From 7dbdb199d3bf88f043ea17e97113eb28d5b100bc Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 18 Sep 2015 17:54:23 -0400 Subject: cgroup: replace cftype->mode with CFTYPE_WORLD_WRITABLE cftype->mode allows controllers to give arbitrary permissions to interface knobs. Except for "cgroup.event_control", the existing uses are spurious. * Some explicitly specify S_IRUGO | S_IWUSR even though that's the default. * "cpuset.memory_pressure" specifies S_IRUGO while also setting a write callback which returns -EACCES. All it needs to do is simply not setting a write callback. "cgroup.event_control" uses cftype->mode to make the file world-writable. It's a misdesigned interface and we don't want controllers to be tweaking interface file permissions in general. This patch removes cftype->mode and all its spurious uses and implements CFTYPE_WORLD_WRITABLE for "cgroup.event_control" which is marked as compatibility-only. Signed-off-by: Tejun Heo Cc: Li Zefan Cc: Johannes Weiner --- kernel/cpuset.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'kernel/cpuset.c') diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 20eedd8098c0..312961ef3ccc 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1597,9 +1597,6 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft, case FILE_MEMORY_PRESSURE_ENABLED: cpuset_memory_pressure_enabled = !!val; break; - case FILE_MEMORY_PRESSURE: - retval = -EACCES; - break; case FILE_SPREAD_PAGE: retval = update_flag(CS_SPREAD_PAGE, cs, val); break; @@ -1866,9 +1863,6 @@ static struct cftype files[] = { { .name = "memory_pressure", .read_u64 = cpuset_read_u64, - .write_u64 = cpuset_write_u64, - .private = FILE_MEMORY_PRESSURE, - .mode = S_IRUGO, }, { -- cgit v1.2.3