From patchwork Wed Sep 13 18:18:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 813559 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=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3xsqmx5yFrz9s7g for ; Thu, 14 Sep 2017 04:24:01 +1000 (AEST) Received: from localhost ([::1]:44007 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dsCKN-00027m-QJ for incoming@patchwork.ozlabs.org; Wed, 13 Sep 2017 14:23:59 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36893) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dsCH7-0008VD-87 for qemu-devel@nongnu.org; Wed, 13 Sep 2017 14:20:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dsCH5-0005Ma-EV for qemu-devel@nongnu.org; Wed, 13 Sep 2017 14:20:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46920) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dsCGy-0005Gc-JH; Wed, 13 Sep 2017 14:20:28 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9D6E5D556B; Wed, 13 Sep 2017 18:20:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 9D6E5D556B Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=mreitz@redhat.com Received: from localhost (ovpn-204-23.brq.redhat.com [10.40.204.23]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 26B854D9E6; Wed, 13 Sep 2017 18:20:19 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Wed, 13 Sep 2017 20:18:59 +0200 Message-Id: <20170913181910.29688-8-mreitz@redhat.com> In-Reply-To: <20170913181910.29688-1-mreitz@redhat.com> References: <20170913181910.29688-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 13 Sep 2017 18:20:27 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 07/18] block/mirror: Wait for in-flight op conflicts X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Fam Zheng , qemu-devel@nongnu.org, Max Reitz , Stefan Hajnoczi , John Snow Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" This patch makes the mirror code differentiate between simply waiting for any operation to complete (mirror_wait_for_free_in_flight_slot()) and specifically waiting for all operations touching a certain range of the virtual disk to complete (mirror_wait_on_conflicts()). Signed-off-by: Max Reitz --- block/mirror.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 70 insertions(+), 15 deletions(-) diff --git a/block/mirror.c b/block/mirror.c index 81253fbad1..2ece38094d 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -14,6 +14,7 @@ #include "qemu/osdep.h" #include "qemu/cutils.h" #include "qemu/coroutine.h" +#include "qemu/range.h" #include "trace.h" #include "block/blockjob_int.h" #include "block/block_int.h" @@ -111,6 +112,41 @@ static BlockErrorAction mirror_error_action(MirrorBlockJob *s, bool read, } } +static void coroutine_fn mirror_wait_on_conflicts(MirrorOp *self, + MirrorBlockJob *s, + uint64_t offset, + uint64_t bytes) +{ + uint64_t self_start_chunk = offset / s->granularity; + uint64_t self_end_chunk = DIV_ROUND_UP(offset + bytes, s->granularity); + uint64_t self_nb_chunks = self_end_chunk - self_start_chunk; + + while (find_next_bit(s->in_flight_bitmap, self_end_chunk, + self_start_chunk) < self_end_chunk && + s->ret >= 0) + { + MirrorOp *op; + + QTAILQ_FOREACH(op, &s->ops_in_flight, next) { + uint64_t op_start_chunk = op->offset / s->granularity; + uint64_t op_nb_chunks = DIV_ROUND_UP(op->offset + op->bytes, + s->granularity) - + op_start_chunk; + + if (op == self) { + continue; + } + + if (ranges_overlap(self_start_chunk, self_nb_chunks, + op_start_chunk, op_nb_chunks)) + { + qemu_co_queue_wait(&op->waiting_requests, NULL); + break; + } + } + } +} + static void coroutine_fn mirror_iteration_done(MirrorOp *op, int ret) { MirrorBlockJob *s = op->s; @@ -238,7 +274,7 @@ static int mirror_cow_align(MirrorBlockJob *s, int64_t *offset, return ret; } -static inline void mirror_wait_for_io(MirrorBlockJob *s) +static inline void mirror_wait_for_free_in_flight_slot(MirrorBlockJob *s) { MirrorOp *op; @@ -287,7 +323,7 @@ static void coroutine_fn mirror_co_read(void *opaque) while (s->buf_free_count < nb_chunks) { trace_mirror_yield_in_flight(s, op->offset, s->in_flight); - mirror_wait_for_io(s); + mirror_wait_for_free_in_flight_slot(s); } /* Now make a QEMUIOVector taking enough granularity-sized chunks @@ -381,8 +417,9 @@ static unsigned mirror_perform(MirrorBlockJob *s, int64_t offset, static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) { BlockDriverState *source = s->source; - int64_t offset, first_chunk; - uint64_t delay_ns = 0; + MirrorOp *pseudo_op; + int64_t offset; + uint64_t delay_ns = 0, ret = 0; /* At least the first dirty chunk is mirrored in one iteration. */ int nb_chunks = 1; int sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; @@ -400,11 +437,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) } bdrv_dirty_bitmap_unlock(s->dirty_bitmap); - first_chunk = offset / s->granularity; - while (test_bit(first_chunk, s->in_flight_bitmap)) { - trace_mirror_yield_in_flight(s, offset, s->in_flight); - mirror_wait_for_io(s); - } + mirror_wait_on_conflicts(NULL, s, offset, 1); block_job_pause_point(&s->common); @@ -442,6 +475,20 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) nb_chunks * sectors_per_chunk); bdrv_dirty_bitmap_unlock(s->dirty_bitmap); + /* Before claiming an area in the in-flight bitmap, we have to + * create a MirrorOp for it so that conflicting requests can wait + * for it. mirror_perform() will create the real MirrorOps later, + * for now we just create a pseudo operation that will wake up all + * conflicting requests once all real operations have been + * launched. */ + pseudo_op = g_new(MirrorOp, 1); + *pseudo_op = (MirrorOp){ + .offset = offset, + .bytes = nb_chunks * s->granularity, + }; + qemu_co_queue_init(&pseudo_op->waiting_requests); + QTAILQ_INSERT_TAIL(&s->ops_in_flight, pseudo_op, next); + bitmap_set(s->in_flight_bitmap, offset / s->granularity, nb_chunks); while (nb_chunks > 0 && offset < s->bdev_length) { int64_t ret; @@ -481,11 +528,12 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) while (s->in_flight >= MAX_IN_FLIGHT) { trace_mirror_yield_in_flight(s, offset, s->in_flight); - mirror_wait_for_io(s); + mirror_wait_for_free_in_flight_slot(s); } if (s->ret < 0) { - return 0; + ret = 0; + goto fail; } io_bytes = mirror_clip_bytes(s, offset, io_bytes); @@ -502,7 +550,14 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) delay_ns = ratelimit_calculate_delay(&s->limit, io_bytes_acct); } } - return delay_ns; + + ret = delay_ns; +fail: + QTAILQ_REMOVE(&s->ops_in_flight, pseudo_op, next); + qemu_co_queue_restart_all(&pseudo_op->waiting_requests); + g_free(pseudo_op); + + return ret; } static void mirror_free_init(MirrorBlockJob *s) @@ -529,7 +584,7 @@ static void mirror_free_init(MirrorBlockJob *s) static void mirror_wait_for_all_io(MirrorBlockJob *s) { while (s->in_flight > 0) { - mirror_wait_for_io(s); + mirror_wait_for_free_in_flight_slot(s); } } @@ -685,7 +740,7 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) if (s->in_flight >= MAX_IN_FLIGHT) { trace_mirror_yield(s, UINT64_MAX, s->buf_free_count, s->in_flight); - mirror_wait_for_io(s); + mirror_wait_for_free_in_flight_slot(s); continue; } @@ -868,7 +923,7 @@ static void coroutine_fn mirror_run(void *opaque) (cnt == 0 && s->in_flight > 0)) { trace_mirror_yield(s, cnt * BDRV_SECTOR_SIZE, s->buf_free_count, s->in_flight); - mirror_wait_for_io(s); + mirror_wait_for_free_in_flight_slot(s); continue; } else if (cnt != 0) { delay_ns = mirror_iteration(s);