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Commit d5a335b8 authored by Lino Sanfilippo's avatar Lino Sanfilippo Committed by Eric Paris
Browse files

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: default avatarLino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: default avatarEric Paris <eparis@redhat.com>
parent e2a29943

fs/notify/mark.c

+30 −12
Original line number Diff line number Diff line
@@ -121,18 +121,18 @@ void fsnotify_put_mark(struct fsnotify_mark *mark) 
 * 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,

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 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark, 
	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 @@ void fsnotify_destroy_mark(struct fsnotify_mark *mark, 
	 */



	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)
@@ -208,7 +220,7 @@ void fsnotify_set_mark_ignored_mask_locked(struct fsnotify_mark *mark, __u32 mas 
 * 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,

int fsnotify_add_mark_locked(struct fsnotify_mark *mark,

			     struct fsnotify_group *group, struct inode *inode,

			     struct vfsmount *mnt, int allow_dups)

{
@@ -216,6 +228,7 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, 


	BUG_ON(inode && mnt);

	BUG_ON(!inode && !mnt);

	BUG_ON(!mutex_is_locked(&group->mark_mutex));



	/*

	 * LOCKING ORDER!!!!
@@ -223,8 +236,6 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, 
	 * mark->lock

	 * inode->i_lock

	 */

	mutex_lock(&group->mark_mutex);



	spin_lock(&mark->lock);

	mark->flags |= FSNOTIFY_MARK_FLAG_ALIVE;
@@ -250,8 +261,6 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, 
	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 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, 
	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 @@ int fsnotify_add_mark(struct fsnotify_mark *mark, 
	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

 */

include/linux/fsnotify_backend.h

+4 −0
Original line number Diff line number Diff line
@@ -408,9 +408,13 @@ extern void fsnotify_set_mark_mask_locked(struct fsnotify_mark *mark, __u32 mask 
/* attach the mark to both the group and the inode */

extern int fsnotify_add_mark(struct fsnotify_mark *mark, struct fsnotify_group *group,

			     struct inode *inode, struct vfsmount *mnt, int allow_dups);

extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark, struct fsnotify_group *group,

				    struct inode *inode, struct vfsmount *mnt, int allow_dups);

/* given a group and a mark, flag mark to be freed when all references are dropped */

extern void fsnotify_destroy_mark(struct fsnotify_mark *mark,

				  struct fsnotify_group *group);

extern void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark,

					 struct fsnotify_group *group);

/* run all the marks in a group, and clear all of the vfsmount marks */

extern void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group);

/* run all the marks in a group, and clear all of the inode marks */