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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 */
19int 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
40static 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
50static 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
65static 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
75static 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
86static void __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);
99 if (hip->extent_state & HFSPLUS_EXT_NEW) {
100 if (res != -ENOENT)
101 return;
102 hfs_brec_insert(fd, hip->cached_extents,
103 sizeof(hfsplus_extent_rec));
104 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
105 } else {
106 if (res)
107 return;
108 hfs_bnode_write(fd->bnode, hip->cached_extents,
109 fd->entryoffset, fd->entrylength);
110 hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
111 }
112
113 /*
114 * We can't just use hfsplus_mark_inode_dirty here, because we
115 * also get called from hfsplus_write_inode, which should not
116 * redirty the inode. Instead the callers have to be careful
117 * to explicily mark the inode dirty, too.
118 */
119 set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
120}
121
122static int hfsplus_ext_write_extent_locked(struct inode *inode)
123{
124 int res;
125
126 if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
127 struct hfs_find_data fd;
128
129 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
130 if (res)
131 return res;
132 __hfsplus_ext_write_extent(inode, &fd);
133 hfs_find_exit(&fd);
134 }
135 return 0;
136}
137
138int hfsplus_ext_write_extent(struct inode *inode)
139{
140 int res;
141
142 mutex_lock(&HFSPLUS_I(inode)->extents_lock);
143 res = hfsplus_ext_write_extent_locked(inode);
144 mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
145
146 return res;
147}
148
149static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
150 struct hfsplus_extent *extent,
151 u32 cnid, u32 block, u8 type)
152{
153 int res;
154
155 hfsplus_ext_build_key(fd->search_key, cnid, block, type);
156 fd->key->ext.cnid = 0;
157 res = hfs_brec_find(fd);
158 if (res && res != -ENOENT)
159 return res;
160 if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
161 fd->key->ext.fork_type != fd->search_key->ext.fork_type)
162 return -ENOENT;
163 if (fd->entrylength != sizeof(hfsplus_extent_rec))
164 return -EIO;
165 hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
166 sizeof(hfsplus_extent_rec));
167 return 0;
168}
169
170static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
171 struct inode *inode, u32 block)
172{
173 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
174 int res;
175
176 WARN_ON(!mutex_is_locked(&hip->extents_lock));
177
178 if (hip->extent_state & HFSPLUS_EXT_DIRTY)
179 __hfsplus_ext_write_extent(inode, fd);
180
181 res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
182 block, HFSPLUS_IS_RSRC(inode) ?
183 HFSPLUS_TYPE_RSRC :
184 HFSPLUS_TYPE_DATA);
185 if (!res) {
186 hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
187 hip->cached_blocks =
188 hfsplus_ext_block_count(hip->cached_extents);
189 } else {
190 hip->cached_start = hip->cached_blocks = 0;
191 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
192 }
193 return res;
194}
195
196static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
197{
198 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
199 struct hfs_find_data fd;
200 int res;
201
202 if (block >= hip->cached_start &&
203 block < hip->cached_start + hip->cached_blocks)
204 return 0;
205
206 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
207 if (!res) {
208 res = __hfsplus_ext_cache_extent(&fd, inode, block);
209 hfs_find_exit(&fd);
210 }
211 return res;
212}
213
214/* Get a block at iblock for inode, possibly allocating if create */
215int hfsplus_get_block(struct inode *inode, sector_t iblock,
216 struct buffer_head *bh_result, int create)
217{
218 struct super_block *sb = inode->i_sb;
219 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
220 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
221 int res = -EIO;
222 u32 ablock, dblock, mask;
223 sector_t sector;
224 int was_dirty = 0;
225 int shift;
226
227 /* Convert inode block to disk allocation block */
228 shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
229 ablock = iblock >> sbi->fs_shift;
230
231 if (iblock >= hip->fs_blocks) {
232 if (iblock > hip->fs_blocks || !create)
233 return -EIO;
234 if (ablock >= hip->alloc_blocks) {
235 res = hfsplus_file_extend(inode);
236 if (res)
237 return res;
238 }
239 } else
240 create = 0;
241
242 if (ablock < hip->first_blocks) {
243 dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
244 goto done;
245 }
246
247 if (inode->i_ino == HFSPLUS_EXT_CNID)
248 return -EIO;
249
250 mutex_lock(&hip->extents_lock);
251
252 /*
253 * hfsplus_ext_read_extent will write out a cached extent into
254 * the extents btree. In that case we may have to mark the inode
255 * dirty even for a pure read of an extent here.
256 */
257 was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
258 res = hfsplus_ext_read_extent(inode, ablock);
259 if (res) {
260 mutex_unlock(&hip->extents_lock);
261 return -EIO;
262 }
263 dblock = hfsplus_ext_find_block(hip->cached_extents,
264 ablock - hip->cached_start);
265 mutex_unlock(&hip->extents_lock);
266
267done:
268 dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n",
269 inode->i_ino, (long long)iblock, dblock);
270
271 mask = (1 << sbi->fs_shift) - 1;
272 sector = ((sector_t)dblock << sbi->fs_shift) +
273 sbi->blockoffset + (iblock & mask);
274 map_bh(bh_result, sb, sector);
275
276 if (create) {
277 set_buffer_new(bh_result);
278 hip->phys_size += sb->s_blocksize;
279 hip->fs_blocks++;
280 inode_add_bytes(inode, sb->s_blocksize);
281 }
282 if (create || was_dirty)
283 mark_inode_dirty(inode);
284 return 0;
285}
286
287static void hfsplus_dump_extent(struct hfsplus_extent *extent)
288{
289 int i;
290
291 dprint(DBG_EXTENT, " ");
292 for (i = 0; i < 8; i++)
293 dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
294 be32_to_cpu(extent[i].block_count));
295 dprint(DBG_EXTENT, "\n");
296}
297
298static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
299 u32 alloc_block, u32 block_count)
300{
301 u32 count, start;
302 int i;
303
304 hfsplus_dump_extent(extent);
305 for (i = 0; i < 8; extent++, i++) {
306 count = be32_to_cpu(extent->block_count);
307 if (offset == count) {
308 start = be32_to_cpu(extent->start_block);
309 if (alloc_block != start + count) {
310 if (++i >= 8)
311 return -ENOSPC;
312 extent++;
313 extent->start_block = cpu_to_be32(alloc_block);
314 } else
315 block_count += count;
316 extent->block_count = cpu_to_be32(block_count);
317 return 0;
318 } else if (offset < count)
319 break;
320 offset -= count;
321 }
322 /* panic? */
323 return -EIO;
324}
325
326static int hfsplus_free_extents(struct super_block *sb,
327 struct hfsplus_extent *extent,
328 u32 offset, u32 block_nr)
329{
330 u32 count, start;
331 int i;
332
333 hfsplus_dump_extent(extent);
334 for (i = 0; i < 8; extent++, i++) {
335 count = be32_to_cpu(extent->block_count);
336 if (offset == count)
337 goto found;
338 else if (offset < count)
339 break;
340 offset -= count;
341 }
342 /* panic? */
343 return -EIO;
344found:
345 for (;;) {
346 start = be32_to_cpu(extent->start_block);
347 if (count <= block_nr) {
348 hfsplus_block_free(sb, start, count);
349 extent->block_count = 0;
350 extent->start_block = 0;
351 block_nr -= count;
352 } else {
353 count -= block_nr;
354 hfsplus_block_free(sb, start + count, block_nr);
355 extent->block_count = cpu_to_be32(count);
356 block_nr = 0;
357 }
358 if (!block_nr || !i)
359 return 0;
360 i--;
361 extent--;
362 count = be32_to_cpu(extent->block_count);
363 }
364}
365
366int hfsplus_free_fork(struct super_block *sb, u32 cnid,
367 struct hfsplus_fork_raw *fork, int type)
368{
369 struct hfs_find_data fd;
370 hfsplus_extent_rec ext_entry;
371 u32 total_blocks, blocks, start;
372 int res, i;
373
374 total_blocks = be32_to_cpu(fork->total_blocks);
375 if (!total_blocks)
376 return 0;
377
378 blocks = 0;
379 for (i = 0; i < 8; i++)
380 blocks += be32_to_cpu(fork->extents[i].block_count);
381
382 res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
383 if (res)
384 return res;
385 if (total_blocks == blocks)
386 return 0;
387
388 res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
389 if (res)
390 return res;
391 do {
392 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
393 total_blocks, type);
394 if (res)
395 break;
396 start = be32_to_cpu(fd.key->ext.start_block);
397 hfsplus_free_extents(sb, ext_entry,
398 total_blocks - start,
399 total_blocks);
400 hfs_brec_remove(&fd);
401 total_blocks = start;
402 } while (total_blocks > blocks);
403 hfs_find_exit(&fd);
404
405 return res;
406}
407
408int hfsplus_file_extend(struct inode *inode)
409{
410 struct super_block *sb = inode->i_sb;
411 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
412 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
413 u32 start, len, goal;
414 int res;
415
416 if (sbi->alloc_file->i_size * 8 <
417 sbi->total_blocks - sbi->free_blocks + 8) {
418 /* extend alloc file */
419 printk(KERN_ERR "hfs: extend alloc file! "
420 "(%llu,%u,%u)\n",
421 sbi->alloc_file->i_size * 8,
422 sbi->total_blocks, sbi->free_blocks);
423 return -ENOSPC;
424 }
425
426 mutex_lock(&hip->extents_lock);
427 if (hip->alloc_blocks == hip->first_blocks)
428 goal = hfsplus_ext_lastblock(hip->first_extents);
429 else {
430 res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
431 if (res)
432 goto out;
433 goal = hfsplus_ext_lastblock(hip->cached_extents);
434 }
435
436 len = hip->clump_blocks;
437 start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
438 if (start >= sbi->total_blocks) {
439 start = hfsplus_block_allocate(sb, goal, 0, &len);
440 if (start >= goal) {
441 res = -ENOSPC;
442 goto out;
443 }
444 }
445
446 dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
447
448 if (hip->alloc_blocks <= hip->first_blocks) {
449 if (!hip->first_blocks) {
450 dprint(DBG_EXTENT, "first extents\n");
451 /* no extents yet */
452 hip->first_extents[0].start_block = cpu_to_be32(start);
453 hip->first_extents[0].block_count = cpu_to_be32(len);
454 res = 0;
455 } else {
456 /* try to append to extents in inode */
457 res = hfsplus_add_extent(hip->first_extents,
458 hip->alloc_blocks,
459 start, len);
460 if (res == -ENOSPC)
461 goto insert_extent;
462 }
463 if (!res) {
464 hfsplus_dump_extent(hip->first_extents);
465 hip->first_blocks += len;
466 }
467 } else {
468 res = hfsplus_add_extent(hip->cached_extents,
469 hip->alloc_blocks - hip->cached_start,
470 start, len);
471 if (!res) {
472 hfsplus_dump_extent(hip->cached_extents);
473 hip->extent_state |= HFSPLUS_EXT_DIRTY;
474 hip->cached_blocks += len;
475 } else if (res == -ENOSPC)
476 goto insert_extent;
477 }
478out:
479 mutex_unlock(&hip->extents_lock);
480 if (!res) {
481 hip->alloc_blocks += len;
482 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
483 }
484 return res;
485
486insert_extent:
487 dprint(DBG_EXTENT, "insert new extent\n");
488 res = hfsplus_ext_write_extent_locked(inode);
489 if (res)
490 goto out;
491
492 memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
493 hip->cached_extents[0].start_block = cpu_to_be32(start);
494 hip->cached_extents[0].block_count = cpu_to_be32(len);
495 hfsplus_dump_extent(hip->cached_extents);
496 hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
497 hip->cached_start = hip->alloc_blocks;
498 hip->cached_blocks = len;
499
500 res = 0;
501 goto out;
502}
503
504void hfsplus_file_truncate(struct inode *inode)
505{
506 struct super_block *sb = inode->i_sb;
507 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
508 struct hfs_find_data fd;
509 u32 alloc_cnt, blk_cnt, start;
510 int res;
511
512 dprint(DBG_INODE, "truncate: %lu, %llu -> %llu\n",
513 inode->i_ino, (long long)hip->phys_size,
514 inode->i_size);
515
516 if (inode->i_size > hip->phys_size) {
517 struct address_space *mapping = inode->i_mapping;
518 struct page *page;
519 void *fsdata;
520 u32 size = inode->i_size;
521
522 res = pagecache_write_begin(NULL, mapping, size, 0,
523 AOP_FLAG_UNINTERRUPTIBLE,
524 &page, &fsdata);
525 if (res)
526 return;
527 res = pagecache_write_end(NULL, mapping, size,
528 0, 0, page, fsdata);
529 if (res < 0)
530 return;
531 mark_inode_dirty(inode);
532 return;
533 } else if (inode->i_size == hip->phys_size)
534 return;
535
536 blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
537 HFSPLUS_SB(sb)->alloc_blksz_shift;
538 alloc_cnt = hip->alloc_blocks;
539 if (blk_cnt == alloc_cnt)
540 goto out;
541
542 mutex_lock(&hip->extents_lock);
543 res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
544 if (res) {
545 mutex_unlock(&hip->extents_lock);
546 /* XXX: We lack error handling of hfsplus_file_truncate() */
547 return;
548 }
549 while (1) {
550 if (alloc_cnt == hip->first_blocks) {
551 hfsplus_free_extents(sb, hip->first_extents,
552 alloc_cnt, alloc_cnt - blk_cnt);
553 hfsplus_dump_extent(hip->first_extents);
554 hip->first_blocks = blk_cnt;
555 break;
556 }
557 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
558 if (res)
559 break;
560 start = hip->cached_start;
561 hfsplus_free_extents(sb, hip->cached_extents,
562 alloc_cnt - start, alloc_cnt - blk_cnt);
563 hfsplus_dump_extent(hip->cached_extents);
564 if (blk_cnt > start) {
565 hip->extent_state |= HFSPLUS_EXT_DIRTY;
566 break;
567 }
568 alloc_cnt = start;
569 hip->cached_start = hip->cached_blocks = 0;
570 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
571 hfs_brec_remove(&fd);
572 }
573 hfs_find_exit(&fd);
574 mutex_unlock(&hip->extents_lock);
575
576 hip->alloc_blocks = blk_cnt;
577out:
578 hip->phys_size = inode->i_size;
579 hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
580 sb->s_blocksize_bits;
581 inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
582 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
583}