cgroup: implement CFTYPE_NO_PREFIX

When cgroup files are created, cgroup core automatically prepends the
name of the subsystem as prefix.  This patch adds CFTYPE_NO_ which
disables the automatic prefix.  This is to work around historical
baggages and shouldn't be used for new files.

This will be used to move "cgroup.event_control" from cgroup core to
memcg.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Glauber Costa <glommer@gmail.com>
This commit is contained in:
Tejun Heo 2013-08-26 18:40:56 -04:00
parent ca8bdcaff0
commit 9fa4db334c
2 changed files with 3 additions and 1 deletions

View file

@ -411,6 +411,7 @@ enum {
CFTYPE_ONLY_ON_ROOT = (1 << 0), /* only create on root cgrp */
CFTYPE_NOT_ON_ROOT = (1 << 1), /* don't create on root cgrp */
CFTYPE_INSANE = (1 << 2), /* don't create if sane_behavior */
CFTYPE_NO_PREFIX = (1 << 3), /* (DON'T USE FOR NEW FILES) no subsys prefix */
};
#define MAX_CFTYPE_NAME 64

View file

@ -2756,7 +2756,8 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cftype *cft)
umode_t mode;
char name[MAX_CGROUP_TYPE_NAMELEN + MAX_CFTYPE_NAME + 2] = { 0 };
if (cft->ss && !(cgrp->root->flags & CGRP_ROOT_NOPREFIX)) {
if (cft->ss && !(cft->flags & CFTYPE_NO_PREFIX) &&
!(cgrp->root->flags & CGRP_ROOT_NOPREFIX)) {
strcpy(name, cft->ss->name);
strcat(name, ".");
}