From d1fdf257d52822695f5ace6c586e059aa17d4b79 Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Fri, 2 Jun 2017 18:01:39 +0300 Subject: [PATCH] nbd: rename read_sync and friends Rename nbd_wr_syncv -> nbd_rwv read_sync -> nbd_read read_sync_eof -> nbd_read_eof write_sync -> nbd_write drop_sync -> nbd_drop 1. nbd_ prefix read_sync and write_sync are already shared, so it is good to have a namespace prefix. drop_sync will be shared, and read_sync_eof is related to read_sync, so let's rename them all. 2. _sync suffix _sync is related to the fact that nbd_wr_syncv doesn't return if a write to socket returns EAGAIN. The first implementation of nbd_wr_syncv (was wr_sync in 7a5ca8648b) just loops while getting EAGAIN, the current implementation yields in this case. Why we want to get rid of it: - it is normal for r/w functions to be synchronous, so having an additional suffix for it looks redundant (contrariwise, we have _aio suffix for async functions) - _sync suffix in block layer is used when function does flush (so using it for other thing is confusing a bit) - keep function names short after adding nbd_ prefix 3. for nbd_wr_syncv let's use more common notation 'rw' Reviewed-by: Eric Blake Signed-off-by: Vladimir Sementsov-Ogievskiy Message-Id: <20170602150150.258222-2-vsementsov@virtuozzo.com> Signed-off-by: Paolo Bonzini --- block/nbd-client.c | 8 ++++---- include/block/nbd.h | 8 ++------ nbd/client.c | 42 +++++++++++++++++++++--------------------- nbd/common.c | 8 ++------ nbd/nbd-internal.h | 26 +++++++++++++------------- nbd/server.c | 12 ++++++------ 6 files changed, 48 insertions(+), 56 deletions(-) diff --git a/block/nbd-client.c b/block/nbd-client.c index 87d19c7253..d64e775385 100644 --- a/block/nbd-client.c +++ b/block/nbd-client.c @@ -144,8 +144,8 @@ static int nbd_co_send_request(BlockDriverState *bs, qio_channel_set_cork(s->ioc, true); rc = nbd_send_request(s->ioc, request); if (rc >= 0) { - ret = nbd_wr_syncv(s->ioc, qiov->iov, qiov->niov, request->len, - false, NULL); + ret = nbd_rwv(s->ioc, qiov->iov, qiov->niov, request->len, false, + NULL); if (ret != request->len) { rc = -EIO; } @@ -173,8 +173,8 @@ static void nbd_co_receive_reply(NBDClientSession *s, reply->error = EIO; } else { if (qiov && reply->error == 0) { - ret = nbd_wr_syncv(s->ioc, qiov->iov, qiov->niov, request->len, - true, NULL); + ret = nbd_rwv(s->ioc, qiov->iov, qiov->niov, request->len, true, + NULL); if (ret != request->len) { reply->error = EIO; } diff --git a/include/block/nbd.h b/include/block/nbd.h index 8fa5ce51f3..6d75d5a670 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -123,12 +123,8 @@ enum { * aren't overflowing some other buffer. */ #define NBD_MAX_NAME_SIZE 256 -ssize_t nbd_wr_syncv(QIOChannel *ioc, - struct iovec *iov, - size_t niov, - size_t length, - bool do_read, - Error **errp); +ssize_t nbd_rwv(QIOChannel *ioc, struct iovec *iov, size_t niov, size_t length, + bool do_read, Error **errp); int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags, QCryptoTLSCreds *tlscreds, const char *hostname, QIOChannel **outioc, diff --git a/nbd/client.c b/nbd/client.c index 595d99ed30..17ac85ff57 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -88,7 +88,7 @@ static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports); /* Discard length bytes from channel. Return -errno on failure and 0 on * success*/ -static int drop_sync(QIOChannel *ioc, size_t size, Error **errp) +static int nbd_drop(QIOChannel *ioc, size_t size, Error **errp) { ssize_t ret = 0; char small[1024]; @@ -97,7 +97,7 @@ static int drop_sync(QIOChannel *ioc, size_t size, Error **errp) buffer = sizeof(small) >= size ? small : g_malloc(MIN(65536, size)); while (size > 0) { ssize_t count = MIN(65536, size); - ret = read_sync(ioc, buffer, MIN(65536, size), errp); + ret = nbd_read(ioc, buffer, MIN(65536, size), errp); if (ret < 0) { goto cleanup; @@ -135,12 +135,12 @@ static int nbd_send_option_request(QIOChannel *ioc, uint32_t opt, stl_be_p(&req.option, opt); stl_be_p(&req.length, len); - if (write_sync(ioc, &req, sizeof(req), errp) < 0) { + if (nbd_write(ioc, &req, sizeof(req), errp) < 0) { error_prepend(errp, "Failed to send option request header"); return -1; } - if (len && write_sync(ioc, (char *) data, len, errp) < 0) { + if (len && nbd_write(ioc, (char *) data, len, errp) < 0) { error_prepend(errp, "Failed to send option request data"); return -1; } @@ -169,7 +169,7 @@ static int nbd_receive_option_reply(QIOChannel *ioc, uint32_t opt, nbd_opt_reply *reply, Error **errp) { QEMU_BUILD_BUG_ON(sizeof(*reply) != 20); - if (read_sync(ioc, reply, sizeof(*reply), errp) < 0) { + if (nbd_read(ioc, reply, sizeof(*reply), errp) < 0) { error_prepend(errp, "failed to read option reply"); nbd_send_opt_abort(ioc); return -1; @@ -218,7 +218,7 @@ static int nbd_handle_reply_err(QIOChannel *ioc, nbd_opt_reply *reply, goto cleanup; } msg = g_malloc(reply->length + 1); - if (read_sync(ioc, msg, reply->length, errp) < 0) { + if (nbd_read(ioc, msg, reply->length, errp) < 0) { error_prepend(errp, "failed to read option error message"); goto cleanup; } @@ -320,7 +320,7 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match, nbd_send_opt_abort(ioc); return -1; } - if (read_sync(ioc, &namelen, sizeof(namelen), errp) < 0) { + if (nbd_read(ioc, &namelen, sizeof(namelen), errp) < 0) { error_prepend(errp, "failed to read option name length"); nbd_send_opt_abort(ioc); return -1; @@ -333,7 +333,7 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match, return -1; } if (namelen != strlen(want)) { - if (drop_sync(ioc, len, errp) < 0) { + if (nbd_drop(ioc, len, errp) < 0) { error_prepend(errp, "failed to skip export name with wrong length"); nbd_send_opt_abort(ioc); return -1; @@ -342,14 +342,14 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match, } assert(namelen < sizeof(name)); - if (read_sync(ioc, name, namelen, errp) < 0) { + if (nbd_read(ioc, name, namelen, errp) < 0) { error_prepend(errp, "failed to read export name"); nbd_send_opt_abort(ioc); return -1; } name[namelen] = '\0'; len -= namelen; - if (drop_sync(ioc, len, errp) < 0) { + if (nbd_drop(ioc, len, errp) < 0) { error_prepend(errp, "failed to read export description"); nbd_send_opt_abort(ioc); return -1; @@ -476,7 +476,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags, goto fail; } - if (read_sync(ioc, buf, 8, errp) < 0) { + if (nbd_read(ioc, buf, 8, errp) < 0) { error_prepend(errp, "Failed to read data"); goto fail; } @@ -502,7 +502,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags, goto fail; } - if (read_sync(ioc, &magic, sizeof(magic), errp) < 0) { + if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) { error_prepend(errp, "Failed to read magic"); goto fail; } @@ -514,7 +514,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags, uint16_t globalflags; bool fixedNewStyle = false; - if (read_sync(ioc, &globalflags, sizeof(globalflags), errp) < 0) { + if (nbd_read(ioc, &globalflags, sizeof(globalflags), errp) < 0) { error_prepend(errp, "Failed to read server flags"); goto fail; } @@ -532,7 +532,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags, } /* client requested flags */ clientflags = cpu_to_be32(clientflags); - if (write_sync(ioc, &clientflags, sizeof(clientflags), errp) < 0) { + if (nbd_write(ioc, &clientflags, sizeof(clientflags), errp) < 0) { error_prepend(errp, "Failed to send clientflags field"); goto fail; } @@ -570,13 +570,13 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags, } /* Read the response */ - if (read_sync(ioc, &s, sizeof(s), errp) < 0) { + if (nbd_read(ioc, &s, sizeof(s), errp) < 0) { error_prepend(errp, "Failed to read export length"); goto fail; } *size = be64_to_cpu(s); - if (read_sync(ioc, flags, sizeof(*flags), errp) < 0) { + if (nbd_read(ioc, flags, sizeof(*flags), errp) < 0) { error_prepend(errp, "Failed to read export flags"); goto fail; } @@ -593,14 +593,14 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags, goto fail; } - if (read_sync(ioc, &s, sizeof(s), errp) < 0) { + if (nbd_read(ioc, &s, sizeof(s), errp) < 0) { error_prepend(errp, "Failed to read export length"); goto fail; } *size = be64_to_cpu(s); TRACE("Size is %" PRIu64, *size); - if (read_sync(ioc, &oldflags, sizeof(oldflags), errp) < 0) { + if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) { error_prepend(errp, "Failed to read export flags"); goto fail; } @@ -616,7 +616,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags, } TRACE("Size is %" PRIu64 ", export flags %" PRIx16, *size, *flags); - if (zeroes && drop_sync(ioc, 124, errp) < 0) { + if (zeroes && nbd_drop(ioc, 124, errp) < 0) { error_prepend(errp, "Failed to read reserved block"); goto fail; } @@ -759,7 +759,7 @@ ssize_t nbd_send_request(QIOChannel *ioc, NBDRequest *request) stq_be_p(buf + 16, request->from); stl_be_p(buf + 24, request->len); - return write_sync(ioc, buf, sizeof(buf), NULL); + return nbd_write(ioc, buf, sizeof(buf), NULL); } ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *reply, Error **errp) @@ -768,7 +768,7 @@ ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *reply, Error **errp) uint32_t magic; ssize_t ret; - ret = read_sync_eof(ioc, buf, sizeof(buf), errp); + ret = nbd_read_eof(ioc, buf, sizeof(buf), errp); if (ret <= 0) { return ret; } diff --git a/nbd/common.c b/nbd/common.c index bd81637ab9..d6b719ddaa 100644 --- a/nbd/common.c +++ b/nbd/common.c @@ -24,12 +24,8 @@ * The function may be called from coroutine or from non-coroutine context. * When called from non-coroutine context @ioc must be in blocking mode. */ -ssize_t nbd_wr_syncv(QIOChannel *ioc, - struct iovec *iov, - size_t niov, - size_t length, - bool do_read, - Error **errp) +ssize_t nbd_rwv(QIOChannel *ioc, struct iovec *iov, size_t niov, size_t length, + bool do_read, Error **errp) { ssize_t done = 0; struct iovec *local_iov = g_new(struct iovec, niov); diff --git a/nbd/nbd-internal.h b/nbd/nbd-internal.h index d6071640a0..753cb9d9c5 100644 --- a/nbd/nbd-internal.h +++ b/nbd/nbd-internal.h @@ -94,14 +94,14 @@ #define NBD_ENOSPC 28 #define NBD_ESHUTDOWN 108 -/* read_sync_eof +/* nbd_read_eof * Tries to read @size bytes from @ioc. Returns number of bytes actually read. * May return a value >= 0 and < size only on EOF, i.e. when iteratively called - * qio_channel_readv() returns 0. So, there are no needs to call read_sync_eof + * qio_channel_readv() returns 0. So, there is no need to call nbd_read_eof * iteratively. */ -static inline ssize_t read_sync_eof(QIOChannel *ioc, void *buffer, size_t size, - Error **errp) +static inline ssize_t nbd_read_eof(QIOChannel *ioc, void *buffer, size_t size, + Error **errp) { struct iovec iov = { .iov_base = buffer, .iov_len = size }; /* Sockets are kept in blocking mode in the negotiation phase. After @@ -109,16 +109,16 @@ static inline ssize_t read_sync_eof(QIOChannel *ioc, void *buffer, size_t size, * our request/reply. Synchronization is done with recv_coroutine, so * that this is coroutine-safe. */ - return nbd_wr_syncv(ioc, &iov, 1, size, true, errp); + return nbd_rwv(ioc, &iov, 1, size, true, errp); } -/* read_sync +/* nbd_read * Reads @size bytes from @ioc. Returns 0 on success. */ -static inline int read_sync(QIOChannel *ioc, void *buffer, size_t size, - Error **errp) +static inline int nbd_read(QIOChannel *ioc, void *buffer, size_t size, + Error **errp) { - ssize_t ret = read_sync_eof(ioc, buffer, size, errp); + ssize_t ret = nbd_read_eof(ioc, buffer, size, errp); if (ret >= 0 && ret != size) { ret = -EINVAL; @@ -128,15 +128,15 @@ static inline int read_sync(QIOChannel *ioc, void *buffer, size_t size, return ret < 0 ? ret : 0; } -/* write_sync +/* nbd_write * Writes @size bytes to @ioc. Returns 0 on success. */ -static inline int write_sync(QIOChannel *ioc, const void *buffer, size_t size, - Error **errp) +static inline int nbd_write(QIOChannel *ioc, const void *buffer, size_t size, + Error **errp) { struct iovec iov = { .iov_base = (void *) buffer, .iov_len = size }; - ssize_t ret = nbd_wr_syncv(ioc, &iov, 1, size, false, errp); + ssize_t ret = nbd_rwv(ioc, &iov, 1, size, false, errp); assert(ret < 0 || ret == size); diff --git a/nbd/server.c b/nbd/server.c index f2b1aa47ce..d8bd927013 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -124,7 +124,7 @@ static int nbd_negotiate_read(QIOChannel *ioc, void *buffer, size_t size) nbd_negotiate_continue, qemu_coroutine_self(), NULL); - ret = read_sync(ioc, buffer, size, NULL); + ret = nbd_read(ioc, buffer, size, NULL); g_source_remove(watch); return ret; @@ -142,7 +142,7 @@ static int nbd_negotiate_write(QIOChannel *ioc, const void *buffer, size_t size) nbd_negotiate_continue, qemu_coroutine_self(), NULL); - ret = write_sync(ioc, buffer, size, NULL); + ret = nbd_write(ioc, buffer, size, NULL); g_source_remove(watch); return ret; } @@ -694,7 +694,7 @@ static ssize_t nbd_receive_request(QIOChannel *ioc, NBDRequest *request) uint32_t magic; ssize_t ret; - ret = read_sync(ioc, buf, sizeof(buf), NULL); + ret = nbd_read(ioc, buf, sizeof(buf), NULL); if (ret < 0) { return ret; } @@ -745,7 +745,7 @@ static ssize_t nbd_send_reply(QIOChannel *ioc, NBDReply *reply) stl_be_p(buf + 4, reply->error); stq_be_p(buf + 8, reply->handle); - return write_sync(ioc, buf, sizeof(buf), NULL); + return nbd_write(ioc, buf, sizeof(buf), NULL); } #define MAX_NBD_REQUESTS 16 @@ -1048,7 +1048,7 @@ static ssize_t nbd_co_send_reply(NBDRequestData *req, NBDReply *reply, qio_channel_set_cork(client->ioc, true); rc = nbd_send_reply(client->ioc, reply); if (rc >= 0) { - ret = write_sync(client->ioc, req->data, len, NULL); + ret = nbd_write(client->ioc, req->data, len, NULL); if (ret < 0) { rc = -EIO; } @@ -1123,7 +1123,7 @@ static ssize_t nbd_co_receive_request(NBDRequestData *req, if (request->type == NBD_CMD_WRITE) { TRACE("Reading %" PRIu32 " byte(s)", request->len); - if (read_sync(client->ioc, req->data, request->len, NULL) < 0) { + if (nbd_read(client->ioc, req->data, request->len, NULL) < 0) { LOG("reading from socket failed"); rc = -EIO; goto out;