{"id":818252,"url":"http://patchwork.ozlabs.org/api/patches/818252/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170925135801.144261-7-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":"<20170925135801.144261-7-vsementsov@virtuozzo.com>","list_archive_url":null,"date":"2017-09-25T13:57:59","name":"[6/8] nbd: Minimal structured read for server","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"3af3ad2f6ad08979c49b157fb77847815c4b9c71","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/20170925135801.144261-7-vsementsov@virtuozzo.com/mbox/","series":[{"id":4967,"url":"http://patchwork.ozlabs.org/api/series/4967/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=4967","date":"2017-09-25T13:58:01","name":"nbd minimal structured read","version":1,"mbox":"http://patchwork.ozlabs.org/series/4967/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/818252/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/818252/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 3y15LW4qDgz9tXC\n\tfor ;\n\tMon, 25 Sep 2017 23:59:47 +1000 (AEST)","from localhost ([::1]:42574 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t)\n\tid 1dwTvF-00074B-N6\n\tfor incoming@patchwork.ozlabs.org; Mon, 25 Sep 2017 09:59:45 -0400","from eggs.gnu.org ([2001:4830:134:3::10]:39657)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from ) id 1dwTtz-0006YZ-KV\n\tfor qemu-devel@nongnu.org; Mon, 25 Sep 2017 09:58:29 -0400","from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from ) id 1dwTtv-0007DW-RN\n\tfor qemu-devel@nongnu.org; Mon, 25 Sep 2017 09:58:27 -0400","from mailhub.sw.ru ([195.214.232.25]:33731 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 1dwTtv-0007C2-An\n\tfor qemu-devel@nongnu.org; Mon, 25 Sep 2017 09:58:23 -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 v8PDw1fw013085;\n\tMon, 25 Sep 2017 16:58:03 +0300 (MSK)"],"From":"Vladimir Sementsov-Ogievskiy ","To":"qemu-devel@nongnu.org, qemu-block@nongnu.org","Date":"Mon, 25 Sep 2017 16:57:59 +0300","Message-Id":"<20170925135801.144261-7-vsementsov@virtuozzo.com>","X-Mailer":"git-send-email 2.11.1","In-Reply-To":"<20170925135801.144261-1-vsementsov@virtuozzo.com>","References":"<20170925135801.144261-1-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 6/8] nbd: Minimal structured read for server","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, Hmreitz@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":"Minimal 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 \n---\n include/block/nbd.h | 31 ++++++++++++++++\n nbd/nbd-internal.h | 1 +\n nbd/server.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++----\n 3 files changed, 126 insertions(+), 6 deletions(-)","diff":"diff --git a/include/block/nbd.h b/include/block/nbd.h\nindex a6df5ce8b5..314f2f9bbc 100644\n--- a/include/block/nbd.h\n+++ b/include/block/nbd.h\n@@ -69,6 +69,25 @@ typedef struct NBDSimpleReply {\n uint64_t handle;\n } QEMU_PACKED NBDSimpleReply;\n \n+typedef struct NBDStructuredReplyChunk {\n+ uint32_t magic; /* NBD_STRUCTURED_REPLY_MAGIC */\n+ uint16_t flags; /* combination of NBD_SREP_FLAG_* */\n+ uint16_t type; /* NBD_SREP_TYPE_* */\n+ uint64_t handle; /* request handle */\n+ uint32_t length; /* length of payload */\n+} QEMU_PACKED NBDStructuredReplyChunk;\n+\n+typedef struct NBDStructuredRead {\n+ NBDStructuredReplyChunk h;\n+ uint64_t offset;\n+} QEMU_PACKED NBDStructuredRead;\n+\n+typedef struct NBDStructuredError {\n+ NBDStructuredReplyChunk h;\n+ uint32_t error;\n+ uint16_t message_length;\n+} QEMU_PACKED NBDStructuredError;\n+\n /* Transmission (export) flags: sent from server to client during handshake,\n but describe what will happen during transmission */\n #define NBD_FLAG_HAS_FLAGS (1 << 0) /* Flags are there */\n@@ -79,6 +98,7 @@ typedef struct NBDSimpleReply {\n rotational media */\n #define NBD_FLAG_SEND_TRIM (1 << 5) /* Send TRIM (discard) */\n #define NBD_FLAG_SEND_WRITE_ZEROES (1 << 6) /* Send WRITE_ZEROES */\n+#define NBD_FLAG_SEND_DF (1 << 7) /* Send DF (Do not Fragment) */\n \n /* New-style handshake (global) flags, sent from server to client, and\n control what will happen during handshake phase. */\n@@ -125,6 +145,7 @@ typedef struct NBDSimpleReply {\n /* Request flags, sent from client to server during transmission phase */\n #define NBD_CMD_FLAG_FUA (1 << 0) /* 'force unit access' during write */\n #define NBD_CMD_FLAG_NO_HOLE (1 << 1) /* don't punch hole on zero run */\n+#define NBD_CMD_FLAG_DF (1 << 2) /* don't fragment structured read */\n \n /* Supported request types */\n enum {\n@@ -149,6 +170,16 @@ enum {\n * aren't overflowing some other buffer. */\n #define NBD_MAX_NAME_SIZE 256\n \n+/* Structured reply flags */\n+#define NBD_SREP_FLAG_DONE (1 << 0) /* This reply-chunk is last */\n+\n+/* Structured reply types */\n+#define NBD_SREP_ERR(value) ((1 << 15) | (value))\n+\n+#define NBD_SREP_TYPE_NONE 0\n+#define NBD_SREP_TYPE_OFFSET_DATA 1\n+#define NBD_SREP_TYPE_ERROR NBD_SREP_ERR(1)\n+\n /* Details collected by NBD_OPT_EXPORT_NAME and NBD_OPT_GO */\n struct NBDExportInfo {\n /* Set by client before nbd_receive_negotiate() */\ndiff --git a/nbd/nbd-internal.h b/nbd/nbd-internal.h\nindex d96c9cc7fd..6b0d1183ba 100644\n--- a/nbd/nbd-internal.h\n+++ b/nbd/nbd-internal.h\n@@ -48,6 +48,7 @@\n \n #define NBD_REQUEST_MAGIC 0x25609513\n #define NBD_SIMPLE_REPLY_MAGIC 0x67446698\n+#define NBD_STRUCTURED_REPLY_MAGIC 0x668e33ef\n #define NBD_OPTS_MAGIC 0x49484156454F5054LL\n #define NBD_CLIENT_MAGIC 0x0000420281861253LL\n #define NBD_REP_MAGIC 0x0003e889045565a9LL\ndiff --git a/nbd/server.c b/nbd/server.c\nindex 57d5598e0f..0af94a293d 100644\n--- a/nbd/server.c\n+++ b/nbd/server.c\n@@ -98,6 +98,8 @@ 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@@ -760,6 +762,20 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags,\n return ret;\n }\n break;\n+\n+ case NBD_OPT_STRUCTURED_REPLY:\n+ if (client->structured_reply) {\n+ error_setg(errp, \"Double negotiation of structured reply\");\n+ return -EINVAL;\n+ }\n+ ret = nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK, option,\n+ errp);\n+ if (ret < 0) {\n+ return ret;\n+ }\n+ client->structured_reply = true;\n+ break;\n+\n default:\n if (nbd_drop(client->ioc, length, errp) < 0) {\n return -EIO;\n@@ -1233,6 +1249,61 @@ static int nbd_co_send_simple_reply(NBDClient *client,\n return nbd_co_send_iov(client, iov, size ? 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 inline int coroutine_fn nbd_co_send_buf(NBDClient *client, void *buf,\n+ size_t size, Error **errp)\n+{\n+ struct iovec iov[] = {\n+ {.iov_base = buf, .iov_len = size}\n+ };\n+\n+ return nbd_co_send_iov(client, iov, 1, errp);\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+ set_be_chunk(&chunk.h, NBD_SREP_FLAG_DONE, NBD_SREP_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+\n+ set_be_chunk(&chunk.h, NBD_SREP_FLAG_DONE, NBD_SREP_TYPE_ERROR, handle,\n+ sizeof(chunk) - sizeof(chunk.h));\n+ stl_be_p(&chunk.error, error);\n+ stw_be_p(&chunk.message_length, 0);\n+\n+ return nbd_co_send_buf(client, &chunk, sizeof(chunk), 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@@ -1304,10 +1375,17 @@ 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+ if (request->flags & ~(NBD_CMD_FLAG_FUA | NBD_CMD_FLAG_NO_HOLE |\n+ NBD_CMD_FLAG_DF))\n+ {\n error_setg(errp, \"unsupported flags (got 0x%x)\", request->flags);\n return -EINVAL;\n }\n+ if (request->type != NBD_CMD_READ && (request->flags & NBD_CMD_FLAG_DF)) {\n+ error_setg(errp, \"DF flag used with command %d (%s) which is not READ\",\n+ request->type, nbd_cmd_lookup(request->type));\n+ return -EINVAL;\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@@ -1374,7 +1452,6 @@ static coroutine_fn void nbd_trip(void *opaque)\n }\n \n reply_data_len = request.len;\n-\n break;\n case NBD_CMD_WRITE:\n if (exp->nbdflags & NBD_FLAG_READ_ONLY) {\n@@ -1447,10 +1524,21 @@ 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 }\n","prefixes":["6/8"]}