GNU Linux-libre 4.19.211-gnu1
[releases.git] / fs / hfsplus / extents.c
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(&fd.tree->tree_lock);
434         } while (total_blocks > blocks);
435         hfs_find_exit(&fd);
436
437         return res;
438 }
439
440 int hfsplus_file_extend(struct inode *inode, bool zeroout)
441 {
442         struct super_block *sb = inode->i_sb;
443         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
444         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
445         u32 start, len, goal;
446         int res;
447
448         if (sbi->alloc_file->i_size * 8 <
449             sbi->total_blocks - sbi->free_blocks + 8) {
450                 /* extend alloc file */
451                 pr_err("extend alloc file! (%llu,%u,%u)\n",
452                        sbi->alloc_file->i_size * 8,
453                        sbi->total_blocks, sbi->free_blocks);
454                 return -ENOSPC;
455         }
456
457         mutex_lock(&hip->extents_lock);
458         if (hip->alloc_blocks == hip->first_blocks)
459                 goal = hfsplus_ext_lastblock(hip->first_extents);
460         else {
461                 res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
462                 if (res)
463                         goto out;
464                 goal = hfsplus_ext_lastblock(hip->cached_extents);
465         }
466
467         len = hip->clump_blocks;
468         start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
469         if (start >= sbi->total_blocks) {
470                 start = hfsplus_block_allocate(sb, goal, 0, &len);
471                 if (start >= goal) {
472                         res = -ENOSPC;
473                         goto out;
474                 }
475         }
476
477         if (zeroout) {
478                 res = sb_issue_zeroout(sb, start, len, GFP_NOFS);
479                 if (res)
480                         goto out;
481         }
482
483         hfs_dbg(EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
484
485         if (hip->alloc_blocks <= hip->first_blocks) {
486                 if (!hip->first_blocks) {
487                         hfs_dbg(EXTENT, "first extents\n");
488                         /* no extents yet */
489                         hip->first_extents[0].start_block = cpu_to_be32(start);
490                         hip->first_extents[0].block_count = cpu_to_be32(len);
491                         res = 0;
492                 } else {
493                         /* try to append to extents in inode */
494                         res = hfsplus_add_extent(hip->first_extents,
495                                                  hip->alloc_blocks,
496                                                  start, len);
497                         if (res == -ENOSPC)
498                                 goto insert_extent;
499                 }
500                 if (!res) {
501                         hfsplus_dump_extent(hip->first_extents);
502                         hip->first_blocks += len;
503                 }
504         } else {
505                 res = hfsplus_add_extent(hip->cached_extents,
506                                          hip->alloc_blocks - hip->cached_start,
507                                          start, len);
508                 if (!res) {
509                         hfsplus_dump_extent(hip->cached_extents);
510                         hip->extent_state |= HFSPLUS_EXT_DIRTY;
511                         hip->cached_blocks += len;
512                 } else if (res == -ENOSPC)
513                         goto insert_extent;
514         }
515 out:
516         if (!res) {
517                 hip->alloc_blocks += len;
518                 mutex_unlock(&hip->extents_lock);
519                 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
520                 return 0;
521         }
522         mutex_unlock(&hip->extents_lock);
523         return res;
524
525 insert_extent:
526         hfs_dbg(EXTENT, "insert new extent\n");
527         res = hfsplus_ext_write_extent_locked(inode);
528         if (res)
529                 goto out;
530
531         memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
532         hip->cached_extents[0].start_block = cpu_to_be32(start);
533         hip->cached_extents[0].block_count = cpu_to_be32(len);
534         hfsplus_dump_extent(hip->cached_extents);
535         hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
536         hip->cached_start = hip->alloc_blocks;
537         hip->cached_blocks = len;
538
539         res = 0;
540         goto out;
541 }
542
543 void hfsplus_file_truncate(struct inode *inode)
544 {
545         struct super_block *sb = inode->i_sb;
546         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
547         struct hfs_find_data fd;
548         u32 alloc_cnt, blk_cnt, start;
549         int res;
550
551         hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\n",
552                 inode->i_ino, (long long)hip->phys_size, inode->i_size);
553
554         if (inode->i_size > hip->phys_size) {
555                 struct address_space *mapping = inode->i_mapping;
556                 struct page *page;
557                 void *fsdata;
558                 loff_t size = inode->i_size;
559
560                 res = pagecache_write_begin(NULL, mapping, size, 0, 0,
561                                             &page, &fsdata);
562                 if (res)
563                         return;
564                 res = pagecache_write_end(NULL, mapping, size,
565                         0, 0, page, fsdata);
566                 if (res < 0)
567                         return;
568                 mark_inode_dirty(inode);
569                 return;
570         } else if (inode->i_size == hip->phys_size)
571                 return;
572
573         blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
574                         HFSPLUS_SB(sb)->alloc_blksz_shift;
575
576         mutex_lock(&hip->extents_lock);
577
578         alloc_cnt = hip->alloc_blocks;
579         if (blk_cnt == alloc_cnt)
580                 goto out_unlock;
581
582         res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
583         if (res) {
584                 mutex_unlock(&hip->extents_lock);
585                 /* XXX: We lack error handling of hfsplus_file_truncate() */
586                 return;
587         }
588         while (1) {
589                 if (alloc_cnt == hip->first_blocks) {
590                         mutex_unlock(&fd.tree->tree_lock);
591                         hfsplus_free_extents(sb, hip->first_extents,
592                                              alloc_cnt, alloc_cnt - blk_cnt);
593                         hfsplus_dump_extent(hip->first_extents);
594                         hip->first_blocks = blk_cnt;
595                         mutex_lock(&fd.tree->tree_lock);
596                         break;
597                 }
598                 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
599                 if (res)
600                         break;
601
602                 start = hip->cached_start;
603                 if (blk_cnt <= start)
604                         hfs_brec_remove(&fd);
605                 mutex_unlock(&fd.tree->tree_lock);
606                 hfsplus_free_extents(sb, hip->cached_extents,
607                                      alloc_cnt - start, alloc_cnt - blk_cnt);
608                 hfsplus_dump_extent(hip->cached_extents);
609                 mutex_lock(&fd.tree->tree_lock);
610                 if (blk_cnt > start) {
611                         hip->extent_state |= HFSPLUS_EXT_DIRTY;
612                         break;
613                 }
614                 alloc_cnt = start;
615                 hip->cached_start = hip->cached_blocks = 0;
616                 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
617         }
618         hfs_find_exit(&fd);
619
620         hip->alloc_blocks = blk_cnt;
621 out_unlock:
622         mutex_unlock(&hip->extents_lock);
623         hip->phys_size = inode->i_size;
624         hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
625                 sb->s_blocksize_bits;
626         inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
627         hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
628 }