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 int __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, hfs_find_rec_by_key);
99 if (hip->extent_state & HFSPLUS_EXT_NEW) {
100 if (res != -ENOENT)
101 return res;
102 /* Fail early and avoid ENOSPC during the btree operation */
103 res = hfs_bmap_reserve(fd->tree, fd->tree->depth + 1);
104 if (res)
105 return res;
106 hfs_brec_insert(fd, hip->cached_extents,
107 sizeof(hfsplus_extent_rec));
108 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
109 } else {
110 if (res)
111 return res;
112 hfs_bnode_write(fd->bnode, hip->cached_extents,
113 fd->entryoffset, fd->entrylength);
114 hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
115 }
116
117 /*
118 * We can't just use hfsplus_mark_inode_dirty here, because we
119 * also get called from hfsplus_write_inode, which should not
120 * redirty the inode. Instead the callers have to be careful
121 * to explicily mark the inode dirty, too.
122 */
123 set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
124
125 return 0;
126 }
127
hfsplus_ext_write_extent_locked(struct inode * inode)128 static int hfsplus_ext_write_extent_locked(struct inode *inode)
129 {
130 int res = 0;
131
132 if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
133 struct hfs_find_data fd;
134
135 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
136 if (res)
137 return res;
138 res = __hfsplus_ext_write_extent(inode, &fd);
139 hfs_find_exit(&fd);
140 }
141 return res;
142 }
143
hfsplus_ext_write_extent(struct inode * inode)144 int hfsplus_ext_write_extent(struct inode *inode)
145 {
146 int res;
147
148 mutex_lock(&HFSPLUS_I(inode)->extents_lock);
149 res = hfsplus_ext_write_extent_locked(inode);
150 mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
151
152 return res;
153 }
154
__hfsplus_ext_read_extent(struct hfs_find_data * fd,struct hfsplus_extent * extent,u32 cnid,u32 block,u8 type)155 static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
156 struct hfsplus_extent *extent,
157 u32 cnid, u32 block, u8 type)
158 {
159 int res;
160
161 hfsplus_ext_build_key(fd->search_key, cnid, block, type);
162 fd->key->ext.cnid = 0;
163 res = hfs_brec_find(fd, hfs_find_rec_by_key);
164 if (res && res != -ENOENT)
165 return res;
166 if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
167 fd->key->ext.fork_type != fd->search_key->ext.fork_type)
168 return -ENOENT;
169 if (fd->entrylength != sizeof(hfsplus_extent_rec))
170 return -EIO;
171 hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
172 sizeof(hfsplus_extent_rec));
173 return 0;
174 }
175
__hfsplus_ext_cache_extent(struct hfs_find_data * fd,struct inode * inode,u32 block)176 static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
177 struct inode *inode, u32 block)
178 {
179 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
180 int res;
181
182 WARN_ON(!mutex_is_locked(&hip->extents_lock));
183
184 if (hip->extent_state & HFSPLUS_EXT_DIRTY) {
185 res = __hfsplus_ext_write_extent(inode, fd);
186 if (res)
187 return res;
188 }
189
190 res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
191 block, HFSPLUS_IS_RSRC(inode) ?
192 HFSPLUS_TYPE_RSRC :
193 HFSPLUS_TYPE_DATA);
194 if (!res) {
195 hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
196 hip->cached_blocks =
197 hfsplus_ext_block_count(hip->cached_extents);
198 } else {
199 hip->cached_start = hip->cached_blocks = 0;
200 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
201 }
202 return res;
203 }
204
hfsplus_ext_read_extent(struct inode * inode,u32 block)205 static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
206 {
207 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
208 struct hfs_find_data fd;
209 int res;
210
211 if (block >= hip->cached_start &&
212 block < hip->cached_start + hip->cached_blocks)
213 return 0;
214
215 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
216 if (!res) {
217 res = __hfsplus_ext_cache_extent(&fd, inode, block);
218 hfs_find_exit(&fd);
219 }
220 return res;
221 }
222
223 /* 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)224 int hfsplus_get_block(struct inode *inode, sector_t iblock,
225 struct buffer_head *bh_result, int create)
226 {
227 struct super_block *sb = inode->i_sb;
228 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
229 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
230 int res = -EIO;
231 u32 ablock, dblock, mask;
232 sector_t sector;
233 int was_dirty = 0;
234
235 /* Convert inode block to disk allocation block */
236 ablock = iblock >> sbi->fs_shift;
237
238 if (iblock >= hip->fs_blocks) {
239 if (!create)
240 return 0;
241 if (iblock > hip->fs_blocks)
242 return -EIO;
243 if (ablock >= hip->alloc_blocks) {
244 res = hfsplus_file_extend(inode, false);
245 if (res)
246 return res;
247 }
248 } else
249 create = 0;
250
251 if (ablock < hip->first_blocks) {
252 dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
253 goto done;
254 }
255
256 if (inode->i_ino == HFSPLUS_EXT_CNID)
257 return -EIO;
258
259 mutex_lock(&hip->extents_lock);
260
261 /*
262 * hfsplus_ext_read_extent will write out a cached extent into
263 * the extents btree. In that case we may have to mark the inode
264 * dirty even for a pure read of an extent here.
265 */
266 was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
267 res = hfsplus_ext_read_extent(inode, ablock);
268 if (res) {
269 mutex_unlock(&hip->extents_lock);
270 return -EIO;
271 }
272 dblock = hfsplus_ext_find_block(hip->cached_extents,
273 ablock - hip->cached_start);
274 mutex_unlock(&hip->extents_lock);
275
276 done:
277 hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n",
278 inode->i_ino, (long long)iblock, dblock);
279
280 mask = (1 << sbi->fs_shift) - 1;
281 sector = ((sector_t)dblock << sbi->fs_shift) +
282 sbi->blockoffset + (iblock & mask);
283 map_bh(bh_result, sb, sector);
284
285 if (create) {
286 set_buffer_new(bh_result);
287 hip->phys_size += sb->s_blocksize;
288 hip->fs_blocks++;
289 inode_add_bytes(inode, sb->s_blocksize);
290 }
291 if (create || was_dirty)
292 mark_inode_dirty(inode);
293 return 0;
294 }
295
hfsplus_dump_extent(struct hfsplus_extent * extent)296 static void hfsplus_dump_extent(struct hfsplus_extent *extent)
297 {
298 int i;
299
300 hfs_dbg(EXTENT, " ");
301 for (i = 0; i < 8; i++)
302 hfs_dbg_cont(EXTENT, " %u:%u",
303 be32_to_cpu(extent[i].start_block),
304 be32_to_cpu(extent[i].block_count));
305 hfs_dbg_cont(EXTENT, "\n");
306 }
307
hfsplus_add_extent(struct hfsplus_extent * extent,u32 offset,u32 alloc_block,u32 block_count)308 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
309 u32 alloc_block, u32 block_count)
310 {
311 u32 count, start;
312 int i;
313
314 hfsplus_dump_extent(extent);
315 for (i = 0; i < 8; extent++, i++) {
316 count = be32_to_cpu(extent->block_count);
317 if (offset == count) {
318 start = be32_to_cpu(extent->start_block);
319 if (alloc_block != start + count) {
320 if (++i >= 8)
321 return -ENOSPC;
322 extent++;
323 extent->start_block = cpu_to_be32(alloc_block);
324 } else
325 block_count += count;
326 extent->block_count = cpu_to_be32(block_count);
327 return 0;
328 } else if (offset < count)
329 break;
330 offset -= count;
331 }
332 /* panic? */
333 return -EIO;
334 }
335
hfsplus_free_extents(struct super_block * sb,struct hfsplus_extent * extent,u32 offset,u32 block_nr)336 static int hfsplus_free_extents(struct super_block *sb,
337 struct hfsplus_extent *extent,
338 u32 offset, u32 block_nr)
339 {
340 u32 count, start;
341 int i;
342 int err = 0;
343
344 hfsplus_dump_extent(extent);
345 for (i = 0; i < 8; extent++, i++) {
346 count = be32_to_cpu(extent->block_count);
347 if (offset == count)
348 goto found;
349 else if (offset < count)
350 break;
351 offset -= count;
352 }
353 /* panic? */
354 return -EIO;
355 found:
356 for (;;) {
357 start = be32_to_cpu(extent->start_block);
358 if (count <= block_nr) {
359 err = hfsplus_block_free(sb, start, count);
360 if (err) {
361 pr_err("can't free extent\n");
362 hfs_dbg(EXTENT, " start: %u count: %u\n",
363 start, count);
364 }
365 extent->block_count = 0;
366 extent->start_block = 0;
367 block_nr -= count;
368 } else {
369 count -= block_nr;
370 err = hfsplus_block_free(sb, start + count, block_nr);
371 if (err) {
372 pr_err("can't free extent\n");
373 hfs_dbg(EXTENT, " start: %u count: %u\n",
374 start, count);
375 }
376 extent->block_count = cpu_to_be32(count);
377 block_nr = 0;
378 }
379 if (!block_nr || !i) {
380 /*
381 * Try to free all extents and
382 * return only last error
383 */
384 return err;
385 }
386 i--;
387 extent--;
388 count = be32_to_cpu(extent->block_count);
389 }
390 }
391
hfsplus_free_fork(struct super_block * sb,u32 cnid,struct hfsplus_fork_raw * fork,int type)392 int hfsplus_free_fork(struct super_block *sb, u32 cnid,
393 struct hfsplus_fork_raw *fork, int type)
394 {
395 struct hfs_find_data fd;
396 hfsplus_extent_rec ext_entry;
397 u32 total_blocks, blocks, start;
398 int res, i;
399
400 total_blocks = be32_to_cpu(fork->total_blocks);
401 if (!total_blocks)
402 return 0;
403
404 blocks = 0;
405 for (i = 0; i < 8; i++)
406 blocks += be32_to_cpu(fork->extents[i].block_count);
407
408 res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
409 if (res)
410 return res;
411 if (total_blocks == blocks)
412 return 0;
413
414 res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
415 if (res)
416 return res;
417 do {
418 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
419 total_blocks, type);
420 if (res)
421 break;
422 start = be32_to_cpu(fd.key->ext.start_block);
423 hfsplus_free_extents(sb, ext_entry,
424 total_blocks - start,
425 total_blocks);
426 hfs_brec_remove(&fd);
427 total_blocks = start;
428 } while (total_blocks > blocks);
429 hfs_find_exit(&fd);
430
431 return res;
432 }
433
hfsplus_file_extend(struct inode * inode,bool zeroout)434 int hfsplus_file_extend(struct inode *inode, bool zeroout)
435 {
436 struct super_block *sb = inode->i_sb;
437 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
438 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
439 u32 start, len, goal;
440 int res;
441
442 if (sbi->alloc_file->i_size * 8 <
443 sbi->total_blocks - sbi->free_blocks + 8) {
444 /* extend alloc file */
445 pr_err("extend alloc file! (%llu,%u,%u)\n",
446 sbi->alloc_file->i_size * 8,
447 sbi->total_blocks, sbi->free_blocks);
448 return -ENOSPC;
449 }
450
451 mutex_lock(&hip->extents_lock);
452 if (hip->alloc_blocks == hip->first_blocks)
453 goal = hfsplus_ext_lastblock(hip->first_extents);
454 else {
455 res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
456 if (res)
457 goto out;
458 goal = hfsplus_ext_lastblock(hip->cached_extents);
459 }
460
461 len = hip->clump_blocks;
462 start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
463 if (start >= sbi->total_blocks) {
464 start = hfsplus_block_allocate(sb, goal, 0, &len);
465 if (start >= goal) {
466 res = -ENOSPC;
467 goto out;
468 }
469 }
470
471 if (zeroout) {
472 res = sb_issue_zeroout(sb, start, len, GFP_NOFS);
473 if (res)
474 goto out;
475 }
476
477 hfs_dbg(EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
478
479 if (hip->alloc_blocks <= hip->first_blocks) {
480 if (!hip->first_blocks) {
481 hfs_dbg(EXTENT, "first extents\n");
482 /* no extents yet */
483 hip->first_extents[0].start_block = cpu_to_be32(start);
484 hip->first_extents[0].block_count = cpu_to_be32(len);
485 res = 0;
486 } else {
487 /* try to append to extents in inode */
488 res = hfsplus_add_extent(hip->first_extents,
489 hip->alloc_blocks,
490 start, len);
491 if (res == -ENOSPC)
492 goto insert_extent;
493 }
494 if (!res) {
495 hfsplus_dump_extent(hip->first_extents);
496 hip->first_blocks += len;
497 }
498 } else {
499 res = hfsplus_add_extent(hip->cached_extents,
500 hip->alloc_blocks - hip->cached_start,
501 start, len);
502 if (!res) {
503 hfsplus_dump_extent(hip->cached_extents);
504 hip->extent_state |= HFSPLUS_EXT_DIRTY;
505 hip->cached_blocks += len;
506 } else if (res == -ENOSPC)
507 goto insert_extent;
508 }
509 out:
510 if (!res) {
511 hip->alloc_blocks += len;
512 mutex_unlock(&hip->extents_lock);
513 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
514 return 0;
515 }
516 mutex_unlock(&hip->extents_lock);
517 return res;
518
519 insert_extent:
520 hfs_dbg(EXTENT, "insert new extent\n");
521 res = hfsplus_ext_write_extent_locked(inode);
522 if (res)
523 goto out;
524
525 memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
526 hip->cached_extents[0].start_block = cpu_to_be32(start);
527 hip->cached_extents[0].block_count = cpu_to_be32(len);
528 hfsplus_dump_extent(hip->cached_extents);
529 hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
530 hip->cached_start = hip->alloc_blocks;
531 hip->cached_blocks = len;
532
533 res = 0;
534 goto out;
535 }
536
hfsplus_file_truncate(struct inode * inode)537 void hfsplus_file_truncate(struct inode *inode)
538 {
539 struct super_block *sb = inode->i_sb;
540 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
541 struct hfs_find_data fd;
542 u32 alloc_cnt, blk_cnt, start;
543 int res;
544
545 hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\n",
546 inode->i_ino, (long long)hip->phys_size, inode->i_size);
547
548 if (inode->i_size > hip->phys_size) {
549 struct address_space *mapping = inode->i_mapping;
550 struct page *page;
551 void *fsdata;
552 loff_t size = inode->i_size;
553
554 res = pagecache_write_begin(NULL, mapping, size, 0,
555 AOP_FLAG_UNINTERRUPTIBLE,
556 &page, &fsdata);
557 if (res)
558 return;
559 res = pagecache_write_end(NULL, mapping, size,
560 0, 0, page, fsdata);
561 if (res < 0)
562 return;
563 mark_inode_dirty(inode);
564 return;
565 } else if (inode->i_size == hip->phys_size)
566 return;
567
568 blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
569 HFSPLUS_SB(sb)->alloc_blksz_shift;
570
571 mutex_lock(&hip->extents_lock);
572
573 alloc_cnt = hip->alloc_blocks;
574 if (blk_cnt == alloc_cnt)
575 goto out_unlock;
576
577 res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
578 if (res) {
579 mutex_unlock(&hip->extents_lock);
580 /* XXX: We lack error handling of hfsplus_file_truncate() */
581 return;
582 }
583 while (1) {
584 if (alloc_cnt == hip->first_blocks) {
585 hfsplus_free_extents(sb, hip->first_extents,
586 alloc_cnt, alloc_cnt - blk_cnt);
587 hfsplus_dump_extent(hip->first_extents);
588 hip->first_blocks = blk_cnt;
589 break;
590 }
591 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
592 if (res)
593 break;
594 start = hip->cached_start;
595 hfsplus_free_extents(sb, hip->cached_extents,
596 alloc_cnt - start, alloc_cnt - blk_cnt);
597 hfsplus_dump_extent(hip->cached_extents);
598 if (blk_cnt > start) {
599 hip->extent_state |= HFSPLUS_EXT_DIRTY;
600 break;
601 }
602 alloc_cnt = start;
603 hip->cached_start = hip->cached_blocks = 0;
604 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
605 hfs_brec_remove(&fd);
606 }
607 hfs_find_exit(&fd);
608
609 hip->alloc_blocks = blk_cnt;
610 out_unlock:
611 mutex_unlock(&hip->extents_lock);
612 hip->phys_size = inode->i_size;
613 hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
614 sb->s_blocksize_bits;
615 inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
616 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
617 }
618