From: Mikulas Patocka <mpatocka@redhat.com>
To: Mike Snitzer <msnitzer@redhat.com>
Cc: dm-devel@redhat.com
Subject: [PATCH] dm: add memory barrier before waitqueue_active
Date: Tue, 5 Feb 2019 05:09:00 -0500 (EST) [thread overview]
Message-ID: <alpine.LRH.2.02.1902050506470.12231@file01.intranet.prod.int.rdu2.redhat.com> (raw)
Hi
Please submit patch this to Linus before 5.0 is released.
Mikulas
waitqueue_active without preceding barrier is unsafe, see the comment
before waitqueue_active definition in include/linux/wait.h.
This patch changes it to wq_has_sleeper.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 6f75723190d8 ("dm: remove the pending IO accounting")
---
drivers/md/dm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Index: linux-2.6/drivers/md/dm.c
===================================================================
--- linux-2.6.orig/drivers/md/dm.c 2019-02-04 20:18:03.000000000 +0100
+++ linux-2.6/drivers/md/dm.c 2019-02-04 20:18:03.000000000 +0100
@@ -699,7 +699,7 @@ static void end_io_acct(struct dm_io *io
true, duration, &io->stats_aux);
/* nudge anyone waiting on suspend queue */
- if (unlikely(waitqueue_active(&md->wait)))
+ if (unlikely(wq_has_sleeper(&md->wait)))
wake_up(&md->wait);
}
next reply other threads:[~2019-02-05 10:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-05 10:09 Mikulas Patocka [this message]
2019-02-05 17:19 ` dm: add memory barrier before waitqueue_active Mike Snitzer
2019-02-05 17:56 ` Mikulas Patocka
2019-02-05 19:05 ` Mike Snitzer
2019-02-05 19:29 ` Mikulas Patocka
2019-02-05 19:58 ` Mike Snitzer
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