if (extent->length == 0 ||
(client->info.min_block && !QEMU_IS_ALIGNED(extent->length,
- client->info.min_block)) ||
- extent->length > orig_length)
- {
+ client->info.min_block))) {
error_setg(errp, "Protocol error: server sent status chunk with "
"invalid length");
return -EINVAL;
}
+ /* The server is allowed to send us extra information on the final
+ * extent; just clamp it to the length we requested. */
+ if (extent->length > orig_length) {
+ extent->length = orig_length;
+ }
+
return 0;
}
const char *export,
QCryptoTLSCreds *tlscreds,
const char *hostname,
+ const char *x_dirty_bitmap,
Error **errp)
{
NBDClientSession *client = nbd_get_client_session(bs);
client->info.request_sizes = true;
client->info.structured_reply = true;
client->info.base_allocation = true;
+ client->info.x_dirty_bitmap = g_strdup(x_dirty_bitmap);
ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), export,
tlscreds, hostname,
&client->ioc, &client->info, errp);
+ g_free(client->info.x_dirty_bitmap);
if (ret < 0) {
logout("Failed to negotiate with the NBD server\n");
return ret;
}
- if (client->info.flags & NBD_FLAG_READ_ONLY &&
- !bdrv_is_read_only(bs)) {
- error_setg(errp,
- "request for write access conflicts with read-only export");
- return -EACCES;
+ if (x_dirty_bitmap && !client->info.base_allocation) {
+ error_setg(errp, "requested x-dirty-bitmap %s not found",
+ x_dirty_bitmap);
+ ret = -EINVAL;
+ goto fail;
+ }
+ if (client->info.flags & NBD_FLAG_READ_ONLY) {
+ ret = bdrv_apply_auto_read_only(bs, "NBD export is read-only", errp);
+ if (ret < 0) {
+ goto fail;
+ }
}
if (client->info.flags & NBD_FLAG_SEND_FUA) {
bs->supported_write_flags = BDRV_REQ_FUA;
logout("Established connection with NBD server\n");
return 0;
+
+ fail:
+ /*
+ * We have connected, but must fail for other reasons. The
+ * connection is still blocking; send NBD_CMD_DISC as a courtesy
+ * to the server.
+ */
+ {
+ NBDRequest request = { .type = NBD_CMD_DISC };
+
+ nbd_send_request(client->ioc ?: QIO_CHANNEL(sioc), &request);
+ return ret;
+ }
}