memcontrol: rcu_read_lock() to protect mm_match_cgroup()

mm_match_cgroup() calls cgroup_subsys_state().

We must use rcu_read_lock() to protect cgroup_subsys_state().

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Lai Jiangshan 2009-01-07 18:08:07 -08:00 committed by Linus Torvalds
parent 18f59ea7de
commit 2e4d40915f
1 changed files with 9 additions and 2 deletions

View File

@ -61,8 +61,15 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem);
extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
#define mm_match_cgroup(mm, cgroup) \
((cgroup) == mem_cgroup_from_task((mm)->owner))
static inline
int mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *cgroup)
{
struct mem_cgroup *mem;
rcu_read_lock();
mem = mem_cgroup_from_task((mm)->owner);
rcu_read_unlock();
return cgroup == mem;
}
extern int
mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr);