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 hfs_brec_insert(fd, hip->cached_extents,
104 sizeof(hfsplus_extent_rec));
105 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
106 } else {
107 if (res)
108 return res;
109 hfs_bnode_write(fd->bnode, hip->cached_extents,
110 fd->entryoffset, fd->entrylength);
111 hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
112 }
113
114 /*
115 * We can't just use hfsplus_mark_inode_dirty here, because we
116 * also get called from hfsplus_write_inode, which should not
117 * redirty the inode. Instead the callers have to be careful
118 * to explicily mark the inode dirty, too.
119 */
120 set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
121
122 return 0;
123 }
124
hfsplus_ext_write_extent_locked(struct inode * inode)125 static int hfsplus_ext_write_extent_locked(struct inode *inode)
126 {
127 int res = 0;
128
129 if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
130 struct hfs_find_data fd;
131
132 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
133 if (res)
134 return res;
135 res = __hfsplus_ext_write_extent(inode, &fd);
136 hfs_find_exit(&fd);
137 }
138 return res;
139 }
140
hfsplus_ext_write_extent(struct inode * inode)141 int hfsplus_ext_write_extent(struct inode *inode)
142 {
143 int res;
144
145 mutex_lock(&HFSPLUS_I(inode)->extents_lock);
146 res = hfsplus_ext_write_extent_locked(inode);
147 mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
148
149 return res;
150 }
151
__hfsplus_ext_read_extent(struct hfs_find_data * fd,struct hfsplus_extent * extent,u32 cnid,u32 block,u8 type)152 static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
153 struct hfsplus_extent *extent,
154 u32 cnid, u32 block, u8 type)
155 {
156 int res;
157
158 hfsplus_ext_build_key(fd->search_key, cnid, block, type);
159 fd->key->ext.cnid = 0;
160 res = hfs_brec_find(fd, hfs_find_rec_by_key);
161 if (res && res != -ENOENT)
162 return res;
163 if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
164 fd->key->ext.fork_type != fd->search_key->ext.fork_type)
165 return -ENOENT;
166 if (fd->entrylength != sizeof(hfsplus_extent_rec))
167 return -EIO;
168 hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
169 sizeof(hfsplus_extent_rec));
170 return 0;
171 }
172
__hfsplus_ext_cache_extent(struct hfs_find_data * fd,struct inode * inode,u32 block)173 static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
174 struct inode *inode, u32 block)
175 {
176 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
177 int res;
178
179 WARN_ON(!mutex_is_locked(&hip->extents_lock));
180
181 if (hip->extent_state & HFSPLUS_EXT_DIRTY) {
182 res = __hfsplus_ext_write_extent(inode, fd);
183 if (res)
184 return res;
185 }
186
187 res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
188 block, HFSPLUS_IS_RSRC(inode) ?
189 HFSPLUS_TYPE_RSRC :
190 HFSPLUS_TYPE_DATA);
191 if (!res) {
192 hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
193 hip->cached_blocks =
194 hfsplus_ext_block_count(hip->cached_extents);
195 } else {
196 hip->cached_start = hip->cached_blocks = 0;
197 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
198 }
199 return res;
200 }
201
hfsplus_ext_read_extent(struct inode * inode,u32 block)202 static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
203 {
204 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
205 struct hfs_find_data fd;
206 int res;
207
208 if (block >= hip->cached_start &&
209 block < hip->cached_start + hip->cached_blocks)
210 return 0;
211
212 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
213 if (!res) {
214 res = __hfsplus_ext_cache_extent(&fd, inode, block);
215 hfs_find_exit(&fd);
216 }
217 return res;
218 }
219
220 /* 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)221 int hfsplus_get_block(struct inode *inode, sector_t iblock,
222 struct buffer_head *bh_result, int create)
223 {
224 struct super_block *sb = inode->i_sb;
225 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
226 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
227 int res = -EIO;
228 u32 ablock, dblock, mask;
229 sector_t sector;
230 int was_dirty = 0;
231
232 /* Convert inode block to disk allocation block */
233 ablock = iblock >> sbi->fs_shift;
234
235 if (iblock >= hip->fs_blocks) {
236 if (iblock > hip->fs_blocks || !create)
237 return -EIO;
238 if (ablock >= hip->alloc_blocks) {
239 res = hfsplus_file_extend(inode, false);
240 if (res)
241 return res;
242 }
243 } else
244 create = 0;
245
246 if (ablock < hip->first_blocks) {
247 dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
248 goto done;
249 }
250
251 if (inode->i_ino == HFSPLUS_EXT_CNID)
252 return -EIO;
253
254 mutex_lock(&hip->extents_lock);
255
256 /*
257 * hfsplus_ext_read_extent will write out a cached extent into
258 * the extents btree. In that case we may have to mark the inode
259 * dirty even for a pure read of an extent here.
260 */
261 was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
262 res = hfsplus_ext_read_extent(inode, ablock);
263 if (res) {
264 mutex_unlock(&hip->extents_lock);
265 return -EIO;
266 }
267 dblock = hfsplus_ext_find_block(hip->cached_extents,
268 ablock - hip->cached_start);
269 mutex_unlock(&hip->extents_lock);
270
271 done:
272 hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n",
273 inode->i_ino, (long long)iblock, dblock);
274
275 mask = (1 << sbi->fs_shift) - 1;
276 sector = ((sector_t)dblock << sbi->fs_shift) +
277 sbi->blockoffset + (iblock & mask);
278 map_bh(bh_result, sb, sector);
279
280 if (create) {
281 set_buffer_new(bh_result);
282 hip->phys_size += sb->s_blocksize;
283 hip->fs_blocks++;
284 inode_add_bytes(inode, sb->s_blocksize);
285 }
286 if (create || was_dirty)
287 mark_inode_dirty(inode);
288 return 0;
289 }
290
hfsplus_dump_extent(struct hfsplus_extent * extent)291 static void hfsplus_dump_extent(struct hfsplus_extent *extent)
292 {
293 int i;
294
295 hfs_dbg(EXTENT, " ");
296 for (i = 0; i < 8; i++)
297 hfs_dbg_cont(EXTENT, " %u:%u",
298 be32_to_cpu(extent[i].start_block),
299 be32_to_cpu(extent[i].block_count));
300 hfs_dbg_cont(EXTENT, "\n");
301 }
302
hfsplus_add_extent(struct hfsplus_extent * extent,u32 offset,u32 alloc_block,u32 block_count)303 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
304 u32 alloc_block, u32 block_count)
305 {
306 u32 count, start;
307 int i;
308
309 hfsplus_dump_extent(extent);
310 for (i = 0; i < 8; extent++, i++) {
311 count = be32_to_cpu(extent->block_count);
312 if (offset == count) {
313 start = be32_to_cpu(extent->start_block);
314 if (alloc_block != start + count) {
315 if (++i >= 8)
316 return -ENOSPC;
317 extent++;
318 extent->start_block = cpu_to_be32(alloc_block);
319 } else
320 block_count += count;
321 extent->block_count = cpu_to_be32(block_count);
322 return 0;
323 } else if (offset < count)
324 break;
325 offset -= count;
326 }
327 /* panic? */
328 return -EIO;
329 }
330
hfsplus_free_extents(struct super_block * sb,struct hfsplus_extent * extent,u32 offset,u32 block_nr)331 static int hfsplus_free_extents(struct super_block *sb,
332 struct hfsplus_extent *extent,
333 u32 offset, u32 block_nr)
334 {
335 u32 count, start;
336 int i;
337 int err = 0;
338
339 /* Mapping the allocation file may lock the extent tree */
340 WARN_ON(mutex_is_locked(&HFSPLUS_SB(sb)->ext_tree->tree_lock));
341
342 hfsplus_dump_extent(extent);
343 for (i = 0; i < 8; extent++, i++) {
344 count = be32_to_cpu(extent->block_count);
345 if (offset == count)
346 goto found;
347 else if (offset < count)
348 break;
349 offset -= count;
350 }
351 /* panic? */
352 return -EIO;
353 found:
354 for (;;) {
355 start = be32_to_cpu(extent->start_block);
356 if (count <= block_nr) {
357 err = hfsplus_block_free(sb, start, count);
358 if (err) {
359 pr_err("can't free extent\n");
360 hfs_dbg(EXTENT, " start: %u count: %u\n",
361 start, count);
362 }
363 extent->block_count = 0;
364 extent->start_block = 0;
365 block_nr -= count;
366 } else {
367 count -= block_nr;
368 err = hfsplus_block_free(sb, start + count, block_nr);
369 if (err) {
370 pr_err("can't free extent\n");
371 hfs_dbg(EXTENT, " start: %u count: %u\n",
372 start, count);
373 }
374 extent->block_count = cpu_to_be32(count);
375 block_nr = 0;
376 }
377 if (!block_nr || !i) {
378 /*
379 * Try to free all extents and
380 * return only last error
381 */
382 return err;
383 }
384 i--;
385 extent--;
386 count = be32_to_cpu(extent->block_count);
387 }
388 }
389
hfsplus_free_fork(struct super_block * sb,u32 cnid,struct hfsplus_fork_raw * fork,int type)390 int hfsplus_free_fork(struct super_block *sb, u32 cnid,
391 struct hfsplus_fork_raw *fork, int type)
392 {
393 struct hfs_find_data fd;
394 hfsplus_extent_rec ext_entry;
395 u32 total_blocks, blocks, start;
396 int res, i;
397
398 total_blocks = be32_to_cpu(fork->total_blocks);
399 if (!total_blocks)
400 return 0;
401
402 blocks = 0;
403 for (i = 0; i < 8; i++)
404 blocks += be32_to_cpu(fork->extents[i].block_count);
405
406 res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
407 if (res)
408 return res;
409 if (total_blocks == blocks)
410 return 0;
411
412 res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
413 if (res)
414 return res;
415 do {
416 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
417 total_blocks, type);
418 if (res)
419 break;
420 start = be32_to_cpu(fd.key->ext.start_block);
421 hfs_brec_remove(&fd);
422
423 mutex_unlock(&fd.tree->tree_lock);
424 hfsplus_free_extents(sb, ext_entry, total_blocks - start,
425 total_blocks);
426 total_blocks = start;
427 mutex_lock(&fd.tree->tree_lock);
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, 0,
555 &page, &fsdata);
556 if (res)
557 return;
558 res = pagecache_write_end(NULL, mapping, size,
559 0, 0, page, fsdata);
560 if (res < 0)
561 return;
562 mark_inode_dirty(inode);
563 return;
564 } else if (inode->i_size == hip->phys_size)
565 return;
566
567 blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
568 HFSPLUS_SB(sb)->alloc_blksz_shift;
569
570 mutex_lock(&hip->extents_lock);
571
572 alloc_cnt = hip->alloc_blocks;
573 if (blk_cnt == alloc_cnt)
574 goto out_unlock;
575
576 res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
577 if (res) {
578 mutex_unlock(&hip->extents_lock);
579 /* XXX: We lack error handling of hfsplus_file_truncate() */
580 return;
581 }
582 while (1) {
583 if (alloc_cnt == hip->first_blocks) {
584 mutex_unlock(&fd.tree->tree_lock);
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 mutex_lock(&fd.tree->tree_lock);
590 break;
591 }
592 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
593 if (res)
594 break;
595 hfs_brec_remove(&fd);
596
597 mutex_unlock(&fd.tree->tree_lock);
598 start = hip->cached_start;
599 hfsplus_free_extents(sb, hip->cached_extents,
600 alloc_cnt - start, alloc_cnt - blk_cnt);
601 hfsplus_dump_extent(hip->cached_extents);
602 if (blk_cnt > start) {
603 hip->extent_state |= HFSPLUS_EXT_DIRTY;
604 break;
605 }
606 alloc_cnt = start;
607 hip->cached_start = hip->cached_blocks = 0;
608 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
609 mutex_lock(&fd.tree->tree_lock);
610 }
611 hfs_find_exit(&fd);
612
613 hip->alloc_blocks = blk_cnt;
614 out_unlock:
615 mutex_unlock(&hip->extents_lock);
616 hip->phys_size = inode->i_size;
617 hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
618 sb->s_blocksize_bits;
619 inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
620 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
621 }
622
