Add support for Future Electronics FWBADAPT-7WVGA expansion board
[wandboard.git] / fs / proc / root.c
blobd6c3b416529b9709f2db526be706dbb415902ea3
1 /*
2 * linux/fs/proc/root.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
6 * proc root directory handling functions
7 */
9 #include <asm/uaccess.h>
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/mount.h>
20 #include <linux/pid_namespace.h>
22 #include "internal.h"
24 static int proc_test_super(struct super_block *sb, void *data)
26 return sb->s_fs_info == data;
29 static int proc_set_super(struct super_block *sb, void *data)
31 int err = set_anon_super(sb, NULL);
32 if (!err) {
33 struct pid_namespace *ns = (struct pid_namespace *)data;
34 sb->s_fs_info = get_pid_ns(ns);
36 return err;
39 static struct dentry *proc_mount(struct file_system_type *fs_type,
40 int flags, const char *dev_name, void *data)
42 int err;
43 struct super_block *sb;
44 struct pid_namespace *ns;
45 struct proc_inode *ei;
47 if (flags & MS_KERNMOUNT)
48 ns = (struct pid_namespace *)data;
49 else
50 ns = current->nsproxy->pid_ns;
52 sb = sget(fs_type, proc_test_super, proc_set_super, ns);
53 if (IS_ERR(sb))
54 return ERR_CAST(sb);
56 if (!sb->s_root) {
57 sb->s_flags = flags;
58 err = proc_fill_super(sb);
59 if (err) {
60 deactivate_locked_super(sb);
61 return ERR_PTR(err);
64 sb->s_flags |= MS_ACTIVE;
67 ei = PROC_I(sb->s_root->d_inode);
68 if (!ei->pid) {
69 rcu_read_lock();
70 ei->pid = get_pid(find_pid_ns(1, ns));
71 rcu_read_unlock();
74 return dget(sb->s_root);
77 static void proc_kill_sb(struct super_block *sb)
79 struct pid_namespace *ns;
81 ns = (struct pid_namespace *)sb->s_fs_info;
82 kill_anon_super(sb);
83 put_pid_ns(ns);
86 static struct file_system_type proc_fs_type = {
87 .name = "proc",
88 .mount = proc_mount,
89 .kill_sb = proc_kill_sb,
92 void __init proc_root_init(void)
94 struct vfsmount *mnt;
95 int err;
97 proc_init_inodecache();
98 err = register_filesystem(&proc_fs_type);
99 if (err)
100 return;
101 mnt = kern_mount_data(&proc_fs_type, &init_pid_ns);
102 if (IS_ERR(mnt)) {
103 unregister_filesystem(&proc_fs_type);
104 return;
107 init_pid_ns.proc_mnt = mnt;
108 proc_symlink("mounts", NULL, "self/mounts");
110 proc_net_init();
112 #ifdef CONFIG_SYSVIPC
113 proc_mkdir("sysvipc", NULL);
114 #endif
115 proc_mkdir("fs", NULL);
116 proc_mkdir("driver", NULL);
117 proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
118 #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
119 /* just give it a mountpoint */
120 proc_mkdir("openprom", NULL);
121 #endif
122 proc_tty_init();
123 #ifdef CONFIG_PROC_DEVICETREE
124 proc_device_tree_init();
125 #endif
126 proc_mkdir("bus", NULL);
127 proc_sys_init();
130 static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
133 generic_fillattr(dentry->d_inode, stat);
134 stat->nlink = proc_root.nlink + nr_processes();
135 return 0;
138 static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
140 if (!proc_lookup(dir, dentry, nd)) {
141 return NULL;
144 return proc_pid_lookup(dir, dentry, nd);
147 static int proc_root_readdir(struct file * filp,
148 void * dirent, filldir_t filldir)
150 unsigned int nr = filp->f_pos;
151 int ret;
153 if (nr < FIRST_PROCESS_ENTRY) {
154 int error = proc_readdir(filp, dirent, filldir);
155 if (error <= 0)
156 return error;
157 filp->f_pos = FIRST_PROCESS_ENTRY;
160 ret = proc_pid_readdir(filp, dirent, filldir);
161 return ret;
165 * The root /proc directory is special, as it has the
166 * <pid> directories. Thus we don't use the generic
167 * directory handling functions for that..
169 static const struct file_operations proc_root_operations = {
170 .read = generic_read_dir,
171 .readdir = proc_root_readdir,
172 .llseek = default_llseek,
176 * proc root can do almost nothing..
178 static const struct inode_operations proc_root_inode_operations = {
179 .lookup = proc_root_lookup,
180 .getattr = proc_root_getattr,
184 * This is the root "inode" in the /proc tree..
186 struct proc_dir_entry proc_root = {
187 .low_ino = PROC_ROOT_INO,
188 .namelen = 5,
189 .name = "/proc",
190 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
191 .nlink = 2,
192 .count = ATOMIC_INIT(1),
193 .proc_iops = &proc_root_inode_operations,
194 .proc_fops = &proc_root_operations,
195 .parent = &proc_root,
198 int pid_ns_prepare_proc(struct pid_namespace *ns)
200 struct vfsmount *mnt;
202 mnt = kern_mount_data(&proc_fs_type, ns);
203 if (IS_ERR(mnt))
204 return PTR_ERR(mnt);
206 ns->proc_mnt = mnt;
207 return 0;
210 void pid_ns_release_proc(struct pid_namespace *ns)
212 mntput(ns->proc_mnt);