From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Jeff Moyer To: axboe@kernel.dk, Markus Pargmann Cc: linux-block@vger.kernel.org, nbd-general@lists.sourceforge.net, linux-kernel@vger.kernel.org, Omar Sandoval Subject: [patch] nbd: blk_mq_init_queue returns an error code on failure, not NULL Date: Mon, 09 Jan 2017 15:20:31 -0500 Message-ID: MIME-Version: 1.0 Content-Type: text/plain List-ID: Additionally, don't assign directly to disk->queue, otherwise blk_put_queue (called via put_disk) will choke (panic) on the errno stored there. Bug found by code inspection after Omar found a similar issue in virtio_blk. Compile-tested only. Signed-off-by: Jeff Moyer diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 38c576f..50a2020 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1042,6 +1042,7 @@ static int __init nbd_init(void) return -ENOMEM; for (i = 0; i < nbds_max; i++) { + struct request_queue *q; struct gendisk *disk = alloc_disk(1 << part_shift); if (!disk) goto out; @@ -1067,12 +1068,13 @@ static int __init nbd_init(void) * every gendisk to have its very own request_queue struct. * These structs are big so we dynamically allocate them. */ - disk->queue = blk_mq_init_queue(&nbd_dev[i].tag_set); - if (!disk->queue) { + q = blk_mq_init_queue(&nbd_dev[i].tag_set); + if (IS_ERR(q)) { blk_mq_free_tag_set(&nbd_dev[i].tag_set); put_disk(disk); goto out; } + disk->queue = q; /* * Tell the block layer that we are not a rotational device