{"id":816238,"url":"http://patchwork.ozlabs.org/api/patches/816238/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170920102311.25736-2-el13635@mail.ntua.gr/","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":"<20170920102311.25736-2-el13635@mail.ntua.gr>","list_archive_url":null,"date":"2017-09-20T10:23:09","name":"[1/3] block: add bdrv_co_drain_end callback","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"6699fc132f2fd048c72e3abae0e2a38aaa243352","submitter":{"id":71571,"url":"http://patchwork.ozlabs.org/api/people/71571/?format=json","name":"Manos Pitsidianakis","email":"el13635@mail.ntua.gr"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170920102311.25736-2-el13635@mail.ntua.gr/mbox/","series":[{"id":4124,"url":"http://patchwork.ozlabs.org/api/series/4124/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=4124","date":"2017-09-20T10:23:09","name":"add bdrv_co_drain_begin/end BlockDriver callbacks","version":1,"mbox":"http://patchwork.ozlabs.org/series/4124/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/816238/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/816238/checks/","tags":{},"related":[],"headers":{"Return-Path":"<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>","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=<UNKNOWN>)","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 3xy1bg3NZKz9s7h\n\tfor <incoming@patchwork.ozlabs.org>;\n\tThu, 21 Sep 2017 00:00:31 +1000 (AEST)","from localhost ([::1]:48267 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>)\n\tid 1dufYD-0005qy-He\n\tfor incoming@patchwork.ozlabs.org; Wed, 20 Sep 2017 10:00:29 -0400","from eggs.gnu.org ([2001:4830:134:3::10]:41727)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from <el13635@mail.ntua.gr>) id 1dufAV-00024V-PE\n\tfor qemu-devel@nongnu.org; Wed, 20 Sep 2017 09:36:00 -0400","from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from <el13635@mail.ntua.gr>) id 1dufAT-00011q-0S\n\tfor qemu-devel@nongnu.org; Wed, 20 Sep 2017 09:35:59 -0400","from smtp1.ntua.gr ([2001:648:2000:de::183]:20570)\n\tby eggs.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from <el13635@mail.ntua.gr>)\n\tid 1dufAP-0000sM-HV; Wed, 20 Sep 2017 09:35:53 -0400","from mail.ntua.gr (carp0.noc.ntua.gr [147.102.222.60])\n\t(authenticated bits=0)\n\tby smtp1.ntua.gr (8.15.2/8.15.2) with ESMTPSA id v8KANNHw022771\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256\n\tverify=NOT); Wed, 20 Sep 2017 13:23:24 +0300 (EEST)\n\t(envelope-from el13635@mail.ntua.gr)"],"X-Authentication-Warning":"smtp1.ntua.gr: Host carp0.noc.ntua.gr\n\t[147.102.222.60] claimed to be mail.ntua.gr","From":"Manos Pitsidianakis <el13635@mail.ntua.gr>","To":"qemu-devel <qemu-devel@nongnu.org>","Date":"Wed, 20 Sep 2017 13:23:09 +0300","Message-Id":"<20170920102311.25736-2-el13635@mail.ntua.gr>","X-Mailer":"git-send-email 2.11.0","In-Reply-To":"<20170920102311.25736-1-el13635@mail.ntua.gr>","References":"<20170920102311.25736-1-el13635@mail.ntua.gr>","X-detected-operating-system":"by eggs.gnu.org: Genre and OS details not\n\trecognized.","X-Received-From":"2001:648:2000:de::183","Subject":"[Qemu-devel] [PATCH 1/3] block: add bdrv_co_drain_end callback","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Id":"<qemu-devel.nongnu.org>","List-Unsubscribe":"<https://lists.nongnu.org/mailman/options/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>","List-Archive":"<http://lists.nongnu.org/archive/html/qemu-devel/>","List-Post":"<mailto:qemu-devel@nongnu.org>","List-Help":"<mailto:qemu-devel-request@nongnu.org?subject=help>","List-Subscribe":"<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=subscribe>","Cc":"Kevin Wolf <kwolf@redhat.com>, Fam Zheng <famz@redhat.com>,\n\tStefan Hajnoczi <stefanha@redhat.com>,\n\tqemu-block <qemu-block@nongnu.org>, Max Reitz <mreitz@redhat.com>","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"\"Qemu-devel\"\n\t<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>"},"content":"BlockDriverState has a bdrv_do_drain() callback but no equivalent for the end\nof the drain. The throttle driver (block/throttle.c) needs a way to mark the\nend of the drain in order to toggle io_limits_disabled correctly, thus\nbdrv_co_drain_end is needed.\n\nSigned-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>\n---\n include/block/block_int.h |  2 ++\n block/io.c                | 43 +++++++++++++++++++++++++++++++------------\n 2 files changed, 33 insertions(+), 12 deletions(-)","diff":"diff --git a/include/block/block_int.h b/include/block/block_int.h\nindex ba4c383393..ea1326e3c7 100644\n--- a/include/block/block_int.h\n+++ b/include/block/block_int.h\n@@ -359,6 +359,8 @@ struct BlockDriver {\n      */\n     void coroutine_fn (*bdrv_co_drain)(BlockDriverState *bs);\n \n+    void coroutine_fn (*bdrv_co_drain_end)(BlockDriverState *bs);\n+\n     void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,\n                            Error **errp);\n     void (*bdrv_del_child)(BlockDriverState *parent, BdrvChild *child,\ndiff --git a/block/io.c b/block/io.c\nindex 4378ae4c7d..465345289d 100644\n--- a/block/io.c\n+++ b/block/io.c\n@@ -153,6 +153,7 @@ typedef struct {\n     Coroutine *co;\n     BlockDriverState *bs;\n     bool done;\n+    bool begin;\n } BdrvCoDrainData;\n \n static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)\n@@ -160,18 +161,23 @@ static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)\n     BdrvCoDrainData *data = opaque;\n     BlockDriverState *bs = data->bs;\n \n-    bs->drv->bdrv_co_drain(bs);\n+    if (data->begin) {\n+        bs->drv->bdrv_co_drain(bs);\n+    } else {\n+        bs->drv->bdrv_co_drain_end(bs);\n+    }\n \n     /* Set data->done before reading bs->wakeup.  */\n     atomic_mb_set(&data->done, true);\n     bdrv_wakeup(bs);\n }\n \n-static void bdrv_drain_invoke(BlockDriverState *bs)\n+static void bdrv_drain_invoke(BlockDriverState *bs, bool begin)\n {\n-    BdrvCoDrainData data = { .bs = bs, .done = false };\n+    BdrvCoDrainData data = { .bs = bs, .done = false, .begin = begin};\n \n-    if (!bs->drv || !bs->drv->bdrv_co_drain) {\n+    if (!bs->drv || (begin && !bs->drv->bdrv_co_drain) ||\n+            (!begin && !bs->drv->bdrv_co_drain_end)) {\n         return;\n     }\n \n@@ -180,7 +186,7 @@ static void bdrv_drain_invoke(BlockDriverState *bs)\n     BDRV_POLL_WHILE(bs, !data.done);\n }\n \n-static bool bdrv_drain_recurse(BlockDriverState *bs)\n+static bool bdrv_drain_recurse(BlockDriverState *bs, bool begin)\n {\n     BdrvChild *child, *tmp;\n     bool waited;\n@@ -188,7 +194,7 @@ static bool bdrv_drain_recurse(BlockDriverState *bs)\n     waited = BDRV_POLL_WHILE(bs, atomic_read(&bs->in_flight) > 0);\n \n     /* Ensure any pending metadata writes are submitted to bs->file.  */\n-    bdrv_drain_invoke(bs);\n+    bdrv_drain_invoke(bs, begin);\n \n     QLIST_FOREACH_SAFE(child, &bs->children, next, tmp) {\n         BlockDriverState *bs = child->bs;\n@@ -205,7 +211,7 @@ static bool bdrv_drain_recurse(BlockDriverState *bs)\n              */\n             bdrv_ref(bs);\n         }\n-        waited |= bdrv_drain_recurse(bs);\n+        waited |= bdrv_drain_recurse(bs, begin);\n         if (in_main_loop) {\n             bdrv_unref(bs);\n         }\n@@ -221,12 +227,18 @@ static void bdrv_co_drain_bh_cb(void *opaque)\n     BlockDriverState *bs = data->bs;\n \n     bdrv_dec_in_flight(bs);\n-    bdrv_drained_begin(bs);\n+    if (data->begin) {\n+        bdrv_drained_begin(bs);\n+    } else {\n+        bdrv_drained_end(bs);\n+    }\n+\n     data->done = true;\n     aio_co_wake(co);\n }\n \n-static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs)\n+static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,\n+                                                bool begin)\n {\n     BdrvCoDrainData data;\n \n@@ -239,6 +251,7 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs)\n         .co = qemu_coroutine_self(),\n         .bs = bs,\n         .done = false,\n+        .begin = begin,\n     };\n     bdrv_inc_in_flight(bs);\n     aio_bh_schedule_oneshot(bdrv_get_aio_context(bs),\n@@ -253,7 +266,7 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs)\n void bdrv_drained_begin(BlockDriverState *bs)\n {\n     if (qemu_in_coroutine()) {\n-        bdrv_co_yield_to_drain(bs);\n+        bdrv_co_yield_to_drain(bs, true);\n         return;\n     }\n \n@@ -262,17 +275,22 @@ void bdrv_drained_begin(BlockDriverState *bs)\n         bdrv_parent_drained_begin(bs);\n     }\n \n-    bdrv_drain_recurse(bs);\n+    bdrv_drain_recurse(bs, true);\n }\n \n void bdrv_drained_end(BlockDriverState *bs)\n {\n+    if (qemu_in_coroutine()) {\n+        bdrv_co_yield_to_drain(bs, false);\n+        return;\n+    }\n     assert(bs->quiesce_counter > 0);\n     if (atomic_fetch_dec(&bs->quiesce_counter) > 1) {\n         return;\n     }\n \n     bdrv_parent_drained_end(bs);\n+    bdrv_drain_recurse(bs, false);\n     aio_enable_external(bdrv_get_aio_context(bs));\n }\n \n@@ -350,7 +368,7 @@ void bdrv_drain_all_begin(void)\n             aio_context_acquire(aio_context);\n             for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {\n                 if (aio_context == bdrv_get_aio_context(bs)) {\n-                    waited |= bdrv_drain_recurse(bs);\n+                    waited |= bdrv_drain_recurse(bs, true);\n                 }\n             }\n             aio_context_release(aio_context);\n@@ -371,6 +389,7 @@ void bdrv_drain_all_end(void)\n         aio_context_acquire(aio_context);\n         aio_enable_external(aio_context);\n         bdrv_parent_drained_end(bs);\n+        bdrv_drain_recurse(bs, false);\n         aio_context_release(aio_context);\n     }\n \n","prefixes":["1/3"]}