fsnotify: introduce locked versions of fsnotify_add_mark() and fsnotify_remove_mark()
This patch introduces fsnotify_add_mark_locked() and fsnotify_remove_mark_locked()
which are essentially the same as fsnotify_add_mark() and fsnotify_remove_mark() but
assume that the caller has already taken the groups mark mutex.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index b77c833..f9dda03 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -121,18 +121,18 @@
* The caller had better be holding a reference to this mark so we don't actually
* do the final put under the mark->lock
*/
-void fsnotify_destroy_mark(struct fsnotify_mark *mark,
- struct fsnotify_group *group)
+void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark,
+ struct fsnotify_group *group)
{
struct inode *inode = NULL;
- mutex_lock(&group->mark_mutex);
+ BUG_ON(!mutex_is_locked(&group->mark_mutex));
+
spin_lock(&mark->lock);
/* something else already called this function on this mark */
if (!(mark->flags & FSNOTIFY_MARK_FLAG_ALIVE)) {
spin_unlock(&mark->lock);
- mutex_unlock(&group->mark_mutex);
return;
}
@@ -149,6 +149,8 @@
list_del_init(&mark->g_list);
spin_unlock(&mark->lock);
+
+ /* release lock temporarily */
mutex_unlock(&group->mark_mutex);
spin_lock(&destroy_lock);
@@ -184,6 +186,16 @@
*/
atomic_dec(&group->num_marks);
+
+ mutex_lock(&group->mark_mutex);
+}
+
+void fsnotify_destroy_mark(struct fsnotify_mark *mark,
+ struct fsnotify_group *group)
+{
+ mutex_lock(&group->mark_mutex);
+ fsnotify_destroy_mark_locked(mark, group);
+ mutex_unlock(&group->mark_mutex);
}
void fsnotify_set_mark_mask_locked(struct fsnotify_mark *mark, __u32 mask)
@@ -208,14 +220,15 @@
* These marks may be used for the fsnotify backend to determine which
* event types should be delivered to which group.
*/
-int fsnotify_add_mark(struct fsnotify_mark *mark,
- struct fsnotify_group *group, struct inode *inode,
- struct vfsmount *mnt, int allow_dups)
+int fsnotify_add_mark_locked(struct fsnotify_mark *mark,
+ struct fsnotify_group *group, struct inode *inode,
+ struct vfsmount *mnt, int allow_dups)
{
int ret = 0;
BUG_ON(inode && mnt);
BUG_ON(!inode && !mnt);
+ BUG_ON(!mutex_is_locked(&group->mark_mutex));
/*
* LOCKING ORDER!!!!
@@ -223,8 +236,6 @@
* mark->lock
* inode->i_lock
*/
- mutex_lock(&group->mark_mutex);
-
spin_lock(&mark->lock);
mark->flags |= FSNOTIFY_MARK_FLAG_ALIVE;
@@ -250,8 +261,6 @@
fsnotify_set_mark_mask_locked(mark, mark->mask);
spin_unlock(&mark->lock);
- mutex_unlock(&group->mark_mutex);
-
if (inode)
__fsnotify_update_child_dentry_flags(inode);
@@ -264,7 +273,6 @@
atomic_dec(&group->num_marks);
spin_unlock(&mark->lock);
- mutex_unlock(&group->mark_mutex);
spin_lock(&destroy_lock);
list_add(&mark->destroy_list, &destroy_list);
@@ -274,6 +282,16 @@
return ret;
}
+int fsnotify_add_mark(struct fsnotify_mark *mark, struct fsnotify_group *group,
+ struct inode *inode, struct vfsmount *mnt, int allow_dups)
+{
+ int ret;
+ mutex_lock(&group->mark_mutex);
+ ret = fsnotify_add_mark_locked(mark, group, inode, mnt, allow_dups);
+ mutex_unlock(&group->mark_mutex);
+ return ret;
+}
+
/*
* clear any marks in a group in which mark->flags & flags is true
*/