• Tejun Heo's avatar
    cgroup: attach cgroup_open_file to all cgroup files · 7da11279
    Tejun Heo authored
    In preparation of conversion to kernfs, cgroup file handling is
    updated so that it can be easily mapped to kernfs.  This patch
    attaches cgroup_open_file, which used to be attached to pidlist files,
    to all cgroup files, introduces seq_css/cft() accessors to determine
    the cgroup_subsys_state and cftype associated with a given cgroup
    seq_file, exports them as public interface.
    
    This doesn't cause any behavior changes but unifies cgroup file
    handling across different file types and will help converting them to
    kernfs seq_show() interface.
    
    v2: Li pointed out that the original patch was using
        single_open_size() incorrectly assuming that the size param is
        private data size.  Fix it by allocating @of separately and
        passing it to single_open() and explicitly freeing it in the
        release path.  This isn't the prettiest but this path is gonna be
        restructured by the following patches pretty soon.
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    Acked-by: default avatarLi Zefan <lizefan@huawei.com>
    7da11279
cgroup.c 146 KB