cgroup: introduce cgroup_taskset and use it in subsys->can_attach(), cancel_attach() and attach()
Currently, there's no way to pass multiple tasks to cgroup_subsys
methods necessitating the need for separate per-process and per-task
methods. This patch introduces cgroup_taskset which can be used to
pass multiple tasks and their associated cgroups to cgroup_subsys
methods.
Three methods - can_attach(), cancel_attach() and attach() - are
converted to use cgroup_taskset. This unifies passed parameters so
that all methods have access to all information. Conversions in this
patchset are identical and don't introduce any behavior change.
-v2: documentation updated as per Paul Menage's suggestion.
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>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: James Morris <jmorris@namei.org>
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 4450fbe..8b5b5d8 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -62,11 +62,12 @@
struct cgroup_subsys devices_subsys;
static int devcgroup_can_attach(struct cgroup_subsys *ss,
- struct cgroup *new_cgroup, struct task_struct *task)
+ struct cgroup *new_cgrp, struct cgroup_taskset *set)
{
- if (current != task && !capable(CAP_SYS_ADMIN))
- return -EPERM;
+ struct task_struct *task = cgroup_taskset_first(set);
+ if (current != task && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
return 0;
}
