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/smp_lock.h>
20 #include <linux/mount.h>
21 #include <linux/pid_namespace.h>
22
23 #include "internal.h"
24
25 struct proc_dir_entry *proc_bus, *proc_root_fs, *proc_root_driver;
26
27 static int proc_test_super(struct super_block *sb, void *data)
28 {
29 return sb->s_fs_info == data;
30 }
31
32 static int proc_set_super(struct super_block *sb, void *data)
33 {
34 struct pid_namespace *ns;
35
36 ns = (struct pid_namespace *)data;
37 sb->s_fs_info = get_pid_ns(ns);
38 return set_anon_super(sb, NULL);
39 }
40
41 static int proc_get_sb(struct file_system_type *fs_type,
42 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
43 {
44 int err;
45 struct super_block *sb;
46 struct pid_namespace *ns;
47 struct proc_inode *ei;
48
49 if (proc_mnt) {
50 /* Seed the root directory with a pid so it doesn't need
51 * to be special in base.c. I would do this earlier but
52 * the only task alive when /proc is mounted the first time
53 * is the init_task and it doesn't have any pids.
54 */
55 ei = PROC_I(proc_mnt->mnt_sb->s_root->d_inode);
56 if (!ei->pid)
57 ei->pid = find_get_pid(1);
58 }
59
60 if (flags & MS_KERNMOUNT)
61 ns = (struct pid_namespace *)data;
62 else
63 ns = current->nsproxy->pid_ns;
64
65 sb = sget(fs_type, proc_test_super, proc_set_super, ns);
66 if (IS_ERR(sb))
67 return PTR_ERR(sb);
68
69 if (!sb->s_root) {
70 sb->s_flags = flags;
71 err = proc_fill_super(sb);
72 if (err) {
73 up_write(&sb->s_umount);
74 deactivate_super(sb);
75 return err;
76 }
77
78 ei = PROC_I(sb->s_root->d_inode);
79 if (!ei->pid) {
80 rcu_read_lock();
81 ei->pid = get_pid(find_pid_ns(1, ns));
82 rcu_read_unlock();
83 }
84
85 sb->s_flags |= MS_ACTIVE;
86 ns->proc_mnt = mnt;
87 }
88
89 return simple_set_mnt(mnt, sb);
90 }
91
92 static void proc_kill_sb(struct super_block *sb)
93 {
94 struct pid_namespace *ns;
95
96 ns = (struct pid_namespace *)sb->s_fs_info;
97 kill_anon_super(sb);
98 put_pid_ns(ns);
99 }
100
101 static struct file_system_type proc_fs_type = {
102 .name = "proc",
103 .get_sb = proc_get_sb,
104 .kill_sb = proc_kill_sb,
105 };
106
107 void __init proc_root_init(void)
108 {
109 int err = proc_init_inodecache();
110 if (err)
111 return;
112 err = register_filesystem(&proc_fs_type);
113 if (err)
114 return;
115 proc_mnt = kern_mount_data(&proc_fs_type, &init_pid_ns);
116 err = PTR_ERR(proc_mnt);
117 if (IS_ERR(proc_mnt)) {
118 unregister_filesystem(&proc_fs_type);
119 return;
120 }
121
122 proc_misc_init();
123
124 proc_net_init();
125
126 #ifdef CONFIG_SYSVIPC
127 proc_mkdir("sysvipc", NULL);
128 #endif
129 proc_root_fs = proc_mkdir("fs", NULL);
130 proc_root_driver = proc_mkdir("driver", NULL);
131 proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
132 #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
133 /* just give it a mountpoint */
134 proc_mkdir("openprom", NULL);
135 #endif
136 proc_tty_init();
137 #ifdef CONFIG_PROC_DEVICETREE
138 proc_device_tree_init();
139 #endif
140 proc_bus = proc_mkdir("bus", NULL);
141 proc_sys_init();
142 }
143
144 static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
145 )
146 {
147 generic_fillattr(dentry->d_inode, stat);
148 stat->nlink = proc_root.nlink + nr_processes();
149 return 0;
150 }
151
152 static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
153 {
154 if (!proc_lookup(dir, dentry, nd)) {
155 return NULL;
156 }
157
158 return proc_pid_lookup(dir, dentry, nd);
159 }
160
161 static int proc_root_readdir(struct file * filp,
162 void * dirent, filldir_t filldir)
163 {
164 unsigned int nr = filp->f_pos;
165 int ret;
166
167 lock_kernel();
168
169 if (nr < FIRST_PROCESS_ENTRY) {
170 int error = proc_readdir(filp, dirent, filldir);
171 if (error <= 0) {
172 unlock_kernel();
173 return error;
174 }
175 filp->f_pos = FIRST_PROCESS_ENTRY;
176 }
177 unlock_kernel();
178
179 ret = proc_pid_readdir(filp, dirent, filldir);
180 return ret;
181 }
182
183 /*
184 * The root /proc directory is special, as it has the
185 * <pid> directories. Thus we don't use the generic
186 * directory handling functions for that..
187 */
188 static const struct file_operations proc_root_operations = {
189 .read = generic_read_dir,
190 .readdir = proc_root_readdir,
191 };
192
193 /*
194 * proc root can do almost nothing..
195 */
196 static const struct inode_operations proc_root_inode_operations = {
197 .lookup = proc_root_lookup,
198 .getattr = proc_root_getattr,
199 };
200
201 /*
202 * This is the root "inode" in the /proc tree..
203 */
204 struct proc_dir_entry proc_root = {
205 .low_ino = PROC_ROOT_INO,
206 .namelen = 5,
207 .name = "/proc",
208 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
209 .nlink = 2,
210 .count = ATOMIC_INIT(1),
211 .proc_iops = &proc_root_inode_operations,
212 .proc_fops = &proc_root_operations,
213 .parent = &proc_root,
214 };
215
216 int pid_ns_prepare_proc(struct pid_namespace *ns)
217 {
218 struct vfsmount *mnt;
219
220 mnt = kern_mount_data(&proc_fs_type, ns);
221 if (IS_ERR(mnt))
222 return PTR_ERR(mnt);
223
224 return 0;
225 }
226
227 void pid_ns_release_proc(struct pid_namespace *ns)
228 {
229 mntput(ns->proc_mnt);
230 }
231
232 EXPORT_SYMBOL(proc_symlink);
233 EXPORT_SYMBOL(proc_mkdir);
234 EXPORT_SYMBOL(create_proc_entry);
235 EXPORT_SYMBOL(proc_create);
236 EXPORT_SYMBOL(remove_proc_entry);
237 EXPORT_SYMBOL(proc_root);
238 EXPORT_SYMBOL(proc_root_fs);
239 EXPORT_SYMBOL(proc_bus);
240 EXPORT_SYMBOL(proc_root_driver);
241
|
This page was automatically generated by the
LXR engine.
|