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 C677FC4332F for ; Tue, 31 Oct 2023 19:01:37 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qxtxq-0003wA-IB; Tue, 31 Oct 2023 14:59:46 -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 1qxtxo-0003va-KG for qemu-devel@nongnu.org; Tue, 31 Oct 2023 14:59:44 -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 1qxtxW-00066C-39 for qemu-devel@nongnu.org; Tue, 31 Oct 2023 14:59:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1698778765; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PjIerUf9u0uFn+Ltsfafs37cS1G262v/Y5EckadG/w8=; b=F1H9uxnzJkARcqP+c2/WVbL85P3ICadv+Yn6ie8XOjjWoW8QwVT4p/ryVRsjohc4gMUSpg WqjwvW+sS0JSLbe6ftzZihuXaZazJK9Y/ko5jYBBB/ZpolQEO9KX9o79/vb7sWwdFZaBWL jWoughsDo1e60yhkZ4GO+gFoSvuFjLk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-668-qVOU4cvEMWGlr7W0ibEOBg-1; Tue, 31 Oct 2023 14:59:23 -0400 X-MC-Unique: qVOU4cvEMWGlr7W0ibEOBg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 16CB08678A7; Tue, 31 Oct 2023 18:59:23 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.194.218]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7A461143; Tue, 31 Oct 2023 18:59:22 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org Subject: [PULL 03/27] qemu-img: rebase: use backing files' BlockBackend for buffer alignment Date: Tue, 31 Oct 2023 19:58:54 +0100 Message-ID: <20231031185918.346940-4-kwolf@redhat.com> In-Reply-To: <20231031185918.346940-1-kwolf@redhat.com> References: <20231031185918.346940-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.481, 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, 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 From: Andrey Drobyshev Since commit bb1c05973cf ("qemu-img: Use qemu_blockalign"), buffers for the data read from the old and new backing files are aligned using BlockDriverState (or BlockBackend later on) referring to the target image. However, this isn't quite right, because buf_new is only being used for reading from the new backing, while buf_old is being used for both reading from the old backing and writing to the target. Let's take that into account and use more appropriate values as alignments. Signed-off-by: Andrey Drobyshev Message-ID: <20230919165804.439110-4-andrey.drobyshev@virtuozzo.com> Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- qemu-img.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/qemu-img.c b/qemu-img.c index 2b2a3a86ca..e61d996e0f 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -3759,8 +3759,13 @@ static int img_rebase(int argc, char **argv) int64_t n; float local_progress = 0; - buf_old = blk_blockalign(blk, IO_BUF_SIZE); - buf_new = blk_blockalign(blk, IO_BUF_SIZE); + if (blk_old_backing && bdrv_opt_mem_align(blk_bs(blk_old_backing)) > + bdrv_opt_mem_align(blk_bs(blk))) { + buf_old = blk_blockalign(blk_old_backing, IO_BUF_SIZE); + } else { + buf_old = blk_blockalign(blk, IO_BUF_SIZE); + } + buf_new = blk_blockalign(blk_new_backing, IO_BUF_SIZE); size = blk_getlength(blk); if (size < 0) { -- 2.41.0