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Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
[mirror_ubuntu-bionic-kernel.git] / fs / btrfs / file-item.c
CommitLineData
6cbd5570
CM
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
065631f6 19#include <linux/bio.h>
5a0e3ad6 20#include <linux/slab.h>
065631f6
CM
21#include <linux/pagemap.h>
22#include <linux/highmem.h>
1e1d2701 23#include "ctree.h"
dee26a9f 24#include "disk-io.h"
9f5fae2f 25#include "transaction.h"
1de037a4 26#include "print-tree.h"
1e1d2701 27
d397712b 28#define MAX_CSUM_ITEMS(r, size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
607d432d
JB
29 sizeof(struct btrfs_item) * 2) / \
30 size) - 1))
07d400a6
YZ
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
b18c6685 37int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
f2eb0a24
SW
38 struct btrfs_root *root,
39 u64 objectid, u64 pos,
40 u64 disk_offset, u64 disk_num_bytes,
c8b97818
CM
41 u64 num_bytes, u64 offset, u64 ram_bytes,
42 u8 compression, u8 encryption, u16 other_encoding)
9f5fae2f 43{
dee26a9f
CM
44 int ret = 0;
45 struct btrfs_file_extent_item *item;
46 struct btrfs_key file_key;
5caf2a00 47 struct btrfs_path *path;
5f39d397 48 struct extent_buffer *leaf;
dee26a9f 49
5caf2a00 50 path = btrfs_alloc_path();
db5b493a
TI
51 if (!path)
52 return -ENOMEM;
dee26a9f 53 file_key.objectid = objectid;
b18c6685 54 file_key.offset = pos;
dee26a9f
CM
55 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
56
b9473439 57 path->leave_spinning = 1;
5caf2a00 58 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
dee26a9f 59 sizeof(*item));
54aa1f4d
CM
60 if (ret < 0)
61 goto out;
9773a788 62 BUG_ON(ret);
5f39d397
CM
63 leaf = path->nodes[0];
64 item = btrfs_item_ptr(leaf, path->slots[0],
dee26a9f 65 struct btrfs_file_extent_item);
f2eb0a24 66 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
db94535d 67 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
f2eb0a24 68 btrfs_set_file_extent_offset(leaf, item, offset);
db94535d 69 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
c8b97818 70 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
5f39d397
CM
71 btrfs_set_file_extent_generation(leaf, item, trans->transid);
72 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
c8b97818
CM
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
5f39d397 77 btrfs_mark_buffer_dirty(leaf);
54aa1f4d 78out:
5caf2a00 79 btrfs_free_path(path);
54aa1f4d 80 return ret;
9f5fae2f 81}
dee26a9f 82
b18c6685
CM
83struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
84 struct btrfs_root *root,
85 struct btrfs_path *path,
d20f7043 86 u64 bytenr, int cow)
6567e837
CM
87{
88 int ret;
89 struct btrfs_key file_key;
90 struct btrfs_key found_key;
91 struct btrfs_csum_item *item;
5f39d397 92 struct extent_buffer *leaf;
6567e837 93 u64 csum_offset = 0;
607d432d
JB
94 u16 csum_size =
95 btrfs_super_csum_size(&root->fs_info->super_copy);
a429e513 96 int csums_in_item;
6567e837 97
d20f7043
CM
98 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
99 file_key.offset = bytenr;
100 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
b18c6685 101 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
6567e837
CM
102 if (ret < 0)
103 goto fail;
5f39d397 104 leaf = path->nodes[0];
6567e837
CM
105 if (ret > 0) {
106 ret = 1;
70b2befd 107 if (path->slots[0] == 0)
6567e837
CM
108 goto fail;
109 path->slots[0]--;
5f39d397 110 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
d20f7043 111 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
6567e837 112 goto fail;
d20f7043
CM
113
114 csum_offset = (bytenr - found_key.offset) >>
6567e837 115 root->fs_info->sb->s_blocksize_bits;
5f39d397 116 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
607d432d 117 csums_in_item /= csum_size;
a429e513
CM
118
119 if (csum_offset >= csums_in_item) {
120 ret = -EFBIG;
6567e837
CM
121 goto fail;
122 }
123 }
124 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
509659cd 125 item = (struct btrfs_csum_item *)((unsigned char *)item +
607d432d 126 csum_offset * csum_size);
6567e837
CM
127 return item;
128fail:
129 if (ret > 0)
b18c6685 130 ret = -ENOENT;
6567e837
CM
131 return ERR_PTR(ret);
132}
133
134
dee26a9f
CM
135int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
136 struct btrfs_root *root,
137 struct btrfs_path *path, u64 objectid,
9773a788 138 u64 offset, int mod)
dee26a9f
CM
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;
70b2befd 146 file_key.offset = offset;
dee26a9f
CM
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}
f254e52c 151
17d217fe 152
4b46fce2
JB
153static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
154 struct inode *inode, struct bio *bio,
155 u64 logical_offset, u32 *dst, int dio)
61b49440
CM
156{
157 u32 sum;
158 struct bio_vec *bvec = bio->bi_io_vec;
159 int bio_index = 0;
4b46fce2 160 u64 offset = 0;
61b49440
CM
161 u64 item_start_offset = 0;
162 u64 item_last_offset = 0;
d20f7043 163 u64 disk_bytenr;
61b49440 164 u32 diff;
607d432d
JB
165 u16 csum_size =
166 btrfs_super_csum_size(&root->fs_info->super_copy);
61b49440
CM
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();
c2db1073
TI
173 if (!path)
174 return -ENOMEM;
4d1b5fb4
CM
175 if (bio->bi_size > PAGE_CACHE_SIZE * 8)
176 path->reada = 2;
61b49440
CM
177
178 WARN_ON(bio->bi_vcnt <= 0);
179
d20f7043 180 disk_bytenr = (u64)bio->bi_sector << 9;
4b46fce2
JB
181 if (dio)
182 offset = logical_offset;
d397712b 183 while (bio_index < bio->bi_vcnt) {
4b46fce2
JB
184 if (!dio)
185 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
d20f7043 186 ret = btrfs_find_ordered_sum(inode, offset, disk_bytenr, &sum);
61b49440
CM
187 if (ret == 0)
188 goto found;
189
d20f7043
CM
190 if (!item || disk_bytenr < item_start_offset ||
191 disk_bytenr >= item_last_offset) {
61b49440
CM
192 struct btrfs_key found_key;
193 u32 item_size;
194
195 if (item)
b3b4aa74 196 btrfs_release_path(path);
d20f7043
CM
197 item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
198 path, disk_bytenr, 0);
61b49440
CM
199 if (IS_ERR(item)) {
200 ret = PTR_ERR(item);
201 if (ret == -ENOENT || ret == -EFBIG)
202 ret = 0;
203 sum = 0;
17d217fe
YZ
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 {
d397712b 210 printk(KERN_INFO "btrfs no csum found "
33345d01
LZ
211 "for inode %llu start %llu\n",
212 (unsigned long long)
213 btrfs_ino(inode),
17d217fe
YZ
214 (unsigned long long)offset);
215 }
6dab8157 216 item = NULL;
b3b4aa74 217 btrfs_release_path(path);
61b49440
CM
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 +
607d432d 227 (item_size / csum_size) *
61b49440
CM
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 */
d20f7043 236 diff = disk_bytenr - item_start_offset;
61b49440 237 diff = diff / root->sectorsize;
607d432d 238 diff = diff * csum_size;
61b49440
CM
239
240 read_extent_buffer(path->nodes[0], &sum,
3de9d6b6 241 ((unsigned long)item) + diff,
607d432d 242 csum_size);
61b49440 243found:
d20f7043
CM
244 if (dst)
245 *dst++ = sum;
246 else
247 set_state_private(io_tree, offset, sum);
248 disk_bytenr += bvec->bv_len;
4b46fce2 249 offset += bvec->bv_len;
61b49440
CM
250 bio_index++;
251 bvec++;
252 }
253 btrfs_free_path(path);
254 return 0;
255}
256
4b46fce2
JB
257int 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
263int 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
17d217fe 269int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
a2de733c 270 struct list_head *list, int search_commit)
17d217fe
YZ
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
a2de733c
AJ
287 if (search_commit) {
288 path->skip_locking = 1;
289 path->reada = 2;
290 path->search_commit_root = 1;
291 }
292
17d217fe
YZ
293 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
294 key.offset = start;
295 key.type = BTRFS_EXTENT_CSUM_KEY;
296
07d400a6 297 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
17d217fe
YZ
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)) {
07d400a6 316 ret = btrfs_next_leaf(root, path);
17d217fe
YZ
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;
87b29b20
YZ
338 if (csum_end <= start) {
339 path->slots[0]++;
340 continue;
341 }
17d217fe 342
07d400a6 343 csum_end = min(csum_end, end + 1);
17d217fe
YZ
344 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
345 struct btrfs_csum_item);
07d400a6
YZ
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);
17d217fe 352
07d400a6
YZ
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 }
17d217fe
YZ
375 path->slots[0]++;
376 }
377 ret = 0;
378fail:
379 btrfs_free_path(path);
380 return ret;
381}
382
3edf7d33 383int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
d20f7043 384 struct bio *bio, u64 file_start, int contig)
e015640f 385{
e6dcd2dc
CM
386 struct btrfs_ordered_sum *sums;
387 struct btrfs_sector_sum *sector_sum;
3edf7d33 388 struct btrfs_ordered_extent *ordered;
e015640f
CM
389 char *data;
390 struct bio_vec *bvec = bio->bi_io_vec;
391 int bio_index = 0;
3edf7d33
CM
392 unsigned long total_bytes = 0;
393 unsigned long this_sum_bytes = 0;
394 u64 offset;
d20f7043 395 u64 disk_bytenr;
e015640f 396
e6dcd2dc
CM
397 WARN_ON(bio->bi_vcnt <= 0);
398 sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
e015640f
CM
399 if (!sums)
400 return -ENOMEM;
3edf7d33 401
ed98b56a 402 sector_sum = sums->sums;
d20f7043 403 disk_bytenr = (u64)bio->bi_sector << 9;
e6dcd2dc
CM
404 sums->len = bio->bi_size;
405 INIT_LIST_HEAD(&sums->list);
d20f7043
CM
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);
3edf7d33 413 BUG_ON(!ordered);
d20f7043 414 sums->bytenr = ordered->start;
e015640f 415
d397712b 416 while (bio_index < bio->bi_vcnt) {
d20f7043
CM
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)) {
3edf7d33
CM
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);
ed98b56a 433 sector_sum = sums->sums;
3edf7d33 434 sums->len = bytes_left;
d20f7043 435 ordered = btrfs_lookup_ordered_extent(inode, offset);
3edf7d33 436 BUG_ON(!ordered);
d20f7043 437 sums->bytenr = ordered->start;
3edf7d33
CM
438 }
439
e015640f 440 data = kmap_atomic(bvec->bv_page, KM_USER0);
e6dcd2dc
CM
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);
e015640f 446 kunmap_atomic(data, KM_USER0);
e6dcd2dc
CM
447 btrfs_csum_final(sector_sum->sum,
448 (char *)&sector_sum->sum);
d20f7043 449 sector_sum->bytenr = disk_bytenr;
ed98b56a 450
e6dcd2dc 451 sector_sum++;
e015640f 452 bio_index++;
3edf7d33
CM
453 total_bytes += bvec->bv_len;
454 this_sum_bytes += bvec->bv_len;
d20f7043
CM
455 disk_bytenr += bvec->bv_len;
456 offset += bvec->bv_len;
e015640f
CM
457 bvec++;
458 }
ed98b56a 459 this_sum_bytes = 0;
3edf7d33
CM
460 btrfs_add_ordered_sum(inode, ordered, sums);
461 btrfs_put_ordered_extent(ordered);
e015640f
CM
462 return 0;
463}
464
459931ec
CM
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 */
476static 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);
459931ec
CM
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);
459931ec
CM
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 */
531int 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();
2a29edc6 547 if (!path)
548 return -ENOMEM;
459931ec 549
d397712b 550 while (1) {
459931ec
CM
551 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
552 key.offset = end_byte - 1;
553 key.type = BTRFS_EXTENT_CSUM_KEY;
554
b9473439 555 path->leave_spinning = 1;
459931ec
CM
556 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
557 if (ret > 0) {
558 if (path->slots[0] == 0)
65a246c5 559 break;
459931ec 560 path->slots[0]--;
ad0397a7 561 } else if (ret < 0) {
65a246c5 562 break;
459931ec 563 }
ad0397a7 564
459931ec
CM
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);
65a246c5
TI
587 if (ret)
588 goto out;
dcbdd4dc
CM
589 if (key.offset == bytenr)
590 break;
459931ec
CM
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);
dcbdd4dc
CM
637 if (key.offset < bytenr)
638 break;
459931ec 639 }
b3b4aa74 640 btrfs_release_path(path);
459931ec 641 }
65a246c5 642 ret = 0;
459931ec
CM
643out:
644 btrfs_free_path(path);
65a246c5 645 return ret;
459931ec
CM
646}
647
065631f6 648int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
d20f7043 649 struct btrfs_root *root,
e6dcd2dc 650 struct btrfs_ordered_sum *sums)
f254e52c 651{
d20f7043 652 u64 bytenr;
f254e52c
CM
653 int ret;
654 struct btrfs_key file_key;
6567e837 655 struct btrfs_key found_key;
065631f6 656 u64 next_offset;
e6dcd2dc 657 u64 total_bytes = 0;
065631f6 658 int found_next;
5caf2a00 659 struct btrfs_path *path;
f254e52c 660 struct btrfs_csum_item *item;
065631f6 661 struct btrfs_csum_item *item_end;
ff79f819 662 struct extent_buffer *leaf = NULL;
6567e837 663 u64 csum_offset;
e6dcd2dc 664 struct btrfs_sector_sum *sector_sum;
f578d4bd
CM
665 u32 nritems;
666 u32 ins_size;
6e92f5e6
CM
667 char *eb_map;
668 char *eb_token;
669 unsigned long map_len;
670 unsigned long map_start;
607d432d
JB
671 u16 csum_size =
672 btrfs_super_csum_size(&root->fs_info->super_copy);
6e92f5e6 673
5caf2a00
CM
674 path = btrfs_alloc_path();
675 BUG_ON(!path);
ed98b56a 676 sector_sum = sums->sums;
065631f6
CM
677again:
678 next_offset = (u64)-1;
679 found_next = 0;
d20f7043
CM
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);
a429e513 684
d20f7043 685 item = btrfs_lookup_csum(trans, root, path, sector_sum->bytenr, 1);
ff79f819
CM
686 if (!IS_ERR(item)) {
687 leaf = path->nodes[0];
639cb586 688 ret = 0;
a429e513 689 goto found;
ff79f819 690 }
a429e513 691 ret = PTR_ERR(item);
4a500fd1
YZ
692 if (ret != -EFBIG && ret != -ENOENT)
693 goto fail_unlock;
694
a429e513
CM
695 if (ret == -EFBIG) {
696 u32 item_size;
697 /* we found one, but it isn't big enough yet */
5f39d397
CM
698 leaf = path->nodes[0];
699 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
607d432d
JB
700 if ((item_size / csum_size) >=
701 MAX_CSUM_ITEMS(root, csum_size)) {
a429e513
CM
702 /* already at max size, make a new one */
703 goto insert;
704 }
705 } else {
f578d4bd 706 int slot = path->slots[0] + 1;
a429e513 707 /* we didn't find a csum item, insert one */
f578d4bd
CM
708 nritems = btrfs_header_nritems(path->nodes[0]);
709 if (path->slots[0] >= nritems - 1) {
710 ret = btrfs_next_leaf(root, path);
b56baf5b 711 if (ret == 1)
f578d4bd 712 found_next = 1;
b56baf5b 713 if (ret != 0)
f578d4bd 714 goto insert;
b56baf5b 715 slot = 0;
f578d4bd
CM
716 }
717 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
d20f7043
CM
718 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
719 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
f578d4bd
CM
720 found_next = 1;
721 goto insert;
722 }
723 next_offset = found_key.offset;
724 found_next = 1;
a429e513
CM
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 */
b3b4aa74 732 btrfs_release_path(path);
6567e837 733 ret = btrfs_search_slot(trans, root, &file_key, path,
607d432d 734 csum_size, 1);
6567e837 735 if (ret < 0)
53863232 736 goto fail_unlock;
459931ec
CM
737
738 if (ret > 0) {
739 if (path->slots[0] == 0)
740 goto insert;
741 path->slots[0]--;
6567e837 742 }
459931ec 743
5f39d397
CM
744 leaf = path->nodes[0];
745 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
d20f7043 746 csum_offset = (bytenr - found_key.offset) >>
6567e837 747 root->fs_info->sb->s_blocksize_bits;
459931ec 748
d20f7043
CM
749 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY ||
750 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
607d432d 751 csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
6567e837
CM
752 goto insert;
753 }
459931ec 754
5f39d397 755 if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
607d432d
JB
756 csum_size) {
757 u32 diff = (csum_offset + 1) * csum_size;
459931ec
CM
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
5f39d397 766 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
d397712b 767 if (diff != csum_size)
3a686375 768 goto insert;
459931ec 769
a429e513 770 ret = btrfs_extend_item(trans, root, path, diff);
6567e837
CM
771 goto csum;
772 }
773
774insert:
b3b4aa74 775 btrfs_release_path(path);
6567e837 776 csum_offset = 0;
f578d4bd 777 if (found_next) {
d20f7043
CM
778 u64 tmp = total_bytes + root->sectorsize;
779 u64 next_sector = sector_sum->bytenr;
780 struct btrfs_sector_sum *next = sector_sum + 1;
781
d397712b 782 while (tmp < sums->len) {
d20f7043
CM
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);
f578d4bd
CM
790 tmp >>= root->fs_info->sb->s_blocksize_bits;
791 tmp = max((u64)1, tmp);
607d432d
JB
792 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
793 ins_size = csum_size * tmp;
f578d4bd 794 } else {
607d432d 795 ins_size = csum_size;
f578d4bd 796 }
b9473439 797 path->leave_spinning = 1;
5caf2a00 798 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
f578d4bd 799 ins_size);
b9473439 800 path->leave_spinning = 0;
54aa1f4d 801 if (ret < 0)
53863232 802 goto fail_unlock;
a429e513 803 if (ret != 0) {
a429e513 804 WARN_ON(1);
53863232 805 goto fail_unlock;
a429e513 806 }
6567e837 807csum:
5f39d397
CM
808 leaf = path->nodes[0];
809 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
f254e52c 810 ret = 0;
509659cd 811 item = (struct btrfs_csum_item *)((unsigned char *)item +
607d432d 812 csum_offset * csum_size);
b18c6685 813found:
065631f6
CM
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]));
6e92f5e6 817 eb_token = NULL;
e6dcd2dc 818next_sector:
aadfeb6e 819
6e92f5e6 820 if (!eb_token ||
607d432d 821 (unsigned long)item + csum_size >= map_start + map_len) {
6e92f5e6
CM
822 int err;
823
824 if (eb_token)
eb20978f 825 unmap_extent_buffer(leaf, eb_token, KM_USER1);
6e92f5e6
CM
826 eb_token = NULL;
827 err = map_private_extent_buffer(leaf, (unsigned long)item,
607d432d 828 csum_size,
6e92f5e6 829 &eb_token, &eb_map,
eb20978f 830 &map_start, &map_len, KM_USER1);
6e92f5e6
CM
831 if (err)
832 eb_token = NULL;
833 }
834 if (eb_token) {
835 memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
607d432d 836 &sector_sum->sum, csum_size);
6e92f5e6 837 } else {
e6dcd2dc 838 write_extent_buffer(leaf, &sector_sum->sum,
607d432d 839 (unsigned long)item, csum_size);
6e92f5e6 840 }
7f3c74fb 841
e6dcd2dc
CM
842 total_bytes += root->sectorsize;
843 sector_sum++;
844 if (total_bytes < sums->len) {
6e92f5e6 845 item = (struct btrfs_csum_item *)((char *)item +
607d432d 846 csum_size);
d20f7043
CM
847 if (item < item_end && bytenr + PAGE_CACHE_SIZE ==
848 sector_sum->bytenr) {
849 bytenr = sector_sum->bytenr;
e6dcd2dc 850 goto next_sector;
2e1a992e 851 }
065631f6 852 }
6e92f5e6 853 if (eb_token) {
eb20978f 854 unmap_extent_buffer(leaf, eb_token, KM_USER1);
6e92f5e6
CM
855 eb_token = NULL;
856 }
5caf2a00 857 btrfs_mark_buffer_dirty(path->nodes[0]);
e6dcd2dc 858 if (total_bytes < sums->len) {
b3b4aa74 859 btrfs_release_path(path);
b9473439 860 cond_resched();
065631f6
CM
861 goto again;
862 }
53863232 863out:
5caf2a00 864 btrfs_free_path(path);
f254e52c 865 return ret;
53863232
CM
866
867fail_unlock:
53863232 868 goto out;
f254e52c 869}