Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc
[cris-mirror.git] / fs / proc / root.c
bloba9000e9cfee54ac804eb71e75d0b72bf989041ed
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 struct pid_namespace *ns;
33 ns = (struct pid_namespace *)data;
34 sb->s_fs_info = get_pid_ns(ns);
35 return set_anon_super(sb, NULL);
38 static struct dentry *proc_mount(struct file_system_type *fs_type,
39 int flags, const char *dev_name, void *data)
41 int err;
42 struct super_block *sb;
43 struct pid_namespace *ns;
44 struct proc_inode *ei;
46 if (flags & MS_KERNMOUNT)
47 ns = (struct pid_namespace *)data;
48 else
49 ns = current->nsproxy->pid_ns;
51 sb = sget(fs_type, proc_test_super, proc_set_super, ns);
52 if (IS_ERR(sb))
53 return ERR_CAST(sb);
55 if (!sb->s_root) {
56 sb->s_flags = flags;
57 err = proc_fill_super(sb);
58 if (err) {
59 deactivate_locked_super(sb);
60 return ERR_PTR(err);
63 sb->s_flags |= MS_ACTIVE;
66 ei = PROC_I(sb->s_root->d_inode);
67 if (!ei->pid) {
68 rcu_read_lock();
69 ei->pid = get_pid(find_pid_ns(1, ns));
70 rcu_read_unlock();
73 return dget(sb->s_root);
76 static void proc_kill_sb(struct super_block *sb)
78 struct pid_namespace *ns;
80 ns = (struct pid_namespace *)sb->s_fs_info;
81 kill_anon_super(sb);
82 put_pid_ns(ns);
85 static struct file_system_type proc_fs_type = {
86 .name = "proc",
87 .mount = proc_mount,
88 .kill_sb = proc_kill_sb,
91 void __init proc_root_init(void)
93 struct vfsmount *mnt;
94 int err;
96 proc_init_inodecache();
97 err = register_filesystem(&proc_fs_type);
98 if (err)
99 return;
100 mnt = kern_mount_data(&proc_fs_type, &init_pid_ns);
101 if (IS_ERR(mnt)) {
102 unregister_filesystem(&proc_fs_type);
103 return;
106 init_pid_ns.proc_mnt = mnt;
107 proc_symlink("mounts", NULL, "self/mounts");
109 proc_net_init();
111 #ifdef CONFIG_SYSVIPC
112 proc_mkdir("sysvipc", NULL);
113 #endif
114 proc_mkdir("fs", NULL);
115 proc_mkdir("driver", NULL);
116 proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
117 #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
118 /* just give it a mountpoint */
119 proc_mkdir("openprom", NULL);
120 #endif
121 proc_tty_init();
122 #ifdef CONFIG_PROC_DEVICETREE
123 proc_device_tree_init();
124 #endif
125 proc_mkdir("bus", NULL);
126 proc_sys_init();
129 static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
132 generic_fillattr(dentry->d_inode, stat);
133 stat->nlink = proc_root.nlink + nr_processes();
134 return 0;
137 static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
139 if (!proc_lookup(dir, dentry, nd)) {
140 return NULL;
143 return proc_pid_lookup(dir, dentry, nd);
146 static int proc_root_readdir(struct file * filp,
147 void * dirent, filldir_t filldir)
149 unsigned int nr = filp->f_pos;
150 int ret;
152 if (nr < FIRST_PROCESS_ENTRY) {
153 int error = proc_readdir(filp, dirent, filldir);
154 if (error <= 0)
155 return error;
156 filp->f_pos = FIRST_PROCESS_ENTRY;
159 ret = proc_pid_readdir(filp, dirent, filldir);
160 return ret;
164 * The root /proc directory is special, as it has the
165 * <pid> directories. Thus we don't use the generic
166 * directory handling functions for that..
168 static const struct file_operations proc_root_operations = {
169 .read = generic_read_dir,
170 .readdir = proc_root_readdir,
171 .llseek = default_llseek,
175 * proc root can do almost nothing..
177 static const struct inode_operations proc_root_inode_operations = {
178 .lookup = proc_root_lookup,
179 .getattr = proc_root_getattr,
183 * This is the root "inode" in the /proc tree..
185 struct proc_dir_entry proc_root = {
186 .low_ino = PROC_ROOT_INO,
187 .namelen = 5,
188 .name = "/proc",
189 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
190 .nlink = 2,
191 .count = ATOMIC_INIT(1),
192 .proc_iops = &proc_root_inode_operations,
193 .proc_fops = &proc_root_operations,
194 .parent = &proc_root,
197 int pid_ns_prepare_proc(struct pid_namespace *ns)
199 struct vfsmount *mnt;
201 mnt = kern_mount_data(&proc_fs_type, ns);
202 if (IS_ERR(mnt))
203 return PTR_ERR(mnt);
205 ns->proc_mnt = mnt;
206 return 0;
209 void pid_ns_release_proc(struct pid_namespace *ns)
211 mntput(ns->proc_mnt);