From patchwork Wed Dec 11 21:08:22 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 300426 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 669642C00AE for ; Thu, 12 Dec 2013 08:18:15 +1100 (EST) Received: from localhost ([::1]:60236 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vqr4O-0002MD-FJ for incoming@patchwork.ozlabs.org; Wed, 11 Dec 2013 16:11:48 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44023) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vqr22-0007nQ-Nh for qemu-devel@nongnu.org; Wed, 11 Dec 2013 16:09:28 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Vqr1w-0000mY-MW for qemu-devel@nongnu.org; Wed, 11 Dec 2013 16:09:22 -0500 Received: from mx1.redhat.com ([209.132.183.28]:3189) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vqr1w-0000mT-E7 for qemu-devel@nongnu.org; Wed, 11 Dec 2013 16:09:16 -0500 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id rBBL9AXX027644 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 11 Dec 2013 16:09:10 -0500 Received: from dhcp-200-207.str.redhat.com (ovpn-116-104.ams2.redhat.com [10.36.116.104]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id rBBL8d90028102; Wed, 11 Dec 2013 16:09:09 -0500 From: Kevin Wolf To: qemu-devel@nongnu.org Date: Wed, 11 Dec 2013 22:08:22 +0100 Message-Id: <1386796109-15264-16-git-send-email-kwolf@redhat.com> In-Reply-To: <1386796109-15264-1-git-send-email-kwolf@redhat.com> References: <1386796109-15264-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.25 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com, pbonzini@redhat.com, pl@kamp.de, stefanha@redhat.com Subject: [Qemu-devel] [PATCH 15/22] block: Allow waiting for overlapping requests between begin/end X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Previously, it was not possible to use wait_for_overlapping_requests() between tracked_request_begin()/end() because it would wait for itself. Ignore the current request in the overlap check and run more of the bdrv_co_do_preadv/pwritev code with a BdrvTrackedRequest present. Signed-off-by: Kevin Wolf --- block.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+), 18 deletions(-) diff --git a/block.c b/block.c index fa888d9..b4f6ead 100644 --- a/block.c +++ b/block.c @@ -2106,7 +2106,7 @@ static bool tracked_request_overlaps(BdrvTrackedRequest *req, } static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, - int64_t offset, unsigned int bytes) + BdrvTrackedRequest *self, int64_t offset, unsigned int bytes) { BdrvTrackedRequest *req; int64_t cluster_offset; @@ -2124,6 +2124,9 @@ static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, do { retry = false; QLIST_FOREACH(req, &bs->tracked_requests, list) { + if (req == self) { + continue; + } if (tracked_request_overlaps(req, cluster_offset, cluster_bytes)) { /* Hitting this means there was a reentrant request, for * example, a block driver issuing nested requests. This must @@ -2721,10 +2724,10 @@ err: * implemented by the caller. */ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, - int64_t offset, unsigned int bytes, QEMUIOVector *qiov, int flags) + BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, + QEMUIOVector *qiov, int flags) { BlockDriver *drv = bs->drv; - BdrvTrackedRequest req; int ret; int64_t sector_num = offset >> BDRV_SECTOR_BITS; @@ -2739,11 +2742,9 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, } if (bs->copy_on_read_in_flight) { - wait_for_overlapping_requests(bs, offset, bytes); + wait_for_overlapping_requests(bs, req, offset, bytes); } - tracked_request_begin(&req, bs, offset, bytes, false); - if (flags & BDRV_REQ_COPY_ON_READ) { int pnum; @@ -2790,8 +2791,6 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, } out: - tracked_request_end(&req); - if (flags & BDRV_REQ_COPY_ON_READ) { bs->copy_on_read_in_flight--; } @@ -2807,6 +2806,8 @@ static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, BdrvRequestFlags flags) { BlockDriver *drv = bs->drv; + BdrvTrackedRequest req; + /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */ uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); uint8_t *head_buf = NULL; @@ -2856,9 +2857,11 @@ static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, bytes = ROUND_UP(bytes, align); } - ret = bdrv_aligned_preadv(bs, offset, bytes, + tracked_request_begin(&req, bs, offset, bytes, false); + ret = bdrv_aligned_preadv(bs, &req, offset, bytes, use_local_qiov ? &local_qiov : qiov, flags); + tracked_request_end(&req); if (use_local_qiov) { qemu_iovec_destroy(&local_qiov); @@ -2977,10 +2980,10 @@ static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, * Forwards an already correctly aligned write request to the BlockDriver. */ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, - int64_t offset, unsigned int bytes, QEMUIOVector *qiov, int flags) + BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, + QEMUIOVector *qiov, int flags) { BlockDriver *drv = bs->drv; - BdrvTrackedRequest req; int ret; int64_t sector_num = offset >> BDRV_SECTOR_BITS; @@ -2990,12 +2993,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); if (bs->copy_on_read_in_flight) { - wait_for_overlapping_requests(bs, offset, bytes); + wait_for_overlapping_requests(bs, req, offset, bytes); } - tracked_request_begin(&req, bs, offset, bytes, true); - - ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req); + ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req); if (ret < 0) { /* Do nothing, write notifier decided to fail this request */ @@ -3018,8 +3019,6 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors); } - tracked_request_end(&req); - return ret; } @@ -3030,6 +3029,7 @@ static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, int64_t offset, unsigned int bytes, QEMUIOVector *qiov, BdrvRequestFlags flags) { + BdrvTrackedRequest req; int ret; if (!bs->drv) { @@ -3047,7 +3047,9 @@ static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, bdrv_io_limits_intercept(bs, bytes << BDRV_SECTOR_BITS, true); } - ret = bdrv_aligned_pwritev(bs, offset, bytes, qiov, flags); + tracked_request_begin(&req, bs, offset, bytes, true); + ret = bdrv_aligned_pwritev(bs, &req, offset, bytes, qiov, flags); + tracked_request_end(&req); return ret; }