md: flush ->event_work before stopping array.

commit ee5d004fd0591536a061451eba2b187092e9127c upstream.

The 'event_work' worker used by dm-raid may still be running
when the array is stopped.  This can result in an oops.

So flush the workqueue on which it is run after detaching
and before destroying the device.

Reported-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Fixes: 9d09e663d550 ("dm: raid456 basic support")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index e4621511d118b5474c3fba22433fb09784556078..e8c44fcb1ad146b7d9609cd4a040a4fbacf42c5b 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5365,6 +5365,8 @@ static void __md_stop(struct mddev *mddev)
 {
        struct md_personality *pers = mddev->pers;
        mddev_detach(mddev);
+       /* Ensure ->event_work is done */
+       flush_workqueue(md_misc_wq);
        spin_lock(&mddev->lock);
        mddev->ready = 0;
        mddev->pers = NULL;