Commit 11a6f8e2 authored by Jan Kara's avatar Jan Kara
Browse files

fsnotify: Clarify connector assignment in fsnotify_add_mark_list() 



Add a comment explaining why WRITE_ONCE() is enough when setting
mark->connector which can get dereferenced by RCU protected readers.

Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent b1da6a51

fs/notify/mark.c

+5 −0
Original line number Diff line number Diff line
@@ -619,6 +619,11 @@ static int fsnotify_add_mark_list(struct fsnotify_mark *mark, 
	/* mark should be the last entry.  last is the current last entry */

	hlist_add_behind_rcu(&mark->obj_list, &last->obj_list);

added:

	/*

	 * Since connector is attached to object using cmpxchg() we are

	 * guaranteed that connector initialization is fully visible by anyone

	 * seeing mark->connector set.

	 */

	WRITE_ONCE(mark->connector, conn);

out_err:

	spin_unlock(&conn->lock);