From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30D50C3A5A2 for ; Tue, 10 Sep 2019 10:34:14 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 06A7F20872 for ; Tue, 10 Sep 2019 10:34:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 06A7F20872 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:37638 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i7dTQ-0002am-Ae for qemu-devel@archiver.kernel.org; Tue, 10 Sep 2019 06:34:12 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56598) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i7dJK-0000S7-Ha for qemu-devel@nongnu.org; Tue, 10 Sep 2019 06:23:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i7dJI-0001ul-Cc for qemu-devel@nongnu.org; Tue, 10 Sep 2019 06:23:45 -0400 Received: from relay.sw.ru ([185.231.240.75]:60074) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i7dJB-0001oL-CN; Tue, 10 Sep 2019 06:23:37 -0400 Received: from [10.94.3.0] (helo=kvm.qa.sw.ru) by relay.sw.ru with esmtp (Exim 4.92) (envelope-from ) id 1i7dJ8-0007it-2d; Tue, 10 Sep 2019 13:23:34 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-block@nongnu.org Date: Tue, 10 Sep 2019 13:23:30 +0300 Message-Id: <20190910102332.20560-13-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20190910102332.20560-1-vsementsov@virtuozzo.com> References: <20190910102332.20560-1-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 v11 12/14] block: add lock/unlock range functions 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Introduce lock/unlock range functionality, based on serialized requests. This is needed to refactor backup, dropping local tracked-request-like synchronization. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Max Reitz --- include/block/block_int.h | 4 ++++ block/io.c | 44 ++++++++++++++++++++++++++++++++++++++- 2 files changed, 47 insertions(+), 1 deletion(-) diff --git a/include/block/block_int.h b/include/block/block_int.h index 0422acdf1c..b59011ca97 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -65,6 +65,7 @@ enum BdrvTrackedRequestType { BDRV_TRACKED_WRITE, BDRV_TRACKED_DISCARD, BDRV_TRACKED_TRUNCATE, + BDRV_TRACKED_LOCK, }; typedef struct BdrvTrackedRequest { @@ -968,6 +969,9 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child, int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child, int64_t offset, unsigned int bytes, QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags); +void *coroutine_fn bdrv_co_try_lock(BlockDriverState *bs, + int64_t offset, unsigned int bytes); +void coroutine_fn bdrv_co_unlock(void *opaque); static inline int coroutine_fn bdrv_co_pread(BdrvChild *child, int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags) diff --git a/block/io.c b/block/io.c index e909736349..b9dd578d56 100644 --- a/block/io.c +++ b/block/io.c @@ -786,6 +786,15 @@ void bdrv_dec_in_flight(BlockDriverState *bs) bdrv_wakeup(bs); } +static bool ignore_intersection(BdrvTrackedRequest *a, BdrvTrackedRequest *b) +{ + return a == b || (!a->serialising && !b->serialising) || + (a->type == BDRV_TRACKED_LOCK && b->type == BDRV_TRACKED_READ && + !b->serialising) || + (b->type == BDRV_TRACKED_LOCK && a->type == BDRV_TRACKED_READ && + !a->serialising); +} + static bool coroutine_fn do_wait_serialising_requests(BdrvTrackedRequest *self, bool wait) { @@ -802,7 +811,7 @@ static bool coroutine_fn do_wait_serialising_requests(BdrvTrackedRequest *self, retry = false; qemu_co_mutex_lock(&bs->reqs_lock); QLIST_FOREACH(req, &bs->tracked_requests, list) { - if (req == self || (!req->serialising && !self->serialising)) { + if (ignore_intersection(self, req)) { continue; } if (tracked_request_overlaps(req, self->overlap_offset, @@ -840,6 +849,12 @@ static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) return do_wait_serialising_requests(self, true); } +static bool coroutine_fn should_wait_serialising_requests( + BdrvTrackedRequest *self) +{ + return do_wait_serialising_requests(self, false); +} + static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset, size_t size) { @@ -3378,3 +3393,30 @@ int bdrv_truncate(BdrvChild *child, int64_t offset, PreallocMode prealloc, return tco.ret; } + +void *coroutine_fn bdrv_co_try_lock(BlockDriverState *bs, + int64_t offset, unsigned int bytes) +{ + BdrvTrackedRequest *req = g_new(BdrvTrackedRequest, 1); + + tracked_request_begin(req, bs, offset, bytes, BDRV_TRACKED_LOCK); + mark_request_serialising(req, bdrv_get_cluster_size(bs)); + + if (should_wait_serialising_requests(req)) { + tracked_request_end(req); + g_free(req); + return NULL; + } + + return req; +} + +void coroutine_fn bdrv_co_unlock(void *opaque) +{ + BdrvTrackedRequest *req = opaque; + + assert(req->type == BDRV_TRACKED_LOCK); + + tracked_request_end(req); + g_free(req); +} -- 2.18.0