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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 73134EB64DA for ; Wed, 5 Jul 2023 21:55:25 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qHASU-0007CU-1E; Wed, 05 Jul 2023 17:54:46 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qHASR-0007C1-S2 for qemu-devel@nongnu.org; Wed, 05 Jul 2023 17:54:43 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qHASQ-0000xS-AE for qemu-devel@nongnu.org; Wed, 05 Jul 2023 17:54:43 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 5FBC621F3E; Wed, 5 Jul 2023 21:54:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1688594080; h=from:from:reply-to: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=5CCCffy8ynJl/oQU+chXPWdPGzu/o82Sk1hhBkw29/U=; b=ZnkwRpjvhoNUz43ATcaCFwH9XJ3f6d53j+ZDQcjBRVi/H/8XHmh93ozSyJ5L+Zxqjx3ArR 3zE1wQ5fhLcPYtDmEOziUvmXV/fENddJg+WHlL2vbEf86dCg2d+zmvQzTPJOpfcyZnFw/D XFb3HSGRgfKCd1LqwSeOj0e9wv0zd3U= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1688594080; h=from:from:reply-to: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=5CCCffy8ynJl/oQU+chXPWdPGzu/o82Sk1hhBkw29/U=; b=UH6BiT2Y2PrvEY1KFmmMj26uIvOmghceUUdz0PtUMLq81nG996HsVoOK3G1BlykkHU8N+o nF3am7+Z1IcYrHBg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id E09A9134F3; Wed, 5 Jul 2023 21:54:39 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id H6L4J5/mpWQ0VAAAMHmgww (envelope-from ); Wed, 05 Jul 2023 21:54:39 +0000 From: Fabiano Rosas To: Peter Xu , qemu-devel@nongnu.org Cc: Leonardo Bras Soares Passos , Juan Quintela , Lukas Straub , Laszlo Ersek , peterx@redhat.com Subject: Re: [PATCH v2 6/7] qemufile: Always return a verbose error In-Reply-To: <20230705163502.331007-7-peterx@redhat.com> References: <20230705163502.331007-1-peterx@redhat.com> <20230705163502.331007-7-peterx@redhat.com> Date: Wed, 05 Jul 2023 18:54:37 -0300 Message-ID: <87bkgq3tya.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain Received-SPF: pass client-ip=195.135.220.28; envelope-from=farosas@suse.de; helo=smtp-out1.suse.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Peter Xu writes: > There're a lot of cases where we only have an errno set in last_error but > without a detailed error description. When this happens, try to generate > an error contains the errno as a descriptive error. > > This will be helpful in cases where one relies on the Error*. E.g., > migration state only caches Error* in MigrationState.error. With this, > we'll display correct error messages in e.g. query-migrate when the error > was only set by qemu_file_set_error(). > > Signed-off-by: Peter Xu > --- > migration/qemu-file.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/migration/qemu-file.c b/migration/qemu-file.c > index acc282654a..419b4092e7 100644 > --- a/migration/qemu-file.c > +++ b/migration/qemu-file.c > @@ -156,15 +156,24 @@ void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks) > * > * Return negative error value if there has been an error on previous > * operations, return 0 if no error happened. > - * Optional, it returns Error* in errp, but it may be NULL even if return value > - * is not 0. > * > + * If errp is specified, a verbose error message will be copied over. > */ > int qemu_file_get_error_obj(QEMUFile *f, Error **errp) > { > + if (!f->last_error) { > + return 0; > + } > + > + /* There is an error */ > if (errp) { > - *errp = f->last_error_obj ? error_copy(f->last_error_obj) : NULL; > + if (f->last_error_obj) { > + *errp = error_copy(f->last_error_obj); > + } else { > + error_setg_errno(errp, -f->last_error, "Channel error"); There are a couple of places that do: ret = vmstate_save(f, se, ms->vmdesc); if (ret) { qemu_file_set_error(f, ret); break; } and vmstate_save() can return > 0 on error. This would make this message say "Unknown error". This is minor. But take a look at qemu_fclose(). It can return f->last_error while the function documentation says it should return negative on error. Should we make qemu_file_set_error() check 'ret' and always set a negative value for f->last_error?