diff options
| -rw-r--r-- | fs/notify/mark.c | 20 | ||||
| -rw-r--r-- | include/linux/fsnotify_backend.h | 7 |
2 files changed, 14 insertions, 13 deletions
diff --git a/fs/notify/mark.c b/fs/notify/mark.c index 0e93d90bb753..fc6b49bf7360 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -150,6 +150,8 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, spin_unlock(&mark->lock); + if (inode && (mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED)) + iput(inode); /* release lock temporarily */ mutex_unlock(&group->mark_mutex); @@ -157,6 +159,11 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, list_add(&mark->destroy_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 @@ -178,22 +185,15 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, * is just a lazy update (and could be a perf win...) */ - if (inode && (mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED)) - iput(inode); - /* - * We don't necessarily have a ref on mark from caller so the above iput - * may have already destroyed it. Don't touch from now on. - */ - atomic_dec(&group->num_marks); - mutex_lock(&group->mark_mutex); + mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING); } void fsnotify_destroy_mark(struct fsnotify_mark *mark, struct fsnotify_group *group) { - mutex_lock(&group->mark_mutex); + mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING); fsnotify_destroy_mark_locked(mark, group); mutex_unlock(&group->mark_mutex); } @@ -300,7 +300,7 @@ void fsnotify_clear_marks_by_group_flags(struct fsnotify_group *group, { struct fsnotify_mark *lmark, *mark; - mutex_lock(&group->mark_mutex); + mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING); list_for_each_entry_safe(mark, lmark, &group->marks_list, g_list) { if (mark->flags & flags) { fsnotify_get_mark(mark); diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 5a8899350456..1af2f6a722c0 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -88,9 +88,10 @@ struct fsnotify_event_private_data; * if the group is interested in this event. * handle_event - main call for a group to handle an fs event * free_group_priv - called when a group refcnt hits 0 to clean up the private union - * freeing-mark - this means that a mark has been flagged to die when everything - * finishes using it. The function is supplied with what must be a - * valid group and inode to use to clean up. + * freeing_mark - called when a mark is being destroyed for some reason. The group + * MUST be holding a reference on each mark and that reference must be + * dropped in this function. inotify uses this function to send + * userspace messages that marks have been removed. */ struct fsnotify_ops { bool (*should_send_event)(struct fsnotify_group *group, struct inode *inode, |