dcache: use a dispose list in select_parent
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / proc / root.c
blob03102d978180eba68469ef01d13ad25465f5b796
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 int err;
96 proc_init_inodecache();
97 err = register_filesystem(&proc_fs_type);
98 if (err)
99 return;
100 err = pid_ns_prepare_proc(&init_pid_ns);
101 if (err) {
102 unregister_filesystem(&proc_fs_type);
103 return;
106 proc_symlink("mounts", NULL, "self/mounts");
108 proc_net_init();
110 #ifdef CONFIG_SYSVIPC
111 proc_mkdir("sysvipc", NULL);
112 #endif
113 proc_mkdir("fs", NULL);
114 proc_mkdir("driver", NULL);
115 proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
116 #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
117 /* just give it a mountpoint */
118 proc_mkdir("openprom", NULL);
119 #endif
120 proc_tty_init();
121 #ifdef CONFIG_PROC_DEVICETREE
122 proc_device_tree_init();
123 #endif
124 proc_mkdir("bus", NULL);
125 proc_sys_init();
128 static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
131 generic_fillattr(dentry->d_inode, stat);
132 stat->nlink = proc_root.nlink + nr_processes();
133 return 0;
136 static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
138 if (!proc_lookup(dir, dentry, nd)) {
139 return NULL;
142 return proc_pid_lookup(dir, dentry, nd);
145 static int proc_root_readdir(struct file * filp,
146 void * dirent, filldir_t filldir)
148 unsigned int nr = filp->f_pos;
149 int ret;
151 if (nr < FIRST_PROCESS_ENTRY) {
152 int error = proc_readdir(filp, dirent, filldir);
153 if (error <= 0)
154 return error;
155 filp->f_pos = FIRST_PROCESS_ENTRY;
158 ret = proc_pid_readdir(filp, dirent, filldir);
159 return ret;
163 * The root /proc directory is special, as it has the
164 * <pid> directories. Thus we don't use the generic
165 * directory handling functions for that..
167 static const struct file_operations proc_root_operations = {
168 .read = generic_read_dir,
169 .readdir = proc_root_readdir,
170 .llseek = default_llseek,
174 * proc root can do almost nothing..
176 static const struct inode_operations proc_root_inode_operations = {
177 .lookup = proc_root_lookup,
178 .getattr = proc_root_getattr,
182 * This is the root "inode" in the /proc tree..
184 struct proc_dir_entry proc_root = {
185 .low_ino = PROC_ROOT_INO,
186 .namelen = 5,
187 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
188 .nlink = 2,
189 .count = ATOMIC_INIT(1),
190 .proc_iops = &proc_root_inode_operations,
191 .proc_fops = &proc_root_operations,
192 .parent = &proc_root,
193 .name = "/proc",
196 int pid_ns_prepare_proc(struct pid_namespace *ns)
198 struct vfsmount *mnt;
200 mnt = kern_mount_data(&proc_fs_type, ns);
201 if (IS_ERR(mnt))
202 return PTR_ERR(mnt);
204 ns->proc_mnt = mnt;
205 return 0;
208 void pid_ns_release_proc(struct pid_namespace *ns)
210 kern_unmount(ns->proc_mnt);