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v4.17
 
  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
 34static 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 retval = 0;
 
 40	struct kernel_lb_addr loc;
 41
 42	loc.logicalBlockNum = bitmap->s_extPosition;
 43	loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
 44
 45	bh = udf_tread(sb, udf_get_lb_pblock(sb, &loc, block));
 
 46	if (!bh)
 47		retval = -EIO;
 48
 49	bitmap->s_block_bitmap[bitmap_nr] = bh;
 50	return retval;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 51}
 52
 53static int __load_block_bitmap(struct super_block *sb,
 54			       struct udf_bitmap *bitmap,
 55			       unsigned int block_group)
 56{
 57	int retval = 0;
 58	int nr_groups = bitmap->s_nr_groups;
 59
 60	if (block_group >= nr_groups) {
 61		udf_debug("block_group (%u) > nr_groups (%d)\n",
 62			  block_group, nr_groups);
 63	}
 64
 65	if (bitmap->s_block_bitmap[block_group])
 66		return block_group;
 67
 68	retval = read_block_bitmap(sb, bitmap, block_group, block_group);
 69	if (retval < 0)
 70		return retval;
 71
 72	return block_group;
 73}
 74
 75static inline int load_block_bitmap(struct super_block *sb,
 76				    struct udf_bitmap *bitmap,
 77				    unsigned int block_group)
 78{
 79	int slot;
 80
 81	slot = __load_block_bitmap(sb, bitmap, block_group);
 82
 83	if (slot < 0)
 84		return slot;
 85
 86	if (!bitmap->s_block_bitmap[slot])
 87		return -EIO;
 88
 89	return slot;
 90}
 91
 92static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
 93{
 94	struct udf_sb_info *sbi = UDF_SB(sb);
 95	struct logicalVolIntegrityDesc *lvid;
 96
 97	if (!sbi->s_lvid_bh)
 98		return;
 99
100	lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
101	le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
102	udf_updated_lvid(sb);
103}
104
105static void udf_bitmap_free_blocks(struct super_block *sb,
106				   struct udf_bitmap *bitmap,
107				   struct kernel_lb_addr *bloc,
108				   uint32_t offset,
109				   uint32_t count)
110{
111	struct udf_sb_info *sbi = UDF_SB(sb);
112	struct buffer_head *bh = NULL;
113	struct udf_part_map *partmap;
114	unsigned long block;
115	unsigned long block_group;
116	unsigned long bit;
117	unsigned long i;
118	int bitmap_nr;
119	unsigned long overflow;
120
121	mutex_lock(&sbi->s_alloc_mutex);
122	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
123	if (bloc->logicalBlockNum + count < count ||
124	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
125		udf_debug("%u < %d || %u + %u > %u\n",
126			  bloc->logicalBlockNum, 0,
127			  bloc->logicalBlockNum, count,
128			  partmap->s_partition_len);
129		goto error_return;
130	}
131
132	block = bloc->logicalBlockNum + offset +
133		(sizeof(struct spaceBitmapDesc) << 3);
134
135	do {
136		overflow = 0;
137		block_group = block >> (sb->s_blocksize_bits + 3);
138		bit = block % (sb->s_blocksize << 3);
139
140		/*
141		* Check to see if we are freeing blocks across a group boundary.
142		*/
143		if (bit + count > (sb->s_blocksize << 3)) {
144			overflow = bit + count - (sb->s_blocksize << 3);
145			count -= overflow;
146		}
147		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
148		if (bitmap_nr < 0)
149			goto error_return;
150
151		bh = bitmap->s_block_bitmap[bitmap_nr];
152		for (i = 0; i < count; i++) {
153			if (udf_set_bit(bit + i, bh->b_data)) {
154				udf_debug("bit %lu already set\n", bit + i);
155				udf_debug("byte=%2x\n",
156					  ((__u8 *)bh->b_data)[(bit + i) >> 3]);
157			}
158		}
159		udf_add_free_space(sb, sbi->s_partition, count);
160		mark_buffer_dirty(bh);
161		if (overflow) {
162			block += count;
163			count = overflow;
164		}
165	} while (overflow);
166
167error_return:
168	mutex_unlock(&sbi->s_alloc_mutex);
169}
170
171static int udf_bitmap_prealloc_blocks(struct super_block *sb,
172				      struct udf_bitmap *bitmap,
173				      uint16_t partition, uint32_t first_block,
174				      uint32_t block_count)
175{
176	struct udf_sb_info *sbi = UDF_SB(sb);
177	int alloc_count = 0;
178	int bit, block, block_group, group_start;
179	int nr_groups, bitmap_nr;
180	struct buffer_head *bh;
181	__u32 part_len;
182
183	mutex_lock(&sbi->s_alloc_mutex);
184	part_len = sbi->s_partmaps[partition].s_partition_len;
185	if (first_block >= part_len)
186		goto out;
187
188	if (first_block + block_count > part_len)
189		block_count = part_len - first_block;
190
191	do {
192		nr_groups = udf_compute_nr_groups(sb, partition);
193		block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
194		block_group = block >> (sb->s_blocksize_bits + 3);
195		group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
196
197		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
198		if (bitmap_nr < 0)
199			goto out;
200		bh = bitmap->s_block_bitmap[bitmap_nr];
201
202		bit = block % (sb->s_blocksize << 3);
203
204		while (bit < (sb->s_blocksize << 3) && block_count > 0) {
205			if (!udf_clear_bit(bit, bh->b_data))
206				goto out;
207			block_count--;
208			alloc_count++;
209			bit++;
210			block++;
211		}
212		mark_buffer_dirty(bh);
213	} while (block_count > 0);
214
215out:
216	udf_add_free_space(sb, partition, -alloc_count);
217	mutex_unlock(&sbi->s_alloc_mutex);
218	return alloc_count;
219}
220
221static udf_pblk_t udf_bitmap_new_block(struct super_block *sb,
222				struct udf_bitmap *bitmap, uint16_t partition,
223				uint32_t goal, int *err)
224{
225	struct udf_sb_info *sbi = UDF_SB(sb);
226	int newbit, bit = 0;
227	udf_pblk_t block;
228	int block_group, group_start;
229	int end_goal, nr_groups, bitmap_nr, i;
230	struct buffer_head *bh = NULL;
231	char *ptr;
232	udf_pblk_t newblock = 0;
233
234	*err = -ENOSPC;
235	mutex_lock(&sbi->s_alloc_mutex);
236
237repeat:
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
318search_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
326got_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
342error_return:
343	*err = -EIO;
344	mutex_unlock(&sbi->s_alloc_mutex);
345	return 0;
346}
347
348static 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	struct udf_inode_info *iinfo;
362
363	mutex_lock(&sbi->s_alloc_mutex);
364	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
365	if (bloc->logicalBlockNum + count < count ||
366	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
367		udf_debug("%u < %d || %u + %u > %u\n",
368			  bloc->logicalBlockNum, 0,
369			  bloc->logicalBlockNum, count,
370			  partmap->s_partition_len);
371		goto error_return;
372	}
373
374	iinfo = UDF_I(table);
375	udf_add_free_space(sb, sbi->s_partition, count);
376
377	start = bloc->logicalBlockNum + offset;
378	end = bloc->logicalBlockNum + offset + count - 1;
379
380	epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
381	elen = 0;
382	epos.block = oepos.block = iinfo->i_location;
383	epos.bh = oepos.bh = NULL;
384
385	while (count &&
386	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
387		if (((eloc.logicalBlockNum +
388			(elen >> sb->s_blocksize_bits)) == start)) {
389			if ((0x3FFFFFFF - elen) <
390					(count << sb->s_blocksize_bits)) {
391				uint32_t tmp = ((0x3FFFFFFF - elen) >>
392							sb->s_blocksize_bits);
393				count -= tmp;
394				start += tmp;
395				elen = (etype << 30) |
396					(0x40000000 - sb->s_blocksize);
397			} else {
398				elen = (etype << 30) |
399					(elen +
400					(count << sb->s_blocksize_bits));
401				start += count;
402				count = 0;
403			}
404			udf_write_aext(table, &oepos, &eloc, elen, 1);
405		} else if (eloc.logicalBlockNum == (end + 1)) {
406			if ((0x3FFFFFFF - elen) <
407					(count << sb->s_blocksize_bits)) {
408				uint32_t tmp = ((0x3FFFFFFF - elen) >>
409						sb->s_blocksize_bits);
410				count -= tmp;
411				end -= tmp;
412				eloc.logicalBlockNum -= tmp;
413				elen = (etype << 30) |
414					(0x40000000 - sb->s_blocksize);
415			} else {
416				eloc.logicalBlockNum = start;
417				elen = (etype << 30) |
418					(elen +
419					(count << sb->s_blocksize_bits));
420				end -= count;
421				count = 0;
422			}
423			udf_write_aext(table, &oepos, &eloc, elen, 1);
424		}
425
426		if (epos.bh != oepos.bh) {
427			oepos.block = epos.block;
428			brelse(oepos.bh);
429			get_bh(epos.bh);
430			oepos.bh = epos.bh;
431			oepos.offset = 0;
432		} else {
433			oepos.offset = epos.offset;
434		}
435	}
436
437	if (count) {
438		/*
439		 * NOTE: we CANNOT use udf_add_aext here, as it can try to
440		 * allocate a new block, and since we hold the super block
441		 * lock already very bad things would happen :)
442		 *
443		 * We copy the behavior of udf_add_aext, but instead of
444		 * trying to allocate a new block close to the existing one,
445		 * we just steal a block from the extent we are trying to add.
446		 *
447		 * It would be nice if the blocks were close together, but it
448		 * isn't required.
449		 */
450
451		int adsize;
452
453		eloc.logicalBlockNum = start;
454		elen = EXT_RECORDED_ALLOCATED |
455			(count << sb->s_blocksize_bits);
456
457		if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
458			adsize = sizeof(struct short_ad);
459		else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
460			adsize = sizeof(struct long_ad);
461		else {
462			brelse(oepos.bh);
463			brelse(epos.bh);
464			goto error_return;
465		}
466
467		if (epos.offset + (2 * adsize) > sb->s_blocksize) {
468			/* Steal a block from the extent being free'd */
469			udf_setup_indirect_aext(table, eloc.logicalBlockNum,
470						&epos);
471
472			eloc.logicalBlockNum++;
473			elen -= sb->s_blocksize;
474		}
475
476		/* It's possible that stealing the block emptied the extent */
477		if (elen)
478			__udf_add_aext(table, &epos, &eloc, elen, 1);
479	}
480
481	brelse(epos.bh);
482	brelse(oepos.bh);
483
484error_return:
485	mutex_unlock(&sbi->s_alloc_mutex);
486	return;
487}
488
489static int udf_table_prealloc_blocks(struct super_block *sb,
490				     struct inode *table, uint16_t partition,
491				     uint32_t first_block, uint32_t block_count)
492{
493	struct udf_sb_info *sbi = UDF_SB(sb);
494	int alloc_count = 0;
495	uint32_t elen, adsize;
496	struct kernel_lb_addr eloc;
497	struct extent_position epos;
498	int8_t etype = -1;
499	struct udf_inode_info *iinfo;
500
501	if (first_block >= sbi->s_partmaps[partition].s_partition_len)
502		return 0;
503
504	iinfo = UDF_I(table);
505	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
506		adsize = sizeof(struct short_ad);
507	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
508		adsize = sizeof(struct long_ad);
509	else
510		return 0;
511
512	mutex_lock(&sbi->s_alloc_mutex);
513	epos.offset = sizeof(struct unallocSpaceEntry);
514	epos.block = iinfo->i_location;
515	epos.bh = NULL;
516	eloc.logicalBlockNum = 0xFFFFFFFF;
517
518	while (first_block != eloc.logicalBlockNum &&
519	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
520		udf_debug("eloc=%u, elen=%u, first_block=%u\n",
521			  eloc.logicalBlockNum, elen, first_block);
522		; /* empty loop body */
523	}
524
525	if (first_block == eloc.logicalBlockNum) {
526		epos.offset -= adsize;
527
528		alloc_count = (elen >> sb->s_blocksize_bits);
529		if (alloc_count > block_count) {
530			alloc_count = block_count;
531			eloc.logicalBlockNum += alloc_count;
532			elen -= (alloc_count << sb->s_blocksize_bits);
533			udf_write_aext(table, &epos, &eloc,
534					(etype << 30) | elen, 1);
535		} else
536			udf_delete_aext(table, epos, eloc,
537					(etype << 30) | elen);
538	} else {
539		alloc_count = 0;
540	}
541
542	brelse(epos.bh);
543
544	if (alloc_count)
545		udf_add_free_space(sb, partition, -alloc_count);
546	mutex_unlock(&sbi->s_alloc_mutex);
547	return alloc_count;
548}
549
550static udf_pblk_t udf_table_new_block(struct super_block *sb,
551			       struct inode *table, uint16_t partition,
552			       uint32_t goal, int *err)
553{
554	struct udf_sb_info *sbi = UDF_SB(sb);
555	uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
556	udf_pblk_t newblock = 0;
557	uint32_t adsize;
558	uint32_t elen, goal_elen = 0;
559	struct kernel_lb_addr eloc, uninitialized_var(goal_eloc);
560	struct extent_position epos, goal_epos;
561	int8_t etype;
562	struct udf_inode_info *iinfo = UDF_I(table);
563
564	*err = -ENOSPC;
565
566	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
567		adsize = sizeof(struct short_ad);
568	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
569		adsize = sizeof(struct long_ad);
570	else
571		return newblock;
572
573	mutex_lock(&sbi->s_alloc_mutex);
574	if (goal >= sbi->s_partmaps[partition].s_partition_len)
575		goal = 0;
576
577	/* We search for the closest matching block to goal. If we find
578	   a exact hit, we stop. Otherwise we keep going till we run out
579	   of extents. We store the buffer_head, bloc, and extoffset
580	   of the current closest match and use that when we are done.
581	 */
582	epos.offset = sizeof(struct unallocSpaceEntry);
583	epos.block = iinfo->i_location;
584	epos.bh = goal_epos.bh = NULL;
585
586	while (spread &&
587	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
588		if (goal >= eloc.logicalBlockNum) {
589			if (goal < eloc.logicalBlockNum +
590					(elen >> sb->s_blocksize_bits))
591				nspread = 0;
592			else
593				nspread = goal - eloc.logicalBlockNum -
594					(elen >> sb->s_blocksize_bits);
595		} else {
596			nspread = eloc.logicalBlockNum - goal;
597		}
598
599		if (nspread < spread) {
600			spread = nspread;
601			if (goal_epos.bh != epos.bh) {
602				brelse(goal_epos.bh);
603				goal_epos.bh = epos.bh;
604				get_bh(goal_epos.bh);
605			}
606			goal_epos.block = epos.block;
607			goal_epos.offset = epos.offset - adsize;
608			goal_eloc = eloc;
609			goal_elen = (etype << 30) | elen;
610		}
611	}
612
613	brelse(epos.bh);
614
615	if (spread == 0xFFFFFFFF) {
616		brelse(goal_epos.bh);
617		mutex_unlock(&sbi->s_alloc_mutex);
618		return 0;
619	}
620
621	/* Only allocate blocks from the beginning of the extent.
622	   That way, we only delete (empty) extents, never have to insert an
623	   extent because of splitting */
624	/* This works, but very poorly.... */
625
626	newblock = goal_eloc.logicalBlockNum;
627	goal_eloc.logicalBlockNum++;
628	goal_elen -= sb->s_blocksize;
629
630	if (goal_elen)
631		udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
632	else
633		udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
634	brelse(goal_epos.bh);
635
636	udf_add_free_space(sb, partition, -1);
637
638	mutex_unlock(&sbi->s_alloc_mutex);
639	*err = 0;
640	return newblock;
641}
642
643void udf_free_blocks(struct super_block *sb, struct inode *inode,
644		     struct kernel_lb_addr *bloc, uint32_t offset,
645		     uint32_t count)
646{
647	uint16_t partition = bloc->partitionReferenceNum;
648	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
649
650	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
651		udf_bitmap_free_blocks(sb, map->s_uspace.s_bitmap,
652				       bloc, offset, count);
653	} else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
654		udf_table_free_blocks(sb, map->s_uspace.s_table,
655				      bloc, offset, count);
656	} else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
657		udf_bitmap_free_blocks(sb, map->s_fspace.s_bitmap,
658				       bloc, offset, count);
659	} else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
660		udf_table_free_blocks(sb, map->s_fspace.s_table,
661				      bloc, offset, count);
662	}
663
664	if (inode) {
665		inode_sub_bytes(inode,
666				((sector_t)count) << sb->s_blocksize_bits);
667	}
668}
669
670inline int udf_prealloc_blocks(struct super_block *sb,
671			       struct inode *inode,
672			       uint16_t partition, uint32_t first_block,
673			       uint32_t block_count)
674{
675	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
676	int allocated;
677
678	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
679		allocated = udf_bitmap_prealloc_blocks(sb,
680						       map->s_uspace.s_bitmap,
681						       partition, first_block,
682						       block_count);
683	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
684		allocated = udf_table_prealloc_blocks(sb,
685						      map->s_uspace.s_table,
686						      partition, first_block,
687						      block_count);
688	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
689		allocated = udf_bitmap_prealloc_blocks(sb,
690						       map->s_fspace.s_bitmap,
691						       partition, first_block,
692						       block_count);
693	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
694		allocated = udf_table_prealloc_blocks(sb,
695						      map->s_fspace.s_table,
696						      partition, first_block,
697						      block_count);
698	else
699		return 0;
700
701	if (inode && allocated > 0)
702		inode_add_bytes(inode, allocated << sb->s_blocksize_bits);
703	return allocated;
704}
705
706inline udf_pblk_t udf_new_block(struct super_block *sb,
707			 struct inode *inode,
708			 uint16_t partition, uint32_t goal, int *err)
709{
710	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
711	udf_pblk_t block;
712
713	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
714		block = udf_bitmap_new_block(sb,
715					     map->s_uspace.s_bitmap,
716					     partition, goal, err);
717	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
718		block = udf_table_new_block(sb,
719					    map->s_uspace.s_table,
720					    partition, goal, err);
721	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
722		block = udf_bitmap_new_block(sb,
723					     map->s_fspace.s_bitmap,
724					     partition, goal, err);
725	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
726		block = udf_table_new_block(sb,
727					    map->s_fspace.s_table,
728					    partition, goal, err);
729	else {
730		*err = -EIO;
731		return 0;
732	}
733	if (inode && block)
734		inode_add_bytes(inode, sb->s_blocksize);
735	return block;
736}
v6.9.4
  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
 22#include "udf_i.h"
 23#include "udf_sb.h"
 24
 25#define udf_clear_bit	__test_and_clear_bit_le
 26#define udf_set_bit	__test_and_set_bit_le
 27#define udf_test_bit	test_bit_le
 28#define udf_find_next_one_bit	find_next_bit_le
 29
 30static int read_block_bitmap(struct super_block *sb,
 31			     struct udf_bitmap *bitmap, unsigned int block,
 32			     unsigned long bitmap_nr)
 33{
 34	struct buffer_head *bh = NULL;
 35	int i;
 36	int max_bits, off, count;
 37	struct kernel_lb_addr loc;
 38
 39	loc.logicalBlockNum = bitmap->s_extPosition;
 40	loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
 41
 42	bh = sb_bread(sb, udf_get_lb_pblock(sb, &loc, block));
 43	bitmap->s_block_bitmap[bitmap_nr] = bh;
 44	if (!bh)
 45		return -EIO;
 46
 47	/* Check consistency of Space Bitmap buffer. */
 48	max_bits = sb->s_blocksize * 8;
 49	if (!bitmap_nr) {
 50		off = sizeof(struct spaceBitmapDesc) << 3;
 51		count = min(max_bits - off, bitmap->s_nr_groups);
 52	} else {
 53		/*
 54		 * Rough check if bitmap number is too big to have any bitmap
 55 		 * blocks reserved.
 56		 */
 57		if (bitmap_nr >
 58		    (bitmap->s_nr_groups >> (sb->s_blocksize_bits + 3)) + 2)
 59			return 0;
 60		off = 0;
 61		count = bitmap->s_nr_groups - bitmap_nr * max_bits +
 62				(sizeof(struct spaceBitmapDesc) << 3);
 63		count = min(count, max_bits);
 64	}
 65
 66	for (i = 0; i < count; i++)
 67		if (udf_test_bit(i + off, bh->b_data))
 68			return -EFSCORRUPTED;
 69	return 0;
 70}
 71
 72static int __load_block_bitmap(struct super_block *sb,
 73			       struct udf_bitmap *bitmap,
 74			       unsigned int block_group)
 75{
 76	int retval = 0;
 77	int nr_groups = bitmap->s_nr_groups;
 78
 79	if (block_group >= nr_groups) {
 80		udf_debug("block_group (%u) > nr_groups (%d)\n",
 81			  block_group, nr_groups);
 82	}
 83
 84	if (bitmap->s_block_bitmap[block_group])
 85		return block_group;
 86
 87	retval = read_block_bitmap(sb, bitmap, block_group, block_group);
 88	if (retval < 0)
 89		return retval;
 90
 91	return block_group;
 92}
 93
 94static inline int load_block_bitmap(struct super_block *sb,
 95				    struct udf_bitmap *bitmap,
 96				    unsigned int block_group)
 97{
 98	int slot;
 99
100	slot = __load_block_bitmap(sb, bitmap, block_group);
101
102	if (slot < 0)
103		return slot;
104
105	if (!bitmap->s_block_bitmap[slot])
106		return -EIO;
107
108	return slot;
109}
110
111static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
112{
113	struct udf_sb_info *sbi = UDF_SB(sb);
114	struct logicalVolIntegrityDesc *lvid;
115
116	if (!sbi->s_lvid_bh)
117		return;
118
119	lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
120	le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
121	udf_updated_lvid(sb);
122}
123
124static void udf_bitmap_free_blocks(struct super_block *sb,
125				   struct udf_bitmap *bitmap,
126				   struct kernel_lb_addr *bloc,
127				   uint32_t offset,
128				   uint32_t count)
129{
130	struct udf_sb_info *sbi = UDF_SB(sb);
131	struct buffer_head *bh = NULL;
132	struct udf_part_map *partmap;
133	unsigned long block;
134	unsigned long block_group;
135	unsigned long bit;
136	unsigned long i;
137	int bitmap_nr;
138	unsigned long overflow;
139
140	mutex_lock(&sbi->s_alloc_mutex);
141	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
142	if (bloc->logicalBlockNum + count < count ||
143	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
144		udf_debug("%u < %d || %u + %u > %u\n",
145			  bloc->logicalBlockNum, 0,
146			  bloc->logicalBlockNum, count,
147			  partmap->s_partition_len);
148		goto error_return;
149	}
150
151	block = bloc->logicalBlockNum + offset +
152		(sizeof(struct spaceBitmapDesc) << 3);
153
154	do {
155		overflow = 0;
156		block_group = block >> (sb->s_blocksize_bits + 3);
157		bit = block % (sb->s_blocksize << 3);
158
159		/*
160		* Check to see if we are freeing blocks across a group boundary.
161		*/
162		if (bit + count > (sb->s_blocksize << 3)) {
163			overflow = bit + count - (sb->s_blocksize << 3);
164			count -= overflow;
165		}
166		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
167		if (bitmap_nr < 0)
168			goto error_return;
169
170		bh = bitmap->s_block_bitmap[bitmap_nr];
171		for (i = 0; i < count; i++) {
172			if (udf_set_bit(bit + i, bh->b_data)) {
173				udf_debug("bit %lu already set\n", bit + i);
174				udf_debug("byte=%2x\n",
175					  ((__u8 *)bh->b_data)[(bit + i) >> 3]);
176			}
177		}
178		udf_add_free_space(sb, sbi->s_partition, count);
179		mark_buffer_dirty(bh);
180		if (overflow) {
181			block += count;
182			count = overflow;
183		}
184	} while (overflow);
185
186error_return:
187	mutex_unlock(&sbi->s_alloc_mutex);
188}
189
190static int udf_bitmap_prealloc_blocks(struct super_block *sb,
191				      struct udf_bitmap *bitmap,
192				      uint16_t partition, uint32_t first_block,
193				      uint32_t block_count)
194{
195	struct udf_sb_info *sbi = UDF_SB(sb);
196	int alloc_count = 0;
197	int bit, block, block_group;
198	int bitmap_nr;
199	struct buffer_head *bh;
200	__u32 part_len;
201
202	mutex_lock(&sbi->s_alloc_mutex);
203	part_len = sbi->s_partmaps[partition].s_partition_len;
204	if (first_block >= part_len)
205		goto out;
206
207	if (first_block + block_count > part_len)
208		block_count = part_len - first_block;
209
210	do {
 
211		block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
212		block_group = block >> (sb->s_blocksize_bits + 3);
 
213
214		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
215		if (bitmap_nr < 0)
216			goto out;
217		bh = bitmap->s_block_bitmap[bitmap_nr];
218
219		bit = block % (sb->s_blocksize << 3);
220
221		while (bit < (sb->s_blocksize << 3) && block_count > 0) {
222			if (!udf_clear_bit(bit, bh->b_data))
223				goto out;
224			block_count--;
225			alloc_count++;
226			bit++;
227			block++;
228		}
229		mark_buffer_dirty(bh);
230	} while (block_count > 0);
231
232out:
233	udf_add_free_space(sb, partition, -alloc_count);
234	mutex_unlock(&sbi->s_alloc_mutex);
235	return alloc_count;
236}
237
238static udf_pblk_t udf_bitmap_new_block(struct super_block *sb,
239				struct udf_bitmap *bitmap, uint16_t partition,
240				uint32_t goal, int *err)
241{
242	struct udf_sb_info *sbi = UDF_SB(sb);
243	int newbit, bit = 0;
244	udf_pblk_t block;
245	int block_group, group_start;
246	int end_goal, nr_groups, bitmap_nr, i;
247	struct buffer_head *bh = NULL;
248	char *ptr;
249	udf_pblk_t newblock = 0;
250
251	*err = -ENOSPC;
252	mutex_lock(&sbi->s_alloc_mutex);
253
254repeat:
255	if (goal >= sbi->s_partmaps[partition].s_partition_len)
256		goal = 0;
257
258	nr_groups = bitmap->s_nr_groups;
259	block = goal + (sizeof(struct spaceBitmapDesc) << 3);
260	block_group = block >> (sb->s_blocksize_bits + 3);
261	group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
262
263	bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
264	if (bitmap_nr < 0)
265		goto error_return;
266	bh = bitmap->s_block_bitmap[bitmap_nr];
267	ptr = memscan((char *)bh->b_data + group_start, 0xFF,
268		      sb->s_blocksize - group_start);
269
270	if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
271		bit = block % (sb->s_blocksize << 3);
272		if (udf_test_bit(bit, bh->b_data))
273			goto got_block;
274
275		end_goal = (bit + 63) & ~63;
276		bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
277		if (bit < end_goal)
278			goto got_block;
279
280		ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
281			      sb->s_blocksize - ((bit + 7) >> 3));
282		newbit = (ptr - ((char *)bh->b_data)) << 3;
283		if (newbit < sb->s_blocksize << 3) {
284			bit = newbit;
285			goto search_back;
286		}
287
288		newbit = udf_find_next_one_bit(bh->b_data,
289					       sb->s_blocksize << 3, bit);
290		if (newbit < sb->s_blocksize << 3) {
291			bit = newbit;
292			goto got_block;
293		}
294	}
295
296	for (i = 0; i < (nr_groups * 2); i++) {
297		block_group++;
298		if (block_group >= nr_groups)
299			block_group = 0;
300		group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
301
302		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
303		if (bitmap_nr < 0)
304			goto error_return;
305		bh = bitmap->s_block_bitmap[bitmap_nr];
306		if (i < nr_groups) {
307			ptr = memscan((char *)bh->b_data + group_start, 0xFF,
308				      sb->s_blocksize - group_start);
309			if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
310				bit = (ptr - ((char *)bh->b_data)) << 3;
311				break;
312			}
313		} else {
314			bit = udf_find_next_one_bit(bh->b_data,
315						    sb->s_blocksize << 3,
316						    group_start << 3);
317			if (bit < sb->s_blocksize << 3)
318				break;
319		}
320	}
321	if (i >= (nr_groups * 2)) {
322		mutex_unlock(&sbi->s_alloc_mutex);
323		return newblock;
324	}
325	if (bit < sb->s_blocksize << 3)
326		goto search_back;
327	else
328		bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
329					    group_start << 3);
330	if (bit >= sb->s_blocksize << 3) {
331		mutex_unlock(&sbi->s_alloc_mutex);
332		return 0;
333	}
334
335search_back:
336	i = 0;
337	while (i < 7 && bit > (group_start << 3) &&
338	       udf_test_bit(bit - 1, bh->b_data)) {
339		++i;
340		--bit;
341	}
342
343got_block:
344	newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
345		(sizeof(struct spaceBitmapDesc) << 3);
346
347	if (newblock >= sbi->s_partmaps[partition].s_partition_len) {
348		/*
349		 * Ran off the end of the bitmap, and bits following are
350		 * non-compliant (not all zero)
351		 */
352		udf_err(sb, "bitmap for partition %d corrupted (block %u marked"
353			" as free, partition length is %u)\n", partition,
354			newblock, sbi->s_partmaps[partition].s_partition_len);
355		goto error_return;
356	}
357
358	if (!udf_clear_bit(bit, bh->b_data)) {
359		udf_debug("bit already cleared for block %d\n", bit);
360		goto repeat;
361	}
362
363	mark_buffer_dirty(bh);
364
365	udf_add_free_space(sb, partition, -1);
366	mutex_unlock(&sbi->s_alloc_mutex);
367	*err = 0;
368	return newblock;
369
370error_return:
371	*err = -EIO;
372	mutex_unlock(&sbi->s_alloc_mutex);
373	return 0;
374}
375
376static void udf_table_free_blocks(struct super_block *sb,
377				  struct inode *table,
378				  struct kernel_lb_addr *bloc,
379				  uint32_t offset,
380				  uint32_t count)
381{
382	struct udf_sb_info *sbi = UDF_SB(sb);
383	struct udf_part_map *partmap;
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	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
393	if (bloc->logicalBlockNum + count < count ||
394	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
395		udf_debug("%u < %d || %u + %u > %u\n",
396			  bloc->logicalBlockNum, 0,
397			  bloc->logicalBlockNum, count,
398			  partmap->s_partition_len);
399		goto error_return;
400	}
401
402	iinfo = UDF_I(table);
403	udf_add_free_space(sb, sbi->s_partition, count);
404
405	start = bloc->logicalBlockNum + offset;
406	end = bloc->logicalBlockNum + offset + count - 1;
407
408	epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
409	elen = 0;
410	epos.block = oepos.block = iinfo->i_location;
411	epos.bh = oepos.bh = NULL;
412
413	while (count &&
414	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
415		if (((eloc.logicalBlockNum +
416			(elen >> sb->s_blocksize_bits)) == start)) {
417			if ((0x3FFFFFFF - elen) <
418					(count << sb->s_blocksize_bits)) {
419				uint32_t tmp = ((0x3FFFFFFF - elen) >>
420							sb->s_blocksize_bits);
421				count -= tmp;
422				start += tmp;
423				elen = (etype << 30) |
424					(0x40000000 - sb->s_blocksize);
425			} else {
426				elen = (etype << 30) |
427					(elen +
428					(count << sb->s_blocksize_bits));
429				start += count;
430				count = 0;
431			}
432			udf_write_aext(table, &oepos, &eloc, elen, 1);
433		} else if (eloc.logicalBlockNum == (end + 1)) {
434			if ((0x3FFFFFFF - elen) <
435					(count << sb->s_blocksize_bits)) {
436				uint32_t tmp = ((0x3FFFFFFF - elen) >>
437						sb->s_blocksize_bits);
438				count -= tmp;
439				end -= tmp;
440				eloc.logicalBlockNum -= tmp;
441				elen = (etype << 30) |
442					(0x40000000 - sb->s_blocksize);
443			} else {
444				eloc.logicalBlockNum = start;
445				elen = (etype << 30) |
446					(elen +
447					(count << sb->s_blocksize_bits));
448				end -= count;
449				count = 0;
450			}
451			udf_write_aext(table, &oepos, &eloc, elen, 1);
452		}
453
454		if (epos.bh != oepos.bh) {
455			oepos.block = epos.block;
456			brelse(oepos.bh);
457			get_bh(epos.bh);
458			oepos.bh = epos.bh;
459			oepos.offset = 0;
460		} else {
461			oepos.offset = epos.offset;
462		}
463	}
464
465	if (count) {
466		/*
467		 * NOTE: we CANNOT use udf_add_aext here, as it can try to
468		 * allocate a new block, and since we hold the super block
469		 * lock already very bad things would happen :)
470		 *
471		 * We copy the behavior of udf_add_aext, but instead of
472		 * trying to allocate a new block close to the existing one,
473		 * we just steal a block from the extent we are trying to add.
474		 *
475		 * It would be nice if the blocks were close together, but it
476		 * isn't required.
477		 */
478
479		int adsize;
480
481		eloc.logicalBlockNum = start;
482		elen = EXT_RECORDED_ALLOCATED |
483			(count << sb->s_blocksize_bits);
484
485		if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
486			adsize = sizeof(struct short_ad);
487		else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
488			adsize = sizeof(struct long_ad);
489		else {
490			brelse(oepos.bh);
491			brelse(epos.bh);
492			goto error_return;
493		}
494
495		if (epos.offset + (2 * adsize) > sb->s_blocksize) {
496			/* Steal a block from the extent being free'd */
497			udf_setup_indirect_aext(table, eloc.logicalBlockNum,
498						&epos);
499
500			eloc.logicalBlockNum++;
501			elen -= sb->s_blocksize;
502		}
503
504		/* It's possible that stealing the block emptied the extent */
505		if (elen)
506			__udf_add_aext(table, &epos, &eloc, elen, 1);
507	}
508
509	brelse(epos.bh);
510	brelse(oepos.bh);
511
512error_return:
513	mutex_unlock(&sbi->s_alloc_mutex);
514	return;
515}
516
517static int udf_table_prealloc_blocks(struct super_block *sb,
518				     struct inode *table, uint16_t partition,
519				     uint32_t first_block, uint32_t block_count)
520{
521	struct udf_sb_info *sbi = UDF_SB(sb);
522	int alloc_count = 0;
523	uint32_t elen, adsize;
524	struct kernel_lb_addr eloc;
525	struct extent_position epos;
526	int8_t etype = -1;
527	struct udf_inode_info *iinfo;
528
529	if (first_block >= sbi->s_partmaps[partition].s_partition_len)
530		return 0;
531
532	iinfo = UDF_I(table);
533	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
534		adsize = sizeof(struct short_ad);
535	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
536		adsize = sizeof(struct long_ad);
537	else
538		return 0;
539
540	mutex_lock(&sbi->s_alloc_mutex);
541	epos.offset = sizeof(struct unallocSpaceEntry);
542	epos.block = iinfo->i_location;
543	epos.bh = NULL;
544	eloc.logicalBlockNum = 0xFFFFFFFF;
545
546	while (first_block != eloc.logicalBlockNum &&
547	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
548		udf_debug("eloc=%u, elen=%u, first_block=%u\n",
549			  eloc.logicalBlockNum, elen, first_block);
550		; /* empty loop body */
551	}
552
553	if (first_block == eloc.logicalBlockNum) {
554		epos.offset -= adsize;
555
556		alloc_count = (elen >> sb->s_blocksize_bits);
557		if (alloc_count > block_count) {
558			alloc_count = block_count;
559			eloc.logicalBlockNum += alloc_count;
560			elen -= (alloc_count << sb->s_blocksize_bits);
561			udf_write_aext(table, &epos, &eloc,
562					(etype << 30) | elen, 1);
563		} else
564			udf_delete_aext(table, epos);
 
565	} else {
566		alloc_count = 0;
567	}
568
569	brelse(epos.bh);
570
571	if (alloc_count)
572		udf_add_free_space(sb, partition, -alloc_count);
573	mutex_unlock(&sbi->s_alloc_mutex);
574	return alloc_count;
575}
576
577static udf_pblk_t udf_table_new_block(struct super_block *sb,
578			       struct inode *table, uint16_t partition,
579			       uint32_t goal, int *err)
580{
581	struct udf_sb_info *sbi = UDF_SB(sb);
582	uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
583	udf_pblk_t newblock = 0;
584	uint32_t adsize;
585	uint32_t elen, goal_elen = 0;
586	struct kernel_lb_addr eloc, goal_eloc;
587	struct extent_position epos, goal_epos;
588	int8_t etype;
589	struct udf_inode_info *iinfo = UDF_I(table);
590
591	*err = -ENOSPC;
592
593	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
594		adsize = sizeof(struct short_ad);
595	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
596		adsize = sizeof(struct long_ad);
597	else
598		return newblock;
599
600	mutex_lock(&sbi->s_alloc_mutex);
601	if (goal >= sbi->s_partmaps[partition].s_partition_len)
602		goal = 0;
603
604	/* We search for the closest matching block to goal. If we find
605	   a exact hit, we stop. Otherwise we keep going till we run out
606	   of extents. We store the buffer_head, bloc, and extoffset
607	   of the current closest match and use that when we are done.
608	 */
609	epos.offset = sizeof(struct unallocSpaceEntry);
610	epos.block = iinfo->i_location;
611	epos.bh = goal_epos.bh = NULL;
612
613	while (spread &&
614	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
615		if (goal >= eloc.logicalBlockNum) {
616			if (goal < eloc.logicalBlockNum +
617					(elen >> sb->s_blocksize_bits))
618				nspread = 0;
619			else
620				nspread = goal - eloc.logicalBlockNum -
621					(elen >> sb->s_blocksize_bits);
622		} else {
623			nspread = eloc.logicalBlockNum - goal;
624		}
625
626		if (nspread < spread) {
627			spread = nspread;
628			if (goal_epos.bh != epos.bh) {
629				brelse(goal_epos.bh);
630				goal_epos.bh = epos.bh;
631				get_bh(goal_epos.bh);
632			}
633			goal_epos.block = epos.block;
634			goal_epos.offset = epos.offset - adsize;
635			goal_eloc = eloc;
636			goal_elen = (etype << 30) | elen;
637		}
638	}
639
640	brelse(epos.bh);
641
642	if (spread == 0xFFFFFFFF) {
643		brelse(goal_epos.bh);
644		mutex_unlock(&sbi->s_alloc_mutex);
645		return 0;
646	}
647
648	/* Only allocate blocks from the beginning of the extent.
649	   That way, we only delete (empty) extents, never have to insert an
650	   extent because of splitting */
651	/* This works, but very poorly.... */
652
653	newblock = goal_eloc.logicalBlockNum;
654	goal_eloc.logicalBlockNum++;
655	goal_elen -= sb->s_blocksize;
656
657	if (goal_elen)
658		udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
659	else
660		udf_delete_aext(table, goal_epos);
661	brelse(goal_epos.bh);
662
663	udf_add_free_space(sb, partition, -1);
664
665	mutex_unlock(&sbi->s_alloc_mutex);
666	*err = 0;
667	return newblock;
668}
669
670void udf_free_blocks(struct super_block *sb, struct inode *inode,
671		     struct kernel_lb_addr *bloc, uint32_t offset,
672		     uint32_t count)
673{
674	uint16_t partition = bloc->partitionReferenceNum;
675	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
676
677	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
678		udf_bitmap_free_blocks(sb, map->s_uspace.s_bitmap,
679				       bloc, offset, count);
680	} else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
681		udf_table_free_blocks(sb, map->s_uspace.s_table,
682				      bloc, offset, count);
 
 
 
 
 
 
683	}
684
685	if (inode) {
686		inode_sub_bytes(inode,
687				((sector_t)count) << sb->s_blocksize_bits);
688	}
689}
690
691inline int udf_prealloc_blocks(struct super_block *sb,
692			       struct inode *inode,
693			       uint16_t partition, uint32_t first_block,
694			       uint32_t block_count)
695{
696	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
697	int allocated;
698
699	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
700		allocated = udf_bitmap_prealloc_blocks(sb,
701						       map->s_uspace.s_bitmap,
702						       partition, first_block,
703						       block_count);
704	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
705		allocated = udf_table_prealloc_blocks(sb,
706						      map->s_uspace.s_table,
707						      partition, first_block,
708						      block_count);
 
 
 
 
 
 
 
 
 
 
709	else
710		return 0;
711
712	if (inode && allocated > 0)
713		inode_add_bytes(inode, allocated << sb->s_blocksize_bits);
714	return allocated;
715}
716
717inline udf_pblk_t udf_new_block(struct super_block *sb,
718			 struct inode *inode,
719			 uint16_t partition, uint32_t goal, int *err)
720{
721	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
722	udf_pblk_t block;
723
724	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
725		block = udf_bitmap_new_block(sb,
726					     map->s_uspace.s_bitmap,
727					     partition, goal, err);
728	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
729		block = udf_table_new_block(sb,
730					    map->s_uspace.s_table,
 
 
 
 
 
 
 
 
731					    partition, goal, err);
732	else {
733		*err = -EIO;
734		return 0;
735	}
736	if (inode && block)
737		inode_add_bytes(inode, sb->s_blocksize);
738	return block;
739}