summaryrefslogtreecommitdiffstats
path: root/fs/hpfs/dnode.c
blob: 86ab7e790b4e5bb14be86b1336576c2918f53d7c (plain) (blame)
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
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
/*
 *  linux/fs/hpfs/dnode.c
 *
 *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
 *
 *  handling directory dnode tree - adding, deleteing & searching for dirents
 */

#include "hpfs_fn.h"

static loff_t get_pos(struct dnode *d, struct hpfs_dirent *fde)
{
	struct hpfs_dirent *de;
	struct hpfs_dirent *de_end = dnode_end_de(d);
	int i = 1;
	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
		if (de == fde) return ((loff_t) le32_to_cpu(d->self) << 4) | (loff_t)i;
		i++;
	}
	pr_info("%s(): not_found\n", __func__);
	return ((loff_t)le32_to_cpu(d->self) << 4) | (loff_t)1;
}

int hpfs_add_pos(struct inode *inode, loff_t *pos)
{
	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
	int i = 0;
	loff_t **ppos;

	if (hpfs_inode->i_rddir_off)
		for (; hpfs_inode->i_rddir_off[i]; i++)
			if (hpfs_inode->i_rddir_off[i] == pos)
				return 0;
	if (!(i&0x0f)) {
		if (!(ppos = kmalloc((i+0x11) * sizeof(loff_t*), GFP_NOFS))) {
			pr_err("out of memory for position list\n");
			return -ENOMEM;
		}
		if (hpfs_inode->i_rddir_off) {
			memcpy(ppos, hpfs_inode->i_rddir_off, i * sizeof(loff_t));
			kfree(hpfs_inode->i_rddir_off);
		}
		hpfs_inode->i_rddir_off = ppos;
	}
	hpfs_inode->i_rddir_off[i] = pos;
	hpfs_inode->i_rddir_off[i + 1] = NULL;
	return 0;
}

void hpfs_del_pos(struct inode *inode, loff_t *pos)
{
	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
	loff_t **i, **j;

	if (!hpfs_inode->i_rddir_off) goto not_f;
	for (i = hpfs_inode->i_rddir_off; *i; i++) if (*i == pos) goto fnd;
	goto not_f;
	fnd:
	for (j = i + 1; *j; j++) ;
	*i = *(j - 1);
	*(j - 1) = NULL;
	if (j - 1 == hpfs_inode->i_rddir_off) {
		kfree(hpfs_inode->i_rddir_off);
		hpfs_inode->i_rddir_off = NULL;
	}
	return;
	not_f:
	/*pr_warn("position pointer %p->%08x not found\n",
		  pos, (int)*pos);*/
	return;
}

static void for_all_poss(struct inode *inode, void (*f)(loff_t *, loff_t, loff_t),
			 loff_t p1, loff_t p2)
{
	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
	loff_t **i;

	if (!hpfs_inode->i_rddir_off) return;
	for (i = hpfs_inode->i_rddir_off; *i; i++) (*f)(*i, p1, p2);
	return;
}

static void hpfs_pos_subst(loff_t *p, loff_t f, loff_t t)
{
	if (*p == f) *p = t;
}

/*void hpfs_hpfs_pos_substd(loff_t *p, loff_t f, loff_t t)
{
	if ((*p & ~0x3f) == (f & ~0x3f)) *p = (t & ~0x3f) | (*p & 0x3f);
}*/

static void hpfs_pos_ins(loff_t *p, loff_t d, loff_t c)
{
	if ((*p & ~0x3f) == (d & ~0x3f) && (*p & 0x3f) >= (d & 0x3f)) {
		int n = (*p & 0x3f) + c;
		if (n > 0x3f)
			pr_err("%s(): %08x + %d\n",
				__func__, (int)*p, (int)c >> 8);
		else
			*p = (*p & ~0x3f) | n;
	}
}

static void hpfs_pos_del(loff_t *p, loff_t d, loff_t c)
{
	if ((*p & ~0x3f) == (d & ~0x3f) && (*p & 0x3f) >= (d & 0x3f)) {
		int n = (*p & 0x3f) - c;
		if (n < 1)
			pr_err("%s(): %08x - %d\n",
				__func__, (int)*p, (int)c >> 8);
		else
			*p = (*p & ~0x3f) | n;
	}
}

static struct hpfs_dirent *dnode_pre_last_de(struct dnode *d)
{
	struct hpfs_dirent *de, *de_end, *dee = NULL, *deee = NULL;
	de_end = dnode_end_de(d);
	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
		deee = dee; dee = de;
	}	
	return deee;
}

static struct hpfs_dirent *dnode_last_de(struct dnode *d)
{
	struct hpfs_dirent *de, *de_end, *dee = NULL;
	de_end = dnode_end_de(d);
	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
		dee = de;
	}	
	return dee;
}

static void set_last_pointer(struct super_block *s, struct dnode *d, dnode_secno ptr)
{
	struct hpfs_dirent *de;
	if (!(de = dnode_last_de(d))) {
		hpfs_error(s, "set_last_pointer: empty dnode %08x", le32_to_cpu(d->self));
		return;
	}
	if (hpfs_sb(s)->sb_chk) {
		if (de->down) {
			hpfs_error(s, "set_last_pointer: dnode %08x has already last pointer %08x",
				le32_to_cpu(d->self), de_down_pointer(de));
			return;
		}
		if (le16_to_cpu(de->length) != 32) {
			hpfs_error(s, "set_last_pointer: bad last dirent in dnode %08x", le32_to_cpu(d->self));
			return;
		}
	}
	if (ptr) {
		le32_add_cpu(&d->first_free, 4);
		if (le32_to_cpu(d->first_free) > 2048) {
			hpfs_error(s, "set_last_pointer: too long dnode %08x", le32_to_cpu(d->self));
			le32_add_cpu(&d->first_free, -4);
			return;
		}
		de->length = cpu_to_le16(36);
		de->down = 1;
		*(__le32 *)((char *)de + 32) = cpu_to_le32(ptr);
	}
}

/* Add an entry to dnode and don't care if it grows over 2048 bytes */

struct hpfs_dirent *hpfs_add_de(struct super_block *s, struct dnode *d,
				const unsigned char *name,
				unsigned namelen, secno down_ptr)
{
	struct hpfs_dirent *de;
	struct hpfs_dirent *de_end = dnode_end_de(d);
	unsigned d_size = de_size(namelen, down_ptr);
	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
		int c = hpfs_compare_names(s, name, namelen, de->name, de->namelen, de->last);
		if (!c) {
			hpfs_error(s, "name (%c,%d) already exists in dnode %08x", *name, namelen, le32_to_cpu(d->self));
			return NULL;
		}
		if (c < 0) break;
	}
	memmove((char *)de + d_size, de, (char *)de_end - (char *)de);
	memset(de, 0, d_size);
	if (down_ptr) {
		*(__le32 *)((char *)de + d_size - 4) = cpu_to_le32(down_ptr);
		de->down = 1;
	}
	de->length = cpu_to_le16(d_size);
	de->not_8x3 = hpfs_is_name_long(name, namelen);
	de->namelen = namelen;
	memcpy(de->name, name, namelen);
	le32_add_cpu(&d->first_free, d_size);
	return de;
}

/* Delete dirent and don't care about its subtree */

static void hpfs_delete_de(struct super_block *s, struct dnode *d,
			   struct hpfs_dirent *de)
{
	if (de->last) {
		hpfs_error(s, "attempt to delete last dirent in dnode %08x", le32_to_cpu(d->self));
		return;
	}
	d->first_free = cpu_to_le32(le32_to_cpu(d->first_free) - le16_to_cpu(de->length));
	memmove(de, de_next_de(de), le32_to_cpu(d->first_free) + (char *)d - (char *)de);
}

static void fix_up_ptrs(struct super_block *s, struct dnode *d)
{
	struct hpfs_dirent *de;
	struct hpfs_dirent *de_end = dnode_end_de(d);
	dnode_secno dno = le32_to_cpu(d->self);
	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de))
		if (de->down) {
			struct quad_buffer_head qbh;
			struct dnode *dd;
			if ((dd = hpfs_map_dnode(s, de_down_pointer(de), &qbh))) {
				if (le32_to_cpu(dd->up) != dno || dd->root_dnode) {
					dd->up = cpu_to_le32(dno);
					dd->root_dnode = 0;
					hpfs_mark_4buffers_dirty(&qbh);
				}
				hpfs_brelse4(&qbh);
			}
		}
}

/* Add an entry to dnode and do dnode splitting if required */

static int hpfs_add_to_dnode(struct inode *i, dnode_secno dno,
			     const unsigned char *name, unsigned namelen,
			     struct hpfs_dirent *new_de, dnode_secno down_ptr)
{
	struct quad_buffer_head qbh, qbh1, qbh2;
	struct dnode *d, *ad, *rd, *nd = NULL;
	dnode_secno adno, rdno;
	struct hpfs_dirent *de;
	struct hpfs_dirent nde;
	unsigned char *nname;
	int h;
	int pos;
	struct buffer_head *bh;
	struct fnode *fnode;
	int c1, c2 = 0;
	if (!(nname = kmalloc(256, GFP_NOFS))) {
		pr_err("out of memory, can't add to dnode\n");
		return 1;
	}
	go_up:
	if (namelen >= 256) {
		hpfs_error(i->i_sb, "%s(): namelen == %d", __func__, namelen);
		kfree(nd);
		kfree(nname);
		return 1;
	}
	if (!(d = hpfs_map_dnode(i->i_sb, dno, &qbh))) {
		kfree(nd);
		kfree(nname);
		return 1;
	}
	go_up_a:
	if (hpfs_sb(i->i_sb)->sb_chk)
		if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "hpfs_add_to_dnode")) {
			hpfs_brelse4(&qbh);
			kfree(nd);
			kfree(nname);
			return 1;
		}
	if (le32_to_cpu(d->first_free) + de_size(namelen, down_ptr) <= 2048) {
		loff_t t;
		copy_de(de=hpfs_add_de(i->i_sb, d, name, namelen, down_ptr), new_de);
		t = get_pos(d, de);
		for_all_poss(i, hpfs_pos_ins, t, 1);
		for_all_poss(i, hpfs_pos_subst, 4, t);
		for_all_poss(i, hpfs_pos_subst, 5, t + 1);
		hpfs_mark_4buffers_dirty(&qbh);
		hpfs_brelse4(&qbh);
		kfree(nd);
		kfree(nname);
		return 0;
	}
	if (!nd) if (!(nd = kmalloc(0x924, GFP_NOFS))) {
		/* 0x924 is a max size of dnode after adding a dirent with
		   max name length. We alloc this only once. There must
		   not be any error while splitting dnodes, otherwise the
		   whole directory, not only file we're adding, would
		   be lost. */
		pr_err("out of memory for dnode splitting\n");
		hpfs_brelse4(&qbh);
		kfree(nname);
		return 1;
	}	
	memcpy(nd, d, le32_to_cpu(d->first_free));
	copy_de(de = hpfs_add_de(i->i_sb, nd, name, namelen, down_ptr), new_de);
	for_all_poss(i, hpfs_pos_ins, get_pos(nd, de), 1);
	h = ((char *)dnode_last_de(nd) - (char *)nd) / 2 + 10;
	if (!(ad = hpfs_alloc_dnode(i->i_sb, le32_to_cpu(d->up), &adno, &qbh1))) {
		hpfs_error(i->i_sb, "unable to alloc dnode - dnode tree will be corrupted");
		hpfs_brelse4(&qbh);
		kfree(nd);
		kfree(nname);
		return 1;
	}
	i->i_size += 2048;
	i->i_blocks += 4;
	pos = 1;
	for (de = dnode_first_de(nd); (char *)de_next_de(de) - (char *)nd < h; de = de_next_de(de)) {
		copy_de(hpfs_add_de(i->i_sb, ad, de->name, de->namelen, de->down ? de_down_pointer(de) : 0), de);
		for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | pos, ((loff_t)adno << 4) | pos);
		pos++;
	}
	copy_de(new_de = &nde, de);
	memcpy(nname, de->name, de->namelen);
	name = nname;
	namelen = de->namelen;
	for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | pos, 4);
	down_ptr = adno;
	set_last_pointer(i->i_sb, ad, de->down ? de_down_pointer(de) : 0);
	de = de_next_de(de);
	memmove((char *)nd + 20, de, le32_to_cpu(nd->first_free) + (char *)nd - (char *)de);
	le32_add_cpu(&nd->first_free, -((char *)de - (char *)nd - 20));
	memcpy(d, nd, le32_to_cpu(nd->first_free));
	for_all_poss(i, hpfs_pos_del, (loff_t)dno << 4, pos);
	fix_up_ptrs(i->i_sb, ad);
	if (!d->root_dnode) {
		ad->up = d->up;
		dno = le32_to_cpu(ad->up);
		hpfs_mark_4buffers_dirty(&qbh);
		hpfs_brelse4(&qbh);
		hpfs_mark_4buffers_dirty(&qbh1);
		hpfs_brelse4(&qbh1);
		goto go_up;
	}
	if (!(rd = hpfs_alloc_dnode(i->i_sb, le32_to_cpu(d->up), &rdno, &qbh2))) {
		hpfs_error(i->i_sb, "unable to alloc dnode - dnode tree will be corrupted");
		hpfs_brelse4(&qbh);
		hpfs_brelse4(&qbh1);
		kfree(nd);
		kfree(nname);
		return 1;
	}
	i->i_size += 2048;
	i->i_blocks += 4;
	rd->root_dnode = 1;
	rd->up = d->up;
	if (!(fnode = hpfs_map_fnode(i->i_sb, le32_to_cpu(d->up), &bh))) {
		hpfs_free_dnode(i->i_sb, rdno);
		hpfs_brelse4(&qbh);
		hpfs_brelse4(&qbh1);
		hpfs_brelse4(&qbh2);
		kfree(nd);
		kfree(nname);
		return 1;
	}
	fnode->u.external[0].disk_secno = cpu_to_le32(rdno);
	mark_buffer_dirty(bh);
	brelse(bh);
	hpfs_i(i)->i_dno = rdno;
	d->up = ad->up = cpu_to_le32(rdno);
	d->root_dnode = ad->root_dnode = 0;
	hpfs_mark_4buffers_dirty(&qbh);
	hpfs_brelse4(&qbh);
	hpfs_mark_4buffers_dirty(&qbh1);
	hpfs_brelse4(&qbh1);
	qbh = qbh2;
	set_last_pointer(i->i_sb, rd, dno);
	dno = rdno;
	d = rd;
	goto go_up_a;
}

/*
 * Add an entry to directory btree.
 * I hate such crazy directory structure.
 * It's easy to read but terrible to write.
 * I wrote this directory code 4 times.
 * I hope, now it's finally bug-free.
 */

int hpfs_add_dirent(struct inode *i,
		    const unsigned char *name, unsigned namelen,
		    struct hpfs_dirent *new_de)
{
	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
	struct dnode *d;
	struct hpfs_dirent *de, *de_end;
	struct quad_buffer_head qbh;
	dnode_secno dno;
	int c;
	int c1, c2 = 0;
	dno = hpfs_inode->i_dno;
	down:
	if (hpfs_sb(i->i_sb)->sb_chk)
		if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "hpfs_add_dirent")) return 1;
	if (!(d = hpfs_map_dnode(i->i_sb, dno, &qbh))) return 1;
	de_end = dnode_end_de(d);
	for (de = dnode_first_de(d); de < de_end; de = de_next_de(de)) {
		if (!(c = hpfs_compare_names(i->i_sb, name, namelen, de->name, de->namelen, de->last))) {
			hpfs_brelse4(&qbh);
			return -1;
		}	
		if (c < 0) {
			if (de->down) {
				dno = de_down_pointer(de);
				hpfs_brelse4(&qbh);
				goto down;
			}
			break;
		}
	}
	hpfs_brelse4(&qbh);
	if (hpfs_check_free_dnodes(i->i_sb, FREE_DNODES_ADD)) {
		c = 1;
		goto ret;
	}	
	i->i_version++;
	c = hpfs_add_to_dnode(i, dno, name, namelen, new_de, 0);
	ret:
	return c;
}

/* 
 * Find dirent with higher name in 'from' subtree and move it to 'to' dnode.
 * Return the dnode we moved from (to be checked later if it's empty)
 */

static secno move_to_top(struct inode *i, dnode_secno from, dnode_secno to)
{
	dnode_secno dno, ddno;
	dnode_secno chk_up = to;
	struct dnode *dnode;
	struct quad_buffer_head qbh;
	struct hpfs_dirent *de, *nde;
	int a;
	loff_t t;
	int c1, c2 = 0;
	dno = from;
	while (1) {
		if (hpfs_sb(i->i_sb)->sb_chk)
			if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "move_to_top"))
				return 0;
		if (!(dnode = hpfs_map_dnode(i->i_sb, dno, &qbh))) return 0;
		if (hpfs_sb(i->i_sb)->sb_chk) {
			if (le32_to_cpu(dnode->up) != chk_up) {
				hpfs_error(i->i_sb, "move_to_top: up pointer from %08x should be %08x, is %08x",
					dno, chk_up, le32_to_cpu(dnode->up));
				hpfs_brelse4(&qbh);
				return 0;
			}
			chk_up = dno;
		}
		if (!(de = dnode_last_de(dnode))) {
			hpfs_error(i->i_sb, "move_to_top: dnode %08x has no last de", dno);
			hpfs_brelse4(&qbh);
			return 0;
		}
		if (!de->down) break;
		dno = de_down_pointer(de);
		hpfs_brelse4(&qbh);
	}
	while (!(de = dnode_pre_last_de(dnode))) {
		dnode_secno up = le32_to_cpu(dnode->up);
		hpfs_brelse4(&qbh);
		hpfs_free_dnode(i->i_sb, dno);
		i->i_size -= 2048;
		i->i_blocks -= 4;
		for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | 1, 5);
		if (up == to) return to;
		if (!(dnode = hpfs_map_dnode(i->i_sb, up, &qbh))) return 0;
		if (dnode->root_dnode) {
			hpfs_error(i->i_sb, "move_to_top: got to root_dnode while moving from %08x to %08x", from, to);
			hpfs_brelse4(&qbh);
			return 0;
		}
		de = dnode_last_de(dnode);
		if (!de || !de->down) {
			hpfs_error(i->i_sb, "move_to_top: dnode %08x doesn't point down to %08x", up, dno);
			hpfs_brelse4(&qbh);
			return 0;
		}
		le32_add_cpu(&dnode->first_free, -4);
		le16_add_cpu(&de->length, -4);
		de->down = 0;
		hpfs_mark_4buffers_dirty(&qbh);
		dno = up;
	}
	t = get_pos(dnode, de);
	for_all_poss(i, hpfs_pos_subst, t, 4);
	for_all_poss(i, hpfs_pos_subst, t + 1, 5);
	if (!(nde = kmalloc(le16_to_cpu(de->length), GFP_NOFS))) {
		hpfs_error(i->i_sb, "out of memory for dirent - directory will be corrupted");
		hpfs_brelse4(&qbh);
		return 0;
	}
	memcpy(nde, de, le16_to_cpu(de->length));
	ddno = de->down ? de_down_pointer(de) : 0;
	hpfs_delete_de(i->i_sb, dnode, de);
	set_last_pointer(i->i_sb, dnode, ddno);
	hpfs_mark_4buffers_dirty(&qbh);
	hpfs_brelse4(&qbh);
	a = hpfs_add_to_dnode(i, to, nde->name, nde->namelen, nde, from);
	kfree(nde);
	if (a) return 0;
	return dno;
}

/* 
 * Check if a dnode is empty and delete it from the tree
 * (chkdsk doesn't like empty dnodes)
 */

static void delete_empty_dnode(struct inode *i, dnode_secno dno)
{
	struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
	struct quad_buffer_head qbh;
	struct dnode *dnode;
	dnode_secno down, up, ndown;
	int p;
	struct hpfs_dirent *de;
	int c1, c2 = 0;
	try_it_again:
	if (hpfs_stop_cycles(i->i_sb, dno, &c1, &c2, "delete_empty_dnode")) return;
	if (!(dnode = hpfs_map_dnode(i->i_sb, dno, &qbh))) return;
	if (le32_to_cpu(dnode->first_free) > 56) goto end;
	if (le32_to_cpu(dnode->first_free) == 52 || le32_to_cpu(dnode->first_free) == 56) {
		struct hpfs_dirent *de_end;
		int root = dnode->root_dnode;
		up = le32_to_cpu(dnode->up);
		de = dnode_first_de(dnode);
		down = de->down ? de_down_pointer(de) : 0;
		if (hpfs_sb(i->i_sb)->sb_chk) if (root && !down) {
			hpfs_error(i->i_sb, "delete_empty_dnode: root dnode %08x is empty", dno);
			goto end;
		}
		hpfs_brelse4(&qbh);
		hpfs_free_dnode(i->i_sb, dno);
		i->i_size -= 2048;
		i->i_blocks -= 4;
		if (root) {
			struct fnode *fnode;
			struct buffer_head *bh;
			struct dnode *d1;
			struct quad_buffer_head qbh1;
			if (hpfs_sb(i->i_sb)->sb_chk)
				if (up != i->i_ino) {
					hpfs_error(i->i_sb,
						   "bad pointer to fnode, dnode %08x, pointing to %08x, should be %08lx",
						   dno, up,
						   (unsigned long)i->i_ino);
					return;
				}
			if ((d1 = hpfs_map_dnode(i->i_sb, down, &qbh1))) {
				d1->up = cpu_to_le32(up);
				d1->root_dnode = 1;
				hpfs_mark_4buffers_dirty(&qbh1);
				hpfs_brelse4(&qbh1);
			}
			if ((fnode = hpfs_map_fnode(i->i_sb, up, &bh))) {
				fnode->u.external[0].disk_secno = cpu_to_le32(down);
				mark_buffer_dirty(bh);
				brelse(bh);
			}
			hpfs_inode->i_dno = down;
			for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | 1, (loff_t) 12);
			return;
		}
		if (!(dnode = hpfs_map_dnode(i->i_sb, up, &qbh))) return;
		p = 1;
		de_end = dnode_end_de(dnode);
		for (de = dnode_first_de(dnode); de < de_end; de = de_next_de(de), p++)
			if (de->down) if (de_down_pointer(de) == dno) goto fnd;
		hpfs_error(i->i_sb, "delete_empty_dnode: pointer to dnode %08x not found in dnode %08x", dno, up);
		goto end;
		fnd:
		for_all_poss(i, hpfs_pos_subst, ((loff_t)dno << 4) | 1, ((loff_t)up << 4) | p);
		if (!down) {
			de->down = 0;
			le16_add_cpu(&de->length, -4);
			le32_add_cpu(&dnode->first_free, -4);
			memmove(de_next_de(de), (char *)de_next_de(de) + 4,
				(char *)dnode + le32_to_cpu(dnode->first_free) - (char *)de_next_de(de));
		} else {
			struct dnode *d1;
			struct quad_buffer_head qbh1;
			*(dnode_secno *) ((void *) de + le16_to_cpu(de->length) - 4) = down;
			if ((d1 = hpfs_map_dnode(i->i_sb, down, &qbh1))) {
				d1->up = cpu_to_le32(up);
				hpfs_mark_4buffers_dirty(&qbh1);
				hpfs_brelse4(&qbh1);
			}
		}
	} else {
		hpfs_error(i->i_sb, "delete_empty_dnode: dnode %08x, first_free == %03x", dno, le32_to_cpu(dnode->first_free));
		goto end;
	}

	if (!de->last) {
		struct hpfs_dirent *de_next = de_next_de(de);
		struct hpfs_dirent *de_cp;
		struct dnode *d1;
		struct quad_buffer_head qbh1;
		if (!de_next->down) goto endm;
		ndown = de_down_pointer(de_next);
		if (!(de_cp = kmalloc(le16_to_cpu(de->length), GFP_NOFS))) {
			pr_err("out of memory for dtree balancing\n");
			goto endm;
		}
		memcpy(de_cp, de, le16_to_cpu(de->length));
		hpfs_delete_de(i->i_sb, dnode, de);
		hpfs_mark_4buffers_dirty(&qbh);
		hpfs_brelse4(&qbh);
		for_all_poss(i, hpfs_pos_subst, ((loff_t)up << 4) | p, 4);
		for_all_poss(i, hpfs_pos_del, ((loff_t)up << 4) | p, 1);
		if (de_cp->down) if ((d1 = hpfs_map_dnode(i->i_sb, de_down_pointer(de_cp), &qbh1))) {
			d1->up = cpu_to_le32(ndown);
			hpfs_mark_4buffers_dirty(&qbh1);
			hpfs_brelse4(&qbh1);
		}
		hpfs_add_to_dnode(i, ndown, de_cp->name, de_cp->namelen, de_cp, de_cp->down ? de_down_pointer(de_cp) : 0);
		/*pr_info("UP-TO-DNODE: %08x (ndown = %08x, down = %08x, dno = %08x)\n",
		  up, ndown, down, dno);*/
		dno = up;
		kfree(de_cp);
		goto try_it_again;
	} else {
		struct hpfs_dirent *de_prev = dnode_pre_last_de(dnode);
		struct hpfs_dirent *de_cp;
		struct dnode *d1;
		struct quad_buffer_head qbh1;
		dnode_secno dlp;
		if (!de_prev) {
			hpfs_error(i->i_sb, "delete_empty_dnode: empty dnode %08x", up);
			hpfs_mark_4buffers_dirty(&qbh);
			hpfs_brelse4(&qbh);
			dno = up;
			goto try_it_again;
		}
		if (!de_prev->down) goto endm;
		ndown = de_down_pointer(de_prev);
		if ((d1 = hpfs_map_dnode(i->i_sb, ndown, &qbh1))) {
			struct hpfs_dirent *del = dnode_last_de(d1);
			dlp = del->down ? de_down_pointer(del) : 0;
			if (!dlp && down) {
				if (le32_to_cpu(d1->first_free) > 2044) {
					if (hpfs_sb(i->i_sb)->sb_chk >= 2) {
						pr_err("unbalanced dnode tree, see hpfs.txt 4 more info\n");
						pr_err("terminating balancing operation\n");
					}
					hpfs_brelse4(&qbh1);
					goto endm;
				}
				if (hpfs_sb(i->i_sb)->sb_chk >= 2) {
					pr_err("unbalanced dnode tree, see hpfs.txt 4 more info\n");
					pr_err("goin'on\n");
				}
				le16_add_cpu(&del->length, 4);
				del->down = 1;
				le32_add_cpu(&d1->first_free, 4);
			}
			if (dlp && !down) {
				le16_add_cpu(&del->length, -4);
				del->down = 0;
				le32_add_cpu(&d1->first_free, -4);
			} else if (down)
				*(__le32 *) ((void *) del + le16_to_cpu(del->length) - 4) = cpu_to_le32(down);
		} else goto endm;
		if (!(de_cp = kmalloc(le16_to_cpu(de_prev->length), GFP_NOFS))) {
			pr_err("out of memory for dtree balancing\n");
			hpfs_brelse4(&qbh1);
			goto endm;
		}
		hpfs_mark_4buffers_dirty(&qbh1);
		hpfs_brelse4(&qbh1);
		memcpy(de_cp, de_prev, le16_to_cpu(de_prev->length));
		hpfs_delete_de(i->i_sb, dnode, de_prev);
		if (!de_prev->down) {
			le16_add_cpu(&de_prev->length, 4);
			de_prev->down = 1;
			le32_add_cpu(&dnode->first_free, 4);
		}
		*(__le32 *) ((void *) de_prev + le16_to_cpu(de_prev->length) - 4) = cpu_to_le32(ndown);
		hpfs_mark_4buffers_dirty(&qbh);
		hpfs_brelse4(&qbh);
		for_all_poss(i, hpfs_pos_subst, ((loff_t)up << 4) | (p - 1), 4);
		for_all_poss(i, hpfs_pos_subst, ((loff_t)up << 4) | p, ((loff_t)up << 4) | (p - 1));
		if (down) if ((d1 = hpfs_map_dnode(i->i_sb, de_down_pointer(de), &qbh1))) {
			d1->up = cpu_to_le32(ndown);
			hpfs_mark_4buffers_dirty(&qbh1);
			hpfs_brelse4(&qbh1);
		}
		hpfs_add_to_dnode(i, ndown, de_cp->name, de_cp->namelen, de_cp, dlp);
		dno = up;
		kfree(de_cp);
		goto try_it_again;
	}
	endm:
	hpfs_mark_4buffers_dirty(&qbh);
	end:
	hpfs_brelse4(&qbh);
}


/* Delete dirent from directory */

int hpfs_remove_dirent(struct inode *i, dnode_secno dno, struct hpfs_dirent *de,
		       struct quad_buffer_head *qbh, int depth)
{
	struct dnode *dnode = qbh->data;
	dnode_secno down = 0;
	loff_t t;
	if (de->first || de->last) {
		hpfs_error(i->i_sb, "hpfs_remove_dirent: attempt to delete first or last dirent in dnode %08x", dno);
		hpfs_brelse4(qbh);
		return 1;
	}
	if (de->down) down = de_down_pointer(de);
	if (depth && (de->down || (de == dnode_first_de(dnode) && de_next_de(de)->last))) {
		if (hpfs_check_free_dnodes(i->i_sb, FREE_DNODES_DEL)) {
			hpfs_brelse4(qbh);
			return 2;
		}
	}
	i->i_version++;
	for_all_poss(i, hpfs_pos_del, (t = get_pos(dnode, de)) + 1, 1);
	hpfs_delete_de(i->i_sb, dnode, de);
	hpfs_mark_4buffers_dirty(qbh);
	hpfs_brelse4(qbh);
	if (down) {
		dnode_secno a = move_to_top(i, down, dno);
		for_all_poss(i, hpfs_pos_subst, 5, t);
		if (a) delete_empty_dnode(i, a);
		return !a;
	}
	delete_empty_dnode(i, dno);
	return 0;
}

void hpfs_count_dnodes(struct super_block *s, dnode_secno dno, int *n_dnodes,
		       int *n_subdirs, int *n_items)
{
	struct dnode *dnode;
	struct quad_buffer_head qbh;
	struct hpfs_dirent *de;
	dnode_secno ptr, odno = 0;
	int c1, c2 = 0;
	int d1, d2 = 0;
	go_down:
	if (n_dnodes) (*n_dnodes)++;
	if (hpfs_sb(s)->sb_chk)
		if (hpfs_stop_cycles(s, dno, &c1, &c2, "hpfs_count_dnodes #1")) return;
	ptr = 0;
	go_up:
	if (!(dnode = hpfs_map_dnode(s, dno, &qbh))) return;
	if (hpfs_sb(s)->sb_chk) if (odno && odno != -1 && le32_to_cpu(dnode->up) != odno)
		hpfs_error(s, "hpfs_count_dnodes: bad up pointer; dnode %08x, down %08x points to %08x", odno, dno, le32_to_cpu(dnode->up));
	de = dnode_first_de(dnode);
	if (ptr) while(1) {
		if (de->down) if (de_down_pointer(de) == ptr) goto process_de;
		if (de->last) {
			hpfs_brelse4(&qbh);
			hpfs_error(s, "hpfs_count_dnodes: pointer to dnode %08x not found in dnode %08x, got here from %08x",
				ptr, dno, odno);
			return;
		}
		de = de_next_de(de);
	}
	next_de:
	if (de->down) {
		odno = dno;
		dno = de_down_pointer(de);
		hpfs_brelse4(&qbh);
		goto go_down;
	}
	process_de:
	if (!de->first && !de->last && de->directory && n_subdirs) (*n_subdirs)++;
	if (!de->first && !de->last && n_items) (*n_items)++;
	if ((de = de_next_de(de)) < dnode_end_de(dnode)) goto next_de;
	ptr = dno;
	dno = le32_to_cpu(dnode->up);
	if (dnode->root_dnode) {
		hpfs_brelse4(&qbh);
		return;
	}
	hpfs_brelse4(&qbh);
	if (hpfs_sb(s)->sb_chk)
		if (hpfs_stop_cycles(s, ptr, &d1, &d2, "hpfs_count_dnodes #2")) return;
	odno = -1;
	goto go_up;
}

static struct hpfs_dirent *map_nth_dirent(struct super_block *s, dnode_secno dno, int n,
					  struct quad_buffer_head *qbh, struct dnode **dn)
{
	int i;
	struct hpfs_dirent *de, *de_end;
	struct dnode *dnode;
	dnode = hpfs_map_dnode(s, dno, qbh);
	if (!dnode) return NULL;
	if (dn) *dn=dnode;
	de = dnode_first_de(dnode);
	de_end = dnode_end_de(dnode);
	for (i = 1; de < de_end; i++, de = de_next_de(de)) {
		if (i == n) {
			return de;
		}	
		if (de->last) break;
	}
	hpfs_brelse4(qbh);
	hpfs_error(s, "map_nth_dirent: n too high; dnode = %08x, requested %08x", dno, n);
	return NULL;
}

dnode_secno hpfs_de_as_down_as_possible(struct super_block *s, dnode_secno dno)
{
	struct quad_buffer_head qbh;
	dnode_secno d = dno;
	dnode_secno up = 0;
	struct hpfs_dirent *de;
	int c1, c2 = 0;

	again:
	if (hpfs_sb(s)->sb_chk)
		if (hpfs_stop_cycles(s, d, &c1, &c2, "hpfs_de_as_down_as_possible"))
			return d;
	if (!(de = map_nth_dirent(s, d, 1, &qbh, NULL))) return dno;
	if (hpfs_sb(s)->sb_chk)
		if (up && le32_to_cpu(((struct dnode *)qbh.data)->up) != up)
			hpfs_error(s, "hpfs_de_as_down_as_possible: bad up pointer; dnode %08x, down %08x points to %08x", up, d, le32_to_cpu(((struct dnode *)qbh.data)->up));
	if (!de->down) {
		hpfs_brelse4(&qbh);
		return d;
	}
	up = d;
	d = de_down_pointer(de);
	hpfs_brelse4(&qbh);
	goto again;
}

struct hpfs_dirent *map_pos_dirent(struct inode *inode, loff_t *posp,
				   struct quad_buffer_head *qbh)
{
	loff_t pos;
	unsigned c;
	dnode_secno dno;
	struct hpfs_dirent *de, *d;
	struct hpfs_dirent *up_de;
	struct hpfs_dirent *end_up_de;
	struct dnode *dnode;
	struct dnode *up_dnode;
	struct quad_buffer_head qbh0;

	pos = *posp;
	dno = pos >> 6 << 2;
	pos &= 077;
	if (!(de = map_nth_dirent(inode->i_sb, dno, pos, qbh, &dnode)))
		goto bail;

	/* Going to the next dirent */
	if ((d = de_next_de(de)) < dnode_end_de(dnode)) {
		if (!(++*posp & 077)) {
			hpfs_error(inode->i_sb,
				"map_pos_dirent: pos crossed dnode boundary; pos = %08llx",
				(unsigned long long)*posp);
			goto bail;
		}
		/* We're going down the tree */
		if (d->down) {
			*posp = ((loff_t) hpfs_de_as_down_as_possible(inode->i_sb, de_down_pointer(d)) << 4) + 1;
		}
	
		return de;
	}

	/* Going up */
	if (dnode->root_dnode) goto bail;

	if (!(up_dnode = hpfs_map_dnode(inode->i_sb, le32_to_cpu(dnode->up), &qbh0)))
		goto bail;

	end_up_de = dnode_end_de(up_dnode);
	c = 0;
	for (up_de = dnode_first_de(up_dnode); up_de < end_up_de;
	     up_de = de_next_de(up_de)) {
		if (!(++c & 077)) hpfs_error(inode->i_sb,
			"map_pos_dirent: pos crossed dnode boundary; dnode = %08x", le32_to_cpu(dnode->up));
		if (up_de->down && de_down_pointer(up_de) == dno) {
			*posp = ((loff_t) le32_to_cpu(dnode->up) << 4) + c;
			hpfs_brelse4(&qbh0);
			return de;
		}
	}
	
	hpfs_error(inode->i_sb, "map_pos_dirent: pointer to dnode %08x not found in parent dnode %08x",
		dno, le32_to_cpu(dnode->up));
	hpfs_brelse4(&qbh0);
	
	bail:
	*posp = 12;
	return de;
}

/* Find a dirent in tree */

struct hpfs_dirent *map_dirent(struct inode *inode, dnode_secno dno,
			       const unsigned char *name, unsigned len,
			       dnode_secno *dd, struct quad_buffer_head *qbh)
{
	struct dnode *dnode;
	struct hpfs_dirent *de;
	struct hpfs_dirent *de_end;
	int c1, c2 = 0;

	if (!S_ISDIR(inode->i_mode)) hpfs_error(inode->i_sb, "map_dirent: not a directory\n");
	again:
	if (hpfs_sb(inode->i_sb)->sb_chk)
		if (hpfs_stop_cycles(inode->i_sb, dno, &c1, &c2, "map_dirent")) return NULL;
	if (!(dnode = hpfs_map_dnode(inode->i_sb, dno, qbh))) return NULL;
	
	de_end = dnode_end_de(dnode);
	for (de = dnode_first_de(dnode); de < de_end; de = de_next_de(de)) {
		int t = hpfs_compare_names(inode->i_sb, name, len, de->name, de->namelen, de->last);
		if (!t) {
			if (dd) *dd = dno;
			return de;
		}
		if (t < 0) {
			if (de->down) {
				dno = de_down_pointer(de);
				hpfs_brelse4(qbh);
				goto again;
			}
		break;
		}
	}
	hpfs_brelse4(qbh);
	return NULL;
}

/*
 * Remove empty directory. In normal cases it is only one dnode with two
 * entries, but we must handle also such obscure cases when it's a tree
 * of empty dnodes.
 */

void hpfs_remove_dtree(struct super_block *s, dnode_secno dno)
{
	struct quad_buffer_head qbh;
	struct dnode *dnode;
	struct hpfs_dirent *de;
	dnode_secno d1, d2, rdno = dno;
	while (1) {
		if (!(dnode = hpfs_map_dnode(s, dno, &qbh))) return;
		de = dnode_first_de(dnode);
		if (de->last) {
			if (de->down) d1 = de_down_pointer(de);
			else goto error;
			hpfs_brelse4(&qbh);
			hpfs_free_dnode(s, dno);
			dno = d1;
		} else break;
	}
	if (!de->first) goto error;
	d1 = de->down ? de_down_pointer(de) : 0;
	de = de_next_de(de);
	if (!de->last) goto error;
	d2 = de->down ? de_down_pointer(de) : 0;
	hpfs_brelse4(&qbh);
	hpfs_free_dnode(s, dno);
	do {
		while (d1) {
			if (!(dnode = hpfs_map_dnode(s, dno = d1, &qbh))) return;
			de = dnode_first_de(dnode);
			if (!de->last) goto error;
			d1 = de->down ? de_down_pointer(de) : 0;
			hpfs_brelse4(&qbh);
			hpfs_free_dnode(s, dno);
		}
		d1 = d2;
		d2 = 0;
	} while (d1);
	return;
	error:
	hpfs_brelse4(&qbh);
	hpfs_free_dnode(s, dno);
	hpfs_error(s, "directory %08x is corrupted or not empty", rdno);
}

/* 
 * Find dirent for specified fnode. Use truncated 15-char name in fnode as
 * a help for searching.
 */

struct hpfs_dirent *map_fnode_dirent(struct super_block *s, fnode_secno fno,
				     struct fnode *f, struct quad_buffer_head *qbh)
{
	unsigned char *name1;
	unsigned char *name2;
	int name1len, name2len;
	struct dnode *d;
	dnode_secno dno, downd;
	struct fnode *upf;
	struct buffer_head *bh;
	struct hpfs_dirent *de, *de_end;
	int c;
	int c1, c2 = 0;
	int d1, d2 = 0;
	name1 = f->name;
	if (!(name2 = kmalloc(256, GFP_NOFS))) {
		pr_err("out of memory, can't map dirent\n");
		return NULL;
	}
	if (f->len <= 15)
		memcpy(name2, name1, name1len = name2len = f->len);
	else {
		memcpy(name2, name1, 15);
		memset(name2 + 15, 0xff, 256 - 15);
		/*name2[15] = 0xff;*/
		name1len = 15; name2len = 256;
	}
	if (!(upf = hpfs_map_fnode(s, le32_to_cpu(f->up), &bh))) {
		kfree(name2);
		return NULL;
	}	
	if (!fnode_is_dir(upf)) {
		brelse(bh);
		hpfs_error(s, "fnode %08x has non-directory parent %08x", fno, le32_to_cpu(f->up));
		kfree(name2);
		return NULL;
	}
	dno = le32_to_cpu(upf->u.external[0].disk_secno);
	brelse(bh);
	go_down:
	downd = 0;
	go_up:
	if (!(d = hpfs_map_dnode(s, dno, qbh))) {
		kfree(name2);
		return NULL;
	}
	de_end = dnode_end_de(d);
	de = dnode_first_de(d);
	if (downd) {
		while (de < de_end) {
			if (de->down) if (de_down_pointer(de) == downd) goto f;
			de = de_next_de(de);
		}
		hpfs_error(s, "pointer to dnode %08x not found in dnode %08x", downd, dno);
		hpfs_brelse4(qbh);
		kfree(name2);
		return NULL;
	}
	next_de:
	if (le32_to_cpu(de->fnode) == fno) {
		kfree(name2);
		return de;
	}
	c = hpfs_compare_names(s, name1, name1len, de->name, de->namelen, de->last);
	if (c < 0 && de->down) {
		dno = de_down_pointer(de);
		hpfs_brelse4(qbh);
		if (hpfs_sb(s)->sb_chk)
			if (hpfs_stop_cycles(s, dno, &c1, &c2, "map_fnode_dirent #1")) {
				kfree(name2);
				return NULL;
		}
		goto go_down;
	}
	f:
	if (le32_to_cpu(de->fnode) == fno) {
		kfree(name2);
		return de;
	}
	c = hpfs_compare_names(s, name2, name2len, de->name, de->namelen, de->last);
	if (c < 0 && !de->last) goto not_found;
	if ((de = de_next_de(de)) < de_end) goto next_de;
	if (d->root_dnode) goto not_found;
	downd = dno;
	dno = le32_to_cpu(d->up);
	hpfs_brelse4(qbh);
	if (hpfs_sb(s)->sb_chk)
		if (hpfs_stop_cycles(s, downd, &d1, &d2, "map_fnode_dirent #2")) {
			kfree(name2);
			return NULL;
		}
	goto go_up;
	not_found:
	hpfs_brelse4(qbh);
	hpfs_error(s, "dirent for fnode %08x not found", fno);
	kfree(name2);
	return NULL;
}