From patchwork Mon Jun 20 14:05:30 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 9187667 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2EDF6607D1 for ; Mon, 20 Jun 2016 14:46:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1C31D2787C for ; Mon, 20 Jun 2016 14:46:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 10B912793A; Mon, 20 Jun 2016 14:46:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 8FE642787C for ; Mon, 20 Jun 2016 14:46:09 +0000 (UTC) Received: from localhost ([::1]:44076 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bF0Sm-0001lB-8j for patchwork-qemu-devel@patchwork.kernel.org; Mon, 20 Jun 2016 10:46:08 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47917) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bEzqL-0008Gd-Qf for qemu-devel@nongnu.org; Mon, 20 Jun 2016 10:06:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bEzqE-0007Ac-Kn for qemu-devel@nongnu.org; Mon, 20 Jun 2016 10:06:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37619) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bEzqE-0007AJ-72 for qemu-devel@nongnu.org; Mon, 20 Jun 2016 10:06:18 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 801EE46217; Mon, 20 Jun 2016 14:06:17 +0000 (UTC) Received: from localhost (ovpn-112-59.ams2.redhat.com [10.36.112.59]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u5KE6Gf2027961; Mon, 20 Jun 2016 10:06:16 -0400 From: Stefan Hajnoczi To: Date: Mon, 20 Jun 2016 15:05:30 +0100 Message-Id: <1466431531-17806-20-git-send-email-stefanha@redhat.com> In-Reply-To: <1466431531-17806-1-git-send-email-stefanha@redhat.com> References: <1466431531-17806-1-git-send-email-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Mon, 20 Jun 2016 14:06:17 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 19/20] mirror: follow AioContext change gracefully X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Fam Zheng , Stefan Hajnoczi Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Add block_job_pause_point() calls to mark quiescent points and make sure to complete in-flight requests when switching AioContexts. This patch solves undefined behavior in the mirror block job when the BDS AioContext is changed by dataplane. Signed-off-by: Stefan Hajnoczi Signed-off-by: Fam Zheng Reviewed-by: Paolo Bonzini Reviewed-by: Fam Zheng Message-id: 1466096189-6477-8-git-send-email-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi --- block/mirror.c | 43 +++++++++++++++++++++++++++++++++++-------- 1 file changed, 35 insertions(+), 8 deletions(-) diff --git a/block/mirror.c b/block/mirror.c index 075384a..a04ed9c 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -331,6 +331,8 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) mirror_wait_for_io(s); } + block_job_pause_point(&s->common); + /* Find the number of consective dirty chunks following the first dirty * one, and wait for in flight requests in them. */ while (nb_chunks * sectors_per_chunk < (s->buf_size >> BDRV_SECTOR_BITS)) { @@ -582,6 +584,8 @@ static void coroutine_fn mirror_run(void *opaque) if (now - last_pause_ns > SLICE_TIME) { last_pause_ns = now; block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, 0); + } else { + block_job_pause_point(&s->common); } if (block_job_is_cancelled(&s->common)) { @@ -613,6 +617,8 @@ static void coroutine_fn mirror_run(void *opaque) goto immediate_exit; } + block_job_pause_point(&s->common); + cnt = bdrv_get_dirty_count(s->dirty_bitmap); /* s->common.offset contains the number of bytes already processed so * far, cnt is the number of dirty sectors remaining and @@ -795,18 +801,39 @@ static void mirror_complete(BlockJob *job, Error **errp) block_job_enter(&s->common); } +/* There is no matching mirror_resume() because mirror_run() will begin + * iterating again when the job is resumed. + */ +static void coroutine_fn mirror_pause(BlockJob *job) +{ + MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); + + mirror_drain(s); +} + +static void mirror_attached_aio_context(BlockJob *job, AioContext *new_context) +{ + MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); + + blk_set_aio_context(s->target, new_context); +} + static const BlockJobDriver mirror_job_driver = { - .instance_size = sizeof(MirrorBlockJob), - .job_type = BLOCK_JOB_TYPE_MIRROR, - .set_speed = mirror_set_speed, - .complete = mirror_complete, + .instance_size = sizeof(MirrorBlockJob), + .job_type = BLOCK_JOB_TYPE_MIRROR, + .set_speed = mirror_set_speed, + .complete = mirror_complete, + .pause = mirror_pause, + .attached_aio_context = mirror_attached_aio_context, }; static const BlockJobDriver commit_active_job_driver = { - .instance_size = sizeof(MirrorBlockJob), - .job_type = BLOCK_JOB_TYPE_COMMIT, - .set_speed = mirror_set_speed, - .complete = mirror_complete, + .instance_size = sizeof(MirrorBlockJob), + .job_type = BLOCK_JOB_TYPE_COMMIT, + .set_speed = mirror_set_speed, + .complete = mirror_complete, + .pause = mirror_pause, + .attached_aio_context = mirror_attached_aio_context, }; static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target,