From 4cdd2ad78098244c1bc9ec4374ea1c225fd1cd6f Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer@redhat.com>
Date: Tue, 13 May 2014 13:49:39 -0400
Subject: [PATCH] dm mpath: fix lock order inconsistency in multipath_ioctl
Commit 3e9f1be1b40 ("dm mpath: remove process_queued_ios()") did not
consistently take the multipath device's spinlock (m->lock) before
calling dm_table_run_md_queue_async() -- which takes the q->queue_lock.
Found with code inspection using hint from reported lockdep warning.
Reported-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm-mpath.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index aa009e865871..fa0f6cbd6a41 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1566,8 +1566,8 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
}
if (m->pg_init_required)
__pg_init_all_paths(m);
- spin_unlock_irqrestore(&m->lock, flags);
dm_table_run_md_queue_async(m->ti->table);
+ spin_unlock_irqrestore(&m->lock, flags);
}
return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg);
--
2.20.1