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