nbd/server: simplify reply transmission

Send qiov via qio_channel_writev_all instead of calling nbd_write twice
with a cork.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20171012095319.136610-8-vsementsov@virtuozzo.com>
[eblake: rebase to tweaks earlier in series]
Signed-off-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2017-10-12 17:29:00 -05:00 committed by Eric Blake
parent 978df1b6bf
commit de79bfc36f

View File

@ -1188,6 +1188,23 @@ void nbd_export_close_all(void)
}
}
static int coroutine_fn nbd_co_send_iov(NBDClient *client, struct iovec *iov,
unsigned niov, Error **errp)
{
int ret;
g_assert(qemu_in_coroutine());
qemu_co_mutex_lock(&client->send_lock);
client->send_coroutine = qemu_coroutine_self();
ret = qio_channel_writev_all(client->ioc, iov, niov, errp) < 0 ? -EIO : 0;
client->send_coroutine = NULL;
qemu_co_mutex_unlock(&client->send_lock);
return ret;
}
static inline void set_be_simple_reply(NBDSimpleReply *reply, uint64_t error,
uint64_t handle)
{
@ -1203,35 +1220,17 @@ static int nbd_co_send_simple_reply(NBDClient *client,
size_t len,
Error **errp)
{
NBDSimpleReply simple_reply;
NBDSimpleReply reply;
int nbd_err = system_errno_to_nbd_errno(error);
int ret;
g_assert(qemu_in_coroutine());
struct iovec iov[] = {
{.iov_base = &reply, .iov_len = sizeof(reply)},
{.iov_base = data, .iov_len = len}
};
trace_nbd_co_send_simple_reply(handle, nbd_err, len);
set_be_simple_reply(&simple_reply, nbd_err, handle);
set_be_simple_reply(&reply, nbd_err, handle);
qemu_co_mutex_lock(&client->send_lock);
client->send_coroutine = qemu_coroutine_self();
if (!len) {
ret = nbd_write(client->ioc, &simple_reply, sizeof(simple_reply), errp);
} else {
qio_channel_set_cork(client->ioc, true);
ret = nbd_write(client->ioc, &simple_reply, sizeof(simple_reply), errp);
if (ret == 0) {
ret = nbd_write(client->ioc, data, len, errp);
if (ret < 0) {
ret = -EIO;
}
}
qio_channel_set_cork(client->ioc, false);
}
client->send_coroutine = NULL;
qemu_co_mutex_unlock(&client->send_lock);
return ret;
return nbd_co_send_iov(client, iov, len ? 2 : 1, errp);
}
/* nbd_co_receive_request