From 13d77c37cab2bb906022309e1e7182c327e49916 Mon Sep 17 00:00:00 2001
From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Date: Wed, 20 Feb 2008 16:53:29 -0800
Subject: [PATCH] latencytop: change /proc task_struct access method
Change getting task_struct by get_proc_task() at read or write time,
and returns -ESRCH if get_proc_task() returns NULL.
This is same behavior as other /proc files.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
fs/proc/base.c | 40 ++++++++++++----------------------------
1 file changed, 12 insertions(+), 28 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 85e06e498078..91a1bd67ac1d 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -314,9 +314,12 @@ static int proc_pid_schedstat(struct task_struct *task, char *buffer)
static int lstats_show_proc(struct seq_file *m, void *v)
{
int i;
- struct task_struct *task = m->private;
- seq_puts(m, "Latency Top version : v0.1\n");
+ struct inode *inode = m->private;
+ struct task_struct *task = get_proc_task(inode);
+ if (!task)
+ return -ESRCH;
+ seq_puts(m, "Latency Top version : v0.1\n");
for (i = 0; i < 32; i++) {
if (task->latency_record[i].backtrace[0]) {
int q;
@@ -341,43 +344,24 @@ static int lstats_show_proc(struct seq_file *m, void *v)
}
}
+ put_task_struct(task);
return 0;
}
static int lstats_open(struct inode *inode, struct file *file)
{
- int ret;
- struct seq_file *m;
- struct task_struct *task = get_proc_task(inode);
-
- if (!task)
- return -ENOENT;
- ret = single_open(file, lstats_show_proc, NULL);
- if (!ret) {
- m = file->private_data;
- m->private = task;
- }
- return ret;
-}
-
-static int lstats_release(struct inode *inode, struct file *file)
-{
- struct seq_file *m = file->private_data;
- struct task_struct *task = m->private;
-
- put_task_struct(task);
- return single_release(inode, file);
+ return single_open(file, lstats_show_proc, inode);
}
static ssize_t lstats_write(struct file *file, const char __user *buf,
size_t count, loff_t *offs)
{
- struct seq_file *m;
- struct task_struct *task;
+ struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
- m = file->private_data;
- task = m->private;
+ if (!task)
+ return -ESRCH;
clear_all_latency_tracing(task);
+ put_task_struct(task);
return count;
}
@@ -387,7 +371,7 @@ static const struct file_operations proc_lstats_operations = {
.read = seq_read,
.write = lstats_write,
.llseek = seq_lseek,
- .release = lstats_release,
+ .release = single_release,
};
#endif