From patchwork Wed Aug 3 14:44:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hanna Czenczek X-Patchwork-Id: 12935591 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 2083EC19F29 for ; Wed, 3 Aug 2022 14:51:01 +0000 (UTC) Received: from localhost ([::1]:44078 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oJFi7-0004rA-QY for qemu-devel@archiver.kernel.org; Wed, 03 Aug 2022 10:50:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44780) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oJFcG-0006Sm-LP for qemu-devel@nongnu.org; Wed, 03 Aug 2022 10:44:56 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:58135) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oJFcF-0002fq-5t for qemu-devel@nongnu.org; Wed, 03 Aug 2022 10:44:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1659537894; 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=K5HfCWfjPKKmO8BGrMcvph/of4e4KrAMKFDU4lZgHjM=; b=MTkOeHjP70tYzg4bzxr2D2/QBAsKJdLVuF6mVJuQN7sEQDkl/zsCSMM9undH3wPcJ0Pmnz T4KwF67J4c6xJ7y10td0A/08X8ZcUwe5EKeX6fDpIic1LlJJTrfhNC4OTk9Ds3LNpisDmw M4782p6K0KgTfwUcKH2Sz5KVYiLf9/Y= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-497-tHV5xX7zPEmNrvHCbAiFXA-1; Wed, 03 Aug 2022 10:44:51 -0400 X-MC-Unique: tHV5xX7zPEmNrvHCbAiFXA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id ECF77801585; Wed, 3 Aug 2022 14:44:50 +0000 (UTC) Received: from localhost (unknown [10.39.193.150]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9B48340CFD0A; Wed, 3 Aug 2022 14:44:50 +0000 (UTC) From: Hanna Reitz To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, Hanna Reitz , Kevin Wolf , Stefan Hajnoczi Subject: [PATCH 2/3] block/qed: Keep auto_backing_file if possible Date: Wed, 3 Aug 2022 16:44:45 +0200 Message-Id: <20220803144446.20723-3-hreitz@redhat.com> In-Reply-To: <20220803144446.20723-1-hreitz@redhat.com> References: <20220803144446.20723-1-hreitz@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 Received-SPF: pass client-ip=170.10.129.124; envelope-from=hreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Just like qcow2, qed invokes its open function in its .bdrv_co_invalidate_cache() implementation. Therefore, just like done for qcow2 in HEAD^, update auto_backing_file only if the backing file string in the image header differs from the one we have read before. Signed-off-by: Hanna Reitz --- block/qed.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/block/qed.c b/block/qed.c index 40943e679b..324ca0e95a 100644 --- a/block/qed.c +++ b/block/qed.c @@ -445,6 +445,8 @@ static int coroutine_fn bdrv_qed_do_open(BlockDriverState *bs, QDict *options, } if ((s->header.features & QED_F_BACKING_FILE)) { + g_autofree char *backing_file_str = NULL; + if ((uint64_t)s->header.backing_filename_offset + s->header.backing_filename_size > s->header.cluster_size * s->header.header_size) { @@ -452,16 +454,21 @@ static int coroutine_fn bdrv_qed_do_open(BlockDriverState *bs, QDict *options, return -EINVAL; } + backing_file_str = g_malloc(sizeof(bs->backing_file)); ret = qed_read_string(bs->file, s->header.backing_filename_offset, s->header.backing_filename_size, - bs->auto_backing_file, - sizeof(bs->auto_backing_file)); + backing_file_str, sizeof(bs->backing_file)); if (ret < 0) { error_setg(errp, "Failed to read backing filename"); return ret; } - pstrcpy(bs->backing_file, sizeof(bs->backing_file), - bs->auto_backing_file); + + if (!g_str_equal(backing_file_str, bs->backing_file)) { + pstrcpy(bs->backing_file, sizeof(bs->backing_file), + backing_file_str); + pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), + backing_file_str); + } if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) { pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw");