diff options
| -rw-r--r-- | mm/memcontrol.c | 27 |
1 files changed, 11 insertions, 16 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 02dae3292668..d00368110b08 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6056,10 +6056,10 @@ static void cgroup_event_ptable_queue_proc(struct file *file, * Input must be in format '<event_fd> <control_fd> <args>'. * Interpretation of args is defined by control file implementation. */ -static int cgroup_write_event_control(struct cgroup_subsys_state *dummy_css, +static int cgroup_write_event_control(struct cgroup_subsys_state *css, struct cftype *cft, const char *buffer) { - struct cgroup *cgrp = dummy_css->cgroup; + struct cgroup *cgrp = css->cgroup; struct cgroup_event *event; struct cgroup_subsys_state *cfile_css; unsigned int efd, cfd; @@ -6082,6 +6082,7 @@ static int cgroup_write_event_control(struct cgroup_subsys_state *dummy_css, if (!event) return -ENOMEM; + event->css = css; INIT_LIST_HEAD(&event->list); init_poll_funcptr(&event->pt, cgroup_event_ptable_queue_proc); init_waitqueue_func_entry(&event->wait, cgroup_event_wake); @@ -6117,23 +6118,17 @@ static int cgroup_write_event_control(struct cgroup_subsys_state *dummy_css, goto out_put_cfile; } - if (!event->cft->ss) { - ret = -EBADF; - goto out_put_cfile; - } - /* - * Determine the css of @cfile, verify it belongs to the same - * cgroup as cgroup.event_control, and associate @event with it. - * Remaining events are automatically removed on cgroup destruction - * but the removal is asynchronous, so take an extra ref. + * Verify @cfile should belong to @css. Also, remaining events are + * automatically removed on cgroup destruction but the removal is + * asynchronous, so take an extra ref on @css. */ rcu_read_lock(); ret = -EINVAL; - event->css = cgroup_css(cgrp, event->cft->ss); - cfile_css = css_from_dir(cfile.file->f_dentry->d_parent, event->cft->ss); - if (event->css && event->css == cfile_css && css_tryget(event->css)) + cfile_css = css_from_dir(cfile.file->f_dentry->d_parent, + &mem_cgroup_subsys); + if (cfile_css == css && css_tryget(css)) ret = 0; rcu_read_unlock(); @@ -6145,7 +6140,7 @@ static int cgroup_write_event_control(struct cgroup_subsys_state *dummy_css, goto out_put_css; } - ret = event->cft->register_event(event->css, event->cft, + ret = event->cft->register_event(css, event->cft, event->eventfd, buffer); if (ret) goto out_put_css; @@ -6162,7 +6157,7 @@ static int cgroup_write_event_control(struct cgroup_subsys_state *dummy_css, return 0; out_put_css: - css_put(event->css); + css_put(css); out_put_cfile: fdput(cfile); out_put_eventfd: |