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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=no 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 0681BC55181 for ; Mon, 20 Apr 2020 23:20:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BD9C522202 for ; Mon, 20 Apr 2020 23:20:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD9C522202 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3D36B8E0007; Mon, 20 Apr 2020 19:20:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 383828E0003; Mon, 20 Apr 2020 19:20:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 299588E0007; Mon, 20 Apr 2020 19:20:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0116.hostedemail.com [216.40.44.116]) by kanga.kvack.org (Postfix) with ESMTP id 0F3448E0003 for ; Mon, 20 Apr 2020 19:20:14 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id ADD14824556B for ; Mon, 20 Apr 2020 23:20:13 +0000 (UTC) X-FDA: 76729803906.15.foot04_765b910180e44 X-HE-Tag: foot04_765b910180e44 X-Filterd-Recvd-Size: 2466 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Mon, 20 Apr 2020 23:20:13 +0000 (UTC) Received: from oasis.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D6F1020B1F; Mon, 20 Apr 2020 23:20:10 +0000 (UTC) Date: Mon, 20 Apr 2020 19:20:09 -0400 From: Steven Rostedt To: Luis Chamberlain Cc: Bart Van Assche , axboe@kernel.dk, viro@zeniv.linux.org.uk, gregkh@linuxfoundation.org, mingo@redhat.com, jack@suse.cz, ming.lei@redhat.com, nstange@suse.de, akpm@linux-foundation.org, mhocko@suse.com, yukuai3@huawei.com, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 05/10] blktrace: upgrade warns to BUG_ON() on unexpected circmunstances Message-ID: <20200420192009.073a1cec@oasis.local.home> In-Reply-To: <20200419230730.GH11244@42.do-not-panic.com> References: <20200419194529.4872-1-mcgrof@kernel.org> <20200419194529.4872-6-mcgrof@kernel.org> <54b63fd9-0c73-5fdc-b43d-6ab4aec3a00d@acm.org> <20200419230730.GH11244@42.do-not-panic.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sun, 19 Apr 2020 23:07:30 +0000 Luis Chamberlain wrote: > On Sun, Apr 19, 2020 at 03:50:13PM -0700, Bart Van Assche wrote: > > On 4/19/20 12:45 PM, Luis Chamberlain wrote: > > > @@ -498,10 +498,7 @@ static struct dentry *blk_trace_debugfs_dir(struct blk_user_trace_setup *buts, > > > struct dentry *dir = NULL; > > > /* This can only happen if we have a bug on our lower layers */ > > > - if (!q->kobj.parent) { > > > - pr_warn("%s: request_queue parent is gone\n", buts->name); > > > - return NULL; > > > - } > > > + BUG_ON(!q->kobj.parent); > > > > Does the following quote from Linus also apply to this patch: "there is NO > > F*CKING EXCUSE to knowingly kill the kernel." See also > > https://lkml.org/lkml/2016/10/4/1. > > We can use WARN_ON() and keep the return NULL, sure. > Yes please. This is definitely not something that should kill the system. -- Steve