ssize_t nbd_wr_syncv(QIOChannel *ioc,
struct iovec *iov,
size_t niov,
size_t length,
bool do_read)
{
ssize_t done = 0;
Error *local_err = NULL;
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, &local_err);
} else {
len = qio_channel_writev(ioc, local_iov, nlocal_iov, &local_err);
}
if (len == QIO_CHANNEL_ERR_BLOCK) {
if (qemu_in_coroutine()) {
/* XXX figure out if we can create a variant on
* qio_channel_yield() that works with AIO contexts
* and consider using that in this branch */
qemu_coroutine_yield();
} else if (done) {
/* XXX this is needed by nbd_reply_ready. */
qio_channel_wait(ioc,
do_read ? G_IO_IN : G_IO_OUT);
} else {
return -EAGAIN;
}
continue;
}
if (len < 0) {
TRACE("I/O error: %s", error_get_pretty(local_err));
error_free(local_err);
/* XXX handle Error objects */
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;
}
int qio_channel_readv_all_eof(QIOChannel *ioc,
const struct iovec *iov,
size_t niov,
Error **errp)
{
int ret = -1;
struct iovec *local_iov = g_new(struct iovec, niov);
struct iovec *local_iov_head = local_iov;
unsigned int nlocal_iov = niov;
bool partial = false;
nlocal_iov = iov_copy(local_iov, nlocal_iov,
iov, niov,
0, iov_size(iov, niov));
while (nlocal_iov > 0) {
ssize_t len;
len = qio_channel_readv(ioc, local_iov, nlocal_iov, errp);
if (len == QIO_CHANNEL_ERR_BLOCK) {
if (qemu_in_coroutine()) {
qio_channel_yield(ioc, G_IO_IN);
} else {
qio_channel_wait(ioc, G_IO_IN);
}
continue;
} else if (len < 0) {
goto cleanup;
} else if (len == 0) {
if (partial) {
error_setg(errp,
"Unexpected end-of-file before all bytes were read");
} else {
ret = 0;
}
goto cleanup;
}
partial = true;
iov_discard_front(&local_iov, &nlocal_iov, len);
}
ret = 1;
cleanup:
g_free(local_iov_head);
return ret;
}
