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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#include <linux/bio.h>
7#include <linux/slab.h>
8#include <linux/pagemap.h>
9#include <linux/highmem.h>
10#include <linux/sched/mm.h>
11#include <crypto/hash.h>
12#include "ctree.h"
13#include "disk-io.h"
14#include "transaction.h"
15#include "volumes.h"
16#include "print-tree.h"
17#include "compression.h"
18
19#define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
20 sizeof(struct btrfs_item) * 2) / \
21 size) - 1))
22
23#define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
24 PAGE_SIZE))
25
26static inline u32 max_ordered_sum_bytes(struct btrfs_fs_info *fs_info,
27 u16 csum_size)
28{
29 u32 ncsums = (PAGE_SIZE - sizeof(struct btrfs_ordered_sum)) / csum_size;
30
31 return ncsums * fs_info->sectorsize;
32}
33
34int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
35 struct btrfs_root *root,
36 u64 objectid, u64 pos,
37 u64 disk_offset, u64 disk_num_bytes,
38 u64 num_bytes, u64 offset, u64 ram_bytes,
39 u8 compression, u8 encryption, u16 other_encoding)
40{
41 int ret = 0;
42 struct btrfs_file_extent_item *item;
43 struct btrfs_key file_key;
44 struct btrfs_path *path;
45 struct extent_buffer *leaf;
46
47 path = btrfs_alloc_path();
48 if (!path)
49 return -ENOMEM;
50 file_key.objectid = objectid;
51 file_key.offset = pos;
52 file_key.type = BTRFS_EXTENT_DATA_KEY;
53
54 path->leave_spinning = 1;
55 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
56 sizeof(*item));
57 if (ret < 0)
58 goto out;
59 BUG_ON(ret); /* Can't happen */
60 leaf = path->nodes[0];
61 item = btrfs_item_ptr(leaf, path->slots[0],
62 struct btrfs_file_extent_item);
63 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
64 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
65 btrfs_set_file_extent_offset(leaf, item, offset);
66 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
67 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
68 btrfs_set_file_extent_generation(leaf, item, trans->transid);
69 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
70 btrfs_set_file_extent_compression(leaf, item, compression);
71 btrfs_set_file_extent_encryption(leaf, item, encryption);
72 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
73
74 btrfs_mark_buffer_dirty(leaf);
75out:
76 btrfs_free_path(path);
77 return ret;
78}
79
80static struct btrfs_csum_item *
81btrfs_lookup_csum(struct btrfs_trans_handle *trans,
82 struct btrfs_root *root,
83 struct btrfs_path *path,
84 u64 bytenr, int cow)
85{
86 struct btrfs_fs_info *fs_info = root->fs_info;
87 int ret;
88 struct btrfs_key file_key;
89 struct btrfs_key found_key;
90 struct btrfs_csum_item *item;
91 struct extent_buffer *leaf;
92 u64 csum_offset = 0;
93 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
94 int csums_in_item;
95
96 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
97 file_key.offset = bytenr;
98 file_key.type = BTRFS_EXTENT_CSUM_KEY;
99 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
100 if (ret < 0)
101 goto fail;
102 leaf = path->nodes[0];
103 if (ret > 0) {
104 ret = 1;
105 if (path->slots[0] == 0)
106 goto fail;
107 path->slots[0]--;
108 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
109 if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
110 goto fail;
111
112 csum_offset = (bytenr - found_key.offset) >>
113 fs_info->sb->s_blocksize_bits;
114 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
115 csums_in_item /= csum_size;
116
117 if (csum_offset == csums_in_item) {
118 ret = -EFBIG;
119 goto fail;
120 } else if (csum_offset > csums_in_item) {
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;
128fail:
129 if (ret > 0)
130 ret = -ENOENT;
131 return ERR_PTR(ret);
132}
133
134int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
135 struct btrfs_root *root,
136 struct btrfs_path *path, u64 objectid,
137 u64 offset, int mod)
138{
139 int ret;
140 struct btrfs_key file_key;
141 int ins_len = mod < 0 ? -1 : 0;
142 int cow = mod != 0;
143
144 file_key.objectid = objectid;
145 file_key.offset = offset;
146 file_key.type = BTRFS_EXTENT_DATA_KEY;
147 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
148 return ret;
149}
150
151static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
152 u64 logical_offset, u8 *dst, int dio)
153{
154 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
155 struct bio_vec bvec;
156 struct bvec_iter iter;
157 struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
158 struct btrfs_csum_item *item = NULL;
159 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
160 struct btrfs_path *path;
161 u8 *csum;
162 u64 offset = 0;
163 u64 item_start_offset = 0;
164 u64 item_last_offset = 0;
165 u64 disk_bytenr;
166 u64 page_bytes_left;
167 u32 diff;
168 int nblocks;
169 int count = 0;
170 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
171
172 path = btrfs_alloc_path();
173 if (!path)
174 return BLK_STS_RESOURCE;
175
176 nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits;
177 if (!dst) {
178 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
179 btrfs_bio->csum = kmalloc_array(nblocks, csum_size,
180 GFP_NOFS);
181 if (!btrfs_bio->csum) {
182 btrfs_free_path(path);
183 return BLK_STS_RESOURCE;
184 }
185 } else {
186 btrfs_bio->csum = btrfs_bio->csum_inline;
187 }
188 csum = btrfs_bio->csum;
189 } else {
190 csum = dst;
191 }
192
193 if (bio->bi_iter.bi_size > PAGE_SIZE * 8)
194 path->reada = READA_FORWARD;
195
196 /*
197 * the free space stuff is only read when it hasn't been
198 * updated in the current transaction. So, we can safely
199 * read from the commit root and sidestep a nasty deadlock
200 * between reading the free space cache and updating the csum tree.
201 */
202 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
203 path->search_commit_root = 1;
204 path->skip_locking = 1;
205 }
206
207 disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
208 if (dio)
209 offset = logical_offset;
210
211 bio_for_each_segment(bvec, bio, iter) {
212 page_bytes_left = bvec.bv_len;
213 if (count)
214 goto next;
215
216 if (!dio)
217 offset = page_offset(bvec.bv_page) + bvec.bv_offset;
218 count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
219 csum, nblocks);
220 if (count)
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, fs_info->csum_root,
231 path, disk_bytenr, 0);
232 if (IS_ERR(item)) {
233 count = 1;
234 memset(csum, 0, csum_size);
235 if (BTRFS_I(inode)->root->root_key.objectid ==
236 BTRFS_DATA_RELOC_TREE_OBJECTID) {
237 set_extent_bits(io_tree, offset,
238 offset + fs_info->sectorsize - 1,
239 EXTENT_NODATASUM);
240 } else {
241 btrfs_info_rl(fs_info,
242 "no csum found for inode %llu start %llu",
243 btrfs_ino(BTRFS_I(inode)), offset);
244 }
245 item = NULL;
246 btrfs_release_path(path);
247 goto found;
248 }
249 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
250 path->slots[0]);
251
252 item_start_offset = found_key.offset;
253 item_size = btrfs_item_size_nr(path->nodes[0],
254 path->slots[0]);
255 item_last_offset = item_start_offset +
256 (item_size / csum_size) *
257 fs_info->sectorsize;
258 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
259 struct btrfs_csum_item);
260 }
261 /*
262 * this byte range must be able to fit inside
263 * a single leaf so it will also fit inside a u32
264 */
265 diff = disk_bytenr - item_start_offset;
266 diff = diff / fs_info->sectorsize;
267 diff = diff * csum_size;
268 count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >>
269 inode->i_sb->s_blocksize_bits);
270 read_extent_buffer(path->nodes[0], csum,
271 ((unsigned long)item) + diff,
272 csum_size * count);
273found:
274 csum += count * csum_size;
275 nblocks -= count;
276next:
277 while (count--) {
278 disk_bytenr += fs_info->sectorsize;
279 offset += fs_info->sectorsize;
280 page_bytes_left -= fs_info->sectorsize;
281 if (!page_bytes_left)
282 break; /* move to next bio */
283 }
284 }
285
286 WARN_ON_ONCE(count);
287 btrfs_free_path(path);
288 return 0;
289}
290
291blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
292 u8 *dst)
293{
294 return __btrfs_lookup_bio_sums(inode, bio, 0, dst, 0);
295}
296
297blk_status_t btrfs_lookup_bio_sums_dio(struct inode *inode, struct bio *bio, u64 offset)
298{
299 return __btrfs_lookup_bio_sums(inode, bio, offset, NULL, 1);
300}
301
302int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
303 struct list_head *list, int search_commit)
304{
305 struct btrfs_fs_info *fs_info = root->fs_info;
306 struct btrfs_key key;
307 struct btrfs_path *path;
308 struct extent_buffer *leaf;
309 struct btrfs_ordered_sum *sums;
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(fs_info->super_copy);
317
318 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
319 IS_ALIGNED(end + 1, fs_info->sectorsize));
320
321 path = btrfs_alloc_path();
322 if (!path)
323 return -ENOMEM;
324
325 if (search_commit) {
326 path->skip_locking = 1;
327 path->reada = READA_FORWARD;
328 path->search_commit_root = 1;
329 }
330
331 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
332 key.offset = start;
333 key.type = BTRFS_EXTENT_CSUM_KEY;
334
335 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
336 if (ret < 0)
337 goto fail;
338 if (ret > 0 && path->slots[0] > 0) {
339 leaf = path->nodes[0];
340 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
341 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
342 key.type == BTRFS_EXTENT_CSUM_KEY) {
343 offset = (start - key.offset) >>
344 fs_info->sb->s_blocksize_bits;
345 if (offset * csum_size <
346 btrfs_item_size_nr(leaf, path->slots[0] - 1))
347 path->slots[0]--;
348 }
349 }
350
351 while (start <= end) {
352 leaf = path->nodes[0];
353 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
354 ret = btrfs_next_leaf(root, path);
355 if (ret < 0)
356 goto fail;
357 if (ret > 0)
358 break;
359 leaf = path->nodes[0];
360 }
361
362 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
363 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
364 key.type != BTRFS_EXTENT_CSUM_KEY ||
365 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) * fs_info->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(fs_info, csum_size));
384 sums = kzalloc(btrfs_ordered_sum_size(fs_info, size),
385 GFP_NOFS);
386 if (!sums) {
387 ret = -ENOMEM;
388 goto fail;
389 }
390
391 sums->bytenr = start;
392 sums->len = (int)size;
393
394 offset = (start - key.offset) >>
395 fs_info->sb->s_blocksize_bits;
396 offset *= csum_size;
397 size >>= fs_info->sb->s_blocksize_bits;
398
399 read_extent_buffer(path->nodes[0],
400 sums->sums,
401 ((unsigned long)item) + offset,
402 csum_size * size);
403
404 start += fs_info->sectorsize * size;
405 list_add_tail(&sums->list, &tmplist);
406 }
407 path->slots[0]++;
408 }
409 ret = 0;
410fail:
411 while (ret < 0 && !list_empty(&tmplist)) {
412 sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list);
413 list_del(&sums->list);
414 kfree(sums);
415 }
416 list_splice_tail(&tmplist, list);
417
418 btrfs_free_path(path);
419 return ret;
420}
421
422/*
423 * btrfs_csum_one_bio - Calculates checksums of the data contained inside a bio
424 * @inode: Owner of the data inside the bio
425 * @bio: Contains the data to be checksummed
426 * @file_start: offset in file this bio begins to describe
427 * @contig: Boolean. If true/1 means all bio vecs in this bio are
428 * contiguous and they begin at @file_start in the file. False/0
429 * means this bio can contains potentially discontigous bio vecs
430 * so the logical offset of each should be calculated separately.
431 */
432blk_status_t btrfs_csum_one_bio(struct inode *inode, struct bio *bio,
433 u64 file_start, int contig)
434{
435 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
436 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
437 struct btrfs_ordered_sum *sums;
438 struct btrfs_ordered_extent *ordered = NULL;
439 char *data;
440 struct bvec_iter iter;
441 struct bio_vec bvec;
442 int index;
443 int nr_sectors;
444 unsigned long total_bytes = 0;
445 unsigned long this_sum_bytes = 0;
446 int i;
447 u64 offset;
448 unsigned nofs_flag;
449 const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
450
451 nofs_flag = memalloc_nofs_save();
452 sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
453 GFP_KERNEL);
454 memalloc_nofs_restore(nofs_flag);
455
456 if (!sums)
457 return BLK_STS_RESOURCE;
458
459 sums->len = bio->bi_iter.bi_size;
460 INIT_LIST_HEAD(&sums->list);
461
462 if (contig)
463 offset = file_start;
464 else
465 offset = 0; /* shut up gcc */
466
467 sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
468 index = 0;
469
470 shash->tfm = fs_info->csum_shash;
471
472 bio_for_each_segment(bvec, bio, iter) {
473 if (!contig)
474 offset = page_offset(bvec.bv_page) + bvec.bv_offset;
475
476 if (!ordered) {
477 ordered = btrfs_lookup_ordered_extent(inode, offset);
478 BUG_ON(!ordered); /* Logic error */
479 }
480
481 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info,
482 bvec.bv_len + fs_info->sectorsize
483 - 1);
484
485 for (i = 0; i < nr_sectors; i++) {
486 if (offset >= ordered->file_offset + ordered->len ||
487 offset < ordered->file_offset) {
488 unsigned long bytes_left;
489
490 sums->len = this_sum_bytes;
491 this_sum_bytes = 0;
492 btrfs_add_ordered_sum(ordered, sums);
493 btrfs_put_ordered_extent(ordered);
494
495 bytes_left = bio->bi_iter.bi_size - total_bytes;
496
497 nofs_flag = memalloc_nofs_save();
498 sums = kvzalloc(btrfs_ordered_sum_size(fs_info,
499 bytes_left), GFP_KERNEL);
500 memalloc_nofs_restore(nofs_flag);
501 BUG_ON(!sums); /* -ENOMEM */
502 sums->len = bytes_left;
503 ordered = btrfs_lookup_ordered_extent(inode,
504 offset);
505 ASSERT(ordered); /* Logic error */
506 sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9)
507 + total_bytes;
508 index = 0;
509 }
510
511 crypto_shash_init(shash);
512 data = kmap_atomic(bvec.bv_page);
513 crypto_shash_update(shash, data + bvec.bv_offset
514 + (i * fs_info->sectorsize),
515 fs_info->sectorsize);
516 kunmap_atomic(data);
517 crypto_shash_final(shash, (char *)(sums->sums + index));
518 index += csum_size;
519 offset += fs_info->sectorsize;
520 this_sum_bytes += fs_info->sectorsize;
521 total_bytes += fs_info->sectorsize;
522 }
523
524 }
525 this_sum_bytes = 0;
526 btrfs_add_ordered_sum(ordered, sums);
527 btrfs_put_ordered_extent(ordered);
528 return 0;
529}
530
531/*
532 * helper function for csum removal, this expects the
533 * key to describe the csum pointed to by the path, and it expects
534 * the csum to overlap the range [bytenr, len]
535 *
536 * The csum should not be entirely contained in the range and the
537 * range should not be entirely contained in the csum.
538 *
539 * This calls btrfs_truncate_item with the correct args based on the
540 * overlap, and fixes up the key as required.
541 */
542static noinline void truncate_one_csum(struct btrfs_fs_info *fs_info,
543 struct btrfs_path *path,
544 struct btrfs_key *key,
545 u64 bytenr, u64 len)
546{
547 struct extent_buffer *leaf;
548 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
549 u64 csum_end;
550 u64 end_byte = bytenr + len;
551 u32 blocksize_bits = fs_info->sb->s_blocksize_bits;
552
553 leaf = path->nodes[0];
554 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
555 csum_end <<= fs_info->sb->s_blocksize_bits;
556 csum_end += key->offset;
557
558 if (key->offset < bytenr && csum_end <= end_byte) {
559 /*
560 * [ bytenr - len ]
561 * [ ]
562 * [csum ]
563 * A simple truncate off the end of the item
564 */
565 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
566 new_size *= csum_size;
567 btrfs_truncate_item(path, new_size, 1);
568 } else if (key->offset >= bytenr && csum_end > end_byte &&
569 end_byte > key->offset) {
570 /*
571 * [ bytenr - len ]
572 * [ ]
573 * [csum ]
574 * we need to truncate from the beginning of the csum
575 */
576 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
577 new_size *= csum_size;
578
579 btrfs_truncate_item(path, new_size, 0);
580
581 key->offset = end_byte;
582 btrfs_set_item_key_safe(fs_info, path, key);
583 } else {
584 BUG();
585 }
586}
587
588/*
589 * deletes the csum items from the csum tree for a given
590 * range of bytes.
591 */
592int btrfs_del_csums(struct btrfs_trans_handle *trans,
593 struct btrfs_fs_info *fs_info, u64 bytenr, u64 len)
594{
595 struct btrfs_root *root = fs_info->csum_root;
596 struct btrfs_path *path;
597 struct btrfs_key key;
598 u64 end_byte = bytenr + len;
599 u64 csum_end;
600 struct extent_buffer *leaf;
601 int ret;
602 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
603 int blocksize_bits = fs_info->sb->s_blocksize_bits;
604
605 path = btrfs_alloc_path();
606 if (!path)
607 return -ENOMEM;
608
609 while (1) {
610 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
611 key.offset = end_byte - 1;
612 key.type = BTRFS_EXTENT_CSUM_KEY;
613
614 path->leave_spinning = 1;
615 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
616 if (ret > 0) {
617 if (path->slots[0] == 0)
618 break;
619 path->slots[0]--;
620 } else if (ret < 0) {
621 break;
622 }
623
624 leaf = path->nodes[0];
625 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
626
627 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
628 key.type != BTRFS_EXTENT_CSUM_KEY) {
629 break;
630 }
631
632 if (key.offset >= end_byte)
633 break;
634
635 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
636 csum_end <<= blocksize_bits;
637 csum_end += key.offset;
638
639 /* this csum ends before we start, we're done */
640 if (csum_end <= bytenr)
641 break;
642
643 /* delete the entire item, it is inside our range */
644 if (key.offset >= bytenr && csum_end <= end_byte) {
645 int del_nr = 1;
646
647 /*
648 * Check how many csum items preceding this one in this
649 * leaf correspond to our range and then delete them all
650 * at once.
651 */
652 if (key.offset > bytenr && path->slots[0] > 0) {
653 int slot = path->slots[0] - 1;
654
655 while (slot >= 0) {
656 struct btrfs_key pk;
657
658 btrfs_item_key_to_cpu(leaf, &pk, slot);
659 if (pk.offset < bytenr ||
660 pk.type != BTRFS_EXTENT_CSUM_KEY ||
661 pk.objectid !=
662 BTRFS_EXTENT_CSUM_OBJECTID)
663 break;
664 path->slots[0] = slot;
665 del_nr++;
666 key.offset = pk.offset;
667 slot--;
668 }
669 }
670 ret = btrfs_del_items(trans, root, path,
671 path->slots[0], del_nr);
672 if (ret)
673 goto out;
674 if (key.offset == bytenr)
675 break;
676 } else if (key.offset < bytenr && csum_end > end_byte) {
677 unsigned long offset;
678 unsigned long shift_len;
679 unsigned long item_offset;
680 /*
681 * [ bytenr - len ]
682 * [csum ]
683 *
684 * Our bytes are in the middle of the csum,
685 * we need to split this item and insert a new one.
686 *
687 * But we can't drop the path because the
688 * csum could change, get removed, extended etc.
689 *
690 * The trick here is the max size of a csum item leaves
691 * enough room in the tree block for a single
692 * item header. So, we split the item in place,
693 * adding a new header pointing to the existing
694 * bytes. Then we loop around again and we have
695 * a nicely formed csum item that we can neatly
696 * truncate.
697 */
698 offset = (bytenr - key.offset) >> blocksize_bits;
699 offset *= csum_size;
700
701 shift_len = (len >> blocksize_bits) * csum_size;
702
703 item_offset = btrfs_item_ptr_offset(leaf,
704 path->slots[0]);
705
706 memzero_extent_buffer(leaf, item_offset + offset,
707 shift_len);
708 key.offset = bytenr;
709
710 /*
711 * btrfs_split_item returns -EAGAIN when the
712 * item changed size or key
713 */
714 ret = btrfs_split_item(trans, root, path, &key, offset);
715 if (ret && ret != -EAGAIN) {
716 btrfs_abort_transaction(trans, ret);
717 goto out;
718 }
719
720 key.offset = end_byte - 1;
721 } else {
722 truncate_one_csum(fs_info, path, &key, bytenr, len);
723 if (key.offset < bytenr)
724 break;
725 }
726 btrfs_release_path(path);
727 }
728 ret = 0;
729out:
730 btrfs_free_path(path);
731 return ret;
732}
733
734int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
735 struct btrfs_root *root,
736 struct btrfs_ordered_sum *sums)
737{
738 struct btrfs_fs_info *fs_info = root->fs_info;
739 struct btrfs_key file_key;
740 struct btrfs_key found_key;
741 struct btrfs_path *path;
742 struct btrfs_csum_item *item;
743 struct btrfs_csum_item *item_end;
744 struct extent_buffer *leaf = NULL;
745 u64 next_offset;
746 u64 total_bytes = 0;
747 u64 csum_offset;
748 u64 bytenr;
749 u32 nritems;
750 u32 ins_size;
751 int index = 0;
752 int found_next;
753 int ret;
754 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
755
756 path = btrfs_alloc_path();
757 if (!path)
758 return -ENOMEM;
759again:
760 next_offset = (u64)-1;
761 found_next = 0;
762 bytenr = sums->bytenr + total_bytes;
763 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
764 file_key.offset = bytenr;
765 file_key.type = BTRFS_EXTENT_CSUM_KEY;
766
767 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
768 if (!IS_ERR(item)) {
769 ret = 0;
770 leaf = path->nodes[0];
771 item_end = btrfs_item_ptr(leaf, path->slots[0],
772 struct btrfs_csum_item);
773 item_end = (struct btrfs_csum_item *)((char *)item_end +
774 btrfs_item_size_nr(leaf, path->slots[0]));
775 goto found;
776 }
777 ret = PTR_ERR(item);
778 if (ret != -EFBIG && ret != -ENOENT)
779 goto fail_unlock;
780
781 if (ret == -EFBIG) {
782 u32 item_size;
783 /* we found one, but it isn't big enough yet */
784 leaf = path->nodes[0];
785 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
786 if ((item_size / csum_size) >=
787 MAX_CSUM_ITEMS(fs_info, csum_size)) {
788 /* already at max size, make a new one */
789 goto insert;
790 }
791 } else {
792 int slot = path->slots[0] + 1;
793 /* we didn't find a csum item, insert one */
794 nritems = btrfs_header_nritems(path->nodes[0]);
795 if (!nritems || (path->slots[0] >= nritems - 1)) {
796 ret = btrfs_next_leaf(root, path);
797 if (ret == 1)
798 found_next = 1;
799 if (ret != 0)
800 goto insert;
801 slot = path->slots[0];
802 }
803 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
804 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
805 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
806 found_next = 1;
807 goto insert;
808 }
809 next_offset = found_key.offset;
810 found_next = 1;
811 goto insert;
812 }
813
814 /*
815 * at this point, we know the tree has an item, but it isn't big
816 * enough yet to put our csum in. Grow it
817 */
818 btrfs_release_path(path);
819 ret = btrfs_search_slot(trans, root, &file_key, path,
820 csum_size, 1);
821 if (ret < 0)
822 goto fail_unlock;
823
824 if (ret > 0) {
825 if (path->slots[0] == 0)
826 goto insert;
827 path->slots[0]--;
828 }
829
830 leaf = path->nodes[0];
831 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
832 csum_offset = (bytenr - found_key.offset) >>
833 fs_info->sb->s_blocksize_bits;
834
835 if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
836 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
837 csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
838 goto insert;
839 }
840
841 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
842 csum_size) {
843 int extend_nr;
844 u64 tmp;
845 u32 diff;
846 u32 free_space;
847
848 if (btrfs_leaf_free_space(leaf) <
849 sizeof(struct btrfs_item) + csum_size * 2)
850 goto insert;
851
852 free_space = btrfs_leaf_free_space(leaf) -
853 sizeof(struct btrfs_item) - csum_size;
854 tmp = sums->len - total_bytes;
855 tmp >>= fs_info->sb->s_blocksize_bits;
856 WARN_ON(tmp < 1);
857
858 extend_nr = max_t(int, 1, (int)tmp);
859 diff = (csum_offset + extend_nr) * csum_size;
860 diff = min(diff,
861 MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
862
863 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
864 diff = min(free_space, diff);
865 diff /= csum_size;
866 diff *= csum_size;
867
868 btrfs_extend_item(path, diff);
869 ret = 0;
870 goto csum;
871 }
872
873insert:
874 btrfs_release_path(path);
875 csum_offset = 0;
876 if (found_next) {
877 u64 tmp;
878
879 tmp = sums->len - total_bytes;
880 tmp >>= fs_info->sb->s_blocksize_bits;
881 tmp = min(tmp, (next_offset - file_key.offset) >>
882 fs_info->sb->s_blocksize_bits);
883
884 tmp = max_t(u64, 1, tmp);
885 tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
886 ins_size = csum_size * tmp;
887 } else {
888 ins_size = csum_size;
889 }
890 path->leave_spinning = 1;
891 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
892 ins_size);
893 path->leave_spinning = 0;
894 if (ret < 0)
895 goto fail_unlock;
896 if (WARN_ON(ret != 0))
897 goto fail_unlock;
898 leaf = path->nodes[0];
899csum:
900 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
901 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
902 btrfs_item_size_nr(leaf, path->slots[0]));
903 item = (struct btrfs_csum_item *)((unsigned char *)item +
904 csum_offset * csum_size);
905found:
906 ins_size = (u32)(sums->len - total_bytes) >>
907 fs_info->sb->s_blocksize_bits;
908 ins_size *= csum_size;
909 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
910 ins_size);
911 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
912 ins_size);
913
914 index += ins_size;
915 ins_size /= csum_size;
916 total_bytes += ins_size * fs_info->sectorsize;
917
918 btrfs_mark_buffer_dirty(path->nodes[0]);
919 if (total_bytes < sums->len) {
920 btrfs_release_path(path);
921 cond_resched();
922 goto again;
923 }
924out:
925 btrfs_free_path(path);
926 return ret;
927
928fail_unlock:
929 goto out;
930}
931
932void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
933 const struct btrfs_path *path,
934 struct btrfs_file_extent_item *fi,
935 const bool new_inline,
936 struct extent_map *em)
937{
938 struct btrfs_fs_info *fs_info = inode->root->fs_info;
939 struct btrfs_root *root = inode->root;
940 struct extent_buffer *leaf = path->nodes[0];
941 const int slot = path->slots[0];
942 struct btrfs_key key;
943 u64 extent_start, extent_end;
944 u64 bytenr;
945 u8 type = btrfs_file_extent_type(leaf, fi);
946 int compress_type = btrfs_file_extent_compression(leaf, fi);
947
948 em->bdev = fs_info->fs_devices->latest_bdev;
949 btrfs_item_key_to_cpu(leaf, &key, slot);
950 extent_start = key.offset;
951
952 if (type == BTRFS_FILE_EXTENT_REG ||
953 type == BTRFS_FILE_EXTENT_PREALLOC) {
954 extent_end = extent_start +
955 btrfs_file_extent_num_bytes(leaf, fi);
956 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
957 size_t size;
958 size = btrfs_file_extent_ram_bytes(leaf, fi);
959 extent_end = ALIGN(extent_start + size,
960 fs_info->sectorsize);
961 }
962
963 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
964 if (type == BTRFS_FILE_EXTENT_REG ||
965 type == BTRFS_FILE_EXTENT_PREALLOC) {
966 em->start = extent_start;
967 em->len = extent_end - extent_start;
968 em->orig_start = extent_start -
969 btrfs_file_extent_offset(leaf, fi);
970 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
971 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
972 if (bytenr == 0) {
973 em->block_start = EXTENT_MAP_HOLE;
974 return;
975 }
976 if (compress_type != BTRFS_COMPRESS_NONE) {
977 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
978 em->compress_type = compress_type;
979 em->block_start = bytenr;
980 em->block_len = em->orig_block_len;
981 } else {
982 bytenr += btrfs_file_extent_offset(leaf, fi);
983 em->block_start = bytenr;
984 em->block_len = em->len;
985 if (type == BTRFS_FILE_EXTENT_PREALLOC)
986 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
987 }
988 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
989 em->block_start = EXTENT_MAP_INLINE;
990 em->start = extent_start;
991 em->len = extent_end - extent_start;
992 /*
993 * Initialize orig_start and block_len with the same values
994 * as in inode.c:btrfs_get_extent().
995 */
996 em->orig_start = EXTENT_MAP_HOLE;
997 em->block_len = (u64)-1;
998 if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) {
999 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
1000 em->compress_type = compress_type;
1001 }
1002 } else {
1003 btrfs_err(fs_info,
1004 "unknown file extent item type %d, inode %llu, offset %llu, "
1005 "root %llu", type, btrfs_ino(inode), extent_start,
1006 root->root_key.objectid);
1007 }
1008}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#include <linux/bio.h>
7#include <linux/slab.h>
8#include <linux/pagemap.h>
9#include <linux/highmem.h>
10#include <linux/sched/mm.h>
11#include <crypto/hash.h>
12#include "ctree.h"
13#include "disk-io.h"
14#include "transaction.h"
15#include "volumes.h"
16#include "print-tree.h"
17#include "compression.h"
18
19#define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
20 sizeof(struct btrfs_item) * 2) / \
21 size) - 1))
22
23#define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
24 PAGE_SIZE))
25
26/**
27 * @inode - the inode we want to update the disk_i_size for
28 * @new_i_size - the i_size we want to set to, 0 if we use i_size
29 *
30 * With NO_HOLES set this simply sets the disk_is_size to whatever i_size_read()
31 * returns as it is perfectly fine with a file that has holes without hole file
32 * extent items.
33 *
34 * However without NO_HOLES we need to only return the area that is contiguous
35 * from the 0 offset of the file. Otherwise we could end up adjust i_size up
36 * to an extent that has a gap in between.
37 *
38 * Finally new_i_size should only be set in the case of truncate where we're not
39 * ready to use i_size_read() as the limiter yet.
40 */
41void btrfs_inode_safe_disk_i_size_write(struct inode *inode, u64 new_i_size)
42{
43 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
44 u64 start, end, i_size;
45 int ret;
46
47 i_size = new_i_size ?: i_size_read(inode);
48 if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
49 BTRFS_I(inode)->disk_i_size = i_size;
50 return;
51 }
52
53 spin_lock(&BTRFS_I(inode)->lock);
54 ret = find_contiguous_extent_bit(&BTRFS_I(inode)->file_extent_tree, 0,
55 &start, &end, EXTENT_DIRTY);
56 if (!ret && start == 0)
57 i_size = min(i_size, end + 1);
58 else
59 i_size = 0;
60 BTRFS_I(inode)->disk_i_size = i_size;
61 spin_unlock(&BTRFS_I(inode)->lock);
62}
63
64/**
65 * @inode - the inode we're modifying
66 * @start - the start file offset of the file extent we've inserted
67 * @len - the logical length of the file extent item
68 *
69 * Call when we are inserting a new file extent where there was none before.
70 * Does not need to call this in the case where we're replacing an existing file
71 * extent, however if not sure it's fine to call this multiple times.
72 *
73 * The start and len must match the file extent item, so thus must be sectorsize
74 * aligned.
75 */
76int btrfs_inode_set_file_extent_range(struct btrfs_inode *inode, u64 start,
77 u64 len)
78{
79 if (len == 0)
80 return 0;
81
82 ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize));
83
84 if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES))
85 return 0;
86 return set_extent_bits(&inode->file_extent_tree, start, start + len - 1,
87 EXTENT_DIRTY);
88}
89
90/**
91 * @inode - the inode we're modifying
92 * @start - the start file offset of the file extent we've inserted
93 * @len - the logical length of the file extent item
94 *
95 * Called when we drop a file extent, for example when we truncate. Doesn't
96 * need to be called for cases where we're replacing a file extent, like when
97 * we've COWed a file extent.
98 *
99 * The start and len must match the file extent item, so thus must be sectorsize
100 * aligned.
101 */
102int btrfs_inode_clear_file_extent_range(struct btrfs_inode *inode, u64 start,
103 u64 len)
104{
105 if (len == 0)
106 return 0;
107
108 ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize) ||
109 len == (u64)-1);
110
111 if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES))
112 return 0;
113 return clear_extent_bit(&inode->file_extent_tree, start,
114 start + len - 1, EXTENT_DIRTY, 0, 0, NULL);
115}
116
117static inline u32 max_ordered_sum_bytes(struct btrfs_fs_info *fs_info,
118 u16 csum_size)
119{
120 u32 ncsums = (PAGE_SIZE - sizeof(struct btrfs_ordered_sum)) / csum_size;
121
122 return ncsums * fs_info->sectorsize;
123}
124
125int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
126 struct btrfs_root *root,
127 u64 objectid, u64 pos,
128 u64 disk_offset, u64 disk_num_bytes,
129 u64 num_bytes, u64 offset, u64 ram_bytes,
130 u8 compression, u8 encryption, u16 other_encoding)
131{
132 int ret = 0;
133 struct btrfs_file_extent_item *item;
134 struct btrfs_key file_key;
135 struct btrfs_path *path;
136 struct extent_buffer *leaf;
137
138 path = btrfs_alloc_path();
139 if (!path)
140 return -ENOMEM;
141 file_key.objectid = objectid;
142 file_key.offset = pos;
143 file_key.type = BTRFS_EXTENT_DATA_KEY;
144
145 path->leave_spinning = 1;
146 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
147 sizeof(*item));
148 if (ret < 0)
149 goto out;
150 BUG_ON(ret); /* Can't happen */
151 leaf = path->nodes[0];
152 item = btrfs_item_ptr(leaf, path->slots[0],
153 struct btrfs_file_extent_item);
154 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
155 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
156 btrfs_set_file_extent_offset(leaf, item, offset);
157 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
158 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
159 btrfs_set_file_extent_generation(leaf, item, trans->transid);
160 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
161 btrfs_set_file_extent_compression(leaf, item, compression);
162 btrfs_set_file_extent_encryption(leaf, item, encryption);
163 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
164
165 btrfs_mark_buffer_dirty(leaf);
166out:
167 btrfs_free_path(path);
168 return ret;
169}
170
171static struct btrfs_csum_item *
172btrfs_lookup_csum(struct btrfs_trans_handle *trans,
173 struct btrfs_root *root,
174 struct btrfs_path *path,
175 u64 bytenr, int cow)
176{
177 struct btrfs_fs_info *fs_info = root->fs_info;
178 int ret;
179 struct btrfs_key file_key;
180 struct btrfs_key found_key;
181 struct btrfs_csum_item *item;
182 struct extent_buffer *leaf;
183 u64 csum_offset = 0;
184 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
185 int csums_in_item;
186
187 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
188 file_key.offset = bytenr;
189 file_key.type = BTRFS_EXTENT_CSUM_KEY;
190 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
191 if (ret < 0)
192 goto fail;
193 leaf = path->nodes[0];
194 if (ret > 0) {
195 ret = 1;
196 if (path->slots[0] == 0)
197 goto fail;
198 path->slots[0]--;
199 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
200 if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
201 goto fail;
202
203 csum_offset = (bytenr - found_key.offset) >>
204 fs_info->sb->s_blocksize_bits;
205 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
206 csums_in_item /= csum_size;
207
208 if (csum_offset == csums_in_item) {
209 ret = -EFBIG;
210 goto fail;
211 } else if (csum_offset > csums_in_item) {
212 goto fail;
213 }
214 }
215 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
216 item = (struct btrfs_csum_item *)((unsigned char *)item +
217 csum_offset * csum_size);
218 return item;
219fail:
220 if (ret > 0)
221 ret = -ENOENT;
222 return ERR_PTR(ret);
223}
224
225int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
226 struct btrfs_root *root,
227 struct btrfs_path *path, u64 objectid,
228 u64 offset, int mod)
229{
230 int ret;
231 struct btrfs_key file_key;
232 int ins_len = mod < 0 ? -1 : 0;
233 int cow = mod != 0;
234
235 file_key.objectid = objectid;
236 file_key.offset = offset;
237 file_key.type = BTRFS_EXTENT_DATA_KEY;
238 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
239 return ret;
240}
241
242/**
243 * btrfs_lookup_bio_sums - Look up checksums for a bio.
244 * @inode: inode that the bio is for.
245 * @bio: bio to look up.
246 * @offset: Unless (u64)-1, look up checksums for this offset in the file.
247 * If (u64)-1, use the page offsets from the bio instead.
248 * @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return
249 * checksum (nblocks = bio->bi_iter.bi_size / fs_info->sectorsize). If
250 * NULL, the checksum buffer is allocated and returned in
251 * btrfs_io_bio(bio)->csum instead.
252 *
253 * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
254 */
255blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
256 u64 offset, u8 *dst)
257{
258 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
259 struct bio_vec bvec;
260 struct bvec_iter iter;
261 struct btrfs_csum_item *item = NULL;
262 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
263 struct btrfs_path *path;
264 const bool page_offsets = (offset == (u64)-1);
265 u8 *csum;
266 u64 item_start_offset = 0;
267 u64 item_last_offset = 0;
268 u64 disk_bytenr;
269 u64 page_bytes_left;
270 u32 diff;
271 int nblocks;
272 int count = 0;
273 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
274
275 path = btrfs_alloc_path();
276 if (!path)
277 return BLK_STS_RESOURCE;
278
279 nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits;
280 if (!dst) {
281 struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
282
283 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
284 btrfs_bio->csum = kmalloc_array(nblocks, csum_size,
285 GFP_NOFS);
286 if (!btrfs_bio->csum) {
287 btrfs_free_path(path);
288 return BLK_STS_RESOURCE;
289 }
290 } else {
291 btrfs_bio->csum = btrfs_bio->csum_inline;
292 }
293 csum = btrfs_bio->csum;
294 } else {
295 csum = dst;
296 }
297
298 if (bio->bi_iter.bi_size > PAGE_SIZE * 8)
299 path->reada = READA_FORWARD;
300
301 /*
302 * the free space stuff is only read when it hasn't been
303 * updated in the current transaction. So, we can safely
304 * read from the commit root and sidestep a nasty deadlock
305 * between reading the free space cache and updating the csum tree.
306 */
307 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
308 path->search_commit_root = 1;
309 path->skip_locking = 1;
310 }
311
312 disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
313
314 bio_for_each_segment(bvec, bio, iter) {
315 page_bytes_left = bvec.bv_len;
316 if (count)
317 goto next;
318
319 if (page_offsets)
320 offset = page_offset(bvec.bv_page) + bvec.bv_offset;
321 count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
322 csum, nblocks);
323 if (count)
324 goto found;
325
326 if (!item || disk_bytenr < item_start_offset ||
327 disk_bytenr >= item_last_offset) {
328 struct btrfs_key found_key;
329 u32 item_size;
330
331 if (item)
332 btrfs_release_path(path);
333 item = btrfs_lookup_csum(NULL, fs_info->csum_root,
334 path, disk_bytenr, 0);
335 if (IS_ERR(item)) {
336 count = 1;
337 memset(csum, 0, csum_size);
338 if (BTRFS_I(inode)->root->root_key.objectid ==
339 BTRFS_DATA_RELOC_TREE_OBJECTID) {
340 set_extent_bits(io_tree, offset,
341 offset + fs_info->sectorsize - 1,
342 EXTENT_NODATASUM);
343 } else {
344 btrfs_info_rl(fs_info,
345 "no csum found for inode %llu start %llu",
346 btrfs_ino(BTRFS_I(inode)), offset);
347 }
348 item = NULL;
349 btrfs_release_path(path);
350 goto found;
351 }
352 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
353 path->slots[0]);
354
355 item_start_offset = found_key.offset;
356 item_size = btrfs_item_size_nr(path->nodes[0],
357 path->slots[0]);
358 item_last_offset = item_start_offset +
359 (item_size / csum_size) *
360 fs_info->sectorsize;
361 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
362 struct btrfs_csum_item);
363 }
364 /*
365 * this byte range must be able to fit inside
366 * a single leaf so it will also fit inside a u32
367 */
368 diff = disk_bytenr - item_start_offset;
369 diff = diff / fs_info->sectorsize;
370 diff = diff * csum_size;
371 count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >>
372 inode->i_sb->s_blocksize_bits);
373 read_extent_buffer(path->nodes[0], csum,
374 ((unsigned long)item) + diff,
375 csum_size * count);
376found:
377 csum += count * csum_size;
378 nblocks -= count;
379next:
380 while (count > 0) {
381 count--;
382 disk_bytenr += fs_info->sectorsize;
383 offset += fs_info->sectorsize;
384 page_bytes_left -= fs_info->sectorsize;
385 if (!page_bytes_left)
386 break; /* move to next bio */
387 }
388 }
389
390 WARN_ON_ONCE(count);
391 btrfs_free_path(path);
392 return BLK_STS_OK;
393}
394
395int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
396 struct list_head *list, int search_commit)
397{
398 struct btrfs_fs_info *fs_info = root->fs_info;
399 struct btrfs_key key;
400 struct btrfs_path *path;
401 struct extent_buffer *leaf;
402 struct btrfs_ordered_sum *sums;
403 struct btrfs_csum_item *item;
404 LIST_HEAD(tmplist);
405 unsigned long offset;
406 int ret;
407 size_t size;
408 u64 csum_end;
409 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
410
411 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
412 IS_ALIGNED(end + 1, fs_info->sectorsize));
413
414 path = btrfs_alloc_path();
415 if (!path)
416 return -ENOMEM;
417
418 if (search_commit) {
419 path->skip_locking = 1;
420 path->reada = READA_FORWARD;
421 path->search_commit_root = 1;
422 }
423
424 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
425 key.offset = start;
426 key.type = BTRFS_EXTENT_CSUM_KEY;
427
428 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
429 if (ret < 0)
430 goto fail;
431 if (ret > 0 && path->slots[0] > 0) {
432 leaf = path->nodes[0];
433 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
434 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
435 key.type == BTRFS_EXTENT_CSUM_KEY) {
436 offset = (start - key.offset) >>
437 fs_info->sb->s_blocksize_bits;
438 if (offset * csum_size <
439 btrfs_item_size_nr(leaf, path->slots[0] - 1))
440 path->slots[0]--;
441 }
442 }
443
444 while (start <= end) {
445 leaf = path->nodes[0];
446 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
447 ret = btrfs_next_leaf(root, path);
448 if (ret < 0)
449 goto fail;
450 if (ret > 0)
451 break;
452 leaf = path->nodes[0];
453 }
454
455 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
456 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
457 key.type != BTRFS_EXTENT_CSUM_KEY ||
458 key.offset > end)
459 break;
460
461 if (key.offset > start)
462 start = key.offset;
463
464 size = btrfs_item_size_nr(leaf, path->slots[0]);
465 csum_end = key.offset + (size / csum_size) * fs_info->sectorsize;
466 if (csum_end <= start) {
467 path->slots[0]++;
468 continue;
469 }
470
471 csum_end = min(csum_end, end + 1);
472 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
473 struct btrfs_csum_item);
474 while (start < csum_end) {
475 size = min_t(size_t, csum_end - start,
476 max_ordered_sum_bytes(fs_info, csum_size));
477 sums = kzalloc(btrfs_ordered_sum_size(fs_info, size),
478 GFP_NOFS);
479 if (!sums) {
480 ret = -ENOMEM;
481 goto fail;
482 }
483
484 sums->bytenr = start;
485 sums->len = (int)size;
486
487 offset = (start - key.offset) >>
488 fs_info->sb->s_blocksize_bits;
489 offset *= csum_size;
490 size >>= fs_info->sb->s_blocksize_bits;
491
492 read_extent_buffer(path->nodes[0],
493 sums->sums,
494 ((unsigned long)item) + offset,
495 csum_size * size);
496
497 start += fs_info->sectorsize * size;
498 list_add_tail(&sums->list, &tmplist);
499 }
500 path->slots[0]++;
501 }
502 ret = 0;
503fail:
504 while (ret < 0 && !list_empty(&tmplist)) {
505 sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list);
506 list_del(&sums->list);
507 kfree(sums);
508 }
509 list_splice_tail(&tmplist, list);
510
511 btrfs_free_path(path);
512 return ret;
513}
514
515/*
516 * btrfs_csum_one_bio - Calculates checksums of the data contained inside a bio
517 * @inode: Owner of the data inside the bio
518 * @bio: Contains the data to be checksummed
519 * @file_start: offset in file this bio begins to describe
520 * @contig: Boolean. If true/1 means all bio vecs in this bio are
521 * contiguous and they begin at @file_start in the file. False/0
522 * means this bio can contains potentially discontigous bio vecs
523 * so the logical offset of each should be calculated separately.
524 */
525blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
526 u64 file_start, int contig)
527{
528 struct btrfs_fs_info *fs_info = inode->root->fs_info;
529 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
530 struct btrfs_ordered_sum *sums;
531 struct btrfs_ordered_extent *ordered = NULL;
532 char *data;
533 struct bvec_iter iter;
534 struct bio_vec bvec;
535 int index;
536 int nr_sectors;
537 unsigned long total_bytes = 0;
538 unsigned long this_sum_bytes = 0;
539 int i;
540 u64 offset;
541 unsigned nofs_flag;
542 const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
543
544 nofs_flag = memalloc_nofs_save();
545 sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
546 GFP_KERNEL);
547 memalloc_nofs_restore(nofs_flag);
548
549 if (!sums)
550 return BLK_STS_RESOURCE;
551
552 sums->len = bio->bi_iter.bi_size;
553 INIT_LIST_HEAD(&sums->list);
554
555 if (contig)
556 offset = file_start;
557 else
558 offset = 0; /* shut up gcc */
559
560 sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
561 index = 0;
562
563 shash->tfm = fs_info->csum_shash;
564
565 bio_for_each_segment(bvec, bio, iter) {
566 if (!contig)
567 offset = page_offset(bvec.bv_page) + bvec.bv_offset;
568
569 if (!ordered) {
570 ordered = btrfs_lookup_ordered_extent(inode, offset);
571 BUG_ON(!ordered); /* Logic error */
572 }
573
574 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info,
575 bvec.bv_len + fs_info->sectorsize
576 - 1);
577
578 for (i = 0; i < nr_sectors; i++) {
579 if (offset >= ordered->file_offset + ordered->num_bytes ||
580 offset < ordered->file_offset) {
581 unsigned long bytes_left;
582
583 sums->len = this_sum_bytes;
584 this_sum_bytes = 0;
585 btrfs_add_ordered_sum(ordered, sums);
586 btrfs_put_ordered_extent(ordered);
587
588 bytes_left = bio->bi_iter.bi_size - total_bytes;
589
590 nofs_flag = memalloc_nofs_save();
591 sums = kvzalloc(btrfs_ordered_sum_size(fs_info,
592 bytes_left), GFP_KERNEL);
593 memalloc_nofs_restore(nofs_flag);
594 BUG_ON(!sums); /* -ENOMEM */
595 sums->len = bytes_left;
596 ordered = btrfs_lookup_ordered_extent(inode,
597 offset);
598 ASSERT(ordered); /* Logic error */
599 sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9)
600 + total_bytes;
601 index = 0;
602 }
603
604 data = kmap_atomic(bvec.bv_page);
605 crypto_shash_digest(shash, data + bvec.bv_offset
606 + (i * fs_info->sectorsize),
607 fs_info->sectorsize,
608 sums->sums + index);
609 kunmap_atomic(data);
610 index += csum_size;
611 offset += fs_info->sectorsize;
612 this_sum_bytes += fs_info->sectorsize;
613 total_bytes += fs_info->sectorsize;
614 }
615
616 }
617 this_sum_bytes = 0;
618 btrfs_add_ordered_sum(ordered, sums);
619 btrfs_put_ordered_extent(ordered);
620 return 0;
621}
622
623/*
624 * helper function for csum removal, this expects the
625 * key to describe the csum pointed to by the path, and it expects
626 * the csum to overlap the range [bytenr, len]
627 *
628 * The csum should not be entirely contained in the range and the
629 * range should not be entirely contained in the csum.
630 *
631 * This calls btrfs_truncate_item with the correct args based on the
632 * overlap, and fixes up the key as required.
633 */
634static noinline void truncate_one_csum(struct btrfs_fs_info *fs_info,
635 struct btrfs_path *path,
636 struct btrfs_key *key,
637 u64 bytenr, u64 len)
638{
639 struct extent_buffer *leaf;
640 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
641 u64 csum_end;
642 u64 end_byte = bytenr + len;
643 u32 blocksize_bits = fs_info->sb->s_blocksize_bits;
644
645 leaf = path->nodes[0];
646 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
647 csum_end <<= fs_info->sb->s_blocksize_bits;
648 csum_end += key->offset;
649
650 if (key->offset < bytenr && csum_end <= end_byte) {
651 /*
652 * [ bytenr - len ]
653 * [ ]
654 * [csum ]
655 * A simple truncate off the end of the item
656 */
657 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
658 new_size *= csum_size;
659 btrfs_truncate_item(path, new_size, 1);
660 } else if (key->offset >= bytenr && csum_end > end_byte &&
661 end_byte > key->offset) {
662 /*
663 * [ bytenr - len ]
664 * [ ]
665 * [csum ]
666 * we need to truncate from the beginning of the csum
667 */
668 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
669 new_size *= csum_size;
670
671 btrfs_truncate_item(path, new_size, 0);
672
673 key->offset = end_byte;
674 btrfs_set_item_key_safe(fs_info, path, key);
675 } else {
676 BUG();
677 }
678}
679
680/*
681 * deletes the csum items from the csum tree for a given
682 * range of bytes.
683 */
684int btrfs_del_csums(struct btrfs_trans_handle *trans,
685 struct btrfs_root *root, u64 bytenr, u64 len)
686{
687 struct btrfs_fs_info *fs_info = trans->fs_info;
688 struct btrfs_path *path;
689 struct btrfs_key key;
690 u64 end_byte = bytenr + len;
691 u64 csum_end;
692 struct extent_buffer *leaf;
693 int ret;
694 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
695 int blocksize_bits = fs_info->sb->s_blocksize_bits;
696
697 ASSERT(root == fs_info->csum_root ||
698 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
699
700 path = btrfs_alloc_path();
701 if (!path)
702 return -ENOMEM;
703
704 while (1) {
705 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
706 key.offset = end_byte - 1;
707 key.type = BTRFS_EXTENT_CSUM_KEY;
708
709 path->leave_spinning = 1;
710 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
711 if (ret > 0) {
712 if (path->slots[0] == 0)
713 break;
714 path->slots[0]--;
715 } else if (ret < 0) {
716 break;
717 }
718
719 leaf = path->nodes[0];
720 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
721
722 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
723 key.type != BTRFS_EXTENT_CSUM_KEY) {
724 break;
725 }
726
727 if (key.offset >= end_byte)
728 break;
729
730 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
731 csum_end <<= blocksize_bits;
732 csum_end += key.offset;
733
734 /* this csum ends before we start, we're done */
735 if (csum_end <= bytenr)
736 break;
737
738 /* delete the entire item, it is inside our range */
739 if (key.offset >= bytenr && csum_end <= end_byte) {
740 int del_nr = 1;
741
742 /*
743 * Check how many csum items preceding this one in this
744 * leaf correspond to our range and then delete them all
745 * at once.
746 */
747 if (key.offset > bytenr && path->slots[0] > 0) {
748 int slot = path->slots[0] - 1;
749
750 while (slot >= 0) {
751 struct btrfs_key pk;
752
753 btrfs_item_key_to_cpu(leaf, &pk, slot);
754 if (pk.offset < bytenr ||
755 pk.type != BTRFS_EXTENT_CSUM_KEY ||
756 pk.objectid !=
757 BTRFS_EXTENT_CSUM_OBJECTID)
758 break;
759 path->slots[0] = slot;
760 del_nr++;
761 key.offset = pk.offset;
762 slot--;
763 }
764 }
765 ret = btrfs_del_items(trans, root, path,
766 path->slots[0], del_nr);
767 if (ret)
768 goto out;
769 if (key.offset == bytenr)
770 break;
771 } else if (key.offset < bytenr && csum_end > end_byte) {
772 unsigned long offset;
773 unsigned long shift_len;
774 unsigned long item_offset;
775 /*
776 * [ bytenr - len ]
777 * [csum ]
778 *
779 * Our bytes are in the middle of the csum,
780 * we need to split this item and insert a new one.
781 *
782 * But we can't drop the path because the
783 * csum could change, get removed, extended etc.
784 *
785 * The trick here is the max size of a csum item leaves
786 * enough room in the tree block for a single
787 * item header. So, we split the item in place,
788 * adding a new header pointing to the existing
789 * bytes. Then we loop around again and we have
790 * a nicely formed csum item that we can neatly
791 * truncate.
792 */
793 offset = (bytenr - key.offset) >> blocksize_bits;
794 offset *= csum_size;
795
796 shift_len = (len >> blocksize_bits) * csum_size;
797
798 item_offset = btrfs_item_ptr_offset(leaf,
799 path->slots[0]);
800
801 memzero_extent_buffer(leaf, item_offset + offset,
802 shift_len);
803 key.offset = bytenr;
804
805 /*
806 * btrfs_split_item returns -EAGAIN when the
807 * item changed size or key
808 */
809 ret = btrfs_split_item(trans, root, path, &key, offset);
810 if (ret && ret != -EAGAIN) {
811 btrfs_abort_transaction(trans, ret);
812 goto out;
813 }
814
815 key.offset = end_byte - 1;
816 } else {
817 truncate_one_csum(fs_info, path, &key, bytenr, len);
818 if (key.offset < bytenr)
819 break;
820 }
821 btrfs_release_path(path);
822 }
823 ret = 0;
824out:
825 btrfs_free_path(path);
826 return ret;
827}
828
829int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
830 struct btrfs_root *root,
831 struct btrfs_ordered_sum *sums)
832{
833 struct btrfs_fs_info *fs_info = root->fs_info;
834 struct btrfs_key file_key;
835 struct btrfs_key found_key;
836 struct btrfs_path *path;
837 struct btrfs_csum_item *item;
838 struct btrfs_csum_item *item_end;
839 struct extent_buffer *leaf = NULL;
840 u64 next_offset;
841 u64 total_bytes = 0;
842 u64 csum_offset;
843 u64 bytenr;
844 u32 nritems;
845 u32 ins_size;
846 int index = 0;
847 int found_next;
848 int ret;
849 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
850
851 path = btrfs_alloc_path();
852 if (!path)
853 return -ENOMEM;
854again:
855 next_offset = (u64)-1;
856 found_next = 0;
857 bytenr = sums->bytenr + total_bytes;
858 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
859 file_key.offset = bytenr;
860 file_key.type = BTRFS_EXTENT_CSUM_KEY;
861
862 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
863 if (!IS_ERR(item)) {
864 ret = 0;
865 leaf = path->nodes[0];
866 item_end = btrfs_item_ptr(leaf, path->slots[0],
867 struct btrfs_csum_item);
868 item_end = (struct btrfs_csum_item *)((char *)item_end +
869 btrfs_item_size_nr(leaf, path->slots[0]));
870 goto found;
871 }
872 ret = PTR_ERR(item);
873 if (ret != -EFBIG && ret != -ENOENT)
874 goto out;
875
876 if (ret == -EFBIG) {
877 u32 item_size;
878 /* we found one, but it isn't big enough yet */
879 leaf = path->nodes[0];
880 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
881 if ((item_size / csum_size) >=
882 MAX_CSUM_ITEMS(fs_info, csum_size)) {
883 /* already at max size, make a new one */
884 goto insert;
885 }
886 } else {
887 int slot = path->slots[0] + 1;
888 /* we didn't find a csum item, insert one */
889 nritems = btrfs_header_nritems(path->nodes[0]);
890 if (!nritems || (path->slots[0] >= nritems - 1)) {
891 ret = btrfs_next_leaf(root, path);
892 if (ret < 0) {
893 goto out;
894 } else if (ret > 0) {
895 found_next = 1;
896 goto insert;
897 }
898 slot = path->slots[0];
899 }
900 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
901 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
902 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
903 found_next = 1;
904 goto insert;
905 }
906 next_offset = found_key.offset;
907 found_next = 1;
908 goto insert;
909 }
910
911 /*
912 * At this point, we know the tree has a checksum item that ends at an
913 * offset matching the start of the checksum range we want to insert.
914 * We try to extend that item as much as possible and then add as many
915 * checksums to it as they fit.
916 *
917 * First check if the leaf has enough free space for at least one
918 * checksum. If it has go directly to the item extension code, otherwise
919 * release the path and do a search for insertion before the extension.
920 */
921 if (btrfs_leaf_free_space(leaf) >= csum_size) {
922 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
923 csum_offset = (bytenr - found_key.offset) >>
924 fs_info->sb->s_blocksize_bits;
925 goto extend_csum;
926 }
927
928 btrfs_release_path(path);
929 ret = btrfs_search_slot(trans, root, &file_key, path,
930 csum_size, 1);
931 if (ret < 0)
932 goto out;
933
934 if (ret > 0) {
935 if (path->slots[0] == 0)
936 goto insert;
937 path->slots[0]--;
938 }
939
940 leaf = path->nodes[0];
941 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
942 csum_offset = (bytenr - found_key.offset) >>
943 fs_info->sb->s_blocksize_bits;
944
945 if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
946 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
947 csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
948 goto insert;
949 }
950
951extend_csum:
952 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
953 csum_size) {
954 int extend_nr;
955 u64 tmp;
956 u32 diff;
957
958 tmp = sums->len - total_bytes;
959 tmp >>= fs_info->sb->s_blocksize_bits;
960 WARN_ON(tmp < 1);
961
962 extend_nr = max_t(int, 1, (int)tmp);
963 diff = (csum_offset + extend_nr) * csum_size;
964 diff = min(diff,
965 MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
966
967 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
968 diff = min_t(u32, btrfs_leaf_free_space(leaf), diff);
969 diff /= csum_size;
970 diff *= csum_size;
971
972 btrfs_extend_item(path, diff);
973 ret = 0;
974 goto csum;
975 }
976
977insert:
978 btrfs_release_path(path);
979 csum_offset = 0;
980 if (found_next) {
981 u64 tmp;
982
983 tmp = sums->len - total_bytes;
984 tmp >>= fs_info->sb->s_blocksize_bits;
985 tmp = min(tmp, (next_offset - file_key.offset) >>
986 fs_info->sb->s_blocksize_bits);
987
988 tmp = max_t(u64, 1, tmp);
989 tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
990 ins_size = csum_size * tmp;
991 } else {
992 ins_size = csum_size;
993 }
994 path->leave_spinning = 1;
995 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
996 ins_size);
997 path->leave_spinning = 0;
998 if (ret < 0)
999 goto out;
1000 if (WARN_ON(ret != 0))
1001 goto out;
1002 leaf = path->nodes[0];
1003csum:
1004 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
1005 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
1006 btrfs_item_size_nr(leaf, path->slots[0]));
1007 item = (struct btrfs_csum_item *)((unsigned char *)item +
1008 csum_offset * csum_size);
1009found:
1010 ins_size = (u32)(sums->len - total_bytes) >>
1011 fs_info->sb->s_blocksize_bits;
1012 ins_size *= csum_size;
1013 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
1014 ins_size);
1015 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
1016 ins_size);
1017
1018 index += ins_size;
1019 ins_size /= csum_size;
1020 total_bytes += ins_size * fs_info->sectorsize;
1021
1022 btrfs_mark_buffer_dirty(path->nodes[0]);
1023 if (total_bytes < sums->len) {
1024 btrfs_release_path(path);
1025 cond_resched();
1026 goto again;
1027 }
1028out:
1029 btrfs_free_path(path);
1030 return ret;
1031}
1032
1033void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
1034 const struct btrfs_path *path,
1035 struct btrfs_file_extent_item *fi,
1036 const bool new_inline,
1037 struct extent_map *em)
1038{
1039 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1040 struct btrfs_root *root = inode->root;
1041 struct extent_buffer *leaf = path->nodes[0];
1042 const int slot = path->slots[0];
1043 struct btrfs_key key;
1044 u64 extent_start, extent_end;
1045 u64 bytenr;
1046 u8 type = btrfs_file_extent_type(leaf, fi);
1047 int compress_type = btrfs_file_extent_compression(leaf, fi);
1048
1049 btrfs_item_key_to_cpu(leaf, &key, slot);
1050 extent_start = key.offset;
1051 extent_end = btrfs_file_extent_end(path);
1052 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1053 if (type == BTRFS_FILE_EXTENT_REG ||
1054 type == BTRFS_FILE_EXTENT_PREALLOC) {
1055 em->start = extent_start;
1056 em->len = extent_end - extent_start;
1057 em->orig_start = extent_start -
1058 btrfs_file_extent_offset(leaf, fi);
1059 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
1060 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1061 if (bytenr == 0) {
1062 em->block_start = EXTENT_MAP_HOLE;
1063 return;
1064 }
1065 if (compress_type != BTRFS_COMPRESS_NONE) {
1066 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
1067 em->compress_type = compress_type;
1068 em->block_start = bytenr;
1069 em->block_len = em->orig_block_len;
1070 } else {
1071 bytenr += btrfs_file_extent_offset(leaf, fi);
1072 em->block_start = bytenr;
1073 em->block_len = em->len;
1074 if (type == BTRFS_FILE_EXTENT_PREALLOC)
1075 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
1076 }
1077 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1078 em->block_start = EXTENT_MAP_INLINE;
1079 em->start = extent_start;
1080 em->len = extent_end - extent_start;
1081 /*
1082 * Initialize orig_start and block_len with the same values
1083 * as in inode.c:btrfs_get_extent().
1084 */
1085 em->orig_start = EXTENT_MAP_HOLE;
1086 em->block_len = (u64)-1;
1087 if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) {
1088 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
1089 em->compress_type = compress_type;
1090 }
1091 } else {
1092 btrfs_err(fs_info,
1093 "unknown file extent item type %d, inode %llu, offset %llu, "
1094 "root %llu", type, btrfs_ino(inode), extent_start,
1095 root->root_key.objectid);
1096 }
1097}
1098
1099/*
1100 * Returns the end offset (non inclusive) of the file extent item the given path
1101 * points to. If it points to an inline extent, the returned offset is rounded
1102 * up to the sector size.
1103 */
1104u64 btrfs_file_extent_end(const struct btrfs_path *path)
1105{
1106 const struct extent_buffer *leaf = path->nodes[0];
1107 const int slot = path->slots[0];
1108 struct btrfs_file_extent_item *fi;
1109 struct btrfs_key key;
1110 u64 end;
1111
1112 btrfs_item_key_to_cpu(leaf, &key, slot);
1113 ASSERT(key.type == BTRFS_EXTENT_DATA_KEY);
1114 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1115
1116 if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
1117 end = btrfs_file_extent_ram_bytes(leaf, fi);
1118 end = ALIGN(key.offset + end, leaf->fs_info->sectorsize);
1119 } else {
1120 end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1121 }
1122
1123 return end;
1124}