Bootlin logo

Elixir Cross Referencer

  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
/*
 * balloc.c
 *
 * PURPOSE
 *	Block allocation handling routines for the OSTA-UDF(tm) filesystem.
 *
 * COPYRIGHT
 *	This file is distributed under the terms of the GNU General Public
 *	License (GPL). Copies of the GPL can be obtained from:
 *		ftp://prep.ai.mit.edu/pub/gnu/GPL
 *	Each contributing author retains all rights to their own work.
 *
 *  (C) 1999-2001 Ben Fennema
 *  (C) 1999 Stelias Computing Inc
 *
 * HISTORY
 *
 *  02/24/99 blf  Created.
 *
 */

#include "udfdecl.h"

#include <linux/quotaops.h>
#include <linux/buffer_head.h>
#include <linux/bitops.h>

#include "udf_i.h"
#include "udf_sb.h"

#define udf_clear_bit(nr, addr) ext2_clear_bit(nr, addr)
#define udf_set_bit(nr, addr) ext2_set_bit(nr, addr)
#define udf_test_bit(nr, addr) ext2_test_bit(nr, addr)
#define udf_find_first_one_bit(addr, size) find_first_one_bit(addr, size)
#define udf_find_next_one_bit(addr, size, offset) \
		find_next_one_bit(addr, size, offset)

#define leBPL_to_cpup(x) leNUM_to_cpup(BITS_PER_LONG, x)
#define leNUM_to_cpup(x, y) xleNUM_to_cpup(x, y)
#define xleNUM_to_cpup(x, y) (le ## x ## _to_cpup(y))
#define uintBPL_t uint(BITS_PER_LONG)
#define uint(x) xuint(x)
#define xuint(x) __le ## x

static inline int find_next_one_bit(void *addr, int size, int offset)
{
	uintBPL_t *p = ((uintBPL_t *) addr) + (offset / BITS_PER_LONG);
	int result = offset & ~(BITS_PER_LONG - 1);
	unsigned long tmp;

	if (offset >= size)
		return size;
	size -= result;
	offset &= (BITS_PER_LONG - 1);
	if (offset) {
		tmp = leBPL_to_cpup(p++);
		tmp &= ~0UL << offset;
		if (size < BITS_PER_LONG)
			goto found_first;
		if (tmp)
			goto found_middle;
		size -= BITS_PER_LONG;
		result += BITS_PER_LONG;
	}
	while (size & ~(BITS_PER_LONG - 1)) {
		tmp = leBPL_to_cpup(p++);
		if (tmp)
			goto found_middle;
		result += BITS_PER_LONG;
		size -= BITS_PER_LONG;
	}
	if (!size)
		return result;
	tmp = leBPL_to_cpup(p);
found_first:
	tmp &= ~0UL >> (BITS_PER_LONG - size);
found_middle:
	return result + ffz(~tmp);
}

#define find_first_one_bit(addr, size)\
	find_next_one_bit((addr), (size), 0)

static int read_block_bitmap(struct super_block *sb,
			     struct udf_bitmap *bitmap, unsigned int block,
			     unsigned long bitmap_nr)
{
	struct buffer_head *bh = NULL;
	int retval = 0;
	struct kernel_lb_addr loc;

	loc.logicalBlockNum = bitmap->s_extPosition;
	loc.partitionReferenceNum = UDF_SB(sb)->s_partition;

	bh = udf_tread(sb, udf_get_lb_pblock(sb, &loc, block));
	if (!bh)
		retval = -EIO;

	bitmap->s_block_bitmap[bitmap_nr] = bh;
	return retval;
}

static int __load_block_bitmap(struct super_block *sb,
			       struct udf_bitmap *bitmap,
			       unsigned int block_group)
{
	int retval = 0;
	int nr_groups = bitmap->s_nr_groups;

	if (block_group >= nr_groups) {
		udf_debug("block_group (%d) > nr_groups (%d)\n", block_group,
			  nr_groups);
	}

	if (bitmap->s_block_bitmap[block_group]) {
		return block_group;
	} else {
		retval = read_block_bitmap(sb, bitmap, block_group,
					   block_group);
		if (retval < 0)
			return retval;
		return block_group;
	}
}

static inline int load_block_bitmap(struct super_block *sb,
				    struct udf_bitmap *bitmap,
				    unsigned int block_group)
{
	int slot;

	slot = __load_block_bitmap(sb, bitmap, block_group);

	if (slot < 0)
		return slot;

	if (!bitmap->s_block_bitmap[slot])
		return -EIO;

	return slot;
}

static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
{
	struct udf_sb_info *sbi = UDF_SB(sb);
	struct logicalVolIntegrityDesc *lvid;

	if (!sbi->s_lvid_bh)
		return;

	lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
	le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
	udf_updated_lvid(sb);
}

static void udf_bitmap_free_blocks(struct super_block *sb,
				   struct inode *inode,
				   struct udf_bitmap *bitmap,
				   struct kernel_lb_addr *bloc,
				   uint32_t offset,
				   uint32_t count)
{
	struct udf_sb_info *sbi = UDF_SB(sb);
	struct buffer_head *bh = NULL;
	struct udf_part_map *partmap;
	unsigned long block;
	unsigned long block_group;
	unsigned long bit;
	unsigned long i;
	int bitmap_nr;
	unsigned long overflow;

	mutex_lock(&sbi->s_alloc_mutex);
	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
	if (bloc->logicalBlockNum < 0 ||
	    (bloc->logicalBlockNum + count) >
		partmap->s_partition_len) {
		udf_debug("%d < %d || %d + %d > %d\n",
			  bloc->logicalBlockNum, 0, bloc->logicalBlockNum,
			  count, partmap->s_partition_len);
		goto error_return;
	}

	block = bloc->logicalBlockNum + offset +
		(sizeof(struct spaceBitmapDesc) << 3);

	do {
		overflow = 0;
		block_group = block >> (sb->s_blocksize_bits + 3);
		bit = block % (sb->s_blocksize << 3);

		/*
		* Check to see if we are freeing blocks across a group boundary.
		*/
		if (bit + count > (sb->s_blocksize << 3)) {
			overflow = bit + count - (sb->s_blocksize << 3);
			count -= overflow;
		}
		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
		if (bitmap_nr < 0)
			goto error_return;

		bh = bitmap->s_block_bitmap[bitmap_nr];
		for (i = 0; i < count; i++) {
			if (udf_set_bit(bit + i, bh->b_data)) {
				udf_debug("bit %ld already set\n", bit + i);
				udf_debug("byte=%2x\n",
					((char *)bh->b_data)[(bit + i) >> 3]);
			} else {
				if (inode)
					vfs_dq_free_block(inode, 1);
				udf_add_free_space(sb, sbi->s_partition, 1);
			}
		}
		mark_buffer_dirty(bh);
		if (overflow) {
			block += count;
			count = overflow;
		}
	} while (overflow);

error_return:
	mutex_unlock(&sbi->s_alloc_mutex);
}

static int udf_bitmap_prealloc_blocks(struct super_block *sb,
				      struct inode *inode,
				      struct udf_bitmap *bitmap,
				      uint16_t partition, uint32_t first_block,
				      uint32_t block_count)
{
	struct udf_sb_info *sbi = UDF_SB(sb);
	int alloc_count = 0;
	int bit, block, block_group, group_start;
	int nr_groups, bitmap_nr;
	struct buffer_head *bh;
	__u32 part_len;

	mutex_lock(&sbi->s_alloc_mutex);
	part_len = sbi->s_partmaps[partition].s_partition_len;
	if (first_block >= part_len)
		goto out;

	if (first_block + block_count > part_len)
		block_count = part_len - first_block;

	do {
		nr_groups = udf_compute_nr_groups(sb, partition);
		block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
		block_group = block >> (sb->s_blocksize_bits + 3);
		group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);

		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
		if (bitmap_nr < 0)
			goto out;
		bh = bitmap->s_block_bitmap[bitmap_nr];

		bit = block % (sb->s_blocksize << 3);

		while (bit < (sb->s_blocksize << 3) && block_count > 0) {
			if (!udf_test_bit(bit, bh->b_data))
				goto out;
			else if (vfs_dq_prealloc_block(inode, 1))
				goto out;
			else if (!udf_clear_bit(bit, bh->b_data)) {
				udf_debug("bit already cleared for block %d\n", bit);
				vfs_dq_free_block(inode, 1);
				goto out;
			}
			block_count--;
			alloc_count++;
			bit++;
			block++;
		}
		mark_buffer_dirty(bh);
	} while (block_count > 0);

out:
	udf_add_free_space(sb, partition, -alloc_count);
	mutex_unlock(&sbi->s_alloc_mutex);
	return alloc_count;
}

static int udf_bitmap_new_block(struct super_block *sb,
				struct inode *inode,
				struct udf_bitmap *bitmap, uint16_t partition,
				uint32_t goal, int *err)
{
	struct udf_sb_info *sbi = UDF_SB(sb);
	int newbit, bit = 0, block, block_group, group_start;
	int end_goal, nr_groups, bitmap_nr, i;
	struct buffer_head *bh = NULL;
	char *ptr;
	int newblock = 0;

	*err = -ENOSPC;
	mutex_lock(&sbi->s_alloc_mutex);

repeat:
	if (goal >= sbi->s_partmaps[partition].s_partition_len)
		goal = 0;

	nr_groups = bitmap->s_nr_groups;
	block = goal + (sizeof(struct spaceBitmapDesc) << 3);
	block_group = block >> (sb->s_blocksize_bits + 3);
	group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);

	bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
	if (bitmap_nr < 0)
		goto error_return;
	bh = bitmap->s_block_bitmap[bitmap_nr];
	ptr = memscan((char *)bh->b_data + group_start, 0xFF,
		      sb->s_blocksize - group_start);

	if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
		bit = block % (sb->s_blocksize << 3);
		if (udf_test_bit(bit, bh->b_data))
			goto got_block;

		end_goal = (bit + 63) & ~63;
		bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
		if (bit < end_goal)
			goto got_block;

		ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
			      sb->s_blocksize - ((bit + 7) >> 3));
		newbit = (ptr - ((char *)bh->b_data)) << 3;
		if (newbit < sb->s_blocksize << 3) {
			bit = newbit;
			goto search_back;
		}

		newbit = udf_find_next_one_bit(bh->b_data,
					       sb->s_blocksize << 3, bit);
		if (newbit < sb->s_blocksize << 3) {
			bit = newbit;
			goto got_block;
		}
	}

	for (i = 0; i < (nr_groups * 2); i++) {
		block_group++;
		if (block_group >= nr_groups)
			block_group = 0;
		group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);

		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
		if (bitmap_nr < 0)
			goto error_return;
		bh = bitmap->s_block_bitmap[bitmap_nr];
		if (i < nr_groups) {
			ptr = memscan((char *)bh->b_data + group_start, 0xFF,
				      sb->s_blocksize - group_start);
			if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
				bit = (ptr - ((char *)bh->b_data)) << 3;
				break;
			}
		} else {
			bit = udf_find_next_one_bit((char *)bh->b_data,
						    sb->s_blocksize << 3,
						    group_start << 3);
			if (bit < sb->s_blocksize << 3)
				break;
		}
	}
	if (i >= (nr_groups * 2)) {
		mutex_unlock(&sbi->s_alloc_mutex);
		return newblock;
	}
	if (bit < sb->s_blocksize << 3)
		goto search_back;
	else
		bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
					    group_start << 3);
	if (bit >= sb->s_blocksize << 3) {
		mutex_unlock(&sbi->s_alloc_mutex);
		return 0;
	}

search_back:
	i = 0;
	while (i < 7 && bit > (group_start << 3) &&
	       udf_test_bit(bit - 1, bh->b_data)) {
		++i;
		--bit;
	}

got_block:

	/*
	 * Check quota for allocation of this block.
	 */
	if (inode && vfs_dq_alloc_block(inode, 1)) {
		mutex_unlock(&sbi->s_alloc_mutex);
		*err = -EDQUOT;
		return 0;
	}

	newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
		(sizeof(struct spaceBitmapDesc) << 3);

	if (!udf_clear_bit(bit, bh->b_data)) {
		udf_debug("bit already cleared for block %d\n", bit);
		goto repeat;
	}

	mark_buffer_dirty(bh);

	udf_add_free_space(sb, partition, -1);
	mutex_unlock(&sbi->s_alloc_mutex);
	*err = 0;
	return newblock;

error_return:
	*err = -EIO;
	mutex_unlock(&sbi->s_alloc_mutex);
	return 0;
}

static void udf_table_free_blocks(struct super_block *sb,
				  struct inode *inode,
				  struct inode *table,
				  struct kernel_lb_addr *bloc,
				  uint32_t offset,
				  uint32_t count)
{
	struct udf_sb_info *sbi = UDF_SB(sb);
	struct udf_part_map *partmap;
	uint32_t start, end;
	uint32_t elen;
	struct kernel_lb_addr eloc;
	struct extent_position oepos, epos;
	int8_t etype;
	int i;
	struct udf_inode_info *iinfo;

	mutex_lock(&sbi->s_alloc_mutex);
	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
	if (bloc->logicalBlockNum < 0 ||
	    (bloc->logicalBlockNum + count) >
		partmap->s_partition_len) {
		udf_debug("%d < %d || %d + %d > %d\n",
			  bloc->logicalBlockNum, 0, bloc->logicalBlockNum, count,
			  partmap->s_partition_len);
		goto error_return;
	}

	iinfo = UDF_I(table);
	/* We do this up front - There are some error conditions that
	   could occure, but.. oh well */
	if (inode)
		vfs_dq_free_block(inode, count);
	udf_add_free_space(sb, sbi->s_partition, count);

	start = bloc->logicalBlockNum + offset;
	end = bloc->logicalBlockNum + offset + count - 1;

	epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
	elen = 0;
	epos.block = oepos.block = iinfo->i_location;
	epos.bh = oepos.bh = NULL;

	while (count &&
	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
		if (((eloc.logicalBlockNum +
			(elen >> sb->s_blocksize_bits)) == start)) {
			if ((0x3FFFFFFF - elen) <
					(count << sb->s_blocksize_bits)) {
				uint32_t tmp = ((0x3FFFFFFF - elen) >>
							sb->s_blocksize_bits);
				count -= tmp;
				start += tmp;
				elen = (etype << 30) |
					(0x40000000 - sb->s_blocksize);
			} else {
				elen = (etype << 30) |
					(elen +
					(count << sb->s_blocksize_bits));
				start += count;
				count = 0;
			}
			udf_write_aext(table, &oepos, &eloc, elen, 1);
		} else if (eloc.logicalBlockNum == (end + 1)) {
			if ((0x3FFFFFFF - elen) <
					(count << sb->s_blocksize_bits)) {
				uint32_t tmp = ((0x3FFFFFFF - elen) >>
						sb->s_blocksize_bits);
				count -= tmp;
				end -= tmp;
				eloc.logicalBlockNum -= tmp;
				elen = (etype << 30) |
					(0x40000000 - sb->s_blocksize);
			} else {
				eloc.logicalBlockNum = start;
				elen = (etype << 30) |
					(elen +
					(count << sb->s_blocksize_bits));
				end -= count;
				count = 0;
			}
			udf_write_aext(table, &oepos, &eloc, elen, 1);
		}

		if (epos.bh != oepos.bh) {
			i = -1;
			oepos.block = epos.block;
			brelse(oepos.bh);
			get_bh(epos.bh);
			oepos.bh = epos.bh;
			oepos.offset = 0;
		} else {
			oepos.offset = epos.offset;
		}
	}

	if (count) {
		/*
		 * NOTE: we CANNOT use udf_add_aext here, as it can try to
		 * allocate a new block, and since we hold the super block
		 * lock already very bad things would happen :)
		 *
		 * We copy the behavior of udf_add_aext, but instead of
		 * trying to allocate a new block close to the existing one,
		 * we just steal a block from the extent we are trying to add.
		 *
		 * It would be nice if the blocks were close together, but it
		 * isn't required.
		 */

		int adsize;
		struct short_ad *sad = NULL;
		struct long_ad *lad = NULL;
		struct allocExtDesc *aed;

		eloc.logicalBlockNum = start;
		elen = EXT_RECORDED_ALLOCATED |
			(count << sb->s_blocksize_bits);

		if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
			adsize = sizeof(struct short_ad);
		else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
			adsize = sizeof(struct long_ad);
		else {
			brelse(oepos.bh);
			brelse(epos.bh);
			goto error_return;
		}

		if (epos.offset + (2 * adsize) > sb->s_blocksize) {
			char *sptr, *dptr;
			int loffset;

			brelse(oepos.bh);
			oepos = epos;

			/* Steal a block from the extent being free'd */
			epos.block.logicalBlockNum = eloc.logicalBlockNum;
			eloc.logicalBlockNum++;
			elen -= sb->s_blocksize;

			epos.bh = udf_tread(sb,
					udf_get_lb_pblock(sb, &epos.block, 0));
			if (!epos.bh) {
				brelse(oepos.bh);
				goto error_return;
			}
			aed = (struct allocExtDesc *)(epos.bh->b_data);
			aed->previousAllocExtLocation =
				cpu_to_le32(oepos.block.logicalBlockNum);
			if (epos.offset + adsize > sb->s_blocksize) {
				loffset = epos.offset;
				aed->lengthAllocDescs = cpu_to_le32(adsize);
				sptr = iinfo->i_ext.i_data + epos.offset
								- adsize;
				dptr = epos.bh->b_data +
					sizeof(struct allocExtDesc);
				memcpy(dptr, sptr, adsize);
				epos.offset = sizeof(struct allocExtDesc) +
						adsize;
			} else {
				loffset = epos.offset + adsize;
				aed->lengthAllocDescs = cpu_to_le32(0);
				if (oepos.bh) {
					sptr = oepos.bh->b_data + epos.offset;
					aed = (struct allocExtDesc *)
						oepos.bh->b_data;
					le32_add_cpu(&aed->lengthAllocDescs,
							adsize);
				} else {
					sptr = iinfo->i_ext.i_data +
								epos.offset;
					iinfo->i_lenAlloc += adsize;
					mark_inode_dirty(table);
				}
				epos.offset = sizeof(struct allocExtDesc);
			}
			if (sbi->s_udfrev >= 0x0200)
				udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
					    3, 1, epos.block.logicalBlockNum,
					    sizeof(struct tag));
			else
				udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
					    2, 1, epos.block.logicalBlockNum,
					    sizeof(struct tag));

			switch (iinfo->i_alloc_type) {
			case ICBTAG_FLAG_AD_SHORT:
				sad = (struct short_ad *)sptr;
				sad->extLength = cpu_to_le32(
					EXT_NEXT_EXTENT_ALLOCDECS |
					sb->s_blocksize);
				sad->extPosition =
					cpu_to_le32(epos.block.logicalBlockNum);
				break;
			case ICBTAG_FLAG_AD_LONG:
				lad = (struct long_ad *)sptr;
				lad->extLength = cpu_to_le32(
					EXT_NEXT_EXTENT_ALLOCDECS |
					sb->s_blocksize);
				lad->extLocation =
					cpu_to_lelb(epos.block);
				break;
			}
			if (oepos.bh) {
				udf_update_tag(oepos.bh->b_data, loffset);
				mark_buffer_dirty(oepos.bh);
			} else {
				mark_inode_dirty(table);
			}
		}

		/* It's possible that stealing the block emptied the extent */
		if (elen) {
			udf_write_aext(table, &epos, &eloc, elen, 1);

			if (!epos.bh) {
				iinfo->i_lenAlloc += adsize;
				mark_inode_dirty(table);
			} else {
				aed = (struct allocExtDesc *)epos.bh->b_data;
				le32_add_cpu(&aed->lengthAllocDescs, adsize);
				udf_update_tag(epos.bh->b_data, epos.offset);
				mark_buffer_dirty(epos.bh);
			}
		}
	}

	brelse(epos.bh);
	brelse(oepos.bh);

error_return:
	mutex_unlock(&sbi->s_alloc_mutex);
	return;
}

static int udf_table_prealloc_blocks(struct super_block *sb,
				     struct inode *inode,
				     struct inode *table, uint16_t partition,
				     uint32_t first_block, uint32_t block_count)
{
	struct udf_sb_info *sbi = UDF_SB(sb);
	int alloc_count = 0;
	uint32_t elen, adsize;
	struct kernel_lb_addr eloc;
	struct extent_position epos;
	int8_t etype = -1;
	struct udf_inode_info *iinfo;

	if (first_block >= sbi->s_partmaps[partition].s_partition_len)
		return 0;

	iinfo = UDF_I(table);
	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
		adsize = sizeof(struct short_ad);
	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
		adsize = sizeof(struct long_ad);
	else
		return 0;

	mutex_lock(&sbi->s_alloc_mutex);
	epos.offset = sizeof(struct unallocSpaceEntry);
	epos.block = iinfo->i_location;
	epos.bh = NULL;
	eloc.logicalBlockNum = 0xFFFFFFFF;

	while (first_block != eloc.logicalBlockNum &&
	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
		udf_debug("eloc=%d, elen=%d, first_block=%d\n",
			  eloc.logicalBlockNum, elen, first_block);
		; /* empty loop body */
	}

	if (first_block == eloc.logicalBlockNum) {
		epos.offset -= adsize;

		alloc_count = (elen >> sb->s_blocksize_bits);
		if (inode && vfs_dq_prealloc_block(inode,
			alloc_count > block_count ? block_count : alloc_count))
			alloc_count = 0;
		else if (alloc_count > block_count) {
			alloc_count = block_count;
			eloc.logicalBlockNum += alloc_count;
			elen -= (alloc_count << sb->s_blocksize_bits);
			udf_write_aext(table, &epos, &eloc,
					(etype << 30) | elen, 1);
		} else
			udf_delete_aext(table, epos, eloc,
					(etype << 30) | elen);
	} else {
		alloc_count = 0;
	}

	brelse(epos.bh);

	if (alloc_count)
		udf_add_free_space(sb, partition, -alloc_count);
	mutex_unlock(&sbi->s_alloc_mutex);
	return alloc_count;
}

static int udf_table_new_block(struct super_block *sb,
			       struct inode *inode,
			       struct inode *table, uint16_t partition,
			       uint32_t goal, int *err)
{
	struct udf_sb_info *sbi = UDF_SB(sb);
	uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
	uint32_t newblock = 0, adsize;
	uint32_t elen, goal_elen = 0;
	struct kernel_lb_addr eloc, uninitialized_var(goal_eloc);
	struct extent_position epos, goal_epos;
	int8_t etype;
	struct udf_inode_info *iinfo = UDF_I(table);

	*err = -ENOSPC;

	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
		adsize = sizeof(struct short_ad);
	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
		adsize = sizeof(struct long_ad);
	else
		return newblock;

	mutex_lock(&sbi->s_alloc_mutex);
	if (goal >= sbi->s_partmaps[partition].s_partition_len)
		goal = 0;

	/* We search for the closest matching block to goal. If we find
	   a exact hit, we stop. Otherwise we keep going till we run out
	   of extents. We store the buffer_head, bloc, and extoffset
	   of the current closest match and use that when we are done.
	 */
	epos.offset = sizeof(struct unallocSpaceEntry);
	epos.block = iinfo->i_location;
	epos.bh = goal_epos.bh = NULL;

	while (spread &&
	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
		if (goal >= eloc.logicalBlockNum) {
			if (goal < eloc.logicalBlockNum +
					(elen >> sb->s_blocksize_bits))
				nspread = 0;
			else
				nspread = goal - eloc.logicalBlockNum -
					(elen >> sb->s_blocksize_bits);
		} else {
			nspread = eloc.logicalBlockNum - goal;
		}

		if (nspread < spread) {
			spread = nspread;
			if (goal_epos.bh != epos.bh) {
				brelse(goal_epos.bh);
				goal_epos.bh = epos.bh;
				get_bh(goal_epos.bh);
			}
			goal_epos.block = epos.block;
			goal_epos.offset = epos.offset - adsize;
			goal_eloc = eloc;
			goal_elen = (etype << 30) | elen;
		}
	}

	brelse(epos.bh);

	if (spread == 0xFFFFFFFF) {
		brelse(goal_epos.bh);
		mutex_unlock(&sbi->s_alloc_mutex);
		return 0;
	}

	/* Only allocate blocks from the beginning of the extent.
	   That way, we only delete (empty) extents, never have to insert an
	   extent because of splitting */
	/* This works, but very poorly.... */

	newblock = goal_eloc.logicalBlockNum;
	goal_eloc.logicalBlockNum++;
	goal_elen -= sb->s_blocksize;

	if (inode && vfs_dq_alloc_block(inode, 1)) {
		brelse(goal_epos.bh);
		mutex_unlock(&sbi->s_alloc_mutex);
		*err = -EDQUOT;
		return 0;
	}

	if (goal_elen)
		udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
	else
		udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
	brelse(goal_epos.bh);

	udf_add_free_space(sb, partition, -1);

	mutex_unlock(&sbi->s_alloc_mutex);
	*err = 0;
	return newblock;
}

void udf_free_blocks(struct super_block *sb, struct inode *inode,
		     struct kernel_lb_addr *bloc, uint32_t offset,
		     uint32_t count)
{
	uint16_t partition = bloc->partitionReferenceNum;
	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];

	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
		udf_bitmap_free_blocks(sb, inode, map->s_uspace.s_bitmap,
				       bloc, offset, count);
	} else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
		udf_table_free_blocks(sb, inode, map->s_uspace.s_table,
				      bloc, offset, count);
	} else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
		udf_bitmap_free_blocks(sb, inode, map->s_fspace.s_bitmap,
				       bloc, offset, count);
	} else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
		udf_table_free_blocks(sb, inode, map->s_fspace.s_table,
				      bloc, offset, count);
	}
}

inline int udf_prealloc_blocks(struct super_block *sb,
			       struct inode *inode,
			       uint16_t partition, uint32_t first_block,
			       uint32_t block_count)
{
	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];

	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
		return udf_bitmap_prealloc_blocks(sb, inode,
						  map->s_uspace.s_bitmap,
						  partition, first_block,
						  block_count);
	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
		return udf_table_prealloc_blocks(sb, inode,
						 map->s_uspace.s_table,
						 partition, first_block,
						 block_count);
	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
		return udf_bitmap_prealloc_blocks(sb, inode,
						  map->s_fspace.s_bitmap,
						  partition, first_block,
						  block_count);
	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
		return udf_table_prealloc_blocks(sb, inode,
						 map->s_fspace.s_table,
						 partition, first_block,
						 block_count);
	else
		return 0;
}

inline int udf_new_block(struct super_block *sb,
			 struct inode *inode,
			 uint16_t partition, uint32_t goal, int *err)
{
	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];

	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
		return udf_bitmap_new_block(sb, inode,
					   map->s_uspace.s_bitmap,
					   partition, goal, err);
	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
		return udf_table_new_block(sb, inode,
					   map->s_uspace.s_table,
					   partition, goal, err);
	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
		return udf_bitmap_new_block(sb, inode,
					    map->s_fspace.s_bitmap,
					    partition, goal, err);
	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
		return udf_table_new_block(sb, inode,
					   map->s_fspace.s_table,
					   partition, goal, err);
	else {
		*err = -EIO;
		return 0;
	}
}