fs/pstore/inode.c - kernel/lockdown - Git at Google

 /*
  * Persistent Storage - ramfs parts.
  *
  * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2 as
  *  published by the Free Software Foundation.
  *
  *  This program is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */

 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/fsnotify.h>
 #include <linux/pagemap.h>
 #include <linux/highmem.h>
 #include <linux/time.h>
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/string.h>
 #include <linux/mount.h>
 #include <linux/seq_file.h>
 #include <linux/ramfs.h>
 #include <linux/parser.h>
 #include <linux/sched.h>
 #include <linux/magic.h>
 #include <linux/pstore.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/uaccess.h>

 #include "internal.h"

 #define	PSTORE_NAMELEN	64

 static DEFINE_SPINLOCK(allpstore_lock);
 static LIST_HEAD(allpstore);

 struct pstore_private {
 	struct list_head list;
 	struct pstore_info *psi;
 	enum pstore_type_id type;
 	u64	id;
 	int	count;
 	ssize_t	size;
 	char	data[];
 };

 struct pstore_ftrace_seq_data {
 	const void *ptr;
 	size_t off;
 	size_t size;
 };

 #define REC_SIZE sizeof(struct pstore_ftrace_record)

 static void *pstore_ftrace_seq_start(struct seq_file *s, loff_t *pos)
 {
 	struct pstore_private *ps = s->private;
 	struct pstore_ftrace_seq_data *data;

 	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return NULL;

 	data->off = ps->size % REC_SIZE;
 	data->off += *pos * REC_SIZE;
 	if (data->off + REC_SIZE > ps->size) {
 		kfree(data);
 		return NULL;
 	}

 	return data;

 }

 static void pstore_ftrace_seq_stop(struct seq_file *s, void *v)
 {
 	kfree(v);
 }

 static void *pstore_ftrace_seq_next(struct seq_file *s, void *v, loff_t *pos)
 {
 	struct pstore_private *ps = s->private;
 	struct pstore_ftrace_seq_data *data = v;

 	data->off += REC_SIZE;
 	if (data->off + REC_SIZE > ps->size)
 		return NULL;

 	(*pos)++;
 	return data;
 }

 static int pstore_ftrace_seq_show(struct seq_file *s, void *v)
 {
 	struct pstore_private *ps = s->private;
 	struct pstore_ftrace_seq_data *data = v;
 	struct pstore_ftrace_record *rec = (void *)(ps->data + data->off);

 	seq_printf(s, "%d %08lx  %08lx  %pf <- %pF\n",
 		pstore_ftrace_decode_cpu(rec), rec->ip, rec->parent_ip,
 		(void *)rec->ip, (void *)rec->parent_ip);

 	return 0;
 }

 static const struct seq_operations pstore_ftrace_seq_ops = {
 	.start	= pstore_ftrace_seq_start,
 	.next	= pstore_ftrace_seq_next,
 	.stop	= pstore_ftrace_seq_stop,
 	.show	= pstore_ftrace_seq_show,
 };

 static ssize_t pstore_file_read(struct file *file, char __user *userbuf,
 						size_t count, loff_t *ppos)
 {
 	struct seq_file *sf = file->private_data;
 	struct pstore_private *ps = sf->private;

 	if (ps->type == PSTORE_TYPE_FTRACE)
 		return seq_read(file, userbuf, count, ppos);
 	return simple_read_from_buffer(userbuf, count, ppos, ps->data, ps->size);
 }

 static int pstore_file_open(struct inode *inode, struct file *file)
 {
 	struct pstore_private *ps = inode->i_private;
 	struct seq_file *sf;
 	int err;
 	const struct seq_operations *sops = NULL;

 	if (ps->type == PSTORE_TYPE_FTRACE)
 		sops = &pstore_ftrace_seq_ops;

 	err = seq_open(file, sops);
 	if (err < 0)
 		return err;

 	sf = file->private_data;
 	sf->private = ps;

 	return 0;
 }

 static loff_t pstore_file_llseek(struct file *file, loff_t off, int whence)
 {
 	struct seq_file *sf = file->private_data;

 	if (sf->op)
 		return seq_lseek(file, off, whence);
 	return default_llseek(file, off, whence);
 }

 static const struct file_operations pstore_file_operations = {
 	.open		= pstore_file_open,
 	.read		= pstore_file_read,
 	.llseek		= pstore_file_llseek,
 	.release	= seq_release,
 };

 /*
  * When a file is unlinked from our file system we call the
  * platform driver to erase the record from persistent store.
  */
 static int pstore_unlink(struct inode *dir, struct dentry *dentry)
 {
 	struct pstore_private *p = dentry->d_inode->i_private;

 	if (p->psi->erase)
 		p->psi->erase(p->type, p->id, p->count,
 			      dentry->d_inode->i_ctime, p->psi);
 	else
 		return -EPERM;

 	return simple_unlink(dir, dentry);
 }

 static void pstore_evict_inode(struct inode *inode)
 {
 	struct pstore_private	*p = inode->i_private;
 	unsigned long		flags;

 	clear_inode(inode);
 	if (p) {
 		spin_lock_irqsave(&allpstore_lock, flags);
 		list_del(&p->list);
 		spin_unlock_irqrestore(&allpstore_lock, flags);
 		kfree(p);
 	}
 }

 static const struct inode_operations pstore_dir_inode_operations = {
 	.lookup		= simple_lookup,
 	.unlink		= pstore_unlink,
 };

 static struct inode *pstore_get_inode(struct super_block *sb)
 {
 	struct inode *inode = new_inode(sb);
 	if (inode) {
 		inode->i_ino = get_next_ino();
 		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 	}
 	return inode;
 }

 enum {
 	Opt_kmsg_bytes, Opt_err
 };

 static const match_table_t tokens = {
 	{Opt_kmsg_bytes, "kmsg_bytes=%u"},
 	{Opt_err, NULL}
 };

 static void parse_options(char *options)
 {
 	char		*p;
 	substring_t	args[MAX_OPT_ARGS];
 	int		option;

 	if (!options)
 		return;

 	while ((p = strsep(&options, ",")) != NULL) {
 		int token;

 		if (!*p)
 			continue;

 		token = match_token(p, tokens, args);
 		switch (token) {
 		case Opt_kmsg_bytes:
 			if (!match_int(&args[0], &option))
 				pstore_set_kmsg_bytes(option);
 			break;
 		}
 	}
 }

 static int pstore_remount(struct super_block *sb, int *flags, char *data)
 {
 	parse_options(data);

 	return 0;
 }

 static const struct super_operations pstore_ops = {
 	.statfs		= simple_statfs,
 	.drop_inode	= generic_delete_inode,
 	.evict_inode	= pstore_evict_inode,
 	.remount_fs	= pstore_remount,
 	.show_options	= generic_show_options,
 };

 static struct super_block *pstore_sb;

 int pstore_is_mounted(void)
 {
 	return pstore_sb != NULL;
 }

 /*
  * Make a regular file in the root directory of our file system.
  * Load it up with "size" bytes of data from "buf".
  * Set the mtime & ctime to the date that this record was originally stored.
  */
 int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
 		  char *data, bool compressed, size_t size,
 		  struct timespec time, struct pstore_info *psi)
 {
 	struct dentry		*root = pstore_sb->s_root;
 	struct dentry		*dentry;
 	struct inode		*inode;
 	int			rc = 0;
 	char			name[PSTORE_NAMELEN];
 	struct pstore_private	*private, *pos;
 	unsigned long		flags;

 	spin_lock_irqsave(&allpstore_lock, flags);
 	list_for_each_entry(pos, &allpstore, list) {
 		if (pos->type == type &&
 		    pos->id == id &&
 		    pos->psi == psi) {
 			rc = -EEXIST;
 			break;
 		}
 	}
 	spin_unlock_irqrestore(&allpstore_lock, flags);
 	if (rc)
 		return rc;

 	rc = -ENOMEM;
 	inode = pstore_get_inode(pstore_sb);
 	if (!inode)
 		goto fail;
 	inode->i_mode = S_IFREG | 0444;
 	inode->i_fop = &pstore_file_operations;
 	private = kmalloc(sizeof *private + size, GFP_KERNEL);
 	if (!private)
 		goto fail_alloc;
 	private->type = type;
 	private->id = id;
 	private->count = count;
 	private->psi = psi;

 	switch (type) {
 	case PSTORE_TYPE_DMESG:
 		sprintf(name, "dmesg-%s-%lld%s", psname, id,
 						compressed ? ".enc.z" : "");
 		break;
 	case PSTORE_TYPE_CONSOLE:
 		sprintf(name, "console-%s-%lld", psname, id);
 		break;
 	case PSTORE_TYPE_FTRACE:
 		sprintf(name, "ftrace-%s-%lld", psname, id);
 		break;
 	case PSTORE_TYPE_MCE:
 		sprintf(name, "mce-%s-%lld", psname, id);
 		break;
 	case PSTORE_TYPE_PPC_RTAS:
 		sprintf(name, "rtas-%s-%lld", psname, id);
 		break;
 	case PSTORE_TYPE_PPC_OF:
 		sprintf(name, "powerpc-ofw-%s-%lld", psname, id);
 		break;
 	case PSTORE_TYPE_PPC_COMMON:
 		sprintf(name, "powerpc-common-%s-%lld", psname, id);
 		break;
 	case PSTORE_TYPE_UNKNOWN:
 		sprintf(name, "unknown-%s-%lld", psname, id);
 		break;
 	default:
 		sprintf(name, "type%d-%s-%lld", type, psname, id);
 		break;
 	}

 	mutex_lock(&root->d_inode->i_mutex);

 	dentry = d_alloc_name(root, name);
 	if (!dentry)
 		goto fail_lockedalloc;

 	memcpy(private->data, data, size);
 	inode->i_size = private->size = size;

 	inode->i_private = private;

 	if (time.tv_sec)
 		inode->i_mtime = inode->i_ctime = time;

 	d_add(dentry, inode);

 	spin_lock_irqsave(&allpstore_lock, flags);
 	list_add(&private->list, &allpstore);
 	spin_unlock_irqrestore(&allpstore_lock, flags);

 	mutex_unlock(&root->d_inode->i_mutex);

 	return 0;

 fail_lockedalloc:
 	mutex_unlock(&root->d_inode->i_mutex);
 	kfree(private);
 fail_alloc:
 	iput(inode);

 fail:
 	return rc;
 }

 static int pstore_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct inode *inode;

 	save_mount_options(sb, data);

 	pstore_sb = sb;

 	sb->s_maxbytes		= MAX_LFS_FILESIZE;
 	sb->s_blocksize		= PAGE_CACHE_SIZE;
 	sb->s_blocksize_bits	= PAGE_CACHE_SHIFT;
 	sb->s_magic		= PSTOREFS_MAGIC;
 	sb->s_op		= &pstore_ops;
 	sb->s_time_gran		= 1;

 	parse_options(data);

 	inode = pstore_get_inode(sb);
 	if (inode) {
 		inode->i_mode = S_IFDIR | 0755;
 		inode->i_op = &pstore_dir_inode_operations;
 		inode->i_fop = &simple_dir_operations;
 		inc_nlink(inode);
 	}
 	sb->s_root = d_make_root(inode);
 	if (!sb->s_root)
 		return -ENOMEM;

 	pstore_get_records(0);

 	return 0;
 }

 static struct dentry *pstore_mount(struct file_system_type *fs_type,
 	int flags, const char *dev_name, void *data)
 {
 	return mount_single(fs_type, flags, data, pstore_fill_super);
 }

 static void pstore_kill_sb(struct super_block *sb)
 {
 	kill_litter_super(sb);
 	pstore_sb = NULL;
 }

 static struct file_system_type pstore_fs_type = {
 	.name		= "pstore",
 	.mount		= pstore_mount,
 	.kill_sb	= pstore_kill_sb,
 };

 static struct kobject *pstore_kobj;

 static int __init init_pstore_fs(void)
 {
 	int err = 0;

 	/* Create a convenient mount point for people to access pstore */
 	pstore_kobj = kobject_create_and_add("pstore", fs_kobj);
 	if (!pstore_kobj) {
 		err = -ENOMEM;
 		goto out;
 	}

 	err = register_filesystem(&pstore_fs_type);
 	if (err < 0)
 		kobject_put(pstore_kobj);

 out:
 	return err;
 }
 module_init(init_pstore_fs)

 MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>");
 MODULE_LICENSE("GPL");
	/*
	* Persistent Storage - ramfs parts.
	*
	* Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <linux/module.h>
	#include <linux/fs.h>
	#include <linux/fsnotify.h>
	#include <linux/pagemap.h>
	#include <linux/highmem.h>
	#include <linux/time.h>
	#include <linux/init.h>
	#include <linux/list.h>
	#include <linux/string.h>
	#include <linux/mount.h>
	#include <linux/seq_file.h>
	#include <linux/ramfs.h>
	#include <linux/parser.h>
	#include <linux/sched.h>
	#include <linux/magic.h>
	#include <linux/pstore.h>
	#include <linux/slab.h>
	#include <linux/spinlock.h>
	#include <linux/uaccess.h>

	#include "internal.h"

	#define PSTORE_NAMELEN 64

	static DEFINE_SPINLOCK(allpstore_lock);
	static LIST_HEAD(allpstore);

	struct pstore_private {
	struct list_head list;
	struct pstore_info *psi;
	enum pstore_type_id type;
	u64 id;
	int count;
	ssize_t size;
	char data[];
	};

	struct pstore_ftrace_seq_data {
	const void *ptr;
	size_t off;
	size_t size;
	};

	#define REC_SIZE sizeof(struct pstore_ftrace_record)

	static void pstore_ftrace_seq_start(struct seq_file s, loff_t *pos)
	{
	struct pstore_private *ps = s->private;
	struct pstore_ftrace_seq_data *data;

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data)
	return NULL;

	data->off = ps->size % REC_SIZE;
	data->off += pos REC_SIZE;
	if (data->off + REC_SIZE > ps->size) {
	kfree(data);
	return NULL;
	}

	return data;

	}

	static void pstore_ftrace_seq_stop(struct seq_file s, void v)
	{
	kfree(v);
	}

	static void pstore_ftrace_seq_next(struct seq_file s, void v, loff_t pos)
	{
	struct pstore_private *ps = s->private;
	struct pstore_ftrace_seq_data *data = v;

	data->off += REC_SIZE;
	if (data->off + REC_SIZE > ps->size)
	return NULL;

	(*pos)++;
	return data;
	}

	static int pstore_ftrace_seq_show(struct seq_file s, void v)
	{
	struct pstore_private *ps = s->private;
	struct pstore_ftrace_seq_data *data = v;
	struct pstore_ftrace_record rec = (void )(ps->data + data->off);

	seq_printf(s, "%d %08lx %08lx %pf <- %pF\n",
	pstore_ftrace_decode_cpu(rec), rec->ip, rec->parent_ip,
	(void )rec->ip, (void )rec->parent_ip);

	return 0;
	}

	static const struct seq_operations pstore_ftrace_seq_ops = {
	.start = pstore_ftrace_seq_start,
	.next = pstore_ftrace_seq_next,
	.stop = pstore_ftrace_seq_stop,
	.show = pstore_ftrace_seq_show,
	};

	static ssize_t pstore_file_read(struct file file, char __user userbuf,
	size_t count, loff_t *ppos)
	{
	struct seq_file *sf = file->private_data;
	struct pstore_private *ps = sf->private;

	if (ps->type == PSTORE_TYPE_FTRACE)
	return seq_read(file, userbuf, count, ppos);
	return simple_read_from_buffer(userbuf, count, ppos, ps->data, ps->size);
	}

	static int pstore_file_open(struct inode inode, struct file file)
	{
	struct pstore_private *ps = inode->i_private;
	struct seq_file *sf;
	int err;
	const struct seq_operations *sops = NULL;

	if (ps->type == PSTORE_TYPE_FTRACE)
	sops = &pstore_ftrace_seq_ops;

	err = seq_open(file, sops);
	if (err < 0)
	return err;

	sf = file->private_data;
	sf->private = ps;

	return 0;
	}

	static loff_t pstore_file_llseek(struct file *file, loff_t off, int whence)
	{
	struct seq_file *sf = file->private_data;

	if (sf->op)
	return seq_lseek(file, off, whence);
	return default_llseek(file, off, whence);
	}

	static const struct file_operations pstore_file_operations = {
	.open = pstore_file_open,
	.read = pstore_file_read,
	.llseek = pstore_file_llseek,
	.release = seq_release,
	};

	/*
	* When a file is unlinked from our file system we call the
	* platform driver to erase the record from persistent store.
	*/
	static int pstore_unlink(struct inode dir, struct dentry dentry)
	{
	struct pstore_private *p = dentry->d_inode->i_private;

	if (p->psi->erase)
	p->psi->erase(p->type, p->id, p->count,
	dentry->d_inode->i_ctime, p->psi);
	else
	return -EPERM;

	return simple_unlink(dir, dentry);
	}

	static void pstore_evict_inode(struct inode *inode)
	{
	struct pstore_private *p = inode->i_private;
	unsigned long flags;

	clear_inode(inode);
	if (p) {
	spin_lock_irqsave(&allpstore_lock, flags);
	list_del(&p->list);
	spin_unlock_irqrestore(&allpstore_lock, flags);
	kfree(p);
	}
	}

	static const struct inode_operations pstore_dir_inode_operations = {
	.lookup = simple_lookup,
	.unlink = pstore_unlink,
	};

	static struct inode pstore_get_inode(struct super_block sb)
	{
	struct inode *inode = new_inode(sb);
	if (inode) {
	inode->i_ino = get_next_ino();
	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	}
	return inode;
	}

	enum {
	Opt_kmsg_bytes, Opt_err
	};

	static const match_table_t tokens = {
	{Opt_kmsg_bytes, "kmsg_bytes=%u"},
	{Opt_err, NULL}
	};

	static void parse_options(char *options)
	{
	char *p;
	substring_t args[MAX_OPT_ARGS];
	int option;

	if (!options)
	return;

	while ((p = strsep(&options, ",")) != NULL) {
	int token;

	if (!*p)
	continue;

	token = match_token(p, tokens, args);
	switch (token) {
	case Opt_kmsg_bytes:
	if (!match_int(&args[0], &option))
	pstore_set_kmsg_bytes(option);
	break;
	}
	}
	}

	static int pstore_remount(struct super_block sb, int flags, char *data)
	{
	parse_options(data);

	return 0;
	}

	static const struct super_operations pstore_ops = {
	.statfs = simple_statfs,
	.drop_inode = generic_delete_inode,
	.evict_inode = pstore_evict_inode,
	.remount_fs = pstore_remount,
	.show_options = generic_show_options,
	};

	static struct super_block *pstore_sb;

	int pstore_is_mounted(void)
	{
	return pstore_sb != NULL;
	}

	/*
	* Make a regular file in the root directory of our file system.
	* Load it up with "size" bytes of data from "buf".
	* Set the mtime & ctime to the date that this record was originally stored.
	*/
	int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
	char *data, bool compressed, size_t size,
	struct timespec time, struct pstore_info *psi)
	{
	struct dentry *root = pstore_sb->s_root;
	struct dentry *dentry;
	struct inode *inode;
	int rc = 0;
	char name[PSTORE_NAMELEN];
	struct pstore_private private, pos;
	unsigned long flags;

	spin_lock_irqsave(&allpstore_lock, flags);
	list_for_each_entry(pos, &allpstore, list) {
	if (pos->type == type &&
	pos->id == id &&
	pos->psi == psi) {
	rc = -EEXIST;
	break;
	}
	}
	spin_unlock_irqrestore(&allpstore_lock, flags);
	if (rc)
	return rc;

	rc = -ENOMEM;
	inode = pstore_get_inode(pstore_sb);
	if (!inode)
	goto fail;
	inode->i_mode = S_IFREG \| 0444;
	inode->i_fop = &pstore_file_operations;
	private = kmalloc(sizeof *private + size, GFP_KERNEL);
	if (!private)
	goto fail_alloc;
	private->type = type;
	private->id = id;
	private->count = count;
	private->psi = psi;

	switch (type) {
	case PSTORE_TYPE_DMESG:
	sprintf(name, "dmesg-%s-%lld%s", psname, id,
	compressed ? ".enc.z" : "");
	break;
	case PSTORE_TYPE_CONSOLE:
	sprintf(name, "console-%s-%lld", psname, id);
	break;
	case PSTORE_TYPE_FTRACE:
	sprintf(name, "ftrace-%s-%lld", psname, id);
	break;
	case PSTORE_TYPE_MCE:
	sprintf(name, "mce-%s-%lld", psname, id);
	break;
	case PSTORE_TYPE_PPC_RTAS:
	sprintf(name, "rtas-%s-%lld", psname, id);
	break;
	case PSTORE_TYPE_PPC_OF:
	sprintf(name, "powerpc-ofw-%s-%lld", psname, id);
	break;
	case PSTORE_TYPE_PPC_COMMON:
	sprintf(name, "powerpc-common-%s-%lld", psname, id);
	break;
	case PSTORE_TYPE_UNKNOWN:
	sprintf(name, "unknown-%s-%lld", psname, id);
	break;
	default:
	sprintf(name, "type%d-%s-%lld", type, psname, id);
	break;
	}

	mutex_lock(&root->d_inode->i_mutex);

	dentry = d_alloc_name(root, name);
	if (!dentry)
	goto fail_lockedalloc;

	memcpy(private->data, data, size);
	inode->i_size = private->size = size;

	inode->i_private = private;

	if (time.tv_sec)
	inode->i_mtime = inode->i_ctime = time;

	d_add(dentry, inode);

	spin_lock_irqsave(&allpstore_lock, flags);
	list_add(&private->list, &allpstore);
	spin_unlock_irqrestore(&allpstore_lock, flags);

	mutex_unlock(&root->d_inode->i_mutex);

	return 0;

	fail_lockedalloc:
	mutex_unlock(&root->d_inode->i_mutex);
	kfree(private);
	fail_alloc:
	iput(inode);

	fail:
	return rc;
	}

	static int pstore_fill_super(struct super_block sb, void data, int silent)
	{
	struct inode *inode;

	save_mount_options(sb, data);

	pstore_sb = sb;

	sb->s_maxbytes = MAX_LFS_FILESIZE;
	sb->s_blocksize = PAGE_CACHE_SIZE;
	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	sb->s_magic = PSTOREFS_MAGIC;
	sb->s_op = &pstore_ops;
	sb->s_time_gran = 1;

	parse_options(data);

	inode = pstore_get_inode(sb);
	if (inode) {
	inode->i_mode = S_IFDIR \| 0755;
	inode->i_op = &pstore_dir_inode_operations;
	inode->i_fop = &simple_dir_operations;
	inc_nlink(inode);
	}
	sb->s_root = d_make_root(inode);
	if (!sb->s_root)
	return -ENOMEM;

	pstore_get_records(0);

	return 0;
	}

	static struct dentry pstore_mount(struct file_system_type fs_type,
	int flags, const char dev_name, void data)
	{
	return mount_single(fs_type, flags, data, pstore_fill_super);
	}

	static void pstore_kill_sb(struct super_block *sb)
	{
	kill_litter_super(sb);
	pstore_sb = NULL;
	}

	static struct file_system_type pstore_fs_type = {
	.name = "pstore",
	.mount = pstore_mount,
	.kill_sb = pstore_kill_sb,
	};

	static struct kobject *pstore_kobj;

	static int __init init_pstore_fs(void)
	{
	int err = 0;

	/* Create a convenient mount point for people to access pstore */
	pstore_kobj = kobject_create_and_add("pstore", fs_kobj);
	if (!pstore_kobj) {
	err = -ENOMEM;
	goto out;
	}

	err = register_filesystem(&pstore_fs_type);
	if (err < 0)
	kobject_put(pstore_kobj);

	out:
	return err;
	}
	module_init(init_pstore_fs)

	MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>");
	MODULE_LICENSE("GPL");