From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58630) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fqi9M-0002i1-Cw for qemu-devel@nongnu.org; Fri, 17 Aug 2018 13:03:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fqi9L-0002CV-3a for qemu-devel@nongnu.org; Fri, 17 Aug 2018 13:03:00 -0400 From: Kevin Wolf Date: Fri, 17 Aug 2018 19:02:44 +0200 Message-Id: <20180817170246.14641-4-kwolf@redhat.com> In-Reply-To: <20180817170246.14641-1-kwolf@redhat.com> References: <20180817170246.14641-1-kwolf@redhat.com> Subject: [Qemu-devel] [RFC PATCH 3/5] job: Drop AioContext lock around aio_poll() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, mreitz@redhat.com, qemu-devel@nongnu.org Simimlar to AIO_WAIT_WHILE(), job_finish_sync() needs to release the AioContext lock of the job before calling aio_poll(). Otherwise, callbacks called by aio_poll() would possibly take the lock a second time and run into a deadlock with a nested AIO_WAIT_WHILE() call. Signed-off-by: Kevin Wolf --- job.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/job.c b/job.c index a746bfe70b..6acf55bceb 100644 --- a/job.c +++ b/job.c @@ -1016,7 +1016,10 @@ int job_finish_sync(Job *job, void (*finish)(Job *, Error **errp), Error **errp) job_drain(job); } while (!job_is_completed(job)) { + AioContext *aio_context = job->aio_context; + aio_context_release(aio_context); aio_poll(qemu_get_aio_context(), true); + aio_context_acquire(aio_context); } ret = (job_is_cancelled(job) && job->ret == 0) ? -ECANCELED : job->ret; job_unref(job); -- 2.13.6