summaryrefslogtreecommitdiff
path: root/fs/pstore/platform.c
blob: 16ecca5b72d815d92163def3f03bd9f26c4cc8b1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
/*
 * Persistent Storage - platform driver interface parts.
 *
 * Copyright (C) 2007-2008 Google, Inc.
 * 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
 */

#define pr_fmt(fmt) "pstore: " fmt

#include <linux/atomic.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kmsg_dump.h>
#include <linux/console.h>
#include <linux/module.h>
#include <linux/pstore.h>
#ifdef CONFIG_PSTORE_ZLIB_COMPRESS
#include <linux/zlib.h>
#endif
#ifdef CONFIG_PSTORE_LZO_COMPRESS
#include <linux/lzo.h>
#endif
#ifdef CONFIG_PSTORE_LZ4_COMPRESS
#include <linux/lz4.h>
#endif
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
#include <linux/jiffies.h>
#include <linux/workqueue.h>

#include "internal.h"

/*
 * We defer making "oops" entries appear in pstore - see
 * whether the system is actually still running well enough
 * to let someone see the entry
 */
static int pstore_update_ms = -1;
module_param_named(update_ms, pstore_update_ms, int, 0600);
MODULE_PARM_DESC(update_ms, "milliseconds before pstore updates its content "
		 "(default is -1, which means runtime updates are disabled; "
		 "enabling this option is not safe, it may lead to further "
		 "corruption on Oopses)");

static int pstore_new_entry;

static void pstore_timefunc(unsigned long);
static DEFINE_TIMER(pstore_timer, pstore_timefunc, 0, 0);

static void pstore_dowork(struct work_struct *);
static DECLARE_WORK(pstore_work, pstore_dowork);

/*
 * pstore_lock just protects "psinfo" during
 * calls to pstore_register()
 */
static DEFINE_SPINLOCK(pstore_lock);
struct pstore_info *psinfo;

static char *backend;

/* Compression parameters */
#ifdef CONFIG_PSTORE_ZLIB_COMPRESS
#define COMPR_LEVEL 6
#define WINDOW_BITS 12
#define MEM_LEVEL 4
static struct z_stream_s stream;
#else
static unsigned char *workspace;
#endif

struct pstore_zbackend {
	int (*compress)(const void *in, void *out, size_t inlen, size_t outlen);
	int (*decompress)(void *in, void *out, size_t inlen, size_t outlen);
	void (*allocate)(void);
	void (*free)(void);

	const char *name;
};

static char *big_oops_buf;
static size_t big_oops_buf_sz;

/* How much of the console log to snapshot */
static unsigned long kmsg_bytes = 10240;

void pstore_set_kmsg_bytes(int bytes)
{
	kmsg_bytes = bytes;
}

/* Tag each group of saved records with a sequence number */
static int	oopscount;

static const char *get_reason_str(enum kmsg_dump_reason reason)
{
	switch (reason) {
	case KMSG_DUMP_PANIC:
		return "Panic";
	case KMSG_DUMP_OOPS:
		return "Oops";
	case KMSG_DUMP_EMERG:
		return "Emergency";
	case KMSG_DUMP_RESTART:
		return "Restart";
	case KMSG_DUMP_HALT:
		return "Halt";
	case KMSG_DUMP_POWEROFF:
		return "Poweroff";
	default:
		return "Unknown";
	}
}

bool pstore_cannot_block_path(enum kmsg_dump_reason reason)
{
	/*
	 * In case of NMI path, pstore shouldn't be blocked
	 * regardless of reason.
	 */
	if (in_nmi())
		return true;

	switch (reason) {
	/* In panic case, other cpus are stopped by smp_send_stop(). */
	case KMSG_DUMP_PANIC:
	/* Emergency restart shouldn't be blocked by spin lock. */
	case KMSG_DUMP_EMERG:
		return true;
	default:
		return false;
	}
}
EXPORT_SYMBOL_GPL(pstore_cannot_block_path);

#ifdef CONFIG_PSTORE_ZLIB_COMPRESS
/* Derived from logfs_compress() */
static int compress_zlib(const void *in, void *out, size_t inlen, size_t outlen)
{
	int err, ret;

	ret = -EIO;
	err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
						MEM_LEVEL, Z_DEFAULT_STRATEGY);
	if (err != Z_OK)
		goto error;

	stream.next_in = in;
	stream.avail_in = inlen;
	stream.total_in = 0;
	stream.next_out = out;
	stream.avail_out = outlen;
	stream.total_out = 0;

	err = zlib_deflate(&stream, Z_FINISH);
	if (err != Z_STREAM_END)
		goto error;

	err = zlib_deflateEnd(&stream);
	if (err != Z_OK)
		goto error;

	if (stream.total_out >= stream.total_in)
		goto error;

	ret = stream.total_out;
error:
	return ret;
}

/* Derived from logfs_uncompress */
static int decompress_zlib(void *in, void *out, size_t inlen, size_t outlen)
{
	int err, ret;

	ret = -EIO;
	err = zlib_inflateInit2(&stream, WINDOW_BITS);
	if (err != Z_OK)
		goto error;

	stream.next_in = in;
	stream.avail_in = inlen;
	stream.total_in = 0;
	stream.next_out = out;
	stream.avail_out = outlen;
	stream.total_out = 0;

	err = zlib_inflate(&stream, Z_FINISH);
	if (err != Z_STREAM_END)
		goto error;

	err = zlib_inflateEnd(&stream);
	if (err != Z_OK)
		goto error;

	ret = stream.total_out;
error:
	return ret;
}

static void allocate_zlib(void)
{
	size_t size;
	size_t cmpr;

	switch (psinfo->bufsize) {
	/* buffer range for efivars */
	case 1000 ... 2000:
		cmpr = 56;
		break;
	case 2001 ... 3000:
		cmpr = 54;
		break;
	case 3001 ... 3999:
		cmpr = 52;
		break;
	/* buffer range for nvram, erst */
	case 4000 ... 10000:
		cmpr = 45;
		break;
	default:
		cmpr = 60;
		break;
	}

	big_oops_buf_sz = (psinfo->bufsize * 100) / cmpr;
	big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
	if (big_oops_buf) {
		size = max(zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL),
			zlib_inflate_workspacesize());
		stream.workspace = kmalloc(size, GFP_KERNEL);
		if (!stream.workspace) {
			pr_err("No memory for compression workspace; skipping compression\n");
			kfree(big_oops_buf);
			big_oops_buf = NULL;
		}
	} else {
		pr_err("No memory for uncompressed data; skipping compression\n");
		stream.workspace = NULL;
	}

}

static void free_zlib(void)
{
	kfree(stream.workspace);
	stream.workspace = NULL;
	kfree(big_oops_buf);
	big_oops_buf = NULL;
	big_oops_buf_sz = 0;
}

static struct pstore_zbackend backend_zlib = {
	.compress	= compress_zlib,
	.decompress	= decompress_zlib,
	.allocate	= allocate_zlib,
	.free		= free_zlib,
	.name		= "zlib",
};
#endif

#ifdef CONFIG_PSTORE_LZO_COMPRESS
static int compress_lzo(const void *in, void *out, size_t inlen, size_t outlen)
{
	int ret;

	ret = lzo1x_1_compress(in, inlen, out, &outlen, workspace);
	if (ret != LZO_E_OK) {
		pr_err("lzo_compress error, ret = %d!\n", ret);
		return -EIO;
	}

	return outlen;
}

static int decompress_lzo(void *in, void *out, size_t inlen, size_t outlen)
{
	int ret;

	ret = lzo1x_decompress_safe(in, inlen, out, &outlen);
	if (ret != LZO_E_OK) {
		pr_err("lzo_decompress error, ret = %d!\n", ret);
		return -EIO;
	}

	return outlen;
}

static void allocate_lzo(void)
{
	big_oops_buf_sz = lzo1x_worst_compress(psinfo->bufsize);
	big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
	if (big_oops_buf) {
		workspace = kmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
		if (!workspace) {
			pr_err("No memory for compression workspace; skipping compression\n");
			kfree(big_oops_buf);
			big_oops_buf = NULL;
		}
	} else {
		pr_err("No memory for uncompressed data; skipping compression\n");
		workspace = NULL;
	}
}

static void free_lzo(void)
{
	kfree(workspace);
	kfree(big_oops_buf);
	big_oops_buf = NULL;
	big_oops_buf_sz = 0;
}

static struct pstore_zbackend backend_lzo = {
	.compress	= compress_lzo,
	.decompress	= decompress_lzo,
	.allocate	= allocate_lzo,
	.free		= free_lzo,
	.name		= "lzo",
};
#endif

#ifdef CONFIG_PSTORE_LZ4_COMPRESS
static int compress_lz4(const void *in, void *out, size_t inlen, size_t outlen)
{
	int ret;

	ret = lz4_compress(in, inlen, out, &outlen, workspace);
	if (ret) {
		pr_err("lz4_compress error, ret = %d!\n", ret);
		return -EIO;
	}

	return outlen;
}

static int decompress_lz4(void *in, void *out, size_t inlen, size_t outlen)
{
	int ret;

	ret = lz4_decompress_unknownoutputsize(in, inlen, out, &outlen);
	if (ret) {
		pr_err("lz4_decompress error, ret = %d!\n", ret);
		return -EIO;
	}

	return outlen;
}

static void allocate_lz4(void)
{
	big_oops_buf_sz = lz4_compressbound(psinfo->bufsize);
	big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
	if (big_oops_buf) {
		workspace = kmalloc(LZ4_MEM_COMPRESS, GFP_KERNEL);
		if (!workspace) {
			pr_err("No memory for compression workspace; skipping compression\n");
			kfree(big_oops_buf);
			big_oops_buf = NULL;
		}
	} else {
		pr_err("No memory for uncompressed data; skipping compression\n");
		workspace = NULL;
	}
}

static void free_lz4(void)
{
	kfree(workspace);
	kfree(big_oops_buf);
	big_oops_buf = NULL;
	big_oops_buf_sz = 0;
}

static struct pstore_zbackend backend_lz4 = {
	.compress	= compress_lz4,
	.decompress	= decompress_lz4,
	.allocate	= allocate_lz4,
	.free		= free_lz4,
	.name		= "lz4",
};
#endif

static struct pstore_zbackend *zbackend =
#if defined(CONFIG_PSTORE_ZLIB_COMPRESS)
	&backend_zlib;
#elif defined(CONFIG_PSTORE_LZO_COMPRESS)
	&backend_lzo;
#elif defined(CONFIG_PSTORE_LZ4_COMPRESS)
	&backend_lz4;
#else
	NULL;
#endif

static int pstore_compress(const void *in, void *out,
			   size_t inlen, size_t outlen)
{
	if (zbackend)
		return zbackend->compress(in, out, inlen, outlen);
	else
		return -EIO;
}

static int pstore_decompress(void *in, void *out, size_t inlen, size_t outlen)
{
	if (zbackend)
		return zbackend->decompress(in, out, inlen, outlen);
	else
		return -EIO;
}

static void allocate_buf_for_compression(void)
{
	if (zbackend) {
		pr_info("using %s compression\n", zbackend->name);
		zbackend->allocate();
	} else {
		pr_err("allocate compression buffer error!\n");
	}
}

static void free_buf_for_compression(void)
{
	if (zbackend)
		zbackend->free();
	else
		pr_err("free compression buffer error!\n");
}

/*
 * Called when compression fails, since the printk buffer
 * would be fetched for compression calling it again when
 * compression fails would have moved the iterator of
 * printk buffer which results in fetching old contents.
 * Copy the recent messages from big_oops_buf to psinfo->buf
 */
static size_t copy_kmsg_to_buffer(int hsize, size_t len)
{
	size_t total_len;
	size_t diff;

	total_len = hsize + len;

	if (total_len > psinfo->bufsize) {
		diff = total_len - psinfo->bufsize + hsize;
		memcpy(psinfo->buf, big_oops_buf, hsize);
		memcpy(psinfo->buf + hsize, big_oops_buf + diff,
					psinfo->bufsize - hsize);
		total_len = psinfo->bufsize;
	} else
		memcpy(psinfo->buf, big_oops_buf, total_len);

	return total_len;
}

/*
 * callback from kmsg_dump. (s2,l2) has the most recently
 * written bytes, older bytes are in (s1,l1). Save as much
 * as we can from the end of the buffer.
 */
static void pstore_dump(struct kmsg_dumper *dumper,
			enum kmsg_dump_reason reason)
{
	unsigned long	total = 0;
	const char	*why;
	u64		id;
	unsigned int	part = 1;
	unsigned long	flags = 0;
	int		is_locked;
	int		ret;

	why = get_reason_str(reason);

	if (pstore_cannot_block_path(reason)) {
		is_locked = spin_trylock_irqsave(&psinfo->buf_lock, flags);
		if (!is_locked) {
			pr_err("pstore dump routine blocked in %s path, may corrupt error record\n"
				       , in_nmi() ? "NMI" : why);
		}
	} else {
		spin_lock_irqsave(&psinfo->buf_lock, flags);
		is_locked = 1;
	}
	oopscount++;
	while (total < kmsg_bytes) {
		char *dst;
		unsigned long size;
		int hsize;
		int zipped_len = -1;
		size_t len;
		bool compressed = false;
		size_t total_len;

		if (big_oops_buf && is_locked) {
			dst = big_oops_buf;
			size = big_oops_buf_sz;
		} else {
			dst = psinfo->buf;
			size = psinfo->bufsize;
		}

		hsize = sprintf(dst, "%s#%d Part%u\n", why, oopscount, part);
		size -= hsize;

		if (!kmsg_dump_get_buffer(dumper, true, dst + hsize,
					  size, &len))
			break;

		if (big_oops_buf && is_locked) {
			zipped_len = pstore_compress(dst, psinfo->buf,
						hsize + len, psinfo->bufsize);

			if (zipped_len > 0) {
				compressed = true;
				total_len = zipped_len;
			} else {
				total_len = copy_kmsg_to_buffer(hsize, len);
			}
		} else {
			total_len = hsize + len;
		}

		ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part,
				    oopscount, compressed, total_len, psinfo);
		if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted())
			pstore_new_entry = 1;

		total += total_len;
		part++;
	}
	if (is_locked)
		spin_unlock_irqrestore(&psinfo->buf_lock, flags);
}

static struct kmsg_dumper pstore_dumper = {
	.dump = pstore_dump,
};

/*
 * Register with kmsg_dump to save last part of console log on panic.
 */
static void pstore_register_kmsg(void)
{
	kmsg_dump_register(&pstore_dumper);
}

static void pstore_unregister_kmsg(void)
{
	kmsg_dump_unregister(&pstore_dumper);
}

#ifdef CONFIG_PSTORE_CONSOLE
static void pstore_console_write(struct console *con, const char *s, unsigned c)
{
	const char *e = s + c;

	while (s < e) {
		unsigned long flags;
		u64 id;

		if (c > psinfo->bufsize)
			c = psinfo->bufsize;

		if (oops_in_progress) {
			if (!spin_trylock_irqsave(&psinfo->buf_lock, flags))
				break;
		} else {
			spin_lock_irqsave(&psinfo->buf_lock, flags);
		}
		memcpy(psinfo->buf, s, c);
		psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, 0, 0, c, psinfo);
		spin_unlock_irqrestore(&psinfo->buf_lock, flags);
		s += c;
		c = e - s;
	}
}

static struct console pstore_console = {
	.name	= "pstore",
	.write	= pstore_console_write,
	.flags	= CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME,
	.index	= -1,
};

static void pstore_register_console(void)
{
	register_console(&pstore_console);
}

static void pstore_unregister_console(void)
{
	unregister_console(&pstore_console);
}
#else
static void pstore_register_console(void) {}
static void pstore_unregister_console(void) {}
#endif

static int pstore_write_compat(enum pstore_type_id type,
			       enum kmsg_dump_reason reason,
			       u64 *id, unsigned int part, int count,
			       bool compressed, size_t size,
			       struct pstore_info *psi)
{
	return psi->write_buf(type, reason, id, part, psinfo->buf, compressed,
			     size, psi);
}

/*
 * platform specific persistent storage driver registers with
 * us here. If pstore is already mounted, call the platform
 * read function right away to populate the file system. If not
 * then the pstore mount code will call us later to fill out
 * the file system.
 */
int pstore_register(struct pstore_info *psi)
{
	struct module *owner = psi->owner;

	if (backend && strcmp(backend, psi->name))
		return -EPERM;

	spin_lock(&pstore_lock);
	if (psinfo) {
		spin_unlock(&pstore_lock);
		return -EBUSY;
	}

	if (!psi->write)
		psi->write = pstore_write_compat;
	psinfo = psi;
	mutex_init(&psinfo->read_mutex);
	spin_unlock(&pstore_lock);

	if (owner && !try_module_get(owner)) {
		psinfo = NULL;
		return -EINVAL;
	}

	allocate_buf_for_compression();

	if (pstore_is_mounted())
		pstore_get_records(0);

	pstore_register_kmsg();

	if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) {
		pstore_register_console();
		pstore_register_ftrace();
		pstore_register_pmsg();
	}

	if (pstore_update_ms >= 0) {
		pstore_timer.expires = jiffies +
			msecs_to_jiffies(pstore_update_ms);
		add_timer(&pstore_timer);
	}

	/*
	 * Update the module parameter backend, so it is visible
	 * through /sys/module/pstore/parameters/backend
	 */
	backend = psi->name;

	module_put(owner);

	pr_info("Registered %s as persistent store backend\n", psi->name);

	return 0;
}
EXPORT_SYMBOL_GPL(pstore_register);

void pstore_unregister(struct pstore_info *psi)
{
	if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) {
		pstore_unregister_pmsg();
		pstore_unregister_ftrace();
		pstore_unregister_console();
	}
	pstore_unregister_kmsg();

	free_buf_for_compression();

	psinfo = NULL;
	backend = NULL;
}
EXPORT_SYMBOL_GPL(pstore_unregister);

/*
 * 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;
	char			*buf = NULL;
	ssize_t			size;
	u64			id;
	int			count;
	enum pstore_type_id	type;
	struct timespec		time;
	int			failed = 0, rc;
	bool			compressed;
	int			unzipped_len = -1;
	ssize_t			ecc_notice_size = 0;

	if (!psi)
		return;

	mutex_lock(&psi->read_mutex);
	if (psi->open && psi->open(psi))
		goto out;

	while ((size = psi->read(&id, &type, &count, &time, &buf, &compressed,
				 &ecc_notice_size, psi)) > 0) {
		if (compressed && (type == PSTORE_TYPE_DMESG)) {
			if (big_oops_buf)
				unzipped_len = pstore_decompress(buf,
							big_oops_buf, size,
							big_oops_buf_sz);

			if (unzipped_len > 0) {
				if (ecc_notice_size)
					memcpy(big_oops_buf + unzipped_len,
					       buf + size, ecc_notice_size);
				kfree(buf);
				buf = big_oops_buf;
				size = unzipped_len;
				compressed = false;
			} else {
				pr_err("decompression failed;returned %d\n",
				       unzipped_len);
				compressed = true;
			}
		}
		rc = pstore_mkfile(type, psi->name, id, count, buf,
				   compressed, size + ecc_notice_size,
				   time, psi);
		if (unzipped_len < 0) {
			/* Free buffer other than big oops */
			kfree(buf);
			buf = NULL;
		} else
			unzipped_len = -1;
		if (rc && (rc != -EEXIST || !quiet))
			failed++;
	}
	if (psi->close)
		psi->close(psi);
out:
	mutex_unlock(&psi->read_mutex);

	if (failed)
		pr_warn("failed to load %d record(s) from '%s'\n",
			failed, psi->name);
}

static void pstore_dowork(struct work_struct *work)
{
	pstore_get_records(1);
}

static void pstore_timefunc(unsigned long dummy)
{
	if (pstore_new_entry) {
		pstore_new_entry = 0;
		schedule_work(&pstore_work);
	}

	mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms));
}

module_param(backend, charp, 0444);
MODULE_PARM_DESC(backend, "Pstore backend to use");