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nbd: consistently return negative errno values

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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 <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2012-03-05 08:56:10 +01:00
parent fc19f8a02e
commit 185b43386a
4 changed files with 93 additions and 96 deletions
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13
block/nbd.c
View File

@ -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);
}

159
nbd.c
View File

@ -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;
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;
}
/* 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);
}

2
nbd.h
View File

@ -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);

15
qemu-nbd.c
View File

@ -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);