From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:43448) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gdDv4-00035F-Dr for qemu-devel@nongnu.org; Sat, 29 Dec 2018 07:40:58 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gdDcB-0007th-JW for qemu-devel@nongnu.org; Sat, 29 Dec 2018 07:21:21 -0500 From: Vladimir Sementsov-Ogievskiy Date: Sat, 29 Dec 2018 15:20:24 +0300 Message-Id: <20181229122027.42245-9-vsementsov@virtuozzo.com> In-Reply-To: <20181229122027.42245-1-vsementsov@virtuozzo.com> References: <20181229122027.42245-1-vsementsov@virtuozzo.com> Subject: [Qemu-devel] [PATCH v5 08/11] block/io: refactor wait_serialising_requests List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org, qemu-devel@nongnu.org Cc: fam@euphon.net, stefanha@redhat.com, jcody@redhat.com, mreitz@redhat.com, kwolf@redhat.com, vsementsov@virtuozzo.com, den@openvz.org, eblake@redhat.com, jsnow@redhat.com 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 --- block/io.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/block/io.c b/block/io.c index bd9d688f8b..b87c11a6ec 100644 --- a/block/io.c +++ b/block/io.c @@ -720,12 +720,13 @@ 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; @@ -751,11 +752,13 @@ 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; } } @@ -763,7 +766,12 @@ 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, -- 2.18.0