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 */
hfsplus_ext_cmp_key(const hfsplus_btree_key * k1,const hfsplus_btree_key * k2)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
hfsplus_ext_build_key(hfsplus_btree_key * key,u32 cnid,u32 block,u8 type)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
hfsplus_ext_find_block(struct hfsplus_extent * ext,u32 off)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
hfsplus_ext_block_count(struct hfsplus_extent * ext)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
hfsplus_ext_lastblock(struct hfsplus_extent * ext)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
__hfsplus_ext_write_extent(struct inode * inode,struct hfs_find_data * fd)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,
125 &HFSPLUS_I(HFSPLUS_EXT_TREE_I(inode->i_sb))->flags);
126 set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
127
128 return 0;
129 }
130
hfsplus_ext_write_extent_locked(struct inode * inode)131 static int hfsplus_ext_write_extent_locked(struct inode *inode)
132 {
133 int res = 0;
134
135 if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
136 struct hfs_find_data fd;
137
138 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
139 if (res)
140 return res;
141 res = __hfsplus_ext_write_extent(inode, &fd);
142 hfs_find_exit(&fd);
143 }
144 return res;
145 }
146
hfsplus_ext_write_extent(struct inode * inode)147 int hfsplus_ext_write_extent(struct inode *inode)
148 {
149 int res;
150
151 mutex_lock(&HFSPLUS_I(inode)->extents_lock);
152 res = hfsplus_ext_write_extent_locked(inode);
153 mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
154
155 return res;
156 }
157
__hfsplus_ext_read_extent(struct hfs_find_data * fd,struct hfsplus_extent * extent,u32 cnid,u32 block,u8 type)158 static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
159 struct hfsplus_extent *extent,
160 u32 cnid, u32 block, u8 type)
161 {
162 int res;
163
164 hfsplus_ext_build_key(fd->search_key, cnid, block, type);
165 fd->key->ext.cnid = 0;
166 res = hfs_brec_find(fd, hfs_find_rec_by_key);
167 if (res && res != -ENOENT)
168 return res;
169 if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
170 fd->key->ext.fork_type != fd->search_key->ext.fork_type)
171 return -ENOENT;
172 if (fd->entrylength != sizeof(hfsplus_extent_rec))
173 return -EIO;
174 hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
175 sizeof(hfsplus_extent_rec));
176 return 0;
177 }
178
__hfsplus_ext_cache_extent(struct hfs_find_data * fd,struct inode * inode,u32 block)179 static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
180 struct inode *inode, u32 block)
181 {
182 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
183 int res;
184
185 WARN_ON(!mutex_is_locked(&hip->extents_lock));
186
187 if (hip->extent_state & HFSPLUS_EXT_DIRTY) {
188 res = __hfsplus_ext_write_extent(inode, fd);
189 if (res)
190 return res;
191 }
192
193 res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
194 block, HFSPLUS_IS_RSRC(inode) ?
195 HFSPLUS_TYPE_RSRC :
196 HFSPLUS_TYPE_DATA);
197 if (!res) {
198 hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
199 hip->cached_blocks =
200 hfsplus_ext_block_count(hip->cached_extents);
201 } else {
202 hip->cached_start = hip->cached_blocks = 0;
203 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
204 }
205 return res;
206 }
207
hfsplus_ext_read_extent(struct inode * inode,u32 block)208 static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
209 {
210 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
211 struct hfs_find_data fd;
212 int res;
213
214 if (block >= hip->cached_start &&
215 block < hip->cached_start + hip->cached_blocks)
216 return 0;
217
218 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
219 if (!res) {
220 res = __hfsplus_ext_cache_extent(&fd, inode, block);
221 hfs_find_exit(&fd);
222 }
223 return res;
224 }
225
226 /* 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)227 int hfsplus_get_block(struct inode *inode, sector_t iblock,
228 struct buffer_head *bh_result, int create)
229 {
230 struct super_block *sb = inode->i_sb;
231 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
232 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
233 int res = -EIO;
234 u32 ablock, dblock, mask;
235 sector_t sector;
236 int was_dirty = 0;
237
238 /* Convert inode block to disk allocation block */
239 ablock = iblock >> sbi->fs_shift;
240
241 if (iblock >= hip->fs_blocks) {
242 if (!create)
243 return 0;
244 if (iblock > hip->fs_blocks)
245 return -EIO;
246 if (ablock >= hip->alloc_blocks) {
247 res = hfsplus_file_extend(inode, false);
248 if (res)
249 return res;
250 }
251 } else
252 create = 0;
253
254 if (ablock < hip->first_blocks) {
255 dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
256 goto done;
257 }
258
259 if (inode->i_ino == HFSPLUS_EXT_CNID)
260 return -EIO;
261
262 mutex_lock(&hip->extents_lock);
263
264 /*
265 * hfsplus_ext_read_extent will write out a cached extent into
266 * the extents btree. In that case we may have to mark the inode
267 * dirty even for a pure read of an extent here.
268 */
269 was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
270 res = hfsplus_ext_read_extent(inode, ablock);
271 if (res) {
272 mutex_unlock(&hip->extents_lock);
273 return -EIO;
274 }
275 dblock = hfsplus_ext_find_block(hip->cached_extents,
276 ablock - hip->cached_start);
277 mutex_unlock(&hip->extents_lock);
278
279 done:
280 hfs_dbg("ino %llu, iblock %llu - dblock %u\n",
281 inode->i_ino, (long long)iblock, dblock);
282
283 mask = (1 << sbi->fs_shift) - 1;
284 sector = ((sector_t)dblock << sbi->fs_shift) +
285 sbi->blockoffset + (iblock & mask);
286 map_bh(bh_result, sb, sector);
287
288 if (create) {
289 set_buffer_new(bh_result);
290 hip->phys_size += sb->s_blocksize;
291 hip->fs_blocks++;
292 inode_add_bytes(inode, sb->s_blocksize);
293 }
294 if (create || was_dirty)
295 mark_inode_dirty(inode);
296 return 0;
297 }
298
hfsplus_dump_extent(struct hfsplus_extent * extent)299 static void hfsplus_dump_extent(struct hfsplus_extent *extent)
300 {
301 int i;
302
303 hfs_dbg("extent ");
304 for (i = 0; i < 8; i++)
305 hfs_dbg(" start_block %u, block_count %u",
306 be32_to_cpu(extent[i].start_block),
307 be32_to_cpu(extent[i].block_count));
308 hfs_dbg("\n");
309 }
310
hfsplus_add_extent(struct hfsplus_extent * extent,u32 offset,u32 alloc_block,u32 block_count)311 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
312 u32 alloc_block, u32 block_count)
313 {
314 u32 count, start;
315 int i;
316
317 hfsplus_dump_extent(extent);
318 for (i = 0; i < 8; extent++, i++) {
319 count = be32_to_cpu(extent->block_count);
320 if (offset == count) {
321 start = be32_to_cpu(extent->start_block);
322 if (alloc_block != start + count) {
323 if (++i >= 8)
324 return -ENOSPC;
325 extent++;
326 extent->start_block = cpu_to_be32(alloc_block);
327 } else
328 block_count += count;
329 extent->block_count = cpu_to_be32(block_count);
330 return 0;
331 } else if (offset < count)
332 break;
333 offset -= count;
334 }
335 /* panic? */
336 return -EIO;
337 }
338
hfsplus_free_extents(struct super_block * sb,struct hfsplus_extent * extent,u32 offset,u32 block_nr)339 static int hfsplus_free_extents(struct super_block *sb,
340 struct hfsplus_extent *extent,
341 u32 offset, u32 block_nr)
342 {
343 u32 count, start;
344 int i;
345 int err = 0;
346
347 hfsplus_dump_extent(extent);
348 for (i = 0; i < 8; extent++, i++) {
349 count = be32_to_cpu(extent->block_count);
350 if (offset == count)
351 goto found;
352 else if (offset < count)
353 break;
354 offset -= count;
355 }
356 /* panic? */
357 return -EIO;
358 found:
359 for (;;) {
360 start = be32_to_cpu(extent->start_block);
361 if (count <= block_nr) {
362 err = hfsplus_block_free(sb, start, count);
363 if (err) {
364 pr_err("can't free extent: start %u, count %u\n",
365 start, count);
366 }
367 extent->block_count = 0;
368 extent->start_block = 0;
369 block_nr -= count;
370 } else {
371 count -= block_nr;
372 err = hfsplus_block_free(sb, start + count, block_nr);
373 if (err) {
374 pr_err("can't free extent: start %u, count %u\n",
375 start, count);
376 }
377 extent->block_count = cpu_to_be32(count);
378 block_nr = 0;
379 }
380 if (!block_nr || !i) {
381 /*
382 * Try to free all extents and
383 * return only last error
384 */
385 return err;
386 }
387 i--;
388 extent--;
389 count = be32_to_cpu(extent->block_count);
390 }
391 }
392
hfsplus_free_fork(struct super_block * sb,u32 cnid,struct hfsplus_fork_raw * fork,int type)393 int hfsplus_free_fork(struct super_block *sb, u32 cnid,
394 struct hfsplus_fork_raw *fork, int type)
395 {
396 struct hfs_find_data fd;
397 hfsplus_extent_rec ext_entry;
398 u32 total_blocks, blocks, start;
399 int res, i;
400
401 total_blocks = be32_to_cpu(fork->total_blocks);
402 if (!total_blocks)
403 return 0;
404
405 blocks = 0;
406 for (i = 0; i < 8; i++)
407 blocks += be32_to_cpu(fork->extents[i].block_count);
408
409 res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
410 if (res)
411 return res;
412 if (total_blocks == blocks)
413 return 0;
414
415 res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
416 if (res)
417 return res;
418 do {
419 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
420 total_blocks, type);
421 if (res)
422 break;
423 start = be32_to_cpu(fd.key->ext.start_block);
424 hfs_brec_remove(&fd);
425
426 mutex_unlock(&fd.tree->tree_lock);
427 hfsplus_free_extents(sb, ext_entry, total_blocks - start,
428 total_blocks);
429 total_blocks = start;
430 mutex_lock_nested(&fd.tree->tree_lock,
431 hfsplus_btree_lock_class(fd.tree));
432 } while (total_blocks > blocks);
433 hfs_find_exit(&fd);
434
435 return res;
436 }
437
hfsplus_file_extend(struct inode * inode,bool zeroout)438 int hfsplus_file_extend(struct inode *inode, bool zeroout)
439 {
440 struct super_block *sb = inode->i_sb;
441 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
442 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
443 u32 start, len, goal;
444 int res;
445
446 if (sbi->alloc_file->i_size * 8 <
447 sbi->total_blocks - sbi->free_blocks + 8) {
448 /* extend alloc file */
449 pr_err_ratelimited("extend alloc file! (%llu,%u,%u)\n",
450 sbi->alloc_file->i_size * 8,
451 sbi->total_blocks, sbi->free_blocks);
452 return -ENOSPC;
453 }
454
455 mutex_lock(&hip->extents_lock);
456 if (hip->alloc_blocks == hip->first_blocks)
457 goal = hfsplus_ext_lastblock(hip->first_extents);
458 else {
459 res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
460 if (res)
461 goto out;
462 goal = hfsplus_ext_lastblock(hip->cached_extents);
463 }
464
465 len = hip->clump_blocks;
466 start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
467 if (start >= sbi->total_blocks) {
468 start = hfsplus_block_allocate(sb, goal, 0, &len);
469 if (start >= goal) {
470 res = -ENOSPC;
471 goto out;
472 }
473 }
474
475 if (zeroout) {
476 res = sb_issue_zeroout(sb, start, len, GFP_NOFS);
477 if (res)
478 goto out;
479 }
480
481 hfs_dbg("ino %llu, start %u, len %u\n", inode->i_ino, start, len);
482
483 if (hip->alloc_blocks <= hip->first_blocks) {
484 if (!hip->first_blocks) {
485 hfs_dbg("first_extent: start %u, len %u\n",
486 start, len);
487 /* no extents yet */
488 hip->first_extents[0].start_block = cpu_to_be32(start);
489 hip->first_extents[0].block_count = cpu_to_be32(len);
490 res = 0;
491 } else {
492 /* try to append to extents in inode */
493 res = hfsplus_add_extent(hip->first_extents,
494 hip->alloc_blocks,
495 start, len);
496 if (res == -ENOSPC)
497 goto insert_extent;
498 }
499 if (!res) {
500 hfsplus_dump_extent(hip->first_extents);
501 hip->first_blocks += len;
502 }
503 } else {
504 res = hfsplus_add_extent(hip->cached_extents,
505 hip->alloc_blocks - hip->cached_start,
506 start, len);
507 if (!res) {
508 hfsplus_dump_extent(hip->cached_extents);
509 hip->extent_state |= HFSPLUS_EXT_DIRTY;
510 hip->cached_blocks += len;
511 } else if (res == -ENOSPC)
512 goto insert_extent;
513 }
514 out:
515 if (!res) {
516 hip->alloc_blocks += len;
517 mutex_unlock(&hip->extents_lock);
518 hfsplus_mark_inode_dirty(HFSPLUS_SB(sb)->alloc_file,
519 HFSPLUS_I_ALLOC_DIRTY);
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("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
hfsplus_file_truncate(struct inode * inode)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("ino %llu, phys_size %llu -> i_size %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 folio *folio;
558 void *fsdata = NULL;
559 loff_t size = inode->i_size;
560
561 res = hfsplus_write_begin(NULL, mapping, size, 0,
562 &folio, &fsdata);
563 if (res)
564 return;
565 res = generic_write_end(NULL, mapping, size, 0, 0,
566 folio, 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
590 while (1) {
591 if (alloc_cnt == hip->first_blocks) {
592 mutex_unlock(&fd.tree->tree_lock);
593 hfsplus_free_extents(sb, hip->first_extents,
594 alloc_cnt, alloc_cnt - blk_cnt);
595 hfsplus_dump_extent(hip->first_extents);
596 hip->first_blocks = blk_cnt;
597 mutex_lock_nested(&fd.tree->tree_lock,
598 hfsplus_btree_lock_class(fd.tree));
599 break;
600 }
601 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
602 if (res)
603 break;
604
605 start = hip->cached_start;
606 if (blk_cnt <= start)
607 hfs_brec_remove(&fd);
608 mutex_unlock(&fd.tree->tree_lock);
609 hfsplus_free_extents(sb, hip->cached_extents,
610 alloc_cnt - start, alloc_cnt - blk_cnt);
611 hfsplus_dump_extent(hip->cached_extents);
612 mutex_lock_nested(&fd.tree->tree_lock,
613 hfsplus_btree_lock_class(fd.tree));
614 if (blk_cnt > start) {
615 hip->extent_state |= HFSPLUS_EXT_DIRTY;
616 break;
617 }
618 alloc_cnt = start;
619 hip->cached_start = hip->cached_blocks = 0;
620 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
621 }
622 hfs_find_exit(&fd);
623
624 hip->alloc_blocks = blk_cnt;
625 out_unlock:
626 mutex_unlock(&hip->extents_lock);
627 hip->phys_size = inode->i_size;
628 hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
629 sb->s_blocksize_bits;
630 inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
631 hfsplus_mark_inode_dirty(HFSPLUS_SB(sb)->alloc_file,
632 HFSPLUS_I_ALLOC_DIRTY);
633 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
634 }
635