From: Jonathan Brassow <jbrassow@redhat.com>
Date: Wed, 16 May 2012 09:06:14 +0000 (-0500)
Subject: MD: Add del_timer_sync to mddev_suspend (fix nasty panic)
X-Git-Tag: v3.2.18~8
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ad87af4331c0b242788fbf668eefe2e311f2cd7f;p=karo-tx-linux.git

MD: Add del_timer_sync to mddev_suspend (fix nasty panic)

commit 0d9f4f135eb6dea06bdcb7065b1e4ff78274a5e9 upstream.

Use del_timer_sync to remove timer before mddev_suspend finishes.

We don't want a timer going off after an mddev_suspend is called.  This is
especially true with device-mapper, since it can call the destructor function
immediately following a suspend.  This results in the removal (kfree) of the
structures upon which the timer depends - resulting in a very ugly panic.
Therefore, we add a del_timer_sync to mddev_suspend to prevent this.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 065ab4f46594..adcd850335b1 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -392,6 +392,8 @@ void mddev_suspend(struct mddev *mddev)
 	synchronize_rcu();
 	wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
 	mddev->pers->quiesce(mddev, 1);
+
+	del_timer_sync(&mddev->safemode_timer);
 }
 EXPORT_SYMBOL_GPL(mddev_suspend);