linux-imx

/*

 *  inode.c - part of tracefs, a pseudo file system for activating tracing

 *

 * Based on debugfs by: Greg Kroah-Hartman <greg@kroah.com>

 *

 *  Copyright (C) 2014 Red Hat Inc, author: Steven Rostedt <srostedt@redhat.com>

 *

 *  This program is free software; you can redistribute it and/or

 *  modify it under the terms of the GNU General Public License version

 *  2 as published by the Free Software Foundation.

 *

 * tracefs is the file system that is used by the tracing infrastructure.

 *

 */

​

#include <linux/module.h>

#include <linux/fs.h>

#include <linux/mount.h>

#include <linux/kobject.h>

#include <linux/namei.h>

#include <linux/tracefs.h>

#include <linux/fsnotify.h>

#include <linux/seq_file.h>

#include <linux/parser.h>

#include <linux/magic.h>

#include <linux/slab.h>

​

#define TRACEFS_DEFAULT_MODE    0700

​

static struct vfsmount *tracefs_mount;

static int tracefs_mount_count;

static bool tracefs_registered;

​

static ssize_t default_read_file(struct file *file, char __user *buf,

                 size_t count, loff_t *ppos)

{

    return 0;

}

​

static ssize_t default_write_file(struct file *file, const char __user *buf,

                   size_t count, loff_t *ppos)

{

    return count;

}

​

static const struct file_operations tracefs_file_operations = {

    .read =     default_read_file,

    .write =    default_write_file,

    .open =     simple_open,

    .llseek =   noop_llseek,

};

​

static struct tracefs_dir_ops {

    int (*mkdir)(const char *name);

    int (*rmdir)(const char *name);

} tracefs_ops __ro_after_init;

​

static char *get_dname(struct dentry *dentry)

{

    const char *dname;

    char *name;

    int len = dentry->d_name.len;

​