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 <linux/module.h>
18 #include <asm/bitops.h>
19 
20 struct proc_dir_entry *proc_net, *proc_net_stat, *proc_bus, *proc_root_fs, *proc_root_driver;
21 
22 #ifdef CONFIG_SYSCTL
23 struct proc_dir_entry *proc_sys_root;
24 #endif
25 
26 static DECLARE_FSTYPE(proc_fs_type, "proc", proc_read_super, FS_SINGLE);
27 
proc_root_init(void)28 void __init proc_root_init(void)
29 {
30 	int err = register_filesystem(&proc_fs_type);
31 	if (err)
32 		return;
33 	proc_mnt = kern_mount(&proc_fs_type);
34 	err = PTR_ERR(proc_mnt);
35 	if (IS_ERR(proc_mnt)) {
36 		unregister_filesystem(&proc_fs_type);
37 		return;
38 	}
39 	proc_misc_init();
40 	proc_net = proc_mkdir("net", 0);
41 	proc_net_stat = proc_mkdir("net/stat", NULL);
42 
43 #ifdef CONFIG_SYSVIPC
44 	proc_mkdir("sysvipc", 0);
45 #endif
46 #ifdef CONFIG_SYSCTL
47 	proc_sys_root = proc_mkdir("sys", 0);
48 #endif
49 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
50 	proc_mkdir("sys/fs", 0);
51 	proc_mkdir("sys/fs/binfmt_misc", 0);
52 #endif
53 	proc_root_fs = proc_mkdir("fs", 0);
54 	proc_root_driver = proc_mkdir("driver", 0);
55 #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
56 	/* just give it a mountpoint */
57 	proc_mkdir("openprom", 0);
58 #endif
59 	proc_tty_init();
60 #ifdef CONFIG_PROC_DEVICETREE
61 	proc_device_tree_init();
62 #endif
63 #ifdef CONFIG_PPC_ISERIES
64 	iSeries_proc_create();
65 #endif
66 #ifdef CONFIG_PPC64
67 	proc_ppc64_init();
68 #endif
69 #ifdef CONFIG_PPC_RTAS
70 	proc_rtas_init();
71 #endif
72 	proc_bus = proc_mkdir("bus", 0);
73 }
74 
proc_root_lookup(struct inode * dir,struct dentry * dentry)75 static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry)
76 {
77 	if (dir->i_ino == PROC_ROOT_INO) { /* check for safety... */
78 		int nlink = proc_root.nlink;
79 
80 		nlink += nr_threads;
81 
82 		dir->i_nlink = nlink;
83 	}
84 
85 	if (!proc_lookup(dir, dentry))
86 		return NULL;
87 
88 	return proc_pid_lookup(dir, dentry);
89 }
90 
proc_root_readdir(struct file * filp,void * dirent,filldir_t filldir)91 static int proc_root_readdir(struct file * filp,
92 	void * dirent, filldir_t filldir)
93 {
94 	unsigned int nr = filp->f_pos;
95 
96 	if (nr < FIRST_PROCESS_ENTRY) {
97 		int error = proc_readdir(filp, dirent, filldir);
98 		if (error <= 0)
99 			return error;
100 		filp->f_pos = FIRST_PROCESS_ENTRY;
101 	}
102 
103 	return proc_pid_readdir(filp, dirent, filldir);
104 }
105 
106 /*
107  * The root /proc directory is special, as it has the
108  * <pid> directories. Thus we don't use the generic
109  * directory handling functions for that..
110  */
111 static struct file_operations proc_root_operations = {
112 	read:		 generic_read_dir,
113 	readdir:	 proc_root_readdir,
114 };
115 
116 /*
117  * proc root can do almost nothing..
118  */
119 static struct inode_operations proc_root_inode_operations = {
120 	lookup:		proc_root_lookup,
121 };
122 
123 /*
124  * This is the root "inode" in the /proc tree..
125  */
126 struct proc_dir_entry proc_root = {
127 	low_ino:	PROC_ROOT_INO,
128 	namelen:	5,
129 	name:		"/proc",
130 	mode:		S_IFDIR | S_IRUGO | S_IXUGO,
131 	nlink:		2,
132 	proc_iops:	&proc_root_inode_operations,
133 	proc_fops:	&proc_root_operations,
134 	parent:		&proc_root,
135 };
136 
137 #ifdef CONFIG_SYSCTL
138 EXPORT_SYMBOL(proc_sys_root);
139 #endif
140 EXPORT_SYMBOL(proc_symlink);
141 EXPORT_SYMBOL(proc_mknod);
142 EXPORT_SYMBOL(proc_mkdir);
143 EXPORT_SYMBOL(create_proc_entry);
144 EXPORT_SYMBOL(remove_proc_entry);
145 EXPORT_SYMBOL(proc_root);
146 EXPORT_SYMBOL(proc_root_fs);
147 EXPORT_SYMBOL(proc_net);
148 EXPORT_SYMBOL(proc_net_stat);
149 EXPORT_SYMBOL(proc_bus);
150 EXPORT_SYMBOL(proc_root_driver);
151