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 37ff00d014b42761aa2e5b1b2d4016380c18032c..7c45286e2662697a91ab3f3f2075080700826443 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5306,6 +5306,8 @@ EXPORT_SYMBOL_GPL(md_stop_writes);
 static void __md_stop(struct mddev *mddev)
 {
        mddev->ready = 0;
+       /* Ensure ->event_work is done */
+       flush_workqueue(md_misc_wq);
        mddev->pers->stop(mddev);
        if (mddev->pers->sync_request && mddev->to_remove == NULL)
                mddev->to_remove = &md_redundancy_group;