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mm-only debug patch...
[mmotm.git] / fs / hfsplus / extents.c
blob0022eec63cdacd97c2a438b8d9f623ff6be88dd4
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 */
19 int 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
40 static 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
50 static 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
65 static 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
75 static 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
86 static void __hfsplus_ext_write_extent(struct inode *inode, struct hfs_find_data *fd)
87 {
88 int res;
89
90 hfsplus_ext_build_key(fd->search_key, inode->i_ino, HFSPLUS_I(inode).cached_start,
91 HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
92 res = hfs_brec_find(fd);
93 if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_NEW) {
94 if (res != -ENOENT)
95 return;
96 hfs_brec_insert(fd, HFSPLUS_I(inode).cached_extents, sizeof(hfsplus_extent_rec));
97 HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
98 } else {
99 if (res)
100 return;
101 hfs_bnode_write(fd->bnode, HFSPLUS_I(inode).cached_extents, fd->entryoffset, fd->entrylength);
102 HFSPLUS_I(inode).flags &= ~HFSPLUS_FLG_EXT_DIRTY;
103 }
104 }
105
106 void hfsplus_ext_write_extent(struct inode *inode)
107 {
108 if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY) {
109 struct hfs_find_data fd;
110
111 hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd);
112 __hfsplus_ext_write_extent(inode, &fd);
113 hfs_find_exit(&fd);
114 }
115 }
116
117 static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
118 struct hfsplus_extent *extent,
119 u32 cnid, u32 block, u8 type)
120 {
121 int res;
122
123 hfsplus_ext_build_key(fd->search_key, cnid, block, type);
124 fd->key->ext.cnid = 0;
125 res = hfs_brec_find(fd);
126 if (res && res != -ENOENT)
127 return res;
128 if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
129 fd->key->ext.fork_type != fd->search_key->ext.fork_type)
130 return -ENOENT;
131 if (fd->entrylength != sizeof(hfsplus_extent_rec))
132 return -EIO;
133 hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfsplus_extent_rec));
134 return 0;
135 }
136
137 static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd, struct inode *inode, u32 block)
138 {
139 int res;
140
141 if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY)
142 __hfsplus_ext_write_extent(inode, fd);
143
144 res = __hfsplus_ext_read_extent(fd, HFSPLUS_I(inode).cached_extents, inode->i_ino,
145 block, HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
146 if (!res) {
147 HFSPLUS_I(inode).cached_start = be32_to_cpu(fd->key->ext.start_block);
148 HFSPLUS_I(inode).cached_blocks = hfsplus_ext_block_count(HFSPLUS_I(inode).cached_extents);
149 } else {
150 HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).cached_blocks = 0;
151 HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
152 }
153 return res;
154 }
155
156 static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
157 {
158 struct hfs_find_data fd;
159 int res;
160
161 if (block >= HFSPLUS_I(inode).cached_start &&
162 block < HFSPLUS_I(inode).cached_start + HFSPLUS_I(inode).cached_blocks)
163 return 0;
164
165 hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd);
166 res = __hfsplus_ext_cache_extent(&fd, inode, block);
167 hfs_find_exit(&fd);
168 return res;
169 }
170
171 /* Get a block at iblock for inode, possibly allocating if create */
172 int hfsplus_get_block(struct inode *inode, sector_t iblock,
173 struct buffer_head *bh_result, int create)
174 {
175 struct super_block *sb;
176 int res = -EIO;
177 u32 ablock, dblock, mask;
178 int shift;
179
180 sb = inode->i_sb;
181
182 /* Convert inode block to disk allocation block */
183 shift = HFSPLUS_SB(sb).alloc_blksz_shift - sb->s_blocksize_bits;
184 ablock = iblock >> HFSPLUS_SB(sb).fs_shift;
185
186 if (iblock >= HFSPLUS_I(inode).fs_blocks) {
187 if (iblock > HFSPLUS_I(inode).fs_blocks || !create)
188 return -EIO;
189 if (ablock >= HFSPLUS_I(inode).alloc_blocks) {
190 res = hfsplus_file_extend(inode);
191 if (res)
192 return res;
193 }
194 } else
195 create = 0;
196
197 if (ablock < HFSPLUS_I(inode).first_blocks) {
198 dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).first_extents, ablock);
199 goto done;
200 }
201
202 if (inode->i_ino == HFSPLUS_EXT_CNID)
203 return -EIO;
204
205 mutex_lock(&HFSPLUS_I(inode).extents_lock);
206 res = hfsplus_ext_read_extent(inode, ablock);
207 if (!res) {
208 dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).cached_extents, ablock -
209 HFSPLUS_I(inode).cached_start);
210 } else {
211 mutex_unlock(&HFSPLUS_I(inode).extents_lock);
212 return -EIO;
213 }
214 mutex_unlock(&HFSPLUS_I(inode).extents_lock);
215
216 done:
217 dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock);
218 mask = (1 << HFSPLUS_SB(sb).fs_shift) - 1;
219 map_bh(bh_result, sb, (dblock << HFSPLUS_SB(sb).fs_shift) + HFSPLUS_SB(sb).blockoffset + (iblock & mask));
220 if (create) {
221 set_buffer_new(bh_result);
222 HFSPLUS_I(inode).phys_size += sb->s_blocksize;
223 HFSPLUS_I(inode).fs_blocks++;
224 inode_add_bytes(inode, sb->s_blocksize);
225 mark_inode_dirty(inode);
226 }
227 return 0;
228 }
229
230 static void hfsplus_dump_extent(struct hfsplus_extent *extent)
231 {
232 int i;
233
234 dprint(DBG_EXTENT, " ");
235 for (i = 0; i < 8; i++)
236 dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
237 be32_to_cpu(extent[i].block_count));
238 dprint(DBG_EXTENT, "\n");
239 }
240
241 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
242 u32 alloc_block, u32 block_count)
243 {
244 u32 count, start;
245 int i;
246
247 hfsplus_dump_extent(extent);
248 for (i = 0; i < 8; extent++, i++) {
249 count = be32_to_cpu(extent->block_count);
250 if (offset == count) {
251 start = be32_to_cpu(extent->start_block);
252 if (alloc_block != start + count) {
253 if (++i >= 8)
254 return -ENOSPC;
255 extent++;
256 extent->start_block = cpu_to_be32(alloc_block);
257 } else
258 block_count += count;
259 extent->block_count = cpu_to_be32(block_count);
260 return 0;
261 } else if (offset < count)
262 break;
263 offset -= count;
264 }
265 /* panic? */
266 return -EIO;
267 }
268
269 static int hfsplus_free_extents(struct super_block *sb,
270 struct hfsplus_extent *extent,
271 u32 offset, u32 block_nr)
272 {
273 u32 count, start;
274 int i;
275
276 hfsplus_dump_extent(extent);
277 for (i = 0; i < 8; extent++, i++) {
278 count = be32_to_cpu(extent->block_count);
279 if (offset == count)
280 goto found;
281 else if (offset < count)
282 break;
283 offset -= count;
284 }
285 /* panic? */
286 return -EIO;
287 found:
288 for (;;) {
289 start = be32_to_cpu(extent->start_block);
290 if (count <= block_nr) {
291 hfsplus_block_free(sb, start, count);
292 extent->block_count = 0;
293 extent->start_block = 0;
294 block_nr -= count;
295 } else {
296 count -= block_nr;
297 hfsplus_block_free(sb, start + count, block_nr);
298 extent->block_count = cpu_to_be32(count);
299 block_nr = 0;
300 }
301 if (!block_nr || !i)
302 return 0;
303 i--;
304 extent--;
305 count = be32_to_cpu(extent->block_count);
306 }
307 }
308
309 int hfsplus_free_fork(struct super_block *sb, u32 cnid, struct hfsplus_fork_raw *fork, int type)
310 {
311 struct hfs_find_data fd;
312 hfsplus_extent_rec ext_entry;
313 u32 total_blocks, blocks, start;
314 int res, i;
315
316 total_blocks = be32_to_cpu(fork->total_blocks);
317 if (!total_blocks)
318 return 0;
319
320 blocks = 0;
321 for (i = 0; i < 8; i++)
322 blocks += be32_to_cpu(fork->extents[i].block_count);
323
324 res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
325 if (res)
326 return res;
327 if (total_blocks == blocks)
328 return 0;
329
330 hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
331 do {
332 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
333 total_blocks, type);
334 if (res)
335 break;
336 start = be32_to_cpu(fd.key->ext.start_block);
337 hfsplus_free_extents(sb, ext_entry,
338 total_blocks - start,
339 total_blocks);
340 hfs_brec_remove(&fd);
341 total_blocks = start;
342 } while (total_blocks > blocks);
343 hfs_find_exit(&fd);
344
345 return res;
346 }
347
348 int hfsplus_file_extend(struct inode *inode)
349 {
350 struct super_block *sb = inode->i_sb;
351 u32 start, len, goal;
352 int res;
353
354 if (HFSPLUS_SB(sb).alloc_file->i_size * 8 < HFSPLUS_SB(sb).total_blocks - HFSPLUS_SB(sb).free_blocks + 8) {
355 // extend alloc file
356 printk(KERN_ERR "hfs: extend alloc file! (%Lu,%u,%u)\n", HFSPLUS_SB(sb).alloc_file->i_size * 8,
357 HFSPLUS_SB(sb).total_blocks, HFSPLUS_SB(sb).free_blocks);
358 return -ENOSPC;
359 }
360
361 mutex_lock(&HFSPLUS_I(inode).extents_lock);
362 if (HFSPLUS_I(inode).alloc_blocks == HFSPLUS_I(inode).first_blocks)
363 goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).first_extents);
364 else {
365 res = hfsplus_ext_read_extent(inode, HFSPLUS_I(inode).alloc_blocks);
366 if (res)
367 goto out;
368 goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).cached_extents);
369 }
370
371 len = HFSPLUS_I(inode).clump_blocks;
372 start = hfsplus_block_allocate(sb, HFSPLUS_SB(sb).total_blocks, goal, &len);
373 if (start >= HFSPLUS_SB(sb).total_blocks) {
374 start = hfsplus_block_allocate(sb, goal, 0, &len);
375 if (start >= goal) {
376 res = -ENOSPC;
377 goto out;
378 }
379 }
380
381 dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
382 if (HFSPLUS_I(inode).alloc_blocks <= HFSPLUS_I(inode).first_blocks) {
383 if (!HFSPLUS_I(inode).first_blocks) {
384 dprint(DBG_EXTENT, "first extents\n");
385 /* no extents yet */
386 HFSPLUS_I(inode).first_extents[0].start_block = cpu_to_be32(start);
387 HFSPLUS_I(inode).first_extents[0].block_count = cpu_to_be32(len);
388 res = 0;
389 } else {
390 /* try to append to extents in inode */
391 res = hfsplus_add_extent(HFSPLUS_I(inode).first_extents,
392 HFSPLUS_I(inode).alloc_blocks,
393 start, len);
394 if (res == -ENOSPC)
395 goto insert_extent;
396 }
397 if (!res) {
398 hfsplus_dump_extent(HFSPLUS_I(inode).first_extents);
399 HFSPLUS_I(inode).first_blocks += len;
400 }
401 } else {
402 res = hfsplus_add_extent(HFSPLUS_I(inode).cached_extents,
403 HFSPLUS_I(inode).alloc_blocks -
404 HFSPLUS_I(inode).cached_start,
405 start, len);
406 if (!res) {
407 hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
408 HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY;
409 HFSPLUS_I(inode).cached_blocks += len;
410 } else if (res == -ENOSPC)
411 goto insert_extent;
412 }
413 out:
414 mutex_unlock(&HFSPLUS_I(inode).extents_lock);
415 if (!res) {
416 HFSPLUS_I(inode).alloc_blocks += len;
417 mark_inode_dirty(inode);
418 }
419 return res;
420
421 insert_extent:
422 dprint(DBG_EXTENT, "insert new extent\n");
423 hfsplus_ext_write_extent(inode);
424
425 memset(HFSPLUS_I(inode).cached_extents, 0, sizeof(hfsplus_extent_rec));
426 HFSPLUS_I(inode).cached_extents[0].start_block = cpu_to_be32(start);
427 HFSPLUS_I(inode).cached_extents[0].block_count = cpu_to_be32(len);
428 hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
429 HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW;
430 HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).alloc_blocks;
431 HFSPLUS_I(inode).cached_blocks = len;
432
433 res = 0;
434 goto out;
435 }
436
437 void hfsplus_file_truncate(struct inode *inode)
438 {
439 struct super_block *sb = inode->i_sb;
440 struct hfs_find_data fd;
441 u32 alloc_cnt, blk_cnt, start;
442 int res;
443
444 dprint(DBG_INODE, "truncate: %lu, %Lu -> %Lu\n", inode->i_ino,
445 (long long)HFSPLUS_I(inode).phys_size, inode->i_size);
446 if (inode->i_size > HFSPLUS_I(inode).phys_size) {
447 struct address_space *mapping = inode->i_mapping;
448 struct page *page;
449 void *fsdata;
450 u32 size = inode->i_size;
451 int res;
452
453 res = pagecache_write_begin(NULL, mapping, size, 0,
454 AOP_FLAG_UNINTERRUPTIBLE,
455 &page, &fsdata);
456 if (res)
457 return;
458 res = pagecache_write_end(NULL, mapping, size, 0, 0, page, fsdata);
459 if (res < 0)
460 return;
461 mark_inode_dirty(inode);
462 return;
463 } else if (inode->i_size == HFSPLUS_I(inode).phys_size)
464 return;
465
466 blk_cnt = (inode->i_size + HFSPLUS_SB(sb).alloc_blksz - 1) >> HFSPLUS_SB(sb).alloc_blksz_shift;
467 alloc_cnt = HFSPLUS_I(inode).alloc_blocks;
468 if (blk_cnt == alloc_cnt)
469 goto out;
470
471 mutex_lock(&HFSPLUS_I(inode).extents_lock);
472 hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
473 while (1) {
474 if (alloc_cnt == HFSPLUS_I(inode).first_blocks) {
475 hfsplus_free_extents(sb, HFSPLUS_I(inode).first_extents,
476 alloc_cnt, alloc_cnt - blk_cnt);
477 hfsplus_dump_extent(HFSPLUS_I(inode).first_extents);
478 HFSPLUS_I(inode).first_blocks = blk_cnt;
479 break;
480 }
481 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
482 if (res)
483 break;
484 start = HFSPLUS_I(inode).cached_start;
485 hfsplus_free_extents(sb, HFSPLUS_I(inode).cached_extents,
486 alloc_cnt - start, alloc_cnt - blk_cnt);
487 hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
488 if (blk_cnt > start) {
489 HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY;
490 break;
491 }
492 alloc_cnt = start;
493 HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).cached_blocks = 0;
494 HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
495 hfs_brec_remove(&fd);
496 }
497 hfs_find_exit(&fd);
498 mutex_unlock(&HFSPLUS_I(inode).extents_lock);
499
500 HFSPLUS_I(inode).alloc_blocks = blk_cnt;
501 out:
502 HFSPLUS_I(inode).phys_size = inode->i_size;
503 HFSPLUS_I(inode).fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
504 inode_set_bytes(inode, HFSPLUS_I(inode).fs_blocks << sb->s_blocksize_bits);
505 mark_inode_dirty(inode);
506 }
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