lkml.org 
[lkml]   [2021]   [Feb]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH v4 05/17] af_vsock: separate wait space loop
On Sun, Feb 07, 2021 at 06:15:41PM +0300, Arseny Krasnov wrote:
>This moves loop that waits for space on send to separate function,
>because it will be used for SEQ_BEGIN/SEQ_END sending before and
>after data transmission. Waiting for SEQ_BEGIN/SEQ_END is needed
>because such packets carries SEQPACKET header that couldn't be
>fragmented by credit mechanism, so to avoid it, sender waits until
>enough space will be ready.
>
>Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
>---
> include/net/af_vsock.h | 2 +
> net/vmw_vsock/af_vsock.c | 93 ++++++++++++++++++++++++++--------------
> 2 files changed, 62 insertions(+), 33 deletions(-)
>
>diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
>index bb6a0e52be86..19f6f22821ec 100644
>--- a/include/net/af_vsock.h
>+++ b/include/net/af_vsock.h
>@@ -205,6 +205,8 @@ void vsock_remove_sock(struct vsock_sock *vsk);
> void vsock_for_each_connected_socket(void (*fn)(struct sock *sk));
> int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);
> bool vsock_find_cid(unsigned int cid);
>+int vsock_wait_space(struct sock *sk, size_t space, int flags,
>+ struct vsock_transport_send_notify_data *send_data);
>
> /**** TAP ****/
>
>diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>index 3d8af987216a..ea99261e88ac 100644
>--- a/net/vmw_vsock/af_vsock.c
>+++ b/net/vmw_vsock/af_vsock.c
>@@ -1693,6 +1693,64 @@ static int vsock_connectible_getsockopt(struct socket *sock,
> return 0;
> }
>
>+int vsock_wait_space(struct sock *sk, size_t space, int flags,
>+ struct vsock_transport_send_notify_data *send_data)
>+{
>+ const struct vsock_transport *transport;
>+ struct vsock_sock *vsk;
>+ long timeout;
>+ int err;
>+
>+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
>+
>+ vsk = vsock_sk(sk);
>+ transport = vsk->transport;
>+ timeout = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
>+ err = 0;
>+
>+ add_wait_queue(sk_sleep(sk), &wait);
>+
>+ while (vsock_stream_has_space(vsk) < space &&
>+ sk->sk_err == 0 &&
>+ !(sk->sk_shutdown & SEND_SHUTDOWN) &&
>+ !(vsk->peer_shutdown & RCV_SHUTDOWN)) {

Maybe a new line here, like in the original code, would help the
readability.

>+ /* Don't wait for non-blocking sockets. */
>+ if (timeout == 0) {
>+ err = -EAGAIN;
>+ goto out_err;
>+ }
>+
>+ if (send_data) {
>+ err = transport->notify_send_pre_block(vsk, send_data);
>+ if (err < 0)
>+ goto out_err;
>+ }
>+
>+ release_sock(sk);
>+ timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
>+ lock_sock(sk);
>+ if (signal_pending(current)) {
>+ err = sock_intr_errno(timeout);
>+ goto out_err;
>+ } else if (timeout == 0) {
>+ err = -EAGAIN;
>+ goto out_err;
>+ }
>+ }
>+
>+ if (sk->sk_err) {
>+ err = -sk->sk_err;
>+ } else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
>+ (vsk->peer_shutdown & RCV_SHUTDOWN)) {
>+ err = -EPIPE;
>+ }
>+
>+out_err:
>+ remove_wait_queue(sk_sleep(sk), &wait);
>+ return err;
>+}
>+EXPORT_SYMBOL_GPL(vsock_wait_space);
>+
> static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
> size_t len)
> {

After removing the wait loop in vsock_connectible_sendmsg(), we should
remove the 'timeout' variable because it is no longer used.

>@@ -1751,39 +1809,8 @@ static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
> while (total_written < len) {
> ssize_t written;
>
>- add_wait_queue(sk_sleep(sk), &wait);
>- while (vsock_stream_has_space(vsk) == 0 &&
>- sk->sk_err == 0 &&
>- !(sk->sk_shutdown & SEND_SHUTDOWN) &&
>- !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
>-
>- /* Don't wait for non-blocking sockets. */
>- if (timeout == 0) {
>- err = -EAGAIN;
>- remove_wait_queue(sk_sleep(sk), &wait);
>- goto out_err;
>- }
>-
>- err = transport->notify_send_pre_block(vsk, &send_data);
>- if (err < 0) {
>- remove_wait_queue(sk_sleep(sk), &wait);
>- goto out_err;
>- }
>-
>- release_sock(sk);
>- timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
>- lock_sock(sk);
>- if (signal_pending(current)) {
>- err = sock_intr_errno(timeout);
>- remove_wait_queue(sk_sleep(sk), &wait);
>- goto out_err;
>- } else if (timeout == 0) {
>- err = -EAGAIN;
>- remove_wait_queue(sk_sleep(sk), &wait);
>- goto out_err;
>- }
>- }
>- remove_wait_queue(sk_sleep(sk), &wait);
>+ if (vsock_wait_space(sk, 1, msg->msg_flags, &send_data))
>+ goto out_err;
>
> /* These checks occur both as part of and after the loop
> * conditional since we need to check before and after
>--
>2.25.1
>

\
 
 \ /
  Last update: 2021-02-11 13:20    [W:1.064 / U:0.036 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site