fsnotify: Move locking into fsnotify_find_mark()

Move locking of a mark list into fsnotify_find_mark(). This reduces code
churn in the following patch changing lock protecting the list.
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/notify/inode_mark.c

@@ -71,13 +71,7 @@ void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group)
 struct fsnotify_mark *fsnotify_find_inode_mark(struct fsnotify_group *group,
 					       struct inode *inode)
 {
-	struct fsnotify_mark *mark;
-
-	spin_lock(&inode->i_lock);
-	mark = fsnotify_find_mark(inode->i_fsnotify_marks, group);
-	spin_unlock(&inode->i_lock);
-
-	return mark;
+	return fsnotify_find_mark(inode->i_fsnotify_marks, group);
 }
 
 /**

fs/notify/mark.c

@@ -485,16 +485,24 @@ struct fsnotify_mark *fsnotify_find_mark(struct fsnotify_mark_connector *conn,
 					 struct fsnotify_group *group)
 {
 	struct fsnotify_mark *mark;
+	spinlock_t *lock;
 
 	if (!conn)
 		return NULL;
 
+	if (conn->flags & FSNOTIFY_OBJ_TYPE_INODE)
+		lock = &conn->inode->i_lock;
+	else
+		lock = &conn->mnt->mnt_root->d_lock;
+	spin_lock(lock);
 	hlist_for_each_entry(mark, &conn->list, obj_list) {
 		if (mark->group == group) {
 			fsnotify_get_mark(mark);
+			spin_unlock(lock);
 			return mark;
 		}
 	}
+	spin_unlock(lock);
 	return NULL;
 }
 

fs/notify/vfsmount_mark.c

@@ -65,11 +65,6 @@ struct fsnotify_mark *fsnotify_find_vfsmount_mark(struct fsnotify_group *group,
 						  struct vfsmount *mnt)
 {
 	struct mount *m = real_mount(mnt);
-	struct fsnotify_mark *mark;
 
-	spin_lock(&mnt->mnt_root->d_lock);
-	mark = fsnotify_find_mark(m->mnt_fsnotify_marks, group);
-	spin_unlock(&mnt->mnt_root->d_lock);
-
-	return mark;
+	return fsnotify_find_mark(m->mnt_fsnotify_marks, group);
 }