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 (%d) > 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("%d < %d || %d + %d > %d\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 %ld already set\n", bit + i);
155				udf_debug("byte=%2x\n",
156					  ((char *)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 int 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, block, block_group, group_start;
227	int end_goal, nr_groups, bitmap_nr, i;
228	struct buffer_head *bh = NULL;
229	char *ptr;
230	int newblock = 0;
231
232	*err = -ENOSPC;
233	mutex_lock(&sbi->s_alloc_mutex);
234
235repeat:
236	if (goal >= sbi->s_partmaps[partition].s_partition_len)
237		goal = 0;
238
239	nr_groups = bitmap->s_nr_groups;
240	block = goal + (sizeof(struct spaceBitmapDesc) << 3);
241	block_group = block >> (sb->s_blocksize_bits + 3);
242	group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
243
244	bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
245	if (bitmap_nr < 0)
246		goto error_return;
247	bh = bitmap->s_block_bitmap[bitmap_nr];
248	ptr = memscan((char *)bh->b_data + group_start, 0xFF,
249		      sb->s_blocksize - group_start);
250
251	if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
252		bit = block % (sb->s_blocksize << 3);
253		if (udf_test_bit(bit, bh->b_data))
254			goto got_block;
255
256		end_goal = (bit + 63) & ~63;
257		bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
258		if (bit < end_goal)
259			goto got_block;
260
261		ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
262			      sb->s_blocksize - ((bit + 7) >> 3));
263		newbit = (ptr - ((char *)bh->b_data)) << 3;
264		if (newbit < sb->s_blocksize << 3) {
265			bit = newbit;
266			goto search_back;
267		}
268
269		newbit = udf_find_next_one_bit(bh->b_data,
270					       sb->s_blocksize << 3, bit);
271		if (newbit < sb->s_blocksize << 3) {
272			bit = newbit;
273			goto got_block;
274		}
275	}
276
277	for (i = 0; i < (nr_groups * 2); i++) {
278		block_group++;
279		if (block_group >= nr_groups)
280			block_group = 0;
281		group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
282
283		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
284		if (bitmap_nr < 0)
285			goto error_return;
286		bh = bitmap->s_block_bitmap[bitmap_nr];
287		if (i < nr_groups) {
288			ptr = memscan((char *)bh->b_data + group_start, 0xFF,
289				      sb->s_blocksize - group_start);
290			if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
291				bit = (ptr - ((char *)bh->b_data)) << 3;
292				break;
293			}
294		} else {
295			bit = udf_find_next_one_bit(bh->b_data,
296						    sb->s_blocksize << 3,
297						    group_start << 3);
298			if (bit < sb->s_blocksize << 3)
299				break;
300		}
301	}
302	if (i >= (nr_groups * 2)) {
303		mutex_unlock(&sbi->s_alloc_mutex);
304		return newblock;
305	}
306	if (bit < sb->s_blocksize << 3)
307		goto search_back;
308	else
309		bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
310					    group_start << 3);
311	if (bit >= sb->s_blocksize << 3) {
312		mutex_unlock(&sbi->s_alloc_mutex);
313		return 0;
314	}
315
316search_back:
317	i = 0;
318	while (i < 7 && bit > (group_start << 3) &&
319	       udf_test_bit(bit - 1, bh->b_data)) {
320		++i;
321		--bit;
322	}
323
324got_block:
325	newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
326		(sizeof(struct spaceBitmapDesc) << 3);
327
328	if (!udf_clear_bit(bit, bh->b_data)) {
329		udf_debug("bit already cleared for block %d\n", bit);
330		goto repeat;
331	}
332
333	mark_buffer_dirty(bh);
334
335	udf_add_free_space(sb, partition, -1);
336	mutex_unlock(&sbi->s_alloc_mutex);
337	*err = 0;
338	return newblock;
339
340error_return:
341	*err = -EIO;
342	mutex_unlock(&sbi->s_alloc_mutex);
343	return 0;
344}
345
346static void udf_table_free_blocks(struct super_block *sb,
347				  struct inode *table,
348				  struct kernel_lb_addr *bloc,
349				  uint32_t offset,
350				  uint32_t count)
351{
352	struct udf_sb_info *sbi = UDF_SB(sb);
353	struct udf_part_map *partmap;
354	uint32_t start, end;
355	uint32_t elen;
356	struct kernel_lb_addr eloc;
357	struct extent_position oepos, epos;
358	int8_t etype;
359	struct udf_inode_info *iinfo;
360
361	mutex_lock(&sbi->s_alloc_mutex);
362	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
363	if (bloc->logicalBlockNum + count < count ||
364	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
365		udf_debug("%d < %d || %d + %d > %d\n",
366			  bloc->logicalBlockNum, 0,
367			  bloc->logicalBlockNum, count,
368			  partmap->s_partition_len);
369		goto error_return;
370	}
371
372	iinfo = UDF_I(table);
373	udf_add_free_space(sb, sbi->s_partition, count);
374
375	start = bloc->logicalBlockNum + offset;
376	end = bloc->logicalBlockNum + offset + count - 1;
377
378	epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
379	elen = 0;
380	epos.block = oepos.block = iinfo->i_location;
381	epos.bh = oepos.bh = NULL;
382
383	while (count &&
384	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
385		if (((eloc.logicalBlockNum +
386			(elen >> sb->s_blocksize_bits)) == start)) {
387			if ((0x3FFFFFFF - elen) <
388					(count << sb->s_blocksize_bits)) {
389				uint32_t tmp = ((0x3FFFFFFF - elen) >>
390							sb->s_blocksize_bits);
391				count -= tmp;
392				start += tmp;
393				elen = (etype << 30) |
394					(0x40000000 - sb->s_blocksize);
395			} else {
396				elen = (etype << 30) |
397					(elen +
398					(count << sb->s_blocksize_bits));
399				start += count;
400				count = 0;
401			}
402			udf_write_aext(table, &oepos, &eloc, elen, 1);
403		} else if (eloc.logicalBlockNum == (end + 1)) {
404			if ((0x3FFFFFFF - elen) <
405					(count << sb->s_blocksize_bits)) {
406				uint32_t tmp = ((0x3FFFFFFF - elen) >>
407						sb->s_blocksize_bits);
408				count -= tmp;
409				end -= tmp;
410				eloc.logicalBlockNum -= tmp;
411				elen = (etype << 30) |
412					(0x40000000 - sb->s_blocksize);
413			} else {
414				eloc.logicalBlockNum = start;
415				elen = (etype << 30) |
416					(elen +
417					(count << sb->s_blocksize_bits));
418				end -= count;
419				count = 0;
420			}
421			udf_write_aext(table, &oepos, &eloc, elen, 1);
422		}
423
424		if (epos.bh != oepos.bh) {
425			oepos.block = epos.block;
426			brelse(oepos.bh);
427			get_bh(epos.bh);
428			oepos.bh = epos.bh;
429			oepos.offset = 0;
430		} else {
431			oepos.offset = epos.offset;
432		}
433	}
434
435	if (count) {
436		/*
437		 * NOTE: we CANNOT use udf_add_aext here, as it can try to
438		 * allocate a new block, and since we hold the super block
439		 * lock already very bad things would happen :)
440		 *
441		 * We copy the behavior of udf_add_aext, but instead of
442		 * trying to allocate a new block close to the existing one,
443		 * we just steal a block from the extent we are trying to add.
444		 *
445		 * It would be nice if the blocks were close together, but it
446		 * isn't required.
447		 */
448
449		int adsize;
450		struct short_ad *sad = NULL;
451		struct long_ad *lad = NULL;
452		struct allocExtDesc *aed;
453
454		eloc.logicalBlockNum = start;
455		elen = EXT_RECORDED_ALLOCATED |
456			(count << sb->s_blocksize_bits);
457
458		if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
459			adsize = sizeof(struct short_ad);
460		else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
461			adsize = sizeof(struct long_ad);
462		else {
463			brelse(oepos.bh);
464			brelse(epos.bh);
465			goto error_return;
466		}
467
468		if (epos.offset + (2 * adsize) > sb->s_blocksize) {
469			unsigned char *sptr, *dptr;
470			int loffset;
471
472			brelse(oepos.bh);
473			oepos = epos;
474
475			/* Steal a block from the extent being free'd */
476			epos.block.logicalBlockNum = eloc.logicalBlockNum;
477			eloc.logicalBlockNum++;
478			elen -= sb->s_blocksize;
479
480			epos.bh = udf_tread(sb,
481					udf_get_lb_pblock(sb, &epos.block, 0));
482			if (!epos.bh) {
483				brelse(oepos.bh);
484				goto error_return;
485			}
486			aed = (struct allocExtDesc *)(epos.bh->b_data);
487			aed->previousAllocExtLocation =
488				cpu_to_le32(oepos.block.logicalBlockNum);
489			if (epos.offset + adsize > sb->s_blocksize) {
490				loffset = epos.offset;
491				aed->lengthAllocDescs = cpu_to_le32(adsize);
492				sptr = iinfo->i_ext.i_data + epos.offset
493								- adsize;
494				dptr = epos.bh->b_data +
495					sizeof(struct allocExtDesc);
496				memcpy(dptr, sptr, adsize);
497				epos.offset = sizeof(struct allocExtDesc) +
498						adsize;
499			} else {
500				loffset = epos.offset + adsize;
501				aed->lengthAllocDescs = cpu_to_le32(0);
502				if (oepos.bh) {
503					sptr = oepos.bh->b_data + epos.offset;
504					aed = (struct allocExtDesc *)
505						oepos.bh->b_data;
506					le32_add_cpu(&aed->lengthAllocDescs,
507							adsize);
508				} else {
509					sptr = iinfo->i_ext.i_data +
510								epos.offset;
511					iinfo->i_lenAlloc += adsize;
512					mark_inode_dirty(table);
513				}
514				epos.offset = sizeof(struct allocExtDesc);
515			}
516			if (sbi->s_udfrev >= 0x0200)
517				udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
518					    3, 1, epos.block.logicalBlockNum,
519					    sizeof(struct tag));
520			else
521				udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
522					    2, 1, epos.block.logicalBlockNum,
523					    sizeof(struct tag));
524
525			switch (iinfo->i_alloc_type) {
526			case ICBTAG_FLAG_AD_SHORT:
527				sad = (struct short_ad *)sptr;
528				sad->extLength = cpu_to_le32(
529					EXT_NEXT_EXTENT_ALLOCDECS |
530					sb->s_blocksize);
531				sad->extPosition =
532					cpu_to_le32(epos.block.logicalBlockNum);
533				break;
534			case ICBTAG_FLAG_AD_LONG:
535				lad = (struct long_ad *)sptr;
536				lad->extLength = cpu_to_le32(
537					EXT_NEXT_EXTENT_ALLOCDECS |
538					sb->s_blocksize);
539				lad->extLocation =
540					cpu_to_lelb(epos.block);
541				break;
542			}
543			if (oepos.bh) {
544				udf_update_tag(oepos.bh->b_data, loffset);
545				mark_buffer_dirty(oepos.bh);
546			} else {
547				mark_inode_dirty(table);
548			}
549		}
550
551		/* It's possible that stealing the block emptied the extent */
552		if (elen) {
553			udf_write_aext(table, &epos, &eloc, elen, 1);
554
555			if (!epos.bh) {
556				iinfo->i_lenAlloc += adsize;
557				mark_inode_dirty(table);
558			} else {
559				aed = (struct allocExtDesc *)epos.bh->b_data;
560				le32_add_cpu(&aed->lengthAllocDescs, adsize);
561				udf_update_tag(epos.bh->b_data, epos.offset);
562				mark_buffer_dirty(epos.bh);
563			}
564		}
565	}
566
567	brelse(epos.bh);
568	brelse(oepos.bh);
569
570error_return:
571	mutex_unlock(&sbi->s_alloc_mutex);
572	return;
573}
574
575static int udf_table_prealloc_blocks(struct super_block *sb,
576				     struct inode *table, uint16_t partition,
577				     uint32_t first_block, uint32_t block_count)
578{
579	struct udf_sb_info *sbi = UDF_SB(sb);
580	int alloc_count = 0;
581	uint32_t elen, adsize;
582	struct kernel_lb_addr eloc;
583	struct extent_position epos;
584	int8_t etype = -1;
585	struct udf_inode_info *iinfo;
586
587	if (first_block >= sbi->s_partmaps[partition].s_partition_len)
588		return 0;
589
590	iinfo = UDF_I(table);
591	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
592		adsize = sizeof(struct short_ad);
593	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
594		adsize = sizeof(struct long_ad);
595	else
596		return 0;
597
598	mutex_lock(&sbi->s_alloc_mutex);
599	epos.offset = sizeof(struct unallocSpaceEntry);
600	epos.block = iinfo->i_location;
601	epos.bh = NULL;
602	eloc.logicalBlockNum = 0xFFFFFFFF;
603
604	while (first_block != eloc.logicalBlockNum &&
605	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
606		udf_debug("eloc=%d, elen=%d, first_block=%d\n",
607			  eloc.logicalBlockNum, elen, first_block);
608		; /* empty loop body */
609	}
610
611	if (first_block == eloc.logicalBlockNum) {
612		epos.offset -= adsize;
613
614		alloc_count = (elen >> sb->s_blocksize_bits);
615		if (alloc_count > block_count) {
616			alloc_count = block_count;
617			eloc.logicalBlockNum += alloc_count;
618			elen -= (alloc_count << sb->s_blocksize_bits);
619			udf_write_aext(table, &epos, &eloc,
620					(etype << 30) | elen, 1);
621		} else
622			udf_delete_aext(table, epos, eloc,
623					(etype << 30) | elen);
624	} else {
625		alloc_count = 0;
626	}
627
628	brelse(epos.bh);
629
630	if (alloc_count)
631		udf_add_free_space(sb, partition, -alloc_count);
632	mutex_unlock(&sbi->s_alloc_mutex);
633	return alloc_count;
634}
635
636static int udf_table_new_block(struct super_block *sb,
637			       struct inode *table, uint16_t partition,
638			       uint32_t goal, int *err)
639{
640	struct udf_sb_info *sbi = UDF_SB(sb);
641	uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
642	uint32_t newblock = 0, adsize;
643	uint32_t elen, goal_elen = 0;
644	struct kernel_lb_addr eloc, uninitialized_var(goal_eloc);
645	struct extent_position epos, goal_epos;
646	int8_t etype;
647	struct udf_inode_info *iinfo = UDF_I(table);
648
649	*err = -ENOSPC;
650
651	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
652		adsize = sizeof(struct short_ad);
653	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
654		adsize = sizeof(struct long_ad);
655	else
656		return newblock;
657
658	mutex_lock(&sbi->s_alloc_mutex);
659	if (goal >= sbi->s_partmaps[partition].s_partition_len)
660		goal = 0;
661
662	/* We search for the closest matching block to goal. If we find
663	   a exact hit, we stop. Otherwise we keep going till we run out
664	   of extents. We store the buffer_head, bloc, and extoffset
665	   of the current closest match and use that when we are done.
666	 */
667	epos.offset = sizeof(struct unallocSpaceEntry);
668	epos.block = iinfo->i_location;
669	epos.bh = goal_epos.bh = NULL;
670
671	while (spread &&
672	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
673		if (goal >= eloc.logicalBlockNum) {
674			if (goal < eloc.logicalBlockNum +
675					(elen >> sb->s_blocksize_bits))
676				nspread = 0;
677			else
678				nspread = goal - eloc.logicalBlockNum -
679					(elen >> sb->s_blocksize_bits);
680		} else {
681			nspread = eloc.logicalBlockNum - goal;
682		}
683
684		if (nspread < spread) {
685			spread = nspread;
686			if (goal_epos.bh != epos.bh) {
687				brelse(goal_epos.bh);
688				goal_epos.bh = epos.bh;
689				get_bh(goal_epos.bh);
690			}
691			goal_epos.block = epos.block;
692			goal_epos.offset = epos.offset - adsize;
693			goal_eloc = eloc;
694			goal_elen = (etype << 30) | elen;
695		}
696	}
697
698	brelse(epos.bh);
699
700	if (spread == 0xFFFFFFFF) {
701		brelse(goal_epos.bh);
702		mutex_unlock(&sbi->s_alloc_mutex);
703		return 0;
704	}
705
706	/* Only allocate blocks from the beginning of the extent.
707	   That way, we only delete (empty) extents, never have to insert an
708	   extent because of splitting */
709	/* This works, but very poorly.... */
710
711	newblock = goal_eloc.logicalBlockNum;
712	goal_eloc.logicalBlockNum++;
713	goal_elen -= sb->s_blocksize;
714
715	if (goal_elen)
716		udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
717	else
718		udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
719	brelse(goal_epos.bh);
720
721	udf_add_free_space(sb, partition, -1);
722
723	mutex_unlock(&sbi->s_alloc_mutex);
724	*err = 0;
725	return newblock;
726}
727
728void udf_free_blocks(struct super_block *sb, struct inode *inode,
729		     struct kernel_lb_addr *bloc, uint32_t offset,
730		     uint32_t count)
731{
732	uint16_t partition = bloc->partitionReferenceNum;
733	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
734
735	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
736		udf_bitmap_free_blocks(sb, map->s_uspace.s_bitmap,
737				       bloc, offset, count);
738	} else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
739		udf_table_free_blocks(sb, map->s_uspace.s_table,
740				      bloc, offset, count);
741	} else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
742		udf_bitmap_free_blocks(sb, map->s_fspace.s_bitmap,
743				       bloc, offset, count);
744	} else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
745		udf_table_free_blocks(sb, map->s_fspace.s_table,
746				      bloc, offset, count);
747	}
748
749	if (inode) {
750		inode_sub_bytes(inode,
751				((sector_t)count) << sb->s_blocksize_bits);
752	}
753}
754
755inline int udf_prealloc_blocks(struct super_block *sb,
756			       struct inode *inode,
757			       uint16_t partition, uint32_t first_block,
758			       uint32_t block_count)
759{
760	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
761	int allocated;
762
763	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
764		allocated = udf_bitmap_prealloc_blocks(sb,
765						       map->s_uspace.s_bitmap,
766						       partition, first_block,
767						       block_count);
768	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
769		allocated = udf_table_prealloc_blocks(sb,
770						      map->s_uspace.s_table,
771						      partition, first_block,
772						      block_count);
773	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
774		allocated = udf_bitmap_prealloc_blocks(sb,
775						       map->s_fspace.s_bitmap,
776						       partition, first_block,
777						       block_count);
778	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
779		allocated = udf_table_prealloc_blocks(sb,
780						      map->s_fspace.s_table,
781						      partition, first_block,
782						      block_count);
783	else
784		return 0;
785
786	if (inode && allocated > 0)
787		inode_add_bytes(inode, allocated << sb->s_blocksize_bits);
788	return allocated;
789}
790
791inline int udf_new_block(struct super_block *sb,
792			 struct inode *inode,
793			 uint16_t partition, uint32_t goal, int *err)
794{
795	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
796	int block;
797
798	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
799		block = udf_bitmap_new_block(sb,
800					     map->s_uspace.s_bitmap,
801					     partition, goal, err);
802	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
803		block = udf_table_new_block(sb,
804					    map->s_uspace.s_table,
805					    partition, goal, err);
806	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
807		block = udf_bitmap_new_block(sb,
808					     map->s_fspace.s_bitmap,
809					     partition, goal, err);
810	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
811		block = udf_table_new_block(sb,
812					    map->s_fspace.s_table,
813					    partition, goal, err);
814	else {
815		*err = -EIO;
816		return 0;
817	}
818	if (inode && block)
819		inode_add_bytes(inode, sb->s_blocksize);
820	return block;
821}
822