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-rw-r--r--fs/btrfs/file-item.c821
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diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
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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))
30int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
31 struct btrfs_root *root,
32 u64 objectid, u64 pos,
33 u64 disk_offset, u64 disk_num_bytes,
34 u64 num_bytes, u64 offset, u64 ram_bytes,
35 u8 compression, u8 encryption, u16 other_encoding)
36{
37 int ret = 0;
38 struct btrfs_file_extent_item *item;
39 struct btrfs_key file_key;
40 struct btrfs_path *path;
41 struct extent_buffer *leaf;
42
43 path = btrfs_alloc_path();
44 BUG_ON(!path);
45 file_key.objectid = objectid;
46 file_key.offset = pos;
47 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
48
49 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
50 sizeof(*item));
51 if (ret < 0)
52 goto out;
53 BUG_ON(ret);
54 leaf = path->nodes[0];
55 item = btrfs_item_ptr(leaf, path->slots[0],
56 struct btrfs_file_extent_item);
57 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
58 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
59 btrfs_set_file_extent_offset(leaf, item, offset);
60 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
61 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
62 btrfs_set_file_extent_generation(leaf, item, trans->transid);
63 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
64 btrfs_set_file_extent_compression(leaf, item, compression);
65 btrfs_set_file_extent_encryption(leaf, item, encryption);
66 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
67
68 btrfs_mark_buffer_dirty(leaf);
69out:
70 btrfs_free_path(path);
71 return ret;
72}
73
74struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
75 struct btrfs_root *root,
76 struct btrfs_path *path,
77 u64 bytenr, int cow)
78{
79 int ret;
80 struct btrfs_key file_key;
81 struct btrfs_key found_key;
82 struct btrfs_csum_item *item;
83 struct extent_buffer *leaf;
84 u64 csum_offset = 0;
85 u16 csum_size =
86 btrfs_super_csum_size(&root->fs_info->super_copy);
87 int csums_in_item;
88
89 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
90 file_key.offset = bytenr;
91 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
92 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
93 if (ret < 0)
94 goto fail;
95 leaf = path->nodes[0];
96 if (ret > 0) {
97 ret = 1;
98 if (path->slots[0] == 0)
99 goto fail;
100 path->slots[0]--;
101 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
102 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
103 goto fail;
104
105 csum_offset = (bytenr - found_key.offset) >>
106 root->fs_info->sb->s_blocksize_bits;
107 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
108 csums_in_item /= csum_size;
109
110 if (csum_offset >= csums_in_item) {
111 ret = -EFBIG;
112 goto fail;
113 }
114 }
115 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
116 item = (struct btrfs_csum_item *)((unsigned char *)item +
117 csum_offset * csum_size);
118 return item;
119fail:
120 if (ret > 0)
121 ret = -ENOENT;
122 return ERR_PTR(ret);
123}
124
125
126int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
127 struct btrfs_root *root,
128 struct btrfs_path *path, u64 objectid,
129 u64 offset, int mod)
130{
131 int ret;
132 struct btrfs_key file_key;
133 int ins_len = mod < 0 ? -1 : 0;
134 int cow = mod != 0;
135
136 file_key.objectid = objectid;
137 file_key.offset = offset;
138 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
139 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
140 return ret;
141}
142
143
144int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
145 struct bio *bio, u32 *dst)
146{
147 u32 sum;
148 struct bio_vec *bvec = bio->bi_io_vec;
149 int bio_index = 0;
150 u64 offset;
151 u64 item_start_offset = 0;
152 u64 item_last_offset = 0;
153 u64 disk_bytenr;
154 u32 diff;
155 u16 csum_size =
156 btrfs_super_csum_size(&root->fs_info->super_copy);
157 int ret;
158 struct btrfs_path *path;
159 struct btrfs_csum_item *item = NULL;
160 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
161
162 path = btrfs_alloc_path();
163 if (bio->bi_size > PAGE_CACHE_SIZE * 8)
164 path->reada = 2;
165
166 WARN_ON(bio->bi_vcnt <= 0);
167
168 disk_bytenr = (u64)bio->bi_sector << 9;
169 while (bio_index < bio->bi_vcnt) {
170 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
171 ret = btrfs_find_ordered_sum(inode, offset, disk_bytenr, &sum);
172 if (ret == 0)
173 goto found;
174
175 if (!item || disk_bytenr < item_start_offset ||
176 disk_bytenr >= item_last_offset) {
177 struct btrfs_key found_key;
178 u32 item_size;
179
180 if (item)
181 btrfs_release_path(root, path);
182 item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
183 path, disk_bytenr, 0);
184 if (IS_ERR(item)) {
185 ret = PTR_ERR(item);
186 if (ret == -ENOENT || ret == -EFBIG)
187 ret = 0;
188 sum = 0;
189 if (BTRFS_I(inode)->root->root_key.objectid ==
190 BTRFS_DATA_RELOC_TREE_OBJECTID) {
191 set_extent_bits(io_tree, offset,
192 offset + bvec->bv_len - 1,
193 EXTENT_NODATASUM, GFP_NOFS);
194 } else {
195 printk(KERN_INFO "btrfs no csum found "
196 "for inode %lu start %llu\n",
197 inode->i_ino,
198 (unsigned long long)offset);
199 }
200 item = NULL;
201 btrfs_release_path(root, path);
202 goto found;
203 }
204 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
205 path->slots[0]);
206
207 item_start_offset = found_key.offset;
208 item_size = btrfs_item_size_nr(path->nodes[0],
209 path->slots[0]);
210 item_last_offset = item_start_offset +
211 (item_size / csum_size) *
212 root->sectorsize;
213 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
214 struct btrfs_csum_item);
215 }
216 /*
217 * this byte range must be able to fit inside
218 * a single leaf so it will also fit inside a u32
219 */
220 diff = disk_bytenr - item_start_offset;
221 diff = diff / root->sectorsize;
222 diff = diff * csum_size;
223
224 read_extent_buffer(path->nodes[0], &sum,
225 ((unsigned long)item) + diff,
226 csum_size);
227found:
228 if (dst)
229 *dst++ = sum;
230 else
231 set_state_private(io_tree, offset, sum);
232 disk_bytenr += bvec->bv_len;
233 bio_index++;
234 bvec++;
235 }
236 btrfs_free_path(path);
237 return 0;
238}
239
240int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
241 struct list_head *list)
242{
243 struct btrfs_key key;
244 struct btrfs_path *path;
245 struct extent_buffer *leaf;
246 struct btrfs_ordered_sum *sums;
247 struct btrfs_sector_sum *sector_sum;
248 struct btrfs_csum_item *item;
249 unsigned long offset;
250 int ret;
251 size_t size;
252 u64 csum_end;
253 u16 csum_size = btrfs_super_csum_size(&root->fs_info->super_copy);
254
255 path = btrfs_alloc_path();
256 BUG_ON(!path);
257
258 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
259 key.offset = start;
260 key.type = BTRFS_EXTENT_CSUM_KEY;
261
262 ret = btrfs_search_slot(NULL, root->fs_info->csum_root,
263 &key, path, 0, 0);
264 if (ret < 0)
265 goto fail;
266 if (ret > 0 && path->slots[0] > 0) {
267 leaf = path->nodes[0];
268 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
269 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
270 key.type == BTRFS_EXTENT_CSUM_KEY) {
271 offset = (start - key.offset) >>
272 root->fs_info->sb->s_blocksize_bits;
273 if (offset * csum_size <
274 btrfs_item_size_nr(leaf, path->slots[0] - 1))
275 path->slots[0]--;
276 }
277 }
278
279 while (start <= end) {
280 leaf = path->nodes[0];
281 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
282 ret = btrfs_next_leaf(root->fs_info->csum_root, path);
283 if (ret < 0)
284 goto fail;
285 if (ret > 0)
286 break;
287 leaf = path->nodes[0];
288 }
289
290 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
291 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
292 key.type != BTRFS_EXTENT_CSUM_KEY)
293 break;
294
295 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
296 if (key.offset > end)
297 break;
298
299 if (key.offset > start)
300 start = key.offset;
301
302 size = btrfs_item_size_nr(leaf, path->slots[0]);
303 csum_end = key.offset + (size / csum_size) * root->sectorsize;
304 if (csum_end <= start) {
305 path->slots[0]++;
306 continue;
307 }
308
309 size = min(csum_end, end + 1) - start;
310 sums = kzalloc(btrfs_ordered_sum_size(root, size), GFP_NOFS);
311 BUG_ON(!sums);
312
313 sector_sum = sums->sums;
314 sums->bytenr = start;
315 sums->len = size;
316
317 offset = (start - key.offset) >>
318 root->fs_info->sb->s_blocksize_bits;
319 offset *= csum_size;
320
321 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
322 struct btrfs_csum_item);
323 while (size > 0) {
324 read_extent_buffer(path->nodes[0], &sector_sum->sum,
325 ((unsigned long)item) + offset,
326 csum_size);
327 sector_sum->bytenr = start;
328
329 size -= root->sectorsize;
330 start += root->sectorsize;
331 offset += csum_size;
332 sector_sum++;
333 }
334 list_add_tail(&sums->list, list);
335
336 path->slots[0]++;
337 }
338 ret = 0;
339fail:
340 btrfs_free_path(path);
341 return ret;
342}
343
344int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
345 struct bio *bio, u64 file_start, int contig)
346{
347 struct btrfs_ordered_sum *sums;
348 struct btrfs_sector_sum *sector_sum;
349 struct btrfs_ordered_extent *ordered;
350 char *data;
351 struct bio_vec *bvec = bio->bi_io_vec;
352 int bio_index = 0;
353 unsigned long total_bytes = 0;
354 unsigned long this_sum_bytes = 0;
355 u64 offset;
356 u64 disk_bytenr;
357
358 WARN_ON(bio->bi_vcnt <= 0);
359 sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
360 if (!sums)
361 return -ENOMEM;
362
363 sector_sum = sums->sums;
364 disk_bytenr = (u64)bio->bi_sector << 9;
365 sums->len = bio->bi_size;
366 INIT_LIST_HEAD(&sums->list);
367
368 if (contig)
369 offset = file_start;
370 else
371 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
372
373 ordered = btrfs_lookup_ordered_extent(inode, offset);
374 BUG_ON(!ordered);
375 sums->bytenr = ordered->start;
376
377 while (bio_index < bio->bi_vcnt) {
378 if (!contig)
379 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
380
381 if (!contig && (offset >= ordered->file_offset + ordered->len ||
382 offset < ordered->file_offset)) {
383 unsigned long bytes_left;
384 sums->len = this_sum_bytes;
385 this_sum_bytes = 0;
386 btrfs_add_ordered_sum(inode, ordered, sums);
387 btrfs_put_ordered_extent(ordered);
388
389 bytes_left = bio->bi_size - total_bytes;
390
391 sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
392 GFP_NOFS);
393 BUG_ON(!sums);
394 sector_sum = sums->sums;
395 sums->len = bytes_left;
396 ordered = btrfs_lookup_ordered_extent(inode, offset);
397 BUG_ON(!ordered);
398 sums->bytenr = ordered->start;
399 }
400
401 data = kmap_atomic(bvec->bv_page, KM_USER0);
402 sector_sum->sum = ~(u32)0;
403 sector_sum->sum = btrfs_csum_data(root,
404 data + bvec->bv_offset,
405 sector_sum->sum,
406 bvec->bv_len);
407 kunmap_atomic(data, KM_USER0);
408 btrfs_csum_final(sector_sum->sum,
409 (char *)&sector_sum->sum);
410 sector_sum->bytenr = disk_bytenr;
411
412 sector_sum++;
413 bio_index++;
414 total_bytes += bvec->bv_len;
415 this_sum_bytes += bvec->bv_len;
416 disk_bytenr += bvec->bv_len;
417 offset += bvec->bv_len;
418 bvec++;
419 }
420 this_sum_bytes = 0;
421 btrfs_add_ordered_sum(inode, ordered, sums);
422 btrfs_put_ordered_extent(ordered);
423 return 0;
424}
425
426/*
427 * helper function for csum removal, this expects the
428 * key to describe the csum pointed to by the path, and it expects
429 * the csum to overlap the range [bytenr, len]
430 *
431 * The csum should not be entirely contained in the range and the
432 * range should not be entirely contained in the csum.
433 *
434 * This calls btrfs_truncate_item with the correct args based on the
435 * overlap, and fixes up the key as required.
436 */
437static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
438 struct btrfs_root *root,
439 struct btrfs_path *path,
440 struct btrfs_key *key,
441 u64 bytenr, u64 len)
442{
443 struct extent_buffer *leaf;
444 u16 csum_size =
445 btrfs_super_csum_size(&root->fs_info->super_copy);
446 u64 csum_end;
447 u64 end_byte = bytenr + len;
448 u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
449 int ret;
450
451 leaf = path->nodes[0];
452 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
453 csum_end <<= root->fs_info->sb->s_blocksize_bits;
454 csum_end += key->offset;
455
456 if (key->offset < bytenr && csum_end <= end_byte) {
457 /*
458 * [ bytenr - len ]
459 * [ ]
460 * [csum ]
461 * A simple truncate off the end of the item
462 */
463 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
464 new_size *= csum_size;
465 ret = btrfs_truncate_item(trans, root, path, new_size, 1);
466 BUG_ON(ret);
467 } else if (key->offset >= bytenr && csum_end > end_byte &&
468 end_byte > key->offset) {
469 /*
470 * [ bytenr - len ]
471 * [ ]
472 * [csum ]
473 * we need to truncate from the beginning of the csum
474 */
475 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
476 new_size *= csum_size;
477
478 ret = btrfs_truncate_item(trans, root, path, new_size, 0);
479 BUG_ON(ret);
480
481 key->offset = end_byte;
482 ret = btrfs_set_item_key_safe(trans, root, path, key);
483 BUG_ON(ret);
484 } else {
485 BUG();
486 }
487 return 0;
488}
489
490/*
491 * deletes the csum items from the csum tree for a given
492 * range of bytes.
493 */
494int btrfs_del_csums(struct btrfs_trans_handle *trans,
495 struct btrfs_root *root, u64 bytenr, u64 len)
496{
497 struct btrfs_path *path;
498 struct btrfs_key key;
499 u64 end_byte = bytenr + len;
500 u64 csum_end;
501 struct extent_buffer *leaf;
502 int ret;
503 u16 csum_size =
504 btrfs_super_csum_size(&root->fs_info->super_copy);
505 int blocksize_bits = root->fs_info->sb->s_blocksize_bits;
506
507 root = root->fs_info->csum_root;
508
509 path = btrfs_alloc_path();
510
511 while (1) {
512 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
513 key.offset = end_byte - 1;
514 key.type = BTRFS_EXTENT_CSUM_KEY;
515
516 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
517 if (ret > 0) {
518 if (path->slots[0] == 0)
519 goto out;
520 path->slots[0]--;
521 }
522 leaf = path->nodes[0];
523 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
524
525 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
526 key.type != BTRFS_EXTENT_CSUM_KEY) {
527 break;
528 }
529
530 if (key.offset >= end_byte)
531 break;
532
533 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
534 csum_end <<= blocksize_bits;
535 csum_end += key.offset;
536
537 /* this csum ends before we start, we're done */
538 if (csum_end <= bytenr)
539 break;
540
541 /* delete the entire item, it is inside our range */
542 if (key.offset >= bytenr && csum_end <= end_byte) {
543 ret = btrfs_del_item(trans, root, path);
544 BUG_ON(ret);
545 if (key.offset == bytenr)
546 break;
547 } else if (key.offset < bytenr && csum_end > end_byte) {
548 unsigned long offset;
549 unsigned long shift_len;
550 unsigned long item_offset;
551 /*
552 * [ bytenr - len ]
553 * [csum ]
554 *
555 * Our bytes are in the middle of the csum,
556 * we need to split this item and insert a new one.
557 *
558 * But we can't drop the path because the
559 * csum could change, get removed, extended etc.
560 *
561 * The trick here is the max size of a csum item leaves
562 * enough room in the tree block for a single
563 * item header. So, we split the item in place,
564 * adding a new header pointing to the existing
565 * bytes. Then we loop around again and we have
566 * a nicely formed csum item that we can neatly
567 * truncate.
568 */
569 offset = (bytenr - key.offset) >> blocksize_bits;
570 offset *= csum_size;
571
572 shift_len = (len >> blocksize_bits) * csum_size;
573
574 item_offset = btrfs_item_ptr_offset(leaf,
575 path->slots[0]);
576
577 memset_extent_buffer(leaf, 0, item_offset + offset,
578 shift_len);
579 key.offset = bytenr;
580
581 /*
582 * btrfs_split_item returns -EAGAIN when the
583 * item changed size or key
584 */
585 ret = btrfs_split_item(trans, root, path, &key, offset);
586 BUG_ON(ret && ret != -EAGAIN);
587
588 key.offset = end_byte - 1;
589 } else {
590 ret = truncate_one_csum(trans, root, path,
591 &key, bytenr, len);
592 BUG_ON(ret);
593 if (key.offset < bytenr)
594 break;
595 }
596 btrfs_release_path(root, path);
597 }
598out:
599 btrfs_free_path(path);
600 return 0;
601}
602
603int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
604 struct btrfs_root *root,
605 struct btrfs_ordered_sum *sums)
606{
607 u64 bytenr;
608 int ret;
609 struct btrfs_key file_key;
610 struct btrfs_key found_key;
611 u64 next_offset;
612 u64 total_bytes = 0;
613 int found_next;
614 struct btrfs_path *path;
615 struct btrfs_csum_item *item;
616 struct btrfs_csum_item *item_end;
617 struct extent_buffer *leaf = NULL;
618 u64 csum_offset;
619 struct btrfs_sector_sum *sector_sum;
620 u32 nritems;
621 u32 ins_size;
622 char *eb_map;
623 char *eb_token;
624 unsigned long map_len;
625 unsigned long map_start;
626 u16 csum_size =
627 btrfs_super_csum_size(&root->fs_info->super_copy);
628
629 path = btrfs_alloc_path();
630 BUG_ON(!path);
631 sector_sum = sums->sums;
632again:
633 next_offset = (u64)-1;
634 found_next = 0;
635 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
636 file_key.offset = sector_sum->bytenr;
637 bytenr = sector_sum->bytenr;
638 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
639
640 item = btrfs_lookup_csum(trans, root, path, sector_sum->bytenr, 1);
641 if (!IS_ERR(item)) {
642 leaf = path->nodes[0];
643 ret = 0;
644 goto found;
645 }
646 ret = PTR_ERR(item);
647 if (ret == -EFBIG) {
648 u32 item_size;
649 /* we found one, but it isn't big enough yet */
650 leaf = path->nodes[0];
651 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
652 if ((item_size / csum_size) >=
653 MAX_CSUM_ITEMS(root, csum_size)) {
654 /* already at max size, make a new one */
655 goto insert;
656 }
657 } else {
658 int slot = path->slots[0] + 1;
659 /* we didn't find a csum item, insert one */
660 nritems = btrfs_header_nritems(path->nodes[0]);
661 if (path->slots[0] >= nritems - 1) {
662 ret = btrfs_next_leaf(root, path);
663 if (ret == 1)
664 found_next = 1;
665 if (ret != 0)
666 goto insert;
667 slot = 0;
668 }
669 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
670 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
671 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
672 found_next = 1;
673 goto insert;
674 }
675 next_offset = found_key.offset;
676 found_next = 1;
677 goto insert;
678 }
679
680 /*
681 * at this point, we know the tree has an item, but it isn't big
682 * enough yet to put our csum in. Grow it
683 */
684 btrfs_release_path(root, path);
685 ret = btrfs_search_slot(trans, root, &file_key, path,
686 csum_size, 1);
687 if (ret < 0)
688 goto fail_unlock;
689
690 if (ret > 0) {
691 if (path->slots[0] == 0)
692 goto insert;
693 path->slots[0]--;
694 }
695
696 leaf = path->nodes[0];
697 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
698 csum_offset = (bytenr - found_key.offset) >>
699 root->fs_info->sb->s_blocksize_bits;
700
701 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY ||
702 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
703 csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
704 goto insert;
705 }
706
707 if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
708 csum_size) {
709 u32 diff = (csum_offset + 1) * csum_size;
710
711 /*
712 * is the item big enough already? we dropped our lock
713 * before and need to recheck
714 */
715 if (diff < btrfs_item_size_nr(leaf, path->slots[0]))
716 goto csum;
717
718 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
719 if (diff != csum_size)
720 goto insert;
721
722 ret = btrfs_extend_item(trans, root, path, diff);
723 BUG_ON(ret);
724 goto csum;
725 }
726
727insert:
728 btrfs_release_path(root, path);
729 csum_offset = 0;
730 if (found_next) {
731 u64 tmp = total_bytes + root->sectorsize;
732 u64 next_sector = sector_sum->bytenr;
733 struct btrfs_sector_sum *next = sector_sum + 1;
734
735 while (tmp < sums->len) {
736 if (next_sector + root->sectorsize != next->bytenr)
737 break;
738 tmp += root->sectorsize;
739 next_sector = next->bytenr;
740 next++;
741 }
742 tmp = min(tmp, next_offset - file_key.offset);
743 tmp >>= root->fs_info->sb->s_blocksize_bits;
744 tmp = max((u64)1, tmp);
745 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
746 ins_size = csum_size * tmp;
747 } else {
748 ins_size = csum_size;
749 }
750 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
751 ins_size);
752 if (ret < 0)
753 goto fail_unlock;
754 if (ret != 0) {
755 WARN_ON(1);
756 goto fail_unlock;
757 }
758csum:
759 leaf = path->nodes[0];
760 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
761 ret = 0;
762 item = (struct btrfs_csum_item *)((unsigned char *)item +
763 csum_offset * csum_size);
764found:
765 item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
766 item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
767 btrfs_item_size_nr(leaf, path->slots[0]));
768 eb_token = NULL;
769 cond_resched();
770next_sector:
771
772 if (!eb_token ||
773 (unsigned long)item + csum_size >= map_start + map_len) {
774 int err;
775
776 if (eb_token)
777 unmap_extent_buffer(leaf, eb_token, KM_USER1);
778 eb_token = NULL;
779 err = map_private_extent_buffer(leaf, (unsigned long)item,
780 csum_size,
781 &eb_token, &eb_map,
782 &map_start, &map_len, KM_USER1);
783 if (err)
784 eb_token = NULL;
785 }
786 if (eb_token) {
787 memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
788 &sector_sum->sum, csum_size);
789 } else {
790 write_extent_buffer(leaf, &sector_sum->sum,
791 (unsigned long)item, csum_size);
792 }
793
794 total_bytes += root->sectorsize;
795 sector_sum++;
796 if (total_bytes < sums->len) {
797 item = (struct btrfs_csum_item *)((char *)item +
798 csum_size);
799 if (item < item_end && bytenr + PAGE_CACHE_SIZE ==
800 sector_sum->bytenr) {
801 bytenr = sector_sum->bytenr;
802 goto next_sector;
803 }
804 }
805 if (eb_token) {
806 unmap_extent_buffer(leaf, eb_token, KM_USER1);
807 eb_token = NULL;
808 }
809 btrfs_mark_buffer_dirty(path->nodes[0]);
810 cond_resched();
811 if (total_bytes < sums->len) {
812 btrfs_release_path(root, path);
813 goto again;
814 }
815out:
816 btrfs_free_path(path);
817 return ret;
818
819fail_unlock:
820 goto out;
821}
generated by cgit v1.2.2 (git 2.25.0) at 2025-03-05 02:53:17 -0500