{"id":813562,"url":"http://patchwork.ozlabs.org/api/patches/813562/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170913181910.29688-6-mreitz@redhat.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":"<20170913181910.29688-6-mreitz@redhat.com>","list_archive_url":null,"date":"2017-09-13T18:18:57","name":"[05/18] block/mirror: Convert to coroutines","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"5d756ac3652fb51ea3cc77705efe29afe7928dee","submitter":{"id":36836,"url":"http://patchwork.ozlabs.org/api/people/36836/?format=json","name":"Max Reitz","email":"mreitz@redhat.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170913181910.29688-6-mreitz@redhat.com/mbox/","series":[{"id":2960,"url":"http://patchwork.ozlabs.org/api/series/2960/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=2960","date":"2017-09-13T18:18:52","name":"block/mirror: Add active-sync mirroring","version":1,"mbox":"http://patchwork.ozlabs.org/series/2960/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/813562/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/813562/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=)","ext-mx10.extmail.prod.ext.phx2.redhat.com;\n\tdmarc=none (p=none dis=none) header.from=redhat.com","ext-mx10.extmail.prod.ext.phx2.redhat.com;\n\tspf=fail smtp.mailfrom=mreitz@redhat.com"],"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 3xsqql25gJz9s3T\n\tfor ;\n\tThu, 14 Sep 2017 04:26:27 +1000 (AEST)","from localhost ([::1]:44023 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t)\n\tid 1dsCMj-0004K1-AW\n\tfor incoming@patchwork.ozlabs.org; Wed, 13 Sep 2017 14:26:25 -0400","from eggs.gnu.org ([2001:4830:134:3::10]:36676)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from ) id 1dsCGn-0008Do-IJ\n\tfor qemu-devel@nongnu.org; Wed, 13 Sep 2017 14:20:19 -0400","from Debian-exim 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+0200","Message-Id":"<20170913181910.29688-6-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 10.5.11.15","X-Greylist":"Sender IP whitelisted, not delayed by milter-greylist-4.5.16\n\t(mx1.redhat.com [10.5.110.39]);\n\tWed, 13 Sep 2017 18:20:08 +0000 (UTC)","X-detected-operating-system":"by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic]\n\t[fuzzy]","X-Received-From":"209.132.183.28","Subject":"[Qemu-devel] [PATCH 05/18] block/mirror: Convert to coroutines","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":"Kevin Wolf , Fam Zheng ,\n\tqemu-devel@nongnu.org, Max Reitz ,\n\tStefan Hajnoczi , John Snow ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"\"Qemu-devel\"\n\t"},"content":"In order to talk to the source BDS (and maybe in the future to the\ntarget BDS as well) directly, we need to convert our existing AIO\nrequests into coroutine I/O requests.\n\nSigned-off-by: Max Reitz \n---\n block/mirror.c | 134 +++++++++++++++++++++++++++++++++------------------------\n 1 file changed, 78 insertions(+), 56 deletions(-)","diff":"diff --git a/block/mirror.c b/block/mirror.c\nindex 4664b0516f..2b3297aa61 100644\n--- a/block/mirror.c\n+++ b/block/mirror.c\n@@ -80,6 +80,9 @@ typedef struct MirrorOp {\n QEMUIOVector qiov;\n int64_t offset;\n uint64_t bytes;\n+\n+ /* Set by mirror_co_read() before yielding for the first time */\n+ uint64_t bytes_copied;\n } MirrorOp;\n \n typedef enum MirrorMethod {\n@@ -101,7 +104,7 @@ static BlockErrorAction mirror_error_action(MirrorBlockJob *s, bool read,\n }\n }\n \n-static void mirror_iteration_done(MirrorOp *op, int ret)\n+static void coroutine_fn mirror_iteration_done(MirrorOp *op, int ret)\n {\n MirrorBlockJob *s = op->s;\n struct iovec *iov;\n@@ -138,9 +141,8 @@ static void mirror_iteration_done(MirrorOp *op, int ret)\n }\n }\n \n-static void mirror_write_complete(void *opaque, int ret)\n+static void coroutine_fn mirror_write_complete(MirrorOp *op, int ret)\n {\n- MirrorOp *op = opaque;\n MirrorBlockJob *s = op->s;\n \n aio_context_acquire(blk_get_aio_context(s->common.blk));\n@@ -158,9 +160,8 @@ static void mirror_write_complete(void *opaque, int ret)\n aio_context_release(blk_get_aio_context(s->common.blk));\n }\n \n-static void mirror_read_complete(void *opaque, int ret)\n+static void coroutine_fn mirror_read_complete(MirrorOp *op, int ret)\n {\n- MirrorOp *op = opaque;\n MirrorBlockJob *s = op->s;\n \n aio_context_acquire(blk_get_aio_context(s->common.blk));\n@@ -176,8 +177,11 @@ static void mirror_read_complete(void *opaque, int ret)\n \n mirror_iteration_done(op, ret);\n } else {\n- blk_aio_pwritev(s->target, op->offset, &op->qiov,\n- 0, mirror_write_complete, op);\n+ int ret;\n+\n+ ret = blk_co_pwritev(s->target, op->offset,\n+ op->qiov.size, &op->qiov, 0);\n+ mirror_write_complete(op, ret);\n }\n aio_context_release(blk_get_aio_context(s->common.blk));\n }\n@@ -242,53 +246,49 @@ static inline void mirror_wait_for_io(MirrorBlockJob *s)\n * (new_end - offset) if tail is rounded up or down due to\n * alignment or buffer limit.\n */\n-static uint64_t mirror_do_read(MirrorBlockJob *s, int64_t offset,\n- uint64_t bytes)\n+static void coroutine_fn mirror_co_read(void *opaque)\n {\n+ MirrorOp *op = opaque;\n+ MirrorBlockJob *s = op->s;\n BlockBackend *source = s->common.blk;\n int nb_chunks;\n uint64_t ret;\n- MirrorOp *op;\n uint64_t max_bytes;\n \n max_bytes = s->granularity * s->max_iov;\n \n /* We can only handle as much as buf_size at a time. */\n- bytes = MIN(s->buf_size, MIN(max_bytes, bytes));\n- assert(bytes);\n- assert(bytes < BDRV_REQUEST_MAX_BYTES);\n- ret = bytes;\n+ op->bytes = MIN(s->buf_size, MIN(max_bytes, op->bytes));\n+ assert(op->bytes);\n+ assert(op->bytes < BDRV_REQUEST_MAX_BYTES);\n+ op->bytes_copied = op->bytes;\n \n if (s->cow_bitmap) {\n- ret += mirror_cow_align(s, &offset, &bytes);\n+ op->bytes_copied += mirror_cow_align(s, &op->offset, &op->bytes);\n }\n- assert(bytes <= s->buf_size);\n+ /* Cannot exceed BDRV_REQUEST_MAX_BYTES + INT_MAX */\n+ assert(op->bytes_copied <= UINT_MAX);\n+ assert(op->bytes <= s->buf_size);\n /* The offset is granularity-aligned because:\n * 1) Caller passes in aligned values;\n * 2) mirror_cow_align is used only when target cluster is larger. */\n- assert(QEMU_IS_ALIGNED(offset, s->granularity));\n+ assert(QEMU_IS_ALIGNED(op->offset, s->granularity));\n /* The range is sector-aligned, since bdrv_getlength() rounds up. */\n- assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));\n- nb_chunks = DIV_ROUND_UP(bytes, s->granularity);\n+ assert(QEMU_IS_ALIGNED(op->bytes, BDRV_SECTOR_SIZE));\n+ nb_chunks = DIV_ROUND_UP(op->bytes, s->granularity);\n \n while (s->buf_free_count < nb_chunks) {\n- trace_mirror_yield_in_flight(s, offset, s->in_flight);\n+ trace_mirror_yield_in_flight(s, op->offset, s->in_flight);\n mirror_wait_for_io(s);\n }\n \n- /* Allocate a MirrorOp that is used as an AIO callback. */\n- op = g_new(MirrorOp, 1);\n- op->s = s;\n- op->offset = offset;\n- op->bytes = bytes;\n-\n /* Now make a QEMUIOVector taking enough granularity-sized chunks\n * from s->buf_free.\n */\n qemu_iovec_init(&op->qiov, nb_chunks);\n while (nb_chunks-- > 0) {\n MirrorBuffer *buf = QSIMPLEQ_FIRST(&s->buf_free);\n- size_t remaining = bytes - op->qiov.size;\n+ size_t remaining = op->bytes - op->qiov.size;\n \n QSIMPLEQ_REMOVE_HEAD(&s->buf_free, next);\n s->buf_free_count--;\n@@ -297,53 +297,75 @@ static uint64_t mirror_do_read(MirrorBlockJob *s, int64_t offset,\n \n /* Copy the dirty cluster. */\n s->in_flight++;\n- s->bytes_in_flight += bytes;\n- trace_mirror_one_iteration(s, offset, bytes);\n+ s->bytes_in_flight += op->bytes;\n+ trace_mirror_one_iteration(s, op->offset, op->bytes);\n \n- blk_aio_preadv(source, offset, &op->qiov, 0, mirror_read_complete, op);\n- return ret;\n+ ret = blk_co_preadv(source, op->offset, op->bytes, &op->qiov, 0);\n+ mirror_read_complete(op, ret);\n }\n \n-static void mirror_do_zero_or_discard(MirrorBlockJob *s,\n- int64_t offset,\n- uint64_t bytes,\n- bool is_discard)\n+static void coroutine_fn mirror_co_zero(void *opaque)\n {\n- MirrorOp *op;\n+ MirrorOp *op = opaque;\n+ int ret;\n \n- /* Allocate a MirrorOp that is used as an AIO callback. The qiov is zeroed\n- * so the freeing in mirror_iteration_done is nop. */\n- op = g_new0(MirrorOp, 1);\n- op->s = s;\n- op->offset = offset;\n- op->bytes = bytes;\n+ op->s->in_flight++;\n+ op->s->bytes_in_flight += op->bytes;\n \n- s->in_flight++;\n- s->bytes_in_flight += bytes;\n- if (is_discard) {\n- blk_aio_pdiscard(s->target, offset,\n- op->bytes, mirror_write_complete, op);\n- } else {\n- blk_aio_pwrite_zeroes(s->target, offset,\n- op->bytes, s->unmap ? BDRV_REQ_MAY_UNMAP : 0,\n- mirror_write_complete, op);\n- }\n+ ret = blk_co_pwrite_zeroes(op->s->target, op->offset, op->bytes,\n+ op->s->unmap ? BDRV_REQ_MAY_UNMAP : 0);\n+ mirror_write_complete(op, ret);\n+}\n+\n+static void coroutine_fn mirror_co_discard(void *opaque)\n+{\n+ MirrorOp *op = opaque;\n+ int ret;\n+\n+ op->s->in_flight++;\n+ op->s->bytes_in_flight += op->bytes;\n+\n+ ret = blk_co_pdiscard(op->s->target, op->offset, op->bytes);\n+ mirror_write_complete(op, ret);\n }\n \n static unsigned mirror_perform(MirrorBlockJob *s, int64_t offset,\n unsigned bytes, MirrorMethod mirror_method)\n {\n+ MirrorOp *op;\n+ Coroutine *co;\n+ unsigned ret = bytes;\n+\n+ op = g_new(MirrorOp, 1);\n+ *op = (MirrorOp){\n+ .s = s,\n+ .offset = offset,\n+ .bytes = bytes,\n+ };\n+\n switch (mirror_method) {\n case MIRROR_METHOD_COPY:\n- return mirror_do_read(s, offset, bytes);\n+ co = qemu_coroutine_create(mirror_co_read, op);\n+ break;\n case MIRROR_METHOD_ZERO:\n+ co = qemu_coroutine_create(mirror_co_zero, op);\n+ break;\n case MIRROR_METHOD_DISCARD:\n- mirror_do_zero_or_discard(s, offset, bytes,\n- mirror_method == MIRROR_METHOD_DISCARD);\n- return bytes;\n+ co = qemu_coroutine_create(mirror_co_discard, op);\n+ break;\n default:\n abort();\n }\n+\n+ qemu_coroutine_enter(co);\n+\n+ if (mirror_method == MIRROR_METHOD_COPY) {\n+ /* Same assertion as in mirror_co_read() */\n+ assert(op->bytes_copied <= UINT_MAX);\n+ ret = op->bytes_copied;\n+ }\n+\n+ return ret;\n }\n \n static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)\n","prefixes":["05/18"]}