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/init.h>
  16 #include <linux/sched.h>
  17 #include <linux/module.h>
  18 #include <linux/bitops.h>
  19 #include <linux/smp_lock.h>
  20 #include <linux/mount.h>
  21
  22 #include "internal.h"
  23
  24 struct proc_dir_entry *proc_net, *proc_net_stat, *proc_bus, *proc_root_fs, *proc_root_driver;
  25
  26 #ifdef CONFIG_SYSCTL
  27 struct proc_dir_entry *proc_sys_root;
  28 #endif
  29
  30 static int proc_get_sb(struct file_system_type *fs_type,
  31         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
  32 {
  33         if (proc_mnt) {
  34                 /* Seed the root directory with a pid so it doesn't need
  35                  * to be special in base.c.  I would do this earlier but
  36                  * the only task alive when /proc is mounted the first time
  37                  * is the init_task and it doesn't have any pids.
  38                  */
  39                 struct proc_inode *ei;
  40                 ei = PROC_I(proc_mnt->mnt_sb->s_root->d_inode);
  41                 if (!ei->pid)
  42                         ei->pid = find_get_pid(1);
  43         }
  44         return get_sb_single(fs_type, flags, data, proc_fill_super, mnt);
  45 }
  46
  47 static struct file_system_type proc_fs_type = {
  48         .name           = "proc",
  49         .get_sb         = proc_get_sb,
  50         .kill_sb        = kill_anon_super,
  51 };
  52
  53 void __init proc_root_init(void)
  54 {
  55         int err = proc_init_inodecache();
  56         if (err)
  57                 return;
  58         err = register_filesystem(&proc_fs_type);
  59         if (err)
  60                 return;
  61         proc_mnt = kern_mount(&proc_fs_type);
  62         err = PTR_ERR(proc_mnt);
  63         if (IS_ERR(proc_mnt)) {
  64                 unregister_filesystem(&proc_fs_type);
  65                 return;
  66         }
  67         proc_misc_init();
  68         proc_net = proc_mkdir("net", NULL);
  69         proc_net_stat = proc_mkdir("net/stat", NULL);
  70
  71 #ifdef CONFIG_SYSVIPC
  72         proc_mkdir("sysvipc", NULL);
  73 #endif
  74 #ifdef CONFIG_SYSCTL
  75         proc_sys_root = proc_mkdir("sys", NULL);
  76 #endif
  77 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
  78         proc_mkdir("sys/fs", NULL);
  79         proc_mkdir("sys/fs/binfmt_misc", NULL);
  80 #endif
  81         proc_root_fs = proc_mkdir("fs", NULL);
  82         proc_root_driver = proc_mkdir("driver", NULL);
  83         proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
  84 #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
  85         /* just give it a mountpoint */
  86         proc_mkdir("openprom", NULL);
  87 #endif
  88         proc_tty_init();
  89 #ifdef CONFIG_PROC_DEVICETREE
  90         proc_device_tree_init();
  91 #endif
  92         proc_bus = proc_mkdir("bus", NULL);
  93 }
  94
  95 static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
  96 )
  97 {
  98         generic_fillattr(dentry->d_inode, stat);
  99         stat->nlink = proc_root.nlink + nr_processes();
 100         return 0;
 101 }
 102
 103 static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
 104 {
 105         if (!proc_lookup(dir, dentry, nd)) {
 106                 return NULL;
 107         }
 108
 109         return proc_pid_lookup(dir, dentry, nd);
 110 }
 111
 112 static int proc_root_readdir(struct file * filp,
 113         void * dirent, filldir_t filldir)
 114 {
 115         unsigned int nr = filp->f_pos;
 116         int ret;
 117
 118         lock_kernel();
 119
 120         if (nr < FIRST_PROCESS_ENTRY) {
 121                 int error = proc_readdir(filp, dirent, filldir);
 122                 if (error <= 0) {
 123                         unlock_kernel();
 124                         return error;
 125                 }
 126                 filp->f_pos = FIRST_PROCESS_ENTRY;
 127         }
 128         unlock_kernel();
 129
 130         ret = proc_pid_readdir(filp, dirent, filldir);
 131         return ret;
 132 }
 133
 134 /*
 135  * The root /proc directory is special, as it has the
 136  * <pid> directories. Thus we don't use the generic
 137  * directory handling functions for that..
 138  */
 139 static const struct file_operations proc_root_operations = {
 140         .read            = generic_read_dir,
 141         .readdir         = proc_root_readdir,
 142 };
 143
 144 /*
 145  * proc root can do almost nothing..
 146  */
 147 static const struct inode_operations proc_root_inode_operations = {
 148         .lookup         = proc_root_lookup,
 149         .getattr        = proc_root_getattr,
 150 };
 151
 152 /*
 153  * This is the root "inode" in the /proc tree..
 154  */
 155 struct proc_dir_entry proc_root = {
 156         .low_ino        = PROC_ROOT_INO,
 157         .namelen        = 5,
 158         .name           = "/proc",
 159         .mode           = S_IFDIR | S_IRUGO | S_IXUGO,
 160         .nlink          = 2,
 161         .proc_iops      = &proc_root_inode_operations,
 162         .proc_fops      = &proc_root_operations,
 163         .parent         = &proc_root,
 164 };
 165
 166 EXPORT_SYMBOL(proc_symlink);
 167 EXPORT_SYMBOL(proc_mkdir);
 168 EXPORT_SYMBOL(create_proc_entry);
 169 EXPORT_SYMBOL(remove_proc_entry);
 170 EXPORT_SYMBOL(proc_root);
 171 EXPORT_SYMBOL(proc_root_fs);
 172 EXPORT_SYMBOL(proc_net);
 173 EXPORT_SYMBOL(proc_net_stat);
 174 EXPORT_SYMBOL(proc_bus);
 175 EXPORT_SYMBOL(proc_root_driver);