From caad53845af2ee607913d844ce6c08a5dbbeceef Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Thu, 12 Oct 2017 12:53:10 +0300 Subject: [PATCH] nbd/server: structurize simple reply header sending Use packed structure instead of pointer arithmetics. Also, merge two redundant traces into one. Signed-off-by: Vladimir Sementsov-Ogievskiy Message-Id: <20171012095319.136610-5-vsementsov@virtuozzo.com> [eblake: tweak and mention impact on traces, fix errp usage] Signed-off-by: Eric Blake --- include/block/nbd.h | 6 ++++++ nbd/server.c | 37 ++++++++++++++----------------------- nbd/trace-events | 1 - 3 files changed, 20 insertions(+), 24 deletions(-) diff --git a/include/block/nbd.h b/include/block/nbd.h index 707fd37575..49008980f4 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -63,6 +63,12 @@ struct NBDReply { }; typedef struct NBDReply NBDReply; +typedef struct NBDSimpleReply { + uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC */ + uint32_t error; + uint64_t handle; +} QEMU_PACKED NBDSimpleReply; + /* Transmission (export) flags: sent from server to client during handshake, but describe what will happen during transmission */ #define NBD_FLAG_HAS_FLAGS (1 << 0) /* Flags are there */ diff --git a/nbd/server.c b/nbd/server.c index ea2f0fa476..4f765ba992 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -902,26 +902,6 @@ static int nbd_receive_request(QIOChannel *ioc, NBDRequest *request, return 0; } -static int nbd_send_reply(QIOChannel *ioc, NBDReply *reply, Error **errp) -{ - uint8_t buf[NBD_REPLY_SIZE]; - - reply->error = system_errno_to_nbd_errno(reply->error); - - trace_nbd_send_reply(reply->error, reply->handle); - - /* Reply - [ 0 .. 3] magic (NBD_SIMPLE_REPLY_MAGIC) - [ 4 .. 7] error (0 == no error) - [ 7 .. 15] handle - */ - stl_be_p(buf, NBD_SIMPLE_REPLY_MAGIC); - stl_be_p(buf + 4, reply->error); - stq_be_p(buf + 8, reply->handle); - - return nbd_write(ioc, buf, sizeof(buf), errp); -} - #define MAX_NBD_REQUESTS 16 void nbd_client_get(NBDClient *client) @@ -1208,24 +1188,35 @@ void nbd_export_close_all(void) } } +static inline void set_be_simple_reply(NBDSimpleReply *reply, uint64_t error, + uint64_t handle) +{ + stl_be_p(&reply->magic, NBD_SIMPLE_REPLY_MAGIC); + stl_be_p(&reply->error, error); + stq_be_p(&reply->handle, handle); +} + static int nbd_co_send_simple_reply(NBDRequestData *req, NBDReply *reply, int len, Error **errp) { NBDClient *client = req->client; + NBDSimpleReply simple_reply; + int nbd_err = system_errno_to_nbd_errno(reply->error); int ret; g_assert(qemu_in_coroutine()); - trace_nbd_co_send_simple_reply(reply->handle, reply->error, len); + trace_nbd_co_send_simple_reply(reply->handle, nbd_err, len); + set_be_simple_reply(&simple_reply, nbd_err, reply->handle); qemu_co_mutex_lock(&client->send_lock); client->send_coroutine = qemu_coroutine_self(); if (!len) { - ret = nbd_send_reply(client->ioc, reply, errp); + ret = nbd_write(client->ioc, &simple_reply, sizeof(simple_reply), errp); } else { qio_channel_set_cork(client->ioc, true); - ret = nbd_send_reply(client->ioc, reply, errp); + ret = nbd_write(client->ioc, &simple_reply, sizeof(simple_reply), errp); if (ret == 0) { ret = nbd_write(client->ioc, req->data, len, errp); if (ret < 0) { diff --git a/nbd/trace-events b/nbd/trace-events index 4d6f86c2d4..e27614f050 100644 --- a/nbd/trace-events +++ b/nbd/trace-events @@ -51,7 +51,6 @@ nbd_negotiate_old_style(uint64_t size, unsigned flags) "advertising size %" PRIu nbd_negotiate_new_style_size_flags(uint64_t size, unsigned flags) "advertising size %" PRIu64 " and flags 0x%x" nbd_negotiate_success(void) "Negotiation succeeded" nbd_receive_request(uint32_t magic, uint16_t flags, uint16_t type, uint64_t from, uint32_t len) "Got request: { magic = 0x%" PRIx32 ", .flags = 0x%" PRIx16 ", .type = 0x%" PRIx16 ", from = %" PRIu64 ", len = %" PRIu32 " }" -nbd_send_reply(int32_t error, uint64_t handle) "Sending response to client: { .error = %" PRId32 ", handle = %" PRIu64 " }" nbd_blk_aio_attached(const char *name, void *ctx) "Export %s: Attaching clients to AIO context %p\n" nbd_blk_aio_detach(const char *name, void *ctx) "Export %s: Detaching clients from AIO context %p\n" nbd_co_send_simple_reply(uint64_t handle, uint32_t error, int len) "Send simple reply: handle = %" PRIu64 ", error = %" PRIu32 ", len = %d" -- GitLab