cgroup: kill subsys->can_attach_task(), pre_attach() and attach_task()

These three methods are no longer used.  Kill them.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul Menage <paul@paulmenage.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>

1 files changed, 0 insertions, 20 deletions

diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt
index 8a2f302327f..a7c96ae5557 100644
--- a/Documentation/cgroups/cgroups.txt
+++ b/Documentation/cgroups/cgroups.txt
@@ -615,13 +615,6 @@ fork. If this method returns 0 (success) then this should remain valid
 while the caller holds cgroup_mutex and it is ensured that either
 attach() or cancel_attach() will be called in future.
 
-int can_attach_task(struct cgroup *cgrp, struct task_struct *tsk);
-(cgroup_mutex held by caller)
-
-As can_attach, but for operations that must be run once per task to be
-attached (possibly many when using cgroup_attach_proc). Called after
-can_attach.
-
 void cancel_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
                    struct cgroup_taskset *tset)
 (cgroup_mutex held by caller)
@@ -632,12 +625,6 @@ function, so that the subsystem can implement a rollback. If not, not necessary.
 This will be called only about subsystems whose can_attach() operation have
 succeeded. The parameters are identical to can_attach().
 
-void pre_attach(struct cgroup *cgrp);
-(cgroup_mutex held by caller)
-
-For any non-per-thread attachment work that needs to happen before
-attach_task. Needed by cpuset.
-
 void attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
             struct cgroup_taskset *tset)
 (cgroup_mutex held by caller)
@@ -646,13 +633,6 @@ Called after the task has been attached to the cgroup, to allow any
 post-attachment activity that requires memory allocations or blocking.
 The parameters are identical to can_attach().
 
-void attach_task(struct cgroup *cgrp, struct task_struct *tsk);
-(cgroup_mutex held by caller)
-
-As attach, but for operations that must be run once per task to be attached,
-like can_attach_task. Called before attach. Currently does not support any
-subsystem that might need the old_cgrp for every thread in the group.
-
 void fork(struct cgroup_subsy *ss, struct task_struct *task)
 
 Called when a task is forked into a cgroup.