From patchwork Tue Oct 31 18:59:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 1857722 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=Ks2UXLE7; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4SKffn48fkz1yQZ for ; Wed, 1 Nov 2023 06:03:13 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qxtyO-0004Jc-LA; Tue, 31 Oct 2023 15:00:20 -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 1qxty8-0004C5-27 for qemu-devel@nongnu.org; Tue, 31 Oct 2023 15:00:04 -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 1qxtxl-00068q-WE for qemu-devel@nongnu.org; Tue, 31 Oct 2023 15:00:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1698778781; 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=vYhvADMLU/Y/UBF/Lr1Z8Sj0udiiZxhJ5mUvN9t2Kf0=; b=Ks2UXLE7PErYQyi7FjoOv78HuxY9+io9M0CXc3q2+Sa66/nCtlq1eo+q281a71DjCvx9yg BJExbFapVD6y/56EyK0DVcWX/ALwhZ6KSW2mOuDEcRnW4vFCM7tgkgtap1Bw3mcvrKPR48 CGIPWdXHP44REJWWVnn331dmifqZmDU= 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-592-froO-M2ZMT6SoI8EvKUMjw-1; Tue, 31 Oct 2023 14:59:38 -0400 X-MC-Unique: froO-M2ZMT6SoI8EvKUMjw-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 B92608678D2; Tue, 31 Oct 2023 18:59:37 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.194.218]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2952125C2; Tue, 31 Oct 2023 18:59:37 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org Subject: [PULL 21/27] block/mirror: determine copy_to_target only once Date: Tue, 31 Oct 2023 19:59:12 +0100 Message-ID: <20231031185918.346940-22-kwolf@redhat.com> In-Reply-To: <20231031185918.346940-1-kwolf@redhat.com> References: <20231031185918.346940-1-kwolf@redhat.com> MIME-Version: 1.0 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=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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Fiona Ebner In preparation to allow changing the copy_mode via QMP. When running in an iothread, it could be that copy_mode is changed from the main thread in between reading copy_mode in bdrv_mirror_top_pwritev() and reading copy_mode in bdrv_mirror_top_do_write(), so they might end up disagreeing about whether copy_to_target is true or false. Avoid that scenario by determining copy_to_target only once and passing it to bdrv_mirror_top_do_write() as an argument. Signed-off-by: Fiona Ebner Reviewed-by: Vladimir Sementsov-Ogievskiy Message-ID: <20231031135431.393137-5-f.ebner@proxmox.com> Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- block/mirror.c | 41 ++++++++++++++++++----------------------- 1 file changed, 18 insertions(+), 23 deletions(-) diff --git a/block/mirror.c b/block/mirror.c index 914d723446..31da1526eb 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -1463,21 +1463,21 @@ bdrv_mirror_top_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags); } +static bool should_copy_to_target(MirrorBDSOpaque *s) +{ + return s->job && s->job->ret >= 0 && + !job_is_cancelled(&s->job->common.job) && + s->job->copy_mode == MIRROR_COPY_MODE_WRITE_BLOCKING; +} + static int coroutine_fn GRAPH_RDLOCK bdrv_mirror_top_do_write(BlockDriverState *bs, MirrorMethod method, - uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, - int flags) + bool copy_to_target, uint64_t offset, uint64_t bytes, + QEMUIOVector *qiov, int flags) { MirrorOp *op = NULL; MirrorBDSOpaque *s = bs->opaque; int ret = 0; - bool copy_to_target = false; - - if (s->job) { - copy_to_target = s->job->ret >= 0 && - !job_is_cancelled(&s->job->common.job) && - s->job->copy_mode == MIRROR_COPY_MODE_WRITE_BLOCKING; - } if (copy_to_target) { op = active_write_prepare(s->job, offset, bytes); @@ -1524,17 +1524,10 @@ static int coroutine_fn GRAPH_RDLOCK bdrv_mirror_top_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, QEMUIOVector *qiov, BdrvRequestFlags flags) { - MirrorBDSOpaque *s = bs->opaque; QEMUIOVector bounce_qiov; void *bounce_buf; int ret = 0; - bool copy_to_target = false; - - if (s->job) { - copy_to_target = s->job->ret >= 0 && - !job_is_cancelled(&s->job->common.job) && - s->job->copy_mode == MIRROR_COPY_MODE_WRITE_BLOCKING; - } + bool copy_to_target = should_copy_to_target(bs->opaque); if (copy_to_target) { /* The guest might concurrently modify the data to write; but @@ -1551,8 +1544,8 @@ bdrv_mirror_top_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, flags &= ~BDRV_REQ_REGISTERED_BUF; } - ret = bdrv_mirror_top_do_write(bs, MIRROR_METHOD_COPY, offset, bytes, qiov, - flags); + ret = bdrv_mirror_top_do_write(bs, MIRROR_METHOD_COPY, copy_to_target, + offset, bytes, qiov, flags); if (copy_to_target) { qemu_iovec_destroy(&bounce_qiov); @@ -1575,15 +1568,17 @@ static int coroutine_fn GRAPH_RDLOCK bdrv_mirror_top_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, BdrvRequestFlags flags) { - return bdrv_mirror_top_do_write(bs, MIRROR_METHOD_ZERO, offset, bytes, NULL, - flags); + bool copy_to_target = should_copy_to_target(bs->opaque); + return bdrv_mirror_top_do_write(bs, MIRROR_METHOD_ZERO, copy_to_target, + offset, bytes, NULL, flags); } static int coroutine_fn GRAPH_RDLOCK bdrv_mirror_top_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) { - return bdrv_mirror_top_do_write(bs, MIRROR_METHOD_DISCARD, offset, bytes, - NULL, 0); + bool copy_to_target = should_copy_to_target(bs->opaque); + return bdrv_mirror_top_do_write(bs, MIRROR_METHOD_DISCARD, copy_to_target, + offset, bytes, NULL, 0); } static void bdrv_mirror_top_refresh_filename(BlockDriverState *bs)