md: md.c: fix oops in mddev_suspend for raid0

Introduced by upstream commit 70d9798b95

The raid0 personality does not create mddev->thread as oposed to
other personalities leading to its unconditional access in
mddev_suspend() causing an oops.

Patch checks for mddev->thread in order to keep the
intention of aforementioned commit.

Fixes: 70d9798b95 ("MD: warn for potential deadlock")
Cc: stable@vger.kernel.org (4.5+)
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
This commit is contained in:
Heinz Mauelshagen 2016-05-03 19:43:57 +02:00 committed by Shaohua Li
parent bc47e84258
commit 092398dce8

View File

@ -307,7 +307,7 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
*/
void mddev_suspend(struct mddev *mddev)
{
WARN_ON_ONCE(current == mddev->thread->tsk);
WARN_ON_ONCE(mddev->thread && current == mddev->thread->tsk);
if (mddev->suspended++)
return;
synchronize_rcu();