From patchwork Fri Aug 30 16:12:25 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Sementsov-Ogievskiy X-Patchwork-Id: 1155987 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com 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 ozlabs.org (Postfix) with ESMTPS id 46KlD95WwWz9s7T for ; Sat, 31 Aug 2019 02:24:09 +1000 (AEST) Received: from localhost ([::1]:35978 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i3jh1-0008Pv-Na for incoming@patchwork.ozlabs.org; Fri, 30 Aug 2019 12:24:07 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49091) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i3jWY-0000Mq-Aw for qemu-devel@nongnu.org; Fri, 30 Aug 2019 12:13:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i3jWV-0004xj-VV for qemu-devel@nongnu.org; Fri, 30 Aug 2019 12:13:17 -0400 Received: from relay.sw.ru ([185.231.240.75]:60630) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i3jWF-0004Fk-8z; Fri, 30 Aug 2019 12:13:02 -0400 Received: from [10.94.3.0] (helo=kvm.qa.sw.ru) by relay.sw.ru with esmtp (Exim 4.92) (envelope-from ) id 1i3jVm-0001X0-Pi; Fri, 30 Aug 2019 19:12:30 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-block@nongnu.org Date: Fri, 30 Aug 2019 19:12:25 +0300 Message-Id: <20190830161228.54238-12-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20190830161228.54238-1-vsementsov@virtuozzo.com> References: <20190830161228.54238-1-vsementsov@virtuozzo.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 185.231.240.75 Subject: [Qemu-devel] [PATCH v10 11/14] block/io: refactor wait_serialising_requests 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: fam@euphon.net, kwolf@redhat.com, vsementsov@virtuozzo.com, wencongyang2@huawei.com, xiechanglong.d@gmail.com, qemu-devel@nongnu.org, armbru@redhat.com, jsnow@redhat.com, stefanha@redhat.com, den@openvz.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Split out do_wait_serialising_requests with additional possibility to not actually wait but just check, that there is something to wait for. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Max Reitz --- block/io.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/block/io.c b/block/io.c index 56bbf195bb..378180b274 100644 --- a/block/io.c +++ b/block/io.c @@ -785,12 +785,13 @@ void bdrv_dec_in_flight(BlockDriverState *bs) bdrv_wakeup(bs); } -static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) +static bool coroutine_fn do_wait_serialising_requests(BdrvTrackedRequest *self, + bool wait) { BlockDriverState *bs = self->bs; BdrvTrackedRequest *req; bool retry; - bool waited = false; + bool found = false; if (!atomic_read(&bs->serialising_in_flight)) { return false; @@ -816,11 +817,13 @@ static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) * will wait for us as soon as it wakes up, then just go on * (instead of producing a deadlock in the former case). */ if (!req->waiting_for) { - self->waiting_for = req; - qemu_co_queue_wait(&req->wait_queue, &bs->reqs_lock); - self->waiting_for = NULL; - retry = true; - waited = true; + found = true; + if (wait) { + self->waiting_for = req; + qemu_co_queue_wait(&req->wait_queue, &bs->reqs_lock); + self->waiting_for = NULL; + retry = true; + } break; } } @@ -828,7 +831,12 @@ static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) qemu_co_mutex_unlock(&bs->reqs_lock); } while (retry); - return waited; + return found; +} + +static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) +{ + return do_wait_serialising_requests(self, true); } static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,