On 21.04.2021 12:38, Stefano Garzarella wrote: > On Wed, Apr 14, 2021 at 01:51:17PM +0300, Arseny Krasnov wrote: >> On 13.04.2021 15:47, Arseny Krasnov wrote: >>> This add logic, that serializes write access to single socket >>> by multiple threads. It is implemented be adding field with TID >>> of current writer. When writer tries to send something, it checks >>> that field is -1(free), else it sleep in the same way as waiting >>> for free space at peers' side. >>> >>> This implementation is PoC and not related to SEQPACKET close, so >>> i've placed it after whole patchset. >>> >>> Signed-off-by: Arseny Krasnov <arseny.krasnov@xxxxxxxxxxxxx> >>> --- >>> include/net/af_vsock.h | 1 + >>> net/vmw_vsock/af_vsock.c | 10 +++++++++- >>> 2 files changed, 10 insertions(+), 1 deletion(-) >>> >>> diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h >>> index 53d3f33dbdbf..786df80b9fc3 100644 >>> --- a/include/net/af_vsock.h >>> +++ b/include/net/af_vsock.h >>> @@ -69,6 +69,7 @@ struct vsock_sock { >>> u64 buffer_size; >>> u64 buffer_min_size; >>> u64 buffer_max_size; >>> + pid_t tid_owner; >>> >>> /* Private to transport. */ >>> void *trans; >>> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c >>> index 54bee7e643f4..d00f8c07a9d3 100644 >>> --- a/net/vmw_vsock/af_vsock.c >>> +++ b/net/vmw_vsock/af_vsock.c >>> @@ -1765,7 +1765,9 @@ static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg, >>> ssize_t written; >>> >>> add_wait_queue(sk_sleep(sk), &wait); >>> - while (vsock_stream_has_space(vsk) == 0 && >>> + while ((vsock_stream_has_space(vsk) == 0 || >>> + (vsk->tid_owner != current->pid && >>> + vsk->tid_owner != -1)) && >>> sk->sk_err == 0 && >>> !(sk->sk_shutdown & SEND_SHUTDOWN) && >>> !(vsk->peer_shutdown & RCV_SHUTDOWN)) { >>> @@ -1796,6 +1798,8 @@ static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg, >>> goto out_err; >>> } >>> } >>> + >>> + vsk->tid_owner = current->pid; >>> remove_wait_queue(sk_sleep(sk), &wait); >>> >>> /* These checks occur both as part of and after the loop >>> @@ -1852,7 +1856,10 @@ static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg, >>> err = total_written; >>> } >>> out: >>> + vsk->tid_owner = -1; >>> release_sock(sk); >>> + sk->sk_write_space(sk); >>> + >>> return err; >>> } >>> >>> @@ -2199,6 +2206,7 @@ static int vsock_create(struct net *net, struct socket *sock, >>> return -ENOMEM; >>> >>> vsk = vsock_sk(sk); >>> + vsk->tid_owner = -1; >> This must be moved to '__vsock_create()' > Okay, I'll review the next version. > > In order to backport this fix to stable branches I think is better to > move at the beginning of this series or even out as a separate patch. Ok, i'll put it as first patch of patchset. I don't like to prepare it as separate patch, because SEQPACKET will use this fix. > > Thanks, > Stefano > >>> if (sock->type == SOCK_DGRAM) { >>> ret = vsock_assign_transport(vsk, NULL); >