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sched: make early bootup sched_clock() use safer
[wrt350n-kernel.git] / fs / hfsplus / extents.c
blob12e899cd78866543edb5bfe6510ce113ced5d721
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 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 HFSPLUS_I(inode).fs_blocks++;
221 inode_add_bytes(inode, sb->s_blocksize);
222 mark_inode_dirty(inode);
223 }
224 return 0;
225 }
226
227 static void hfsplus_dump_extent(struct hfsplus_extent *extent)
228 {
229 int i;
230
231 dprint(DBG_EXTENT, " ");
232 for (i = 0; i < 8; i++)
233 dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
234 be32_to_cpu(extent[i].block_count));
235 dprint(DBG_EXTENT, "\n");
236 }
237
238 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
239 u32 alloc_block, u32 block_count)
240 {
241 u32 count, start;
242 int i;
243
244 hfsplus_dump_extent(extent);
245 for (i = 0; i < 8; extent++, i++) {
246 count = be32_to_cpu(extent->block_count);
247 if (offset == count) {
248 start = be32_to_cpu(extent->start_block);
249 if (alloc_block != start + count) {
250 if (++i >= 8)
251 return -ENOSPC;
252 extent++;
253 extent->start_block = cpu_to_be32(alloc_block);
254 } else
255 block_count += count;
256 extent->block_count = cpu_to_be32(block_count);
257 return 0;
258 } else if (offset < count)
259 break;
260 offset -= count;
261 }
262 /* panic? */
263 return -EIO;
264 }
265
266 static int hfsplus_free_extents(struct super_block *sb,
267 struct hfsplus_extent *extent,
268 u32 offset, u32 block_nr)
269 {
270 u32 count, start;
271 int i;
272
273 hfsplus_dump_extent(extent);
274 for (i = 0; i < 8; extent++, i++) {
275 count = be32_to_cpu(extent->block_count);
276 if (offset == count)
277 goto found;
278 else if (offset < count)
279 break;
280 offset -= count;
281 }
282 /* panic? */
283 return -EIO;
284 found:
285 for (;;) {
286 start = be32_to_cpu(extent->start_block);
287 if (count <= block_nr) {
288 hfsplus_block_free(sb, start, count);
289 extent->block_count = 0;
290 extent->start_block = 0;
291 block_nr -= count;
292 } else {
293 count -= block_nr;
294 hfsplus_block_free(sb, start + count, block_nr);
295 extent->block_count = cpu_to_be32(count);
296 block_nr = 0;
297 }
298 if (!block_nr || !i)
299 return 0;
300 i--;
301 extent--;
302 count = be32_to_cpu(extent->block_count);
303 }
304 }
305
306 int hfsplus_free_fork(struct super_block *sb, u32 cnid, struct hfsplus_fork_raw *fork, int type)
307 {
308 struct hfs_find_data fd;
309 hfsplus_extent_rec ext_entry;
310 u32 total_blocks, blocks, start;
311 int res, i;
312
313 total_blocks = be32_to_cpu(fork->total_blocks);
314 if (!total_blocks)
315 return 0;
316
317 blocks = 0;
318 for (i = 0; i < 8; i++)
319 blocks += be32_to_cpu(fork->extents[i].block_count);
320
321 res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
322 if (res)
323 return res;
324 if (total_blocks == blocks)
325 return 0;
326
327 hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
328 do {
329 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
330 total_blocks, type);
331 if (res)
332 break;
333 start = be32_to_cpu(fd.key->ext.start_block);
334 hfsplus_free_extents(sb, ext_entry,
335 total_blocks - start,
336 total_blocks);
337 hfs_brec_remove(&fd);
338 total_blocks = start;
339 } while (total_blocks > blocks);
340 hfs_find_exit(&fd);
341
342 return res;
343 }
344
345 int hfsplus_file_extend(struct inode *inode)
346 {
347 struct super_block *sb = inode->i_sb;
348 u32 start, len, goal;
349 int res;
350
351 if (HFSPLUS_SB(sb).alloc_file->i_size * 8 < HFSPLUS_SB(sb).total_blocks - HFSPLUS_SB(sb).free_blocks + 8) {
352 // extend alloc file
353 printk(KERN_ERR "hfs: extend alloc file! (%Lu,%u,%u)\n", HFSPLUS_SB(sb).alloc_file->i_size * 8,
354 HFSPLUS_SB(sb).total_blocks, HFSPLUS_SB(sb).free_blocks);
355 return -ENOSPC;
356 }
357
358 down(&HFSPLUS_I(inode).extents_lock);
359 if (HFSPLUS_I(inode).alloc_blocks == HFSPLUS_I(inode).first_blocks)
360 goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).first_extents);
361 else {
362 res = hfsplus_ext_read_extent(inode, HFSPLUS_I(inode).alloc_blocks);
363 if (res)
364 goto out;
365 goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).cached_extents);
366 }
367
368 len = HFSPLUS_I(inode).clump_blocks;
369 start = hfsplus_block_allocate(sb, HFSPLUS_SB(sb).total_blocks, goal, &len);
370 if (start >= HFSPLUS_SB(sb).total_blocks) {
371 start = hfsplus_block_allocate(sb, goal, 0, &len);
372 if (start >= goal) {
373 res = -ENOSPC;
374 goto out;
375 }
376 }
377
378 dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
379 if (HFSPLUS_I(inode).alloc_blocks <= HFSPLUS_I(inode).first_blocks) {
380 if (!HFSPLUS_I(inode).first_blocks) {
381 dprint(DBG_EXTENT, "first extents\n");
382 /* no extents yet */
383 HFSPLUS_I(inode).first_extents[0].start_block = cpu_to_be32(start);
384 HFSPLUS_I(inode).first_extents[0].block_count = cpu_to_be32(len);
385 res = 0;
386 } else {
387 /* try to append to extents in inode */
388 res = hfsplus_add_extent(HFSPLUS_I(inode).first_extents,
389 HFSPLUS_I(inode).alloc_blocks,
390 start, len);
391 if (res == -ENOSPC)
392 goto insert_extent;
393 }
394 if (!res) {
395 hfsplus_dump_extent(HFSPLUS_I(inode).first_extents);
396 HFSPLUS_I(inode).first_blocks += len;
397 }
398 } else {
399 res = hfsplus_add_extent(HFSPLUS_I(inode).cached_extents,
400 HFSPLUS_I(inode).alloc_blocks -
401 HFSPLUS_I(inode).cached_start,
402 start, len);
403 if (!res) {
404 hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
405 HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY;
406 HFSPLUS_I(inode).cached_blocks += len;
407 } else if (res == -ENOSPC)
408 goto insert_extent;
409 }
410 out:
411 up(&HFSPLUS_I(inode).extents_lock);
412 if (!res) {
413 HFSPLUS_I(inode).alloc_blocks += len;
414 mark_inode_dirty(inode);
415 }
416 return res;
417
418 insert_extent:
419 dprint(DBG_EXTENT, "insert new extent\n");
420 hfsplus_ext_write_extent(inode);
421
422 memset(HFSPLUS_I(inode).cached_extents, 0, sizeof(hfsplus_extent_rec));
423 HFSPLUS_I(inode).cached_extents[0].start_block = cpu_to_be32(start);
424 HFSPLUS_I(inode).cached_extents[0].block_count = cpu_to_be32(len);
425 hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
426 HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW;
427 HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).alloc_blocks;
428 HFSPLUS_I(inode).cached_blocks = len;
429
430 res = 0;
431 goto out;
432 }
433
434 void hfsplus_file_truncate(struct inode *inode)
435 {
436 struct super_block *sb = inode->i_sb;
437 struct hfs_find_data fd;
438 u32 alloc_cnt, blk_cnt, start;
439 int res;
440
441 dprint(DBG_INODE, "truncate: %lu, %Lu -> %Lu\n", inode->i_ino,
442 (long long)HFSPLUS_I(inode).phys_size, inode->i_size);
443 if (inode->i_size > HFSPLUS_I(inode).phys_size) {
444 struct address_space *mapping = inode->i_mapping;
445 struct page *page;
446 void *fsdata;
447 u32 size = inode->i_size;
448 int res;
449
450 res = pagecache_write_begin(NULL, mapping, size, 0,
451 AOP_FLAG_UNINTERRUPTIBLE,
452 &page, &fsdata);
453 if (res)
454 return;
455 res = pagecache_write_end(NULL, mapping, size, 0, 0, page, fsdata);
456 if (res < 0)
457 return;
458 mark_inode_dirty(inode);
459 return;
460 } else if (inode->i_size == HFSPLUS_I(inode).phys_size)
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 HFSPLUS_I(inode).fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
501 inode_set_bytes(inode, HFSPLUS_I(inode).fs_blocks << sb->s_blocksize_bits);
502 mark_inode_dirty(inode);
503 }
WRT350N Kernel Patches