aboutsummaryrefslogtreecommitdiff
path: root/fs/jffs2/summary.c
blob: e537fb0e0184e97eae8907a97c34d46920d9f129 (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
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2004  Ferenc Havasi <havasi@inf.u-szeged.hu>,
 *		     Zoltan Sogor <weth@inf.u-szeged.hu>,
 *		     Patrik Kluba <pajko@halom.u-szeged.hu>,
 *		     University of Szeged, Hungary
 *	       2006  KaiGai Kohei <kaigai@ak.jp.nec.com>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/pagemap.h>
#include <linux/crc32.h>
#include <linux/compiler.h>
#include <linux/vmalloc.h>
#include "nodelist.h"
#include "debug.h"

int jffs2_sum_init(struct jffs2_sb_info *c)
{
	uint32_t sum_size = min_t(uint32_t, c->sector_size, MAX_SUMMARY_SIZE);

	c->summary = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);

	if (!c->summary) {
		JFFS2_WARNING("Can't allocate memory for summary information!\n");
		return -ENOMEM;
	}

	c->summary->sum_buf = kmalloc(sum_size, GFP_KERNEL);

	if (!c->summary->sum_buf) {
		JFFS2_WARNING("Can't allocate buffer for writing out summary information!\n");
		kfree(c->summary);
		return -ENOMEM;
	}

	dbg_summary("returned successfully\n");

	return 0;
}

void jffs2_sum_exit(struct jffs2_sb_info *c)
{
	dbg_summary("called\n");

	jffs2_sum_disable_collecting(c->summary);

	kfree(c->summary->sum_buf);
	c->summary->sum_buf = NULL;

	kfree(c->summary);
	c->summary = NULL;
}

static int jffs2_sum_add_mem(struct jffs2_summary *s, union jffs2_sum_mem *item)
{
	if (!s->sum_list_head)
		s->sum_list_head = (union jffs2_sum_mem *) item;
	if (s->sum_list_tail)
		s->sum_list_tail->u.next = (union jffs2_sum_mem *) item;
	s->sum_list_tail = (union jffs2_sum_mem *) item;

	switch (je16_to_cpu(item->u.nodetype)) {
		case JFFS2_NODETYPE_INODE:
			s->sum_size += JFFS2_SUMMARY_INODE_SIZE;
			s->sum_num++;
			dbg_summary("inode (%u) added to summary\n",
						je32_to_cpu(item->i.inode));
			break;
		case JFFS2_NODETYPE_DIRENT:
			s->sum_size += JFFS2_SUMMARY_DIRENT_SIZE(item->d.nsize);
			s->sum_num++;
			dbg_summary("dirent (%u) added to summary\n",
						je32_to_cpu(item->d.ino));
			break;
#ifdef CONFIG_JFFS2_FS_XATTR
		case JFFS2_NODETYPE_XATTR:
			s->sum_size += JFFS2_SUMMARY_XATTR_SIZE;
			s->sum_num++;
			dbg_summary("xattr (xid=%u, version=%u) added to summary\n",
				    je32_to_cpu(item->x.xid), je32_to_cpu(item->x.version));
			break;
		case JFFS2_NODETYPE_XREF:
			s->sum_size += JFFS2_SUMMARY_XREF_SIZE;
			s->sum_num++;
			dbg_summary("xref added to summary\n");
			break;
#endif
		default:
			JFFS2_WARNING("UNKNOWN node type %u\n",
					    je16_to_cpu(item->u.nodetype));
			return 1;
	}
	return 0;
}


/* The following 3 functions are called from scan.c to collect summary info for not closed jeb */

int jffs2_sum_add_padding_mem(struct jffs2_summary *s, uint32_t size)
{
	dbg_summary("called with %u\n", size);
	s->sum_padded += size;
	return 0;
}

int jffs2_sum_add_inode_mem(struct jffs2_summary *s, struct jffs2_raw_inode *ri,
				uint32_t ofs)
{
	struct jffs2_sum_inode_mem *temp = kmalloc(sizeof(struct jffs2_sum_inode_mem), GFP_KERNEL);

	if (!temp)
		return -ENOMEM;

	temp->nodetype = ri->nodetype;
	temp->inode = ri->ino;
	temp->version = ri->version;
	temp->offset = cpu_to_je32(ofs); /* relative offset from the beginning of the jeb */
	temp->totlen = ri->totlen;
	temp->next = NULL;

	return jffs2_sum_add_mem(s, (union jffs2_sum_mem *)temp);
}

int jffs2_sum_add_dirent_mem(struct jffs2_summary *s, struct jffs2_raw_dirent *rd,
				uint32_t ofs)
{
	struct jffs2_sum_dirent_mem *temp =
		kmalloc(sizeof(struct jffs2_sum_dirent_mem) + rd->nsize, GFP_KERNEL);

	if (!temp)
		return -ENOMEM;

	temp->nodetype = rd->nodetype;
	temp->totlen = rd->totlen;
	temp->offset = cpu_to_je32(ofs);	/* relative from the beginning of the jeb */
	temp->pino = rd->pino;
	temp->version = rd->version;
	temp->ino = rd->ino;
	temp->nsize = rd->nsize;
	temp->type = rd->type;
	temp->next = NULL;

	memcpy(temp->name, rd->name, rd->nsize);

	return jffs2_sum_add_mem(s, (union jffs2_sum_mem *)temp);
}

#ifdef CONFIG_JFFS2_FS_XATTR
int jffs2_sum_add_xattr_mem(struct jffs2_summary *s, struct jffs2_raw_xattr *rx, uint32_t ofs)
{
	struct jffs2_sum_xattr_mem *temp;

	temp = kmalloc(sizeof(struct jffs2_sum_xattr_mem), GFP_KERNEL);
	if (!temp)
		return -ENOMEM;

	temp->nodetype = rx->nodetype;
	temp->xid = rx->xid;
	temp->version = rx->version;
	temp->offset = cpu_to_je32(ofs);
	temp->totlen = rx->totlen;
	temp->next = NULL;

	return jffs2_sum_add_mem(s, (union jffs2_sum_mem *)temp);
}

int jffs2_sum_add_xref_mem(struct jffs2_summary *s, struct jffs2_raw_xref *rr, uint32_t ofs)
{
	struct jffs2_sum_xref_mem *temp;

	temp = kmalloc(sizeof(struct jffs2_sum_xref_mem), GFP_KERNEL);
	if (!temp)
		return -ENOMEM;

	temp->nodetype = rr->nodetype;
	temp->offset = cpu_to_je32(ofs);
	temp->next = NULL;

	return jffs2_sum_add_mem(s, (union jffs2_sum_mem *)temp);
}
#endif
/* Cleanup every collected summary information */

static void jffs2_sum_clean_collected(struct jffs2_summary *s)
{
	union jffs2_sum_mem *temp;

	if (!s->sum_list_head) {
		dbg_summary("already empty\n");
	}
	while (s->sum_list_head) {
		temp = s->sum_list_head;
		s->sum_list_head = s->sum_list_head->u.next;
		kfree(temp);
	}
	s->sum_list_tail = NULL;
	s->sum_padded = 0;
	s->sum_num = 0;
}

void jffs2_sum_reset_collected(struct jffs2_summary *s)
{
	dbg_summary("called\n");
	jffs2_sum_clean_collected(s);
	s->sum_size = 0;
}

void jffs2_sum_disable_collecting(struct jffs2_summary *s)
{
	dbg_summary("called\n");
	jffs2_sum_clean_collected(s);
	s->sum_size = JFFS2_SUMMARY_NOSUM_SIZE;
}

int jffs2_sum_is_disabled(struct jffs2_summary *s)
{
	return (s->sum_size == JFFS2_SUMMARY_NOSUM_SIZE);
}

/* Move the collected summary information into sb (called from scan.c) */

void jffs2_sum_move_collected(struct jffs2_sb_info *c, struct jffs2_summary *s)
{
	dbg_summary("oldsize=0x%x oldnum=%u => newsize=0x%x newnum=%u\n",
				c->summary->sum_size, c->summary->sum_num,
				s->sum_size, s->sum_num);

	c->summary->sum_size = s->sum_size;
	c->summary->sum_num = s->sum_num;
	c->summary->sum_padded = s->sum_padded;
	c->summary->sum_list_head = s->sum_list_head;
	c->summary->sum_list_tail = s->sum_list_tail;

	s->sum_list_head = s->sum_list_tail = NULL;
}

/* Called from wbuf.c to collect writed node info */

int jffs2_sum_add_kvec(struct jffs2_sb_info *c, const struct kvec *invecs,
				unsigned long count, uint32_t ofs)
{
	union jffs2_node_union *node;
	struct jffs2_eraseblock *jeb;

	if (c->summary->sum_size == JFFS2_SUMMARY_NOSUM_SIZE) {
		dbg_summary("Summary is disabled for this jeb! Skipping summary info!\n");
		return 0;
	}

	node = invecs[0].iov_base;
	jeb = &c->blocks[ofs / c->sector_size];
	ofs -= jeb->offset;

	switch (je16_to_cpu(node->u.nodetype)) {
		case JFFS2_NODETYPE_INODE: {
			struct jffs2_sum_inode_mem *temp =
				kmalloc(sizeof(struct jffs2_sum_inode_mem), GFP_KERNEL);

			if (!temp)
				goto no_mem;

			temp->nodetype = node->i.nodetype;
			temp->inode = node->i.ino;
			temp->version = node->i.version;
			temp->offset = cpu_to_je32(ofs);
			temp->totlen = node->i.totlen;
			temp->next = NULL;

			return jffs2_sum_add_mem(c->summary, (union jffs2_sum_mem *)temp);
		}

		case JFFS2_NODETYPE_DIRENT: {
			struct jffs2_sum_dirent_mem *temp =
				kmalloc(sizeof(struct jffs2_sum_dirent_mem) + node->d.nsize, GFP_KERNEL);

			if (!temp)
				goto no_mem;

			temp->nodetype = node->d.nodetype;
			temp->totlen = node->d.totlen;
			temp->offset = cpu_to_je32(ofs);
			temp->pino = node->d.pino;
			temp->version = node->d.version;
			temp->ino = node->d.ino;
			temp->nsize = node->d.nsize;
			temp->type = node->d.type;
			temp->next = NULL;

			switch (count) {
				case 1:
					memcpy(temp->name,node->d.name,node->d.nsize);
					break;

				case 2:
					memcpy(temp->name,invecs[1].iov_base,node->d.nsize);
					break;

				default:
					BUG();	/* impossible count value */
					break;
			}

			return jffs2_sum_add_mem(c->summary, (union jffs2_sum_mem *)temp);
		}
#ifdef CONFIG_JFFS2_FS_XATTR
		case JFFS2_NODETYPE_XATTR: {
			struct jffs2_sum_xattr_mem *temp;
			temp = kmalloc(sizeof(struct jffs2_sum_xattr_mem), GFP_KERNEL);
			if (!temp)
				goto no_mem;

			temp->nodetype = node->x.nodetype;
			temp->xid = node->x.xid;
			temp->version = node->x.version;
			temp->totlen = node->x.totlen;
			temp->offset = cpu_to_je32(ofs);
			temp->next = NULL;

			return jffs2_sum_add_mem(c->summary, (union jffs2_sum_mem *)temp);
		}
		case JFFS2_NODETYPE_XREF: {
			struct jffs2_sum_xref_mem *temp;
			temp = kmalloc(sizeof(struct jffs2_sum_xref_mem), GFP_KERNEL);
			if (!temp)
				goto no_mem;
			temp->nodetype = node->r.nodetype;
			temp->offset = cpu_to_je32(ofs);
			temp->next = NULL;

			return jffs2_sum_add_mem(c->summary, (union jffs2_sum_mem *)temp);
		}
#endif
		case JFFS2_NODETYPE_PADDING:
			dbg_summary("node PADDING\n");
			c->summary->sum_padded += je32_to_cpu(node->u.totlen);
			break;

		case JFFS2_NODETYPE_CLEANMARKER:
			dbg_summary("node CLEANMARKER\n");
			break;

		case JFFS2_NODETYPE_SUMMARY:
			dbg_summary("node SUMMARY\n");
			break;

		default:
			/* If you implement a new node type you should also implement
			   summary support for it or disable summary.
			*/
			BUG();
			break;
	}

	return 0;

no_mem:
	JFFS2_WARNING("MEMORY ALLOCATION ERROR!");
	return -ENOMEM;
}

static struct jffs2_raw_node_ref *sum_link_node_ref(struct jffs2_sb_info *c,
						    struct jffs2_eraseblock *jeb,
						    uint32_t ofs, uint32_t len,
						    struct jffs2_inode_cache *ic)
{
	/* If there was a gap, mark it dirty */
	if ((ofs & ~3) > c->sector_size - jeb->free_size) {
		/* Ew. Summary doesn't actually tell us explicitly about dirty space */
		jffs2_scan_dirty_space(c, jeb, (ofs & ~3) - (c->sector_size - jeb->free_size));
	}

	return jffs2_link_node_ref(c, jeb, jeb->offset + ofs, len, ic);
}

/* Process the stored summary information - helper function for jffs2_sum_scan_sumnode() */

static int jffs2_sum_process_sum_data(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
				struct jffs2_raw_summary *summary, uint32_t *pseudo_random)
{
	struct jffs2_inode_cache *ic;
	struct jffs2_full_dirent *fd;
	void *sp;
	int i, ino;
	int err;

	sp = summary->sum;

	for (i=0; i<je32_to_cpu(summary->sum_num); i++) {
		dbg_summary("processing summary index %d\n", i);

		cond_resched();

		/* Make sure there's a spare ref for dirty space */
		err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
		if (err)
			return err;

		switch (je16_to_cpu(((struct jffs2_sum_unknown_flash *)sp)->nodetype)) {
			case JFFS2_NODETYPE_INODE: {
				struct jffs2_sum_inode_flash *spi;
				spi = sp;

				ino = je32_to_cpu(spi->inode);

				dbg_summary("Inode at 0x%08x-0x%08x\n",
					    jeb->offset + je32_to_cpu(spi->offset),
					    jeb->offset + je32_to_cpu(spi->offset) + je32_to_cpu(spi->totlen));

				ic = jffs2_scan_make_ino_cache(c, ino);
				if (!ic) {
					JFFS2_NOTICE("scan_make_ino_cache failed\n");
					return -ENOMEM;
				}

				sum_link_node_ref(c, jeb, je32_to_cpu(spi->offset) | REF_UNCHECKED,
						  PAD(je32_to_cpu(spi->totlen)), ic);

				*pseudo_random += je32_to_cpu(spi->version);

				sp += JFFS2_SUMMARY_INODE_SIZE;

				break;
			}

			case JFFS2_NODETYPE_DIRENT: {
				struct jffs2_sum_dirent_flash *spd;
				int checkedlen;
				spd = sp;

				dbg_summary("Dirent at 0x%08x-0x%08x\n",
					    jeb->offset + je32_to_cpu(spd->offset),
					    jeb->offset + je32_to_cpu(spd->offset) + je32_to_cpu(spd->totlen));


				/* This should never happen, but https://dev.laptop.org/ticket/4184 */
				checkedlen = strnlen(spd->name, spd->nsize);
				if (!checkedlen) {
					printk(KERN_ERR "Dirent at %08x has zero at start of name. Aborting mount.\n",
					       jeb->offset + je32_to_cpu(spd->offset));
					return -EIO;
				}
				if (checkedlen < spd->nsize) {
					printk(KERN_ERR "Dirent at %08x has zeroes in name. Truncating to %d chars\n",
					       jeb->offset + je32_to_cpu(spd->offset), checkedlen);
				}


				fd = jffs2_alloc_full_dirent(checkedlen+1);
				if (!fd)
					return -ENOMEM;

				memcpy(&fd->name, spd->name, checkedlen);
				fd->name[checkedlen] = 0;

				ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(spd->pino));
				if (!ic) {
					jffs2_free_full_dirent(fd);
					return -ENOMEM;
				}

				fd->raw = sum_link_node_ref(c, jeb,  je32_to_cpu(spd->offset) | REF_UNCHECKED,
							    PAD(je32_to_cpu(spd->totlen)), ic);

				fd->next = NULL;
				fd->version = je32_to_cpu(spd->version);
				fd->ino = je32_to_cpu(spd->ino);
				fd->nhash = full_name_hash(fd->name, checkedlen);
				fd->type = spd->type;

				jffs2_add_fd_to_list(c, fd, &ic->scan_dents);

				*pseudo_random += je32_to_cpu(spd->version);

				sp += JFFS2_SUMMARY_DIRENT_SIZE(spd->nsize);

				break;
			}
#ifdef CONFIG_JFFS2_FS_XATTR
			case JFFS2_NODETYPE_XATTR: {
				struct jffs2_xattr_datum *xd;
				struct jffs2_sum_xattr_flash *spx;

				spx = (struct jffs2_sum_xattr_flash *)sp;
				dbg_summary("xattr at %#08x-%#08x (xid=%u, version=%u)\n", 
					    jeb->offset + je32_to_cpu(spx->offset),
					    jeb->offset + je32_to_cpu(spx->offset) + je32_to_cpu(spx->totlen),
					    je32_to_cpu(spx->xid), je32_to_cpu(spx->version));

				xd = jffs2_setup_xattr_datum(c, je32_to_cpu(spx->xid),
								je32_to_cpu(spx->version));
				if (IS_ERR(xd))
					return PTR_ERR(xd);
				if (xd->version > je32_to_cpu(spx->version)) {
					/* node is not the newest one */
					struct jffs2_raw_node_ref *raw
						= sum_link_node_ref(c, jeb, je32_to_cpu(spx->offset) | REF_UNCHECKED,
								    PAD(je32_to_cpu(spx->totlen)), NULL);
					raw->next_in_ino = xd->node->next_in_ino;
					xd->node->next_in_ino = raw;
				} else {
					xd->version = je32_to_cpu(spx->version);
					sum_link_node_ref(c, jeb, je32_to_cpu(spx->offset) | REF_UNCHECKED,
							  PAD(je32_to_cpu(spx->totlen)), (void *)xd);
				}
				*pseudo_random += je32_to_cpu(spx->xid);
				sp += JFFS2_SUMMARY_XATTR_SIZE;

				break;
			}
			case JFFS2_NODETYPE_XREF: {
				struct jffs2_xattr_ref *ref;
				struct jffs2_sum_xref_flash *spr;

				spr = (struct jffs2_sum_xref_flash *)sp;
				dbg_summary("xref at %#08x-%#08x\n",
					    jeb->offset + je32_to_cpu(spr->offset),
					    jeb->offset + je32_to_cpu(spr->offset) + 
					    (uint32_t)PAD(sizeof(struct jffs2_raw_xref)));

				ref = jffs2_alloc_xattr_ref();
				if (!ref) {
					JFFS2_NOTICE("allocation of xattr_datum failed\n");
					return -ENOMEM;
				}
				ref->next = c->xref_temp;
				c->xref_temp = ref;

				sum_link_node_ref(c, jeb, je32_to_cpu(spr->offset) | REF_UNCHECKED,
						  PAD(sizeof(struct jffs2_raw_xref)), (void *)ref);

				*pseudo_random += ref->node->flash_offset;
				sp += JFFS2_SUMMARY_XREF_SIZE;

				break;
			}
#endif
			default : {
				uint16_t nodetype = je16_to_cpu(((struct jffs2_sum_unknown_flash *)sp)->nodetype);
				JFFS2_WARNING("Unsupported node type %x found in summary! Exiting...\n", nodetype);
				if ((nodetype & JFFS2_COMPAT_MASK) == JFFS2_FEATURE_INCOMPAT)
					return -EIO;

				/* For compatible node types, just fall back to the full scan */
				c->wasted_size -= jeb->wasted_size;
				c->free_size += c->sector_size - jeb->free_size;
				c->used_size -= jeb->used_size;
				c->dirty_size -= jeb->dirty_size;
				jeb->wasted_size = jeb->used_size = jeb->dirty_size = 0;
				jeb->free_size = c->sector_size;

				jffs2_free_jeb_node_refs(c, jeb);
				return -ENOTRECOVERABLE;
			}
		}
	}
	return 0;
}

/* Process the summary node - called from jffs2_scan_eraseblock() */
int jffs2_sum_scan_sumnode(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
			   struct jffs2_raw_summary *summary, uint32_t sumsize,
			   uint32_t *pseudo_random)
{
	struct jffs2_unknown_node crcnode;
	int ret, ofs;
	uint32_t crc;

	ofs = c->sector_size - sumsize;

	dbg_summary("summary found for 0x%08x at 0x%08x (0x%x bytes)\n",
		    jeb->offset, jeb->offset + ofs, sumsize);

	/* OK, now check for node validity and CRC */
	crcnode.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
	crcnode.nodetype = cpu_to_je16(JFFS2_NODETYPE_SUMMARY);
	crcnode.totlen = summary->totlen;
	crc = crc32(0, &crcnode, sizeof(crcnode)-4);

	if (je32_to_cpu(summary->hdr_crc) != crc) {
		dbg_summary("Summary node header is corrupt (bad CRC or "
				"no summary at all)\n");
		goto crc_err;
	}

	if (je32_to_cpu(summary->totlen) != sumsize) {
		dbg_summary("Summary node is corrupt (wrong erasesize?)\n");
		goto crc_err;
	}

	crc = crc32(0, summary, sizeof(struct jffs2_raw_summary)-8);

	if (je32_to_cpu(summary->node_crc) != crc) {
		dbg_summary("Summary node is corrupt (bad CRC)\n");
		goto crc_err;
	}

	crc = crc32(0, summary->sum, sumsize - sizeof(struct jffs2_raw_summary));

	if (je32_to_cpu(summary->sum_crc) != crc) {
		dbg_summary("Summary node data is corrupt (bad CRC)\n");
		goto crc_err;
	}

	if ( je32_to_cpu(summary->cln_mkr) ) {

		dbg_summary("Summary : CLEANMARKER node \n");

		ret = jffs2_prealloc_raw_node_refs(c, jeb, 1);
		if (ret)
			return ret;

		if (je32_to_cpu(summary->cln_mkr) != c->cleanmarker_size) {
			dbg_summary("CLEANMARKER node has totlen 0x%x != normal 0x%x\n",
				je32_to_cpu(summary->cln_mkr), c->cleanmarker_size);
			if ((ret = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(summary->cln_mkr)))))
				return ret;
		} else if (jeb->first_node) {
			dbg_summary("CLEANMARKER node not first node in block "
					"(0x%08x)\n", jeb->offset);
			if ((ret = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(summary->cln_mkr)))))
				return ret;
		} else {
			jffs2_link_node_ref(c, jeb, jeb->offset | REF_NORMAL,
					    je32_to_cpu(summary->cln_mkr), NULL);
		}
	}

	ret = jffs2_sum_process_sum_data(c, jeb, summary, pseudo_random);
	/* -ENOTRECOVERABLE isn't a fatal error -- it means we should do a full
	   scan of this eraseblock. So return zero */
	if (ret == -ENOTRECOVERABLE)
		return 0;
	if (ret)
		return ret;		/* real error */

	/* for PARANOIA_CHECK */
	ret = jffs2_prealloc_raw_node_refs(c, jeb, 2);
	if (ret)
		return ret;

	sum_link_node_ref(c, jeb, ofs | REF_NORMAL, sumsize, NULL);

	if (unlikely(jeb->free_size)) {
		JFFS2_WARNING("Free size 0x%x bytes in eraseblock @0x%08x with summary?\n",
			      jeb->free_size, jeb->offset);
		jeb->wasted_size += jeb->free_size;
		c->wasted_size += jeb->free_size;
		c->free_size -= jeb->free_size;
		jeb->free_size = 0;
	}

	return jffs2_scan_classify_jeb(c, jeb);

crc_err:
	JFFS2_WARNING("Summary node crc error, skipping summary information.\n");

	return 0;
}

/* Write summary data to flash - helper function for jffs2_sum_write_sumnode() */

static int jffs2_sum_write_data(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
				uint32_t infosize, uint32_t datasize, int padsize)
{
	struct jffs2_raw_summary isum;
	union jffs2_sum_mem *temp;
	struct jffs2_sum_marker *sm;
	struct kvec vecs[2];
	uint32_t sum_ofs;
	void *wpage;
	int ret;
	size_t retlen;

	if (padsize + datasize > MAX_SUMMARY_SIZE) {
		/* It won't fit in the buffer. Abort summary for this jeb */
		jffs2_sum_disable_collecting(c->summary);

		JFFS2_WARNING("Summary too big (%d data, %d pad) in eraseblock at %08x\n",
			      datasize, padsize, jeb->offset);
		/* Non-fatal */
		return 0;
	}
	/* Is there enough space for summary? */
	if (padsize < 0) {
		/* don't try to write out summary for this jeb */
		jffs2_sum_disable_collecting(c->summary);

		JFFS2_WARNING("Not enough space for summary, padsize = %d\n",
			      padsize);
		/* Non-fatal */
		return 0;
	}

	memset(c->summary->sum_buf, 0xff, datasize);
	memset(&isum, 0, sizeof(isum));

	isum.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
	isum.nodetype = cpu_to_je16(JFFS2_NODETYPE_SUMMARY);
	isum.totlen = cpu_to_je32(infosize);
	isum.hdr_crc = cpu_to_je32(crc32(0, &isum, sizeof(struct jffs2_unknown_node) - 4));
	isum.padded = cpu_to_je32(c->summary->sum_padded);
	isum.cln_mkr = cpu_to_je32(c->cleanmarker_size);
	isum.sum_num = cpu_to_je32(c->summary->sum_num);
	wpage = c->summary->sum_buf;

	while (c->summary->sum_num) {
		temp = c->summary->sum_list_head;

		switch (je16_to_cpu(temp->u.nodetype)) {
			case JFFS2_NODETYPE_INODE: {
				struct jffs2_sum_inode_flash *sino_ptr = wpage;

				sino_ptr->nodetype = temp->i.nodetype;
				sino_ptr->inode = temp->i.inode;
				sino_ptr->version = temp->i.version;
				sino_ptr->offset = temp->i.offset;
				sino_ptr->totlen = temp->i.totlen;

				wpage += JFFS2_SUMMARY_INODE_SIZE;

				break;
			}

			case JFFS2_NODETYPE_DIRENT: {
				struct jffs2_sum_dirent_flash *sdrnt_ptr = wpage;

				sdrnt_ptr->nodetype = temp->d.nodetype;
				sdrnt_ptr->totlen = temp->d.totlen;
				sdrnt_ptr->offset = temp->d.offset;
				sdrnt_ptr->pino = temp->d.pino;
				sdrnt_ptr->version = temp->d.version;
				sdrnt_ptr->ino = temp->d.ino;
				sdrnt_ptr->nsize = temp->d.nsize;
				sdrnt_ptr->type = temp->d.type;

				memcpy(sdrnt_ptr->name, temp->d.name,
							temp->d.nsize);

				wpage += JFFS2_SUMMARY_DIRENT_SIZE(temp->d.nsize);

				break;
			}
#ifdef CONFIG_JFFS2_FS_XATTR
			case JFFS2_NODETYPE_XATTR: {
				struct jffs2_sum_xattr_flash *sxattr_ptr = wpage;

				temp = c->summary->sum_list_head;
				sxattr_ptr->nodetype = temp->x.nodetype;
				sxattr_ptr->xid = temp->x.xid;
				sxattr_ptr->version = temp->x.version;
				sxattr_ptr->offset = temp->x.offset;
				sxattr_ptr->totlen = temp->x.totlen;

				wpage += JFFS2_SUMMARY_XATTR_SIZE;
				break;
			}
			case JFFS2_NODETYPE_XREF: {
				struct jffs2_sum_xref_flash *sxref_ptr = wpage;

				temp = c->summary->sum_list_head;
				sxref_ptr->nodetype = temp->r.nodetype;
				sxref_ptr->offset = temp->r.offset;

				wpage += JFFS2_SUMMARY_XREF_SIZE;
				break;
			}
#endif
			default : {
				if ((je16_to_cpu(temp->u.nodetype) & JFFS2_COMPAT_MASK)
				    == JFFS2_FEATURE_RWCOMPAT_COPY) {
					dbg_summary("Writing unknown RWCOMPAT_COPY node type %x\n",
						    je16_to_cpu(temp->u.nodetype));
					jffs2_sum_disable_collecting(c->summary);
				} else {
					BUG();	/* unknown node in summary information */
				}
			}
		}

		c->summary->sum_list_head = temp->u.next;
		kfree(temp);

		c->summary->sum_num--;
	}

	jffs2_sum_reset_collected(c->summary);

	wpage += padsize;

	sm = wpage;
	sm->offset = cpu_to_je32(c->sector_size - jeb->free_size);
	sm->magic = cpu_to_je32(JFFS2_SUM_MAGIC);

	isum.sum_crc = cpu_to_je32(crc32(0, c->summary->sum_buf, datasize));
	isum.node_crc = cpu_to_je32(crc32(0, &isum, sizeof(isum) - 8));

	vecs[0].iov_base = &isum;
	vecs[0].iov_len = sizeof(isum);
	vecs[1].iov_base = c->summary->sum_buf;
	vecs[1].iov_len = datasize;

	sum_ofs = jeb->offset + c->sector_size - jeb->free_size;

	dbg_summary("JFFS2: writing out data to flash to pos : 0x%08x\n",
		    sum_ofs);

	ret = jffs2_flash_writev(c, vecs, 2, sum_ofs, &retlen, 0);

	if (ret || (retlen != infosize)) {

		JFFS2_WARNING("Write of %u bytes at 0x%08x failed. returned %d, retlen %zd\n",
			      infosize, sum_ofs, ret, retlen);

		if (retlen) {
			/* Waste remaining space */
			spin_lock(&c->erase_completion_lock);
			jffs2_link_node_ref(c, jeb, sum_ofs | REF_OBSOLETE, infosize, NULL);
			spin_unlock(&c->erase_completion_lock);
		}

		c->summary->sum_size = JFFS2_SUMMARY_NOSUM_SIZE;

		return 0;
	}

	spin_lock(&c->erase_completion_lock);
	jffs2_link_node_ref(c, jeb, sum_ofs | REF_NORMAL, infosize, NULL);
	spin_unlock(&c->erase_completion_lock);

	return 0;
}

/* Write out summary information - called from jffs2_do_reserve_space */

int jffs2_sum_write_sumnode(struct jffs2_sb_info *c)
{
	int datasize, infosize, padsize;
	struct jffs2_eraseblock *jeb;
	int ret = 0;

	dbg_summary("called\n");

	spin_unlock(&c->erase_completion_lock);

	jeb = c->nextblock;
	jffs2_prealloc_raw_node_refs(c, jeb, 1);

	if (!c->summary->sum_num || !c->summary->sum_list_head) {
		JFFS2_WARNING("Empty summary info!!!\n");
		BUG();
	}

	datasize = c->summary->sum_size + sizeof(struct jffs2_sum_marker);
	infosize = sizeof(struct jffs2_raw_summary) + datasize;
	padsize = jeb->free_size - infosize;
	infosize += padsize;
	datasize += padsize;

	ret = jffs2_sum_write_data(c, jeb, infosize, datasize, padsize);
	spin_lock(&c->erase_completion_lock);
	return ret;
}