Release 4.11 fs/pstore/inode.c

/*
 * 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 <linux/syslog.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;

}

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95
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1
100.00%



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

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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;
}

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66
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1
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66
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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, "CPU:%d ts:%llu %08lx  %08lx  %pf <- %pF\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;
}

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Anton Vorontsov
88
93.62%
1
50.00%
Joel Fernandes
6
6.38%
1
50.00%
Total
94
100.00%
2
100.00%


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 int pstore_check_syslog_permissions(struct pstore_private *ps)
{
	switch (ps->type) {
	case PSTORE_TYPE_DMESG:
	case PSTORE_TYPE_CONSOLE:
		return check_syslog_permissions(SYSLOG_ACTION_READ_ALL,
			SYSLOG_FROM_READER);
	default:
		return 0;
	}
}

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37
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1
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37
100.00%
1
100.00%



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);
}

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Tony Luck
48
60.76%
1
50.00%
Anton Vorontsov
31
39.24%
1
50.00%
Total
79
100.00%
2
100.00%



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;

	err = pstore_check_syslog_permissions(ps);
	if (err)
		return err;

	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;
}

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CommitProp
Anton Vorontsov
87
86.14%
1
50.00%
Sebastian Schmidt
14
13.86%
1
50.00%
Total
101
100.00%
2
100.00%



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);
}

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Anton Vorontsov
49
94.23%
1
50.00%
Andrew Morton
3
5.77%
1
50.00%
Total
52
100.00%
2
100.00%


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;
	int err;

	err = pstore_check_syslog_permissions(p);
	if (err)
		return err;

	if (p->psi->erase) {
		mutex_lock(&p->psi->read_mutex);
		p->psi->erase(p->type, p->id, p->count,
			      d_inode(dentry)->i_ctime, p->psi);
		mutex_unlock(&p->psi->read_mutex);
	} else {
		return -EPERM;
	}

	return simple_unlink(dir, dentry);
}

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Tony Luck
42
35.00%
1
10.00%
Namhyung Kim
24
20.00%
1
10.00%
Sebastian Schmidt
17
14.17%
1
10.00%
Matthew Garrett
10
8.33%
2
20.00%
Kees Cook
8
6.67%
1
10.00%
Seiji Aguchi
8
6.67%
2
20.00%
David Howells
6
5.00%
1
10.00%
Aruna Balakrishnaiah
5
4.17%
1
10.00%
Total
120
100.00%
10
100.00%



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);
	}
}

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Tony Luck
63
98.44%
2
66.67%
Jan Kara
1
1.56%
1
33.33%
Total
64
100.00%
3
100.00%


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;
}

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Tony Luck
52
92.86%
1
50.00%
Deepa Dinamani
4
7.14%
1
50.00%
Total
56
100.00%
2
100.00%

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;
		}
	}
}

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1
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98
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1
100.00%



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

	return 0;
}

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Tony Luck
27
84.38%
1
50.00%
Theodore Y. Ts'o
5
15.62%
1
50.00%
Total
32
100.00%
2
100.00%


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;



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

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11
91.67%
2
66.67%
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1
8.33%
1
33.33%
Total
12
100.00%
3
100.00%

/*
 * 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:
		scnprintf(name, sizeof(name), "dmesg-%s-%lld%s",
			  psname, id, compressed ? ".enc.z" : "");
		break;
	case PSTORE_TYPE_CONSOLE:
		scnprintf(name, sizeof(name), "console-%s-%lld", psname, id);
		break;
	case PSTORE_TYPE_FTRACE:
		scnprintf(name, sizeof(name), "ftrace-%s-%lld", psname, id);
		break;
	case PSTORE_TYPE_MCE:
		scnprintf(name, sizeof(name), "mce-%s-%lld", psname, id);
		break;
	case PSTORE_TYPE_PPC_RTAS:
		scnprintf(name, sizeof(name), "rtas-%s-%lld", psname, id);
		break;
	case PSTORE_TYPE_PPC_OF:
		scnprintf(name, sizeof(name), "powerpc-ofw-%s-%lld",
			  psname, id);
		break;
	case PSTORE_TYPE_PPC_COMMON:
		scnprintf(name, sizeof(name), "powerpc-common-%s-%lld",
			  psname, id);
		break;
	case PSTORE_TYPE_PMSG:
		scnprintf(name, sizeof(name), "pmsg-%s-%lld", psname, id);
		break;
	case PSTORE_TYPE_PPC_OPAL:
		sprintf(name, "powerpc-opal-%s-%lld", psname, id);
		break;
	case PSTORE_TYPE_UNKNOWN:
		scnprintf(name, sizeof(name), "unknown-%s-%lld", psname, id);
		break;
	default:
		scnprintf(name, sizeof(name), "type%d-%s-%lld",
			  type, psname, id);
		break;
	}

	inode_lock(d_inode(root));

	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);

	inode_unlock(d_inode(root));

	return 0;

fail_lockedalloc:
	inode_unlock(d_inode(root));
	kfree(private);
fail_alloc:
	iput(inode);

fail:
	return rc;
}

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Tony Luck
371
63.10%
3
15.00%
Mark Salyzyn
74
12.59%
2
10.00%
Aruna Balakrishnaiah
52
8.84%
4
20.00%
Anton Vorontsov
22
3.74%
2
10.00%
Al Viro
18
3.06%
2
10.00%
Hari Bathini
15
2.55%
1
5.00%
Matthew Garrett
11
1.87%
2
10.00%
Seiji Aguchi
9
1.53%
1
5.00%
David Howells
9
1.53%
1
5.00%
Valdis Kletnieks
6
1.02%
1
5.00%
Dan Carpenter
1
0.17%
1
5.00%
Total
588
100.00%
20
100.00%



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_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 | 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;
}

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Tony Luck
111
77.08%
3
37.50%
Al Viro
30
20.83%
3
37.50%
Kirill A. Shutemov
2
1.39%
1
12.50%
Anton Vorontsov
1
0.69%
1
12.50%
Total
144
100.00%
8
100.00%



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);
}

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Tony Luck
37
100.00%
2
100.00%
Total
37
100.00%
2
100.00%



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

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20
100.00%
1
100.00%
Total
20
100.00%
1
100.00%


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



static int __init init_pstore_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;
}
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Josh Boyer
31
56.36%
1
33.33%
Tony Luck
15
27.27%
1
33.33%
Eric W. Biedermann
9
16.36%
1
33.33%
Total
55
100.00%
3
100.00%

module_init(init_pstore_fs)



static void __exit exit_pstore_fs(void)
{
	unregister_filesystem(&pstore_fs_type);
	sysfs_remove_mount_point(fs_kobj, "pstore");
}
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1
100.00%
Total
22
100.00%
1
100.00%

module_exit(exit_pstore_fs)

MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>");
MODULE_LICENSE("GPL");
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Tony Luck
1128
53.49%
5
12.50%
Anton Vorontsov
517
24.51%
3
7.50%
Mark Salyzyn
74
3.51%
2
5.00%
Sebastian Schmidt
71
3.37%
1
2.50%
Aruna Balakrishnaiah
57
2.70%
5
12.50%
Al Viro
48
2.28%
4
10.00%
Geliang Tang
32
1.52%
2
5.00%
Matthew Garrett
32
1.52%
2
5.00%
Josh Boyer
31
1.47%
1
2.50%
Namhyung Kim
24
1.14%
1
2.50%
Seiji Aguchi
20
0.95%
2
5.00%
David Howells
15
0.71%
1
2.50%
Hari Bathini
15
0.71%
1
2.50%
Eric W. Biedermann
9
0.43%
1
2.50%
Kees Cook
8
0.38%
1
2.50%
Joel Fernandes
6
0.28%
1
2.50%
Valdis Kletnieks
6
0.28%
1
2.50%
Theodore Y. Ts'o
5
0.24%
1
2.50%
Deepa Dinamani
4
0.19%
1
2.50%
Andrew Morton
3
0.14%
1
2.50%
Kirill A. Shutemov
2
0.09%
1
2.50%
Dan Carpenter
1
0.05%
1
2.50%
Jan Kara
1
0.05%
1
2.50%
Total
2109
100.00%
40
100.00%
Directory: fs/pstore

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