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* linux/fs/proc/root.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* proc root directory handling functions
*/
#include <asm/uaccess.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/config.h>
#include <linux/init.h>
#include <asm/bitops.h>
struct proc_dir_entry *proc_net, *proc_bus, *proc_root_fs, *proc_root_driver;
#ifdef CONFIG_SYSCTL
struct proc_dir_entry *proc_sys_root;
#endif
/*
* /proc/self:
*/
static int proc_self_readlink(struct dentry *dentry, char *buffer, int buflen)
{
char tmp[30];
sprintf(tmp, "%d", current->pid);
return vfs_readlink(dentry,buffer,buflen,tmp);
}
static int proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
{
char tmp[30];
sprintf(tmp, "%d", current->pid);
return vfs_follow_link(nd,tmp);
}
static struct inode_operations proc_self_inode_operations = {
readlink: proc_self_readlink,
follow_link: proc_self_follow_link
};
static struct proc_dir_entry proc_root_self = {
0, 4, "self",
S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO, 1, 0, 0,
64, &proc_self_inode_operations,
};
void __init proc_root_init(void)
{
proc_misc_init();
proc_register(&proc_root, &proc_root_self);
proc_net = proc_mkdir("net", 0);
#ifdef CONFIG_SYSVIPC
proc_mkdir("sysvipc", 0);
#endif
#ifdef CONFIG_SYSCTL
proc_sys_root = proc_mkdir("sys", 0);
#endif
proc_root_fs = proc_mkdir("fs", 0);
proc_root_driver = proc_mkdir("driver", 0);
#if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
/* just give it a mountpoint */
proc_mkdir("openprom", 0);
#endif
proc_tty_init();
#ifdef CONFIG_PROC_DEVICETREE
proc_device_tree_init();
#endif
proc_bus = proc_mkdir("bus", 0);
}
static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry)
{
struct task_struct *p;
if (dir->i_ino == PROC_ROOT_INO) { /* check for safety... */
extern unsigned long total_forks;
static int last_timestamp = 0;
/*
* this one can be a serious 'ps' performance problem if
* there are many threads running - thus we do 'lazy'
* link-recalculation - we change it only if the number
* of threads has increased.
*/
if (total_forks != last_timestamp) {
int nlink = proc_root.nlink;
read_lock(&tasklist_lock);
last_timestamp = total_forks;
for_each_task(p)
nlink++;
read_unlock(&tasklist_lock);
/*
* subtract the # of idle threads which
* do not show up in /proc:
*/
dir->i_nlink = nlink - smp_num_cpus;
}
}
if (!proc_lookup(dir, dentry))
return NULL;
return proc_pid_lookup(dir, dentry);
}
static int proc_root_readdir(struct file * filp,
void * dirent, filldir_t filldir)
{
unsigned int nr = filp->f_pos;
if (nr < FIRST_PROCESS_ENTRY) {
int error = proc_readdir(filp, dirent, filldir);
if (error <= 0)
return error;
filp->f_pos = FIRST_PROCESS_ENTRY;
}
return proc_pid_readdir(filp, dirent, filldir);
}
/*
* The root /proc directory is special, as it has the
* <pid> directories. Thus we don't use the generic
* directory handling functions for that..
*/
static struct file_operations proc_root_operations = {
readdir: proc_root_readdir,
};
/*
* proc root can do almost nothing..
*/
static struct inode_operations proc_root_inode_operations = {
lookup: proc_root_lookup,
};
/*
* This is the root "inode" in the /proc tree..
*/
struct proc_dir_entry proc_root = {
PROC_ROOT_INO, 5, "/proc",
S_IFDIR | S_IRUGO | S_IXUGO, 2, 0, 0,
0, &proc_root_inode_operations, &proc_root_operations,
NULL, NULL,
NULL,
&proc_root, NULL
};
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