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