From: Lars Ellenberg Date: Wed, 22 Aug 2012 12:59:06 +0000 (+0200) Subject: drbd: fix potential list_add corruption X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b792b655cdf79d4d90b4d46fa37e260ba0296850;p=linux-beck.git drbd: fix potential list_add corruption If the md_sync_timer triggers a second time, while the work queued during the first time is still pending, this could result in list_add() of an already added item, and corrupt the work item list. This likely only triggered because of the erroneous batch-dequeueing of work items fixed with drbd: dequeue single work items in wait_for_work() Still, skip queueing if md_sync_work is already queued. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index d831e85f1515..732053de1dbf 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -3314,7 +3314,9 @@ static void md_sync_timer_fn(unsigned long data) { struct drbd_conf *mdev = (struct drbd_conf *) data; - drbd_queue_work_front(&mdev->tconn->sender_work, &mdev->md_sync_work); + /* must not double-queue! */ + if (list_empty(&mdev->md_sync_work.list)) + drbd_queue_work_front(&mdev->tconn->sender_work, &mdev->md_sync_work); } static int w_md_sync(struct drbd_work *w, int unused)