writeback: remove smp_mb(), it's not needed with list_add_tail_rcu()
list_add_tail_rcu contains required barriers.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 3475775..59c99e7 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -151,10 +151,10 @@
BUG_ON(!bdi->wb_cnt);
/*
- * Make sure stores are seen before it appears on the list
+ * list_add_tail_rcu() contains the necessary barriers to
+ * make sure the above stores are seen before the item is
+ * noticed on the list
*/
- smp_mb();
-
spin_lock(&bdi->wb_lock);
list_add_tail_rcu(&work->list, &bdi->work_list);
spin_unlock(&bdi->wb_lock);