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 */
hfsplus_ext_cmp_key(const hfsplus_btree_key * k1,const hfsplus_btree_key * k2)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
hfsplus_ext_build_key(hfsplus_btree_key * key,u32 cnid,u32 block,u8 type)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
hfsplus_ext_find_block(struct hfsplus_extent * ext,u32 off)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
hfsplus_ext_block_count(struct hfsplus_extent * ext)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
hfsplus_ext_lastblock(struct hfsplus_extent * ext)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
__hfsplus_ext_write_extent(struct inode * inode,struct hfs_find_data * fd)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
hfsplus_ext_write_extent_locked(struct inode * inode)122 static void hfsplus_ext_write_extent_locked(struct inode *inode)
123 {
124 if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
125 struct hfs_find_data fd;
126
127 hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
128 __hfsplus_ext_write_extent(inode, &fd);
129 hfs_find_exit(&fd);
130 }
131 }
132
hfsplus_ext_write_extent(struct inode * inode)133 void hfsplus_ext_write_extent(struct inode *inode)
134 {
135 mutex_lock(&HFSPLUS_I(inode)->extents_lock);
136 hfsplus_ext_write_extent_locked(inode);
137 mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
138 }
139
__hfsplus_ext_read_extent(struct hfs_find_data * fd,struct hfsplus_extent * extent,u32 cnid,u32 block,u8 type)140 static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
141 struct hfsplus_extent *extent,
142 u32 cnid, u32 block, u8 type)
143 {
144 int res;
145
146 hfsplus_ext_build_key(fd->search_key, cnid, block, type);
147 fd->key->ext.cnid = 0;
148 res = hfs_brec_find(fd);
149 if (res && res != -ENOENT)
150 return res;
151 if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
152 fd->key->ext.fork_type != fd->search_key->ext.fork_type)
153 return -ENOENT;
154 if (fd->entrylength != sizeof(hfsplus_extent_rec))
155 return -EIO;
156 hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
157 sizeof(hfsplus_extent_rec));
158 return 0;
159 }
160
__hfsplus_ext_cache_extent(struct hfs_find_data * fd,struct inode * inode,u32 block)161 static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
162 struct inode *inode, u32 block)
163 {
164 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
165 int res;
166
167 WARN_ON(!mutex_is_locked(&hip->extents_lock));
168
169 if (hip->extent_state & HFSPLUS_EXT_DIRTY)
170 __hfsplus_ext_write_extent(inode, fd);
171
172 res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
173 block, HFSPLUS_IS_RSRC(inode) ?
174 HFSPLUS_TYPE_RSRC :
175 HFSPLUS_TYPE_DATA);
176 if (!res) {
177 hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
178 hip->cached_blocks =
179 hfsplus_ext_block_count(hip->cached_extents);
180 } else {
181 hip->cached_start = hip->cached_blocks = 0;
182 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
183 }
184 return res;
185 }
186
hfsplus_ext_read_extent(struct inode * inode,u32 block)187 static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
188 {
189 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
190 struct hfs_find_data fd;
191 int res;
192
193 if (block >= hip->cached_start &&
194 block < hip->cached_start + hip->cached_blocks)
195 return 0;
196
197 hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
198 res = __hfsplus_ext_cache_extent(&fd, inode, block);
199 hfs_find_exit(&fd);
200 return res;
201 }
202
203 /* Get a block at iblock for inode, possibly allocating if create */
hfsplus_get_block(struct inode * inode,sector_t iblock,struct buffer_head * bh_result,int create)204 int hfsplus_get_block(struct inode *inode, sector_t iblock,
205 struct buffer_head *bh_result, int create)
206 {
207 struct super_block *sb = inode->i_sb;
208 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
209 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
210 int res = -EIO;
211 u32 ablock, dblock, mask;
212 int was_dirty = 0;
213 int shift;
214
215 /* Convert inode block to disk allocation block */
216 shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
217 ablock = iblock >> sbi->fs_shift;
218
219 if (iblock >= hip->fs_blocks) {
220 if (iblock > hip->fs_blocks || !create)
221 return -EIO;
222 if (ablock >= hip->alloc_blocks) {
223 res = hfsplus_file_extend(inode);
224 if (res)
225 return res;
226 }
227 } else
228 create = 0;
229
230 if (ablock < hip->first_blocks) {
231 dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
232 goto done;
233 }
234
235 if (inode->i_ino == HFSPLUS_EXT_CNID)
236 return -EIO;
237
238 mutex_lock(&hip->extents_lock);
239
240 /*
241 * hfsplus_ext_read_extent will write out a cached extent into
242 * the extents btree. In that case we may have to mark the inode
243 * dirty even for a pure read of an extent here.
244 */
245 was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
246 res = hfsplus_ext_read_extent(inode, ablock);
247 if (res) {
248 mutex_unlock(&hip->extents_lock);
249 return -EIO;
250 }
251 dblock = hfsplus_ext_find_block(hip->cached_extents,
252 ablock - hip->cached_start);
253 mutex_unlock(&hip->extents_lock);
254
255 done:
256 dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n",
257 inode->i_ino, (long long)iblock, dblock);
258 mask = (1 << sbi->fs_shift) - 1;
259 map_bh(bh_result, sb,
260 (dblock << sbi->fs_shift) + sbi->blockoffset +
261 (iblock & mask));
262 if (create) {
263 set_buffer_new(bh_result);
264 hip->phys_size += sb->s_blocksize;
265 hip->fs_blocks++;
266 inode_add_bytes(inode, sb->s_blocksize);
267 }
268 if (create || was_dirty)
269 mark_inode_dirty(inode);
270 return 0;
271 }
272
hfsplus_dump_extent(struct hfsplus_extent * extent)273 static void hfsplus_dump_extent(struct hfsplus_extent *extent)
274 {
275 int i;
276
277 dprint(DBG_EXTENT, " ");
278 for (i = 0; i < 8; i++)
279 dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
280 be32_to_cpu(extent[i].block_count));
281 dprint(DBG_EXTENT, "\n");
282 }
283
hfsplus_add_extent(struct hfsplus_extent * extent,u32 offset,u32 alloc_block,u32 block_count)284 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
285 u32 alloc_block, u32 block_count)
286 {
287 u32 count, start;
288 int i;
289
290 hfsplus_dump_extent(extent);
291 for (i = 0; i < 8; extent++, i++) {
292 count = be32_to_cpu(extent->block_count);
293 if (offset == count) {
294 start = be32_to_cpu(extent->start_block);
295 if (alloc_block != start + count) {
296 if (++i >= 8)
297 return -ENOSPC;
298 extent++;
299 extent->start_block = cpu_to_be32(alloc_block);
300 } else
301 block_count += count;
302 extent->block_count = cpu_to_be32(block_count);
303 return 0;
304 } else if (offset < count)
305 break;
306 offset -= count;
307 }
308 /* panic? */
309 return -EIO;
310 }
311
hfsplus_free_extents(struct super_block * sb,struct hfsplus_extent * extent,u32 offset,u32 block_nr)312 static int hfsplus_free_extents(struct super_block *sb,
313 struct hfsplus_extent *extent,
314 u32 offset, u32 block_nr)
315 {
316 u32 count, start;
317 int i;
318
319 hfsplus_dump_extent(extent);
320 for (i = 0; i < 8; extent++, i++) {
321 count = be32_to_cpu(extent->block_count);
322 if (offset == count)
323 goto found;
324 else if (offset < count)
325 break;
326 offset -= count;
327 }
328 /* panic? */
329 return -EIO;
330 found:
331 for (;;) {
332 start = be32_to_cpu(extent->start_block);
333 if (count <= block_nr) {
334 hfsplus_block_free(sb, start, count);
335 extent->block_count = 0;
336 extent->start_block = 0;
337 block_nr -= count;
338 } else {
339 count -= block_nr;
340 hfsplus_block_free(sb, start + count, block_nr);
341 extent->block_count = cpu_to_be32(count);
342 block_nr = 0;
343 }
344 if (!block_nr || !i)
345 return 0;
346 i--;
347 extent--;
348 count = be32_to_cpu(extent->block_count);
349 }
350 }
351
hfsplus_free_fork(struct super_block * sb,u32 cnid,struct hfsplus_fork_raw * fork,int type)352 int hfsplus_free_fork(struct super_block *sb, u32 cnid,
353 struct hfsplus_fork_raw *fork, int type)
354 {
355 struct hfs_find_data fd;
356 hfsplus_extent_rec ext_entry;
357 u32 total_blocks, blocks, start;
358 int res, i;
359
360 total_blocks = be32_to_cpu(fork->total_blocks);
361 if (!total_blocks)
362 return 0;
363
364 blocks = 0;
365 for (i = 0; i < 8; i++)
366 blocks += be32_to_cpu(fork->extents[i].block_count);
367
368 res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
369 if (res)
370 return res;
371 if (total_blocks == blocks)
372 return 0;
373
374 hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
375 do {
376 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
377 total_blocks, type);
378 if (res)
379 break;
380 start = be32_to_cpu(fd.key->ext.start_block);
381 hfsplus_free_extents(sb, ext_entry,
382 total_blocks - start,
383 total_blocks);
384 hfs_brec_remove(&fd);
385 total_blocks = start;
386 } while (total_blocks > blocks);
387 hfs_find_exit(&fd);
388
389 return res;
390 }
391
hfsplus_file_extend(struct inode * inode)392 int hfsplus_file_extend(struct inode *inode)
393 {
394 struct super_block *sb = inode->i_sb;
395 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
396 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
397 u32 start, len, goal;
398 int res;
399
400 if (sbi->alloc_file->i_size * 8 <
401 sbi->total_blocks - sbi->free_blocks + 8) {
402 /* extend alloc file */
403 printk(KERN_ERR "hfs: extend alloc file! "
404 "(%llu,%u,%u)\n",
405 sbi->alloc_file->i_size * 8,
406 sbi->total_blocks, sbi->free_blocks);
407 return -ENOSPC;
408 }
409
410 mutex_lock(&hip->extents_lock);
411 if (hip->alloc_blocks == hip->first_blocks)
412 goal = hfsplus_ext_lastblock(hip->first_extents);
413 else {
414 res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
415 if (res)
416 goto out;
417 goal = hfsplus_ext_lastblock(hip->cached_extents);
418 }
419
420 len = hip->clump_blocks;
421 start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
422 if (start >= sbi->total_blocks) {
423 start = hfsplus_block_allocate(sb, goal, 0, &len);
424 if (start >= goal) {
425 res = -ENOSPC;
426 goto out;
427 }
428 }
429
430 dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
431
432 if (hip->alloc_blocks <= hip->first_blocks) {
433 if (!hip->first_blocks) {
434 dprint(DBG_EXTENT, "first extents\n");
435 /* no extents yet */
436 hip->first_extents[0].start_block = cpu_to_be32(start);
437 hip->first_extents[0].block_count = cpu_to_be32(len);
438 res = 0;
439 } else {
440 /* try to append to extents in inode */
441 res = hfsplus_add_extent(hip->first_extents,
442 hip->alloc_blocks,
443 start, len);
444 if (res == -ENOSPC)
445 goto insert_extent;
446 }
447 if (!res) {
448 hfsplus_dump_extent(hip->first_extents);
449 hip->first_blocks += len;
450 }
451 } else {
452 res = hfsplus_add_extent(hip->cached_extents,
453 hip->alloc_blocks - hip->cached_start,
454 start, len);
455 if (!res) {
456 hfsplus_dump_extent(hip->cached_extents);
457 hip->extent_state |= HFSPLUS_EXT_DIRTY;
458 hip->cached_blocks += len;
459 } else if (res == -ENOSPC)
460 goto insert_extent;
461 }
462 out:
463 mutex_unlock(&hip->extents_lock);
464 if (!res) {
465 hip->alloc_blocks += len;
466 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
467 }
468 return res;
469
470 insert_extent:
471 dprint(DBG_EXTENT, "insert new extent\n");
472 hfsplus_ext_write_extent_locked(inode);
473
474 memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
475 hip->cached_extents[0].start_block = cpu_to_be32(start);
476 hip->cached_extents[0].block_count = cpu_to_be32(len);
477 hfsplus_dump_extent(hip->cached_extents);
478 hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
479 hip->cached_start = hip->alloc_blocks;
480 hip->cached_blocks = len;
481
482 res = 0;
483 goto out;
484 }
485
hfsplus_file_truncate(struct inode * inode)486 void hfsplus_file_truncate(struct inode *inode)
487 {
488 struct super_block *sb = inode->i_sb;
489 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
490 struct hfs_find_data fd;
491 u32 alloc_cnt, blk_cnt, start;
492 int res;
493
494 dprint(DBG_INODE, "truncate: %lu, %llu -> %llu\n",
495 inode->i_ino, (long long)hip->phys_size,
496 inode->i_size);
497
498 if (inode->i_size > hip->phys_size) {
499 struct address_space *mapping = inode->i_mapping;
500 struct page *page;
501 void *fsdata;
502 u32 size = inode->i_size;
503 int res;
504
505 res = pagecache_write_begin(NULL, mapping, size, 0,
506 AOP_FLAG_UNINTERRUPTIBLE,
507 &page, &fsdata);
508 if (res)
509 return;
510 res = pagecache_write_end(NULL, mapping, size,
511 0, 0, page, fsdata);
512 if (res < 0)
513 return;
514 mark_inode_dirty(inode);
515 return;
516 } else if (inode->i_size == hip->phys_size)
517 return;
518
519 blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
520 HFSPLUS_SB(sb)->alloc_blksz_shift;
521 alloc_cnt = hip->alloc_blocks;
522 if (blk_cnt == alloc_cnt)
523 goto out;
524
525 mutex_lock(&hip->extents_lock);
526 hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
527 while (1) {
528 if (alloc_cnt == hip->first_blocks) {
529 hfsplus_free_extents(sb, hip->first_extents,
530 alloc_cnt, alloc_cnt - blk_cnt);
531 hfsplus_dump_extent(hip->first_extents);
532 hip->first_blocks = blk_cnt;
533 break;
534 }
535 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
536 if (res)
537 break;
538 start = hip->cached_start;
539 hfsplus_free_extents(sb, hip->cached_extents,
540 alloc_cnt - start, alloc_cnt - blk_cnt);
541 hfsplus_dump_extent(hip->cached_extents);
542 if (blk_cnt > start) {
543 hip->extent_state |= HFSPLUS_EXT_DIRTY;
544 break;
545 }
546 alloc_cnt = start;
547 hip->cached_start = hip->cached_blocks = 0;
548 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
549 hfs_brec_remove(&fd);
550 }
551 hfs_find_exit(&fd);
552 mutex_unlock(&hip->extents_lock);
553
554 hip->alloc_blocks = blk_cnt;
555 out:
556 hip->phys_size = inode->i_size;
557 hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
558 sb->s_blocksize_bits;
559 inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
560 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
561 }
562