?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
initial commit with v2.6.9
[linux-2.6.9-moxart.git] / fs / hfsplus / extents.c
blob51d4b1255d11e364b86d478f2c598561e46186c0
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 #include <linux/version.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(hfsplus_btree_key *k1, 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 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 >= inode->i_blocks) {
187 if (iblock > inode->i_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 down(&HFSPLUS_I(inode).extents_lock);
203 res = hfsplus_ext_read_extent(inode, ablock);
204 if (!res) {
205 dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).cached_extents, ablock -
206 HFSPLUS_I(inode).cached_start);
207 } else {
208 up(&HFSPLUS_I(inode).extents_lock);
209 return -EIO;
210 }
211 up(&HFSPLUS_I(inode).extents_lock);
212
213 done:
214 dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock);
215 mask = (1 << HFSPLUS_SB(sb).fs_shift) - 1;
216 map_bh(bh_result, sb, (dblock << HFSPLUS_SB(sb).fs_shift) + HFSPLUS_SB(sb).blockoffset + (iblock & mask));
217 if (create) {
218 set_buffer_new(bh_result);
219 HFSPLUS_I(inode).phys_size += sb->s_blocksize;
220 inode->i_blocks++;
221 mark_inode_dirty(inode);
222 }
223 return 0;
224 }
225
226 static void hfsplus_dump_extent(struct hfsplus_extent *extent)
227 {
228 int i;
229
230 dprint(DBG_EXTENT, " ");
231 for (i = 0; i < 8; i++)
232 dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
233 be32_to_cpu(extent[i].block_count));
234 dprint(DBG_EXTENT, "\n");
235 }
236
237 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
238 u32 alloc_block, u32 block_count)
239 {
240 u32 count, start;
241 int i;
242
243 hfsplus_dump_extent(extent);
244 for (i = 0; i < 8; extent++, i++) {
245 count = be32_to_cpu(extent->block_count);
246 if (offset == count) {
247 start = be32_to_cpu(extent->start_block);
248 if (alloc_block != start + count) {
249 if (++i >= 8)
250 return -ENOSPC;
251 extent++;
252 extent->start_block = cpu_to_be32(alloc_block);
253 } else
254 block_count += count;
255 extent->block_count = cpu_to_be32(block_count);
256 return 0;
257 } else if (offset < count)
258 break;
259 offset -= count;
260 }
261 /* panic? */
262 return -EIO;
263 }
264
265 int hfsplus_free_extents(struct super_block *sb, struct hfsplus_extent *extent,
266 u32 offset, u32 block_nr)
267 {
268 u32 count, start;
269 int i;
270
271 hfsplus_dump_extent(extent);
272 for (i = 0; i < 8; extent++, i++) {
273 count = be32_to_cpu(extent->block_count);
274 if (offset == count)
275 goto found;
276 else if (offset < count)
277 break;
278 offset -= count;
279 }
280 /* panic? */
281 return -EIO;
282 found:
283 for (;;) {
284 start = be32_to_cpu(extent->start_block);
285 if (count <= block_nr) {
286 hfsplus_block_free(sb, start, count);
287 extent->block_count = 0;
288 extent->start_block = 0;
289 block_nr -= count;
290 } else {
291 count -= block_nr;
292 hfsplus_block_free(sb, start + count, block_nr);
293 extent->block_count = cpu_to_be32(count);
294 block_nr = 0;
295 }
296 if (!block_nr || !i)
297 return 0;
298 i--;
299 extent--;
300 count = be32_to_cpu(extent->block_count);
301 }
302 }
303
304 int hfsplus_free_fork(struct super_block *sb, u32 cnid, struct hfsplus_fork_raw *fork, int type)
305 {
306 struct hfs_find_data fd;
307 hfsplus_extent_rec ext_entry;
308 u32 total_blocks, blocks, start;
309 int res, i;
310
311 total_blocks = be32_to_cpu(fork->total_blocks);
312 if (!total_blocks)
313 return 0;
314
315 blocks = 0;
316 for (i = 0; i < 8; i++)
317 blocks += be32_to_cpu(fork->extents[i].block_count);
318
319 res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
320 if (res)
321 return res;
322 if (total_blocks == blocks)
323 return 0;
324
325 hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
326 do {
327 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
328 total_blocks, type);
329 if (res)
330 break;
331 start = be32_to_cpu(fd.key->ext.start_block);
332 hfsplus_free_extents(sb, ext_entry,
333 total_blocks - start,
334 total_blocks);
335 hfs_brec_remove(&fd);
336 total_blocks = start;
337 } while (total_blocks > blocks);
338 hfs_find_exit(&fd);
339
340 return res;
341 }
342
343 int hfsplus_file_extend(struct inode *inode)
344 {
345 struct super_block *sb = inode->i_sb;
346 u32 start, len, goal;
347 int res;
348
349 if (HFSPLUS_SB(sb).alloc_file->i_size * 8 < HFSPLUS_SB(sb).total_blocks - HFSPLUS_SB(sb).free_blocks + 8) {
350 // extend alloc file
351 printk("extend alloc file! (%Lu,%u,%u)\n", HFSPLUS_SB(sb).alloc_file->i_size * 8,
352 HFSPLUS_SB(sb).total_blocks, HFSPLUS_SB(sb).free_blocks);
353 return -ENOSPC;
354 //BUG();
355 }
356
357 down(&HFSPLUS_I(inode).extents_lock);
358 if (HFSPLUS_I(inode).alloc_blocks == HFSPLUS_I(inode).first_blocks)
359 goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).first_extents);
360 else {
361 res = hfsplus_ext_read_extent(inode, HFSPLUS_I(inode).alloc_blocks);
362 if (res)
363 goto out;
364 goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).cached_extents);
365 }
366
367 len = HFSPLUS_I(inode).clump_blocks;
368 start = hfsplus_block_allocate(sb, HFSPLUS_SB(sb).total_blocks, goal, &len);
369 if (start >= HFSPLUS_SB(sb).total_blocks) {
370 start = hfsplus_block_allocate(sb, goal, 0, &len);
371 if (start >= goal) {
372 res = -ENOSPC;
373 goto out;
374 }
375 }
376
377 dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
378 if (HFSPLUS_I(inode).alloc_blocks <= HFSPLUS_I(inode).first_blocks) {
379 if (!HFSPLUS_I(inode).first_blocks) {
380 dprint(DBG_EXTENT, "first extents\n");
381 /* no extents yet */
382 HFSPLUS_I(inode).first_extents[0].start_block = cpu_to_be32(start);
383 HFSPLUS_I(inode).first_extents[0].block_count = cpu_to_be32(len);
384 res = 0;
385 } else {
386 /* try to append to extents in inode */
387 res = hfsplus_add_extent(HFSPLUS_I(inode).first_extents,
388 HFSPLUS_I(inode).alloc_blocks,
389 start, len);
390 if (res == -ENOSPC)
391 goto insert_extent;
392 }
393 if (!res) {
394 hfsplus_dump_extent(HFSPLUS_I(inode).first_extents);
395 HFSPLUS_I(inode).first_blocks += len;
396 }
397 } else {
398 res = hfsplus_add_extent(HFSPLUS_I(inode).cached_extents,
399 HFSPLUS_I(inode).alloc_blocks -
400 HFSPLUS_I(inode).cached_start,
401 start, len);
402 if (!res) {
403 hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
404 HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY;
405 HFSPLUS_I(inode).cached_blocks += len;
406 } else if (res == -ENOSPC)
407 goto insert_extent;
408 }
409 out:
410 up(&HFSPLUS_I(inode).extents_lock);
411 if (!res) {
412 HFSPLUS_I(inode).alloc_blocks += len;
413 mark_inode_dirty(inode);
414 }
415 return res;
416
417 insert_extent:
418 dprint(DBG_EXTENT, "insert new extent\n");
419 hfsplus_ext_write_extent(inode);
420
421 memset(HFSPLUS_I(inode).cached_extents, 0, sizeof(hfsplus_extent_rec));
422 HFSPLUS_I(inode).cached_extents[0].start_block = cpu_to_be32(start);
423 HFSPLUS_I(inode).cached_extents[0].block_count = cpu_to_be32(len);
424 hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
425 HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW;
426 HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).alloc_blocks;
427 HFSPLUS_I(inode).cached_blocks = len;
428
429 res = 0;
430 goto out;
431 }
432
433 void hfsplus_file_truncate(struct inode *inode)
434 {
435 struct super_block *sb = inode->i_sb;
436 struct hfs_find_data fd;
437 u32 alloc_cnt, blk_cnt, start;
438 int res;
439
440 dprint(DBG_INODE, "truncate: %lu, %Lu -> %Lu\n", inode->i_ino,
441 (long long)HFSPLUS_I(inode).phys_size, inode->i_size);
442 if (inode->i_size > HFSPLUS_I(inode).phys_size) {
443 struct address_space *mapping = inode->i_mapping;
444 struct page *page;
445 u32 size = inode->i_size - 1;
446 int res;
447
448 page = grab_cache_page(mapping, size >> PAGE_CACHE_SHIFT);
449 if (!page)
450 return;
451 size &= PAGE_CACHE_SIZE - 1;
452 size++;
453 res = mapping->a_ops->prepare_write(NULL, page, size, size);
454 if (!res)
455 res = mapping->a_ops->commit_write(NULL, page, size, size);
456 if (res)
457 inode->i_size = HFSPLUS_I(inode).phys_size;
458 unlock_page(page);
459 page_cache_release(page);
460 mark_inode_dirty(inode);
461 return;
462 }
463 blk_cnt = (inode->i_size + HFSPLUS_SB(sb).alloc_blksz - 1) >> HFSPLUS_SB(sb).alloc_blksz_shift;
464 alloc_cnt = HFSPLUS_I(inode).alloc_blocks;
465 if (blk_cnt == alloc_cnt)
466 goto out;
467
468 down(&HFSPLUS_I(inode).extents_lock);
469 hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
470 while (1) {
471 if (alloc_cnt == HFSPLUS_I(inode).first_blocks) {
472 hfsplus_free_extents(sb, HFSPLUS_I(inode).first_extents,
473 alloc_cnt, alloc_cnt - blk_cnt);
474 hfsplus_dump_extent(HFSPLUS_I(inode).first_extents);
475 HFSPLUS_I(inode).first_blocks = blk_cnt;
476 break;
477 }
478 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
479 if (res)
480 break;
481 start = HFSPLUS_I(inode).cached_start;
482 hfsplus_free_extents(sb, HFSPLUS_I(inode).cached_extents,
483 alloc_cnt - start, alloc_cnt - blk_cnt);
484 hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
485 if (blk_cnt > start) {
486 HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY;
487 break;
488 }
489 alloc_cnt = start;
490 HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).cached_blocks = 0;
491 HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
492 hfs_brec_remove(&fd);
493 }
494 hfs_find_exit(&fd);
495 up(&HFSPLUS_I(inode).extents_lock);
496
497 HFSPLUS_I(inode).alloc_blocks = blk_cnt;
498 out:
499 HFSPLUS_I(inode).phys_size = inode->i_size;
500 mark_inode_dirty(inode);
501 inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
502 }
MOXA 2.6.9 from sdlinux-moxaart.tgz