• Tejun Heo's avatar
    cgroup: replace cftype->mode with CFTYPE_WORLD_WRITABLE · 7dbdb199
    Tejun Heo authored
    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: default avatarTejun Heo <tj@kernel.org>
    Cc: Li Zefan <lizefan@huawei.com>
    Cc: Johannes Weiner <hannes@cmpxchg.org>
    7dbdb199
cpuset.c 75.2 KB