Re: [dpdk-dev] [PATCH] vhostuser: fix deadlock when vhost unregister

[孙文杰 <findtheonlyway@gmail.com>]

Will do, thanks!

Maxime Coquelin <maxime.coquelin@redhat.com> 于2019年1月10日周四 下午10:48写道：

> Hi Sunwenjie,
>
> Thanks for your patch.
>
> Please resend with following contribution guidelines, that can be
> found in doc/guides/contributing/.
>
> First, the commit message prefix should be vhost.
> For other comments, please see inline:
>
>
> On 1/8/19 12:45 PM, sunwenjie wrote:
> >   When rte_vhost_driver_unregister  delete the connection fd,
> fdset_try_del will
> >   always try and donot release the  vhostuser.mutex if the fd is busy,
> but the
> >   fdset_event_dispatch will set the  fd to busy and call
> vhost_user_msg_handler
> >   to get vhostuser.mutex, which will  cause deadlock.
> >
>
> The commit message should not be indented, and wrapped at 72 chars.
>
> > To fix it:
> >      Unlock the vhost_user.mutex if fdset_try_del fail and relock it when
> >      retry.
>
> You need to add your Sined-off-by with your full name.
>
> > ---
> >   lib/librte_vhost/socket.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
> > index 9cf34ad17..a9effa115 100644
> > --- a/lib/librte_vhost/socket.c
> > +++ b/lib/librte_vhost/socket.c
> > @@ -961,13 +961,12 @@ rte_vhost_driver_unregister(const char *path)
> >       int count;
> >       struct vhost_user_connection *conn, *next;
> >
> > +again:
> >       pthread_mutex_lock(&vhost_user.mutex);
> >
> >       for (i = 0; i < vhost_user.vsocket_cnt; i++) {
> >               struct vhost_user_socket *vsocket = vhost_user.vsockets[i];
> > -
>
> Keep this new line, it is out of the scope of the change.
>
> >               if (!strcmp(vsocket->path, path)) {
> > -again:
> >                       pthread_mutex_lock(&vsocket->conn_mutex);
> >                       for (conn = TAILQ_FIRST(&vsocket->conn_list);
> >                            conn != NULL;
> > @@ -981,6 +980,7 @@ rte_vhost_driver_unregister(const char *path)
> >                                */
> >                               if (fdset_try_del(&vhost_user.fdset,
> >                                                 conn->connfd) == -1) {
> > +
>  pthread_mutex_unlock(&vhost_user.mutex);
> >                                       pthread_mutex_unlock(
> >
>  &vsocket->conn_mutex);
> >                                       goto again;
> >
>
> Thanks,
> Maxime
>