xref: /openbmc/linux/fs/udf/balloc.c (revision 8165c844)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * balloc.c
4  *
5  * PURPOSE
6  *	Block allocation handling routines for the OSTA-UDF(tm) filesystem.
7  *
8  * COPYRIGHT
9  *  (C) 1999-2001 Ben Fennema
10  *  (C) 1999 Stelias Computing Inc
11  *
12  * HISTORY
13  *
14  *  02/24/99 blf  Created.
15  *
16  */
17 
18 #include "udfdecl.h"
19 
20 #include <linux/bitops.h>
21 #include <linux/overflow.h>
22 
23 #include "udf_i.h"
24 #include "udf_sb.h"
25 
26 #define udf_clear_bit	__test_and_clear_bit_le
27 #define udf_set_bit	__test_and_set_bit_le
28 #define udf_test_bit	test_bit_le
29 #define udf_find_next_one_bit	find_next_bit_le
30 
31 static int read_block_bitmap(struct super_block *sb,
32 			     struct udf_bitmap *bitmap, unsigned int block,
33 			     unsigned long bitmap_nr)
34 {
35 	struct buffer_head *bh = NULL;
36 	int i;
37 	int max_bits, off, count;
38 	struct kernel_lb_addr loc;
39 
40 	loc.logicalBlockNum = bitmap->s_extPosition;
41 	loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
42 
43 	bh = sb_bread(sb, udf_get_lb_pblock(sb, &loc, block));
44 	bitmap->s_block_bitmap[bitmap_nr] = bh;
45 	if (!bh)
46 		return -EIO;
47 
48 	/* Check consistency of Space Bitmap buffer. */
49 	max_bits = sb->s_blocksize * 8;
50 	if (!bitmap_nr) {
51 		off = sizeof(struct spaceBitmapDesc) << 3;
52 		count = min(max_bits - off, bitmap->s_nr_groups);
53 	} else {
54 		/*
55 		 * Rough check if bitmap number is too big to have any bitmap
56  		 * blocks reserved.
57 		 */
58 		if (bitmap_nr >
59 		    (bitmap->s_nr_groups >> (sb->s_blocksize_bits + 3)) + 2)
60 			return 0;
61 		off = 0;
62 		count = bitmap->s_nr_groups - bitmap_nr * max_bits +
63 				(sizeof(struct spaceBitmapDesc) << 3);
64 		count = min(count, max_bits);
65 	}
66 
67 	for (i = 0; i < count; i++)
68 		if (udf_test_bit(i + off, bh->b_data)) {
69 			bitmap->s_block_bitmap[bitmap_nr] =
70 							ERR_PTR(-EFSCORRUPTED);
71 			brelse(bh);
72 			return -EFSCORRUPTED;
73 		}
74 	return 0;
75 }
76 
77 static int __load_block_bitmap(struct super_block *sb,
78 			       struct udf_bitmap *bitmap,
79 			       unsigned int block_group)
80 {
81 	int retval = 0;
82 	int nr_groups = bitmap->s_nr_groups;
83 
84 	if (block_group >= nr_groups) {
85 		udf_debug("block_group (%u) > nr_groups (%d)\n",
86 			  block_group, nr_groups);
87 	}
88 
89 	if (bitmap->s_block_bitmap[block_group]) {
90 		/*
91 		 * The bitmap failed verification in the past. No point in
92 		 * trying again.
93 		 */
94 		if (IS_ERR(bitmap->s_block_bitmap[block_group]))
95 			return PTR_ERR(bitmap->s_block_bitmap[block_group]);
96 		return block_group;
97 	}
98 
99 	retval = read_block_bitmap(sb, bitmap, block_group, block_group);
100 	if (retval < 0)
101 		return retval;
102 
103 	return block_group;
104 }
105 
106 static inline int load_block_bitmap(struct super_block *sb,
107 				    struct udf_bitmap *bitmap,
108 				    unsigned int block_group)
109 {
110 	int slot;
111 
112 	slot = __load_block_bitmap(sb, bitmap, block_group);
113 
114 	if (slot < 0)
115 		return slot;
116 
117 	if (!bitmap->s_block_bitmap[slot])
118 		return -EIO;
119 
120 	return slot;
121 }
122 
123 static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
124 {
125 	struct udf_sb_info *sbi = UDF_SB(sb);
126 	struct logicalVolIntegrityDesc *lvid;
127 
128 	if (!sbi->s_lvid_bh)
129 		return;
130 
131 	lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
132 	le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
133 	udf_updated_lvid(sb);
134 }
135 
136 static void udf_bitmap_free_blocks(struct super_block *sb,
137 				   struct udf_bitmap *bitmap,
138 				   struct kernel_lb_addr *bloc,
139 				   uint32_t offset,
140 				   uint32_t count)
141 {
142 	struct udf_sb_info *sbi = UDF_SB(sb);
143 	struct buffer_head *bh = NULL;
144 	unsigned long block;
145 	unsigned long block_group;
146 	unsigned long bit;
147 	unsigned long i;
148 	int bitmap_nr;
149 	unsigned long overflow;
150 
151 	mutex_lock(&sbi->s_alloc_mutex);
152 	/* We make sure this cannot overflow when mounting the filesystem */
153 	block = bloc->logicalBlockNum + offset +
154 		(sizeof(struct spaceBitmapDesc) << 3);
155 	do {
156 		overflow = 0;
157 		block_group = block >> (sb->s_blocksize_bits + 3);
158 		bit = block % (sb->s_blocksize << 3);
159 
160 		/*
161 		* Check to see if we are freeing blocks across a group boundary.
162 		*/
163 		if (bit + count > (sb->s_blocksize << 3)) {
164 			overflow = bit + count - (sb->s_blocksize << 3);
165 			count -= overflow;
166 		}
167 		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
168 		if (bitmap_nr < 0)
169 			goto error_return;
170 
171 		bh = bitmap->s_block_bitmap[bitmap_nr];
172 		for (i = 0; i < count; i++) {
173 			if (udf_set_bit(bit + i, bh->b_data)) {
174 				udf_debug("bit %lu already set\n", bit + i);
175 				udf_debug("byte=%2x\n",
176 					  ((__u8 *)bh->b_data)[(bit + i) >> 3]);
177 			}
178 		}
179 		udf_add_free_space(sb, sbi->s_partition, count);
180 		mark_buffer_dirty(bh);
181 		if (overflow) {
182 			block += count;
183 			count = overflow;
184 		}
185 	} while (overflow);
186 
187 error_return:
188 	mutex_unlock(&sbi->s_alloc_mutex);
189 }
190 
191 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
192 				      struct udf_bitmap *bitmap,
193 				      uint16_t partition, uint32_t first_block,
194 				      uint32_t block_count)
195 {
196 	struct udf_sb_info *sbi = UDF_SB(sb);
197 	int alloc_count = 0;
198 	int bit, block, block_group;
199 	int bitmap_nr;
200 	struct buffer_head *bh;
201 	__u32 part_len;
202 
203 	mutex_lock(&sbi->s_alloc_mutex);
204 	part_len = sbi->s_partmaps[partition].s_partition_len;
205 	if (first_block >= part_len)
206 		goto out;
207 
208 	if (first_block + block_count > part_len)
209 		block_count = part_len - first_block;
210 
211 	do {
212 		block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
213 		block_group = block >> (sb->s_blocksize_bits + 3);
214 
215 		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
216 		if (bitmap_nr < 0)
217 			goto out;
218 		bh = bitmap->s_block_bitmap[bitmap_nr];
219 
220 		bit = block % (sb->s_blocksize << 3);
221 
222 		while (bit < (sb->s_blocksize << 3) && block_count > 0) {
223 			if (!udf_clear_bit(bit, bh->b_data))
224 				goto out;
225 			block_count--;
226 			alloc_count++;
227 			bit++;
228 			block++;
229 		}
230 		mark_buffer_dirty(bh);
231 	} while (block_count > 0);
232 
233 out:
234 	udf_add_free_space(sb, partition, -alloc_count);
235 	mutex_unlock(&sbi->s_alloc_mutex);
236 	return alloc_count;
237 }
238 
239 static udf_pblk_t udf_bitmap_new_block(struct super_block *sb,
240 				struct udf_bitmap *bitmap, uint16_t partition,
241 				uint32_t goal, int *err)
242 {
243 	struct udf_sb_info *sbi = UDF_SB(sb);
244 	int newbit, bit = 0;
245 	udf_pblk_t block;
246 	int block_group, group_start;
247 	int end_goal, nr_groups, bitmap_nr, i;
248 	struct buffer_head *bh = NULL;
249 	char *ptr;
250 	udf_pblk_t newblock = 0;
251 
252 	*err = -ENOSPC;
253 	mutex_lock(&sbi->s_alloc_mutex);
254 
255 repeat:
256 	if (goal >= sbi->s_partmaps[partition].s_partition_len)
257 		goal = 0;
258 
259 	nr_groups = bitmap->s_nr_groups;
260 	block = goal + (sizeof(struct spaceBitmapDesc) << 3);
261 	block_group = block >> (sb->s_blocksize_bits + 3);
262 	group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
263 
264 	bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
265 	if (bitmap_nr < 0)
266 		goto error_return;
267 	bh = bitmap->s_block_bitmap[bitmap_nr];
268 	ptr = memscan((char *)bh->b_data + group_start, 0xFF,
269 		      sb->s_blocksize - group_start);
270 
271 	if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
272 		bit = block % (sb->s_blocksize << 3);
273 		if (udf_test_bit(bit, bh->b_data))
274 			goto got_block;
275 
276 		end_goal = (bit + 63) & ~63;
277 		bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
278 		if (bit < end_goal)
279 			goto got_block;
280 
281 		ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
282 			      sb->s_blocksize - ((bit + 7) >> 3));
283 		newbit = (ptr - ((char *)bh->b_data)) << 3;
284 		if (newbit < sb->s_blocksize << 3) {
285 			bit = newbit;
286 			goto search_back;
287 		}
288 
289 		newbit = udf_find_next_one_bit(bh->b_data,
290 					       sb->s_blocksize << 3, bit);
291 		if (newbit < sb->s_blocksize << 3) {
292 			bit = newbit;
293 			goto got_block;
294 		}
295 	}
296 
297 	for (i = 0; i < (nr_groups * 2); i++) {
298 		block_group++;
299 		if (block_group >= nr_groups)
300 			block_group = 0;
301 		group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
302 
303 		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
304 		if (bitmap_nr < 0)
305 			goto error_return;
306 		bh = bitmap->s_block_bitmap[bitmap_nr];
307 		if (i < nr_groups) {
308 			ptr = memscan((char *)bh->b_data + group_start, 0xFF,
309 				      sb->s_blocksize - group_start);
310 			if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
311 				bit = (ptr - ((char *)bh->b_data)) << 3;
312 				break;
313 			}
314 		} else {
315 			bit = udf_find_next_one_bit(bh->b_data,
316 						    sb->s_blocksize << 3,
317 						    group_start << 3);
318 			if (bit < sb->s_blocksize << 3)
319 				break;
320 		}
321 	}
322 	if (i >= (nr_groups * 2)) {
323 		mutex_unlock(&sbi->s_alloc_mutex);
324 		return newblock;
325 	}
326 	if (bit < sb->s_blocksize << 3)
327 		goto search_back;
328 	else
329 		bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
330 					    group_start << 3);
331 	if (bit >= sb->s_blocksize << 3) {
332 		mutex_unlock(&sbi->s_alloc_mutex);
333 		return 0;
334 	}
335 
336 search_back:
337 	i = 0;
338 	while (i < 7 && bit > (group_start << 3) &&
339 	       udf_test_bit(bit - 1, bh->b_data)) {
340 		++i;
341 		--bit;
342 	}
343 
344 got_block:
345 	newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
346 		(sizeof(struct spaceBitmapDesc) << 3);
347 
348 	if (newblock >= sbi->s_partmaps[partition].s_partition_len) {
349 		/*
350 		 * Ran off the end of the bitmap, and bits following are
351 		 * non-compliant (not all zero)
352 		 */
353 		udf_err(sb, "bitmap for partition %d corrupted (block %u marked"
354 			" as free, partition length is %u)\n", partition,
355 			newblock, sbi->s_partmaps[partition].s_partition_len);
356 		goto error_return;
357 	}
358 
359 	if (!udf_clear_bit(bit, bh->b_data)) {
360 		udf_debug("bit already cleared for block %d\n", bit);
361 		goto repeat;
362 	}
363 
364 	mark_buffer_dirty(bh);
365 
366 	udf_add_free_space(sb, partition, -1);
367 	mutex_unlock(&sbi->s_alloc_mutex);
368 	*err = 0;
369 	return newblock;
370 
371 error_return:
372 	*err = -EIO;
373 	mutex_unlock(&sbi->s_alloc_mutex);
374 	return 0;
375 }
376 
377 static void udf_table_free_blocks(struct super_block *sb,
378 				  struct inode *table,
379 				  struct kernel_lb_addr *bloc,
380 				  uint32_t offset,
381 				  uint32_t count)
382 {
383 	struct udf_sb_info *sbi = UDF_SB(sb);
384 	uint32_t start, end;
385 	uint32_t elen;
386 	struct kernel_lb_addr eloc;
387 	struct extent_position oepos, epos;
388 	int8_t etype;
389 	struct udf_inode_info *iinfo;
390 
391 	mutex_lock(&sbi->s_alloc_mutex);
392 	iinfo = UDF_I(table);
393 	udf_add_free_space(sb, sbi->s_partition, count);
394 
395 	start = bloc->logicalBlockNum + offset;
396 	end = bloc->logicalBlockNum + offset + count - 1;
397 
398 	epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
399 	elen = 0;
400 	epos.block = oepos.block = iinfo->i_location;
401 	epos.bh = oepos.bh = NULL;
402 
403 	while (count &&
404 	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
405 		if (((eloc.logicalBlockNum +
406 			(elen >> sb->s_blocksize_bits)) == start)) {
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 				start += tmp;
413 				elen = (etype << 30) |
414 					(0x40000000 - sb->s_blocksize);
415 			} else {
416 				elen = (etype << 30) |
417 					(elen +
418 					(count << sb->s_blocksize_bits));
419 				start += count;
420 				count = 0;
421 			}
422 			udf_write_aext(table, &oepos, &eloc, elen, 1);
423 		} else if (eloc.logicalBlockNum == (end + 1)) {
424 			if ((0x3FFFFFFF - elen) <
425 					(count << sb->s_blocksize_bits)) {
426 				uint32_t tmp = ((0x3FFFFFFF - elen) >>
427 						sb->s_blocksize_bits);
428 				count -= tmp;
429 				end -= tmp;
430 				eloc.logicalBlockNum -= tmp;
431 				elen = (etype << 30) |
432 					(0x40000000 - sb->s_blocksize);
433 			} else {
434 				eloc.logicalBlockNum = start;
435 				elen = (etype << 30) |
436 					(elen +
437 					(count << sb->s_blocksize_bits));
438 				end -= count;
439 				count = 0;
440 			}
441 			udf_write_aext(table, &oepos, &eloc, elen, 1);
442 		}
443 
444 		if (epos.bh != oepos.bh) {
445 			oepos.block = epos.block;
446 			brelse(oepos.bh);
447 			get_bh(epos.bh);
448 			oepos.bh = epos.bh;
449 			oepos.offset = 0;
450 		} else {
451 			oepos.offset = epos.offset;
452 		}
453 	}
454 
455 	if (count) {
456 		/*
457 		 * NOTE: we CANNOT use udf_add_aext here, as it can try to
458 		 * allocate a new block, and since we hold the super block
459 		 * lock already very bad things would happen :)
460 		 *
461 		 * We copy the behavior of udf_add_aext, but instead of
462 		 * trying to allocate a new block close to the existing one,
463 		 * we just steal a block from the extent we are trying to add.
464 		 *
465 		 * It would be nice if the blocks were close together, but it
466 		 * isn't required.
467 		 */
468 
469 		int adsize;
470 
471 		eloc.logicalBlockNum = start;
472 		elen = EXT_RECORDED_ALLOCATED |
473 			(count << sb->s_blocksize_bits);
474 
475 		if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
476 			adsize = sizeof(struct short_ad);
477 		else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
478 			adsize = sizeof(struct long_ad);
479 		else {
480 			brelse(oepos.bh);
481 			brelse(epos.bh);
482 			goto error_return;
483 		}
484 
485 		if (epos.offset + (2 * adsize) > sb->s_blocksize) {
486 			/* Steal a block from the extent being free'd */
487 			udf_setup_indirect_aext(table, eloc.logicalBlockNum,
488 						&epos);
489 
490 			eloc.logicalBlockNum++;
491 			elen -= sb->s_blocksize;
492 		}
493 
494 		/* It's possible that stealing the block emptied the extent */
495 		if (elen)
496 			__udf_add_aext(table, &epos, &eloc, elen, 1);
497 	}
498 
499 	brelse(epos.bh);
500 	brelse(oepos.bh);
501 
502 error_return:
503 	mutex_unlock(&sbi->s_alloc_mutex);
504 	return;
505 }
506 
507 static int udf_table_prealloc_blocks(struct super_block *sb,
508 				     struct inode *table, uint16_t partition,
509 				     uint32_t first_block, uint32_t block_count)
510 {
511 	struct udf_sb_info *sbi = UDF_SB(sb);
512 	int alloc_count = 0;
513 	uint32_t elen, adsize;
514 	struct kernel_lb_addr eloc;
515 	struct extent_position epos;
516 	int8_t etype = -1;
517 	struct udf_inode_info *iinfo;
518 
519 	if (first_block >= sbi->s_partmaps[partition].s_partition_len)
520 		return 0;
521 
522 	iinfo = UDF_I(table);
523 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
524 		adsize = sizeof(struct short_ad);
525 	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
526 		adsize = sizeof(struct long_ad);
527 	else
528 		return 0;
529 
530 	mutex_lock(&sbi->s_alloc_mutex);
531 	epos.offset = sizeof(struct unallocSpaceEntry);
532 	epos.block = iinfo->i_location;
533 	epos.bh = NULL;
534 	eloc.logicalBlockNum = 0xFFFFFFFF;
535 
536 	while (first_block != eloc.logicalBlockNum &&
537 	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
538 		udf_debug("eloc=%u, elen=%u, first_block=%u\n",
539 			  eloc.logicalBlockNum, elen, first_block);
540 		; /* empty loop body */
541 	}
542 
543 	if (first_block == eloc.logicalBlockNum) {
544 		epos.offset -= adsize;
545 
546 		alloc_count = (elen >> sb->s_blocksize_bits);
547 		if (alloc_count > block_count) {
548 			alloc_count = block_count;
549 			eloc.logicalBlockNum += alloc_count;
550 			elen -= (alloc_count << sb->s_blocksize_bits);
551 			udf_write_aext(table, &epos, &eloc,
552 					(etype << 30) | elen, 1);
553 		} else
554 			udf_delete_aext(table, epos);
555 	} else {
556 		alloc_count = 0;
557 	}
558 
559 	brelse(epos.bh);
560 
561 	if (alloc_count)
562 		udf_add_free_space(sb, partition, -alloc_count);
563 	mutex_unlock(&sbi->s_alloc_mutex);
564 	return alloc_count;
565 }
566 
567 static udf_pblk_t udf_table_new_block(struct super_block *sb,
568 			       struct inode *table, uint16_t partition,
569 			       uint32_t goal, int *err)
570 {
571 	struct udf_sb_info *sbi = UDF_SB(sb);
572 	uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
573 	udf_pblk_t newblock = 0;
574 	uint32_t adsize;
575 	uint32_t elen, goal_elen = 0;
576 	struct kernel_lb_addr eloc, goal_eloc;
577 	struct extent_position epos, goal_epos;
578 	int8_t etype;
579 	struct udf_inode_info *iinfo = UDF_I(table);
580 
581 	*err = -ENOSPC;
582 
583 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
584 		adsize = sizeof(struct short_ad);
585 	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
586 		adsize = sizeof(struct long_ad);
587 	else
588 		return newblock;
589 
590 	mutex_lock(&sbi->s_alloc_mutex);
591 	if (goal >= sbi->s_partmaps[partition].s_partition_len)
592 		goal = 0;
593 
594 	/* We search for the closest matching block to goal. If we find
595 	   a exact hit, we stop. Otherwise we keep going till we run out
596 	   of extents. We store the buffer_head, bloc, and extoffset
597 	   of the current closest match and use that when we are done.
598 	 */
599 	epos.offset = sizeof(struct unallocSpaceEntry);
600 	epos.block = iinfo->i_location;
601 	epos.bh = goal_epos.bh = NULL;
602 
603 	while (spread &&
604 	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
605 		if (goal >= eloc.logicalBlockNum) {
606 			if (goal < eloc.logicalBlockNum +
607 					(elen >> sb->s_blocksize_bits))
608 				nspread = 0;
609 			else
610 				nspread = goal - eloc.logicalBlockNum -
611 					(elen >> sb->s_blocksize_bits);
612 		} else {
613 			nspread = eloc.logicalBlockNum - goal;
614 		}
615 
616 		if (nspread < spread) {
617 			spread = nspread;
618 			if (goal_epos.bh != epos.bh) {
619 				brelse(goal_epos.bh);
620 				goal_epos.bh = epos.bh;
621 				get_bh(goal_epos.bh);
622 			}
623 			goal_epos.block = epos.block;
624 			goal_epos.offset = epos.offset - adsize;
625 			goal_eloc = eloc;
626 			goal_elen = (etype << 30) | elen;
627 		}
628 	}
629 
630 	brelse(epos.bh);
631 
632 	if (spread == 0xFFFFFFFF) {
633 		brelse(goal_epos.bh);
634 		mutex_unlock(&sbi->s_alloc_mutex);
635 		return 0;
636 	}
637 
638 	/* Only allocate blocks from the beginning of the extent.
639 	   That way, we only delete (empty) extents, never have to insert an
640 	   extent because of splitting */
641 	/* This works, but very poorly.... */
642 
643 	newblock = goal_eloc.logicalBlockNum;
644 	goal_eloc.logicalBlockNum++;
645 	goal_elen -= sb->s_blocksize;
646 
647 	if (goal_elen)
648 		udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
649 	else
650 		udf_delete_aext(table, goal_epos);
651 	brelse(goal_epos.bh);
652 
653 	udf_add_free_space(sb, partition, -1);
654 
655 	mutex_unlock(&sbi->s_alloc_mutex);
656 	*err = 0;
657 	return newblock;
658 }
659 
660 void udf_free_blocks(struct super_block *sb, struct inode *inode,
661 		     struct kernel_lb_addr *bloc, uint32_t offset,
662 		     uint32_t count)
663 {
664 	uint16_t partition = bloc->partitionReferenceNum;
665 	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
666 	uint32_t blk;
667 
668 	if (check_add_overflow(bloc->logicalBlockNum, offset, &blk) ||
669 	    check_add_overflow(blk, count, &blk) ||
670 	    bloc->logicalBlockNum + count > map->s_partition_len) {
671 		udf_debug("Invalid request to free blocks: (%d, %u), off %u, "
672 			  "len %u, partition len %u\n",
673 			  partition, bloc->logicalBlockNum, offset, count,
674 			  map->s_partition_len);
675 		return;
676 	}
677 
678 	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
679 		udf_bitmap_free_blocks(sb, map->s_uspace.s_bitmap,
680 				       bloc, offset, count);
681 	} else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
682 		udf_table_free_blocks(sb, map->s_uspace.s_table,
683 				      bloc, offset, count);
684 	}
685 
686 	if (inode) {
687 		inode_sub_bytes(inode,
688 				((sector_t)count) << sb->s_blocksize_bits);
689 	}
690 }
691 
692 inline int udf_prealloc_blocks(struct super_block *sb,
693 			       struct inode *inode,
694 			       uint16_t partition, uint32_t first_block,
695 			       uint32_t block_count)
696 {
697 	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
698 	int allocated;
699 
700 	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
701 		allocated = udf_bitmap_prealloc_blocks(sb,
702 						       map->s_uspace.s_bitmap,
703 						       partition, first_block,
704 						       block_count);
705 	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
706 		allocated = udf_table_prealloc_blocks(sb,
707 						      map->s_uspace.s_table,
708 						      partition, first_block,
709 						      block_count);
710 	else
711 		return 0;
712 
713 	if (inode && allocated > 0)
714 		inode_add_bytes(inode, allocated << sb->s_blocksize_bits);
715 	return allocated;
716 }
717 
718 inline udf_pblk_t udf_new_block(struct super_block *sb,
719 			 struct inode *inode,
720 			 uint16_t partition, uint32_t goal, int *err)
721 {
722 	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
723 	udf_pblk_t block;
724 
725 	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
726 		block = udf_bitmap_new_block(sb,
727 					     map->s_uspace.s_bitmap,
728 					     partition, goal, err);
729 	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
730 		block = udf_table_new_block(sb,
731 					    map->s_uspace.s_table,
732 					    partition, goal, err);
733 	else {
734 		*err = -EIO;
735 		return 0;
736 	}
737 	if (inode && block)
738 		inode_add_bytes(inode, sb->s_blocksize);
739 	return block;
740 }
741