From 13d77c37cab2bb906022309e1e7182c327e49916 Mon Sep 17 00:00:00 2001 From: Hiroshi Shimamoto 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 Signed-off-by: Ingo Molnar --- 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 -- 2.20.1