commit 006f4ac49742b5f70ef7e39176fd42a500144ccc
author Zefan Li <lizefan@huawei.com> Thu Sep 18 16:03:15 2014 +0800
committer Tejun Heo <tj@kernel.org> Thu Sep 18 13:27:23 2014 -0400
tree 976006e7b7a5a0df635538fe51348e4648d9df8c
parent 971ff49355387fef41d1327434d8939721a4eb35

cgroup: simplify proc_cgroup_show()

Use the ONE macro instead of REG, and we can simplify proc_cgroup_show().

Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

kernel/cgroup.c

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index db19a48..df7733b 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -5030,12 +5030,9 @@
  *  - Print task's cgroup paths into seq_file, one line for each hierarchy
  *  - Used for /proc/<pid>/cgroup.
  */
-
-/* TODO: Use a proper seq_file iterator */
-int proc_cgroup_show(struct seq_file *m, void *v)
+int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
+		     struct pid *pid, struct task_struct *tsk)
 {
-	struct pid *pid;
-	struct task_struct *tsk;
 	char *buf, *path;
 	int retval;
 	struct cgroup_root *root;
@@ -5045,14 +5042,6 @@
 	if (!buf)
 		goto out;
 
-	retval = -ESRCH;
-	pid = m->private;
-	tsk = get_pid_task(pid, PIDTYPE_PID);
-	if (!tsk)
-		goto out_free;
-
-	retval = 0;
-
 	mutex_lock(&cgroup_mutex);
 	down_read(&css_set_rwsem);
 
@@ -5082,11 +5071,10 @@
 		seq_putc(m, '\n');
 	}
 
+	retval = 0;
 out_unlock:
 	up_read(&css_set_rwsem);
 	mutex_unlock(&cgroup_mutex);
-	put_task_struct(tsk);
-out_free:
 	kfree(buf);
 out:
 	return retval;