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Merge tag 'renesas-soc-r8a7790-for-v3.10' of git://git.kernel.org/pub/scm/linux/kerne...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / btrfs / file-item.c
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) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
29 sizeof(struct btrfs_item) * 2) / \
30 size) - 1))
31
32 #define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
33 PAGE_CACHE_SIZE))
34
35 #define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
36 sizeof(struct btrfs_ordered_sum)) / \
37 sizeof(struct btrfs_sector_sum) * \
38 (r)->sectorsize - (r)->sectorsize)
39
40 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
41 struct btrfs_root *root,
42 u64 objectid, u64 pos,
43 u64 disk_offset, u64 disk_num_bytes,
44 u64 num_bytes, u64 offset, u64 ram_bytes,
45 u8 compression, u8 encryption, u16 other_encoding)
46 {
47 int ret = 0;
48 struct btrfs_file_extent_item *item;
49 struct btrfs_key file_key;
50 struct btrfs_path *path;
51 struct extent_buffer *leaf;
52
53 path = btrfs_alloc_path();
54 if (!path)
55 return -ENOMEM;
56 file_key.objectid = objectid;
57 file_key.offset = pos;
58 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
59
60 path->leave_spinning = 1;
61 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
62 sizeof(*item));
63 if (ret < 0)
64 goto out;
65 BUG_ON(ret); /* Can't happen */
66 leaf = path->nodes[0];
67 item = btrfs_item_ptr(leaf, path->slots[0],
68 struct btrfs_file_extent_item);
69 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
70 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
71 btrfs_set_file_extent_offset(leaf, item, offset);
72 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
73 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
74 btrfs_set_file_extent_generation(leaf, item, trans->transid);
75 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
76 btrfs_set_file_extent_compression(leaf, item, compression);
77 btrfs_set_file_extent_encryption(leaf, item, encryption);
78 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
79
80 btrfs_mark_buffer_dirty(leaf);
81 out:
82 btrfs_free_path(path);
83 return ret;
84 }
85
86 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
87 struct btrfs_root *root,
88 struct btrfs_path *path,
89 u64 bytenr, int cow)
90 {
91 int ret;
92 struct btrfs_key file_key;
93 struct btrfs_key found_key;
94 struct btrfs_csum_item *item;
95 struct extent_buffer *leaf;
96 u64 csum_offset = 0;
97 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
98 int csums_in_item;
99
100 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
101 file_key.offset = bytenr;
102 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
103 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
104 if (ret < 0)
105 goto fail;
106 leaf = path->nodes[0];
107 if (ret > 0) {
108 ret = 1;
109 if (path->slots[0] == 0)
110 goto fail;
111 path->slots[0]--;
112 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
113 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
114 goto fail;
115
116 csum_offset = (bytenr - found_key.offset) >>
117 root->fs_info->sb->s_blocksize_bits;
118 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
119 csums_in_item /= csum_size;
120
121 if (csum_offset == csums_in_item) {
122 ret = -EFBIG;
123 goto fail;
124 } else if (csum_offset > csums_in_item) {
125 goto fail;
126 }
127 }
128 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
129 item = (struct btrfs_csum_item *)((unsigned char *)item +
130 csum_offset * csum_size);
131 return item;
132 fail:
133 if (ret > 0)
134 ret = -ENOENT;
135 return ERR_PTR(ret);
136 }
137
138 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
139 struct btrfs_root *root,
140 struct btrfs_path *path, u64 objectid,
141 u64 offset, int mod)
142 {
143 int ret;
144 struct btrfs_key file_key;
145 int ins_len = mod < 0 ? -1 : 0;
146 int cow = mod != 0;
147
148 file_key.objectid = objectid;
149 file_key.offset = offset;
150 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
151 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
152 return ret;
153 }
154
155 u64 btrfs_file_extent_length(struct btrfs_path *path)
156 {
157 int extent_type;
158 struct btrfs_file_extent_item *fi;
159 u64 len;
160
161 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
162 struct btrfs_file_extent_item);
163 extent_type = btrfs_file_extent_type(path->nodes[0], fi);
164
165 if (extent_type == BTRFS_FILE_EXTENT_REG ||
166 extent_type == BTRFS_FILE_EXTENT_PREALLOC)
167 len = btrfs_file_extent_num_bytes(path->nodes[0], fi);
168 else if (extent_type == BTRFS_FILE_EXTENT_INLINE)
169 len = btrfs_file_extent_inline_len(path->nodes[0], fi);
170 else
171 BUG();
172
173 return len;
174 }
175
176 static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
177 struct inode *inode, struct bio *bio,
178 u64 logical_offset, u32 *dst, int dio)
179 {
180 u32 sum;
181 struct bio_vec *bvec = bio->bi_io_vec;
182 int bio_index = 0;
183 u64 offset = 0;
184 u64 item_start_offset = 0;
185 u64 item_last_offset = 0;
186 u64 disk_bytenr;
187 u32 diff;
188 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
189 int ret;
190 struct btrfs_path *path;
191 struct btrfs_csum_item *item = NULL;
192 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
193
194 path = btrfs_alloc_path();
195 if (!path)
196 return -ENOMEM;
197 if (bio->bi_size > PAGE_CACHE_SIZE * 8)
198 path->reada = 2;
199
200 WARN_ON(bio->bi_vcnt <= 0);
201
202 /*
203 * the free space stuff is only read when it hasn't been
204 * updated in the current transaction. So, we can safely
205 * read from the commit root and sidestep a nasty deadlock
206 * between reading the free space cache and updating the csum tree.
207 */
208 if (btrfs_is_free_space_inode(inode)) {
209 path->search_commit_root = 1;
210 path->skip_locking = 1;
211 }
212
213 disk_bytenr = (u64)bio->bi_sector << 9;
214 if (dio)
215 offset = logical_offset;
216 while (bio_index < bio->bi_vcnt) {
217 if (!dio)
218 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
219 ret = btrfs_find_ordered_sum(inode, offset, disk_bytenr, &sum);
220 if (ret == 0)
221 goto found;
222
223 if (!item || disk_bytenr < item_start_offset ||
224 disk_bytenr >= item_last_offset) {
225 struct btrfs_key found_key;
226 u32 item_size;
227
228 if (item)
229 btrfs_release_path(path);
230 item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
231 path, disk_bytenr, 0);
232 if (IS_ERR(item)) {
233 ret = PTR_ERR(item);
234 if (ret == -ENOENT || ret == -EFBIG)
235 ret = 0;
236 sum = 0;
237 if (BTRFS_I(inode)->root->root_key.objectid ==
238 BTRFS_DATA_RELOC_TREE_OBJECTID) {
239 set_extent_bits(io_tree, offset,
240 offset + bvec->bv_len - 1,
241 EXTENT_NODATASUM, GFP_NOFS);
242 } else {
243 printk(KERN_INFO "btrfs no csum found "
244 "for inode %llu start %llu\n",
245 (unsigned long long)
246 btrfs_ino(inode),
247 (unsigned long long)offset);
248 }
249 item = NULL;
250 btrfs_release_path(path);
251 goto found;
252 }
253 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
254 path->slots[0]);
255
256 item_start_offset = found_key.offset;
257 item_size = btrfs_item_size_nr(path->nodes[0],
258 path->slots[0]);
259 item_last_offset = item_start_offset +
260 (item_size / csum_size) *
261 root->sectorsize;
262 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
263 struct btrfs_csum_item);
264 }
265 /*
266 * this byte range must be able to fit inside
267 * a single leaf so it will also fit inside a u32
268 */
269 diff = disk_bytenr - item_start_offset;
270 diff = diff / root->sectorsize;
271 diff = diff * csum_size;
272
273 read_extent_buffer(path->nodes[0], &sum,
274 ((unsigned long)item) + diff,
275 csum_size);
276 found:
277 if (dst)
278 *dst++ = sum;
279 else
280 set_state_private(io_tree, offset, sum);
281 disk_bytenr += bvec->bv_len;
282 offset += bvec->bv_len;
283 bio_index++;
284 bvec++;
285 }
286 btrfs_free_path(path);
287 return 0;
288 }
289
290 int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
291 struct bio *bio, u32 *dst)
292 {
293 return __btrfs_lookup_bio_sums(root, inode, bio, 0, dst, 0);
294 }
295
296 int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
297 struct bio *bio, u64 offset)
298 {
299 return __btrfs_lookup_bio_sums(root, inode, bio, offset, NULL, 1);
300 }
301
302 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
303 struct list_head *list, int search_commit)
304 {
305 struct btrfs_key key;
306 struct btrfs_path *path;
307 struct extent_buffer *leaf;
308 struct btrfs_ordered_sum *sums;
309 struct btrfs_sector_sum *sector_sum;
310 struct btrfs_csum_item *item;
311 LIST_HEAD(tmplist);
312 unsigned long offset;
313 int ret;
314 size_t size;
315 u64 csum_end;
316 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
317
318 path = btrfs_alloc_path();
319 if (!path)
320 return -ENOMEM;
321
322 if (search_commit) {
323 path->skip_locking = 1;
324 path->reada = 2;
325 path->search_commit_root = 1;
326 }
327
328 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
329 key.offset = start;
330 key.type = BTRFS_EXTENT_CSUM_KEY;
331
332 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
333 if (ret < 0)
334 goto fail;
335 if (ret > 0 && path->slots[0] > 0) {
336 leaf = path->nodes[0];
337 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
338 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
339 key.type == BTRFS_EXTENT_CSUM_KEY) {
340 offset = (start - key.offset) >>
341 root->fs_info->sb->s_blocksize_bits;
342 if (offset * csum_size <
343 btrfs_item_size_nr(leaf, path->slots[0] - 1))
344 path->slots[0]--;
345 }
346 }
347
348 while (start <= end) {
349 leaf = path->nodes[0];
350 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
351 ret = btrfs_next_leaf(root, path);
352 if (ret < 0)
353 goto fail;
354 if (ret > 0)
355 break;
356 leaf = path->nodes[0];
357 }
358
359 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
360 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
361 key.type != BTRFS_EXTENT_CSUM_KEY)
362 break;
363
364 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
365 if (key.offset > end)
366 break;
367
368 if (key.offset > start)
369 start = key.offset;
370
371 size = btrfs_item_size_nr(leaf, path->slots[0]);
372 csum_end = key.offset + (size / csum_size) * root->sectorsize;
373 if (csum_end <= start) {
374 path->slots[0]++;
375 continue;
376 }
377
378 csum_end = min(csum_end, end + 1);
379 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
380 struct btrfs_csum_item);
381 while (start < csum_end) {
382 size = min_t(size_t, csum_end - start,
383 MAX_ORDERED_SUM_BYTES(root));
384 sums = kzalloc(btrfs_ordered_sum_size(root, size),
385 GFP_NOFS);
386 if (!sums) {
387 ret = -ENOMEM;
388 goto fail;
389 }
390
391 sector_sum = sums->sums;
392 sums->bytenr = start;
393 sums->len = size;
394
395 offset = (start - key.offset) >>
396 root->fs_info->sb->s_blocksize_bits;
397 offset *= csum_size;
398
399 while (size > 0) {
400 read_extent_buffer(path->nodes[0],
401 &sector_sum->sum,
402 ((unsigned long)item) +
403 offset, csum_size);
404 sector_sum->bytenr = start;
405
406 size -= root->sectorsize;
407 start += root->sectorsize;
408 offset += csum_size;
409 sector_sum++;
410 }
411 list_add_tail(&sums->list, &tmplist);
412 }
413 path->slots[0]++;
414 }
415 ret = 0;
416 fail:
417 while (ret < 0 && !list_empty(&tmplist)) {
418 sums = list_entry(&tmplist, struct btrfs_ordered_sum, list);
419 list_del(&sums->list);
420 kfree(sums);
421 }
422 list_splice_tail(&tmplist, list);
423
424 btrfs_free_path(path);
425 return ret;
426 }
427
428 int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
429 struct bio *bio, u64 file_start, int contig)
430 {
431 struct btrfs_ordered_sum *sums;
432 struct btrfs_sector_sum *sector_sum;
433 struct btrfs_ordered_extent *ordered;
434 char *data;
435 struct bio_vec *bvec = bio->bi_io_vec;
436 int bio_index = 0;
437 unsigned long total_bytes = 0;
438 unsigned long this_sum_bytes = 0;
439 u64 offset;
440 u64 disk_bytenr;
441
442 WARN_ON(bio->bi_vcnt <= 0);
443 sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
444 if (!sums)
445 return -ENOMEM;
446
447 sector_sum = sums->sums;
448 disk_bytenr = (u64)bio->bi_sector << 9;
449 sums->len = bio->bi_size;
450 INIT_LIST_HEAD(&sums->list);
451
452 if (contig)
453 offset = file_start;
454 else
455 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
456
457 ordered = btrfs_lookup_ordered_extent(inode, offset);
458 BUG_ON(!ordered); /* Logic error */
459 sums->bytenr = ordered->start;
460
461 while (bio_index < bio->bi_vcnt) {
462 if (!contig)
463 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
464
465 if (offset >= ordered->file_offset + ordered->len ||
466 offset < ordered->file_offset) {
467 unsigned long bytes_left;
468 sums->len = this_sum_bytes;
469 this_sum_bytes = 0;
470 btrfs_add_ordered_sum(inode, ordered, sums);
471 btrfs_put_ordered_extent(ordered);
472
473 bytes_left = bio->bi_size - total_bytes;
474
475 sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
476 GFP_NOFS);
477 BUG_ON(!sums); /* -ENOMEM */
478 sector_sum = sums->sums;
479 sums->len = bytes_left;
480 ordered = btrfs_lookup_ordered_extent(inode, offset);
481 BUG_ON(!ordered); /* Logic error */
482 sums->bytenr = ordered->start;
483 }
484
485 data = kmap_atomic(bvec->bv_page);
486 sector_sum->sum = ~(u32)0;
487 sector_sum->sum = btrfs_csum_data(root,
488 data + bvec->bv_offset,
489 sector_sum->sum,
490 bvec->bv_len);
491 kunmap_atomic(data);
492 btrfs_csum_final(sector_sum->sum,
493 (char *)&sector_sum->sum);
494 sector_sum->bytenr = disk_bytenr;
495
496 sector_sum++;
497 bio_index++;
498 total_bytes += bvec->bv_len;
499 this_sum_bytes += bvec->bv_len;
500 disk_bytenr += bvec->bv_len;
501 offset += bvec->bv_len;
502 bvec++;
503 }
504 this_sum_bytes = 0;
505 btrfs_add_ordered_sum(inode, ordered, sums);
506 btrfs_put_ordered_extent(ordered);
507 return 0;
508 }
509
510 /*
511 * helper function for csum removal, this expects the
512 * key to describe the csum pointed to by the path, and it expects
513 * the csum to overlap the range [bytenr, len]
514 *
515 * The csum should not be entirely contained in the range and the
516 * range should not be entirely contained in the csum.
517 *
518 * This calls btrfs_truncate_item with the correct args based on the
519 * overlap, and fixes up the key as required.
520 */
521 static noinline void truncate_one_csum(struct btrfs_trans_handle *trans,
522 struct btrfs_root *root,
523 struct btrfs_path *path,
524 struct btrfs_key *key,
525 u64 bytenr, u64 len)
526 {
527 struct extent_buffer *leaf;
528 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
529 u64 csum_end;
530 u64 end_byte = bytenr + len;
531 u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
532
533 leaf = path->nodes[0];
534 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
535 csum_end <<= root->fs_info->sb->s_blocksize_bits;
536 csum_end += key->offset;
537
538 if (key->offset < bytenr && csum_end <= end_byte) {
539 /*
540 * [ bytenr - len ]
541 * [ ]
542 * [csum ]
543 * A simple truncate off the end of the item
544 */
545 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
546 new_size *= csum_size;
547 btrfs_truncate_item(trans, root, path, new_size, 1);
548 } else if (key->offset >= bytenr && csum_end > end_byte &&
549 end_byte > key->offset) {
550 /*
551 * [ bytenr - len ]
552 * [ ]
553 * [csum ]
554 * we need to truncate from the beginning of the csum
555 */
556 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
557 new_size *= csum_size;
558
559 btrfs_truncate_item(trans, root, path, new_size, 0);
560
561 key->offset = end_byte;
562 btrfs_set_item_key_safe(trans, root, path, key);
563 } else {
564 BUG();
565 }
566 }
567
568 /*
569 * deletes the csum items from the csum tree for a given
570 * range of bytes.
571 */
572 int btrfs_del_csums(struct btrfs_trans_handle *trans,
573 struct btrfs_root *root, u64 bytenr, u64 len)
574 {
575 struct btrfs_path *path;
576 struct btrfs_key key;
577 u64 end_byte = bytenr + len;
578 u64 csum_end;
579 struct extent_buffer *leaf;
580 int ret;
581 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
582 int blocksize_bits = root->fs_info->sb->s_blocksize_bits;
583
584 root = root->fs_info->csum_root;
585
586 path = btrfs_alloc_path();
587 if (!path)
588 return -ENOMEM;
589
590 while (1) {
591 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
592 key.offset = end_byte - 1;
593 key.type = BTRFS_EXTENT_CSUM_KEY;
594
595 path->leave_spinning = 1;
596 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
597 if (ret > 0) {
598 if (path->slots[0] == 0)
599 break;
600 path->slots[0]--;
601 } else if (ret < 0) {
602 break;
603 }
604
605 leaf = path->nodes[0];
606 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
607
608 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
609 key.type != BTRFS_EXTENT_CSUM_KEY) {
610 break;
611 }
612
613 if (key.offset >= end_byte)
614 break;
615
616 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
617 csum_end <<= blocksize_bits;
618 csum_end += key.offset;
619
620 /* this csum ends before we start, we're done */
621 if (csum_end <= bytenr)
622 break;
623
624 /* delete the entire item, it is inside our range */
625 if (key.offset >= bytenr && csum_end <= end_byte) {
626 ret = btrfs_del_item(trans, root, path);
627 if (ret)
628 goto out;
629 if (key.offset == bytenr)
630 break;
631 } else if (key.offset < bytenr && csum_end > end_byte) {
632 unsigned long offset;
633 unsigned long shift_len;
634 unsigned long item_offset;
635 /*
636 * [ bytenr - len ]
637 * [csum ]
638 *
639 * Our bytes are in the middle of the csum,
640 * we need to split this item and insert a new one.
641 *
642 * But we can't drop the path because the
643 * csum could change, get removed, extended etc.
644 *
645 * The trick here is the max size of a csum item leaves
646 * enough room in the tree block for a single
647 * item header. So, we split the item in place,
648 * adding a new header pointing to the existing
649 * bytes. Then we loop around again and we have
650 * a nicely formed csum item that we can neatly
651 * truncate.
652 */
653 offset = (bytenr - key.offset) >> blocksize_bits;
654 offset *= csum_size;
655
656 shift_len = (len >> blocksize_bits) * csum_size;
657
658 item_offset = btrfs_item_ptr_offset(leaf,
659 path->slots[0]);
660
661 memset_extent_buffer(leaf, 0, item_offset + offset,
662 shift_len);
663 key.offset = bytenr;
664
665 /*
666 * btrfs_split_item returns -EAGAIN when the
667 * item changed size or key
668 */
669 ret = btrfs_split_item(trans, root, path, &key, offset);
670 if (ret && ret != -EAGAIN) {
671 btrfs_abort_transaction(trans, root, ret);
672 goto out;
673 }
674
675 key.offset = end_byte - 1;
676 } else {
677 truncate_one_csum(trans, root, path, &key, bytenr, len);
678 if (key.offset < bytenr)
679 break;
680 }
681 btrfs_release_path(path);
682 }
683 ret = 0;
684 out:
685 btrfs_free_path(path);
686 return ret;
687 }
688
689 static u64 btrfs_sector_sum_left(struct btrfs_ordered_sum *sums,
690 struct btrfs_sector_sum *sector_sum,
691 u64 total_bytes, u64 sectorsize)
692 {
693 u64 tmp = sectorsize;
694 u64 next_sector = sector_sum->bytenr;
695 struct btrfs_sector_sum *next = sector_sum + 1;
696
697 while ((tmp + total_bytes) < sums->len) {
698 if (next_sector + sectorsize != next->bytenr)
699 break;
700 tmp += sectorsize;
701 next_sector = next->bytenr;
702 next++;
703 }
704 return tmp;
705 }
706
707 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
708 struct btrfs_root *root,
709 struct btrfs_ordered_sum *sums)
710 {
711 u64 bytenr;
712 int ret;
713 struct btrfs_key file_key;
714 struct btrfs_key found_key;
715 u64 next_offset;
716 u64 total_bytes = 0;
717 int found_next;
718 struct btrfs_path *path;
719 struct btrfs_csum_item *item;
720 struct btrfs_csum_item *item_end;
721 struct extent_buffer *leaf = NULL;
722 u64 csum_offset;
723 struct btrfs_sector_sum *sector_sum;
724 u32 nritems;
725 u32 ins_size;
726 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
727
728 path = btrfs_alloc_path();
729 if (!path)
730 return -ENOMEM;
731
732 sector_sum = sums->sums;
733 again:
734 next_offset = (u64)-1;
735 found_next = 0;
736 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
737 file_key.offset = sector_sum->bytenr;
738 bytenr = sector_sum->bytenr;
739 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
740
741 item = btrfs_lookup_csum(trans, root, path, sector_sum->bytenr, 1);
742 if (!IS_ERR(item)) {
743 leaf = path->nodes[0];
744 ret = 0;
745 goto found;
746 }
747 ret = PTR_ERR(item);
748 if (ret != -EFBIG && ret != -ENOENT)
749 goto fail_unlock;
750
751 if (ret == -EFBIG) {
752 u32 item_size;
753 /* we found one, but it isn't big enough yet */
754 leaf = path->nodes[0];
755 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
756 if ((item_size / csum_size) >=
757 MAX_CSUM_ITEMS(root, csum_size)) {
758 /* already at max size, make a new one */
759 goto insert;
760 }
761 } else {
762 int slot = path->slots[0] + 1;
763 /* we didn't find a csum item, insert one */
764 nritems = btrfs_header_nritems(path->nodes[0]);
765 if (path->slots[0] >= nritems - 1) {
766 ret = btrfs_next_leaf(root, path);
767 if (ret == 1)
768 found_next = 1;
769 if (ret != 0)
770 goto insert;
771 slot = 0;
772 }
773 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
774 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
775 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
776 found_next = 1;
777 goto insert;
778 }
779 next_offset = found_key.offset;
780 found_next = 1;
781 goto insert;
782 }
783
784 /*
785 * at this point, we know the tree has an item, but it isn't big
786 * enough yet to put our csum in. Grow it
787 */
788 btrfs_release_path(path);
789 ret = btrfs_search_slot(trans, root, &file_key, path,
790 csum_size, 1);
791 if (ret < 0)
792 goto fail_unlock;
793
794 if (ret > 0) {
795 if (path->slots[0] == 0)
796 goto insert;
797 path->slots[0]--;
798 }
799
800 leaf = path->nodes[0];
801 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
802 csum_offset = (bytenr - found_key.offset) >>
803 root->fs_info->sb->s_blocksize_bits;
804
805 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY ||
806 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
807 csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
808 goto insert;
809 }
810
811 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
812 csum_size) {
813 int extend_nr;
814 u64 tmp;
815 u32 diff;
816 u32 free_space;
817
818 if (btrfs_leaf_free_space(root, leaf) <
819 sizeof(struct btrfs_item) + csum_size * 2)
820 goto insert;
821
822 free_space = btrfs_leaf_free_space(root, leaf) -
823 sizeof(struct btrfs_item) - csum_size;
824 tmp = btrfs_sector_sum_left(sums, sector_sum, total_bytes,
825 root->sectorsize);
826 tmp >>= root->fs_info->sb->s_blocksize_bits;
827 WARN_ON(tmp < 1);
828
829 extend_nr = max_t(int, 1, (int)tmp);
830 diff = (csum_offset + extend_nr) * csum_size;
831 diff = min(diff, MAX_CSUM_ITEMS(root, csum_size) * csum_size);
832
833 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
834 diff = min(free_space, diff);
835 diff /= csum_size;
836 diff *= csum_size;
837
838 btrfs_extend_item(trans, root, path, diff);
839 goto csum;
840 }
841
842 insert:
843 btrfs_release_path(path);
844 csum_offset = 0;
845 if (found_next) {
846 u64 tmp;
847
848 tmp = btrfs_sector_sum_left(sums, sector_sum, total_bytes,
849 root->sectorsize);
850 tmp >>= root->fs_info->sb->s_blocksize_bits;
851 tmp = min(tmp, (next_offset - file_key.offset) >>
852 root->fs_info->sb->s_blocksize_bits);
853
854 tmp = max((u64)1, tmp);
855 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
856 ins_size = csum_size * tmp;
857 } else {
858 ins_size = csum_size;
859 }
860 path->leave_spinning = 1;
861 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
862 ins_size);
863 path->leave_spinning = 0;
864 if (ret < 0)
865 goto fail_unlock;
866 if (ret != 0) {
867 WARN_ON(1);
868 goto fail_unlock;
869 }
870 csum:
871 leaf = path->nodes[0];
872 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
873 ret = 0;
874 item = (struct btrfs_csum_item *)((unsigned char *)item +
875 csum_offset * csum_size);
876 found:
877 item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
878 item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
879 btrfs_item_size_nr(leaf, path->slots[0]));
880 next_sector:
881
882 write_extent_buffer(leaf, &sector_sum->sum, (unsigned long)item, csum_size);
883
884 total_bytes += root->sectorsize;
885 sector_sum++;
886 if (total_bytes < sums->len) {
887 item = (struct btrfs_csum_item *)((char *)item +
888 csum_size);
889 if (item < item_end && bytenr + PAGE_CACHE_SIZE ==
890 sector_sum->bytenr) {
891 bytenr = sector_sum->bytenr;
892 goto next_sector;
893 }
894 }
895
896 btrfs_mark_buffer_dirty(path->nodes[0]);
897 if (total_bytes < sums->len) {
898 btrfs_release_path(path);
899 cond_resched();
900 goto again;
901 }
902 out:
903 btrfs_free_path(path);
904 return ret;
905
906 fail_unlock:
907 goto out;
908 }
kernel source for telekom puls (alcatel/mediatek)