ssize_t nbd_wr_syncv(QIOChannel *ioc, struct iovec *iov, size_t niov, size_t length, bool do_read, Error **errp) { ssize_t done = 0; struct iovec *local_iov = g_new(struct iovec, niov); struct iovec *local_iov_head = local_iov; unsigned int nlocal_iov = niov; nlocal_iov = iov_copy(local_iov, nlocal_iov, iov, niov, 0, length); while (nlocal_iov > 0) { ssize_t len; if (do_read) { len = qio_channel_readv(ioc, local_iov, nlocal_iov, errp); } else { len = qio_channel_writev(ioc, local_iov, nlocal_iov, errp); } if (len == QIO_CHANNEL_ERR_BLOCK) { /* errp should not be set */ assert(qemu_in_coroutine()); qio_channel_yield(ioc, do_read ? G_IO_IN : G_IO_OUT); continue; } if (len < 0) { done = -EIO; goto cleanup; } if (do_read && len == 0) { break; } iov_discard_front(&local_iov, &nlocal_iov, len); done += len; } cleanup: g_free(local_iov_head); return done; }