1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/hfsplus/extents.c
4 *
5 * Copyright (C) 2001
6 * Brad Boyer (flar@allandria.com)
7 * (C) 2003 Ardis Technologies <roman@ardistech.com>
8 *
9 * Handling of Extents both in catalog and extents overflow trees
10 */
11
12 #include <linux/errno.h>
13 #include <linux/fs.h>
14 #include <linux/pagemap.h>
15
16 #include "hfsplus_fs.h"
17 #include "hfsplus_raw.h"
18
19 /* Compare two extents keys, returns 0 on same, pos/neg for difference */
20 int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
21 const hfsplus_btree_key *k2)
22 {
23 __be32 k1id, k2id;
24 __be32 k1s, k2s;
25
26 k1id = k1->ext.cnid;
27 k2id = k2->ext.cnid;
28 if (k1id != k2id)
29 return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;
30
31 if (k1->ext.fork_type != k2->ext.fork_type)
32 return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;
33
34 k1s = k1->ext.start_block;
35 k2s = k2->ext.start_block;
36 if (k1s == k2s)
37 return 0;
38 return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
39 }
40
41 static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
42 u32 block, u8 type)
43 {
44 key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
45 key->ext.cnid = cpu_to_be32(cnid);
46 key->ext.start_block = cpu_to_be32(block);
47 key->ext.fork_type = type;
48 key->ext.pad = 0;
49 }
50
51 static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
52 {
53 int i;
54 u32 count;
55
56 for (i = 0; i < 8; ext++, i++) {
57 count = be32_to_cpu(ext->block_count);
58 if (off < count)
59 return be32_to_cpu(ext->start_block) + off;
60 off -= count;
61 }
62 /* panic? */
63 return 0;
64 }
65
66 static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
67 {
68 int i;
69 u32 count = 0;
70
71 for (i = 0; i < 8; ext++, i++)
72 count += be32_to_cpu(ext->block_count);
73 return count;
74 }
75
76 static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
77 {
78 int i;
79
80 ext += 7;
81 for (i = 0; i < 7; ext--, i++)
82 if (ext->block_count)
83 break;
84 return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
85 }
86
87 static int __hfsplus_ext_write_extent(struct inode *inode,
88 struct hfs_find_data *fd)
89 {
90 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
91 int res;
92
93 WARN_ON(!mutex_is_locked(&hip->extents_lock));
94
95 hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,
96 HFSPLUS_IS_RSRC(inode) ?
97 HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
98
99 res = hfs_brec_find(fd, hfs_find_rec_by_key);
100 if (hip->extent_state & HFSPLUS_EXT_NEW) {
101 if (res != -ENOENT)
102 return res;
103 /* Fail early and avoid ENOSPC during the btree operation */
104 res = hfs_bmap_reserve(fd->tree, fd->tree->depth + 1);
105 if (res)
106 return res;
107 hfs_brec_insert(fd, hip->cached_extents,
108 sizeof(hfsplus_extent_rec));
109 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
110 } else {
111 if (res)
112 return res;
113 hfs_bnode_write(fd->bnode, hip->cached_extents,
114 fd->entryoffset, fd->entrylength);
115 hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
116 }
117
118 /*
119 * We can't just use hfsplus_mark_inode_dirty here, because we
120 * also get called from hfsplus_write_inode, which should not
121 * redirty the inode. Instead the callers have to be careful
122 * to explicily mark the inode dirty, too.
123 */
124 set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
125
126 return 0;
127 }
128
129 static int hfsplus_ext_write_extent_locked(struct inode *inode)
130 {
131 int res = 0;
132
133 if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
134 struct hfs_find_data fd;
135
136 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
137 if (res)
138 return res;
139 res = __hfsplus_ext_write_extent(inode, &fd);
140 hfs_find_exit(&fd);
141 }
142 return res;
143 }
144
145 int hfsplus_ext_write_extent(struct inode *inode)
146 {
147 int res;
148
149 mutex_lock(&HFSPLUS_I(inode)->extents_lock);
150 res = hfsplus_ext_write_extent_locked(inode);
151 mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
152
153 return res;
154 }
155
156 static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
157 struct hfsplus_extent *extent,
158 u32 cnid, u32 block, u8 type)
159 {
160 int res;
161
162 hfsplus_ext_build_key(fd->search_key, cnid, block, type);
163 fd->key->ext.cnid = 0;
164 res = hfs_brec_find(fd, hfs_find_rec_by_key);
165 if (res && res != -ENOENT)
166 return res;
167 if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
168 fd->key->ext.fork_type != fd->search_key->ext.fork_type)
169 return -ENOENT;
170 if (fd->entrylength != sizeof(hfsplus_extent_rec))
171 return -EIO;
172 hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
173 sizeof(hfsplus_extent_rec));
174 return 0;
175 }
176
177 static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
178 struct inode *inode, u32 block)
179 {
180 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
181 int res;
182
183 WARN_ON(!mutex_is_locked(&hip->extents_lock));
184
185 if (hip->extent_state & HFSPLUS_EXT_DIRTY) {
186 res = __hfsplus_ext_write_extent(inode, fd);
187 if (res)
188 return res;
189 }
190
191 res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
192 block, HFSPLUS_IS_RSRC(inode) ?
193 HFSPLUS_TYPE_RSRC :
194 HFSPLUS_TYPE_DATA);
195 if (!res) {
196 hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
197 hip->cached_blocks =
198 hfsplus_ext_block_count(hip->cached_extents);
199 } else {
200 hip->cached_start = hip->cached_blocks = 0;
201 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
202 }
203 return res;
204 }
205
206 static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
207 {
208 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
209 struct hfs_find_data fd;
210 int res;
211
212 if (block >= hip->cached_start &&
213 block < hip->cached_start + hip->cached_blocks)
214 return 0;
215
216 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
217 if (!res) {
218 res = __hfsplus_ext_cache_extent(&fd, inode, block);
219 hfs_find_exit(&fd);
220 }
221 return res;
222 }
223
224 /* Get a block at iblock for inode, possibly allocating if create */
225 int hfsplus_get_block(struct inode *inode, sector_t iblock,
226 struct buffer_head *bh_result, int create)
227 {
228 struct super_block *sb = inode->i_sb;
229 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
230 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
231 int res = -EIO;
232 u32 ablock, dblock, mask;
233 sector_t sector;
234 int was_dirty = 0;
235
236 /* Convert inode block to disk allocation block */
237 ablock = iblock >> sbi->fs_shift;
238
239 if (iblock >= hip->fs_blocks) {
240 if (!create)
241 return 0;
242 if (iblock > hip->fs_blocks)
243 return -EIO;
244 if (ablock >= hip->alloc_blocks) {
245 res = hfsplus_file_extend(inode, false);
246 if (res)
247 return res;
248 }
249 } else
250 create = 0;
251
252 if (ablock < hip->first_blocks) {
253 dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
254 goto done;
255 }
256
257 if (inode->i_ino == HFSPLUS_EXT_CNID)
258 return -EIO;
259
260 mutex_lock(&hip->extents_lock);
261
262 /*
263 * hfsplus_ext_read_extent will write out a cached extent into
264 * the extents btree. In that case we may have to mark the inode
265 * dirty even for a pure read of an extent here.
266 */
267 was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
268 res = hfsplus_ext_read_extent(inode, ablock);
269 if (res) {
270 mutex_unlock(&hip->extents_lock);
271 return -EIO;
272 }
273 dblock = hfsplus_ext_find_block(hip->cached_extents,
274 ablock - hip->cached_start);
275 mutex_unlock(&hip->extents_lock);
276
277 done:
278 hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n",
279 inode->i_ino, (long long)iblock, dblock);
280
281 mask = (1 << sbi->fs_shift) - 1;
282 sector = ((sector_t)dblock << sbi->fs_shift) +
283 sbi->blockoffset + (iblock & mask);
284 map_bh(bh_result, sb, sector);
285
286 if (create) {
287 set_buffer_new(bh_result);
288 hip->phys_size += sb->s_blocksize;
289 hip->fs_blocks++;
290 inode_add_bytes(inode, sb->s_blocksize);
291 }
292 if (create || was_dirty)
293 mark_inode_dirty(inode);
294 return 0;
295 }
296
297 static void hfsplus_dump_extent(struct hfsplus_extent *extent)
298 {
299 int i;
300
301 hfs_dbg(EXTENT, " ");
302 for (i = 0; i < 8; i++)
303 hfs_dbg_cont(EXTENT, " %u:%u",
304 be32_to_cpu(extent[i].start_block),
305 be32_to_cpu(extent[i].block_count));
306 hfs_dbg_cont(EXTENT, "\n");
307 }
308
309 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
310 u32 alloc_block, u32 block_count)
311 {
312 u32 count, start;
313 int i;
314
315 hfsplus_dump_extent(extent);
316 for (i = 0; i < 8; extent++, i++) {
317 count = be32_to_cpu(extent->block_count);
318 if (offset == count) {
319 start = be32_to_cpu(extent->start_block);
320 if (alloc_block != start + count) {
321 if (++i >= 8)
322 return -ENOSPC;
323 extent++;
324 extent->start_block = cpu_to_be32(alloc_block);
325 } else
326 block_count += count;
327 extent->block_count = cpu_to_be32(block_count);
328 return 0;
329 } else if (offset < count)
330 break;
331 offset -= count;
332 }
333 /* panic? */
334 return -EIO;
335 }
336
337 static int hfsplus_free_extents(struct super_block *sb,
338 struct hfsplus_extent *extent,
339 u32 offset, u32 block_nr)
340 {
341 u32 count, start;
342 int i;
343 int err = 0;
344
345 /* Mapping the allocation file may lock the extent tree */
346 WARN_ON(mutex_is_locked(&HFSPLUS_SB(sb)->ext_tree->tree_lock));
347
348 hfsplus_dump_extent(extent);
349 for (i = 0; i < 8; extent++, i++) {
350 count = be32_to_cpu(extent->block_count);
351 if (offset == count)
352 goto found;
353 else if (offset < count)
354 break;
355 offset -= count;
356 }
357 /* panic? */
358 return -EIO;
359 found:
360 for (;;) {
361 start = be32_to_cpu(extent->start_block);
362 if (count <= block_nr) {
363 err = hfsplus_block_free(sb, start, count);
364 if (err) {
365 pr_err("can't free extent\n");
366 hfs_dbg(EXTENT, " start: %u count: %u\n",
367 start, count);
368 }
369 extent->block_count = 0;
370 extent->start_block = 0;
371 block_nr -= count;
372 } else {
373 count -= block_nr;
374 err = hfsplus_block_free(sb, start + count, block_nr);
375 if (err) {
376 pr_err("can't free extent\n");
377 hfs_dbg(EXTENT, " start: %u count: %u\n",
378 start, count);
379 }
380 extent->block_count = cpu_to_be32(count);
381 block_nr = 0;
382 }
383 if (!block_nr || !i) {
384 /*
385 * Try to free all extents and
386 * return only last error
387 */
388 return err;
389 }
390 i--;
391 extent--;
392 count = be32_to_cpu(extent->block_count);
393 }
394 }
395
396 int hfsplus_free_fork(struct super_block *sb, u32 cnid,
397 struct hfsplus_fork_raw *fork, int type)
398 {
399 struct hfs_find_data fd;
400 hfsplus_extent_rec ext_entry;
401 u32 total_blocks, blocks, start;
402 int res, i;
403
404 total_blocks = be32_to_cpu(fork->total_blocks);
405 if (!total_blocks)
406 return 0;
407
408 blocks = 0;
409 for (i = 0; i < 8; i++)
410 blocks += be32_to_cpu(fork->extents[i].block_count);
411
412 res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
413 if (res)
414 return res;
415 if (total_blocks == blocks)
416 return 0;
417
418 res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
419 if (res)
420 return res;
421 do {
422 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
423 total_blocks, type);
424 if (res)
425 break;
426 start = be32_to_cpu(fd.key->ext.start_block);
427 hfs_brec_remove(&fd);
428
429 mutex_unlock(&fd.tree->tree_lock);
430 hfsplus_free_extents(sb, ext_entry, total_blocks - start,
431 total_blocks);
432 total_blocks = start;
433 mutex_lock_nested(&fd.tree->tree_lock,
434 hfsplus_btree_lock_class(fd.tree));
435 } while (total_blocks > blocks);
436 hfs_find_exit(&fd);
437
438 return res;
439 }
440
441 int hfsplus_file_extend(struct inode *inode, bool zeroout)
442 {
443 struct super_block *sb = inode->i_sb;
444 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
445 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
446 u32 start, len, goal;
447 int res;
448
449 if (sbi->alloc_file->i_size * 8 <
450 sbi->total_blocks - sbi->free_blocks + 8) {
451 /* extend alloc file */
452 pr_err_ratelimited("extend alloc file! (%llu,%u,%u)\n",
453 sbi->alloc_file->i_size * 8,
454 sbi->total_blocks, sbi->free_blocks);
455 return -ENOSPC;
456 }
457
458 mutex_lock(&hip->extents_lock);
459 if (hip->alloc_blocks == hip->first_blocks)
460 goal = hfsplus_ext_lastblock(hip->first_extents);
461 else {
462 res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
463 if (res)
464 goto out;
465 goal = hfsplus_ext_lastblock(hip->cached_extents);
466 }
467
468 len = hip->clump_blocks;
469 start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
470 if (start >= sbi->total_blocks) {
471 start = hfsplus_block_allocate(sb, goal, 0, &len);
472 if (start >= goal) {
473 res = -ENOSPC;
474 goto out;
475 }
476 }
477
478 if (zeroout) {
479 res = sb_issue_zeroout(sb, start, len, GFP_NOFS);
480 if (res)
481 goto out;
482 }
483
484 hfs_dbg(EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
485
486 if (hip->alloc_blocks <= hip->first_blocks) {
487 if (!hip->first_blocks) {
488 hfs_dbg(EXTENT, "first extents\n");
489 /* no extents yet */
490 hip->first_extents[0].start_block = cpu_to_be32(start);
491 hip->first_extents[0].block_count = cpu_to_be32(len);
492 res = 0;
493 } else {
494 /* try to append to extents in inode */
495 res = hfsplus_add_extent(hip->first_extents,
496 hip->alloc_blocks,
497 start, len);
498 if (res == -ENOSPC)
499 goto insert_extent;
500 }
501 if (!res) {
502 hfsplus_dump_extent(hip->first_extents);
503 hip->first_blocks += len;
504 }
505 } else {
506 res = hfsplus_add_extent(hip->cached_extents,
507 hip->alloc_blocks - hip->cached_start,
508 start, len);
509 if (!res) {
510 hfsplus_dump_extent(hip->cached_extents);
511 hip->extent_state |= HFSPLUS_EXT_DIRTY;
512 hip->cached_blocks += len;
513 } else if (res == -ENOSPC)
514 goto insert_extent;
515 }
516 out:
517 if (!res) {
518 hip->alloc_blocks += len;
519 mutex_unlock(&hip->extents_lock);
520 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
521 return 0;
522 }
523 mutex_unlock(&hip->extents_lock);
524 return res;
525
526 insert_extent:
527 hfs_dbg(EXTENT, "insert new extent\n");
528 res = hfsplus_ext_write_extent_locked(inode);
529 if (res)
530 goto out;
531
532 memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
533 hip->cached_extents[0].start_block = cpu_to_be32(start);
534 hip->cached_extents[0].block_count = cpu_to_be32(len);
535 hfsplus_dump_extent(hip->cached_extents);
536 hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
537 hip->cached_start = hip->alloc_blocks;
538 hip->cached_blocks = len;
539
540 res = 0;
541 goto out;
542 }
543
544 void hfsplus_file_truncate(struct inode *inode)
545 {
546 struct super_block *sb = inode->i_sb;
547 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
548 struct hfs_find_data fd;
549 u32 alloc_cnt, blk_cnt, start;
550 int res;
551
552 hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\n",
553 inode->i_ino, (long long)hip->phys_size, inode->i_size);
554
555 if (inode->i_size > hip->phys_size) {
556 struct address_space *mapping = inode->i_mapping;
557 struct page *page;
558 void *fsdata = NULL;
559 loff_t size = inode->i_size;
560
561 res = hfsplus_write_begin(NULL, mapping, size, 0,
562 &page, &fsdata);
563 if (res)
564 return;
565 res = generic_write_end(NULL, mapping, size, 0, 0,
566 page, fsdata);
567 if (res < 0)
568 return;
569 mark_inode_dirty(inode);
570 return;
571 } else if (inode->i_size == hip->phys_size)
572 return;
573
574 blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
575 HFSPLUS_SB(sb)->alloc_blksz_shift;
576
577 mutex_lock(&hip->extents_lock);
578
579 alloc_cnt = hip->alloc_blocks;
580 if (blk_cnt == alloc_cnt)
581 goto out_unlock;
582
583 res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
584 if (res) {
585 mutex_unlock(&hip->extents_lock);
586 /* XXX: We lack error handling of hfsplus_file_truncate() */
587 return;
588 }
589 while (1) {
590 if (alloc_cnt == hip->first_blocks) {
591 mutex_unlock(&fd.tree->tree_lock);
592 hfsplus_free_extents(sb, hip->first_extents,
593 alloc_cnt, alloc_cnt - blk_cnt);
594 hfsplus_dump_extent(hip->first_extents);
595 hip->first_blocks = blk_cnt;
596 mutex_lock_nested(&fd.tree->tree_lock,
597 hfsplus_btree_lock_class(fd.tree));
598 break;
599 }
600 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
601 if (res)
602 break;
603
604 start = hip->cached_start;
605 if (blk_cnt <= start)
606 hfs_brec_remove(&fd);
607 mutex_unlock(&fd.tree->tree_lock);
608 hfsplus_free_extents(sb, hip->cached_extents,
609 alloc_cnt - start, alloc_cnt - blk_cnt);
610 hfsplus_dump_extent(hip->cached_extents);
611 mutex_lock_nested(&fd.tree->tree_lock,
612 hfsplus_btree_lock_class(fd.tree));
613 if (blk_cnt > start) {
614 hip->extent_state |= HFSPLUS_EXT_DIRTY;
615 break;
616 }
617 alloc_cnt = start;
618 hip->cached_start = hip->cached_blocks = 0;
619 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
620 }
621 hfs_find_exit(&fd);
622
623 hip->alloc_blocks = blk_cnt;
624 out_unlock:
625 mutex_unlock(&hip->extents_lock);
626 hip->phys_size = inode->i_size;
627 hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
628 sb->s_blocksize_bits;
629 inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
630 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
631 }
632
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