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Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[wrt350n-kernel.git] / fs / udf / balloc.c
blobf855dcbbdfb854e1704566ae0cebd187c656c45f
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/quotaops.h>
25 #include <linux/buffer_head.h>
26 #include <linux/bitops.h>
27
28 #include "udf_i.h"
29 #include "udf_sb.h"
30
31 #define udf_clear_bit(nr, addr) ext2_clear_bit(nr, addr)
32 #define udf_set_bit(nr, addr) ext2_set_bit(nr, addr)
33 #define udf_test_bit(nr, addr) ext2_test_bit(nr, addr)
34 #define udf_find_first_one_bit(addr, size) find_first_one_bit(addr, size)
35 #define udf_find_next_one_bit(addr, size, offset) \
36 find_next_one_bit(addr, size, offset)
37
38 #define leBPL_to_cpup(x) leNUM_to_cpup(BITS_PER_LONG, x)
39 #define leNUM_to_cpup(x, y) xleNUM_to_cpup(x, y)
40 #define xleNUM_to_cpup(x, y) (le ## x ## _to_cpup(y))
41 #define uintBPL_t uint(BITS_PER_LONG)
42 #define uint(x) xuint(x)
43 #define xuint(x) __le ## x
44
45 static inline int find_next_one_bit(void *addr, int size, int offset)
46 {
47 uintBPL_t *p = ((uintBPL_t *) addr) + (offset / BITS_PER_LONG);
48 int result = offset & ~(BITS_PER_LONG - 1);
49 unsigned long tmp;
50
51 if (offset >= size)
52 return size;
53 size -= result;
54 offset &= (BITS_PER_LONG - 1);
55 if (offset) {
56 tmp = leBPL_to_cpup(p++);
57 tmp &= ~0UL << offset;
58 if (size < BITS_PER_LONG)
59 goto found_first;
60 if (tmp)
61 goto found_middle;
62 size -= BITS_PER_LONG;
63 result += BITS_PER_LONG;
64 }
65 while (size & ~(BITS_PER_LONG - 1)) {
66 tmp = leBPL_to_cpup(p++);
67 if (tmp)
68 goto found_middle;
69 result += BITS_PER_LONG;
70 size -= BITS_PER_LONG;
71 }
72 if (!size)
73 return result;
74 tmp = leBPL_to_cpup(p);
75 found_first:
76 tmp &= ~0UL >> (BITS_PER_LONG - size);
77 found_middle:
78 return result + ffz(~tmp);
79 }
80
81 #define find_first_one_bit(addr, size)\
82 find_next_one_bit((addr), (size), 0)
83
84 static int read_block_bitmap(struct super_block *sb,
85 struct udf_bitmap *bitmap, unsigned int block,
86 unsigned long bitmap_nr)
87 {
88 struct buffer_head *bh = NULL;
89 int retval = 0;
90 kernel_lb_addr loc;
91
92 loc.logicalBlockNum = bitmap->s_extPosition;
93 loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
94
95 bh = udf_tread(sb, udf_get_lb_pblock(sb, loc, block));
96 if (!bh)
97 retval = -EIO;
98
99 bitmap->s_block_bitmap[bitmap_nr] = bh;
100 return retval;
101 }
102
103 static int __load_block_bitmap(struct super_block *sb,
104 struct udf_bitmap *bitmap,
105 unsigned int block_group)
106 {
107 int retval = 0;
108 int nr_groups = bitmap->s_nr_groups;
109
110 if (block_group >= nr_groups) {
111 udf_debug("block_group (%d) > nr_groups (%d)\n", block_group,
112 nr_groups);
113 }
114
115 if (bitmap->s_block_bitmap[block_group]) {
116 return block_group;
117 } else {
118 retval = read_block_bitmap(sb, bitmap, block_group,
119 block_group);
120 if (retval < 0)
121 return retval;
122 return block_group;
123 }
124 }
125
126 static inline int load_block_bitmap(struct super_block *sb,
127 struct udf_bitmap *bitmap,
128 unsigned int block_group)
129 {
130 int slot;
131
132 slot = __load_block_bitmap(sb, bitmap, block_group);
133
134 if (slot < 0)
135 return slot;
136
137 if (!bitmap->s_block_bitmap[slot])
138 return -EIO;
139
140 return slot;
141 }
142
143 static bool udf_add_free_space(struct udf_sb_info *sbi,
144 u16 partition, u32 cnt)
145 {
146 struct logicalVolIntegrityDesc *lvid;
147
148 if (sbi->s_lvid_bh == NULL)
149 return false;
150
151 lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
152 lvid->freeSpaceTable[partition] = cpu_to_le32(le32_to_cpu(
153 lvid->freeSpaceTable[partition]) + cnt);
154 return true;
155 }
156
157 static void udf_bitmap_free_blocks(struct super_block *sb,
158 struct inode *inode,
159 struct udf_bitmap *bitmap,
160 kernel_lb_addr bloc, uint32_t offset,
161 uint32_t count)
162 {
163 struct udf_sb_info *sbi = UDF_SB(sb);
164 struct buffer_head *bh = NULL;
165 unsigned long block;
166 unsigned long block_group;
167 unsigned long bit;
168 unsigned long i;
169 int bitmap_nr;
170 unsigned long overflow;
171
172 mutex_lock(&sbi->s_alloc_mutex);
173 if (bloc.logicalBlockNum < 0 ||
174 (bloc.logicalBlockNum + count) >
175 sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
176 udf_debug("%d < %d || %d + %d > %d\n",
177 bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
178 sbi->s_partmaps[bloc.partitionReferenceNum].
179 s_partition_len);
180 goto error_return;
181 }
182
183 block = bloc.logicalBlockNum + offset +
184 (sizeof(struct spaceBitmapDesc) << 3);
185
186 do {
187 overflow = 0;
188 block_group = block >> (sb->s_blocksize_bits + 3);
189 bit = block % (sb->s_blocksize << 3);
190
191 /*
192 * Check to see if we are freeing blocks across a group boundary.
193 */
194 if (bit + count > (sb->s_blocksize << 3)) {
195 overflow = bit + count - (sb->s_blocksize << 3);
196 count -= overflow;
197 }
198 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
199 if (bitmap_nr < 0)
200 goto error_return;
201
202 bh = bitmap->s_block_bitmap[bitmap_nr];
203 for (i = 0; i < count; i++) {
204 if (udf_set_bit(bit + i, bh->b_data)) {
205 udf_debug("bit %ld already set\n", bit + i);
206 udf_debug("byte=%2x\n",
207 ((char *)bh->b_data)[(bit + i) >> 3]);
208 } else {
209 if (inode)
210 DQUOT_FREE_BLOCK(inode, 1);
211 udf_add_free_space(sbi, sbi->s_partition, 1);
212 }
213 }
214 mark_buffer_dirty(bh);
215 if (overflow) {
216 block += count;
217 count = overflow;
218 }
219 } while (overflow);
220
221 error_return:
222 sb->s_dirt = 1;
223 if (sbi->s_lvid_bh)
224 mark_buffer_dirty(sbi->s_lvid_bh);
225 mutex_unlock(&sbi->s_alloc_mutex);
226 }
227
228 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
229 struct inode *inode,
230 struct udf_bitmap *bitmap,
231 uint16_t partition, uint32_t first_block,
232 uint32_t block_count)
233 {
234 struct udf_sb_info *sbi = UDF_SB(sb);
235 int alloc_count = 0;
236 int bit, block, block_group, group_start;
237 int nr_groups, bitmap_nr;
238 struct buffer_head *bh;
239 __u32 part_len;
240
241 mutex_lock(&sbi->s_alloc_mutex);
242 part_len = sbi->s_partmaps[partition].s_partition_len;
243 if (first_block < 0 || first_block >= part_len)
244 goto out;
245
246 if (first_block + block_count > part_len)
247 block_count = part_len - first_block;
248
249 do {
250 nr_groups = udf_compute_nr_groups(sb, partition);
251 block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
252 block_group = block >> (sb->s_blocksize_bits + 3);
253 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
254
255 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
256 if (bitmap_nr < 0)
257 goto out;
258 bh = bitmap->s_block_bitmap[bitmap_nr];
259
260 bit = block % (sb->s_blocksize << 3);
261
262 while (bit < (sb->s_blocksize << 3) && block_count > 0) {
263 if (!udf_test_bit(bit, bh->b_data))
264 goto out;
265 else if (DQUOT_PREALLOC_BLOCK(inode, 1))
266 goto out;
267 else if (!udf_clear_bit(bit, bh->b_data)) {
268 udf_debug("bit already cleared for block %d\n", bit);
269 DQUOT_FREE_BLOCK(inode, 1);
270 goto out;
271 }
272 block_count--;
273 alloc_count++;
274 bit++;
275 block++;
276 }
277 mark_buffer_dirty(bh);
278 } while (block_count > 0);
279
280 out:
281 if (udf_add_free_space(sbi, partition, -alloc_count))
282 mark_buffer_dirty(sbi->s_lvid_bh);
283 sb->s_dirt = 1;
284 mutex_unlock(&sbi->s_alloc_mutex);
285 return alloc_count;
286 }
287
288 static int udf_bitmap_new_block(struct super_block *sb,
289 struct inode *inode,
290 struct udf_bitmap *bitmap, uint16_t partition,
291 uint32_t goal, int *err)
292 {
293 struct udf_sb_info *sbi = UDF_SB(sb);
294 int newbit, bit = 0, block, block_group, group_start;
295 int end_goal, nr_groups, bitmap_nr, i;
296 struct buffer_head *bh = NULL;
297 char *ptr;
298 int newblock = 0;
299
300 *err = -ENOSPC;
301 mutex_lock(&sbi->s_alloc_mutex);
302
303 repeat:
304 if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
305 goal = 0;
306
307 nr_groups = bitmap->s_nr_groups;
308 block = goal + (sizeof(struct spaceBitmapDesc) << 3);
309 block_group = block >> (sb->s_blocksize_bits + 3);
310 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
311
312 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
313 if (bitmap_nr < 0)
314 goto error_return;
315 bh = bitmap->s_block_bitmap[bitmap_nr];
316 ptr = memscan((char *)bh->b_data + group_start, 0xFF,
317 sb->s_blocksize - group_start);
318
319 if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
320 bit = block % (sb->s_blocksize << 3);
321 if (udf_test_bit(bit, bh->b_data))
322 goto got_block;
323
324 end_goal = (bit + 63) & ~63;
325 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
326 if (bit < end_goal)
327 goto got_block;
328
329 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
330 sb->s_blocksize - ((bit + 7) >> 3));
331 newbit = (ptr - ((char *)bh->b_data)) << 3;
332 if (newbit < sb->s_blocksize << 3) {
333 bit = newbit;
334 goto search_back;
335 }
336
337 newbit = udf_find_next_one_bit(bh->b_data,
338 sb->s_blocksize << 3, bit);
339 if (newbit < sb->s_blocksize << 3) {
340 bit = newbit;
341 goto got_block;
342 }
343 }
344
345 for (i = 0; i < (nr_groups * 2); i++) {
346 block_group++;
347 if (block_group >= nr_groups)
348 block_group = 0;
349 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
350
351 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
352 if (bitmap_nr < 0)
353 goto error_return;
354 bh = bitmap->s_block_bitmap[bitmap_nr];
355 if (i < nr_groups) {
356 ptr = memscan((char *)bh->b_data + group_start, 0xFF,
357 sb->s_blocksize - group_start);
358 if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
359 bit = (ptr - ((char *)bh->b_data)) << 3;
360 break;
361 }
362 } else {
363 bit = udf_find_next_one_bit((char *)bh->b_data,
364 sb->s_blocksize << 3,
365 group_start << 3);
366 if (bit < sb->s_blocksize << 3)
367 break;
368 }
369 }
370 if (i >= (nr_groups * 2)) {
371 mutex_unlock(&sbi->s_alloc_mutex);
372 return newblock;
373 }
374 if (bit < sb->s_blocksize << 3)
375 goto search_back;
376 else
377 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
378 group_start << 3);
379 if (bit >= sb->s_blocksize << 3) {
380 mutex_unlock(&sbi->s_alloc_mutex);
381 return 0;
382 }
383
384 search_back:
385 i = 0;
386 while (i < 7 && bit > (group_start << 3) &&
387 udf_test_bit(bit - 1, bh->b_data)) {
388 ++i;
389 --bit;
390 }
391
392 got_block:
393
394 /*
395 * Check quota for allocation of this block.
396 */
397 if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
398 mutex_unlock(&sbi->s_alloc_mutex);
399 *err = -EDQUOT;
400 return 0;
401 }
402
403 newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
404 (sizeof(struct spaceBitmapDesc) << 3);
405
406 if (!udf_clear_bit(bit, bh->b_data)) {
407 udf_debug("bit already cleared for block %d\n", bit);
408 goto repeat;
409 }
410
411 mark_buffer_dirty(bh);
412
413 if (udf_add_free_space(sbi, partition, -1))
414 mark_buffer_dirty(sbi->s_lvid_bh);
415 sb->s_dirt = 1;
416 mutex_unlock(&sbi->s_alloc_mutex);
417 *err = 0;
418 return newblock;
419
420 error_return:
421 *err = -EIO;
422 mutex_unlock(&sbi->s_alloc_mutex);
423 return 0;
424 }
425
426 static void udf_table_free_blocks(struct super_block *sb,
427 struct inode *inode,
428 struct inode *table,
429 kernel_lb_addr bloc, uint32_t offset,
430 uint32_t count)
431 {
432 struct udf_sb_info *sbi = UDF_SB(sb);
433 uint32_t start, end;
434 uint32_t elen;
435 kernel_lb_addr eloc;
436 struct extent_position oepos, epos;
437 int8_t etype;
438 int i;
439 struct udf_inode_info *iinfo;
440
441 mutex_lock(&sbi->s_alloc_mutex);
442 if (bloc.logicalBlockNum < 0 ||
443 (bloc.logicalBlockNum + count) >
444 sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
445 udf_debug("%d < %d || %d + %d > %d\n",
446 bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
447 sbi->s_partmaps[bloc.partitionReferenceNum].
448 s_partition_len);
449 goto error_return;
450 }
451
452 iinfo = UDF_I(table);
453 /* We do this up front - There are some error conditions that
454 could occure, but.. oh well */
455 if (inode)
456 DQUOT_FREE_BLOCK(inode, count);
457 if (udf_add_free_space(sbi, sbi->s_partition, count))
458 mark_buffer_dirty(sbi->s_lvid_bh);
459
460 start = bloc.logicalBlockNum + offset;
461 end = bloc.logicalBlockNum + offset + count - 1;
462
463 epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
464 elen = 0;
465 epos.block = oepos.block = iinfo->i_location;
466 epos.bh = oepos.bh = NULL;
467
468 while (count &&
469 (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
470 if (((eloc.logicalBlockNum +
471 (elen >> sb->s_blocksize_bits)) == start)) {
472 if ((0x3FFFFFFF - elen) <
473 (count << sb->s_blocksize_bits)) {
474 uint32_t tmp = ((0x3FFFFFFF - elen) >>
475 sb->s_blocksize_bits);
476 count -= tmp;
477 start += tmp;
478 elen = (etype << 30) |
479 (0x40000000 - sb->s_blocksize);
480 } else {
481 elen = (etype << 30) |
482 (elen +
483 (count << sb->s_blocksize_bits));
484 start += count;
485 count = 0;
486 }
487 udf_write_aext(table, &oepos, eloc, elen, 1);
488 } else if (eloc.logicalBlockNum == (end + 1)) {
489 if ((0x3FFFFFFF - elen) <
490 (count << sb->s_blocksize_bits)) {
491 uint32_t tmp = ((0x3FFFFFFF - elen) >>
492 sb->s_blocksize_bits);
493 count -= tmp;
494 end -= tmp;
495 eloc.logicalBlockNum -= tmp;
496 elen = (etype << 30) |
497 (0x40000000 - sb->s_blocksize);
498 } else {
499 eloc.logicalBlockNum = start;
500 elen = (etype << 30) |
501 (elen +
502 (count << sb->s_blocksize_bits));
503 end -= count;
504 count = 0;
505 }
506 udf_write_aext(table, &oepos, eloc, elen, 1);
507 }
508
509 if (epos.bh != oepos.bh) {
510 i = -1;
511 oepos.block = epos.block;
512 brelse(oepos.bh);
513 get_bh(epos.bh);
514 oepos.bh = epos.bh;
515 oepos.offset = 0;
516 } else {
517 oepos.offset = epos.offset;
518 }
519 }
520
521 if (count) {
522 /*
523 * NOTE: we CANNOT use udf_add_aext here, as it can try to
524 * allocate a new block, and since we hold the super block
525 * lock already very bad things would happen :)
526 *
527 * We copy the behavior of udf_add_aext, but instead of
528 * trying to allocate a new block close to the existing one,
529 * we just steal a block from the extent we are trying to add.
530 *
531 * It would be nice if the blocks were close together, but it
532 * isn't required.
533 */
534
535 int adsize;
536 short_ad *sad = NULL;
537 long_ad *lad = NULL;
538 struct allocExtDesc *aed;
539
540 eloc.logicalBlockNum = start;
541 elen = EXT_RECORDED_ALLOCATED |
542 (count << sb->s_blocksize_bits);
543
544 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
545 adsize = sizeof(short_ad);
546 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
547 adsize = sizeof(long_ad);
548 else {
549 brelse(oepos.bh);
550 brelse(epos.bh);
551 goto error_return;
552 }
553
554 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
555 char *sptr, *dptr;
556 int loffset;
557
558 brelse(oepos.bh);
559 oepos = epos;
560
561 /* Steal a block from the extent being free'd */
562 epos.block.logicalBlockNum = eloc.logicalBlockNum;
563 eloc.logicalBlockNum++;
564 elen -= sb->s_blocksize;
565
566 epos.bh = udf_tread(sb,
567 udf_get_lb_pblock(sb, epos.block, 0));
568 if (!epos.bh) {
569 brelse(oepos.bh);
570 goto error_return;
571 }
572 aed = (struct allocExtDesc *)(epos.bh->b_data);
573 aed->previousAllocExtLocation =
574 cpu_to_le32(oepos.block.logicalBlockNum);
575 if (epos.offset + adsize > sb->s_blocksize) {
576 loffset = epos.offset;
577 aed->lengthAllocDescs = cpu_to_le32(adsize);
578 sptr = iinfo->i_ext.i_data + epos.offset
579 - adsize;
580 dptr = epos.bh->b_data +
581 sizeof(struct allocExtDesc);
582 memcpy(dptr, sptr, adsize);
583 epos.offset = sizeof(struct allocExtDesc) +
584 adsize;
585 } else {
586 loffset = epos.offset + adsize;
587 aed->lengthAllocDescs = cpu_to_le32(0);
588 if (oepos.bh) {
589 sptr = oepos.bh->b_data + epos.offset;
590 aed = (struct allocExtDesc *)
591 oepos.bh->b_data;
592 aed->lengthAllocDescs =
593 cpu_to_le32(le32_to_cpu(
594 aed->lengthAllocDescs) +
595 adsize);
596 } else {
597 sptr = iinfo->i_ext.i_data +
598 epos.offset;
599 iinfo->i_lenAlloc += adsize;
600 mark_inode_dirty(table);
601 }
602 epos.offset = sizeof(struct allocExtDesc);
603 }
604 if (sbi->s_udfrev >= 0x0200)
605 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
606 3, 1, epos.block.logicalBlockNum,
607 sizeof(tag));
608 else
609 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
610 2, 1, epos.block.logicalBlockNum,
611 sizeof(tag));
612
613 switch (iinfo->i_alloc_type) {
614 case ICBTAG_FLAG_AD_SHORT:
615 sad = (short_ad *)sptr;
616 sad->extLength = cpu_to_le32(
617 EXT_NEXT_EXTENT_ALLOCDECS |
618 sb->s_blocksize);
619 sad->extPosition =
620 cpu_to_le32(epos.block.logicalBlockNum);
621 break;
622 case ICBTAG_FLAG_AD_LONG:
623 lad = (long_ad *)sptr;
624 lad->extLength = cpu_to_le32(
625 EXT_NEXT_EXTENT_ALLOCDECS |
626 sb->s_blocksize);
627 lad->extLocation =
628 cpu_to_lelb(epos.block);
629 break;
630 }
631 if (oepos.bh) {
632 udf_update_tag(oepos.bh->b_data, loffset);
633 mark_buffer_dirty(oepos.bh);
634 } else {
635 mark_inode_dirty(table);
636 }
637 }
638
639 /* It's possible that stealing the block emptied the extent */
640 if (elen) {
641 udf_write_aext(table, &epos, eloc, elen, 1);
642
643 if (!epos.bh) {
644 iinfo->i_lenAlloc += adsize;
645 mark_inode_dirty(table);
646 } else {
647 aed = (struct allocExtDesc *)epos.bh->b_data;
648 aed->lengthAllocDescs =
649 cpu_to_le32(le32_to_cpu(
650 aed->lengthAllocDescs) + adsize);
651 udf_update_tag(epos.bh->b_data, epos.offset);
652 mark_buffer_dirty(epos.bh);
653 }
654 }
655 }
656
657 brelse(epos.bh);
658 brelse(oepos.bh);
659
660 error_return:
661 sb->s_dirt = 1;
662 mutex_unlock(&sbi->s_alloc_mutex);
663 return;
664 }
665
666 static int udf_table_prealloc_blocks(struct super_block *sb,
667 struct inode *inode,
668 struct inode *table, uint16_t partition,
669 uint32_t first_block, uint32_t block_count)
670 {
671 struct udf_sb_info *sbi = UDF_SB(sb);
672 int alloc_count = 0;
673 uint32_t elen, adsize;
674 kernel_lb_addr eloc;
675 struct extent_position epos;
676 int8_t etype = -1;
677 struct udf_inode_info *iinfo;
678
679 if (first_block < 0 ||
680 first_block >= sbi->s_partmaps[partition].s_partition_len)
681 return 0;
682
683 iinfo = UDF_I(table);
684 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
685 adsize = sizeof(short_ad);
686 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
687 adsize = sizeof(long_ad);
688 else
689 return 0;
690
691 mutex_lock(&sbi->s_alloc_mutex);
692 epos.offset = sizeof(struct unallocSpaceEntry);
693 epos.block = iinfo->i_location;
694 epos.bh = NULL;
695 eloc.logicalBlockNum = 0xFFFFFFFF;
696
697 while (first_block != eloc.logicalBlockNum &&
698 (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
699 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
700 eloc.logicalBlockNum, elen, first_block);
701 ; /* empty loop body */
702 }
703
704 if (first_block == eloc.logicalBlockNum) {
705 epos.offset -= adsize;
706
707 alloc_count = (elen >> sb->s_blocksize_bits);
708 if (inode && DQUOT_PREALLOC_BLOCK(inode,
709 alloc_count > block_count ? block_count : alloc_count))
710 alloc_count = 0;
711 else if (alloc_count > block_count) {
712 alloc_count = block_count;
713 eloc.logicalBlockNum += alloc_count;
714 elen -= (alloc_count << sb->s_blocksize_bits);
715 udf_write_aext(table, &epos, eloc,
716 (etype << 30) | elen, 1);
717 } else
718 udf_delete_aext(table, epos, eloc,
719 (etype << 30) | elen);
720 } else {
721 alloc_count = 0;
722 }
723
724 brelse(epos.bh);
725
726 if (alloc_count && udf_add_free_space(sbi, partition, -alloc_count)) {
727 mark_buffer_dirty(sbi->s_lvid_bh);
728 sb->s_dirt = 1;
729 }
730 mutex_unlock(&sbi->s_alloc_mutex);
731 return alloc_count;
732 }
733
734 static int udf_table_new_block(struct super_block *sb,
735 struct inode *inode,
736 struct inode *table, uint16_t partition,
737 uint32_t goal, int *err)
738 {
739 struct udf_sb_info *sbi = UDF_SB(sb);
740 uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
741 uint32_t newblock = 0, adsize;
742 uint32_t elen, goal_elen = 0;
743 kernel_lb_addr eloc, uninitialized_var(goal_eloc);
744 struct extent_position epos, goal_epos;
745 int8_t etype;
746 struct udf_inode_info *iinfo = UDF_I(table);
747
748 *err = -ENOSPC;
749
750 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
751 adsize = sizeof(short_ad);
752 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
753 adsize = sizeof(long_ad);
754 else
755 return newblock;
756
757 mutex_lock(&sbi->s_alloc_mutex);
758 if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
759 goal = 0;
760
761 /* We search for the closest matching block to goal. If we find
762 a exact hit, we stop. Otherwise we keep going till we run out
763 of extents. We store the buffer_head, bloc, and extoffset
764 of the current closest match and use that when we are done.
765 */
766 epos.offset = sizeof(struct unallocSpaceEntry);
767 epos.block = iinfo->i_location;
768 epos.bh = goal_epos.bh = NULL;
769
770 while (spread &&
771 (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
772 if (goal >= eloc.logicalBlockNum) {
773 if (goal < eloc.logicalBlockNum +
774 (elen >> sb->s_blocksize_bits))
775 nspread = 0;
776 else
777 nspread = goal - eloc.logicalBlockNum -
778 (elen >> sb->s_blocksize_bits);
779 } else {
780 nspread = eloc.logicalBlockNum - goal;
781 }
782
783 if (nspread < spread) {
784 spread = nspread;
785 if (goal_epos.bh != epos.bh) {
786 brelse(goal_epos.bh);
787 goal_epos.bh = epos.bh;
788 get_bh(goal_epos.bh);
789 }
790 goal_epos.block = epos.block;
791 goal_epos.offset = epos.offset - adsize;
792 goal_eloc = eloc;
793 goal_elen = (etype << 30) | elen;
794 }
795 }
796
797 brelse(epos.bh);
798
799 if (spread == 0xFFFFFFFF) {
800 brelse(goal_epos.bh);
801 mutex_unlock(&sbi->s_alloc_mutex);
802 return 0;
803 }
804
805 /* Only allocate blocks from the beginning of the extent.
806 That way, we only delete (empty) extents, never have to insert an
807 extent because of splitting */
808 /* This works, but very poorly.... */
809
810 newblock = goal_eloc.logicalBlockNum;
811 goal_eloc.logicalBlockNum++;
812 goal_elen -= sb->s_blocksize;
813
814 if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
815 brelse(goal_epos.bh);
816 mutex_unlock(&sbi->s_alloc_mutex);
817 *err = -EDQUOT;
818 return 0;
819 }
820
821 if (goal_elen)
822 udf_write_aext(table, &goal_epos, goal_eloc, goal_elen, 1);
823 else
824 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
825 brelse(goal_epos.bh);
826
827 if (udf_add_free_space(sbi, partition, -1))
828 mark_buffer_dirty(sbi->s_lvid_bh);
829
830 sb->s_dirt = 1;
831 mutex_unlock(&sbi->s_alloc_mutex);
832 *err = 0;
833 return newblock;
834 }
835
836 inline void udf_free_blocks(struct super_block *sb,
837 struct inode *inode,
838 kernel_lb_addr bloc, uint32_t offset,
839 uint32_t count)
840 {
841 uint16_t partition = bloc.partitionReferenceNum;
842 struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
843
844 if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
845 return udf_bitmap_free_blocks(sb, inode,
846 map->s_uspace.s_bitmap,
847 bloc, offset, count);
848 } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
849 return udf_table_free_blocks(sb, inode,
850 map->s_uspace.s_table,
851 bloc, offset, count);
852 } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
853 return udf_bitmap_free_blocks(sb, inode,
854 map->s_fspace.s_bitmap,
855 bloc, offset, count);
856 } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
857 return udf_table_free_blocks(sb, inode,
858 map->s_fspace.s_table,
859 bloc, offset, count);
860 } else {
861 return;
862 }
863 }
864
865 inline int udf_prealloc_blocks(struct super_block *sb,
866 struct inode *inode,
867 uint16_t partition, uint32_t first_block,
868 uint32_t block_count)
869 {
870 struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
871
872 if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
873 return udf_bitmap_prealloc_blocks(sb, inode,
874 map->s_uspace.s_bitmap,
875 partition, first_block,
876 block_count);
877 else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
878 return udf_table_prealloc_blocks(sb, inode,
879 map->s_uspace.s_table,
880 partition, first_block,
881 block_count);
882 else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
883 return udf_bitmap_prealloc_blocks(sb, inode,
884 map->s_fspace.s_bitmap,
885 partition, first_block,
886 block_count);
887 else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
888 return udf_table_prealloc_blocks(sb, inode,
889 map->s_fspace.s_table,
890 partition, first_block,
891 block_count);
892 else
893 return 0;
894 }
895
896 inline int udf_new_block(struct super_block *sb,
897 struct inode *inode,
898 uint16_t partition, uint32_t goal, int *err)
899 {
900 struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
901
902 if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
903 return udf_bitmap_new_block(sb, inode,
904 map->s_uspace.s_bitmap,
905 partition, goal, err);
906 else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
907 return udf_table_new_block(sb, inode,
908 map->s_uspace.s_table,
909 partition, goal, err);
910 else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
911 return udf_bitmap_new_block(sb, inode,
912 map->s_fspace.s_bitmap,
913 partition, goal, err);
914 else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
915 return udf_table_new_block(sb, inode,
916 map->s_fspace.s_table,
917 partition, goal, err);
918 else {
919 *err = -EIO;
920 return 0;
921 }
922 }
WRT350N Kernel Patches