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gma500: oops.. thou shalt stg add...
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / btrfs / file-item.c
blob90d4ee52cd458ac9f7bf87dfe4a34c99be27bc30
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/slab.h>
21 #include <linux/pagemap.h>
22 #include <linux/highmem.h>
23 #include "ctree.h"
24 #include "disk-io.h"
25 #include "transaction.h"
26 #include "print-tree.h"
27
28 #define MAX_CSUM_ITEMS(r, size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
29 sizeof(struct btrfs_item) * 2) / \
30 size) - 1))
31
32 #define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
33 sizeof(struct btrfs_ordered_sum)) / \
34 sizeof(struct btrfs_sector_sum) * \
35 (r)->sectorsize - (r)->sectorsize)
36
37 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
38 struct btrfs_root *root,
39 u64 objectid, u64 pos,
40 u64 disk_offset, u64 disk_num_bytes,
41 u64 num_bytes, u64 offset, u64 ram_bytes,
42 u8 compression, u8 encryption, u16 other_encoding)
43 {
44 int ret = 0;
45 struct btrfs_file_extent_item *item;
46 struct btrfs_key file_key;
47 struct btrfs_path *path;
48 struct extent_buffer *leaf;
49
50 path = btrfs_alloc_path();
51 if (!path)
52 return -ENOMEM;
53 file_key.objectid = objectid;
54 file_key.offset = pos;
55 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
56
57 path->leave_spinning = 1;
58 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
59 sizeof(*item));
60 if (ret < 0)
61 goto out;
62 BUG_ON(ret);
63 leaf = path->nodes[0];
64 item = btrfs_item_ptr(leaf, path->slots[0],
65 struct btrfs_file_extent_item);
66 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
67 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
68 btrfs_set_file_extent_offset(leaf, item, offset);
69 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
70 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
71 btrfs_set_file_extent_generation(leaf, item, trans->transid);
72 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
73 btrfs_set_file_extent_compression(leaf, item, compression);
74 btrfs_set_file_extent_encryption(leaf, item, encryption);
75 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
76
77 btrfs_mark_buffer_dirty(leaf);
78 out:
79 btrfs_free_path(path);
80 return ret;
81 }
82
83 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
84 struct btrfs_root *root,
85 struct btrfs_path *path,
86 u64 bytenr, int cow)
87 {
88 int ret;
89 struct btrfs_key file_key;
90 struct btrfs_key found_key;
91 struct btrfs_csum_item *item;
92 struct extent_buffer *leaf;
93 u64 csum_offset = 0;
94 u16 csum_size =
95 btrfs_super_csum_size(&root->fs_info->super_copy);
96 int csums_in_item;
97
98 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
99 file_key.offset = bytenr;
100 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
101 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
102 if (ret < 0)
103 goto fail;
104 leaf = path->nodes[0];
105 if (ret > 0) {
106 ret = 1;
107 if (path->slots[0] == 0)
108 goto fail;
109 path->slots[0]--;
110 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
111 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
112 goto fail;
113
114 csum_offset = (bytenr - found_key.offset) >>
115 root->fs_info->sb->s_blocksize_bits;
116 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
117 csums_in_item /= csum_size;
118
119 if (csum_offset >= csums_in_item) {
120 ret = -EFBIG;
121 goto fail;
122 }
123 }
124 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
125 item = (struct btrfs_csum_item *)((unsigned char *)item +
126 csum_offset * csum_size);
127 return item;
128 fail:
129 if (ret > 0)
130 ret = -ENOENT;
131 return ERR_PTR(ret);
132 }
133
134
135 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
136 struct btrfs_root *root,
137 struct btrfs_path *path, u64 objectid,
138 u64 offset, int mod)
139 {
140 int ret;
141 struct btrfs_key file_key;
142 int ins_len = mod < 0 ? -1 : 0;
143 int cow = mod != 0;
144
145 file_key.objectid = objectid;
146 file_key.offset = offset;
147 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
148 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
149 return ret;
150 }
151
152
153 static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
154 struct inode *inode, struct bio *bio,
155 u64 logical_offset, u32 *dst, int dio)
156 {
157 u32 sum;
158 struct bio_vec *bvec = bio->bi_io_vec;
159 int bio_index = 0;
160 u64 offset = 0;
161 u64 item_start_offset = 0;
162 u64 item_last_offset = 0;
163 u64 disk_bytenr;
164 u32 diff;
165 u16 csum_size =
166 btrfs_super_csum_size(&root->fs_info->super_copy);
167 int ret;
168 struct btrfs_path *path;
169 struct btrfs_csum_item *item = NULL;
170 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
171
172 path = btrfs_alloc_path();
173 if (!path)
174 return -ENOMEM;
175 if (bio->bi_size > PAGE_CACHE_SIZE * 8)
176 path->reada = 2;
177
178 WARN_ON(bio->bi_vcnt <= 0);
179
180 disk_bytenr = (u64)bio->bi_sector << 9;
181 if (dio)
182 offset = logical_offset;
183 while (bio_index < bio->bi_vcnt) {
184 if (!dio)
185 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
186 ret = btrfs_find_ordered_sum(inode, offset, disk_bytenr, &sum);
187 if (ret == 0)
188 goto found;
189
190 if (!item || disk_bytenr < item_start_offset ||
191 disk_bytenr >= item_last_offset) {
192 struct btrfs_key found_key;
193 u32 item_size;
194
195 if (item)
196 btrfs_release_path(path);
197 item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
198 path, disk_bytenr, 0);
199 if (IS_ERR(item)) {
200 ret = PTR_ERR(item);
201 if (ret == -ENOENT || ret == -EFBIG)
202 ret = 0;
203 sum = 0;
204 if (BTRFS_I(inode)->root->root_key.objectid ==
205 BTRFS_DATA_RELOC_TREE_OBJECTID) {
206 set_extent_bits(io_tree, offset,
207 offset + bvec->bv_len - 1,
208 EXTENT_NODATASUM, GFP_NOFS);
209 } else {
210 printk(KERN_INFO "btrfs no csum found "
211 "for inode %llu start %llu\n",
212 (unsigned long long)
213 btrfs_ino(inode),
214 (unsigned long long)offset);
215 }
216 item = NULL;
217 btrfs_release_path(path);
218 goto found;
219 }
220 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
221 path->slots[0]);
222
223 item_start_offset = found_key.offset;
224 item_size = btrfs_item_size_nr(path->nodes[0],
225 path->slots[0]);
226 item_last_offset = item_start_offset +
227 (item_size / csum_size) *
228 root->sectorsize;
229 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
230 struct btrfs_csum_item);
231 }
232 /*
233 * this byte range must be able to fit inside
234 * a single leaf so it will also fit inside a u32
235 */
236 diff = disk_bytenr - item_start_offset;
237 diff = diff / root->sectorsize;
238 diff = diff * csum_size;
239
240 read_extent_buffer(path->nodes[0], &sum,
241 ((unsigned long)item) + diff,
242 csum_size);
243 found:
244 if (dst)
245 *dst++ = sum;
246 else
247 set_state_private(io_tree, offset, sum);
248 disk_bytenr += bvec->bv_len;
249 offset += bvec->bv_len;
250 bio_index++;
251 bvec++;
252 }
253 btrfs_free_path(path);
254 return 0;
255 }
256
257 int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
258 struct bio *bio, u32 *dst)
259 {
260 return __btrfs_lookup_bio_sums(root, inode, bio, 0, dst, 0);
261 }
262
263 int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
264 struct bio *bio, u64 offset, u32 *dst)
265 {
266 return __btrfs_lookup_bio_sums(root, inode, bio, offset, dst, 1);
267 }
268
269 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
270 struct list_head *list, int search_commit)
271 {
272 struct btrfs_key key;
273 struct btrfs_path *path;
274 struct extent_buffer *leaf;
275 struct btrfs_ordered_sum *sums;
276 struct btrfs_sector_sum *sector_sum;
277 struct btrfs_csum_item *item;
278 unsigned long offset;
279 int ret;
280 size_t size;
281 u64 csum_end;
282 u16 csum_size = btrfs_super_csum_size(&root->fs_info->super_copy);
283
284 path = btrfs_alloc_path();
285 BUG_ON(!path);
286
287 if (search_commit) {
288 path->skip_locking = 1;
289 path->reada = 2;
290 path->search_commit_root = 1;
291 }
292
293 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
294 key.offset = start;
295 key.type = BTRFS_EXTENT_CSUM_KEY;
296
297 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
298 if (ret < 0)
299 goto fail;
300 if (ret > 0 && path->slots[0] > 0) {
301 leaf = path->nodes[0];
302 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
303 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
304 key.type == BTRFS_EXTENT_CSUM_KEY) {
305 offset = (start - key.offset) >>
306 root->fs_info->sb->s_blocksize_bits;
307 if (offset * csum_size <
308 btrfs_item_size_nr(leaf, path->slots[0] - 1))
309 path->slots[0]--;
310 }
311 }
312
313 while (start <= end) {
314 leaf = path->nodes[0];
315 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
316 ret = btrfs_next_leaf(root, path);
317 if (ret < 0)
318 goto fail;
319 if (ret > 0)
320 break;
321 leaf = path->nodes[0];
322 }
323
324 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
325 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
326 key.type != BTRFS_EXTENT_CSUM_KEY)
327 break;
328
329 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
330 if (key.offset > end)
331 break;
332
333 if (key.offset > start)
334 start = key.offset;
335
336 size = btrfs_item_size_nr(leaf, path->slots[0]);
337 csum_end = key.offset + (size / csum_size) * root->sectorsize;
338 if (csum_end <= start) {
339 path->slots[0]++;
340 continue;
341 }
342
343 csum_end = min(csum_end, end + 1);
344 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
345 struct btrfs_csum_item);
346 while (start < csum_end) {
347 size = min_t(size_t, csum_end - start,
348 MAX_ORDERED_SUM_BYTES(root));
349 sums = kzalloc(btrfs_ordered_sum_size(root, size),
350 GFP_NOFS);
351 BUG_ON(!sums);
352
353 sector_sum = sums->sums;
354 sums->bytenr = start;
355 sums->len = size;
356
357 offset = (start - key.offset) >>
358 root->fs_info->sb->s_blocksize_bits;
359 offset *= csum_size;
360
361 while (size > 0) {
362 read_extent_buffer(path->nodes[0],
363 &sector_sum->sum,
364 ((unsigned long)item) +
365 offset, csum_size);
366 sector_sum->bytenr = start;
367
368 size -= root->sectorsize;
369 start += root->sectorsize;
370 offset += csum_size;
371 sector_sum++;
372 }
373 list_add_tail(&sums->list, list);
374 }
375 path->slots[0]++;
376 }
377 ret = 0;
378 fail:
379 btrfs_free_path(path);
380 return ret;
381 }
382
383 int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
384 struct bio *bio, u64 file_start, int contig)
385 {
386 struct btrfs_ordered_sum *sums;
387 struct btrfs_sector_sum *sector_sum;
388 struct btrfs_ordered_extent *ordered;
389 char *data;
390 struct bio_vec *bvec = bio->bi_io_vec;
391 int bio_index = 0;
392 unsigned long total_bytes = 0;
393 unsigned long this_sum_bytes = 0;
394 u64 offset;
395 u64 disk_bytenr;
396
397 WARN_ON(bio->bi_vcnt <= 0);
398 sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
399 if (!sums)
400 return -ENOMEM;
401
402 sector_sum = sums->sums;
403 disk_bytenr = (u64)bio->bi_sector << 9;
404 sums->len = bio->bi_size;
405 INIT_LIST_HEAD(&sums->list);
406
407 if (contig)
408 offset = file_start;
409 else
410 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
411
412 ordered = btrfs_lookup_ordered_extent(inode, offset);
413 BUG_ON(!ordered);
414 sums->bytenr = ordered->start;
415
416 while (bio_index < bio->bi_vcnt) {
417 if (!contig)
418 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
419
420 if (!contig && (offset >= ordered->file_offset + ordered->len ||
421 offset < ordered->file_offset)) {
422 unsigned long bytes_left;
423 sums->len = this_sum_bytes;
424 this_sum_bytes = 0;
425 btrfs_add_ordered_sum(inode, ordered, sums);
426 btrfs_put_ordered_extent(ordered);
427
428 bytes_left = bio->bi_size - total_bytes;
429
430 sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
431 GFP_NOFS);
432 BUG_ON(!sums);
433 sector_sum = sums->sums;
434 sums->len = bytes_left;
435 ordered = btrfs_lookup_ordered_extent(inode, offset);
436 BUG_ON(!ordered);
437 sums->bytenr = ordered->start;
438 }
439
440 data = kmap_atomic(bvec->bv_page, KM_USER0);
441 sector_sum->sum = ~(u32)0;
442 sector_sum->sum = btrfs_csum_data(root,
443 data + bvec->bv_offset,
444 sector_sum->sum,
445 bvec->bv_len);
446 kunmap_atomic(data, KM_USER0);
447 btrfs_csum_final(sector_sum->sum,
448 (char *)&sector_sum->sum);
449 sector_sum->bytenr = disk_bytenr;
450
451 sector_sum++;
452 bio_index++;
453 total_bytes += bvec->bv_len;
454 this_sum_bytes += bvec->bv_len;
455 disk_bytenr += bvec->bv_len;
456 offset += bvec->bv_len;
457 bvec++;
458 }
459 this_sum_bytes = 0;
460 btrfs_add_ordered_sum(inode, ordered, sums);
461 btrfs_put_ordered_extent(ordered);
462 return 0;
463 }
464
465 /*
466 * helper function for csum removal, this expects the
467 * key to describe the csum pointed to by the path, and it expects
468 * the csum to overlap the range [bytenr, len]
469 *
470 * The csum should not be entirely contained in the range and the
471 * range should not be entirely contained in the csum.
472 *
473 * This calls btrfs_truncate_item with the correct args based on the
474 * overlap, and fixes up the key as required.
475 */
476 static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
477 struct btrfs_root *root,
478 struct btrfs_path *path,
479 struct btrfs_key *key,
480 u64 bytenr, u64 len)
481 {
482 struct extent_buffer *leaf;
483 u16 csum_size =
484 btrfs_super_csum_size(&root->fs_info->super_copy);
485 u64 csum_end;
486 u64 end_byte = bytenr + len;
487 u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
488 int ret;
489
490 leaf = path->nodes[0];
491 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
492 csum_end <<= root->fs_info->sb->s_blocksize_bits;
493 csum_end += key->offset;
494
495 if (key->offset < bytenr && csum_end <= end_byte) {
496 /*
497 * [ bytenr - len ]
498 * [ ]
499 * [csum ]
500 * A simple truncate off the end of the item
501 */
502 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
503 new_size *= csum_size;
504 ret = btrfs_truncate_item(trans, root, path, new_size, 1);
505 } else if (key->offset >= bytenr && csum_end > end_byte &&
506 end_byte > key->offset) {
507 /*
508 * [ bytenr - len ]
509 * [ ]
510 * [csum ]
511 * we need to truncate from the beginning of the csum
512 */
513 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
514 new_size *= csum_size;
515
516 ret = btrfs_truncate_item(trans, root, path, new_size, 0);
517
518 key->offset = end_byte;
519 ret = btrfs_set_item_key_safe(trans, root, path, key);
520 BUG_ON(ret);
521 } else {
522 BUG();
523 }
524 return 0;
525 }
526
527 /*
528 * deletes the csum items from the csum tree for a given
529 * range of bytes.
530 */
531 int btrfs_del_csums(struct btrfs_trans_handle *trans,
532 struct btrfs_root *root, u64 bytenr, u64 len)
533 {
534 struct btrfs_path *path;
535 struct btrfs_key key;
536 u64 end_byte = bytenr + len;
537 u64 csum_end;
538 struct extent_buffer *leaf;
539 int ret;
540 u16 csum_size =
541 btrfs_super_csum_size(&root->fs_info->super_copy);
542 int blocksize_bits = root->fs_info->sb->s_blocksize_bits;
543
544 root = root->fs_info->csum_root;
545
546 path = btrfs_alloc_path();
547 if (!path)
548 return -ENOMEM;
549
550 while (1) {
551 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
552 key.offset = end_byte - 1;
553 key.type = BTRFS_EXTENT_CSUM_KEY;
554
555 path->leave_spinning = 1;
556 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
557 if (ret > 0) {
558 if (path->slots[0] == 0)
559 break;
560 path->slots[0]--;
561 } else if (ret < 0) {
562 break;
563 }
564
565 leaf = path->nodes[0];
566 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
567
568 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
569 key.type != BTRFS_EXTENT_CSUM_KEY) {
570 break;
571 }
572
573 if (key.offset >= end_byte)
574 break;
575
576 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
577 csum_end <<= blocksize_bits;
578 csum_end += key.offset;
579
580 /* this csum ends before we start, we're done */
581 if (csum_end <= bytenr)
582 break;
583
584 /* delete the entire item, it is inside our range */
585 if (key.offset >= bytenr && csum_end <= end_byte) {
586 ret = btrfs_del_item(trans, root, path);
587 if (ret)
588 goto out;
589 if (key.offset == bytenr)
590 break;
591 } else if (key.offset < bytenr && csum_end > end_byte) {
592 unsigned long offset;
593 unsigned long shift_len;
594 unsigned long item_offset;
595 /*
596 * [ bytenr - len ]
597 * [csum ]
598 *
599 * Our bytes are in the middle of the csum,
600 * we need to split this item and insert a new one.
601 *
602 * But we can't drop the path because the
603 * csum could change, get removed, extended etc.
604 *
605 * The trick here is the max size of a csum item leaves
606 * enough room in the tree block for a single
607 * item header. So, we split the item in place,
608 * adding a new header pointing to the existing
609 * bytes. Then we loop around again and we have
610 * a nicely formed csum item that we can neatly
611 * truncate.
612 */
613 offset = (bytenr - key.offset) >> blocksize_bits;
614 offset *= csum_size;
615
616 shift_len = (len >> blocksize_bits) * csum_size;
617
618 item_offset = btrfs_item_ptr_offset(leaf,
619 path->slots[0]);
620
621 memset_extent_buffer(leaf, 0, item_offset + offset,
622 shift_len);
623 key.offset = bytenr;
624
625 /*
626 * btrfs_split_item returns -EAGAIN when the
627 * item changed size or key
628 */
629 ret = btrfs_split_item(trans, root, path, &key, offset);
630 BUG_ON(ret && ret != -EAGAIN);
631
632 key.offset = end_byte - 1;
633 } else {
634 ret = truncate_one_csum(trans, root, path,
635 &key, bytenr, len);
636 BUG_ON(ret);
637 if (key.offset < bytenr)
638 break;
639 }
640 btrfs_release_path(path);
641 }
642 ret = 0;
643 out:
644 btrfs_free_path(path);
645 return ret;
646 }
647
648 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
649 struct btrfs_root *root,
650 struct btrfs_ordered_sum *sums)
651 {
652 u64 bytenr;
653 int ret;
654 struct btrfs_key file_key;
655 struct btrfs_key found_key;
656 u64 next_offset;
657 u64 total_bytes = 0;
658 int found_next;
659 struct btrfs_path *path;
660 struct btrfs_csum_item *item;
661 struct btrfs_csum_item *item_end;
662 struct extent_buffer *leaf = NULL;
663 u64 csum_offset;
664 struct btrfs_sector_sum *sector_sum;
665 u32 nritems;
666 u32 ins_size;
667 char *eb_map;
668 char *eb_token;
669 unsigned long map_len;
670 unsigned long map_start;
671 u16 csum_size =
672 btrfs_super_csum_size(&root->fs_info->super_copy);
673
674 path = btrfs_alloc_path();
675 BUG_ON(!path);
676 sector_sum = sums->sums;
677 again:
678 next_offset = (u64)-1;
679 found_next = 0;
680 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
681 file_key.offset = sector_sum->bytenr;
682 bytenr = sector_sum->bytenr;
683 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
684
685 item = btrfs_lookup_csum(trans, root, path, sector_sum->bytenr, 1);
686 if (!IS_ERR(item)) {
687 leaf = path->nodes[0];
688 ret = 0;
689 goto found;
690 }
691 ret = PTR_ERR(item);
692 if (ret != -EFBIG && ret != -ENOENT)
693 goto fail_unlock;
694
695 if (ret == -EFBIG) {
696 u32 item_size;
697 /* we found one, but it isn't big enough yet */
698 leaf = path->nodes[0];
699 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
700 if ((item_size / csum_size) >=
701 MAX_CSUM_ITEMS(root, csum_size)) {
702 /* already at max size, make a new one */
703 goto insert;
704 }
705 } else {
706 int slot = path->slots[0] + 1;
707 /* we didn't find a csum item, insert one */
708 nritems = btrfs_header_nritems(path->nodes[0]);
709 if (path->slots[0] >= nritems - 1) {
710 ret = btrfs_next_leaf(root, path);
711 if (ret == 1)
712 found_next = 1;
713 if (ret != 0)
714 goto insert;
715 slot = 0;
716 }
717 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
718 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
719 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
720 found_next = 1;
721 goto insert;
722 }
723 next_offset = found_key.offset;
724 found_next = 1;
725 goto insert;
726 }
727
728 /*
729 * at this point, we know the tree has an item, but it isn't big
730 * enough yet to put our csum in. Grow it
731 */
732 btrfs_release_path(path);
733 ret = btrfs_search_slot(trans, root, &file_key, path,
734 csum_size, 1);
735 if (ret < 0)
736 goto fail_unlock;
737
738 if (ret > 0) {
739 if (path->slots[0] == 0)
740 goto insert;
741 path->slots[0]--;
742 }
743
744 leaf = path->nodes[0];
745 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
746 csum_offset = (bytenr - found_key.offset) >>
747 root->fs_info->sb->s_blocksize_bits;
748
749 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY ||
750 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
751 csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
752 goto insert;
753 }
754
755 if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
756 csum_size) {
757 u32 diff = (csum_offset + 1) * csum_size;
758
759 /*
760 * is the item big enough already? we dropped our lock
761 * before and need to recheck
762 */
763 if (diff < btrfs_item_size_nr(leaf, path->slots[0]))
764 goto csum;
765
766 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
767 if (diff != csum_size)
768 goto insert;
769
770 ret = btrfs_extend_item(trans, root, path, diff);
771 goto csum;
772 }
773
774 insert:
775 btrfs_release_path(path);
776 csum_offset = 0;
777 if (found_next) {
778 u64 tmp = total_bytes + root->sectorsize;
779 u64 next_sector = sector_sum->bytenr;
780 struct btrfs_sector_sum *next = sector_sum + 1;
781
782 while (tmp < sums->len) {
783 if (next_sector + root->sectorsize != next->bytenr)
784 break;
785 tmp += root->sectorsize;
786 next_sector = next->bytenr;
787 next++;
788 }
789 tmp = min(tmp, next_offset - file_key.offset);
790 tmp >>= root->fs_info->sb->s_blocksize_bits;
791 tmp = max((u64)1, tmp);
792 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
793 ins_size = csum_size * tmp;
794 } else {
795 ins_size = csum_size;
796 }
797 path->leave_spinning = 1;
798 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
799 ins_size);
800 path->leave_spinning = 0;
801 if (ret < 0)
802 goto fail_unlock;
803 if (ret != 0) {
804 WARN_ON(1);
805 goto fail_unlock;
806 }
807 csum:
808 leaf = path->nodes[0];
809 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
810 ret = 0;
811 item = (struct btrfs_csum_item *)((unsigned char *)item +
812 csum_offset * csum_size);
813 found:
814 item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
815 item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
816 btrfs_item_size_nr(leaf, path->slots[0]));
817 eb_token = NULL;
818 next_sector:
819
820 if (!eb_token ||
821 (unsigned long)item + csum_size >= map_start + map_len) {
822 int err;
823
824 if (eb_token)
825 unmap_extent_buffer(leaf, eb_token, KM_USER1);
826 eb_token = NULL;
827 err = map_private_extent_buffer(leaf, (unsigned long)item,
828 csum_size,
829 &eb_token, &eb_map,
830 &map_start, &map_len, KM_USER1);
831 if (err)
832 eb_token = NULL;
833 }
834 if (eb_token) {
835 memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
836 &sector_sum->sum, csum_size);
837 } else {
838 write_extent_buffer(leaf, &sector_sum->sum,
839 (unsigned long)item, csum_size);
840 }
841
842 total_bytes += root->sectorsize;
843 sector_sum++;
844 if (total_bytes < sums->len) {
845 item = (struct btrfs_csum_item *)((char *)item +
846 csum_size);
847 if (item < item_end && bytenr + PAGE_CACHE_SIZE ==
848 sector_sum->bytenr) {
849 bytenr = sector_sum->bytenr;
850 goto next_sector;
851 }
852 }
853 if (eb_token) {
854 unmap_extent_buffer(leaf, eb_token, KM_USER1);
855 eb_token = NULL;
856 }
857 btrfs_mark_buffer_dirty(path->nodes[0]);
858 if (total_bytes < sums->len) {
859 btrfs_release_path(path);
860 cond_resched();
861 goto again;
862 }
863 out:
864 btrfs_free_path(path);
865 return ret;
866
867 fail_unlock:
868 goto out;
869 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree