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>
This commit is contained in:
Zefan Li 2014-09-18 16:03:15 +08:00 committed by Tejun Heo
parent 971ff49355
commit 006f4ac497
3 changed files with 7 additions and 33 deletions

View file

@ -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),

View file

@ -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,

View file

@ -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;