Merge git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6
[linux-2.6] / fs / udf / balloc.c
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/quotaops.h>
25 #include <linux/buffer_head.h>
26 #include <linux/bitops.h>
27
28 #include "udf_i.h"
29 #include "udf_sb.h"
30
31 #define udf_clear_bit(nr, addr) ext2_clear_bit(nr, addr)
32 #define udf_set_bit(nr, addr) ext2_set_bit(nr, addr)
33 #define udf_test_bit(nr, addr) ext2_test_bit(nr, addr)
34 #define udf_find_first_one_bit(addr, size) find_first_one_bit(addr, size)
35 #define udf_find_next_one_bit(addr, size, offset) \
36                 find_next_one_bit(addr, size, offset)
37
38 #define leBPL_to_cpup(x) leNUM_to_cpup(BITS_PER_LONG, x)
39 #define leNUM_to_cpup(x, y) xleNUM_to_cpup(x, y)
40 #define xleNUM_to_cpup(x, y) (le ## x ## _to_cpup(y))
41 #define uintBPL_t uint(BITS_PER_LONG)
42 #define uint(x) xuint(x)
43 #define xuint(x) __le ## x
44
45 static inline int find_next_one_bit(void *addr, int size, int offset)
46 {
47         uintBPL_t *p = ((uintBPL_t *) addr) + (offset / BITS_PER_LONG);
48         int result = offset & ~(BITS_PER_LONG - 1);
49         unsigned long tmp;
50
51         if (offset >= size)
52                 return size;
53         size -= result;
54         offset &= (BITS_PER_LONG - 1);
55         if (offset) {
56                 tmp = leBPL_to_cpup(p++);
57                 tmp &= ~0UL << offset;
58                 if (size < BITS_PER_LONG)
59                         goto found_first;
60                 if (tmp)
61                         goto found_middle;
62                 size -= BITS_PER_LONG;
63                 result += BITS_PER_LONG;
64         }
65         while (size & ~(BITS_PER_LONG - 1)) {
66                 tmp = leBPL_to_cpup(p++);
67                 if (tmp)
68                         goto found_middle;
69                 result += BITS_PER_LONG;
70                 size -= BITS_PER_LONG;
71         }
72         if (!size)
73                 return result;
74         tmp = leBPL_to_cpup(p);
75 found_first:
76         tmp &= ~0UL >> (BITS_PER_LONG - size);
77 found_middle:
78         return result + ffz(~tmp);
79 }
80
81 #define find_first_one_bit(addr, size)\
82         find_next_one_bit((addr), (size), 0)
83
84 static int read_block_bitmap(struct super_block *sb,
85                              struct udf_bitmap *bitmap, unsigned int block,
86                              unsigned long bitmap_nr)
87 {
88         struct buffer_head *bh = NULL;
89         int retval = 0;
90         kernel_lb_addr loc;
91
92         loc.logicalBlockNum = bitmap->s_extPosition;
93         loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
94
95         bh = udf_tread(sb, udf_get_lb_pblock(sb, loc, block));
96         if (!bh)
97                 retval = -EIO;
98
99         bitmap->s_block_bitmap[bitmap_nr] = bh;
100         return retval;
101 }
102
103 static int __load_block_bitmap(struct super_block *sb,
104                                struct udf_bitmap *bitmap,
105                                unsigned int block_group)
106 {
107         int retval = 0;
108         int nr_groups = bitmap->s_nr_groups;
109
110         if (block_group >= nr_groups) {
111                 udf_debug("block_group (%d) > nr_groups (%d)\n", block_group,
112                           nr_groups);
113         }
114
115         if (bitmap->s_block_bitmap[block_group]) {
116                 return block_group;
117         } else {
118                 retval = read_block_bitmap(sb, bitmap, block_group,
119                                            block_group);
120                 if (retval < 0)
121                         return retval;
122                 return block_group;
123         }
124 }
125
126 static inline int load_block_bitmap(struct super_block *sb,
127                                     struct udf_bitmap *bitmap,
128                                     unsigned int block_group)
129 {
130         int slot;
131
132         slot = __load_block_bitmap(sb, bitmap, block_group);
133
134         if (slot < 0)
135                 return slot;
136
137         if (!bitmap->s_block_bitmap[slot])
138                 return -EIO;
139
140         return slot;
141 }
142
143 static bool udf_add_free_space(struct udf_sb_info *sbi,
144                                 u16 partition, u32 cnt)
145 {
146         struct logicalVolIntegrityDesc *lvid;
147
148         if (sbi->s_lvid_bh == NULL)
149                 return false;
150
151         lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
152         le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
153         return true;
154 }
155
156 static void udf_bitmap_free_blocks(struct super_block *sb,
157                                    struct inode *inode,
158                                    struct udf_bitmap *bitmap,
159                                    kernel_lb_addr bloc, uint32_t offset,
160                                    uint32_t count)
161 {
162         struct udf_sb_info *sbi = UDF_SB(sb);
163         struct buffer_head *bh = NULL;
164         unsigned long block;
165         unsigned long block_group;
166         unsigned long bit;
167         unsigned long i;
168         int bitmap_nr;
169         unsigned long overflow;
170
171         mutex_lock(&sbi->s_alloc_mutex);
172         if (bloc.logicalBlockNum < 0 ||
173             (bloc.logicalBlockNum + count) >
174                 sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
175                 udf_debug("%d < %d || %d + %d > %d\n",
176                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
177                           sbi->s_partmaps[bloc.partitionReferenceNum].
178                                                         s_partition_len);
179                 goto error_return;
180         }
181
182         block = bloc.logicalBlockNum + offset +
183                 (sizeof(struct spaceBitmapDesc) << 3);
184
185         do {
186                 overflow = 0;
187                 block_group = block >> (sb->s_blocksize_bits + 3);
188                 bit = block % (sb->s_blocksize << 3);
189
190                 /*
191                 * Check to see if we are freeing blocks across a group boundary.
192                 */
193                 if (bit + count > (sb->s_blocksize << 3)) {
194                         overflow = bit + count - (sb->s_blocksize << 3);
195                         count -= overflow;
196                 }
197                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
198                 if (bitmap_nr < 0)
199                         goto error_return;
200
201                 bh = bitmap->s_block_bitmap[bitmap_nr];
202                 for (i = 0; i < count; i++) {
203                         if (udf_set_bit(bit + i, bh->b_data)) {
204                                 udf_debug("bit %ld already set\n", bit + i);
205                                 udf_debug("byte=%2x\n",
206                                         ((char *)bh->b_data)[(bit + i) >> 3]);
207                         } else {
208                                 if (inode)
209                                         vfs_dq_free_block(inode, 1);
210                                 udf_add_free_space(sbi, sbi->s_partition, 1);
211                         }
212                 }
213                 mark_buffer_dirty(bh);
214                 if (overflow) {
215                         block += count;
216                         count = overflow;
217                 }
218         } while (overflow);
219
220 error_return:
221         sb->s_dirt = 1;
222         if (sbi->s_lvid_bh)
223                 mark_buffer_dirty(sbi->s_lvid_bh);
224         mutex_unlock(&sbi->s_alloc_mutex);
225 }
226
227 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
228                                       struct inode *inode,
229                                       struct udf_bitmap *bitmap,
230                                       uint16_t partition, uint32_t first_block,
231                                       uint32_t block_count)
232 {
233         struct udf_sb_info *sbi = UDF_SB(sb);
234         int alloc_count = 0;
235         int bit, block, block_group, group_start;
236         int nr_groups, bitmap_nr;
237         struct buffer_head *bh;
238         __u32 part_len;
239
240         mutex_lock(&sbi->s_alloc_mutex);
241         part_len = sbi->s_partmaps[partition].s_partition_len;
242         if (first_block < 0 || first_block >= part_len)
243                 goto out;
244
245         if (first_block + block_count > part_len)
246                 block_count = part_len - first_block;
247
248         do {
249                 nr_groups = udf_compute_nr_groups(sb, partition);
250                 block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
251                 block_group = block >> (sb->s_blocksize_bits + 3);
252                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
253
254                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
255                 if (bitmap_nr < 0)
256                         goto out;
257                 bh = bitmap->s_block_bitmap[bitmap_nr];
258
259                 bit = block % (sb->s_blocksize << 3);
260
261                 while (bit < (sb->s_blocksize << 3) && block_count > 0) {
262                         if (!udf_test_bit(bit, bh->b_data))
263                                 goto out;
264                         else if (vfs_dq_prealloc_block(inode, 1))
265                                 goto out;
266                         else if (!udf_clear_bit(bit, bh->b_data)) {
267                                 udf_debug("bit already cleared for block %d\n", bit);
268                                 vfs_dq_free_block(inode, 1);
269                                 goto out;
270                         }
271                         block_count--;
272                         alloc_count++;
273                         bit++;
274                         block++;
275                 }
276                 mark_buffer_dirty(bh);
277         } while (block_count > 0);
278
279 out:
280         if (udf_add_free_space(sbi, partition, -alloc_count))
281                 mark_buffer_dirty(sbi->s_lvid_bh);
282         sb->s_dirt = 1;
283         mutex_unlock(&sbi->s_alloc_mutex);
284         return alloc_count;
285 }
286
287 static int udf_bitmap_new_block(struct super_block *sb,
288                                 struct inode *inode,
289                                 struct udf_bitmap *bitmap, uint16_t partition,
290                                 uint32_t goal, int *err)
291 {
292         struct udf_sb_info *sbi = UDF_SB(sb);
293         int newbit, bit = 0, block, block_group, group_start;
294         int end_goal, nr_groups, bitmap_nr, i;
295         struct buffer_head *bh = NULL;
296         char *ptr;
297         int newblock = 0;
298
299         *err = -ENOSPC;
300         mutex_lock(&sbi->s_alloc_mutex);
301
302 repeat:
303         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
304                 goal = 0;
305
306         nr_groups = bitmap->s_nr_groups;
307         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
308         block_group = block >> (sb->s_blocksize_bits + 3);
309         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
310
311         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
312         if (bitmap_nr < 0)
313                 goto error_return;
314         bh = bitmap->s_block_bitmap[bitmap_nr];
315         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
316                       sb->s_blocksize - group_start);
317
318         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
319                 bit = block % (sb->s_blocksize << 3);
320                 if (udf_test_bit(bit, bh->b_data))
321                         goto got_block;
322
323                 end_goal = (bit + 63) & ~63;
324                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
325                 if (bit < end_goal)
326                         goto got_block;
327
328                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
329                               sb->s_blocksize - ((bit + 7) >> 3));
330                 newbit = (ptr - ((char *)bh->b_data)) << 3;
331                 if (newbit < sb->s_blocksize << 3) {
332                         bit = newbit;
333                         goto search_back;
334                 }
335
336                 newbit = udf_find_next_one_bit(bh->b_data,
337                                                sb->s_blocksize << 3, bit);
338                 if (newbit < sb->s_blocksize << 3) {
339                         bit = newbit;
340                         goto got_block;
341                 }
342         }
343
344         for (i = 0; i < (nr_groups * 2); i++) {
345                 block_group++;
346                 if (block_group >= nr_groups)
347                         block_group = 0;
348                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
349
350                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
351                 if (bitmap_nr < 0)
352                         goto error_return;
353                 bh = bitmap->s_block_bitmap[bitmap_nr];
354                 if (i < nr_groups) {
355                         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
356                                       sb->s_blocksize - group_start);
357                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
358                                 bit = (ptr - ((char *)bh->b_data)) << 3;
359                                 break;
360                         }
361                 } else {
362                         bit = udf_find_next_one_bit((char *)bh->b_data,
363                                                     sb->s_blocksize << 3,
364                                                     group_start << 3);
365                         if (bit < sb->s_blocksize << 3)
366                                 break;
367                 }
368         }
369         if (i >= (nr_groups * 2)) {
370                 mutex_unlock(&sbi->s_alloc_mutex);
371                 return newblock;
372         }
373         if (bit < sb->s_blocksize << 3)
374                 goto search_back;
375         else
376                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
377                                             group_start << 3);
378         if (bit >= sb->s_blocksize << 3) {
379                 mutex_unlock(&sbi->s_alloc_mutex);
380                 return 0;
381         }
382
383 search_back:
384         i = 0;
385         while (i < 7 && bit > (group_start << 3) &&
386                udf_test_bit(bit - 1, bh->b_data)) {
387                 ++i;
388                 --bit;
389         }
390
391 got_block:
392
393         /*
394          * Check quota for allocation of this block.
395          */
396         if (inode && vfs_dq_alloc_block(inode, 1)) {
397                 mutex_unlock(&sbi->s_alloc_mutex);
398                 *err = -EDQUOT;
399                 return 0;
400         }
401
402         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
403                 (sizeof(struct spaceBitmapDesc) << 3);
404
405         if (!udf_clear_bit(bit, bh->b_data)) {
406                 udf_debug("bit already cleared for block %d\n", bit);
407                 goto repeat;
408         }
409
410         mark_buffer_dirty(bh);
411
412         if (udf_add_free_space(sbi, partition, -1))
413                 mark_buffer_dirty(sbi->s_lvid_bh);
414         sb->s_dirt = 1;
415         mutex_unlock(&sbi->s_alloc_mutex);
416         *err = 0;
417         return newblock;
418
419 error_return:
420         *err = -EIO;
421         mutex_unlock(&sbi->s_alloc_mutex);
422         return 0;
423 }
424
425 static void udf_table_free_blocks(struct super_block *sb,
426                                   struct inode *inode,
427                                   struct inode *table,
428                                   kernel_lb_addr bloc, uint32_t offset,
429                                   uint32_t count)
430 {
431         struct udf_sb_info *sbi = UDF_SB(sb);
432         uint32_t start, end;
433         uint32_t elen;
434         kernel_lb_addr eloc;
435         struct extent_position oepos, epos;
436         int8_t etype;
437         int i;
438         struct udf_inode_info *iinfo;
439
440         mutex_lock(&sbi->s_alloc_mutex);
441         if (bloc.logicalBlockNum < 0 ||
442             (bloc.logicalBlockNum + count) >
443                 sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
444                 udf_debug("%d < %d || %d + %d > %d\n",
445                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
446                           sbi->s_partmaps[bloc.partitionReferenceNum].
447                                                         s_partition_len);
448                 goto error_return;
449         }
450
451         iinfo = UDF_I(table);
452         /* We do this up front - There are some error conditions that
453            could occure, but.. oh well */
454         if (inode)
455                 vfs_dq_free_block(inode, count);
456         if (udf_add_free_space(sbi, sbi->s_partition, count))
457                 mark_buffer_dirty(sbi->s_lvid_bh);
458
459         start = bloc.logicalBlockNum + offset;
460         end = bloc.logicalBlockNum + offset + count - 1;
461
462         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
463         elen = 0;
464         epos.block = oepos.block = iinfo->i_location;
465         epos.bh = oepos.bh = NULL;
466
467         while (count &&
468                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
469                 if (((eloc.logicalBlockNum +
470                         (elen >> sb->s_blocksize_bits)) == start)) {
471                         if ((0x3FFFFFFF - elen) <
472                                         (count << sb->s_blocksize_bits)) {
473                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
474                                                         sb->s_blocksize_bits);
475                                 count -= tmp;
476                                 start += tmp;
477                                 elen = (etype << 30) |
478                                         (0x40000000 - sb->s_blocksize);
479                         } else {
480                                 elen = (etype << 30) |
481                                         (elen +
482                                         (count << sb->s_blocksize_bits));
483                                 start += count;
484                                 count = 0;
485                         }
486                         udf_write_aext(table, &oepos, eloc, elen, 1);
487                 } else if (eloc.logicalBlockNum == (end + 1)) {
488                         if ((0x3FFFFFFF - elen) <
489                                         (count << sb->s_blocksize_bits)) {
490                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
491                                                 sb->s_blocksize_bits);
492                                 count -= tmp;
493                                 end -= tmp;
494                                 eloc.logicalBlockNum -= tmp;
495                                 elen = (etype << 30) |
496                                         (0x40000000 - sb->s_blocksize);
497                         } else {
498                                 eloc.logicalBlockNum = start;
499                                 elen = (etype << 30) |
500                                         (elen +
501                                         (count << sb->s_blocksize_bits));
502                                 end -= count;
503                                 count = 0;
504                         }
505                         udf_write_aext(table, &oepos, eloc, elen, 1);
506                 }
507
508                 if (epos.bh != oepos.bh) {
509                         i = -1;
510                         oepos.block = epos.block;
511                         brelse(oepos.bh);
512                         get_bh(epos.bh);
513                         oepos.bh = epos.bh;
514                         oepos.offset = 0;
515                 } else {
516                         oepos.offset = epos.offset;
517                 }
518         }
519
520         if (count) {
521                 /*
522                  * NOTE: we CANNOT use udf_add_aext here, as it can try to
523                  * allocate a new block, and since we hold the super block
524                  * lock already very bad things would happen :)
525                  *
526                  * We copy the behavior of udf_add_aext, but instead of
527                  * trying to allocate a new block close to the existing one,
528                  * we just steal a block from the extent we are trying to add.
529                  *
530                  * It would be nice if the blocks were close together, but it
531                  * isn't required.
532                  */
533
534                 int adsize;
535                 short_ad *sad = NULL;
536                 long_ad *lad = NULL;
537                 struct allocExtDesc *aed;
538
539                 eloc.logicalBlockNum = start;
540                 elen = EXT_RECORDED_ALLOCATED |
541                         (count << sb->s_blocksize_bits);
542
543                 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
544                         adsize = sizeof(short_ad);
545                 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
546                         adsize = sizeof(long_ad);
547                 else {
548                         brelse(oepos.bh);
549                         brelse(epos.bh);
550                         goto error_return;
551                 }
552
553                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
554                         char *sptr, *dptr;
555                         int loffset;
556
557                         brelse(oepos.bh);
558                         oepos = epos;
559
560                         /* Steal a block from the extent being free'd */
561                         epos.block.logicalBlockNum = eloc.logicalBlockNum;
562                         eloc.logicalBlockNum++;
563                         elen -= sb->s_blocksize;
564
565                         epos.bh = udf_tread(sb,
566                                         udf_get_lb_pblock(sb, epos.block, 0));
567                         if (!epos.bh) {
568                                 brelse(oepos.bh);
569                                 goto error_return;
570                         }
571                         aed = (struct allocExtDesc *)(epos.bh->b_data);
572                         aed->previousAllocExtLocation =
573                                 cpu_to_le32(oepos.block.logicalBlockNum);
574                         if (epos.offset + adsize > sb->s_blocksize) {
575                                 loffset = epos.offset;
576                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
577                                 sptr = iinfo->i_ext.i_data + epos.offset
578                                                                 - adsize;
579                                 dptr = epos.bh->b_data +
580                                         sizeof(struct allocExtDesc);
581                                 memcpy(dptr, sptr, adsize);
582                                 epos.offset = sizeof(struct allocExtDesc) +
583                                                 adsize;
584                         } else {
585                                 loffset = epos.offset + adsize;
586                                 aed->lengthAllocDescs = cpu_to_le32(0);
587                                 if (oepos.bh) {
588                                         sptr = oepos.bh->b_data + epos.offset;
589                                         aed = (struct allocExtDesc *)
590                                                 oepos.bh->b_data;
591                                         le32_add_cpu(&aed->lengthAllocDescs,
592                                                         adsize);
593                                 } else {
594                                         sptr = iinfo->i_ext.i_data +
595                                                                 epos.offset;
596                                         iinfo->i_lenAlloc += adsize;
597                                         mark_inode_dirty(table);
598                                 }
599                                 epos.offset = sizeof(struct allocExtDesc);
600                         }
601                         if (sbi->s_udfrev >= 0x0200)
602                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
603                                             3, 1, epos.block.logicalBlockNum,
604                                             sizeof(tag));
605                         else
606                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
607                                             2, 1, epos.block.logicalBlockNum,
608                                             sizeof(tag));
609
610                         switch (iinfo->i_alloc_type) {
611                         case ICBTAG_FLAG_AD_SHORT:
612                                 sad = (short_ad *)sptr;
613                                 sad->extLength = cpu_to_le32(
614                                         EXT_NEXT_EXTENT_ALLOCDECS |
615                                         sb->s_blocksize);
616                                 sad->extPosition =
617                                         cpu_to_le32(epos.block.logicalBlockNum);
618                                 break;
619                         case ICBTAG_FLAG_AD_LONG:
620                                 lad = (long_ad *)sptr;
621                                 lad->extLength = cpu_to_le32(
622                                         EXT_NEXT_EXTENT_ALLOCDECS |
623                                         sb->s_blocksize);
624                                 lad->extLocation =
625                                         cpu_to_lelb(epos.block);
626                                 break;
627                         }
628                         if (oepos.bh) {
629                                 udf_update_tag(oepos.bh->b_data, loffset);
630                                 mark_buffer_dirty(oepos.bh);
631                         } else {
632                                 mark_inode_dirty(table);
633                         }
634                 }
635
636                 /* It's possible that stealing the block emptied the extent */
637                 if (elen) {
638                         udf_write_aext(table, &epos, eloc, elen, 1);
639
640                         if (!epos.bh) {
641                                 iinfo->i_lenAlloc += adsize;
642                                 mark_inode_dirty(table);
643                         } else {
644                                 aed = (struct allocExtDesc *)epos.bh->b_data;
645                                 le32_add_cpu(&aed->lengthAllocDescs, adsize);
646                                 udf_update_tag(epos.bh->b_data, epos.offset);
647                                 mark_buffer_dirty(epos.bh);
648                         }
649                 }
650         }
651
652         brelse(epos.bh);
653         brelse(oepos.bh);
654
655 error_return:
656         sb->s_dirt = 1;
657         mutex_unlock(&sbi->s_alloc_mutex);
658         return;
659 }
660
661 static int udf_table_prealloc_blocks(struct super_block *sb,
662                                      struct inode *inode,
663                                      struct inode *table, uint16_t partition,
664                                      uint32_t first_block, uint32_t block_count)
665 {
666         struct udf_sb_info *sbi = UDF_SB(sb);
667         int alloc_count = 0;
668         uint32_t elen, adsize;
669         kernel_lb_addr eloc;
670         struct extent_position epos;
671         int8_t etype = -1;
672         struct udf_inode_info *iinfo;
673
674         if (first_block < 0 ||
675                 first_block >= sbi->s_partmaps[partition].s_partition_len)
676                 return 0;
677
678         iinfo = UDF_I(table);
679         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
680                 adsize = sizeof(short_ad);
681         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
682                 adsize = sizeof(long_ad);
683         else
684                 return 0;
685
686         mutex_lock(&sbi->s_alloc_mutex);
687         epos.offset = sizeof(struct unallocSpaceEntry);
688         epos.block = iinfo->i_location;
689         epos.bh = NULL;
690         eloc.logicalBlockNum = 0xFFFFFFFF;
691
692         while (first_block != eloc.logicalBlockNum &&
693                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
694                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
695                           eloc.logicalBlockNum, elen, first_block);
696                 ; /* empty loop body */
697         }
698
699         if (first_block == eloc.logicalBlockNum) {
700                 epos.offset -= adsize;
701
702                 alloc_count = (elen >> sb->s_blocksize_bits);
703                 if (inode && vfs_dq_prealloc_block(inode,
704                         alloc_count > block_count ? block_count : alloc_count))
705                         alloc_count = 0;
706                 else if (alloc_count > block_count) {
707                         alloc_count = block_count;
708                         eloc.logicalBlockNum += alloc_count;
709                         elen -= (alloc_count << sb->s_blocksize_bits);
710                         udf_write_aext(table, &epos, eloc,
711                                         (etype << 30) | elen, 1);
712                 } else
713                         udf_delete_aext(table, epos, eloc,
714                                         (etype << 30) | elen);
715         } else {
716                 alloc_count = 0;
717         }
718
719         brelse(epos.bh);
720
721         if (alloc_count && udf_add_free_space(sbi, partition, -alloc_count)) {
722                 mark_buffer_dirty(sbi->s_lvid_bh);
723                 sb->s_dirt = 1;
724         }
725         mutex_unlock(&sbi->s_alloc_mutex);
726         return alloc_count;
727 }
728
729 static int udf_table_new_block(struct super_block *sb,
730                                struct inode *inode,
731                                struct inode *table, uint16_t partition,
732                                uint32_t goal, int *err)
733 {
734         struct udf_sb_info *sbi = UDF_SB(sb);
735         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
736         uint32_t newblock = 0, adsize;
737         uint32_t elen, goal_elen = 0;
738         kernel_lb_addr eloc, uninitialized_var(goal_eloc);
739         struct extent_position epos, goal_epos;
740         int8_t etype;
741         struct udf_inode_info *iinfo = UDF_I(table);
742
743         *err = -ENOSPC;
744
745         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
746                 adsize = sizeof(short_ad);
747         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
748                 adsize = sizeof(long_ad);
749         else
750                 return newblock;
751
752         mutex_lock(&sbi->s_alloc_mutex);
753         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
754                 goal = 0;
755
756         /* We search for the closest matching block to goal. If we find
757            a exact hit, we stop. Otherwise we keep going till we run out
758            of extents. We store the buffer_head, bloc, and extoffset
759            of the current closest match and use that when we are done.
760          */
761         epos.offset = sizeof(struct unallocSpaceEntry);
762         epos.block = iinfo->i_location;
763         epos.bh = goal_epos.bh = NULL;
764
765         while (spread &&
766                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
767                 if (goal >= eloc.logicalBlockNum) {
768                         if (goal < eloc.logicalBlockNum +
769                                         (elen >> sb->s_blocksize_bits))
770                                 nspread = 0;
771                         else
772                                 nspread = goal - eloc.logicalBlockNum -
773                                         (elen >> sb->s_blocksize_bits);
774                 } else {
775                         nspread = eloc.logicalBlockNum - goal;
776                 }
777
778                 if (nspread < spread) {
779                         spread = nspread;
780                         if (goal_epos.bh != epos.bh) {
781                                 brelse(goal_epos.bh);
782                                 goal_epos.bh = epos.bh;
783                                 get_bh(goal_epos.bh);
784                         }
785                         goal_epos.block = epos.block;
786                         goal_epos.offset = epos.offset - adsize;
787                         goal_eloc = eloc;
788                         goal_elen = (etype << 30) | elen;
789                 }
790         }
791
792         brelse(epos.bh);
793
794         if (spread == 0xFFFFFFFF) {
795                 brelse(goal_epos.bh);
796                 mutex_unlock(&sbi->s_alloc_mutex);
797                 return 0;
798         }
799
800         /* Only allocate blocks from the beginning of the extent.
801            That way, we only delete (empty) extents, never have to insert an
802            extent because of splitting */
803         /* This works, but very poorly.... */
804
805         newblock = goal_eloc.logicalBlockNum;
806         goal_eloc.logicalBlockNum++;
807         goal_elen -= sb->s_blocksize;
808
809         if (inode && vfs_dq_alloc_block(inode, 1)) {
810                 brelse(goal_epos.bh);
811                 mutex_unlock(&sbi->s_alloc_mutex);
812                 *err = -EDQUOT;
813                 return 0;
814         }
815
816         if (goal_elen)
817                 udf_write_aext(table, &goal_epos, goal_eloc, goal_elen, 1);
818         else
819                 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
820         brelse(goal_epos.bh);
821
822         if (udf_add_free_space(sbi, partition, -1))
823                 mark_buffer_dirty(sbi->s_lvid_bh);
824
825         sb->s_dirt = 1;
826         mutex_unlock(&sbi->s_alloc_mutex);
827         *err = 0;
828         return newblock;
829 }
830
831 inline void udf_free_blocks(struct super_block *sb,
832                             struct inode *inode,
833                             kernel_lb_addr bloc, uint32_t offset,
834                             uint32_t count)
835 {
836         uint16_t partition = bloc.partitionReferenceNum;
837         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
838
839         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
840                 return udf_bitmap_free_blocks(sb, inode,
841                                               map->s_uspace.s_bitmap,
842                                               bloc, offset, count);
843         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
844                 return udf_table_free_blocks(sb, inode,
845                                              map->s_uspace.s_table,
846                                              bloc, offset, count);
847         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
848                 return udf_bitmap_free_blocks(sb, inode,
849                                               map->s_fspace.s_bitmap,
850                                               bloc, offset, count);
851         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
852                 return udf_table_free_blocks(sb, inode,
853                                              map->s_fspace.s_table,
854                                              bloc, offset, count);
855         } else {
856                 return;
857         }
858 }
859
860 inline int udf_prealloc_blocks(struct super_block *sb,
861                                struct inode *inode,
862                                uint16_t partition, uint32_t first_block,
863                                uint32_t block_count)
864 {
865         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
866
867         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
868                 return udf_bitmap_prealloc_blocks(sb, inode,
869                                                   map->s_uspace.s_bitmap,
870                                                   partition, first_block,
871                                                   block_count);
872         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
873                 return udf_table_prealloc_blocks(sb, inode,
874                                                  map->s_uspace.s_table,
875                                                  partition, first_block,
876                                                  block_count);
877         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
878                 return udf_bitmap_prealloc_blocks(sb, inode,
879                                                   map->s_fspace.s_bitmap,
880                                                   partition, first_block,
881                                                   block_count);
882         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
883                 return udf_table_prealloc_blocks(sb, inode,
884                                                  map->s_fspace.s_table,
885                                                  partition, first_block,
886                                                  block_count);
887         else
888                 return 0;
889 }
890
891 inline int udf_new_block(struct super_block *sb,
892                          struct inode *inode,
893                          uint16_t partition, uint32_t goal, int *err)
894 {
895         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
896
897         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
898                 return udf_bitmap_new_block(sb, inode,
899                                            map->s_uspace.s_bitmap,
900                                            partition, goal, err);
901         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
902                 return udf_table_new_block(sb, inode,
903                                            map->s_uspace.s_table,
904                                            partition, goal, err);
905         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
906                 return udf_bitmap_new_block(sb, inode,
907                                             map->s_fspace.s_bitmap,
908                                             partition, goal, err);
909         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
910                 return udf_table_new_block(sb, inode,
911                                            map->s_fspace.s_table,
912                                            partition, goal, err);
913         else {
914                 *err = -EIO;
915                 return 0;
916         }
917 }