{"id":831191,"url":"http://patchwork.ozlabs.org/api/1.2/patches/831191/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20171027104037.8319-8-eblake@redhat.com/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/1.2/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":"<20171027104037.8319-8-eblake@redhat.com>","list_archive_url":null,"date":"2017-10-27T10:40:32","name":"[v6,07/12] nbd: Minimal structured read for server","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"d61eedeb8a9e142d656dfa3955d44a9a1e59e9c6","submitter":{"id":6591,"url":"http://patchwork.ozlabs.org/api/1.2/people/6591/?format=json","name":"Eric Blake","email":"eblake@redhat.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20171027104037.8319-8-eblake@redhat.com/mbox/","series":[{"id":10552,"url":"http://patchwork.ozlabs.org/api/1.2/series/10552/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=10552","date":"2017-10-27T10:40:27","name":"nbd minimal structured read","version":6,"mbox":"http://patchwork.ozlabs.org/series/10552/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/831191/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/831191/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; 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+0200","Message-Id":"<20171027104037.8319-8-eblake@redhat.com>","In-Reply-To":"<20171027104037.8319-1-eblake@redhat.com>","References":"<20171027104037.8319-1-eblake@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\n\t(mx1.redhat.com [10.5.110.31]);\n\tFri, 27 Oct 2017 10:40:55 +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 v6 07/12] nbd: Minimal structured read for\n\tserver","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":"pbonzini@redhat.com, vsementsov@virtuozzo.com, qemu-block@nongnu.org","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"\"Qemu-devel\"\n\t"},"content":"From: Vladimir Sementsov-Ogievskiy \n\nMinimal implementation of structured read: one structured reply chunk,\nno segmentation.\nMinimal structured error implementation: no text message.\nSupport DF flag, but just ignore it, as there is no segmentation any\nway.\n\nSigned-off-by: Vladimir Sementsov-Ogievskiy \nSigned-off-by: Eric Blake \n\n---\nv6: only set structured_reply when replying with ack [Vladimir]\nv5: correct DF flag spelling, include errname in trace, handle any bogus\npayload from option\nv4: better _DF flag handling, convert errno to wire format, add\ncomments and tracing, rework structured error for less churn when adding\ntext message later, don't kill connection on redundant client option\n---\n nbd/server.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++++------\n nbd/trace-events | 2 ++\n 2 files changed, 99 insertions(+), 10 deletions(-)","diff":"diff --git a/nbd/server.c b/nbd/server.c\nindex a98f5622c9..5d6d9a2ddd 100644\n--- a/nbd/server.c\n+++ b/nbd/server.c\n@@ -100,6 +100,8 @@ struct NBDClient {\n QTAILQ_ENTRY(NBDClient) next;\n int nb_requests;\n bool closing;\n+\n+ bool structured_reply;\n };\n\n /* That's all folks */\n@@ -768,6 +770,23 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags,\n \"TLS not configured\");\n }\n break;\n+\n+ case NBD_OPT_STRUCTURED_REPLY:\n+ if (length) {\n+ ret = nbd_reject_length(client, length, option, false,\n+ errp);\n+ } else if (client->structured_reply) {\n+ ret = nbd_negotiate_send_rep_err(\n+ client->ioc, NBD_REP_ERR_INVALID, option, errp,\n+ \"structured reply already negotiated\");\n+ } else {\n+ ret = nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK,\n+ option, errp);\n+ client->structured_reply = true;\n+ myflags |= NBD_FLAG_SEND_DF;\n+ }\n+ break;\n+\n default:\n if (nbd_drop(client->ioc, length, errp) < 0) {\n return -EIO;\n@@ -1242,6 +1261,60 @@ static int nbd_co_send_simple_reply(NBDClient *client,\n return nbd_co_send_iov(client, iov, len ? 2 : 1, errp);\n }\n\n+static inline void set_be_chunk(NBDStructuredReplyChunk *chunk, uint16_t flags,\n+ uint16_t type, uint64_t handle, uint32_t length)\n+{\n+ stl_be_p(&chunk->magic, NBD_STRUCTURED_REPLY_MAGIC);\n+ stw_be_p(&chunk->flags, flags);\n+ stw_be_p(&chunk->type, type);\n+ stq_be_p(&chunk->handle, handle);\n+ stl_be_p(&chunk->length, length);\n+}\n+\n+static int coroutine_fn nbd_co_send_structured_read(NBDClient *client,\n+ uint64_t handle,\n+ uint64_t offset,\n+ void *data,\n+ size_t size,\n+ Error **errp)\n+{\n+ NBDStructuredRead chunk;\n+ struct iovec iov[] = {\n+ {.iov_base = &chunk, .iov_len = sizeof(chunk)},\n+ {.iov_base = data, .iov_len = size}\n+ };\n+\n+ trace_nbd_co_send_structured_read(handle, offset, data, size);\n+ set_be_chunk(&chunk.h, NBD_REPLY_FLAG_DONE, NBD_REPLY_TYPE_OFFSET_DATA,\n+ handle, sizeof(chunk) - sizeof(chunk.h) + size);\n+ stq_be_p(&chunk.offset, offset);\n+\n+ return nbd_co_send_iov(client, iov, 2, errp);\n+}\n+\n+static int coroutine_fn nbd_co_send_structured_error(NBDClient *client,\n+ uint64_t handle,\n+ uint32_t error,\n+ Error **errp)\n+{\n+ NBDStructuredError chunk;\n+ int nbd_err = system_errno_to_nbd_errno(error);\n+ struct iovec iov[] = {\n+ {.iov_base = &chunk, .iov_len = sizeof(chunk)},\n+ /* FIXME: Support human-readable error message */\n+ };\n+\n+ assert(nbd_err);\n+ trace_nbd_co_send_structured_error(handle, nbd_err,\n+ nbd_err_lookup(nbd_err));\n+ set_be_chunk(&chunk.h, NBD_REPLY_FLAG_DONE, NBD_REPLY_TYPE_ERROR, handle,\n+ sizeof(chunk) - sizeof(chunk.h));\n+ stl_be_p(&chunk.error, nbd_err);\n+ stw_be_p(&chunk.message_length, 0);\n+\n+ return nbd_co_send_iov(client, iov, 1, errp);\n+}\n+\n /* nbd_co_receive_request\n * Collect a client request. Return 0 if request looks valid, -EIO to drop\n * connection right away, and any other negative value to report an error to\n@@ -1252,6 +1325,7 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request,\n Error **errp)\n {\n NBDClient *client = req->client;\n+ int valid_flags;\n\n g_assert(qemu_in_coroutine());\n assert(client->recv_coroutine == qemu_coroutine_self());\n@@ -1313,13 +1387,15 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request,\n (uint64_t)client->exp->size);\n return request->type == NBD_CMD_WRITE ? -ENOSPC : -EINVAL;\n }\n- if (request->flags & ~(NBD_CMD_FLAG_FUA | NBD_CMD_FLAG_NO_HOLE)) {\n- error_setg(errp, \"unsupported flags (got 0x%x)\", request->flags);\n- return -EINVAL;\n+ valid_flags = NBD_CMD_FLAG_FUA;\n+ if (request->type == NBD_CMD_READ && client->structured_reply) {\n+ valid_flags |= NBD_CMD_FLAG_DF;\n+ } else if (request->type == NBD_CMD_WRITE_ZEROES) {\n+ valid_flags |= NBD_CMD_FLAG_NO_HOLE;\n }\n- if (request->type != NBD_CMD_WRITE_ZEROES &&\n- (request->flags & NBD_CMD_FLAG_NO_HOLE)) {\n- error_setg(errp, \"unexpected flags (got 0x%x)\", request->flags);\n+ if (request->flags & ~valid_flags) {\n+ error_setg(errp, \"unsupported flags for command %s (got 0x%x)\",\n+ nbd_cmd_lookup(request->type), request->flags);\n return -EINVAL;\n }\n\n@@ -1457,10 +1533,21 @@ reply:\n local_err = NULL;\n }\n\n- if (nbd_co_send_simple_reply(req->client, request.handle,\n- ret < 0 ? -ret : 0,\n- req->data, reply_data_len, &local_err) < 0)\n- {\n+ if (client->structured_reply && request.type == NBD_CMD_READ) {\n+ if (ret < 0) {\n+ ret = nbd_co_send_structured_error(req->client, request.handle,\n+ -ret, &local_err);\n+ } else {\n+ ret = nbd_co_send_structured_read(req->client, request.handle,\n+ request.from, req->data,\n+ reply_data_len, &local_err);\n+ }\n+ } else {\n+ ret = nbd_co_send_simple_reply(req->client, request.handle,\n+ ret < 0 ? -ret : 0,\n+ req->data, reply_data_len, &local_err);\n+ }\n+ if (ret < 0) {\n error_prepend(&local_err, \"Failed to send reply: \");\n goto disconnect;\n }\ndiff --git a/nbd/trace-events b/nbd/trace-events\nindex ab3d7dad4f..6894f8bbb4 100644\n--- a/nbd/trace-events\n+++ b/nbd/trace-events\n@@ -56,6 +56,8 @@ nbd_receive_request(uint32_t magic, uint16_t flags, uint16_t type, uint64_t from\n nbd_blk_aio_attached(const char *name, void *ctx) \"Export %s: Attaching clients to AIO context %p\\n\"\n nbd_blk_aio_detach(const char *name, void *ctx) \"Export %s: Detaching clients from AIO context %p\\n\"\n nbd_co_send_simple_reply(uint64_t handle, uint32_t error, const char *errname, int len) \"Send simple reply: handle = %\" PRIu64 \", error = %\" PRIu32 \" (%s), len = %d\"\n+nbd_co_send_structured_read(uint64_t handle, uint64_t offset, void *data, size_t size) \"Send structured read data reply: handle = %\" PRIu64 \", offset = %\" PRIu64 \", data = %p, len = %zu\"\n+nbd_co_send_structured_error(uint64_t handle, int err, const char *errname) \"Send structured error reply: handle = %\" PRIu64 \", error = %d (%s)\"\n nbd_co_receive_request_decode_type(uint64_t handle, uint16_t type, const char *name) \"Decoding type: handle = %\" PRIu64 \", type = %\" PRIu16 \" (%s)\"\n nbd_co_receive_request_payload_received(uint64_t handle, uint32_t len) \"Payload received: handle = %\" PRIu64 \", len = %\" PRIu32\n nbd_co_receive_request_cmd_write(uint32_t len) \"Reading %\" PRIu32 \" byte(s)\"\n","prefixes":["v6","07/12"]}