xref: /linux/fs/udf/balloc.c (revision 7effbd18e496a954540fb6319db0d87d28a70496)
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/bitops.h>
25 
26 #include "udf_i.h"
27 #include "udf_sb.h"
28 
29 #define udf_clear_bit	__test_and_clear_bit_le
30 #define udf_set_bit	__test_and_set_bit_le
31 #define udf_test_bit	test_bit_le
32 #define udf_find_next_one_bit	find_next_bit_le
33 
34 static int read_block_bitmap(struct super_block *sb,
35 			     struct udf_bitmap *bitmap, unsigned int block,
36 			     unsigned long bitmap_nr)
37 {
38 	struct buffer_head *bh = NULL;
39 	int i;
40 	int max_bits, off, count;
41 	struct kernel_lb_addr loc;
42 
43 	loc.logicalBlockNum = bitmap->s_extPosition;
44 	loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
45 
46 	bh = sb_bread(sb, udf_get_lb_pblock(sb, &loc, block));
47 	bitmap->s_block_bitmap[bitmap_nr] = bh;
48 	if (!bh)
49 		return -EIO;
50 
51 	/* Check consistency of Space Bitmap buffer. */
52 	max_bits = sb->s_blocksize * 8;
53 	if (!bitmap_nr) {
54 		off = sizeof(struct spaceBitmapDesc) << 3;
55 		count = min(max_bits - off, bitmap->s_nr_groups);
56 	} else {
57 		/*
58 		 * Rough check if bitmap number is too big to have any bitmap
59  		 * blocks reserved.
60 		 */
61 		if (bitmap_nr >
62 		    (bitmap->s_nr_groups >> (sb->s_blocksize_bits + 3)) + 2)
63 			return 0;
64 		off = 0;
65 		count = bitmap->s_nr_groups - bitmap_nr * max_bits +
66 				(sizeof(struct spaceBitmapDesc) << 3);
67 		count = min(count, max_bits);
68 	}
69 
70 	for (i = 0; i < count; i++)
71 		if (udf_test_bit(i + off, bh->b_data))
72 			return -EFSCORRUPTED;
73 	return 0;
74 }
75 
76 static int __load_block_bitmap(struct super_block *sb,
77 			       struct udf_bitmap *bitmap,
78 			       unsigned int block_group)
79 {
80 	int retval = 0;
81 	int nr_groups = bitmap->s_nr_groups;
82 
83 	if (block_group >= nr_groups) {
84 		udf_debug("block_group (%u) > nr_groups (%d)\n",
85 			  block_group, nr_groups);
86 	}
87 
88 	if (bitmap->s_block_bitmap[block_group])
89 		return block_group;
90 
91 	retval = read_block_bitmap(sb, bitmap, block_group, block_group);
92 	if (retval < 0)
93 		return retval;
94 
95 	return block_group;
96 }
97 
98 static inline int load_block_bitmap(struct super_block *sb,
99 				    struct udf_bitmap *bitmap,
100 				    unsigned int block_group)
101 {
102 	int slot;
103 
104 	slot = __load_block_bitmap(sb, bitmap, block_group);
105 
106 	if (slot < 0)
107 		return slot;
108 
109 	if (!bitmap->s_block_bitmap[slot])
110 		return -EIO;
111 
112 	return slot;
113 }
114 
115 static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
116 {
117 	struct udf_sb_info *sbi = UDF_SB(sb);
118 	struct logicalVolIntegrityDesc *lvid;
119 
120 	if (!sbi->s_lvid_bh)
121 		return;
122 
123 	lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
124 	le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
125 	udf_updated_lvid(sb);
126 }
127 
128 static void udf_bitmap_free_blocks(struct super_block *sb,
129 				   struct udf_bitmap *bitmap,
130 				   struct kernel_lb_addr *bloc,
131 				   uint32_t offset,
132 				   uint32_t count)
133 {
134 	struct udf_sb_info *sbi = UDF_SB(sb);
135 	struct buffer_head *bh = NULL;
136 	struct udf_part_map *partmap;
137 	unsigned long block;
138 	unsigned long block_group;
139 	unsigned long bit;
140 	unsigned long i;
141 	int bitmap_nr;
142 	unsigned long overflow;
143 
144 	mutex_lock(&sbi->s_alloc_mutex);
145 	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
146 	if (bloc->logicalBlockNum + count < count ||
147 	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
148 		udf_debug("%u < %d || %u + %u > %u\n",
149 			  bloc->logicalBlockNum, 0,
150 			  bloc->logicalBlockNum, count,
151 			  partmap->s_partition_len);
152 		goto error_return;
153 	}
154 
155 	block = bloc->logicalBlockNum + offset +
156 		(sizeof(struct spaceBitmapDesc) << 3);
157 
158 	do {
159 		overflow = 0;
160 		block_group = block >> (sb->s_blocksize_bits + 3);
161 		bit = block % (sb->s_blocksize << 3);
162 
163 		/*
164 		* Check to see if we are freeing blocks across a group boundary.
165 		*/
166 		if (bit + count > (sb->s_blocksize << 3)) {
167 			overflow = bit + count - (sb->s_blocksize << 3);
168 			count -= overflow;
169 		}
170 		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
171 		if (bitmap_nr < 0)
172 			goto error_return;
173 
174 		bh = bitmap->s_block_bitmap[bitmap_nr];
175 		for (i = 0; i < count; i++) {
176 			if (udf_set_bit(bit + i, bh->b_data)) {
177 				udf_debug("bit %lu already set\n", bit + i);
178 				udf_debug("byte=%2x\n",
179 					  ((__u8 *)bh->b_data)[(bit + i) >> 3]);
180 			}
181 		}
182 		udf_add_free_space(sb, sbi->s_partition, count);
183 		mark_buffer_dirty(bh);
184 		if (overflow) {
185 			block += count;
186 			count = overflow;
187 		}
188 	} while (overflow);
189 
190 error_return:
191 	mutex_unlock(&sbi->s_alloc_mutex);
192 }
193 
194 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
195 				      struct udf_bitmap *bitmap,
196 				      uint16_t partition, uint32_t first_block,
197 				      uint32_t block_count)
198 {
199 	struct udf_sb_info *sbi = UDF_SB(sb);
200 	int alloc_count = 0;
201 	int bit, block, block_group;
202 	int bitmap_nr;
203 	struct buffer_head *bh;
204 	__u32 part_len;
205 
206 	mutex_lock(&sbi->s_alloc_mutex);
207 	part_len = sbi->s_partmaps[partition].s_partition_len;
208 	if (first_block >= part_len)
209 		goto out;
210 
211 	if (first_block + block_count > part_len)
212 		block_count = part_len - first_block;
213 
214 	do {
215 		block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
216 		block_group = block >> (sb->s_blocksize_bits + 3);
217 
218 		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
219 		if (bitmap_nr < 0)
220 			goto out;
221 		bh = bitmap->s_block_bitmap[bitmap_nr];
222 
223 		bit = block % (sb->s_blocksize << 3);
224 
225 		while (bit < (sb->s_blocksize << 3) && block_count > 0) {
226 			if (!udf_clear_bit(bit, bh->b_data))
227 				goto out;
228 			block_count--;
229 			alloc_count++;
230 			bit++;
231 			block++;
232 		}
233 		mark_buffer_dirty(bh);
234 	} while (block_count > 0);
235 
236 out:
237 	udf_add_free_space(sb, partition, -alloc_count);
238 	mutex_unlock(&sbi->s_alloc_mutex);
239 	return alloc_count;
240 }
241 
242 static udf_pblk_t udf_bitmap_new_block(struct super_block *sb,
243 				struct udf_bitmap *bitmap, uint16_t partition,
244 				uint32_t goal, int *err)
245 {
246 	struct udf_sb_info *sbi = UDF_SB(sb);
247 	int newbit, bit = 0;
248 	udf_pblk_t block;
249 	int block_group, group_start;
250 	int end_goal, nr_groups, bitmap_nr, i;
251 	struct buffer_head *bh = NULL;
252 	char *ptr;
253 	udf_pblk_t newblock = 0;
254 
255 	*err = -ENOSPC;
256 	mutex_lock(&sbi->s_alloc_mutex);
257 
258 repeat:
259 	if (goal >= sbi->s_partmaps[partition].s_partition_len)
260 		goal = 0;
261 
262 	nr_groups = bitmap->s_nr_groups;
263 	block = goal + (sizeof(struct spaceBitmapDesc) << 3);
264 	block_group = block >> (sb->s_blocksize_bits + 3);
265 	group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
266 
267 	bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
268 	if (bitmap_nr < 0)
269 		goto error_return;
270 	bh = bitmap->s_block_bitmap[bitmap_nr];
271 	ptr = memscan((char *)bh->b_data + group_start, 0xFF,
272 		      sb->s_blocksize - group_start);
273 
274 	if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
275 		bit = block % (sb->s_blocksize << 3);
276 		if (udf_test_bit(bit, bh->b_data))
277 			goto got_block;
278 
279 		end_goal = (bit + 63) & ~63;
280 		bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
281 		if (bit < end_goal)
282 			goto got_block;
283 
284 		ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
285 			      sb->s_blocksize - ((bit + 7) >> 3));
286 		newbit = (ptr - ((char *)bh->b_data)) << 3;
287 		if (newbit < sb->s_blocksize << 3) {
288 			bit = newbit;
289 			goto search_back;
290 		}
291 
292 		newbit = udf_find_next_one_bit(bh->b_data,
293 					       sb->s_blocksize << 3, bit);
294 		if (newbit < sb->s_blocksize << 3) {
295 			bit = newbit;
296 			goto got_block;
297 		}
298 	}
299 
300 	for (i = 0; i < (nr_groups * 2); i++) {
301 		block_group++;
302 		if (block_group >= nr_groups)
303 			block_group = 0;
304 		group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
305 
306 		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
307 		if (bitmap_nr < 0)
308 			goto error_return;
309 		bh = bitmap->s_block_bitmap[bitmap_nr];
310 		if (i < nr_groups) {
311 			ptr = memscan((char *)bh->b_data + group_start, 0xFF,
312 				      sb->s_blocksize - group_start);
313 			if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
314 				bit = (ptr - ((char *)bh->b_data)) << 3;
315 				break;
316 			}
317 		} else {
318 			bit = udf_find_next_one_bit(bh->b_data,
319 						    sb->s_blocksize << 3,
320 						    group_start << 3);
321 			if (bit < sb->s_blocksize << 3)
322 				break;
323 		}
324 	}
325 	if (i >= (nr_groups * 2)) {
326 		mutex_unlock(&sbi->s_alloc_mutex);
327 		return newblock;
328 	}
329 	if (bit < sb->s_blocksize << 3)
330 		goto search_back;
331 	else
332 		bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
333 					    group_start << 3);
334 	if (bit >= sb->s_blocksize << 3) {
335 		mutex_unlock(&sbi->s_alloc_mutex);
336 		return 0;
337 	}
338 
339 search_back:
340 	i = 0;
341 	while (i < 7 && bit > (group_start << 3) &&
342 	       udf_test_bit(bit - 1, bh->b_data)) {
343 		++i;
344 		--bit;
345 	}
346 
347 got_block:
348 	newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
349 		(sizeof(struct spaceBitmapDesc) << 3);
350 
351 	if (newblock >= sbi->s_partmaps[partition].s_partition_len) {
352 		/*
353 		 * Ran off the end of the bitmap, and bits following are
354 		 * non-compliant (not all zero)
355 		 */
356 		udf_err(sb, "bitmap for partition %d corrupted (block %u marked"
357 			" as free, partition length is %u)\n", partition,
358 			newblock, sbi->s_partmaps[partition].s_partition_len);
359 		goto error_return;
360 	}
361 
362 	if (!udf_clear_bit(bit, bh->b_data)) {
363 		udf_debug("bit already cleared for block %d\n", bit);
364 		goto repeat;
365 	}
366 
367 	mark_buffer_dirty(bh);
368 
369 	udf_add_free_space(sb, partition, -1);
370 	mutex_unlock(&sbi->s_alloc_mutex);
371 	*err = 0;
372 	return newblock;
373 
374 error_return:
375 	*err = -EIO;
376 	mutex_unlock(&sbi->s_alloc_mutex);
377 	return 0;
378 }
379 
380 static void udf_table_free_blocks(struct super_block *sb,
381 				  struct inode *table,
382 				  struct kernel_lb_addr *bloc,
383 				  uint32_t offset,
384 				  uint32_t count)
385 {
386 	struct udf_sb_info *sbi = UDF_SB(sb);
387 	struct udf_part_map *partmap;
388 	uint32_t start, end;
389 	uint32_t elen;
390 	struct kernel_lb_addr eloc;
391 	struct extent_position oepos, epos;
392 	int8_t etype;
393 	struct udf_inode_info *iinfo;
394 
395 	mutex_lock(&sbi->s_alloc_mutex);
396 	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
397 	if (bloc->logicalBlockNum + count < count ||
398 	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
399 		udf_debug("%u < %d || %u + %u > %u\n",
400 			  bloc->logicalBlockNum, 0,
401 			  bloc->logicalBlockNum, count,
402 			  partmap->s_partition_len);
403 		goto error_return;
404 	}
405 
406 	iinfo = UDF_I(table);
407 	udf_add_free_space(sb, sbi->s_partition, count);
408 
409 	start = bloc->logicalBlockNum + offset;
410 	end = bloc->logicalBlockNum + offset + count - 1;
411 
412 	epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
413 	elen = 0;
414 	epos.block = oepos.block = iinfo->i_location;
415 	epos.bh = oepos.bh = NULL;
416 
417 	while (count &&
418 	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
419 		if (((eloc.logicalBlockNum +
420 			(elen >> sb->s_blocksize_bits)) == start)) {
421 			if ((0x3FFFFFFF - elen) <
422 					(count << sb->s_blocksize_bits)) {
423 				uint32_t tmp = ((0x3FFFFFFF - elen) >>
424 							sb->s_blocksize_bits);
425 				count -= tmp;
426 				start += tmp;
427 				elen = (etype << 30) |
428 					(0x40000000 - sb->s_blocksize);
429 			} else {
430 				elen = (etype << 30) |
431 					(elen +
432 					(count << sb->s_blocksize_bits));
433 				start += count;
434 				count = 0;
435 			}
436 			udf_write_aext(table, &oepos, &eloc, elen, 1);
437 		} else if (eloc.logicalBlockNum == (end + 1)) {
438 			if ((0x3FFFFFFF - elen) <
439 					(count << sb->s_blocksize_bits)) {
440 				uint32_t tmp = ((0x3FFFFFFF - elen) >>
441 						sb->s_blocksize_bits);
442 				count -= tmp;
443 				end -= tmp;
444 				eloc.logicalBlockNum -= tmp;
445 				elen = (etype << 30) |
446 					(0x40000000 - sb->s_blocksize);
447 			} else {
448 				eloc.logicalBlockNum = start;
449 				elen = (etype << 30) |
450 					(elen +
451 					(count << sb->s_blocksize_bits));
452 				end -= count;
453 				count = 0;
454 			}
455 			udf_write_aext(table, &oepos, &eloc, elen, 1);
456 		}
457 
458 		if (epos.bh != oepos.bh) {
459 			oepos.block = epos.block;
460 			brelse(oepos.bh);
461 			get_bh(epos.bh);
462 			oepos.bh = epos.bh;
463 			oepos.offset = 0;
464 		} else {
465 			oepos.offset = epos.offset;
466 		}
467 	}
468 
469 	if (count) {
470 		/*
471 		 * NOTE: we CANNOT use udf_add_aext here, as it can try to
472 		 * allocate a new block, and since we hold the super block
473 		 * lock already very bad things would happen :)
474 		 *
475 		 * We copy the behavior of udf_add_aext, but instead of
476 		 * trying to allocate a new block close to the existing one,
477 		 * we just steal a block from the extent we are trying to add.
478 		 *
479 		 * It would be nice if the blocks were close together, but it
480 		 * isn't required.
481 		 */
482 
483 		int adsize;
484 
485 		eloc.logicalBlockNum = start;
486 		elen = EXT_RECORDED_ALLOCATED |
487 			(count << sb->s_blocksize_bits);
488 
489 		if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
490 			adsize = sizeof(struct short_ad);
491 		else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
492 			adsize = sizeof(struct long_ad);
493 		else {
494 			brelse(oepos.bh);
495 			brelse(epos.bh);
496 			goto error_return;
497 		}
498 
499 		if (epos.offset + (2 * adsize) > sb->s_blocksize) {
500 			/* Steal a block from the extent being free'd */
501 			udf_setup_indirect_aext(table, eloc.logicalBlockNum,
502 						&epos);
503 
504 			eloc.logicalBlockNum++;
505 			elen -= sb->s_blocksize;
506 		}
507 
508 		/* It's possible that stealing the block emptied the extent */
509 		if (elen)
510 			__udf_add_aext(table, &epos, &eloc, elen, 1);
511 	}
512 
513 	brelse(epos.bh);
514 	brelse(oepos.bh);
515 
516 error_return:
517 	mutex_unlock(&sbi->s_alloc_mutex);
518 	return;
519 }
520 
521 static int udf_table_prealloc_blocks(struct super_block *sb,
522 				     struct inode *table, uint16_t partition,
523 				     uint32_t first_block, uint32_t block_count)
524 {
525 	struct udf_sb_info *sbi = UDF_SB(sb);
526 	int alloc_count = 0;
527 	uint32_t elen, adsize;
528 	struct kernel_lb_addr eloc;
529 	struct extent_position epos;
530 	int8_t etype = -1;
531 	struct udf_inode_info *iinfo;
532 
533 	if (first_block >= sbi->s_partmaps[partition].s_partition_len)
534 		return 0;
535 
536 	iinfo = UDF_I(table);
537 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
538 		adsize = sizeof(struct short_ad);
539 	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
540 		adsize = sizeof(struct long_ad);
541 	else
542 		return 0;
543 
544 	mutex_lock(&sbi->s_alloc_mutex);
545 	epos.offset = sizeof(struct unallocSpaceEntry);
546 	epos.block = iinfo->i_location;
547 	epos.bh = NULL;
548 	eloc.logicalBlockNum = 0xFFFFFFFF;
549 
550 	while (first_block != eloc.logicalBlockNum &&
551 	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
552 		udf_debug("eloc=%u, elen=%u, first_block=%u\n",
553 			  eloc.logicalBlockNum, elen, first_block);
554 		; /* empty loop body */
555 	}
556 
557 	if (first_block == eloc.logicalBlockNum) {
558 		epos.offset -= adsize;
559 
560 		alloc_count = (elen >> sb->s_blocksize_bits);
561 		if (alloc_count > block_count) {
562 			alloc_count = block_count;
563 			eloc.logicalBlockNum += alloc_count;
564 			elen -= (alloc_count << sb->s_blocksize_bits);
565 			udf_write_aext(table, &epos, &eloc,
566 					(etype << 30) | elen, 1);
567 		} else
568 			udf_delete_aext(table, epos);
569 	} else {
570 		alloc_count = 0;
571 	}
572 
573 	brelse(epos.bh);
574 
575 	if (alloc_count)
576 		udf_add_free_space(sb, partition, -alloc_count);
577 	mutex_unlock(&sbi->s_alloc_mutex);
578 	return alloc_count;
579 }
580 
581 static udf_pblk_t udf_table_new_block(struct super_block *sb,
582 			       struct inode *table, uint16_t partition,
583 			       uint32_t goal, int *err)
584 {
585 	struct udf_sb_info *sbi = UDF_SB(sb);
586 	uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
587 	udf_pblk_t newblock = 0;
588 	uint32_t adsize;
589 	uint32_t elen, goal_elen = 0;
590 	struct kernel_lb_addr eloc, goal_eloc;
591 	struct extent_position epos, goal_epos;
592 	int8_t etype;
593 	struct udf_inode_info *iinfo = UDF_I(table);
594 
595 	*err = -ENOSPC;
596 
597 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
598 		adsize = sizeof(struct short_ad);
599 	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
600 		adsize = sizeof(struct long_ad);
601 	else
602 		return newblock;
603 
604 	mutex_lock(&sbi->s_alloc_mutex);
605 	if (goal >= sbi->s_partmaps[partition].s_partition_len)
606 		goal = 0;
607 
608 	/* We search for the closest matching block to goal. If we find
609 	   a exact hit, we stop. Otherwise we keep going till we run out
610 	   of extents. We store the buffer_head, bloc, and extoffset
611 	   of the current closest match and use that when we are done.
612 	 */
613 	epos.offset = sizeof(struct unallocSpaceEntry);
614 	epos.block = iinfo->i_location;
615 	epos.bh = goal_epos.bh = NULL;
616 
617 	while (spread &&
618 	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
619 		if (goal >= eloc.logicalBlockNum) {
620 			if (goal < eloc.logicalBlockNum +
621 					(elen >> sb->s_blocksize_bits))
622 				nspread = 0;
623 			else
624 				nspread = goal - eloc.logicalBlockNum -
625 					(elen >> sb->s_blocksize_bits);
626 		} else {
627 			nspread = eloc.logicalBlockNum - goal;
628 		}
629 
630 		if (nspread < spread) {
631 			spread = nspread;
632 			if (goal_epos.bh != epos.bh) {
633 				brelse(goal_epos.bh);
634 				goal_epos.bh = epos.bh;
635 				get_bh(goal_epos.bh);
636 			}
637 			goal_epos.block = epos.block;
638 			goal_epos.offset = epos.offset - adsize;
639 			goal_eloc = eloc;
640 			goal_elen = (etype << 30) | elen;
641 		}
642 	}
643 
644 	brelse(epos.bh);
645 
646 	if (spread == 0xFFFFFFFF) {
647 		brelse(goal_epos.bh);
648 		mutex_unlock(&sbi->s_alloc_mutex);
649 		return 0;
650 	}
651 
652 	/* Only allocate blocks from the beginning of the extent.
653 	   That way, we only delete (empty) extents, never have to insert an
654 	   extent because of splitting */
655 	/* This works, but very poorly.... */
656 
657 	newblock = goal_eloc.logicalBlockNum;
658 	goal_eloc.logicalBlockNum++;
659 	goal_elen -= sb->s_blocksize;
660 
661 	if (goal_elen)
662 		udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
663 	else
664 		udf_delete_aext(table, goal_epos);
665 	brelse(goal_epos.bh);
666 
667 	udf_add_free_space(sb, partition, -1);
668 
669 	mutex_unlock(&sbi->s_alloc_mutex);
670 	*err = 0;
671 	return newblock;
672 }
673 
674 void udf_free_blocks(struct super_block *sb, struct inode *inode,
675 		     struct kernel_lb_addr *bloc, uint32_t offset,
676 		     uint32_t count)
677 {
678 	uint16_t partition = bloc->partitionReferenceNum;
679 	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
680 
681 	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
682 		udf_bitmap_free_blocks(sb, map->s_uspace.s_bitmap,
683 				       bloc, offset, count);
684 	} else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
685 		udf_table_free_blocks(sb, map->s_uspace.s_table,
686 				      bloc, offset, count);
687 	}
688 
689 	if (inode) {
690 		inode_sub_bytes(inode,
691 				((sector_t)count) << sb->s_blocksize_bits);
692 	}
693 }
694 
695 inline int udf_prealloc_blocks(struct super_block *sb,
696 			       struct inode *inode,
697 			       uint16_t partition, uint32_t first_block,
698 			       uint32_t block_count)
699 {
700 	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
701 	int allocated;
702 
703 	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
704 		allocated = udf_bitmap_prealloc_blocks(sb,
705 						       map->s_uspace.s_bitmap,
706 						       partition, first_block,
707 						       block_count);
708 	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
709 		allocated = udf_table_prealloc_blocks(sb,
710 						      map->s_uspace.s_table,
711 						      partition, first_block,
712 						      block_count);
713 	else
714 		return 0;
715 
716 	if (inode && allocated > 0)
717 		inode_add_bytes(inode, allocated << sb->s_blocksize_bits);
718 	return allocated;
719 }
720 
721 inline udf_pblk_t udf_new_block(struct super_block *sb,
722 			 struct inode *inode,
723 			 uint16_t partition, uint32_t goal, int *err)
724 {
725 	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
726 	udf_pblk_t block;
727 
728 	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
729 		block = udf_bitmap_new_block(sb,
730 					     map->s_uspace.s_bitmap,
731 					     partition, goal, err);
732 	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
733 		block = udf_table_new_block(sb,
734 					    map->s_uspace.s_table,
735 					    partition, goal, err);
736 	else {
737 		*err = -EIO;
738 		return 0;
739 	}
740 	if (inode && block)
741 		inode_add_bytes(inode, sb->s_blocksize);
742 	return block;
743 }
744