From 9fa4db334c7d9570aec7a5121e84fae99aae1d04 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 26 Aug 2013 18:40:56 -0400 Subject: [PATCH] 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 Acked-by: Li Zefan Acked-by: Kirill A. Shutemov Cc: Glauber Costa --- include/linux/cgroup.h | 1 + kernel/cgroup.c | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 21ba29869eb8..3561d305b1e0 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -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 diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 7516668d8325..a41dc87cd07e 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -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, "."); }