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Commit | Line | Data |
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1da177e4 LT |
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> | |
1da177e4 | 15 | #include <linux/init.h> |
914e2637 | 16 | #include <linux/sched.h> |
1da177e4 LT |
17 | #include <linux/module.h> |
18 | #include <linux/bitops.h> | |
f6c7a1f3 | 19 | #include <linux/mount.h> |
07543f5c | 20 | #include <linux/pid_namespace.h> |
1da177e4 | 21 | |
fee781e6 AB |
22 | #include "internal.h" |
23 | ||
07543f5c PE |
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 | struct pid_namespace *ns; | |
32 | ||
33 | ns = (struct pid_namespace *)data; | |
34 | sb->s_fs_info = get_pid_ns(ns); | |
35 | return set_anon_super(sb, NULL); | |
36 | } | |
37 | ||
454e2398 DH |
38 | static int proc_get_sb(struct file_system_type *fs_type, |
39 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) | |
1da177e4 | 40 | { |
07543f5c PE |
41 | int err; |
42 | struct super_block *sb; | |
43 | struct pid_namespace *ns; | |
44 | struct proc_inode *ei; | |
45 | ||
f6c7a1f3 EB |
46 | if (proc_mnt) { |
47 | /* Seed the root directory with a pid so it doesn't need | |
48 | * to be special in base.c. I would do this earlier but | |
49 | * the only task alive when /proc is mounted the first time | |
50 | * is the init_task and it doesn't have any pids. | |
51 | */ | |
f6c7a1f3 EB |
52 | ei = PROC_I(proc_mnt->mnt_sb->s_root->d_inode); |
53 | if (!ei->pid) | |
54 | ei->pid = find_get_pid(1); | |
55 | } | |
07543f5c PE |
56 | |
57 | if (flags & MS_KERNMOUNT) | |
58 | ns = (struct pid_namespace *)data; | |
59 | else | |
60 | ns = current->nsproxy->pid_ns; | |
61 | ||
62 | sb = sget(fs_type, proc_test_super, proc_set_super, ns); | |
63 | if (IS_ERR(sb)) | |
64 | return PTR_ERR(sb); | |
65 | ||
66 | if (!sb->s_root) { | |
67 | sb->s_flags = flags; | |
68 | err = proc_fill_super(sb); | |
69 | if (err) { | |
70 | up_write(&sb->s_umount); | |
71 | deactivate_super(sb); | |
72 | return err; | |
73 | } | |
74 | ||
75 | ei = PROC_I(sb->s_root->d_inode); | |
76 | if (!ei->pid) { | |
77 | rcu_read_lock(); | |
78 | ei->pid = get_pid(find_pid_ns(1, ns)); | |
79 | rcu_read_unlock(); | |
80 | } | |
81 | ||
82 | sb->s_flags |= MS_ACTIVE; | |
83 | ns->proc_mnt = mnt; | |
84 | } | |
85 | ||
a3ec947c SB |
86 | simple_set_mnt(mnt, sb); |
87 | return 0; | |
07543f5c PE |
88 | } |
89 | ||
90 | static void proc_kill_sb(struct super_block *sb) | |
91 | { | |
92 | struct pid_namespace *ns; | |
93 | ||
94 | ns = (struct pid_namespace *)sb->s_fs_info; | |
95 | kill_anon_super(sb); | |
96 | put_pid_ns(ns); | |
1da177e4 LT |
97 | } |
98 | ||
c2319540 | 99 | static struct file_system_type proc_fs_type = { |
1da177e4 LT |
100 | .name = "proc", |
101 | .get_sb = proc_get_sb, | |
07543f5c | 102 | .kill_sb = proc_kill_sb, |
1da177e4 LT |
103 | }; |
104 | ||
1da177e4 LT |
105 | void __init proc_root_init(void) |
106 | { | |
5bcd7ff9 AD |
107 | int err; |
108 | ||
109 | proc_init_inodecache(); | |
1da177e4 LT |
110 | err = register_filesystem(&proc_fs_type); |
111 | if (err) | |
112 | return; | |
07543f5c | 113 | proc_mnt = kern_mount_data(&proc_fs_type, &init_pid_ns); |
1da177e4 LT |
114 | err = PTR_ERR(proc_mnt); |
115 | if (IS_ERR(proc_mnt)) { | |
116 | unregister_filesystem(&proc_fs_type); | |
117 | return; | |
118 | } | |
07543f5c | 119 | |
59c7572e | 120 | proc_symlink("mounts", NULL, "self/mounts"); |
457c4cbc EB |
121 | |
122 | proc_net_init(); | |
1da177e4 LT |
123 | |
124 | #ifdef CONFIG_SYSVIPC | |
125 | proc_mkdir("sysvipc", NULL); | |
1da177e4 | 126 | #endif |
36a5aeb8 | 127 | proc_mkdir("fs", NULL); |
928b4d8c | 128 | proc_mkdir("driver", NULL); |
1da177e4 LT |
129 | proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */ |
130 | #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE) | |
131 | /* just give it a mountpoint */ | |
132 | proc_mkdir("openprom", NULL); | |
133 | #endif | |
134 | proc_tty_init(); | |
135 | #ifdef CONFIG_PROC_DEVICETREE | |
136 | proc_device_tree_init(); | |
137 | #endif | |
9c37066d | 138 | proc_mkdir("bus", NULL); |
77b14db5 | 139 | proc_sys_init(); |
1da177e4 LT |
140 | } |
141 | ||
76b6159b AV |
142 | static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat |
143 | ) | |
1da177e4 | 144 | { |
76b6159b AV |
145 | generic_fillattr(dentry->d_inode, stat); |
146 | stat->nlink = proc_root.nlink + nr_processes(); | |
147 | return 0; | |
148 | } | |
1da177e4 | 149 | |
76b6159b AV |
150 | static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd) |
151 | { | |
1da177e4 LT |
152 | if (!proc_lookup(dir, dentry, nd)) { |
153 | return NULL; | |
154 | } | |
155 | ||
156 | return proc_pid_lookup(dir, dentry, nd); | |
157 | } | |
158 | ||
159 | static int proc_root_readdir(struct file * filp, | |
160 | void * dirent, filldir_t filldir) | |
161 | { | |
162 | unsigned int nr = filp->f_pos; | |
163 | int ret; | |
164 | ||
1da177e4 LT |
165 | if (nr < FIRST_PROCESS_ENTRY) { |
166 | int error = proc_readdir(filp, dirent, filldir); | |
b4df2b92 | 167 | if (error <= 0) |
1da177e4 | 168 | return error; |
1da177e4 LT |
169 | filp->f_pos = FIRST_PROCESS_ENTRY; |
170 | } | |
1da177e4 LT |
171 | |
172 | ret = proc_pid_readdir(filp, dirent, filldir); | |
173 | return ret; | |
174 | } | |
175 | ||
176 | /* | |
177 | * The root /proc directory is special, as it has the | |
178 | * <pid> directories. Thus we don't use the generic | |
179 | * directory handling functions for that.. | |
180 | */ | |
00977a59 | 181 | static const struct file_operations proc_root_operations = { |
1da177e4 LT |
182 | .read = generic_read_dir, |
183 | .readdir = proc_root_readdir, | |
184 | }; | |
185 | ||
186 | /* | |
187 | * proc root can do almost nothing.. | |
188 | */ | |
c5ef1c42 | 189 | static const struct inode_operations proc_root_inode_operations = { |
1da177e4 | 190 | .lookup = proc_root_lookup, |
76b6159b | 191 | .getattr = proc_root_getattr, |
1da177e4 LT |
192 | }; |
193 | ||
194 | /* | |
195 | * This is the root "inode" in the /proc tree.. | |
196 | */ | |
197 | struct proc_dir_entry proc_root = { | |
198 | .low_ino = PROC_ROOT_INO, | |
199 | .namelen = 5, | |
200 | .name = "/proc", | |
201 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, | |
202 | .nlink = 2, | |
5a622f2d | 203 | .count = ATOMIC_INIT(1), |
1da177e4 LT |
204 | .proc_iops = &proc_root_inode_operations, |
205 | .proc_fops = &proc_root_operations, | |
206 | .parent = &proc_root, | |
207 | }; | |
208 | ||
6f4e6433 PE |
209 | int pid_ns_prepare_proc(struct pid_namespace *ns) |
210 | { | |
211 | struct vfsmount *mnt; | |
212 | ||
213 | mnt = kern_mount_data(&proc_fs_type, ns); | |
214 | if (IS_ERR(mnt)) | |
215 | return PTR_ERR(mnt); | |
216 | ||
217 | return 0; | |
218 | } | |
219 | ||
220 | void pid_ns_release_proc(struct pid_namespace *ns) | |
221 | { | |
222 | mntput(ns->proc_mnt); | |
223 | } | |
224 | ||
1da177e4 LT |
225 | EXPORT_SYMBOL(proc_symlink); |
226 | EXPORT_SYMBOL(proc_mkdir); | |
227 | EXPORT_SYMBOL(create_proc_entry); | |
59b74351 | 228 | EXPORT_SYMBOL(proc_create_data); |
1da177e4 | 229 | EXPORT_SYMBOL(remove_proc_entry); |