hfs: get rid of hfs_sync_super
[linux/fpc-iii.git] / fs / proc / root.c
blob9a2d9fd7cadd2acde77a4e00615f9bbafefc8d96
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>
21 #include <linux/parser.h>
23 #include "internal.h"
25 static int proc_test_super(struct super_block *sb, void *data)
27 return sb->s_fs_info == data;
30 static int proc_set_super(struct super_block *sb, void *data)
32 int err = set_anon_super(sb, NULL);
33 if (!err) {
34 struct pid_namespace *ns = (struct pid_namespace *)data;
35 sb->s_fs_info = get_pid_ns(ns);
37 return err;
40 enum {
41 Opt_gid, Opt_hidepid, Opt_err,
44 static const match_table_t tokens = {
45 {Opt_hidepid, "hidepid=%u"},
46 {Opt_gid, "gid=%u"},
47 {Opt_err, NULL},
50 static int proc_parse_options(char *options, struct pid_namespace *pid)
52 char *p;
53 substring_t args[MAX_OPT_ARGS];
54 int option;
56 if (!options)
57 return 1;
59 while ((p = strsep(&options, ",")) != NULL) {
60 int token;
61 if (!*p)
62 continue;
64 args[0].to = args[0].from = 0;
65 token = match_token(p, tokens, args);
66 switch (token) {
67 case Opt_gid:
68 if (match_int(&args[0], &option))
69 return 0;
70 pid->pid_gid = make_kgid(current_user_ns(), option);
71 break;
72 case Opt_hidepid:
73 if (match_int(&args[0], &option))
74 return 0;
75 if (option < 0 || option > 2) {
76 pr_err("proc: hidepid value must be between 0 and 2.\n");
77 return 0;
79 pid->hide_pid = option;
80 break;
81 default:
82 pr_err("proc: unrecognized mount option \"%s\" "
83 "or missing value\n", p);
84 return 0;
88 return 1;
91 int proc_remount(struct super_block *sb, int *flags, char *data)
93 struct pid_namespace *pid = sb->s_fs_info;
94 return !proc_parse_options(data, pid);
97 static struct dentry *proc_mount(struct file_system_type *fs_type,
98 int flags, const char *dev_name, void *data)
100 int err;
101 struct super_block *sb;
102 struct pid_namespace *ns;
103 struct proc_inode *ei;
104 char *options;
106 if (flags & MS_KERNMOUNT) {
107 ns = (struct pid_namespace *)data;
108 options = NULL;
109 } else {
110 ns = current->nsproxy->pid_ns;
111 options = data;
114 sb = sget(fs_type, proc_test_super, proc_set_super, flags, ns);
115 if (IS_ERR(sb))
116 return ERR_CAST(sb);
118 if (!proc_parse_options(options, ns)) {
119 deactivate_locked_super(sb);
120 return ERR_PTR(-EINVAL);
123 if (!sb->s_root) {
124 err = proc_fill_super(sb);
125 if (err) {
126 deactivate_locked_super(sb);
127 return ERR_PTR(err);
130 sb->s_flags |= MS_ACTIVE;
133 ei = PROC_I(sb->s_root->d_inode);
134 if (!ei->pid) {
135 rcu_read_lock();
136 ei->pid = get_pid(find_pid_ns(1, ns));
137 rcu_read_unlock();
140 return dget(sb->s_root);
143 static void proc_kill_sb(struct super_block *sb)
145 struct pid_namespace *ns;
147 ns = (struct pid_namespace *)sb->s_fs_info;
148 kill_anon_super(sb);
149 put_pid_ns(ns);
152 static struct file_system_type proc_fs_type = {
153 .name = "proc",
154 .mount = proc_mount,
155 .kill_sb = proc_kill_sb,
158 void __init proc_root_init(void)
160 int err;
162 proc_init_inodecache();
163 err = register_filesystem(&proc_fs_type);
164 if (err)
165 return;
166 err = pid_ns_prepare_proc(&init_pid_ns);
167 if (err) {
168 unregister_filesystem(&proc_fs_type);
169 return;
172 proc_symlink("mounts", NULL, "self/mounts");
174 proc_net_init();
176 #ifdef CONFIG_SYSVIPC
177 proc_mkdir("sysvipc", NULL);
178 #endif
179 proc_mkdir("fs", NULL);
180 proc_mkdir("driver", NULL);
181 proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
182 #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
183 /* just give it a mountpoint */
184 proc_mkdir("openprom", NULL);
185 #endif
186 proc_tty_init();
187 #ifdef CONFIG_PROC_DEVICETREE
188 proc_device_tree_init();
189 #endif
190 proc_mkdir("bus", NULL);
191 proc_sys_init();
194 static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
197 generic_fillattr(dentry->d_inode, stat);
198 stat->nlink = proc_root.nlink + nr_processes();
199 return 0;
202 static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
204 if (!proc_lookup(dir, dentry, flags))
205 return NULL;
207 return proc_pid_lookup(dir, dentry, flags);
210 static int proc_root_readdir(struct file * filp,
211 void * dirent, filldir_t filldir)
213 unsigned int nr = filp->f_pos;
214 int ret;
216 if (nr < FIRST_PROCESS_ENTRY) {
217 int error = proc_readdir(filp, dirent, filldir);
218 if (error <= 0)
219 return error;
220 filp->f_pos = FIRST_PROCESS_ENTRY;
223 ret = proc_pid_readdir(filp, dirent, filldir);
224 return ret;
228 * The root /proc directory is special, as it has the
229 * <pid> directories. Thus we don't use the generic
230 * directory handling functions for that..
232 static const struct file_operations proc_root_operations = {
233 .read = generic_read_dir,
234 .readdir = proc_root_readdir,
235 .llseek = default_llseek,
239 * proc root can do almost nothing..
241 static const struct inode_operations proc_root_inode_operations = {
242 .lookup = proc_root_lookup,
243 .getattr = proc_root_getattr,
247 * This is the root "inode" in the /proc tree..
249 struct proc_dir_entry proc_root = {
250 .low_ino = PROC_ROOT_INO,
251 .namelen = 5,
252 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
253 .nlink = 2,
254 .count = ATOMIC_INIT(1),
255 .proc_iops = &proc_root_inode_operations,
256 .proc_fops = &proc_root_operations,
257 .parent = &proc_root,
258 .name = "/proc",
261 int pid_ns_prepare_proc(struct pid_namespace *ns)
263 struct vfsmount *mnt;
265 mnt = kern_mount_data(&proc_fs_type, ns);
266 if (IS_ERR(mnt))
267 return PTR_ERR(mnt);
269 ns->proc_mnt = mnt;
270 return 0;
273 void pid_ns_release_proc(struct pid_namespace *ns)
275 kern_unmount(ns->proc_mnt);