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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 EA73BC433E0 for ; Wed, 24 Feb 2021 17:23:45 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3682D64F0D for ; Wed, 24 Feb 2021 17:23:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3682D64F0D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:48344 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lExt2-0000Qi-6z for qemu-devel@archiver.kernel.org; Wed, 24 Feb 2021 12:23:44 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:45812) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lExaZ-0007gN-1V for qemu-devel@nongnu.org; Wed, 24 Feb 2021 12:04:40 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:34484) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lExaK-0000W2-BE for qemu-devel@nongnu.org; Wed, 24 Feb 2021 12:04:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614186261; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=vAKRQMVWy4LJyfobS8j37UjALrYlzzxexycDVD+gCSQ=; b=PkhkTDUt4EVe6L+EDXfergwrf1Uks1KoRT38GrEvgYboS+6hKLpdmzjrSsPv+i10KBmgg1 Bb0SN6QFrhflb0S8LjcXxUf5QgBn2FNzn7CVuFx8W5F74aWTUXKbb/tEIJIDSxzBS0wfY+ GGBOs2ZKzWa40Oalt1hGs3rcMfX7Wo0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-536-7J5LbhUKP0Wda37qu4zmZw-1; Wed, 24 Feb 2021 12:04:18 -0500 X-MC-Unique: 7J5LbhUKP0Wda37qu4zmZw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BA1F51876555; Wed, 24 Feb 2021 17:04:17 +0000 (UTC) Received: from merkur.fritz.box (ovpn-114-142.ams2.redhat.com [10.36.114.142]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6F4895D6D3; Wed, 24 Feb 2021 17:04:16 +0000 (UTC) Date: Wed, 24 Feb 2021 18:04:14 +0100 From: Kevin Wolf To: Stefano Garzarella Subject: Re: [PATCH] blockjob: report a better error message Message-ID: <20210224170414.GG11025@merkur.fritz.box> References: <20210223131150.124867-1-sgarzare@redhat.com> <20210224143620.GB11025@merkur.fritz.box> <20210224155925.kzyatjog67ldwpzf@steredhat> MIME-Version: 1.0 In-Reply-To: <20210224155925.kzyatjog67ldwpzf@steredhat> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=63.128.21.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Vladimir Sementsov-Ogievskiy , John Snow , qemu-devel@nongnu.org, qemu-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 24.02.2021 um 16:59 hat Stefano Garzarella geschrieben: > On Wed, Feb 24, 2021 at 03:36:20PM +0100, Kevin Wolf wrote: > > Am 23.02.2021 um 14:11 hat Stefano Garzarella geschrieben: > > > When a block job fails, we report 'strerror(-job->job.ret)' error > > > message, also if the job set an error object. > > > Let's report a better error message using 'error_get_pretty(job->job.err)'. > > > > > > If an error object was not set, strerror(-job->ret) is used as fallback, > > > as explained in include/qemu/job.h: > > > > > > typedef struct Job { > > > ... > > > /** > > > * Error object for a failed job. > > > * If job->ret is nonzero and an error object was not set, it will be set > > > * to strerror(-job->ret) during job_completed. > > > */ > > > Error *err; > > > } > > > > This is true, but there is a short time where job->ret is already set, > > but not turned into job->err yet if necessary. The latter is done in a > > bottom half scheduled after the former has happened. > > > > It doesn't matter for block_job_event_completed(), which is called only > > after both, but block_job_query() could in theory be called in this > > window. > > > > > Suggested-by: Kevin Wolf > > > Signed-off-by: Stefano Garzarella > > > --- > > > blockjob.c | 5 +++-- > > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > > > diff --git a/blockjob.c b/blockjob.c > > > index f2feff051d..a696f3408d 100644 > > > --- a/blockjob.c > > > +++ b/blockjob.c > > > @@ -319,7 +319,8 @@ BlockJobInfo *block_job_query(BlockJob *job, Error **errp) > > > info->auto_finalize = job->job.auto_finalize; > > > info->auto_dismiss = job->job.auto_dismiss; > > > info->has_error = job->job.ret != 0; > > > - info->error = job->job.ret ? g_strdup(strerror(-job->job.ret)) : NULL; > > > + info->error = job->job.ret ? > > > + g_strdup(error_get_pretty(job->job.err)) : NULL; > > > > So I think we can't rely on job->job.err being non-NULL here. > > Do you think is better to leave it as it was or do something like this? > > if (job->job.ret) { > info->has_error = true; > info->error = job->job.err ? g_strdup(error_get_pretty(job->job.err)) : > g_strdup(strerror(-job->job.ret); > } Yes, I think this is the best solution. Use the error when we have it, fall back to strerror() when we don't have it. Kevin