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v3.1
  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
 24static int proc_test_super(struct super_block *sb, void *data)
 25{
 26	return sb->s_fs_info == data;
 27}
 28
 29static 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
 39static 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
 77static 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
 86static struct file_system_type proc_fs_type = {
 87	.name		= "proc",
 88	.mount		= proc_mount,
 89	.kill_sb	= proc_kill_sb,
 90};
 91
 92void __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
130static 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
138static 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
147static 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 */
169static 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 */
178static 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 */
186struct proc_dir_entry proc_root = {
187	.low_ino	= PROC_ROOT_INO, 
188	.namelen	= 5, 
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,
195	.name		= "/proc",
196};
197
198int 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
210void pid_ns_release_proc(struct pid_namespace *ns)
211{
212	mntput(ns->proc_mnt);
213}
v3.1
  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
 24static int proc_test_super(struct super_block *sb, void *data)
 25{
 26	return sb->s_fs_info == data;
 27}
 28
 29static 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
 39static 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
 77static 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
 86static struct file_system_type proc_fs_type = {
 87	.name		= "proc",
 88	.mount		= proc_mount,
 89	.kill_sb	= proc_kill_sb,
 90};
 91
 92void __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
130static 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
138static 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
147static 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 */
169static 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 */
178static 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 */
186struct proc_dir_entry proc_root = {
187	.low_ino	= PROC_ROOT_INO, 
188	.namelen	= 5, 
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,
195	.name		= "/proc",
196};
197
198int 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
210void pid_ns_release_proc(struct pid_namespace *ns)
211{
212	mntput(ns->proc_mnt);
213}