Patch "dm rq: check blk_mq_register_dev() return value in dm_mq_init_request_queue()" has been added to the 4.9-stable tree

Patch "dm rq: check blk_mq_register_dev() return value in dm_mq_init_request_queue()" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    dm rq: check blk_mq_register_dev() return value in dm_mq_init_request_queue()

to the 4.9-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-rq-check-blk_mq_register_dev-return-value-in-dm_mq_init_request_queue.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 23a601248958fa4142d49294352fe8d1fdf3e509 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bart.vanassche@sandisk.com>
Date: Thu, 27 Apr 2017 10:11:19 -0700
Subject: dm rq: check blk_mq_register_dev() return value in dm_mq_init_request_queue()

From: Bart Van Assche <bart.vanassche@sandisk.com>

commit 23a601248958fa4142d49294352fe8d1fdf3e509 upstream.

Otherwise the request-based DM blk-mq request_queue will be put into
service without being properly exported via sysfs.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/md/dm-rq.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -997,10 +997,14 @@ int dm_mq_init_request_queue(struct mapp
 	dm_init_md_queue(md);
 
 	/* backfill 'mq' sysfs registration normally done in blk_register_queue */
-	blk_mq_register_dev(disk_to_dev(md->disk), q);
+	err = blk_mq_register_dev(disk_to_dev(md->disk), q);
+	if (err)
+		goto out_cleanup_queue;
 
 	return 0;
 
+out_cleanup_queue:
+	blk_cleanup_queue(q);
 out_tag_set:
 	blk_mq_free_tag_set(md->tag_set);
 out_kfree_tag_set:


Patches currently in stable-queue which might be from bart.vanassche@sandisk.com are

queue-4.9/target-fileio-fix-zero-length-read-and-write-handling.patch
queue-4.9/dm-rq-check-blk_mq_register_dev-return-value-in-dm_mq_init_request_queue.patch