static void nbd_teardown_connection(NbdClientSession *client)
{
struct nbd_request request = {
.type = NBD_CMD_DISC,
.from = 0,
.len = 0
};
nbd_send_request(client->sock, &request);
/* finish any pending coroutines */
shutdown(client->sock, 2);
nbd_recv_coroutines_enter_all(client);
qemu_aio_set_fd_handler(client->sock, NULL, NULL, NULL);
closesocket(client->sock);
client->sock = -1;
}
void nbd_client_session_close(NbdClientSession *client)
{
if (!client->bs) {
return;
}
nbd_teardown_connection(client);
client->bs = NULL;
}
int nbd_client_session_init(NbdClientSession *client, BlockDriverState *bs,
int sock, const char *export)
{
int ret;
/* NBD handshake */
logout("session init %s\n", export);
qemu_set_block(sock);
ret = nbd_receive_negotiate(sock, export,
&client->nbdflags, &client->size,
&client->blocksize);
if (ret < 0) {
logout("Failed to negotiate with the NBD server\n");
closesocket(sock);
return ret;
}
qemu_co_mutex_init(&client->send_mutex);
qemu_co_mutex_init(&client->free_sema);
client->bs = bs;
client->sock = sock;
/* Now that we're connected, set the socket to be non-blocking and
* kick the reply mechanism. */
qemu_set_nonblock(sock);
qemu_aio_set_fd_handler(sock, nbd_reply_ready, NULL, client);
logout("Established connection with NBD server\n");
return 0;
}
static void nbd_close(BlockDriverState *bs)
{
BDRVNBDState *s = bs->opaque;
g_free(s->export_name);
g_free(s->host_spec);
nbd_teardown_connection(bs);
}
void nbd_client_close(BlockDriverState *bs)
{
NBDClientSession *client = nbd_get_client_session(bs);
NBDRequest request = { .type = NBD_CMD_DISC };
if (client->ioc == NULL) {
return;
}
nbd_send_request(client->ioc, &request);
nbd_teardown_connection(bs);
}
void nbd_client_close(BlockDriverState *bs)
{
NbdClientSession *client = nbd_get_client_session(bs);
struct nbd_request request = {
.type = NBD_CMD_DISC,
.from = 0,
.len = 0
};
if (client->sock == -1) {
return;
}
nbd_send_request(client->sock, &request);
nbd_teardown_connection(bs);
}
int nbd_client_init(BlockDriverState *bs, int sock, const char *export,
Error **errp)
{
NbdClientSession *client = nbd_get_client_session(bs);
int ret;
/* NBD handshake */
logout("session init %s\n", export);
qemu_set_block(sock);
ret = nbd_receive_negotiate(sock, export,
&client->nbdflags, &client->size,
&client->blocksize, errp);
if (ret < 0) {
logout("Failed to negotiate with the NBD server\n");
closesocket(sock);
return ret;
}
qemu_co_mutex_init(&client->send_mutex);
qemu_co_mutex_init(&client->free_sema);
client->sock = sock;
/* Now that we're connected, set the socket to be non-blocking and
* kick the reply mechanism. */
qemu_set_nonblock(sock);
nbd_client_attach_aio_context(bs, bdrv_get_aio_context(bs));
logout("Established connection with NBD server\n");
return 0;
}
static void nbd_reply_ready(void *opaque)
{
BlockDriverState *bs = opaque;
NbdClientSession *s = nbd_get_client_session(bs);
uint64_t i;
int ret;
if (!s->ioc) { /* Already closed */
return;
}
if (s->reply.handle == 0) {
/* No reply already in flight. Fetch a header. It is possible
* that another thread has done the same thing in parallel, so
* the socket is not readable anymore.
*/
ret = nbd_receive_reply(s->ioc, &s->reply);
if (ret == -EAGAIN) {
return;
}
if (ret < 0) {
s->reply.handle = 0;
goto fail;
}
}
/* There's no need for a mutex on the receive side, because the
* handler acts as a synchronization point and ensures that only
* one coroutine is called until the reply finishes. */
i = HANDLE_TO_INDEX(s, s->reply.handle);
if (i >= MAX_NBD_REQUESTS) {
goto fail;
}
if (s->recv_coroutine[i]) {
qemu_coroutine_enter(s->recv_coroutine[i], NULL);
return;
}
fail:
nbd_teardown_connection(bs);
}
void nbd_client_close(BlockDriverState *bs)
{
NbdClientSession *client = nbd_get_client_session(bs);
struct nbd_request request = {
.type = NBD_CMD_DISC,
.from = 0,
.len = 0
};
if (client->ioc == NULL) {
return;
}
nbd_send_request(client->ioc, &request);
nbd_teardown_connection(bs);
}
int nbd_client_init(BlockDriverState *bs,
QIOChannelSocket *sioc,
const char *export,
QCryptoTLSCreds *tlscreds,
const char *hostname,
Error **errp)
{
NbdClientSession *client = nbd_get_client_session(bs);
int ret;
/* NBD handshake */
logout("session init %s\n", export);
qio_channel_set_blocking(QIO_CHANNEL(sioc), true, NULL);
ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), export,
&client->nbdflags,
tlscreds, hostname,
&client->ioc,
&client->size, errp);
if (ret < 0) {
logout("Failed to negotiate with the NBD server\n");
return ret;
}
qemu_co_mutex_init(&client->send_mutex);
qemu_co_mutex_init(&client->free_sema);
client->sioc = sioc;
object_ref(OBJECT(client->sioc));
if (!client->ioc) {
client->ioc = QIO_CHANNEL(sioc);
object_ref(OBJECT(client->ioc));
}
/* Now that we're connected, set the socket to be non-blocking and
* kick the reply mechanism. */
qio_channel_set_blocking(QIO_CHANNEL(sioc), false, NULL);
nbd_client_attach_aio_context(bs, bdrv_get_aio_context(bs));
logout("Established connection with NBD server\n");
return 0;
}
