From patchwork Fri Dec 6 17:22:53 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 298197 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 C44D92C00A8 for ; Sat, 7 Dec 2013 05:56:08 +1100 (EST) Received: from localhost ([::1]:60656 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VozF4-0003CP-Km for incoming@patchwork.ozlabs.org; Fri, 06 Dec 2013 12:31:06 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44774) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Voz7t-0001gN-99 for qemu-devel@nongnu.org; Fri, 06 Dec 2013 12:23:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Voz7n-0001tV-91 for qemu-devel@nongnu.org; Fri, 06 Dec 2013 12:23:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57387) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Voz7n-0001tP-1G for qemu-devel@nongnu.org; Fri, 06 Dec 2013 12:23:35 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id rB6HNYsK015435 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Fri, 6 Dec 2013 12:23:34 -0500 Received: from dhcp-200-207.str.redhat.com (ovpn-116-51.ams2.redhat.com [10.36.116.51]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id rB6HNAUF012982; Fri, 6 Dec 2013 12:23:32 -0500 From: Kevin Wolf To: qemu-devel@nongnu.org Date: Fri, 6 Dec 2013 18:22:53 +0100 Message-Id: <1386350580-5666-13-git-send-email-kwolf@redhat.com> In-Reply-To: <1386350580-5666-1-git-send-email-kwolf@redhat.com> References: <1386350580-5666-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 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, armbru@redhat.com, stefanha@redhat.com Subject: [Qemu-devel] [RFC PATCH 12/19] 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 2f1d72e..5eaeb3a 100644 --- a/block.c +++ b/block.c @@ -2083,7 +2083,7 @@ 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; @@ -2101,6 +2101,9 @@ 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 @@ -2659,10 +2662,10 @@ 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; @@ -2677,11 +2680,9 @@ 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; @@ -2728,8 +2729,6 @@ 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--; } @@ -2745,6 +2744,8 @@ 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; @@ -2794,9 +2795,11 @@ 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); @@ -2871,10 +2874,10 @@ 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; @@ -2884,12 +2887,10 @@ 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 */ @@ -2914,8 +2915,6 @@ 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; } @@ -2926,6 +2925,7 @@ 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) { @@ -2943,7 +2943,9 @@ 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; }