From patchwork Wed Oct 6 15:19:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hanna Czenczek X-Patchwork-Id: 12539569 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 727FDC433F5 for ; Wed, 6 Oct 2021 15:28:28 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id DBEC961027 for ; Wed, 6 Oct 2021 15:28:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org DBEC961027 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:45516 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mY8qJ-000819-2v for qemu-devel@archiver.kernel.org; Wed, 06 Oct 2021 11:28:27 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46700) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mY8iS-0002Dd-GR for qemu-devel@nongnu.org; Wed, 06 Oct 2021 11:20:21 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:59306) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mY8iE-0007R7-3W for qemu-devel@nongnu.org; Wed, 06 Oct 2021 11:20:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1633533605; 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=jtVVhpt/GTuIsvrXckctrOewHToDJdpZ0XW1WhtEpBM=; b=VCzRVglHFY+a2cfDXyUEpAM3KCOiVOhKEgP+mUP3wy0nQA4EeyUdkMKeQLnH5ZvFoQekC8 U4hhHtWOXl2ZlesUnFHdIOTUS0hRpPQ4Ez89cJpSK1ey2oUSCIkCWgSPn7YwJ0BNgB1cXm OmR2wJ2ZiLL83y37IUE0WyZR5nA2npY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-431-EVPQPaS4PIKDzpb6h57yPA-1; Wed, 06 Oct 2021 11:20:02 -0400 X-MC-Unique: EVPQPaS4PIKDzpb6h57yPA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5A5F219253CB; Wed, 6 Oct 2021 15:20:01 +0000 (UTC) Received: from localhost (unknown [10.39.193.194]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EAE9C5D9C6; Wed, 6 Oct 2021 15:20:00 +0000 (UTC) From: Hanna Reitz To: qemu-block@nongnu.org Subject: [PATCH v5 06/13] jobs: Give Job.force_cancel more meaning Date: Wed, 6 Oct 2021 17:19:33 +0200 Message-Id: <20211006151940.214590-7-hreitz@redhat.com> In-Reply-To: <20211006151940.214590-1-hreitz@redhat.com> References: <20211006151940.214590-1-hreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=hreitz@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; 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=-0.05, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, 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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Hanna Reitz , Vladimir Sementsov-Ogievskiy , Eric Blake , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" We largely have two cancel modes for jobs: First, there is actual cancelling. The job is terminated as soon as possible, without trying to reach a consistent result. Second, we have mirror in the READY state. Technically, the job is not really cancelled, but it just is a different completion mode. The job can still run for an indefinite amount of time while it tries to reach a consistent result. We want to be able to clearly distinguish which cancel mode a job is in (when it has been cancelled). We can use Job.force_cancel for this, but right now it only reflects cancel requests from the user with force=true, but clearly, jobs that do not even distinguish between force=false and force=true are effectively always force-cancelled. So this patch has Job.force_cancel signify whether the job will terminate as soon as possible (force_cancel=true) or whether it will effectively remain running despite being "cancelled" (force_cancel=false). To this end, we let jobs that provide JobDriver.cancel() tell the generic job code whether they will terminate as soon as possible or not, and for jobs that do not provide that method we assume they will. Signed-off-by: Hanna Reitz Reviewed-by: Eric Blake Reviewed-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Kevin Wolf --- include/qemu/job.h | 11 ++++++++++- block/backup.c | 3 ++- block/mirror.c | 24 ++++++++++++++++++------ job.c | 6 +++++- 4 files changed, 35 insertions(+), 9 deletions(-) diff --git a/include/qemu/job.h b/include/qemu/job.h index 2eddf3b536..90f6abbd6a 100644 --- a/include/qemu/job.h +++ b/include/qemu/job.h @@ -253,8 +253,17 @@ struct JobDriver { /** * If the callback is not NULL, it will be invoked in job_cancel_async + * + * This function must return true if the job will be cancelled + * immediately without any further I/O (mandatory if @force is + * true), and false otherwise. This lets the generic job layer + * know whether a job has been truly (force-)cancelled, or whether + * it is just in a special completion mode (like mirror after + * READY). + * (If the callback is NULL, the job is assumed to terminate + * without I/O.) */ - void (*cancel)(Job *job, bool force); + bool (*cancel)(Job *job, bool force); /** Called when the job is freed */ diff --git a/block/backup.c b/block/backup.c index 687d2882bc..e8a13f9178 100644 --- a/block/backup.c +++ b/block/backup.c @@ -327,11 +327,12 @@ static void coroutine_fn backup_set_speed(BlockJob *job, int64_t speed) } } -static void backup_cancel(Job *job, bool force) +static bool backup_cancel(Job *job, bool force) { BackupBlockJob *s = container_of(job, BackupBlockJob, common.job); bdrv_cancel_in_flight(s->target_bs); + return true; } static const BlockJobDriver backup_job_driver = { diff --git a/block/mirror.c b/block/mirror.c index 035106bbb4..010b9e1672 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -1094,9 +1094,7 @@ static int coroutine_fn mirror_run(Job *job, Error **errp) trace_mirror_before_sleep(s, cnt, job_is_ready(&s->common.job), delay_ns); job_sleep_ns(&s->common.job, delay_ns); - if (job_is_cancelled(&s->common.job) && - (!job_is_ready(&s->common.job) || s->common.job.force_cancel)) - { + if (job_is_cancelled(&s->common.job) && s->common.job.force_cancel) { break; } s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); @@ -1109,7 +1107,7 @@ immediate_exit: * the target is a copy of the source. */ assert(ret < 0 || - ((s->common.job.force_cancel || !job_is_ready(&s->common.job)) && + (s->common.job.force_cancel && job_is_cancelled(&s->common.job))); assert(need_drain); mirror_wait_for_all_io(s); @@ -1195,14 +1193,27 @@ static bool mirror_drained_poll(BlockJob *job) return !!s->in_flight; } -static void mirror_cancel(Job *job, bool force) +static bool mirror_cancel(Job *job, bool force) { MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job); BlockDriverState *target = blk_bs(s->target); - if (force || !job_is_ready(job)) { + /* + * Before the job is READY, we treat any cancellation like a + * force-cancellation. + */ + force = force || !job_is_ready(job); + + if (force) { bdrv_cancel_in_flight(target); } + return force; +} + +static bool commit_active_cancel(Job *job, bool force) +{ + /* Same as above in mirror_cancel() */ + return force || !job_is_ready(job); } static const BlockJobDriver mirror_job_driver = { @@ -1232,6 +1243,7 @@ static const BlockJobDriver commit_active_job_driver = { .abort = mirror_abort, .pause = mirror_pause, .complete = mirror_complete, + .cancel = commit_active_cancel, }, .drained_poll = mirror_drained_poll, }; diff --git a/job.c b/job.c index dfac35d553..81c016eb10 100644 --- a/job.c +++ b/job.c @@ -719,8 +719,12 @@ static int job_finalize_single(Job *job) static void job_cancel_async(Job *job, bool force) { if (job->driver->cancel) { - job->driver->cancel(job, force); + force = job->driver->cancel(job, force); + } else { + /* No .cancel() means the job will behave as if force-cancelled */ + force = true; } + if (job->user_paused) { /* Do not call job_enter here, the caller will handle it. */ if (job->driver->user_resume) {