diff options
-rw-r--r-- | fs/cifs/cached_dir.c | 428 | ||||
-rw-r--r-- | fs/cifs/cached_dir.h | 20 | ||||
-rw-r--r-- | fs/cifs/inode.c | 6 | ||||
-rw-r--r-- | fs/cifs/smb2ops.c | 2 |
4 files changed, 263 insertions, 193 deletions
diff --git a/fs/cifs/cached_dir.c b/fs/cifs/cached_dir.c index b705dac383f9..e5573d4e2d83 100644 --- a/fs/cifs/cached_dir.c +++ b/fs/cifs/cached_dir.c @@ -11,7 +11,53 @@ #include "smb2proto.h" #include "cached_dir.h" -struct cached_fid *init_cached_dir(const char *path); +static struct cached_fid *init_cached_dir(const char *path); +static void free_cached_dir(struct cached_fid *cfid); + +static struct cached_fid *find_or_create_cached_dir(struct cached_fids *cfids, + const char *path, + bool lookup_only) +{ + struct cached_fid *cfid; + + spin_lock(&cfids->cfid_list_lock); + list_for_each_entry(cfid, &cfids->entries, entry) { + if (!strcmp(cfid->path, path)) { + /* + * If it doesn't have a lease it is either not yet + * fully cached or it may be in the process of + * being deleted due to a lease break. + */ + if (!cfid->has_lease) { + spin_unlock(&cfids->cfid_list_lock); + return NULL; + } + kref_get(&cfid->refcount); + spin_unlock(&cfids->cfid_list_lock); + return cfid; + } + } + if (lookup_only) { + spin_unlock(&cfids->cfid_list_lock); + return NULL; + } + if (cfids->num_entries >= MAX_CACHED_FIDS) { + spin_unlock(&cfids->cfid_list_lock); + return NULL; + } + cfid = init_cached_dir(path); + if (cfid == NULL) { + spin_unlock(&cfids->cfid_list_lock); + return NULL; + } + cfid->cfids = cfids; + cfids->num_entries++; + list_add(&cfid->entry, &cfids->entries); + cfid->on_list = true; + kref_get(&cfid->refcount); + spin_unlock(&cfids->cfid_list_lock); + return cfid; +} /* * Open the and cache a directory handle. @@ -33,61 +79,65 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon, struct kvec open_iov[SMB2_CREATE_IOV_SIZE]; struct kvec qi_iov[1]; int rc, flags = 0; - __le16 utf16_path = 0; /* Null - since an open of top of share */ + __le16 *utf16_path = NULL; u8 oplock = SMB2_OPLOCK_LEVEL_II; struct cifs_fid *pfid; - struct dentry *dentry; + struct dentry *dentry = NULL; struct cached_fid *cfid; + struct cached_fids *cfids; - if (tcon == NULL || tcon->nohandlecache || + + if (tcon == NULL || tcon->cfids == NULL || tcon->nohandlecache || is_smb1_server(tcon->ses->server)) return -EOPNOTSUPP; ses = tcon->ses; server = ses->server; + cfids = tcon->cfids; + + if (!server->ops->new_lease_key) + return -EIO; if (cifs_sb->root == NULL) return -ENOENT; + /* + * TODO: for better caching we need to find and use the dentry also + * for non-root directories. + */ if (!path[0]) dentry = cifs_sb->root; - else - return -ENOENT; - cfid = tcon->cfids->cfid; - if (cfid == NULL) { - cfid = init_cached_dir(path); - tcon->cfids->cfid = cfid; - } - if (cfid == NULL) + utf16_path = cifs_convert_path_to_utf16(path, cifs_sb); + if (!utf16_path) return -ENOMEM; - mutex_lock(&cfid->fid_mutex); - if (cfid->is_valid) { - cifs_dbg(FYI, "found a cached root file handle\n"); + cfid = find_or_create_cached_dir(cfids, path, lookup_only); + if (cfid == NULL) { + kfree(utf16_path); + return -ENOENT; + } + /* + * At this point we either have a lease already and we can just + * return it. If not we are guaranteed to be the only thread accessing + * this cfid. + */ + if (cfid->has_lease) { *ret_cfid = cfid; - kref_get(&cfid->refcount); - mutex_unlock(&cfid->fid_mutex); + kfree(utf16_path); return 0; } /* * We do not hold the lock for the open because in case - * SMB2_open needs to reconnect, it will end up calling - * cifs_mark_open_files_invalid() which takes the lock again - * thus causing a deadlock + * SMB2_open needs to reconnect. + * This is safe because no other thread will be able to get a ref + * to the cfid until we have finished opening the file and (possibly) + * acquired a lease. */ - mutex_unlock(&cfid->fid_mutex); - - if (lookup_only) - return -ENOENT; - if (smb3_encryption_required(tcon)) flags |= CIFS_TRANSFORM_REQ; - if (!server->ops->new_lease_key) - return -EIO; - pfid = &cfid->fid; server->ops->new_lease_key(pfid); @@ -108,7 +158,7 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon, oparms.reconnect = false; rc = SMB2_open_init(tcon, server, - &rqst[0], &oplock, &oparms, &utf16_path); + &rqst[0], &oplock, &oparms, utf16_path); if (rc) goto oshr_free; smb2_set_next_command(tcon, &rqst[0]); @@ -131,47 +181,13 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon, rc = compound_send_recv(xid, ses, server, flags, 2, rqst, resp_buftype, rsp_iov); - mutex_lock(&cfid->fid_mutex); - - /* - * Now we need to check again as the cached root might have - * been successfully re-opened from a concurrent process - */ - - if (cfid->is_valid) { - /* work was already done */ - - /* stash fids for close() later */ - struct cifs_fid fid = { - .persistent_fid = pfid->persistent_fid, - .volatile_fid = pfid->volatile_fid, - }; - - /* - * caller expects this func to set the fid in cfid to valid - * cached root, so increment the refcount. - */ - kref_get(&cfid->refcount); - - mutex_unlock(&cfid->fid_mutex); - - if (rc == 0) { - /* close extra handle outside of crit sec */ - SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid); - } - rc = 0; - goto oshr_free; - } - - /* Cached root is still invalid, continue normaly */ - if (rc) { if (rc == -EREMCHG) { tcon->need_reconnect = true; pr_warn_once("server share %s deleted\n", tcon->tree_name); } - goto oshr_exit; + goto oshr_free; } atomic_inc(&tcon->num_remote_opens); @@ -184,46 +200,54 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon, #endif /* CIFS_DEBUG2 */ cfid->tcon = tcon; - cfid->is_valid = true; - cfid->dentry = dentry; - if (dentry) + if (dentry) { + cfid->dentry = dentry; dget(dentry); - kref_init(&cfid->refcount); - + } /* BB TBD check to see if oplock level check can be removed below */ - if (o_rsp->OplockLevel == SMB2_OPLOCK_LEVEL_LEASE) { - /* - * See commit 2f94a3125b87. Increment the refcount when we - * get a lease for root, release it if lease break occurs - */ - kref_get(&cfid->refcount); - cfid->has_lease = true; - smb2_parse_contexts(server, o_rsp, - &oparms.fid->epoch, - oparms.fid->lease_key, &oplock, - NULL, NULL); - } else - goto oshr_exit; + if (o_rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE) + goto oshr_free; + + + smb2_parse_contexts(server, o_rsp, + &oparms.fid->epoch, + oparms.fid->lease_key, &oplock, + NULL, NULL); qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base; if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info)) - goto oshr_exit; + goto oshr_free; if (!smb2_validate_and_copy_iov( le16_to_cpu(qi_rsp->OutputBufferOffset), sizeof(struct smb2_file_all_info), &rsp_iov[1], sizeof(struct smb2_file_all_info), (char *)&cfid->file_all_info)) cfid->file_all_info_is_valid = true; - cfid->time = jiffies; + cfid->is_open = true; + cfid->has_lease = true; -oshr_exit: - mutex_unlock(&cfid->fid_mutex); oshr_free: + kfree(utf16_path); SMB2_open_free(&rqst[0]); SMB2_query_info_free(&rqst[1]); free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base); free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base); + spin_lock(&cfids->cfid_list_lock); + if (!cfid->has_lease) { + if (cfid->on_list) { + list_del(&cfid->entry); + cfid->on_list = false; + cfids->num_entries--; + } + rc = -ENOENT; + } + spin_unlock(&cfids->cfid_list_lock); + if (rc) { + free_cached_dir(cfid); + cfid = NULL; + } + if (rc == 0) *ret_cfid = cfid; @@ -235,20 +259,22 @@ int open_cached_dir_by_dentry(struct cifs_tcon *tcon, struct cached_fid **ret_cfid) { struct cached_fid *cfid; + struct cached_fids *cfids = tcon->cfids; - cfid = tcon->cfids->cfid; - if (cfid == NULL) + if (cfids == NULL) return -ENOENT; - mutex_lock(&cfid->fid_mutex); - if (cfid->dentry == dentry) { - cifs_dbg(FYI, "found a cached root file handle by dentry\n"); - *ret_cfid = cfid; - kref_get(&cfid->refcount); - mutex_unlock(&cfid->fid_mutex); - return 0; + spin_lock(&cfids->cfid_list_lock); + list_for_each_entry(cfid, &cfids->entries, entry) { + if (dentry && cfid->dentry == dentry) { + cifs_dbg(FYI, "found a cached root file handle by dentry\n"); + kref_get(&cfid->refcount); + *ret_cfid = cfid; + spin_unlock(&cfids->cfid_list_lock); + return 0; + } } - mutex_unlock(&cfid->fid_mutex); + spin_unlock(&cfids->cfid_list_lock); return -ENOENT; } @@ -257,63 +283,29 @@ smb2_close_cached_fid(struct kref *ref) { struct cached_fid *cfid = container_of(ref, struct cached_fid, refcount); - struct cached_dirent *dirent, *q; - if (cfid->is_valid) { - cifs_dbg(FYI, "clear cached root file handle\n"); - SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid, - cfid->fid.volatile_fid); + spin_lock(&cfid->cfids->cfid_list_lock); + if (cfid->on_list) { + list_del(&cfid->entry); + cfid->on_list = false; + cfid->cfids->num_entries--; } + spin_unlock(&cfid->cfids->cfid_list_lock); - /* - * We only check validity above to send SMB2_close, - * but we still need to invalidate these entries - * when this function is called - */ - cfid->is_valid = false; - cfid->file_all_info_is_valid = false; - cfid->has_lease = false; - if (cfid->dentry) { - dput(cfid->dentry); - cfid->dentry = NULL; - } - /* - * Delete all cached dirent names - */ - mutex_lock(&cfid->dirents.de_mutex); - list_for_each_entry_safe(dirent, q, &cfid->dirents.entries, entry) { - list_del(&dirent->entry); - kfree(dirent->name); - kfree(dirent); + dput(cfid->dentry); + cfid->dentry = NULL; + + if (cfid->is_open) { + SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid, + cfid->fid.volatile_fid); } - cfid->dirents.is_valid = 0; - cfid->dirents.is_failed = 0; - cfid->dirents.ctx = NULL; - cfid->dirents.pos = 0; - mutex_unlock(&cfid->dirents.de_mutex); + free_cached_dir(cfid); } void close_cached_dir(struct cached_fid *cfid) { - mutex_lock(&cfid->fid_mutex); kref_put(&cfid->refcount, smb2_close_cached_fid); - mutex_unlock(&cfid->fid_mutex); -} - -void close_cached_dir_lease_locked(struct cached_fid *cfid) -{ - if (cfid->has_lease) { - cfid->has_lease = false; - kref_put(&cfid->refcount, smb2_close_cached_fid); - } -} - -void close_cached_dir_lease(struct cached_fid *cfid) -{ - mutex_lock(&cfid->fid_mutex); - close_cached_dir_lease_locked(cfid); - mutex_unlock(&cfid->fid_mutex); } /* @@ -326,41 +318,62 @@ void close_all_cached_dirs(struct cifs_sb_info *cifs_sb) struct cached_fid *cfid; struct cifs_tcon *tcon; struct tcon_link *tlink; + struct cached_fids *cfids; for (node = rb_first(root); node; node = rb_next(node)) { tlink = rb_entry(node, struct tcon_link, tl_rbnode); tcon = tlink_tcon(tlink); if (IS_ERR(tcon)) continue; - cfid = tcon->cfids->cfid; - if (cfid == NULL) + cfids = tcon->cfids; + if (cfids == NULL) continue; - mutex_lock(&cfid->fid_mutex); - if (cfid->dentry) { + list_for_each_entry(cfid, &cfids->entries, entry) { dput(cfid->dentry); cfid->dentry = NULL; } - mutex_unlock(&cfid->fid_mutex); } } /* - * Invalidate and close all cached dirs when a TCON has been reset + * Invalidate all cached dirs when a TCON has been reset * due to a session loss. */ void invalidate_all_cached_dirs(struct cifs_tcon *tcon) { - struct cached_fid *cfid = tcon->cfids->cfid; - - if (cfid == NULL) - return; - - mutex_lock(&cfid->fid_mutex); - cfid->is_valid = false; - /* cached handle is not valid, so SMB2_CLOSE won't be sent below */ - close_cached_dir_lease_locked(cfid); - memset(&cfid->fid, 0, sizeof(struct cifs_fid)); - mutex_unlock(&cfid->fid_mutex); + struct cached_fids *cfids = tcon->cfids; + struct cached_fid *cfid, *q; + struct list_head entry; + + INIT_LIST_HEAD(&entry); + spin_lock(&cfids->cfid_list_lock); + list_for_each_entry_safe(cfid, q, &cfids->entries, entry) { + list_del(&cfid->entry); + list_add(&cfid->entry, &entry); + cfids->num_entries--; + cfid->is_open = false; + /* To prevent race with smb2_cached_lease_break() */ + kref_get(&cfid->refcount); + } + spin_unlock(&cfids->cfid_list_lock); + + list_for_each_entry_safe(cfid, q, &entry, entry) { + cfid->on_list = false; + list_del(&cfid->entry); + cancel_work_sync(&cfid->lease_break); + if (cfid->has_lease) { + /* + * We lease was never cancelled from the server so we + * need to drop the reference. + */ + spin_lock(&cfids->cfid_list_lock); + cfid->has_lease = false; + spin_unlock(&cfids->cfid_list_lock); + kref_put(&cfid->refcount, smb2_close_cached_fid); + } + /* Drop the extra reference opened above*/ + kref_put(&cfid->refcount, smb2_close_cached_fid); + } } static void @@ -369,51 +382,83 @@ smb2_cached_lease_break(struct work_struct *work) struct cached_fid *cfid = container_of(work, struct cached_fid, lease_break); - close_cached_dir_lease(cfid); + spin_lock(&cfid->cfids->cfid_list_lock); + cfid->has_lease = false; + spin_unlock(&cfid->cfids->cfid_list_lock); + kref_put(&cfid->refcount, smb2_close_cached_fid); } int cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16]) { - struct cached_fid *cfid = tcon->cfids->cfid; + struct cached_fids *cfids = tcon->cfids; + struct cached_fid *cfid; - if (cfid == NULL) + if (cfids == NULL) return false; - if (cfid->is_valid && - !memcmp(lease_key, - cfid->fid.lease_key, - SMB2_LEASE_KEY_SIZE)) { - cfid->time = 0; - INIT_WORK(&cfid->lease_break, - smb2_cached_lease_break); - queue_work(cifsiod_wq, - &cfid->lease_break); - return true; + spin_lock(&cfids->cfid_list_lock); + list_for_each_entry(cfid, &cfids->entries, entry) { + if (cfid->has_lease && + !memcmp(lease_key, + cfid->fid.lease_key, + SMB2_LEASE_KEY_SIZE)) { + cfid->time = 0; + /* + * We found a lease remove it from the list + * so no threads can access it. + */ + list_del(&cfid->entry); + cfid->on_list = false; + cfids->num_entries--; + + queue_work(cifsiod_wq, + &cfid->lease_break); + spin_unlock(&cfids->cfid_list_lock); + return true; + } } + spin_unlock(&cfids->cfid_list_lock); return false; } -struct cached_fid *init_cached_dir(const char *path) +static struct cached_fid *init_cached_dir(const char *path) { struct cached_fid *cfid; - cfid = kzalloc(sizeof(*cfid), GFP_KERNEL); + cfid = kzalloc(sizeof(*cfid), GFP_ATOMIC); if (!cfid) return NULL; - cfid->path = kstrdup(path, GFP_KERNEL); + cfid->path = kstrdup(path, GFP_ATOMIC); if (!cfid->path) { kfree(cfid); return NULL; } + INIT_WORK(&cfid->lease_break, smb2_cached_lease_break); + INIT_LIST_HEAD(&cfid->entry); INIT_LIST_HEAD(&cfid->dirents.entries); mutex_init(&cfid->dirents.de_mutex); - mutex_init(&cfid->fid_mutex); + spin_lock_init(&cfid->fid_lock); + kref_init(&cfid->refcount); return cfid; } -void free_cached_dir(struct cached_fid *cfid) +static void free_cached_dir(struct cached_fid *cfid) { + struct cached_dirent *dirent, *q; + + dput(cfid->dentry); + cfid->dentry = NULL; + + /* + * Delete all cached dirent names + */ + list_for_each_entry_safe(dirent, q, &cfid->dirents.entries, entry) { + list_del(&dirent->entry); + kfree(dirent->name); + kfree(dirent); + } + kfree(cfid->path); cfid->path = NULL; kfree(cfid); @@ -426,15 +471,34 @@ struct cached_fids *init_cached_dirs(void) cfids = kzalloc(sizeof(*cfids), GFP_KERNEL); if (!cfids) return NULL; - mutex_init(&cfids->cfid_list_mutex); + spin_lock_init(&cfids->cfid_list_lock); + INIT_LIST_HEAD(&cfids->entries); return cfids; } +/* + * Called from tconInfoFree when we are tearing down the tcon. + * There are no active users or open files/directories at this point. + */ void free_cached_dirs(struct cached_fids *cfids) { - if (cfids->cfid) { - free_cached_dir(cfids->cfid); - cfids->cfid = NULL; + struct cached_fid *cfid, *q; + struct list_head entry; + + INIT_LIST_HEAD(&entry); + spin_lock(&cfids->cfid_list_lock); + list_for_each_entry_safe(cfid, q, &cfids->entries, entry) { + cfid->on_list = false; + cfid->is_open = false; + list_del(&cfid->entry); + list_add(&cfid->entry, &entry); } + spin_unlock(&cfids->cfid_list_lock); + + list_for_each_entry_safe(cfid, q, &entry, entry) { + list_del(&cfid->entry); + free_cached_dir(cfid); + } + kfree(cfids); } diff --git a/fs/cifs/cached_dir.h b/fs/cifs/cached_dir.h index bdf6c3866653..e536304ca2ce 100644 --- a/fs/cifs/cached_dir.h +++ b/fs/cifs/cached_dir.h @@ -31,14 +31,17 @@ struct cached_dirents { }; struct cached_fid { + struct list_head entry; + struct cached_fids *cfids; const char *path; - bool is_valid:1; /* Do we have a useable root fid */ - bool file_all_info_is_valid:1; bool has_lease:1; + bool is_open:1; + bool on_list:1; + bool file_all_info_is_valid:1; unsigned long time; /* jiffies of when lease was taken */ struct kref refcount; struct cifs_fid fid; - struct mutex fid_mutex; + spinlock_t fid_lock; struct cifs_tcon *tcon; struct dentry *dentry; struct work_struct lease_break; @@ -46,9 +49,14 @@ struct cached_fid { struct cached_dirents dirents; }; +#define MAX_CACHED_FIDS 16 struct cached_fids { - struct mutex cfid_list_mutex; - struct cached_fid *cfid; + /* Must be held when: + * - accessing the cfids->entries list + */ + spinlock_t cfid_list_lock; + int num_entries; + struct list_head entries; }; extern struct cached_fids *init_cached_dirs(void); @@ -61,8 +69,6 @@ extern int open_cached_dir_by_dentry(struct cifs_tcon *tcon, struct dentry *dentry, struct cached_fid **cfid); extern void close_cached_dir(struct cached_fid *cfid); -extern void close_cached_dir_lease(struct cached_fid *cfid); -extern void close_cached_dir_lease_locked(struct cached_fid *cfid); extern void close_all_cached_dirs(struct cifs_sb_info *cifs_sb); extern void invalidate_all_cached_dirs(struct cifs_tcon *tcon); extern int cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16]); diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index be6dafcb25e3..7cf96e581d24 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -2299,13 +2299,13 @@ cifs_dentry_needs_reval(struct dentry *dentry) return true; if (!open_cached_dir_by_dentry(tcon, dentry->d_parent, &cfid)) { - mutex_lock(&cfid->fid_mutex); + spin_lock(&cfid->fid_lock); if (cfid->time && cifs_i->time > cfid->time) { - mutex_unlock(&cfid->fid_mutex); + spin_unlock(&cfid->fid_lock); close_cached_dir(cfid); return false; } - mutex_unlock(&cfid->fid_mutex); + spin_unlock(&cfid->fid_lock); close_cached_dir(cfid); } /* diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 73e951e9858c..b907d1fab8d9 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -801,7 +801,7 @@ smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon, rc = open_cached_dir(xid, tcon, full_path, cifs_sb, true, &cfid); if (!rc) { - if (cfid->is_valid) { + if (cfid->has_lease) { close_cached_dir(cfid); return 0; } |