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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 "messages.h"
13#include "misc.h"
14#include "ctree.h"
15#include "disk-io.h"
16#include "transaction.h"
17#include "bio.h"
18#include "print-tree.h"
19#include "compression.h"
20#include "fs.h"
21#include "accessors.h"
22#include "file-item.h"
23#include "super.h"
24
25#define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
26 sizeof(struct btrfs_item) * 2) / \
27 size) - 1))
28
29#define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
30 PAGE_SIZE))
31
32/*
33 * Set inode's size according to filesystem options.
34 *
35 * @inode: inode we want to update the disk_i_size for
36 * @new_i_size: i_size we want to set to, 0 if we use i_size
37 *
38 * With NO_HOLES set this simply sets the disk_is_size to whatever i_size_read()
39 * returns as it is perfectly fine with a file that has holes without hole file
40 * extent items.
41 *
42 * However without NO_HOLES we need to only return the area that is contiguous
43 * from the 0 offset of the file. Otherwise we could end up adjust i_size up
44 * to an extent that has a gap in between.
45 *
46 * Finally new_i_size should only be set in the case of truncate where we're not
47 * ready to use i_size_read() as the limiter yet.
48 */
49void btrfs_inode_safe_disk_i_size_write(struct btrfs_inode *inode, u64 new_i_size)
50{
51 struct btrfs_fs_info *fs_info = inode->root->fs_info;
52 u64 start, end, i_size;
53 int ret;
54
55 i_size = new_i_size ?: i_size_read(&inode->vfs_inode);
56 if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
57 inode->disk_i_size = i_size;
58 return;
59 }
60
61 spin_lock(&inode->lock);
62 ret = find_contiguous_extent_bit(&inode->file_extent_tree, 0, &start,
63 &end, EXTENT_DIRTY);
64 if (!ret && start == 0)
65 i_size = min(i_size, end + 1);
66 else
67 i_size = 0;
68 inode->disk_i_size = i_size;
69 spin_unlock(&inode->lock);
70}
71
72/*
73 * Mark range within a file as having a new extent inserted.
74 *
75 * @inode: inode being modified
76 * @start: start file offset of the file extent we've inserted
77 * @len: logical length of the file extent item
78 *
79 * Call when we are inserting a new file extent where there was none before.
80 * Does not need to call this in the case where we're replacing an existing file
81 * extent, however if not sure it's fine to call this multiple times.
82 *
83 * The start and len must match the file extent item, so thus must be sectorsize
84 * aligned.
85 */
86int btrfs_inode_set_file_extent_range(struct btrfs_inode *inode, u64 start,
87 u64 len)
88{
89 if (len == 0)
90 return 0;
91
92 ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize));
93
94 if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES))
95 return 0;
96 return set_extent_bits(&inode->file_extent_tree, start, start + len - 1,
97 EXTENT_DIRTY);
98}
99
100/*
101 * Mark an inode range as not having a backing extent.
102 *
103 * @inode: inode being modified
104 * @start: start file offset of the file extent we've inserted
105 * @len: logical length of the file extent item
106 *
107 * Called when we drop a file extent, for example when we truncate. Doesn't
108 * need to be called for cases where we're replacing a file extent, like when
109 * we've COWed a file extent.
110 *
111 * The start and len must match the file extent item, so thus must be sectorsize
112 * aligned.
113 */
114int btrfs_inode_clear_file_extent_range(struct btrfs_inode *inode, u64 start,
115 u64 len)
116{
117 if (len == 0)
118 return 0;
119
120 ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize) ||
121 len == (u64)-1);
122
123 if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES))
124 return 0;
125 return clear_extent_bit(&inode->file_extent_tree, start,
126 start + len - 1, EXTENT_DIRTY, NULL);
127}
128
129static size_t bytes_to_csum_size(const struct btrfs_fs_info *fs_info, u32 bytes)
130{
131 ASSERT(IS_ALIGNED(bytes, fs_info->sectorsize));
132
133 return (bytes >> fs_info->sectorsize_bits) * fs_info->csum_size;
134}
135
136static size_t csum_size_to_bytes(const struct btrfs_fs_info *fs_info, u32 csum_size)
137{
138 ASSERT(IS_ALIGNED(csum_size, fs_info->csum_size));
139
140 return (csum_size / fs_info->csum_size) << fs_info->sectorsize_bits;
141}
142
143static inline u32 max_ordered_sum_bytes(const struct btrfs_fs_info *fs_info)
144{
145 u32 max_csum_size = round_down(PAGE_SIZE - sizeof(struct btrfs_ordered_sum),
146 fs_info->csum_size);
147
148 return csum_size_to_bytes(fs_info, max_csum_size);
149}
150
151/*
152 * Calculate the total size needed to allocate for an ordered sum structure
153 * spanning @bytes in the file.
154 */
155static int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info, unsigned long bytes)
156{
157 return sizeof(struct btrfs_ordered_sum) + bytes_to_csum_size(fs_info, bytes);
158}
159
160int btrfs_insert_hole_extent(struct btrfs_trans_handle *trans,
161 struct btrfs_root *root,
162 u64 objectid, u64 pos, u64 num_bytes)
163{
164 int ret = 0;
165 struct btrfs_file_extent_item *item;
166 struct btrfs_key file_key;
167 struct btrfs_path *path;
168 struct extent_buffer *leaf;
169
170 path = btrfs_alloc_path();
171 if (!path)
172 return -ENOMEM;
173 file_key.objectid = objectid;
174 file_key.offset = pos;
175 file_key.type = BTRFS_EXTENT_DATA_KEY;
176
177 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
178 sizeof(*item));
179 if (ret < 0)
180 goto out;
181 BUG_ON(ret); /* Can't happen */
182 leaf = path->nodes[0];
183 item = btrfs_item_ptr(leaf, path->slots[0],
184 struct btrfs_file_extent_item);
185 btrfs_set_file_extent_disk_bytenr(leaf, item, 0);
186 btrfs_set_file_extent_disk_num_bytes(leaf, item, 0);
187 btrfs_set_file_extent_offset(leaf, item, 0);
188 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
189 btrfs_set_file_extent_ram_bytes(leaf, item, num_bytes);
190 btrfs_set_file_extent_generation(leaf, item, trans->transid);
191 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
192 btrfs_set_file_extent_compression(leaf, item, 0);
193 btrfs_set_file_extent_encryption(leaf, item, 0);
194 btrfs_set_file_extent_other_encoding(leaf, item, 0);
195
196 btrfs_mark_buffer_dirty(leaf);
197out:
198 btrfs_free_path(path);
199 return ret;
200}
201
202static struct btrfs_csum_item *
203btrfs_lookup_csum(struct btrfs_trans_handle *trans,
204 struct btrfs_root *root,
205 struct btrfs_path *path,
206 u64 bytenr, int cow)
207{
208 struct btrfs_fs_info *fs_info = root->fs_info;
209 int ret;
210 struct btrfs_key file_key;
211 struct btrfs_key found_key;
212 struct btrfs_csum_item *item;
213 struct extent_buffer *leaf;
214 u64 csum_offset = 0;
215 const u32 csum_size = fs_info->csum_size;
216 int csums_in_item;
217
218 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
219 file_key.offset = bytenr;
220 file_key.type = BTRFS_EXTENT_CSUM_KEY;
221 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
222 if (ret < 0)
223 goto fail;
224 leaf = path->nodes[0];
225 if (ret > 0) {
226 ret = 1;
227 if (path->slots[0] == 0)
228 goto fail;
229 path->slots[0]--;
230 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
231 if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
232 goto fail;
233
234 csum_offset = (bytenr - found_key.offset) >>
235 fs_info->sectorsize_bits;
236 csums_in_item = btrfs_item_size(leaf, path->slots[0]);
237 csums_in_item /= csum_size;
238
239 if (csum_offset == csums_in_item) {
240 ret = -EFBIG;
241 goto fail;
242 } else if (csum_offset > csums_in_item) {
243 goto fail;
244 }
245 }
246 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
247 item = (struct btrfs_csum_item *)((unsigned char *)item +
248 csum_offset * csum_size);
249 return item;
250fail:
251 if (ret > 0)
252 ret = -ENOENT;
253 return ERR_PTR(ret);
254}
255
256int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
257 struct btrfs_root *root,
258 struct btrfs_path *path, u64 objectid,
259 u64 offset, int mod)
260{
261 struct btrfs_key file_key;
262 int ins_len = mod < 0 ? -1 : 0;
263 int cow = mod != 0;
264
265 file_key.objectid = objectid;
266 file_key.offset = offset;
267 file_key.type = BTRFS_EXTENT_DATA_KEY;
268
269 return btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
270}
271
272/*
273 * Find checksums for logical bytenr range [disk_bytenr, disk_bytenr + len) and
274 * store the result to @dst.
275 *
276 * Return >0 for the number of sectors we found.
277 * Return 0 for the range [disk_bytenr, disk_bytenr + sectorsize) has no csum
278 * for it. Caller may want to try next sector until one range is hit.
279 * Return <0 for fatal error.
280 */
281static int search_csum_tree(struct btrfs_fs_info *fs_info,
282 struct btrfs_path *path, u64 disk_bytenr,
283 u64 len, u8 *dst)
284{
285 struct btrfs_root *csum_root;
286 struct btrfs_csum_item *item = NULL;
287 struct btrfs_key key;
288 const u32 sectorsize = fs_info->sectorsize;
289 const u32 csum_size = fs_info->csum_size;
290 u32 itemsize;
291 int ret;
292 u64 csum_start;
293 u64 csum_len;
294
295 ASSERT(IS_ALIGNED(disk_bytenr, sectorsize) &&
296 IS_ALIGNED(len, sectorsize));
297
298 /* Check if the current csum item covers disk_bytenr */
299 if (path->nodes[0]) {
300 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
301 struct btrfs_csum_item);
302 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
303 itemsize = btrfs_item_size(path->nodes[0], path->slots[0]);
304
305 csum_start = key.offset;
306 csum_len = (itemsize / csum_size) * sectorsize;
307
308 if (in_range(disk_bytenr, csum_start, csum_len))
309 goto found;
310 }
311
312 /* Current item doesn't contain the desired range, search again */
313 btrfs_release_path(path);
314 csum_root = btrfs_csum_root(fs_info, disk_bytenr);
315 item = btrfs_lookup_csum(NULL, csum_root, path, disk_bytenr, 0);
316 if (IS_ERR(item)) {
317 ret = PTR_ERR(item);
318 goto out;
319 }
320 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
321 itemsize = btrfs_item_size(path->nodes[0], path->slots[0]);
322
323 csum_start = key.offset;
324 csum_len = (itemsize / csum_size) * sectorsize;
325 ASSERT(in_range(disk_bytenr, csum_start, csum_len));
326
327found:
328 ret = (min(csum_start + csum_len, disk_bytenr + len) -
329 disk_bytenr) >> fs_info->sectorsize_bits;
330 read_extent_buffer(path->nodes[0], dst, (unsigned long)item,
331 ret * csum_size);
332out:
333 if (ret == -ENOENT || ret == -EFBIG)
334 ret = 0;
335 return ret;
336}
337
338/*
339 * Locate the file_offset of @cur_disk_bytenr of a @bio.
340 *
341 * Bio of btrfs represents read range of
342 * [bi_sector << 9, bi_sector << 9 + bi_size).
343 * Knowing this, we can iterate through each bvec to locate the page belong to
344 * @cur_disk_bytenr and get the file offset.
345 *
346 * @inode is used to determine if the bvec page really belongs to @inode.
347 *
348 * Return 0 if we can't find the file offset
349 * Return >0 if we find the file offset and restore it to @file_offset_ret
350 */
351static int search_file_offset_in_bio(struct bio *bio, struct inode *inode,
352 u64 disk_bytenr, u64 *file_offset_ret)
353{
354 struct bvec_iter iter;
355 struct bio_vec bvec;
356 u64 cur = bio->bi_iter.bi_sector << SECTOR_SHIFT;
357 int ret = 0;
358
359 bio_for_each_segment(bvec, bio, iter) {
360 struct page *page = bvec.bv_page;
361
362 if (cur > disk_bytenr)
363 break;
364 if (cur + bvec.bv_len <= disk_bytenr) {
365 cur += bvec.bv_len;
366 continue;
367 }
368 ASSERT(in_range(disk_bytenr, cur, bvec.bv_len));
369 if (page->mapping && page->mapping->host &&
370 page->mapping->host == inode) {
371 ret = 1;
372 *file_offset_ret = page_offset(page) + bvec.bv_offset +
373 disk_bytenr - cur;
374 break;
375 }
376 }
377 return ret;
378}
379
380/*
381 * Lookup the checksum for the read bio in csum tree.
382 *
383 * @inode: inode that the bio is for.
384 * @bio: bio to look up.
385 * @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return
386 * checksum (nblocks = bio->bi_iter.bi_size / fs_info->sectorsize). If
387 * NULL, the checksum buffer is allocated and returned in
388 * btrfs_bio(bio)->csum instead.
389 *
390 * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
391 */
392blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst)
393{
394 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
395 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
396 struct btrfs_bio *bbio = NULL;
397 struct btrfs_path *path;
398 const u32 sectorsize = fs_info->sectorsize;
399 const u32 csum_size = fs_info->csum_size;
400 u32 orig_len = bio->bi_iter.bi_size;
401 u64 orig_disk_bytenr = bio->bi_iter.bi_sector << SECTOR_SHIFT;
402 u64 cur_disk_bytenr;
403 u8 *csum;
404 const unsigned int nblocks = orig_len >> fs_info->sectorsize_bits;
405 int count = 0;
406 blk_status_t ret = BLK_STS_OK;
407
408 if ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) ||
409 test_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state))
410 return BLK_STS_OK;
411
412 /*
413 * This function is only called for read bio.
414 *
415 * This means two things:
416 * - All our csums should only be in csum tree
417 * No ordered extents csums, as ordered extents are only for write
418 * path.
419 * - No need to bother any other info from bvec
420 * Since we're looking up csums, the only important info is the
421 * disk_bytenr and the length, which can be extracted from bi_iter
422 * directly.
423 */
424 ASSERT(bio_op(bio) == REQ_OP_READ);
425 path = btrfs_alloc_path();
426 if (!path)
427 return BLK_STS_RESOURCE;
428
429 if (!dst) {
430 bbio = btrfs_bio(bio);
431
432 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
433 bbio->csum = kmalloc_array(nblocks, csum_size, GFP_NOFS);
434 if (!bbio->csum) {
435 btrfs_free_path(path);
436 return BLK_STS_RESOURCE;
437 }
438 } else {
439 bbio->csum = bbio->csum_inline;
440 }
441 csum = bbio->csum;
442 } else {
443 csum = dst;
444 }
445
446 /*
447 * If requested number of sectors is larger than one leaf can contain,
448 * kick the readahead for csum tree.
449 */
450 if (nblocks > fs_info->csums_per_leaf)
451 path->reada = READA_FORWARD;
452
453 /*
454 * the free space stuff is only read when it hasn't been
455 * updated in the current transaction. So, we can safely
456 * read from the commit root and sidestep a nasty deadlock
457 * between reading the free space cache and updating the csum tree.
458 */
459 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
460 path->search_commit_root = 1;
461 path->skip_locking = 1;
462 }
463
464 for (cur_disk_bytenr = orig_disk_bytenr;
465 cur_disk_bytenr < orig_disk_bytenr + orig_len;
466 cur_disk_bytenr += (count * sectorsize)) {
467 u64 search_len = orig_disk_bytenr + orig_len - cur_disk_bytenr;
468 unsigned int sector_offset;
469 u8 *csum_dst;
470
471 /*
472 * Although both cur_disk_bytenr and orig_disk_bytenr is u64,
473 * we're calculating the offset to the bio start.
474 *
475 * Bio size is limited to UINT_MAX, thus unsigned int is large
476 * enough to contain the raw result, not to mention the right
477 * shifted result.
478 */
479 ASSERT(cur_disk_bytenr - orig_disk_bytenr < UINT_MAX);
480 sector_offset = (cur_disk_bytenr - orig_disk_bytenr) >>
481 fs_info->sectorsize_bits;
482 csum_dst = csum + sector_offset * csum_size;
483
484 count = search_csum_tree(fs_info, path, cur_disk_bytenr,
485 search_len, csum_dst);
486 if (count < 0) {
487 ret = errno_to_blk_status(count);
488 if (bbio)
489 btrfs_bio_free_csum(bbio);
490 break;
491 }
492
493 /*
494 * We didn't find a csum for this range. We need to make sure
495 * we complain loudly about this, because we are not NODATASUM.
496 *
497 * However for the DATA_RELOC inode we could potentially be
498 * relocating data extents for a NODATASUM inode, so the inode
499 * itself won't be marked with NODATASUM, but the extent we're
500 * copying is in fact NODATASUM. If we don't find a csum we
501 * assume this is the case.
502 */
503 if (count == 0) {
504 memset(csum_dst, 0, csum_size);
505 count = 1;
506
507 if (BTRFS_I(inode)->root->root_key.objectid ==
508 BTRFS_DATA_RELOC_TREE_OBJECTID) {
509 u64 file_offset;
510 int ret;
511
512 ret = search_file_offset_in_bio(bio, inode,
513 cur_disk_bytenr, &file_offset);
514 if (ret)
515 set_extent_bits(io_tree, file_offset,
516 file_offset + sectorsize - 1,
517 EXTENT_NODATASUM);
518 } else {
519 btrfs_warn_rl(fs_info,
520 "csum hole found for disk bytenr range [%llu, %llu)",
521 cur_disk_bytenr, cur_disk_bytenr + sectorsize);
522 }
523 }
524 }
525
526 btrfs_free_path(path);
527 return ret;
528}
529
530int btrfs_lookup_csums_list(struct btrfs_root *root, u64 start, u64 end,
531 struct list_head *list, int search_commit,
532 bool nowait)
533{
534 struct btrfs_fs_info *fs_info = root->fs_info;
535 struct btrfs_key key;
536 struct btrfs_path *path;
537 struct extent_buffer *leaf;
538 struct btrfs_ordered_sum *sums;
539 struct btrfs_csum_item *item;
540 LIST_HEAD(tmplist);
541 int ret;
542
543 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
544 IS_ALIGNED(end + 1, fs_info->sectorsize));
545
546 path = btrfs_alloc_path();
547 if (!path)
548 return -ENOMEM;
549
550 path->nowait = nowait;
551 if (search_commit) {
552 path->skip_locking = 1;
553 path->reada = READA_FORWARD;
554 path->search_commit_root = 1;
555 }
556
557 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
558 key.offset = start;
559 key.type = BTRFS_EXTENT_CSUM_KEY;
560
561 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
562 if (ret < 0)
563 goto fail;
564 if (ret > 0 && path->slots[0] > 0) {
565 leaf = path->nodes[0];
566 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
567
568 /*
569 * There are two cases we can hit here for the previous csum
570 * item:
571 *
572 * |<- search range ->|
573 * |<- csum item ->|
574 *
575 * Or
576 * |<- search range ->|
577 * |<- csum item ->|
578 *
579 * Check if the previous csum item covers the leading part of
580 * the search range. If so we have to start from previous csum
581 * item.
582 */
583 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
584 key.type == BTRFS_EXTENT_CSUM_KEY) {
585 if (bytes_to_csum_size(fs_info, start - key.offset) <
586 btrfs_item_size(leaf, path->slots[0] - 1))
587 path->slots[0]--;
588 }
589 }
590
591 while (start <= end) {
592 u64 csum_end;
593
594 leaf = path->nodes[0];
595 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
596 ret = btrfs_next_leaf(root, path);
597 if (ret < 0)
598 goto fail;
599 if (ret > 0)
600 break;
601 leaf = path->nodes[0];
602 }
603
604 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
605 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
606 key.type != BTRFS_EXTENT_CSUM_KEY ||
607 key.offset > end)
608 break;
609
610 if (key.offset > start)
611 start = key.offset;
612
613 csum_end = key.offset + csum_size_to_bytes(fs_info,
614 btrfs_item_size(leaf, path->slots[0]));
615 if (csum_end <= start) {
616 path->slots[0]++;
617 continue;
618 }
619
620 csum_end = min(csum_end, end + 1);
621 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
622 struct btrfs_csum_item);
623 while (start < csum_end) {
624 unsigned long offset;
625 size_t size;
626
627 size = min_t(size_t, csum_end - start,
628 max_ordered_sum_bytes(fs_info));
629 sums = kzalloc(btrfs_ordered_sum_size(fs_info, size),
630 GFP_NOFS);
631 if (!sums) {
632 ret = -ENOMEM;
633 goto fail;
634 }
635
636 sums->bytenr = start;
637 sums->len = (int)size;
638
639 offset = bytes_to_csum_size(fs_info, start - key.offset);
640
641 read_extent_buffer(path->nodes[0],
642 sums->sums,
643 ((unsigned long)item) + offset,
644 bytes_to_csum_size(fs_info, size));
645
646 start += size;
647 list_add_tail(&sums->list, &tmplist);
648 }
649 path->slots[0]++;
650 }
651 ret = 0;
652fail:
653 while (ret < 0 && !list_empty(&tmplist)) {
654 sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list);
655 list_del(&sums->list);
656 kfree(sums);
657 }
658 list_splice_tail(&tmplist, list);
659
660 btrfs_free_path(path);
661 return ret;
662}
663
664/*
665 * Do the same work as btrfs_lookup_csums_list(), the difference is in how
666 * we return the result.
667 *
668 * This version will set the corresponding bits in @csum_bitmap to represent
669 * that there is a csum found.
670 * Each bit represents a sector. Thus caller should ensure @csum_buf passed
671 * in is large enough to contain all csums.
672 */
673int btrfs_lookup_csums_bitmap(struct btrfs_root *root, u64 start, u64 end,
674 u8 *csum_buf, unsigned long *csum_bitmap)
675{
676 struct btrfs_fs_info *fs_info = root->fs_info;
677 struct btrfs_key key;
678 struct btrfs_path *path;
679 struct extent_buffer *leaf;
680 struct btrfs_csum_item *item;
681 const u64 orig_start = start;
682 int ret;
683
684 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
685 IS_ALIGNED(end + 1, fs_info->sectorsize));
686
687 path = btrfs_alloc_path();
688 if (!path)
689 return -ENOMEM;
690
691 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
692 key.type = BTRFS_EXTENT_CSUM_KEY;
693 key.offset = start;
694
695 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
696 if (ret < 0)
697 goto fail;
698 if (ret > 0 && path->slots[0] > 0) {
699 leaf = path->nodes[0];
700 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
701
702 /*
703 * There are two cases we can hit here for the previous csum
704 * item:
705 *
706 * |<- search range ->|
707 * |<- csum item ->|
708 *
709 * Or
710 * |<- search range ->|
711 * |<- csum item ->|
712 *
713 * Check if the previous csum item covers the leading part of
714 * the search range. If so we have to start from previous csum
715 * item.
716 */
717 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
718 key.type == BTRFS_EXTENT_CSUM_KEY) {
719 if (bytes_to_csum_size(fs_info, start - key.offset) <
720 btrfs_item_size(leaf, path->slots[0] - 1))
721 path->slots[0]--;
722 }
723 }
724
725 while (start <= end) {
726 u64 csum_end;
727
728 leaf = path->nodes[0];
729 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
730 ret = btrfs_next_leaf(root, path);
731 if (ret < 0)
732 goto fail;
733 if (ret > 0)
734 break;
735 leaf = path->nodes[0];
736 }
737
738 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
739 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
740 key.type != BTRFS_EXTENT_CSUM_KEY ||
741 key.offset > end)
742 break;
743
744 if (key.offset > start)
745 start = key.offset;
746
747 csum_end = key.offset + csum_size_to_bytes(fs_info,
748 btrfs_item_size(leaf, path->slots[0]));
749 if (csum_end <= start) {
750 path->slots[0]++;
751 continue;
752 }
753
754 csum_end = min(csum_end, end + 1);
755 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
756 struct btrfs_csum_item);
757 while (start < csum_end) {
758 unsigned long offset;
759 size_t size;
760 u8 *csum_dest = csum_buf + bytes_to_csum_size(fs_info,
761 start - orig_start);
762
763 size = min_t(size_t, csum_end - start, end + 1 - start);
764
765 offset = bytes_to_csum_size(fs_info, start - key.offset);
766
767 read_extent_buffer(path->nodes[0], csum_dest,
768 ((unsigned long)item) + offset,
769 bytes_to_csum_size(fs_info, size));
770
771 bitmap_set(csum_bitmap,
772 (start - orig_start) >> fs_info->sectorsize_bits,
773 size >> fs_info->sectorsize_bits);
774
775 start += size;
776 }
777 path->slots[0]++;
778 }
779 ret = 0;
780fail:
781 btrfs_free_path(path);
782 return ret;
783}
784
785/*
786 * Calculate checksums of the data contained inside a bio.
787 *
788 * @inode: Owner of the data inside the bio
789 * @bio: Contains the data to be checksummed
790 * @offset: If (u64)-1, @bio may contain discontiguous bio vecs, so the
791 * file offsets are determined from the page offsets in the bio.
792 * Otherwise, this is the starting file offset of the bio vecs in
793 * @bio, which must be contiguous.
794 * @one_ordered: If true, @bio only refers to one ordered extent.
795 */
796blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
797 u64 offset, bool one_ordered)
798{
799 struct btrfs_fs_info *fs_info = inode->root->fs_info;
800 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
801 struct btrfs_ordered_sum *sums;
802 struct btrfs_ordered_extent *ordered = NULL;
803 const bool use_page_offsets = (offset == (u64)-1);
804 char *data;
805 struct bvec_iter iter;
806 struct bio_vec bvec;
807 int index;
808 unsigned int blockcount;
809 unsigned long total_bytes = 0;
810 unsigned long this_sum_bytes = 0;
811 int i;
812 unsigned nofs_flag;
813
814 nofs_flag = memalloc_nofs_save();
815 sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
816 GFP_KERNEL);
817 memalloc_nofs_restore(nofs_flag);
818
819 if (!sums)
820 return BLK_STS_RESOURCE;
821
822 sums->len = bio->bi_iter.bi_size;
823 INIT_LIST_HEAD(&sums->list);
824
825 sums->bytenr = bio->bi_iter.bi_sector << 9;
826 index = 0;
827
828 shash->tfm = fs_info->csum_shash;
829
830 bio_for_each_segment(bvec, bio, iter) {
831 if (use_page_offsets)
832 offset = page_offset(bvec.bv_page) + bvec.bv_offset;
833
834 if (!ordered) {
835 ordered = btrfs_lookup_ordered_extent(inode, offset);
836 /*
837 * The bio range is not covered by any ordered extent,
838 * must be a code logic error.
839 */
840 if (unlikely(!ordered)) {
841 WARN(1, KERN_WARNING
842 "no ordered extent for root %llu ino %llu offset %llu\n",
843 inode->root->root_key.objectid,
844 btrfs_ino(inode), offset);
845 kvfree(sums);
846 return BLK_STS_IOERR;
847 }
848 }
849
850 blockcount = BTRFS_BYTES_TO_BLKS(fs_info,
851 bvec.bv_len + fs_info->sectorsize
852 - 1);
853
854 for (i = 0; i < blockcount; i++) {
855 if (!one_ordered &&
856 !in_range(offset, ordered->file_offset,
857 ordered->num_bytes)) {
858 unsigned long bytes_left;
859
860 sums->len = this_sum_bytes;
861 this_sum_bytes = 0;
862 btrfs_add_ordered_sum(ordered, sums);
863 btrfs_put_ordered_extent(ordered);
864
865 bytes_left = bio->bi_iter.bi_size - total_bytes;
866
867 nofs_flag = memalloc_nofs_save();
868 sums = kvzalloc(btrfs_ordered_sum_size(fs_info,
869 bytes_left), GFP_KERNEL);
870 memalloc_nofs_restore(nofs_flag);
871 BUG_ON(!sums); /* -ENOMEM */
872 sums->len = bytes_left;
873 ordered = btrfs_lookup_ordered_extent(inode,
874 offset);
875 ASSERT(ordered); /* Logic error */
876 sums->bytenr = (bio->bi_iter.bi_sector << 9)
877 + total_bytes;
878 index = 0;
879 }
880
881 data = bvec_kmap_local(&bvec);
882 crypto_shash_digest(shash,
883 data + (i * fs_info->sectorsize),
884 fs_info->sectorsize,
885 sums->sums + index);
886 kunmap_local(data);
887 index += fs_info->csum_size;
888 offset += fs_info->sectorsize;
889 this_sum_bytes += fs_info->sectorsize;
890 total_bytes += fs_info->sectorsize;
891 }
892
893 }
894 this_sum_bytes = 0;
895 btrfs_add_ordered_sum(ordered, sums);
896 btrfs_put_ordered_extent(ordered);
897 return 0;
898}
899
900/*
901 * Remove one checksum overlapping a range.
902 *
903 * This expects the key to describe the csum pointed to by the path, and it
904 * expects the csum to overlap the range [bytenr, len]
905 *
906 * The csum should not be entirely contained in the range and the range should
907 * not be entirely contained in the csum.
908 *
909 * This calls btrfs_truncate_item with the correct args based on the overlap,
910 * and fixes up the key as required.
911 */
912static noinline void truncate_one_csum(struct btrfs_fs_info *fs_info,
913 struct btrfs_path *path,
914 struct btrfs_key *key,
915 u64 bytenr, u64 len)
916{
917 struct extent_buffer *leaf;
918 const u32 csum_size = fs_info->csum_size;
919 u64 csum_end;
920 u64 end_byte = bytenr + len;
921 u32 blocksize_bits = fs_info->sectorsize_bits;
922
923 leaf = path->nodes[0];
924 csum_end = btrfs_item_size(leaf, path->slots[0]) / csum_size;
925 csum_end <<= blocksize_bits;
926 csum_end += key->offset;
927
928 if (key->offset < bytenr && csum_end <= end_byte) {
929 /*
930 * [ bytenr - len ]
931 * [ ]
932 * [csum ]
933 * A simple truncate off the end of the item
934 */
935 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
936 new_size *= csum_size;
937 btrfs_truncate_item(path, new_size, 1);
938 } else if (key->offset >= bytenr && csum_end > end_byte &&
939 end_byte > key->offset) {
940 /*
941 * [ bytenr - len ]
942 * [ ]
943 * [csum ]
944 * we need to truncate from the beginning of the csum
945 */
946 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
947 new_size *= csum_size;
948
949 btrfs_truncate_item(path, new_size, 0);
950
951 key->offset = end_byte;
952 btrfs_set_item_key_safe(fs_info, path, key);
953 } else {
954 BUG();
955 }
956}
957
958/*
959 * Delete the csum items from the csum tree for a given range of bytes.
960 */
961int btrfs_del_csums(struct btrfs_trans_handle *trans,
962 struct btrfs_root *root, u64 bytenr, u64 len)
963{
964 struct btrfs_fs_info *fs_info = trans->fs_info;
965 struct btrfs_path *path;
966 struct btrfs_key key;
967 u64 end_byte = bytenr + len;
968 u64 csum_end;
969 struct extent_buffer *leaf;
970 int ret = 0;
971 const u32 csum_size = fs_info->csum_size;
972 u32 blocksize_bits = fs_info->sectorsize_bits;
973
974 ASSERT(root->root_key.objectid == BTRFS_CSUM_TREE_OBJECTID ||
975 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
976
977 path = btrfs_alloc_path();
978 if (!path)
979 return -ENOMEM;
980
981 while (1) {
982 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
983 key.offset = end_byte - 1;
984 key.type = BTRFS_EXTENT_CSUM_KEY;
985
986 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
987 if (ret > 0) {
988 ret = 0;
989 if (path->slots[0] == 0)
990 break;
991 path->slots[0]--;
992 } else if (ret < 0) {
993 break;
994 }
995
996 leaf = path->nodes[0];
997 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
998
999 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
1000 key.type != BTRFS_EXTENT_CSUM_KEY) {
1001 break;
1002 }
1003
1004 if (key.offset >= end_byte)
1005 break;
1006
1007 csum_end = btrfs_item_size(leaf, path->slots[0]) / csum_size;
1008 csum_end <<= blocksize_bits;
1009 csum_end += key.offset;
1010
1011 /* this csum ends before we start, we're done */
1012 if (csum_end <= bytenr)
1013 break;
1014
1015 /* delete the entire item, it is inside our range */
1016 if (key.offset >= bytenr && csum_end <= end_byte) {
1017 int del_nr = 1;
1018
1019 /*
1020 * Check how many csum items preceding this one in this
1021 * leaf correspond to our range and then delete them all
1022 * at once.
1023 */
1024 if (key.offset > bytenr && path->slots[0] > 0) {
1025 int slot = path->slots[0] - 1;
1026
1027 while (slot >= 0) {
1028 struct btrfs_key pk;
1029
1030 btrfs_item_key_to_cpu(leaf, &pk, slot);
1031 if (pk.offset < bytenr ||
1032 pk.type != BTRFS_EXTENT_CSUM_KEY ||
1033 pk.objectid !=
1034 BTRFS_EXTENT_CSUM_OBJECTID)
1035 break;
1036 path->slots[0] = slot;
1037 del_nr++;
1038 key.offset = pk.offset;
1039 slot--;
1040 }
1041 }
1042 ret = btrfs_del_items(trans, root, path,
1043 path->slots[0], del_nr);
1044 if (ret)
1045 break;
1046 if (key.offset == bytenr)
1047 break;
1048 } else if (key.offset < bytenr && csum_end > end_byte) {
1049 unsigned long offset;
1050 unsigned long shift_len;
1051 unsigned long item_offset;
1052 /*
1053 * [ bytenr - len ]
1054 * [csum ]
1055 *
1056 * Our bytes are in the middle of the csum,
1057 * we need to split this item and insert a new one.
1058 *
1059 * But we can't drop the path because the
1060 * csum could change, get removed, extended etc.
1061 *
1062 * The trick here is the max size of a csum item leaves
1063 * enough room in the tree block for a single
1064 * item header. So, we split the item in place,
1065 * adding a new header pointing to the existing
1066 * bytes. Then we loop around again and we have
1067 * a nicely formed csum item that we can neatly
1068 * truncate.
1069 */
1070 offset = (bytenr - key.offset) >> blocksize_bits;
1071 offset *= csum_size;
1072
1073 shift_len = (len >> blocksize_bits) * csum_size;
1074
1075 item_offset = btrfs_item_ptr_offset(leaf,
1076 path->slots[0]);
1077
1078 memzero_extent_buffer(leaf, item_offset + offset,
1079 shift_len);
1080 key.offset = bytenr;
1081
1082 /*
1083 * btrfs_split_item returns -EAGAIN when the
1084 * item changed size or key
1085 */
1086 ret = btrfs_split_item(trans, root, path, &key, offset);
1087 if (ret && ret != -EAGAIN) {
1088 btrfs_abort_transaction(trans, ret);
1089 break;
1090 }
1091 ret = 0;
1092
1093 key.offset = end_byte - 1;
1094 } else {
1095 truncate_one_csum(fs_info, path, &key, bytenr, len);
1096 if (key.offset < bytenr)
1097 break;
1098 }
1099 btrfs_release_path(path);
1100 }
1101 btrfs_free_path(path);
1102 return ret;
1103}
1104
1105static int find_next_csum_offset(struct btrfs_root *root,
1106 struct btrfs_path *path,
1107 u64 *next_offset)
1108{
1109 const u32 nritems = btrfs_header_nritems(path->nodes[0]);
1110 struct btrfs_key found_key;
1111 int slot = path->slots[0] + 1;
1112 int ret;
1113
1114 if (nritems == 0 || slot >= nritems) {
1115 ret = btrfs_next_leaf(root, path);
1116 if (ret < 0) {
1117 return ret;
1118 } else if (ret > 0) {
1119 *next_offset = (u64)-1;
1120 return 0;
1121 }
1122 slot = path->slots[0];
1123 }
1124
1125 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
1126
1127 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
1128 found_key.type != BTRFS_EXTENT_CSUM_KEY)
1129 *next_offset = (u64)-1;
1130 else
1131 *next_offset = found_key.offset;
1132
1133 return 0;
1134}
1135
1136int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
1137 struct btrfs_root *root,
1138 struct btrfs_ordered_sum *sums)
1139{
1140 struct btrfs_fs_info *fs_info = root->fs_info;
1141 struct btrfs_key file_key;
1142 struct btrfs_key found_key;
1143 struct btrfs_path *path;
1144 struct btrfs_csum_item *item;
1145 struct btrfs_csum_item *item_end;
1146 struct extent_buffer *leaf = NULL;
1147 u64 next_offset;
1148 u64 total_bytes = 0;
1149 u64 csum_offset;
1150 u64 bytenr;
1151 u32 ins_size;
1152 int index = 0;
1153 int found_next;
1154 int ret;
1155 const u32 csum_size = fs_info->csum_size;
1156
1157 path = btrfs_alloc_path();
1158 if (!path)
1159 return -ENOMEM;
1160again:
1161 next_offset = (u64)-1;
1162 found_next = 0;
1163 bytenr = sums->bytenr + total_bytes;
1164 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
1165 file_key.offset = bytenr;
1166 file_key.type = BTRFS_EXTENT_CSUM_KEY;
1167
1168 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
1169 if (!IS_ERR(item)) {
1170 ret = 0;
1171 leaf = path->nodes[0];
1172 item_end = btrfs_item_ptr(leaf, path->slots[0],
1173 struct btrfs_csum_item);
1174 item_end = (struct btrfs_csum_item *)((char *)item_end +
1175 btrfs_item_size(leaf, path->slots[0]));
1176 goto found;
1177 }
1178 ret = PTR_ERR(item);
1179 if (ret != -EFBIG && ret != -ENOENT)
1180 goto out;
1181
1182 if (ret == -EFBIG) {
1183 u32 item_size;
1184 /* we found one, but it isn't big enough yet */
1185 leaf = path->nodes[0];
1186 item_size = btrfs_item_size(leaf, path->slots[0]);
1187 if ((item_size / csum_size) >=
1188 MAX_CSUM_ITEMS(fs_info, csum_size)) {
1189 /* already at max size, make a new one */
1190 goto insert;
1191 }
1192 } else {
1193 /* We didn't find a csum item, insert one. */
1194 ret = find_next_csum_offset(root, path, &next_offset);
1195 if (ret < 0)
1196 goto out;
1197 found_next = 1;
1198 goto insert;
1199 }
1200
1201 /*
1202 * At this point, we know the tree has a checksum item that ends at an
1203 * offset matching the start of the checksum range we want to insert.
1204 * We try to extend that item as much as possible and then add as many
1205 * checksums to it as they fit.
1206 *
1207 * First check if the leaf has enough free space for at least one
1208 * checksum. If it has go directly to the item extension code, otherwise
1209 * release the path and do a search for insertion before the extension.
1210 */
1211 if (btrfs_leaf_free_space(leaf) >= csum_size) {
1212 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1213 csum_offset = (bytenr - found_key.offset) >>
1214 fs_info->sectorsize_bits;
1215 goto extend_csum;
1216 }
1217
1218 btrfs_release_path(path);
1219 path->search_for_extension = 1;
1220 ret = btrfs_search_slot(trans, root, &file_key, path,
1221 csum_size, 1);
1222 path->search_for_extension = 0;
1223 if (ret < 0)
1224 goto out;
1225
1226 if (ret > 0) {
1227 if (path->slots[0] == 0)
1228 goto insert;
1229 path->slots[0]--;
1230 }
1231
1232 leaf = path->nodes[0];
1233 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1234 csum_offset = (bytenr - found_key.offset) >> fs_info->sectorsize_bits;
1235
1236 if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
1237 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
1238 csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
1239 goto insert;
1240 }
1241
1242extend_csum:
1243 if (csum_offset == btrfs_item_size(leaf, path->slots[0]) /
1244 csum_size) {
1245 int extend_nr;
1246 u64 tmp;
1247 u32 diff;
1248
1249 tmp = sums->len - total_bytes;
1250 tmp >>= fs_info->sectorsize_bits;
1251 WARN_ON(tmp < 1);
1252 extend_nr = max_t(int, 1, tmp);
1253
1254 /*
1255 * A log tree can already have checksum items with a subset of
1256 * the checksums we are trying to log. This can happen after
1257 * doing a sequence of partial writes into prealloc extents and
1258 * fsyncs in between, with a full fsync logging a larger subrange
1259 * of an extent for which a previous fast fsync logged a smaller
1260 * subrange. And this happens in particular due to merging file
1261 * extent items when we complete an ordered extent for a range
1262 * covered by a prealloc extent - this is done at
1263 * btrfs_mark_extent_written().
1264 *
1265 * So if we try to extend the previous checksum item, which has
1266 * a range that ends at the start of the range we want to insert,
1267 * make sure we don't extend beyond the start offset of the next
1268 * checksum item. If we are at the last item in the leaf, then
1269 * forget the optimization of extending and add a new checksum
1270 * item - it is not worth the complexity of releasing the path,
1271 * getting the first key for the next leaf, repeat the btree
1272 * search, etc, because log trees are temporary anyway and it
1273 * would only save a few bytes of leaf space.
1274 */
1275 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
1276 if (path->slots[0] + 1 >=
1277 btrfs_header_nritems(path->nodes[0])) {
1278 ret = find_next_csum_offset(root, path, &next_offset);
1279 if (ret < 0)
1280 goto out;
1281 found_next = 1;
1282 goto insert;
1283 }
1284
1285 ret = find_next_csum_offset(root, path, &next_offset);
1286 if (ret < 0)
1287 goto out;
1288
1289 tmp = (next_offset - bytenr) >> fs_info->sectorsize_bits;
1290 if (tmp <= INT_MAX)
1291 extend_nr = min_t(int, extend_nr, tmp);
1292 }
1293
1294 diff = (csum_offset + extend_nr) * csum_size;
1295 diff = min(diff,
1296 MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
1297
1298 diff = diff - btrfs_item_size(leaf, path->slots[0]);
1299 diff = min_t(u32, btrfs_leaf_free_space(leaf), diff);
1300 diff /= csum_size;
1301 diff *= csum_size;
1302
1303 btrfs_extend_item(path, diff);
1304 ret = 0;
1305 goto csum;
1306 }
1307
1308insert:
1309 btrfs_release_path(path);
1310 csum_offset = 0;
1311 if (found_next) {
1312 u64 tmp;
1313
1314 tmp = sums->len - total_bytes;
1315 tmp >>= fs_info->sectorsize_bits;
1316 tmp = min(tmp, (next_offset - file_key.offset) >>
1317 fs_info->sectorsize_bits);
1318
1319 tmp = max_t(u64, 1, tmp);
1320 tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
1321 ins_size = csum_size * tmp;
1322 } else {
1323 ins_size = csum_size;
1324 }
1325 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
1326 ins_size);
1327 if (ret < 0)
1328 goto out;
1329 if (WARN_ON(ret != 0))
1330 goto out;
1331 leaf = path->nodes[0];
1332csum:
1333 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
1334 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
1335 btrfs_item_size(leaf, path->slots[0]));
1336 item = (struct btrfs_csum_item *)((unsigned char *)item +
1337 csum_offset * csum_size);
1338found:
1339 ins_size = (u32)(sums->len - total_bytes) >> fs_info->sectorsize_bits;
1340 ins_size *= csum_size;
1341 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
1342 ins_size);
1343 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
1344 ins_size);
1345
1346 index += ins_size;
1347 ins_size /= csum_size;
1348 total_bytes += ins_size * fs_info->sectorsize;
1349
1350 btrfs_mark_buffer_dirty(path->nodes[0]);
1351 if (total_bytes < sums->len) {
1352 btrfs_release_path(path);
1353 cond_resched();
1354 goto again;
1355 }
1356out:
1357 btrfs_free_path(path);
1358 return ret;
1359}
1360
1361void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
1362 const struct btrfs_path *path,
1363 struct btrfs_file_extent_item *fi,
1364 struct extent_map *em)
1365{
1366 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1367 struct btrfs_root *root = inode->root;
1368 struct extent_buffer *leaf = path->nodes[0];
1369 const int slot = path->slots[0];
1370 struct btrfs_key key;
1371 u64 extent_start, extent_end;
1372 u64 bytenr;
1373 u8 type = btrfs_file_extent_type(leaf, fi);
1374 int compress_type = btrfs_file_extent_compression(leaf, fi);
1375
1376 btrfs_item_key_to_cpu(leaf, &key, slot);
1377 extent_start = key.offset;
1378 extent_end = btrfs_file_extent_end(path);
1379 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1380 em->generation = btrfs_file_extent_generation(leaf, fi);
1381 if (type == BTRFS_FILE_EXTENT_REG ||
1382 type == BTRFS_FILE_EXTENT_PREALLOC) {
1383 em->start = extent_start;
1384 em->len = extent_end - extent_start;
1385 em->orig_start = extent_start -
1386 btrfs_file_extent_offset(leaf, fi);
1387 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
1388 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1389 if (bytenr == 0) {
1390 em->block_start = EXTENT_MAP_HOLE;
1391 return;
1392 }
1393 if (compress_type != BTRFS_COMPRESS_NONE) {
1394 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
1395 em->compress_type = compress_type;
1396 em->block_start = bytenr;
1397 em->block_len = em->orig_block_len;
1398 } else {
1399 bytenr += btrfs_file_extent_offset(leaf, fi);
1400 em->block_start = bytenr;
1401 em->block_len = em->len;
1402 if (type == BTRFS_FILE_EXTENT_PREALLOC)
1403 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
1404 }
1405 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1406 em->block_start = EXTENT_MAP_INLINE;
1407 em->start = extent_start;
1408 em->len = extent_end - extent_start;
1409 /*
1410 * Initialize orig_start and block_len with the same values
1411 * as in inode.c:btrfs_get_extent().
1412 */
1413 em->orig_start = EXTENT_MAP_HOLE;
1414 em->block_len = (u64)-1;
1415 em->compress_type = compress_type;
1416 if (compress_type != BTRFS_COMPRESS_NONE)
1417 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
1418 } else {
1419 btrfs_err(fs_info,
1420 "unknown file extent item type %d, inode %llu, offset %llu, "
1421 "root %llu", type, btrfs_ino(inode), extent_start,
1422 root->root_key.objectid);
1423 }
1424}
1425
1426/*
1427 * Returns the end offset (non inclusive) of the file extent item the given path
1428 * points to. If it points to an inline extent, the returned offset is rounded
1429 * up to the sector size.
1430 */
1431u64 btrfs_file_extent_end(const struct btrfs_path *path)
1432{
1433 const struct extent_buffer *leaf = path->nodes[0];
1434 const int slot = path->slots[0];
1435 struct btrfs_file_extent_item *fi;
1436 struct btrfs_key key;
1437 u64 end;
1438
1439 btrfs_item_key_to_cpu(leaf, &key, slot);
1440 ASSERT(key.type == BTRFS_EXTENT_DATA_KEY);
1441 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1442
1443 if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
1444 end = btrfs_file_extent_ram_bytes(leaf, fi);
1445 end = ALIGN(key.offset + end, leaf->fs_info->sectorsize);
1446 } else {
1447 end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1448 }
1449
1450 return end;
1451}
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}