diff options
| -rw-r--r-- | fs/notify/fsnotify.c | 3 | ||||
| -rw-r--r-- | fs/notify/mark.c | 30 | ||||
| -rw-r--r-- | include/linux/fsnotify.h | 19 | ||||
| -rw-r--r-- | include/linux/fsnotify_backend.h | 11 |
4 files changed, 54 insertions, 9 deletions
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index fb3f36bc6ea9..2ae965ef37e8 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -100,6 +100,9 @@ void fsnotify_sb_delete(struct super_block *sb) /* Wait for outstanding object references from connectors */ wait_var_event(fsnotify_sb_watched_objects(sb), !atomic_long_read(fsnotify_sb_watched_objects(sb))); + WARN_ON(fsnotify_sb_has_priority_watchers(sb, FSNOTIFY_PRIO_CONTENT)); + WARN_ON(fsnotify_sb_has_priority_watchers(sb, + FSNOTIFY_PRIO_PRE_CONTENT)); kfree(sbinfo); } diff --git a/fs/notify/mark.c b/fs/notify/mark.c index b2f5d8c9cce1..c3eefa70633c 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -161,13 +161,36 @@ static void fsnotify_put_inode_ref(struct inode *inode) static void fsnotify_update_sb_watchers(struct super_block *sb, struct fsnotify_mark_connector *conn) { + struct fsnotify_sb_info *sbinfo = fsnotify_sb_info(sb); bool is_watched = conn->flags & FSNOTIFY_CONN_FLAG_IS_WATCHED; - bool has_marks = conn->obj && !hlist_empty(&conn->list); + struct fsnotify_mark *first_mark = NULL; + unsigned int highest_prio = 0; - if (has_marks && !is_watched) { + if (conn->obj) + first_mark = hlist_entry_safe(conn->list.first, + struct fsnotify_mark, obj_list); + if (first_mark) + highest_prio = first_mark->group->priority; + if (WARN_ON(highest_prio >= __FSNOTIFY_PRIO_NUM)) + highest_prio = 0; + + /* + * If the highest priority of group watching this object is prio, + * then watched object has a reference on counters [0..prio]. + * Update priority >= 1 watched objects counters. + */ + for (unsigned int p = conn->prio + 1; p <= highest_prio; p++) + atomic_long_inc(&sbinfo->watched_objects[p]); + for (unsigned int p = conn->prio; p > highest_prio; p--) + atomic_long_dec(&sbinfo->watched_objects[p]); + conn->prio = highest_prio; + + /* Update priority >= 0 (a.k.a total) watched objects counter */ + BUILD_BUG_ON(FSNOTIFY_PRIO_NORMAL != 0); + if (first_mark && !is_watched) { conn->flags |= FSNOTIFY_CONN_FLAG_IS_WATCHED; fsnotify_get_sb_watched_objects(sb); - } else if (!has_marks && is_watched) { + } else if (!first_mark && is_watched) { conn->flags &= ~FSNOTIFY_CONN_FLAG_IS_WATCHED; fsnotify_put_sb_watched_objects(sb); } @@ -600,6 +623,7 @@ static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp, spin_lock_init(&conn->lock); INIT_HLIST_HEAD(&conn->list); conn->flags = 0; + conn->prio = 0; conn->type = obj_type; conn->obj = obj; diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index 48dc65702415..4da80e92f804 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -17,8 +17,9 @@ #include <linux/slab.h> #include <linux/bug.h> -/* Are there any inode/mount/sb objects that are being watched at all? */ -static inline bool fsnotify_sb_has_watchers(struct super_block *sb) +/* Are there any inode/mount/sb objects watched with priority prio or above? */ +static inline bool fsnotify_sb_has_priority_watchers(struct super_block *sb, + int prio) { struct fsnotify_sb_info *sbinfo = fsnotify_sb_info(sb); @@ -26,7 +27,13 @@ static inline bool fsnotify_sb_has_watchers(struct super_block *sb) if (!sbinfo) return false; - return atomic_long_read(&sbinfo->watched_objects); + return atomic_long_read(&sbinfo->watched_objects[prio]); +} + +/* Are there any inode/mount/sb objects that are being watched at all? */ +static inline bool fsnotify_sb_has_watchers(struct super_block *sb) +{ + return fsnotify_sb_has_priority_watchers(sb, 0); } /* @@ -109,6 +116,12 @@ static inline int fsnotify_file(struct file *file, __u32 mask) return 0; path = &file->f_path; + /* Permission events require group prio >= FSNOTIFY_PRIO_CONTENT */ + if (mask & ALL_FSNOTIFY_PERM_EVENTS && + !fsnotify_sb_has_priority_watchers(path->dentry->d_sb, + FSNOTIFY_PRIO_CONTENT)) + return 0; + return fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH); } diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index fc38587d8564..7f1ab8264e41 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -468,7 +468,8 @@ FSNOTIFY_ITER_FUNCS(sb, SB) */ struct fsnotify_mark_connector { spinlock_t lock; - unsigned short type; /* Type of object [lock] */ + unsigned char type; /* Type of object [lock] */ + unsigned char prio; /* Highest priority group */ #define FSNOTIFY_CONN_FLAG_IS_WATCHED 0x01 #define FSNOTIFY_CONN_FLAG_HAS_IREF 0x02 unsigned short flags; /* flags [lock] */ @@ -490,8 +491,12 @@ struct fsnotify_sb_info { /* * Number of inode/mount/sb objects that are being watched in this sb. * Note that inodes objects are currently double-accounted. + * + * The value in watched_objects[prio] is the number of objects that are + * watched by groups of priority >= prio, so watched_objects[0] is the + * total number of watched objects in this sb. */ - atomic_long_t watched_objects; + atomic_long_t watched_objects[__FSNOTIFY_PRIO_NUM]; }; static inline struct fsnotify_sb_info *fsnotify_sb_info(struct super_block *sb) @@ -505,7 +510,7 @@ static inline struct fsnotify_sb_info *fsnotify_sb_info(struct super_block *sb) static inline atomic_long_t *fsnotify_sb_watched_objects(struct super_block *sb) { - return &fsnotify_sb_info(sb)->watched_objects; + return &fsnotify_sb_info(sb)->watched_objects[0]; } /* |