diff --git a/fs/notify/mark.c b/fs/notify/mark.c index 3e594ce41010..92e48c70f0f0 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -152,15 +152,31 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, BUG(); list_del_init(&mark->g_list); + spin_unlock(&mark->lock); if (inode && (mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED)) iput(inode); + /* release lock temporarily */ + mutex_unlock(&group->mark_mutex); spin_lock(&destroy_lock); list_add(&mark->g_list, &destroy_list); spin_unlock(&destroy_lock); wake_up(&destroy_waitq); + /* + * We don't necessarily have a ref on mark from caller so the above destroy + * may have actually freed it, unless this group provides a 'freeing_mark' + * function which must be holding a reference. + */ + + /* + * Some groups like to know that marks are being freed. This is a + * callback to the group function to let it know that this mark + * is being freed. + */ + if (group->ops->freeing_mark) + group->ops->freeing_mark(mark, group); /* * __fsnotify_update_child_dentry_flags(inode); @@ -175,6 +191,8 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, */ atomic_dec(&group->num_marks); + + mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING); } void fsnotify_destroy_mark(struct fsnotify_mark *mark, @@ -187,10 +205,7 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark, /* * Destroy all marks in the given list. The marks must be already detached from - * the original inode / vfsmount. Note that we can race with - * fsnotify_clear_marks_by_group_flags(). However we hold a reference to each - * mark so they won't get freed from under us and nobody else touches our - * free_list list_head. + * the original inode / vfsmount. */ void fsnotify_destroy_marks(struct list_head *to_free) { @@ -391,7 +406,7 @@ struct fsnotify_mark *fsnotify_find_mark(struct hlist_head *head, } /* - * Clear any marks in a group in which mark->flags & flags is true. + * clear any marks in a group in which mark->flags & flags is true */ void fsnotify_clear_marks_by_group_flags(struct fsnotify_group *group, unsigned int flags) @@ -445,7 +460,6 @@ static int fsnotify_mark_destroy(void *ignored) { struct fsnotify_mark *mark, *next; struct list_head private_destroy_list; - struct fsnotify_group *group; for (;;) { spin_lock(&destroy_lock); @@ -457,14 +471,6 @@ static int fsnotify_mark_destroy(void *ignored) list_for_each_entry_safe(mark, next, &private_destroy_list, g_list) { list_del_init(&mark->g_list); - group = mark->group; - /* - * Some groups like to know that marks are being freed. - * This is a callback to the group function to let it - * know that this mark is being freed. - */ - if (group && group->ops->freeing_mark) - group->ops->freeing_mark(mark, group); fsnotify_put_mark(mark); }