From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34326) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d0qoV-0004cp-5v for qemu-devel@nongnu.org; Wed, 19 Apr 2017 10:42:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d0qoU-0001XY-5o for qemu-devel@nongnu.org; Wed, 19 Apr 2017 10:42:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48254) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d0qoT-0001XD-VK for qemu-devel@nongnu.org; Wed, 19 Apr 2017 10:42:34 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (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 E3F032D8E8E for ; Wed, 19 Apr 2017 14:42:32 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-118-57.ams2.redhat.com [10.36.118.57] (may be forged)) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v3JEgK5K001048 for ; Wed, 19 Apr 2017 10:42:32 -0400 From: Paolo Bonzini Date: Wed, 19 Apr 2017 16:42:19 +0200 Message-Id: <20170419144219.20371-12-pbonzini@redhat.com> In-Reply-To: <20170419144219.20371-1-pbonzini@redhat.com> References: <20170419144219.20371-1-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 11/11] blockjob: use deferred_to_main_loop to indicate the coroutine has ended List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org 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. Signed-off-by: Paolo Bonzini --- 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 e8b6247..295478d 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 cbf984b..a9751a7 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. * -- 2.9.3