From 185b43386ad999c80bdc58e41b87f05e5b3e8463 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 5 Mar 2012 08:56:10 +0100 Subject: [PATCH] nbd: consistently return negative errno values In the next patch we need to look at the return code of nbd_wr_sync. To avoid percolating the socket_error() ugliness all around, let's handle errors by returning negative errno values. Signed-off-by: Paolo Bonzini --- block/nbd.c | 13 ++--- nbd.c | 159 ++++++++++++++++++++++++++-------------------------- nbd.h | 2 +- qemu-nbd.c | 15 ++--- 4 files changed, 93 insertions(+), 96 deletions(-) diff --git a/block/nbd.c b/block/nbd.c index 25e52689d1..1b0e384c39 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -200,8 +200,7 @@ static int nbd_co_send_request(BDRVNBDState *s, struct nbd_request *request, if (rc >= 0 && iov) { ret = qemu_co_sendv(s->sock, iov, request->len, offset); if (ret != request->len) { - errno = -EIO; - rc = -1; + return -EIO; } } qemu_aio_set_fd_handler(s->sock, nbd_reply_ready, NULL, @@ -271,7 +270,7 @@ static int nbd_establish_connection(BlockDriverState *bs) if (ret < 0) { logout("Failed to negotiate with the NBD server\n"); closesocket(sock); - return -errno; + return ret; } /* Now that we're connected, set the socket to be non-blocking and @@ -340,7 +339,7 @@ static int nbd_co_readv_1(BlockDriverState *bs, int64_t sector_num, nbd_coroutine_start(s, &request); ret = nbd_co_send_request(s, &request, NULL, 0); if (ret < 0) { - reply.error = errno; + reply.error = -ret; } else { nbd_co_receive_reply(s, &request, &reply, qiov->iov, offset); } @@ -369,7 +368,7 @@ static int nbd_co_writev_1(BlockDriverState *bs, int64_t sector_num, nbd_coroutine_start(s, &request); ret = nbd_co_send_request(s, &request, qiov->iov, offset); if (ret < 0) { - reply.error = errno; + reply.error = -ret; } else { nbd_co_receive_reply(s, &request, &reply, NULL, 0); } @@ -437,7 +436,7 @@ static int nbd_co_flush(BlockDriverState *bs) nbd_coroutine_start(s, &request); ret = nbd_co_send_request(s, &request, NULL, 0); if (ret < 0) { - reply.error = errno; + reply.error = -ret; } else { nbd_co_receive_reply(s, &request, &reply, NULL, 0); } @@ -463,7 +462,7 @@ static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num, nbd_coroutine_start(s, &request); ret = nbd_co_send_request(s, &request, NULL, 0); if (ret < 0) { - reply.error = errno; + reply.error = -ret; } else { nbd_co_receive_reply(s, &request, &reply, NULL, 0); } diff --git a/nbd.c b/nbd.c index 9832aa02c5..b31b3b2a4f 100644 --- a/nbd.c +++ b/nbd.c @@ -81,9 +81,10 @@ #define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true) #define write_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, false) -size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read) +ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read) { size_t offset = 0; + int err; if (qemu_in_coroutine()) { if (do_read) { @@ -103,15 +104,15 @@ size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read) } if (len < 0) { - errno = socket_error(); + err = socket_error(); /* recoverable error */ - if (errno == EINTR || errno == EAGAIN) { + if (err == EINTR || err == EAGAIN) { continue; } /* unrecoverable error */ - return 0; + return -err; } /* eof */ @@ -192,6 +193,7 @@ int unix_socket_outgoing(const char *path) static int nbd_send_negotiate(int csock, off_t size, uint32_t flags) { char buf[8 + 8 + 8 + 128]; + int rc; /* Negotiate [ 0 .. 7] passwd ("NBDMAGIC") @@ -201,6 +203,8 @@ static int nbd_send_negotiate(int csock, off_t size, uint32_t flags) [28 .. 151] reserved (0) */ + rc = -EINVAL; + TRACE("Beginning negotiation."); memcpy(buf, "NBDMAGIC", 8); cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL); @@ -212,13 +216,13 @@ static int nbd_send_negotiate(int csock, off_t size, uint32_t flags) if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { LOG("write failed"); - errno = EINVAL; - return -1; + goto fail; } TRACE("Negotiation succeeded."); - - return 0; + rc = 0; +fail: + return rc; } int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, @@ -227,20 +231,21 @@ int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, char buf[256]; uint64_t magic, s; uint16_t tmp; + int rc; TRACE("Receiving negotiation."); + rc = -EINVAL; + if (read_sync(csock, buf, 8) != 8) { LOG("read failed"); - errno = EINVAL; - return -1; + goto fail; } buf[8] = '\0'; if (strlen(buf) == 0) { LOG("server connection closed"); - errno = EINVAL; - return -1; + goto fail; } TRACE("Magic is %c%c%c%c%c%c%c%c", @@ -255,14 +260,12 @@ int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, if (memcmp(buf, "NBDMAGIC", 8) != 0) { LOG("Invalid magic received"); - errno = EINVAL; - return -1; + goto fail; } if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { LOG("read failed"); - errno = EINVAL; - return -1; + goto fail; } magic = be64_to_cpu(magic); TRACE("Magic is 0x%" PRIx64, magic); @@ -275,61 +278,52 @@ int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, TRACE("Checking magic (opts_magic)"); if (magic != 0x49484156454F5054LL) { LOG("Bad magic received"); - errno = EINVAL; - return -1; + goto fail; } if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { LOG("flags read failed"); - errno = EINVAL; - return -1; + goto fail; } *flags = be16_to_cpu(tmp) << 16; /* reserved for future use */ if (write_sync(csock, &reserved, sizeof(reserved)) != sizeof(reserved)) { LOG("write failed (reserved)"); - errno = EINVAL; - return -1; + goto fail; } /* write the export name */ magic = cpu_to_be64(magic); if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { LOG("write failed (magic)"); - errno = EINVAL; - return -1; + goto fail; } opt = cpu_to_be32(NBD_OPT_EXPORT_NAME); if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { LOG("write failed (opt)"); - errno = EINVAL; - return -1; + goto fail; } namesize = cpu_to_be32(strlen(name)); if (write_sync(csock, &namesize, sizeof(namesize)) != sizeof(namesize)) { LOG("write failed (namesize)"); - errno = EINVAL; - return -1; + goto fail; } if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) { LOG("write failed (name)"); - errno = EINVAL; - return -1; + goto fail; } } else { TRACE("Checking magic (cli_magic)"); if (magic != 0x00420281861253LL) { LOG("Bad magic received"); - errno = EINVAL; - return -1; + goto fail; } } if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) { LOG("read failed"); - errno = EINVAL; - return -1; + goto fail; } *size = be64_to_cpu(s); *blocksize = 1024; @@ -338,24 +332,24 @@ int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, if (!name) { if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) { LOG("read failed (flags)"); - errno = EINVAL; - return -1; + goto fail; } *flags = be32_to_cpup(flags); } else { if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { LOG("read failed (tmp)"); - errno = EINVAL; - return -1; + goto fail; } *flags |= be32_to_cpu(tmp); } if (read_sync(csock, &buf, 124) != 124) { LOG("read failed (buf)"); - errno = EINVAL; - return -1; + goto fail; } - return 0; + rc = 0; + +fail: + return rc; } #ifdef __linux__ @@ -366,8 +360,7 @@ int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) if (ioctl(fd, NBD_SET_SOCK, csock) < 0) { int serrno = errno; LOG("Failed to set NBD socket"); - errno = serrno; - return -1; + return -serrno; } TRACE("Setting block size to %lu", (unsigned long)blocksize); @@ -375,8 +368,7 @@ int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) < 0) { int serrno = errno; LOG("Failed setting NBD block size"); - errno = serrno; - return -1; + return -serrno; } TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize)); @@ -384,8 +376,7 @@ int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) < 0) { int serrno = errno; LOG("Failed setting size (in blocks)"); - errno = serrno; - return -1; + return -serrno; } if (flags & NBD_FLAG_READ_ONLY) { @@ -395,8 +386,7 @@ int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) { int serrno = errno; LOG("Failed setting read-only attribute"); - errno = serrno; - return -1; + return -serrno; } } @@ -404,8 +394,7 @@ int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) && errno != ENOTTY) { int serrno = errno; LOG("Failed setting flags"); - errno = serrno; - return -1; + return -serrno; } TRACE("Negotiation ended"); @@ -452,26 +441,24 @@ int nbd_client(int fd) #else int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) { - errno = ENOTSUP; - return -1; + return -ENOTSUP; } int nbd_disconnect(int fd) { - errno = ENOTSUP; - return -1; + return -ENOTSUP; } int nbd_client(int fd) { - errno = ENOTSUP; - return -1; + return -ENOTSUP; } #endif ssize_t nbd_send_request(int csock, struct nbd_request *request) { uint8_t buf[4 + 4 + 8 + 8 + 4]; + ssize_t ret; cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC); cpu_to_be32w((uint32_t*)(buf + 4), request->type); @@ -483,10 +470,14 @@ ssize_t nbd_send_request(int csock, struct nbd_request *request) "{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}", request->from, request->len, request->handle, request->type); - if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { + ret = write_sync(csock, buf, sizeof(buf)); + if (ret < 0) { + return ret; + } + + if (ret != sizeof(buf)) { LOG("writing to socket failed"); - errno = EINVAL; - return -1; + return -EINVAL; } return 0; } @@ -495,11 +486,16 @@ static ssize_t nbd_receive_request(int csock, struct nbd_request *request) { uint8_t buf[4 + 4 + 8 + 8 + 4]; uint32_t magic; + ssize_t ret; - if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { + ret = read_sync(csock, buf, sizeof(buf)); + if (ret < 0) { + return ret; + } + + if (ret != sizeof(buf)) { LOG("read failed"); - errno = EINVAL; - return -1; + return -EINVAL; } /* Request @@ -522,8 +518,7 @@ static ssize_t nbd_receive_request(int csock, struct nbd_request *request) if (magic != NBD_REQUEST_MAGIC) { LOG("invalid magic (got 0x%x)", magic); - errno = EINVAL; - return -1; + return -EINVAL; } return 0; } @@ -532,11 +527,16 @@ ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply) { uint8_t buf[NBD_REPLY_SIZE]; uint32_t magic; + ssize_t ret; + + ret = read_sync(csock, buf, sizeof(buf)); + if (ret < 0) { + return ret; + } - if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { + if (ret != sizeof(buf)) { LOG("read failed"); - errno = EINVAL; - return -1; + return -EINVAL; } /* Reply @@ -555,8 +555,7 @@ ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply) if (magic != NBD_REPLY_MAGIC) { LOG("invalid magic (got 0x%x)", magic); - errno = EINVAL; - return -1; + return -EINVAL; } return 0; } @@ -564,6 +563,7 @@ ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply) static ssize_t nbd_send_reply(int csock, struct nbd_reply *reply) { uint8_t buf[4 + 4 + 8]; + ssize_t ret; /* Reply [ 0 .. 3] magic (NBD_REPLY_MAGIC) @@ -576,10 +576,14 @@ static ssize_t nbd_send_reply(int csock, struct nbd_reply *reply) TRACE("Sending response to client"); - if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { + ret = write_sync(csock, buf, sizeof(buf)); + if (ret < 0) { + return ret; + } + + if (ret != sizeof(buf)) { LOG("writing to socket failed"); - errno = EINVAL; - return -1; + return -EINVAL; } return 0; } @@ -713,22 +717,15 @@ static ssize_t nbd_co_send_reply(NBDRequest *req, struct nbd_reply *reply, if (!len) { rc = nbd_send_reply(csock, reply); - if (rc < 0) { - rc = -errno; - } } else { socket_set_cork(csock, 1); rc = nbd_send_reply(csock, reply); if (rc >= 0) { ret = qemu_co_send(csock, req->data, len); if (ret != len) { - errno = EIO; - rc = -1; + rc = -EIO; } } - if (rc < 0) { - rc = -errno; - } socket_set_cork(csock, 0); } diff --git a/nbd.h b/nbd.h index 217a82d80d..40d58d359f 100644 --- a/nbd.h +++ b/nbd.h @@ -59,7 +59,7 @@ enum { #define NBD_BUFFER_SIZE (1024*1024) -size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read); +ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read); int tcp_socket_outgoing(const char *address, uint16_t port); int tcp_socket_incoming(const char *address, uint16_t port); int tcp_socket_outgoing_spec(const char *address_and_port); diff --git a/qemu-nbd.c b/qemu-nbd.c index 19cfb04d96..6c3f9b5de5 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -126,8 +126,7 @@ static int find_partition(BlockDriverState *bs, int partition, } if (data[510] != 0x55 || data[511] != 0xaa) { - errno = -EINVAL; - return -1; + return -EINVAL; } for (i = 0; i < 4; i++) { @@ -165,8 +164,7 @@ static int find_partition(BlockDriverState *bs, int partition, } } - errno = -ENOENT; - return -1; + return -ENOENT; } static void termsig_handler(int signum) @@ -491,9 +489,12 @@ int main(int argc, char **argv) fd_size = bs->total_sectors * 512; - if (partition != -1 && - find_partition(bs, partition, &dev_offset, &fd_size)) { - err(EXIT_FAILURE, "Could not find partition %d", partition); + if (partition != -1) { + ret = find_partition(bs, partition, &dev_offset, &fd_size); + if (ret < 0) { + errno = -ret; + err(EXIT_FAILURE, "Could not find partition %d", partition); + } } exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags); -- GitLab