cgroup: replace cftype->trigger() with cftype->write()

cftype->trigger() is pointless.  It's trivial to ignore the input
buffer from a regular ->write() operation.  Convert all ->trigger()
users to ->write() and remove ->trigger().

This patch doesn't introduce any visible behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>

1 files changed, 0 insertions, 8 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index aecdc84fe128..08eb71ee600b 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -500,14 +500,6 @@ struct cftype {
                          s64 val);
 
         /*
-         * trigger() callback can be used to get some kick from the
-         * userspace, when the actual string written is not important
-         * at all. The private field can be used to determine the
-         * kick type for multiplexing.
-         */
-        int (*trigger)(struct cgroup_subsys_state *css, unsigned int event);
-
-        /*
          * write() is the generic write callback which maps directly to
          * kernfs write operation and overrides all other operations.
          * Maximum write size is determined by ->max_write_len.  Use