From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1164094AbdAIUUg (ORCPT ); Mon, 9 Jan 2017 15:20:36 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42592 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161313AbdAIUUc (ORCPT ); Mon, 9 Jan 2017 15:20:32 -0500 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 X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Mon, 09 Jan 2017 15:20:31 -0500 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Mon, 09 Jan 2017 20:20:33 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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