arm: tegra: enterprise: Add drivers for flashless XMM modem
[linux-2.6.git] / fs / hfsplus / extents.c
1 /*
2  *  linux/fs/hfsplus/extents.c
3  *
4  * Copyright (C) 2001
5  * Brad Boyer (flar@allandria.com)
6  * (C) 2003 Ardis Technologies <roman@ardistech.com>
7  *
8  * Handling of Extents both in catalog and extents overflow trees
9  */
10
11 #include <linux/errno.h>
12 #include <linux/fs.h>
13 #include <linux/pagemap.h>
14
15 #include "hfsplus_fs.h"
16 #include "hfsplus_raw.h"
17
18 /* Compare two extents keys, returns 0 on same, pos/neg for difference */
19 int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
20                         const hfsplus_btree_key *k2)
21 {
22         __be32 k1id, k2id;
23         __be32 k1s, k2s;
24
25         k1id = k1->ext.cnid;
26         k2id = k2->ext.cnid;
27         if (k1id != k2id)
28                 return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;
29
30         if (k1->ext.fork_type != k2->ext.fork_type)
31                 return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;
32
33         k1s = k1->ext.start_block;
34         k2s = k2->ext.start_block;
35         if (k1s == k2s)
36                 return 0;
37         return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
38 }
39
40 static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
41                                   u32 block, u8 type)
42 {
43         key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
44         key->ext.cnid = cpu_to_be32(cnid);
45         key->ext.start_block = cpu_to_be32(block);
46         key->ext.fork_type = type;
47         key->ext.pad = 0;
48 }
49
50 static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
51 {
52         int i;
53         u32 count;
54
55         for (i = 0; i < 8; ext++, i++) {
56                 count = be32_to_cpu(ext->block_count);
57                 if (off < count)
58                         return be32_to_cpu(ext->start_block) + off;
59                 off -= count;
60         }
61         /* panic? */
62         return 0;
63 }
64
65 static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
66 {
67         int i;
68         u32 count = 0;
69
70         for (i = 0; i < 8; ext++, i++)
71                 count += be32_to_cpu(ext->block_count);
72         return count;
73 }
74
75 static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
76 {
77         int i;
78
79         ext += 7;
80         for (i = 0; i < 7; ext--, i++)
81                 if (ext->block_count)
82                         break;
83         return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
84 }
85
86 static void __hfsplus_ext_write_extent(struct inode *inode,
87                 struct hfs_find_data *fd)
88 {
89         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
90         int res;
91
92         WARN_ON(!mutex_is_locked(&hip->extents_lock));
93
94         hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,
95                               HFSPLUS_IS_RSRC(inode) ?
96                                 HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
97
98         res = hfs_brec_find(fd);
99         if (hip->extent_state & HFSPLUS_EXT_NEW) {
100                 if (res != -ENOENT)
101                         return;
102                 hfs_brec_insert(fd, hip->cached_extents,
103                                 sizeof(hfsplus_extent_rec));
104                 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
105         } else {
106                 if (res)
107                         return;
108                 hfs_bnode_write(fd->bnode, hip->cached_extents,
109                                 fd->entryoffset, fd->entrylength);
110                 hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
111         }
112
113         /*
114          * We can't just use hfsplus_mark_inode_dirty here, because we
115          * also get called from hfsplus_write_inode, which should not
116          * redirty the inode.  Instead the callers have to be careful
117          * to explicily mark the inode dirty, too.
118          */
119         set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
120 }
121
122 static int hfsplus_ext_write_extent_locked(struct inode *inode)
123 {
124         int res;
125
126         if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
127                 struct hfs_find_data fd;
128
129                 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
130                 if (res)
131                         return res;
132                 __hfsplus_ext_write_extent(inode, &fd);
133                 hfs_find_exit(&fd);
134         }
135         return 0;
136 }
137
138 int hfsplus_ext_write_extent(struct inode *inode)
139 {
140         int res;
141
142         mutex_lock(&HFSPLUS_I(inode)->extents_lock);
143         res = hfsplus_ext_write_extent_locked(inode);
144         mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
145
146         return res;
147 }
148
149 static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
150                                             struct hfsplus_extent *extent,
151                                             u32 cnid, u32 block, u8 type)
152 {
153         int res;
154
155         hfsplus_ext_build_key(fd->search_key, cnid, block, type);
156         fd->key->ext.cnid = 0;
157         res = hfs_brec_find(fd);
158         if (res && res != -ENOENT)
159                 return res;
160         if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
161             fd->key->ext.fork_type != fd->search_key->ext.fork_type)
162                 return -ENOENT;
163         if (fd->entrylength != sizeof(hfsplus_extent_rec))
164                 return -EIO;
165         hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
166                 sizeof(hfsplus_extent_rec));
167         return 0;
168 }
169
170 static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
171                 struct inode *inode, u32 block)
172 {
173         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
174         int res;
175
176         WARN_ON(!mutex_is_locked(&hip->extents_lock));
177
178         if (hip->extent_state & HFSPLUS_EXT_DIRTY)
179                 __hfsplus_ext_write_extent(inode, fd);
180
181         res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
182                                         block, HFSPLUS_IS_RSRC(inode) ?
183                                                 HFSPLUS_TYPE_RSRC :
184                                                 HFSPLUS_TYPE_DATA);
185         if (!res) {
186                 hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
187                 hip->cached_blocks =
188                         hfsplus_ext_block_count(hip->cached_extents);
189         } else {
190                 hip->cached_start = hip->cached_blocks = 0;
191                 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
192         }
193         return res;
194 }
195
196 static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
197 {
198         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
199         struct hfs_find_data fd;
200         int res;
201
202         if (block >= hip->cached_start &&
203             block < hip->cached_start + hip->cached_blocks)
204                 return 0;
205
206         res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
207         if (!res) {
208                 res = __hfsplus_ext_cache_extent(&fd, inode, block);
209                 hfs_find_exit(&fd);
210         }
211         return res;
212 }
213
214 /* Get a block at iblock for inode, possibly allocating if create */
215 int hfsplus_get_block(struct inode *inode, sector_t iblock,
216                       struct buffer_head *bh_result, int create)
217 {
218         struct super_block *sb = inode->i_sb;
219         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
220         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
221         int res = -EIO;
222         u32 ablock, dblock, mask;
223         sector_t sector;
224         int was_dirty = 0;
225         int shift;
226
227         /* Convert inode block to disk allocation block */
228         shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
229         ablock = iblock >> sbi->fs_shift;
230
231         if (iblock >= hip->fs_blocks) {
232                 if (iblock > hip->fs_blocks || !create)
233                         return -EIO;
234                 if (ablock >= hip->alloc_blocks) {
235                         res = hfsplus_file_extend(inode);
236                         if (res)
237                                 return res;
238                 }
239         } else
240                 create = 0;
241
242         if (ablock < hip->first_blocks) {
243                 dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
244                 goto done;
245         }
246
247         if (inode->i_ino == HFSPLUS_EXT_CNID)
248                 return -EIO;
249
250         mutex_lock(&hip->extents_lock);
251
252         /*
253          * hfsplus_ext_read_extent will write out a cached extent into
254          * the extents btree.  In that case we may have to mark the inode
255          * dirty even for a pure read of an extent here.
256          */
257         was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
258         res = hfsplus_ext_read_extent(inode, ablock);
259         if (res) {
260                 mutex_unlock(&hip->extents_lock);
261                 return -EIO;
262         }
263         dblock = hfsplus_ext_find_block(hip->cached_extents,
264                                         ablock - hip->cached_start);
265         mutex_unlock(&hip->extents_lock);
266
267 done:
268         dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n",
269                 inode->i_ino, (long long)iblock, dblock);
270
271         mask = (1 << sbi->fs_shift) - 1;
272         sector = ((sector_t)dblock << sbi->fs_shift) +
273                   sbi->blockoffset + (iblock & mask);
274         map_bh(bh_result, sb, sector);
275
276         if (create) {
277                 set_buffer_new(bh_result);
278                 hip->phys_size += sb->s_blocksize;
279                 hip->fs_blocks++;
280                 inode_add_bytes(inode, sb->s_blocksize);
281         }
282         if (create || was_dirty)
283                 mark_inode_dirty(inode);
284         return 0;
285 }
286
287 static void hfsplus_dump_extent(struct hfsplus_extent *extent)
288 {
289         int i;
290
291         dprint(DBG_EXTENT, "   ");
292         for (i = 0; i < 8; i++)
293                 dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
294                                  be32_to_cpu(extent[i].block_count));
295         dprint(DBG_EXTENT, "\n");
296 }
297
298 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
299                               u32 alloc_block, u32 block_count)
300 {
301         u32 count, start;
302         int i;
303
304         hfsplus_dump_extent(extent);
305         for (i = 0; i < 8; extent++, i++) {
306                 count = be32_to_cpu(extent->block_count);
307                 if (offset == count) {
308                         start = be32_to_cpu(extent->start_block);
309                         if (alloc_block != start + count) {
310                                 if (++i >= 8)
311                                         return -ENOSPC;
312                                 extent++;
313                                 extent->start_block = cpu_to_be32(alloc_block);
314                         } else
315                                 block_count += count;
316                         extent->block_count = cpu_to_be32(block_count);
317                         return 0;
318                 } else if (offset < count)
319                         break;
320                 offset -= count;
321         }
322         /* panic? */
323         return -EIO;
324 }
325
326 static int hfsplus_free_extents(struct super_block *sb,
327                                 struct hfsplus_extent *extent,
328                                 u32 offset, u32 block_nr)
329 {
330         u32 count, start;
331         int i;
332
333         hfsplus_dump_extent(extent);
334         for (i = 0; i < 8; extent++, i++) {
335                 count = be32_to_cpu(extent->block_count);
336                 if (offset == count)
337                         goto found;
338                 else if (offset < count)
339                         break;
340                 offset -= count;
341         }
342         /* panic? */
343         return -EIO;
344 found:
345         for (;;) {
346                 start = be32_to_cpu(extent->start_block);
347                 if (count <= block_nr) {
348                         hfsplus_block_free(sb, start, count);
349                         extent->block_count = 0;
350                         extent->start_block = 0;
351                         block_nr -= count;
352                 } else {
353                         count -= block_nr;
354                         hfsplus_block_free(sb, start + count, block_nr);
355                         extent->block_count = cpu_to_be32(count);
356                         block_nr = 0;
357                 }
358                 if (!block_nr || !i)
359                         return 0;
360                 i--;
361                 extent--;
362                 count = be32_to_cpu(extent->block_count);
363         }
364 }
365
366 int hfsplus_free_fork(struct super_block *sb, u32 cnid,
367                 struct hfsplus_fork_raw *fork, int type)
368 {
369         struct hfs_find_data fd;
370         hfsplus_extent_rec ext_entry;
371         u32 total_blocks, blocks, start;
372         int res, i;
373
374         total_blocks = be32_to_cpu(fork->total_blocks);
375         if (!total_blocks)
376                 return 0;
377
378         blocks = 0;
379         for (i = 0; i < 8; i++)
380                 blocks += be32_to_cpu(fork->extents[i].block_count);
381
382         res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
383         if (res)
384                 return res;
385         if (total_blocks == blocks)
386                 return 0;
387
388         res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
389         if (res)
390                 return res;
391         do {
392                 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
393                                                 total_blocks, type);
394                 if (res)
395                         break;
396                 start = be32_to_cpu(fd.key->ext.start_block);
397                 hfsplus_free_extents(sb, ext_entry,
398                                      total_blocks - start,
399                                      total_blocks);
400                 hfs_brec_remove(&fd);
401                 total_blocks = start;
402         } while (total_blocks > blocks);
403         hfs_find_exit(&fd);
404
405         return res;
406 }
407
408 int hfsplus_file_extend(struct inode *inode)
409 {
410         struct super_block *sb = inode->i_sb;
411         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
412         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
413         u32 start, len, goal;
414         int res;
415
416         if (sbi->alloc_file->i_size * 8 <
417             sbi->total_blocks - sbi->free_blocks + 8) {
418                 /* extend alloc file */
419                 printk(KERN_ERR "hfs: extend alloc file! "
420                                 "(%llu,%u,%u)\n",
421                         sbi->alloc_file->i_size * 8,
422                         sbi->total_blocks, sbi->free_blocks);
423                 return -ENOSPC;
424         }
425
426         mutex_lock(&hip->extents_lock);
427         if (hip->alloc_blocks == hip->first_blocks)
428                 goal = hfsplus_ext_lastblock(hip->first_extents);
429         else {
430                 res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
431                 if (res)
432                         goto out;
433                 goal = hfsplus_ext_lastblock(hip->cached_extents);
434         }
435
436         len = hip->clump_blocks;
437         start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
438         if (start >= sbi->total_blocks) {
439                 start = hfsplus_block_allocate(sb, goal, 0, &len);
440                 if (start >= goal) {
441                         res = -ENOSPC;
442                         goto out;
443                 }
444         }
445
446         dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
447
448         if (hip->alloc_blocks <= hip->first_blocks) {
449                 if (!hip->first_blocks) {
450                         dprint(DBG_EXTENT, "first extents\n");
451                         /* no extents yet */
452                         hip->first_extents[0].start_block = cpu_to_be32(start);
453                         hip->first_extents[0].block_count = cpu_to_be32(len);
454                         res = 0;
455                 } else {
456                         /* try to append to extents in inode */
457                         res = hfsplus_add_extent(hip->first_extents,
458                                                  hip->alloc_blocks,
459                                                  start, len);
460                         if (res == -ENOSPC)
461                                 goto insert_extent;
462                 }
463                 if (!res) {
464                         hfsplus_dump_extent(hip->first_extents);
465                         hip->first_blocks += len;
466                 }
467         } else {
468                 res = hfsplus_add_extent(hip->cached_extents,
469                                          hip->alloc_blocks - hip->cached_start,
470                                          start, len);
471                 if (!res) {
472                         hfsplus_dump_extent(hip->cached_extents);
473                         hip->extent_state |= HFSPLUS_EXT_DIRTY;
474                         hip->cached_blocks += len;
475                 } else if (res == -ENOSPC)
476                         goto insert_extent;
477         }
478 out:
479         mutex_unlock(&hip->extents_lock);
480         if (!res) {
481                 hip->alloc_blocks += len;
482                 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
483         }
484         return res;
485
486 insert_extent:
487         dprint(DBG_EXTENT, "insert new extent\n");
488         res = hfsplus_ext_write_extent_locked(inode);
489         if (res)
490                 goto out;
491
492         memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
493         hip->cached_extents[0].start_block = cpu_to_be32(start);
494         hip->cached_extents[0].block_count = cpu_to_be32(len);
495         hfsplus_dump_extent(hip->cached_extents);
496         hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
497         hip->cached_start = hip->alloc_blocks;
498         hip->cached_blocks = len;
499
500         res = 0;
501         goto out;
502 }
503
504 void hfsplus_file_truncate(struct inode *inode)
505 {
506         struct super_block *sb = inode->i_sb;
507         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
508         struct hfs_find_data fd;
509         u32 alloc_cnt, blk_cnt, start;
510         int res;
511
512         dprint(DBG_INODE, "truncate: %lu, %llu -> %llu\n",
513                 inode->i_ino, (long long)hip->phys_size,
514                 inode->i_size);
515
516         if (inode->i_size > hip->phys_size) {
517                 struct address_space *mapping = inode->i_mapping;
518                 struct page *page;
519                 void *fsdata;
520                 u32 size = inode->i_size;
521
522                 res = pagecache_write_begin(NULL, mapping, size, 0,
523                                                 AOP_FLAG_UNINTERRUPTIBLE,
524                                                 &page, &fsdata);
525                 if (res)
526                         return;
527                 res = pagecache_write_end(NULL, mapping, size,
528                         0, 0, page, fsdata);
529                 if (res < 0)
530                         return;
531                 mark_inode_dirty(inode);
532                 return;
533         } else if (inode->i_size == hip->phys_size)
534                 return;
535
536         blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
537                         HFSPLUS_SB(sb)->alloc_blksz_shift;
538         alloc_cnt = hip->alloc_blocks;
539         if (blk_cnt == alloc_cnt)
540                 goto out;
541
542         mutex_lock(&hip->extents_lock);
543         res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
544         if (res) {
545                 mutex_unlock(&hip->extents_lock);
546                 /* XXX: We lack error handling of hfsplus_file_truncate() */
547                 return;
548         }
549         while (1) {
550                 if (alloc_cnt == hip->first_blocks) {
551                         hfsplus_free_extents(sb, hip->first_extents,
552                                              alloc_cnt, alloc_cnt - blk_cnt);
553                         hfsplus_dump_extent(hip->first_extents);
554                         hip->first_blocks = blk_cnt;
555                         break;
556                 }
557                 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
558                 if (res)
559                         break;
560                 start = hip->cached_start;
561                 hfsplus_free_extents(sb, hip->cached_extents,
562                                      alloc_cnt - start, alloc_cnt - blk_cnt);
563                 hfsplus_dump_extent(hip->cached_extents);
564                 if (blk_cnt > start) {
565                         hip->extent_state |= HFSPLUS_EXT_DIRTY;
566                         break;
567                 }
568                 alloc_cnt = start;
569                 hip->cached_start = hip->cached_blocks = 0;
570                 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
571                 hfs_brec_remove(&fd);
572         }
573         hfs_find_exit(&fd);
574         mutex_unlock(&hip->extents_lock);
575
576         hip->alloc_blocks = blk_cnt;
577 out:
578         hip->phys_size = inode->i_size;
579         hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
580                 sb->s_blocksize_bits;
581         inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
582         hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
583 }