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Commit | Line | Data |
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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/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 | ||
22 | #include "internal.h" | |
23 | ||
24 | static int proc_test_super(struct super_block *sb, void *data) | |
25 | { | |
26 | return sb->s_fs_info == data; | |
27 | } | |
28 | ||
29 | static int proc_set_super(struct super_block *sb, void *data) | |
30 | { | |
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); | |
35 | } | |
36 | return err; | |
37 | } | |
38 | ||
39 | static struct dentry *proc_mount(struct file_system_type *fs_type, | |
40 | int flags, const char *dev_name, void *data) | |
41 | { | |
42 | int err; | |
43 | struct super_block *sb; | |
44 | struct pid_namespace *ns; | |
45 | struct proc_inode *ei; | |
46 | ||
47 | if (flags & MS_KERNMOUNT) | |
48 | ns = (struct pid_namespace *)data; | |
49 | else | |
50 | ns = current->nsproxy->pid_ns; | |
51 | ||
52 | sb = sget(fs_type, proc_test_super, proc_set_super, ns); | |
53 | if (IS_ERR(sb)) | |
54 | return ERR_CAST(sb); | |
55 | ||
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); | |
62 | } | |
63 | ||
64 | sb->s_flags |= MS_ACTIVE; | |
65 | } | |
66 | ||
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(); | |
72 | } | |
73 | ||
74 | return dget(sb->s_root); | |
75 | } | |
76 | ||
77 | static void proc_kill_sb(struct super_block *sb) | |
78 | { | |
79 | struct pid_namespace *ns; | |
80 | ||
81 | ns = (struct pid_namespace *)sb->s_fs_info; | |
82 | kill_anon_super(sb); | |
83 | put_pid_ns(ns); | |
84 | } | |
85 | ||
86 | static struct file_system_type proc_fs_type = { | |
87 | .name = "proc", | |
88 | .mount = proc_mount, | |
89 | .kill_sb = proc_kill_sb, | |
90 | }; | |
91 | ||
92 | void __init proc_root_init(void) | |
93 | { | |
94 | struct vfsmount *mnt; | |
95 | int err; | |
96 | ||
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; | |
105 | } | |
106 | ||
107 | init_pid_ns.proc_mnt = mnt; | |
108 | proc_symlink("mounts", NULL, "self/mounts"); | |
109 | ||
110 | proc_net_init(); | |
111 | ||
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(); | |
128 | } | |
129 | ||
130 | static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat | |
131 | ) | |
132 | { | |
133 | generic_fillattr(dentry->d_inode, stat); | |
134 | stat->nlink = proc_root.nlink + nr_processes(); | |
135 | return 0; | |
136 | } | |
137 | ||
138 | static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd) | |
139 | { | |
140 | if (!proc_lookup(dir, dentry, nd)) { | |
141 | return NULL; | |
142 | } | |
143 | ||
144 | return proc_pid_lookup(dir, dentry, nd); | |
145 | } | |
146 | ||
147 | static int proc_root_readdir(struct file * filp, | |
148 | void * dirent, filldir_t filldir) | |
149 | { | |
150 | unsigned int nr = filp->f_pos; | |
151 | int ret; | |
152 | ||
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; | |
158 | } | |
159 | ||
160 | ret = proc_pid_readdir(filp, dirent, filldir); | |
161 | return ret; | |
162 | } | |
163 | ||
164 | /* | |
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.. | |
168 | */ | |
169 | static const struct file_operations proc_root_operations = { | |
170 | .read = generic_read_dir, | |
171 | .readdir = proc_root_readdir, | |
172 | .llseek = default_llseek, | |
173 | }; | |
174 | ||
175 | /* | |
176 | * proc root can do almost nothing.. | |
177 | */ | |
178 | static const struct inode_operations proc_root_inode_operations = { | |
179 | .lookup = proc_root_lookup, | |
180 | .getattr = proc_root_getattr, | |
181 | }; | |
182 | ||
183 | /* | |
184 | * This is the root "inode" in the /proc tree.. | |
185 | */ | |
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, | |
196 | }; | |
197 | ||
198 | int pid_ns_prepare_proc(struct pid_namespace *ns) | |
199 | { | |
200 | struct vfsmount *mnt; | |
201 | ||
202 | mnt = kern_mount_data(&proc_fs_type, ns); | |
203 | if (IS_ERR(mnt)) | |
204 | return PTR_ERR(mnt); | |
205 | ||
206 | ns->proc_mnt = mnt; | |
207 | return 0; | |
208 | } | |
209 | ||
210 | void pid_ns_release_proc(struct pid_namespace *ns) | |
211 | { | |
212 | mntput(ns->proc_mnt); | |
213 | } |