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/time.h>
  13 #include <linux/proc_fs.h>
  14 #include <linux/stat.h>
  15 #include <linux/config.h>
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/bitops.h>
  19 #include <linux/smp_lock.h>
  20
  21 #include "internal.h"
  22
  23 struct proc_dir_entry *proc_net, *proc_net_stat, *proc_bus, *proc_root_fs, *proc_root_driver;
  24
  25 #ifdef CONFIG_SYSCTL
  26 struct proc_dir_entry *proc_sys_root;
  27 #endif
  28
  29 static struct super_block *proc_get_sb(struct file_system_type *fs_type,
  30         int flags, const char *dev_name, void *data)
  31 {
  32         return get_sb_single(fs_type, flags, data, proc_fill_super);
  33 }
  34
  35 static struct file_system_type proc_fs_type = {
  36         .name           = "proc",
  37         .get_sb         = proc_get_sb,
  38         .kill_sb        = kill_anon_super,
  39 };
  40
  41 void __init proc_root_init(void)
  42 {
  43         int err = proc_init_inodecache();
  44         if (err)
  45                 return;
  46         err = register_filesystem(&proc_fs_type);
  47         if (err)
  48                 return;
  49         proc_mnt = kern_mount(&proc_fs_type);
  50         err = PTR_ERR(proc_mnt);
  51         if (IS_ERR(proc_mnt)) {
  52                 unregister_filesystem(&proc_fs_type);
  53                 return;
  54         }
  55         proc_misc_init();
  56         proc_net = proc_mkdir("net", NULL);
  57         proc_net_stat = proc_mkdir("net/stat", NULL);
  58
  59 #ifdef CONFIG_SYSVIPC
  60         proc_mkdir("sysvipc", NULL);
  61 #endif
  62 #ifdef CONFIG_SYSCTL
  63         proc_sys_root = proc_mkdir("sys", NULL);
  64 #endif
  65 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
  66         proc_mkdir("sys/fs", NULL);
  67         proc_mkdir("sys/fs/binfmt_misc", NULL);
  68 #endif
  69         proc_root_fs = proc_mkdir("fs", NULL);
  70         proc_root_driver = proc_mkdir("driver", NULL);
  71         proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
  72 #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
  73         /* just give it a mountpoint */
  74         proc_mkdir("openprom", NULL);
  75 #endif
  76         proc_tty_init();
  77 #ifdef CONFIG_PROC_DEVICETREE
  78         proc_device_tree_init();
  79 #endif
  80         proc_bus = proc_mkdir("bus", NULL);
  81 }
  82
  83 static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
  84 {
  85         /*
  86          * nr_threads is actually protected by the tasklist_lock;
  87          * however, it's conventional to do reads, especially for
  88          * reporting, without any locking whatsoever.
  89          */
  90         if (dir->i_ino == PROC_ROOT_INO) /* check for safety... */
  91                 dir->i_nlink = proc_root.nlink + nr_threads;
  92
  93         if (!proc_lookup(dir, dentry, nd)) {
  94                 return NULL;
  95         }
  96
  97         return proc_pid_lookup(dir, dentry, nd);
  98 }
  99
 100 static int proc_root_readdir(struct file * filp,
 101         void * dirent, filldir_t filldir)
 102 {
 103         unsigned int nr = filp->f_pos;
 104         int ret;
 105
 106         lock_kernel();
 107
 108         if (nr < FIRST_PROCESS_ENTRY) {
 109                 int error = proc_readdir(filp, dirent, filldir);
 110                 if (error <= 0) {
 111                         unlock_kernel();
 112                         return error;
 113                 }
 114                 filp->f_pos = FIRST_PROCESS_ENTRY;
 115         }
 116         unlock_kernel();
 117
 118         ret = proc_pid_readdir(filp, dirent, filldir);
 119         return ret;
 120 }
 121
 122 /*
 123  * The root /proc directory is special, as it has the
 124  * <pid> directories. Thus we don't use the generic
 125  * directory handling functions for that..
 126  */
 127 static struct file_operations proc_root_operations = {
 128         .read            = generic_read_dir,
 129         .readdir         = proc_root_readdir,
 130 };
 131
 132 /*
 133  * proc root can do almost nothing..
 134  */
 135 static struct inode_operations proc_root_inode_operations = {
 136         .lookup         = proc_root_lookup,
 137 };
 138
 139 /*
 140  * This is the root "inode" in the /proc tree..
 141  */
 142 struct proc_dir_entry proc_root = {
 143         .low_ino        = PROC_ROOT_INO,
 144         .namelen        = 5,
 145         .name           = "/proc",
 146         .mode           = S_IFDIR | S_IRUGO | S_IXUGO,
 147         .nlink          = 2,
 148         .proc_iops      = &proc_root_inode_operations,
 149         .proc_fops      = &proc_root_operations,
 150         .parent         = &proc_root,
 151 };
 152
 153 EXPORT_SYMBOL(proc_symlink);
 154 EXPORT_SYMBOL(proc_mkdir);
 155 EXPORT_SYMBOL(create_proc_entry);
 156 EXPORT_SYMBOL(remove_proc_entry);
 157 EXPORT_SYMBOL(proc_root);
 158 EXPORT_SYMBOL(proc_root_fs);
 159 EXPORT_SYMBOL(proc_net);
 160 EXPORT_SYMBOL(proc_net_stat);
 161 EXPORT_SYMBOL(proc_bus);
 162 EXPORT_SYMBOL(proc_root_driver);