fs/proc/root.c

   1 /*
   2  *  linux/fs/proc/root.c
   3  *
   4  *  Copyright (C) 1991, 1992 Linus Torvalds
   5  *
   6  *  proc root directory handling functions
   7  */
   8
   9 #include <asm/uaccess.h>
  10
  11 #include <linux/errno.h>
  12 #include <linux/sched.h>
  13 #include <linux/proc_fs.h>
  14 #include <linux/stat.h>
  15 #include <linux/config.h>
  16 #include <linux/init.h>
  17 #include <asm/bitops.h>
  18
  19 struct proc_dir_entry *proc_net, *proc_bus, *proc_root_fs, *proc_root_driver;
  20
  21 #ifdef CONFIG_SYSCTL
  22 struct proc_dir_entry *proc_sys_root;
  23 #endif
  24
  25 void __init proc_root_init(void)
  26 {
  27         proc_misc_init();
  28         proc_net = proc_mkdir("net", 0);
  29 #ifdef CONFIG_SYSVIPC
  30         proc_mkdir("sysvipc", 0);
  31 #endif
  32 #ifdef CONFIG_SYSCTL
  33         proc_sys_root = proc_mkdir("sys", 0);
  34 #endif
  35         proc_root_fs = proc_mkdir("fs", 0);
  36         proc_root_driver = proc_mkdir("driver", 0);
  37 #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
  38         /* just give it a mountpoint */
  39         proc_mkdir("openprom", 0);
  40 #endif
  41         proc_tty_init();
  42 #ifdef CONFIG_PROC_DEVICETREE
  43         proc_device_tree_init();
  44 #endif
  45         proc_bus = proc_mkdir("bus", 0);
  46 }
  47
  48 static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry)
  49 {
  50         if (dir->i_ino == PROC_ROOT_INO) { /* check for safety... */
  51                 int nlink = proc_root.nlink;
  52
  53                 nlink += nr_threads;
  54
  55                 dir->i_nlink = nlink;
  56         }
  57
  58         if (!proc_lookup(dir, dentry))
  59                 return NULL;
  60
  61         return proc_pid_lookup(dir, dentry);
  62 }
  63
  64 static int proc_root_readdir(struct file * filp,
  65         void * dirent, filldir_t filldir)
  66 {
  67         unsigned int nr = filp->f_pos;
  68
  69         if (nr < FIRST_PROCESS_ENTRY) {
  70                 int error = proc_readdir(filp, dirent, filldir);
  71                 if (error <= 0)
  72                         return error;
  73                 filp->f_pos = FIRST_PROCESS_ENTRY;
  74         }
  75
  76         return proc_pid_readdir(filp, dirent, filldir);
  77 }
  78
  79 /*
  80  * The root /proc directory is special, as it has the
  81  * <pid> directories. Thus we don't use the generic
  82  * directory handling functions for that..
  83  */
  84 static struct file_operations proc_root_operations = {
  85         read:            generic_read_dir,
  86         readdir:         proc_root_readdir,
  87 };
  88
  89 /*
  90  * proc root can do almost nothing..
  91  */
  92 static struct inode_operations proc_root_inode_operations = {
  93         lookup:         proc_root_lookup,
  94 };
  95
  96 /*
  97  * This is the root "inode" in the /proc tree..
  98  */
  99 struct proc_dir_entry proc_root = {
 100         low_ino:        PROC_ROOT_INO,
 101         namelen:        5,
 102         name:           "/proc",
 103         mode:           S_IFDIR | S_IRUGO | S_IXUGO,
 104         nlink:          2,
 105         proc_iops:      &proc_root_inode_operations,
 106         proc_fops:      &proc_root_operations,
 107         parent:         &proc_root,
 108 };