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authorVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>2017-10-12 17:29:00 -0500
committerEric Blake <eblake@redhat.com>2017-10-13 08:05:16 -0500
commitde79bfc36f08e9ad29866506ba58e20ff1f4b162 (patch)
tree1603820cc5e27503bdb0c6c7d5a83cd0b69019d1 /nbd
parent978df1b6bf813a9fac3253073688f60bcc0a9733 (diff)
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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>
Diffstat (limited to 'nbd')
-rw-r--r--nbd/server.c49
1 files changed, 24 insertions, 25 deletions
diff --git a/nbd/server.c b/nbd/server.c
index 3fcc3d3..3df3548 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -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);
-
- 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);
- }
+ set_be_simple_reply(&reply, nbd_err, handle);
- 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