aboutsummaryrefslogtreecommitdiff
path: root/fs/jffs2/readinode.c
blob: 85a285b2a309825a9bf551abbeea0d5314b4dade (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
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright (C) 2001-2003 Red Hat, Inc.
 *
 * Created by David Woodhouse <dwmw2@infradead.org>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 * $Id: readinode.c,v 1.131 2005/07/27 14:46:11 dedekind Exp $
 *
 */

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

void jffs2_truncate_fragtree (struct jffs2_sb_info *c, struct rb_root *list, uint32_t size)
{
	struct jffs2_node_frag *frag = jffs2_lookup_node_frag(list, size);

	D1(printk(KERN_DEBUG "Truncating fraglist to 0x%08x bytes\n", size));

	/* We know frag->ofs <= size. That's what lookup does for us */
	if (frag && frag->ofs != size) {
		if (frag->ofs+frag->size >= size) {
			D1(printk(KERN_DEBUG "Truncating frag 0x%08x-0x%08x\n", frag->ofs, frag->ofs+frag->size));
			frag->size = size - frag->ofs;
		}
		frag = frag_next(frag);
	}
	while (frag && frag->ofs >= size) {
		struct jffs2_node_frag *next = frag_next(frag);

		D1(printk(KERN_DEBUG "Removing frag 0x%08x-0x%08x\n", frag->ofs, frag->ofs+frag->size));
		frag_erase(frag, list);
		jffs2_obsolete_node_frag(c, frag);
		frag = next;
	}
}

/* 
 * Put a new tmp_dnode_info into the temporaty RB-tree, keeping the list in 
 * order of increasing version.
 */
static void jffs2_add_tn_to_tree(struct jffs2_tmp_dnode_info *tn, struct rb_root *list)
{
	struct rb_node **p = &list->rb_node;
	struct rb_node * parent = NULL;
	struct jffs2_tmp_dnode_info *this;

	while (*p) {
		parent = *p;
		this = rb_entry(parent, struct jffs2_tmp_dnode_info, rb);

		/* There may actually be a collision here, but it doesn't
		   actually matter. As long as the two nodes with the same
		   version are together, it's all fine. */
		if (tn->version < this->version)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
        }

	rb_link_node(&tn->rb, parent, p);
	rb_insert_color(&tn->rb, list);
}

static void jffs2_free_tmp_dnode_info_list(struct rb_root *list)
{
	struct rb_node *this;
	struct jffs2_tmp_dnode_info *tn;

	this = list->rb_node;

	/* Now at bottom of tree */
	while (this) {
		if (this->rb_left)
			this = this->rb_left;
		else if (this->rb_right)
			this = this->rb_right;
		else {
			tn = rb_entry(this, struct jffs2_tmp_dnode_info, rb);
			jffs2_free_full_dnode(tn->fn);
			jffs2_free_tmp_dnode_info(tn);

			this = this->rb_parent;
			if (!this)
				break;

			if (this->rb_left == &tn->rb)
				this->rb_left = NULL;
			else if (this->rb_right == &tn->rb)
				this->rb_right = NULL;
			else BUG();
		}
	}
	list->rb_node = NULL;
}

static void jffs2_free_full_dirent_list(struct jffs2_full_dirent *fd)
{
	struct jffs2_full_dirent *next;

	while (fd) {
		next = fd->next;
		jffs2_free_full_dirent(fd);
		fd = next;
	}
}

/* Returns first valid node after 'ref'. May return 'ref' */
static struct jffs2_raw_node_ref *jffs2_first_valid_node(struct jffs2_raw_node_ref *ref)
{
	while (ref && ref->next_in_ino) {
		if (!ref_obsolete(ref))
			return ref;
		D1(printk(KERN_DEBUG "node at 0x%08x is obsoleted. Ignoring.\n", ref_offset(ref)));
		ref = ref->next_in_ino;
	}
	return NULL;
}

/*
 * Helper function for jffs2_get_inode_nodes().
 * It is called every time an directory entry node is found.
 *
 * Returns: 0 on succes;
 * 	    1 if the node should be marked obsolete;
 * 	    negative error code on failure.
 */
static inline int
read_direntry(struct jffs2_sb_info *c,
	      struct jffs2_raw_node_ref *ref,
	      struct jffs2_raw_dirent *rd,
	      uint32_t read,
	      struct jffs2_full_dirent **fdp,
	      int32_t *latest_mctime,
	      uint32_t *mctime_ver)
{
	struct jffs2_full_dirent *fd;
	
	/* The direntry nodes are checked during the flash scanning */
	BUG_ON(ref_flags(ref) == REF_UNCHECKED);
	/* Obsoleted. This cannot happen, surely? dwmw2 20020308 */
	BUG_ON(ref_obsolete(ref));
			
	/* Sanity check */
	if (unlikely(PAD((rd->nsize + sizeof(*rd))) != PAD(je32_to_cpu(rd->totlen)))) {
		printk(KERN_ERR "Error! Illegal nsize in node at %#08x: nsize %#02x, totlen %#04x\n",
		       ref_offset(ref), rd->nsize, je32_to_cpu(rd->totlen));
		return 1;
	}
	
	fd = jffs2_alloc_full_dirent(rd->nsize + 1);
	if (unlikely(!fd))
		return -ENOMEM;

	fd->raw = ref;
	fd->version = je32_to_cpu(rd->version);
	fd->ino = je32_to_cpu(rd->ino);
	fd->type = rd->type;

	/* Pick out the mctime of the latest dirent */
	if(fd->version > *mctime_ver) {
		*mctime_ver = fd->version;
		*latest_mctime = je32_to_cpu(rd->mctime);
	}

	/* 
	 * Copy as much of the name as possible from the raw
	 * dirent we've already read from the flash.
	 */
	if (read > sizeof(*rd))
		memcpy(&fd->name[0], &rd->name[0],
		       min_t(uint32_t, rd->nsize, (read - sizeof(*rd)) ));
		
	/* Do we need to copy any more of the name directly from the flash? */
	if (rd->nsize + sizeof(*rd) > read) {
		/* FIXME: point() */
		int err;
		int already = read - sizeof(*rd);
			
		err = jffs2_flash_read(c, (ref_offset(ref)) + read, 
				rd->nsize - already, &read, &fd->name[already]);
		if (unlikely(read != rd->nsize - already) && likely(!err))
			return -EIO;
			
		if (unlikely(err)) {
			printk(KERN_WARNING "Read remainder of name: error %d\n", err);
			jffs2_free_full_dirent(fd);
			return -EIO;
		}
	}
	
	fd->nhash = full_name_hash(fd->name, rd->nsize);
	fd->next = NULL;
	fd->name[rd->nsize] = '\0';
	
	/*
	 * Wheee. We now have a complete jffs2_full_dirent structure, with
	 * the name in it and everything. Link it into the list 
	 */
	D1(printk(KERN_DEBUG "Adding fd \"%s\", ino #%u\n", fd->name, fd->ino));

	jffs2_add_fd_to_list(c, fd, fdp);

	return 0;
}

/*
 * Helper function for jffs2_get_inode_nodes().
 * It is called every time an inode node is found.
 *
 * Returns: 0 on succes;
 * 	    1 if the node should be marked obsolete;
 * 	    negative error code on failure.
 */
static inline int
read_dnode(struct jffs2_sb_info *c,
	   struct jffs2_raw_node_ref *ref,
	   struct jffs2_raw_inode *rd,
	   uint32_t read,
	   struct rb_root *tnp,
	   int32_t *latest_mctime,
	   uint32_t *mctime_ver)
{
	struct jffs2_eraseblock *jeb;
	struct jffs2_tmp_dnode_info *tn;
	
	/* Obsoleted. This cannot happen, surely? dwmw2 20020308 */
	BUG_ON(ref_obsolete(ref));

	/* If we've never checked the CRCs on this node, check them now */
	if (ref_flags(ref) == REF_UNCHECKED) {
		uint32_t crc, len;

		crc = crc32(0, rd, sizeof(*rd) - 8);
		if (unlikely(crc != je32_to_cpu(rd->node_crc))) {
			printk(KERN_WARNING "Header CRC failed on node at %#08x: read %#08x, calculated %#08x\n",
					ref_offset(ref), je32_to_cpu(rd->node_crc), crc);
			return 1;
		}
		
		/* Sanity checks */
		if (unlikely(je32_to_cpu(rd->offset) > je32_to_cpu(rd->isize)) ||
		    unlikely(PAD(je32_to_cpu(rd->csize) + sizeof(*rd)) != PAD(je32_to_cpu(rd->totlen)))) {
			printk(KERN_WARNING "Inode corrupted at %#08x, totlen %d, #ino  %d, version %d, "
				"isize %d, csize %d, dsize %d \n",
				ref_offset(ref),  je32_to_cpu(rd->totlen),  je32_to_cpu(rd->ino),
				je32_to_cpu(rd->version),  je32_to_cpu(rd->isize), 
				je32_to_cpu(rd->csize), je32_to_cpu(rd->dsize));
			return 1;
		}

		if (rd->compr != JFFS2_COMPR_ZERO && je32_to_cpu(rd->csize)) {
			unsigned char *buf = NULL;
			uint32_t pointed = 0;
			int err;
#ifndef __ECOS
			if (c->mtd->point) {
				err = c->mtd->point (c->mtd, ref_offset(ref) + sizeof(*rd), je32_to_cpu(rd->csize),
						     &read, &buf);
				if (unlikely(read < je32_to_cpu(rd->csize)) && likely(!err)) {
					D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", read));
					c->mtd->unpoint(c->mtd, buf, ref_offset(ref) + sizeof(*rd),
							je32_to_cpu(rd->csize));
				} else if (unlikely(err)){
					D1(printk(KERN_DEBUG "MTD point failed %d\n", err));
				} else
					pointed = 1; /* succefully pointed to device */
			}
#endif					
			if(!pointed){
				buf = kmalloc(je32_to_cpu(rd->csize), GFP_KERNEL);
				if (!buf)
					return -ENOMEM;
				
				err = jffs2_flash_read(c, ref_offset(ref) + sizeof(*rd), je32_to_cpu(rd->csize),
							&read, buf);
				if (unlikely(read != je32_to_cpu(rd->csize)) && likely(!err))
					err = -EIO;
				if (err) {
					kfree(buf);
					return err;
				}
			}
			crc = crc32(0, buf, je32_to_cpu(rd->csize));
			if(!pointed)
				kfree(buf);
#ifndef __ECOS
			else
				c->mtd->unpoint(c->mtd, buf, ref_offset(ref) + sizeof(*rd), je32_to_cpu(rd->csize));
#endif

			if (crc != je32_to_cpu(rd->data_crc)) {
				printk(KERN_NOTICE "Data CRC failed on node at %#08x: read %#08x, calculated %#08x\n",
				       ref_offset(ref), je32_to_cpu(rd->data_crc), crc);
				return 1;
			}
			
		}

		/* Mark the node as having been checked and fix the accounting accordingly */
		jeb = &c->blocks[ref->flash_offset / c->sector_size];
		len = ref_totlen(c, jeb, ref);

		spin_lock(&c->erase_completion_lock);
		jeb->used_size += len;
		jeb->unchecked_size -= len;
		c->used_size += len;
		c->unchecked_size -= len;

		/* If node covers at least a whole page, or if it starts at the 
		   beginning of a page and runs to the end of the file, or if 
		   it's a hole node, mark it REF_PRISTINE, else REF_NORMAL. 

		   If it's actually overlapped, it'll get made NORMAL (or OBSOLETE) 
		   when the overlapping node(s) get added to the tree anyway. 
		*/
		if ((je32_to_cpu(rd->dsize) >= PAGE_CACHE_SIZE) ||
		    ( ((je32_to_cpu(rd->offset) & (PAGE_CACHE_SIZE-1))==0) &&
		      (je32_to_cpu(rd->dsize) + je32_to_cpu(rd->offset) == je32_to_cpu(rd->isize)))) {
			D1(printk(KERN_DEBUG "Marking node at %#08x REF_PRISTINE\n", ref_offset(ref)));
			ref->flash_offset = ref_offset(ref) | REF_PRISTINE;
		} else {
			D1(printk(KERN_DEBUG "Marking node at %#08x REF_NORMAL\n", ref_offset(ref)));
			ref->flash_offset = ref_offset(ref) | REF_NORMAL;
		}
		spin_unlock(&c->erase_completion_lock);
	}

	tn = jffs2_alloc_tmp_dnode_info();
	if (!tn) {
		D1(printk(KERN_DEBUG "alloc tn failed\n"));
		return -ENOMEM;
	}

	tn->fn = jffs2_alloc_full_dnode();
	if (!tn->fn) {
		D1(printk(KERN_DEBUG "alloc fn failed\n"));
		jffs2_free_tmp_dnode_info(tn);
		return -ENOMEM;
	}
	
	tn->version = je32_to_cpu(rd->version);
	tn->fn->ofs = je32_to_cpu(rd->offset);
	tn->fn->raw = ref;
	
	/* There was a bug where we wrote hole nodes out with
	   csize/dsize swapped. Deal with it */
	if (rd->compr == JFFS2_COMPR_ZERO && !je32_to_cpu(rd->dsize) && je32_to_cpu(rd->csize))
		tn->fn->size = je32_to_cpu(rd->csize);
	else // normal case...
		tn->fn->size = je32_to_cpu(rd->dsize);

	D1(printk(KERN_DEBUG "dnode @%08x: ver %u, offset %#04x, dsize %#04x\n",
		  ref_offset(ref), je32_to_cpu(rd->version),
		  je32_to_cpu(rd->offset), je32_to_cpu(rd->dsize)));
	
	jffs2_add_tn_to_tree(tn, tnp);

	return 0;
}

/*
 * Helper function for jffs2_get_inode_nodes().
 * It is called every time an unknown node is found.
 *
 * Returns: 0 on succes;
 * 	    1 if the node should be marked obsolete;
 * 	    negative error code on failure.
 */
static inline int
read_unknown(struct jffs2_sb_info *c,
	     struct jffs2_raw_node_ref *ref,
	     struct jffs2_unknown_node *un,
	     uint32_t read)
{
	/* We don't mark unknown nodes as REF_UNCHECKED */
	BUG_ON(ref_flags(ref) == REF_UNCHECKED);
	
	un->nodetype = cpu_to_je16(JFFS2_NODE_ACCURATE | je16_to_cpu(un->nodetype));

	if (crc32(0, un, sizeof(struct jffs2_unknown_node) - 4) != je32_to_cpu(un->hdr_crc)) {

		/* Hmmm. This should have been caught at scan time. */
		printk(KERN_WARNING "Warning! Node header CRC failed at %#08x. "
				"But it must have been OK earlier.\n", ref_offset(ref));
		D1(printk(KERN_DEBUG "Node was: { %#04x, %#04x, %#08x, %#08x }\n", 
			je16_to_cpu(un->magic), je16_to_cpu(un->nodetype),
			je32_to_cpu(un->totlen), je32_to_cpu(un->hdr_crc)));
		return 1;
	} else {
		switch(je16_to_cpu(un->nodetype) & JFFS2_COMPAT_MASK) {

		case JFFS2_FEATURE_INCOMPAT:
			printk(KERN_NOTICE "Unknown INCOMPAT nodetype %#04X at %#08x\n",
					je16_to_cpu(un->nodetype), ref_offset(ref));
			/* EEP */
			BUG();
			break;

		case JFFS2_FEATURE_ROCOMPAT:
			printk(KERN_NOTICE "Unknown ROCOMPAT nodetype %#04X at %#08x\n",
					je16_to_cpu(un->nodetype), ref_offset(ref));
			BUG_ON(!(c->flags & JFFS2_SB_FLAG_RO));
			break;

		case JFFS2_FEATURE_RWCOMPAT_COPY:
			printk(KERN_NOTICE "Unknown RWCOMPAT_COPY nodetype %#04X at %#08x\n",
					je16_to_cpu(un->nodetype), ref_offset(ref));
			break;

		case JFFS2_FEATURE_RWCOMPAT_DELETE:
			printk(KERN_NOTICE "Unknown RWCOMPAT_DELETE nodetype %#04X at %#08x\n",
					je16_to_cpu(un->nodetype), ref_offset(ref));
			return 1;
		}
	}

	return 0;
}

/* Get tmp_dnode_info and full_dirent for all non-obsolete nodes associated
   with this ino, returning the former in order of version */

static int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
				 struct rb_root *tnp, struct jffs2_full_dirent **fdp,
				 uint32_t *highest_version, uint32_t *latest_mctime,
				 uint32_t *mctime_ver)
{
	struct jffs2_raw_node_ref *ref, *valid_ref;
	struct rb_root ret_tn = RB_ROOT;
	struct jffs2_full_dirent *ret_fd = NULL;
	union jffs2_node_union node;
	size_t retlen;
	int err;

	*mctime_ver = 0;
	
	D1(printk(KERN_DEBUG "jffs2_get_inode_nodes(): ino #%u\n", f->inocache->ino));

	spin_lock(&c->erase_completion_lock);

	valid_ref = jffs2_first_valid_node(f->inocache->nodes);

	if (!valid_ref && (f->inocache->ino != 1))
		printk(KERN_WARNING "Eep. No valid nodes for ino #%u\n", f->inocache->ino);

	while (valid_ref) {
		/* We can hold a pointer to a non-obsolete node without the spinlock,
		   but _obsolete_ nodes may disappear at any time, if the block
		   they're in gets erased. So if we mark 'ref' obsolete while we're
		   not holding the lock, it can go away immediately. For that reason,
		   we find the next valid node first, before processing 'ref'.
		*/
		ref = valid_ref;
		valid_ref = jffs2_first_valid_node(ref->next_in_ino);
		spin_unlock(&c->erase_completion_lock);

		cond_resched();

		/* FIXME: point() */
		err = jffs2_flash_read(c, (ref_offset(ref)), 
				       min_t(uint32_t, ref_totlen(c, NULL, ref), sizeof(node)),
				       &retlen, (void *)&node);
		if (err) {
			printk(KERN_WARNING "error %d reading node at 0x%08x in get_inode_nodes()\n", err, ref_offset(ref));
			goto free_out;
		}
			
		switch (je16_to_cpu(node.u.nodetype)) {
			
		case JFFS2_NODETYPE_DIRENT:
			D1(printk(KERN_DEBUG "Node at %08x (%d) is a dirent node\n", ref_offset(ref), ref_flags(ref)));
			
			if (retlen < sizeof(node.d)) {
				printk(KERN_WARNING "Warning! Short read dirent at %#08x\n", ref_offset(ref));
				err = -EIO;
				goto free_out;
			}

			err = read_direntry(c, ref, &node.d, retlen, &ret_fd, latest_mctime, mctime_ver);
			if (err == 1) {
				jffs2_mark_node_obsolete(c, ref);
				break;
			} else if (unlikely(err))
				goto free_out;
			
			if (je32_to_cpu(node.d.version) > *highest_version)
				*highest_version = je32_to_cpu(node.d.version);

			break;

		case JFFS2_NODETYPE_INODE:
			D1(printk(KERN_DEBUG "Node at %08x (%d) is a data node\n", ref_offset(ref), ref_flags(ref)));
			
			if (retlen < sizeof(node.i)) {
				printk(KERN_WARNING "Warning! Short read dnode at %#08x\n", ref_offset(ref));
				err = -EIO;
				goto free_out;
			}

			err = read_dnode(c, ref, &node.i, retlen, &ret_tn, latest_mctime, mctime_ver);
			if (err == 1) {
				jffs2_mark_node_obsolete(c, ref);
				break;
			} else if (unlikely(err))
				goto free_out;

			if (je32_to_cpu(node.i.version) > *highest_version)
				*highest_version = je32_to_cpu(node.i.version);
			
			D1(printk(KERN_DEBUG "version %d, highest_version now %d\n",
					je32_to_cpu(node.i.version), *highest_version));

			break;

		default:
			/* Check we've managed to read at least the common node header */
			if (retlen < sizeof(struct jffs2_unknown_node)) {
				printk(KERN_WARNING "Warning! Short read unknown node at %#08x\n",
						ref_offset(ref));
				return -EIO;
			}

			err = read_unknown(c, ref, &node.u, retlen);
			if (err == 1) {
				jffs2_mark_node_obsolete(c, ref);
				break;
			} else if (unlikely(err))
				goto free_out;

		}
		spin_lock(&c->erase_completion_lock);

	}
	spin_unlock(&c->erase_completion_lock);
	*tnp = ret_tn;
	*fdp = ret_fd;

	return 0;

 free_out:
	jffs2_free_tmp_dnode_info_list(&ret_tn);
	jffs2_free_full_dirent_list(ret_fd);
	return err;
}

static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c, 
					struct jffs2_inode_info *f,
					struct jffs2_raw_inode *latest_node)
{
	struct jffs2_tmp_dnode_info *tn = NULL;
	struct rb_root tn_list;
	struct rb_node *rb, *repl_rb;
	struct jffs2_full_dirent *fd_list;
	struct jffs2_full_dnode *fn = NULL;
	uint32_t crc;
	uint32_t latest_mctime, mctime_ver;
	uint32_t mdata_ver = 0;
	size_t retlen;
	int ret;

	D1(printk(KERN_DEBUG "jffs2_do_read_inode_internal(): ino #%u nlink is %d\n", f->inocache->ino, f->inocache->nlink));

	/* Grab all nodes relevant to this ino */
	ret = jffs2_get_inode_nodes(c, f, &tn_list, &fd_list, &f->highest_version, &latest_mctime, &mctime_ver);

	if (ret) {
		printk(KERN_CRIT "jffs2_get_inode_nodes() for ino %u returned %d\n", f->inocache->ino, ret);
		if (f->inocache->state == INO_STATE_READING)
			jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
		return ret;
	}
	f->dents = fd_list;

	rb = rb_first(&tn_list);

	while (rb) {
		tn = rb_entry(rb, struct jffs2_tmp_dnode_info, rb);
		fn = tn->fn;

		if (f->metadata) {
			if (likely(tn->version >= mdata_ver)) {
				D1(printk(KERN_DEBUG "Obsoleting old metadata at 0x%08x\n", ref_offset(f->metadata->raw)));
				jffs2_mark_node_obsolete(c, f->metadata->raw);
				jffs2_free_full_dnode(f->metadata);
				f->metadata = NULL;
				
				mdata_ver = 0;
			} else {
				/* This should never happen. */
				printk(KERN_WARNING "Er. New metadata at 0x%08x with ver %d is actually older than previous ver %d at 0x%08x\n",
					  ref_offset(fn->raw), tn->version, mdata_ver, ref_offset(f->metadata->raw));
				jffs2_mark_node_obsolete(c, fn->raw);
				jffs2_free_full_dnode(fn);
				/* Fill in latest_node from the metadata, not this one we're about to free... */
				fn = f->metadata;
				goto next_tn;
			}
		}

		if (fn->size) {
			jffs2_add_full_dnode_to_inode(c, f, fn);
		} else {
			/* Zero-sized node at end of version list. Just a metadata update */
			D1(printk(KERN_DEBUG "metadata @%08x: ver %d\n", ref_offset(fn->raw), tn->version));
			f->metadata = fn;
			mdata_ver = tn->version;
		}
	next_tn:
		BUG_ON(rb->rb_left);
		if (rb->rb_parent && rb->rb_parent->rb_left == rb) {
			/* We were then left-hand child of our parent. We need
			   to move our own right-hand child into our place. */
			repl_rb = rb->rb_right;
			if (repl_rb)
				repl_rb->rb_parent = rb->rb_parent;
		} else
			repl_rb = NULL;

		rb = rb_next(rb);

		/* Remove the spent tn from the tree; don't bother rebalancing
		   but put our right-hand child in our own place. */
		if (tn->rb.rb_parent) {
			if (tn->rb.rb_parent->rb_left == &tn->rb)
				tn->rb.rb_parent->rb_left = repl_rb;
			else if (tn->rb.rb_parent->rb_right == &tn->rb)
				tn->rb.rb_parent->rb_right = repl_rb;
			else BUG();
		} else if (tn->rb.rb_right)
			tn->rb.rb_right->rb_parent = NULL;

		jffs2_free_tmp_dnode_info(tn);
	}
	jffs2_dbg_fragtree_paranoia_check_nolock(f);

	if (!fn) {
		/* No data nodes for this inode. */
		if (f->inocache->ino != 1) {
			printk(KERN_WARNING "jffs2_do_read_inode(): No data nodes found for ino #%u\n", f->inocache->ino);
			if (!fd_list) {
				if (f->inocache->state == INO_STATE_READING)
					jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
				return -EIO;
			}
			printk(KERN_WARNING "jffs2_do_read_inode(): But it has children so we fake some modes for it\n");
		}
		latest_node->mode = cpu_to_jemode(S_IFDIR|S_IRUGO|S_IWUSR|S_IXUGO);
		latest_node->version = cpu_to_je32(0);
		latest_node->atime = latest_node->ctime = latest_node->mtime = cpu_to_je32(0);
		latest_node->isize = cpu_to_je32(0);
		latest_node->gid = cpu_to_je16(0);
		latest_node->uid = cpu_to_je16(0);
		if (f->inocache->state == INO_STATE_READING)
			jffs2_set_inocache_state(c, f->inocache, INO_STATE_PRESENT);
		return 0;
	}

	ret = jffs2_flash_read(c, ref_offset(fn->raw), sizeof(*latest_node), &retlen, (void *)latest_node);
	if (ret || retlen != sizeof(*latest_node)) {
		printk(KERN_NOTICE "MTD read in jffs2_do_read_inode() failed: Returned %d, %zd of %zd bytes read\n",
		       ret, retlen, sizeof(*latest_node));
		/* FIXME: If this fails, there seems to be a memory leak. Find it. */
		up(&f->sem);
		jffs2_do_clear_inode(c, f);
		return ret?ret:-EIO;
	}

	crc = crc32(0, latest_node, sizeof(*latest_node)-8);
	if (crc != je32_to_cpu(latest_node->node_crc)) {
		printk(KERN_NOTICE "CRC failed for read_inode of inode %u at physical location 0x%x\n", f->inocache->ino, ref_offset(fn->raw));
		up(&f->sem);
		jffs2_do_clear_inode(c, f);
		return -EIO;
	}

	switch(jemode_to_cpu(latest_node->mode) & S_IFMT) {
	case S_IFDIR:
		if (mctime_ver > je32_to_cpu(latest_node->version)) {
			/* The times in the latest_node are actually older than
			   mctime in the latest dirent. Cheat. */
			latest_node->ctime = latest_node->mtime = cpu_to_je32(latest_mctime);
		}
		break;

			
	case S_IFREG:
		/* If it was a regular file, truncate it to the latest node's isize */
		jffs2_truncate_fragtree(c, &f->fragtree, je32_to_cpu(latest_node->isize));
		break;

	case S_IFLNK:
		/* Hack to work around broken isize in old symlink code.
		   Remove this when dwmw2 comes to his senses and stops
		   symlinks from being an entirely gratuitous special
		   case. */
		if (!je32_to_cpu(latest_node->isize))
			latest_node->isize = latest_node->dsize;

		if (f->inocache->state != INO_STATE_CHECKING) {
			/* Symlink's inode data is the target path. Read it and
			 * keep in RAM to facilitate quick follow symlink
			 * operation. */
			f->target = kmalloc(je32_to_cpu(latest_node->csize) + 1, GFP_KERNEL);
			if (!f->target) {
				printk(KERN_WARNING "Can't allocate %d bytes of memory "
						"for the symlink target path cache\n",
						je32_to_cpu(latest_node->csize));
				up(&f->sem);
				jffs2_do_clear_inode(c, f);
				return -ENOMEM;
			}
			
			ret = jffs2_flash_read(c, ref_offset(fn->raw) + sizeof(*latest_node),
						je32_to_cpu(latest_node->csize), &retlen, (char *)f->target);
			
			if (ret  || retlen != je32_to_cpu(latest_node->csize)) {
				if (retlen != je32_to_cpu(latest_node->csize))
					ret = -EIO;
				kfree(f->target);
				f->target = NULL;
				up(&f->sem);
				jffs2_do_clear_inode(c, f);
				return -ret;
			}

			f->target[je32_to_cpu(latest_node->csize)] = '\0';
			D1(printk(KERN_DEBUG "jffs2_do_read_inode(): symlink's target '%s' cached\n",
						f->target));
		}
		
		/* fall through... */

	case S_IFBLK:
	case S_IFCHR:
		/* Certain inode types should have only one data node, and it's
		   kept as the metadata node */
		if (f->metadata) {
			printk(KERN_WARNING "Argh. Special inode #%u with mode 0%o had metadata node\n",
			       f->inocache->ino, jemode_to_cpu(latest_node->mode));
			up(&f->sem);
			jffs2_do_clear_inode(c, f);
			return -EIO;
		}
		if (!frag_first(&f->fragtree)) {
			printk(KERN_WARNING "Argh. Special inode #%u with mode 0%o has no fragments\n",
			       f->inocache->ino, jemode_to_cpu(latest_node->mode));
			up(&f->sem);
			jffs2_do_clear_inode(c, f);
			return -EIO;
		}
		/* ASSERT: f->fraglist != NULL */
		if (frag_next(frag_first(&f->fragtree))) {
			printk(KERN_WARNING "Argh. Special inode #%u with mode 0x%x had more than one node\n",
			       f->inocache->ino, jemode_to_cpu(latest_node->mode));
			/* FIXME: Deal with it - check crc32, check for duplicate node, check times and discard the older one */
			up(&f->sem);
			jffs2_do_clear_inode(c, f);
			return -EIO;
		}
		/* OK. We're happy */
		f->metadata = frag_first(&f->fragtree)->node;
		jffs2_free_node_frag(frag_first(&f->fragtree));
		f->fragtree = RB_ROOT;
		break;
	}
	if (f->inocache->state == INO_STATE_READING)
		jffs2_set_inocache_state(c, f->inocache, INO_STATE_PRESENT);

	return 0;
}

/* Scan the list of all nodes present for this ino, build map of versions, etc. */
int jffs2_do_read_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, 
			uint32_t ino, struct jffs2_raw_inode *latest_node)
{
	D2(printk(KERN_DEBUG "jffs2_do_read_inode(): getting inocache\n"));

 retry_inocache:
	spin_lock(&c->inocache_lock);
	f->inocache = jffs2_get_ino_cache(c, ino);

	D2(printk(KERN_DEBUG "jffs2_do_read_inode(): Got inocache at %p\n", f->inocache));

	if (f->inocache) {
		/* Check its state. We may need to wait before we can use it */
		switch(f->inocache->state) {
		case INO_STATE_UNCHECKED:
		case INO_STATE_CHECKEDABSENT:
			f->inocache->state = INO_STATE_READING;
			break;
			
		case INO_STATE_CHECKING:
		case INO_STATE_GC:
			/* If it's in either of these states, we need
			   to wait for whoever's got it to finish and
			   put it back. */
			D1(printk(KERN_DEBUG "jffs2_get_ino_cache_read waiting for ino #%u in state %d\n",
				  ino, f->inocache->state));
			sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
			goto retry_inocache;

		case INO_STATE_READING:
		case INO_STATE_PRESENT:
			/* Eep. This should never happen. It can
			happen if Linux calls read_inode() again
			before clear_inode() has finished though. */
			printk(KERN_WARNING "Eep. Trying to read_inode #%u when it's already in state %d!\n", ino, f->inocache->state);
			/* Fail. That's probably better than allowing it to succeed */
			f->inocache = NULL;
			break;

		default:
			BUG();
		}
	}
	spin_unlock(&c->inocache_lock);

	if (!f->inocache && ino == 1) {
		/* Special case - no root inode on medium */
		f->inocache = jffs2_alloc_inode_cache();
		if (!f->inocache) {
			printk(KERN_CRIT "jffs2_do_read_inode(): Cannot allocate inocache for root inode\n");
			return -ENOMEM;
		}
		D1(printk(KERN_DEBUG "jffs2_do_read_inode(): Creating inocache for root inode\n"));
		memset(f->inocache, 0, sizeof(struct jffs2_inode_cache));
		f->inocache->ino = f->inocache->nlink = 1;
		f->inocache->nodes = (struct jffs2_raw_node_ref *)f->inocache;
		f->inocache->state = INO_STATE_READING;
		jffs2_add_ino_cache(c, f->inocache);
	}
	if (!f->inocache) {
		printk(KERN_WARNING "jffs2_do_read_inode() on nonexistent ino %u\n", ino);
		return -ENOENT;
	}

	return jffs2_do_read_inode_internal(c, f, latest_node);
}

int jffs2_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
{
	struct jffs2_raw_inode n;
	struct jffs2_inode_info *f = kmalloc(sizeof(*f), GFP_KERNEL);
	int ret;

	if (!f)
		return -ENOMEM;

	memset(f, 0, sizeof(*f));
	init_MUTEX_LOCKED(&f->sem);
	f->inocache = ic;

	ret = jffs2_do_read_inode_internal(c, f, &n);
	if (!ret) {
		up(&f->sem);
		jffs2_do_clear_inode(c, f);
	}
	kfree (f);
	return ret;
}

void jffs2_do_clear_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f)
{
	struct jffs2_full_dirent *fd, *fds;
	int deleted;

	down(&f->sem);
	deleted = f->inocache && !f->inocache->nlink;

	if (f->inocache && f->inocache->state != INO_STATE_CHECKING)
		jffs2_set_inocache_state(c, f->inocache, INO_STATE_CLEARING);

	if (f->metadata) {
		if (deleted)
			jffs2_mark_node_obsolete(c, f->metadata->raw);
		jffs2_free_full_dnode(f->metadata);
	}

	jffs2_kill_fragtree(&f->fragtree, deleted?c:NULL);

	if (f->target) {
		kfree(f->target);
		f->target = NULL;
	}
	
	fds = f->dents;
	while(fds) {
		fd = fds;
		fds = fd->next;
		jffs2_free_full_dirent(fd);
	}

	if (f->inocache && f->inocache->state != INO_STATE_CHECKING) {
		jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
		if (f->inocache->nodes == (void *)f->inocache)
			jffs2_del_ino_cache(c, f->inocache);
	}

	up(&f->sem);
}