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Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm...
[linux-2.6.git] / fs / udf / balloc.c
blob1ba2baaf43671889f2eb0339e92996a1bf41f7ca
1 /*
2 * balloc.c
3 *
4 * PURPOSE
5 * Block allocation handling routines for the OSTA-UDF(tm) filesystem.
6 *
7 * COPYRIGHT
8 * This file is distributed under the terms of the GNU General Public
9 * License (GPL). Copies of the GPL can be obtained from:
10 * ftp://prep.ai.mit.edu/pub/gnu/GPL
11 * Each contributing author retains all rights to their own work.
12 *
13 * (C) 1999-2001 Ben Fennema
14 * (C) 1999 Stelias Computing Inc
15 *
16 * HISTORY
17 *
18 * 02/24/99 blf Created.
19 *
20 */
21
22 #include "udfdecl.h"
23
24 #include <linux/buffer_head.h>
25 #include <linux/bitops.h>
26
27 #include "udf_i.h"
28 #include "udf_sb.h"
29
30 #define udf_clear_bit __test_and_clear_bit_le
31 #define udf_set_bit __test_and_set_bit_le
32 #define udf_test_bit test_bit_le
33 #define udf_find_next_one_bit find_next_bit_le
34
35 static int read_block_bitmap(struct super_block *sb,
36 struct udf_bitmap *bitmap, unsigned int block,
37 unsigned long bitmap_nr)
38 {
39 struct buffer_head *bh = NULL;
40 int retval = 0;
41 struct kernel_lb_addr loc;
42
43 loc.logicalBlockNum = bitmap->s_extPosition;
44 loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
45
46 bh = udf_tread(sb, udf_get_lb_pblock(sb, &loc, block));
47 if (!bh)
48 retval = -EIO;
49
50 bitmap->s_block_bitmap[bitmap_nr] = bh;
51 return retval;
52 }
53
54 static int __load_block_bitmap(struct super_block *sb,
55 struct udf_bitmap *bitmap,
56 unsigned int block_group)
57 {
58 int retval = 0;
59 int nr_groups = bitmap->s_nr_groups;
60
61 if (block_group >= nr_groups) {
62 udf_debug("block_group (%d) > nr_groups (%d)\n",
63 block_group, nr_groups);
64 }
65
66 if (bitmap->s_block_bitmap[block_group]) {
67 return block_group;
68 } else {
69 retval = read_block_bitmap(sb, bitmap, block_group,
70 block_group);
71 if (retval < 0)
72 return retval;
73 return block_group;
74 }
75 }
76
77 static inline int load_block_bitmap(struct super_block *sb,
78 struct udf_bitmap *bitmap,
79 unsigned int block_group)
80 {
81 int slot;
82
83 slot = __load_block_bitmap(sb, bitmap, block_group);
84
85 if (slot < 0)
86 return slot;
87
88 if (!bitmap->s_block_bitmap[slot])
89 return -EIO;
90
91 return slot;
92 }
93
94 static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
95 {
96 struct udf_sb_info *sbi = UDF_SB(sb);
97 struct logicalVolIntegrityDesc *lvid;
98
99 if (!sbi->s_lvid_bh)
100 return;
101
102 lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
103 le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
104 udf_updated_lvid(sb);
105 }
106
107 static void udf_bitmap_free_blocks(struct super_block *sb,
108 struct udf_bitmap *bitmap,
109 struct kernel_lb_addr *bloc,
110 uint32_t offset,
111 uint32_t count)
112 {
113 struct udf_sb_info *sbi = UDF_SB(sb);
114 struct buffer_head *bh = NULL;
115 struct udf_part_map *partmap;
116 unsigned long block;
117 unsigned long block_group;
118 unsigned long bit;
119 unsigned long i;
120 int bitmap_nr;
121 unsigned long overflow;
122
123 mutex_lock(&sbi->s_alloc_mutex);
124 partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
125 if (bloc->logicalBlockNum + count < count ||
126 (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
127 udf_debug("%d < %d || %d + %d > %d\n",
128 bloc->logicalBlockNum, 0,
129 bloc->logicalBlockNum, count,
130 partmap->s_partition_len);
131 goto error_return;
132 }
133
134 block = bloc->logicalBlockNum + offset +
135 (sizeof(struct spaceBitmapDesc) << 3);
136
137 do {
138 overflow = 0;
139 block_group = block >> (sb->s_blocksize_bits + 3);
140 bit = block % (sb->s_blocksize << 3);
141
142 /*
143 * Check to see if we are freeing blocks across a group boundary.
144 */
145 if (bit + count > (sb->s_blocksize << 3)) {
146 overflow = bit + count - (sb->s_blocksize << 3);
147 count -= overflow;
148 }
149 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
150 if (bitmap_nr < 0)
151 goto error_return;
152
153 bh = bitmap->s_block_bitmap[bitmap_nr];
154 for (i = 0; i < count; i++) {
155 if (udf_set_bit(bit + i, bh->b_data)) {
156 udf_debug("bit %ld already set\n", bit + i);
157 udf_debug("byte=%2x\n",
158 ((char *)bh->b_data)[(bit + i) >> 3]);
159 }
160 }
161 udf_add_free_space(sb, sbi->s_partition, count);
162 mark_buffer_dirty(bh);
163 if (overflow) {
164 block += count;
165 count = overflow;
166 }
167 } while (overflow);
168
169 error_return:
170 mutex_unlock(&sbi->s_alloc_mutex);
171 }
172
173 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
174 struct udf_bitmap *bitmap,
175 uint16_t partition, uint32_t first_block,
176 uint32_t block_count)
177 {
178 struct udf_sb_info *sbi = UDF_SB(sb);
179 int alloc_count = 0;
180 int bit, block, block_group, group_start;
181 int nr_groups, bitmap_nr;
182 struct buffer_head *bh;
183 __u32 part_len;
184
185 mutex_lock(&sbi->s_alloc_mutex);
186 part_len = sbi->s_partmaps[partition].s_partition_len;
187 if (first_block >= part_len)
188 goto out;
189
190 if (first_block + block_count > part_len)
191 block_count = part_len - first_block;
192
193 do {
194 nr_groups = udf_compute_nr_groups(sb, partition);
195 block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
196 block_group = block >> (sb->s_blocksize_bits + 3);
197 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
198
199 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
200 if (bitmap_nr < 0)
201 goto out;
202 bh = bitmap->s_block_bitmap[bitmap_nr];
203
204 bit = block % (sb->s_blocksize << 3);
205
206 while (bit < (sb->s_blocksize << 3) && block_count > 0) {
207 if (!udf_clear_bit(bit, bh->b_data))
208 goto out;
209 block_count--;
210 alloc_count++;
211 bit++;
212 block++;
213 }
214 mark_buffer_dirty(bh);
215 } while (block_count > 0);
216
217 out:
218 udf_add_free_space(sb, partition, -alloc_count);
219 mutex_unlock(&sbi->s_alloc_mutex);
220 return alloc_count;
221 }
222
223 static int udf_bitmap_new_block(struct super_block *sb,
224 struct udf_bitmap *bitmap, uint16_t partition,
225 uint32_t goal, int *err)
226 {
227 struct udf_sb_info *sbi = UDF_SB(sb);
228 int newbit, bit = 0, block, block_group, group_start;
229 int end_goal, nr_groups, bitmap_nr, i;
230 struct buffer_head *bh = NULL;
231 char *ptr;
232 int newblock = 0;
233
234 *err = -ENOSPC;
235 mutex_lock(&sbi->s_alloc_mutex);
236
237 repeat:
238 if (goal >= sbi->s_partmaps[partition].s_partition_len)
239 goal = 0;
240
241 nr_groups = bitmap->s_nr_groups;
242 block = goal + (sizeof(struct spaceBitmapDesc) << 3);
243 block_group = block >> (sb->s_blocksize_bits + 3);
244 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
245
246 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
247 if (bitmap_nr < 0)
248 goto error_return;
249 bh = bitmap->s_block_bitmap[bitmap_nr];
250 ptr = memscan((char *)bh->b_data + group_start, 0xFF,
251 sb->s_blocksize - group_start);
252
253 if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
254 bit = block % (sb->s_blocksize << 3);
255 if (udf_test_bit(bit, bh->b_data))
256 goto got_block;
257
258 end_goal = (bit + 63) & ~63;
259 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
260 if (bit < end_goal)
261 goto got_block;
262
263 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
264 sb->s_blocksize - ((bit + 7) >> 3));
265 newbit = (ptr - ((char *)bh->b_data)) << 3;
266 if (newbit < sb->s_blocksize << 3) {
267 bit = newbit;
268 goto search_back;
269 }
270
271 newbit = udf_find_next_one_bit(bh->b_data,
272 sb->s_blocksize << 3, bit);
273 if (newbit < sb->s_blocksize << 3) {
274 bit = newbit;
275 goto got_block;
276 }
277 }
278
279 for (i = 0; i < (nr_groups * 2); i++) {
280 block_group++;
281 if (block_group >= nr_groups)
282 block_group = 0;
283 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
284
285 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
286 if (bitmap_nr < 0)
287 goto error_return;
288 bh = bitmap->s_block_bitmap[bitmap_nr];
289 if (i < nr_groups) {
290 ptr = memscan((char *)bh->b_data + group_start, 0xFF,
291 sb->s_blocksize - group_start);
292 if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
293 bit = (ptr - ((char *)bh->b_data)) << 3;
294 break;
295 }
296 } else {
297 bit = udf_find_next_one_bit(bh->b_data,
298 sb->s_blocksize << 3,
299 group_start << 3);
300 if (bit < sb->s_blocksize << 3)
301 break;
302 }
303 }
304 if (i >= (nr_groups * 2)) {
305 mutex_unlock(&sbi->s_alloc_mutex);
306 return newblock;
307 }
308 if (bit < sb->s_blocksize << 3)
309 goto search_back;
310 else
311 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
312 group_start << 3);
313 if (bit >= sb->s_blocksize << 3) {
314 mutex_unlock(&sbi->s_alloc_mutex);
315 return 0;
316 }
317
318 search_back:
319 i = 0;
320 while (i < 7 && bit > (group_start << 3) &&
321 udf_test_bit(bit - 1, bh->b_data)) {
322 ++i;
323 --bit;
324 }
325
326 got_block:
327 newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
328 (sizeof(struct spaceBitmapDesc) << 3);
329
330 if (!udf_clear_bit(bit, bh->b_data)) {
331 udf_debug("bit already cleared for block %d\n", bit);
332 goto repeat;
333 }
334
335 mark_buffer_dirty(bh);
336
337 udf_add_free_space(sb, partition, -1);
338 mutex_unlock(&sbi->s_alloc_mutex);
339 *err = 0;
340 return newblock;
341
342 error_return:
343 *err = -EIO;
344 mutex_unlock(&sbi->s_alloc_mutex);
345 return 0;
346 }
347
348 static void udf_table_free_blocks(struct super_block *sb,
349 struct inode *table,
350 struct kernel_lb_addr *bloc,
351 uint32_t offset,
352 uint32_t count)
353 {
354 struct udf_sb_info *sbi = UDF_SB(sb);
355 struct udf_part_map *partmap;
356 uint32_t start, end;
357 uint32_t elen;
358 struct kernel_lb_addr eloc;
359 struct extent_position oepos, epos;
360 int8_t etype;
361 int i;
362 struct udf_inode_info *iinfo;
363
364 mutex_lock(&sbi->s_alloc_mutex);
365 partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
366 if (bloc->logicalBlockNum + count < count ||
367 (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
368 udf_debug("%d < %d || %d + %d > %d\n",
369 bloc->logicalBlockNum, 0,
370 bloc->logicalBlockNum, count,
371 partmap->s_partition_len);
372 goto error_return;
373 }
374
375 iinfo = UDF_I(table);
376 udf_add_free_space(sb, sbi->s_partition, count);
377
378 start = bloc->logicalBlockNum + offset;
379 end = bloc->logicalBlockNum + offset + count - 1;
380
381 epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
382 elen = 0;
383 epos.block = oepos.block = iinfo->i_location;
384 epos.bh = oepos.bh = NULL;
385
386 while (count &&
387 (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
388 if (((eloc.logicalBlockNum +
389 (elen >> sb->s_blocksize_bits)) == start)) {
390 if ((0x3FFFFFFF - elen) <
391 (count << sb->s_blocksize_bits)) {
392 uint32_t tmp = ((0x3FFFFFFF - elen) >>
393 sb->s_blocksize_bits);
394 count -= tmp;
395 start += tmp;
396 elen = (etype << 30) |
397 (0x40000000 - sb->s_blocksize);
398 } else {
399 elen = (etype << 30) |
400 (elen +
401 (count << sb->s_blocksize_bits));
402 start += count;
403 count = 0;
404 }
405 udf_write_aext(table, &oepos, &eloc, elen, 1);
406 } else if (eloc.logicalBlockNum == (end + 1)) {
407 if ((0x3FFFFFFF - elen) <
408 (count << sb->s_blocksize_bits)) {
409 uint32_t tmp = ((0x3FFFFFFF - elen) >>
410 sb->s_blocksize_bits);
411 count -= tmp;
412 end -= tmp;
413 eloc.logicalBlockNum -= tmp;
414 elen = (etype << 30) |
415 (0x40000000 - sb->s_blocksize);
416 } else {
417 eloc.logicalBlockNum = start;
418 elen = (etype << 30) |
419 (elen +
420 (count << sb->s_blocksize_bits));
421 end -= count;
422 count = 0;
423 }
424 udf_write_aext(table, &oepos, &eloc, elen, 1);
425 }
426
427 if (epos.bh != oepos.bh) {
428 i = -1;
429 oepos.block = epos.block;
430 brelse(oepos.bh);
431 get_bh(epos.bh);
432 oepos.bh = epos.bh;
433 oepos.offset = 0;
434 } else {
435 oepos.offset = epos.offset;
436 }
437 }
438
439 if (count) {
440 /*
441 * NOTE: we CANNOT use udf_add_aext here, as it can try to
442 * allocate a new block, and since we hold the super block
443 * lock already very bad things would happen :)
444 *
445 * We copy the behavior of udf_add_aext, but instead of
446 * trying to allocate a new block close to the existing one,
447 * we just steal a block from the extent we are trying to add.
448 *
449 * It would be nice if the blocks were close together, but it
450 * isn't required.
451 */
452
453 int adsize;
454 struct short_ad *sad = NULL;
455 struct long_ad *lad = NULL;
456 struct allocExtDesc *aed;
457
458 eloc.logicalBlockNum = start;
459 elen = EXT_RECORDED_ALLOCATED |
460 (count << sb->s_blocksize_bits);
461
462 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
463 adsize = sizeof(struct short_ad);
464 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
465 adsize = sizeof(struct long_ad);
466 else {
467 brelse(oepos.bh);
468 brelse(epos.bh);
469 goto error_return;
470 }
471
472 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
473 unsigned char *sptr, *dptr;
474 int loffset;
475
476 brelse(oepos.bh);
477 oepos = epos;
478
479 /* Steal a block from the extent being free'd */
480 epos.block.logicalBlockNum = eloc.logicalBlockNum;
481 eloc.logicalBlockNum++;
482 elen -= sb->s_blocksize;
483
484 epos.bh = udf_tread(sb,
485 udf_get_lb_pblock(sb, &epos.block, 0));
486 if (!epos.bh) {
487 brelse(oepos.bh);
488 goto error_return;
489 }
490 aed = (struct allocExtDesc *)(epos.bh->b_data);
491 aed->previousAllocExtLocation =
492 cpu_to_le32(oepos.block.logicalBlockNum);
493 if (epos.offset + adsize > sb->s_blocksize) {
494 loffset = epos.offset;
495 aed->lengthAllocDescs = cpu_to_le32(adsize);
496 sptr = iinfo->i_ext.i_data + epos.offset
497 - adsize;
498 dptr = epos.bh->b_data +
499 sizeof(struct allocExtDesc);
500 memcpy(dptr, sptr, adsize);
501 epos.offset = sizeof(struct allocExtDesc) +
502 adsize;
503 } else {
504 loffset = epos.offset + adsize;
505 aed->lengthAllocDescs = cpu_to_le32(0);
506 if (oepos.bh) {
507 sptr = oepos.bh->b_data + epos.offset;
508 aed = (struct allocExtDesc *)
509 oepos.bh->b_data;
510 le32_add_cpu(&aed->lengthAllocDescs,
511 adsize);
512 } else {
513 sptr = iinfo->i_ext.i_data +
514 epos.offset;
515 iinfo->i_lenAlloc += adsize;
516 mark_inode_dirty(table);
517 }
518 epos.offset = sizeof(struct allocExtDesc);
519 }
520 if (sbi->s_udfrev >= 0x0200)
521 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
522 3, 1, epos.block.logicalBlockNum,
523 sizeof(struct tag));
524 else
525 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
526 2, 1, epos.block.logicalBlockNum,
527 sizeof(struct tag));
528
529 switch (iinfo->i_alloc_type) {
530 case ICBTAG_FLAG_AD_SHORT:
531 sad = (struct short_ad *)sptr;
532 sad->extLength = cpu_to_le32(
533 EXT_NEXT_EXTENT_ALLOCDECS |
534 sb->s_blocksize);
535 sad->extPosition =
536 cpu_to_le32(epos.block.logicalBlockNum);
537 break;
538 case ICBTAG_FLAG_AD_LONG:
539 lad = (struct long_ad *)sptr;
540 lad->extLength = cpu_to_le32(
541 EXT_NEXT_EXTENT_ALLOCDECS |
542 sb->s_blocksize);
543 lad->extLocation =
544 cpu_to_lelb(epos.block);
545 break;
546 }
547 if (oepos.bh) {
548 udf_update_tag(oepos.bh->b_data, loffset);
549 mark_buffer_dirty(oepos.bh);
550 } else {
551 mark_inode_dirty(table);
552 }
553 }
554
555 /* It's possible that stealing the block emptied the extent */
556 if (elen) {
557 udf_write_aext(table, &epos, &eloc, elen, 1);
558
559 if (!epos.bh) {
560 iinfo->i_lenAlloc += adsize;
561 mark_inode_dirty(table);
562 } else {
563 aed = (struct allocExtDesc *)epos.bh->b_data;
564 le32_add_cpu(&aed->lengthAllocDescs, adsize);
565 udf_update_tag(epos.bh->b_data, epos.offset);
566 mark_buffer_dirty(epos.bh);
567 }
568 }
569 }
570
571 brelse(epos.bh);
572 brelse(oepos.bh);
573
574 error_return:
575 mutex_unlock(&sbi->s_alloc_mutex);
576 return;
577 }
578
579 static int udf_table_prealloc_blocks(struct super_block *sb,
580 struct inode *table, uint16_t partition,
581 uint32_t first_block, uint32_t block_count)
582 {
583 struct udf_sb_info *sbi = UDF_SB(sb);
584 int alloc_count = 0;
585 uint32_t elen, adsize;
586 struct kernel_lb_addr eloc;
587 struct extent_position epos;
588 int8_t etype = -1;
589 struct udf_inode_info *iinfo;
590
591 if (first_block >= sbi->s_partmaps[partition].s_partition_len)
592 return 0;
593
594 iinfo = UDF_I(table);
595 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
596 adsize = sizeof(struct short_ad);
597 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
598 adsize = sizeof(struct long_ad);
599 else
600 return 0;
601
602 mutex_lock(&sbi->s_alloc_mutex);
603 epos.offset = sizeof(struct unallocSpaceEntry);
604 epos.block = iinfo->i_location;
605 epos.bh = NULL;
606 eloc.logicalBlockNum = 0xFFFFFFFF;
607
608 while (first_block != eloc.logicalBlockNum &&
609 (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
610 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
611 eloc.logicalBlockNum, elen, first_block);
612 ; /* empty loop body */
613 }
614
615 if (first_block == eloc.logicalBlockNum) {
616 epos.offset -= adsize;
617
618 alloc_count = (elen >> sb->s_blocksize_bits);
619 if (alloc_count > block_count) {
620 alloc_count = block_count;
621 eloc.logicalBlockNum += alloc_count;
622 elen -= (alloc_count << sb->s_blocksize_bits);
623 udf_write_aext(table, &epos, &eloc,
624 (etype << 30) | elen, 1);
625 } else
626 udf_delete_aext(table, epos, eloc,
627 (etype << 30) | elen);
628 } else {
629 alloc_count = 0;
630 }
631
632 brelse(epos.bh);
633
634 if (alloc_count)
635 udf_add_free_space(sb, partition, -alloc_count);
636 mutex_unlock(&sbi->s_alloc_mutex);
637 return alloc_count;
638 }
639
640 static int udf_table_new_block(struct super_block *sb,
641 struct inode *table, uint16_t partition,
642 uint32_t goal, int *err)
643 {
644 struct udf_sb_info *sbi = UDF_SB(sb);
645 uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
646 uint32_t newblock = 0, adsize;
647 uint32_t elen, goal_elen = 0;
648 struct kernel_lb_addr eloc, uninitialized_var(goal_eloc);
649 struct extent_position epos, goal_epos;
650 int8_t etype;
651 struct udf_inode_info *iinfo = UDF_I(table);
652
653 *err = -ENOSPC;
654
655 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
656 adsize = sizeof(struct short_ad);
657 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
658 adsize = sizeof(struct long_ad);
659 else
660 return newblock;
661
662 mutex_lock(&sbi->s_alloc_mutex);
663 if (goal >= sbi->s_partmaps[partition].s_partition_len)
664 goal = 0;
665
666 /* We search for the closest matching block to goal. If we find
667 a exact hit, we stop. Otherwise we keep going till we run out
668 of extents. We store the buffer_head, bloc, and extoffset
669 of the current closest match and use that when we are done.
670 */
671 epos.offset = sizeof(struct unallocSpaceEntry);
672 epos.block = iinfo->i_location;
673 epos.bh = goal_epos.bh = NULL;
674
675 while (spread &&
676 (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
677 if (goal >= eloc.logicalBlockNum) {
678 if (goal < eloc.logicalBlockNum +
679 (elen >> sb->s_blocksize_bits))
680 nspread = 0;
681 else
682 nspread = goal - eloc.logicalBlockNum -
683 (elen >> sb->s_blocksize_bits);
684 } else {
685 nspread = eloc.logicalBlockNum - goal;
686 }
687
688 if (nspread < spread) {
689 spread = nspread;
690 if (goal_epos.bh != epos.bh) {
691 brelse(goal_epos.bh);
692 goal_epos.bh = epos.bh;
693 get_bh(goal_epos.bh);
694 }
695 goal_epos.block = epos.block;
696 goal_epos.offset = epos.offset - adsize;
697 goal_eloc = eloc;
698 goal_elen = (etype << 30) | elen;
699 }
700 }
701
702 brelse(epos.bh);
703
704 if (spread == 0xFFFFFFFF) {
705 brelse(goal_epos.bh);
706 mutex_unlock(&sbi->s_alloc_mutex);
707 return 0;
708 }
709
710 /* Only allocate blocks from the beginning of the extent.
711 That way, we only delete (empty) extents, never have to insert an
712 extent because of splitting */
713 /* This works, but very poorly.... */
714
715 newblock = goal_eloc.logicalBlockNum;
716 goal_eloc.logicalBlockNum++;
717 goal_elen -= sb->s_blocksize;
718
719 if (goal_elen)
720 udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
721 else
722 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
723 brelse(goal_epos.bh);
724
725 udf_add_free_space(sb, partition, -1);
726
727 mutex_unlock(&sbi->s_alloc_mutex);
728 *err = 0;
729 return newblock;
730 }
731
732 void udf_free_blocks(struct super_block *sb, struct inode *inode,
733 struct kernel_lb_addr *bloc, uint32_t offset,
734 uint32_t count)
735 {
736 uint16_t partition = bloc->partitionReferenceNum;
737 struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
738
739 if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
740 udf_bitmap_free_blocks(sb, map->s_uspace.s_bitmap,
741 bloc, offset, count);
742 } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
743 udf_table_free_blocks(sb, map->s_uspace.s_table,
744 bloc, offset, count);
745 } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
746 udf_bitmap_free_blocks(sb, map->s_fspace.s_bitmap,
747 bloc, offset, count);
748 } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
749 udf_table_free_blocks(sb, map->s_fspace.s_table,
750 bloc, offset, count);
751 }
752
753 if (inode) {
754 inode_sub_bytes(inode,
755 ((sector_t)count) << sb->s_blocksize_bits);
756 }
757 }
758
759 inline int udf_prealloc_blocks(struct super_block *sb,
760 struct inode *inode,
761 uint16_t partition, uint32_t first_block,
762 uint32_t block_count)
763 {
764 struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
765 sector_t allocated;
766
767 if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
768 allocated = udf_bitmap_prealloc_blocks(sb,
769 map->s_uspace.s_bitmap,
770 partition, first_block,
771 block_count);
772 else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
773 allocated = udf_table_prealloc_blocks(sb,
774 map->s_uspace.s_table,
775 partition, first_block,
776 block_count);
777 else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
778 allocated = udf_bitmap_prealloc_blocks(sb,
779 map->s_fspace.s_bitmap,
780 partition, first_block,
781 block_count);
782 else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
783 allocated = udf_table_prealloc_blocks(sb,
784 map->s_fspace.s_table,
785 partition, first_block,
786 block_count);
787 else
788 return 0;
789
790 if (inode && allocated > 0)
791 inode_add_bytes(inode, allocated << sb->s_blocksize_bits);
792 return allocated;
793 }
794
795 inline int udf_new_block(struct super_block *sb,
796 struct inode *inode,
797 uint16_t partition, uint32_t goal, int *err)
798 {
799 struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
800 int block;
801
802 if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
803 block = udf_bitmap_new_block(sb,
804 map->s_uspace.s_bitmap,
805 partition, goal, err);
806 else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
807 block = udf_table_new_block(sb,
808 map->s_uspace.s_table,
809 partition, goal, err);
810 else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
811 block = udf_bitmap_new_block(sb,
812 map->s_fspace.s_bitmap,
813 partition, goal, err);
814 else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
815 block = udf_table_new_block(sb,
816 map->s_fspace.s_table,
817 partition, goal, err);
818 else {
819 *err = -EIO;
820 return 0;
821 }
822 if (inode && block)
823 inode_add_bytes(inode, sb->s_blocksize);
824 return block;
825 }
Linus' kernel tree