*/
#include "nbd.h"
+#include "block.h"
+
+#include "qemu-coroutine.h"
#include <errno.h>
#include <string.h>
#include <ctype.h>
#include <inttypes.h>
+#ifdef __linux__
+#include <linux/fs.h>
+#endif
+
#include "qemu_socket.h"
+#include "qemu-queue.h"
//#define DEBUG_NBD
/* This is all part of the "official" NBD API */
+#define NBD_REQUEST_SIZE (4 + 4 + 8 + 8 + 4)
#define NBD_REPLY_SIZE (4 + 4 + 8)
#define NBD_REQUEST_MAGIC 0x25609513
#define NBD_REPLY_MAGIC 0x67446698
+#define NBD_OPTS_MAGIC 0x49484156454F5054LL
+#define NBD_CLIENT_MAGIC 0x0000420281861253LL
#define NBD_SET_SOCK _IO(0xab, 0)
#define NBD_SET_BLKSIZE _IO(0xab, 1)
#define NBD_PRINT_DEBUG _IO(0xab, 6)
#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
#define NBD_DISCONNECT _IO(0xab, 8)
+#define NBD_SET_TIMEOUT _IO(0xab, 9)
+#define NBD_SET_FLAGS _IO(0xab, 10)
#define NBD_OPT_EXPORT_NAME (1 << 0)
-/* That's all folks */
+/* Definitions for opaque data types */
+
+typedef struct NBDRequest NBDRequest;
+
+struct NBDRequest {
+ QSIMPLEQ_ENTRY(NBDRequest) entry;
+ NBDClient *client;
+ uint8_t *data;
+};
-#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)
+struct NBDExport {
+ BlockDriverState *bs;
+ off_t dev_offset;
+ off_t size;
+ uint32_t nbdflags;
+ QSIMPLEQ_HEAD(, NBDRequest) requests;
+};
-size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read)
+struct NBDClient {
+ int refcount;
+ void (*close)(NBDClient *client);
+
+ NBDExport *exp;
+ int sock;
+
+ Coroutine *recv_coroutine;
+
+ CoMutex send_lock;
+ Coroutine *send_coroutine;
+
+ int nb_requests;
+};
+
+/* That's all folks */
+
+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) {
+ return qemu_co_recv(fd, buffer, size);
+ } else {
+ return qemu_co_send(fd, buffer, size);
+ }
+ }
while (offset < size) {
ssize_t len;
if (do_read) {
- len = recv(fd, buffer + offset, size - offset, 0);
+ len = qemu_recv(fd, buffer + offset, size - offset, 0);
} else {
len = send(fd, buffer + offset, size - offset, 0);
}
- if (len == -1)
- errno = socket_error();
+ if (len < 0) {
+ err = socket_error();
- /* recoverable error */
- if (len == -1 && (errno == EAGAIN || errno == EINTR)) {
- continue;
+ /* recoverable error */
+ if (err == EINTR || (offset > 0 && err == EAGAIN)) {
+ continue;
+ }
+
+ /* unrecoverable error */
+ return -err;
}
/* eof */
break;
}
- /* unrecoverable error */
- if (len == -1) {
- return 0;
- }
-
offset += len;
}
return offset;
}
+static ssize_t read_sync(int fd, void *buffer, size_t size)
+{
+ /* Sockets are kept in blocking mode in the negotiation phase. After
+ * that, a non-readable socket simply means that another thread stole
+ * our request/reply. Synchronization is done with recv_coroutine, so
+ * that this is coroutine-safe.
+ */
+ return nbd_wr_sync(fd, buffer, size, true);
+}
+
+static ssize_t write_sync(int fd, void *buffer, size_t size)
+{
+ int ret;
+ do {
+ /* For writes, we do expect the socket to be writable. */
+ ret = nbd_wr_sync(fd, buffer, size, false);
+ } while (ret == -EAGAIN);
+ return ret;
+}
+
static void combine_addr(char *buf, size_t len, const char* address,
uint16_t port)
{
int tcp_socket_outgoing_spec(const char *address_and_port)
{
- return inet_connect(address_and_port, SOCK_STREAM);
+ return inet_connect(address_and_port, true, NULL, NULL);
}
int tcp_socket_incoming(const char *address, uint16_t port)
{
char *ostr = NULL;
int olen = 0;
- return inet_listen(address_and_port, ostr, olen, SOCK_STREAM, 0);
+ return inet_listen(address_and_port, ostr, olen, SOCK_STREAM, 0, NULL);
}
int unix_socket_incoming(const char *path)
Request (type == 2)
*/
-int nbd_negotiate(int csock, off_t size)
+static int nbd_send_negotiate(NBDClient *client)
{
+ int csock = client->sock;
char buf[8 + 8 + 8 + 128];
+ int rc;
/* Negotiate
[ 0 .. 7] passwd ("NBDMAGIC")
- [ 8 .. 15] magic (0x00420281861253)
+ [ 8 .. 15] magic (NBD_CLIENT_MAGIC)
[16 .. 23] size
- [24 .. 151] reserved (0)
+ [24 .. 27] flags
+ [28 .. 151] reserved (0)
*/
+ socket_set_block(csock);
+ rc = -EINVAL;
+
TRACE("Beginning negotiation.");
memcpy(buf, "NBDMAGIC", 8);
- cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL);
- cpu_to_be64w((uint64_t*)(buf + 16), size);
- memset(buf + 24, 0, 128);
+ cpu_to_be64w((uint64_t*)(buf + 8), NBD_CLIENT_MAGIC);
+ cpu_to_be64w((uint64_t*)(buf + 16), client->exp->size);
+ cpu_to_be32w((uint32_t*)(buf + 24),
+ client->exp->nbdflags | NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM |
+ NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA);
+ memset(buf + 28, 0, 124);
if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
LOG("write failed");
- errno = EINVAL;
- return -1;
+ goto fail;
}
- TRACE("Negotation succeeded.");
-
- return 0;
+ TRACE("Negotiation succeeded.");
+ rc = 0;
+fail:
+ socket_set_nonblock(csock);
+ return rc;
}
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 negotation.");
+ TRACE("Receiving negotiation.");
+
+ socket_set_block(csock);
+ 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",
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);
uint32_t namesize;
TRACE("Checking magic (opts_magic)");
- if (magic != 0x49484156454F5054LL) {
+ if (magic != NBD_OPTS_MAGIC) {
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) {
+ if (magic != NBD_CLIENT_MAGIC) {
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;
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:
+ socket_set_nonblock(csock);
+ return rc;
}
-#ifndef _WIN32
-int nbd_init(int fd, int csock, off_t size, size_t blocksize)
+#ifdef __linux__
+int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
{
+ TRACE("Setting NBD socket");
+
+ if (ioctl(fd, NBD_SET_SOCK, csock) < 0) {
+ int serrno = errno;
+ LOG("Failed to set NBD socket");
+ return -serrno;
+ }
+
TRACE("Setting block size to %lu", (unsigned long)blocksize);
- if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) {
+ 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));
- if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) == -1) {
+ 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;
}
- TRACE("Clearing NBD socket");
+ if (flags & NBD_FLAG_READ_ONLY) {
+ int read_only = 1;
+ TRACE("Setting readonly attribute");
- if (ioctl(fd, NBD_CLEAR_SOCK) == -1) {
- int serrno = errno;
- LOG("Failed clearing NBD socket");
- errno = serrno;
- return -1;
+ if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
+ int serrno = errno;
+ LOG("Failed setting read-only attribute");
+ return -serrno;
+ }
}
- TRACE("Setting NBD socket");
-
- if (ioctl(fd, NBD_SET_SOCK, csock) == -1) {
+ if (ioctl(fd, NBD_SET_FLAGS, flags) < 0
+ && errno != ENOTTY) {
int serrno = errno;
- LOG("Failed to set NBD socket");
- errno = serrno;
- return -1;
+ LOG("Failed setting flags");
+ return -serrno;
}
TRACE("Negotiation ended");
TRACE("Doing NBD loop");
ret = ioctl(fd, NBD_DO_IT);
+ if (ret < 0 && errno == EPIPE) {
+ /* NBD_DO_IT normally returns EPIPE when someone has disconnected
+ * the socket via NBD_DISCONNECT. We do not want to return 1 in
+ * that case.
+ */
+ ret = 0;
+ }
serrno = errno;
TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
return ret;
}
#else
-int nbd_init(int fd, int csock, off_t size, size_t blocksize)
+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
-int nbd_send_request(int csock, struct nbd_request *request)
+ssize_t nbd_send_request(int csock, struct nbd_request *request)
{
- uint8_t buf[4 + 4 + 8 + 8 + 4];
+ uint8_t buf[NBD_REQUEST_SIZE];
+ ssize_t ret;
cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
cpu_to_be32w((uint32_t*)(buf + 4), request->type);
"{ .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;
}
-static int nbd_receive_request(int csock, struct nbd_request *request)
+static ssize_t nbd_receive_request(int csock, struct nbd_request *request)
{
- uint8_t buf[4 + 4 + 8 + 8 + 4];
+ uint8_t buf[NBD_REQUEST_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;
}
/* Request
if (magic != NBD_REQUEST_MAGIC) {
LOG("invalid magic (got 0x%x)", magic);
- errno = EINVAL;
- return -1;
+ return -EINVAL;
}
return 0;
}
-int nbd_receive_reply(int csock, struct nbd_reply *reply)
+ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply)
{
uint8_t buf[NBD_REPLY_SIZE];
uint32_t magic;
+ ssize_t ret;
- memset(buf, 0xAA, sizeof(buf));
+ 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
if (magic != NBD_REPLY_MAGIC) {
LOG("invalid magic (got 0x%x)", magic);
- errno = EINVAL;
- return -1;
+ return -EINVAL;
}
return 0;
}
-static int nbd_send_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];
+ uint8_t buf[NBD_REPLY_SIZE];
+ ssize_t ret;
/* Reply
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
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;
}
-int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
- off_t *offset, bool readonly, uint8_t *data, int data_size)
+#define MAX_NBD_REQUESTS 16
+
+static void nbd_client_get(NBDClient *client)
{
- struct nbd_request request;
- struct nbd_reply reply;
+ client->refcount++;
+}
- TRACE("Reading request.");
+static void nbd_client_put(NBDClient *client)
+{
+ if (--client->refcount == 0) {
+ g_free(client);
+ }
+}
+
+static void nbd_client_close(NBDClient *client)
+{
+ qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL);
+ close(client->sock);
+ client->sock = -1;
+ if (client->close) {
+ client->close(client);
+ }
+ nbd_client_put(client);
+}
+
+static NBDRequest *nbd_request_get(NBDClient *client)
+{
+ NBDRequest *req;
+ NBDExport *exp = client->exp;
+
+ assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
+ client->nb_requests++;
+
+ if (QSIMPLEQ_EMPTY(&exp->requests)) {
+ req = g_malloc0(sizeof(NBDRequest));
+ req->data = qemu_blockalign(exp->bs, NBD_BUFFER_SIZE);
+ } else {
+ req = QSIMPLEQ_FIRST(&exp->requests);
+ QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry);
+ }
+ nbd_client_get(client);
+ req->client = client;
+ return req;
+}
+
+static void nbd_request_put(NBDRequest *req)
+{
+ NBDClient *client = req->client;
+ QSIMPLEQ_INSERT_HEAD(&client->exp->requests, req, entry);
+ if (client->nb_requests-- == MAX_NBD_REQUESTS) {
+ qemu_notify_event();
+ }
+ nbd_client_put(client);
+}
+
+NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
+ off_t size, uint32_t nbdflags)
+{
+ NBDExport *exp = g_malloc0(sizeof(NBDExport));
+ QSIMPLEQ_INIT(&exp->requests);
+ exp->bs = bs;
+ exp->dev_offset = dev_offset;
+ exp->nbdflags = nbdflags;
+ exp->size = size == -1 ? bdrv_getlength(bs) : size;
+ return exp;
+}
+
+void nbd_export_close(NBDExport *exp)
+{
+ while (!QSIMPLEQ_EMPTY(&exp->requests)) {
+ NBDRequest *first = QSIMPLEQ_FIRST(&exp->requests);
+ QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry);
+ qemu_vfree(first->data);
+ g_free(first);
+ }
+
+ g_free(exp);
+}
+
+static int nbd_can_read(void *opaque);
+static void nbd_read(void *opaque);
+static void nbd_restart_write(void *opaque);
+
+static ssize_t nbd_co_send_reply(NBDRequest *req, struct nbd_reply *reply,
+ int len)
+{
+ NBDClient *client = req->client;
+ int csock = client->sock;
+ ssize_t rc, ret;
- if (nbd_receive_request(csock, &request) == -1)
- return -1;
+ qemu_co_mutex_lock(&client->send_lock);
+ qemu_set_fd_handler2(csock, nbd_can_read, nbd_read,
+ nbd_restart_write, client);
+ client->send_coroutine = qemu_coroutine_self();
- if (request.len + NBD_REPLY_SIZE > data_size) {
+ if (!len) {
+ rc = nbd_send_reply(csock, reply);
+ } 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) {
+ rc = -EIO;
+ }
+ }
+ socket_set_cork(csock, 0);
+ }
+
+ client->send_coroutine = NULL;
+ qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
+ qemu_co_mutex_unlock(&client->send_lock);
+ return rc;
+}
+
+static ssize_t nbd_co_receive_request(NBDRequest *req, struct nbd_request *request)
+{
+ NBDClient *client = req->client;
+ int csock = client->sock;
+ ssize_t rc;
+
+ client->recv_coroutine = qemu_coroutine_self();
+ rc = nbd_receive_request(csock, request);
+ if (rc < 0) {
+ if (rc != -EAGAIN) {
+ rc = -EIO;
+ }
+ goto out;
+ }
+
+ if (request->len > NBD_BUFFER_SIZE) {
LOG("len (%u) is larger than max len (%u)",
- request.len + NBD_REPLY_SIZE, data_size);
- errno = EINVAL;
- return -1;
+ request->len, NBD_BUFFER_SIZE);
+ rc = -EINVAL;
+ goto out;
}
- if ((request.from + request.len) < request.from) {
+ if ((request->from + request->len) < request->from) {
LOG("integer overflow detected! "
"you're probably being attacked");
- errno = EINVAL;
- return -1;
+ rc = -EINVAL;
+ goto out;
}
- if ((request.from + request.len) > size) {
- LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
- ", Offset: %" PRIu64 "\n",
- request.from, request.len, (uint64_t)size, dev_offset);
- LOG("requested operation past EOF--bad client?");
- errno = EINVAL;
- return -1;
+ TRACE("Decoding type");
+
+ if ((request->type & NBD_CMD_MASK_COMMAND) == NBD_CMD_WRITE) {
+ TRACE("Reading %u byte(s)", request->len);
+
+ if (qemu_co_recv(csock, req->data, request->len) != request->len) {
+ LOG("reading from socket failed");
+ rc = -EIO;
+ goto out;
+ }
}
+ rc = 0;
- TRACE("Decoding type");
+out:
+ client->recv_coroutine = NULL;
+ return rc;
+}
+
+static void nbd_trip(void *opaque)
+{
+ NBDClient *client = opaque;
+ NBDRequest *req = nbd_request_get(client);
+ NBDExport *exp = client->exp;
+ struct nbd_request request;
+ struct nbd_reply reply;
+ ssize_t ret;
+
+ TRACE("Reading request.");
+
+ ret = nbd_co_receive_request(req, &request);
+ if (ret == -EAGAIN) {
+ goto done;
+ }
+ if (ret == -EIO) {
+ goto out;
+ }
reply.handle = request.handle;
reply.error = 0;
- switch (request.type) {
+ if (ret < 0) {
+ reply.error = -ret;
+ goto error_reply;
+ }
+
+ if ((request.from + request.len) > exp->size) {
+ LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
+ ", Offset: %" PRIu64 "\n",
+ request.from, request.len,
+ (uint64_t)exp->size, (uint64_t)exp->dev_offset);
+ LOG("requested operation past EOF--bad client?");
+ goto invalid_request;
+ }
+
+ switch (request.type & NBD_CMD_MASK_COMMAND) {
case NBD_CMD_READ:
TRACE("Request type is READ");
- if (bdrv_read(bs, (request.from + dev_offset) / 512,
- data + NBD_REPLY_SIZE,
- request.len / 512) == -1) {
+ if (request.type & NBD_CMD_FLAG_FUA) {
+ ret = bdrv_co_flush(exp->bs);
+ if (ret < 0) {
+ LOG("flush failed");
+ reply.error = -ret;
+ goto error_reply;
+ }
+ }
+
+ ret = bdrv_read(exp->bs, (request.from + exp->dev_offset) / 512,
+ req->data, request.len / 512);
+ if (ret < 0) {
LOG("reading from file failed");
- errno = EINVAL;
- return -1;
+ reply.error = -ret;
+ goto error_reply;
}
- *offset += request.len;
TRACE("Read %u byte(s)", request.len);
-
- /* Reply
- [ 0 .. 3] magic (NBD_REPLY_MAGIC)
- [ 4 .. 7] error (0 == no error)
- [ 7 .. 15] handle
- */
-
- cpu_to_be32w((uint32_t*)data, NBD_REPLY_MAGIC);
- cpu_to_be32w((uint32_t*)(data + 4), reply.error);
- cpu_to_be64w((uint64_t*)(data + 8), reply.handle);
-
- TRACE("Sending data to client");
-
- if (write_sync(csock, data,
- request.len + NBD_REPLY_SIZE) !=
- request.len + NBD_REPLY_SIZE) {
- LOG("writing to socket failed");
- errno = EINVAL;
- return -1;
- }
+ if (nbd_co_send_reply(req, &reply, request.len) < 0)
+ goto out;
break;
case NBD_CMD_WRITE:
TRACE("Request type is WRITE");
- TRACE("Reading %u byte(s)", request.len);
-
- if (read_sync(csock, data, request.len) != request.len) {
- LOG("reading from socket failed");
- errno = EINVAL;
- return -1;
+ if (exp->nbdflags & NBD_FLAG_READ_ONLY) {
+ TRACE("Server is read-only, return error");
+ reply.error = EROFS;
+ goto error_reply;
}
- if (readonly) {
- TRACE("Server is read-only, return error");
- reply.error = 1;
- } else {
- TRACE("Writing to device");
+ TRACE("Writing to device");
- if (bdrv_write(bs, (request.from + dev_offset) / 512,
- data, request.len / 512) == -1) {
- LOG("writing to file failed");
- errno = EINVAL;
- return -1;
- }
+ ret = bdrv_write(exp->bs, (request.from + exp->dev_offset) / 512,
+ req->data, request.len / 512);
+ if (ret < 0) {
+ LOG("writing to file failed");
+ reply.error = -ret;
+ goto error_reply;
+ }
- *offset += request.len;
+ if (request.type & NBD_CMD_FLAG_FUA) {
+ ret = bdrv_co_flush(exp->bs);
+ if (ret < 0) {
+ LOG("flush failed");
+ reply.error = -ret;
+ goto error_reply;
+ }
}
- if (nbd_send_reply(csock, &reply) == -1)
- return -1;
+ if (nbd_co_send_reply(req, &reply, 0) < 0) {
+ goto out;
+ }
break;
case NBD_CMD_DISC:
TRACE("Request type is DISCONNECT");
errno = 0;
- return 1;
+ goto out;
+ case NBD_CMD_FLUSH:
+ TRACE("Request type is FLUSH");
+
+ ret = bdrv_co_flush(exp->bs);
+ if (ret < 0) {
+ LOG("flush failed");
+ reply.error = -ret;
+ }
+ if (nbd_co_send_reply(req, &reply, 0) < 0) {
+ goto out;
+ }
+ break;
+ case NBD_CMD_TRIM:
+ TRACE("Request type is TRIM");
+ ret = bdrv_co_discard(exp->bs, (request.from + exp->dev_offset) / 512,
+ request.len / 512);
+ if (ret < 0) {
+ LOG("discard failed");
+ reply.error = -ret;
+ }
+ if (nbd_co_send_reply(req, &reply, 0) < 0) {
+ goto out;
+ }
+ break;
default:
LOG("invalid request type (%u) received", request.type);
- errno = EINVAL;
- return -1;
+ invalid_request:
+ reply.error = -EINVAL;
+ error_reply:
+ if (nbd_co_send_reply(req, &reply, 0) < 0) {
+ goto out;
+ }
+ break;
}
TRACE("Request/Reply complete");
- return 0;
+done:
+ nbd_request_put(req);
+ return;
+
+out:
+ nbd_request_put(req);
+ nbd_client_close(client);
+}
+
+static int nbd_can_read(void *opaque)
+{
+ NBDClient *client = opaque;
+
+ return client->recv_coroutine || client->nb_requests < MAX_NBD_REQUESTS;
+}
+
+static void nbd_read(void *opaque)
+{
+ NBDClient *client = opaque;
+
+ if (client->recv_coroutine) {
+ qemu_coroutine_enter(client->recv_coroutine, NULL);
+ } else {
+ qemu_coroutine_enter(qemu_coroutine_create(nbd_trip), client);
+ }
+}
+
+static void nbd_restart_write(void *opaque)
+{
+ NBDClient *client = opaque;
+
+ qemu_coroutine_enter(client->send_coroutine, NULL);
+}
+
+NBDClient *nbd_client_new(NBDExport *exp, int csock,
+ void (*close)(NBDClient *))
+{
+ NBDClient *client;
+ client = g_malloc0(sizeof(NBDClient));
+ client->refcount = 1;
+ client->exp = exp;
+ client->sock = csock;
+ if (nbd_send_negotiate(client) < 0) {
+ g_free(client);
+ return NULL;
+ }
+ client->close = close;
+ qemu_co_mutex_init(&client->send_lock);
+ qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
+ return client;
}
projects / qemu.git / blobdiff