From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C7C95C433DF for ; Sun, 11 Oct 2020 14:53:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 776CD2078B for ; Sun, 11 Oct 2020 14:53:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729163AbgJKOxZ (ORCPT ); Sun, 11 Oct 2020 10:53:25 -0400 Received: from mx2.suse.de ([195.135.220.15]:53634 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725863AbgJKOxZ (ORCPT ); Sun, 11 Oct 2020 10:53:25 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 9EE40AC3F; Sun, 11 Oct 2020 14:53:23 +0000 (UTC) Subject: Re: [PATCH] block: switch to pr_warn() in __device_add_disk() To: Rustam Kovhaev , axboe@kernel.dk, linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org References: <20201011130347.562264-1-rkovhaev@gmail.com> From: Hannes Reinecke Message-ID: <745dd869-00ba-19fd-3643-27a92326f424@suse.de> Date: Sun, 11 Oct 2020 16:53:22 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20201011130347.562264-1-rkovhaev@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 10/11/20 3:03 PM, Rustam Kovhaev wrote: > syzbot triggered a warning while fuzzing with failslab fault injection > enabled > let's convert WARN_ON() to pr_warn() > > Reported-and-tested-by: syzbot+f41893bb8c45cd18cf08@syzkaller.appspotmail.com > Link: https://syzkaller.appspot.com/bug?extid=f41893bb8c45cd18cf08 > Signed-off-by: Rustam Kovhaev > --- > block/genhd.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/block/genhd.c b/block/genhd.c > index 99c64641c314..be9ce35cf0fe 100644 > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -822,7 +822,8 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk, > /* Register BDI before referencing it from bdev */ > dev->devt = devt; > ret = bdi_register(bdi, "%u:%u", MAJOR(devt), MINOR(devt)); > - WARN_ON(ret); > + if (ret) > + pr_warn("%s: failed to register backing dev info\n", disk->disk_name); > bdi_set_owner(bdi, dev); > blk_register_region(disk_devt(disk), disk->minors, NULL, > exact_match, exact_lock, disk); > Please, don't. Where is the point in continuing here? I'd rather have it fixed up properly, either by having a return value to __device_add_disk() or by allowing the caller to check (eg by checking GENHD_FL_UP) if the call succeeded. Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer