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1/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/bio.h>
20#include <linux/slab.h>
21#include <linux/pagemap.h>
22#include <linux/highmem.h>
23#include "ctree.h"
24#include "disk-io.h"
25#include "transaction.h"
26#include "volumes.h"
27#include "print-tree.h"
28#include "compression.h"
29
30#define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
31 sizeof(struct btrfs_item) * 2) / \
32 size) - 1))
33
34#define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
35 PAGE_SIZE))
36
37#define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
38 sizeof(struct btrfs_ordered_sum)) / \
39 sizeof(u32) * (r)->sectorsize)
40
41int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
42 struct btrfs_root *root,
43 u64 objectid, u64 pos,
44 u64 disk_offset, u64 disk_num_bytes,
45 u64 num_bytes, u64 offset, u64 ram_bytes,
46 u8 compression, u8 encryption, u16 other_encoding)
47{
48 int ret = 0;
49 struct btrfs_file_extent_item *item;
50 struct btrfs_key file_key;
51 struct btrfs_path *path;
52 struct extent_buffer *leaf;
53
54 path = btrfs_alloc_path();
55 if (!path)
56 return -ENOMEM;
57 file_key.objectid = objectid;
58 file_key.offset = pos;
59 file_key.type = BTRFS_EXTENT_DATA_KEY;
60
61 path->leave_spinning = 1;
62 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
63 sizeof(*item));
64 if (ret < 0)
65 goto out;
66 BUG_ON(ret); /* Can't happen */
67 leaf = path->nodes[0];
68 item = btrfs_item_ptr(leaf, path->slots[0],
69 struct btrfs_file_extent_item);
70 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
71 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
72 btrfs_set_file_extent_offset(leaf, item, offset);
73 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
74 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
75 btrfs_set_file_extent_generation(leaf, item, trans->transid);
76 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
77 btrfs_set_file_extent_compression(leaf, item, compression);
78 btrfs_set_file_extent_encryption(leaf, item, encryption);
79 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
80
81 btrfs_mark_buffer_dirty(leaf);
82out:
83 btrfs_free_path(path);
84 return ret;
85}
86
87static struct btrfs_csum_item *
88btrfs_lookup_csum(struct btrfs_trans_handle *trans,
89 struct btrfs_root *root,
90 struct btrfs_path *path,
91 u64 bytenr, int cow)
92{
93 int ret;
94 struct btrfs_key file_key;
95 struct btrfs_key found_key;
96 struct btrfs_csum_item *item;
97 struct extent_buffer *leaf;
98 u64 csum_offset = 0;
99 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
100 int csums_in_item;
101
102 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
103 file_key.offset = bytenr;
104 file_key.type = BTRFS_EXTENT_CSUM_KEY;
105 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
106 if (ret < 0)
107 goto fail;
108 leaf = path->nodes[0];
109 if (ret > 0) {
110 ret = 1;
111 if (path->slots[0] == 0)
112 goto fail;
113 path->slots[0]--;
114 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
115 if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
116 goto fail;
117
118 csum_offset = (bytenr - found_key.offset) >>
119 root->fs_info->sb->s_blocksize_bits;
120 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
121 csums_in_item /= csum_size;
122
123 if (csum_offset == csums_in_item) {
124 ret = -EFBIG;
125 goto fail;
126 } else if (csum_offset > csums_in_item) {
127 goto fail;
128 }
129 }
130 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
131 item = (struct btrfs_csum_item *)((unsigned char *)item +
132 csum_offset * csum_size);
133 return item;
134fail:
135 if (ret > 0)
136 ret = -ENOENT;
137 return ERR_PTR(ret);
138}
139
140int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
141 struct btrfs_root *root,
142 struct btrfs_path *path, u64 objectid,
143 u64 offset, int mod)
144{
145 int ret;
146 struct btrfs_key file_key;
147 int ins_len = mod < 0 ? -1 : 0;
148 int cow = mod != 0;
149
150 file_key.objectid = objectid;
151 file_key.offset = offset;
152 file_key.type = BTRFS_EXTENT_DATA_KEY;
153 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
154 return ret;
155}
156
157static void btrfs_io_bio_endio_readpage(struct btrfs_io_bio *bio, int err)
158{
159 kfree(bio->csum_allocated);
160}
161
162static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
163 struct inode *inode, struct bio *bio,
164 u64 logical_offset, u32 *dst, int dio)
165{
166 struct bio_vec *bvec = bio->bi_io_vec;
167 struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
168 struct btrfs_csum_item *item = NULL;
169 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
170 struct btrfs_path *path;
171 u8 *csum;
172 u64 offset = 0;
173 u64 item_start_offset = 0;
174 u64 item_last_offset = 0;
175 u64 disk_bytenr;
176 u64 page_bytes_left;
177 u32 diff;
178 int nblocks;
179 int bio_index = 0;
180 int count;
181 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
182
183 path = btrfs_alloc_path();
184 if (!path)
185 return -ENOMEM;
186
187 nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits;
188 if (!dst) {
189 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
190 btrfs_bio->csum_allocated = kmalloc_array(nblocks,
191 csum_size, GFP_NOFS);
192 if (!btrfs_bio->csum_allocated) {
193 btrfs_free_path(path);
194 return -ENOMEM;
195 }
196 btrfs_bio->csum = btrfs_bio->csum_allocated;
197 btrfs_bio->end_io = btrfs_io_bio_endio_readpage;
198 } else {
199 btrfs_bio->csum = btrfs_bio->csum_inline;
200 }
201 csum = btrfs_bio->csum;
202 } else {
203 csum = (u8 *)dst;
204 }
205
206 if (bio->bi_iter.bi_size > PAGE_SIZE * 8)
207 path->reada = READA_FORWARD;
208
209 WARN_ON(bio->bi_vcnt <= 0);
210
211 /*
212 * the free space stuff is only read when it hasn't been
213 * updated in the current transaction. So, we can safely
214 * read from the commit root and sidestep a nasty deadlock
215 * between reading the free space cache and updating the csum tree.
216 */
217 if (btrfs_is_free_space_inode(inode)) {
218 path->search_commit_root = 1;
219 path->skip_locking = 1;
220 }
221
222 disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
223 if (dio)
224 offset = logical_offset;
225
226 page_bytes_left = bvec->bv_len;
227 while (bio_index < bio->bi_vcnt) {
228 if (!dio)
229 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
230 count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
231 (u32 *)csum, nblocks);
232 if (count)
233 goto found;
234
235 if (!item || disk_bytenr < item_start_offset ||
236 disk_bytenr >= item_last_offset) {
237 struct btrfs_key found_key;
238 u32 item_size;
239
240 if (item)
241 btrfs_release_path(path);
242 item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
243 path, disk_bytenr, 0);
244 if (IS_ERR(item)) {
245 count = 1;
246 memset(csum, 0, csum_size);
247 if (BTRFS_I(inode)->root->root_key.objectid ==
248 BTRFS_DATA_RELOC_TREE_OBJECTID) {
249 set_extent_bits(io_tree, offset,
250 offset + root->sectorsize - 1,
251 EXTENT_NODATASUM, GFP_NOFS);
252 } else {
253 btrfs_info(BTRFS_I(inode)->root->fs_info,
254 "no csum found for inode %llu start %llu",
255 btrfs_ino(inode), offset);
256 }
257 item = NULL;
258 btrfs_release_path(path);
259 goto found;
260 }
261 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
262 path->slots[0]);
263
264 item_start_offset = found_key.offset;
265 item_size = btrfs_item_size_nr(path->nodes[0],
266 path->slots[0]);
267 item_last_offset = item_start_offset +
268 (item_size / csum_size) *
269 root->sectorsize;
270 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
271 struct btrfs_csum_item);
272 }
273 /*
274 * this byte range must be able to fit inside
275 * a single leaf so it will also fit inside a u32
276 */
277 diff = disk_bytenr - item_start_offset;
278 diff = diff / root->sectorsize;
279 diff = diff * csum_size;
280 count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >>
281 inode->i_sb->s_blocksize_bits);
282 read_extent_buffer(path->nodes[0], csum,
283 ((unsigned long)item) + diff,
284 csum_size * count);
285found:
286 csum += count * csum_size;
287 nblocks -= count;
288
289 while (count--) {
290 disk_bytenr += root->sectorsize;
291 offset += root->sectorsize;
292 page_bytes_left -= root->sectorsize;
293 if (!page_bytes_left) {
294 bio_index++;
295 /*
296 * make sure we're still inside the
297 * bio before we update page_bytes_left
298 */
299 if (bio_index >= bio->bi_vcnt) {
300 WARN_ON_ONCE(count);
301 goto done;
302 }
303 bvec++;
304 page_bytes_left = bvec->bv_len;
305 }
306
307 }
308 }
309
310done:
311 btrfs_free_path(path);
312 return 0;
313}
314
315int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
316 struct bio *bio, u32 *dst)
317{
318 return __btrfs_lookup_bio_sums(root, inode, bio, 0, dst, 0);
319}
320
321int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
322 struct bio *bio, u64 offset)
323{
324 return __btrfs_lookup_bio_sums(root, inode, bio, offset, NULL, 1);
325}
326
327int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
328 struct list_head *list, int search_commit)
329{
330 struct btrfs_key key;
331 struct btrfs_path *path;
332 struct extent_buffer *leaf;
333 struct btrfs_ordered_sum *sums;
334 struct btrfs_csum_item *item;
335 LIST_HEAD(tmplist);
336 unsigned long offset;
337 int ret;
338 size_t size;
339 u64 csum_end;
340 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
341
342 ASSERT(IS_ALIGNED(start, root->sectorsize) &&
343 IS_ALIGNED(end + 1, root->sectorsize));
344
345 path = btrfs_alloc_path();
346 if (!path)
347 return -ENOMEM;
348
349 if (search_commit) {
350 path->skip_locking = 1;
351 path->reada = READA_FORWARD;
352 path->search_commit_root = 1;
353 }
354
355 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
356 key.offset = start;
357 key.type = BTRFS_EXTENT_CSUM_KEY;
358
359 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
360 if (ret < 0)
361 goto fail;
362 if (ret > 0 && path->slots[0] > 0) {
363 leaf = path->nodes[0];
364 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
365 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
366 key.type == BTRFS_EXTENT_CSUM_KEY) {
367 offset = (start - key.offset) >>
368 root->fs_info->sb->s_blocksize_bits;
369 if (offset * csum_size <
370 btrfs_item_size_nr(leaf, path->slots[0] - 1))
371 path->slots[0]--;
372 }
373 }
374
375 while (start <= end) {
376 leaf = path->nodes[0];
377 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
378 ret = btrfs_next_leaf(root, path);
379 if (ret < 0)
380 goto fail;
381 if (ret > 0)
382 break;
383 leaf = path->nodes[0];
384 }
385
386 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
387 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
388 key.type != BTRFS_EXTENT_CSUM_KEY ||
389 key.offset > end)
390 break;
391
392 if (key.offset > start)
393 start = key.offset;
394
395 size = btrfs_item_size_nr(leaf, path->slots[0]);
396 csum_end = key.offset + (size / csum_size) * root->sectorsize;
397 if (csum_end <= start) {
398 path->slots[0]++;
399 continue;
400 }
401
402 csum_end = min(csum_end, end + 1);
403 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
404 struct btrfs_csum_item);
405 while (start < csum_end) {
406 size = min_t(size_t, csum_end - start,
407 MAX_ORDERED_SUM_BYTES(root));
408 sums = kzalloc(btrfs_ordered_sum_size(root, size),
409 GFP_NOFS);
410 if (!sums) {
411 ret = -ENOMEM;
412 goto fail;
413 }
414
415 sums->bytenr = start;
416 sums->len = (int)size;
417
418 offset = (start - key.offset) >>
419 root->fs_info->sb->s_blocksize_bits;
420 offset *= csum_size;
421 size >>= root->fs_info->sb->s_blocksize_bits;
422
423 read_extent_buffer(path->nodes[0],
424 sums->sums,
425 ((unsigned long)item) + offset,
426 csum_size * size);
427
428 start += root->sectorsize * size;
429 list_add_tail(&sums->list, &tmplist);
430 }
431 path->slots[0]++;
432 }
433 ret = 0;
434fail:
435 while (ret < 0 && !list_empty(&tmplist)) {
436 sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list);
437 list_del(&sums->list);
438 kfree(sums);
439 }
440 list_splice_tail(&tmplist, list);
441
442 btrfs_free_path(path);
443 return ret;
444}
445
446int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
447 struct bio *bio, u64 file_start, int contig)
448{
449 struct btrfs_ordered_sum *sums;
450 struct btrfs_ordered_extent *ordered;
451 char *data;
452 struct bio_vec *bvec = bio->bi_io_vec;
453 int bio_index = 0;
454 int index;
455 int nr_sectors;
456 int i;
457 unsigned long total_bytes = 0;
458 unsigned long this_sum_bytes = 0;
459 u64 offset;
460
461 WARN_ON(bio->bi_vcnt <= 0);
462 sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_iter.bi_size),
463 GFP_NOFS);
464 if (!sums)
465 return -ENOMEM;
466
467 sums->len = bio->bi_iter.bi_size;
468 INIT_LIST_HEAD(&sums->list);
469
470 if (contig)
471 offset = file_start;
472 else
473 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
474
475 ordered = btrfs_lookup_ordered_extent(inode, offset);
476 BUG_ON(!ordered); /* Logic error */
477 sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
478 index = 0;
479
480 while (bio_index < bio->bi_vcnt) {
481 if (!contig)
482 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
483
484 data = kmap_atomic(bvec->bv_page);
485
486 nr_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info,
487 bvec->bv_len + root->sectorsize
488 - 1);
489
490 for (i = 0; i < nr_sectors; i++) {
491 if (offset >= ordered->file_offset + ordered->len ||
492 offset < ordered->file_offset) {
493 unsigned long bytes_left;
494
495 kunmap_atomic(data);
496 sums->len = this_sum_bytes;
497 this_sum_bytes = 0;
498 btrfs_add_ordered_sum(inode, ordered, sums);
499 btrfs_put_ordered_extent(ordered);
500
501 bytes_left = bio->bi_iter.bi_size - total_bytes;
502
503 sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
504 GFP_NOFS);
505 BUG_ON(!sums); /* -ENOMEM */
506 sums->len = bytes_left;
507 ordered = btrfs_lookup_ordered_extent(inode,
508 offset);
509 ASSERT(ordered); /* Logic error */
510 sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9)
511 + total_bytes;
512 index = 0;
513
514 data = kmap_atomic(bvec->bv_page);
515 }
516
517 sums->sums[index] = ~(u32)0;
518 sums->sums[index]
519 = btrfs_csum_data(data + bvec->bv_offset
520 + (i * root->sectorsize),
521 sums->sums[index],
522 root->sectorsize);
523 btrfs_csum_final(sums->sums[index],
524 (char *)(sums->sums + index));
525 index++;
526 offset += root->sectorsize;
527 this_sum_bytes += root->sectorsize;
528 total_bytes += root->sectorsize;
529 }
530
531 kunmap_atomic(data);
532
533 bio_index++;
534 bvec++;
535 }
536 this_sum_bytes = 0;
537 btrfs_add_ordered_sum(inode, ordered, sums);
538 btrfs_put_ordered_extent(ordered);
539 return 0;
540}
541
542/*
543 * helper function for csum removal, this expects the
544 * key to describe the csum pointed to by the path, and it expects
545 * the csum to overlap the range [bytenr, len]
546 *
547 * The csum should not be entirely contained in the range and the
548 * range should not be entirely contained in the csum.
549 *
550 * This calls btrfs_truncate_item with the correct args based on the
551 * overlap, and fixes up the key as required.
552 */
553static noinline void truncate_one_csum(struct btrfs_root *root,
554 struct btrfs_path *path,
555 struct btrfs_key *key,
556 u64 bytenr, u64 len)
557{
558 struct extent_buffer *leaf;
559 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
560 u64 csum_end;
561 u64 end_byte = bytenr + len;
562 u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
563
564 leaf = path->nodes[0];
565 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
566 csum_end <<= root->fs_info->sb->s_blocksize_bits;
567 csum_end += key->offset;
568
569 if (key->offset < bytenr && csum_end <= end_byte) {
570 /*
571 * [ bytenr - len ]
572 * [ ]
573 * [csum ]
574 * A simple truncate off the end of the item
575 */
576 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
577 new_size *= csum_size;
578 btrfs_truncate_item(root, path, new_size, 1);
579 } else if (key->offset >= bytenr && csum_end > end_byte &&
580 end_byte > key->offset) {
581 /*
582 * [ bytenr - len ]
583 * [ ]
584 * [csum ]
585 * we need to truncate from the beginning of the csum
586 */
587 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
588 new_size *= csum_size;
589
590 btrfs_truncate_item(root, path, new_size, 0);
591
592 key->offset = end_byte;
593 btrfs_set_item_key_safe(root->fs_info, path, key);
594 } else {
595 BUG();
596 }
597}
598
599/*
600 * deletes the csum items from the csum tree for a given
601 * range of bytes.
602 */
603int btrfs_del_csums(struct btrfs_trans_handle *trans,
604 struct btrfs_root *root, u64 bytenr, u64 len)
605{
606 struct btrfs_path *path;
607 struct btrfs_key key;
608 u64 end_byte = bytenr + len;
609 u64 csum_end;
610 struct extent_buffer *leaf;
611 int ret;
612 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
613 int blocksize_bits = root->fs_info->sb->s_blocksize_bits;
614
615 root = root->fs_info->csum_root;
616
617 path = btrfs_alloc_path();
618 if (!path)
619 return -ENOMEM;
620
621 while (1) {
622 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
623 key.offset = end_byte - 1;
624 key.type = BTRFS_EXTENT_CSUM_KEY;
625
626 path->leave_spinning = 1;
627 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
628 if (ret > 0) {
629 if (path->slots[0] == 0)
630 break;
631 path->slots[0]--;
632 } else if (ret < 0) {
633 break;
634 }
635
636 leaf = path->nodes[0];
637 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
638
639 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
640 key.type != BTRFS_EXTENT_CSUM_KEY) {
641 break;
642 }
643
644 if (key.offset >= end_byte)
645 break;
646
647 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
648 csum_end <<= blocksize_bits;
649 csum_end += key.offset;
650
651 /* this csum ends before we start, we're done */
652 if (csum_end <= bytenr)
653 break;
654
655 /* delete the entire item, it is inside our range */
656 if (key.offset >= bytenr && csum_end <= end_byte) {
657 ret = btrfs_del_item(trans, root, path);
658 if (ret)
659 goto out;
660 if (key.offset == bytenr)
661 break;
662 } else if (key.offset < bytenr && csum_end > end_byte) {
663 unsigned long offset;
664 unsigned long shift_len;
665 unsigned long item_offset;
666 /*
667 * [ bytenr - len ]
668 * [csum ]
669 *
670 * Our bytes are in the middle of the csum,
671 * we need to split this item and insert a new one.
672 *
673 * But we can't drop the path because the
674 * csum could change, get removed, extended etc.
675 *
676 * The trick here is the max size of a csum item leaves
677 * enough room in the tree block for a single
678 * item header. So, we split the item in place,
679 * adding a new header pointing to the existing
680 * bytes. Then we loop around again and we have
681 * a nicely formed csum item that we can neatly
682 * truncate.
683 */
684 offset = (bytenr - key.offset) >> blocksize_bits;
685 offset *= csum_size;
686
687 shift_len = (len >> blocksize_bits) * csum_size;
688
689 item_offset = btrfs_item_ptr_offset(leaf,
690 path->slots[0]);
691
692 memset_extent_buffer(leaf, 0, item_offset + offset,
693 shift_len);
694 key.offset = bytenr;
695
696 /*
697 * btrfs_split_item returns -EAGAIN when the
698 * item changed size or key
699 */
700 ret = btrfs_split_item(trans, root, path, &key, offset);
701 if (ret && ret != -EAGAIN) {
702 btrfs_abort_transaction(trans, root, ret);
703 goto out;
704 }
705
706 key.offset = end_byte - 1;
707 } else {
708 truncate_one_csum(root, path, &key, bytenr, len);
709 if (key.offset < bytenr)
710 break;
711 }
712 btrfs_release_path(path);
713 }
714 ret = 0;
715out:
716 btrfs_free_path(path);
717 return ret;
718}
719
720int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
721 struct btrfs_root *root,
722 struct btrfs_ordered_sum *sums)
723{
724 struct btrfs_key file_key;
725 struct btrfs_key found_key;
726 struct btrfs_path *path;
727 struct btrfs_csum_item *item;
728 struct btrfs_csum_item *item_end;
729 struct extent_buffer *leaf = NULL;
730 u64 next_offset;
731 u64 total_bytes = 0;
732 u64 csum_offset;
733 u64 bytenr;
734 u32 nritems;
735 u32 ins_size;
736 int index = 0;
737 int found_next;
738 int ret;
739 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
740
741 path = btrfs_alloc_path();
742 if (!path)
743 return -ENOMEM;
744again:
745 next_offset = (u64)-1;
746 found_next = 0;
747 bytenr = sums->bytenr + total_bytes;
748 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
749 file_key.offset = bytenr;
750 file_key.type = BTRFS_EXTENT_CSUM_KEY;
751
752 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
753 if (!IS_ERR(item)) {
754 ret = 0;
755 leaf = path->nodes[0];
756 item_end = btrfs_item_ptr(leaf, path->slots[0],
757 struct btrfs_csum_item);
758 item_end = (struct btrfs_csum_item *)((char *)item_end +
759 btrfs_item_size_nr(leaf, path->slots[0]));
760 goto found;
761 }
762 ret = PTR_ERR(item);
763 if (ret != -EFBIG && ret != -ENOENT)
764 goto fail_unlock;
765
766 if (ret == -EFBIG) {
767 u32 item_size;
768 /* we found one, but it isn't big enough yet */
769 leaf = path->nodes[0];
770 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
771 if ((item_size / csum_size) >=
772 MAX_CSUM_ITEMS(root, csum_size)) {
773 /* already at max size, make a new one */
774 goto insert;
775 }
776 } else {
777 int slot = path->slots[0] + 1;
778 /* we didn't find a csum item, insert one */
779 nritems = btrfs_header_nritems(path->nodes[0]);
780 if (!nritems || (path->slots[0] >= nritems - 1)) {
781 ret = btrfs_next_leaf(root, path);
782 if (ret == 1)
783 found_next = 1;
784 if (ret != 0)
785 goto insert;
786 slot = path->slots[0];
787 }
788 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
789 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
790 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
791 found_next = 1;
792 goto insert;
793 }
794 next_offset = found_key.offset;
795 found_next = 1;
796 goto insert;
797 }
798
799 /*
800 * at this point, we know the tree has an item, but it isn't big
801 * enough yet to put our csum in. Grow it
802 */
803 btrfs_release_path(path);
804 ret = btrfs_search_slot(trans, root, &file_key, path,
805 csum_size, 1);
806 if (ret < 0)
807 goto fail_unlock;
808
809 if (ret > 0) {
810 if (path->slots[0] == 0)
811 goto insert;
812 path->slots[0]--;
813 }
814
815 leaf = path->nodes[0];
816 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
817 csum_offset = (bytenr - found_key.offset) >>
818 root->fs_info->sb->s_blocksize_bits;
819
820 if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
821 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
822 csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
823 goto insert;
824 }
825
826 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
827 csum_size) {
828 int extend_nr;
829 u64 tmp;
830 u32 diff;
831 u32 free_space;
832
833 if (btrfs_leaf_free_space(root, leaf) <
834 sizeof(struct btrfs_item) + csum_size * 2)
835 goto insert;
836
837 free_space = btrfs_leaf_free_space(root, leaf) -
838 sizeof(struct btrfs_item) - csum_size;
839 tmp = sums->len - total_bytes;
840 tmp >>= root->fs_info->sb->s_blocksize_bits;
841 WARN_ON(tmp < 1);
842
843 extend_nr = max_t(int, 1, (int)tmp);
844 diff = (csum_offset + extend_nr) * csum_size;
845 diff = min(diff, MAX_CSUM_ITEMS(root, csum_size) * csum_size);
846
847 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
848 diff = min(free_space, diff);
849 diff /= csum_size;
850 diff *= csum_size;
851
852 btrfs_extend_item(root, path, diff);
853 ret = 0;
854 goto csum;
855 }
856
857insert:
858 btrfs_release_path(path);
859 csum_offset = 0;
860 if (found_next) {
861 u64 tmp;
862
863 tmp = sums->len - total_bytes;
864 tmp >>= root->fs_info->sb->s_blocksize_bits;
865 tmp = min(tmp, (next_offset - file_key.offset) >>
866 root->fs_info->sb->s_blocksize_bits);
867
868 tmp = max((u64)1, tmp);
869 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
870 ins_size = csum_size * tmp;
871 } else {
872 ins_size = csum_size;
873 }
874 path->leave_spinning = 1;
875 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
876 ins_size);
877 path->leave_spinning = 0;
878 if (ret < 0)
879 goto fail_unlock;
880 if (WARN_ON(ret != 0))
881 goto fail_unlock;
882 leaf = path->nodes[0];
883csum:
884 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
885 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
886 btrfs_item_size_nr(leaf, path->slots[0]));
887 item = (struct btrfs_csum_item *)((unsigned char *)item +
888 csum_offset * csum_size);
889found:
890 ins_size = (u32)(sums->len - total_bytes) >>
891 root->fs_info->sb->s_blocksize_bits;
892 ins_size *= csum_size;
893 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
894 ins_size);
895 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
896 ins_size);
897
898 ins_size /= csum_size;
899 total_bytes += ins_size * root->sectorsize;
900 index += ins_size;
901
902 btrfs_mark_buffer_dirty(path->nodes[0]);
903 if (total_bytes < sums->len) {
904 btrfs_release_path(path);
905 cond_resched();
906 goto again;
907 }
908out:
909 btrfs_free_path(path);
910 return ret;
911
912fail_unlock:
913 goto out;
914}
915
916void btrfs_extent_item_to_extent_map(struct inode *inode,
917 const struct btrfs_path *path,
918 struct btrfs_file_extent_item *fi,
919 const bool new_inline,
920 struct extent_map *em)
921{
922 struct btrfs_root *root = BTRFS_I(inode)->root;
923 struct extent_buffer *leaf = path->nodes[0];
924 const int slot = path->slots[0];
925 struct btrfs_key key;
926 u64 extent_start, extent_end;
927 u64 bytenr;
928 u8 type = btrfs_file_extent_type(leaf, fi);
929 int compress_type = btrfs_file_extent_compression(leaf, fi);
930
931 em->bdev = root->fs_info->fs_devices->latest_bdev;
932 btrfs_item_key_to_cpu(leaf, &key, slot);
933 extent_start = key.offset;
934
935 if (type == BTRFS_FILE_EXTENT_REG ||
936 type == BTRFS_FILE_EXTENT_PREALLOC) {
937 extent_end = extent_start +
938 btrfs_file_extent_num_bytes(leaf, fi);
939 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
940 size_t size;
941 size = btrfs_file_extent_inline_len(leaf, slot, fi);
942 extent_end = ALIGN(extent_start + size, root->sectorsize);
943 }
944
945 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
946 if (type == BTRFS_FILE_EXTENT_REG ||
947 type == BTRFS_FILE_EXTENT_PREALLOC) {
948 em->start = extent_start;
949 em->len = extent_end - extent_start;
950 em->orig_start = extent_start -
951 btrfs_file_extent_offset(leaf, fi);
952 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
953 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
954 if (bytenr == 0) {
955 em->block_start = EXTENT_MAP_HOLE;
956 return;
957 }
958 if (compress_type != BTRFS_COMPRESS_NONE) {
959 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
960 em->compress_type = compress_type;
961 em->block_start = bytenr;
962 em->block_len = em->orig_block_len;
963 } else {
964 bytenr += btrfs_file_extent_offset(leaf, fi);
965 em->block_start = bytenr;
966 em->block_len = em->len;
967 if (type == BTRFS_FILE_EXTENT_PREALLOC)
968 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
969 }
970 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
971 em->block_start = EXTENT_MAP_INLINE;
972 em->start = extent_start;
973 em->len = extent_end - extent_start;
974 /*
975 * Initialize orig_start and block_len with the same values
976 * as in inode.c:btrfs_get_extent().
977 */
978 em->orig_start = EXTENT_MAP_HOLE;
979 em->block_len = (u64)-1;
980 if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) {
981 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
982 em->compress_type = compress_type;
983 }
984 } else {
985 btrfs_err(root->fs_info,
986 "unknown file extent item type %d, inode %llu, offset %llu, root %llu",
987 type, btrfs_ino(inode), extent_start,
988 root->root_key.objectid);
989 }
990}
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 struct btrfs_fs_info *fs_info = inode->root->fs_info;
49 u64 start, end, i_size;
50 int ret;
51
52 spin_lock(&inode->lock);
53 i_size = new_i_size ?: i_size_read(&inode->vfs_inode);
54 if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
55 inode->disk_i_size = i_size;
56 goto out_unlock;
57 }
58
59 ret = find_contiguous_extent_bit(inode->file_extent_tree, 0, &start,
60 &end, EXTENT_DIRTY);
61 if (!ret && start == 0)
62 i_size = min(i_size, end + 1);
63 else
64 i_size = 0;
65 inode->disk_i_size = i_size;
66out_unlock:
67 spin_unlock(&inode->lock);
68}
69
70/*
71 * Mark range within a file as having a new extent inserted.
72 *
73 * @inode: inode being modified
74 * @start: start file offset of the file extent we've inserted
75 * @len: logical length of the file extent item
76 *
77 * Call when we are inserting a new file extent where there was none before.
78 * Does not need to call this in the case where we're replacing an existing file
79 * extent, however if not sure it's fine to call this multiple times.
80 *
81 * The start and len must match the file extent item, so thus must be sectorsize
82 * aligned.
83 */
84int btrfs_inode_set_file_extent_range(struct btrfs_inode *inode, u64 start,
85 u64 len)
86{
87 if (len == 0)
88 return 0;
89
90 ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize));
91
92 if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES))
93 return 0;
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 (len == 0)
116 return 0;
117
118 ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize) ||
119 len == (u64)-1);
120
121 if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES))
122 return 0;
123 return clear_extent_bit(inode->file_extent_tree, start,
124 start + len - 1, EXTENT_DIRTY, NULL);
125}
126
127static size_t bytes_to_csum_size(const struct btrfs_fs_info *fs_info, u32 bytes)
128{
129 ASSERT(IS_ALIGNED(bytes, fs_info->sectorsize));
130
131 return (bytes >> fs_info->sectorsize_bits) * fs_info->csum_size;
132}
133
134static size_t csum_size_to_bytes(const struct btrfs_fs_info *fs_info, u32 csum_size)
135{
136 ASSERT(IS_ALIGNED(csum_size, fs_info->csum_size));
137
138 return (csum_size / fs_info->csum_size) << fs_info->sectorsize_bits;
139}
140
141static inline u32 max_ordered_sum_bytes(const struct btrfs_fs_info *fs_info)
142{
143 u32 max_csum_size = round_down(PAGE_SIZE - sizeof(struct btrfs_ordered_sum),
144 fs_info->csum_size);
145
146 return csum_size_to_bytes(fs_info, max_csum_size);
147}
148
149/*
150 * Calculate the total size needed to allocate for an ordered sum structure
151 * spanning @bytes in the file.
152 */
153static int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info, unsigned long bytes)
154{
155 return sizeof(struct btrfs_ordered_sum) + bytes_to_csum_size(fs_info, bytes);
156}
157
158int btrfs_insert_hole_extent(struct btrfs_trans_handle *trans,
159 struct btrfs_root *root,
160 u64 objectid, u64 pos, u64 num_bytes)
161{
162 int ret = 0;
163 struct btrfs_file_extent_item *item;
164 struct btrfs_key file_key;
165 struct btrfs_path *path;
166 struct extent_buffer *leaf;
167
168 path = btrfs_alloc_path();
169 if (!path)
170 return -ENOMEM;
171 file_key.objectid = objectid;
172 file_key.offset = pos;
173 file_key.type = BTRFS_EXTENT_DATA_KEY;
174
175 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
176 sizeof(*item));
177 if (ret < 0)
178 goto out;
179 leaf = path->nodes[0];
180 item = btrfs_item_ptr(leaf, path->slots[0],
181 struct btrfs_file_extent_item);
182 btrfs_set_file_extent_disk_bytenr(leaf, item, 0);
183 btrfs_set_file_extent_disk_num_bytes(leaf, item, 0);
184 btrfs_set_file_extent_offset(leaf, item, 0);
185 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
186 btrfs_set_file_extent_ram_bytes(leaf, item, num_bytes);
187 btrfs_set_file_extent_generation(leaf, item, trans->transid);
188 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
189 btrfs_set_file_extent_compression(leaf, item, 0);
190 btrfs_set_file_extent_encryption(leaf, item, 0);
191 btrfs_set_file_extent_other_encoding(leaf, item, 0);
192
193 btrfs_mark_buffer_dirty(trans, leaf);
194out:
195 btrfs_free_path(path);
196 return ret;
197}
198
199static struct btrfs_csum_item *
200btrfs_lookup_csum(struct btrfs_trans_handle *trans,
201 struct btrfs_root *root,
202 struct btrfs_path *path,
203 u64 bytenr, int cow)
204{
205 struct btrfs_fs_info *fs_info = root->fs_info;
206 int ret;
207 struct btrfs_key file_key;
208 struct btrfs_key found_key;
209 struct btrfs_csum_item *item;
210 struct extent_buffer *leaf;
211 u64 csum_offset = 0;
212 const u32 csum_size = fs_info->csum_size;
213 int csums_in_item;
214
215 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
216 file_key.offset = bytenr;
217 file_key.type = BTRFS_EXTENT_CSUM_KEY;
218 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
219 if (ret < 0)
220 goto fail;
221 leaf = path->nodes[0];
222 if (ret > 0) {
223 ret = 1;
224 if (path->slots[0] == 0)
225 goto fail;
226 path->slots[0]--;
227 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
228 if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
229 goto fail;
230
231 csum_offset = (bytenr - found_key.offset) >>
232 fs_info->sectorsize_bits;
233 csums_in_item = btrfs_item_size(leaf, path->slots[0]);
234 csums_in_item /= csum_size;
235
236 if (csum_offset == csums_in_item) {
237 ret = -EFBIG;
238 goto fail;
239 } else if (csum_offset > csums_in_item) {
240 goto fail;
241 }
242 }
243 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
244 item = (struct btrfs_csum_item *)((unsigned char *)item +
245 csum_offset * csum_size);
246 return item;
247fail:
248 if (ret > 0)
249 ret = -ENOENT;
250 return ERR_PTR(ret);
251}
252
253int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
254 struct btrfs_root *root,
255 struct btrfs_path *path, u64 objectid,
256 u64 offset, int mod)
257{
258 struct btrfs_key file_key;
259 int ins_len = mod < 0 ? -1 : 0;
260 int cow = mod != 0;
261
262 file_key.objectid = objectid;
263 file_key.offset = offset;
264 file_key.type = BTRFS_EXTENT_DATA_KEY;
265
266 return btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
267}
268
269/*
270 * Find checksums for logical bytenr range [disk_bytenr, disk_bytenr + len) and
271 * store the result to @dst.
272 *
273 * Return >0 for the number of sectors we found.
274 * Return 0 for the range [disk_bytenr, disk_bytenr + sectorsize) has no csum
275 * for it. Caller may want to try next sector until one range is hit.
276 * Return <0 for fatal error.
277 */
278static int search_csum_tree(struct btrfs_fs_info *fs_info,
279 struct btrfs_path *path, u64 disk_bytenr,
280 u64 len, u8 *dst)
281{
282 struct btrfs_root *csum_root;
283 struct btrfs_csum_item *item = NULL;
284 struct btrfs_key key;
285 const u32 sectorsize = fs_info->sectorsize;
286 const u32 csum_size = fs_info->csum_size;
287 u32 itemsize;
288 int ret;
289 u64 csum_start;
290 u64 csum_len;
291
292 ASSERT(IS_ALIGNED(disk_bytenr, sectorsize) &&
293 IS_ALIGNED(len, sectorsize));
294
295 /* Check if the current csum item covers disk_bytenr */
296 if (path->nodes[0]) {
297 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
298 struct btrfs_csum_item);
299 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
300 itemsize = btrfs_item_size(path->nodes[0], path->slots[0]);
301
302 csum_start = key.offset;
303 csum_len = (itemsize / csum_size) * sectorsize;
304
305 if (in_range(disk_bytenr, csum_start, csum_len))
306 goto found;
307 }
308
309 /* Current item doesn't contain the desired range, search again */
310 btrfs_release_path(path);
311 csum_root = btrfs_csum_root(fs_info, disk_bytenr);
312 item = btrfs_lookup_csum(NULL, csum_root, path, disk_bytenr, 0);
313 if (IS_ERR(item)) {
314 ret = PTR_ERR(item);
315 goto out;
316 }
317 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
318 itemsize = btrfs_item_size(path->nodes[0], path->slots[0]);
319
320 csum_start = key.offset;
321 csum_len = (itemsize / csum_size) * sectorsize;
322 ASSERT(in_range(disk_bytenr, csum_start, csum_len));
323
324found:
325 ret = (min(csum_start + csum_len, disk_bytenr + len) -
326 disk_bytenr) >> fs_info->sectorsize_bits;
327 read_extent_buffer(path->nodes[0], dst, (unsigned long)item,
328 ret * csum_size);
329out:
330 if (ret == -ENOENT || ret == -EFBIG)
331 ret = 0;
332 return ret;
333}
334
335/*
336 * Lookup the checksum for the read bio in csum tree.
337 *
338 * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
339 */
340blk_status_t btrfs_lookup_bio_sums(struct btrfs_bio *bbio)
341{
342 struct btrfs_inode *inode = bbio->inode;
343 struct btrfs_fs_info *fs_info = inode->root->fs_info;
344 struct bio *bio = &bbio->bio;
345 struct btrfs_path *path;
346 const u32 sectorsize = fs_info->sectorsize;
347 const u32 csum_size = fs_info->csum_size;
348 u32 orig_len = bio->bi_iter.bi_size;
349 u64 orig_disk_bytenr = bio->bi_iter.bi_sector << SECTOR_SHIFT;
350 const unsigned int nblocks = orig_len >> fs_info->sectorsize_bits;
351 blk_status_t ret = BLK_STS_OK;
352 u32 bio_offset = 0;
353
354 if ((inode->flags & BTRFS_INODE_NODATASUM) ||
355 test_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state))
356 return BLK_STS_OK;
357
358 /*
359 * This function is only called for read bio.
360 *
361 * This means two things:
362 * - All our csums should only be in csum tree
363 * No ordered extents csums, as ordered extents are only for write
364 * path.
365 * - No need to bother any other info from bvec
366 * Since we're looking up csums, the only important info is the
367 * disk_bytenr and the length, which can be extracted from bi_iter
368 * directly.
369 */
370 ASSERT(bio_op(bio) == REQ_OP_READ);
371 path = btrfs_alloc_path();
372 if (!path)
373 return BLK_STS_RESOURCE;
374
375 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
376 bbio->csum = kmalloc_array(nblocks, csum_size, GFP_NOFS);
377 if (!bbio->csum) {
378 btrfs_free_path(path);
379 return BLK_STS_RESOURCE;
380 }
381 } else {
382 bbio->csum = bbio->csum_inline;
383 }
384
385 /*
386 * If requested number of sectors is larger than one leaf can contain,
387 * kick the readahead for csum tree.
388 */
389 if (nblocks > fs_info->csums_per_leaf)
390 path->reada = READA_FORWARD;
391
392 /*
393 * the free space stuff is only read when it hasn't been
394 * updated in the current transaction. So, we can safely
395 * read from the commit root and sidestep a nasty deadlock
396 * between reading the free space cache and updating the csum tree.
397 */
398 if (btrfs_is_free_space_inode(inode)) {
399 path->search_commit_root = 1;
400 path->skip_locking = 1;
401 }
402
403 while (bio_offset < orig_len) {
404 int count;
405 u64 cur_disk_bytenr = orig_disk_bytenr + bio_offset;
406 u8 *csum_dst = bbio->csum +
407 (bio_offset >> fs_info->sectorsize_bits) * csum_size;
408
409 count = search_csum_tree(fs_info, path, cur_disk_bytenr,
410 orig_len - bio_offset, csum_dst);
411 if (count < 0) {
412 ret = errno_to_blk_status(count);
413 if (bbio->csum != bbio->csum_inline)
414 kfree(bbio->csum);
415 bbio->csum = NULL;
416 break;
417 }
418
419 /*
420 * We didn't find a csum for this range. We need to make sure
421 * we complain loudly about this, because we are not NODATASUM.
422 *
423 * However for the DATA_RELOC inode we could potentially be
424 * relocating data extents for a NODATASUM inode, so the inode
425 * itself won't be marked with NODATASUM, but the extent we're
426 * copying is in fact NODATASUM. If we don't find a csum we
427 * assume this is the case.
428 */
429 if (count == 0) {
430 memset(csum_dst, 0, csum_size);
431 count = 1;
432
433 if (inode->root->root_key.objectid ==
434 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
453int btrfs_lookup_csums_list(struct btrfs_root *root, u64 start, u64 end,
454 struct list_head *list, int search_commit,
455 bool nowait)
456{
457 struct btrfs_fs_info *fs_info = root->fs_info;
458 struct btrfs_key key;
459 struct btrfs_path *path;
460 struct extent_buffer *leaf;
461 struct btrfs_ordered_sum *sums;
462 struct btrfs_csum_item *item;
463 LIST_HEAD(tmplist);
464 int ret;
465
466 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
467 IS_ALIGNED(end + 1, fs_info->sectorsize));
468
469 path = btrfs_alloc_path();
470 if (!path)
471 return -ENOMEM;
472
473 path->nowait = nowait;
474 if (search_commit) {
475 path->skip_locking = 1;
476 path->reada = READA_FORWARD;
477 path->search_commit_root = 1;
478 }
479
480 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
481 key.offset = start;
482 key.type = BTRFS_EXTENT_CSUM_KEY;
483
484 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
485 if (ret < 0)
486 goto fail;
487 if (ret > 0 && path->slots[0] > 0) {
488 leaf = path->nodes[0];
489 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
490
491 /*
492 * There are two cases we can hit here for the previous csum
493 * item:
494 *
495 * |<- search range ->|
496 * |<- csum item ->|
497 *
498 * Or
499 * |<- search range ->|
500 * |<- csum item ->|
501 *
502 * Check if the previous csum item covers the leading part of
503 * the search range. If so we have to start from previous csum
504 * item.
505 */
506 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
507 key.type == BTRFS_EXTENT_CSUM_KEY) {
508 if (bytes_to_csum_size(fs_info, start - key.offset) <
509 btrfs_item_size(leaf, path->slots[0] - 1))
510 path->slots[0]--;
511 }
512 }
513
514 while (start <= end) {
515 u64 csum_end;
516
517 leaf = path->nodes[0];
518 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
519 ret = btrfs_next_leaf(root, path);
520 if (ret < 0)
521 goto fail;
522 if (ret > 0)
523 break;
524 leaf = path->nodes[0];
525 }
526
527 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
528 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
529 key.type != BTRFS_EXTENT_CSUM_KEY ||
530 key.offset > end)
531 break;
532
533 if (key.offset > start)
534 start = key.offset;
535
536 csum_end = key.offset + csum_size_to_bytes(fs_info,
537 btrfs_item_size(leaf, path->slots[0]));
538 if (csum_end <= start) {
539 path->slots[0]++;
540 continue;
541 }
542
543 csum_end = min(csum_end, end + 1);
544 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
545 struct btrfs_csum_item);
546 while (start < csum_end) {
547 unsigned long offset;
548 size_t size;
549
550 size = min_t(size_t, csum_end - start,
551 max_ordered_sum_bytes(fs_info));
552 sums = kzalloc(btrfs_ordered_sum_size(fs_info, size),
553 GFP_NOFS);
554 if (!sums) {
555 ret = -ENOMEM;
556 goto fail;
557 }
558
559 sums->logical = start;
560 sums->len = size;
561
562 offset = bytes_to_csum_size(fs_info, start - key.offset);
563
564 read_extent_buffer(path->nodes[0],
565 sums->sums,
566 ((unsigned long)item) + offset,
567 bytes_to_csum_size(fs_info, size));
568
569 start += size;
570 list_add_tail(&sums->list, &tmplist);
571 }
572 path->slots[0]++;
573 }
574 ret = 0;
575fail:
576 while (ret < 0 && !list_empty(&tmplist)) {
577 sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list);
578 list_del(&sums->list);
579 kfree(sums);
580 }
581 list_splice_tail(&tmplist, list);
582
583 btrfs_free_path(path);
584 return ret;
585}
586
587/*
588 * Do the same work as btrfs_lookup_csums_list(), the difference is in how
589 * we return the result.
590 *
591 * This version will set the corresponding bits in @csum_bitmap to represent
592 * that there is a csum found.
593 * Each bit represents a sector. Thus caller should ensure @csum_buf passed
594 * in is large enough to contain all csums.
595 */
596int btrfs_lookup_csums_bitmap(struct btrfs_root *root, struct btrfs_path *path,
597 u64 start, u64 end, u8 *csum_buf,
598 unsigned long *csum_bitmap)
599{
600 struct btrfs_fs_info *fs_info = root->fs_info;
601 struct btrfs_key key;
602 struct extent_buffer *leaf;
603 struct btrfs_csum_item *item;
604 const u64 orig_start = start;
605 bool free_path = false;
606 int ret;
607
608 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
609 IS_ALIGNED(end + 1, fs_info->sectorsize));
610
611 if (!path) {
612 path = btrfs_alloc_path();
613 if (!path)
614 return -ENOMEM;
615 free_path = true;
616 }
617
618 /* Check if we can reuse the previous path. */
619 if (path->nodes[0]) {
620 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
621
622 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
623 key.type == BTRFS_EXTENT_CSUM_KEY &&
624 key.offset <= start)
625 goto search_forward;
626 btrfs_release_path(path);
627 }
628
629 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
630 key.type = BTRFS_EXTENT_CSUM_KEY;
631 key.offset = start;
632
633 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
634 if (ret < 0)
635 goto fail;
636 if (ret > 0 && path->slots[0] > 0) {
637 leaf = path->nodes[0];
638 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
639
640 /*
641 * There are two cases we can hit here for the previous csum
642 * item:
643 *
644 * |<- search range ->|
645 * |<- csum item ->|
646 *
647 * Or
648 * |<- search range ->|
649 * |<- csum item ->|
650 *
651 * Check if the previous csum item covers the leading part of
652 * the search range. If so we have to start from previous csum
653 * item.
654 */
655 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
656 key.type == BTRFS_EXTENT_CSUM_KEY) {
657 if (bytes_to_csum_size(fs_info, start - key.offset) <
658 btrfs_item_size(leaf, path->slots[0] - 1))
659 path->slots[0]--;
660 }
661 }
662
663search_forward:
664 while (start <= end) {
665 u64 csum_end;
666
667 leaf = path->nodes[0];
668 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
669 ret = btrfs_next_leaf(root, path);
670 if (ret < 0)
671 goto fail;
672 if (ret > 0)
673 break;
674 leaf = path->nodes[0];
675 }
676
677 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
678 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
679 key.type != BTRFS_EXTENT_CSUM_KEY ||
680 key.offset > end)
681 break;
682
683 if (key.offset > start)
684 start = key.offset;
685
686 csum_end = key.offset + csum_size_to_bytes(fs_info,
687 btrfs_item_size(leaf, path->slots[0]));
688 if (csum_end <= start) {
689 path->slots[0]++;
690 continue;
691 }
692
693 csum_end = min(csum_end, end + 1);
694 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
695 struct btrfs_csum_item);
696 while (start < csum_end) {
697 unsigned long offset;
698 size_t size;
699 u8 *csum_dest = csum_buf + bytes_to_csum_size(fs_info,
700 start - orig_start);
701
702 size = min_t(size_t, csum_end - start, end + 1 - start);
703
704 offset = bytes_to_csum_size(fs_info, start - key.offset);
705
706 read_extent_buffer(path->nodes[0], csum_dest,
707 ((unsigned long)item) + offset,
708 bytes_to_csum_size(fs_info, size));
709
710 bitmap_set(csum_bitmap,
711 (start - orig_start) >> fs_info->sectorsize_bits,
712 size >> fs_info->sectorsize_bits);
713
714 start += size;
715 }
716 path->slots[0]++;
717 }
718 ret = 0;
719fail:
720 if (free_path)
721 btrfs_free_path(path);
722 return ret;
723}
724
725/*
726 * Calculate checksums of the data contained inside a bio.
727 */
728blk_status_t btrfs_csum_one_bio(struct btrfs_bio *bbio)
729{
730 struct btrfs_ordered_extent *ordered = bbio->ordered;
731 struct btrfs_inode *inode = bbio->inode;
732 struct btrfs_fs_info *fs_info = inode->root->fs_info;
733 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
734 struct bio *bio = &bbio->bio;
735 struct btrfs_ordered_sum *sums;
736 char *data;
737 struct bvec_iter iter;
738 struct bio_vec bvec;
739 int index;
740 unsigned int blockcount;
741 int i;
742 unsigned nofs_flag;
743
744 nofs_flag = memalloc_nofs_save();
745 sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
746 GFP_KERNEL);
747 memalloc_nofs_restore(nofs_flag);
748
749 if (!sums)
750 return BLK_STS_RESOURCE;
751
752 sums->len = bio->bi_iter.bi_size;
753 INIT_LIST_HEAD(&sums->list);
754
755 sums->logical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
756 index = 0;
757
758 shash->tfm = fs_info->csum_shash;
759
760 bio_for_each_segment(bvec, bio, iter) {
761 blockcount = BTRFS_BYTES_TO_BLKS(fs_info,
762 bvec.bv_len + fs_info->sectorsize
763 - 1);
764
765 for (i = 0; i < blockcount; i++) {
766 data = bvec_kmap_local(&bvec);
767 crypto_shash_digest(shash,
768 data + (i * fs_info->sectorsize),
769 fs_info->sectorsize,
770 sums->sums + index);
771 kunmap_local(data);
772 index += fs_info->csum_size;
773 }
774
775 }
776
777 bbio->sums = sums;
778 btrfs_add_ordered_sum(ordered, sums);
779 return 0;
780}
781
782/*
783 * Nodatasum I/O on zoned file systems still requires an btrfs_ordered_sum to
784 * record the updated logical address on Zone Append completion.
785 * Allocate just the structure with an empty sums array here for that case.
786 */
787blk_status_t btrfs_alloc_dummy_sum(struct btrfs_bio *bbio)
788{
789 bbio->sums = kmalloc(sizeof(*bbio->sums), GFP_NOFS);
790 if (!bbio->sums)
791 return BLK_STS_RESOURCE;
792 bbio->sums->len = bbio->bio.bi_iter.bi_size;
793 bbio->sums->logical = bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT;
794 btrfs_add_ordered_sum(bbio->ordered, bbio->sums);
795 return 0;
796}
797
798/*
799 * Remove one checksum overlapping a range.
800 *
801 * This expects the key to describe the csum pointed to by the path, and it
802 * expects the csum to overlap the range [bytenr, len]
803 *
804 * The csum should not be entirely contained in the range and the range should
805 * not be entirely contained in the csum.
806 *
807 * This calls btrfs_truncate_item with the correct args based on the overlap,
808 * and fixes up the key as required.
809 */
810static noinline void truncate_one_csum(struct btrfs_trans_handle *trans,
811 struct btrfs_path *path,
812 struct btrfs_key *key,
813 u64 bytenr, u64 len)
814{
815 struct btrfs_fs_info *fs_info = trans->fs_info;
816 struct extent_buffer *leaf;
817 const u32 csum_size = fs_info->csum_size;
818 u64 csum_end;
819 u64 end_byte = bytenr + len;
820 u32 blocksize_bits = fs_info->sectorsize_bits;
821
822 leaf = path->nodes[0];
823 csum_end = btrfs_item_size(leaf, path->slots[0]) / csum_size;
824 csum_end <<= blocksize_bits;
825 csum_end += key->offset;
826
827 if (key->offset < bytenr && csum_end <= end_byte) {
828 /*
829 * [ bytenr - len ]
830 * [ ]
831 * [csum ]
832 * A simple truncate off the end of the item
833 */
834 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
835 new_size *= csum_size;
836 btrfs_truncate_item(trans, path, new_size, 1);
837 } else if (key->offset >= bytenr && csum_end > end_byte &&
838 end_byte > key->offset) {
839 /*
840 * [ bytenr - len ]
841 * [ ]
842 * [csum ]
843 * we need to truncate from the beginning of the csum
844 */
845 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
846 new_size *= csum_size;
847
848 btrfs_truncate_item(trans, path, new_size, 0);
849
850 key->offset = end_byte;
851 btrfs_set_item_key_safe(trans, path, key);
852 } else {
853 BUG();
854 }
855}
856
857/*
858 * Delete the csum items from the csum tree for a given range of bytes.
859 */
860int btrfs_del_csums(struct btrfs_trans_handle *trans,
861 struct btrfs_root *root, u64 bytenr, u64 len)
862{
863 struct btrfs_fs_info *fs_info = trans->fs_info;
864 struct btrfs_path *path;
865 struct btrfs_key key;
866 u64 end_byte = bytenr + len;
867 u64 csum_end;
868 struct extent_buffer *leaf;
869 int ret = 0;
870 const u32 csum_size = fs_info->csum_size;
871 u32 blocksize_bits = fs_info->sectorsize_bits;
872
873 ASSERT(root->root_key.objectid == BTRFS_CSUM_TREE_OBJECTID ||
874 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
875
876 path = btrfs_alloc_path();
877 if (!path)
878 return -ENOMEM;
879
880 while (1) {
881 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
882 key.offset = end_byte - 1;
883 key.type = BTRFS_EXTENT_CSUM_KEY;
884
885 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
886 if (ret > 0) {
887 ret = 0;
888 if (path->slots[0] == 0)
889 break;
890 path->slots[0]--;
891 } else if (ret < 0) {
892 break;
893 }
894
895 leaf = path->nodes[0];
896 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
897
898 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
899 key.type != BTRFS_EXTENT_CSUM_KEY) {
900 break;
901 }
902
903 if (key.offset >= end_byte)
904 break;
905
906 csum_end = btrfs_item_size(leaf, path->slots[0]) / csum_size;
907 csum_end <<= blocksize_bits;
908 csum_end += key.offset;
909
910 /* this csum ends before we start, we're done */
911 if (csum_end <= bytenr)
912 break;
913
914 /* delete the entire item, it is inside our range */
915 if (key.offset >= bytenr && csum_end <= end_byte) {
916 int del_nr = 1;
917
918 /*
919 * Check how many csum items preceding this one in this
920 * leaf correspond to our range and then delete them all
921 * at once.
922 */
923 if (key.offset > bytenr && path->slots[0] > 0) {
924 int slot = path->slots[0] - 1;
925
926 while (slot >= 0) {
927 struct btrfs_key pk;
928
929 btrfs_item_key_to_cpu(leaf, &pk, slot);
930 if (pk.offset < bytenr ||
931 pk.type != BTRFS_EXTENT_CSUM_KEY ||
932 pk.objectid !=
933 BTRFS_EXTENT_CSUM_OBJECTID)
934 break;
935 path->slots[0] = slot;
936 del_nr++;
937 key.offset = pk.offset;
938 slot--;
939 }
940 }
941 ret = btrfs_del_items(trans, root, path,
942 path->slots[0], del_nr);
943 if (ret)
944 break;
945 if (key.offset == bytenr)
946 break;
947 } else if (key.offset < bytenr && csum_end > end_byte) {
948 unsigned long offset;
949 unsigned long shift_len;
950 unsigned long item_offset;
951 /*
952 * [ bytenr - len ]
953 * [csum ]
954 *
955 * Our bytes are in the middle of the csum,
956 * we need to split this item and insert a new one.
957 *
958 * But we can't drop the path because the
959 * csum could change, get removed, extended etc.
960 *
961 * The trick here is the max size of a csum item leaves
962 * enough room in the tree block for a single
963 * item header. So, we split the item in place,
964 * adding a new header pointing to the existing
965 * bytes. Then we loop around again and we have
966 * a nicely formed csum item that we can neatly
967 * truncate.
968 */
969 offset = (bytenr - key.offset) >> blocksize_bits;
970 offset *= csum_size;
971
972 shift_len = (len >> blocksize_bits) * csum_size;
973
974 item_offset = btrfs_item_ptr_offset(leaf,
975 path->slots[0]);
976
977 memzero_extent_buffer(leaf, item_offset + offset,
978 shift_len);
979 key.offset = bytenr;
980
981 /*
982 * btrfs_split_item returns -EAGAIN when the
983 * item changed size or key
984 */
985 ret = btrfs_split_item(trans, root, path, &key, offset);
986 if (ret && ret != -EAGAIN) {
987 btrfs_abort_transaction(trans, ret);
988 break;
989 }
990 ret = 0;
991
992 key.offset = end_byte - 1;
993 } else {
994 truncate_one_csum(trans, path, &key, bytenr, len);
995 if (key.offset < bytenr)
996 break;
997 }
998 btrfs_release_path(path);
999 }
1000 btrfs_free_path(path);
1001 return ret;
1002}
1003
1004static int find_next_csum_offset(struct btrfs_root *root,
1005 struct btrfs_path *path,
1006 u64 *next_offset)
1007{
1008 const u32 nritems = btrfs_header_nritems(path->nodes[0]);
1009 struct btrfs_key found_key;
1010 int slot = path->slots[0] + 1;
1011 int ret;
1012
1013 if (nritems == 0 || slot >= nritems) {
1014 ret = btrfs_next_leaf(root, path);
1015 if (ret < 0) {
1016 return ret;
1017 } else if (ret > 0) {
1018 *next_offset = (u64)-1;
1019 return 0;
1020 }
1021 slot = path->slots[0];
1022 }
1023
1024 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
1025
1026 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
1027 found_key.type != BTRFS_EXTENT_CSUM_KEY)
1028 *next_offset = (u64)-1;
1029 else
1030 *next_offset = found_key.offset;
1031
1032 return 0;
1033}
1034
1035int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
1036 struct btrfs_root *root,
1037 struct btrfs_ordered_sum *sums)
1038{
1039 struct btrfs_fs_info *fs_info = root->fs_info;
1040 struct btrfs_key file_key;
1041 struct btrfs_key found_key;
1042 struct btrfs_path *path;
1043 struct btrfs_csum_item *item;
1044 struct btrfs_csum_item *item_end;
1045 struct extent_buffer *leaf = NULL;
1046 u64 next_offset;
1047 u64 total_bytes = 0;
1048 u64 csum_offset;
1049 u64 bytenr;
1050 u32 ins_size;
1051 int index = 0;
1052 int found_next;
1053 int ret;
1054 const u32 csum_size = fs_info->csum_size;
1055
1056 path = btrfs_alloc_path();
1057 if (!path)
1058 return -ENOMEM;
1059again:
1060 next_offset = (u64)-1;
1061 found_next = 0;
1062 bytenr = sums->logical + total_bytes;
1063 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
1064 file_key.offset = bytenr;
1065 file_key.type = BTRFS_EXTENT_CSUM_KEY;
1066
1067 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
1068 if (!IS_ERR(item)) {
1069 ret = 0;
1070 leaf = path->nodes[0];
1071 item_end = btrfs_item_ptr(leaf, path->slots[0],
1072 struct btrfs_csum_item);
1073 item_end = (struct btrfs_csum_item *)((char *)item_end +
1074 btrfs_item_size(leaf, path->slots[0]));
1075 goto found;
1076 }
1077 ret = PTR_ERR(item);
1078 if (ret != -EFBIG && ret != -ENOENT)
1079 goto out;
1080
1081 if (ret == -EFBIG) {
1082 u32 item_size;
1083 /* we found one, but it isn't big enough yet */
1084 leaf = path->nodes[0];
1085 item_size = btrfs_item_size(leaf, path->slots[0]);
1086 if ((item_size / csum_size) >=
1087 MAX_CSUM_ITEMS(fs_info, csum_size)) {
1088 /* already at max size, make a new one */
1089 goto insert;
1090 }
1091 } else {
1092 /* We didn't find a csum item, insert one. */
1093 ret = find_next_csum_offset(root, path, &next_offset);
1094 if (ret < 0)
1095 goto out;
1096 found_next = 1;
1097 goto insert;
1098 }
1099
1100 /*
1101 * At this point, we know the tree has a checksum item that ends at an
1102 * offset matching the start of the checksum range we want to insert.
1103 * We try to extend that item as much as possible and then add as many
1104 * checksums to it as they fit.
1105 *
1106 * First check if the leaf has enough free space for at least one
1107 * checksum. If it has go directly to the item extension code, otherwise
1108 * release the path and do a search for insertion before the extension.
1109 */
1110 if (btrfs_leaf_free_space(leaf) >= csum_size) {
1111 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1112 csum_offset = (bytenr - found_key.offset) >>
1113 fs_info->sectorsize_bits;
1114 goto extend_csum;
1115 }
1116
1117 btrfs_release_path(path);
1118 path->search_for_extension = 1;
1119 ret = btrfs_search_slot(trans, root, &file_key, path,
1120 csum_size, 1);
1121 path->search_for_extension = 0;
1122 if (ret < 0)
1123 goto out;
1124
1125 if (ret > 0) {
1126 if (path->slots[0] == 0)
1127 goto insert;
1128 path->slots[0]--;
1129 }
1130
1131 leaf = path->nodes[0];
1132 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1133 csum_offset = (bytenr - found_key.offset) >> fs_info->sectorsize_bits;
1134
1135 if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
1136 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
1137 csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
1138 goto insert;
1139 }
1140
1141extend_csum:
1142 if (csum_offset == btrfs_item_size(leaf, path->slots[0]) /
1143 csum_size) {
1144 int extend_nr;
1145 u64 tmp;
1146 u32 diff;
1147
1148 tmp = sums->len - total_bytes;
1149 tmp >>= fs_info->sectorsize_bits;
1150 WARN_ON(tmp < 1);
1151 extend_nr = max_t(int, 1, tmp);
1152
1153 /*
1154 * A log tree can already have checksum items with a subset of
1155 * the checksums we are trying to log. This can happen after
1156 * doing a sequence of partial writes into prealloc extents and
1157 * fsyncs in between, with a full fsync logging a larger subrange
1158 * of an extent for which a previous fast fsync logged a smaller
1159 * subrange. And this happens in particular due to merging file
1160 * extent items when we complete an ordered extent for a range
1161 * covered by a prealloc extent - this is done at
1162 * btrfs_mark_extent_written().
1163 *
1164 * So if we try to extend the previous checksum item, which has
1165 * a range that ends at the start of the range we want to insert,
1166 * make sure we don't extend beyond the start offset of the next
1167 * checksum item. If we are at the last item in the leaf, then
1168 * forget the optimization of extending and add a new checksum
1169 * item - it is not worth the complexity of releasing the path,
1170 * getting the first key for the next leaf, repeat the btree
1171 * search, etc, because log trees are temporary anyway and it
1172 * would only save a few bytes of leaf space.
1173 */
1174 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
1175 if (path->slots[0] + 1 >=
1176 btrfs_header_nritems(path->nodes[0])) {
1177 ret = find_next_csum_offset(root, path, &next_offset);
1178 if (ret < 0)
1179 goto out;
1180 found_next = 1;
1181 goto insert;
1182 }
1183
1184 ret = find_next_csum_offset(root, path, &next_offset);
1185 if (ret < 0)
1186 goto out;
1187
1188 tmp = (next_offset - bytenr) >> fs_info->sectorsize_bits;
1189 if (tmp <= INT_MAX)
1190 extend_nr = min_t(int, extend_nr, tmp);
1191 }
1192
1193 diff = (csum_offset + extend_nr) * csum_size;
1194 diff = min(diff,
1195 MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
1196
1197 diff = diff - btrfs_item_size(leaf, path->slots[0]);
1198 diff = min_t(u32, btrfs_leaf_free_space(leaf), diff);
1199 diff /= csum_size;
1200 diff *= csum_size;
1201
1202 btrfs_extend_item(trans, path, diff);
1203 ret = 0;
1204 goto csum;
1205 }
1206
1207insert:
1208 btrfs_release_path(path);
1209 csum_offset = 0;
1210 if (found_next) {
1211 u64 tmp;
1212
1213 tmp = sums->len - total_bytes;
1214 tmp >>= fs_info->sectorsize_bits;
1215 tmp = min(tmp, (next_offset - file_key.offset) >>
1216 fs_info->sectorsize_bits);
1217
1218 tmp = max_t(u64, 1, tmp);
1219 tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
1220 ins_size = csum_size * tmp;
1221 } else {
1222 ins_size = csum_size;
1223 }
1224 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
1225 ins_size);
1226 if (ret < 0)
1227 goto out;
1228 leaf = path->nodes[0];
1229csum:
1230 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
1231 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
1232 btrfs_item_size(leaf, path->slots[0]));
1233 item = (struct btrfs_csum_item *)((unsigned char *)item +
1234 csum_offset * csum_size);
1235found:
1236 ins_size = (u32)(sums->len - total_bytes) >> fs_info->sectorsize_bits;
1237 ins_size *= csum_size;
1238 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
1239 ins_size);
1240 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
1241 ins_size);
1242
1243 index += ins_size;
1244 ins_size /= csum_size;
1245 total_bytes += ins_size * fs_info->sectorsize;
1246
1247 btrfs_mark_buffer_dirty(trans, path->nodes[0]);
1248 if (total_bytes < sums->len) {
1249 btrfs_release_path(path);
1250 cond_resched();
1251 goto again;
1252 }
1253out:
1254 btrfs_free_path(path);
1255 return ret;
1256}
1257
1258void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
1259 const struct btrfs_path *path,
1260 struct btrfs_file_extent_item *fi,
1261 struct extent_map *em)
1262{
1263 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1264 struct btrfs_root *root = inode->root;
1265 struct extent_buffer *leaf = path->nodes[0];
1266 const int slot = path->slots[0];
1267 struct btrfs_key key;
1268 u64 extent_start, extent_end;
1269 u64 bytenr;
1270 u8 type = btrfs_file_extent_type(leaf, fi);
1271 int compress_type = btrfs_file_extent_compression(leaf, fi);
1272
1273 btrfs_item_key_to_cpu(leaf, &key, slot);
1274 extent_start = key.offset;
1275 extent_end = btrfs_file_extent_end(path);
1276 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1277 em->generation = btrfs_file_extent_generation(leaf, fi);
1278 if (type == BTRFS_FILE_EXTENT_REG ||
1279 type == BTRFS_FILE_EXTENT_PREALLOC) {
1280 em->start = extent_start;
1281 em->len = extent_end - extent_start;
1282 em->orig_start = extent_start -
1283 btrfs_file_extent_offset(leaf, fi);
1284 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
1285 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1286 if (bytenr == 0) {
1287 em->block_start = EXTENT_MAP_HOLE;
1288 return;
1289 }
1290 if (compress_type != BTRFS_COMPRESS_NONE) {
1291 extent_map_set_compression(em, compress_type);
1292 em->block_start = bytenr;
1293 em->block_len = em->orig_block_len;
1294 } else {
1295 bytenr += btrfs_file_extent_offset(leaf, fi);
1296 em->block_start = bytenr;
1297 em->block_len = em->len;
1298 if (type == BTRFS_FILE_EXTENT_PREALLOC)
1299 em->flags |= EXTENT_FLAG_PREALLOC;
1300 }
1301 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1302 em->block_start = EXTENT_MAP_INLINE;
1303 em->start = extent_start;
1304 em->len = extent_end - extent_start;
1305 /*
1306 * Initialize orig_start and block_len with the same values
1307 * as in inode.c:btrfs_get_extent().
1308 */
1309 em->orig_start = EXTENT_MAP_HOLE;
1310 em->block_len = (u64)-1;
1311 extent_map_set_compression(em, compress_type);
1312 } else {
1313 btrfs_err(fs_info,
1314 "unknown file extent item type %d, inode %llu, offset %llu, "
1315 "root %llu", type, btrfs_ino(inode), extent_start,
1316 root->root_key.objectid);
1317 }
1318}
1319
1320/*
1321 * Returns the end offset (non inclusive) of the file extent item the given path
1322 * points to. If it points to an inline extent, the returned offset is rounded
1323 * up to the sector size.
1324 */
1325u64 btrfs_file_extent_end(const struct btrfs_path *path)
1326{
1327 const struct extent_buffer *leaf = path->nodes[0];
1328 const int slot = path->slots[0];
1329 struct btrfs_file_extent_item *fi;
1330 struct btrfs_key key;
1331 u64 end;
1332
1333 btrfs_item_key_to_cpu(leaf, &key, slot);
1334 ASSERT(key.type == BTRFS_EXTENT_DATA_KEY);
1335 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1336
1337 if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
1338 end = btrfs_file_extent_ram_bytes(leaf, fi);
1339 end = ALIGN(key.offset + end, leaf->fs_info->sectorsize);
1340 } else {
1341 end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1342 }
1343
1344 return end;
1345}