This is a note to let you know that I've just added the patch titled
dm mpath: do not lock up a CPU with requeuing activity
to the 4.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dm-mpath-do-not-lock-up-a-cpu-with-requeuing-activity.patch
and it can be found in the queue-4.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1c23484c355ec360ca2f37914f8a4802c6baeead Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bart.vanassche@xxxxxxx>
Date: Wed, 9 Aug 2017 11:32:12 -0700
Subject: dm mpath: do not lock up a CPU with requeuing activity
From: Bart Van Assche <bart.vanassche@xxxxxxx>
commit 1c23484c355ec360ca2f37914f8a4802c6baeead upstream.
When using the block layer in single queue mode, get_request()
returns ERR_PTR(-EAGAIN) if the queue is dying and the REQ_NOWAIT
flag has been passed to get_request(). Avoid that the kernel
reports soft lockup complaints in this case due to continuous
requeuing activity.
Fixes: 7083abbbf ("dm mpath: avoid that path removal can trigger an infinite loop")
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Tested-by: Laurence Oberman <loberman@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm-mpath.c | 1 -
1 file changed, 1 deletion(-)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -504,7 +504,6 @@ static int multipath_clone_and_map(struc
if (queue_dying) {
atomic_inc(&m->pg_init_in_progress);
activate_or_offline_path(pgpath);
- return DM_MAPIO_REQUEUE;
}
return DM_MAPIO_DELAY_REQUEUE;
}
Patches currently in stable-queue which might be from bart.vanassche@xxxxxxx are
queue-4.12/dm-mpath-do-not-lock-up-a-cpu-with-requeuing-activity.patch