Commit 075b593f authored by Tetsuo Handa's avatar Tetsuo Handa Committed by Tejun Heo
Browse files

cgroup: Use cgroup_attach_{lock,unlock}() from cgroup_attach_task_all() 



No behavior changes; preparing for potential locking changes in future.

Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: default avatarMukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 265efc94

kernel/cgroup/cgroup-internal.h

+2 −0
Original line number Diff line number Diff line
@@ -250,6 +250,8 @@ int cgroup_migrate(struct task_struct *leader, bool threadgroup, 


int cgroup_attach_task(struct cgroup *dst_cgrp, struct task_struct *leader,

		       bool threadgroup);

void cgroup_attach_lock(bool lock_threadgroup);

void cgroup_attach_unlock(bool lock_threadgroup);

struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup,

					     bool *locked)

	__acquires(&cgroup_threadgroup_rwsem);

kernel/cgroup/cgroup-v1.c

+2 −4
Original line number Diff line number Diff line
@@ -59,8 +59,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) 
	int retval = 0;



	mutex_lock(&cgroup_mutex);

	cpus_read_lock();

	percpu_down_write(&cgroup_threadgroup_rwsem);

	cgroup_attach_lock(true);

	for_each_root(root) {

		struct cgroup *from_cgrp;
@@ -72,8 +71,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) 
		if (retval)

			break;

	}

	percpu_up_write(&cgroup_threadgroup_rwsem);

	cpus_read_unlock();

	cgroup_attach_unlock(true);

	mutex_unlock(&cgroup_mutex);



	return retval;

kernel/cgroup/cgroup.c

+2 −2
Original line number Diff line number Diff line
@@ -2393,7 +2393,7 @@ EXPORT_SYMBOL_GPL(task_cgroup_path); 
 * write-locking cgroup_threadgroup_rwsem. This allows ->attach() to assume that

 * CPU hotplug is disabled on entry.

 */

static void cgroup_attach_lock(bool lock_threadgroup)

void cgroup_attach_lock(bool lock_threadgroup)

{

	cpus_read_lock();

	if (lock_threadgroup)
@@ -2404,7 +2404,7 @@ static void cgroup_attach_lock(bool lock_threadgroup) 
 * cgroup_attach_unlock - Undo cgroup_attach_lock()

 * @lock_threadgroup: whether to up_write cgroup_threadgroup_rwsem

 */

static void cgroup_attach_unlock(bool lock_threadgroup)

void cgroup_attach_unlock(bool lock_threadgroup)

{

	if (lock_threadgroup)

		percpu_up_write(&cgroup_threadgroup_rwsem);