{"id":814950,"url":"http://patchwork.ozlabs.org/api/patches/814950/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170918135935.255591-8-vsementsov@virtuozzo.com/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20170918135935.255591-8-vsementsov@virtuozzo.com>","list_archive_url":null,"date":"2017-09-18T13:59:35","name":"[v2,7/7] block/nbd-client: do not yield from nbd_read_reply_entry","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"ff11114f0bca13e378eeb5057924e778ffb24933","submitter":{"id":66592,"url":"http://patchwork.ozlabs.org/api/people/66592/?format=json","name":"Vladimir Sementsov-Ogievskiy","email":"vsementsov@virtuozzo.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170918135935.255591-8-vsementsov@virtuozzo.com/mbox/","series":[{"id":3654,"url":"http://patchwork.ozlabs.org/api/series/3654/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=3654","date":"2017-09-18T13:59:31","name":"nbd client refactoring and fixing","version":2,"mbox":"http://patchwork.ozlabs.org/series/3654/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/814950/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/814950/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":"ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=nongnu.org\n\t(client-ip=2001:4830:134:3::11; helo=lists.gnu.org;\n\tenvelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n\treceiver=)","Received":["from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11])\n\t(using TLSv1 with cipher AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xwnlz45Ylz9s7c\n\tfor ;\n\tTue, 19 Sep 2017 00:03:27 +1000 (AEST)","from localhost ([::1]:36799 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t)\n\tid 1dtwdx-0004a5-LX\n\tfor incoming@patchwork.ozlabs.org; Mon, 18 Sep 2017 10:03:25 -0400","from eggs.gnu.org ([2001:4830:134:3::10]:38436)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from ) id 1dtwaR-0001iK-9i\n\tfor qemu-devel@nongnu.org; Mon, 18 Sep 2017 09:59:48 -0400","from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from ) id 1dtwaN-0001QL-Me\n\tfor qemu-devel@nongnu.org; Mon, 18 Sep 2017 09:59:47 -0400","from mailhub.sw.ru ([195.214.232.25]:10237 helo=relay.sw.ru)\n\tby eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)\n\t(Exim 4.71) (envelope-from )\n\tid 1dtwaN-0001Pg-B7\n\tfor qemu-devel@nongnu.org; Mon, 18 Sep 2017 09:59:43 -0400","from kvm.sw.ru (msk-vpn.virtuozzo.com [195.214.232.6])\n\tby relay.sw.ru (8.13.4/8.13.4) with ESMTP id v8IDxZdb022049;\n\tMon, 18 Sep 2017 16:59:37 +0300 (MSK)"],"From":"Vladimir Sementsov-Ogievskiy ","To":"qemu-block@nongnu.org, qemu-devel@nongnu.org","Date":"Mon, 18 Sep 2017 16:59:35 +0300","Message-Id":"<20170918135935.255591-8-vsementsov@virtuozzo.com>","X-Mailer":"git-send-email 2.11.1","In-Reply-To":"<20170918135935.255591-1-vsementsov@virtuozzo.com>","References":"<20170918135935.255591-1-vsementsov@virtuozzo.com>","X-detected-operating-system":"by eggs.gnu.org: OpenBSD 3.x [fuzzy]","X-Received-From":"195.214.232.25","Subject":"[Qemu-devel] [PATCH v2 7/7] block/nbd-client: do not yield from\n\tnbd_read_reply_entry","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"kwolf@redhat.com, vsementsov@virtuozzo.com, mreitz@redhat.com,\n\tden@openvz.org, pbonzini@redhat.com","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"\"Qemu-devel\"\n\t"},"content":"Refactor nbd client to not yield from nbd_read_reply_entry. It's\npossible now as all reading is done in nbd_read_reply_entry and\nall request-related data is stored in per-request s->requests[i].\n\nWe need here some additional work with s->requests[i].ret and\ns->quit to not fail requests on normal disconnet and to not report\nreading errors on normal disconnect.\n\nSigned-off-by: Vladimir Sementsov-Ogievskiy \n---\n block/nbd-client.c | 29 ++++++++++-------------------\n 1 file changed, 10 insertions(+), 19 deletions(-)","diff":"diff --git a/block/nbd-client.c b/block/nbd-client.c\nindex f80a4c5564..bf20d5d5e6 100644\n--- a/block/nbd-client.c\n+++ b/block/nbd-client.c\n@@ -79,7 +79,11 @@ static coroutine_fn void nbd_read_reply_entry(void *opaque)\n while (!s->quit) {\n ret = nbd_receive_reply(s->ioc, &reply, &local_err);\n if (ret < 0) {\n- error_report_err(local_err);\n+ if (s->quit) {\n+ error_free(local_err);\n+ } else {\n+ error_report_err(local_err);\n+ }\n }\n if (ret <= 0 || s->quit) {\n break;\n@@ -112,19 +116,8 @@ static coroutine_fn void nbd_read_reply_entry(void *opaque)\n }\n }\n \n- /* We're woken up again by the request itself. Note that there\n- * is no race between yielding and reentering read_reply_co. This\n- * is because:\n- *\n- * - if the request runs on the same AioContext, it is only\n- * entered after we yield\n- *\n- * - if the request runs on a different AioContext, reentering\n- * read_reply_co happens through a bottom half, which can only\n- * run after we yield.\n- */\n+ s->requests[i].receiving = false;\n aio_co_wake(s->requests[i].coroutine);\n- qemu_coroutine_yield();\n }\n \n s->quit = true;\n@@ -157,6 +150,7 @@ static int nbd_co_send_request(BlockDriverState *bs,\n \n s->requests[i].coroutine = qemu_coroutine_self();\n s->requests[i].receiving = false;\n+ s->requests[i].ret = -EIO;\n \n request->handle = INDEX_TO_HANDLE(s, i);\n s->requests[i].request = request;\n@@ -210,7 +204,7 @@ static int nbd_co_receive_reply(NBDClientSession *s, NBDRequest *request)\n s->requests[i].receiving = true;\n qemu_coroutine_yield();\n s->requests[i].receiving = false;\n- if (!s->ioc || s->quit) {\n+ if (!s->ioc) {\n ret = -EIO;\n } else {\n ret = s->requests[i].ret;\n@@ -218,11 +212,6 @@ static int nbd_co_receive_reply(NBDClientSession *s, NBDRequest *request)\n \n s->requests[i].coroutine = NULL;\n \n- /* Kick the read_reply_co to get the next reply. */\n- if (s->read_reply_co) {\n- aio_co_wake(s->read_reply_co);\n- }\n-\n qemu_co_mutex_lock(&s->send_mutex);\n s->in_flight--;\n qemu_co_queue_next(&s->free_sema);\n@@ -364,6 +353,8 @@ void nbd_client_close(BlockDriverState *bs)\n \n nbd_send_request(client->ioc, &request);\n \n+ client->quit = true;\n+\n nbd_teardown_connection(bs);\n }\n \n","prefixes":["v2","7/7"]}