Loading...
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 "ctree.h"
11#include "disk-io.h"
12#include "transaction.h"
13#include "volumes.h"
14#include "print-tree.h"
15#include "compression.h"
16
17#define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
18 sizeof(struct btrfs_item) * 2) / \
19 size) - 1))
20
21#define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
22 PAGE_SIZE))
23
24#define MAX_ORDERED_SUM_BYTES(fs_info) ((PAGE_SIZE - \
25 sizeof(struct btrfs_ordered_sum)) / \
26 sizeof(u32) * (fs_info)->sectorsize)
27
28int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
29 struct btrfs_root *root,
30 u64 objectid, u64 pos,
31 u64 disk_offset, u64 disk_num_bytes,
32 u64 num_bytes, u64 offset, u64 ram_bytes,
33 u8 compression, u8 encryption, u16 other_encoding)
34{
35 int ret = 0;
36 struct btrfs_file_extent_item *item;
37 struct btrfs_key file_key;
38 struct btrfs_path *path;
39 struct extent_buffer *leaf;
40
41 path = btrfs_alloc_path();
42 if (!path)
43 return -ENOMEM;
44 file_key.objectid = objectid;
45 file_key.offset = pos;
46 file_key.type = BTRFS_EXTENT_DATA_KEY;
47
48 path->leave_spinning = 1;
49 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
50 sizeof(*item));
51 if (ret < 0)
52 goto out;
53 BUG_ON(ret); /* Can't happen */
54 leaf = path->nodes[0];
55 item = btrfs_item_ptr(leaf, path->slots[0],
56 struct btrfs_file_extent_item);
57 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
58 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
59 btrfs_set_file_extent_offset(leaf, item, offset);
60 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
61 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
62 btrfs_set_file_extent_generation(leaf, item, trans->transid);
63 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
64 btrfs_set_file_extent_compression(leaf, item, compression);
65 btrfs_set_file_extent_encryption(leaf, item, encryption);
66 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
67
68 btrfs_mark_buffer_dirty(leaf);
69out:
70 btrfs_free_path(path);
71 return ret;
72}
73
74static struct btrfs_csum_item *
75btrfs_lookup_csum(struct btrfs_trans_handle *trans,
76 struct btrfs_root *root,
77 struct btrfs_path *path,
78 u64 bytenr, int cow)
79{
80 struct btrfs_fs_info *fs_info = root->fs_info;
81 int ret;
82 struct btrfs_key file_key;
83 struct btrfs_key found_key;
84 struct btrfs_csum_item *item;
85 struct extent_buffer *leaf;
86 u64 csum_offset = 0;
87 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
88 int csums_in_item;
89
90 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
91 file_key.offset = bytenr;
92 file_key.type = BTRFS_EXTENT_CSUM_KEY;
93 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
94 if (ret < 0)
95 goto fail;
96 leaf = path->nodes[0];
97 if (ret > 0) {
98 ret = 1;
99 if (path->slots[0] == 0)
100 goto fail;
101 path->slots[0]--;
102 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
103 if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
104 goto fail;
105
106 csum_offset = (bytenr - found_key.offset) >>
107 fs_info->sb->s_blocksize_bits;
108 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
109 csums_in_item /= csum_size;
110
111 if (csum_offset == csums_in_item) {
112 ret = -EFBIG;
113 goto fail;
114 } else if (csum_offset > csums_in_item) {
115 goto fail;
116 }
117 }
118 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
119 item = (struct btrfs_csum_item *)((unsigned char *)item +
120 csum_offset * csum_size);
121 return item;
122fail:
123 if (ret > 0)
124 ret = -ENOENT;
125 return ERR_PTR(ret);
126}
127
128int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
129 struct btrfs_root *root,
130 struct btrfs_path *path, u64 objectid,
131 u64 offset, int mod)
132{
133 int ret;
134 struct btrfs_key file_key;
135 int ins_len = mod < 0 ? -1 : 0;
136 int cow = mod != 0;
137
138 file_key.objectid = objectid;
139 file_key.offset = offset;
140 file_key.type = BTRFS_EXTENT_DATA_KEY;
141 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
142 return ret;
143}
144
145static void btrfs_io_bio_endio_readpage(struct btrfs_io_bio *bio, int err)
146{
147 kfree(bio->csum_allocated);
148}
149
150static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
151 u64 logical_offset, u32 *dst, int dio)
152{
153 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
154 struct bio_vec bvec;
155 struct bvec_iter iter;
156 struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
157 struct btrfs_csum_item *item = NULL;
158 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
159 struct btrfs_path *path;
160 u8 *csum;
161 u64 offset = 0;
162 u64 item_start_offset = 0;
163 u64 item_last_offset = 0;
164 u64 disk_bytenr;
165 u64 page_bytes_left;
166 u32 diff;
167 int nblocks;
168 int count = 0;
169 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
170
171 path = btrfs_alloc_path();
172 if (!path)
173 return BLK_STS_RESOURCE;
174
175 nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits;
176 if (!dst) {
177 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
178 btrfs_bio->csum_allocated = kmalloc_array(nblocks,
179 csum_size, GFP_NOFS);
180 if (!btrfs_bio->csum_allocated) {
181 btrfs_free_path(path);
182 return BLK_STS_RESOURCE;
183 }
184 btrfs_bio->csum = btrfs_bio->csum_allocated;
185 btrfs_bio->end_io = btrfs_io_bio_endio_readpage;
186 } else {
187 btrfs_bio->csum = btrfs_bio->csum_inline;
188 }
189 csum = btrfs_bio->csum;
190 } else {
191 csum = (u8 *)dst;
192 }
193
194 if (bio->bi_iter.bi_size > PAGE_SIZE * 8)
195 path->reada = READA_FORWARD;
196
197 /*
198 * the free space stuff is only read when it hasn't been
199 * updated in the current transaction. So, we can safely
200 * read from the commit root and sidestep a nasty deadlock
201 * between reading the free space cache and updating the csum tree.
202 */
203 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
204 path->search_commit_root = 1;
205 path->skip_locking = 1;
206 }
207
208 disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
209 if (dio)
210 offset = logical_offset;
211
212 bio_for_each_segment(bvec, bio, iter) {
213 page_bytes_left = bvec.bv_len;
214 if (count)
215 goto next;
216
217 if (!dio)
218 offset = page_offset(bvec.bv_page) + bvec.bv_offset;
219 count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
220 (u32 *)csum, nblocks);
221 if (count)
222 goto found;
223
224 if (!item || disk_bytenr < item_start_offset ||
225 disk_bytenr >= item_last_offset) {
226 struct btrfs_key found_key;
227 u32 item_size;
228
229 if (item)
230 btrfs_release_path(path);
231 item = btrfs_lookup_csum(NULL, fs_info->csum_root,
232 path, disk_bytenr, 0);
233 if (IS_ERR(item)) {
234 count = 1;
235 memset(csum, 0, csum_size);
236 if (BTRFS_I(inode)->root->root_key.objectid ==
237 BTRFS_DATA_RELOC_TREE_OBJECTID) {
238 set_extent_bits(io_tree, offset,
239 offset + fs_info->sectorsize - 1,
240 EXTENT_NODATASUM);
241 } else {
242 btrfs_info_rl(fs_info,
243 "no csum found for inode %llu start %llu",
244 btrfs_ino(BTRFS_I(inode)), offset);
245 }
246 item = NULL;
247 btrfs_release_path(path);
248 goto found;
249 }
250 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
251 path->slots[0]);
252
253 item_start_offset = found_key.offset;
254 item_size = btrfs_item_size_nr(path->nodes[0],
255 path->slots[0]);
256 item_last_offset = item_start_offset +
257 (item_size / csum_size) *
258 fs_info->sectorsize;
259 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
260 struct btrfs_csum_item);
261 }
262 /*
263 * this byte range must be able to fit inside
264 * a single leaf so it will also fit inside a u32
265 */
266 diff = disk_bytenr - item_start_offset;
267 diff = diff / fs_info->sectorsize;
268 diff = diff * csum_size;
269 count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >>
270 inode->i_sb->s_blocksize_bits);
271 read_extent_buffer(path->nodes[0], csum,
272 ((unsigned long)item) + diff,
273 csum_size * count);
274found:
275 csum += count * csum_size;
276 nblocks -= count;
277next:
278 while (count--) {
279 disk_bytenr += fs_info->sectorsize;
280 offset += fs_info->sectorsize;
281 page_bytes_left -= fs_info->sectorsize;
282 if (!page_bytes_left)
283 break; /* move to next bio */
284 }
285 }
286
287 WARN_ON_ONCE(count);
288 btrfs_free_path(path);
289 return 0;
290}
291
292blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u32 *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));
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
422blk_status_t btrfs_csum_one_bio(struct inode *inode, struct bio *bio,
423 u64 file_start, int contig)
424{
425 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
426 struct btrfs_ordered_sum *sums;
427 struct btrfs_ordered_extent *ordered = NULL;
428 char *data;
429 struct bvec_iter iter;
430 struct bio_vec bvec;
431 int index;
432 int nr_sectors;
433 unsigned long total_bytes = 0;
434 unsigned long this_sum_bytes = 0;
435 int i;
436 u64 offset;
437
438 sums = kzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
439 GFP_NOFS);
440 if (!sums)
441 return BLK_STS_RESOURCE;
442
443 sums->len = bio->bi_iter.bi_size;
444 INIT_LIST_HEAD(&sums->list);
445
446 if (contig)
447 offset = file_start;
448 else
449 offset = 0; /* shut up gcc */
450
451 sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
452 index = 0;
453
454 bio_for_each_segment(bvec, bio, iter) {
455 if (!contig)
456 offset = page_offset(bvec.bv_page) + bvec.bv_offset;
457
458 if (!ordered) {
459 ordered = btrfs_lookup_ordered_extent(inode, offset);
460 BUG_ON(!ordered); /* Logic error */
461 }
462
463 data = kmap_atomic(bvec.bv_page);
464
465 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info,
466 bvec.bv_len + fs_info->sectorsize
467 - 1);
468
469 for (i = 0; i < nr_sectors; i++) {
470 if (offset >= ordered->file_offset + ordered->len ||
471 offset < ordered->file_offset) {
472 unsigned long bytes_left;
473
474 kunmap_atomic(data);
475 sums->len = this_sum_bytes;
476 this_sum_bytes = 0;
477 btrfs_add_ordered_sum(inode, ordered, sums);
478 btrfs_put_ordered_extent(ordered);
479
480 bytes_left = bio->bi_iter.bi_size - total_bytes;
481
482 sums = kzalloc(btrfs_ordered_sum_size(fs_info, bytes_left),
483 GFP_NOFS);
484 BUG_ON(!sums); /* -ENOMEM */
485 sums->len = bytes_left;
486 ordered = btrfs_lookup_ordered_extent(inode,
487 offset);
488 ASSERT(ordered); /* Logic error */
489 sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9)
490 + total_bytes;
491 index = 0;
492
493 data = kmap_atomic(bvec.bv_page);
494 }
495
496 sums->sums[index] = ~(u32)0;
497 sums->sums[index]
498 = btrfs_csum_data(data + bvec.bv_offset
499 + (i * fs_info->sectorsize),
500 sums->sums[index],
501 fs_info->sectorsize);
502 btrfs_csum_final(sums->sums[index],
503 (char *)(sums->sums + index));
504 index++;
505 offset += fs_info->sectorsize;
506 this_sum_bytes += fs_info->sectorsize;
507 total_bytes += fs_info->sectorsize;
508 }
509
510 kunmap_atomic(data);
511 }
512 this_sum_bytes = 0;
513 btrfs_add_ordered_sum(inode, ordered, sums);
514 btrfs_put_ordered_extent(ordered);
515 return 0;
516}
517
518/*
519 * helper function for csum removal, this expects the
520 * key to describe the csum pointed to by the path, and it expects
521 * the csum to overlap the range [bytenr, len]
522 *
523 * The csum should not be entirely contained in the range and the
524 * range should not be entirely contained in the csum.
525 *
526 * This calls btrfs_truncate_item with the correct args based on the
527 * overlap, and fixes up the key as required.
528 */
529static noinline void truncate_one_csum(struct btrfs_fs_info *fs_info,
530 struct btrfs_path *path,
531 struct btrfs_key *key,
532 u64 bytenr, u64 len)
533{
534 struct extent_buffer *leaf;
535 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
536 u64 csum_end;
537 u64 end_byte = bytenr + len;
538 u32 blocksize_bits = fs_info->sb->s_blocksize_bits;
539
540 leaf = path->nodes[0];
541 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
542 csum_end <<= fs_info->sb->s_blocksize_bits;
543 csum_end += key->offset;
544
545 if (key->offset < bytenr && csum_end <= end_byte) {
546 /*
547 * [ bytenr - len ]
548 * [ ]
549 * [csum ]
550 * A simple truncate off the end of the item
551 */
552 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
553 new_size *= csum_size;
554 btrfs_truncate_item(fs_info, path, new_size, 1);
555 } else if (key->offset >= bytenr && csum_end > end_byte &&
556 end_byte > key->offset) {
557 /*
558 * [ bytenr - len ]
559 * [ ]
560 * [csum ]
561 * we need to truncate from the beginning of the csum
562 */
563 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
564 new_size *= csum_size;
565
566 btrfs_truncate_item(fs_info, path, new_size, 0);
567
568 key->offset = end_byte;
569 btrfs_set_item_key_safe(fs_info, path, key);
570 } else {
571 BUG();
572 }
573}
574
575/*
576 * deletes the csum items from the csum tree for a given
577 * range of bytes.
578 */
579int btrfs_del_csums(struct btrfs_trans_handle *trans,
580 struct btrfs_fs_info *fs_info, u64 bytenr, u64 len)
581{
582 struct btrfs_root *root = fs_info->csum_root;
583 struct btrfs_path *path;
584 struct btrfs_key key;
585 u64 end_byte = bytenr + len;
586 u64 csum_end;
587 struct extent_buffer *leaf;
588 int ret;
589 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
590 int blocksize_bits = fs_info->sb->s_blocksize_bits;
591
592 path = btrfs_alloc_path();
593 if (!path)
594 return -ENOMEM;
595
596 while (1) {
597 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
598 key.offset = end_byte - 1;
599 key.type = BTRFS_EXTENT_CSUM_KEY;
600
601 path->leave_spinning = 1;
602 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
603 if (ret > 0) {
604 if (path->slots[0] == 0)
605 break;
606 path->slots[0]--;
607 } else if (ret < 0) {
608 break;
609 }
610
611 leaf = path->nodes[0];
612 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
613
614 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
615 key.type != BTRFS_EXTENT_CSUM_KEY) {
616 break;
617 }
618
619 if (key.offset >= end_byte)
620 break;
621
622 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
623 csum_end <<= blocksize_bits;
624 csum_end += key.offset;
625
626 /* this csum ends before we start, we're done */
627 if (csum_end <= bytenr)
628 break;
629
630 /* delete the entire item, it is inside our range */
631 if (key.offset >= bytenr && csum_end <= end_byte) {
632 int del_nr = 1;
633
634 /*
635 * Check how many csum items preceding this one in this
636 * leaf correspond to our range and then delete them all
637 * at once.
638 */
639 if (key.offset > bytenr && path->slots[0] > 0) {
640 int slot = path->slots[0] - 1;
641
642 while (slot >= 0) {
643 struct btrfs_key pk;
644
645 btrfs_item_key_to_cpu(leaf, &pk, slot);
646 if (pk.offset < bytenr ||
647 pk.type != BTRFS_EXTENT_CSUM_KEY ||
648 pk.objectid !=
649 BTRFS_EXTENT_CSUM_OBJECTID)
650 break;
651 path->slots[0] = slot;
652 del_nr++;
653 key.offset = pk.offset;
654 slot--;
655 }
656 }
657 ret = btrfs_del_items(trans, root, path,
658 path->slots[0], del_nr);
659 if (ret)
660 goto out;
661 if (key.offset == bytenr)
662 break;
663 } else if (key.offset < bytenr && csum_end > end_byte) {
664 unsigned long offset;
665 unsigned long shift_len;
666 unsigned long item_offset;
667 /*
668 * [ bytenr - len ]
669 * [csum ]
670 *
671 * Our bytes are in the middle of the csum,
672 * we need to split this item and insert a new one.
673 *
674 * But we can't drop the path because the
675 * csum could change, get removed, extended etc.
676 *
677 * The trick here is the max size of a csum item leaves
678 * enough room in the tree block for a single
679 * item header. So, we split the item in place,
680 * adding a new header pointing to the existing
681 * bytes. Then we loop around again and we have
682 * a nicely formed csum item that we can neatly
683 * truncate.
684 */
685 offset = (bytenr - key.offset) >> blocksize_bits;
686 offset *= csum_size;
687
688 shift_len = (len >> blocksize_bits) * csum_size;
689
690 item_offset = btrfs_item_ptr_offset(leaf,
691 path->slots[0]);
692
693 memzero_extent_buffer(leaf, item_offset + offset,
694 shift_len);
695 key.offset = bytenr;
696
697 /*
698 * btrfs_split_item returns -EAGAIN when the
699 * item changed size or key
700 */
701 ret = btrfs_split_item(trans, root, path, &key, offset);
702 if (ret && ret != -EAGAIN) {
703 btrfs_abort_transaction(trans, ret);
704 goto out;
705 }
706
707 key.offset = end_byte - 1;
708 } else {
709 truncate_one_csum(fs_info, path, &key, bytenr, len);
710 if (key.offset < bytenr)
711 break;
712 }
713 btrfs_release_path(path);
714 }
715 ret = 0;
716out:
717 btrfs_free_path(path);
718 return ret;
719}
720
721int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
722 struct btrfs_root *root,
723 struct btrfs_ordered_sum *sums)
724{
725 struct btrfs_fs_info *fs_info = root->fs_info;
726 struct btrfs_key file_key;
727 struct btrfs_key found_key;
728 struct btrfs_path *path;
729 struct btrfs_csum_item *item;
730 struct btrfs_csum_item *item_end;
731 struct extent_buffer *leaf = NULL;
732 u64 next_offset;
733 u64 total_bytes = 0;
734 u64 csum_offset;
735 u64 bytenr;
736 u32 nritems;
737 u32 ins_size;
738 int index = 0;
739 int found_next;
740 int ret;
741 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
742
743 path = btrfs_alloc_path();
744 if (!path)
745 return -ENOMEM;
746again:
747 next_offset = (u64)-1;
748 found_next = 0;
749 bytenr = sums->bytenr + total_bytes;
750 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
751 file_key.offset = bytenr;
752 file_key.type = BTRFS_EXTENT_CSUM_KEY;
753
754 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
755 if (!IS_ERR(item)) {
756 ret = 0;
757 leaf = path->nodes[0];
758 item_end = btrfs_item_ptr(leaf, path->slots[0],
759 struct btrfs_csum_item);
760 item_end = (struct btrfs_csum_item *)((char *)item_end +
761 btrfs_item_size_nr(leaf, path->slots[0]));
762 goto found;
763 }
764 ret = PTR_ERR(item);
765 if (ret != -EFBIG && ret != -ENOENT)
766 goto fail_unlock;
767
768 if (ret == -EFBIG) {
769 u32 item_size;
770 /* we found one, but it isn't big enough yet */
771 leaf = path->nodes[0];
772 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
773 if ((item_size / csum_size) >=
774 MAX_CSUM_ITEMS(fs_info, csum_size)) {
775 /* already at max size, make a new one */
776 goto insert;
777 }
778 } else {
779 int slot = path->slots[0] + 1;
780 /* we didn't find a csum item, insert one */
781 nritems = btrfs_header_nritems(path->nodes[0]);
782 if (!nritems || (path->slots[0] >= nritems - 1)) {
783 ret = btrfs_next_leaf(root, path);
784 if (ret == 1)
785 found_next = 1;
786 if (ret != 0)
787 goto insert;
788 slot = path->slots[0];
789 }
790 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
791 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
792 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
793 found_next = 1;
794 goto insert;
795 }
796 next_offset = found_key.offset;
797 found_next = 1;
798 goto insert;
799 }
800
801 /*
802 * at this point, we know the tree has an item, but it isn't big
803 * enough yet to put our csum in. Grow it
804 */
805 btrfs_release_path(path);
806 ret = btrfs_search_slot(trans, root, &file_key, path,
807 csum_size, 1);
808 if (ret < 0)
809 goto fail_unlock;
810
811 if (ret > 0) {
812 if (path->slots[0] == 0)
813 goto insert;
814 path->slots[0]--;
815 }
816
817 leaf = path->nodes[0];
818 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
819 csum_offset = (bytenr - found_key.offset) >>
820 fs_info->sb->s_blocksize_bits;
821
822 if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
823 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
824 csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
825 goto insert;
826 }
827
828 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
829 csum_size) {
830 int extend_nr;
831 u64 tmp;
832 u32 diff;
833 u32 free_space;
834
835 if (btrfs_leaf_free_space(fs_info, leaf) <
836 sizeof(struct btrfs_item) + csum_size * 2)
837 goto insert;
838
839 free_space = btrfs_leaf_free_space(fs_info, leaf) -
840 sizeof(struct btrfs_item) - csum_size;
841 tmp = sums->len - total_bytes;
842 tmp >>= fs_info->sb->s_blocksize_bits;
843 WARN_ON(tmp < 1);
844
845 extend_nr = max_t(int, 1, (int)tmp);
846 diff = (csum_offset + extend_nr) * csum_size;
847 diff = min(diff,
848 MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
849
850 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
851 diff = min(free_space, diff);
852 diff /= csum_size;
853 diff *= csum_size;
854
855 btrfs_extend_item(fs_info, path, diff);
856 ret = 0;
857 goto csum;
858 }
859
860insert:
861 btrfs_release_path(path);
862 csum_offset = 0;
863 if (found_next) {
864 u64 tmp;
865
866 tmp = sums->len - total_bytes;
867 tmp >>= fs_info->sb->s_blocksize_bits;
868 tmp = min(tmp, (next_offset - file_key.offset) >>
869 fs_info->sb->s_blocksize_bits);
870
871 tmp = max_t(u64, 1, tmp);
872 tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
873 ins_size = csum_size * tmp;
874 } else {
875 ins_size = csum_size;
876 }
877 path->leave_spinning = 1;
878 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
879 ins_size);
880 path->leave_spinning = 0;
881 if (ret < 0)
882 goto fail_unlock;
883 if (WARN_ON(ret != 0))
884 goto fail_unlock;
885 leaf = path->nodes[0];
886csum:
887 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
888 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
889 btrfs_item_size_nr(leaf, path->slots[0]));
890 item = (struct btrfs_csum_item *)((unsigned char *)item +
891 csum_offset * csum_size);
892found:
893 ins_size = (u32)(sums->len - total_bytes) >>
894 fs_info->sb->s_blocksize_bits;
895 ins_size *= csum_size;
896 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
897 ins_size);
898 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
899 ins_size);
900
901 ins_size /= csum_size;
902 total_bytes += ins_size * fs_info->sectorsize;
903 index += ins_size;
904
905 btrfs_mark_buffer_dirty(path->nodes[0]);
906 if (total_bytes < sums->len) {
907 btrfs_release_path(path);
908 cond_resched();
909 goto again;
910 }
911out:
912 btrfs_free_path(path);
913 return ret;
914
915fail_unlock:
916 goto out;
917}
918
919void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
920 const struct btrfs_path *path,
921 struct btrfs_file_extent_item *fi,
922 const bool new_inline,
923 struct extent_map *em)
924{
925 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
926 struct btrfs_root *root = inode->root;
927 struct extent_buffer *leaf = path->nodes[0];
928 const int slot = path->slots[0];
929 struct btrfs_key key;
930 u64 extent_start, extent_end;
931 u64 bytenr;
932 u8 type = btrfs_file_extent_type(leaf, fi);
933 int compress_type = btrfs_file_extent_compression(leaf, fi);
934
935 em->bdev = fs_info->fs_devices->latest_bdev;
936 btrfs_item_key_to_cpu(leaf, &key, slot);
937 extent_start = key.offset;
938
939 if (type == BTRFS_FILE_EXTENT_REG ||
940 type == BTRFS_FILE_EXTENT_PREALLOC) {
941 extent_end = extent_start +
942 btrfs_file_extent_num_bytes(leaf, fi);
943 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
944 size_t size;
945 size = btrfs_file_extent_inline_len(leaf, slot, fi);
946 extent_end = ALIGN(extent_start + size,
947 fs_info->sectorsize);
948 }
949
950 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
951 if (type == BTRFS_FILE_EXTENT_REG ||
952 type == BTRFS_FILE_EXTENT_PREALLOC) {
953 em->start = extent_start;
954 em->len = extent_end - extent_start;
955 em->orig_start = extent_start -
956 btrfs_file_extent_offset(leaf, fi);
957 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
958 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
959 if (bytenr == 0) {
960 em->block_start = EXTENT_MAP_HOLE;
961 return;
962 }
963 if (compress_type != BTRFS_COMPRESS_NONE) {
964 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
965 em->compress_type = compress_type;
966 em->block_start = bytenr;
967 em->block_len = em->orig_block_len;
968 } else {
969 bytenr += btrfs_file_extent_offset(leaf, fi);
970 em->block_start = bytenr;
971 em->block_len = em->len;
972 if (type == BTRFS_FILE_EXTENT_PREALLOC)
973 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
974 }
975 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
976 em->block_start = EXTENT_MAP_INLINE;
977 em->start = extent_start;
978 em->len = extent_end - extent_start;
979 /*
980 * Initialize orig_start and block_len with the same values
981 * as in inode.c:btrfs_get_extent().
982 */
983 em->orig_start = EXTENT_MAP_HOLE;
984 em->block_len = (u64)-1;
985 if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) {
986 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
987 em->compress_type = compress_type;
988 }
989 } else {
990 btrfs_err(fs_info,
991 "unknown file extent item type %d, inode %llu, offset %llu, "
992 "root %llu", type, btrfs_ino(inode), extent_start,
993 root->root_key.objectid);
994 }
995}