From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Thumshirn Subject: Re: scsi: BUG in scsi_init_io Date: Tue, 31 Jan 2017 10:58:22 +0100 Message-ID: <20170131095822.GC3687@linux-x5ow.site> References: <20170131092048.GB3687@linux-x5ow.site> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Received: from mx2.suse.de ([195.135.220.15]:52253 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750896AbdAaJ6m (ORCPT ); Tue, 31 Jan 2017 04:58:42 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Dmitry Vyukov Cc: jejb@linux.vnet.ibm.com, "Martin K. Petersen" , linux-scsi , LKML , Al Viro , syzkaller , Hannes Reinecke On Tue, Jan 31, 2017 at 10:50:49AM +0100, Dmitry Vyukov wrote: > On Tue, Jan 31, 2017 at 10:20 AM, Johannes Thumshirn wrote: > > On Tue, Jan 31, 2017 at 09:55:52AM +0100, Dmitry Vyukov wrote: [...] > Please-please-please, let's not use WARN for something that is not a > kernel bug and is user-triggerable. This makes it impossible to > automate kernel testing and requires hiring an army of people doing > mechanical job of sorting out WARNING reports into kernel-bugs and > non-kernel-bugs. > If the message is absolutely necessary (while kernel does not > generally explain every EINVAL on console), the following will do: > > if (!blk_rq_nr_phys_segments(rq)) { > pr_err("you are doing something wrong\n"); > return -EINVAL; > } Yes I understand that. OTOH having the WARN helps you finding the caller because of to the stack trace. But arguably that could be accomplished with function graph tracing as well. I'll re-send a v2 as a proper patch. Thanks, Johannes -- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850