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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 "messages.h"
13#include "ctree.h"
14#include "disk-io.h"
15#include "transaction.h"
16#include "bio.h"
17#include "compression.h"
18#include "fs.h"
19#include "accessors.h"
20#include "file-item.h"
21
22#define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
23 sizeof(struct btrfs_item) * 2) / \
24 size) - 1))
25
26#define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
27 PAGE_SIZE))
28
29/*
30 * Set inode's size according to filesystem options.
31 *
32 * @inode: inode we want to update the disk_i_size for
33 * @new_i_size: i_size we want to set to, 0 if we use i_size
34 *
35 * With NO_HOLES set this simply sets the disk_is_size to whatever i_size_read()
36 * returns as it is perfectly fine with a file that has holes without hole file
37 * extent items.
38 *
39 * However without NO_HOLES we need to only return the area that is contiguous
40 * from the 0 offset of the file. Otherwise we could end up adjust i_size up
41 * to an extent that has a gap in between.
42 *
43 * Finally new_i_size should only be set in the case of truncate where we're not
44 * ready to use i_size_read() as the limiter yet.
45 */
46void btrfs_inode_safe_disk_i_size_write(struct btrfs_inode *inode, u64 new_i_size)
47{
48 u64 start, end, i_size;
49 int ret;
50
51 spin_lock(&inode->lock);
52 i_size = new_i_size ?: i_size_read(&inode->vfs_inode);
53 if (!inode->file_extent_tree) {
54 inode->disk_i_size = i_size;
55 goto out_unlock;
56 }
57
58 ret = find_contiguous_extent_bit(inode->file_extent_tree, 0, &start,
59 &end, EXTENT_DIRTY);
60 if (!ret && start == 0)
61 i_size = min(i_size, end + 1);
62 else
63 i_size = 0;
64 inode->disk_i_size = i_size;
65out_unlock:
66 spin_unlock(&inode->lock);
67}
68
69/*
70 * Mark range within a file as having a new extent inserted.
71 *
72 * @inode: inode being modified
73 * @start: start file offset of the file extent we've inserted
74 * @len: logical length of the file extent item
75 *
76 * Call when we are inserting a new file extent where there was none before.
77 * Does not need to call this in the case where we're replacing an existing file
78 * extent, however if not sure it's fine to call this multiple times.
79 *
80 * The start and len must match the file extent item, so thus must be sectorsize
81 * aligned.
82 */
83int btrfs_inode_set_file_extent_range(struct btrfs_inode *inode, u64 start,
84 u64 len)
85{
86 if (!inode->file_extent_tree)
87 return 0;
88
89 if (len == 0)
90 return 0;
91
92 ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize));
93
94 return set_extent_bit(inode->file_extent_tree, start, start + len - 1,
95 EXTENT_DIRTY, NULL);
96}
97
98/*
99 * Mark an inode range as not having a backing extent.
100 *
101 * @inode: inode being modified
102 * @start: start file offset of the file extent we've inserted
103 * @len: logical length of the file extent item
104 *
105 * Called when we drop a file extent, for example when we truncate. Doesn't
106 * need to be called for cases where we're replacing a file extent, like when
107 * we've COWed a file extent.
108 *
109 * The start and len must match the file extent item, so thus must be sectorsize
110 * aligned.
111 */
112int btrfs_inode_clear_file_extent_range(struct btrfs_inode *inode, u64 start,
113 u64 len)
114{
115 if (!inode->file_extent_tree)
116 return 0;
117
118 if (len == 0)
119 return 0;
120
121 ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize) ||
122 len == (u64)-1);
123
124 return clear_extent_bit(inode->file_extent_tree, start,
125 start + len - 1, EXTENT_DIRTY, NULL);
126}
127
128static size_t bytes_to_csum_size(const struct btrfs_fs_info *fs_info, u32 bytes)
129{
130 ASSERT(IS_ALIGNED(bytes, fs_info->sectorsize));
131
132 return (bytes >> fs_info->sectorsize_bits) * fs_info->csum_size;
133}
134
135static size_t csum_size_to_bytes(const struct btrfs_fs_info *fs_info, u32 csum_size)
136{
137 ASSERT(IS_ALIGNED(csum_size, fs_info->csum_size));
138
139 return (csum_size / fs_info->csum_size) << fs_info->sectorsize_bits;
140}
141
142static inline u32 max_ordered_sum_bytes(const struct btrfs_fs_info *fs_info)
143{
144 u32 max_csum_size = round_down(PAGE_SIZE - sizeof(struct btrfs_ordered_sum),
145 fs_info->csum_size);
146
147 return csum_size_to_bytes(fs_info, max_csum_size);
148}
149
150/*
151 * Calculate the total size needed to allocate for an ordered sum structure
152 * spanning @bytes in the file.
153 */
154static int btrfs_ordered_sum_size(const struct btrfs_fs_info *fs_info, unsigned long bytes)
155{
156 return sizeof(struct btrfs_ordered_sum) + bytes_to_csum_size(fs_info, bytes);
157}
158
159int btrfs_insert_hole_extent(struct btrfs_trans_handle *trans,
160 struct btrfs_root *root,
161 u64 objectid, u64 pos, u64 num_bytes)
162{
163 int ret = 0;
164 struct btrfs_file_extent_item *item;
165 struct btrfs_key file_key;
166 struct btrfs_path *path;
167 struct extent_buffer *leaf;
168
169 path = btrfs_alloc_path();
170 if (!path)
171 return -ENOMEM;
172 file_key.objectid = objectid;
173 file_key.offset = pos;
174 file_key.type = BTRFS_EXTENT_DATA_KEY;
175
176 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
177 sizeof(*item));
178 if (ret < 0)
179 goto out;
180 leaf = path->nodes[0];
181 item = btrfs_item_ptr(leaf, path->slots[0],
182 struct btrfs_file_extent_item);
183 btrfs_set_file_extent_disk_bytenr(leaf, item, 0);
184 btrfs_set_file_extent_disk_num_bytes(leaf, item, 0);
185 btrfs_set_file_extent_offset(leaf, item, 0);
186 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
187 btrfs_set_file_extent_ram_bytes(leaf, item, num_bytes);
188 btrfs_set_file_extent_generation(leaf, item, trans->transid);
189 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
190 btrfs_set_file_extent_compression(leaf, item, 0);
191 btrfs_set_file_extent_encryption(leaf, item, 0);
192 btrfs_set_file_extent_other_encoding(leaf, item, 0);
193
194 btrfs_mark_buffer_dirty(trans, leaf);
195out:
196 btrfs_free_path(path);
197 return ret;
198}
199
200static struct btrfs_csum_item *
201btrfs_lookup_csum(struct btrfs_trans_handle *trans,
202 struct btrfs_root *root,
203 struct btrfs_path *path,
204 u64 bytenr, int cow)
205{
206 struct btrfs_fs_info *fs_info = root->fs_info;
207 int ret;
208 struct btrfs_key file_key;
209 struct btrfs_key found_key;
210 struct btrfs_csum_item *item;
211 struct extent_buffer *leaf;
212 u64 csum_offset = 0;
213 const u32 csum_size = fs_info->csum_size;
214 int csums_in_item;
215
216 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
217 file_key.offset = bytenr;
218 file_key.type = BTRFS_EXTENT_CSUM_KEY;
219 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
220 if (ret < 0)
221 goto fail;
222 leaf = path->nodes[0];
223 if (ret > 0) {
224 ret = 1;
225 if (path->slots[0] == 0)
226 goto fail;
227 path->slots[0]--;
228 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
229 if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
230 goto fail;
231
232 csum_offset = (bytenr - found_key.offset) >>
233 fs_info->sectorsize_bits;
234 csums_in_item = btrfs_item_size(leaf, path->slots[0]);
235 csums_in_item /= csum_size;
236
237 if (csum_offset == csums_in_item) {
238 ret = -EFBIG;
239 goto fail;
240 } else if (csum_offset > csums_in_item) {
241 goto fail;
242 }
243 }
244 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
245 item = (struct btrfs_csum_item *)((unsigned char *)item +
246 csum_offset * csum_size);
247 return item;
248fail:
249 if (ret > 0)
250 ret = -ENOENT;
251 return ERR_PTR(ret);
252}
253
254int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
255 struct btrfs_root *root,
256 struct btrfs_path *path, u64 objectid,
257 u64 offset, int mod)
258{
259 struct btrfs_key file_key;
260 int ins_len = mod < 0 ? -1 : 0;
261 int cow = mod != 0;
262
263 file_key.objectid = objectid;
264 file_key.offset = offset;
265 file_key.type = BTRFS_EXTENT_DATA_KEY;
266
267 return btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
268}
269
270/*
271 * Find checksums for logical bytenr range [disk_bytenr, disk_bytenr + len) and
272 * store the result to @dst.
273 *
274 * Return >0 for the number of sectors we found.
275 * Return 0 for the range [disk_bytenr, disk_bytenr + sectorsize) has no csum
276 * for it. Caller may want to try next sector until one range is hit.
277 * Return <0 for fatal error.
278 */
279static int search_csum_tree(struct btrfs_fs_info *fs_info,
280 struct btrfs_path *path, u64 disk_bytenr,
281 u64 len, u8 *dst)
282{
283 struct btrfs_root *csum_root;
284 struct btrfs_csum_item *item = NULL;
285 struct btrfs_key key;
286 const u32 sectorsize = fs_info->sectorsize;
287 const u32 csum_size = fs_info->csum_size;
288 u32 itemsize;
289 int ret;
290 u64 csum_start;
291 u64 csum_len;
292
293 ASSERT(IS_ALIGNED(disk_bytenr, sectorsize) &&
294 IS_ALIGNED(len, sectorsize));
295
296 /* Check if the current csum item covers disk_bytenr */
297 if (path->nodes[0]) {
298 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
299 struct btrfs_csum_item);
300 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
301 itemsize = btrfs_item_size(path->nodes[0], path->slots[0]);
302
303 csum_start = key.offset;
304 csum_len = (itemsize / csum_size) * sectorsize;
305
306 if (in_range(disk_bytenr, csum_start, csum_len))
307 goto found;
308 }
309
310 /* Current item doesn't contain the desired range, search again */
311 btrfs_release_path(path);
312 csum_root = btrfs_csum_root(fs_info, disk_bytenr);
313 item = btrfs_lookup_csum(NULL, csum_root, path, disk_bytenr, 0);
314 if (IS_ERR(item)) {
315 ret = PTR_ERR(item);
316 goto out;
317 }
318 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
319 itemsize = btrfs_item_size(path->nodes[0], path->slots[0]);
320
321 csum_start = key.offset;
322 csum_len = (itemsize / csum_size) * sectorsize;
323 ASSERT(in_range(disk_bytenr, csum_start, csum_len));
324
325found:
326 ret = (min(csum_start + csum_len, disk_bytenr + len) -
327 disk_bytenr) >> fs_info->sectorsize_bits;
328 read_extent_buffer(path->nodes[0], dst, (unsigned long)item,
329 ret * csum_size);
330out:
331 if (ret == -ENOENT || ret == -EFBIG)
332 ret = 0;
333 return ret;
334}
335
336/*
337 * Lookup the checksum for the read bio in csum tree.
338 *
339 * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
340 */
341blk_status_t btrfs_lookup_bio_sums(struct btrfs_bio *bbio)
342{
343 struct btrfs_inode *inode = bbio->inode;
344 struct btrfs_fs_info *fs_info = inode->root->fs_info;
345 struct bio *bio = &bbio->bio;
346 struct btrfs_path *path;
347 const u32 sectorsize = fs_info->sectorsize;
348 const u32 csum_size = fs_info->csum_size;
349 u32 orig_len = bio->bi_iter.bi_size;
350 u64 orig_disk_bytenr = bio->bi_iter.bi_sector << SECTOR_SHIFT;
351 const unsigned int nblocks = orig_len >> fs_info->sectorsize_bits;
352 blk_status_t ret = BLK_STS_OK;
353 u32 bio_offset = 0;
354
355 if ((inode->flags & BTRFS_INODE_NODATASUM) ||
356 test_bit(BTRFS_FS_STATE_NO_DATA_CSUMS, &fs_info->fs_state))
357 return BLK_STS_OK;
358
359 /*
360 * This function is only called for read bio.
361 *
362 * This means two things:
363 * - All our csums should only be in csum tree
364 * No ordered extents csums, as ordered extents are only for write
365 * path.
366 * - No need to bother any other info from bvec
367 * Since we're looking up csums, the only important info is the
368 * disk_bytenr and the length, which can be extracted from bi_iter
369 * directly.
370 */
371 ASSERT(bio_op(bio) == REQ_OP_READ);
372 path = btrfs_alloc_path();
373 if (!path)
374 return BLK_STS_RESOURCE;
375
376 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
377 bbio->csum = kmalloc_array(nblocks, csum_size, GFP_NOFS);
378 if (!bbio->csum) {
379 btrfs_free_path(path);
380 return BLK_STS_RESOURCE;
381 }
382 } else {
383 bbio->csum = bbio->csum_inline;
384 }
385
386 /*
387 * If requested number of sectors is larger than one leaf can contain,
388 * kick the readahead for csum tree.
389 */
390 if (nblocks > fs_info->csums_per_leaf)
391 path->reada = READA_FORWARD;
392
393 /*
394 * the free space stuff is only read when it hasn't been
395 * updated in the current transaction. So, we can safely
396 * read from the commit root and sidestep a nasty deadlock
397 * between reading the free space cache and updating the csum tree.
398 */
399 if (btrfs_is_free_space_inode(inode)) {
400 path->search_commit_root = 1;
401 path->skip_locking = 1;
402 }
403
404 while (bio_offset < orig_len) {
405 int count;
406 u64 cur_disk_bytenr = orig_disk_bytenr + bio_offset;
407 u8 *csum_dst = bbio->csum +
408 (bio_offset >> fs_info->sectorsize_bits) * csum_size;
409
410 count = search_csum_tree(fs_info, path, cur_disk_bytenr,
411 orig_len - bio_offset, csum_dst);
412 if (count < 0) {
413 ret = errno_to_blk_status(count);
414 if (bbio->csum != bbio->csum_inline)
415 kfree(bbio->csum);
416 bbio->csum = NULL;
417 break;
418 }
419
420 /*
421 * We didn't find a csum for this range. We need to make sure
422 * we complain loudly about this, because we are not NODATASUM.
423 *
424 * However for the DATA_RELOC inode we could potentially be
425 * relocating data extents for a NODATASUM inode, so the inode
426 * itself won't be marked with NODATASUM, but the extent we're
427 * copying is in fact NODATASUM. If we don't find a csum we
428 * assume this is the case.
429 */
430 if (count == 0) {
431 memset(csum_dst, 0, csum_size);
432 count = 1;
433
434 if (btrfs_root_id(inode->root) == BTRFS_DATA_RELOC_TREE_OBJECTID) {
435 u64 file_offset = bbio->file_offset + bio_offset;
436
437 set_extent_bit(&inode->io_tree, file_offset,
438 file_offset + sectorsize - 1,
439 EXTENT_NODATASUM, NULL);
440 } else {
441 btrfs_warn_rl(fs_info,
442 "csum hole found for disk bytenr range [%llu, %llu)",
443 cur_disk_bytenr, cur_disk_bytenr + sectorsize);
444 }
445 }
446 bio_offset += count * sectorsize;
447 }
448
449 btrfs_free_path(path);
450 return ret;
451}
452
453/*
454 * Search for checksums for a given logical range.
455 *
456 * @root: The root where to look for checksums.
457 * @start: Logical address of target checksum range.
458 * @end: End offset (inclusive) of the target checksum range.
459 * @list: List for adding each checksum that was found.
460 * Can be NULL in case the caller only wants to check if
461 * there any checksums for the range.
462 * @nowait: Indicate if the search must be non-blocking or not.
463 *
464 * Return < 0 on error, 0 if no checksums were found, or 1 if checksums were
465 * found.
466 */
467int btrfs_lookup_csums_list(struct btrfs_root *root, u64 start, u64 end,
468 struct list_head *list, bool nowait)
469{
470 struct btrfs_fs_info *fs_info = root->fs_info;
471 struct btrfs_key key;
472 struct btrfs_path *path;
473 struct extent_buffer *leaf;
474 struct btrfs_ordered_sum *sums;
475 struct btrfs_csum_item *item;
476 int ret;
477 bool found_csums = false;
478
479 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
480 IS_ALIGNED(end + 1, fs_info->sectorsize));
481
482 path = btrfs_alloc_path();
483 if (!path)
484 return -ENOMEM;
485
486 path->nowait = nowait;
487
488 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
489 key.offset = start;
490 key.type = BTRFS_EXTENT_CSUM_KEY;
491
492 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
493 if (ret < 0)
494 goto out;
495 if (ret > 0 && path->slots[0] > 0) {
496 leaf = path->nodes[0];
497 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
498
499 /*
500 * There are two cases we can hit here for the previous csum
501 * item:
502 *
503 * |<- search range ->|
504 * |<- csum item ->|
505 *
506 * Or
507 * |<- search range ->|
508 * |<- csum item ->|
509 *
510 * Check if the previous csum item covers the leading part of
511 * the search range. If so we have to start from previous csum
512 * item.
513 */
514 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
515 key.type == BTRFS_EXTENT_CSUM_KEY) {
516 if (bytes_to_csum_size(fs_info, start - key.offset) <
517 btrfs_item_size(leaf, path->slots[0] - 1))
518 path->slots[0]--;
519 }
520 }
521
522 while (start <= end) {
523 u64 csum_end;
524
525 leaf = path->nodes[0];
526 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
527 ret = btrfs_next_leaf(root, path);
528 if (ret < 0)
529 goto out;
530 if (ret > 0)
531 break;
532 leaf = path->nodes[0];
533 }
534
535 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
536 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
537 key.type != BTRFS_EXTENT_CSUM_KEY ||
538 key.offset > end)
539 break;
540
541 if (key.offset > start)
542 start = key.offset;
543
544 csum_end = key.offset + csum_size_to_bytes(fs_info,
545 btrfs_item_size(leaf, path->slots[0]));
546 if (csum_end <= start) {
547 path->slots[0]++;
548 continue;
549 }
550
551 found_csums = true;
552 if (!list)
553 goto out;
554
555 csum_end = min(csum_end, end + 1);
556 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
557 struct btrfs_csum_item);
558 while (start < csum_end) {
559 unsigned long offset;
560 size_t size;
561
562 size = min_t(size_t, csum_end - start,
563 max_ordered_sum_bytes(fs_info));
564 sums = kzalloc(btrfs_ordered_sum_size(fs_info, size),
565 GFP_NOFS);
566 if (!sums) {
567 ret = -ENOMEM;
568 goto out;
569 }
570
571 sums->logical = start;
572 sums->len = size;
573
574 offset = bytes_to_csum_size(fs_info, start - key.offset);
575
576 read_extent_buffer(path->nodes[0],
577 sums->sums,
578 ((unsigned long)item) + offset,
579 bytes_to_csum_size(fs_info, size));
580
581 start += size;
582 list_add_tail(&sums->list, list);
583 }
584 path->slots[0]++;
585 }
586out:
587 btrfs_free_path(path);
588 if (ret < 0) {
589 if (list) {
590 struct btrfs_ordered_sum *tmp_sums;
591
592 list_for_each_entry_safe(sums, tmp_sums, list, list)
593 kfree(sums);
594 }
595
596 return ret;
597 }
598
599 return found_csums ? 1 : 0;
600}
601
602/*
603 * Do the same work as btrfs_lookup_csums_list(), the difference is in how
604 * we return the result.
605 *
606 * This version will set the corresponding bits in @csum_bitmap to represent
607 * that there is a csum found.
608 * Each bit represents a sector. Thus caller should ensure @csum_buf passed
609 * in is large enough to contain all csums.
610 */
611int btrfs_lookup_csums_bitmap(struct btrfs_root *root, struct btrfs_path *path,
612 u64 start, u64 end, u8 *csum_buf,
613 unsigned long *csum_bitmap)
614{
615 struct btrfs_fs_info *fs_info = root->fs_info;
616 struct btrfs_key key;
617 struct extent_buffer *leaf;
618 struct btrfs_csum_item *item;
619 const u64 orig_start = start;
620 bool free_path = false;
621 int ret;
622
623 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
624 IS_ALIGNED(end + 1, fs_info->sectorsize));
625
626 if (!path) {
627 path = btrfs_alloc_path();
628 if (!path)
629 return -ENOMEM;
630 free_path = true;
631 }
632
633 /* Check if we can reuse the previous path. */
634 if (path->nodes[0]) {
635 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
636
637 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
638 key.type == BTRFS_EXTENT_CSUM_KEY &&
639 key.offset <= start)
640 goto search_forward;
641 btrfs_release_path(path);
642 }
643
644 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
645 key.type = BTRFS_EXTENT_CSUM_KEY;
646 key.offset = start;
647
648 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
649 if (ret < 0)
650 goto fail;
651 if (ret > 0 && path->slots[0] > 0) {
652 leaf = path->nodes[0];
653 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
654
655 /*
656 * There are two cases we can hit here for the previous csum
657 * item:
658 *
659 * |<- search range ->|
660 * |<- csum item ->|
661 *
662 * Or
663 * |<- search range ->|
664 * |<- csum item ->|
665 *
666 * Check if the previous csum item covers the leading part of
667 * the search range. If so we have to start from previous csum
668 * item.
669 */
670 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
671 key.type == BTRFS_EXTENT_CSUM_KEY) {
672 if (bytes_to_csum_size(fs_info, start - key.offset) <
673 btrfs_item_size(leaf, path->slots[0] - 1))
674 path->slots[0]--;
675 }
676 }
677
678search_forward:
679 while (start <= end) {
680 u64 csum_end;
681
682 leaf = path->nodes[0];
683 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
684 ret = btrfs_next_leaf(root, path);
685 if (ret < 0)
686 goto fail;
687 if (ret > 0)
688 break;
689 leaf = path->nodes[0];
690 }
691
692 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
693 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
694 key.type != BTRFS_EXTENT_CSUM_KEY ||
695 key.offset > end)
696 break;
697
698 if (key.offset > start)
699 start = key.offset;
700
701 csum_end = key.offset + csum_size_to_bytes(fs_info,
702 btrfs_item_size(leaf, path->slots[0]));
703 if (csum_end <= start) {
704 path->slots[0]++;
705 continue;
706 }
707
708 csum_end = min(csum_end, end + 1);
709 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
710 struct btrfs_csum_item);
711 while (start < csum_end) {
712 unsigned long offset;
713 size_t size;
714 u8 *csum_dest = csum_buf + bytes_to_csum_size(fs_info,
715 start - orig_start);
716
717 size = min_t(size_t, csum_end - start, end + 1 - start);
718
719 offset = bytes_to_csum_size(fs_info, start - key.offset);
720
721 read_extent_buffer(path->nodes[0], csum_dest,
722 ((unsigned long)item) + offset,
723 bytes_to_csum_size(fs_info, size));
724
725 bitmap_set(csum_bitmap,
726 (start - orig_start) >> fs_info->sectorsize_bits,
727 size >> fs_info->sectorsize_bits);
728
729 start += size;
730 }
731 path->slots[0]++;
732 }
733 ret = 0;
734fail:
735 if (free_path)
736 btrfs_free_path(path);
737 return ret;
738}
739
740/*
741 * Calculate checksums of the data contained inside a bio.
742 */
743blk_status_t btrfs_csum_one_bio(struct btrfs_bio *bbio)
744{
745 struct btrfs_ordered_extent *ordered = bbio->ordered;
746 struct btrfs_inode *inode = bbio->inode;
747 struct btrfs_fs_info *fs_info = inode->root->fs_info;
748 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
749 struct bio *bio = &bbio->bio;
750 struct btrfs_ordered_sum *sums;
751 char *data;
752 struct bvec_iter iter;
753 struct bio_vec bvec;
754 int index;
755 unsigned int blockcount;
756 int i;
757 unsigned nofs_flag;
758
759 nofs_flag = memalloc_nofs_save();
760 sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
761 GFP_KERNEL);
762 memalloc_nofs_restore(nofs_flag);
763
764 if (!sums)
765 return BLK_STS_RESOURCE;
766
767 sums->len = bio->bi_iter.bi_size;
768 INIT_LIST_HEAD(&sums->list);
769
770 sums->logical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
771 index = 0;
772
773 shash->tfm = fs_info->csum_shash;
774
775 bio_for_each_segment(bvec, bio, iter) {
776 blockcount = BTRFS_BYTES_TO_BLKS(fs_info,
777 bvec.bv_len + fs_info->sectorsize
778 - 1);
779
780 for (i = 0; i < blockcount; i++) {
781 data = bvec_kmap_local(&bvec);
782 crypto_shash_digest(shash,
783 data + (i * fs_info->sectorsize),
784 fs_info->sectorsize,
785 sums->sums + index);
786 kunmap_local(data);
787 index += fs_info->csum_size;
788 }
789
790 }
791
792 bbio->sums = sums;
793 btrfs_add_ordered_sum(ordered, sums);
794 return 0;
795}
796
797/*
798 * Nodatasum I/O on zoned file systems still requires an btrfs_ordered_sum to
799 * record the updated logical address on Zone Append completion.
800 * Allocate just the structure with an empty sums array here for that case.
801 */
802blk_status_t btrfs_alloc_dummy_sum(struct btrfs_bio *bbio)
803{
804 bbio->sums = kmalloc(sizeof(*bbio->sums), GFP_NOFS);
805 if (!bbio->sums)
806 return BLK_STS_RESOURCE;
807 bbio->sums->len = bbio->bio.bi_iter.bi_size;
808 bbio->sums->logical = bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT;
809 btrfs_add_ordered_sum(bbio->ordered, bbio->sums);
810 return 0;
811}
812
813/*
814 * Remove one checksum overlapping a range.
815 *
816 * This expects the key to describe the csum pointed to by the path, and it
817 * expects the csum to overlap the range [bytenr, len]
818 *
819 * The csum should not be entirely contained in the range and the range should
820 * not be entirely contained in the csum.
821 *
822 * This calls btrfs_truncate_item with the correct args based on the overlap,
823 * and fixes up the key as required.
824 */
825static noinline void truncate_one_csum(struct btrfs_trans_handle *trans,
826 struct btrfs_path *path,
827 struct btrfs_key *key,
828 u64 bytenr, u64 len)
829{
830 struct btrfs_fs_info *fs_info = trans->fs_info;
831 struct extent_buffer *leaf;
832 const u32 csum_size = fs_info->csum_size;
833 u64 csum_end;
834 u64 end_byte = bytenr + len;
835 u32 blocksize_bits = fs_info->sectorsize_bits;
836
837 leaf = path->nodes[0];
838 csum_end = btrfs_item_size(leaf, path->slots[0]) / csum_size;
839 csum_end <<= blocksize_bits;
840 csum_end += key->offset;
841
842 if (key->offset < bytenr && csum_end <= end_byte) {
843 /*
844 * [ bytenr - len ]
845 * [ ]
846 * [csum ]
847 * A simple truncate off the end of the item
848 */
849 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
850 new_size *= csum_size;
851 btrfs_truncate_item(trans, path, new_size, 1);
852 } else if (key->offset >= bytenr && csum_end > end_byte &&
853 end_byte > key->offset) {
854 /*
855 * [ bytenr - len ]
856 * [ ]
857 * [csum ]
858 * we need to truncate from the beginning of the csum
859 */
860 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
861 new_size *= csum_size;
862
863 btrfs_truncate_item(trans, path, new_size, 0);
864
865 key->offset = end_byte;
866 btrfs_set_item_key_safe(trans, path, key);
867 } else {
868 BUG();
869 }
870}
871
872/*
873 * Delete the csum items from the csum tree for a given range of bytes.
874 */
875int btrfs_del_csums(struct btrfs_trans_handle *trans,
876 struct btrfs_root *root, u64 bytenr, u64 len)
877{
878 struct btrfs_fs_info *fs_info = trans->fs_info;
879 struct btrfs_path *path;
880 struct btrfs_key key;
881 u64 end_byte = bytenr + len;
882 u64 csum_end;
883 struct extent_buffer *leaf;
884 int ret = 0;
885 const u32 csum_size = fs_info->csum_size;
886 u32 blocksize_bits = fs_info->sectorsize_bits;
887
888 ASSERT(btrfs_root_id(root) == BTRFS_CSUM_TREE_OBJECTID ||
889 btrfs_root_id(root) == BTRFS_TREE_LOG_OBJECTID);
890
891 path = btrfs_alloc_path();
892 if (!path)
893 return -ENOMEM;
894
895 while (1) {
896 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
897 key.offset = end_byte - 1;
898 key.type = BTRFS_EXTENT_CSUM_KEY;
899
900 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
901 if (ret > 0) {
902 ret = 0;
903 if (path->slots[0] == 0)
904 break;
905 path->slots[0]--;
906 } else if (ret < 0) {
907 break;
908 }
909
910 leaf = path->nodes[0];
911 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
912
913 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
914 key.type != BTRFS_EXTENT_CSUM_KEY) {
915 break;
916 }
917
918 if (key.offset >= end_byte)
919 break;
920
921 csum_end = btrfs_item_size(leaf, path->slots[0]) / csum_size;
922 csum_end <<= blocksize_bits;
923 csum_end += key.offset;
924
925 /* this csum ends before we start, we're done */
926 if (csum_end <= bytenr)
927 break;
928
929 /* delete the entire item, it is inside our range */
930 if (key.offset >= bytenr && csum_end <= end_byte) {
931 int del_nr = 1;
932
933 /*
934 * Check how many csum items preceding this one in this
935 * leaf correspond to our range and then delete them all
936 * at once.
937 */
938 if (key.offset > bytenr && path->slots[0] > 0) {
939 int slot = path->slots[0] - 1;
940
941 while (slot >= 0) {
942 struct btrfs_key pk;
943
944 btrfs_item_key_to_cpu(leaf, &pk, slot);
945 if (pk.offset < bytenr ||
946 pk.type != BTRFS_EXTENT_CSUM_KEY ||
947 pk.objectid !=
948 BTRFS_EXTENT_CSUM_OBJECTID)
949 break;
950 path->slots[0] = slot;
951 del_nr++;
952 key.offset = pk.offset;
953 slot--;
954 }
955 }
956 ret = btrfs_del_items(trans, root, path,
957 path->slots[0], del_nr);
958 if (ret)
959 break;
960 if (key.offset == bytenr)
961 break;
962 } else if (key.offset < bytenr && csum_end > end_byte) {
963 unsigned long offset;
964 unsigned long shift_len;
965 unsigned long item_offset;
966 /*
967 * [ bytenr - len ]
968 * [csum ]
969 *
970 * Our bytes are in the middle of the csum,
971 * we need to split this item and insert a new one.
972 *
973 * But we can't drop the path because the
974 * csum could change, get removed, extended etc.
975 *
976 * The trick here is the max size of a csum item leaves
977 * enough room in the tree block for a single
978 * item header. So, we split the item in place,
979 * adding a new header pointing to the existing
980 * bytes. Then we loop around again and we have
981 * a nicely formed csum item that we can neatly
982 * truncate.
983 */
984 offset = (bytenr - key.offset) >> blocksize_bits;
985 offset *= csum_size;
986
987 shift_len = (len >> blocksize_bits) * csum_size;
988
989 item_offset = btrfs_item_ptr_offset(leaf,
990 path->slots[0]);
991
992 memzero_extent_buffer(leaf, item_offset + offset,
993 shift_len);
994 key.offset = bytenr;
995
996 /*
997 * btrfs_split_item returns -EAGAIN when the
998 * item changed size or key
999 */
1000 ret = btrfs_split_item(trans, root, path, &key, offset);
1001 if (ret && ret != -EAGAIN) {
1002 btrfs_abort_transaction(trans, ret);
1003 break;
1004 }
1005 ret = 0;
1006
1007 key.offset = end_byte - 1;
1008 } else {
1009 truncate_one_csum(trans, path, &key, bytenr, len);
1010 if (key.offset < bytenr)
1011 break;
1012 }
1013 btrfs_release_path(path);
1014 }
1015 btrfs_free_path(path);
1016 return ret;
1017}
1018
1019static int find_next_csum_offset(struct btrfs_root *root,
1020 struct btrfs_path *path,
1021 u64 *next_offset)
1022{
1023 const u32 nritems = btrfs_header_nritems(path->nodes[0]);
1024 struct btrfs_key found_key;
1025 int slot = path->slots[0] + 1;
1026 int ret;
1027
1028 if (nritems == 0 || slot >= nritems) {
1029 ret = btrfs_next_leaf(root, path);
1030 if (ret < 0) {
1031 return ret;
1032 } else if (ret > 0) {
1033 *next_offset = (u64)-1;
1034 return 0;
1035 }
1036 slot = path->slots[0];
1037 }
1038
1039 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
1040
1041 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
1042 found_key.type != BTRFS_EXTENT_CSUM_KEY)
1043 *next_offset = (u64)-1;
1044 else
1045 *next_offset = found_key.offset;
1046
1047 return 0;
1048}
1049
1050int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
1051 struct btrfs_root *root,
1052 struct btrfs_ordered_sum *sums)
1053{
1054 struct btrfs_fs_info *fs_info = root->fs_info;
1055 struct btrfs_key file_key;
1056 struct btrfs_key found_key;
1057 struct btrfs_path *path;
1058 struct btrfs_csum_item *item;
1059 struct btrfs_csum_item *item_end;
1060 struct extent_buffer *leaf = NULL;
1061 u64 next_offset;
1062 u64 total_bytes = 0;
1063 u64 csum_offset;
1064 u64 bytenr;
1065 u32 ins_size;
1066 int index = 0;
1067 int found_next;
1068 int ret;
1069 const u32 csum_size = fs_info->csum_size;
1070
1071 path = btrfs_alloc_path();
1072 if (!path)
1073 return -ENOMEM;
1074again:
1075 next_offset = (u64)-1;
1076 found_next = 0;
1077 bytenr = sums->logical + total_bytes;
1078 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
1079 file_key.offset = bytenr;
1080 file_key.type = BTRFS_EXTENT_CSUM_KEY;
1081
1082 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
1083 if (!IS_ERR(item)) {
1084 ret = 0;
1085 leaf = path->nodes[0];
1086 item_end = btrfs_item_ptr(leaf, path->slots[0],
1087 struct btrfs_csum_item);
1088 item_end = (struct btrfs_csum_item *)((char *)item_end +
1089 btrfs_item_size(leaf, path->slots[0]));
1090 goto found;
1091 }
1092 ret = PTR_ERR(item);
1093 if (ret != -EFBIG && ret != -ENOENT)
1094 goto out;
1095
1096 if (ret == -EFBIG) {
1097 u32 item_size;
1098 /* we found one, but it isn't big enough yet */
1099 leaf = path->nodes[0];
1100 item_size = btrfs_item_size(leaf, path->slots[0]);
1101 if ((item_size / csum_size) >=
1102 MAX_CSUM_ITEMS(fs_info, csum_size)) {
1103 /* already at max size, make a new one */
1104 goto insert;
1105 }
1106 } else {
1107 /* We didn't find a csum item, insert one. */
1108 ret = find_next_csum_offset(root, path, &next_offset);
1109 if (ret < 0)
1110 goto out;
1111 found_next = 1;
1112 goto insert;
1113 }
1114
1115 /*
1116 * At this point, we know the tree has a checksum item that ends at an
1117 * offset matching the start of the checksum range we want to insert.
1118 * We try to extend that item as much as possible and then add as many
1119 * checksums to it as they fit.
1120 *
1121 * First check if the leaf has enough free space for at least one
1122 * checksum. If it has go directly to the item extension code, otherwise
1123 * release the path and do a search for insertion before the extension.
1124 */
1125 if (btrfs_leaf_free_space(leaf) >= csum_size) {
1126 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1127 csum_offset = (bytenr - found_key.offset) >>
1128 fs_info->sectorsize_bits;
1129 goto extend_csum;
1130 }
1131
1132 btrfs_release_path(path);
1133 path->search_for_extension = 1;
1134 ret = btrfs_search_slot(trans, root, &file_key, path,
1135 csum_size, 1);
1136 path->search_for_extension = 0;
1137 if (ret < 0)
1138 goto out;
1139
1140 if (ret > 0) {
1141 if (path->slots[0] == 0)
1142 goto insert;
1143 path->slots[0]--;
1144 }
1145
1146 leaf = path->nodes[0];
1147 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1148 csum_offset = (bytenr - found_key.offset) >> fs_info->sectorsize_bits;
1149
1150 if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
1151 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
1152 csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
1153 goto insert;
1154 }
1155
1156extend_csum:
1157 if (csum_offset == btrfs_item_size(leaf, path->slots[0]) /
1158 csum_size) {
1159 int extend_nr;
1160 u64 tmp;
1161 u32 diff;
1162
1163 tmp = sums->len - total_bytes;
1164 tmp >>= fs_info->sectorsize_bits;
1165 WARN_ON(tmp < 1);
1166 extend_nr = max_t(int, 1, tmp);
1167
1168 /*
1169 * A log tree can already have checksum items with a subset of
1170 * the checksums we are trying to log. This can happen after
1171 * doing a sequence of partial writes into prealloc extents and
1172 * fsyncs in between, with a full fsync logging a larger subrange
1173 * of an extent for which a previous fast fsync logged a smaller
1174 * subrange. And this happens in particular due to merging file
1175 * extent items when we complete an ordered extent for a range
1176 * covered by a prealloc extent - this is done at
1177 * btrfs_mark_extent_written().
1178 *
1179 * So if we try to extend the previous checksum item, which has
1180 * a range that ends at the start of the range we want to insert,
1181 * make sure we don't extend beyond the start offset of the next
1182 * checksum item. If we are at the last item in the leaf, then
1183 * forget the optimization of extending and add a new checksum
1184 * item - it is not worth the complexity of releasing the path,
1185 * getting the first key for the next leaf, repeat the btree
1186 * search, etc, because log trees are temporary anyway and it
1187 * would only save a few bytes of leaf space.
1188 */
1189 if (btrfs_root_id(root) == BTRFS_TREE_LOG_OBJECTID) {
1190 if (path->slots[0] + 1 >=
1191 btrfs_header_nritems(path->nodes[0])) {
1192 ret = find_next_csum_offset(root, path, &next_offset);
1193 if (ret < 0)
1194 goto out;
1195 found_next = 1;
1196 goto insert;
1197 }
1198
1199 ret = find_next_csum_offset(root, path, &next_offset);
1200 if (ret < 0)
1201 goto out;
1202
1203 tmp = (next_offset - bytenr) >> fs_info->sectorsize_bits;
1204 if (tmp <= INT_MAX)
1205 extend_nr = min_t(int, extend_nr, tmp);
1206 }
1207
1208 diff = (csum_offset + extend_nr) * csum_size;
1209 diff = min(diff,
1210 MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
1211
1212 diff = diff - btrfs_item_size(leaf, path->slots[0]);
1213 diff = min_t(u32, btrfs_leaf_free_space(leaf), diff);
1214 diff /= csum_size;
1215 diff *= csum_size;
1216
1217 btrfs_extend_item(trans, path, diff);
1218 ret = 0;
1219 goto csum;
1220 }
1221
1222insert:
1223 btrfs_release_path(path);
1224 csum_offset = 0;
1225 if (found_next) {
1226 u64 tmp;
1227
1228 tmp = sums->len - total_bytes;
1229 tmp >>= fs_info->sectorsize_bits;
1230 tmp = min(tmp, (next_offset - file_key.offset) >>
1231 fs_info->sectorsize_bits);
1232
1233 tmp = max_t(u64, 1, tmp);
1234 tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
1235 ins_size = csum_size * tmp;
1236 } else {
1237 ins_size = csum_size;
1238 }
1239 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
1240 ins_size);
1241 if (ret < 0)
1242 goto out;
1243 leaf = path->nodes[0];
1244csum:
1245 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
1246 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
1247 btrfs_item_size(leaf, path->slots[0]));
1248 item = (struct btrfs_csum_item *)((unsigned char *)item +
1249 csum_offset * csum_size);
1250found:
1251 ins_size = (u32)(sums->len - total_bytes) >> fs_info->sectorsize_bits;
1252 ins_size *= csum_size;
1253 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
1254 ins_size);
1255 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
1256 ins_size);
1257
1258 index += ins_size;
1259 ins_size /= csum_size;
1260 total_bytes += ins_size * fs_info->sectorsize;
1261
1262 btrfs_mark_buffer_dirty(trans, path->nodes[0]);
1263 if (total_bytes < sums->len) {
1264 btrfs_release_path(path);
1265 cond_resched();
1266 goto again;
1267 }
1268out:
1269 btrfs_free_path(path);
1270 return ret;
1271}
1272
1273void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
1274 const struct btrfs_path *path,
1275 const struct btrfs_file_extent_item *fi,
1276 struct extent_map *em)
1277{
1278 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1279 struct btrfs_root *root = inode->root;
1280 struct extent_buffer *leaf = path->nodes[0];
1281 const int slot = path->slots[0];
1282 struct btrfs_key key;
1283 u64 extent_start;
1284 u8 type = btrfs_file_extent_type(leaf, fi);
1285 int compress_type = btrfs_file_extent_compression(leaf, fi);
1286
1287 btrfs_item_key_to_cpu(leaf, &key, slot);
1288 extent_start = key.offset;
1289 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1290 em->generation = btrfs_file_extent_generation(leaf, fi);
1291 if (type == BTRFS_FILE_EXTENT_REG ||
1292 type == BTRFS_FILE_EXTENT_PREALLOC) {
1293 const u64 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1294
1295 em->start = extent_start;
1296 em->len = btrfs_file_extent_end(path) - extent_start;
1297 if (disk_bytenr == 0) {
1298 em->disk_bytenr = EXTENT_MAP_HOLE;
1299 em->disk_num_bytes = 0;
1300 em->offset = 0;
1301 return;
1302 }
1303 em->disk_bytenr = disk_bytenr;
1304 em->disk_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1305 em->offset = btrfs_file_extent_offset(leaf, fi);
1306 if (compress_type != BTRFS_COMPRESS_NONE) {
1307 extent_map_set_compression(em, compress_type);
1308 } else {
1309 /*
1310 * Older kernels can create regular non-hole data
1311 * extents with ram_bytes smaller than disk_num_bytes.
1312 * Not a big deal, just always use disk_num_bytes
1313 * for ram_bytes.
1314 */
1315 em->ram_bytes = em->disk_num_bytes;
1316 if (type == BTRFS_FILE_EXTENT_PREALLOC)
1317 em->flags |= EXTENT_FLAG_PREALLOC;
1318 }
1319 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1320 /* Tree-checker has ensured this. */
1321 ASSERT(extent_start == 0);
1322
1323 em->disk_bytenr = EXTENT_MAP_INLINE;
1324 em->start = 0;
1325 em->len = fs_info->sectorsize;
1326 em->offset = 0;
1327 extent_map_set_compression(em, compress_type);
1328 } else {
1329 btrfs_err(fs_info,
1330 "unknown file extent item type %d, inode %llu, offset %llu, "
1331 "root %llu", type, btrfs_ino(inode), extent_start,
1332 btrfs_root_id(root));
1333 }
1334}
1335
1336/*
1337 * Returns the end offset (non inclusive) of the file extent item the given path
1338 * points to. If it points to an inline extent, the returned offset is rounded
1339 * up to the sector size.
1340 */
1341u64 btrfs_file_extent_end(const struct btrfs_path *path)
1342{
1343 const struct extent_buffer *leaf = path->nodes[0];
1344 const int slot = path->slots[0];
1345 struct btrfs_file_extent_item *fi;
1346 struct btrfs_key key;
1347 u64 end;
1348
1349 btrfs_item_key_to_cpu(leaf, &key, slot);
1350 ASSERT(key.type == BTRFS_EXTENT_DATA_KEY);
1351 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1352
1353 if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE)
1354 end = leaf->fs_info->sectorsize;
1355 else
1356 end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1357
1358 return end;
1359}