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/buffer_head.h>
25#include <linux/bitops.h>
26
27#include "udf_i.h"
28#include "udf_sb.h"
29
30#define udf_clear_bit(nr, addr) ext2_clear_bit(nr, addr)
31#define udf_set_bit(nr, addr) ext2_set_bit(nr, addr)
32#define udf_test_bit(nr, addr) ext2_test_bit(nr, addr)
33#define udf_find_next_one_bit(addr, size, offset) \
34		ext2_find_next_bit(addr, size, offset)
35
36static int read_block_bitmap(struct super_block *sb,
37			     struct udf_bitmap *bitmap, unsigned int block,
38			     unsigned long bitmap_nr)
39{
40	struct buffer_head *bh = NULL;
41	int retval = 0;
42	struct kernel_lb_addr loc;
43
44	loc.logicalBlockNum = bitmap->s_extPosition;
45	loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
46
47	bh = udf_tread(sb, udf_get_lb_pblock(sb, &loc, block));
48	if (!bh)
49		retval = -EIO;
50
51	bitmap->s_block_bitmap[bitmap_nr] = bh;
52	return retval;
53}
54
55static int __load_block_bitmap(struct super_block *sb,
56			       struct udf_bitmap *bitmap,
57			       unsigned int block_group)
58{
59	int retval = 0;
60	int nr_groups = bitmap->s_nr_groups;
61
62	if (block_group >= nr_groups) {
63		udf_debug("block_group (%d) > nr_groups (%d)\n", block_group,
64			  nr_groups);
65	}
66
67	if (bitmap->s_block_bitmap[block_group]) {
68		return block_group;
69	} else {
70		retval = read_block_bitmap(sb, bitmap, block_group,
71					   block_group);
72		if (retval < 0)
73			return retval;
74		return block_group;
75	}
76}
77
78static inline int load_block_bitmap(struct super_block *sb,
79				    struct udf_bitmap *bitmap,
80				    unsigned int block_group)
81{
82	int slot;
83
84	slot = __load_block_bitmap(sb, bitmap, block_group);
85
86	if (slot < 0)
87		return slot;
88
89	if (!bitmap->s_block_bitmap[slot])
90		return -EIO;
91
92	return slot;
93}
94
95static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
96{
97	struct udf_sb_info *sbi = UDF_SB(sb);
98	struct logicalVolIntegrityDesc *lvid;
99
100	if (!sbi->s_lvid_bh)
101		return;
102
103	lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
104	le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
105	udf_updated_lvid(sb);
106}
107
108static void udf_bitmap_free_blocks(struct super_block *sb,
109				   struct inode *inode,
110				   struct udf_bitmap *bitmap,
111				   struct kernel_lb_addr *bloc,
112				   uint32_t offset,
113				   uint32_t count)
114{
115	struct udf_sb_info *sbi = UDF_SB(sb);
116	struct buffer_head *bh = NULL;
117	struct udf_part_map *partmap;
118	unsigned long block;
119	unsigned long block_group;
120	unsigned long bit;
121	unsigned long i;
122	int bitmap_nr;
123	unsigned long overflow;
124
125	mutex_lock(&sbi->s_alloc_mutex);
126	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
127	if (bloc->logicalBlockNum + count < count ||
128	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
129		udf_debug("%d < %d || %d + %d > %d\n",
130			  bloc->logicalBlockNum, 0, bloc->logicalBlockNum,
131			  count, partmap->s_partition_len);
132		goto error_return;
133	}
134
135	block = bloc->logicalBlockNum + offset +
136		(sizeof(struct spaceBitmapDesc) << 3);
137
138	do {
139		overflow = 0;
140		block_group = block >> (sb->s_blocksize_bits + 3);
141		bit = block % (sb->s_blocksize << 3);
142
143		/*
144		* Check to see if we are freeing blocks across a group boundary.
145		*/
146		if (bit + count > (sb->s_blocksize << 3)) {
147			overflow = bit + count - (sb->s_blocksize << 3);
148			count -= overflow;
149		}
150		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
151		if (bitmap_nr < 0)
152			goto error_return;
153
154		bh = bitmap->s_block_bitmap[bitmap_nr];
155		for (i = 0; i < count; i++) {
156			if (udf_set_bit(bit + i, bh->b_data)) {
157				udf_debug("bit %ld already set\n", bit + i);
158				udf_debug("byte=%2x\n",
159					((char *)bh->b_data)[(bit + i) >> 3]);
160			} else {
161				udf_add_free_space(sb, sbi->s_partition, 1);
162			}
163		}
164		mark_buffer_dirty(bh);
165		if (overflow) {
166			block += count;
167			count = overflow;
168		}
169	} while (overflow);
170
171error_return:
172	mutex_unlock(&sbi->s_alloc_mutex);
173}
174
175static int udf_bitmap_prealloc_blocks(struct super_block *sb,
176				      struct inode *inode,
177				      struct udf_bitmap *bitmap,
178				      uint16_t partition, uint32_t first_block,
179				      uint32_t block_count)
180{
181	struct udf_sb_info *sbi = UDF_SB(sb);
182	int alloc_count = 0;
183	int bit, block, block_group, group_start;
184	int nr_groups, bitmap_nr;
185	struct buffer_head *bh;
186	__u32 part_len;
187
188	mutex_lock(&sbi->s_alloc_mutex);
189	part_len = sbi->s_partmaps[partition].s_partition_len;
190	if (first_block >= part_len)
191		goto out;
192
193	if (first_block + block_count > part_len)
194		block_count = part_len - first_block;
195
196	do {
197		nr_groups = udf_compute_nr_groups(sb, partition);
198		block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
199		block_group = block >> (sb->s_blocksize_bits + 3);
200		group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
201
202		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
203		if (bitmap_nr < 0)
204			goto out;
205		bh = bitmap->s_block_bitmap[bitmap_nr];
206
207		bit = block % (sb->s_blocksize << 3);
208
209		while (bit < (sb->s_blocksize << 3) && block_count > 0) {
210			if (!udf_clear_bit(bit, bh->b_data))
211				goto out;
212			block_count--;
213			alloc_count++;
214			bit++;
215			block++;
216		}
217		mark_buffer_dirty(bh);
218	} while (block_count > 0);
219
220out:
221	udf_add_free_space(sb, partition, -alloc_count);
222	mutex_unlock(&sbi->s_alloc_mutex);
223	return alloc_count;
224}
225
226static int udf_bitmap_new_block(struct super_block *sb,
227				struct inode *inode,
228				struct udf_bitmap *bitmap, uint16_t partition,
229				uint32_t goal, int *err)
230{
231	struct udf_sb_info *sbi = UDF_SB(sb);
232	int newbit, bit = 0, block, block_group, group_start;
233	int end_goal, nr_groups, bitmap_nr, i;
234	struct buffer_head *bh = NULL;
235	char *ptr;
236	int newblock = 0;
237
238	*err = -ENOSPC;
239	mutex_lock(&sbi->s_alloc_mutex);
240
241repeat:
242	if (goal >= sbi->s_partmaps[partition].s_partition_len)
243		goal = 0;
244
245	nr_groups = bitmap->s_nr_groups;
246	block = goal + (sizeof(struct spaceBitmapDesc) << 3);
247	block_group = block >> (sb->s_blocksize_bits + 3);
248	group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
249
250	bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
251	if (bitmap_nr < 0)
252		goto error_return;
253	bh = bitmap->s_block_bitmap[bitmap_nr];
254	ptr = memscan((char *)bh->b_data + group_start, 0xFF,
255		      sb->s_blocksize - group_start);
256
257	if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
258		bit = block % (sb->s_blocksize << 3);
259		if (udf_test_bit(bit, bh->b_data))
260			goto got_block;
261
262		end_goal = (bit + 63) & ~63;
263		bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
264		if (bit < end_goal)
265			goto got_block;
266
267		ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
268			      sb->s_blocksize - ((bit + 7) >> 3));
269		newbit = (ptr - ((char *)bh->b_data)) << 3;
270		if (newbit < sb->s_blocksize << 3) {
271			bit = newbit;
272			goto search_back;
273		}
274
275		newbit = udf_find_next_one_bit(bh->b_data,
276					       sb->s_blocksize << 3, bit);
277		if (newbit < sb->s_blocksize << 3) {
278			bit = newbit;
279			goto got_block;
280		}
281	}
282
283	for (i = 0; i < (nr_groups * 2); i++) {
284		block_group++;
285		if (block_group >= nr_groups)
286			block_group = 0;
287		group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
288
289		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
290		if (bitmap_nr < 0)
291			goto error_return;
292		bh = bitmap->s_block_bitmap[bitmap_nr];
293		if (i < nr_groups) {
294			ptr = memscan((char *)bh->b_data + group_start, 0xFF,
295				      sb->s_blocksize - group_start);
296			if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
297				bit = (ptr - ((char *)bh->b_data)) << 3;
298				break;
299			}
300		} else {
301			bit = udf_find_next_one_bit((char *)bh->b_data,
302						    sb->s_blocksize << 3,
303						    group_start << 3);
304			if (bit < sb->s_blocksize << 3)
305				break;
306		}
307	}
308	if (i >= (nr_groups * 2)) {
309		mutex_unlock(&sbi->s_alloc_mutex);
310		return newblock;
311	}
312	if (bit < sb->s_blocksize << 3)
313		goto search_back;
314	else
315		bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
316					    group_start << 3);
317	if (bit >= sb->s_blocksize << 3) {
318		mutex_unlock(&sbi->s_alloc_mutex);
319		return 0;
320	}
321
322search_back:
323	i = 0;
324	while (i < 7 && bit > (group_start << 3) &&
325	       udf_test_bit(bit - 1, bh->b_data)) {
326		++i;
327		--bit;
328	}
329
330got_block:
331	newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
332		(sizeof(struct spaceBitmapDesc) << 3);
333
334	if (!udf_clear_bit(bit, bh->b_data)) {
335		udf_debug("bit already cleared for block %d\n", bit);
336		goto repeat;
337	}
338
339	mark_buffer_dirty(bh);
340
341	udf_add_free_space(sb, partition, -1);
342	mutex_unlock(&sbi->s_alloc_mutex);
343	*err = 0;
344	return newblock;
345
346error_return:
347	*err = -EIO;
348	mutex_unlock(&sbi->s_alloc_mutex);
349	return 0;
350}
351
352static void udf_table_free_blocks(struct super_block *sb,
353				  struct inode *inode,
354				  struct inode *table,
355				  struct kernel_lb_addr *bloc,
356				  uint32_t offset,
357				  uint32_t count)
358{
359	struct udf_sb_info *sbi = UDF_SB(sb);
360	struct udf_part_map *partmap;
361	uint32_t start, end;
362	uint32_t elen;
363	struct kernel_lb_addr eloc;
364	struct extent_position oepos, epos;
365	int8_t etype;
366	int i;
367	struct udf_inode_info *iinfo;
368
369	mutex_lock(&sbi->s_alloc_mutex);
370	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
371	if (bloc->logicalBlockNum + count < count ||
372	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
373		udf_debug("%d < %d || %d + %d > %d\n",
374			  bloc->logicalBlockNum, 0, bloc->logicalBlockNum, count,
375			  partmap->s_partition_len);
376		goto error_return;
377	}
378
379	iinfo = UDF_I(table);
380	udf_add_free_space(sb, sbi->s_partition, count);
381
382	start = bloc->logicalBlockNum + offset;
383	end = bloc->logicalBlockNum + offset + count - 1;
384
385	epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
386	elen = 0;
387	epos.block = oepos.block = iinfo->i_location;
388	epos.bh = oepos.bh = NULL;
389
390	while (count &&
391	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
392		if (((eloc.logicalBlockNum +
393			(elen >> sb->s_blocksize_bits)) == start)) {
394			if ((0x3FFFFFFF - elen) <
395					(count << sb->s_blocksize_bits)) {
396				uint32_t tmp = ((0x3FFFFFFF - elen) >>
397							sb->s_blocksize_bits);
398				count -= tmp;
399				start += tmp;
400				elen = (etype << 30) |
401					(0x40000000 - sb->s_blocksize);
402			} else {
403				elen = (etype << 30) |
404					(elen +
405					(count << sb->s_blocksize_bits));
406				start += count;
407				count = 0;
408			}
409			udf_write_aext(table, &oepos, &eloc, elen, 1);
410		} else if (eloc.logicalBlockNum == (end + 1)) {
411			if ((0x3FFFFFFF - elen) <
412					(count << sb->s_blocksize_bits)) {
413				uint32_t tmp = ((0x3FFFFFFF - elen) >>
414						sb->s_blocksize_bits);
415				count -= tmp;
416				end -= tmp;
417				eloc.logicalBlockNum -= tmp;
418				elen = (etype << 30) |
419					(0x40000000 - sb->s_blocksize);
420			} else {
421				eloc.logicalBlockNum = start;
422				elen = (etype << 30) |
423					(elen +
424					(count << sb->s_blocksize_bits));
425				end -= count;
426				count = 0;
427			}
428			udf_write_aext(table, &oepos, &eloc, elen, 1);
429		}
430
431		if (epos.bh != oepos.bh) {
432			i = -1;
433			oepos.block = epos.block;
434			brelse(oepos.bh);
435			get_bh(epos.bh);
436			oepos.bh = epos.bh;
437			oepos.offset = 0;
438		} else {
439			oepos.offset = epos.offset;
440		}
441	}
442
443	if (count) {
444		/*
445		 * NOTE: we CANNOT use udf_add_aext here, as it can try to
446		 * allocate a new block, and since we hold the super block
447		 * lock already very bad things would happen :)
448		 *
449		 * We copy the behavior of udf_add_aext, but instead of
450		 * trying to allocate a new block close to the existing one,
451		 * we just steal a block from the extent we are trying to add.
452		 *
453		 * It would be nice if the blocks were close together, but it
454		 * isn't required.
455		 */
456
457		int adsize;
458		struct short_ad *sad = NULL;
459		struct long_ad *lad = NULL;
460		struct allocExtDesc *aed;
461
462		eloc.logicalBlockNum = start;
463		elen = EXT_RECORDED_ALLOCATED |
464			(count << sb->s_blocksize_bits);
465
466		if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
467			adsize = sizeof(struct short_ad);
468		else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
469			adsize = sizeof(struct long_ad);
470		else {
471			brelse(oepos.bh);
472			brelse(epos.bh);
473			goto error_return;
474		}
475
476		if (epos.offset + (2 * adsize) > sb->s_blocksize) {
477			unsigned char *sptr, *dptr;
478			int loffset;
479
480			brelse(oepos.bh);
481			oepos = epos;
482
483			/* Steal a block from the extent being free'd */
484			epos.block.logicalBlockNum = eloc.logicalBlockNum;
485			eloc.logicalBlockNum++;
486			elen -= sb->s_blocksize;
487
488			epos.bh = udf_tread(sb,
489					udf_get_lb_pblock(sb, &epos.block, 0));
490			if (!epos.bh) {
491				brelse(oepos.bh);
492				goto error_return;
493			}
494			aed = (struct allocExtDesc *)(epos.bh->b_data);
495			aed->previousAllocExtLocation =
496				cpu_to_le32(oepos.block.logicalBlockNum);
497			if (epos.offset + adsize > sb->s_blocksize) {
498				loffset = epos.offset;
499				aed->lengthAllocDescs = cpu_to_le32(adsize);
500				sptr = iinfo->i_ext.i_data + epos.offset
501								- adsize;
502				dptr = epos.bh->b_data +
503					sizeof(struct allocExtDesc);
504				memcpy(dptr, sptr, adsize);
505				epos.offset = sizeof(struct allocExtDesc) +
506						adsize;
507			} else {
508				loffset = epos.offset + adsize;
509				aed->lengthAllocDescs = cpu_to_le32(0);
510				if (oepos.bh) {
511					sptr = oepos.bh->b_data + epos.offset;
512					aed = (struct allocExtDesc *)
513						oepos.bh->b_data;
514					le32_add_cpu(&aed->lengthAllocDescs,
515							adsize);
516				} else {
517					sptr = iinfo->i_ext.i_data +
518								epos.offset;
519					iinfo->i_lenAlloc += adsize;
520					mark_inode_dirty(table);
521				}
522				epos.offset = sizeof(struct allocExtDesc);
523			}
524			if (sbi->s_udfrev >= 0x0200)
525				udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
526					    3, 1, epos.block.logicalBlockNum,
527					    sizeof(struct tag));
528			else
529				udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
530					    2, 1, epos.block.logicalBlockNum,
531					    sizeof(struct tag));
532
533			switch (iinfo->i_alloc_type) {
534			case ICBTAG_FLAG_AD_SHORT:
535				sad = (struct short_ad *)sptr;
536				sad->extLength = cpu_to_le32(
537					EXT_NEXT_EXTENT_ALLOCDECS |
538					sb->s_blocksize);
539				sad->extPosition =
540					cpu_to_le32(epos.block.logicalBlockNum);
541				break;
542			case ICBTAG_FLAG_AD_LONG:
543				lad = (struct long_ad *)sptr;
544				lad->extLength = cpu_to_le32(
545					EXT_NEXT_EXTENT_ALLOCDECS |
546					sb->s_blocksize);
547				lad->extLocation =
548					cpu_to_lelb(epos.block);
549				break;
550			}
551			if (oepos.bh) {
552				udf_update_tag(oepos.bh->b_data, loffset);
553				mark_buffer_dirty(oepos.bh);
554			} else {
555				mark_inode_dirty(table);
556			}
557		}
558
559		/* It's possible that stealing the block emptied the extent */
560		if (elen) {
561			udf_write_aext(table, &epos, &eloc, elen, 1);
562
563			if (!epos.bh) {
564				iinfo->i_lenAlloc += adsize;
565				mark_inode_dirty(table);
566			} else {
567				aed = (struct allocExtDesc *)epos.bh->b_data;
568				le32_add_cpu(&aed->lengthAllocDescs, adsize);
569				udf_update_tag(epos.bh->b_data, epos.offset);
570				mark_buffer_dirty(epos.bh);
571			}
572		}
573	}
574
575	brelse(epos.bh);
576	brelse(oepos.bh);
577
578error_return:
579	mutex_unlock(&sbi->s_alloc_mutex);
580	return;
581}
582
583static int udf_table_prealloc_blocks(struct super_block *sb,
584				     struct inode *inode,
585				     struct inode *table, uint16_t partition,
586				     uint32_t first_block, uint32_t block_count)
587{
588	struct udf_sb_info *sbi = UDF_SB(sb);
589	int alloc_count = 0;
590	uint32_t elen, adsize;
591	struct kernel_lb_addr eloc;
592	struct extent_position epos;
593	int8_t etype = -1;
594	struct udf_inode_info *iinfo;
595
596	if (first_block >= sbi->s_partmaps[partition].s_partition_len)
597		return 0;
598
599	iinfo = UDF_I(table);
600	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
601		adsize = sizeof(struct short_ad);
602	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
603		adsize = sizeof(struct long_ad);
604	else
605		return 0;
606
607	mutex_lock(&sbi->s_alloc_mutex);
608	epos.offset = sizeof(struct unallocSpaceEntry);
609	epos.block = iinfo->i_location;
610	epos.bh = NULL;
611	eloc.logicalBlockNum = 0xFFFFFFFF;
612
613	while (first_block != eloc.logicalBlockNum &&
614	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
615		udf_debug("eloc=%d, elen=%d, first_block=%d\n",
616			  eloc.logicalBlockNum, elen, first_block);
617		; /* empty loop body */
618	}
619
620	if (first_block == eloc.logicalBlockNum) {
621		epos.offset -= adsize;
622
623		alloc_count = (elen >> sb->s_blocksize_bits);
624		if (alloc_count > block_count) {
625			alloc_count = block_count;
626			eloc.logicalBlockNum += alloc_count;
627			elen -= (alloc_count << sb->s_blocksize_bits);
628			udf_write_aext(table, &epos, &eloc,
629					(etype << 30) | elen, 1);
630		} else
631			udf_delete_aext(table, epos, eloc,
632					(etype << 30) | elen);
633	} else {
634		alloc_count = 0;
635	}
636
637	brelse(epos.bh);
638
639	if (alloc_count)
640		udf_add_free_space(sb, partition, -alloc_count);
641	mutex_unlock(&sbi->s_alloc_mutex);
642	return alloc_count;
643}
644
645static int udf_table_new_block(struct super_block *sb,
646			       struct inode *inode,
647			       struct inode *table, uint16_t partition,
648			       uint32_t goal, int *err)
649{
650	struct udf_sb_info *sbi = UDF_SB(sb);
651	uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
652	uint32_t newblock = 0, adsize;
653	uint32_t elen, goal_elen = 0;
654	struct kernel_lb_addr eloc, uninitialized_var(goal_eloc);
655	struct extent_position epos, goal_epos;
656	int8_t etype;
657	struct udf_inode_info *iinfo = UDF_I(table);
658
659	*err = -ENOSPC;
660
661	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
662		adsize = sizeof(struct short_ad);
663	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
664		adsize = sizeof(struct long_ad);
665	else
666		return newblock;
667
668	mutex_lock(&sbi->s_alloc_mutex);
669	if (goal >= sbi->s_partmaps[partition].s_partition_len)
670		goal = 0;
671
672	/* We search for the closest matching block to goal. If we find
673	   a exact hit, we stop. Otherwise we keep going till we run out
674	   of extents. We store the buffer_head, bloc, and extoffset
675	   of the current closest match and use that when we are done.
676	 */
677	epos.offset = sizeof(struct unallocSpaceEntry);
678	epos.block = iinfo->i_location;
679	epos.bh = goal_epos.bh = NULL;
680
681	while (spread &&
682	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
683		if (goal >= eloc.logicalBlockNum) {
684			if (goal < eloc.logicalBlockNum +
685					(elen >> sb->s_blocksize_bits))
686				nspread = 0;
687			else
688				nspread = goal - eloc.logicalBlockNum -
689					(elen >> sb->s_blocksize_bits);
690		} else {
691			nspread = eloc.logicalBlockNum - goal;
692		}
693
694		if (nspread < spread) {
695			spread = nspread;
696			if (goal_epos.bh != epos.bh) {
697				brelse(goal_epos.bh);
698				goal_epos.bh = epos.bh;
699				get_bh(goal_epos.bh);
700			}
701			goal_epos.block = epos.block;
702			goal_epos.offset = epos.offset - adsize;
703			goal_eloc = eloc;
704			goal_elen = (etype << 30) | elen;
705		}
706	}
707
708	brelse(epos.bh);
709
710	if (spread == 0xFFFFFFFF) {
711		brelse(goal_epos.bh);
712		mutex_unlock(&sbi->s_alloc_mutex);
713		return 0;
714	}
715
716	/* Only allocate blocks from the beginning of the extent.
717	   That way, we only delete (empty) extents, never have to insert an
718	   extent because of splitting */
719	/* This works, but very poorly.... */
720
721	newblock = goal_eloc.logicalBlockNum;
722	goal_eloc.logicalBlockNum++;
723	goal_elen -= sb->s_blocksize;
724
725	if (goal_elen)
726		udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
727	else
728		udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
729	brelse(goal_epos.bh);
730
731	udf_add_free_space(sb, partition, -1);
732
733	mutex_unlock(&sbi->s_alloc_mutex);
734	*err = 0;
735	return newblock;
736}
737
738void udf_free_blocks(struct super_block *sb, struct inode *inode,
739		     struct kernel_lb_addr *bloc, uint32_t offset,
740		     uint32_t count)
741{
742	uint16_t partition = bloc->partitionReferenceNum;
743	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
744
745	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
746		udf_bitmap_free_blocks(sb, inode, map->s_uspace.s_bitmap,
747				       bloc, offset, count);
748	} else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
749		udf_table_free_blocks(sb, inode, map->s_uspace.s_table,
750				      bloc, offset, count);
751	} else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
752		udf_bitmap_free_blocks(sb, inode, map->s_fspace.s_bitmap,
753				       bloc, offset, count);
754	} else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
755		udf_table_free_blocks(sb, inode, map->s_fspace.s_table,
756				      bloc, offset, count);
757	}
758}
759
760inline int udf_prealloc_blocks(struct super_block *sb,
761			       struct inode *inode,
762			       uint16_t partition, uint32_t first_block,
763			       uint32_t block_count)
764{
765	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
766
767	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
768		return udf_bitmap_prealloc_blocks(sb, inode,
769						  map->s_uspace.s_bitmap,
770						  partition, first_block,
771						  block_count);
772	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
773		return udf_table_prealloc_blocks(sb, inode,
774						 map->s_uspace.s_table,
775						 partition, first_block,
776						 block_count);
777	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
778		return udf_bitmap_prealloc_blocks(sb, inode,
779						  map->s_fspace.s_bitmap,
780						  partition, first_block,
781						  block_count);
782	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
783		return udf_table_prealloc_blocks(sb, inode,
784						 map->s_fspace.s_table,
785						 partition, first_block,
786						 block_count);
787	else
788		return 0;
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
797	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
798		return udf_bitmap_new_block(sb, inode,
799					   map->s_uspace.s_bitmap,
800					   partition, goal, err);
801	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
802		return udf_table_new_block(sb, inode,
803					   map->s_uspace.s_table,
804					   partition, goal, err);
805	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
806		return udf_bitmap_new_block(sb, inode,
807					    map->s_fspace.s_bitmap,
808					    partition, goal, err);
809	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
810		return udf_table_new_block(sb, inode,
811					   map->s_fspace.s_table,
812					   partition, goal, err);
813	else {
814		*err = -EIO;
815		return 0;
816	}
817}
818