Commit 006f4ac4 authored by Zefan Li's avatar Zefan Li Committed by Tejun Heo
Browse files

cgroup: simplify proc_cgroup_show() 



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

Signed-off-by: default avatarZefan Li <lizefan@huawei.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 971ff493

fs/proc/base.c

+2 −17
Original line number Diff line number Diff line
@@ -376,21 +376,6 @@ static const struct file_operations proc_lstats_operations = { 


#endif



#ifdef CONFIG_CGROUPS

static int cgroup_open(struct inode *inode, struct file *file)

{

	struct pid *pid = PROC_I(inode)->pid;

	return single_open(file, proc_cgroup_show, pid);

}



static const struct file_operations proc_cgroup_operations = {

	.open		= cgroup_open,

	.read		= seq_read,

	.llseek		= seq_lseek,

	.release	= single_release,

};

#endif



#ifdef CONFIG_PROC_PID_CPUSET



static int cpuset_open(struct inode *inode, struct file *file)
@@ -2576,7 +2561,7 @@ static const struct pid_entry tgid_base_stuff[] = { 
	REG("cpuset",     S_IRUGO, proc_cpuset_operations),

#endif

#ifdef CONFIG_CGROUPS

	REG("cgroup",  S_IRUGO, proc_cgroup_operations),

	ONE("cgroup",  S_IRUGO, proc_cgroup_show),

#endif

	ONE("oom_score",  S_IRUGO, proc_oom_score),

	REG("oom_adj",    S_IRUGO|S_IWUSR, proc_oom_adj_operations),
@@ -2922,7 +2907,7 @@ static const struct pid_entry tid_base_stuff[] = { 
	REG("cpuset",    S_IRUGO, proc_cpuset_operations),

#endif

#ifdef CONFIG_CGROUPS

	REG("cgroup",  S_IRUGO, proc_cgroup_operations),

	ONE("cgroup",  S_IRUGO, proc_cgroup_show),

#endif

	ONE("oom_score", S_IRUGO, proc_oom_score),

	REG("oom_adj",   S_IRUGO|S_IWUSR, proc_oom_adj_operations),

include/linux/cgroup.h

+2 −1
Original line number Diff line number Diff line
@@ -37,7 +37,8 @@ extern void cgroup_exit(struct task_struct *p); 
extern int cgroupstats_build(struct cgroupstats *stats,

				struct dentry *dentry);



extern int proc_cgroup_show(struct seq_file *, void *);

extern int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,

			    struct pid *pid, struct task_struct *tsk);



/* define the enumeration of all cgroup subsystems */

#define SUBSYS(_x) _x ## _cgrp_id,

kernel/cgroup.c

+3 −15
Original line number Diff line number Diff line
@@ -5030,12 +5030,9 @@ core_initcall(cgroup_wq_init); 
 *  - 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 @@ int proc_cgroup_show(struct seq_file *m, void *v) 
	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 @@ int proc_cgroup_show(struct seq_file *m, void *v) 
		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;