#define NBD_DEFAULT_PORT 10809
-#define NBD_BUFFER_SIZE (1024*1024)
+/* Maximum size of a single READ/WRITE data buffer */
+#define NBD_MAX_BUFFER_SIZE (32 * 1024 * 1024)
ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read);
int tcp_socket_incoming(const char *address, uint16_t port);
static NBDRequest *nbd_request_get(NBDClient *client)
{
NBDRequest *req;
- NBDExport *exp = client->exp;
assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
client->nb_requests++;
req = g_slice_new0(NBDRequest);
- req->data = qemu_blockalign(exp->bs, NBD_BUFFER_SIZE);
nbd_client_get(client);
req->client = client;
return req;
{
NBDClient *client = req->client;
- qemu_vfree(req->data);
+ if (req->data) {
+ qemu_vfree(req->data);
+ }
g_slice_free(NBDRequest, req);
if (client->nb_requests-- == MAX_NBD_REQUESTS) {
{
NBDClient *client = req->client;
int csock = client->sock;
+ uint32_t command;
ssize_t rc;
client->recv_coroutine = qemu_coroutine_self();
goto out;
}
- if (request->len > NBD_BUFFER_SIZE) {
+ if (request->len > NBD_MAX_BUFFER_SIZE) {
LOG("len (%u) is larger than max len (%u)",
- request->len, NBD_BUFFER_SIZE);
+ request->len, NBD_MAX_BUFFER_SIZE);
rc = -EINVAL;
goto out;
}
TRACE("Decoding type");
- if ((request->type & NBD_CMD_MASK_COMMAND) == NBD_CMD_WRITE) {
+ command = request->type & NBD_CMD_MASK_COMMAND;
+ if (command == NBD_CMD_READ || command == NBD_CMD_WRITE) {
+ req->data = qemu_blockalign(client->exp->bs, request->len);
+ }
+ if (command == NBD_CMD_WRITE) {
TRACE("Reading %u byte(s)", request->len);
if (qemu_co_recv(csock, req->data, request->len) != request->len) {