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