From nobody Tue May 7 18:55:49 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1511951264171532.9708865721667; Wed, 29 Nov 2017 02:27:44 -0800 (PST) Received: from localhost ([::1]:42157 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eJzaX-0000Ve-Bv for importer@patchew.org; Wed, 29 Nov 2017 05:27:33 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43746) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eJzYa-00070U-0p for qemu-devel@nongnu.org; Wed, 29 Nov 2017 05:25:34 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eJzYU-000539-6z for qemu-devel@nongnu.org; Wed, 29 Nov 2017 05:25:32 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43176) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eJzYQ-00051T-L9; Wed, 29 Nov 2017 05:25:22 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D17734ACA0; Wed, 29 Nov 2017 10:25:21 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-117-214.ams2.redhat.com [10.36.117.214]) by smtp.corp.redhat.com (Postfix) with ESMTP id 66BEC600D5; Wed, 29 Nov 2017 10:25:20 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Wed, 29 Nov 2017 11:25:10 +0100 Message-Id: <20171129102513.9153-2-pbonzini@redhat.com> In-Reply-To: <20171129102513.9153-1-pbonzini@redhat.com> References: <20171129102513.9153-1-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Wed, 29 Nov 2017 10:25:21 +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 1/4] block: Expect graph changes in bdrv_parent_drained_begin/end 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: kwolf@redhat.com, jcody@redhat.com, famz@redhat.com, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Kevin Wolf The .drained_begin/end callbacks can (directly or indirectly via aio_poll()) cause block nodes to be removed or the current BdrvChild to point to a different child node. Use QLIST_FOREACH_SAFE() to make sure we don't access invalid BlockDriverStates or accidentally continue iterating the parents of the new child node instead of the node we actually came from. Signed-off-by: Kevin Wolf Tested-by: Jeff Cody Reviewed-by: Stefan Hajnoczi Reviewed-by: Jeff Cody Reviewed-by: Alberto Garcia Reviewed-by: Fam Zheng Tested-By: Jeff Cody --- block/io.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/block/io.c b/block/io.c index 4fdf93a014..6773926fc1 100644 --- a/block/io.c +++ b/block/io.c @@ -42,9 +42,9 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDri= verState *bs, =20 void bdrv_parent_drained_begin(BlockDriverState *bs) { - BdrvChild *c; + BdrvChild *c, *next; =20 - QLIST_FOREACH(c, &bs->parents, next_parent) { + QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) { if (c->role->drained_begin) { c->role->drained_begin(c); } @@ -53,9 +53,9 @@ void bdrv_parent_drained_begin(BlockDriverState *bs) =20 void bdrv_parent_drained_end(BlockDriverState *bs) { - BdrvChild *c; + BdrvChild *c, *next; =20 - QLIST_FOREACH(c, &bs->parents, next_parent) { + QLIST_FOREACH_SAFE(c, &bs->parents, next_parent, next) { if (c->role->drained_end) { c->role->drained_end(c); } --=20 2.14.3 From nobody Tue May 7 18:55:49 2024 Delivered-To: importer@patchew.org Received-SPF: temperror (zoho.com: Error in retrieving data from DNS) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=temperror (zoho.com: Error in retrieving data from DNS) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1511951257767189.47316533306878; Wed, 29 Nov 2017 02:27:37 -0800 (PST) Received: from localhost ([::1]:42156 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eJzaS-00008s-SM for importer@patchew.org; Wed, 29 Nov 2017 05:27:28 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43699) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eJzYW-0006xL-Tt for qemu-devel@nongnu.org; Wed, 29 Nov 2017 05:25:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eJzYV-00054G-MY for qemu-devel@nongnu.org; Wed, 29 Nov 2017 05:25:28 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43210) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eJzYS-000528-DC; Wed, 29 Nov 2017 05:25:24 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7B07F4ACA0; Wed, 29 Nov 2017 10:25:23 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-117-214.ams2.redhat.com [10.36.117.214]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2F5EF600D5; Wed, 29 Nov 2017 10:25:22 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Wed, 29 Nov 2017 11:25:11 +0100 Message-Id: <20171129102513.9153-3-pbonzini@redhat.com> In-Reply-To: <20171129102513.9153-1-pbonzini@redhat.com> References: <20171129102513.9153-1-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Wed, 29 Nov 2017 10:25:23 +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 2/4] blockjob: remove clock argument from block_job_sleep_ns 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: kwolf@redhat.com, jcody@redhat.com, famz@redhat.com, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_6 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" All callers are using QEMU_CLOCK_REALTIME, and it will not be possible to support more than one clock when block_job_sleep_ns switches to a single timer stored in the BlockJob struct. Signed-off-by: Paolo Bonzini Reviewed-by: Alberto Garcia Reviewed-by: Fam Zheng Reviewed-by: Jeff Cody Reviewed-by: Stefan Hajnoczi Tested-By: Jeff Cody --- block/backup.c | 4 ++-- block/commit.c | 2 +- block/mirror.c | 6 +++--- block/stream.c | 2 +- blockjob.c | 5 +++-- include/block/blockjob_int.h | 7 +++---- tests/test-blockjob-txn.c | 2 +- 7 files changed, 14 insertions(+), 14 deletions(-) diff --git a/block/backup.c b/block/backup.c index 06ddbfd03d..99e6bcc748 100644 --- a/block/backup.c +++ b/block/backup.c @@ -346,9 +346,9 @@ static bool coroutine_fn yield_and_check(BackupBlockJob= *job) uint64_t delay_ns =3D ratelimit_calculate_delay(&job->limit, job->bytes_read); job->bytes_read =3D 0; - block_job_sleep_ns(&job->common, QEMU_CLOCK_REALTIME, delay_ns); + block_job_sleep_ns(&job->common, delay_ns); } else { - block_job_sleep_ns(&job->common, QEMU_CLOCK_REALTIME, 0); + block_job_sleep_ns(&job->common, 0); } =20 if (block_job_is_cancelled(&job->common)) { diff --git a/block/commit.c b/block/commit.c index 5036eec434..c5327551ce 100644 --- a/block/commit.c +++ b/block/commit.c @@ -174,7 +174,7 @@ static void coroutine_fn commit_run(void *opaque) /* Note that even when no rate limit is applied we need to yield * with no pending I/O here so that bdrv_drain_all() returns. */ - block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); + block_job_sleep_ns(&s->common, delay_ns); if (block_job_is_cancelled(&s->common)) { break; } diff --git a/block/mirror.c b/block/mirror.c index 307b6391a8..c9badc1203 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -598,7 +598,7 @@ static void mirror_throttle(MirrorBlockJob *s) =20 if (now - s->last_pause_ns > SLICE_TIME) { s->last_pause_ns =3D now; - block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, 0); + block_job_sleep_ns(&s->common, 0); } else { block_job_pause_point(&s->common); } @@ -870,13 +870,13 @@ static void coroutine_fn mirror_run(void *opaque) ret =3D 0; trace_mirror_before_sleep(s, cnt, s->synced, delay_ns); if (!s->synced) { - block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); + block_job_sleep_ns(&s->common, delay_ns); if (block_job_is_cancelled(&s->common)) { break; } } else if (!should_complete) { delay_ns =3D (s->in_flight =3D=3D 0 && cnt =3D=3D 0 ? SLICE_TI= ME : 0); - block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); + block_job_sleep_ns(&s->common, delay_ns); } s->last_pause_ns =3D qemu_clock_get_ns(QEMU_CLOCK_REALTIME); } diff --git a/block/stream.c b/block/stream.c index e6f72346e5..499cdacdb0 100644 --- a/block/stream.c +++ b/block/stream.c @@ -141,7 +141,7 @@ static void coroutine_fn stream_run(void *opaque) /* Note that even when no rate limit is applied we need to yield * with no pending I/O here so that bdrv_drain_all() returns. */ - block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); + block_job_sleep_ns(&s->common, delay_ns); if (block_job_is_cancelled(&s->common)) { break; } diff --git a/blockjob.c b/blockjob.c index 2f0cc1528b..db9e4fc89a 100644 --- a/blockjob.c +++ b/blockjob.c @@ -788,7 +788,7 @@ bool block_job_is_cancelled(BlockJob *job) return job->cancelled; } =20 -void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns) +void block_job_sleep_ns(BlockJob *job, int64_t ns) { assert(job->busy); =20 @@ -803,7 +803,8 @@ void block_job_sleep_ns(BlockJob *job, QEMUClockType ty= pe, int64_t ns) * it wakes and runs, otherwise we risk double-entry or entry after * completion. */ if (!block_job_should_pause(job)) { - co_aio_sleep_ns(blk_get_aio_context(job->blk), type, ns); + co_aio_sleep_ns(blk_get_aio_context(job->blk), + QEMU_CLOCK_REALTIME, ns); } =20 block_job_pause_point(job); diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h index 43f3be2965..f7ab183a39 100644 --- a/include/block/blockjob_int.h +++ b/include/block/blockjob_int.h @@ -139,14 +139,13 @@ void *block_job_create(const char *job_id, const Bloc= kJobDriver *driver, /** * block_job_sleep_ns: * @job: The job that calls the function. - * @clock: The clock to sleep on. * @ns: How many nanoseconds to stop for. * * Put the job to sleep (assuming that it wasn't canceled) for @ns - * nanoseconds. Canceling the job will not interrupt the wait, so the - * cancel will not process until the coroutine wakes up. + * %QEMU_CLOCK_REALTIME nanoseconds. Canceling the job will not interrupt + * the wait, so the cancel will not process until the coroutine wakes up. */ -void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns); +void block_job_sleep_ns(BlockJob *job, int64_t ns); =20 /** * block_job_yield: diff --git a/tests/test-blockjob-txn.c b/tests/test-blockjob-txn.c index c77343fc04..3591c9617f 100644 --- a/tests/test-blockjob-txn.c +++ b/tests/test-blockjob-txn.c @@ -44,7 +44,7 @@ static void coroutine_fn test_block_job_run(void *opaque) =20 while (s->iterations--) { if (s->use_timer) { - block_job_sleep_ns(job, QEMU_CLOCK_REALTIME, 0); + block_job_sleep_ns(job, 0); } else { block_job_yield(job); } --=20 2.14.3 From nobody Tue May 7 18:55:49 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 15119512527261003.1263888764557; Wed, 29 Nov 2017 02:27:32 -0800 (PST) Received: from localhost ([::1]:42154 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eJzaG-0008Ev-PX for importer@patchew.org; Wed, 29 Nov 2017 05:27:16 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43707) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eJzYX-0006xj-6A for qemu-devel@nongnu.org; Wed, 29 Nov 2017 05:25:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eJzYW-00054s-Cs for qemu-devel@nongnu.org; Wed, 29 Nov 2017 05:25:29 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43014) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eJzYU-00052p-4J; Wed, 29 Nov 2017 05:25:26 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3F08E37E87; Wed, 29 Nov 2017 10:25:25 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-117-214.ams2.redhat.com [10.36.117.214]) by smtp.corp.redhat.com (Postfix) with ESMTP id CD3E0600D1; Wed, 29 Nov 2017 10:25:23 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Wed, 29 Nov 2017 11:25:12 +0100 Message-Id: <20171129102513.9153-4-pbonzini@redhat.com> In-Reply-To: <20171129102513.9153-1-pbonzini@redhat.com> References: <20171129102513.9153-1-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 29 Nov 2017 10:25:25 +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 3/4] blockjob: introduce block_job_do_yield 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: kwolf@redhat.com, jcody@redhat.com, famz@redhat.com, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Hide the clearing of job->busy in a single function, and set it in block_job_enter. This lets block_job_do_yield verify that qemu_coroutine_enter is not used while job->busy =3D false. Signed-off-by: Paolo Bonzini Reviewed-by: Fam Zheng Reviewed-by: Jeff Cody Reviewed-by: Stefan Hajnoczi Tested-By: Jeff Cody --- blockjob.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/blockjob.c b/blockjob.c index db9e4fc89a..4d22b7d2fb 100644 --- a/blockjob.c +++ b/blockjob.c @@ -729,6 +729,15 @@ static bool block_job_should_pause(BlockJob *job) return job->pause_count > 0; } =20 +static void block_job_do_yield(BlockJob *job) +{ + job->busy =3D false; + qemu_coroutine_yield(); + + /* Set by block_job_enter before re-entering the coroutine. */ + assert(job->busy); +} + void coroutine_fn block_job_pause_point(BlockJob *job) { assert(job && block_job_started(job)); @@ -746,9 +755,7 @@ void coroutine_fn block_job_pause_point(BlockJob *job) =20 if (block_job_should_pause(job) && !block_job_is_cancelled(job)) { job->paused =3D true; - job->busy =3D false; - qemu_coroutine_yield(); /* wait for block_job_resume() */ - job->busy =3D true; + block_job_do_yield(job); job->paused =3D false; } =20 @@ -778,9 +785,12 @@ void block_job_enter(BlockJob *job) return; } =20 - if (!job->busy) { - bdrv_coroutine_enter(blk_bs(job->blk), job->co); + if (job->busy) { + return; } + + job->busy =3D true; + aio_co_wake(job->co); } =20 bool block_job_is_cancelled(BlockJob *job) @@ -819,11 +829,9 @@ void block_job_yield(BlockJob *job) return; } =20 - job->busy =3D false; if (!block_job_should_pause(job)) { - qemu_coroutine_yield(); + block_job_do_yield(job); } - job->busy =3D true; =20 block_job_pause_point(job); } --=20 2.14.3 From nobody Tue May 7 18:55:49 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 151195138178322.742175670487313; Wed, 29 Nov 2017 02:29:41 -0800 (PST) Received: from localhost ([::1]:42166 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eJzcJ-0002KL-16 for importer@patchew.org; Wed, 29 Nov 2017 05:29:23 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43768) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eJzYc-000736-53 for qemu-devel@nongnu.org; Wed, 29 Nov 2017 05:25:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eJzYZ-00056T-1J for qemu-devel@nongnu.org; Wed, 29 Nov 2017 05:25:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54354) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eJzYV-00053r-RG; Wed, 29 Nov 2017 05:25:28 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0A18CC0587DE; Wed, 29 Nov 2017 10:25:27 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-117-214.ams2.redhat.com [10.36.117.214]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8EAE6600D1; Wed, 29 Nov 2017 10:25:25 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Wed, 29 Nov 2017 11:25:13 +0100 Message-Id: <20171129102513.9153-5-pbonzini@redhat.com> In-Reply-To: <20171129102513.9153-1-pbonzini@redhat.com> References: <20171129102513.9153-1-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 29 Nov 2017 10:25:27 +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 4/4] blockjob: reimplement block_job_sleep_ns to allow cancellation 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: kwolf@redhat.com, jcody@redhat.com, famz@redhat.com, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" This reverts the effects of commit 4afeffc857 ("blockjob: do not allow coroutine double entry or entry-after-completion", 2017-11-21) This fixed the symptom of a bug rather than the root cause. Canceling the wait on a sleeping blockjob coroutine is generally fine, we just need to make it work correctly across AioContexts. To do so, use a QEMUTimer that calls block_job_enter. Use a mutex to ensure that block_job_enter synchronizes correctly with block_job_sleep_ns. Signed-off-by: Paolo Bonzini Reviewed-by: Fam Zheng Reviewed-by: Jeff Cody Reviewed-by: Stefan Hajnoczi Tested-By: Jeff Cody --- blockjob.c | 57 +++++++++++++++++++++++++++++++++++-----= ---- include/block/blockjob.h | 5 +++- include/block/blockjob_int.h | 4 ++-- 3 files changed, 52 insertions(+), 14 deletions(-) diff --git a/blockjob.c b/blockjob.c index 4d22b7d2fb..3fdaabbc1f 100644 --- a/blockjob.c +++ b/blockjob.c @@ -37,6 +37,26 @@ #include "qemu/timer.h" #include "qapi-event.h" =20 +/* Right now, this mutex is only needed to synchronize accesses to job->bu= sy, + * especially concurrent calls to block_job_enter. + */ +static QemuMutex block_job_mutex; + +static void block_job_lock(void) +{ + qemu_mutex_lock(&block_job_mutex); +} + +static void block_job_unlock(void) +{ + qemu_mutex_unlock(&block_job_mutex); +} + +static void __attribute__((__constructor__)) block_job_init(void) +{ + qemu_mutex_init(&block_job_mutex); +} + static void block_job_event_cancelled(BlockJob *job); static void block_job_event_completed(BlockJob *job, const char *msg); =20 @@ -161,6 +181,7 @@ void block_job_unref(BlockJob *job) blk_unref(job->blk); error_free(job->blocker); g_free(job->id); + assert(!timer_pending(&job->sleep_timer)); g_free(job); } } @@ -287,6 +308,13 @@ static void coroutine_fn block_job_co_entry(void *opaq= ue) job->driver->start(job); } =20 +static void block_job_sleep_timer_cb(void *opaque) +{ + BlockJob *job =3D opaque; + + block_job_enter(job); +} + void block_job_start(BlockJob *job) { assert(job && !block_job_started(job) && job->paused && @@ -556,7 +584,7 @@ BlockJobInfo *block_job_query(BlockJob *job, Error **er= rp) info->type =3D g_strdup(BlockJobType_str(job->driver->job_type)); info->device =3D g_strdup(job->id); info->len =3D job->len; - info->busy =3D job->busy; + info->busy =3D atomic_read(&job->busy); info->paused =3D job->pause_count > 0; info->offset =3D job->offset; info->speed =3D job->speed; @@ -664,6 +692,9 @@ void *block_job_create(const char *job_id, const BlockJ= obDriver *driver, job->paused =3D true; job->pause_count =3D 1; job->refcnt =3D 1; + aio_timer_init(qemu_get_aio_context(), &job->sleep_timer, + QEMU_CLOCK_REALTIME, SCALE_NS, + block_job_sleep_timer_cb, job); =20 error_setg(&job->blocker, "block device is in use by block job: %s", BlockJobType_str(driver->job_type)); @@ -729,9 +760,14 @@ static bool block_job_should_pause(BlockJob *job) return job->pause_count > 0; } =20 -static void block_job_do_yield(BlockJob *job) +static void block_job_do_yield(BlockJob *job, uint64_t ns) { + block_job_lock(); + if (ns !=3D -1) { + timer_mod(&job->sleep_timer, ns); + } job->busy =3D false; + block_job_unlock(); qemu_coroutine_yield(); =20 /* Set by block_job_enter before re-entering the coroutine. */ @@ -755,7 +791,7 @@ void coroutine_fn block_job_pause_point(BlockJob *job) =20 if (block_job_should_pause(job) && !block_job_is_cancelled(job)) { job->paused =3D true; - block_job_do_yield(job); + block_job_do_yield(job, -1); job->paused =3D false; } =20 @@ -785,11 +821,16 @@ void block_job_enter(BlockJob *job) return; } =20 + block_job_lock(); if (job->busy) { + block_job_unlock(); return; } =20 + assert(!job->deferred_to_main_loop); + timer_del(&job->sleep_timer); job->busy =3D true; + block_job_unlock(); aio_co_wake(job->co); } =20 @@ -807,14 +848,8 @@ void block_job_sleep_ns(BlockJob *job, int64_t ns) return; } =20 - /* We need to leave job->busy set here, because when we have - * put a coroutine to 'sleep', we have scheduled it to run in - * the future. We cannot enter that same coroutine again before - * it wakes and runs, otherwise we risk double-entry or entry after - * completion. */ if (!block_job_should_pause(job)) { - co_aio_sleep_ns(blk_get_aio_context(job->blk), - QEMU_CLOCK_REALTIME, ns); + block_job_do_yield(job, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + n= s); } =20 block_job_pause_point(job); @@ -830,7 +865,7 @@ void block_job_yield(BlockJob *job) } =20 if (!block_job_should_pause(job)) { - block_job_do_yield(job); + block_job_do_yield(job, -1); } =20 block_job_pause_point(job); diff --git a/include/block/blockjob.h b/include/block/blockjob.h index 67c0968fa5..956f0d6819 100644 --- a/include/block/blockjob.h +++ b/include/block/blockjob.h @@ -77,7 +77,7 @@ typedef struct BlockJob { /** * Set to false by the job while the coroutine has yielded and may be * re-entered by block_job_enter(). There may still be I/O or event l= oop - * activity pending. + * activity pending. Accessed under block_job_mutex (in blockjob.c). */ bool busy; =20 @@ -135,6 +135,9 @@ typedef struct BlockJob { */ int ret; =20 + /** Timer that is used by @block_job_sleep_ns. */ + QEMUTimer sleep_timer; + /** Non-NULL if this job is part of a transaction */ BlockJobTxn *txn; QLIST_ENTRY(BlockJob) txn_list; diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h index f7ab183a39..c9b23b0cc9 100644 --- a/include/block/blockjob_int.h +++ b/include/block/blockjob_int.h @@ -142,8 +142,8 @@ void *block_job_create(const char *job_id, const BlockJ= obDriver *driver, * @ns: How many nanoseconds to stop for. * * Put the job to sleep (assuming that it wasn't canceled) for @ns - * %QEMU_CLOCK_REALTIME nanoseconds. Canceling the job will not interrupt - * the wait, so the cancel will not process until the coroutine wakes up. + * %QEMU_CLOCK_REALTIME nanoseconds. Canceling the job will immediately + * interrupt the wait. */ void block_job_sleep_ns(BlockJob *job, int64_t ns); =20 --=20 2.14.3