diff options
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 41 |
1 files changed, 24 insertions, 17 deletions
diff --git a/fs/namei.c b/fs/namei.c index 2358b326b22..1ab641f2e78 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -919,12 +919,11 @@ static inline bool managed_dentry_might_block(struct dentry *dentry) } /* - * Skip to top of mountpoint pile in rcuwalk mode. We abort the rcu-walk if we - * meet a managed dentry and we're not walking to "..". True is returned to - * continue, false to abort. + * Try to skip to top of mountpoint pile in rcuwalk mode. Fail if + * we meet a managed dentry that would need blocking. */ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, - struct inode **inode, bool reverse_transit) + struct inode **inode) { for (;;) { struct vfsmount *mounted; @@ -933,8 +932,7 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, * that wants to block transit. */ *inode = path->dentry->d_inode; - if (!reverse_transit && - unlikely(managed_dentry_might_block(path->dentry))) + if (unlikely(managed_dentry_might_block(path->dentry))) return false; if (!d_mountpoint(path->dentry)) @@ -947,16 +945,24 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, path->dentry = mounted->mnt_root; nd->seq = read_seqcount_begin(&path->dentry->d_seq); } - - if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT)) - return reverse_transit; return true; } -static int follow_dotdot_rcu(struct nameidata *nd) +static void follow_mount_rcu(struct nameidata *nd) { - struct inode *inode = nd->inode; + while (d_mountpoint(nd->path.dentry)) { + struct vfsmount *mounted; + mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry, 1); + if (!mounted) + break; + nd->path.mnt = mounted; + nd->path.dentry = mounted->mnt_root; + nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq); + } +} +static int follow_dotdot_rcu(struct nameidata *nd) +{ set_root_rcu(nd); while (1) { @@ -972,7 +978,6 @@ static int follow_dotdot_rcu(struct nameidata *nd) seq = read_seqcount_begin(&parent->d_seq); if (read_seqcount_retry(&old->d_seq, nd->seq)) goto failed; - inode = parent->d_inode; nd->path.dentry = parent; nd->seq = seq; break; @@ -980,10 +985,9 @@ static int follow_dotdot_rcu(struct nameidata *nd) 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, true); - nd->inode = inode; + follow_mount_rcu(nd); + nd->inode = nd->path.dentry->d_inode; return 0; failed: @@ -1157,8 +1161,11 @@ static int do_lookup(struct nameidata *nd, struct qstr *name, } path->mnt = mnt; path->dentry = dentry; - if (likely(__follow_mount_rcu(nd, path, inode, false))) - return 0; + if (unlikely(!__follow_mount_rcu(nd, path, inode))) + goto unlazy; + if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT)) + goto unlazy; + return 0; unlazy: if (unlazy_walk(nd, dentry)) return -ECHILD; |