Re: [RFC PATCH 27/27] epoll: take epitem list out of struct file

Qian Cai
2020-10-05T20:37:29Z

On Sun, 2020-10-04 at 03:39 +0100, Al Viro wrote:
> /*
> * Must be called with "mtx" held.
> */
> @@ -1367,19 +1454,21 @@ static int ep_insert(struct eventpoll *ep, const
> struct epoll_event *event,
> epi->event = *event;
> epi->next = EP_UNACTIVE_PTR;
>
> - atomic_long_inc(&ep->user->epoll_watches);
> -
> if (tep)
> mutex_lock(&tep->mtx);
> /* Add the current item to the list of active epoll hook for this file
> */
> - spin_lock(&tfile->f_lock);
> - hlist_add_head_rcu(&epi->fllink, &tfile->f_ep_links);
> - spin_unlock(&tfile->f_lock);
> - if (full_check && !tep) {
> - get_file(tfile);
> - list_add(&tfile->f_tfile_llink, &tfile_check_list);
> + if (unlikely(attach_epitem(tfile, epi) < 0)) {
> + kmem_cache_free(epi_cache, epi);
> + if (tep)
> + mutex_lock(&tep->mtx);

Shouldn't this be mutex_unlock() instead?

> + return -ENOMEM;
> }
>