From patchwork Fri May 26 19:24:03 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Cody X-Patchwork-Id: 767529 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3wZGXm5zJSz9s7C for ; Sat, 27 May 2017 05:34:16 +1000 (AEST) Received: from localhost ([::1]:38125 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dEL02-0004xH-Er for incoming@patchwork.ozlabs.org; Fri, 26 May 2017 15:34:14 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46367) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dEKqi-0002dj-6v for qemu-devel@nongnu.org; Fri, 26 May 2017 15:24:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dEKqh-00060k-2B for qemu-devel@nongnu.org; Fri, 26 May 2017 15:24:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50394) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dEKqb-0005zB-Bs; Fri, 26 May 2017 15:24:29 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5407480515; Fri, 26 May 2017 19:24:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 5407480515 Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=jcody@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 5407480515 Received: from localhost (ovpn-117-108.phx2.redhat.com [10.3.117.108]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1FE1A60462; Fri, 26 May 2017 19:24:28 +0000 (UTC) From: Jeff Cody To: qemu-block@nongnu.org Date: Fri, 26 May 2017 15:24:03 -0400 Message-Id: <20170526192404.32186-12-jcody@redhat.com> In-Reply-To: <20170526192404.32186-1-jcody@redhat.com> References: <20170526192404.32186-1-jcody@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 26 May 2017 19:24:28 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 11/12] blockjob: use deferred_to_main_loop to indicate the coroutine has ended 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@linaro.org, jcody@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, Paolo Bonzini Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Paolo Bonzini All block jobs are using block_job_defer_to_main_loop as the final step just before the coroutine terminates. At this point, block_job_enter should do nothing, but currently it restarts the freed coroutine. Now, the job->co states should probably be changed to an enum (e.g. BEFORE_START, STARTED, YIELDED, COMPLETED) subsuming block_job_started, job->deferred_to_main_loop and job->busy. For now, this patch eliminates the problematic reenter by removing the reset of job->deferred_to_main_loop (which served no purpose, as far as I could see) and checking the flag in block_job_enter. Reviewed-by: Stefan Hajnoczi Signed-off-by: Paolo Bonzini Message-id: 20170508141310.8674-12-pbonzini@redhat.com Signed-off-by: Jeff Cody --- blockjob.c | 10 ++++++++-- include/block/blockjob_int.h | 3 ++- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/blockjob.c b/blockjob.c index 9a97c73..a0d7e29 100644 --- a/blockjob.c +++ b/blockjob.c @@ -771,7 +771,14 @@ void block_job_resume_all(void) void block_job_enter(BlockJob *job) { - if (job->co && !job->busy) { + if (!block_job_started(job)) { + return; + } + if (job->deferred_to_main_loop) { + return; + } + + if (!job->busy) { bdrv_coroutine_enter(blk_bs(job->blk), job->co); } } @@ -899,7 +906,6 @@ static void block_job_defer_to_main_loop_bh(void *opaque) aio_context_acquire(aio_context); } - data->job->deferred_to_main_loop = false; data->fn(data->job, data->opaque); if (aio_context != data->aio_context) { diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h index 4f2d2ac..f13ad05 100644 --- a/include/block/blockjob_int.h +++ b/include/block/blockjob_int.h @@ -241,7 +241,8 @@ typedef void BlockJobDeferToMainLoopFn(BlockJob *job, void *opaque); * @fn: The function to run in the main loop * @opaque: The opaque value that is passed to @fn * - * Execute a given function in the main loop with the BlockDriverState + * This function must be called by the main job coroutine just before it + * returns. @fn is executed in the main loop with the BlockDriverState * AioContext acquired. Block jobs must call bdrv_unref(), bdrv_close(), and * anything that uses bdrv_drain_all() in the main loop. *