> -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Huawei Xie > Sent: Tuesday, June 30, 2015 5:21 PM > To: dev at dpdk.org > Subject: [dpdk-dev] [PATCH v4 1/4] vhost: call fdset_del_slot to remove > connection fd > > In the event handler of connection fd, the connection fd could be possibly > closed. The event dispatch loop would then try to remove the fd from fdset. > Between these two actions, another thread might register a new listenfd > reusing the val of just closed fd, so we couldn't call fdset_del which would > wrongly clean up the new listenfd. A new function fdset_del_slot is provided > to cleanup the fd at the specified location. > > v4 changes: > - call fdset_del_slot to remove connection fd > > Signed-off-by: Huawei Xie <huawei.xie at intel.com>
Acked-by: Changchun Ouyang <changchun.ouyang at intel.com> > --- > lib/librte_vhost/vhost_user/fd_man.c | 27 > ++++++++++++++++++++++++++- > 1 file changed, 26 insertions(+), 1 deletion(-) > > diff --git a/lib/librte_vhost/vhost_user/fd_man.c > b/lib/librte_vhost/vhost_user/fd_man.c > index 831c9c1..bd30f8d 100644 > --- a/lib/librte_vhost/vhost_user/fd_man.c > +++ b/lib/librte_vhost/vhost_user/fd_man.c > @@ -188,6 +188,24 @@ fdset_del(struct fdset *pfdset, int fd) } > > /** > + * Unregister the fd at the specified slot from the fdset. > + */ > +static void > +fdset_del_slot(struct fdset *pfdset, int index) { > + if (pfdset == NULL || index < 0 || index >= MAX_FDS) > + return; > + > + pthread_mutex_lock(&pfdset->fd_mutex); > + > + pfdset->fd[index].fd = -1; > + pfdset->fd[index].rcb = pfdset->fd[index].wcb = NULL; > + pfdset->num--; > + > + pthread_mutex_unlock(&pfdset->fd_mutex); > +} > + > +/** > * This functions runs in infinite blocking loop until there is no fd in > * pfdset. It calls corresponding r/w handler if there is event on the fd. > * > @@ -248,8 +266,15 @@ fdset_event_dispatch(struct fdset *pfdset) > * We don't allow fdset_del to be called in callback > * directly. > */ > + /* > + * When we are to clean up the fd from fdset, > + * because the fd is closed in the cb, > + * the old fd val could be reused by when creates > new > + * listen fd in another thread, we couldn't call > + * fd_set_del. > + */ > if (remove1 || remove2) > - fdset_del(pfdset, fd); > + fdset_del_slot(pfdset, i); > } > } > } > -- > 1.8.1.4