[linux-block.git] / fs / pstore / inode.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Persistent Storage - ramfs parts.
 *
 * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
 */

#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_record *record;
	size_t total_size;
};

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

#define REC_SIZE sizeof(struct pstore_ftrace_record)

static void free_pstore_private(struct pstore_private *private)
{
	if (!private)
		return;
	if (private->record) {
		kfree(private->record->buf);
		kfree(private->record);
	}
	kfree(private);
}

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->total_size % REC_SIZE;
	data->off += *pos * REC_SIZE;
	if (data->off + REC_SIZE > ps->total_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;

	(*pos)++;
	data->off += REC_SIZE;
	if (data->off + REC_SIZE > ps->total_size)
		return NULL;

	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;

	if (!data)
		return 0;

	rec = (struct pstore_ftrace_record *)(ps->record->buf + data->off);

	seq_printf(s, "CPU:%d ts:%llu %08lx  %08lx  %ps <- %pS\n",
		   pstore_ftrace_decode_cpu(rec),
		   pstore_ftrace_read_timestamp(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->record->type == PSTORE_TYPE_FTRACE)
		return seq_read(file, userbuf, count, ppos);
	return simple_read_from_buffer(userbuf, count, ppos,
				       ps->record->buf, ps->total_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->record->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 = d_inode(dentry)->i_private;
	struct pstore_record *record = p->record;

	if (!record->psi->erase)
		return -EPERM;

	mutex_lock(&record->psi->read_mutex);
	record->psi->erase(record);
	mutex_unlock(&record->psi->read_mutex);

	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);
		free_pstore_private(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(inode);
	}
	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;
		}
	}
}

/*
 * Display the mount options in /proc/mounts.
 */
static int pstore_show_options(struct seq_file *m, struct dentry *root)
{
	if (kmsg_bytes != PSTORE_DEFAULT_KMSG_BYTES)
		seq_printf(m, ",kmsg_bytes=%lu", kmsg_bytes);
	return 0;
}

static int pstore_remount(struct super_block *sb, int *flags, char *data)
{
	sync_filesystem(sb);
	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	= pstore_show_options,
};

static struct super_block *pstore_sb;

bool 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(struct dentry *root, struct pstore_record *record)
{
	struct dentry		*dentry;
	struct inode		*inode;
	int			rc = 0;
	char			name[PSTORE_NAMELEN];
	struct pstore_private	*private, *pos;
	unsigned long		flags;
	size_t			size = record->size + record->ecc_notice_size;

	WARN_ON(!inode_is_locked(d_inode(root)));

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

	rc = -ENOMEM;
	inode = pstore_get_inode(root->d_sb);
	if (!inode)
		goto fail;
	inode->i_mode = S_IFREG | 0444;
	inode->i_fop = &pstore_file_operations;
	scnprintf(name, sizeof(name), "%s-%s-%llu%s",
			pstore_type_to_name(record->type),
			record->psi->name, record->id,
			record->compressed ? ".enc.z" : "");

	private = kzalloc(sizeof(*private), GFP_KERNEL);
	if (!private)
		goto fail_inode;

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

	private->record = record;
	inode->i_size = private->total_size = size;
	inode->i_private = private;

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

	d_add(dentry, inode);

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

	return 0;

fail_private:
	free_pstore_private(private);
fail_inode:
	iput(inode);

fail:
	return rc;
}

/*
 * Read all the records from the persistent store. Create
 * files in our filesystem.  Don't warn about -EEXIST errors
 * when we are re-scanning the backing store looking to add new
 * error records.
 */
void pstore_get_records(int quiet)
{
	struct pstore_info *psi = psinfo;
	struct dentry *root;

	if (!psi || !pstore_sb)
		return;

	root = pstore_sb->s_root;

	inode_lock(d_inode(root));
	pstore_get_backend_records(psi, root, quiet);
	inode_unlock(d_inode(root));
}

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

	pstore_sb = sb;

	sb->s_maxbytes		= MAX_LFS_FILESIZE;
	sb->s_blocksize		= PAGE_SIZE;
	sb->s_blocksize_bits	= PAGE_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 | 0750;
		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 = {
	.owner          = THIS_MODULE,
	.name		= "pstore",
	.mount		= pstore_mount,
	.kill_sb	= pstore_kill_sb,
};

int __init pstore_init_fs(void)
{
	int err;

	/* Create a convenient mount point for people to access pstore */
	err = sysfs_create_mount_point(fs_kobj, "pstore");
	if (err)
		goto out;

	err = register_filesystem(&pstore_fs_type);
	if (err < 0)
		sysfs_remove_mount_point(fs_kobj, "pstore");

out:
	return err;
}

void __exit pstore_exit_fs(void)
{
	unregister_filesystem(&pstore_fs_type);
	sysfs_remove_mount_point(fs_kobj, "pstore");
}
Commit	Line	Data
45051539	1	// SPDX-License-Identifier: GPL-2.0-only
ca01d6dd TL	2	/*
	3	* Persistent Storage - ramfs parts.
	4	*
	5	* Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
ca01d6dd TL	6	*/
	7
	8	#include <linux/module.h>
	9	#include <linux/fs.h>
	10	#include <linux/fsnotify.h>
	11	#include <linux/pagemap.h>
	12	#include <linux/highmem.h>
	13	#include <linux/time.h>
	14	#include <linux/init.h>
6dda9266	15	#include <linux/list.h>
ca01d6dd TL	16	#include <linux/string.h>
ca01d6dd TL	17	#include <linux/mount.h>
060287b8	18	#include <linux/seq_file.h>
ca01d6dd	19	#include <linux/ramfs.h>
366f7e7a	20	#include <linux/parser.h>
ca01d6dd TL	21	#include <linux/sched.h>
	22	#include <linux/magic.h>
	23	#include <linux/pstore.h>
	24	#include <linux/slab.h>
6dda9266	25	#include <linux/spinlock.h>
ca01d6dd TL	26	#include <linux/uaccess.h>
	27
	28	#include "internal.h"
	29
	30	#define PSTORE_NAMELEN 64
	31
6dda9266 LT	32	static DEFINE_SPINLOCK(allpstore_lock);
	33	static LIST_HEAD(allpstore);
	34
ca01d6dd	35	struct pstore_private {
6dda9266	36	struct list_head list;
83f70f07 KC	37	struct pstore_record *record;
83f70f07 KC	38	size_t total_size;
ca01d6dd TL	39	};
ca01d6dd TL	40
060287b8 AV	41	struct pstore_ftrace_seq_data {
	42	const void *ptr;
	43	size_t off;
	44	size_t size;
	45	};
	46
	47	#define REC_SIZE sizeof(struct pstore_ftrace_record)
	48
1dfff7dd KC	49	static void free_pstore_private(struct pstore_private *private)
	50	{
	51	if (!private)
	52	return;
83f70f07 KC	53	if (private->record) {
	54	kfree(private->record->buf);
	55	kfree(private->record);
	56	}
1dfff7dd KC	57	kfree(private);
	58	}
	59
060287b8 AV	60	static void pstore_ftrace_seq_start(struct seq_file s, loff_t *pos)
	61	{
	62	struct pstore_private *ps = s->private;
	63	struct pstore_ftrace_seq_data *data;
	64
	65	data = kzalloc(sizeof(*data), GFP_KERNEL);
	66	if (!data)
	67	return NULL;
	68
83f70f07	69	data->off = ps->total_size % REC_SIZE;
060287b8	70	data->off += pos REC_SIZE;
83f70f07	71	if (data->off + REC_SIZE > ps->total_size) {
060287b8 AV	72	kfree(data);
	73	return NULL;
	74	}
	75
	76	return data;
	77
	78	}
	79
	80	static void pstore_ftrace_seq_stop(struct seq_file s, void v)
	81	{
	82	kfree(v);
	83	}
	84
	85	static void pstore_ftrace_seq_next(struct seq_file s, void v, loff_t pos)
	86	{
	87	struct pstore_private *ps = s->private;
	88	struct pstore_ftrace_seq_data *data = v;
	89
6c871b73	90	(*pos)++;
060287b8	91	data->off += REC_SIZE;
83f70f07	92	if (data->off + REC_SIZE > ps->total_size)
060287b8 AV	93	return NULL;
060287b8 AV	94
060287b8 AV	95	return data;
	96	}
	97
	98	static int pstore_ftrace_seq_show(struct seq_file s, void v)
	99	{
	100	struct pstore_private *ps = s->private;
	101	struct pstore_ftrace_seq_data *data = v;
83f70f07 KC	102	struct pstore_ftrace_record *rec;
83f70f07 KC	103
6c871b73 VA	104	if (!data)
	105	return 0;
	106
83f70f07	107	rec = (struct pstore_ftrace_record *)(ps->record->buf + data->off);
060287b8	108
d75f773c	109	seq_printf(s, "CPU:%d ts:%llu %08lx %08lx %ps <- %pS\n",
fbccdeb8 JF	110	pstore_ftrace_decode_cpu(rec),
	111	pstore_ftrace_read_timestamp(rec),
	112	rec->ip, rec->parent_ip, (void *)rec->ip,
	113	(void *)rec->parent_ip);
060287b8 AV	114
	115	return 0;
	116	}
	117
	118	static const struct seq_operations pstore_ftrace_seq_ops = {
	119	.start = pstore_ftrace_seq_start,
	120	.next = pstore_ftrace_seq_next,
	121	.stop = pstore_ftrace_seq_stop,
	122	.show = pstore_ftrace_seq_show,
	123	};
	124
fbe0aa1f TL	125	static ssize_t pstore_file_read(struct file file, char __user userbuf,
	126	size_t count, loff_t *ppos)
	127	{
060287b8 AV	128	struct seq_file *sf = file->private_data;
060287b8 AV	129	struct pstore_private *ps = sf->private;
fbe0aa1f	130
83f70f07	131	if (ps->record->type == PSTORE_TYPE_FTRACE)
060287b8	132	return seq_read(file, userbuf, count, ppos);
83f70f07 KC	133	return simple_read_from_buffer(userbuf, count, ppos,
83f70f07 KC	134	ps->record->buf, ps->total_size);
fbe0aa1f TL	135	}
fbe0aa1f TL	136
060287b8 AV	137	static int pstore_file_open(struct inode inode, struct file file)
	138	{
	139	struct pstore_private *ps = inode->i_private;
	140	struct seq_file *sf;
	141	int err;
	142	const struct seq_operations *sops = NULL;
	143
83f70f07	144	if (ps->record->type == PSTORE_TYPE_FTRACE)
060287b8 AV	145	sops = &pstore_ftrace_seq_ops;
	146
	147	err = seq_open(file, sops);
	148	if (err < 0)
	149	return err;
	150
	151	sf = file->private_data;
	152	sf->private = ps;
	153
	154	return 0;
	155	}
	156
965c8e59	157	static loff_t pstore_file_llseek(struct file *file, loff_t off, int whence)
060287b8 AV	158	{
	159	struct seq_file *sf = file->private_data;
	160
	161	if (sf->op)
965c8e59 AM	162	return seq_lseek(file, off, whence);
965c8e59 AM	163	return default_llseek(file, off, whence);
060287b8 AV	164	}
060287b8 AV	165
fbe0aa1f	166	static const struct file_operations pstore_file_operations = {
060287b8 AV	167	.open = pstore_file_open,
	168	.read = pstore_file_read,
	169	.llseek = pstore_file_llseek,
	170	.release = seq_release,
fbe0aa1f	171	};
ca01d6dd TL	172
	173	/*
	174	* When a file is unlinked from our file system we call the
	175	* platform driver to erase the record from persistent store.
	176	*/
	177	static int pstore_unlink(struct inode dir, struct dentry dentry)
	178	{
2b0143b5	179	struct pstore_private *p = d_inode(dentry)->i_private;
83f70f07	180	struct pstore_record *record = p->record;
ca01d6dd	181
a61072aa	182	if (!record->psi->erase)
bf288333	183	return -EPERM;
a61072aa KC	184
	185	mutex_lock(&record->psi->read_mutex);
	186	record->psi->erase(record);
	187	mutex_unlock(&record->psi->read_mutex);
ca01d6dd TL	188
	189	return simple_unlink(dir, dentry);
	190	}
	191
a872d510 TL	192	static void pstore_evict_inode(struct inode *inode)
a872d510 TL	193	{
6dda9266 LT	194	struct pstore_private *p = inode->i_private;
	195	unsigned long flags;
	196
dbd5768f	197	clear_inode(inode);
6dda9266 LT	198	if (p) {
	199	spin_lock_irqsave(&allpstore_lock, flags);
	200	list_del(&p->list);
	201	spin_unlock_irqrestore(&allpstore_lock, flags);
1dfff7dd	202	free_pstore_private(p);
6dda9266	203	}
a872d510 TL	204	}
a872d510 TL	205
ca01d6dd TL	206	static const struct inode_operations pstore_dir_inode_operations = {
	207	.lookup = simple_lookup,
	208	.unlink = pstore_unlink,
	209	};
	210
22a71c30	211	static struct inode pstore_get_inode(struct super_block sb)
fbe0aa1f TL	212	{
fbe0aa1f TL	213	struct inode *inode = new_inode(sb);
fbe0aa1f TL	214	if (inode) {
fbe0aa1f TL	215	inode->i_ino = get_next_ino();
078cd827	216	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
fbe0aa1f TL	217	}
	218	return inode;
	219	}
	220
366f7e7a LT	221	enum {
	222	Opt_kmsg_bytes, Opt_err
	223	};
	224
	225	static const match_table_t tokens = {
	226	{Opt_kmsg_bytes, "kmsg_bytes=%u"},
	227	{Opt_err, NULL}
	228	};
	229
	230	static void parse_options(char *options)
	231	{
	232	char *p;
	233	substring_t args[MAX_OPT_ARGS];
	234	int option;
	235
	236	if (!options)
	237	return;
	238
	239	while ((p = strsep(&options, ",")) != NULL) {
	240	int token;
	241
	242	if (!*p)
	243	continue;
	244
	245	token = match_token(p, tokens, args);
	246	switch (token) {
	247	case Opt_kmsg_bytes:
	248	if (!match_int(&args[0], &option))
	249	pstore_set_kmsg_bytes(option);
	250	break;
	251	}
	252	}
	253	}
	254
349d7438 DH	255	/*
	256	* Display the mount options in /proc/mounts.
	257	*/
	258	static int pstore_show_options(struct seq_file m, struct dentry root)
	259	{
	260	if (kmsg_bytes != PSTORE_DEFAULT_KMSG_BYTES)
	261	seq_printf(m, ",kmsg_bytes=%lu", kmsg_bytes);
	262	return 0;
	263	}
	264
366f7e7a LT	265	static int pstore_remount(struct super_block sb, int flags, char *data)
366f7e7a LT	266	{
02b9984d	267	sync_filesystem(sb);
366f7e7a LT	268	parse_options(data);
	269
	270	return 0;
	271	}
	272
ca01d6dd TL	273	static const struct super_operations pstore_ops = {
	274	.statfs = simple_statfs,
	275	.drop_inode = generic_delete_inode,
a872d510	276	.evict_inode = pstore_evict_inode,
366f7e7a	277	.remount_fs = pstore_remount,
349d7438	278	.show_options = pstore_show_options,
ca01d6dd TL	279	};
	280
	281	static struct super_block *pstore_sb;
ca01d6dd	282
7e26e9ff	283	bool pstore_is_mounted(void)
ca01d6dd	284	{
fbe0aa1f	285	return pstore_sb != NULL;
ca01d6dd TL	286	}
	287
	288	/*
	289	* Make a regular file in the root directory of our file system.
	290	* Load it up with "size" bytes of data from "buf".
	291	* Set the mtime & ctime to the date that this record was originally stored.
	292	*/
3a7d2fd1	293	int pstore_mkfile(struct dentry root, struct pstore_record record)
ca01d6dd	294	{
ca01d6dd TL	295	struct dentry *dentry;
ca01d6dd TL	296	struct inode *inode;
6dda9266	297	int rc = 0;
ca01d6dd	298	char name[PSTORE_NAMELEN];
6dda9266 LT	299	struct pstore_private private, pos;
6dda9266 LT	300	unsigned long flags;
1edd1aa3	301	size_t size = record->size + record->ecc_notice_size;
6dda9266	302
3a7d2fd1 KC	303	WARN_ON(!inode_is_locked(d_inode(root)));
3a7d2fd1 KC	304
6dda9266 LT	305	spin_lock_irqsave(&allpstore_lock, flags);
6dda9266 LT	306	list_for_each_entry(pos, &allpstore, list) {
83f70f07 KC	307	if (pos->record->type == record->type &&
	308	pos->record->id == record->id &&
	309	pos->record->psi == record->psi) {
6dda9266 LT	310	rc = -EEXIST;
	311	break;
	312	}
	313	}
	314	spin_unlock_irqrestore(&allpstore_lock, flags);
	315	if (rc)
	316	return rc;
ca01d6dd TL	317
ca01d6dd TL	318	rc = -ENOMEM;
3a7d2fd1	319	inode = pstore_get_inode(root->d_sb);
ca01d6dd TL	320	if (!inode)
ca01d6dd TL	321	goto fail;
22a71c30 AV	322	inode->i_mode = S_IFREG \| 0444;
22a71c30 AV	323	inode->i_fop = &pstore_file_operations;
f0f23e54 JFG	324	scnprintf(name, sizeof(name), "%s-%s-%llu%s",
	325	pstore_type_to_name(record->type),
	326	record->psi->name, record->id,
	327	record->compressed ? ".enc.z" : "");
ca01d6dd	328
4c6d80e1 NM	329	private = kzalloc(sizeof(*private), GFP_KERNEL);
	330	if (!private)
	331	goto fail_inode;
	332
ca01d6dd	333	dentry = d_alloc_name(root, name);
c39524e6	334	if (!dentry)
3a7d2fd1	335	goto fail_private;
ca01d6dd	336
4c6d80e1	337	private->record = record;
83f70f07	338	inode->i_size = private->total_size = size;
ca01d6dd TL	339	inode->i_private = private;
ca01d6dd TL	340
1edd1aa3 KC	341	if (record->time.tv_sec)
1edd1aa3 KC	342	inode->i_mtime = inode->i_ctime = record->time;
ca01d6dd	343
fbe0aa1f	344	d_add(dentry, inode);
ca01d6dd	345
6dda9266 LT	346	spin_lock_irqsave(&allpstore_lock, flags);
	347	list_add(&private->list, &allpstore);
	348	spin_unlock_irqrestore(&allpstore_lock, flags);
	349
fbe0aa1f	350	return 0;
ca01d6dd	351
3a7d2fd1	352	fail_private:
1dfff7dd	353	free_pstore_private(private);
4c6d80e1	354	fail_inode:
ca01d6dd TL	355	iput(inode);
	356
	357	fail:
	358	return rc;
	359	}
	360
3a7d2fd1 KC	361	/*
	362	* Read all the records from the persistent store. Create
	363	* files in our filesystem. Don't warn about -EEXIST errors
	364	* when we are re-scanning the backing store looking to add new
	365	* error records.
	366	*/
	367	void pstore_get_records(int quiet)
	368	{
	369	struct pstore_info *psi = psinfo;
	370	struct dentry *root;
	371
	372	if (!psi \|\| !pstore_sb)
	373	return;
	374
	375	root = pstore_sb->s_root;
	376
	377	inode_lock(d_inode(root));
	378	pstore_get_backend_records(psi, root, quiet);
	379	inode_unlock(d_inode(root));
	380	}
	381
364ed2f4	382	static int pstore_fill_super(struct super_block sb, void data, int silent)
ca01d6dd	383	{
318ceed0	384	struct inode *inode;
ca01d6dd	385
ca01d6dd TL	386	pstore_sb = sb;
	387
	388	sb->s_maxbytes = MAX_LFS_FILESIZE;
09cbfeaf KS	389	sb->s_blocksize = PAGE_SIZE;
09cbfeaf KS	390	sb->s_blocksize_bits = PAGE_SHIFT;
ca01d6dd TL	391	sb->s_magic = PSTOREFS_MAGIC;
	392	sb->s_op = &pstore_ops;
	393	sb->s_time_gran = 1;
	394
366f7e7a LT	395	parse_options(data);
366f7e7a LT	396
22a71c30	397	inode = pstore_get_inode(sb);
318ceed0	398	if (inode) {
d7caa336	399	inode->i_mode = S_IFDIR \| 0750;
318ceed0	400	inode->i_op = &pstore_dir_inode_operations;
22a71c30 AV	401	inode->i_fop = &simple_dir_operations;
22a71c30 AV	402	inc_nlink(inode);
ca01d6dd	403	}
318ceed0 AV	404	sb->s_root = d_make_root(inode);
	405	if (!sb->s_root)
	406	return -ENOMEM;
ca01d6dd	407
6dda9266	408	pstore_get_records(0);
ca01d6dd TL	409
ca01d6dd TL	410	return 0;
ca01d6dd TL	411	}
ca01d6dd TL	412
fbe0aa1f TL	413	static struct dentry pstore_mount(struct file_system_type fs_type,
fbe0aa1f TL	414	int flags, const char dev_name, void data)
ca01d6dd	415	{
fbe0aa1f	416	return mount_single(fs_type, flags, data, pstore_fill_super);
ca01d6dd TL	417	}
	418
	419	static void pstore_kill_sb(struct super_block *sb)
	420	{
	421	kill_litter_super(sb);
	422	pstore_sb = NULL;
ca01d6dd TL	423	}
	424
	425	static struct file_system_type pstore_fs_type = {
ee1d2674	426	.owner = THIS_MODULE,
ca01d6dd	427	.name = "pstore",
fbe0aa1f	428	.mount = pstore_mount,
ca01d6dd TL	429	.kill_sb = pstore_kill_sb,
	430	};
	431
cb095afd	432	int __init pstore_init_fs(void)
ca01d6dd	433	{
f9bb4882	434	int err;
fb0af3f2 JB	435
fb0af3f2 JB	436	/* Create a convenient mount point for people to access pstore */
f9bb4882 EB	437	err = sysfs_create_mount_point(fs_kobj, "pstore");
f9bb4882 EB	438	if (err)
fb0af3f2	439	goto out;
fb0af3f2 JB	440
	441	err = register_filesystem(&pstore_fs_type);
	442	if (err < 0)
f9bb4882	443	sysfs_remove_mount_point(fs_kobj, "pstore");
fb0af3f2 JB	444
	445	out:
	446	return err;
ca01d6dd	447	}
ca01d6dd	448
cb095afd	449	void __exit pstore_exit_fs(void)
ee1d2674 GT	450	{
	451	unregister_filesystem(&pstore_fs_type);
	452	sysfs_remove_mount_point(fs_kobj, "pstore");
	453	}