Error *local_err = NULL;
while (!s->quit) {
+ /*
+ * The NBD client can only really be considered idle when it has
+ * yielded from qio_channel_readv_all_eof(), waiting for data. This is
+ * the point where the additional scheduled coroutine entry happens
+ * after nbd_client_attach_aio_context().
+ *
+ * Therefore we keep an additional in_flight reference all the time and
+ * only drop it temporarily here.
+ *
+ * FIXME This is not safe because the QIOChannel could wake up the
+ * coroutine for a second time; it is not prepared for coroutine
+ * resumption from external code.
+ */
+ bdrv_dec_in_flight(s->bs);
assert(s->reply.handle == 0);
ret = nbd_receive_reply(s->ioc, &s->reply, &local_err);
+ bdrv_inc_in_flight(s->bs);
+
if (local_err) {
trace_nbd_read_reply_entry_fail(ret, error_get_pretty(local_err));
error_free(local_err);
s->quit = true;
nbd_recv_coroutines_wake_all(s);
+ bdrv_dec_in_flight(s->bs);
+
s->connection_co = NULL;
aio_wait_kick();
}
{
NBDClientSession *client = nbd_get_client_session(bs);
qio_channel_attach_aio_context(QIO_CHANNEL(client->ioc), new_context);
+
+ /* FIXME Really need a bdrv_inc_in_flight() here */
aio_co_schedule(new_context, client->connection_co);
}
* kick the reply mechanism. */
qio_channel_set_blocking(QIO_CHANNEL(sioc), false, NULL);
client->connection_co = qemu_coroutine_create(nbd_connection_entry, client);
+ bdrv_inc_in_flight(bs);
nbd_client_attach_aio_context(bs, bdrv_get_aio_context(bs));
logout("Established connection with NBD server\n");
{
NBDClientSession *client = nbd_get_client_session(bs);
+ client->bs = bs;
qemu_co_mutex_init(&client->send_mutex);
qemu_co_queue_init(&client->free_sema);