Stefano Garzarella
2021-Feb-11 12:14 UTC
[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 at 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 >