[PATCH 3/3] fsnotify: Remove destroy_list from fsnotify_mark

[Jan Kara <jack@suse.cz>]

destroy_list is used to track marks which still need waiting for srcu
period end before they can be freed. However by the time mark is added
to destroy_list it isn't in group's list of marks anymore and thus we
can reuse fsnotify_mark->g_list for queueing into destroy_list. This
saves two pointers for each fsnotify_mark.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/notify/mark.c                 | 8 ++++----
 include/linux/fsnotify_backend.h | 1 -
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 70dba449c33f..b6237ce85e3e 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -150,7 +150,7 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark,
 	mutex_unlock(&group->mark_mutex);
 
 	spin_lock(&destroy_lock);
-	list_add(&mark->destroy_list, &destroy_list);
+	list_add(&mark->g_list, &destroy_list);
 	spin_unlock(&destroy_lock);
 	wake_up(&destroy_waitq);
 	/*
@@ -360,7 +360,7 @@ err:
 	spin_unlock(&mark->lock);
 
 	spin_lock(&destroy_lock);
-	list_add(&mark->destroy_list, &destroy_list);
+	list_add(&mark->g_list, &destroy_list);
 	spin_unlock(&destroy_lock);
 	wake_up(&destroy_waitq);
 
@@ -459,8 +459,8 @@ static int fsnotify_mark_destroy(void *ignored)
 
 		synchronize_srcu(&fsnotify_mark_srcu);
 
-		list_for_each_entry_safe(mark, next, &private_destroy_list, destroy_list) {
-			list_del_init(&mark->destroy_list);
+		list_for_each_entry_safe(mark, next, &private_destroy_list, g_list) {
+			list_del_init(&mark->g_list);
 			fsnotify_put_mark(mark);
 		}
 
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 82022da18035..e12b81579408 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -226,7 +226,6 @@ struct fsnotify_mark {
 #define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY	0x08
 #define FSNOTIFY_MARK_FLAG_ALIVE		0x10
 	unsigned int flags;		/* vfsmount or inode mark? */
-	struct list_head destroy_list;
 	void (*free_mark)(struct fsnotify_mark *mark); /* called on final put+free */
 };
 
-- 
1.8.1.4