blob: cf3046638b09406947198ba81ac4c93aa01ec7f8 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/init.h>
Al Viro914e2632006-10-18 13:55:46 -040016#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/module.h>
18#include <linux/bitops.h>
19#include <linux/smp_lock.h>
Eric W. Biedermanf6c7a1f2006-10-02 02:17:07 -070020#include <linux/mount.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021
Adrian Bunkfee781e2006-01-08 01:04:16 -080022#include "internal.h"
23
Eric W. Biederman457c4cb2007-09-12 12:01:34 +020024struct proc_dir_entry *proc_bus, *proc_root_fs, *proc_root_driver;
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
David Howells454e2392006-06-23 02:02:57 -070026static int proc_get_sb(struct file_system_type *fs_type,
27 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
Linus Torvalds1da177e2005-04-16 15:20:36 -070028{
Eric W. Biedermanf6c7a1f2006-10-02 02:17:07 -070029 if (proc_mnt) {
30 /* Seed the root directory with a pid so it doesn't need
31 * to be special in base.c. I would do this earlier but
32 * the only task alive when /proc is mounted the first time
33 * is the init_task and it doesn't have any pids.
34 */
35 struct proc_inode *ei;
36 ei = PROC_I(proc_mnt->mnt_sb->s_root->d_inode);
37 if (!ei->pid)
38 ei->pid = find_get_pid(1);
39 }
David Howells454e2392006-06-23 02:02:57 -070040 return get_sb_single(fs_type, flags, data, proc_fill_super, mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -070041}
42
43static struct file_system_type proc_fs_type = {
44 .name = "proc",
45 .get_sb = proc_get_sb,
46 .kill_sb = kill_anon_super,
47};
48
Linus Torvalds1da177e2005-04-16 15:20:36 -070049void __init proc_root_init(void)
50{
51 int err = proc_init_inodecache();
52 if (err)
53 return;
54 err = register_filesystem(&proc_fs_type);
55 if (err)
56 return;
57 proc_mnt = kern_mount(&proc_fs_type);
58 err = PTR_ERR(proc_mnt);
59 if (IS_ERR(proc_mnt)) {
60 unregister_filesystem(&proc_fs_type);
61 return;
62 }
63 proc_misc_init();
Eric W. Biederman457c4cb2007-09-12 12:01:34 +020064
65 proc_net_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67#ifdef CONFIG_SYSVIPC
68 proc_mkdir("sysvipc", NULL);
69#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 proc_root_fs = proc_mkdir("fs", NULL);
71 proc_root_driver = proc_mkdir("driver", NULL);
72 proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
73#if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
74 /* just give it a mountpoint */
75 proc_mkdir("openprom", NULL);
76#endif
77 proc_tty_init();
78#ifdef CONFIG_PROC_DEVICETREE
79 proc_device_tree_init();
80#endif
81 proc_bus = proc_mkdir("bus", NULL);
Eric W. Biederman77b14db2007-02-14 00:34:12 -080082 proc_sys_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -070083}
84
Al Viro76b61592006-02-08 14:37:40 -050085static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
86)
87{
88 generic_fillattr(dentry->d_inode, stat);
89 stat->nlink = proc_root.nlink + nr_processes();
90 return 0;
91}
92
Linus Torvalds1da177e2005-04-16 15:20:36 -070093static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
94{
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 if (!proc_lookup(dir, dentry, nd)) {
96 return NULL;
97 }
98
99 return proc_pid_lookup(dir, dentry, nd);
100}
101
102static int proc_root_readdir(struct file * filp,
103 void * dirent, filldir_t filldir)
104{
105 unsigned int nr = filp->f_pos;
106 int ret;
107
108 lock_kernel();
109
110 if (nr < FIRST_PROCESS_ENTRY) {
111 int error = proc_readdir(filp, dirent, filldir);
112 if (error <= 0) {
113 unlock_kernel();
114 return error;
115 }
116 filp->f_pos = FIRST_PROCESS_ENTRY;
117 }
118 unlock_kernel();
119
120 ret = proc_pid_readdir(filp, dirent, filldir);
121 return ret;
122}
123
124/*
125 * The root /proc directory is special, as it has the
126 * <pid> directories. Thus we don't use the generic
127 * directory handling functions for that..
128 */
Arjan van de Ven00977a52007-02-12 00:55:34 -0800129static const struct file_operations proc_root_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 .read = generic_read_dir,
131 .readdir = proc_root_readdir,
132};
133
134/*
135 * proc root can do almost nothing..
136 */
Arjan van de Venc5ef1c42007-02-12 00:55:40 -0800137static const struct inode_operations proc_root_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 .lookup = proc_root_lookup,
Al Viro76b61592006-02-08 14:37:40 -0500139 .getattr = proc_root_getattr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140};
141
142/*
143 * This is the root "inode" in the /proc tree..
144 */
145struct proc_dir_entry proc_root = {
146 .low_ino = PROC_ROOT_INO,
147 .namelen = 5,
148 .name = "/proc",
149 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
150 .nlink = 2,
151 .proc_iops = &proc_root_inode_operations,
152 .proc_fops = &proc_root_operations,
153 .parent = &proc_root,
154};
155
156EXPORT_SYMBOL(proc_symlink);
157EXPORT_SYMBOL(proc_mkdir);
158EXPORT_SYMBOL(create_proc_entry);
159EXPORT_SYMBOL(remove_proc_entry);
160EXPORT_SYMBOL(proc_root);
161EXPORT_SYMBOL(proc_root_fs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162EXPORT_SYMBOL(proc_bus);
163EXPORT_SYMBOL(proc_root_driver);