cgroups: show correct file mode

We have some read-only files and write-only files, but currently they are
all set to 0644, which is counter-intuitive and cause trouble for some
cgroup tools like libcgroup.

This patch adds 'mode' to struct cftype to allow cgroup subsys to set it's
own files' file mode, and for the most cases cft->mode can be default to 0
and cgroup will figure out proper mode.

Acked-by: Paul Menage <menage@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index f76db9dcaa05..ee5ec386aa8b 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1706,6 +1706,7 @@ static struct cftype files[] = {
                 .read_u64 = cpuset_read_u64,
                 .write_u64 = cpuset_write_u64,
                 .private = FILE_MEMORY_PRESSURE,
+                .mode = S_IRUGO,
         },
 
         {