(struct dentry *result, void *context) { struct dentry *dentry, *toput = NULL; + struct inode *inode; if (acceptable(context, result)) return result; - spin_lock(&dcache_lock); - list_for_each_entry(dentry, &result->d_inode->i_dentry, d_alias) { - dget_locked(dentry); - spin_unlock(&dcache_lock); + inode = result->d_inode; + spin_lock(&inode->i_lock); + list_for_each_entry(dentry, &inode->i_dentry, d_alias) { + dget(dentry); + spin_unlock(&inode->i_lock); if (toput) dput(toput); if (dentry != result && acceptable(context, dentry)) { dput(result); return dentry; } - spin_lock(&dcache_lock); + spin_lock(&inode->i_lock); toput = dentry; } - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); if (toput) dput(toput); diff --git a/fs/ext2/acl.c b/fs/ext2/acl.c index 2bcc0431bad..7b4180554a6 100644 --- a/fs/ext2/acl.c +++ b/fs/ext2/acl.c @@ -232,10 +232,17 @@ ext2_set_acl(struct inode *inode, int type, struct posix_acl *acl) } int -ext2_check_acl(struct inode *inode, int mask) +ext2_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct posix_acl *acl = ext2_get_acl(inode, ACL_TYPE_ACCESS); + struct posix_acl *acl; + + if (flags & IPERM_FLAG_RCU) { + if (!negative_cached_acl(inode, ACL_TYPE_ACCESS)) + return -ECHILD; + return -EAGAIN; + } + acl = ext2_get_acl(inode, ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); if (acl) { diff --git a/fs/ext2/acl.h b/fs/ext2/acl.h index 3ff6cbb9ac4..c939b7b1209 100644 --- a/fs/ext2/acl.h +++ b/fs/ext2/acl.h @@ -54,7 +54,7 @@ static inline int ext2_acl_count(size_t size) #ifdef CONFIG_EXT2_FS_POSIX_ACL /* acl.c */ -extern int ext2_check_acl (struct inode *, int); +extern int ext2_check_acl (struct inode *, int, unsigned int); extern int ext2_acl_chmod (struct inode *); extern int ext2_init_acl (struct inode *, struct inode *); diff --git a/fs/ext2/super.c b/fs/ext2/super.c index d89e0b6a2d7..e0c6380ff99 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -161,11 +161,18 @@ static struct inode *ext2_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void ext2_destroy_inode(struct inode *inode) +static void ext2_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(ext2_inode_cachep, EXT2_I(inode)); } +static void ext2_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, ext2_i_callback); +} + static void init_once(void *foo) { struct ext2_inode_info *ei = (struct ext2_inode_info *) foo; diff --git a/fs/ext3/acl.c b/fs/ext3/acl.c index 8a11fe21218..e4fa49e6c53 100644 --- a/fs/ext3/acl.c +++ b/fs/ext3/acl.c @@ -240,10 +240,17 @@ ext3_set_acl(handle_t *handle, struct inode *inode, int type, } int -ext3_check_acl(struct inode *inode, int mask) +ext3_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct posix_acl *acl = ext3_get_acl(inode, ACL_TYPE_ACCESS); + struct posix_acl *acl; + + if (flags & IPERM_FLAG_RCU) { + if (!negative_cached_acl(inode, ACL_TYPE_ACCESS)) + return -ECHILD; + return -EAGAIN; + } + acl = ext3_get_acl(inode, ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); if (acl) { diff --git a/fs/ext3/acl.h b/fs/ext3/acl.h index 597334626de..5faf8048e90 100644 --- a/fs/ext3/acl.h +++ b/fs/ext3/acl.h @@ -54,7 +54,7 @@ static inline int ext3_acl_count(size_t size) #ifdef CONFIG_EXT3_FS_POSIX_ACL /* acl.c */ -extern int ext3_check_acl (struct inode *, int); +extern int ext3_check_acl (struct inode *, int, unsigned int); extern int ext3_acl_chmod (struct inode *); extern int ext3_init_acl (handle_t *, struct inode *, struct inode *); diff --git a/fs/ext3/super.c b/fs/ext3/super.c index acf8695fa8f..77ce1616f72 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -479,6 +479,13 @@ static struct inode *ext3_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } +static void ext3_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(ext3_inode_cachep, EXT3_I(inode)); +} + static void ext3_destroy_inode(struct inode *inode) { if (!list_empty(&(EXT3_I(inode)->i_orphan))) { @@ -489,7 +496,7 @@ static void ext3_destroy_inode(struct inode *inode) false); dump_stack(); } - kmem_cache_free(ext3_inode_cachep, EXT3_I(inode)); + call_rcu(&inode->i_rcu, ext3_i_callback); } static void init_once(void *foo) diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c index 5e2ed4504ea..e0270d1f8d8 100644 --- a/fs/ext4/acl.c +++ b/fs/ext4/acl.c @@ -238,10 +238,17 @@ ext4_set_acl(handle_t *handle, struct inode *inode, int type, } int -ext4_check_acl(struct inode *inode, int mask) +ext4_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct posix_acl *acl = ext4_get_acl(inode, ACL_TYPE_ACCESS); + struct posix_acl *acl; + + if (flags & IPERM_FLAG_RCU) { + if (!negative_cached_acl(inode, ACL_TYPE_ACCESS)) + return -ECHILD; + return -EAGAIN; + } + acl = ext4_get_acl(inode, ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); if (acl) { diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h index 9d843d5deac..dec821168fd 100644 --- a/fs/ext4/acl.h +++ b/fs/ext4/acl.h @@ -54,7 +54,7 @@ static inline int ext4_acl_count(size_t size) #ifdef CONFIG_EXT4_FS_POSIX_ACL /* acl.c */ -extern int ext4_check_acl(struct inode *, int); +extern int ext4_check_acl(struct inode *, int, unsigned int); extern int ext4_acl_chmod(struct inode *); extern int ext4_init_acl(handle_t *, struct inode *, struct inode *); diff --git a/fs/ext4/super.c b/fs/ext4/super.c index fb15c9c0be7..cd37f9d5e44 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -841,6 +841,13 @@ static int ext4_drop_inode(struct inode *inode) return drop; } +static void ext4_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(ext4_inode_cachep, EXT4_I(inode)); +} + static void ext4_destroy_inode(struct inode *inode) { ext4_ioend_wait(inode); @@ -853,7 +860,7 @@ static void ext4_destroy_inode(struct inode *inode) true); dump_stack(); } - kmem_cache_free(ext4_inode_cachep, EXT4_I(inode)); + call_rcu(&inode->i_rcu, ext4_i_callback); } static void init_once(void *foo) diff --git a/fs/fat/inode.c b/fs/fat/inode.c index ad6998a92c3..206351af7c5 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -514,11 +514,18 @@ static struct inode *fat_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void fat_destroy_inode(struct inode *inode) +static void fat_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); } +static void fat_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, fat_i_callback); +} + static void init_once(void *foo) { struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; @@ -743,7 +750,7 @@ static struct dentry *fat_fh_to_dentry(struct super_block *sb, */ result = d_obtain_alias(inode); if (!IS_ERR(result)) - result->d_op = sb->s_root->d_op; + d_set_d_op(result, sb->s_root->d_op); return result; } @@ -793,7 +800,7 @@ static struct dentry *fat_get_parent(struct dentry *child) parent = d_obtain_alias(inode); if (!IS_ERR(parent)) - parent->d_op = sb->s_root->d_op; + d_set_d_op(parent, sb->s_root->d_op); out: unlock_super(sb); diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c index 3345aabd1dd..35ffe43afa4 100644 --- a/fs/fat/namei_msdos.c +++ b/fs/fat/namei_msdos.c @@ -148,7 +148,8 @@ static int msdos_find(struct inode *dir, const unsigned char *name, int len, * that the existing dentry can be used. The msdos fs routines will * return ENOENT or EINVAL as appropriate. */ -static int msdos_hash(struct dentry *dentry, struct qstr *qstr) +static int msdos_hash(const struct dentry *dentry, const struct inode *inode, + struct qstr *qstr) { struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options; unsigned char msdos_name[MSDOS_NAME]; @@ -164,16 +165,18 @@ static int msdos_hash(struct dentry *dentry, struct qstr *qstr) * Compare two msdos names. If either of the names are invalid, * we fall back to doing the standard name comparison. */ -static int msdos_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b) +static int msdos_cmp(const struct dentry *parent, const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options; + struct fat_mount_options *options = &MSDOS_SB(parent->d_sb)->options; unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME]; int error; - error = msdos_format_name(a->name, a->len, a_msdos_name, options); + error = msdos_format_name(name->name, name->len, a_msdos_name, options); if (error) goto old_compare; - error = msdos_format_name(b->name, b->len, b_msdos_name, options); + error = msdos_format_name(str, len, b_msdos_name, options); if (error) goto old_compare; error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME); @@ -182,8 +185,8 @@ out: old_compare: error = 1; - if (a->len == b->len) - error = memcmp(a->name, b->name, a->len); + if (name->len == len) + error = memcmp(name->name, str, len); goto out; } @@ -224,10 +227,10 @@ static struct dentry *msdos_lookup(struct inode *dir, struct dentry *dentry, } out: unlock_super(sb); - dentry->d_op = &msdos_dentry_operations; + d_set_d_op(dentry, &msdos_dentry_operations); dentry = d_splice_alias(inode, dentry); if (dentry) - dentry->d_op = &msdos_dentry_operations; + d_set_d_op(dentry, &msdos_dentry_operations); return dentry; error: @@ -670,7 +673,7 @@ static int msdos_fill_super(struct super_block *sb, void *data, int silent) } sb->s_flags |= MS_NOATIME; - sb->s_root->d_op = &msdos_dentry_operations; + d_set_d_op(sb->s_root, &msdos_dentry_operations); unlock_super(sb); return 0; } diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c index b936703b892..e3ffc5e1233 100644 --- a/fs/fat/namei_vfat.c +++ b/fs/fat/namei_vfat.c @@ -43,6 +43,9 @@ static int vfat_revalidate_shortname(struct dentry *dentry) static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd) { + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + /* This is not negative dentry. Always valid. */ if (dentry->d_inode) return 1; @@ -51,6 +54,9 @@ static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd) static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd) { + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + /* * This is not negative dentry. Always valid. * @@ -85,22 +91,26 @@ static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd) } /* returns the length of a struct qstr, ignoring trailing dots */ -static unsigned int vfat_striptail_len(struct qstr *qstr) +static unsigned int __vfat_striptail_len(unsigned int len, const char *name) { - unsigned int len = qstr->len; - - while (len && qstr->name[len - 1] == '.') + while (len && name[len - 1] == '.') len--; return len; } +static unsigned int vfat_striptail_len(const struct qstr *qstr) +{ + return __vfat_striptail_len(qstr->len, qstr->name); +} + /* * Compute the hash for the vfat name corresponding to the dentry. * Note: if the name is invalid, we leave the hash code unchanged so * that the existing dentry can be used. The vfat fs routines will * return ENOENT or EINVAL as appropriate. */ -static int vfat_hash(struct dentry *dentry, struct qstr *qstr) +static int vfat_hash(const struct dentry *dentry, const struct inode *inode, + struct qstr *qstr) { qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr)); return 0; @@ -112,9 +122,10 @@ static int vfat_hash(struct dentry *dentry, struct qstr *qstr) * that the existing dentry can be used. The vfat fs routines will * return ENOENT or EINVAL as appropriate. */ -static int vfat_hashi(struct dentry *dentry, struct qstr *qstr) +static int vfat_hashi(const struct dentry *dentry, const struct inode *inode, + struct qstr *qstr) { - struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io; + struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io; const unsigned char *name; unsigned int len; unsigned long hash; @@ -133,16 +144,18 @@ static int vfat_hashi(struct dentry *dentry, struct qstr *qstr) /* * Case insensitive compare of two vfat names. */ -static int vfat_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b) +static int vfat_cmpi(const struct dentry *parent, const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io; + struct nls_table *t = MSDOS_SB(parent->d_sb)->nls_io; unsigned int alen, blen; /* A filename cannot end in '.' or we treat it like it has none */ - alen = vfat_striptail_len(a); - blen = vfat_striptail_len(b); + alen = vfat_striptail_len(name); + blen = __vfat_striptail_len(len, str); if (alen == blen) { - if (nls_strnicmp(t, a->name, b->name, alen) == 0) + if (nls_strnicmp(t, name->name, str, alen) == 0) return 0; } return 1; @@ -151,15 +164,17 @@ static int vfat_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b) /* * Case sensitive compare of two vfat names. */ -static int vfat_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b) +static int vfat_cmp(const struct dentry *parent, const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { unsigned int alen, blen; /* A filename cannot end in '.' or we treat it like it has none */ - alen = vfat_striptail_len(a); - blen = vfat_striptail_len(b); + alen = vfat_striptail_len(name); + blen = __vfat_striptail_len(len, str); if (alen == blen) { - if (strncmp(a->name, b->name, alen) == 0) + if (strncmp(name->name, str, alen) == 0) return 0; } return 1; @@ -757,11 +772,11 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry, out: unlock_super(sb); - dentry->d_op = sb->s_root->d_op; + d_set_d_op(dentry, sb->s_root->d_op); dentry->d_time = dentry->d_parent->d_inode->i_version; dentry = d_splice_alias(inode, dentry); if (dentry) { - dentry->d_op = sb->s_root->d_op; + d_set_d_op(dentry, sb->s_root->d_op); dentry->d_time = dentry->d_parent->d_inode->i_version; } return dentry; @@ -1063,9 +1078,9 @@ static int vfat_fill_super(struct super_block *sb, void *data, int silent) } if (MSDOS_SB(sb)->options.name_check != 's') - sb->s_root->d_op = &vfat_ci_dentry_ops; + d_set_d_op(sb->s_root, &vfat_ci_dentry_ops); else - sb->s_root->d_op = &vfat_dentry_ops; + d_set_d_op(sb->s_root, &vfat_dentry_ops); unlock_super(sb); return 0; diff --git a/fs/filesystems.c b/fs/filesystems.c index 68ba492d8ee..751d6b255a1 100644 --- a/fs/filesystems.c +++ b/fs/filesystems.c @@ -115,6 +115,9 @@ int unregister_filesystem(struct file_system_type * fs) tmp = &(*tmp)->next; } write_unlock(&file_systems_lock); + + synchronize_rcu(); + return -EINVAL; } diff --git a/fs/freevxfs/vxfs_inode.c b/fs/freevxfs/vxfs_inode.c index 8c04eac5079..2ba6719ac61 100644 --- a/fs/freevxfs/vxfs_inode.c +++ b/fs/freevxfs/vxfs_inode.c @@ -337,6 +337,13 @@ vxfs_iget(struct super_block *sbp, ino_t ino) return ip; } +static void vxfs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(vxfs_inode_cachep, inode->i_private); +} + /** * vxfs_evict_inode - remove inode from main memory * @ip: inode to discard. @@ -350,5 +357,5 @@ vxfs_evict_inode(struct inode *ip) { truncate_inode_pages(&ip->i_data, 0); end_writeback(ip); - kmem_cache_free(vxfs_inode_cachep, ip->i_private); + call_rcu(&ip->i_rcu, vxfs_i_callback); } diff --git a/fs/fs_struct.c b/fs/fs_struct.c index ed45a9cf5f3..68ca487bedb 100644 --- a/fs/fs_struct.c +++ b/fs/fs_struct.c @@ -14,12 +14,14 @@ void set_fs_root(struct fs_struct *fs, struct path *path) struct path old_root; spin_lock(&fs->lock); + write_seqcount_begin(&fs->seq); old_root = fs->root; fs->root = *path; - path_get(path); + path_get_long(path); + write_seqcount_end(&fs->seq); spin_unlock(&fs->lock); if (old_root.dentry) - path_put(&old_root); + path_put_long(&old_root); } /* @@ -31,13 +33,15 @@ void set_fs_pwd(struct fs_struct *fs, struct path *path) struct path old_pwd; spin_lock(&fs->lock); + write_seqcount_begin(&fs->seq); old_pwd = fs->pwd; fs->pwd = *path; - path_get(path); + path_get_long(path); + write_seqcount_end(&fs->seq); spin_unlock(&fs->lock); if (old_pwd.dentry) - path_put(&old_pwd); + path_put_long(&old_pwd); } void chroot_fs_refs(struct path *old_root, struct path *new_root) @@ -52,31 +56,33 @@ void chroot_fs_refs(struct path *old_root, struct path *new_root) fs = p->fs; if (fs) { spin_lock(&fs->lock); + write_seqcount_begin(&fs->seq); if (fs->root.dentry == old_root->dentry && fs->root.mnt == old_root->mnt) { - path_get(new_root); + path_get_long(new_root); fs->root = *new_root; count++; } if (fs->pwd.dentry == old_root->dentry && fs->pwd.mnt == old_root->mnt) { - path_get(new_root); + path_get_long(new_root); fs->pwd = *new_root; count++; } + write_seqcount_end(&fs->seq); spin_unlock(&fs->lock); } task_unlock(p); } while_each_thread(g, p); read_unlock(&tasklist_lock); while (count--) - path_put(old_root); + path_put_long(old_root); } void free_fs_struct(struct fs_struct *fs) { - path_put(&fs->root); - path_put(&fs->pwd); + path_put_long(&fs->root); + path_put_long(&fs->pwd); kmem_cache_free(fs_cachep, fs); } @@ -88,8 +94,10 @@ void exit_fs(struct task_struct *tsk) int kill; task_lock(tsk); spin_lock(&fs->lock); + write_seqcount_begin(&fs->seq); tsk->fs = NULL; kill = !--fs->users; + write_seqcount_end(&fs->seq); spin_unlock(&fs->lock); task_unlock(tsk); if (kill) @@ -105,8 +113,15 @@ struct fs_struct *copy_fs_struct(struct fs_struct *old) fs->users = 1; fs->in_exec = 0; spin_lock_init(&fs->lock); + seqcount_init(&fs->seq); fs->umask = old->umask; - get_fs_root_and_pwd(old, &fs->root, &fs->pwd); + + spin_lock(&old->lock); + fs->root = old->root; + path_get_long(&fs->root); + fs->pwd = old->pwd; + path_get_long(&fs->pwd); + spin_unlock(&old->lock); } return fs; } @@ -144,6 +159,7 @@ EXPORT_SYMBOL(current_umask); struct fs_struct init_fs = { .users = 1, .lock = __SPIN_LOCK_UNLOCKED(init_fs.lock), + .seq = SEQCNT_ZERO, .umask = 0022, }; diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index c9627c95482..f738599fd8c 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -156,8 +156,12 @@ u64 fuse_get_attr_version(struct fuse_conn *fc) */ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd) { - struct inode *inode = entry->d_inode; + struct inode *inode; + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + + inode = entry->d_inode; if (inode && is_bad_inode(inode)) return 0; else if (fuse_dentry_time(entry) < get_jiffies_64()) { @@ -347,7 +351,7 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, } entry = newent ? newent : entry; - entry->d_op = &fuse_dentry_operations; + d_set_d_op(entry, &fuse_dentry_operations); if (outarg_valid) fuse_change_entry_timeout(entry, &outarg); else @@ -981,12 +985,15 @@ static int fuse_access(struct inode *inode, int mask) * access request is sent. Execute permission is still checked * locally based on file mode. */ -static int fuse_permission(struct inode *inode, int mask) +static int fuse_permission(struct inode *inode, int mask, unsigned int flags) { struct fuse_conn *fc = get_fuse_conn(inode); bool refreshed = false; int err = 0; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + if (!fuse_allow_task(fc, current)) return -EACCES; @@ -1001,7 +1008,7 @@ static int fuse_permission(struct inode *inode, int mask) } if (fc->flags & FUSE_DEFAULT_PERMISSIONS) { - err = generic_permission(inode, mask, NULL); + err = generic_permission(inode, mask, flags, NULL); /* If permission is denied, try to refresh file attributes. This is also needed, because the root @@ -1009,7 +1016,8 @@ static int fuse_permission(struct inode *inode, int mask) if (err == -EACCES && !refreshed) { err = fuse_do_getattr(inode, NULL, NULL); if (!err) - err = generic_permission(inode, mask, NULL); + err = generic_permission(inode, mask, + flags, NULL); } /* Note: the opposite of the above test does not diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index cfce3ad86a9..a8b31da19b9 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -99,6 +99,13 @@ static struct inode *fuse_alloc_inode(struct super_block *sb) return inode; } +static void fuse_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(fuse_inode_cachep, inode); +} + static void fuse_destroy_inode(struct inode *inode) { struct fuse_inode *fi = get_fuse_inode(inode); @@ -106,7 +113,7 @@ static void fuse_destroy_inode(struct inode *inode) BUG_ON(!list_empty(&fi->queued_writes)); if (fi->forget_req) fuse_request_free(fi->forget_req); - kmem_cache_free(fuse_inode_cachep, inode); + call_rcu(&inode->i_rcu, fuse_i_callback); } void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req, @@ -619,7 +626,7 @@ static struct dentry *fuse_get_dentry(struct super_block *sb, entry = d_obtain_alias(inode); if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) { - entry->d_op = &fuse_dentry_operations; + d_set_d_op(entry, &fuse_dentry_operations); fuse_invalidate_entry_cache(entry); } @@ -721,7 +728,7 @@ static struct dentry *fuse_get_parent(struct dentry *child) parent = d_obtain_alias(inode); if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) { - parent->d_op = &fuse_dentry_operations; + d_set_d_op(parent, &fuse_dentry_operations); fuse_invalidate_entry_cache(parent); } diff --git a/fs/generic_acl.c b/fs/generic_acl.c index 6bc9e3a5a69..06c48a89183 100644 --- a/fs/generic_acl.c +++ b/fs/generic_acl.c @@ -190,14 +190,20 @@ generic_acl_chmod(struct inode *inode) } int -generic_check_acl(struct inode *inode, int mask) +generic_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct posix_acl *acl = get_cached_acl(inode, ACL_TYPE_ACCESS); - - if (acl) { - int error = posix_acl_permission(inode, acl, mask); - posix_acl_release(acl); - return error; + if (flags & IPERM_FLAG_RCU) { + if (!negative_cached_acl(inode, ACL_TYPE_ACCESS)) + return -ECHILD; + } else { + struct posix_acl *acl; + + acl = get_cached_acl(inode, ACL_TYPE_ACCESS); + if (acl) { + int error = posix_acl_permission(inode, acl, mask); + posix_acl_release(acl); + return error; + } } return -EAGAIN; } diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c index 48171f4c943..7118f1a780a 100644 --- a/fs/gfs2/acl.c +++ b/fs/gfs2/acl.c @@ -75,11 +75,14 @@ static struct posix_acl *gfs2_acl_get(struct gfs2_inode *ip, int type) * Returns: errno */ -int gfs2_check_acl(struct inode *inode, int mask) +int gfs2_check_acl(struct inode *inode, int mask, unsigned int flags) { struct posix_acl *acl; int error; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + acl = gfs2_acl_get(GFS2_I(inode), ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); diff --git a/fs/gfs2/acl.h b/fs/gfs2/acl.h index b522b0cb39e..a93907c8159 100644 --- a/fs/gfs2/acl.h +++ b/fs/gfs2/acl.h @@ -16,7 +16,7 @@ #define GFS2_POSIX_ACL_DEFAULT "posix_acl_default" #define GFS2_ACL_MAX_ENTRIES 25 -extern int gfs2_check_acl(struct inode *inode, int mask); +extern int gfs2_check_acl(struct inode *inode, int mask, unsigned int); extern int gfs2_acl_create(struct gfs2_inode *dip, struct inode *inode); extern int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr); extern const struct xattr_handler gfs2_xattr_system_handler; diff --git a/fs/gfs2/dentry.c b/fs/gfs2/dentry.c index 6798755b385..4a456338b87 100644 --- a/fs/gfs2/dentry.c +++ b/fs/gfs2/dentry.c @@ -11,6 +11,7 @@ #include <linux/completion.h> #include <linux/buffer_head.h> #include <linux/gfs2_ondisk.h> +#include <linux/namei.h> #include <linux/crc32.h> #include "gfs2.h" @@ -34,15 +35,23 @@ static int gfs2_drevalidate(struct dentry *dentry, struct nameidata *nd) { - struct dentry *parent = dget_parent(dentry); - struct gfs2_sbd *sdp = GFS2_SB(parent->d_inode); - struct gfs2_inode *dip = GFS2_I(parent->d_inode); - struct inode *inode = dentry->d_inode; + struct dentry *parent; + struct gfs2_sbd *sdp; + struct gfs2_inode *dip; + struct inode *inode; struct gfs2_holder d_gh; struct gfs2_inode *ip = NULL; int error; int had_lock = 0; + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + + parent = dget_parent(dentry); + sdp = GFS2_SB(parent->d_inode); + dip = GFS2_I(parent->d_inode); + inode = dentry->d_inode; + if (inode) { if (is_bad_inode(inode)) goto invalid; @@ -100,13 +109,14 @@ fail: return 0; } -static int gfs2_dhash(struct dentry *dentry, struct qstr *str) +static int gfs2_dhash(const struct dentry *dentry, const struct inode *inode, + struct qstr *str) { str->hash = gfs2_disk_hash(str->name, str->len); return 0; } -static int gfs2_dentry_delete(struct dentry *dentry) +static int gfs2_dentry_delete(const struct dentry *dentry) { struct gfs2_inode *ginode; diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c index 5ab3839dfcb..97012ecff56 100644 --- a/fs/gfs2/export.c +++ b/fs/gfs2/export.c @@ -130,7 +130,7 @@ static struct dentry *gfs2_get_parent(struct dentry *child) dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &gfs2_qdotdot, 1)); if (!IS_ERR(dentry)) - dentry->d_op = &gfs2_dops; + d_set_d_op(dentry, &gfs2_dops); return dentry; } @@ -158,7 +158,7 @@ static struct dentry *gfs2_get_dentry(struct super_block *sb, out_inode: dentry = d_obtain_alias(inode); if (!IS_ERR(dentry)) - dentry->d_op = &gfs2_dops; + d_set_d_op(dentry, &gfs2_dops); return dentry; } diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index aa996471ec5..fca6689e12e 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -241,7 +241,7 @@ static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask) !capable(CAP_LINUX_IMMUTABLE)) goto out; if (!IS_IMMUTABLE(inode)) { - error = gfs2_permission(inode, MAY_WRITE); + error = gfs2_permission(inode, MAY_WRITE, 0); if (error) goto out; } diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c index 14e682dbe8b..2232b3c780b 100644 --- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -509,7 +509,7 @@ struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name, } if (!is_root) { - error = gfs2_permission(dir, MAY_EXEC); + error = gfs2_permission(dir, MAY_EXEC, 0); if (error) goto out; } @@ -539,7 +539,7 @@ static int create_ok(struct gfs2_inode *dip, const struct qstr *name, { int error; - error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC); + error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, 0); if (error) return error; diff --git a/fs/gfs2/inode.h b/fs/gfs2/inode.h index d8499fadcc5..732a183efdb 100644 --- a/fs/gfs2/inode.h +++ b/fs/gfs2/inode.h @@ -113,7 +113,7 @@ extern struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name, extern struct inode *gfs2_createi(struct gfs2_holder *ghs, const struct qstr *name, unsigned int mode, dev_t dev); -extern int gfs2_permission(struct inode *inode, int mask); +extern int gfs2_permission(struct inode *inode, int mask, unsigned int flags); extern int gfs2_setattr_simple(struct gfs2_inode *ip, struct iattr *attr); extern struct inode *gfs2_lookup_simple(struct inode *dip, const char *name); extern void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf); diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index 3eb1393f7b8..2aeabd4218c 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -440,7 +440,7 @@ static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr, iput(inode); return -ENOMEM; } - dentry->d_op = &gfs2_dops; + d_set_d_op(dentry, &gfs2_dops); *dptr = dentry; return 0; } diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c index 1db6b734322..1501db4f0e6 100644 --- a/fs/gfs2/ops_inode.c +++ b/fs/gfs2/ops_inode.c @@ -106,7 +106,7 @@ static struct dentry *gfs2_lookup(struct inode *dir, struct dentry *dentry, { struct inode *inode = NULL; - dentry->d_op = &gfs2_dops; + d_set_d_op(dentry, &gfs2_dops); inode = gfs2_lookupi(dir, &dentry->d_name, 0); if (inode && IS_ERR(inode)) @@ -166,7 +166,7 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir, if (error) goto out_child; - error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC); + error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC, 0); if (error) goto out_gunlock; @@ -289,7 +289,7 @@ static int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name, if (IS_APPEND(&dip->i_inode)) return -EPERM; - error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC); + error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, 0); if (error) return error; @@ -822,7 +822,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry, } } } else { - error = gfs2_permission(ndir, MAY_WRITE | MAY_EXEC); + error = gfs2_permission(ndir, MAY_WRITE | MAY_EXEC, 0); if (error) goto out_gunlock; @@ -857,7 +857,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry, /* Check out the dir to be renamed */ if (dir_rename) { - error = gfs2_permission(odentry->d_inode, MAY_WRITE); + error = gfs2_permission(odentry->d_inode, MAY_WRITE, 0); if (error) goto out_gunlock; } @@ -1041,13 +1041,17 @@ static void gfs2_put_link(struct dentry *dentry, struct nameidata *nd, void *p) * Returns: errno */ -int gfs2_permission(struct inode *inode, int mask) +int gfs2_permission(struct inode *inode, int mask, unsigned int flags) { - struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_inode *ip; struct gfs2_holder i_gh; int error; int unlock = 0; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + + ip = GFS2_I(inode); if (gfs2_glock_is_locked_by_me(ip->i_gl) == NULL) { error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); if (error) @@ -1058,7 +1062,7 @@ int gfs2_permission(struct inode *inode, int mask) if ((mask & MAY_WRITE) && IS_IMMUTABLE(inode)) error = -EACCES; else - error = generic_permission(inode, mask, gfs2_check_acl); + error = generic_permission(inode, mask, flags, gfs2_check_acl); if (unlock) gfs2_glock_dq_uninit(&i_gh); diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c index 2b2c4997430..16c2ecac7eb 100644 --- a/fs/gfs2/super.c +++ b/fs/gfs2/super.c @@ -1405,11 +1405,18 @@ static struct inode *gfs2_alloc_inode(struct super_block *sb) return &ip->i_inode; } -static void gfs2_destroy_inode(struct inode *inode) +static void gfs2_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(gfs2_inode_cachep, inode); } +static void gfs2_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, gfs2_i_callback); +} + const struct super_operations gfs2_super_ops = { .alloc_inode = gfs2_alloc_inode, .destroy_inode = gfs2_destroy_inode, diff --git a/fs/hfs/dir.c b/fs/hfs/dir.c index 2b3b8611b41..ea4aefe7c65 100644 --- a/fs/hfs/dir.c +++ b/fs/hfs/dir.c @@ -25,7 +25,7 @@ static struct dentry *hfs_lookup(struct inode *dir, struct dentry *dentry, struct inode *inode = NULL; int res; - dentry->d_op = &hfs_dentry_operations; + d_set_d_op(dentry, &hfs_dentry_operations); hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd); hfs_cat_build_key(dir->i_sb, fd.search_key, dir->i_ino, &dentry->d_name); diff --git a/fs/hfs/hfs_fs.h b/fs/hfs/hfs_fs.h index c8cffb81e84..ad97c2d5828 100644 --- a/fs/hfs/hfs_fs.h +++ b/fs/hfs/hfs_fs.h @@ -213,10 +213,14 @@ extern int hfs_part_find(struct super_block *, sector_t *, sector_t *); /* string.c */ extern const struct dentry_operations hfs_dentry_operations; -extern int hfs_hash_dentry(struct dentry *, struct qstr *); +extern int hfs_hash_dentry(const struct dentry *, const struct inode *, + struct qstr *); extern int hfs_strcmp(const unsigned char *, unsigned int, const unsigned char *, unsigned int); -extern int hfs_compare_dentry(struct dentry *, struct qstr *, struct qstr *); +extern int hfs_compare_dentry(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name); /* trans.c */ extern void hfs_asc2mac(struct super_block *, struct hfs_name *, struct qstr *); diff --git a/fs/hfs/string.c b/fs/hfs/string.c index 927a5af7942..495a976a3cc 100644 --- a/fs/hfs/string.c +++ b/fs/hfs/string.c @@ -51,7 +51,8 @@ static unsigned char caseorder[256] = { /* * Hash a string to an integer in a case-independent way */ -int hfs_hash_dentry(struct dentry *dentry, struct qstr *this) +int hfs_hash_dentry(const struct dentry *dentry, const struct inode *inode, + struct qstr *this) { const unsigned char *name = this->name; unsigned int hash, len = this->len; @@ -92,21 +93,21 @@ int hfs_strcmp(const unsigned char *s1, unsigned int len1, * Test for equality of two strings in the HFS filename character ordering. * return 1 on failure and 0 on success */ -int hfs_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *s2) +int hfs_compare_dentry(const struct dentry *parent, const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { const unsigned char *n1, *n2; - int len; - len = s1->len; if (len >= HFS_NAMELEN) { - if (s2->len < HFS_NAMELEN) + if (name->len < HFS_NAMELEN) return 1; len = HFS_NAMELEN; - } else if (len != s2->len) + } else if (len != name->len) return 1; - n1 = s1->name; - n2 = s2->name; + n1 = str; + n2 = name->name; while (len--) { if (caseorder[*n1++] != caseorder[*n2++]) return 1; diff --git a/fs/hfs/super.c b/fs/hfs/super.c index 4824c27cebb..0bef62aa4f4 100644 --- a/fs/hfs/super.c +++ b/fs/hfs/super.c @@ -167,11 +167,18 @@ static struct inode *hfs_alloc_inode(struct super_block *sb) return i ? &i->vfs_inode : NULL; } -static void hfs_destroy_inode(struct inode *inode) +static void hfs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(hfs_inode_cachep, HFS_I(inode)); } +static void hfs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, hfs_i_callback); +} + static const struct super_operations hfs_super_operations = { .alloc_inode = hfs_alloc_inode, .destroy_inode = hfs_destroy_inode, @@ -427,7 +434,7 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent) if (!sb->s_root) goto bail_iput; - sb->s_root->d_op = &hfs_dentry_operations; + d_set_d_op(sb->s_root, &hfs_dentry_operations); /* everything's okay */ return 0; diff --git a/fs/hfs/sysdep.c b/fs/hfs/sysdep.c index 7478f5c219a..19cf291eb91 100644 --- a/fs/hfs/sysdep.c +++ b/fs/hfs/sysdep.c @@ -8,15 +8,20 @@ * This file contains the code to do various system dependent things. */ +#include <linux/namei.h> #include "hfs_fs.h" /* dentry case-handling: just lowercase everything */ static int hfs_revalidate_dentry(struct dentry *dentry, struct nameidata *nd) { - struct inode *inode = dentry->d_inode; + struct inode *inode; int diff; + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + + inode = dentry->d_inode; if(!inode) return 1; diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c index 9d59c0571f5..ccab87145f7 100644 --- a/fs/hfsplus/dir.c +++ b/fs/hfsplus/dir.c @@ -37,7 +37,7 @@ static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry, sb = dir->i_sb; - dentry->d_op = &hfsplus_dentry_operations; + d_set_d_op(dentry, &hfsplus_dentry_operations); dentry->d_fsdata = NULL; hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd); hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name); diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h index cb3653efb57..a5308f491e3 100644 --- a/fs/hfsplus/hfsplus_fs.h +++ b/fs/hfsplus/hfsplus_fs.h @@ -379,8 +379,12 @@ int hfsplus_strcasecmp(const struct hfsplus_unistr *, const struct hfsplus_unist int hfsplus_strcmp(const struct hfsplus_unistr *, const struct hfsplus_unistr *); int hfsplus_uni2asc(struct super_block *, const struct hfsplus_unistr *, char *, int *); int hfsplus_asc2uni(struct super_block *, struct hfsplus_unistr *, const char *, int); -int hfsplus_hash_dentry(struct dentry *dentry, struct qstr *str); -int hfsplus_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *s2); +int hfsplus_hash_dentry(const struct dentry *dentry, const struct inode *inode, + struct qstr *str); +int hfsplus_compare_dentry(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name); /* wrapper.c */ int hfsplus_read_wrapper(struct super_block *); diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c index 52cc746d3ba..ddf712e4700 100644 --- a/fs/hfsplus/super.c +++ b/fs/hfsplus/super.c @@ -419,7 +419,7 @@ static int hfsplus_fill_super(struct super_block *sb, void *data, int silent) err = -ENOMEM; goto cleanup; } - sb->s_root->d_op = &hfsplus_dentry_operations; + d_set_d_op(sb->s_root, &hfsplus_dentry_operations); str.len = sizeof(HFSP_HIDDENDIR_NAME) - 1; str.name = HFSP_HIDDENDIR_NAME; @@ -488,11 +488,19 @@ static struct inode *hfsplus_alloc_inode(struct super_block *sb) return i ? &i->vfs_inode : NULL; } -static void hfsplus_destroy_inode(struct inode *inode) +static void hfsplus_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(hfsplus_inode_cachep, HFSPLUS_I(inode)); } +static void hfsplus_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, hfsplus_i_callback); +} + #define HFSPLUS_INODE_SIZE sizeof(struct hfsplus_inode_info) static struct dentry *hfsplus_mount(struct file_system_type *fs_type, diff --git a/fs/hfsplus/unicode.c b/fs/hfsplus/unicode.c index b66d67de882..d800aa0f2c8 100644 --- a/fs/hfsplus/unicode.c +++ b/fs/hfsplus/unicode.c @@ -320,7 +320,8 @@ int hfsplus_asc2uni(struct super_block *sb, struct hfsplus_unistr *ustr, * Composed unicode characters are decomposed and case-folding is performed * if the appropriate bits are (un)set on the superblock. */ -int hfsplus_hash_dentry(struct dentry *dentry, struct qstr *str) +int hfsplus_hash_dentry(const struct dentry *dentry, const struct inode *inode, + struct qstr *str) { struct super_block *sb = dentry->d_sb; const char *astr; @@ -363,9 +364,12 @@ int hfsplus_hash_dentry(struct dentry *dentry, struct qstr *str) * Composed unicode characters are decomposed and case-folding is performed * if the appropriate bits are (un)set on the superblock. */ -int hfsplus_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *s2) +int hfsplus_compare_dentry(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - struct super_block *sb = dentry->d_sb; + struct super_block *sb = parent->d_sb; int casefold, decompose, size; int dsize1, dsize2, len1, len2; const u16 *dstr1, *dstr2; @@ -375,10 +379,10 @@ int hfsplus_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr * casefold = test_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags); decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags); - astr1 = s1->name; - len1 = s1->len; - astr2 = s2->name; - len2 = s2->len; + astr1 = str; + len1 = len; + astr2 = name->name; + len2 = name->len; dsize1 = dsize2 = 0; dstr1 = dstr2 = NULL; diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c index 2c0f148a49e..d3244d949a4 100644 --- a/fs/hostfs/hostfs_kern.c +++ b/fs/hostfs/hostfs_kern.c @@ -32,7 +32,7 @@ static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode) -static int hostfs_d_delete(struct dentry *dentry) +static int hostfs_d_delete(const struct dentry *dentry) { return 1; } @@ -92,12 +92,10 @@ __uml_setup("hostfs=", hostfs_args, static char *__dentry_name(struct dentry *dentry, char *name) { - char *p = __dentry_path(dentry, name, PATH_MAX); + char *p = dentry_path_raw(dentry, name, PATH_MAX); char *root; size_t len; - spin_unlock(&dcache_lock); - root = dentry->d_sb->s_fs_info; len = strlen(root); if (IS_ERR(p)) { @@ -123,25 +121,23 @@ static char *dentry_name(struct dentry *dentry) if (!name) return NULL; - spin_lock(&dcache_lock); return __dentry_name(dentry, name); /* will unlock */ } static char *inode_name(struct inode *ino) { struct dentry *dentry; - char *name = __getname(); - if (!name) - return NULL; + char *name; - spin_lock(&dcache_lock); - if (list_empty(&ino->i_dentry)) { - spin_unlock(&dcache_lock); - __putname(name); + dentry = d_find_alias(ino); + if (!dentry) return NULL; - } - dentry = list_first_entry(&ino->i_dentry, struct dentry, d_alias); - return __dentry_name(dentry, name); /* will unlock */ + + name = dentry_name(dentry); + + dput(dentry); + + return name; } static char *follow_link(char *link) @@ -251,11 +247,18 @@ static void hostfs_evict_inode(struct inode *inode) } } -static void hostfs_destroy_inode(struct inode *inode) +static void hostfs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kfree(HOSTFS_I(inode)); } +static void hostfs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, hostfs_i_callback); +} + static int hostfs_show_options(struct seq_file *seq, struct vfsmount *vfs) { const char *root_path = vfs->mnt_sb->s_fs_info; @@ -609,7 +612,7 @@ struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, goto out_put; d_add(dentry, inode); - dentry->d_op = &hostfs_dentry_ops; + d_set_d_op(dentry, &hostfs_dentry_ops); return NULL; out_put: @@ -746,11 +749,14 @@ int hostfs_rename(struct inode *from_ino, struct dentry *from, return err; } -int hostfs_permission(struct inode *ino, int desired) +int hostfs_permission(struct inode *ino, int desired, unsigned int flags) { char *name; int r = 0, w = 0, x = 0, err; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + if (desired & MAY_READ) r = 1; if (desired & MAY_WRITE) w = 1; if (desired & MAY_EXEC) x = 1; @@ -765,7 +771,7 @@ int hostfs_permission(struct inode *ino, int desired) err = access_file(name, r, w, x); __putname(name); if (!err) - err = generic_permission(ino, desired, NULL); + err = generic_permission(ino, desired, flags, NULL); return err; } diff --git a/fs/hpfs/dentry.c b/fs/hpfs/dentry.c index 67d9d36b3d5..32c13a94e1e 100644 --- a/fs/hpfs/dentry.c +++ b/fs/hpfs/dentry.c @@ -12,7 +12,8 @@ * Note: the dentry argument is the parent dentry. */ -static int hpfs_hash_dentry(struct dentry *dentry, struct qstr *qstr) +static int hpfs_hash_dentry(const struct dentry *dentry, const struct inode *inode, + struct qstr *qstr) { unsigned long hash; int i; @@ -34,19 +35,25 @@ static int hpfs_hash_dentry(struct dentry *dentry, struct qstr *qstr) return 0; } -static int hpfs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b) +static int hpfs_compare_dentry(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - unsigned al=a->len; - unsigned bl=b->len; - hpfs_adjust_length(a->name, &al); + unsigned al = len; + unsigned bl = name->len; + + hpfs_adjust_length(str, &al); /*hpfs_adjust_length(b->name, &bl);*/ - /* 'a' is the qstr of an already existing dentry, so the name - * must be valid. 'b' must be validated first. + + /* + * 'str' is the nane of an already existing dentry, so the name + * must be valid. 'name' must be validated first. */ - if (hpfs_chk_name(b->name, &bl)) + if (hpfs_chk_name(name->name, &bl)) return 1; - if (hpfs_compare_names(dentry->d_sb, a->name, al, b->name, bl, 0)) + if (hpfs_compare_names(parent->d_sb, str, al, name->name, bl, 0)) return 1; return 0; } @@ -58,5 +65,5 @@ static const struct dentry_operations hpfs_dentry_operations = { void hpfs_set_dentry_operations(struct dentry *dentry) { - dentry->d_op = &hpfs_dentry_operations; + d_set_d_op(dentry, &hpfs_dentry_operations); } diff --git a/fs/hpfs/namei.c b/fs/hpfs/namei.c index 11c2b4080f6..f4ad9e31ddc 100644 --- a/fs/hpfs/namei.c +++ b/fs/hpfs/namei.c @@ -419,7 +419,7 @@ again: unlock_kernel(); return -ENOSPC; } - if (generic_permission(inode, MAY_WRITE, NULL) || + if (generic_permission(inode, MAY_WRITE, 0, NULL) || !S_ISREG(inode->i_mode) || get_write_access(inode)) { d_rehash(dentry); diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c index 6c5f01597c3..49935ba78db 100644 --- a/fs/hpfs/super.c +++ b/fs/hpfs/super.c @@ -177,11 +177,18 @@ static struct inode *hpfs_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void hpfs_destroy_inode(struct inode *inode) +static void hpfs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(hpfs_inode_cachep, hpfs_i(inode)); } +static void hpfs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, hpfs_i_callback); +} + static void init_once(void *foo) { struct hpfs_inode_info *ei = (struct hpfs_inode_info *) foo; diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c index f702b5f713f..87ed48e0343 100644 --- a/fs/hppfs/hppfs.c +++ b/fs/hppfs/hppfs.c @@ -632,11 +632,18 @@ void hppfs_evict_inode(struct inode *ino) mntput(ino->i_sb->s_fs_info); } -static void hppfs_destroy_inode(struct inode *inode) +static void hppfs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kfree(HPPFS_I(inode)); } +static void hppfs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, hppfs_i_callback); +} + static const struct super_operations hppfs_sbops = { .alloc_inode = hppfs_alloc_inode, .destroy_inode = hppfs_destroy_inode, diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index a5fe68189ee..9885082b470 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -663,11 +663,18 @@ static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) return &p->vfs_inode; } +static void hugetlbfs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); +} + static void hugetlbfs_destroy_inode(struct inode *inode) { hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); - kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); + call_rcu(&inode->i_rcu, hugetlbfs_i_callback); } static const struct address_space_operations hugetlbfs_aops = { diff --git a/fs/inode.c b/fs/inode.c index ae2727ab0c3..da85e56378f 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -102,26 +102,29 @@ static DECLARE_RWSEM(iprune_sem); */ struct inodes_stat_t inodes_stat; -static struct percpu_counter nr_inodes __cacheline_aligned_in_smp; -static struct percpu_counter nr_inodes_unused __cacheline_aligned_in_smp; +static DEFINE_PER_CPU(unsigned int, nr_inodes); static struct kmem_cache *inode_cachep __read_mostly; -static inline int get_nr_inodes(void) +static int get_nr_inodes(void) { - return percpu_counter_sum_positive(&nr_inodes); + int i; + int sum = 0; + for_each_possible_cpu(i) + sum += per_cpu(nr_inodes, i); + return sum < 0 ? 0 : sum; } static inline int get_nr_inodes_unused(void) { - return percpu_counter_sum_positive(&nr_inodes_unused); + return inodes_stat.nr_unused; } int get_nr_dirty_inodes(void) { + /* not actually dirty inodes, but a wild approximation */ int nr_dirty = get_nr_inodes() - get_nr_inodes_unused(); return nr_dirty > 0 ? nr_dirty : 0; - } /* @@ -132,7 +135,6 @@ int proc_nr_inodes(ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { inodes_stat.nr_inodes = get_nr_inodes(); - inodes_stat.nr_unused = get_nr_inodes_unused(); return proc_dointvec(table, write, buffer, lenp, ppos); } #endif @@ -224,7 +226,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode) inode->i_fsnotify_mask = 0; #endif - percpu_counter_inc(&nr_inodes); + this_cpu_inc(nr_inodes); return 0; out: @@ -255,6 +257,12 @@ static struct inode *alloc_inode(struct super_block *sb) return inode; } +void free_inode_nonrcu(struct inode *inode) +{ + kmem_cache_free(inode_cachep, inode); +} +EXPORT_SYMBOL(free_inode_nonrcu); + void __destroy_inode(struct inode *inode) { BUG_ON(inode_has_buffers(inode)); @@ -266,10 +274,17 @@ void __destroy_inode(struct inode *inode) if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED) posix_acl_release(inode->i_default_acl); #endif - percpu_counter_dec(&nr_inodes); + this_cpu_dec(nr_inodes); } EXPORT_SYMBOL(__destroy_inode); +static void i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(inode_cachep, inode); +} + static void destroy_inode(struct inode *inode) { BUG_ON(!list_empty(&inode->i_lru)); @@ -277,7 +292,7 @@ static void destroy_inode(struct inode *inode) if (inode->i_sb->s_op->destroy_inode) inode->i_sb->s_op->destroy_inode(inode); else - kmem_cache_free(inode_cachep, (inode)); + call_rcu(&inode->i_rcu, i_callback); } /* @@ -335,7 +350,7 @@ static void inode_lru_list_add(struct inode *inode) { if (list_empty(&inode->i_lru)) { list_add(&inode->i_lru, &inode_lru); - percpu_counter_inc(&nr_inodes_unused); + inodes_stat.nr_unused++; } } @@ -343,7 +358,7 @@ static void inode_lru_list_del(struct inode *inode) { if (!list_empty(&inode->i_lru)) { list_del_init(&inode->i_lru); - percpu_counter_dec(&nr_inodes_unused); + inodes_stat.nr_unused--; } } @@ -430,6 +445,7 @@ void end_writeback(struct inode *inode) BUG_ON(!(inode->i_state & I_FREEING)); BUG_ON(inode->i_state & I_CLEAR); inode_sync_wait(inode); + /* don't need i_lock here, no concurrent mods to i_state */ inode->i_state = I_FREEING | I_CLEAR; } EXPORT_SYMBOL(end_writeback); @@ -513,7 +529,7 @@ void evict_inodes(struct super_block *sb) list_move(&inode->i_lru, &dispose); list_del_init(&inode->i_wb_list); if (!(inode->i_state & (I_DIRTY | I_SYNC))) - percpu_counter_dec(&nr_inodes_unused); + inodes_stat.nr_unused--; } spin_unlock(&inode_lock); @@ -554,7 +570,7 @@ int invalidate_inodes(struct super_block *sb) list_move(&inode->i_lru, &dispose); list_del_init(&inode->i_wb_list); if (!(inode->i_state & (I_DIRTY | I_SYNC))) - percpu_counter_dec(&nr_inodes_unused); + inodes_stat.nr_unused--; } spin_unlock(&inode_lock); @@ -616,7 +632,7 @@ static void prune_icache(int nr_to_scan) if (atomic_read(&inode->i_count) || (inode->i_state & ~I_REFERENCED)) { list_del_init(&inode->i_lru); - percpu_counter_dec(&nr_inodes_unused); + inodes_stat.nr_unused--; continue; } @@ -650,7 +666,7 @@ static void prune_icache(int nr_to_scan) */ list_move(&inode->i_lru, &freeable); list_del_init(&inode->i_wb_list); - percpu_counter_dec(&nr_inodes_unused); + inodes_stat.nr_unused--; } if (current_is_kswapd()) __count_vm_events(KSWAPD_INODESTEAL, reap); @@ -1648,8 +1664,6 @@ void __init inode_init(void) SLAB_MEM_SPREAD), init_once); register_shrinker(&icache_shrinker); - percpu_counter_init(&nr_inodes, 0); - percpu_counter_init(&nr_inodes_unused, 0); /* Hash may have been set up in inode_init_early */ if (!hashdist) diff --git a/fs/internal.h b/fs/internal.h index e43b9a4dbf4..9687c2ee273 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -63,6 +63,7 @@ extern int copy_mount_string(const void __user *, char **); extern void free_vfsmnt(struct vfsmount *); extern struct vfsmount *alloc_vfsmnt(const char *); +extern unsigned int mnt_get_count(struct vfsmount *mnt); extern struct vfsmount *__lookup_mnt(struct vfsmount *, struct dentry *, int); extern void mnt_set_mountpoint(struct vfsmount *, struct dentry *, struct vfsmount *); diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c index bfdeb82a53b..844a7903c72 100644 --- a/fs/isofs/inode.c +++ b/fs/isofs/inode.c @@ -26,16 +26,32 @@ #define BEQUIET -static int isofs_hashi(struct dentry *parent, struct qstr *qstr); -static int isofs_hash(struct dentry *parent, struct qstr *qstr); -static int isofs_dentry_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b); -static int isofs_dentry_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b); +static int isofs_hashi(const struct dentry *parent, const struct inode *inode, + struct qstr *qstr); +static int isofs_hash(const struct dentry *parent, const struct inode *inode, + struct qstr *qstr); +static int isofs_dentry_cmpi(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name); +static int isofs_dentry_cmp(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name); #ifdef CONFIG_JOLIET -static int isofs_hashi_ms(struct dentry *parent, struct qstr *qstr); -static int isofs_hash_ms(struct dentry *parent, struct qstr *qstr); -static int isofs_dentry_cmpi_ms(struct dentry *dentry, struct qstr *a, struct qstr *b); -static int isofs_dentry_cmp_ms(struct dentry *dentry, struct qstr *a, struct qstr *b); +static int isofs_hashi_ms(const struct dentry *parent, const struct inode *inode, + struct qstr *qstr); +static int isofs_hash_ms(const struct dentry *parent, const struct inode *inode, + struct qstr *qstr); +static int isofs_dentry_cmpi_ms(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name); +static int isofs_dentry_cmp_ms(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name); #endif static void isofs_put_super(struct super_block *sb) @@ -65,11 +81,18 @@ static struct inode *isofs_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void isofs_destroy_inode(struct inode *inode) +static void isofs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(isofs_inode_cachep, ISOFS_I(inode)); } +static void isofs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, isofs_i_callback); +} + static void init_once(void *foo) { struct iso_inode_info *ei = foo; @@ -160,7 +183,7 @@ struct iso9660_options{ * Compute the hash for the isofs name corresponding to the dentry. */ static int -isofs_hash_common(struct dentry *dentry, struct qstr *qstr, int ms) +isofs_hash_common(const struct dentry *dentry, struct qstr *qstr, int ms) { const char *name; int len; @@ -181,7 +204,7 @@ isofs_hash_common(struct dentry *dentry, struct qstr *qstr, int ms) * Compute the hash for the isofs name corresponding to the dentry. */ static int -isofs_hashi_common(struct dentry *dentry, struct qstr *qstr, int ms) +isofs_hashi_common(const struct dentry *dentry, struct qstr *qstr, int ms) { const char *name; int len; @@ -206,100 +229,94 @@ isofs_hashi_common(struct dentry *dentry, struct qstr *qstr, int ms) } /* - * Case insensitive compare of two isofs names. - */ -static int isofs_dentry_cmpi_common(struct dentry *dentry, struct qstr *a, - struct qstr *b, int ms) -{ - int alen, blen; - - /* A filename cannot end in '.' or we treat it like it has none */ - alen = a->len; - blen = b->len; - if (ms) { - while (alen && a->name[alen-1] == '.') - alen--; - while (blen && b->name[blen-1] == '.') - blen--; - } - if (alen == blen) { - if (strnicmp(a->name, b->name, alen) == 0) - return 0; - } - return 1; -} - -/* - * Case sensitive compare of two isofs names. + * Compare of two isofs names. */ -static int isofs_dentry_cmp_common(struct dentry *dentry, struct qstr *a, - struct qstr *b, int ms) +static int isofs_dentry_cmp_common( + unsigned int len, const char *str, + const struct qstr *name, int ms, int ci) { int alen, blen; /* A filename cannot end in '.' or we treat it like it has none */ - alen = a->len; - blen = b->len; + alen = name->len; + blen = len; if (ms) { - while (alen && a->name[alen-1] == '.') + while (alen && name->name[alen-1] == '.') alen--; - while (blen && b->name[blen-1] == '.') + while (blen && str[blen-1] == '.') blen--; } if (alen == blen) { - if (strncmp(a->name, b->name, alen) == 0) - return 0; + if (ci) { + if (strnicmp(name->name, str, alen) == 0) + return 0; + } else { + if (strncmp(name->name, str, alen) == 0) + return 0; + } } return 1; } static int -isofs_hash(struct dentry *dentry, struct qstr *qstr) +isofs_hash(const struct dentry *dentry, const struct inode *inode, + struct qstr *qstr) { return isofs_hash_common(dentry, qstr, 0); } static int -isofs_hashi(struct dentry *dentry, struct qstr *qstr) +isofs_hashi(const struct dentry *dentry, const struct inode *inode, + struct qstr *qstr) { return isofs_hashi_common(dentry, qstr, 0); } static int -isofs_dentry_cmp(struct dentry *dentry,struct qstr *a,struct qstr *b) +isofs_dentry_cmp(const struct dentry *parent, const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - return isofs_dentry_cmp_common(dentry, a, b, 0); + return isofs_dentry_cmp_common(len, str, name, 0, 0); } static int -isofs_dentry_cmpi(struct dentry *dentry,struct qstr *a,struct qstr *b) +isofs_dentry_cmpi(const struct dentry *parent, const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - return isofs_dentry_cmpi_common(dentry, a, b, 0); + return isofs_dentry_cmp_common(len, str, name, 0, 1); } #ifdef CONFIG_JOLIET static int -isofs_hash_ms(struct dentry *dentry, struct qstr *qstr) +isofs_hash_ms(const struct dentry *dentry, const struct inode *inode, + struct qstr *qstr) { return isofs_hash_common(dentry, qstr, 1); } static int -isofs_hashi_ms(struct dentry *dentry, struct qstr *qstr) +isofs_hashi_ms(const struct dentry *dentry, const struct inode *inode, + struct qstr *qstr) { return isofs_hashi_common(dentry, qstr, 1); } static int -isofs_dentry_cmp_ms(struct dentry *dentry,struct qstr *a,struct qstr *b) +isofs_dentry_cmp_ms(const struct dentry *parent, const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - return isofs_dentry_cmp_common(dentry, a, b, 1); + return isofs_dentry_cmp_common(len, str, name, 1, 0); } static int -isofs_dentry_cmpi_ms(struct dentry *dentry,struct qstr *a,struct qstr *b) +isofs_dentry_cmpi_ms(const struct dentry *parent, const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - return isofs_dentry_cmpi_common(dentry, a, b, 1); + return isofs_dentry_cmp_common(len, str, name, 1, 1); } #endif @@ -932,7 +949,7 @@ root_found: table += 2; if (opt.check == 'r') table++; - s->s_root->d_op = &isofs_dentry_ops[table]; + d_set_d_op(s->s_root, &isofs_dentry_ops[table]); kfree(opt.iocharset); diff --git a/fs/isofs/namei.c b/fs/isofs/namei.c index 0d23abfd428..679a849c3b2 100644 --- a/fs/isofs/namei.c +++ b/fs/isofs/namei.c @@ -37,7 +37,8 @@ isofs_cmp(struct dentry *dentry, const char *compare, int dlen) qstr.name = compare; qstr.len = dlen; - return dentry->d_op->d_compare(dentry, &dentry->d_name, &qstr); + return dentry->d_op->d_compare(NULL, NULL, NULL, NULL, + dentry->d_name.len, dentry->d_name.name, &qstr); } /* @@ -171,7 +172,7 @@ struct dentry *isofs_lookup(struct inode *dir, struct dentry *dentry, struct nam struct inode *inode; struct page *page; - dentry->d_op = dir->i_sb->s_root->d_op; + d_set_d_op(dentry, dir->i_sb->s_root->d_op); page = alloc_page(GFP_USER); if (!page) diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c index 54a92fd02bb..95b79672150 100644 --- a/fs/jffs2/acl.c +++ b/fs/jffs2/acl.c @@ -259,11 +259,14 @@ static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl) return rc; } -int jffs2_check_acl(struct inode *inode, int mask) +int jffs2_check_acl(struct inode *inode, int mask, unsigned int flags) { struct posix_acl *acl; int rc; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); diff --git a/fs/jffs2/acl.h b/fs/jffs2/acl.h index 5e42de8d954..3119f59253d 100644 --- a/fs/jffs2/acl.h +++ b/fs/jffs2/acl.h @@ -26,7 +26,7 @@ struct jffs2_acl_header { #ifdef CONFIG_JFFS2_FS_POSIX_ACL -extern int jffs2_check_acl(struct inode *, int); +extern int jffs2_check_acl(struct inode *, int, unsigned int); extern int jffs2_acl_chmod(struct inode *); extern int jffs2_init_acl_pre(struct inode *, struct inode *, int *); extern int jffs2_init_acl_post(struct inode *); diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c index c86041b866a..853b8e30008 100644 --- a/fs/jffs2/super.c +++ b/fs/jffs2/super.c @@ -40,11 +40,18 @@ static struct inode *jffs2_alloc_inode(struct super_block *sb) return &f->vfs_inode; } -static void jffs2_destroy_inode(struct inode *inode) +static void jffs2_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode)); } +static void jffs2_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, jffs2_i_callback); +} + static void jffs2_i_init_once(void *foo) { struct jffs2_inode_info *f = foo; diff --git a/fs/jfs/acl.c b/fs/jfs/acl.c index 1057a4998e4..e5de9422fa3 100644 --- a/fs/jfs/acl.c +++ b/fs/jfs/acl.c @@ -114,10 +114,14 @@ out: return rc; } -int jfs_check_acl(struct inode *inode, int mask) +int jfs_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS); + struct posix_acl *acl; + + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + acl = jfs_get_acl(inode, ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); if (acl) { diff --git a/fs/jfs/jfs_acl.h b/fs/jfs/jfs_acl.h index 54e07559878..f9285c4900f 100644 --- a/fs/jfs/jfs_acl.h +++ b/fs/jfs/jfs_acl.h @@ -20,7 +20,7 @@ #ifdef CONFIG_JFS_POSIX_ACL -int jfs_check_acl(struct inode *, int); +int jfs_check_acl(struct inode *, int, unsigned int flags); int jfs_init_acl(tid_t, struct inode *, struct inode *); int jfs_acl_chmod(struct inode *inode); diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c index 231ca4af9bc..4414e3a4226 100644 --- a/fs/jfs/namei.c +++ b/fs/jfs/namei.c @@ -18,6 +18,7 @@ */ #include <linux/fs.h> +#include <linux/namei.h> #include <linux/ctype.h> #include <linux/quotaops.h> #include <linux/exportfs.h> @@ -1465,7 +1466,7 @@ static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, struc jfs_info("jfs_lookup: name = %s", name); if (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2) - dentry->d_op = &jfs_ci_dentry_operations; + d_set_d_op(dentry, &jfs_ci_dentry_operations); if ((name[0] == '.') && (len == 1)) inum = dip->i_ino; @@ -1494,7 +1495,7 @@ static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, struc dentry = d_splice_alias(ip, dentry); if (dentry && (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2)) - dentry->d_op = &jfs_ci_dentry_operations; + d_set_d_op(dentry, &jfs_ci_dentry_operations); return dentry; } @@ -1573,7 +1574,8 @@ const struct file_operations jfs_dir_operations = { .llseek = generic_file_llseek, }; -static int jfs_ci_hash(struct dentry *dir, struct qstr *this) +static int jfs_ci_hash(const struct dentry *dir, const struct inode *inode, + struct qstr *this) { unsigned long hash; int i; @@ -1586,32 +1588,63 @@ static int jfs_ci_hash(struct dentry *dir, struct qstr *this) return 0; } -static int jfs_ci_compare(struct dentry *dir, struct qstr *a, struct qstr *b) +static int jfs_ci_compare(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { int i, result = 1; - if (a->len != b->len) + if (len != name->len) goto out; - for (i=0; i < a->len; i++) { - if (tolower(a->name[i]) != tolower(b->name[i])) + for (i=0; i < len; i++) { + if (tolower(str[i]) != tolower(name->name[i])) goto out; } result = 0; +out: + return result; +} +static int jfs_ci_revalidate(struct dentry *dentry, struct nameidata *nd) +{ + if (nd->flags & LOOKUP_RCU) + return -ECHILD; /* - * We want creates to preserve case. A negative dentry, a, that - * has a different case than b may cause a new entry to be created - * with the wrong case. Since we can't tell if a comes from a negative - * dentry, we blindly replace it with b. This should be harmless if - * a is not a negative dentry. + * This is not negative dentry. Always valid. + * + * Note, rename() to existing directory entry will have ->d_inode, + * and will use existing name which isn't specified name by user. + * + * We may be able to drop this positive dentry here. But dropping + * positive dentry isn't good idea. So it's unsupported like + * rename("filename", "FILENAME") for now. */ - memcpy((unsigned char *)a->name, b->name, a->len); -out: - return result; + if (dentry->d_inode) + return 1; + + /* + * This may be nfsd (or something), anyway, we can't see the + * intent of this. So, since this can be for creation, drop it. + */ + if (!nd) + return 0; + + /* + * Drop the negative dentry, in order to make sure to use the + * case sensitive name which is specified by user if this is + * for creation. + */ + if (!(nd->flags & (LOOKUP_CONTINUE | LOOKUP_PARENT))) { + if (nd->flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)) + return 0; + } + return 1; } const struct dentry_operations jfs_ci_dentry_operations = { .d_hash = jfs_ci_hash, .d_compare = jfs_ci_compare, + .d_revalidate = jfs_ci_revalidate, }; diff --git a/fs/jfs/super.c b/fs/jfs/super.c index 0669fc1cc3b..3150d766e0d 100644 --- a/fs/jfs/super.c +++ b/fs/jfs/super.c @@ -115,6 +115,14 @@ static struct inode *jfs_alloc_inode(struct super_block *sb) return &jfs_inode->vfs_inode; } +static void jfs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + struct jfs_inode_info *ji = JFS_IP(inode); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(jfs_inode_cachep, ji); +} + static void jfs_destroy_inode(struct inode *inode) { struct jfs_inode_info *ji = JFS_IP(inode); @@ -128,7 +136,7 @@ static void jfs_destroy_inode(struct inode *inode) ji->active_ag = -1; } spin_unlock_irq(&ji->ag_lock); - kmem_cache_free(jfs_inode_cachep, ji); + call_rcu(&inode->i_rcu, jfs_i_callback); } static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf) @@ -517,7 +525,7 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent) goto out_no_root; if (sbi->mntflag & JFS_OS2) - sb->s_root->d_op = &jfs_ci_dentry_operations; + d_set_d_op(sb->s_root, &jfs_ci_dentry_operations); /* logical blocks are represented by 40 bits in pxd_t, etc. */ sb->s_maxbytes = ((u64) sb->s_blocksize) << 40; diff --git a/fs/libfs.c b/fs/libfs.c index a3accdf528a..889311e3d06 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -16,6 +16,11 @@ #include <asm/uaccess.h> +static inline int simple_positive(struct dentry *dentry) +{ + return dentry->d_inode && !d_unhashed(dentry); +} + int simple_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { @@ -37,7 +42,7 @@ int simple_statfs(struct dentry *dentry, struct kstatfs *buf) * Retaining negative dentries for an in-memory filesystem just wastes * memory and lookup time: arrange for them to be deleted immediately. */ -static int simple_delete_dentry(struct dentry *dentry) +static int simple_delete_dentry(const struct dentry *dentry) { return 1; } @@ -54,7 +59,7 @@ struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, struct na if (dentry->d_name.len > NAME_MAX) return ERR_PTR(-ENAMETOOLONG); - dentry->d_op = &simple_dentry_operations; + d_set_d_op(dentry, &simple_dentry_operations); d_add(dentry, NULL); return NULL; } @@ -76,7 +81,8 @@ int dcache_dir_close(struct inode *inode, struct file *file) loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin) { - mutex_lock(&file->f_path.dentry->d_inode->i_mutex); + struct dentry *dentry = file->f_path.dentry; + mutex_lock(&dentry->d_inode->i_mutex); switch (origin) { case 1: offset += file->f_pos; @@ -84,7 +90,7 @@ loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin) if (offset >= 0) break; default: - mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); + mutex_unlock(&dentry->d_inode->i_mutex); return -EINVAL; } if (offset != file->f_pos) { @@ -94,21 +100,24 @@ loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin) struct dentry *cursor = file->private_data; loff_t n = file->f_pos - 2; - spin_lock(&dcache_lock); + spin_lock(&dentry->d_lock); + /* d_lock not required for cursor */ list_del(&cursor->d_u.d_child); - p = file->f_path.dentry->d_subdirs.next; - while (n && p != &file->f_path.dentry->d_subdirs) { + p = dentry->d_subdirs.next; + while (n && p != &dentry->d_subdirs) { struct dentry *next; next = list_entry(p, struct dentry, d_u.d_child); - if (!d_unhashed(next) && next->d_inode) + spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED); + if (simple_positive(next)) n--; + spin_unlock(&next->d_lock); p = p->next; } list_add_tail(&cursor->d_u.d_child, p); - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); } } - mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); + mutex_unlock(&dentry->d_inode->i_mutex); return offset; } @@ -148,29 +157,35 @@ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir) i++; /* fallthrough */ default: - spin_lock(&dcache_lock); + spin_lock(&dentry->d_lock); if (filp->f_pos == 2) list_move(q, &dentry->d_subdirs); for (p=q->next; p != &dentry->d_subdirs; p=p->next) { struct dentry *next; next = list_entry(p, struct dentry, d_u.d_child); - if (d_unhashed(next) || !next->d_inode) + spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED); + if (!simple_positive(next)) { + spin_unlock(&next->d_lock); continue; + } - spin_unlock(&dcache_lock); + spin_unlock(&next->d_lock); + spin_unlock(&dentry->d_lock); if (filldir(dirent, next->d_name.name, next->d_name.len, filp->f_pos, next->d_inode->i_ino, dt_type(next->d_inode)) < 0) return 0; - spin_lock(&dcache_lock); + spin_lock(&dentry->d_lock); + spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED); /* next is still alive */ list_move(q, p); + spin_unlock(&next->d_lock); p = q; filp->f_pos++; } - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); } return 0; } @@ -259,23 +274,23 @@ int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *den return 0; } -static inline int simple_positive(struct dentry *dentry) -{ - return dentry->d_inode && !d_unhashed(dentry); -} - int simple_empty(struct dentry *dentry) { struct dentry *child; int ret = 0; - spin_lock(&dcache_lock); - list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child) - if (simple_positive(child)) + spin_lock(&dentry->d_lock); + list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child) { + spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED); + if (simple_positive(child)) { + spin_unlock(&child->d_lock); goto out; + } + spin_unlock(&child->d_lock); + } ret = 1; out: - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); return ret; } diff --git a/fs/locks.c b/fs/locks.c index 8729347bcd1..08415b2a6d3 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1389,7 +1389,7 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp) if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0)) goto out; if ((arg == F_WRLCK) - && ((atomic_read(&dentry->d_count) > 1) + && ((dentry->d_count > 1) || (atomic_read(&inode->i_count) > 1))) goto out; } diff --git a/fs/logfs/dir.c b/fs/logfs/dir.c index 409dfd65e9a..f9ddf0c388c 100644 --- a/fs/logfs/dir.c +++ b/fs/logfs/dir.c @@ -555,9 +555,11 @@ static int logfs_symlink(struct inode *dir, struct dentry *dentry, return __logfs_create(dir, dentry, inode, target, destlen); } -static int logfs_permission(struct inode *inode, int mask) +static int logfs_permission(struct inode *inode, int mask, unsigned int flags) { - return generic_permission(inode, mask, NULL); + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + return generic_permission(inode, mask, flags, NULL); } static int logfs_link(struct dentry *old_dentry, struct inode *dir, diff --git a/fs/logfs/inode.c b/fs/logfs/inode.c index d8c71ece098..03b8c240aed 100644 --- a/fs/logfs/inode.c +++ b/fs/logfs/inode.c @@ -141,13 +141,20 @@ struct inode *logfs_safe_iget(struct super_block *sb, ino_t ino, int *is_cached) return __logfs_iget(sb, ino); } +static void logfs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(logfs_inode_cache, logfs_inode(inode)); +} + static void __logfs_destroy_inode(struct inode *inode) { struct logfs_inode *li = logfs_inode(inode); BUG_ON(li->li_block); list_del(&li->li_freeing_list); - kmem_cache_free(logfs_inode_cache, li); + call_rcu(&inode->i_rcu, logfs_i_callback); } static void logfs_destroy_inode(struct inode *inode) diff --git a/fs/minix/inode.c b/fs/minix/inode.c index fb2020858a3..ae0b83f476a 100644 --- a/fs/minix/inode.c +++ b/fs/minix/inode.c @@ -68,11 +68,18 @@ static struct inode *minix_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void minix_destroy_inode(struct inode *inode) +static void minix_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(minix_inode_cachep, minix_i(inode)); } +static void minix_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, minix_i_callback); +} + static void init_once(void *foo) { struct minix_inode_info *ei = (struct minix_inode_info *) foo; diff --git a/fs/minix/namei.c b/fs/minix/namei.c index c0d35a3acce..1b9e07728a9 100644 --- a/fs/minix/namei.c +++ b/fs/minix/namei.c @@ -23,7 +23,7 @@ static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, st struct inode * inode = NULL; ino_t ino; - dentry->d_op = dir->i_sb->s_root->d_op; + d_set_d_op(dentry, dir->i_sb->s_root->d_op); if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen) return ERR_PTR(-ENAMETOOLONG); diff --git a/fs/namei.c b/fs/namei.c index 4ff7ca53053..19433cdba01 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -169,8 +169,8 @@ EXPORT_SYMBOL(putname); /* * This does basic POSIX ACL permission checking */ -static int acl_permission_check(struct inode *inode, int mask, - int (*check_acl)(struct inode *inode, int mask)) +static int acl_permission_check(struct inode *inode, int mask, unsigned int flags, + int (*check_acl)(struct inode *inode, int mask, unsigned int flags)) { umode_t mode = inode->i_mode; @@ -180,7 +180,7 @@ static int acl_permission_check(struct inode *inode, int mask, mode >>= 6; else { if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) { - int error = check_acl(inode, mask); + int error = check_acl(inode, mask, flags); if (error != -EAGAIN) return error; } @@ -198,25 +198,30 @@ static int acl_permission_check(struct inode *inode, int mask, } /** - * generic_permission - check for access rights on a Posix-like filesystem + * generic_permission - check for access rights on a Posix-like filesystem * @inode: inode to check access rights for * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) * @check_acl: optional callback to check for Posix ACLs + * @flags IPERM_FLAG_ flags. * * Used to check for read/write/execute permissions on a file. * We use "fsuid" for this, letting us set arbitrary permissions * for filesystem access without changing the "normal" uids which - * are used for other things.. + * are used for other things. + * + * generic_permission is rcu-walk aware. It returns -ECHILD in case an rcu-walk + * request cannot be satisfied (eg. requires blocking or too much complexity). + * It would then be called again in ref-walk mode. */ -int generic_permission(struct inode *inode, int mask, - int (*check_acl)(struct inode *inode, int mask)) +int generic_permission(struct inode *inode, int mask, unsigned int flags, + int (*check_acl)(struct inode *inode, int mask, unsigned int flags)) { int ret; /* * Do the basic POSIX ACL permission checks. */ - ret = acl_permission_check(inode, mask, check_acl); + ret = acl_permission_check(inode, mask, flags, check_acl); if (ret != -EACCES) return ret; @@ -271,9 +276,10 @@ int inode_permission(struct inode *inode, int mask) } if (inode->i_op->permission) - retval = inode->i_op->permission(inode, mask); + retval = inode->i_op->permission(inode, mask, 0); else - retval = generic_permission(inode, mask, inode->i_op->check_acl); + retval = generic_permission(inode, mask, 0, + inode->i_op->check_acl); if (retval) return retval; @@ -362,6 +368,18 @@ void path_get(struct path *path) EXPORT_SYMBOL(path_get); /** + * path_get_long - get a long reference to a path + * @path: path to get the reference to + * + * Given a path increment the reference count to the dentry and the vfsmount. + */ +void path_get_long(struct path *path) +{ + mntget_long(path->mnt); + dget(path->dentry); +} + +/** * path_put - put a reference to a path * @path: path to put the reference to * @@ -375,6 +393,185 @@ void path_put(struct path *path) EXPORT_SYMBOL(path_put); /** + * path_put_long - put a long reference to a path + * @path: path to put the reference to + * + * Given a path decrement the reference count to the dentry and the vfsmount. + */ +void path_put_long(struct path *path) +{ + dput(path->dentry); + mntput_long(path->mnt); +} + +/** + * nameidata_drop_rcu - drop this nameidata out of rcu-walk + * @nd: nameidata pathwalk data to drop + * @Returns: 0 on success, -ECHLID on failure + * + * Path walking has 2 modes, rcu-walk and ref-walk (see + * Documentation/filesystems/path-lookup.txt). __drop_rcu* functions attempt + * to drop out of rcu-walk mode and take normal reference counts on dentries + * and vfsmounts to transition to rcu-walk mode. __drop_rcu* functions take + * refcounts at the last known good point before rcu-walk got stuck, so + * ref-walk may continue from there. If this is not successful (eg. a seqcount + * has changed), then failure is returned and path walk restarts from the + * beginning in ref-walk mode. + * + * nameidata_drop_rcu attempts to drop the current nd->path and nd->root into + * ref-walk. Must be called from rcu-walk context. + */ +static int nameidata_drop_rcu(struct nameidata *nd) +{ + struct fs_struct *fs = current->fs; + struct dentry *dentry = nd->path.dentry; + + BUG_ON(!(nd->flags & LOOKUP_RCU)); + if (nd->root.mnt) { + spin_lock(&fs->lock); + if (nd->root.mnt != fs->root.mnt || + nd->root.dentry != fs->root.dentry) + goto err_root; + } + spin_lock(&dentry->d_lock); + if (!__d_rcu_to_refcount(dentry, nd->seq)) + goto err; + BUG_ON(nd->inode != dentry->d_inode); + spin_unlock(&dentry->d_lock); + if (nd->root.mnt) { + path_get(&nd->root); + spin_unlock(&fs->lock); + } + mntget(nd->path.mnt); + + rcu_read_unlock(); + br_read_unlock(vfsmount_lock); + nd->flags &= ~LOOKUP_RCU; + return 0; +err: + spin_unlock(&dentry->d_lock); +err_root: + if (nd->root.mnt) + spin_unlock(&fs->lock); + return -ECHILD; +} + +/* Try to drop out of rcu-walk mode if we were in it, otherwise do nothing. */ +static inline int nameidata_drop_rcu_maybe(struct nameidata *nd) +{ + if (nd->flags & LOOKUP_RCU) + return nameidata_drop_rcu(nd); + return 0; +} + +/** + * nameidata_dentry_drop_rcu - drop nameidata and dentry out of rcu-walk + * @nd: nameidata pathwalk data to drop + * @dentry: dentry to drop + * @Returns: 0 on success, -ECHLID on failure + * + * nameidata_dentry_drop_rcu attempts to drop the current nd->path and nd->root, + * and dentry into ref-walk. @dentry must be a path found by a do_lookup call on + * @nd. Must be called from rcu-walk context. + */ +static int nameidata_dentry_drop_rcu(struct nameidata *nd, struct dentry *dentry) +{ + struct fs_struct *fs = current->fs; + struct dentry *parent = nd->path.dentry; + + BUG_ON(!(nd->flags & LOOKUP_RCU)); + if (nd->root.mnt) { + spin_lock(&fs->lock); + if (nd->root.mnt != fs->root.mnt || + nd->root.dentry != fs->root.dentry) + goto err_root; + } + spin_lock(&parent->d_lock); + spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); + if (!__d_rcu_to_refcount(dentry, nd->seq)) + goto err; + /* + * If the sequence check on the child dentry passed, then the child has + * not been removed from its parent. This means the parent dentry must + * be valid and able to take a reference at this point. + */ + BUG_ON(!IS_ROOT(dentry) && dentry->d_parent != parent); + BUG_ON(!parent->d_count); + parent->d_count++; + spin_unlock(&dentry->d_lock); + spin_unlock(&parent->d_lock); + if (nd->root.mnt) { + path_get(&nd->root); + spin_unlock(&fs->lock); + } + mntget(nd->path.mnt); + + rcu_read_unlock(); + br_read_unlock(vfsmount_lock); + nd->flags &= ~LOOKUP_RCU; + return 0; +err: + spin_unlock(&dentry->d_lock); + spin_unlock(&parent->d_lock); +err_root: + if (nd->root.mnt) + spin_unlock(&fs->lock); + return -ECHILD; +} + +/* Try to drop out of rcu-walk mode if we were in it, otherwise do nothing. */ +static inline int nameidata_dentry_drop_rcu_maybe(struct nameidata *nd, struct dentry *dentry) +{ + if (nd->flags & LOOKUP_RCU) + return nameidata_dentry_drop_rcu(nd, dentry); + return 0; +} + +/** + * nameidata_drop_rcu_last - drop nameidata ending path walk out of rcu-walk + * @nd: nameidata pathwalk data to drop + * @Returns: 0 on success, -ECHLID on failure + * + * nameidata_drop_rcu_last attempts to drop the current nd->path into ref-walk. + * nd->path should be the final element of the lookup, so nd->root is discarded. + * Must be called from rcu-walk context. + */ +static int nameidata_drop_rcu_last(struct nameidata *nd) +{ + struct dentry *dentry = nd->path.dentry; + + BUG_ON(!(nd->flags & LOOKUP_RCU)); + nd->flags &= ~LOOKUP_RCU; + nd->root.mnt = NULL; + spin_lock(&dentry->d_lock); + if (!__d_rcu_to_refcount(dentry, nd->seq)) + goto err_unlock; + BUG_ON(nd->inode != dentry->d_inode); + spin_unlock(&dentry->d_lock); + + mntget(nd->path.mnt); + + rcu_read_unlock(); + br_read_unlock(vfsmount_lock); + + return 0; + +err_unlock: + spin_unlock(&dentry->d_lock); + rcu_read_unlock(); + br_read_unlock(vfsmount_lock); + return -ECHILD; +} + +/* Try to drop out of rcu-walk mode if we were in it, otherwise do nothing. */ +static inline int nameidata_drop_rcu_last_maybe(struct nameidata *nd) +{ + if (likely(nd->flags & LOOKUP_RCU)) + return nameidata_drop_rcu_last(nd); + return 0; +} + +/** * release_open_intent - free up open intent resources * @nd: pointer to nameidata */ @@ -386,10 +583,26 @@ void release_open_intent(struct nameidata *nd) fput(nd->intent.open.file); } +static int d_revalidate(struct dentry *dentry, struct nameidata *nd) +{ + int status; + + status = dentry->d_op->d_revalidate(dentry, nd); + if (status == -ECHILD) { + if (nameidata_dentry_drop_rcu(nd, dentry)) + return status; + status = dentry->d_op->d_revalidate(dentry, nd); + } + + return status; +} + static inline struct dentry * do_revalidate(struct dentry *dentry, struct nameidata *nd) { - int status = dentry->d_op->d_revalidate(dentry, nd); + int status; + + status = d_revalidate(dentry, nd); if (unlikely(status <= 0)) { /* * The dentry failed validation. @@ -397,19 +610,36 @@ do_revalidate(struct dentry *dentry, struct nameidata *nd) * the dentry otherwise d_revalidate is asking us * to return a fail status. */ - if (!status) { + if (status < 0) { + /* If we're in rcu-walk, we don't have a ref */ + if (!(nd->flags & LOOKUP_RCU)) + dput(dentry); + dentry = ERR_PTR(status); + + } else { + /* Don't d_invalidate in rcu-walk mode */ + if (nameidata_dentry_drop_rcu_maybe(nd, dentry)) + return ERR_PTR(-ECHILD); if (!d_invalidate(dentry)) { dput(dentry); dentry = NULL; } - } else { - dput(dentry); - dentry = ERR_PTR(status); } } return dentry; } +static inline int need_reval_dot(struct dentry *dentry) +{ + if (likely(!(dentry->d_flags & DCACHE_OP_REVALIDATE))) + return 0; + + if (likely(!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT))) + return 0; + + return 1; +} + /* * force_reval_path - force revalidation of a dentry * @@ -433,13 +663,12 @@ force_reval_path(struct path *path, struct nameidata *nd) /* * only check on filesystems where it's possible for the dentry to - * become stale. It's assumed that if this flag is set then the - * d_revalidate op will also be defined. + * become stale. */ - if (!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)) + if (!need_reval_dot(dentry)) return 0; - status = dentry->d_op->d_revalidate(dentry, nd); + status = d_revalidate(dentry, nd); if (status > 0) return 0; @@ -459,26 +688,27 @@ force_reval_path(struct path *path, struct nameidata *nd) * short-cut DAC fails, then call ->permission() to do more * complete permission check. */ -static int exec_permission(struct inode *inode) +static inline int exec_permission(struct inode *inode, unsigned int flags) { int ret; if (inode->i_op->permission) { - ret = inode->i_op->permission(inode, MAY_EXEC); - if (!ret) - goto ok; - return ret; + ret = inode->i_op->permission(inode, MAY_EXEC, flags); + } else { + ret = acl_permission_check(inode, MAY_EXEC, flags, + inode->i_op->check_acl); } - ret = acl_permission_check(inode, MAY_EXEC, inode->i_op->check_acl); - if (!ret) + if (likely(!ret)) goto ok; + if (ret == -ECHILD) + return ret; if (capable(CAP_DAC_OVERRIDE) || capable(CAP_DAC_READ_SEARCH)) goto ok; return ret; ok: - return security_inode_permission(inode, MAY_EXEC); + return security_inode_exec_permission(inode, flags); } static __always_inline void set_root(struct nameidata *nd) @@ -489,8 +719,23 @@ static __always_inline void set_root(struct nameidata *nd) static int link_path_walk(const char *, struct nameidata *); +static __always_inline void set_root_rcu(struct nameidata *nd) +{ + if (!nd->root.mnt) { + struct fs_struct *fs = current->fs; + unsigned seq; + + do { + seq = read_seqcount_begin(&fs->seq); + nd->root = fs->root; + } while (read_seqcount_retry(&fs->seq, seq)); + } +} + static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *link) { + int ret; + if (IS_ERR(link)) goto fail; @@ -500,8 +745,10 @@ static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *l nd->path = nd->root; path_get(&nd->root); } + nd->inode = nd->path.dentry->d_inode; - return link_path_walk(link, nd); + ret = link_path_walk(link, nd); + return ret; fail: path_put(&nd->path); return PTR_ERR(link); @@ -516,11 +763,12 @@ static void path_put_conditional(struct path *path, struct nameidata *nd) static inline void path_to_nameidata(struct path *path, struct nameidata *nd) { - dput(nd->path.dentry); - if (nd->path.mnt != path->mnt) { - mntput(nd->path.mnt); - nd->path.mnt = path->mnt; + if (!(nd->flags & LOOKUP_RCU)) { + dput(nd->path.dentry); + if (nd->path.mnt != path->mnt) + mntput(nd->path.mnt); } + nd->path.mnt = path->mnt; nd->path.dentry = path->dentry; } @@ -535,9 +783,11 @@ __do_follow_link(struct path *path, struct nameidata *nd, void **p) if (path->mnt != nd->path.mnt) { path_to_nameidata(path, nd); + nd->inode = nd->path.dentry->d_inode; dget(dentry); } mntget(path->mnt); + nd->last_type = LAST_BIND; *p = dentry->d_inode->i_op->follow_link(dentry, nd); error = PTR_ERR(*p); @@ -591,6 +841,20 @@ loop: return err; } +static int follow_up_rcu(struct path *path) +{ + struct vfsmount *parent; + struct dentry *mountpoint; + + parent = path->mnt->mnt_parent; + if (parent == path->mnt) + return 0; + mountpoint = path->mnt->mnt_mountpoint; + path->dentry = mountpoint; + path->mnt = parent; + return 1; +} + int follow_up(struct path *path) { struct vfsmount *parent; @@ -612,9 +876,24 @@ int follow_up(struct path *path) return 1; } -/* no need for dcache_lock, as serialization is taken care in - * namespace.c +/* + * serialization is taken care of in namespace.c */ +static void __follow_mount_rcu(struct nameidata *nd, struct path *path, + struct inode **inode) +{ + while (d_mountpoint(path->dentry)) { + struct vfsmount *mounted; + mounted = __lookup_mnt(path->mnt, path->dentry, 1); + if (!mounted) + return; + path->mnt = mounted; + path->dentry = mounted->mnt_root; + nd->seq = read_seqcount_begin(&path->dentry->d_seq); + *inode = path->dentry->d_inode; + } +} + static int __follow_mount(struct path *path) { int res = 0; @@ -645,9 +924,6 @@ static void follow_mount(struct path *path) } } -/* no need for dcache_lock, as serialization is taken care in - * namespace.c - */ int follow_down(struct path *path) { struct vfsmount *mounted; @@ -663,7 +939,42 @@ int follow_down(struct path *path) return 0; } -static __always_inline void follow_dotdot(struct nameidata *nd) +static int follow_dotdot_rcu(struct nameidata *nd) +{ + struct inode *inode = nd->inode; + + set_root_rcu(nd); + + while(1) { + if (nd->path.dentry == nd->root.dentry && + nd->path.mnt == nd->root.mnt) { + break; + } + if (nd->path.dentry != nd->path.mnt->mnt_root) { + struct dentry *old = nd->path.dentry; + struct dentry *parent = old->d_parent; + unsigned seq; + + seq = read_seqcount_begin(&parent->d_seq); + if (read_seqcount_retry(&old->d_seq, nd->seq)) + return -ECHILD; + inode = parent->d_inode; + nd->path.dentry = parent; + nd->seq = seq; + break; + } + if (!follow_up_rcu(&nd->path)) + break; + nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq); + inode = nd->path.dentry->d_inode; + } + __follow_mount_rcu(nd, &nd->path, &inode); + nd->inode = inode; + + return 0; +} + +static void follow_dotdot(struct nameidata *nd) { set_root(nd); @@ -684,6 +995,7 @@ static __always_inline void follow_dotdot(struct nameidata *nd) break; } follow_mount(&nd->path); + nd->inode = nd->path.dentry->d_inode; } /* @@ -721,17 +1033,17 @@ static struct dentry *d_alloc_and_lookup(struct dentry *parent, * It _is_ time-critical. */ static int do_lookup(struct nameidata *nd, struct qstr *name, - struct path *path) + struct path *path, struct inode **inode) { struct vfsmount *mnt = nd->path.mnt; - struct dentry *dentry, *parent; + struct dentry *dentry, *parent = nd->path.dentry; struct inode *dir; /* * See if the low-level filesystem might want * to use its own hash.. */ - if (nd->path.dentry->d_op && nd->path.dentry->d_op->d_hash) { - int err = nd->path.dentry->d_op->d_hash(nd->path.dentry, name); + if (unlikely(parent->d_flags & DCACHE_OP_HASH)) { + int err = parent->d_op->d_hash(parent, nd->inode, name); if (err < 0) return err; } @@ -741,21 +1053,44 @@ static int do_lookup(struct nameidata *nd, struct qstr *name, * of a false negative due to a concurrent rename, we're going to * do the non-racy lookup, below. */ - dentry = __d_lookup(nd->path.dentry, name); - if (!dentry) - goto need_lookup; + if (nd->flags & LOOKUP_RCU) { + unsigned seq; + + *inode = nd->inode; + dentry = __d_lookup_rcu(parent, name, &seq, inode); + if (!dentry) { + if (nameidata_drop_rcu(nd)) + return -ECHILD; + goto need_lookup; + } + /* Memory barrier in read_seqcount_begin of child is enough */ + if (__read_seqcount_retry(&parent->d_seq, nd->seq)) + return -ECHILD; + + nd->seq = seq; + if (dentry->d_flags & DCACHE_OP_REVALIDATE) + goto need_revalidate; + path->mnt = mnt; + path->dentry = dentry; + __follow_mount_rcu(nd, path, inode); + } else { + dentry = __d_lookup(parent, name); + if (!dentry) + goto need_lookup; found: - if (dentry->d_op && dentry->d_op->d_revalidate) - goto need_revalidate; + if (dentry->d_flags & DCACHE_OP_REVALIDATE) + goto need_revalidate; done: - path->mnt = mnt; - path->dentry = dentry; - __follow_mount(path); + path->mnt = mnt; + path->dentry = dentry; + __follow_mount(path); + *inode = path->dentry->d_inode; + } return 0; need_lookup: - parent = nd->path.dentry; dir = parent->d_inode; + BUG_ON(nd->inode != dir); mutex_lock(&dir->i_mutex); /* @@ -817,7 +1152,6 @@ static inline int follow_on_final(struct inode *inode, unsigned lookup_flags) static int link_path_walk(const char *name, struct nameidata *nd) { struct path next; - struct inode *inode; int err; unsigned int lookup_flags = nd->flags; @@ -826,18 +1160,28 @@ static int link_path_walk(const char *name, struct nameidata *nd) if (!*name) goto return_reval; - inode = nd->path.dentry->d_inode; if (nd->depth) lookup_flags = LOOKUP_FOLLOW | (nd->flags & LOOKUP_CONTINUE); /* At this point we know we have a real path component. */ for(;;) { + struct inode *inode; unsigned long hash; struct qstr this; unsigned int c; nd->flags |= LOOKUP_CONTINUE; - err = exec_permission(inode); + if (nd->flags & LOOKUP_RCU) { + err = exec_permission(nd->inode, IPERM_FLAG_RCU); + if (err == -ECHILD) { + if (nameidata_drop_rcu(nd)) + return -ECHILD; + goto exec_again; + } + } else { +exec_again: + err = exec_permission(nd->inode, 0); + } if (err) break; @@ -868,37 +1212,44 @@ static int link_path_walk(const char *name, struct nameidata *nd) if (this.name[0] == '.') switch (this.len) { default: break; - case 2: + case 2: if (this.name[1] != '.') break; - follow_dotdot(nd); - inode = nd->path.dentry->d_inode; + if (nd->flags & LOOKUP_RCU) { + if (follow_dotdot_rcu(nd)) + return -ECHILD; + } else + follow_dotdot(nd); /* fallthrough */ case 1: continue; } /* This does the actual lookups.. */ - err = do_lookup(nd, &this, &next); + err = do_lookup(nd, &this, &next, &inode); if (err) break; - err = -ENOENT; - inode = next.dentry->d_inode; if (!inode) goto out_dput; if (inode->i_op->follow_link) { + /* We commonly drop rcu-walk here */ + if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry)) + return -ECHILD; + BUG_ON(inode != next.dentry->d_inode); err = do_follow_link(&next, nd); if (err) goto return_err; + nd->inode = nd->path.dentry->d_inode; err = -ENOENT; - inode = nd->path.dentry->d_inode; - if (!inode) + if (!nd->inode) break; - } else + } else { path_to_nameidata(&next, nd); + nd->inode = inode; + } err = -ENOTDIR; - if (!inode->i_op->lookup) + if (!nd->inode->i_op->lookup) break; continue; /* here ends the main loop */ @@ -913,32 +1264,39 @@ last_component: if (this.name[0] == '.') switch (this.len) { default: break; - case 2: + case 2: if (this.name[1] != '.') break; - follow_dotdot(nd); - inode = nd->path.dentry->d_inode; + if (nd->flags & LOOKUP_RCU) { + if (follow_dotdot_rcu(nd)) + return -ECHILD; + } else + follow_dotdot(nd); /* fallthrough */ case 1: goto return_reval; } - err = do_lookup(nd, &this, &next); + err = do_lookup(nd, &this, &next, &inode); if (err) break; - inode = next.dentry->d_inode; if (follow_on_final(inode, lookup_flags)) { + if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry)) + return -ECHILD; + BUG_ON(inode != next.dentry->d_inode); err = do_follow_link(&next, nd); if (err) goto return_err; - inode = nd->path.dentry->d_inode; - } else + nd->inode = nd->path.dentry->d_inode; + } else { path_to_nameidata(&next, nd); + nd->inode = inode; + } err = -ENOENT; - if (!inode) + if (!nd->inode) break; if (lookup_flags & LOOKUP_DIRECTORY) { err = -ENOTDIR; - if (!inode->i_op->lookup) + if (!nd->inode->i_op->lookup) break; } goto return_base; @@ -958,25 +1316,43 @@ return_reval: * We bypassed the ordinary revalidation routines. * We may need to check the cached dentry for staleness. */ - if (nd->path.dentry && nd->path.dentry->d_sb && - (nd->path.dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)) { - err = -ESTALE; + if (need_reval_dot(nd->path.dentry)) { /* Note: we do not d_invalidate() */ - if (!nd->path.dentry->d_op->d_revalidate( - nd->path.dentry, nd)) + err = d_revalidate(nd->path.dentry, nd); + if (!err) + err = -ESTALE; + if (err < 0) break; } return_base: + if (nameidata_drop_rcu_last_maybe(nd)) + return -ECHILD; return 0; out_dput: - path_put_conditional(&next, nd); + if (!(nd->flags & LOOKUP_RCU)) + path_put_conditional(&next, nd); break; } - path_put(&nd->path); + if (!(nd->flags & LOOKUP_RCU)) + path_put(&nd->path); return_err: return err; } +static inline int path_walk_rcu(const char *name, struct nameidata *nd) +{ + current->total_link_count = 0; + + return link_path_walk(name, nd); +} + +static inline int path_walk_simple(const char *name, struct nameidata *nd) +{ + current->total_link_count = 0; + + return link_path_walk(name, nd); +} + static int path_walk(const char *name, struct nameidata *nd) { struct path save = nd->path; @@ -1002,6 +1378,93 @@ static int path_walk(const char *name, struct nameidata *nd) return result; } +static void path_finish_rcu(struct nameidata *nd) +{ + if (nd->flags & LOOKUP_RCU) { + /* RCU dangling. Cancel it. */ + nd->flags &= ~LOOKUP_RCU; + nd->root.mnt = NULL; + rcu_read_unlock(); + br_read_unlock(vfsmount_lock); + } + if (nd->file) + fput(nd->file); +} + +static int path_init_rcu(int dfd, const char *name, unsigned int flags, struct nameidata *nd) +{ + int retval = 0; + int fput_needed; + struct file *file; + + nd->last_type = LAST_ROOT; /* if there are only slashes... */ + nd->flags = flags | LOOKUP_RCU; + nd->depth = 0; + nd->root.mnt = NULL; + nd->file = NULL; + + if (*name=='/') { + struct fs_struct *fs = current->fs; + unsigned seq; + + br_read_lock(vfsmount_lock); + rcu_read_lock(); + + do { + seq = read_seqcount_begin(&fs->seq); + nd->root = fs->root; + nd->path = nd->root; + nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq); + } while (read_seqcount_retry(&fs->seq, seq)); + + } else if (dfd == AT_FDCWD) { + struct fs_struct *fs = current->fs; + unsigned seq; + + br_read_lock(vfsmount_lock); + rcu_read_lock(); + + do { + seq = read_seqcount_begin(&fs->seq); + nd->path = fs->pwd; + nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq); + } while (read_seqcount_retry(&fs->seq, seq)); + + } else { + struct dentry *dentry; + + file = fget_light(dfd, &fput_needed); + retval = -EBADF; + if (!file) + goto out_fail; + + dentry = file->f_path.dentry; + + retval = -ENOTDIR; + if (!S_ISDIR(dentry->d_inode->i_mode)) + goto fput_fail; + + retval = file_permission(file, MAY_EXEC); + if (retval) + goto fput_fail; + + nd->path = file->f_path; + if (fput_needed) + nd->file = file; + + nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq); + br_read_lock(vfsmount_lock); + rcu_read_lock(); + } + nd->inode = nd->path.dentry->d_inode; + return 0; + +fput_fail: + fput_light(file, fput_needed); +out_fail: + return retval; +} + static int path_init(int dfd, const char *name, unsigned int flags, struct nameidata *nd) { int retval = 0; @@ -1042,6 +1505,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, struct namei fput_light(file, fput_needed); } + nd->inode = nd->path.dentry->d_inode; return 0; fput_fail: @@ -1054,16 +1518,53 @@ out_fail: static int do_path_lookup(int dfd, const char *name, unsigned int flags, struct nameidata *nd) { - int retval = path_init(dfd, name, flags, nd); - if (!retval) - retval = path_walk(name, nd); - if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && - nd->path.dentry->d_inode)) - audit_inode(name, nd->path.dentry); + int retval; + + /* + * Path walking is largely split up into 2 different synchronisation + * schemes, rcu-walk and ref-walk (explained in + * Documentation/filesystems/path-lookup.txt). These share much of the + * path walk code, but some things particularly setup, cleanup, and + * following mounts are sufficiently divergent that functions are + * duplicated. Typically there is a function foo(), and its RCU + * analogue, foo_rcu(). + * + * -ECHILD is the error number of choice (just to avoid clashes) that + * is returned if some aspect of an rcu-walk fails. Such an error must + * be handled by restarting a traditional ref-walk (which will always + * be able to complete). + */ + retval = path_init_rcu(dfd, name, flags, nd); + if (unlikely(retval)) + return retval; + retval = path_walk_rcu(name, nd); + path_finish_rcu(nd); if (nd->root.mnt) { path_put(&nd->root); nd->root.mnt = NULL; } + + if (unlikely(retval == -ECHILD || retval == -ESTALE)) { + /* slower, locked walk */ + if (retval == -ESTALE) + flags |= LOOKUP_REVAL; + retval = path_init(dfd, name, flags, nd); + if (unlikely(retval)) + return retval; + retval = path_walk(name, nd); + if (nd->root.mnt) { + path_put(&nd->root); + nd->root.mnt = NULL; + } + } + + if (likely(!retval)) { + if (unlikely(!audit_dummy_context())) { + if (nd->path.dentry && nd->inode) + audit_inode(name, nd->path.dentry); + } + } + return retval; } @@ -1106,10 +1607,11 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, path_get(&nd->path); nd->root = nd->path; path_get(&nd->root); + nd->inode = nd->path.dentry->d_inode; retval = path_walk(name, nd); if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && - nd->path.dentry->d_inode)) + nd->inode)) audit_inode(name, nd->path.dentry); path_put(&nd->root); @@ -1125,7 +1627,7 @@ static struct dentry *__lookup_hash(struct qstr *name, struct dentry *dentry; int err; - err = exec_permission(inode); + err = exec_permission(inode, 0); if (err) return ERR_PTR(err); @@ -1133,8 +1635,8 @@ static struct dentry *__lookup_hash(struct qstr *name, * See if the low-level filesystem might want * to use its own hash.. */ - if (base->d_op && base->d_op->d_hash) { - err = base->d_op->d_hash(base, name); + if (base->d_flags & DCACHE_OP_HASH) { + err = base->d_op->d_hash(base, inode, name); dentry = ERR_PTR(err); if (err < 0) goto out; @@ -1147,7 +1649,7 @@ static struct dentry *__lookup_hash(struct qstr *name, */ dentry = d_lookup(base, name); - if (dentry && dentry->d_op && dentry->d_op->d_revalidate) + if (dentry && (dentry->d_flags & DCACHE_OP_REVALIDATE)) dentry = do_revalidate(dentry, nd); if (!dentry) @@ -1490,6 +1992,7 @@ out_unlock: mutex_unlock(&dir->d_inode->i_mutex); dput(nd->path.dentry); nd->path.dentry = path->dentry; + if (error) return error; /* Don't check for write permission, don't truncate */ @@ -1584,6 +2087,9 @@ exit: return ERR_PTR(error); } +/* + * Handle O_CREAT case for do_filp_open + */ static struct file *do_last(struct nameidata *nd, struct path *path, int open_flag, int acc_mode, int mode, const char *pathname) @@ -1597,50 +2103,25 @@ static struct file *do_last(struct nameidata *nd, struct path *path, follow_dotdot(nd); dir = nd->path.dentry; case LAST_DOT: - if (nd->path.mnt->mnt_sb->s_type->fs_flags & FS_REVAL_DOT) { - if (!dir->d_op->d_revalidate(dir, nd)) { + if (need_reval_dot(dir)) { + error = d_revalidate(nd->path.dentry, nd); + if (!error) error = -ESTALE; + if (error < 0) goto exit; - } } /* fallthrough */ case LAST_ROOT: - if (open_flag & O_CREAT) - goto exit; - /* fallthrough */ + goto exit; case LAST_BIND: audit_inode(pathname, dir); goto ok; } /* trailing slashes? */ - if (nd->last.name[nd->last.len]) { - if (open_flag & O_CREAT) - goto exit; - nd->flags |= LOOKUP_DIRECTORY | LOOKUP_FOLLOW; - } - - /* just plain open? */ - if (!(open_flag & O_CREAT)) { - error = do_lookup(nd, &nd->last, path); - if (error) - goto exit; - error = -ENOENT; - if (!path->dentry->d_inode) - goto exit_dput; - if (path->dentry->d_inode->i_op->follow_link) - return NULL; - error = -ENOTDIR; - if (nd->flags & LOOKUP_DIRECTORY) { - if (!path->dentry->d_inode->i_op->lookup) - goto exit_dput; - } - path_to_nameidata(path, nd); - audit_inode(pathname, nd->path.dentry); - goto ok; - } + if (nd->last.name[nd->last.len]) + goto exit; - /* OK, it's O_CREAT */ mutex_lock(&dir->d_inode->i_mutex); path->dentry = lookup_hash(nd); @@ -1711,8 +2192,9 @@ static struct file *do_last(struct nameidata *nd, struct path *path, return NULL; path_to_nameidata(path, nd); + nd->inode = path->dentry->d_inode; error = -EISDIR; - if (S_ISDIR(path->dentry->d_inode->i_mode)) + if (S_ISDIR(nd->inode->i_mode)) goto exit; ok: filp = finish_open(nd, open_flag, acc_mode); @@ -1743,7 +2225,7 @@ struct file *do_filp_open(int dfd, const char *pathname, struct path path; int count = 0; int flag = open_to_namei_flags(open_flag); - int force_reval = 0; + int flags; if (!(open_flag & O_CREAT)) mode = 0; @@ -1772,54 +2254,84 @@ struct file *do_filp_open(int dfd, const char *pathname, if (open_flag & O_APPEND) acc_mode |= MAY_APPEND; - /* find the parent */ -reval: - error = path_init(dfd, pathname, LOOKUP_PARENT, &nd); + flags = LOOKUP_OPEN; + if (open_flag & O_CREAT) { + flags |= LOOKUP_CREATE; + if (open_flag & O_EXCL) + flags |= LOOKUP_EXCL; + } + if (open_flag & O_DIRECTORY) + flags |= LOOKUP_DIRECTORY; + if (!(open_flag & O_NOFOLLOW)) + flags |= LOOKUP_FOLLOW; + + filp = get_empty_filp(); + if (!filp) + return ERR_PTR(-ENFILE); + + filp->f_flags = open_flag; + nd.intent.open.file = filp; + nd.intent.open.flags = flag; + nd.intent.open.create_mode = mode; + + if (open_flag & O_CREAT) + goto creat; + + /* !O_CREAT, simple open */ + error = do_path_lookup(dfd, pathname, flags, &nd); + if (unlikely(error)) + goto out_filp; + error = -ELOOP; + if (!(nd.flags & LOOKUP_FOLLOW)) { + if (nd.inode->i_op->follow_link) + goto out_path; + } + error = -ENOTDIR; + if (nd.flags & LOOKUP_DIRECTORY) { + if (!nd.inode->i_op->lookup) + goto out_path; + } + audit_inode(pathname, nd.path.dentry); + filp = finish_open(&nd, open_flag, acc_mode); + return filp; + +creat: + /* OK, have to create the file. Find the parent. */ + error = path_init_rcu(dfd, pathname, + LOOKUP_PARENT | (flags & LOOKUP_REVAL), &nd); if (error) - return ERR_PTR(error); - if (force_reval) - nd.flags |= LOOKUP_REVAL; + goto out_filp; + error = path_walk_rcu(pathname, &nd); + path_finish_rcu(&nd); + if (unlikely(error == -ECHILD || error == -ESTALE)) { + /* slower, locked walk */ + if (error == -ESTALE) { +reval: + flags |= LOOKUP_REVAL; + } + error = path_init(dfd, pathname, + LOOKUP_PARENT | (flags & LOOKUP_REVAL), &nd); + if (error) + goto out_filp; - current->total_link_count = 0; - error = link_path_walk(pathname, &nd); - if (error) { - filp = ERR_PTR(error); - goto out; + error = path_walk_simple(pathname, &nd); } - if (unlikely(!audit_dummy_context()) && (open_flag & O_CREAT)) + if (unlikely(error)) + goto out_filp; + if (unlikely(!audit_dummy_context())) audit_inode(pathname, nd.path.dentry); /* * We have the parent and last component. */ - - error = -ENFILE; - filp = get_empty_filp(); - if (filp == NULL) - goto exit_parent; - nd.intent.open.file = filp; - filp->f_flags = open_flag; - nd.intent.open.flags = flag; - nd.intent.open.create_mode = mode; - nd.flags &= ~LOOKUP_PARENT; - nd.flags |= LOOKUP_OPEN; - if (open_flag & O_CREAT) { - nd.flags |= LOOKUP_CREATE; - if (open_flag & O_EXCL) - nd.flags |= LOOKUP_EXCL; - } - if (open_flag & O_DIRECTORY) - nd.flags |= LOOKUP_DIRECTORY; - if (!(open_flag & O_NOFOLLOW)) - nd.flags |= LOOKUP_FOLLOW; + nd.flags = flags; filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname); while (unlikely(!filp)) { /* trailing symlink */ struct path holder; - struct inode *inode = path.dentry->d_inode; void *cookie; error = -ELOOP; /* S_ISDIR part is a temporary automount kludge */ - if (!(nd.flags & LOOKUP_FOLLOW) && !S_ISDIR(inode->i_mode)) + if (!(nd.flags & LOOKUP_FOLLOW) && !S_ISDIR(nd.inode->i_mode)) goto exit_dput; if (count++ == 32) goto exit_dput; @@ -1840,36 +2352,33 @@ reval: goto exit_dput; error = __do_follow_link(&path, &nd, &cookie); if (unlikely(error)) { + if (!IS_ERR(cookie) && nd.inode->i_op->put_link) + nd.inode->i_op->put_link(path.dentry, &nd, cookie); /* nd.path had been dropped */ - if (!IS_ERR(cookie) && inode->i_op->put_link) - inode->i_op->put_link(path.dentry, &nd, cookie); - path_put(&path); - release_open_intent(&nd); - filp = ERR_PTR(error); - goto out; + nd.path = path; + goto out_path; } holder = path; nd.flags &= ~LOOKUP_PARENT; filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname); - if (inode->i_op->put_link) - inode->i_op->put_link(holder.dentry, &nd, cookie); + if (nd.inode->i_op->put_link) + nd.inode->i_op->put_link(holder.dentry, &nd, cookie); path_put(&holder); } out: if (nd.root.mnt) path_put(&nd.root); - if (filp == ERR_PTR(-ESTALE) && !force_reval) { - force_reval = 1; + if (filp == ERR_PTR(-ESTALE) && !(flags & LOOKUP_REVAL)) goto reval; - } return filp; exit_dput: path_put_conditional(&path, &nd); +out_path: + path_put(&nd.path); +out_filp: if (!IS_ERR(nd.intent.open.file)) release_open_intent(&nd); -exit_parent: - path_put(&nd.path); filp = ERR_PTR(error); goto out; } @@ -2130,12 +2639,10 @@ void dentry_unhash(struct dentry *dentry) { dget(dentry); shrink_dcache_parent(dentry); - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); - if (atomic_read(&dentry->d_count) == 2) + if (dentry->d_count == 2) __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); } int vfs_rmdir(struct inode *dir, struct dentry *dentry) diff --git a/fs/namespace.c b/fs/namespace.c index 3dbfc072ec7..3ddfd9046c4 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -138,6 +138,64 @@ void mnt_release_group_id(struct vfsmount *mnt) mnt->mnt_group_id = 0; } +/* + * vfsmount lock must be held for read + */ +static inline void mnt_add_count(struct vfsmount *mnt, int n) +{ +#ifdef CONFIG_SMP + this_cpu_add(mnt->mnt_pcp->mnt_count, n); +#else + preempt_disable(); + mnt->mnt_count += n; + preempt_enable(); +#endif +} + +static inline void mnt_set_count(struct vfsmount *mnt, int n) +{ +#ifdef CONFIG_SMP + this_cpu_write(mnt->mnt_pcp->mnt_count, n); +#else + mnt->mnt_count = n; +#endif +} + +/* + * vfsmount lock must be held for read + */ +static inline void mnt_inc_count(struct vfsmount *mnt) +{ + mnt_add_count(mnt, 1); +} + +/* + * vfsmount lock must be held for read + */ +static inline void mnt_dec_count(struct vfsmount *mnt) +{ + mnt_add_count(mnt, -1); +} + +/* + * vfsmount lock must be held for write + */ +unsigned int mnt_get_count(struct vfsmount *mnt) +{ +#ifdef CONFIG_SMP + unsigned int count = atomic_read(&mnt->mnt_longrefs); + int cpu; + + for_each_possible_cpu(cpu) { + count += per_cpu_ptr(mnt->mnt_pcp, cpu)->mnt_count; + } + + return count; +#else + return mnt->mnt_count; +#endif +} + struct vfsmount *alloc_vfsmnt(const char *name) { struct vfsmount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL); @@ -154,7 +212,17 @@ struct vfsmount *alloc_vfsmnt(const char *name) goto out_free_id; } - atomic_set(&mnt->mnt_count, 1); +#ifdef CONFIG_SMP + mnt->mnt_pcp = alloc_percpu(struct mnt_pcp); + if (!mnt->mnt_pcp) + goto out_free_devname; + + atomic_set(&mnt->mnt_longrefs, 1); +#else + mnt->mnt_count = 1; + mnt->mnt_writers = 0; +#endif + INIT_LIST_HEAD(&mnt->mnt_hash); INIT_LIST_HEAD(&mnt->mnt_child); INIT_LIST_HEAD(&mnt->mnt_mounts); @@ -166,13 +234,6 @@ struct vfsmount *alloc_vfsmnt(const char *name) #ifdef CONFIG_FSNOTIFY INIT_HLIST_HEAD(&mnt->mnt_fsnotify_marks); #endif -#ifdef CONFIG_SMP - mnt->mnt_writers = alloc_percpu(int); - if (!mnt->mnt_writers) - goto out_free_devname; -#else - mnt->mnt_writers = 0; -#endif } return mnt; @@ -216,32 +277,32 @@ int __mnt_is_readonly(struct vfsmount *mnt) } EXPORT_SYMBOL_GPL(__mnt_is_readonly); -static inline void inc_mnt_writers(struct vfsmount *mnt) +static inline void mnt_inc_writers(struct vfsmount *mnt) { #ifdef CONFIG_SMP - (*per_cpu_ptr(mnt->mnt_writers, smp_processor_id()))++; + this_cpu_inc(mnt->mnt_pcp->mnt_writers); #else mnt->mnt_writers++; #endif } -static inline void dec_mnt_writers(struct vfsmount *mnt) +static inline void mnt_dec_writers(struct vfsmount *mnt) { #ifdef CONFIG_SMP - (*per_cpu_ptr(mnt->mnt_writers, smp_processor_id()))--; + this_cpu_dec(mnt->mnt_pcp->mnt_writers); #else mnt->mnt_writers--; #endif } -static unsigned int count_mnt_writers(struct vfsmount *mnt) +static unsigned int mnt_get_writers(struct vfsmount *mnt) { #ifdef CONFIG_SMP unsigned int count = 0; int cpu; for_each_possible_cpu(cpu) { - count += *per_cpu_ptr(mnt->mnt_writers, cpu); + count += per_cpu_ptr(mnt->mnt_pcp, cpu)->mnt_writers; } return count; @@ -273,9 +334,9 @@ int mnt_want_write(struct vfsmount *mnt) int ret = 0; preempt_disable(); - inc_mnt_writers(mnt); + mnt_inc_writers(mnt); /* - * The store to inc_mnt_writers must be visible before we pass + * The store to mnt_inc_writers must be visible before we pass * MNT_WRITE_HOLD loop below, so that the slowpath can see our * incremented count after it has set MNT_WRITE_HOLD. */ @@ -289,7 +350,7 @@ int mnt_want_write(struct vfsmount *mnt) */ smp_rmb(); if (__mnt_is_readonly(mnt)) { - dec_mnt_writers(mnt); + mnt_dec_writers(mnt); ret = -EROFS; goto out; } @@ -317,7 +378,7 @@ int mnt_clone_write(struct vfsmount *mnt) if (__mnt_is_readonly(mnt)) return -EROFS; preempt_disable(); - inc_mnt_writers(mnt); + mnt_inc_writers(mnt); preempt_enable(); return 0; } @@ -351,7 +412,7 @@ EXPORT_SYMBOL_GPL(mnt_want_write_file); void mnt_drop_write(struct vfsmount *mnt) { preempt_disable(); - dec_mnt_writers(mnt); + mnt_dec_writers(mnt); preempt_enable(); } EXPORT_SYMBOL_GPL(mnt_drop_write); @@ -384,7 +445,7 @@ static int mnt_make_readonly(struct vfsmount *mnt) * MNT_WRITE_HOLD, so it can't be decremented by another CPU while * we're counting up here. */ - if (count_mnt_writers(mnt) > 0) + if (mnt_get_writers(mnt) > 0) ret = -EBUSY; else mnt->mnt_flags |= MNT_READONLY; @@ -418,7 +479,7 @@ void free_vfsmnt(struct vfsmount *mnt) kfree(mnt->mnt_devname); mnt_free_id(mnt); #ifdef CONFIG_SMP - free_percpu(mnt->mnt_writers); + free_percpu(mnt->mnt_pcp); #endif kmem_cache_free(mnt_cache, mnt); } @@ -492,6 +553,27 @@ static void __touch_mnt_namespace(struct mnt_namespace *ns) } /* + * Clear dentry's mounted state if it has no remaining mounts. + * vfsmount_lock must be held for write. + */ +static void dentry_reset_mounted(struct vfsmount *mnt, struct dentry *dentry) +{ + unsigned u; + + for (u = 0; u < HASH_SIZE; u++) { + struct vfsmount *p; + + list_for_each_entry(p, &mount_hashtable[u], mnt_hash) { + if (p->mnt_mountpoint == dentry) + return; + } + } + spin_lock(&dentry->d_lock); + dentry->d_flags &= ~DCACHE_MOUNTED; + spin_unlock(&dentry->d_lock); +} + +/* * vfsmount lock must be held for write */ static void detach_mnt(struct vfsmount *mnt, struct path *old_path) @@ -502,7 +584,7 @@ static void detach_mnt(struct vfsmount *mnt, struct path *old_path) mnt->mnt_mountpoint = mnt->mnt_root; list_del_init(&mnt->mnt_child); list_del_init(&mnt->mnt_hash); - old_path->dentry->d_mounted--; + dentry_reset_mounted(old_path->mnt, old_path->dentry); } /* @@ -513,7 +595,9 @@ void mnt_set_mountpoint(struct vfsmount *mnt, struct dentry *dentry, { child_mnt->mnt_parent = mntget(mnt); child_mnt->mnt_mountpoint = dget(dentry); - dentry->d_mounted++; + spin_lock(&dentry->d_lock); + dentry->d_flags |= DCACHE_MOUNTED; + spin_unlock(&dentry->d_lock); } /* @@ -629,9 +713,10 @@ static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root, return NULL; } -static inline void __mntput(struct vfsmount *mnt) +static inline void mntfree(struct vfsmount *mnt) { struct super_block *sb = mnt->mnt_sb; + /* * This probably indicates that somebody messed * up a mnt_want/drop_write() pair. If this @@ -639,38 +724,123 @@ static inline void __mntput(struct vfsmount *mnt) * to make r/w->r/o transitions. */ /* - * atomic_dec_and_lock() used to deal with ->mnt_count decrements - * provides barriers, so count_mnt_writers() below is safe. AV + * The locking used to deal with mnt_count decrement provides barriers, + * so mnt_get_writers() below is safe. */ - WARN_ON(count_mnt_writers(mnt)); + WARN_ON(mnt_get_writers(mnt)); fsnotify_vfsmount_delete(mnt); dput(mnt->mnt_root); free_vfsmnt(mnt); deactivate_super(sb); } -void mntput_no_expire(struct vfsmount *mnt) -{ -repeat: - if (atomic_add_unless(&mnt->mnt_count, -1, 1)) - return; +#ifdef CONFIG_SMP +static inline void __mntput(struct vfsmount *mnt, int longrefs) +{ + if (!longrefs) { +put_again: + br_read_lock(vfsmount_lock); + if (likely(atomic_read(&mnt->mnt_longrefs))) { + mnt_dec_count(mnt); + br_read_unlock(vfsmount_lock); + return; + } + br_read_unlock(vfsmount_lock); + } else { + BUG_ON(!atomic_read(&mnt->mnt_longrefs)); + if (atomic_add_unless(&mnt->mnt_longrefs, -1, 1)) + return; + } + br_write_lock(vfsmount_lock); - if (!atomic_dec_and_test(&mnt->mnt_count)) { + if (!longrefs) + mnt_dec_count(mnt); + else + atomic_dec(&mnt->mnt_longrefs); + if (mnt_get_count(mnt)) { br_write_unlock(vfsmount_lock); return; } - if (likely(!mnt->mnt_pinned)) { + if (unlikely(mnt->mnt_pinned)) { + mnt_add_count(mnt, mnt->mnt_pinned + 1); + mnt->mnt_pinned = 0; br_write_unlock(vfsmount_lock); - __mntput(mnt); + acct_auto_close_mnt(mnt); + goto put_again; + } + br_write_unlock(vfsmount_lock); + mntfree(mnt); +} +#else +static inline void __mntput(struct vfsmount *mnt, int longrefs) +{ +put_again: + mnt_dec_count(mnt); + if (likely(mnt_get_count(mnt))) return; + br_write_lock(vfsmount_lock); + if (unlikely(mnt->mnt_pinned)) { + mnt_add_count(mnt, mnt->mnt_pinned + 1); + mnt->mnt_pinned = 0; + br_write_unlock(vfsmount_lock); + acct_auto_close_mnt(mnt); + goto put_again; } - atomic_add(mnt->mnt_pinned + 1, &mnt->mnt_count); - mnt->mnt_pinned = 0; br_write_unlock(vfsmount_lock); - acct_auto_close_mnt(mnt); - goto repeat; + mntfree(mnt); +} +#endif + +static void mntput_no_expire(struct vfsmount *mnt) +{ + __mntput(mnt, 0); +} + +void mntput(struct vfsmount *mnt) +{ + if (mnt) { + /* avoid cacheline pingpong, hope gcc doesn't get "smart" */ + if (unlikely(mnt->mnt_expiry_mark)) + mnt->mnt_expiry_mark = 0; + __mntput(mnt, 0); + } +} +EXPORT_SYMBOL(mntput); + +struct vfsmount *mntget(struct vfsmount *mnt) +{ + if (mnt) + mnt_inc_count(mnt); + return mnt; } -EXPORT_SYMBOL(mntput_no_expire); +EXPORT_SYMBOL(mntget); + +void mntput_long(struct vfsmount *mnt) +{ +#ifdef CONFIG_SMP + if (mnt) { + /* avoid cacheline pingpong, hope gcc doesn't get "smart" */ + if (unlikely(mnt->mnt_expiry_mark)) + mnt->mnt_expiry_mark = 0; + __mntput(mnt, 1); + } +#else + mntput(mnt); +#endif +} +EXPORT_SYMBOL(mntput_long); + +struct vfsmount *mntget_long(struct vfsmount *mnt) +{ +#ifdef CONFIG_SMP + if (mnt) + atomic_inc(&mnt->mnt_longrefs); + return mnt; +#else + return mntget(mnt); +#endif +} +EXPORT_SYMBOL(mntget_long); void mnt_pin(struct vfsmount *mnt) { @@ -678,19 +848,17 @@ void mnt_pin(struct vfsmount *mnt) mnt->mnt_pinned++; br_write_unlock(vfsmount_lock); } - EXPORT_SYMBOL(mnt_pin); void mnt_unpin(struct vfsmount *mnt) { br_write_lock(vfsmount_lock); if (mnt->mnt_pinned) { - atomic_inc(&mnt->mnt_count); + mnt_inc_count(mnt); mnt->mnt_pinned--; } br_write_unlock(vfsmount_lock); } - EXPORT_SYMBOL(mnt_unpin); static inline void mangle(struct seq_file *m, const char *s) @@ -985,12 +1153,13 @@ int may_umount_tree(struct vfsmount *mnt) int minimum_refs = 0; struct vfsmount *p; - br_read_lock(vfsmount_lock); + /* write lock needed for mnt_get_count */ + br_write_lock(vfsmount_lock); for (p = mnt; p; p = next_mnt(p, mnt)) { - actual_refs += atomic_read(&p->mnt_count); + actual_refs += mnt_get_count(p); minimum_refs += 2; } - br_read_unlock(vfsmount_lock); + br_write_unlock(vfsmount_lock); if (actual_refs > minimum_refs) return 0; @@ -1017,10 +1186,10 @@ int may_umount(struct vfsmount *mnt) { int ret = 1; down_read(&namespace_sem); - br_read_lock(vfsmount_lock); + br_write_lock(vfsmount_lock); if (propagate_mount_busy(mnt, 2)) ret = 0; - br_read_unlock(vfsmount_lock); + br_write_unlock(vfsmount_lock); up_read(&namespace_sem); return ret; } @@ -1047,7 +1216,7 @@ void release_mounts(struct list_head *head) dput(dentry); mntput(m); } - mntput(mnt); + mntput_long(mnt); } } @@ -1073,7 +1242,7 @@ void umount_tree(struct vfsmount *mnt, int propagate, struct list_head *kill) list_del_init(&p->mnt_child); if (p->mnt_parent != p) { p->mnt_parent->mnt_ghosts++; - p->mnt_mountpoint->d_mounted--; + dentry_reset_mounted(p->mnt_parent, p->mnt_mountpoint); } change_mnt_propagation(p, MS_PRIVATE); } @@ -1102,8 +1271,16 @@ static int do_umount(struct vfsmount *mnt, int flags) flags & (MNT_FORCE | MNT_DETACH)) return -EINVAL; - if (atomic_read(&mnt->mnt_count) != 2) + /* + * probably don't strictly need the lock here if we examined + * all race cases, but it's a slowpath. + */ + br_write_lock(vfsmount_lock); + if (mnt_get_count(mnt) != 2) { + br_write_lock(vfsmount_lock); return -EBUSY; + } + br_write_unlock(vfsmount_lock); if (!xchg(&mnt->mnt_expiry_mark, 1)) return -EAGAIN; @@ -1792,7 +1969,7 @@ int do_add_mount(struct vfsmount *newmnt, struct path *path, unlock: up_write(&namespace_sem); - mntput(newmnt); + mntput_long(newmnt); return err; } @@ -2125,11 +2302,11 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, if (fs) { if (p == fs->root.mnt) { rootmnt = p; - fs->root.mnt = mntget(q); + fs->root.mnt = mntget_long(q); } if (p == fs->pwd.mnt) { pwdmnt = p; - fs->pwd.mnt = mntget(q); + fs->pwd.mnt = mntget_long(q); } } p = next_mnt(p, mnt_ns->root); @@ -2138,9 +2315,9 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, up_write(&namespace_sem); if (rootmnt) - mntput(rootmnt); + mntput_long(rootmnt); if (pwdmnt) - mntput(pwdmnt); + mntput_long(pwdmnt); return new_ns; } @@ -2327,6 +2504,7 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, touch_mnt_namespace(current->nsproxy->mnt_ns); br_write_unlock(vfsmount_lock); chroot_fs_refs(&root, &new); + error = 0; path_put(&root_parent); path_put(&parent_path); @@ -2353,6 +2531,7 @@ static void __init init_mount_tree(void) mnt = do_kern_mount("rootfs", 0, "rootfs", NULL); if (IS_ERR(mnt)) panic("Can't create rootfs"); + ns = create_mnt_ns(mnt); if (IS_ERR(ns)) panic("Can't allocate initial namespace"); diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c index f22b12e7d33..28f136d4aae 100644 --- a/fs/ncpfs/dir.c +++ b/fs/ncpfs/dir.c @@ -17,6 +17,7 @@ #include <linux/kernel.h> #include <linux/vmalloc.h> #include <linux/mm.h> +#include <linux/namei.h> #include <asm/uaccess.h> #include <asm/byteorder.h> @@ -74,9 +75,12 @@ const struct inode_operations ncp_dir_inode_operations = * Dentry operations routines */ static int ncp_lookup_validate(struct dentry *, struct nameidata *); -static int ncp_hash_dentry(struct dentry *, struct qstr *); -static int ncp_compare_dentry (struct dentry *, struct qstr *, struct qstr *); -static int ncp_delete_dentry(struct dentry *); +static int ncp_hash_dentry(const struct dentry *, const struct inode *, + struct qstr *); +static int ncp_compare_dentry(const struct dentry *, const struct inode *, + const struct dentry *, const struct inode *, + unsigned int, const char *, const struct qstr *); +static int ncp_delete_dentry(const struct dentry *); static const struct dentry_operations ncp_dentry_operations = { @@ -113,10 +117,10 @@ static inline int ncp_preserve_entry_case(struct inode *i, __u32 nscreator) #define ncp_preserve_case(i) (ncp_namespace(i) != NW_NS_DOS) -static inline int ncp_case_sensitive(struct dentry *dentry) +static inline int ncp_case_sensitive(const struct inode *i) { #ifdef CONFIG_NCPFS_NFS_NS - return ncp_namespace(dentry->d_inode) == NW_NS_NFS; + return ncp_namespace(i) == NW_NS_NFS; #else return 0; #endif /* CONFIG_NCPFS_NFS_NS */ @@ -127,14 +131,16 @@ static inline int ncp_case_sensitive(struct dentry *dentry) * is case-sensitive. */ static int -ncp_hash_dentry(struct dentry *dentry, struct qstr *this) +ncp_hash_dentry(const struct dentry *dentry, const struct inode *inode, + struct qstr *this) { - if (!ncp_case_sensitive(dentry)) { + if (!ncp_case_sensitive(inode)) { + struct super_block *sb = dentry->d_sb; struct nls_table *t; unsigned long hash; int i; - t = NCP_IO_TABLE(dentry); + t = NCP_IO_TABLE(sb); hash = init_name_hash(); for (i=0; i<this->len ; i++) hash = partial_name_hash(ncp_tolower(t, this->name[i]), @@ -145,15 +151,17 @@ ncp_hash_dentry(struct dentry *dentry, struct qstr *this) } static int -ncp_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b) +ncp_compare_dentry(const struct dentry *parent, const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - if (a->len != b->len) + if (len != name->len) return 1; - if (ncp_case_sensitive(dentry)) - return strncmp(a->name, b->name, a->len); + if (ncp_case_sensitive(pinode)) + return strncmp(str, name->name, len); - return ncp_strnicmp(NCP_IO_TABLE(dentry), a->name, b->name, a->len); + return ncp_strnicmp(NCP_IO_TABLE(pinode->i_sb), str, name->name, len); } /* @@ -162,7 +170,7 @@ ncp_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b) * Closing files can be safely postponed until iput() - it's done there anyway. */ static int -ncp_delete_dentry(struct dentry * dentry) +ncp_delete_dentry(const struct dentry * dentry) { struct inode *inode = dentry->d_inode; @@ -301,6 +309,9 @@ ncp_lookup_validate(struct dentry *dentry, struct nameidata *nd) int res, val = 0, len; __u8 __name[NCP_MAXPATHLEN + 1]; + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + parent = dget_parent(dentry); dir = parent->d_inode; @@ -384,21 +395,21 @@ ncp_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos) } /* If a pointer is invalid, we search the dentry. */ - spin_lock(&dcache_lock); + spin_lock(&parent->d_lock); next = parent->d_subdirs.next; while (next != &parent->d_subdirs) { dent = list_entry(next, struct dentry, d_u.d_child); if ((unsigned long)dent->d_fsdata == fpos) { if (dent->d_inode) - dget_locked(dent); + dget(dent); else dent = NULL; - spin_unlock(&dcache_lock); + spin_unlock(&parent->d_lock); goto out; } next = next->next; } - spin_unlock(&dcache_lock); + spin_unlock(&parent->d_lock); return NULL; out: @@ -592,7 +603,7 @@ ncp_fill_cache(struct file *filp, void *dirent, filldir_t filldir, qname.hash = full_name_hash(qname.name, qname.len); if (dentry->d_op && dentry->d_op->d_hash) - if (dentry->d_op->d_hash(dentry, &qname) != 0) + if (dentry->d_op->d_hash(dentry, dentry->d_inode, &qname) != 0) goto end_advance; newdent = d_lookup(dentry, &qname); @@ -611,35 +622,12 @@ ncp_fill_cache(struct file *filp, void *dirent, filldir_t filldir, shrink_dcache_parent(newdent); /* - * It is not as dangerous as it looks. NetWare's OS2 namespace is - * case preserving yet case insensitive. So we update dentry's name - * as received from server. We found dentry via d_lookup with our - * hash, so we know that hash does not change, and so replacing name - * should be reasonably safe. + * NetWare's OS2 namespace is case preserving yet case + * insensitive. So we update dentry's name as received from + * server. Parent dir's i_mutex is locked because we're in + * readdir. */ - if (qname.len == newdent->d_name.len && - memcmp(newdent->d_name.name, qname.name, newdent->d_name.len)) { - struct inode *inode = newdent->d_inode; - - /* - * Inside ncpfs all uses of d_name are either for debugging, - * or on functions which acquire inode mutex (mknod, creat, - * lookup). So grab i_mutex here, to be sure. d_path - * uses dcache_lock when generating path, so we should too. - * And finally d_compare is protected by dentry's d_lock, so - * here we go. - */ - if (inode) - mutex_lock(&inode->i_mutex); - spin_lock(&dcache_lock); - spin_lock(&newdent->d_lock); - memcpy((char *) newdent->d_name.name, qname.name, - newdent->d_name.len); - spin_unlock(&newdent->d_lock); - spin_unlock(&dcache_lock); - if (inode) - mutex_unlock(&inode->i_mutex); - } + dentry_update_name_case(newdent, &qname); } if (!newdent->d_inode) { @@ -649,7 +637,7 @@ ncp_fill_cache(struct file *filp, void *dirent, filldir_t filldir, entry->ino = iunique(dir->i_sb, 2); inode = ncp_iget(dir->i_sb, entry); if (inode) { - newdent->d_op = &ncp_dentry_operations; + d_set_d_op(newdent, &ncp_dentry_operations); d_instantiate(newdent, inode); if (!hashed) d_rehash(newdent); @@ -657,7 +645,7 @@ ncp_fill_cache(struct file *filp, void *dirent, filldir_t filldir, } else { struct inode *inode = newdent->d_inode; - mutex_lock(&inode->i_mutex); + mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD); ncp_update_inode2(inode, entry); mutex_unlock(&inode->i_mutex); } @@ -905,7 +893,7 @@ static struct dentry *ncp_lookup(struct inode *dir, struct dentry *dentry, struc if (inode) { ncp_new_dentry(dentry); add_entry: - dentry->d_op = &ncp_dentry_operations; + d_set_d_op(dentry, &ncp_dentry_operations); d_add(dentry, inode); error = 0; } diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c index 8fb93b604e7..9531c052d7a 100644 --- a/fs/ncpfs/inode.c +++ b/fs/ncpfs/inode.c @@ -29,6 +29,7 @@ #include <linux/vfs.h> #include <linux/mount.h> #include <linux/seq_file.h> +#include <linux/namei.h> #include <linux/ncp_fs.h> @@ -58,11 +59,18 @@ static struct inode *ncp_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void ncp_destroy_inode(struct inode *inode) +static void ncp_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(ncp_inode_cachep, NCP_FINFO(inode)); } +static void ncp_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, ncp_i_callback); +} + static void init_once(void *foo) { struct ncp_inode_info *ei = (struct ncp_inode_info *) foo; @@ -710,7 +718,7 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent) sb->s_root = d_alloc_root(root_inode); if (!sb->s_root) goto out_no_root; - sb->s_root->d_op = &ncp_root_dentry_operations; + d_set_d_op(sb->s_root, &ncp_root_dentry_operations); return 0; out_no_root: diff --git a/fs/ncpfs/ncplib_kernel.h b/fs/ncpfs/ncplib_kernel.h index 3c57eca634c..1220df75ff2 100644 --- a/fs/ncpfs/ncplib_kernel.h +++ b/fs/ncpfs/ncplib_kernel.h @@ -135,7 +135,7 @@ int ncp__vol2io(struct ncp_server *, unsigned char *, unsigned int *, const unsigned char *, unsigned int, int); #define NCP_ESC ':' -#define NCP_IO_TABLE(dentry) (NCP_SERVER((dentry)->d_inode)->nls_io) +#define NCP_IO_TABLE(sb) (NCP_SBP(sb)->nls_io) #define ncp_tolower(t, c) nls_tolower(t, c) #define ncp_toupper(t, c) nls_toupper(t, c) #define ncp_strnicmp(t, s1, s2, len) \ @@ -150,15 +150,15 @@ int ncp__io2vol(unsigned char *, unsigned int *, int ncp__vol2io(unsigned char *, unsigned int *, const unsigned char *, unsigned int, int); -#define NCP_IO_TABLE(dentry) NULL +#define NCP_IO_TABLE(sb) NULL #define ncp_tolower(t, c) tolower(c) #define ncp_toupper(t, c) toupper(c) #define ncp_io2vol(S,m,i,n,k,U) ncp__io2vol(m,i,n,k,U) #define ncp_vol2io(S,m,i,n,k,U) ncp__vol2io(m,i,n,k,U) -static inline int ncp_strnicmp(struct nls_table *t, const unsigned char *s1, - const unsigned char *s2, int len) +static inline int ncp_strnicmp(const struct nls_table *t, + const unsigned char *s1, const unsigned char *s2, int len) { while (len--) { if (tolower(*s1++) != tolower(*s2++)) @@ -193,7 +193,7 @@ ncp_renew_dentries(struct dentry *parent) struct list_head *next; struct dentry *dentry; - spin_lock(&dcache_lock); + spin_lock(&parent->d_lock); next = parent->d_subdirs.next; while (next != &parent->d_subdirs) { dentry = list_entry(next, struct dentry, d_u.d_child); @@ -205,7 +205,7 @@ ncp_renew_dentries(struct dentry *parent) next = next->next; } - spin_unlock(&dcache_lock); + spin_unlock(&parent->d_lock); } static inline void @@ -215,7 +215,7 @@ ncp_invalidate_dircache_entries(struct dentry *parent) struct list_head *next; struct dentry *dentry; - spin_lock(&dcache_lock); + spin_lock(&parent->d_lock); next = parent->d_subdirs.next; while (next != &parent->d_subdirs) { dentry = list_entry(next, struct dentry, d_u.d_child); @@ -223,7 +223,7 @@ ncp_invalidate_dircache_entries(struct dentry *parent) ncp_age_dentry(server, dentry); next = next->next; } - spin_unlock(&dcache_lock); + spin_unlock(&parent->d_lock); } struct ncp_cache_head { diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 996dd8989a9..d33da530097 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -438,7 +438,7 @@ void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry) if (dentry == NULL) return; - dentry->d_op = NFS_PROTO(dir)->dentry_ops; + d_set_d_op(dentry, NFS_PROTO(dir)->dentry_ops); inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr); if (IS_ERR(inode)) goto out; @@ -938,7 +938,8 @@ static int nfs_check_verifier(struct inode *dir, struct dentry *dentry) * component of the path. * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT. */ -static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask) +static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, + unsigned int mask) { if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT)) return 0; @@ -1018,7 +1019,7 @@ int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, * If the parent directory is seen to have changed, we throw out the * cached dentry and do a new lookup. */ -static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd) +static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd) { struct inode *dir; struct inode *inode; @@ -1027,6 +1028,9 @@ static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd) struct nfs_fattr *fattr = NULL; int error; + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + parent = dget_parent(dentry); dir = parent->d_inode; nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE); @@ -1117,7 +1121,7 @@ out_error: /* * This is called from dput() when d_count is going to 0. */ -static int nfs_dentry_delete(struct dentry *dentry) +static int nfs_dentry_delete(const struct dentry *dentry) { dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n", dentry->d_parent->d_name.name, dentry->d_name.name, @@ -1188,7 +1192,7 @@ static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, stru if (dentry->d_name.len > NFS_SERVER(dir)->namelen) goto out; - dentry->d_op = NFS_PROTO(dir)->dentry_ops; + d_set_d_op(dentry, NFS_PROTO(dir)->dentry_ops); /* * If we're doing an exclusive create, optimize away the lookup @@ -1333,7 +1337,7 @@ static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry res = ERR_PTR(-ENAMETOOLONG); goto out; } - dentry->d_op = NFS_PROTO(dir)->dentry_ops; + d_set_d_op(dentry, NFS_PROTO(dir)->dentry_ops); /* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash * the dentry. */ @@ -1718,11 +1722,9 @@ static int nfs_unlink(struct inode *dir, struct dentry *dentry) dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); - if (atomic_read(&dentry->d_count) > 1) { + if (dentry->d_count > 1) { spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); /* Start asynchronous writeout of the inode */ write_inode_now(dentry->d_inode, 0); error = nfs_sillyrename(dir, dentry); @@ -1733,7 +1735,6 @@ static int nfs_unlink(struct inode *dir, struct dentry *dentry) need_rehash = 1; } spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); error = nfs_safe_remove(dentry); if (!error || error == -ENOENT) { nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); @@ -1868,7 +1869,7 @@ static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n", old_dentry->d_parent->d_name.name, old_dentry->d_name.name, new_dentry->d_parent->d_name.name, new_dentry->d_name.name, - atomic_read(&new_dentry->d_count)); + new_dentry->d_count); /* * For non-directories, check whether the target is busy and if so, @@ -1886,7 +1887,7 @@ static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, rehash = new_dentry; } - if (atomic_read(&new_dentry->d_count) > 2) { + if (new_dentry->d_count > 2) { int err; /* copy the target dentry's name */ @@ -2188,11 +2189,14 @@ int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags) return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags)); } -int nfs_permission(struct inode *inode, int mask) +int nfs_permission(struct inode *inode, int mask, unsigned int flags) { struct rpc_cred *cred; int res = 0; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + nfs_inc_stats(inode, NFSIOS_VFSACCESS); if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) @@ -2240,7 +2244,7 @@ out: out_notsup: res = nfs_revalidate_inode(NFS_SERVER(inode), inode); if (res == 0) - res = generic_permission(inode, mask, NULL); + res = generic_permission(inode, mask, flags, NULL); goto out; } diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c index ac7b814ce16..5596c6a2881 100644 --- a/fs/nfs/getroot.c +++ b/fs/nfs/getroot.c @@ -63,9 +63,11 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i * This again causes shrink_dcache_for_umount_subtree() to * Oops, since the test for IS_ROOT() will fail. */ - spin_lock(&dcache_lock); + spin_lock(&sb->s_root->d_inode->i_lock); + spin_lock(&sb->s_root->d_lock); list_del_init(&sb->s_root->d_alias); - spin_unlock(&dcache_lock); + spin_unlock(&sb->s_root->d_lock); + spin_unlock(&sb->s_root->d_inode->i_lock); } return 0; } @@ -119,7 +121,7 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh) security_d_instantiate(ret, inode); if (ret->d_op == NULL) - ret->d_op = server->nfs_client->rpc_ops->dentry_ops; + d_set_d_op(ret, server->nfs_client->rpc_ops->dentry_ops); out: nfs_free_fattr(fsinfo.fattr); return ret; @@ -226,7 +228,7 @@ struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh) security_d_instantiate(ret, inode); if (ret->d_op == NULL) - ret->d_op = server->nfs_client->rpc_ops->dentry_ops; + d_set_d_op(ret, server->nfs_client->rpc_ops->dentry_ops); out: nfs_free_fattr(fattr); diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index e67e31c7341..017daa3bed3 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -1438,11 +1438,18 @@ struct inode *nfs_alloc_inode(struct super_block *sb) return &nfsi->vfs_inode; } -void nfs_destroy_inode(struct inode *inode) +static void nfs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(nfs_inode_cachep, NFS_I(inode)); } +void nfs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, nfs_i_callback); +} + static inline void nfs4_init_once(struct nfs_inode *nfsi) { #ifdef CONFIG_NFS_V4 diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c index db6aa3673cf..74aaf3963c1 100644 --- a/fs/nfs/namespace.c +++ b/fs/nfs/namespace.c @@ -49,12 +49,17 @@ char *nfs_path(const char *base, const struct dentry *dentry, char *buffer, ssize_t buflen) { - char *end = buffer+buflen; + char *end; int namelen; + unsigned seq; +rename_retry: + end = buffer+buflen; *--end = '\0'; buflen--; - spin_lock(&dcache_lock); + + seq = read_seqbegin(&rename_lock); + rcu_read_lock(); while (!IS_ROOT(dentry) && dentry != droot) { namelen = dentry->d_name.len; buflen -= namelen + 1; @@ -65,7 +70,9 @@ char *nfs_path(const char *base, *--end = '/'; dentry = dentry->d_parent; } - spin_unlock(&dcache_lock); + rcu_read_unlock(); + if (read_seqretry(&rename_lock, seq)) + goto rename_retry; if (*end != '/') { if (--buflen < 0) goto Elong; @@ -82,7 +89,9 @@ char *nfs_path(const char *base, memcpy(end, base, namelen); return end; Elong_unlock: - spin_unlock(&dcache_lock); + rcu_read_unlock(); + if (read_seqretry(&rename_lock, seq)) + goto rename_retry; Elong: return ERR_PTR(-ENAMETOOLONG); } diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c index 7bdec853140..8fe9eb47a97 100644 --- a/fs/nfs/unlink.c +++ b/fs/nfs/unlink.c @@ -496,7 +496,7 @@ nfs_sillyrename(struct inode *dir, struct dentry *dentry) dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n", dentry->d_parent->d_name.name, dentry->d_name.name, - atomic_read(&dentry->d_count)); + dentry->d_count); nfs_inc_stats(dir, NFSIOS_SILLYRENAME); /* diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 184938fcff0..3a359023c9f 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1756,8 +1756,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, goto out_dput_new; if (svc_msnfs(ffhp) && - ((atomic_read(&odentry->d_count) > 1) - || (atomic_read(&ndentry->d_count) > 1))) { + ((odentry->d_count > 1) || (ndentry->d_count > 1))) { host_err = -EPERM; goto out_dput_new; } @@ -1843,7 +1842,7 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, if (type != S_IFDIR) { /* It's UNLINK */ #ifdef MSNFS if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && - (atomic_read(&rdentry->d_count) > 1)) { + (rdentry->d_count > 1)) { host_err = -EPERM; } else #endif diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index 71d4bc8464e..77b48c8fab1 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -785,15 +785,19 @@ out_err: return err; } -int nilfs_permission(struct inode *inode, int mask) +int nilfs_permission(struct inode *inode, int mask, unsigned int flags) { - struct nilfs_root *root = NILFS_I(inode)->i_root; + struct nilfs_root *root; + + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + root = NILFS_I(inode)->i_root; if ((mask & MAY_WRITE) && root && root->cno != NILFS_CPTREE_CURRENT_CNO) return -EROFS; /* snapshot is not writable */ - return generic_permission(inode, mask, NULL); + return generic_permission(inode, mask, flags, NULL); } int nilfs_load_inode_block(struct nilfs_sb_info *sbi, struct inode *inode, diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h index f7560da5a56..0ca98823db5 100644 --- a/fs/nilfs2/nilfs.h +++ b/fs/nilfs2/nilfs.h @@ -256,7 +256,7 @@ extern void nilfs_update_inode(struct inode *, struct buffer_head *); extern void nilfs_truncate(struct inode *); extern void nilfs_evict_inode(struct inode *); extern int nilfs_setattr(struct dentry *, struct iattr *); -int nilfs_permission(struct inode *inode, int mask); +int nilfs_permission(struct inode *inode, int mask, unsigned int flags); extern int nilfs_load_inode_block(struct nilfs_sb_info *, struct inode *, struct buffer_head **); extern int nilfs_inode_dirty(struct inode *); diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index f804d41ec9d..e2dcc9c733f 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -162,10 +162,13 @@ struct inode *nilfs_alloc_inode(struct super_block *sb) return &ii->vfs_inode; } -void nilfs_destroy_inode(struct inode *inode) +static void nilfs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); struct nilfs_mdt_info *mdi = NILFS_MDT(inode); + INIT_LIST_HEAD(&inode->i_dentry); + if (mdi) { kfree(mdi->mi_bgl); /* kfree(NULL) is safe */ kfree(mdi); @@ -173,6 +176,11 @@ void nilfs_destroy_inode(struct inode *inode) kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode)); } +void nilfs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, nilfs_i_callback); +} + static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag) { struct the_nilfs *nilfs = sbi->s_nilfs; @@ -838,7 +846,7 @@ static int nilfs_attach_snapshot(struct super_block *s, __u64 cno, static int nilfs_tree_was_touched(struct dentry *root_dentry) { - return atomic_read(&root_dentry->d_count) > 1; + return root_dentry->d_count > 1; } /** diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 20dc218707c..79b47cbb5cd 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -59,7 +59,7 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode) /* determine if the children should tell inode about their events */ watched = fsnotify_inode_watches_children(inode); - spin_lock(&dcache_lock); + spin_lock(&inode->i_lock); /* run all of the dentries associated with this inode. Since this is a * directory, there damn well better only be one item on this list */ list_for_each_entry(alias, &inode->i_dentry, d_alias) { @@ -68,19 +68,21 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode) /* run all of the children of the original inode and fix their * d_flags to indicate parental interest (their parent is the * original inode) */ + spin_lock(&alias->d_lock); list_for_each_entry(child, &alias->d_subdirs, d_u.d_child) { if (!child->d_inode) continue; - spin_lock(&child->d_lock); + spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED); if (watched) child->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; else child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED; spin_unlock(&child->d_lock); } + spin_unlock(&alias->d_lock); } - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); } /* Notify this dentry's parent about a child's events. */ diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c index 93622b175fc..a627ed82c0a 100644 --- a/fs/ntfs/inode.c +++ b/fs/ntfs/inode.c @@ -332,6 +332,13 @@ struct inode *ntfs_alloc_big_inode(struct super_block *sb) return NULL; } +static void ntfs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(ntfs_big_inode_cache, NTFS_I(inode)); +} + void ntfs_destroy_big_inode(struct inode *inode) { ntfs_inode *ni = NTFS_I(inode); @@ -340,7 +347,7 @@ void ntfs_destroy_big_inode(struct inode *inode) BUG_ON(ni->page); if (!atomic_dec_and_test(&ni->count)) BUG(); - kmem_cache_free(ntfs_big_inode_cache, NTFS_I(inode)); + call_rcu(&inode->i_rcu, ntfs_i_callback); } static inline ntfs_inode *ntfs_alloc_extent_inode(void) diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c index 391915093fe..704f6b1742f 100644 --- a/fs/ocfs2/acl.c +++ b/fs/ocfs2/acl.c @@ -291,13 +291,17 @@ static int ocfs2_set_acl(handle_t *handle, return ret; } -int ocfs2_check_acl(struct inode *inode, int mask) +int ocfs2_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); + struct ocfs2_super *osb; struct buffer_head *di_bh = NULL; struct posix_acl *acl; int ret = -EAGAIN; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + + osb = OCFS2_SB(inode->i_sb); if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL)) return ret; diff --git a/fs/ocfs2/acl.h b/fs/ocfs2/acl.h index 5c5d31f0585..4fe7c9cf4bf 100644 --- a/fs/ocfs2/acl.h +++ b/fs/ocfs2/acl.h @@ -26,7 +26,7 @@ struct ocfs2_acl_entry { __le32 e_id; }; -extern int ocfs2_check_acl(struct inode *, int); +extern int ocfs2_check_acl(struct inode *, int, unsigned int); extern int ocfs2_acl_chmod(struct inode *); extern int ocfs2_init_acl(handle_t *, struct inode *, struct inode *, struct buffer_head *, struct buffer_head *, diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c index 895532ac4d9..6d80ecc7834 100644 --- a/fs/ocfs2/dcache.c +++ b/fs/ocfs2/dcache.c @@ -52,9 +52,15 @@ void ocfs2_dentry_attach_gen(struct dentry *dentry) static int ocfs2_dentry_revalidate(struct dentry *dentry, struct nameidata *nd) { - struct inode *inode = dentry->d_inode; + struct inode *inode; int ret = 0; /* if all else fails, just return false */ - struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb); + struct ocfs2_super *osb; + + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + + inode = dentry->d_inode; + osb = OCFS2_SB(dentry->d_sb); mlog_entry("(0x%p, '%.*s')\n", dentry, dentry->d_name.len, dentry->d_name.name); @@ -169,23 +175,25 @@ struct dentry *ocfs2_find_local_alias(struct inode *inode, struct list_head *p; struct dentry *dentry = NULL; - spin_lock(&dcache_lock); - + spin_lock(&inode->i_lock); list_for_each(p, &inode->i_dentry) { dentry = list_entry(p, struct dentry, d_alias); + spin_lock(&dentry->d_lock); if (ocfs2_match_dentry(dentry, parent_blkno, skip_unhashed)) { mlog(0, "dentry found: %.*s\n", dentry->d_name.len, dentry->d_name.name); - dget_locked(dentry); + dget_dlock(dentry); + spin_unlock(&dentry->d_lock); break; } + spin_unlock(&dentry->d_lock); dentry = NULL; } - spin_unlock(&dcache_lock); + spin_unlock(&inode->i_lock); return dentry; } diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c index b2df490a19e..8c5c0eddc36 100644 --- a/fs/ocfs2/dlmfs/dlmfs.c +++ b/fs/ocfs2/dlmfs/dlmfs.c @@ -351,11 +351,18 @@ static struct inode *dlmfs_alloc_inode(struct super_block *sb) return &ip->ip_vfs_inode; } -static void dlmfs_destroy_inode(struct inode *inode) +static void dlmfs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(dlmfs_inode_cache, DLMFS_I(inode)); } +static void dlmfs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, dlmfs_i_callback); +} + static void dlmfs_evict_inode(struct inode *inode) { int status; diff --git a/fs/ocfs2/export.c b/fs/ocfs2/export.c index 19ad145d2af..6adafa57606 100644 --- a/fs/ocfs2/export.c +++ b/fs/ocfs2/export.c @@ -138,7 +138,7 @@ check_gen: result = d_obtain_alias(inode); if (!IS_ERR(result)) - result->d_op = &ocfs2_dentry_ops; + d_set_d_op(result, &ocfs2_dentry_ops); else mlog_errno(PTR_ERR(result)); @@ -176,7 +176,7 @@ static struct dentry *ocfs2_get_parent(struct dentry *child) parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0)); if (!IS_ERR(parent)) - parent->d_op = &ocfs2_dentry_ops; + d_set_d_op(parent, &ocfs2_dentry_ops); bail_unlock: ocfs2_inode_unlock(dir, 0); diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index f6cba566429..bdadbae0909 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -1307,10 +1307,13 @@ bail: return err; } -int ocfs2_permission(struct inode *inode, int mask) +int ocfs2_permission(struct inode *inode, int mask, unsigned int flags) { int ret; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + mlog_entry_void(); ret = ocfs2_inode_lock(inode, NULL, 0); @@ -1320,7 +1323,7 @@ int ocfs2_permission(struct inode *inode, int mask) goto out; } - ret = generic_permission(inode, mask, ocfs2_check_acl); + ret = generic_permission(inode, mask, flags, ocfs2_check_acl); ocfs2_inode_unlock(inode, 0); out: diff --git a/fs/ocfs2/file.h b/fs/ocfs2/file.h index 97bf761c9e7..f5afbbef670 100644 --- a/fs/ocfs2/file.h +++ b/fs/ocfs2/file.h @@ -61,7 +61,7 @@ int ocfs2_zero_extend(struct inode *inode, struct buffer_head *di_bh, int ocfs2_setattr(struct dentry *dentry, struct iattr *attr); int ocfs2_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat); -int ocfs2_permission(struct inode *inode, int mask); +int ocfs2_permission(struct inode *inode, int mask, unsigned int flags); int ocfs2_should_update_atime(struct inode *inode, struct vfsmount *vfsmnt); diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c index ff5744e1e36..d14cad6e2e4 100644 --- a/fs/ocfs2/namei.c +++ b/fs/ocfs2/namei.c @@ -147,7 +147,7 @@ static struct dentry *ocfs2_lookup(struct inode *dir, struct dentry *dentry, spin_unlock(&oi->ip_lock); bail_add: - dentry->d_op = &ocfs2_dentry_ops; + d_set_d_op(dentry, &ocfs2_dentry_ops); ret = d_splice_alias(inode, dentry); if (inode) { @@ -415,7 +415,7 @@ static int ocfs2_mknod(struct inode *dir, mlog_errno(status); goto leave; } - dentry->d_op = &ocfs2_dentry_ops; + d_set_d_op(dentry, &ocfs2_dentry_ops); status = ocfs2_add_entry(handle, dentry, inode, OCFS2_I(inode)->ip_blkno, parent_fe_bh, @@ -743,7 +743,7 @@ static int ocfs2_link(struct dentry *old_dentry, } ihold(inode); - dentry->d_op = &ocfs2_dentry_ops; + d_set_d_op(dentry, &ocfs2_dentry_ops); d_instantiate(dentry, inode); out_commit: @@ -1794,7 +1794,7 @@ static int ocfs2_symlink(struct inode *dir, mlog_errno(status); goto bail; } - dentry->d_op = &ocfs2_dentry_ops; + d_set_d_op(dentry, &ocfs2_dentry_ops); status = ocfs2_add_entry(handle, dentry, inode, le64_to_cpu(fe->i_blkno), parent_fe_bh, @@ -2459,7 +2459,7 @@ int ocfs2_mv_orphaned_inode_to_new(struct inode *dir, goto out_commit; } - dentry->d_op = &ocfs2_dentry_ops; + d_set_d_op(dentry, &ocfs2_dentry_ops); d_instantiate(dentry, inode); status = 0; out_commit: diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index cfeab7ce369..17ff46fa8a1 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -569,11 +569,18 @@ static struct inode *ocfs2_alloc_inode(struct super_block *sb) return &oi->vfs_inode; } -static void ocfs2_destroy_inode(struct inode *inode) +static void ocfs2_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(ocfs2_inode_cachep, OCFS2_I(inode)); } +static void ocfs2_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, ocfs2_i_callback); +} + static unsigned long long ocfs2_max_file_offset(unsigned int bbits, unsigned int cbits) { diff --git a/fs/openpromfs/inode.c b/fs/openpromfs/inode.c index 911e61f348f..a2a5bff774e 100644 --- a/fs/openpromfs/inode.c +++ b/fs/openpromfs/inode.c @@ -343,11 +343,18 @@ static struct inode *openprom_alloc_inode(struct super_block *sb) return &oi->vfs_inode; } -static void openprom_destroy_inode(struct inode *inode) +static void openprom_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(op_inode_cachep, OP_I(inode)); } +static void openprom_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, openprom_i_callback); +} + static struct inode *openprom_iget(struct super_block *sb, ino_t ino) { struct inode *inode; diff --git a/fs/pipe.c b/fs/pipe.c index 04629f36e39..68f1f8e4e23 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -999,12 +999,12 @@ struct file *create_write_pipe(int flags) goto err; err = -ENOMEM; - path.dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &name); + path.dentry = d_alloc_pseudo(pipe_mnt->mnt_sb, &name); if (!path.dentry) goto err_inode; path.mnt = mntget(pipe_mnt); - path.dentry->d_op = &pipefs_dentry_operations; + d_set_d_op(path.dentry, &pipefs_dentry_operations); d_instantiate(path.dentry, inode); err = -ENFILE; @@ -1253,6 +1253,10 @@ out: return ret; } +static const struct super_operations pipefs_ops = { + .destroy_inode = free_inode_nonrcu, +}; + /* * pipefs should _never_ be mounted by userland - too much of security hassle, * no real gain from having the whole whorehouse mounted. So we don't need @@ -1262,7 +1266,7 @@ out: static struct dentry *pipefs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { - return mount_pseudo(fs_type, "pipe:", NULL, PIPEFS_MAGIC); + return mount_pseudo(fs_type, "pipe:", &pipefs_ops, PIPEFS_MAGIC); } static struct file_system_type pipe_fs_type = { @@ -1288,7 +1292,7 @@ static int __init init_pipe_fs(void) static void __exit exit_pipe_fs(void) { unregister_filesystem(&pipe_fs_type); - mntput(pipe_mnt); + mntput_long(pipe_mnt); } fs_initcall(init_pipe_fs); diff --git a/fs/pnode.c b/fs/pnode.c index 8066b8dd748..d42514e3238 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -288,7 +288,7 @@ out: */ static inline int do_refcount_check(struct vfsmount *mnt, int count) { - int mycount = atomic_read(&mnt->mnt_count) - mnt->mnt_ghosts; + int mycount = mnt_get_count(mnt) - mnt->mnt_ghosts; return (mycount > count); } @@ -300,7 +300,7 @@ static inline int do_refcount_check(struct vfsmount *mnt, int count) * Check if any of these mounts that **do not have submounts** * have more references than 'refcnt'. If so return busy. * - * vfsmount lock must be held for read or write + * vfsmount lock must be held for write */ int propagate_mount_busy(struct vfsmount *mnt, int refcnt) { diff --git a/fs/proc/base.c b/fs/proc/base.c index 08cba2c3b61..b20962c71a5 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1795,10 +1795,16 @@ static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat */ static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) { - struct inode *inode = dentry->d_inode; - struct task_struct *task = get_proc_task(inode); + struct inode *inode; + struct task_struct *task; const struct cred *cred; + if (nd && nd->flags & LOOKUP_RCU) + return -ECHILD; + + inode = dentry->d_inode; + task = get_proc_task(inode); + if (task) { if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) || task_dumpable(task)) { @@ -1820,7 +1826,7 @@ static int pid_revalidate(struct dentry *dentry, struct nameidata *nd) return 0; } -static int pid_delete_dentry(struct dentry * dentry) +static int pid_delete_dentry(const struct dentry * dentry) { /* Is the task we represent dead? * If so, then don't put the dentry on the lru list, @@ -1964,12 +1970,19 @@ static int proc_fd_link(struct inode *inode, struct path *path) static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd) { - struct inode *inode = dentry->d_inode; - struct task_struct *task = get_proc_task(inode); - int fd = proc_fd(inode); + struct inode *inode; + struct task_struct *task; + int fd; struct files_struct *files; const struct cred *cred; + if (nd && nd->flags & LOOKUP_RCU) + return -ECHILD; + + inode = dentry->d_inode; + task = get_proc_task(inode); + fd = proc_fd(inode); + if (task) { files = get_files_struct(task); if (files) { @@ -2045,7 +2058,7 @@ static struct dentry *proc_fd_instantiate(struct inode *dir, inode->i_op = &proc_pid_link_inode_operations; inode->i_size = 64; ei->op.proc_get_link = proc_fd_link; - dentry->d_op = &tid_fd_dentry_operations; + d_set_d_op(dentry, &tid_fd_dentry_operations); d_add(dentry, inode); /* Close the race of the process dying before we return the dentry */ if (tid_fd_revalidate(dentry, NULL)) @@ -2177,11 +2190,13 @@ static const struct file_operations proc_fd_operations = { * /proc/pid/fd needs a special permission handler so that a process can still * access /proc/self/fd after it has executed a setuid(). */ -static int proc_fd_permission(struct inode *inode, int mask) +static int proc_fd_permission(struct inode *inode, int mask, unsigned int flags) { int rv; - rv = generic_permission(inode, mask, NULL); + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + rv = generic_permission(inode, mask, flags, NULL); if (rv == 0) return 0; if (task_pid(current) == proc_pid(inode)) @@ -2213,7 +2228,7 @@ static struct dentry *proc_fdinfo_instantiate(struct inode *dir, ei->fd = fd; inode->i_mode = S_IFREG | S_IRUSR; inode->i_fop = &proc_fdinfo_file_operations; - dentry->d_op = &tid_fd_dentry_operations; + d_set_d_op(dentry, &tid_fd_dentry_operations); d_add(dentry, inode); /* Close the race of the process dying before we return the dentry */ if (tid_fd_revalidate(dentry, NULL)) @@ -2272,7 +2287,7 @@ static struct dentry *proc_pident_instantiate(struct inode *dir, if (p->fop) inode->i_fop = p->fop; ei->op = p->op; - dentry->d_op = &pid_dentry_operations; + d_set_d_op(dentry, &pid_dentry_operations); d_add(dentry, inode); /* Close the race of the process dying before we return the dentry */ if (pid_revalidate(dentry, NULL)) @@ -2639,8 +2654,14 @@ static const struct pid_entry proc_base_stuff[] = { */ static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) { - struct inode *inode = dentry->d_inode; - struct task_struct *task = get_proc_task(inode); + struct inode *inode; + struct task_struct *task; + + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + + inode = dentry->d_inode; + task = get_proc_task(inode); if (task) { put_task_struct(task); return 1; @@ -2691,7 +2712,7 @@ static struct dentry *proc_base_instantiate(struct inode *dir, if (p->fop) inode->i_fop = p->fop; ei->op = p->op; - dentry->d_op = &proc_base_dentry_operations; + d_set_d_op(dentry, &proc_base_dentry_operations); d_add(dentry, inode); error = NULL; out: @@ -3005,7 +3026,7 @@ static struct dentry *proc_pid_instantiate(struct inode *dir, inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff)); - dentry->d_op = &pid_dentry_operations; + d_set_d_op(dentry, &pid_dentry_operations); d_add(dentry, inode); /* Close the race of the process dying before we return the dentry */ @@ -3248,7 +3269,7 @@ static struct dentry *proc_task_instantiate(struct inode *dir, inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff, ARRAY_SIZE(tid_base_stuff)); - dentry->d_op = &pid_dentry_operations; + d_set_d_op(dentry, &pid_dentry_operations); d_add(dentry, inode); /* Close the race of the process dying before we return the dentry */ diff --git a/fs/proc/generic.c b/fs/proc/generic.c index dd29f033766..f766be29d2c 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -400,7 +400,7 @@ static const struct inode_operations proc_link_inode_operations = { * smarter: we could keep a "volatile" flag in the * inode to indicate which ones to keep. */ -static int proc_delete_dentry(struct dentry * dentry) +static int proc_delete_dentry(const struct dentry * dentry) { return 1; } @@ -439,7 +439,7 @@ struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir, out_unlock: if (inode) { - dentry->d_op = &proc_dentry_operations; + d_set_d_op(dentry, &proc_dentry_operations); d_add(dentry, inode); return NULL; } diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 3ddb6068177..6bcb926b101 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -65,11 +65,18 @@ static struct inode *proc_alloc_inode(struct super_block *sb) return inode; } -static void proc_destroy_inode(struct inode *inode) +static void proc_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(proc_inode_cachep, PROC_I(inode)); } +static void proc_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, proc_i_callback); +} + static void init_once(void *foo) { struct proc_inode *ei = (struct proc_inode *) foo; diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index b652cb00906..09a1f92a34e 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -5,6 +5,7 @@ #include <linux/sysctl.h> #include <linux/proc_fs.h> #include <linux/security.h> +#include <linux/namei.h> #include "internal.h" static const struct dentry_operations proc_sys_dentry_operations; @@ -120,7 +121,7 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, goto out; err = NULL; - dentry->d_op = &proc_sys_dentry_operations; + d_set_d_op(dentry, &proc_sys_dentry_operations); d_add(dentry, inode); out: @@ -201,7 +202,7 @@ static int proc_sys_fill_cache(struct file *filp, void *dirent, dput(child); return -ENOMEM; } else { - child->d_op = &proc_sys_dentry_operations; + d_set_d_op(child, &proc_sys_dentry_operations); d_add(child, inode); } } else { @@ -294,7 +295,7 @@ out: return ret; } -static int proc_sys_permission(struct inode *inode, int mask) +static int proc_sys_permission(struct inode *inode, int mask,unsigned int flags) { /* * sysctl entries that are not writeable, @@ -304,6 +305,9 @@ static int proc_sys_permission(struct inode *inode, int mask) struct ctl_table *table; int error; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + /* Executable files are not allowed under /proc/sys/ */ if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) return -EACCES; @@ -389,23 +393,30 @@ static const struct inode_operations proc_sys_dir_operations = { static int proc_sys_revalidate(struct dentry *dentry, struct nameidata *nd) { + if (nd->flags & LOOKUP_RCU) + return -ECHILD; return !PROC_I(dentry->d_inode)->sysctl->unregistering; } -static int proc_sys_delete(struct dentry *dentry) +static int proc_sys_delete(const struct dentry *dentry) { return !!PROC_I(dentry->d_inode)->sysctl->unregistering; } -static int proc_sys_compare(struct dentry *dir, struct qstr *qstr, - struct qstr *name) +static int proc_sys_compare(const struct dentry *parent, + const struct inode *pinode, + const struct dentry *dentry, const struct inode *inode, + unsigned int len, const char *str, const struct qstr *name) { - struct dentry *dentry = container_of(qstr, struct dentry, d_name); - if (qstr->len != name->len) + /* Although proc doesn't have negative dentries, rcu-walk means + * that inode here can be NULL */ + if (!inode) + return 0; + if (name->len != len) return 1; - if (memcmp(qstr->name, name->name, name->len)) + if (memcmp(name->name, str, len)) return 1; - return !sysctl_is_seen(PROC_I(dentry->d_inode)->sysctl); + return !sysctl_is_seen(PROC_I(inode)->sysctl); } static const struct dentry_operations proc_sys_dentry_operations = { diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c index fcada42f1aa..e63b4171d58 100644 --- a/fs/qnx4/inode.c +++ b/fs/qnx4/inode.c @@ -425,11 +425,18 @@ static struct inode *qnx4_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void qnx4_destroy_inode(struct inode *inode) +static void qnx4_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode)); } +static void qnx4_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, qnx4_i_callback); +} + static void init_once(void *foo) { struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo; diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c index b243117b875..2575682a9ea 100644 --- a/fs/reiserfs/super.c +++ b/fs/reiserfs/super.c @@ -529,11 +529,18 @@ static struct inode *reiserfs_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void reiserfs_destroy_inode(struct inode *inode) +static void reiserfs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(reiserfs_inode_cachep, REISERFS_I(inode)); } +static void reiserfs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, reiserfs_i_callback); +} + static void init_once(void *foo) { struct reiserfs_inode_info *ei = (struct reiserfs_inode_info *)foo; diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c index 5d04a7828e7..3cfb2e93364 100644 --- a/fs/reiserfs/xattr.c +++ b/fs/reiserfs/xattr.c @@ -870,11 +870,14 @@ out: return err; } -static int reiserfs_check_acl(struct inode *inode, int mask) +static int reiserfs_check_acl(struct inode *inode, int mask, unsigned int flags) { struct posix_acl *acl; int error = -EAGAIN; /* do regular unix permission checks by default */ + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS); if (acl) { @@ -951,8 +954,10 @@ static int xattr_mount_check(struct super_block *s) return 0; } -int reiserfs_permission(struct inode *inode, int mask) +int reiserfs_permission(struct inode *inode, int mask, unsigned int flags) { + if (flags & IPERM_FLAG_RCU) + return -ECHILD; /* * We don't do permission checks on the internal objects. * Permissions are determined by the "owning" object. @@ -965,13 +970,16 @@ int reiserfs_permission(struct inode *inode, int mask) * Stat data v1 doesn't support ACLs. */ if (get_inode_sd_version(inode) != STAT_DATA_V1) - return generic_permission(inode, mask, reiserfs_check_acl); + return generic_permission(inode, mask, flags, + reiserfs_check_acl); #endif - return generic_permission(inode, mask, NULL); + return generic_permission(inode, mask, flags, NULL); } static int xattr_hide_revalidate(struct dentry *dentry, struct nameidata *nd) { + if (nd->flags & LOOKUP_RCU) + return -ECHILD; return -EPERM; } @@ -990,7 +998,7 @@ int reiserfs_lookup_privroot(struct super_block *s) strlen(PRIVROOT_NAME)); if (!IS_ERR(dentry)) { REISERFS_SB(s)->priv_root = dentry; - dentry->d_op = &xattr_lookup_poison_ops; + d_set_d_op(dentry, &xattr_lookup_poison_ops); if (dentry->d_inode) dentry->d_inode->i_flags |= S_PRIVATE; } else diff --git a/fs/romfs/super.c b/fs/romfs/super.c index 6647f90e55c..2305e3121cb 100644 --- a/fs/romfs/super.c +++ b/fs/romfs/super.c @@ -400,11 +400,18 @@ static struct inode *romfs_alloc_inode(struct super_block *sb) /* * return a spent inode to the slab cache */ -static void romfs_destroy_inode(struct inode *inode) +static void romfs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(romfs_inode_cachep, ROMFS_I(inode)); } +static void romfs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, romfs_i_callback); +} + /* * get filesystem statistics */ diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c index 24de30ba34c..20700b9f2b4 100644 --- a/fs/squashfs/super.c +++ b/fs/squashfs/super.c @@ -440,11 +440,18 @@ static struct inode *squashfs_alloc_inode(struct super_block *sb) } -static void squashfs_destroy_inode(struct inode *inode) +static void squashfs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(squashfs_inode_cachep, squashfs_i(inode)); } +static void squashfs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, squashfs_i_callback); +} + static struct file_system_type squashfs_fs_type = { .owner = THIS_MODULE, diff --git a/fs/super.c b/fs/super.c index ca696155cd9..823e061faa8 100644 --- a/fs/super.c +++ b/fs/super.c @@ -30,6 +30,7 @@ #include <linux/idr.h> #include <linux/mutex.h> #include <linux/backing-dev.h> +#include <linux/rculist_bl.h> #include "internal.h" @@ -71,7 +72,7 @@ static struct super_block *alloc_super(struct file_system_type *type) INIT_LIST_HEAD(&s->s_files); #endif INIT_LIST_HEAD(&s->s_instances); - INIT_HLIST_HEAD(&s->s_anon); + INIT_HLIST_BL_HEAD(&s->s_anon); INIT_LIST_HEAD(&s->s_inodes); INIT_LIST_HEAD(&s->s_dentry_lru); init_rwsem(&s->s_umount); @@ -1139,7 +1140,7 @@ static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype) return mnt; err: - mntput(mnt); + mntput_long(mnt); return ERR_PTR(err); } diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 7e54bac8c4b..ea9120a830d 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -231,7 +231,7 @@ void release_sysfs_dirent(struct sysfs_dirent * sd) goto repeat; } -static int sysfs_dentry_delete(struct dentry *dentry) +static int sysfs_dentry_delete(const struct dentry *dentry) { struct sysfs_dirent *sd = dentry->d_fsdata; return !!(sd->s_flags & SYSFS_FLAG_REMOVED); @@ -239,9 +239,13 @@ static int sysfs_dentry_delete(struct dentry *dentry) static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd) { - struct sysfs_dirent *sd = dentry->d_fsdata; + struct sysfs_dirent *sd; int is_dir; + if (nd->flags & LOOKUP_RCU) + return -ECHILD; + + sd = dentry->d_fsdata; mutex_lock(&sysfs_mutex); /* The sysfs dirent has been deleted */ @@ -701,7 +705,7 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, /* instantiate and hash dentry */ ret = d_find_alias(inode); if (!ret) { - dentry->d_op = &sysfs_dentry_ops; + d_set_d_op(dentry, &sysfs_dentry_ops); dentry->d_fsdata = sysfs_get(sd); d_add(dentry, inode); } else { diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index cffb1fd8ba3..30ac2734558 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -348,13 +348,18 @@ int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns, const cha return -ENOENT; } -int sysfs_permission(struct inode *inode, int mask) +int sysfs_permission(struct inode *inode, int mask, unsigned int flags) { - struct sysfs_dirent *sd = inode->i_private; + struct sysfs_dirent *sd; + + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + + sd = inode->i_private; mutex_lock(&sysfs_mutex); sysfs_refresh_inode(sd, inode); mutex_unlock(&sysfs_mutex); - return generic_permission(inode, mask, NULL); + return generic_permission(inode, mask, flags, NULL); } diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index d9be60a2e95..ffaaa816bfb 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -200,7 +200,7 @@ static inline void __sysfs_put(struct sysfs_dirent *sd) struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd); void sysfs_evict_inode(struct inode *inode); int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr); -int sysfs_permission(struct inode *inode, int mask); +int sysfs_permission(struct inode *inode, int mask, unsigned int flags); int sysfs_setattr(struct dentry *dentry, struct iattr *iattr); int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat); int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value, diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c index de44d067b9e..0630eb969a2 100644 --- a/fs/sysv/inode.c +++ b/fs/sysv/inode.c @@ -333,11 +333,18 @@ static struct inode *sysv_alloc_inode(struct super_block *sb) return &si->vfs_inode; } -static void sysv_destroy_inode(struct inode *inode) +static void sysv_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(sysv_inode_cachep, SYSV_I(inode)); } +static void sysv_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, sysv_i_callback); +} + static void init_once(void *p) { struct sysv_inode_info *si = (struct sysv_inode_info *)p; diff --git a/fs/sysv/namei.c b/fs/sysv/namei.c index 11e7f7d11cd..b5e68da2db3 100644 --- a/fs/sysv/namei.c +++ b/fs/sysv/namei.c @@ -27,7 +27,8 @@ static int add_nondir(struct dentry *dentry, struct inode *inode) return err; } -static int sysv_hash(struct dentry *dentry, struct qstr *qstr) +static int sysv_hash(const struct dentry *dentry, const struct inode *inode, + struct qstr *qstr) { /* Truncate the name in place, avoids having to define a compare function. */ @@ -47,7 +48,7 @@ static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, st struct inode * inode = NULL; ino_t ino; - dentry->d_op = dir->i_sb->s_root->d_op; + d_set_d_op(dentry, dir->i_sb->s_root->d_op); if (dentry->d_name.len > SYSV_NAMELEN) return ERR_PTR(-ENAMETOOLONG); ino = sysv_inode_by_name(dentry); diff --git a/fs/sysv/super.c b/fs/sysv/super.c index 3d9c62be0c1..76712aefc4a 100644 --- a/fs/sysv/super.c +++ b/fs/sysv/super.c @@ -346,7 +346,7 @@ static int complete_read_super(struct super_block *sb, int silent, int size) if (sbi->s_forced_ro) sb->s_flags |= MS_RDONLY; if (sbi->s_truncate) - sb->s_root->d_op = &sysv_dentry_operations; + d_set_d_op(sb->s_root, &sysv_dentry_operations); return 1; } diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index 91fac54c70e..6e11c2975dc 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -272,12 +272,20 @@ static struct inode *ubifs_alloc_inode(struct super_block *sb) return &ui->vfs_inode; }; +static void ubifs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + struct ubifs_inode *ui = ubifs_inode(inode); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(ubifs_inode_slab, ui); +} + static void ubifs_destroy_inode(struct inode *inode) { struct ubifs_inode *ui = ubifs_inode(inode); kfree(ui->data); - kmem_cache_free(ubifs_inode_slab, inode); + call_rcu(&inode->i_rcu, ubifs_i_callback); } /* diff --git a/fs/udf/super.c b/fs/udf/super.c index 4a5c7c61836..b539d53320f 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -139,11 +139,18 @@ static struct inode *udf_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void udf_destroy_inode(struct inode *inode) +static void udf_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(udf_inode_cachep, UDF_I(inode)); } +static void udf_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, udf_i_callback); +} + static void init_once(void *foo) { struct udf_inode_info *ei = (struct udf_inode_info *)foo; diff --git a/fs/ufs/super.c b/fs/ufs/super.c index 2c47daed56d..2c61ac5d4e4 100644 --- a/fs/ufs/super.c +++ b/fs/ufs/super.c @@ -1412,11 +1412,18 @@ static struct inode *ufs_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void ufs_destroy_inode(struct inode *inode) +static void ufs_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(ufs_inode_cachep, UFS_I(inode)); } +static void ufs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, ufs_i_callback); +} + static void init_once(void *foo) { struct ufs_inode_info *ei = (struct ufs_inode_info *) foo; diff --git a/fs/xfs/linux-2.6/xfs_acl.c b/fs/xfs/linux-2.6/xfs_acl.c index b2771862fd3..39f4f809bb6 100644 --- a/fs/xfs/linux-2.6/xfs_acl.c +++ b/fs/xfs/linux-2.6/xfs_acl.c @@ -219,12 +219,13 @@ xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl) } int -xfs_check_acl(struct inode *inode, int mask) +xfs_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct xfs_inode *ip = XFS_I(inode); + struct xfs_inode *ip; struct posix_acl *acl; int error = -EAGAIN; + ip = XFS_I(inode); trace_xfs_check_acl(ip); /* @@ -234,6 +235,12 @@ xfs_check_acl(struct inode *inode, int mask) if (!XFS_IFORK_Q(ip)) return -EAGAIN; + if (flags & IPERM_FLAG_RCU) { + if (!negative_cached_acl(inode, ACL_TYPE_ACCESS)) + return -ECHILD; + return -EAGAIN; + } + acl = xfs_get_acl(inode, ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); diff --git a/fs/xfs/xfs_acl.h b/fs/xfs/xfs_acl.h index 0135e2a669d..11dd72070cb 100644 --- a/fs/xfs/xfs_acl.h +++ b/fs/xfs/xfs_acl.h @@ -42,7 +42,7 @@ struct xfs_acl { #define SGI_ACL_DEFAULT_SIZE (sizeof(SGI_ACL_DEFAULT)-1) #ifdef CONFIG_XFS_POSIX_ACL -extern int xfs_check_acl(struct inode *inode, int mask); +extern int xfs_check_acl(struct inode *inode, int mask, unsigned int flags); extern struct posix_acl *xfs_get_acl(struct inode *inode, int type); extern int xfs_inherit_acl(struct inode *inode, struct posix_acl *default_acl); extern int xfs_acl_chmod(struct inode *inode); diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c index 0cdd26932d8..d7de5a3f786 100644 --- a/fs/xfs/xfs_iget.c +++ b/fs/xfs/xfs_iget.c @@ -91,6 +91,17 @@ xfs_inode_alloc( return ip; } +STATIC void +xfs_inode_free_callback( + struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + struct xfs_inode *ip = XFS_I(inode); + + INIT_LIST_HEAD(&inode->i_dentry); + kmem_zone_free(xfs_inode_zone, ip); +} + void xfs_inode_free( struct xfs_inode *ip) @@ -134,7 +145,7 @@ xfs_inode_free( ASSERT(!spin_is_locked(&ip->i_flags_lock)); ASSERT(completion_done(&ip->i_flush)); - kmem_zone_free(xfs_inode_zone, ip); + call_rcu(&ip->i_vnode.i_rcu, xfs_inode_free_callback); } /* diff --git a/include/linux/bit_spinlock.h b/include/linux/bit_spinlock.h index 7113a32a86e..e612575a259 100644 --- a/include/linux/bit_spinlock.h +++ b/include/linux/bit_spinlock.h @@ -1,6 +1,10 @@ #ifndef __LINUX_BIT_SPINLOCK_H #define __LINUX_BIT_SPINLOCK_H +#include <linux/kernel.h> +#include <linux/preempt.h> +#include <asm/atomic.h> + /* * bit-based spin_lock() * diff --git a/include/linux/coda_linux.h b/include/linux/coda_linux.h index 2e914d0771b..4ccc59c1ea8 100644 --- a/include/linux/coda_linux.h +++ b/include/linux/coda_linux.h @@ -37,7 +37,7 @@ extern const struct file_operations coda_ioctl_operations; /* operations shared over more than one file */ int coda_open(struct inode *i, struct file *f); int coda_release(struct inode *i, struct file *f); -int coda_permission(struct inode *inode, int mask); +int coda_permission(struct inode *inode, int mask, unsigned int flags); int coda_revalidate_inode(struct dentry *); int coda_getattr(struct vfsmount *, struct dentry *, struct kstat *); int coda_setattr(struct dentry *, struct iattr *); diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 6a4aea30aa0..bd07758943e 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -4,7 +4,9 @@ #include <asm/atomic.h> #include <linux/list.h> #include <linux/rculist.h> +#include <linux/rculist_bl.h> #include <linux/spinlock.h> +#include <linux/seqlock.h> #include <linux/cache.h> #include <linux/rcupdate.h> @@ -45,6 +47,27 @@ struct dentry_stat_t { }; extern struct dentry_stat_t dentry_stat; +/* + * Compare 2 name strings, return 0 if they match, otherwise non-zero. + * The strings are both count bytes long, and count is non-zero. + */ +static inline int dentry_cmp(const unsigned char *cs, size_t scount, + const unsigned char *ct, size_t tcount) +{ + int ret; + if (scount != tcount) + return 1; + do { + ret = (*cs != *ct); + if (ret) + break; + cs++; + ct++; + tcount--; + } while (tcount); + return ret; +} + /* Name hashing routines. Initial hash value */ /* Hash courtesy of the R5 hash in reiserfs modulo sign bits */ #define init_name_hash() 0 @@ -81,25 +104,33 @@ full_name_hash(const unsigned char *name, unsigned int len) * large memory footprint increase). */ #ifdef CONFIG_64BIT -#define DNAME_INLINE_LEN_MIN 32 /* 192 bytes */ +# define DNAME_INLINE_LEN 32 /* 192 bytes */ #else -#define DNAME_INLINE_LEN_MIN 40 /* 128 bytes */ +# ifdef CONFIG_SMP +# define DNAME_INLINE_LEN 36 /* 128 bytes */ +# else +# define DNAME_INLINE_LEN 40 /* 128 bytes */ +# endif #endif struct dentry { - atomic_t d_count; + /* RCU lookup touched fields */ unsigned int d_flags; /* protected by d_lock */ - spinlock_t d_lock; /* per dentry lock */ - int d_mounted; - struct inode *d_inode; /* Where the name belongs to - NULL is - * negative */ - /* - * The next three fields are touched by __d_lookup. Place them here - * so they all fit in a cache line. - */ - struct hlist_node d_hash; /* lookup hash list */ + seqcount_t d_seq; /* per dentry seqlock */ + struct hlist_bl_node d_hash; /* lookup hash list */ struct dentry *d_parent; /* parent directory */ struct qstr d_name; + struct inode *d_inode; /* Where the name belongs to - NULL is + * negative */ + unsigned char d_iname[DNAME_INLINE_LEN]; /* small names */ + + /* Ref lookup also touches following */ + unsigned int d_count; /* protected by d_lock */ + spinlock_t d_lock; /* per dentry lock */ + const struct dentry_operations *d_op; + struct super_block *d_sb; /* The root of the dentry tree */ + unsigned long d_time; /* used by d_revalidate */ + void *d_fsdata; /* fs-specific data */ struct list_head d_lru; /* LRU list */ /* @@ -111,12 +142,6 @@ struct dentry { } d_u; struct list_head d_subdirs; /* our children */ struct list_head d_alias; /* inode alias list */ - unsigned long d_time; /* used by d_revalidate */ - const struct dentry_operations *d_op; - struct super_block *d_sb; /* The root of the dentry tree */ - void *d_fsdata; /* fs-specific data */ - - unsigned char d_iname[DNAME_INLINE_LEN_MIN]; /* small names */ }; /* @@ -133,96 +158,61 @@ enum dentry_d_lock_class struct dentry_operations { int (*d_revalidate)(struct dentry *, struct nameidata *); - int (*d_hash) (struct dentry *, struct qstr *); - int (*d_compare) (struct dentry *, struct qstr *, struct qstr *); - int (*d_delete)(struct dentry *); + int (*d_hash)(const struct dentry *, const struct inode *, + struct qstr *); + int (*d_compare)(const struct dentry *, const struct inode *, + const struct dentry *, const struct inode *, + unsigned int, const char *, const struct qstr *); + int (*d_delete)(const struct dentry *); void (*d_release)(struct dentry *); void (*d_iput)(struct dentry *, struct inode *); char *(*d_dname)(struct dentry *, char *, int); -}; - -/* the dentry parameter passed to d_hash and d_compare is the parent - * directory of the entries to be compared. It is used in case these - * functions need any directory specific information for determining - * equivalency classes. Using the dentry itself might not work, as it - * might be a negative dentry which has no information associated with - * it */ +} ____cacheline_aligned; /* -locking rules: - big lock dcache_lock d_lock may block -d_revalidate: no no no yes -d_hash no no no yes -d_compare: no yes yes no -d_delete: no yes no no -d_release: no no no yes -d_iput: no no no yes + * Locking rules for dentry_operations callbacks are to be found in + * Documentation/filesystems/Locking. Keep it updated! + * + * FUrther descriptions are found in Documentation/filesystems/vfs.txt. + * Keep it updated too! */ /* d_flags entries */ #define DCACHE_AUTOFS_PENDING 0x0001 /* autofs: "under construction" */ -#define DCACHE_NFSFS_RENAMED 0x0002 /* this dentry has been "silly - * renamed" and has to be - * deleted on the last dput() - */ -#define DCACHE_DISCONNECTED 0x0004 - /* This dentry is possibly not currently connected to the dcache tree, - * in which case its parent will either be itself, or will have this - * flag as well. nfsd will not use a dentry with this bit set, but will - * first endeavour to clear the bit either by discovering that it is - * connected, or by performing lookup operations. Any filesystem which - * supports nfsd_operations MUST have a lookup function which, if it finds - * a directory inode with a DCACHE_DISCONNECTED dentry, will d_move - * that dentry into place and return that dentry rather than the passed one, - * typically using d_splice_alias. - */ +#define DCACHE_NFSFS_RENAMED 0x0002 + /* this dentry has been "silly renamed" and has to be deleted on the last + * dput() */ + +#define DCACHE_DISCONNECTED 0x0004 + /* This dentry is possibly not currently connected to the dcache tree, in + * which case its parent will either be itself, or will have this flag as + * well. nfsd will not use a dentry with this bit set, but will first + * endeavour to clear the bit either by discovering that it is connected, + * or by performing lookup operations. Any filesystem which supports + * nfsd_operations MUST have a lookup function which, if it finds a + * directory inode with a DCACHE_DISCONNECTED dentry, will d_move that + * dentry into place and return that dentry rather than the passed one, + * typically using d_splice_alias. */ #define DCACHE_REFERENCED 0x0008 /* Recently used, don't discard. */ #define DCACHE_UNHASHED 0x0010 - -#define DCACHE_INOTIFY_PARENT_WATCHED 0x0020 /* Parent inode is watched by inotify */ +#define DCACHE_INOTIFY_PARENT_WATCHED 0x0020 + /* Parent inode is watched by inotify */ #define DCACHE_COOKIE 0x0040 /* For use by dcookie subsystem */ - -#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x0080 /* Parent inode is watched by some fsnotify listener */ +#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x0080 + /* Parent inode is watched by some fsnotify listener */ #define DCACHE_CANT_MOUNT 0x0100 +#define DCACHE_GENOCIDE 0x0200 +#define DCACHE_MOUNTED 0x0400 /* is a mountpoint */ -extern spinlock_t dcache_lock; -extern seqlock_t rename_lock; - -/** - * d_drop - drop a dentry - * @dentry: dentry to drop - * - * d_drop() unhashes the entry from the parent dentry hashes, so that it won't - * be found through a VFS lookup any more. Note that this is different from - * deleting the dentry - d_delete will try to mark the dentry negative if - * possible, giving a successful _negative_ lookup, while d_drop will - * just make the cache lookup fail. - * - * d_drop() is used mainly for stuff that wants to invalidate a dentry for some - * reason (NFS timeouts or autofs deletes). - * - * __d_drop requires dentry->d_lock. - */ - -static inline void __d_drop(struct dentry *dentry) -{ - if (!(dentry->d_flags & DCACHE_UNHASHED)) { - dentry->d_flags |= DCACHE_UNHASHED; - hlist_del_rcu(&dentry->d_hash); - } -} +#define DCACHE_OP_HASH 0x1000 +#define DCACHE_OP_COMPARE 0x2000 +#define DCACHE_OP_REVALIDATE 0x4000 +#define DCACHE_OP_DELETE 0x8000 -static inline void d_drop(struct dentry *dentry) -{ - spin_lock(&dcache_lock); - spin_lock(&dentry->d_lock); - __d_drop(dentry); - spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); -} +extern seqlock_t rename_lock; static inline int dname_external(struct dentry *dentry) { @@ -235,10 +225,14 @@ static inline int dname_external(struct dentry *dentry) extern void d_instantiate(struct dentry *, struct inode *); extern struct dentry * d_instantiate_unique(struct dentry *, struct inode *); extern struct dentry * d_materialise_unique(struct dentry *, struct inode *); +extern void __d_drop(struct dentry *dentry); +extern void d_drop(struct dentry *dentry); extern void d_delete(struct dentry *); +extern void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op); /* allocate/de-allocate */ extern struct dentry * d_alloc(struct dentry *, const struct qstr *); +extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *); extern struct dentry * d_splice_alias(struct inode *, struct dentry *); extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *); extern struct dentry * d_obtain_alias(struct inode *); @@ -296,14 +290,40 @@ static inline struct dentry *d_add_unique(struct dentry *entry, struct inode *in return res; } +extern void dentry_update_name_case(struct dentry *, struct qstr *); + /* used for rename() and baskets */ extern void d_move(struct dentry *, struct dentry *); extern struct dentry *d_ancestor(struct dentry *, struct dentry *); /* appendix may either be NULL or be used for transname suffixes */ -extern struct dentry * d_lookup(struct dentry *, struct qstr *); -extern struct dentry * __d_lookup(struct dentry *, struct qstr *); -extern struct dentry * d_hash_and_lookup(struct dentry *, struct qstr *); +extern struct dentry *d_lookup(struct dentry *, struct qstr *); +extern struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *); +extern struct dentry *__d_lookup(struct dentry *, struct qstr *); +extern struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name, + unsigned *seq, struct inode **inode); + +/** + * __d_rcu_to_refcount - take a refcount on dentry if sequence check is ok + * @dentry: dentry to take a ref on + * @seq: seqcount to verify against + * @Returns: 0 on failure, else 1. + * + * __d_rcu_to_refcount operates on a dentry,seq pair that was returned + * by __d_lookup_rcu, to get a reference on an rcu-walk dentry. + */ +static inline int __d_rcu_to_refcount(struct dentry *dentry, unsigned seq) +{ + int ret = 0; + + assert_spin_locked(&dentry->d_lock); + if (!read_seqcount_retry(&dentry->d_seq, seq)) { + ret = 1; + dentry->d_count++; + } + + return ret; +} /* validate "insecure" dentry pointer */ extern int d_validate(struct dentry *, struct dentry *); @@ -316,34 +336,37 @@ extern char *dynamic_dname(struct dentry *, char *, int, const char *, ...); extern char *__d_path(const struct path *path, struct path *root, char *, int); extern char *d_path(const struct path *, char *, int); extern char *d_path_with_unreachable(const struct path *, char *, int); -extern char *__dentry_path(struct dentry *, char *, int); +extern char *dentry_path_raw(struct dentry *, char *, int); extern char *dentry_path(struct dentry *, char *, int); /* Allocation counts.. */ /** - * dget, dget_locked - get a reference to a dentry + * dget, dget_dlock - get a reference to a dentry * @dentry: dentry to get a reference to * * Given a dentry or %NULL pointer increment the reference count * if appropriate and return the dentry. A dentry will not be - * destroyed when it has references. dget() should never be - * called for dentries with zero reference counter. For these cases - * (preferably none, functions in dcache.c are sufficient for normal - * needs and they take necessary precautions) you should hold dcache_lock - * and call dget_locked() instead of dget(). + * destroyed when it has references. */ - +static inline struct dentry *dget_dlock(struct dentry *dentry) +{ + if (dentry) + dentry->d_count++; + return dentry; +} + static inline struct dentry *dget(struct dentry *dentry) { if (dentry) { - BUG_ON(!atomic_read(&dentry->d_count)); - atomic_inc(&dentry->d_count); + spin_lock(&dentry->d_lock); + dget_dlock(dentry); + spin_unlock(&dentry->d_lock); } return dentry; } -extern struct dentry * dget_locked(struct dentry *); +extern struct dentry *dget_parent(struct dentry *dentry); /** * d_unhashed - is dentry hashed @@ -374,21 +397,11 @@ static inline void dont_mount(struct dentry *dentry) spin_unlock(&dentry->d_lock); } -static inline struct dentry *dget_parent(struct dentry *dentry) -{ - struct dentry *ret; - - spin_lock(&dentry->d_lock); - ret = dget(dentry->d_parent); - spin_unlock(&dentry->d_lock); - return ret; -} - extern void dput(struct dentry *); static inline int d_mountpoint(struct dentry *dentry) { - return dentry->d_mounted; + return dentry->d_flags & DCACHE_MOUNTED; } extern struct vfsmount *lookup_mnt(struct path *); diff --git a/include/linux/fs.h b/include/linux/fs.h index 090f0eacde2..baf3e556ff0 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -392,6 +392,7 @@ struct inodes_stat_t { #include <linux/capability.h> #include <linux/semaphore.h> #include <linux/fiemap.h> +#include <linux/rculist_bl.h> #include <asm/atomic.h> #include <asm/byteorder.h> @@ -733,16 +734,31 @@ struct posix_acl; #define ACL_NOT_CACHED ((void *)(-1)) struct inode { + /* RCU path lookup touches following: */ + umode_t i_mode; + uid_t i_uid; + gid_t i_gid; + const struct inode_operations *i_op; + struct super_block *i_sb; + + spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */ + unsigned int i_flags; + struct mutex i_mutex; + + unsigned long i_state; + unsigned long dirtied_when; /* jiffies of first dirtying */ + struct hlist_node i_hash; struct list_head i_wb_list; /* backing dev IO list */ struct list_head i_lru; /* inode LRU list */ struct list_head i_sb_list; - struct list_head i_dentry; + union { + struct list_head i_dentry; + struct rcu_head i_rcu; + }; unsigned long i_ino; atomic_t i_count; unsigned int i_nlink; - uid_t i_uid; - gid_t i_gid; dev_t i_rdev; unsigned int i_blkbits; u64 i_version; @@ -755,13 +771,8 @@ struct inode { struct timespec i_ctime; blkcnt_t i_blocks; unsigned short i_bytes; - umode_t i_mode; - spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */ - struct mutex i_mutex; struct rw_semaphore i_alloc_sem; - const struct inode_operations *i_op; const struct file_operations *i_fop; /* former ->i_op->default_file_ops */ - struct super_block *i_sb; struct file_lock *i_flock; struct address_space *i_mapping; struct address_space i_data; @@ -782,11 +793,6 @@ struct inode { struct hlist_head i_fsnotify_marks; #endif - unsigned long i_state; - unsigned long dirtied_when; /* jiffies of first dirtying */ - - unsigned int i_flags; - #ifdef CONFIG_IMA /* protected by i_lock */ unsigned int i_readcount; /* struct files open RO */ @@ -1372,13 +1378,13 @@ struct super_block { const struct xattr_handler **s_xattr; struct list_head s_inodes; /* all inodes */ - struct hlist_head s_anon; /* anonymous dentries for (nfs) exporting */ + struct hlist_bl_head s_anon; /* anonymous dentries for (nfs) exporting */ #ifdef CONFIG_SMP struct list_head __percpu *s_files; #else struct list_head s_files; #endif - /* s_dentry_lru and s_nr_dentry_unused are protected by dcache_lock */ + /* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */ struct list_head s_dentry_lru; /* unused dentry lru */ int s_nr_dentry_unused; /* # of dentry on lru */ @@ -1545,9 +1551,18 @@ struct file_operations { int (*setlease)(struct file *, long, struct file_lock **); }; +#define IPERM_FLAG_RCU 0x0001 + struct inode_operations { - int (*create) (struct inode *,struct dentry *,int, struct nameidata *); struct dentry * (*lookup) (struct inode *,struct dentry *, struct nameidata *); + void * (*follow_link) (struct dentry *, struct nameidata *); + int (*permission) (struct inode *, int, unsigned int); + int (*check_acl)(struct inode *, int, unsigned int); + + int (*readlink) (struct dentry *, char __user *,int); + void (*put_link) (struct dentry *, struct nameidata *, void *); + + int (*create) (struct inode *,struct dentry *,int, struct nameidata *); int (*link) (struct dentry *,struct inode *,struct dentry *); int (*unlink) (struct inode *,struct dentry *); int (*symlink) (struct inode *,struct dentry *,const char *); @@ -1556,12 +1571,7 @@ struct inode_operations { int (*mknod) (struct inode *,struct dentry *,int,dev_t); int (*rename) (struct inode *, struct dentry *, struct inode *, struct dentry *); - int (*readlink) (struct dentry *, char __user *,int); - void * (*follow_link) (struct dentry *, struct nameidata *); - void (*put_link) (struct dentry *, struct nameidata *, void *); void (*truncate) (struct inode *); - int (*permission) (struct inode *, int); - int (*check_acl)(struct inode *, int); int (*setattr) (struct dentry *, struct iattr *); int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *); int (*setxattr) (struct dentry *, const char *,const void *,size_t,int); @@ -1573,7 +1583,7 @@ struct inode_operations { loff_t len); int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start, u64 len); -}; +} ____cacheline_aligned; struct seq_file; @@ -2158,8 +2168,8 @@ extern sector_t bmap(struct inode *, sector_t); #endif extern int notify_change(struct dentry *, struct iattr *); extern int inode_permission(struct inode *, int); -extern int generic_permission(struct inode *, int, - int (*check_acl)(struct inode *, int)); +extern int generic_permission(struct inode *, int, unsigned int, + int (*check_acl)(struct inode *, int, unsigned int)); static inline bool execute_ok(struct inode *inode) { @@ -2230,6 +2240,7 @@ extern void iget_failed(struct inode *); extern void end_writeback(struct inode *); extern void __destroy_inode(struct inode *); extern struct inode *new_inode(struct super_block *); +extern void free_inode_nonrcu(struct inode *inode); extern int should_remove_suid(struct dentry *); extern int file_remove_suid(struct file *); @@ -2446,6 +2457,10 @@ static inline ino_t parent_ino(struct dentry *dentry) { ino_t res; + /* + * Don't strictly need d_lock here? If the parent ino could change + * then surely we'd have a deeper race in the caller? + */ spin_lock(&dentry->d_lock); res = dentry->d_parent->d_inode->i_ino; spin_unlock(&dentry->d_lock); diff --git a/include/linux/fs_struct.h b/include/linux/fs_struct.h index a42b5bf02f8..003dc0fd734 100644 --- a/include/linux/fs_struct.h +++ b/include/linux/fs_struct.h @@ -2,10 +2,13 @@ #define _LINUX_FS_STRUCT_H #include <linux/path.h> +#include <linux/spinlock.h> +#include <linux/seqlock.h> struct fs_struct { int users; spinlock_t lock; + seqcount_t seq; int umask; int in_exec; struct path root, pwd; diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index b10bcdeaef7..2a53f10712b 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -17,7 +17,6 @@ /* * fsnotify_d_instantiate - instantiate a dentry for inode - * Called with dcache_lock held. */ static inline void fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode) @@ -62,7 +61,6 @@ static inline int fsnotify_perm(struct file *file, int mask) /* * fsnotify_d_move - dentry has been moved - * Called with dcache_lock and dentry->d_lock held. */ static inline void fsnotify_d_move(struct dentry *dentry) { diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 7380763595d..69ad89b5048 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -329,9 +329,15 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry) { struct dentry *parent; - assert_spin_locked(&dcache_lock); assert_spin_locked(&dentry->d_lock); + /* + * Serialisation of setting PARENT_WATCHED on the dentries is provided + * by d_lock. If inotify_inode_watched changes after we have taken + * d_lock, the following __fsnotify_update_child_dentry_flags call will + * find our entry, so it will spin until we complete here, and update + * us with the new state. + */ parent = dentry->d_parent; if (parent->d_inode && fsnotify_inode_watches_children(parent->d_inode)) dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; @@ -341,15 +347,12 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry) /* * fsnotify_d_instantiate - instantiate a dentry for inode - * Called with dcache_lock held. */ static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode) { if (!inode) return; - assert_spin_locked(&dcache_lock); - spin_lock(&dentry->d_lock); __fsnotify_update_dcache_flags(dentry); spin_unlock(&dentry->d_lock); diff --git a/include/linux/generic_acl.h b/include/linux/generic_acl.h index 574bea4013b..0437e377b55 100644 --- a/include/linux/generic_acl.h +++ b/include/linux/generic_acl.h @@ -10,6 +10,6 @@ extern const struct xattr_handler generic_acl_default_handler; int generic_acl_init(struct inode *, struct inode *); int generic_acl_chmod(struct inode *); -int generic_check_acl(struct inode *inode, int mask); +int generic_check_acl(struct inode *inode, int mask, unsigned int flags); #endif /* LINUX_GENERIC_ACL_H */ diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h new file mode 100644 index 00000000000..9ee97e7f2be --- /dev/null +++ b/include/linux/list_bl.h @@ -0,0 +1,144 @@ +#ifndef _LINUX_LIST_BL_H +#define _LINUX_LIST_BL_H + +#include <linux/list.h> + +/* + * Special version of lists, where head of the list has a lock in the lowest + * bit. This is useful for scalable hash tables without increasing memory + * footprint overhead. + * + * For modification operations, the 0 bit of hlist_bl_head->first + * pointer must be set. + * + * With some small modifications, this can easily be adapted to store several + * arbitrary bits (not just a single lock bit), if the need arises to store + * some fast and compact auxiliary data. + */ + +#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) +#define LIST_BL_LOCKMASK 1UL +#else +#define LIST_BL_LOCKMASK 0UL +#endif + +#ifdef CONFIG_DEBUG_LIST +#define LIST_BL_BUG_ON(x) BUG_ON(x) +#else +#define LIST_BL_BUG_ON(x) +#endif + + +struct hlist_bl_head { + struct hlist_bl_node *first; +}; + +struct hlist_bl_node { + struct hlist_bl_node *next, **pprev; +}; +#define INIT_HLIST_BL_HEAD(ptr) \ + ((ptr)->first = NULL) + +static inline void INIT_HLIST_BL_NODE(struct hlist_bl_node *h) +{ + h->next = NULL; + h->pprev = NULL; +} + +#define hlist_bl_entry(ptr, type, member) container_of(ptr,type,member) + +static inline int hlist_bl_unhashed(const struct hlist_bl_node *h) +{ + return !h->pprev; +} + +static inline struct hlist_bl_node *hlist_bl_first(struct hlist_bl_head *h) +{ + return (struct hlist_bl_node *) + ((unsigned long)h->first & ~LIST_BL_LOCKMASK); +} + +static inline void hlist_bl_set_first(struct hlist_bl_head *h, + struct hlist_bl_node *n) +{ + LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK); + LIST_BL_BUG_ON(!((unsigned long)h->first & LIST_BL_LOCKMASK)); + h->first = (struct hlist_bl_node *)((unsigned long)n | LIST_BL_LOCKMASK); +} + +static inline int hlist_bl_empty(const struct hlist_bl_head *h) +{ + return !((unsigned long)h->first & ~LIST_BL_LOCKMASK); +} + +static inline void hlist_bl_add_head(struct hlist_bl_node *n, + struct hlist_bl_head *h) +{ + struct hlist_bl_node *first = hlist_bl_first(h); + + n->next = first; + if (first) + first->pprev = &n->next; + n->pprev = &h->first; + hlist_bl_set_first(h, n); +} + +static inline void __hlist_bl_del(struct hlist_bl_node *n) +{ + struct hlist_bl_node *next = n->next; + struct hlist_bl_node **pprev = n->pprev; + + LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK); + + /* pprev may be `first`, so be careful not to lose the lock bit */ + *pprev = (struct hlist_bl_node *) + ((unsigned long)next | + ((unsigned long)*pprev & LIST_BL_LOCKMASK)); + if (next) + next->pprev = pprev; +} + +static inline void hlist_bl_del(struct hlist_bl_node *n) +{ + __hlist_bl_del(n); + n->next = LIST_POISON1; + n->pprev = LIST_POISON2; +} + +static inline void hlist_bl_del_init(struct hlist_bl_node *n) +{ + if (!hlist_bl_unhashed(n)) { + __hlist_bl_del(n); + INIT_HLIST_BL_NODE(n); + } +} + +/** + * hlist_bl_for_each_entry - iterate over list of given type + * @tpos: the type * to use as a loop cursor. + * @pos: the &struct hlist_node to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the hlist_node within the struct. + * + */ +#define hlist_bl_for_each_entry(tpos, pos, head, member) \ + for (pos = hlist_bl_first(head); \ + pos && \ + ({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1;}); \ + pos = pos->next) + +/** + * hlist_bl_for_each_entry_safe - iterate over list of given type safe against removal of list entry + * @tpos: the type * to use as a loop cursor. + * @pos: the &struct hlist_node to use as a loop cursor. + * @n: another &struct hlist_node to use as temporary storage + * @head: the head for your list. + * @member: the name of the hlist_node within the struct. + */ +#define hlist_bl_for_each_entry_safe(tpos, pos, n, head, member) \ + for (pos = hlist_bl_first(head); \ + pos && ({ n = pos->next; 1; }) && \ + ({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1;}); \ + pos = n) + +#endif diff --git a/include/linux/mount.h b/include/linux/mount.h index 5e7a59408dd..1869ea24a73 100644 --- a/include/linux/mount.h +++ b/include/linux/mount.h @@ -13,6 +13,7 @@ #include <linux/list.h> #include <linux/nodemask.h> #include <linux/spinlock.h> +#include <linux/seqlock.h> #include <asm/atomic.h> struct super_block; @@ -46,12 +47,24 @@ struct mnt_namespace; #define MNT_INTERNAL 0x4000 +struct mnt_pcp { + int mnt_count; + int mnt_writers; +}; + struct vfsmount { struct list_head mnt_hash; struct vfsmount *mnt_parent; /* fs we are mounted on */ struct dentry *mnt_mountpoint; /* dentry of mountpoint */ struct dentry *mnt_root; /* root of the mounted tree */ struct super_block *mnt_sb; /* pointer to superblock */ +#ifdef CONFIG_SMP + struct mnt_pcp __percpu *mnt_pcp; + atomic_t mnt_longrefs; +#else + int mnt_count; + int mnt_writers; +#endif struct list_head mnt_mounts; /* list of children, anchored here */ struct list_head mnt_child; /* and going through their mnt_child */ int mnt_flags; @@ -70,57 +83,25 @@ struct vfsmount { struct mnt_namespace *mnt_ns; /* containing namespace */ int mnt_id; /* mount identifier */ int mnt_group_id; /* peer group identifier */ - /* - * We put mnt_count & mnt_expiry_mark at the end of struct vfsmount - * to let these frequently modified fields in a separate cache line - * (so that reads of mnt_flags wont ping-pong on SMP machines) - */ - atomic_t mnt_count; int mnt_expiry_mark; /* true if marked for expiry */ int mnt_pinned; int mnt_ghosts; -#ifdef CONFIG_SMP - int __percpu *mnt_writers; -#else - int mnt_writers; -#endif }; -static inline int *get_mnt_writers_ptr(struct vfsmount *mnt) -{ -#ifdef CONFIG_SMP - return mnt->mnt_writers; -#else - return &mnt->mnt_writers; -#endif -} - -static inline struct vfsmount *mntget(struct vfsmount *mnt) -{ - if (mnt) - atomic_inc(&mnt->mnt_count); - return mnt; -} - struct file; /* forward dec */ extern int mnt_want_write(struct vfsmount *mnt); extern int mnt_want_write_file(struct file *file); extern int mnt_clone_write(struct vfsmount *mnt); extern void mnt_drop_write(struct vfsmount *mnt); -extern void mntput_no_expire(struct vfsmount *mnt); +extern void mntput(struct vfsmount *mnt); +extern struct vfsmount *mntget(struct vfsmount *mnt); +extern void mntput_long(struct vfsmount *mnt); +extern struct vfsmount *mntget_long(struct vfsmount *mnt); extern void mnt_pin(struct vfsmount *mnt); extern void mnt_unpin(struct vfsmount *mnt); extern int __mnt_is_readonly(struct vfsmount *mnt); -static inline void mntput(struct vfsmount *mnt) -{ - if (mnt) { - mnt->mnt_expiry_mark = 0; - mntput_no_expire(mnt); - } -} - extern struct vfsmount *do_kern_mount(const char *fstype, int flags, const char *name, void *data); diff --git a/include/linux/namei.h b/include/linux/namei.h index 05b441d9364..18d06add0a4 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -19,7 +19,10 @@ struct nameidata { struct path path; struct qstr last; struct path root; + struct file *file; + struct inode *inode; /* path.dentry.d_inode */ unsigned int flags; + unsigned seq; int last_type; unsigned depth; char *saved_names[MAX_NESTED_LINKS + 1]; @@ -41,14 +44,15 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND}; * - require a directory * - ending slashes ok even for nonexistent files * - internal "there are more path components" flag - * - locked when lookup done with dcache_lock held * - dentry cache is untrusted; force a real lookup */ -#define LOOKUP_FOLLOW 1 -#define LOOKUP_DIRECTORY 2 -#define LOOKUP_CONTINUE 4 -#define LOOKUP_PARENT 16 -#define LOOKUP_REVAL 64 +#define LOOKUP_FOLLOW 0x0001 +#define LOOKUP_DIRECTORY 0x0002 +#define LOOKUP_CONTINUE 0x0004 + +#define LOOKUP_PARENT 0x0010 +#define LOOKUP_REVAL 0x0020 +#define LOOKUP_RCU 0x0040 /* * Intent data */ diff --git a/include/linux/ncp_fs.h b/include/linux/ncp_fs.h index ef663061d5a..1c27f201c85 100644 --- a/include/linux/ncp_fs.h +++ b/include/linux/ncp_fs.h @@ -184,13 +184,13 @@ struct ncp_entry_info { __u8 file_handle[6]; }; -static inline struct ncp_server *NCP_SBP(struct super_block *sb) +static inline struct ncp_server *NCP_SBP(const struct super_block *sb) { return sb->s_fs_info; } #define NCP_SERVER(inode) NCP_SBP((inode)->i_sb) -static inline struct ncp_inode_info *NCP_FINFO(struct inode *inode) +static inline struct ncp_inode_info *NCP_FINFO(const struct inode *inode) { return container_of(inode, struct ncp_inode_info, vfs_inode); } diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 29d504d5d1c..0779bb8f95b 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -351,7 +351,7 @@ extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *); extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr); extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr); extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *); -extern int nfs_permission(struct inode *, int); +extern int nfs_permission(struct inode *, int, unsigned int); extern int nfs_open(struct inode *, struct file *); extern int nfs_release(struct inode *, struct file *); extern int nfs_attribute_timeout(struct inode *inode); diff --git a/include/linux/path.h b/include/linux/path.h index edc98dec626..a581e8c0653 100644 --- a/include/linux/path.h +++ b/include/linux/path.h @@ -10,7 +10,9 @@ struct path { }; extern void path_get(struct path *); +extern void path_get_long(struct path *); extern void path_put(struct path *); +extern void path_put_long(struct path *); static inline int path_equal(const struct path *path1, const struct path *path2) { diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h index 67608161df6..d68283a898b 100644 --- a/include/linux/posix_acl.h +++ b/include/linux/posix_acl.h @@ -108,6 +108,25 @@ static inline struct posix_acl *get_cached_acl(struct inode *inode, int type) return acl; } +static inline int negative_cached_acl(struct inode *inode, int type) +{ + struct posix_acl **p, *acl; + switch (type) { + case ACL_TYPE_ACCESS: + p = &inode->i_acl; + break; + case ACL_TYPE_DEFAULT: + p = &inode->i_default_acl; + break; + default: + BUG(); + } + acl = ACCESS_ONCE(*p); + if (acl) + return 0; + return 1; +} + static inline void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl) diff --git a/include/linux/rculist_bl.h b/include/linux/rculist_bl.h new file mode 100644 index 00000000000..b872b493724 --- /dev/null +++ b/include/linux/rculist_bl.h @@ -0,0 +1,127 @@ +#ifndef _LINUX_RCULIST_BL_H +#define _LINUX_RCULIST_BL_H + +/* + * RCU-protected bl list version. See include/linux/list_bl.h. + */ +#include <linux/list_bl.h> +#include <linux/rcupdate.h> + +static inline void hlist_bl_set_first_rcu(struct hlist_bl_head *h, + struct hlist_bl_node *n) +{ + LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK); + LIST_BL_BUG_ON(!((unsigned long)h->first & LIST_BL_LOCKMASK)); + rcu_assign_pointer(h->first, + (struct hlist_bl_node *)((unsigned long)n | LIST_BL_LOCKMASK)); +} + +static inline struct hlist_bl_node *hlist_bl_first_rcu(struct hlist_bl_head *h) +{ + return (struct hlist_bl_node *) + ((unsigned long)rcu_dereference(h->first) & ~LIST_BL_LOCKMASK); +} + +/** + * hlist_bl_del_init_rcu - deletes entry from hash list with re-initialization + * @n: the element to delete from the hash list. + * + * Note: hlist_bl_unhashed() on the node returns true after this. It is + * useful for RCU based read lockfree traversal if the writer side + * must know if the list entry is still hashed or already unhashed. + * + * In particular, it means that we can not poison the forward pointers + * that may still be used for walking the hash list and we can only + * zero the pprev pointer so list_unhashed() will return true after + * this. + * + * The caller must take whatever precautions are necessary (such as + * holding appropriate locks) to avoid racing with another + * list-mutation primitive, such as hlist_bl_add_head_rcu() or + * hlist_bl_del_rcu(), running on this same list. However, it is + * perfectly legal to run concurrently with the _rcu list-traversal + * primitives, such as hlist_bl_for_each_entry_rcu(). + */ +static inline void hlist_bl_del_init_rcu(struct hlist_bl_node *n) +{ + if (!hlist_bl_unhashed(n)) { + __hlist_bl_del(n); + n->pprev = NULL; + } +} + +/** + * hlist_bl_del_rcu - deletes entry from hash list without re-initialization + * @n: the element to delete from the hash list. + * + * Note: hlist_bl_unhashed() on entry does not return true after this, + * the entry is in an undefined state. It is useful for RCU based + * lockfree traversal. + * + * In particular, it means that we can not poison the forward + * pointers that may still be used for walking the hash list. + * + * The caller must take whatever precautions are necessary + * (such as holding appropriate locks) to avoid racing + * with another list-mutation primitive, such as hlist_bl_add_head_rcu() + * or hlist_bl_del_rcu(), running on this same list. + * However, it is perfectly legal to run concurrently with + * the _rcu list-traversal primitives, such as + * hlist_bl_for_each_entry(). + */ +static inline void hlist_bl_del_rcu(struct hlist_bl_node *n) +{ + __hlist_bl_del(n); + n->pprev = LIST_POISON2; +} + +/** + * hlist_bl_add_head_rcu + * @n: the element to add to the hash list. + * @h: the list to add to. + * + * Description: + * Adds the specified element to the specified hlist_bl, + * while permitting racing traversals. + * + * The caller must take whatever precautions are necessary + * (such as holding appropriate locks) to avoid racing + * with another list-mutation primitive, such as hlist_bl_add_head_rcu() + * or hlist_bl_del_rcu(), running on this same list. + * However, it is perfectly legal to run concurrently with + * the _rcu list-traversal primitives, such as + * hlist_bl_for_each_entry_rcu(), used to prevent memory-consistency + * problems on Alpha CPUs. Regardless of the type of CPU, the + * list-traversal primitive must be guarded by rcu_read_lock(). + */ +static inline void hlist_bl_add_head_rcu(struct hlist_bl_node *n, + struct hlist_bl_head *h) +{ + struct hlist_bl_node *first; + + /* don't need hlist_bl_first_rcu because we're under lock */ + first = hlist_bl_first(h); + + n->next = first; + if (first) + first->pprev = &n->next; + n->pprev = &h->first; + + /* need _rcu because we can have concurrent lock free readers */ + hlist_bl_set_first_rcu(h, n); +} +/** + * hlist_bl_for_each_entry_rcu - iterate over rcu list of given type + * @tpos: the type * to use as a loop cursor. + * @pos: the &struct hlist_bl_node to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the hlist_bl_node within the struct. + * + */ +#define hlist_bl_for_each_entry_rcu(tpos, pos, head, member) \ + for (pos = hlist_bl_first_rcu(head); \ + pos && \ + ({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1; }); \ + pos = rcu_dereference_raw(pos->next)) + +#endif diff --git a/include/linux/reiserfs_xattr.h b/include/linux/reiserfs_xattr.h index b2cf2089769..3b94c91f20a 100644 --- a/include/linux/reiserfs_xattr.h +++ b/include/linux/reiserfs_xattr.h @@ -41,7 +41,7 @@ int reiserfs_xattr_init(struct super_block *sb, int mount_flags); int reiserfs_lookup_privroot(struct super_block *sb); int reiserfs_delete_xattrs(struct inode *inode); int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs); -int reiserfs_permission(struct inode *inode, int mask); +int reiserfs_permission(struct inode *inode, int mask, unsigned int flags); #ifdef CONFIG_REISERFS_FS_XATTR #define has_xattr_dir(inode) (REISERFS_I(inode)->i_flags & i_has_xattr_dir) diff --git a/include/linux/security.h b/include/linux/security.h index d47a4c24b3e..1ac42475ea0 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -457,7 +457,6 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * called when the actual read/write operations are performed. * @inode contains the inode structure to check. * @mask contains the permission mask. - * @nd contains the nameidata (may be NULL). * Return 0 if permission is granted. * @inode_setattr: * Check permission before setting file attributes. Note that the kernel @@ -1713,6 +1712,7 @@ int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry, int security_inode_readlink(struct dentry *dentry); int security_inode_follow_link(struct dentry *dentry, struct nameidata *nd); int security_inode_permission(struct inode *inode, int mask); +int security_inode_exec_permission(struct inode *inode, unsigned int flags); int security_inode_setattr(struct dentry *dentry, struct iattr *attr); int security_inode_getattr(struct vfsmount *mnt, struct dentry *dentry); int security_inode_setxattr(struct dentry *dentry, const char *name, @@ -2102,6 +2102,12 @@ static inline int security_inode_permission(struct inode *inode, int mask) return 0; } +static inline int security_inode_exec_permission(struct inode *inode, + unsigned int flags) +{ + return 0; +} + static inline int security_inode_setattr(struct dentry *dentry, struct iattr *attr) { diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index 632205ccc25..e98cd2e5719 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -107,7 +107,7 @@ static __always_inline int read_seqretry(const seqlock_t *sl, unsigned start) { smp_rmb(); - return (sl->sequence != start); + return unlikely(sl->sequence != start); } @@ -125,14 +125,25 @@ typedef struct seqcount { #define SEQCNT_ZERO { 0 } #define seqcount_init(x) do { *(x) = (seqcount_t) SEQCNT_ZERO; } while (0) -/* Start of read using pointer to a sequence counter only. */ -static inline unsigned read_seqcount_begin(const seqcount_t *s) +/** + * __read_seqcount_begin - begin a seq-read critical section (without barrier) + * @s: pointer to seqcount_t + * Returns: count to be passed to read_seqcount_retry + * + * __read_seqcount_begin is like read_seqcount_begin, but has no smp_rmb() + * barrier. Callers should ensure that smp_rmb() or equivalent ordering is + * provided before actually loading any of the variables that are to be + * protected in this critical section. + * + * Use carefully, only in critical code, and comment how the barrier is + * provided. + */ +static inline unsigned __read_seqcount_begin(const seqcount_t *s) { unsigned ret; repeat: ret = s->sequence; - smp_rmb(); if (unlikely(ret & 1)) { cpu_relax(); goto repeat; @@ -140,14 +151,56 @@ repeat: return ret; } -/* - * Test if reader processed invalid data because sequence number has changed. +/** + * read_seqcount_begin - begin a seq-read critical section + * @s: pointer to seqcount_t + * Returns: count to be passed to read_seqcount_retry + * + * read_seqcount_begin opens a read critical section of the given seqcount. + * Validity of the critical section is tested by checking read_seqcount_retry + * function. + */ +static inline unsigned read_seqcount_begin(const seqcount_t *s) +{ + unsigned ret = __read_seqcount_begin(s); + smp_rmb(); + return ret; +} + +/** + * __read_seqcount_retry - end a seq-read critical section (without barrier) + * @s: pointer to seqcount_t + * @start: count, from read_seqcount_begin + * Returns: 1 if retry is required, else 0 + * + * __read_seqcount_retry is like read_seqcount_retry, but has no smp_rmb() + * barrier. Callers should ensure that smp_rmb() or equivalent ordering is + * provided before actually loading any of the variables that are to be + * protected in this critical section. + * + * Use carefully, only in critical code, and comment how the barrier is + * provided. + */ +static inline int __read_seqcount_retry(const seqcount_t *s, unsigned start) +{ + return unlikely(s->sequence != start); +} + +/** + * read_seqcount_retry - end a seq-read critical section + * @s: pointer to seqcount_t + * @start: count, from read_seqcount_begin + * Returns: 1 if retry is required, else 0 + * + * read_seqcount_retry closes a read critical section of the given seqcount. + * If the critical section was invalid, it must be ignored (and typically + * retried). */ static inline int read_seqcount_retry(const seqcount_t *s, unsigned start) { smp_rmb(); - return s->sequence != start; + return __read_seqcount_retry(s, start); } @@ -167,6 +220,19 @@ static inline void write_seqcount_end(seqcount_t *s) s->sequence++; } +/** + * write_seqcount_barrier - invalidate in-progress read-side seq operations + * @s: pointer to seqcount_t + * + * After write_seqcount_barrier, no read-side seq operations will complete + * successfully and see data older than this. + */ +static inline void write_seqcount_barrier(seqcount_t *s) +{ + smp_wmb(); + s->sequence+=2; +} + /* * Possible sw/hw IRQ protected versions of the interfaces. */ diff --git a/include/linux/slab.h b/include/linux/slab.h index 59260e21bdf..fa9086647eb 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -106,8 +106,6 @@ int kmem_cache_shrink(struct kmem_cache *); void kmem_cache_free(struct kmem_cache *, void *); unsigned int kmem_cache_size(struct kmem_cache *); const char *kmem_cache_name(struct kmem_cache *); -int kern_ptr_validate(const void *ptr, unsigned long size); -int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr); /* * Please use this macro to create slab caches. Simply specify the diff --git a/ipc/mqueue.c b/ipc/mqueue.c index 035f4399edb..14fb6d67e6a 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -237,11 +237,18 @@ static struct inode *mqueue_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } -static void mqueue_destroy_inode(struct inode *inode) +static void mqueue_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); } +static void mqueue_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, mqueue_i_callback); +} + static void mqueue_evict_inode(struct inode *inode) { struct mqueue_inode_info *info; diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 66a416b42c1..51cddc11cd8 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -763,6 +763,8 @@ EXPORT_SYMBOL_GPL(cgroup_unlock); * -> cgroup_mkdir. */ +static struct dentry *cgroup_lookup(struct inode *dir, + struct dentry *dentry, struct nameidata *nd); static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, int mode); static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry); static int cgroup_populate_dir(struct cgroup *cgrp); @@ -874,25 +876,29 @@ static void cgroup_clear_directory(struct dentry *dentry) struct list_head *node; BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex)); - spin_lock(&dcache_lock); + spin_lock(&dentry->d_lock); node = dentry->d_subdirs.next; while (node != &dentry->d_subdirs) { struct dentry *d = list_entry(node, struct dentry, d_u.d_child); + + spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED); list_del_init(node); if (d->d_inode) { /* This should never be called on a cgroup * directory with child cgroups */ BUG_ON(d->d_inode->i_mode & S_IFDIR); - d = dget_locked(d); - spin_unlock(&dcache_lock); + dget_dlock(d); + spin_unlock(&d->d_lock); + spin_unlock(&dentry->d_lock); d_delete(d); simple_unlink(dentry->d_inode, d); dput(d); - spin_lock(&dcache_lock); - } + spin_lock(&dentry->d_lock); + } else + spin_unlock(&d->d_lock); node = dentry->d_subdirs.next; } - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); } /* @@ -900,11 +906,16 @@ static void cgroup_clear_directory(struct dentry *dentry) */ static void cgroup_d_remove_dir(struct dentry *dentry) { + struct dentry *parent; + cgroup_clear_directory(dentry); - spin_lock(&dcache_lock); + parent = dentry->d_parent; + spin_lock(&parent->d_lock); + spin_lock(&dentry->d_lock); list_del_init(&dentry->d_u.d_child); - spin_unlock(&dcache_lock); + spin_unlock(&dentry->d_lock); + spin_unlock(&parent->d_lock); remove_dir(dentry); } @@ -2180,7 +2191,7 @@ static const struct file_operations cgroup_file_operations = { }; static const struct inode_operations cgroup_dir_inode_operations = { - .lookup = simple_lookup, + .lookup = cgroup_lookup, .mkdir = cgroup_mkdir, .rmdir = cgroup_rmdir, .rename = cgroup_rename, @@ -2196,13 +2207,29 @@ static inline struct cftype *__file_cft(struct file *file) return __d_cft(file->f_dentry); } -static int cgroup_create_file(struct dentry *dentry, mode_t mode, - struct super_block *sb) +static int cgroup_delete_dentry(const struct dentry *dentry) +{ + return 1; +} + +static struct dentry *cgroup_lookup(struct inode *dir, + struct dentry *dentry, struct nameidata *nd) { - static const struct dentry_operations cgroup_dops = { + static const struct dentry_operations cgroup_dentry_operations = { + .d_delete = cgroup_delete_dentry, .d_iput = cgroup_diput, }; + if (dentry->d_name.len > NAME_MAX) + return ERR_PTR(-ENAMETOOLONG); + d_set_d_op(dentry, &cgroup_dentry_operations); + d_add(dentry, NULL); + return NULL; +} + +static int cgroup_create_file(struct dentry *dentry, mode_t mode, + struct super_block *sb) +{ struct inode *inode; if (!dentry) @@ -2228,7 +2255,6 @@ static int cgroup_create_file(struct dentry *dentry, mode_t mode, inode->i_size = 0; inode->i_fop = &cgroup_file_operations; } - dentry->d_op = &cgroup_dops; d_instantiate(dentry, inode); dget(dentry); /* Extra count - pin the dentry in core */ return 0; @@ -3638,9 +3664,7 @@ again: list_del(&cgrp->sibling); cgroup_unlock_hierarchy(cgrp->root); - spin_lock(&cgrp->dentry->d_lock); d = dget(cgrp->dentry); - spin_unlock(&d->d_lock); cgroup_d_remove_dir(d); dput(d); diff --git a/mm/filemap.c b/mm/filemap.c index 6b9aee20f24..ca389394fa2 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -102,9 +102,6 @@ * ->inode_lock (zap_pte_range->set_page_dirty) * ->private_lock (zap_pte_range->__set_page_dirty_buffers) * - * ->task->proc_lock - * ->dcache_lock (proc_pid_lookup) - * * (code doesn't rely on that order, so you could switch it around) * ->tasklist_lock (memory_failure, collect_procs_ao) * ->i_mmap_lock diff --git a/mm/shmem.c b/mm/shmem.c index 47fdeeb9d63..5ee67c99060 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2415,13 +2415,20 @@ static struct inode *shmem_alloc_inode(struct super_block *sb) return &p->vfs_inode; } +static void shmem_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode)); +} + static void shmem_destroy_inode(struct inode *inode) { if ((inode->i_mode & S_IFMT) == S_IFREG) { /* only struct inode is valid if it's an inline symlink */ mpol_free_shared_policy(&SHMEM_I(inode)->policy); } - kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode)); + call_rcu(&inode->i_rcu, shmem_i_callback); } static void init_once(void *foo) diff --git a/mm/slab.c b/mm/slab.c index b1e40dafbab..6107f2380e0 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2781,7 +2781,7 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp, /* * Map pages beginning at addr to the given cache and slab. This is required * for the slab allocator to be able to lookup the cache and slab of a - * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging. + * virtual address for kfree, ksize, and slab debugging. */ static void slab_map_pages(struct kmem_cache *cache, struct slab *slab, void *addr) @@ -3660,36 +3660,6 @@ void *kmem_cache_alloc_notrace(struct kmem_cache *cachep, gfp_t flags) EXPORT_SYMBOL(kmem_cache_alloc_notrace); #endif -/** - * kmem_ptr_validate - check if an untrusted pointer might be a slab entry. - * @cachep: the cache we're checking against - * @ptr: pointer to validate - * - * This verifies that the untrusted pointer looks sane; - * it is _not_ a guarantee that the pointer is actually - * part of the slab cache in question, but it at least - * validates that the pointer can be dereferenced and - * looks half-way sane. - * - * Currently only used for dentry validation. - */ -int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr) -{ - unsigned long size = cachep->buffer_size; - struct page *page; - - if (unlikely(!kern_ptr_validate(ptr, size))) - goto out; - page = virt_to_page(ptr); - if (unlikely(!PageSlab(page))) - goto out; - if (unlikely(page_get_cache(page) != cachep)) - goto out; - return 1; -out: - return 0; -} - #ifdef CONFIG_NUMA void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) { diff --git a/mm/slob.c b/mm/slob.c index 617b6d6c42c..3588eaaef72 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -678,11 +678,6 @@ int kmem_cache_shrink(struct kmem_cache *d) } EXPORT_SYMBOL(kmem_cache_shrink); -int kmem_ptr_validate(struct kmem_cache *a, const void *b) -{ - return 0; -} - static unsigned int slob_ready __read_mostly; int slab_is_available(void) diff --git a/mm/slub.c b/mm/slub.c index bec0e355fba..a2fe1727ed8 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1917,17 +1917,6 @@ void kmem_cache_free(struct kmem_cache *s, void *x) } EXPORT_SYMBOL(kmem_cache_free); -/* Figure out on which slab page the object resides */ -static struct page *get_object_page(const void *x) -{ - struct page *page = virt_to_head_page(x); - - if (!PageSlab(page)) - return NULL; - - return page; -} - /* * Object placement in a slab is made very easy because we always start at * offset 0. If we tune the size of the object to the alignment then we can @@ -2386,35 +2375,6 @@ error: } /* - * Check if a given pointer is valid - */ -int kmem_ptr_validate(struct kmem_cache *s, const void *object) -{ - struct page *page; - - if (!kern_ptr_validate(object, s->size)) - return 0; - - page = get_object_page(object); - - if (!page || s != page->slab) - /* No slab or wrong slab */ - return 0; - - if (!check_valid_pointer(s, page, object)) - return 0; - - /* - * We could also check if the object is on the slabs freelist. - * But this would be too expensive and it seems that the main - * purpose of kmem_ptr_valid() is to check if the object belongs - * to a certain slab. - */ - return 1; -} -EXPORT_SYMBOL(kmem_ptr_validate); - -/* * Determine the size of a slab object */ unsigned int kmem_cache_size(struct kmem_cache *s) diff --git a/mm/util.c b/mm/util.c index 73dac81e9f7..f126975ef23 100644 --- a/mm/util.c +++ b/mm/util.c @@ -186,27 +186,6 @@ void kzfree(const void *p) } EXPORT_SYMBOL(kzfree); -int kern_ptr_validate(const void *ptr, unsigned long size) -{ - unsigned long addr = (unsigned long)ptr; - unsigned long min_addr = PAGE_OFFSET; - unsigned long align_mask = sizeof(void *) - 1; - - if (unlikely(addr < min_addr)) - goto out; - if (unlikely(addr > (unsigned long)high_memory - size)) - goto out; - if (unlikely(addr & align_mask)) - goto out; - if (unlikely(!kern_addr_valid(addr))) - goto out; - if (unlikely(!kern_addr_valid(addr + size - 1))) - goto out; - return 1; -out: - return 0; -} - /* * strndup_user - duplicate an existing string from user space * @s: The string to duplicate diff --git a/net/socket.c b/net/socket.c index c1663c0ff3d..ccc576a6a50 100644 --- a/net/socket.c +++ b/net/socket.c @@ -262,6 +262,7 @@ static struct inode *sock_alloc_inode(struct super_block *sb) } + static void wq_free_rcu(struct rcu_head *head) { struct socket_wq *wq = container_of(head, struct socket_wq, rcu); @@ -360,14 +361,14 @@ static int sock_alloc_file(struct socket *sock, struct file **f, int flags) if (unlikely(fd < 0)) return fd; - path.dentry = d_alloc(sock_mnt->mnt_sb->s_root, &name); + path.dentry = d_alloc_pseudo(sock_mnt->mnt_sb, &name); if (unlikely(!path.dentry)) { put_unused_fd(fd); return -ENOMEM; } path.mnt = mntget(sock_mnt); - path.dentry->d_op = &sockfs_dentry_operations; + d_set_d_op(path.dentry, &sockfs_dentry_operations); d_instantiate(path.dentry, SOCK_INODE(sock)); SOCK_INODE(sock)->i_fop = &socket_file_ops; @@ -2390,6 +2391,8 @@ EXPORT_SYMBOL(sock_unregister); static int __init sock_init(void) { + int err; + /* * Initialize sock SLAB cache. */ @@ -2406,8 +2409,15 @@ static int __init sock_init(void) */ init_inodecache(); - register_filesystem(&sock_fs_type); + + err = register_filesystem(&sock_fs_type); + if (err) + goto out_fs; sock_mnt = kern_mount(&sock_fs_type); + if (IS_ERR(sock_mnt)) { + err = PTR_ERR(sock_mnt); + goto out_mount; + } /* The real protocol initialization is performed in later initcalls. */ @@ -2420,7 +2430,13 @@ static int __init sock_init(void) skb_timestamping_init(); #endif - return 0; +out: + return err; + +out_mount: + unregister_filesystem(&sock_fs_type); +out_fs: + goto out; } core_initcall(sock_init); /* early initcall */ diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c index 10a17a37ec4..09f01f41e55 100644 --- a/net/sunrpc/rpc_pipe.c +++ b/net/sunrpc/rpc_pipe.c @@ -162,11 +162,19 @@ rpc_alloc_inode(struct super_block *sb) } static void -rpc_destroy_inode(struct inode *inode) +rpc_i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(rpc_inode_cachep, RPC_I(inode)); } +static void +rpc_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, rpc_i_callback); +} + static int rpc_pipe_open(struct inode *inode, struct file *filp) { @@ -430,7 +438,7 @@ void rpc_put_mount(void) } EXPORT_SYMBOL_GPL(rpc_put_mount); -static int rpc_delete_dentry(struct dentry *dentry) +static int rpc_delete_dentry(const struct dentry *dentry) { return 1; } @@ -583,7 +591,7 @@ static struct dentry *__rpc_lookup_create(struct dentry *parent, } } if (!dentry->d_inode) - dentry->d_op = &rpc_dentry_operations; + d_set_d_op(dentry, &rpc_dentry_operations); out_err: return dentry; } diff --git a/security/security.c b/security/security.c index e5fb07a3052..739e40362f4 100644 --- a/security/security.c +++ b/security/security.c @@ -513,6 +513,15 @@ int security_inode_permission(struct inode *inode, int mask) return security_ops->inode_permission(inode, mask); } +int security_inode_exec_permission(struct inode *inode, unsigned int flags) +{ + if (unlikely(IS_PRIVATE(inode))) + return 0; + if (flags) + return -ECHILD; + return security_ops->inode_permission(inode, MAY_EXEC); +} + int security_inode_setattr(struct dentry *dentry, struct iattr *attr) { if (unlikely(IS_PRIVATE(dentry->d_inode))) diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 073fd5b0a53..43deac21949 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -1145,24 +1145,28 @@ static void sel_remove_entries(struct dentry *de) { struct list_head *node; - spin_lock(&dcache_lock); + spin_lock(&de->d_lock); node = de->d_subdirs.next; while (node != &de->d_subdirs) { struct dentry *d = list_entry(node, struct dentry, d_u.d_child); + + spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED); list_del_init(node); if (d->d_inode) { - d = dget_locked(d); - spin_unlock(&dcache_lock); + dget_dlock(d); + spin_unlock(&de->d_lock); + spin_unlock(&d->d_lock); d_delete(d); simple_unlink(de->d_inode, d); dput(d); - spin_lock(&dcache_lock); - } + spin_lock(&de->d_lock); + } else + spin_unlock(&d->d_lock); node = de->d_subdirs.next; } - spin_unlock(&dcache_lock); + spin_unlock(&de->d_lock); } #define BOOL_DIR_NAME "booleans" diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c index 1d0bf8fa192..d1e05b04771 100644 --- a/security/tomoyo/realpath.c +++ b/security/tomoyo/realpath.c @@ -14,6 +14,7 @@ #include <linux/slab.h> #include <net/sock.h> #include "common.h" +#include "../../fs/internal.h" /** * tomoyo_encode: Convert binary string to ascii string. |