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

BugLink: http://bugs.launchpad.net/bugs/1692898
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>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 6e702fc69a83cb27f6bc1792d4871ad18d708f71..1153478d3545af2207dfa1675e33c2bf8dc6c572 100644 (file)
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -961,10 +961,14 @@ int dm_mq_init_request_queue(struct mapped_device *md, struct dm_table *t)
        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: