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 396E3C433FE for ; Fri, 4 Nov 2022 16:09:51 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oqzEl-0000PH-I6; Fri, 04 Nov 2022 12:08:07 -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 1oqzEG-0008B6-Nf for qemu-devel@nongnu.org; Fri, 04 Nov 2022 12:07:37 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oqzE4-0007eR-9i for qemu-devel@nongnu.org; Fri, 04 Nov 2022 12:07:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667578040; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=s4t8jY1wjKzzbbd84P/Q3HKuQ2LWGEfxE4+t1s3j2z4=; b=Zree0JzggR6ivshX4ognBqsXSfdpG+i0rpK4LXR17C3NoKKO7Y/zSfxO0onqLK14PeSDXu 6xttAoQ30S80Vy4UxgpluekJQkHlKoOvgIaJ90jCkG8qzK6MHefViVik4ARCJnSyVWzqH7 ulVypbgZCpoyqxnLj2GbmUtHJjFWlcc= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-84-MM8u4uS1MmOX_MWPpforBw-1; Fri, 04 Nov 2022 12:07:15 -0400 X-MC-Unique: MM8u4uS1MmOX_MWPpforBw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id AACBE1C09075; Fri, 4 Nov 2022 16:07:14 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.193.175]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 85093C15BA4; Fri, 4 Nov 2022 16:07:14 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 47B1F21E66C6; Fri, 4 Nov 2022 17:07:12 +0100 (CET) From: Markus Armbruster To: qemu-devel@nongnu.org Cc: jsnow@redhat.com, eblake@redhat.com, michael.roth@amd.com, Kevin Wolf , Hanna Reitz , qemu-block@nongnu.org Subject: [PATCH v3 08/30] blockdev: Clean up abuse of DriveBackup member format Date: Fri, 4 Nov 2022 17:06:50 +0100 Message-Id: <20221104160712.3005652-9-armbru@redhat.com> In-Reply-To: <20221104160712.3005652-1-armbru@redhat.com> References: <20221104160712.3005652-1-armbru@redhat.com> MIME-Version: 1.0 Content-type: text/plain Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.045, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Qemu-devel" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org drive-backup argument @format defaults to the format of the source unless @mode is "existing". drive_backup_prepare() implements this by copying the source's @format_name to DriveBackup member @format. It leaves @has_format false, violating the "has_format == !!format" invariant. Unclean. Falls apart when we elide @has_format (commit after next): then QAPI passes @format, which is a string constant, to g_free(). iotest 056 duly explodes. Clean it up. Since the value stored in member @format is not actually used outside this function, use a local variable instead of modifying the QAPI object. Signed-off-by: Markus Armbruster Cc: Kevin Wolf Cc: Hanna Reitz Cc: qemu-block@nongnu.org --- blockdev.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/blockdev.c b/blockdev.c index 3f1dec6242..d6550e0dc8 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1686,6 +1686,7 @@ static void drive_backup_prepare(BlkActionState *common, Error **errp) BlockDriverState *source = NULL; AioContext *aio_context; AioContext *old_context; + const char *format; QDict *options; Error *local_err = NULL; int flags; @@ -1717,9 +1718,9 @@ static void drive_backup_prepare(BlkActionState *common, Error **errp) /* Paired with .clean() */ bdrv_drained_begin(bs); - if (!backup->has_format) { - backup->format = backup->mode == NEW_IMAGE_MODE_EXISTING ? - NULL : (char *) bs->drv->format_name; + format = backup->format; + if (!format && backup->mode != NEW_IMAGE_MODE_EXISTING) { + format = bs->drv->format_name; } /* Early check to avoid creating target */ @@ -1758,19 +1759,19 @@ static void drive_backup_prepare(BlkActionState *common, Error **errp) } if (backup->mode != NEW_IMAGE_MODE_EXISTING) { - assert(backup->format); + assert(format); if (source) { /* Implicit filters should not appear in the filename */ BlockDriverState *explicit_backing = bdrv_skip_implicit_filters(source); bdrv_refresh_filename(explicit_backing); - bdrv_img_create(backup->target, backup->format, + bdrv_img_create(backup->target, format, explicit_backing->filename, explicit_backing->drv->format_name, NULL, size, flags, false, &local_err); } else { - bdrv_img_create(backup->target, backup->format, NULL, NULL, NULL, + bdrv_img_create(backup->target, format, NULL, NULL, NULL, size, flags, false, &local_err); } } @@ -1783,8 +1784,8 @@ static void drive_backup_prepare(BlkActionState *common, Error **errp) options = qdict_new(); qdict_put_str(options, "discard", "unmap"); qdict_put_str(options, "detect-zeroes", "unmap"); - if (backup->format) { - qdict_put_str(options, "driver", backup->format); + if (format) { + qdict_put_str(options, "driver", format); } target_bs = bdrv_open(backup->target, NULL, options, flags, errp); -- 2.37.3