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1 | /* |
2 | * Copyright (C) 2007 Oracle. All rights reserved. |
3 | * |
4 | * This program is free software; you can redistribute it and/or |
5 | * modify it under the terms of the GNU General Public |
6 | * License v2 as published by the Free Software Foundation. |
7 | * |
8 | * This program is distributed in the hope that it will be useful, |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
11 | * General Public License for more details. |
12 | * |
13 | * You should have received a copy of the GNU General Public |
14 | * License along with this program; if not, write to the |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
16 | * Boston, MA 021110-1307, USA. |
17 | */ |
18 | |
19 | #include <linux/bio.h> |
20 | #include <linux/pagemap.h> |
21 | #include <linux/highmem.h> |
22 | #include "ctree.h" |
23 | #include "disk-io.h" |
24 | #include "transaction.h" |
25 | #include "print-tree.h" |
26 | |
27 | #define MAX_CSUM_ITEMS(r, size) ((((BTRFS_LEAF_DATA_SIZE(r) - \ |
28 | sizeof(struct btrfs_item) * 2) / \ |
29 | size) - 1)) |
30 | |
31 | #define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \ |
32 | sizeof(struct btrfs_ordered_sum)) / \ |
33 | sizeof(struct btrfs_sector_sum) * \ |
34 | (r)->sectorsize - (r)->sectorsize) |
35 | |
36 | int btrfs_insert_file_extent(struct btrfs_trans_handle *trans, |
37 | struct btrfs_root *root, |
38 | u64 objectid, u64 pos, |
39 | u64 disk_offset, u64 disk_num_bytes, |
40 | u64 num_bytes, u64 offset, u64 ram_bytes, |
41 | u8 compression, u8 encryption, u16 other_encoding) |
42 | { |
43 | int ret = 0; |
44 | struct btrfs_file_extent_item *item; |
45 | struct btrfs_key file_key; |
46 | struct btrfs_path *path; |
47 | struct extent_buffer *leaf; |
48 | |
49 | path = btrfs_alloc_path(); |
50 | BUG_ON(!path); |
51 | file_key.objectid = objectid; |
52 | file_key.offset = pos; |
53 | btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY); |
54 | |
55 | path->leave_spinning = 1; |
56 | ret = btrfs_insert_empty_item(trans, root, path, &file_key, |
57 | sizeof(*item)); |
58 | if (ret < 0) |
59 | goto out; |
60 | BUG_ON(ret); |
61 | leaf = path->nodes[0]; |
62 | item = btrfs_item_ptr(leaf, path->slots[0], |
63 | struct btrfs_file_extent_item); |
64 | btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset); |
65 | btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes); |
66 | btrfs_set_file_extent_offset(leaf, item, offset); |
67 | btrfs_set_file_extent_num_bytes(leaf, item, num_bytes); |
68 | btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes); |
69 | btrfs_set_file_extent_generation(leaf, item, trans->transid); |
70 | btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG); |
71 | btrfs_set_file_extent_compression(leaf, item, compression); |
72 | btrfs_set_file_extent_encryption(leaf, item, encryption); |
73 | btrfs_set_file_extent_other_encoding(leaf, item, other_encoding); |
74 | |
75 | btrfs_mark_buffer_dirty(leaf); |
76 | out: |
77 | btrfs_free_path(path); |
78 | return ret; |
79 | } |
80 | |
81 | struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans, |
82 | struct btrfs_root *root, |
83 | struct btrfs_path *path, |
84 | u64 bytenr, int cow) |
85 | { |
86 | int ret; |
87 | struct btrfs_key file_key; |
88 | struct btrfs_key found_key; |
89 | struct btrfs_csum_item *item; |
90 | struct extent_buffer *leaf; |
91 | u64 csum_offset = 0; |
92 | u16 csum_size = |
93 | btrfs_super_csum_size(&root->fs_info->super_copy); |
94 | int csums_in_item; |
95 | |
96 | file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; |
97 | file_key.offset = bytenr; |
98 | btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY); |
99 | ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow); |
100 | if (ret < 0) |
101 | goto fail; |
102 | leaf = path->nodes[0]; |
103 | if (ret > 0) { |
104 | ret = 1; |
105 | if (path->slots[0] == 0) |
106 | goto fail; |
107 | path->slots[0]--; |
108 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
109 | if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY) |
110 | goto fail; |
111 | |
112 | csum_offset = (bytenr - found_key.offset) >> |
113 | root->fs_info->sb->s_blocksize_bits; |
114 | csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]); |
115 | csums_in_item /= csum_size; |
116 | |
117 | if (csum_offset >= csums_in_item) { |
118 | ret = -EFBIG; |
119 | goto fail; |
120 | } |
121 | } |
122 | item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item); |
123 | item = (struct btrfs_csum_item *)((unsigned char *)item + |
124 | csum_offset * csum_size); |
125 | return item; |
126 | fail: |
127 | if (ret > 0) |
128 | ret = -ENOENT; |
129 | return ERR_PTR(ret); |
130 | } |
131 | |
132 | |
133 | int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, |
134 | struct btrfs_root *root, |
135 | struct btrfs_path *path, u64 objectid, |
136 | u64 offset, int mod) |
137 | { |
138 | int ret; |
139 | struct btrfs_key file_key; |
140 | int ins_len = mod < 0 ? -1 : 0; |
141 | int cow = mod != 0; |
142 | |
143 | file_key.objectid = objectid; |
144 | file_key.offset = offset; |
145 | btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY); |
146 | ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow); |
147 | return ret; |
148 | } |
149 | |
150 | |
151 | int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode, |
152 | struct bio *bio, u32 *dst) |
153 | { |
154 | u32 sum; |
155 | struct bio_vec *bvec = bio->bi_io_vec; |
156 | int bio_index = 0; |
157 | u64 offset; |
158 | u64 item_start_offset = 0; |
159 | u64 item_last_offset = 0; |
160 | u64 disk_bytenr; |
161 | u32 diff; |
162 | u16 csum_size = |
163 | btrfs_super_csum_size(&root->fs_info->super_copy); |
164 | int ret; |
165 | struct btrfs_path *path; |
166 | struct btrfs_csum_item *item = NULL; |
167 | struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; |
168 | |
169 | path = btrfs_alloc_path(); |
170 | if (bio->bi_size > PAGE_CACHE_SIZE * 8) |
171 | path->reada = 2; |
172 | |
173 | WARN_ON(bio->bi_vcnt <= 0); |
174 | |
175 | disk_bytenr = (u64)bio->bi_sector << 9; |
176 | while (bio_index < bio->bi_vcnt) { |
177 | offset = page_offset(bvec->bv_page) + bvec->bv_offset; |
178 | ret = btrfs_find_ordered_sum(inode, offset, disk_bytenr, &sum); |
179 | if (ret == 0) |
180 | goto found; |
181 | |
182 | if (!item || disk_bytenr < item_start_offset || |
183 | disk_bytenr >= item_last_offset) { |
184 | struct btrfs_key found_key; |
185 | u32 item_size; |
186 | |
187 | if (item) |
188 | btrfs_release_path(root, path); |
189 | item = btrfs_lookup_csum(NULL, root->fs_info->csum_root, |
190 | path, disk_bytenr, 0); |
191 | if (IS_ERR(item)) { |
192 | ret = PTR_ERR(item); |
193 | if (ret == -ENOENT || ret == -EFBIG) |
194 | ret = 0; |
195 | sum = 0; |
196 | if (BTRFS_I(inode)->root->root_key.objectid == |
197 | BTRFS_DATA_RELOC_TREE_OBJECTID) { |
198 | set_extent_bits(io_tree, offset, |
199 | offset + bvec->bv_len - 1, |
200 | EXTENT_NODATASUM, GFP_NOFS); |
201 | } else { |
202 | printk(KERN_INFO "btrfs no csum found " |
203 | "for inode %lu start %llu\n", |
204 | inode->i_ino, |
205 | (unsigned long long)offset); |
206 | } |
207 | item = NULL; |
208 | btrfs_release_path(root, path); |
209 | goto found; |
210 | } |
211 | btrfs_item_key_to_cpu(path->nodes[0], &found_key, |
212 | path->slots[0]); |
213 | |
214 | item_start_offset = found_key.offset; |
215 | item_size = btrfs_item_size_nr(path->nodes[0], |
216 | path->slots[0]); |
217 | item_last_offset = item_start_offset + |
218 | (item_size / csum_size) * |
219 | root->sectorsize; |
220 | item = btrfs_item_ptr(path->nodes[0], path->slots[0], |
221 | struct btrfs_csum_item); |
222 | } |
223 | /* |
224 | * this byte range must be able to fit inside |
225 | * a single leaf so it will also fit inside a u32 |
226 | */ |
227 | diff = disk_bytenr - item_start_offset; |
228 | diff = diff / root->sectorsize; |
229 | diff = diff * csum_size; |
230 | |
231 | read_extent_buffer(path->nodes[0], &sum, |
232 | ((unsigned long)item) + diff, |
233 | csum_size); |
234 | found: |
235 | if (dst) |
236 | *dst++ = sum; |
237 | else |
238 | set_state_private(io_tree, offset, sum); |
239 | disk_bytenr += bvec->bv_len; |
240 | bio_index++; |
241 | bvec++; |
242 | } |
243 | btrfs_free_path(path); |
244 | return 0; |
245 | } |
246 | |
247 | int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end, |
248 | struct list_head *list) |
249 | { |
250 | struct btrfs_key key; |
251 | struct btrfs_path *path; |
252 | struct extent_buffer *leaf; |
253 | struct btrfs_ordered_sum *sums; |
254 | struct btrfs_sector_sum *sector_sum; |
255 | struct btrfs_csum_item *item; |
256 | unsigned long offset; |
257 | int ret; |
258 | size_t size; |
259 | u64 csum_end; |
260 | u16 csum_size = btrfs_super_csum_size(&root->fs_info->super_copy); |
261 | |
262 | path = btrfs_alloc_path(); |
263 | BUG_ON(!path); |
264 | |
265 | key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; |
266 | key.offset = start; |
267 | key.type = BTRFS_EXTENT_CSUM_KEY; |
268 | |
269 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
270 | if (ret < 0) |
271 | goto fail; |
272 | if (ret > 0 && path->slots[0] > 0) { |
273 | leaf = path->nodes[0]; |
274 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1); |
275 | if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID && |
276 | key.type == BTRFS_EXTENT_CSUM_KEY) { |
277 | offset = (start - key.offset) >> |
278 | root->fs_info->sb->s_blocksize_bits; |
279 | if (offset * csum_size < |
280 | btrfs_item_size_nr(leaf, path->slots[0] - 1)) |
281 | path->slots[0]--; |
282 | } |
283 | } |
284 | |
285 | while (start <= end) { |
286 | leaf = path->nodes[0]; |
287 | if (path->slots[0] >= btrfs_header_nritems(leaf)) { |
288 | ret = btrfs_next_leaf(root, path); |
289 | if (ret < 0) |
290 | goto fail; |
291 | if (ret > 0) |
292 | break; |
293 | leaf = path->nodes[0]; |
294 | } |
295 | |
296 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
297 | if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || |
298 | key.type != BTRFS_EXTENT_CSUM_KEY) |
299 | break; |
300 | |
301 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
302 | if (key.offset > end) |
303 | break; |
304 | |
305 | if (key.offset > start) |
306 | start = key.offset; |
307 | |
308 | size = btrfs_item_size_nr(leaf, path->slots[0]); |
309 | csum_end = key.offset + (size / csum_size) * root->sectorsize; |
310 | if (csum_end <= start) { |
311 | path->slots[0]++; |
312 | continue; |
313 | } |
314 | |
315 | csum_end = min(csum_end, end + 1); |
316 | item = btrfs_item_ptr(path->nodes[0], path->slots[0], |
317 | struct btrfs_csum_item); |
318 | while (start < csum_end) { |
319 | size = min_t(size_t, csum_end - start, |
320 | MAX_ORDERED_SUM_BYTES(root)); |
321 | sums = kzalloc(btrfs_ordered_sum_size(root, size), |
322 | GFP_NOFS); |
323 | BUG_ON(!sums); |
324 | |
325 | sector_sum = sums->sums; |
326 | sums->bytenr = start; |
327 | sums->len = size; |
328 | |
329 | offset = (start - key.offset) >> |
330 | root->fs_info->sb->s_blocksize_bits; |
331 | offset *= csum_size; |
332 | |
333 | while (size > 0) { |
334 | read_extent_buffer(path->nodes[0], |
335 | §or_sum->sum, |
336 | ((unsigned long)item) + |
337 | offset, csum_size); |
338 | sector_sum->bytenr = start; |
339 | |
340 | size -= root->sectorsize; |
341 | start += root->sectorsize; |
342 | offset += csum_size; |
343 | sector_sum++; |
344 | } |
345 | list_add_tail(&sums->list, list); |
346 | } |
347 | path->slots[0]++; |
348 | } |
349 | ret = 0; |
350 | fail: |
351 | btrfs_free_path(path); |
352 | return ret; |
353 | } |
354 | |
355 | int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode, |
356 | struct bio *bio, u64 file_start, int contig) |
357 | { |
358 | struct btrfs_ordered_sum *sums; |
359 | struct btrfs_sector_sum *sector_sum; |
360 | struct btrfs_ordered_extent *ordered; |
361 | char *data; |
362 | struct bio_vec *bvec = bio->bi_io_vec; |
363 | int bio_index = 0; |
364 | unsigned long total_bytes = 0; |
365 | unsigned long this_sum_bytes = 0; |
366 | u64 offset; |
367 | u64 disk_bytenr; |
368 | |
369 | WARN_ON(bio->bi_vcnt <= 0); |
370 | sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS); |
371 | if (!sums) |
372 | return -ENOMEM; |
373 | |
374 | sector_sum = sums->sums; |
375 | disk_bytenr = (u64)bio->bi_sector << 9; |
376 | sums->len = bio->bi_size; |
377 | INIT_LIST_HEAD(&sums->list); |
378 | |
379 | if (contig) |
380 | offset = file_start; |
381 | else |
382 | offset = page_offset(bvec->bv_page) + bvec->bv_offset; |
383 | |
384 | ordered = btrfs_lookup_ordered_extent(inode, offset); |
385 | BUG_ON(!ordered); |
386 | sums->bytenr = ordered->start; |
387 | |
388 | while (bio_index < bio->bi_vcnt) { |
389 | if (!contig) |
390 | offset = page_offset(bvec->bv_page) + bvec->bv_offset; |
391 | |
392 | if (!contig && (offset >= ordered->file_offset + ordered->len || |
393 | offset < ordered->file_offset)) { |
394 | unsigned long bytes_left; |
395 | sums->len = this_sum_bytes; |
396 | this_sum_bytes = 0; |
397 | btrfs_add_ordered_sum(inode, ordered, sums); |
398 | btrfs_put_ordered_extent(ordered); |
399 | |
400 | bytes_left = bio->bi_size - total_bytes; |
401 | |
402 | sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left), |
403 | GFP_NOFS); |
404 | BUG_ON(!sums); |
405 | sector_sum = sums->sums; |
406 | sums->len = bytes_left; |
407 | ordered = btrfs_lookup_ordered_extent(inode, offset); |
408 | BUG_ON(!ordered); |
409 | sums->bytenr = ordered->start; |
410 | } |
411 | |
412 | data = kmap_atomic(bvec->bv_page, KM_USER0); |
413 | sector_sum->sum = ~(u32)0; |
414 | sector_sum->sum = btrfs_csum_data(root, |
415 | data + bvec->bv_offset, |
416 | sector_sum->sum, |
417 | bvec->bv_len); |
418 | kunmap_atomic(data, KM_USER0); |
419 | btrfs_csum_final(sector_sum->sum, |
420 | (char *)§or_sum->sum); |
421 | sector_sum->bytenr = disk_bytenr; |
422 | |
423 | sector_sum++; |
424 | bio_index++; |
425 | total_bytes += bvec->bv_len; |
426 | this_sum_bytes += bvec->bv_len; |
427 | disk_bytenr += bvec->bv_len; |
428 | offset += bvec->bv_len; |
429 | bvec++; |
430 | } |
431 | this_sum_bytes = 0; |
432 | btrfs_add_ordered_sum(inode, ordered, sums); |
433 | btrfs_put_ordered_extent(ordered); |
434 | return 0; |
435 | } |
436 | |
437 | /* |
438 | * helper function for csum removal, this expects the |
439 | * key to describe the csum pointed to by the path, and it expects |
440 | * the csum to overlap the range [bytenr, len] |
441 | * |
442 | * The csum should not be entirely contained in the range and the |
443 | * range should not be entirely contained in the csum. |
444 | * |
445 | * This calls btrfs_truncate_item with the correct args based on the |
446 | * overlap, and fixes up the key as required. |
447 | */ |
448 | static noinline int truncate_one_csum(struct btrfs_trans_handle *trans, |
449 | struct btrfs_root *root, |
450 | struct btrfs_path *path, |
451 | struct btrfs_key *key, |
452 | u64 bytenr, u64 len) |
453 | { |
454 | struct extent_buffer *leaf; |
455 | u16 csum_size = |
456 | btrfs_super_csum_size(&root->fs_info->super_copy); |
457 | u64 csum_end; |
458 | u64 end_byte = bytenr + len; |
459 | u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits; |
460 | int ret; |
461 | |
462 | leaf = path->nodes[0]; |
463 | csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size; |
464 | csum_end <<= root->fs_info->sb->s_blocksize_bits; |
465 | csum_end += key->offset; |
466 | |
467 | if (key->offset < bytenr && csum_end <= end_byte) { |
468 | /* |
469 | * [ bytenr - len ] |
470 | * [ ] |
471 | * [csum ] |
472 | * A simple truncate off the end of the item |
473 | */ |
474 | u32 new_size = (bytenr - key->offset) >> blocksize_bits; |
475 | new_size *= csum_size; |
476 | ret = btrfs_truncate_item(trans, root, path, new_size, 1); |
477 | BUG_ON(ret); |
478 | } else if (key->offset >= bytenr && csum_end > end_byte && |
479 | end_byte > key->offset) { |
480 | /* |
481 | * [ bytenr - len ] |
482 | * [ ] |
483 | * [csum ] |
484 | * we need to truncate from the beginning of the csum |
485 | */ |
486 | u32 new_size = (csum_end - end_byte) >> blocksize_bits; |
487 | new_size *= csum_size; |
488 | |
489 | ret = btrfs_truncate_item(trans, root, path, new_size, 0); |
490 | BUG_ON(ret); |
491 | |
492 | key->offset = end_byte; |
493 | ret = btrfs_set_item_key_safe(trans, root, path, key); |
494 | BUG_ON(ret); |
495 | } else { |
496 | BUG(); |
497 | } |
498 | return 0; |
499 | } |
500 | |
501 | /* |
502 | * deletes the csum items from the csum tree for a given |
503 | * range of bytes. |
504 | */ |
505 | int btrfs_del_csums(struct btrfs_trans_handle *trans, |
506 | struct btrfs_root *root, u64 bytenr, u64 len) |
507 | { |
508 | struct btrfs_path *path; |
509 | struct btrfs_key key; |
510 | u64 end_byte = bytenr + len; |
511 | u64 csum_end; |
512 | struct extent_buffer *leaf; |
513 | int ret; |
514 | u16 csum_size = |
515 | btrfs_super_csum_size(&root->fs_info->super_copy); |
516 | int blocksize_bits = root->fs_info->sb->s_blocksize_bits; |
517 | |
518 | root = root->fs_info->csum_root; |
519 | |
520 | path = btrfs_alloc_path(); |
521 | |
522 | while (1) { |
523 | key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; |
524 | key.offset = end_byte - 1; |
525 | key.type = BTRFS_EXTENT_CSUM_KEY; |
526 | |
527 | path->leave_spinning = 1; |
528 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
529 | if (ret > 0) { |
530 | if (path->slots[0] == 0) |
531 | goto out; |
532 | path->slots[0]--; |
533 | } |
534 | leaf = path->nodes[0]; |
535 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
536 | |
537 | if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || |
538 | key.type != BTRFS_EXTENT_CSUM_KEY) { |
539 | break; |
540 | } |
541 | |
542 | if (key.offset >= end_byte) |
543 | break; |
544 | |
545 | csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size; |
546 | csum_end <<= blocksize_bits; |
547 | csum_end += key.offset; |
548 | |
549 | /* this csum ends before we start, we're done */ |
550 | if (csum_end <= bytenr) |
551 | break; |
552 | |
553 | /* delete the entire item, it is inside our range */ |
554 | if (key.offset >= bytenr && csum_end <= end_byte) { |
555 | ret = btrfs_del_item(trans, root, path); |
556 | BUG_ON(ret); |
557 | if (key.offset == bytenr) |
558 | break; |
559 | } else if (key.offset < bytenr && csum_end > end_byte) { |
560 | unsigned long offset; |
561 | unsigned long shift_len; |
562 | unsigned long item_offset; |
563 | /* |
564 | * [ bytenr - len ] |
565 | * [csum ] |
566 | * |
567 | * Our bytes are in the middle of the csum, |
568 | * we need to split this item and insert a new one. |
569 | * |
570 | * But we can't drop the path because the |
571 | * csum could change, get removed, extended etc. |
572 | * |
573 | * The trick here is the max size of a csum item leaves |
574 | * enough room in the tree block for a single |
575 | * item header. So, we split the item in place, |
576 | * adding a new header pointing to the existing |
577 | * bytes. Then we loop around again and we have |
578 | * a nicely formed csum item that we can neatly |
579 | * truncate. |
580 | */ |
581 | offset = (bytenr - key.offset) >> blocksize_bits; |
582 | offset *= csum_size; |
583 | |
584 | shift_len = (len >> blocksize_bits) * csum_size; |
585 | |
586 | item_offset = btrfs_item_ptr_offset(leaf, |
587 | path->slots[0]); |
588 | |
589 | memset_extent_buffer(leaf, 0, item_offset + offset, |
590 | shift_len); |
591 | key.offset = bytenr; |
592 | |
593 | /* |
594 | * btrfs_split_item returns -EAGAIN when the |
595 | * item changed size or key |
596 | */ |
597 | ret = btrfs_split_item(trans, root, path, &key, offset); |
598 | BUG_ON(ret && ret != -EAGAIN); |
599 | |
600 | key.offset = end_byte - 1; |
601 | } else { |
602 | ret = truncate_one_csum(trans, root, path, |
603 | &key, bytenr, len); |
604 | BUG_ON(ret); |
605 | if (key.offset < bytenr) |
606 | break; |
607 | } |
608 | btrfs_release_path(root, path); |
609 | } |
610 | out: |
611 | btrfs_free_path(path); |
612 | return 0; |
613 | } |
614 | |
615 | int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans, |
616 | struct btrfs_root *root, |
617 | struct btrfs_ordered_sum *sums) |
618 | { |
619 | u64 bytenr; |
620 | int ret; |
621 | struct btrfs_key file_key; |
622 | struct btrfs_key found_key; |
623 | u64 next_offset; |
624 | u64 total_bytes = 0; |
625 | int found_next; |
626 | struct btrfs_path *path; |
627 | struct btrfs_csum_item *item; |
628 | struct btrfs_csum_item *item_end; |
629 | struct extent_buffer *leaf = NULL; |
630 | u64 csum_offset; |
631 | struct btrfs_sector_sum *sector_sum; |
632 | u32 nritems; |
633 | u32 ins_size; |
634 | char *eb_map; |
635 | char *eb_token; |
636 | unsigned long map_len; |
637 | unsigned long map_start; |
638 | u16 csum_size = |
639 | btrfs_super_csum_size(&root->fs_info->super_copy); |
640 | |
641 | path = btrfs_alloc_path(); |
642 | BUG_ON(!path); |
643 | sector_sum = sums->sums; |
644 | again: |
645 | next_offset = (u64)-1; |
646 | found_next = 0; |
647 | file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; |
648 | file_key.offset = sector_sum->bytenr; |
649 | bytenr = sector_sum->bytenr; |
650 | btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY); |
651 | |
652 | item = btrfs_lookup_csum(trans, root, path, sector_sum->bytenr, 1); |
653 | if (!IS_ERR(item)) { |
654 | leaf = path->nodes[0]; |
655 | ret = 0; |
656 | goto found; |
657 | } |
658 | ret = PTR_ERR(item); |
659 | if (ret == -EFBIG) { |
660 | u32 item_size; |
661 | /* we found one, but it isn't big enough yet */ |
662 | leaf = path->nodes[0]; |
663 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
664 | if ((item_size / csum_size) >= |
665 | MAX_CSUM_ITEMS(root, csum_size)) { |
666 | /* already at max size, make a new one */ |
667 | goto insert; |
668 | } |
669 | } else { |
670 | int slot = path->slots[0] + 1; |
671 | /* we didn't find a csum item, insert one */ |
672 | nritems = btrfs_header_nritems(path->nodes[0]); |
673 | if (path->slots[0] >= nritems - 1) { |
674 | ret = btrfs_next_leaf(root, path); |
675 | if (ret == 1) |
676 | found_next = 1; |
677 | if (ret != 0) |
678 | goto insert; |
679 | slot = 0; |
680 | } |
681 | btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot); |
682 | if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || |
683 | found_key.type != BTRFS_EXTENT_CSUM_KEY) { |
684 | found_next = 1; |
685 | goto insert; |
686 | } |
687 | next_offset = found_key.offset; |
688 | found_next = 1; |
689 | goto insert; |
690 | } |
691 | |
692 | /* |
693 | * at this point, we know the tree has an item, but it isn't big |
694 | * enough yet to put our csum in. Grow it |
695 | */ |
696 | btrfs_release_path(root, path); |
697 | ret = btrfs_search_slot(trans, root, &file_key, path, |
698 | csum_size, 1); |
699 | if (ret < 0) |
700 | goto fail_unlock; |
701 | |
702 | if (ret > 0) { |
703 | if (path->slots[0] == 0) |
704 | goto insert; |
705 | path->slots[0]--; |
706 | } |
707 | |
708 | leaf = path->nodes[0]; |
709 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
710 | csum_offset = (bytenr - found_key.offset) >> |
711 | root->fs_info->sb->s_blocksize_bits; |
712 | |
713 | if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY || |
714 | found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || |
715 | csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) { |
716 | goto insert; |
717 | } |
718 | |
719 | if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) / |
720 | csum_size) { |
721 | u32 diff = (csum_offset + 1) * csum_size; |
722 | |
723 | /* |
724 | * is the item big enough already? we dropped our lock |
725 | * before and need to recheck |
726 | */ |
727 | if (diff < btrfs_item_size_nr(leaf, path->slots[0])) |
728 | goto csum; |
729 | |
730 | diff = diff - btrfs_item_size_nr(leaf, path->slots[0]); |
731 | if (diff != csum_size) |
732 | goto insert; |
733 | |
734 | ret = btrfs_extend_item(trans, root, path, diff); |
735 | BUG_ON(ret); |
736 | goto csum; |
737 | } |
738 | |
739 | insert: |
740 | btrfs_release_path(root, path); |
741 | csum_offset = 0; |
742 | if (found_next) { |
743 | u64 tmp = total_bytes + root->sectorsize; |
744 | u64 next_sector = sector_sum->bytenr; |
745 | struct btrfs_sector_sum *next = sector_sum + 1; |
746 | |
747 | while (tmp < sums->len) { |
748 | if (next_sector + root->sectorsize != next->bytenr) |
749 | break; |
750 | tmp += root->sectorsize; |
751 | next_sector = next->bytenr; |
752 | next++; |
753 | } |
754 | tmp = min(tmp, next_offset - file_key.offset); |
755 | tmp >>= root->fs_info->sb->s_blocksize_bits; |
756 | tmp = max((u64)1, tmp); |
757 | tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size)); |
758 | ins_size = csum_size * tmp; |
759 | } else { |
760 | ins_size = csum_size; |
761 | } |
762 | path->leave_spinning = 1; |
763 | ret = btrfs_insert_empty_item(trans, root, path, &file_key, |
764 | ins_size); |
765 | path->leave_spinning = 0; |
766 | if (ret < 0) |
767 | goto fail_unlock; |
768 | if (ret != 0) { |
769 | WARN_ON(1); |
770 | goto fail_unlock; |
771 | } |
772 | csum: |
773 | leaf = path->nodes[0]; |
774 | item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item); |
775 | ret = 0; |
776 | item = (struct btrfs_csum_item *)((unsigned char *)item + |
777 | csum_offset * csum_size); |
778 | found: |
779 | item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item); |
780 | item_end = (struct btrfs_csum_item *)((unsigned char *)item_end + |
781 | btrfs_item_size_nr(leaf, path->slots[0])); |
782 | eb_token = NULL; |
783 | next_sector: |
784 | |
785 | if (!eb_token || |
786 | (unsigned long)item + csum_size >= map_start + map_len) { |
787 | int err; |
788 | |
789 | if (eb_token) |
790 | unmap_extent_buffer(leaf, eb_token, KM_USER1); |
791 | eb_token = NULL; |
792 | err = map_private_extent_buffer(leaf, (unsigned long)item, |
793 | csum_size, |
794 | &eb_token, &eb_map, |
795 | &map_start, &map_len, KM_USER1); |
796 | if (err) |
797 | eb_token = NULL; |
798 | } |
799 | if (eb_token) { |
800 | memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)), |
801 | §or_sum->sum, csum_size); |
802 | } else { |
803 | write_extent_buffer(leaf, §or_sum->sum, |
804 | (unsigned long)item, csum_size); |
805 | } |
806 | |
807 | total_bytes += root->sectorsize; |
808 | sector_sum++; |
809 | if (total_bytes < sums->len) { |
810 | item = (struct btrfs_csum_item *)((char *)item + |
811 | csum_size); |
812 | if (item < item_end && bytenr + PAGE_CACHE_SIZE == |
813 | sector_sum->bytenr) { |
814 | bytenr = sector_sum->bytenr; |
815 | goto next_sector; |
816 | } |
817 | } |
818 | if (eb_token) { |
819 | unmap_extent_buffer(leaf, eb_token, KM_USER1); |
820 | eb_token = NULL; |
821 | } |
822 | btrfs_mark_buffer_dirty(path->nodes[0]); |
823 | if (total_bytes < sums->len) { |
824 | btrfs_release_path(root, path); |
825 | cond_resched(); |
826 | goto again; |
827 | } |
828 | out: |
829 | btrfs_free_path(path); |
830 | return ret; |
831 | |
832 | fail_unlock: |
833 | goto out; |
834 | } |
835 |
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v2.6.34-rc5
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