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authorPaolo Bonzini <pbonzini@redhat.com>2012-03-05 08:56:10 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2012-04-19 16:36:43 +0200
commit185b43386ad999c80bdc58e41b87f05e5b3e8463 (patch)
tree326967bbfb0f72801848e9aebbad859f33873828 /nbd.c
parentfc19f8a02e45c4d8ad24dd7eb374330b03dfc28e (diff)
downloadqemu-arm-185b43386ad999c80bdc58e41b87f05e5b3e8463.tar.gz
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 <pbonzini@redhat.com>
Diffstat (limited to 'nbd.c')
-rw-r--r--nbd.c159
1 files changed, 78 insertions, 81 deletions
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);
}