cgroup: make cftype->[un]register_event() deal with cgroup_subsys_state instead of cgroup
cgroup is in the process of converting to css (cgroup_subsys_state)
from cgroup as the principal subsystem interface handle. This is
mostly to prepare for the unified hierarchy support where css's will
be created and destroyed dynamically but also helps cleaning up
subsystem implementations as css is usually what they are interested
in anyway.
cftype->[un]register_event() is among the remaining couple interfaces
which still use struct cgroup. Convert it to cgroup_subsys_state.
The conversion is mostly mechanical and removes the last users of
mem_cgroup_from_cont() and cg_to_vmpressure(), which are removed.
v2: indentation update as suggested by Li Zefan.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 8c57301..a71f2e0 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -159,9 +159,9 @@
*/
struct cgroup_event {
/*
- * Cgroup which the event belongs to.
+ * css which the event belongs to.
*/
- struct cgroup *cgrp;
+ struct cgroup_subsys_state *css;
/*
* Control file which the event associated.
*/
@@ -3955,11 +3955,12 @@
{
struct cgroup_event *event = container_of(work, struct cgroup_event,
remove);
- struct cgroup *cgrp = event->cgrp;
+ struct cgroup_subsys_state *css = event->css;
+ struct cgroup *cgrp = css->cgroup;
remove_wait_queue(event->wqh, &event->wait);
- event->cft->unregister_event(cgrp, event->cft, event->eventfd);
+ event->cft->unregister_event(css, event->cft, event->eventfd);
/* Notify userspace the event is going away. */
eventfd_signal(event->eventfd, 1);
@@ -3979,7 +3980,7 @@
{
struct cgroup_event *event = container_of(wait,
struct cgroup_event, wait);
- struct cgroup *cgrp = event->cgrp;
+ struct cgroup *cgrp = event->css->cgroup;
unsigned long flags = (unsigned long)key;
if (flags & POLLHUP) {
@@ -4048,7 +4049,7 @@
event = kzalloc(sizeof(*event), GFP_KERNEL);
if (!event)
return -ENOMEM;
- event->cgrp = cgrp;
+ 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);
@@ -4099,7 +4100,7 @@
goto out_put_cfile;
}
- ret = event->cft->register_event(cgrp, event->cft,
+ ret = event->cft->register_event(css, event->cft,
event->eventfd, buffer);
if (ret)
goto out_put_cfile;
