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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 "ctree.h"
14#include "disk-io.h"
15#include "transaction.h"
16#include "bio.h"
17#include "compression.h"
18#include "fs.h"
19#include "accessors.h"
20#include "file-item.h"
21
22#define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
23 sizeof(struct btrfs_item) * 2) / \
24 size) - 1))
25
26#define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
27 PAGE_SIZE))
28
29/*
30 * Set inode's size according to filesystem options.
31 *
32 * @inode: inode we want to update the disk_i_size for
33 * @new_i_size: i_size we want to set to, 0 if we use i_size
34 *
35 * With NO_HOLES set this simply sets the disk_is_size to whatever i_size_read()
36 * returns as it is perfectly fine with a file that has holes without hole file
37 * extent items.
38 *
39 * However without NO_HOLES we need to only return the area that is contiguous
40 * from the 0 offset of the file. Otherwise we could end up adjust i_size up
41 * to an extent that has a gap in between.
42 *
43 * Finally new_i_size should only be set in the case of truncate where we're not
44 * ready to use i_size_read() as the limiter yet.
45 */
46void btrfs_inode_safe_disk_i_size_write(struct btrfs_inode *inode, u64 new_i_size)
47{
48 u64 start, end, i_size;
49 int ret;
50
51 spin_lock(&inode->lock);
52 i_size = new_i_size ?: i_size_read(&inode->vfs_inode);
53 if (!inode->file_extent_tree) {
54 inode->disk_i_size = i_size;
55 goto out_unlock;
56 }
57
58 ret = find_contiguous_extent_bit(inode->file_extent_tree, 0, &start,
59 &end, EXTENT_DIRTY);
60 if (!ret && start == 0)
61 i_size = min(i_size, end + 1);
62 else
63 i_size = 0;
64 inode->disk_i_size = i_size;
65out_unlock:
66 spin_unlock(&inode->lock);
67}
68
69/*
70 * Mark range within a file as having a new extent inserted.
71 *
72 * @inode: inode being modified
73 * @start: start file offset of the file extent we've inserted
74 * @len: logical length of the file extent item
75 *
76 * Call when we are inserting a new file extent where there was none before.
77 * Does not need to call this in the case where we're replacing an existing file
78 * extent, however if not sure it's fine to call this multiple times.
79 *
80 * The start and len must match the file extent item, so thus must be sectorsize
81 * aligned.
82 */
83int btrfs_inode_set_file_extent_range(struct btrfs_inode *inode, u64 start,
84 u64 len)
85{
86 if (!inode->file_extent_tree)
87 return 0;
88
89 if (len == 0)
90 return 0;
91
92 ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize));
93
94 return set_extent_bit(inode->file_extent_tree, start, start + len - 1,
95 EXTENT_DIRTY, NULL);
96}
97
98/*
99 * Mark an inode range as not having a backing extent.
100 *
101 * @inode: inode being modified
102 * @start: start file offset of the file extent we've inserted
103 * @len: logical length of the file extent item
104 *
105 * Called when we drop a file extent, for example when we truncate. Doesn't
106 * need to be called for cases where we're replacing a file extent, like when
107 * we've COWed a file extent.
108 *
109 * The start and len must match the file extent item, so thus must be sectorsize
110 * aligned.
111 */
112int btrfs_inode_clear_file_extent_range(struct btrfs_inode *inode, u64 start,
113 u64 len)
114{
115 if (!inode->file_extent_tree)
116 return 0;
117
118 if (len == 0)
119 return 0;
120
121 ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize) ||
122 len == (u64)-1);
123
124 return clear_extent_bit(inode->file_extent_tree, start,
125 start + len - 1, EXTENT_DIRTY, NULL);
126}
127
128static size_t bytes_to_csum_size(const struct btrfs_fs_info *fs_info, u32 bytes)
129{
130 ASSERT(IS_ALIGNED(bytes, fs_info->sectorsize));
131
132 return (bytes >> fs_info->sectorsize_bits) * fs_info->csum_size;
133}
134
135static size_t csum_size_to_bytes(const struct btrfs_fs_info *fs_info, u32 csum_size)
136{
137 ASSERT(IS_ALIGNED(csum_size, fs_info->csum_size));
138
139 return (csum_size / fs_info->csum_size) << fs_info->sectorsize_bits;
140}
141
142static inline u32 max_ordered_sum_bytes(const struct btrfs_fs_info *fs_info)
143{
144 u32 max_csum_size = round_down(PAGE_SIZE - sizeof(struct btrfs_ordered_sum),
145 fs_info->csum_size);
146
147 return csum_size_to_bytes(fs_info, max_csum_size);
148}
149
150/*
151 * Calculate the total size needed to allocate for an ordered sum structure
152 * spanning @bytes in the file.
153 */
154static int btrfs_ordered_sum_size(const struct btrfs_fs_info *fs_info, unsigned long bytes)
155{
156 return sizeof(struct btrfs_ordered_sum) + bytes_to_csum_size(fs_info, bytes);
157}
158
159int btrfs_insert_hole_extent(struct btrfs_trans_handle *trans,
160 struct btrfs_root *root,
161 u64 objectid, u64 pos, u64 num_bytes)
162{
163 int ret = 0;
164 struct btrfs_file_extent_item *item;
165 struct btrfs_key file_key;
166 struct btrfs_path *path;
167 struct extent_buffer *leaf;
168
169 path = btrfs_alloc_path();
170 if (!path)
171 return -ENOMEM;
172 file_key.objectid = objectid;
173 file_key.offset = pos;
174 file_key.type = BTRFS_EXTENT_DATA_KEY;
175
176 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
177 sizeof(*item));
178 if (ret < 0)
179 goto out;
180 leaf = path->nodes[0];
181 item = btrfs_item_ptr(leaf, path->slots[0],
182 struct btrfs_file_extent_item);
183 btrfs_set_file_extent_disk_bytenr(leaf, item, 0);
184 btrfs_set_file_extent_disk_num_bytes(leaf, item, 0);
185 btrfs_set_file_extent_offset(leaf, item, 0);
186 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
187 btrfs_set_file_extent_ram_bytes(leaf, item, num_bytes);
188 btrfs_set_file_extent_generation(leaf, item, trans->transid);
189 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
190 btrfs_set_file_extent_compression(leaf, item, 0);
191 btrfs_set_file_extent_encryption(leaf, item, 0);
192 btrfs_set_file_extent_other_encoding(leaf, item, 0);
193
194 btrfs_mark_buffer_dirty(trans, leaf);
195out:
196 btrfs_free_path(path);
197 return ret;
198}
199
200static struct btrfs_csum_item *
201btrfs_lookup_csum(struct btrfs_trans_handle *trans,
202 struct btrfs_root *root,
203 struct btrfs_path *path,
204 u64 bytenr, int cow)
205{
206 struct btrfs_fs_info *fs_info = root->fs_info;
207 int ret;
208 struct btrfs_key file_key;
209 struct btrfs_key found_key;
210 struct btrfs_csum_item *item;
211 struct extent_buffer *leaf;
212 u64 csum_offset = 0;
213 const u32 csum_size = fs_info->csum_size;
214 int csums_in_item;
215
216 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
217 file_key.offset = bytenr;
218 file_key.type = BTRFS_EXTENT_CSUM_KEY;
219 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
220 if (ret < 0)
221 goto fail;
222 leaf = path->nodes[0];
223 if (ret > 0) {
224 ret = 1;
225 if (path->slots[0] == 0)
226 goto fail;
227 path->slots[0]--;
228 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
229 if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
230 goto fail;
231
232 csum_offset = (bytenr - found_key.offset) >>
233 fs_info->sectorsize_bits;
234 csums_in_item = btrfs_item_size(leaf, path->slots[0]);
235 csums_in_item /= csum_size;
236
237 if (csum_offset == csums_in_item) {
238 ret = -EFBIG;
239 goto fail;
240 } else if (csum_offset > csums_in_item) {
241 goto fail;
242 }
243 }
244 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
245 item = (struct btrfs_csum_item *)((unsigned char *)item +
246 csum_offset * csum_size);
247 return item;
248fail:
249 if (ret > 0)
250 ret = -ENOENT;
251 return ERR_PTR(ret);
252}
253
254int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
255 struct btrfs_root *root,
256 struct btrfs_path *path, u64 objectid,
257 u64 offset, int mod)
258{
259 struct btrfs_key file_key;
260 int ins_len = mod < 0 ? -1 : 0;
261 int cow = mod != 0;
262
263 file_key.objectid = objectid;
264 file_key.offset = offset;
265 file_key.type = BTRFS_EXTENT_DATA_KEY;
266
267 return btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
268}
269
270/*
271 * Find checksums for logical bytenr range [disk_bytenr, disk_bytenr + len) and
272 * store the result to @dst.
273 *
274 * Return >0 for the number of sectors we found.
275 * Return 0 for the range [disk_bytenr, disk_bytenr + sectorsize) has no csum
276 * for it. Caller may want to try next sector until one range is hit.
277 * Return <0 for fatal error.
278 */
279static int search_csum_tree(struct btrfs_fs_info *fs_info,
280 struct btrfs_path *path, u64 disk_bytenr,
281 u64 len, u8 *dst)
282{
283 struct btrfs_root *csum_root;
284 struct btrfs_csum_item *item = NULL;
285 struct btrfs_key key;
286 const u32 sectorsize = fs_info->sectorsize;
287 const u32 csum_size = fs_info->csum_size;
288 u32 itemsize;
289 int ret;
290 u64 csum_start;
291 u64 csum_len;
292
293 ASSERT(IS_ALIGNED(disk_bytenr, sectorsize) &&
294 IS_ALIGNED(len, sectorsize));
295
296 /* Check if the current csum item covers disk_bytenr */
297 if (path->nodes[0]) {
298 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
299 struct btrfs_csum_item);
300 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
301 itemsize = btrfs_item_size(path->nodes[0], path->slots[0]);
302
303 csum_start = key.offset;
304 csum_len = (itemsize / csum_size) * sectorsize;
305
306 if (in_range(disk_bytenr, csum_start, csum_len))
307 goto found;
308 }
309
310 /* Current item doesn't contain the desired range, search again */
311 btrfs_release_path(path);
312 csum_root = btrfs_csum_root(fs_info, disk_bytenr);
313 item = btrfs_lookup_csum(NULL, csum_root, path, disk_bytenr, 0);
314 if (IS_ERR(item)) {
315 ret = PTR_ERR(item);
316 goto out;
317 }
318 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
319 itemsize = btrfs_item_size(path->nodes[0], path->slots[0]);
320
321 csum_start = key.offset;
322 csum_len = (itemsize / csum_size) * sectorsize;
323 ASSERT(in_range(disk_bytenr, csum_start, csum_len));
324
325found:
326 ret = (min(csum_start + csum_len, disk_bytenr + len) -
327 disk_bytenr) >> fs_info->sectorsize_bits;
328 read_extent_buffer(path->nodes[0], dst, (unsigned long)item,
329 ret * csum_size);
330out:
331 if (ret == -ENOENT || ret == -EFBIG)
332 ret = 0;
333 return ret;
334}
335
336/*
337 * Lookup the checksum for the read bio in csum tree.
338 *
339 * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
340 */
341blk_status_t btrfs_lookup_bio_sums(struct btrfs_bio *bbio)
342{
343 struct btrfs_inode *inode = bbio->inode;
344 struct btrfs_fs_info *fs_info = inode->root->fs_info;
345 struct bio *bio = &bbio->bio;
346 struct btrfs_path *path;
347 const u32 sectorsize = fs_info->sectorsize;
348 const u32 csum_size = fs_info->csum_size;
349 u32 orig_len = bio->bi_iter.bi_size;
350 u64 orig_disk_bytenr = bio->bi_iter.bi_sector << SECTOR_SHIFT;
351 const unsigned int nblocks = orig_len >> fs_info->sectorsize_bits;
352 blk_status_t ret = BLK_STS_OK;
353 u32 bio_offset = 0;
354
355 if ((inode->flags & BTRFS_INODE_NODATASUM) ||
356 test_bit(BTRFS_FS_STATE_NO_DATA_CSUMS, &fs_info->fs_state))
357 return BLK_STS_OK;
358
359 /*
360 * This function is only called for read bio.
361 *
362 * This means two things:
363 * - All our csums should only be in csum tree
364 * No ordered extents csums, as ordered extents are only for write
365 * path.
366 * - No need to bother any other info from bvec
367 * Since we're looking up csums, the only important info is the
368 * disk_bytenr and the length, which can be extracted from bi_iter
369 * directly.
370 */
371 ASSERT(bio_op(bio) == REQ_OP_READ);
372 path = btrfs_alloc_path();
373 if (!path)
374 return BLK_STS_RESOURCE;
375
376 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
377 bbio->csum = kmalloc_array(nblocks, csum_size, GFP_NOFS);
378 if (!bbio->csum) {
379 btrfs_free_path(path);
380 return BLK_STS_RESOURCE;
381 }
382 } else {
383 bbio->csum = bbio->csum_inline;
384 }
385
386 /*
387 * If requested number of sectors is larger than one leaf can contain,
388 * kick the readahead for csum tree.
389 */
390 if (nblocks > fs_info->csums_per_leaf)
391 path->reada = READA_FORWARD;
392
393 /*
394 * the free space stuff is only read when it hasn't been
395 * updated in the current transaction. So, we can safely
396 * read from the commit root and sidestep a nasty deadlock
397 * between reading the free space cache and updating the csum tree.
398 */
399 if (btrfs_is_free_space_inode(inode)) {
400 path->search_commit_root = 1;
401 path->skip_locking = 1;
402 }
403
404 while (bio_offset < orig_len) {
405 int count;
406 u64 cur_disk_bytenr = orig_disk_bytenr + bio_offset;
407 u8 *csum_dst = bbio->csum +
408 (bio_offset >> fs_info->sectorsize_bits) * csum_size;
409
410 count = search_csum_tree(fs_info, path, cur_disk_bytenr,
411 orig_len - bio_offset, csum_dst);
412 if (count < 0) {
413 ret = errno_to_blk_status(count);
414 if (bbio->csum != bbio->csum_inline)
415 kfree(bbio->csum);
416 bbio->csum = NULL;
417 break;
418 }
419
420 /*
421 * We didn't find a csum for this range. We need to make sure
422 * we complain loudly about this, because we are not NODATASUM.
423 *
424 * However for the DATA_RELOC inode we could potentially be
425 * relocating data extents for a NODATASUM inode, so the inode
426 * itself won't be marked with NODATASUM, but the extent we're
427 * copying is in fact NODATASUM. If we don't find a csum we
428 * assume this is the case.
429 */
430 if (count == 0) {
431 memset(csum_dst, 0, csum_size);
432 count = 1;
433
434 if (btrfs_root_id(inode->root) == BTRFS_DATA_RELOC_TREE_OBJECTID) {
435 u64 file_offset = bbio->file_offset + bio_offset;
436
437 set_extent_bit(&inode->io_tree, file_offset,
438 file_offset + sectorsize - 1,
439 EXTENT_NODATASUM, NULL);
440 } else {
441 btrfs_warn_rl(fs_info,
442 "csum hole found for disk bytenr range [%llu, %llu)",
443 cur_disk_bytenr, cur_disk_bytenr + sectorsize);
444 }
445 }
446 bio_offset += count * sectorsize;
447 }
448
449 btrfs_free_path(path);
450 return ret;
451}
452
453/*
454 * Search for checksums for a given logical range.
455 *
456 * @root: The root where to look for checksums.
457 * @start: Logical address of target checksum range.
458 * @end: End offset (inclusive) of the target checksum range.
459 * @list: List for adding each checksum that was found.
460 * Can be NULL in case the caller only wants to check if
461 * there any checksums for the range.
462 * @nowait: Indicate if the search must be non-blocking or not.
463 *
464 * Return < 0 on error, 0 if no checksums were found, or 1 if checksums were
465 * found.
466 */
467int btrfs_lookup_csums_list(struct btrfs_root *root, u64 start, u64 end,
468 struct list_head *list, bool nowait)
469{
470 struct btrfs_fs_info *fs_info = root->fs_info;
471 struct btrfs_key key;
472 struct btrfs_path *path;
473 struct extent_buffer *leaf;
474 struct btrfs_ordered_sum *sums;
475 struct btrfs_csum_item *item;
476 int ret;
477 bool found_csums = false;
478
479 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
480 IS_ALIGNED(end + 1, fs_info->sectorsize));
481
482 path = btrfs_alloc_path();
483 if (!path)
484 return -ENOMEM;
485
486 path->nowait = nowait;
487
488 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
489 key.offset = start;
490 key.type = BTRFS_EXTENT_CSUM_KEY;
491
492 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
493 if (ret < 0)
494 goto out;
495 if (ret > 0 && path->slots[0] > 0) {
496 leaf = path->nodes[0];
497 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
498
499 /*
500 * There are two cases we can hit here for the previous csum
501 * item:
502 *
503 * |<- search range ->|
504 * |<- csum item ->|
505 *
506 * Or
507 * |<- search range ->|
508 * |<- csum item ->|
509 *
510 * Check if the previous csum item covers the leading part of
511 * the search range. If so we have to start from previous csum
512 * item.
513 */
514 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
515 key.type == BTRFS_EXTENT_CSUM_KEY) {
516 if (bytes_to_csum_size(fs_info, start - key.offset) <
517 btrfs_item_size(leaf, path->slots[0] - 1))
518 path->slots[0]--;
519 }
520 }
521
522 while (start <= end) {
523 u64 csum_end;
524
525 leaf = path->nodes[0];
526 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
527 ret = btrfs_next_leaf(root, path);
528 if (ret < 0)
529 goto out;
530 if (ret > 0)
531 break;
532 leaf = path->nodes[0];
533 }
534
535 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
536 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
537 key.type != BTRFS_EXTENT_CSUM_KEY ||
538 key.offset > end)
539 break;
540
541 if (key.offset > start)
542 start = key.offset;
543
544 csum_end = key.offset + csum_size_to_bytes(fs_info,
545 btrfs_item_size(leaf, path->slots[0]));
546 if (csum_end <= start) {
547 path->slots[0]++;
548 continue;
549 }
550
551 found_csums = true;
552 if (!list)
553 goto out;
554
555 csum_end = min(csum_end, end + 1);
556 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
557 struct btrfs_csum_item);
558 while (start < csum_end) {
559 unsigned long offset;
560 size_t size;
561
562 size = min_t(size_t, csum_end - start,
563 max_ordered_sum_bytes(fs_info));
564 sums = kzalloc(btrfs_ordered_sum_size(fs_info, size),
565 GFP_NOFS);
566 if (!sums) {
567 ret = -ENOMEM;
568 goto out;
569 }
570
571 sums->logical = start;
572 sums->len = size;
573
574 offset = bytes_to_csum_size(fs_info, start - key.offset);
575
576 read_extent_buffer(path->nodes[0],
577 sums->sums,
578 ((unsigned long)item) + offset,
579 bytes_to_csum_size(fs_info, size));
580
581 start += size;
582 list_add_tail(&sums->list, list);
583 }
584 path->slots[0]++;
585 }
586out:
587 btrfs_free_path(path);
588 if (ret < 0) {
589 if (list) {
590 struct btrfs_ordered_sum *tmp_sums;
591
592 list_for_each_entry_safe(sums, tmp_sums, list, list)
593 kfree(sums);
594 }
595
596 return ret;
597 }
598
599 return found_csums ? 1 : 0;
600}
601
602/*
603 * Do the same work as btrfs_lookup_csums_list(), the difference is in how
604 * we return the result.
605 *
606 * This version will set the corresponding bits in @csum_bitmap to represent
607 * that there is a csum found.
608 * Each bit represents a sector. Thus caller should ensure @csum_buf passed
609 * in is large enough to contain all csums.
610 */
611int btrfs_lookup_csums_bitmap(struct btrfs_root *root, struct btrfs_path *path,
612 u64 start, u64 end, u8 *csum_buf,
613 unsigned long *csum_bitmap)
614{
615 struct btrfs_fs_info *fs_info = root->fs_info;
616 struct btrfs_key key;
617 struct extent_buffer *leaf;
618 struct btrfs_csum_item *item;
619 const u64 orig_start = start;
620 bool free_path = false;
621 int ret;
622
623 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
624 IS_ALIGNED(end + 1, fs_info->sectorsize));
625
626 if (!path) {
627 path = btrfs_alloc_path();
628 if (!path)
629 return -ENOMEM;
630 free_path = true;
631 }
632
633 /* Check if we can reuse the previous path. */
634 if (path->nodes[0]) {
635 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
636
637 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
638 key.type == BTRFS_EXTENT_CSUM_KEY &&
639 key.offset <= start)
640 goto search_forward;
641 btrfs_release_path(path);
642 }
643
644 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
645 key.type = BTRFS_EXTENT_CSUM_KEY;
646 key.offset = start;
647
648 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
649 if (ret < 0)
650 goto fail;
651 if (ret > 0 && path->slots[0] > 0) {
652 leaf = path->nodes[0];
653 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
654
655 /*
656 * There are two cases we can hit here for the previous csum
657 * item:
658 *
659 * |<- search range ->|
660 * |<- csum item ->|
661 *
662 * Or
663 * |<- search range ->|
664 * |<- csum item ->|
665 *
666 * Check if the previous csum item covers the leading part of
667 * the search range. If so we have to start from previous csum
668 * item.
669 */
670 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
671 key.type == BTRFS_EXTENT_CSUM_KEY) {
672 if (bytes_to_csum_size(fs_info, start - key.offset) <
673 btrfs_item_size(leaf, path->slots[0] - 1))
674 path->slots[0]--;
675 }
676 }
677
678search_forward:
679 while (start <= end) {
680 u64 csum_end;
681
682 leaf = path->nodes[0];
683 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
684 ret = btrfs_next_leaf(root, path);
685 if (ret < 0)
686 goto fail;
687 if (ret > 0)
688 break;
689 leaf = path->nodes[0];
690 }
691
692 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
693 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
694 key.type != BTRFS_EXTENT_CSUM_KEY ||
695 key.offset > end)
696 break;
697
698 if (key.offset > start)
699 start = key.offset;
700
701 csum_end = key.offset + csum_size_to_bytes(fs_info,
702 btrfs_item_size(leaf, path->slots[0]));
703 if (csum_end <= start) {
704 path->slots[0]++;
705 continue;
706 }
707
708 csum_end = min(csum_end, end + 1);
709 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
710 struct btrfs_csum_item);
711 while (start < csum_end) {
712 unsigned long offset;
713 size_t size;
714 u8 *csum_dest = csum_buf + bytes_to_csum_size(fs_info,
715 start - orig_start);
716
717 size = min_t(size_t, csum_end - start, end + 1 - start);
718
719 offset = bytes_to_csum_size(fs_info, start - key.offset);
720
721 read_extent_buffer(path->nodes[0], csum_dest,
722 ((unsigned long)item) + offset,
723 bytes_to_csum_size(fs_info, size));
724
725 bitmap_set(csum_bitmap,
726 (start - orig_start) >> fs_info->sectorsize_bits,
727 size >> fs_info->sectorsize_bits);
728
729 start += size;
730 }
731 path->slots[0]++;
732 }
733 ret = 0;
734fail:
735 if (free_path)
736 btrfs_free_path(path);
737 return ret;
738}
739
740/*
741 * Calculate checksums of the data contained inside a bio.
742 */
743blk_status_t btrfs_csum_one_bio(struct btrfs_bio *bbio)
744{
745 struct btrfs_ordered_extent *ordered = bbio->ordered;
746 struct btrfs_inode *inode = bbio->inode;
747 struct btrfs_fs_info *fs_info = inode->root->fs_info;
748 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
749 struct bio *bio = &bbio->bio;
750 struct btrfs_ordered_sum *sums;
751 char *data;
752 struct bvec_iter iter;
753 struct bio_vec bvec;
754 int index;
755 unsigned int blockcount;
756 int i;
757 unsigned nofs_flag;
758
759 nofs_flag = memalloc_nofs_save();
760 sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
761 GFP_KERNEL);
762 memalloc_nofs_restore(nofs_flag);
763
764 if (!sums)
765 return BLK_STS_RESOURCE;
766
767 sums->len = bio->bi_iter.bi_size;
768 INIT_LIST_HEAD(&sums->list);
769
770 sums->logical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
771 index = 0;
772
773 shash->tfm = fs_info->csum_shash;
774
775 bio_for_each_segment(bvec, bio, iter) {
776 blockcount = BTRFS_BYTES_TO_BLKS(fs_info,
777 bvec.bv_len + fs_info->sectorsize
778 - 1);
779
780 for (i = 0; i < blockcount; i++) {
781 data = bvec_kmap_local(&bvec);
782 crypto_shash_digest(shash,
783 data + (i * fs_info->sectorsize),
784 fs_info->sectorsize,
785 sums->sums + index);
786 kunmap_local(data);
787 index += fs_info->csum_size;
788 }
789
790 }
791
792 bbio->sums = sums;
793 btrfs_add_ordered_sum(ordered, sums);
794 return 0;
795}
796
797/*
798 * Nodatasum I/O on zoned file systems still requires an btrfs_ordered_sum to
799 * record the updated logical address on Zone Append completion.
800 * Allocate just the structure with an empty sums array here for that case.
801 */
802blk_status_t btrfs_alloc_dummy_sum(struct btrfs_bio *bbio)
803{
804 bbio->sums = kmalloc(sizeof(*bbio->sums), GFP_NOFS);
805 if (!bbio->sums)
806 return BLK_STS_RESOURCE;
807 bbio->sums->len = bbio->bio.bi_iter.bi_size;
808 bbio->sums->logical = bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT;
809 btrfs_add_ordered_sum(bbio->ordered, bbio->sums);
810 return 0;
811}
812
813/*
814 * Remove one checksum overlapping a range.
815 *
816 * This expects the key to describe the csum pointed to by the path, and it
817 * expects the csum to overlap the range [bytenr, len]
818 *
819 * The csum should not be entirely contained in the range and the range should
820 * not be entirely contained in the csum.
821 *
822 * This calls btrfs_truncate_item with the correct args based on the overlap,
823 * and fixes up the key as required.
824 */
825static noinline void truncate_one_csum(struct btrfs_trans_handle *trans,
826 struct btrfs_path *path,
827 struct btrfs_key *key,
828 u64 bytenr, u64 len)
829{
830 struct btrfs_fs_info *fs_info = trans->fs_info;
831 struct extent_buffer *leaf;
832 const u32 csum_size = fs_info->csum_size;
833 u64 csum_end;
834 u64 end_byte = bytenr + len;
835 u32 blocksize_bits = fs_info->sectorsize_bits;
836
837 leaf = path->nodes[0];
838 csum_end = btrfs_item_size(leaf, path->slots[0]) / csum_size;
839 csum_end <<= blocksize_bits;
840 csum_end += key->offset;
841
842 if (key->offset < bytenr && csum_end <= end_byte) {
843 /*
844 * [ bytenr - len ]
845 * [ ]
846 * [csum ]
847 * A simple truncate off the end of the item
848 */
849 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
850 new_size *= csum_size;
851 btrfs_truncate_item(trans, path, new_size, 1);
852 } else if (key->offset >= bytenr && csum_end > end_byte &&
853 end_byte > key->offset) {
854 /*
855 * [ bytenr - len ]
856 * [ ]
857 * [csum ]
858 * we need to truncate from the beginning of the csum
859 */
860 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
861 new_size *= csum_size;
862
863 btrfs_truncate_item(trans, path, new_size, 0);
864
865 key->offset = end_byte;
866 btrfs_set_item_key_safe(trans, path, key);
867 } else {
868 BUG();
869 }
870}
871
872/*
873 * Delete the csum items from the csum tree for a given range of bytes.
874 */
875int btrfs_del_csums(struct btrfs_trans_handle *trans,
876 struct btrfs_root *root, u64 bytenr, u64 len)
877{
878 struct btrfs_fs_info *fs_info = trans->fs_info;
879 struct btrfs_path *path;
880 struct btrfs_key key;
881 u64 end_byte = bytenr + len;
882 u64 csum_end;
883 struct extent_buffer *leaf;
884 int ret = 0;
885 const u32 csum_size = fs_info->csum_size;
886 u32 blocksize_bits = fs_info->sectorsize_bits;
887
888 ASSERT(btrfs_root_id(root) == BTRFS_CSUM_TREE_OBJECTID ||
889 btrfs_root_id(root) == BTRFS_TREE_LOG_OBJECTID);
890
891 path = btrfs_alloc_path();
892 if (!path)
893 return -ENOMEM;
894
895 while (1) {
896 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
897 key.offset = end_byte - 1;
898 key.type = BTRFS_EXTENT_CSUM_KEY;
899
900 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
901 if (ret > 0) {
902 ret = 0;
903 if (path->slots[0] == 0)
904 break;
905 path->slots[0]--;
906 } else if (ret < 0) {
907 break;
908 }
909
910 leaf = path->nodes[0];
911 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
912
913 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
914 key.type != BTRFS_EXTENT_CSUM_KEY) {
915 break;
916 }
917
918 if (key.offset >= end_byte)
919 break;
920
921 csum_end = btrfs_item_size(leaf, path->slots[0]) / csum_size;
922 csum_end <<= blocksize_bits;
923 csum_end += key.offset;
924
925 /* this csum ends before we start, we're done */
926 if (csum_end <= bytenr)
927 break;
928
929 /* delete the entire item, it is inside our range */
930 if (key.offset >= bytenr && csum_end <= end_byte) {
931 int del_nr = 1;
932
933 /*
934 * Check how many csum items preceding this one in this
935 * leaf correspond to our range and then delete them all
936 * at once.
937 */
938 if (key.offset > bytenr && path->slots[0] > 0) {
939 int slot = path->slots[0] - 1;
940
941 while (slot >= 0) {
942 struct btrfs_key pk;
943
944 btrfs_item_key_to_cpu(leaf, &pk, slot);
945 if (pk.offset < bytenr ||
946 pk.type != BTRFS_EXTENT_CSUM_KEY ||
947 pk.objectid !=
948 BTRFS_EXTENT_CSUM_OBJECTID)
949 break;
950 path->slots[0] = slot;
951 del_nr++;
952 key.offset = pk.offset;
953 slot--;
954 }
955 }
956 ret = btrfs_del_items(trans, root, path,
957 path->slots[0], del_nr);
958 if (ret)
959 break;
960 if (key.offset == bytenr)
961 break;
962 } else if (key.offset < bytenr && csum_end > end_byte) {
963 unsigned long offset;
964 unsigned long shift_len;
965 unsigned long item_offset;
966 /*
967 * [ bytenr - len ]
968 * [csum ]
969 *
970 * Our bytes are in the middle of the csum,
971 * we need to split this item and insert a new one.
972 *
973 * But we can't drop the path because the
974 * csum could change, get removed, extended etc.
975 *
976 * The trick here is the max size of a csum item leaves
977 * enough room in the tree block for a single
978 * item header. So, we split the item in place,
979 * adding a new header pointing to the existing
980 * bytes. Then we loop around again and we have
981 * a nicely formed csum item that we can neatly
982 * truncate.
983 */
984 offset = (bytenr - key.offset) >> blocksize_bits;
985 offset *= csum_size;
986
987 shift_len = (len >> blocksize_bits) * csum_size;
988
989 item_offset = btrfs_item_ptr_offset(leaf,
990 path->slots[0]);
991
992 memzero_extent_buffer(leaf, item_offset + offset,
993 shift_len);
994 key.offset = bytenr;
995
996 /*
997 * btrfs_split_item returns -EAGAIN when the
998 * item changed size or key
999 */
1000 ret = btrfs_split_item(trans, root, path, &key, offset);
1001 if (ret && ret != -EAGAIN) {
1002 btrfs_abort_transaction(trans, ret);
1003 break;
1004 }
1005 ret = 0;
1006
1007 key.offset = end_byte - 1;
1008 } else {
1009 truncate_one_csum(trans, path, &key, bytenr, len);
1010 if (key.offset < bytenr)
1011 break;
1012 }
1013 btrfs_release_path(path);
1014 }
1015 btrfs_free_path(path);
1016 return ret;
1017}
1018
1019static int find_next_csum_offset(struct btrfs_root *root,
1020 struct btrfs_path *path,
1021 u64 *next_offset)
1022{
1023 const u32 nritems = btrfs_header_nritems(path->nodes[0]);
1024 struct btrfs_key found_key;
1025 int slot = path->slots[0] + 1;
1026 int ret;
1027
1028 if (nritems == 0 || slot >= nritems) {
1029 ret = btrfs_next_leaf(root, path);
1030 if (ret < 0) {
1031 return ret;
1032 } else if (ret > 0) {
1033 *next_offset = (u64)-1;
1034 return 0;
1035 }
1036 slot = path->slots[0];
1037 }
1038
1039 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
1040
1041 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
1042 found_key.type != BTRFS_EXTENT_CSUM_KEY)
1043 *next_offset = (u64)-1;
1044 else
1045 *next_offset = found_key.offset;
1046
1047 return 0;
1048}
1049
1050int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
1051 struct btrfs_root *root,
1052 struct btrfs_ordered_sum *sums)
1053{
1054 struct btrfs_fs_info *fs_info = root->fs_info;
1055 struct btrfs_key file_key;
1056 struct btrfs_key found_key;
1057 struct btrfs_path *path;
1058 struct btrfs_csum_item *item;
1059 struct btrfs_csum_item *item_end;
1060 struct extent_buffer *leaf = NULL;
1061 u64 next_offset;
1062 u64 total_bytes = 0;
1063 u64 csum_offset;
1064 u64 bytenr;
1065 u32 ins_size;
1066 int index = 0;
1067 int found_next;
1068 int ret;
1069 const u32 csum_size = fs_info->csum_size;
1070
1071 path = btrfs_alloc_path();
1072 if (!path)
1073 return -ENOMEM;
1074again:
1075 next_offset = (u64)-1;
1076 found_next = 0;
1077 bytenr = sums->logical + total_bytes;
1078 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
1079 file_key.offset = bytenr;
1080 file_key.type = BTRFS_EXTENT_CSUM_KEY;
1081
1082 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
1083 if (!IS_ERR(item)) {
1084 ret = 0;
1085 leaf = path->nodes[0];
1086 item_end = btrfs_item_ptr(leaf, path->slots[0],
1087 struct btrfs_csum_item);
1088 item_end = (struct btrfs_csum_item *)((char *)item_end +
1089 btrfs_item_size(leaf, path->slots[0]));
1090 goto found;
1091 }
1092 ret = PTR_ERR(item);
1093 if (ret != -EFBIG && ret != -ENOENT)
1094 goto out;
1095
1096 if (ret == -EFBIG) {
1097 u32 item_size;
1098 /* we found one, but it isn't big enough yet */
1099 leaf = path->nodes[0];
1100 item_size = btrfs_item_size(leaf, path->slots[0]);
1101 if ((item_size / csum_size) >=
1102 MAX_CSUM_ITEMS(fs_info, csum_size)) {
1103 /* already at max size, make a new one */
1104 goto insert;
1105 }
1106 } else {
1107 /* We didn't find a csum item, insert one. */
1108 ret = find_next_csum_offset(root, path, &next_offset);
1109 if (ret < 0)
1110 goto out;
1111 found_next = 1;
1112 goto insert;
1113 }
1114
1115 /*
1116 * At this point, we know the tree has a checksum item that ends at an
1117 * offset matching the start of the checksum range we want to insert.
1118 * We try to extend that item as much as possible and then add as many
1119 * checksums to it as they fit.
1120 *
1121 * First check if the leaf has enough free space for at least one
1122 * checksum. If it has go directly to the item extension code, otherwise
1123 * release the path and do a search for insertion before the extension.
1124 */
1125 if (btrfs_leaf_free_space(leaf) >= csum_size) {
1126 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1127 csum_offset = (bytenr - found_key.offset) >>
1128 fs_info->sectorsize_bits;
1129 goto extend_csum;
1130 }
1131
1132 btrfs_release_path(path);
1133 path->search_for_extension = 1;
1134 ret = btrfs_search_slot(trans, root, &file_key, path,
1135 csum_size, 1);
1136 path->search_for_extension = 0;
1137 if (ret < 0)
1138 goto out;
1139
1140 if (ret > 0) {
1141 if (path->slots[0] == 0)
1142 goto insert;
1143 path->slots[0]--;
1144 }
1145
1146 leaf = path->nodes[0];
1147 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1148 csum_offset = (bytenr - found_key.offset) >> fs_info->sectorsize_bits;
1149
1150 if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
1151 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
1152 csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
1153 goto insert;
1154 }
1155
1156extend_csum:
1157 if (csum_offset == btrfs_item_size(leaf, path->slots[0]) /
1158 csum_size) {
1159 int extend_nr;
1160 u64 tmp;
1161 u32 diff;
1162
1163 tmp = sums->len - total_bytes;
1164 tmp >>= fs_info->sectorsize_bits;
1165 WARN_ON(tmp < 1);
1166 extend_nr = max_t(int, 1, tmp);
1167
1168 /*
1169 * A log tree can already have checksum items with a subset of
1170 * the checksums we are trying to log. This can happen after
1171 * doing a sequence of partial writes into prealloc extents and
1172 * fsyncs in between, with a full fsync logging a larger subrange
1173 * of an extent for which a previous fast fsync logged a smaller
1174 * subrange. And this happens in particular due to merging file
1175 * extent items when we complete an ordered extent for a range
1176 * covered by a prealloc extent - this is done at
1177 * btrfs_mark_extent_written().
1178 *
1179 * So if we try to extend the previous checksum item, which has
1180 * a range that ends at the start of the range we want to insert,
1181 * make sure we don't extend beyond the start offset of the next
1182 * checksum item. If we are at the last item in the leaf, then
1183 * forget the optimization of extending and add a new checksum
1184 * item - it is not worth the complexity of releasing the path,
1185 * getting the first key for the next leaf, repeat the btree
1186 * search, etc, because log trees are temporary anyway and it
1187 * would only save a few bytes of leaf space.
1188 */
1189 if (btrfs_root_id(root) == BTRFS_TREE_LOG_OBJECTID) {
1190 if (path->slots[0] + 1 >=
1191 btrfs_header_nritems(path->nodes[0])) {
1192 ret = find_next_csum_offset(root, path, &next_offset);
1193 if (ret < 0)
1194 goto out;
1195 found_next = 1;
1196 goto insert;
1197 }
1198
1199 ret = find_next_csum_offset(root, path, &next_offset);
1200 if (ret < 0)
1201 goto out;
1202
1203 tmp = (next_offset - bytenr) >> fs_info->sectorsize_bits;
1204 if (tmp <= INT_MAX)
1205 extend_nr = min_t(int, extend_nr, tmp);
1206 }
1207
1208 diff = (csum_offset + extend_nr) * csum_size;
1209 diff = min(diff,
1210 MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
1211
1212 diff = diff - btrfs_item_size(leaf, path->slots[0]);
1213 diff = min_t(u32, btrfs_leaf_free_space(leaf), diff);
1214 diff /= csum_size;
1215 diff *= csum_size;
1216
1217 btrfs_extend_item(trans, path, diff);
1218 ret = 0;
1219 goto csum;
1220 }
1221
1222insert:
1223 btrfs_release_path(path);
1224 csum_offset = 0;
1225 if (found_next) {
1226 u64 tmp;
1227
1228 tmp = sums->len - total_bytes;
1229 tmp >>= fs_info->sectorsize_bits;
1230 tmp = min(tmp, (next_offset - file_key.offset) >>
1231 fs_info->sectorsize_bits);
1232
1233 tmp = max_t(u64, 1, tmp);
1234 tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
1235 ins_size = csum_size * tmp;
1236 } else {
1237 ins_size = csum_size;
1238 }
1239 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
1240 ins_size);
1241 if (ret < 0)
1242 goto out;
1243 leaf = path->nodes[0];
1244csum:
1245 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
1246 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
1247 btrfs_item_size(leaf, path->slots[0]));
1248 item = (struct btrfs_csum_item *)((unsigned char *)item +
1249 csum_offset * csum_size);
1250found:
1251 ins_size = (u32)(sums->len - total_bytes) >> fs_info->sectorsize_bits;
1252 ins_size *= csum_size;
1253 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
1254 ins_size);
1255 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
1256 ins_size);
1257
1258 index += ins_size;
1259 ins_size /= csum_size;
1260 total_bytes += ins_size * fs_info->sectorsize;
1261
1262 btrfs_mark_buffer_dirty(trans, path->nodes[0]);
1263 if (total_bytes < sums->len) {
1264 btrfs_release_path(path);
1265 cond_resched();
1266 goto again;
1267 }
1268out:
1269 btrfs_free_path(path);
1270 return ret;
1271}
1272
1273void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
1274 const struct btrfs_path *path,
1275 const struct btrfs_file_extent_item *fi,
1276 struct extent_map *em)
1277{
1278 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1279 struct btrfs_root *root = inode->root;
1280 struct extent_buffer *leaf = path->nodes[0];
1281 const int slot = path->slots[0];
1282 struct btrfs_key key;
1283 u64 extent_start;
1284 u8 type = btrfs_file_extent_type(leaf, fi);
1285 int compress_type = btrfs_file_extent_compression(leaf, fi);
1286
1287 btrfs_item_key_to_cpu(leaf, &key, slot);
1288 extent_start = key.offset;
1289 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1290 em->generation = btrfs_file_extent_generation(leaf, fi);
1291 if (type == BTRFS_FILE_EXTENT_REG ||
1292 type == BTRFS_FILE_EXTENT_PREALLOC) {
1293 const u64 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1294
1295 em->start = extent_start;
1296 em->len = btrfs_file_extent_end(path) - extent_start;
1297 if (disk_bytenr == 0) {
1298 em->disk_bytenr = EXTENT_MAP_HOLE;
1299 em->disk_num_bytes = 0;
1300 em->offset = 0;
1301 return;
1302 }
1303 em->disk_bytenr = disk_bytenr;
1304 em->disk_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1305 em->offset = btrfs_file_extent_offset(leaf, fi);
1306 if (compress_type != BTRFS_COMPRESS_NONE) {
1307 extent_map_set_compression(em, compress_type);
1308 } else {
1309 /*
1310 * Older kernels can create regular non-hole data
1311 * extents with ram_bytes smaller than disk_num_bytes.
1312 * Not a big deal, just always use disk_num_bytes
1313 * for ram_bytes.
1314 */
1315 em->ram_bytes = em->disk_num_bytes;
1316 if (type == BTRFS_FILE_EXTENT_PREALLOC)
1317 em->flags |= EXTENT_FLAG_PREALLOC;
1318 }
1319 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1320 /* Tree-checker has ensured this. */
1321 ASSERT(extent_start == 0);
1322
1323 em->disk_bytenr = EXTENT_MAP_INLINE;
1324 em->start = 0;
1325 em->len = fs_info->sectorsize;
1326 em->offset = 0;
1327 extent_map_set_compression(em, compress_type);
1328 } else {
1329 btrfs_err(fs_info,
1330 "unknown file extent item type %d, inode %llu, offset %llu, "
1331 "root %llu", type, btrfs_ino(inode), extent_start,
1332 btrfs_root_id(root));
1333 }
1334}
1335
1336/*
1337 * Returns the end offset (non inclusive) of the file extent item the given path
1338 * points to. If it points to an inline extent, the returned offset is rounded
1339 * up to the sector size.
1340 */
1341u64 btrfs_file_extent_end(const struct btrfs_path *path)
1342{
1343 const struct extent_buffer *leaf = path->nodes[0];
1344 const int slot = path->slots[0];
1345 struct btrfs_file_extent_item *fi;
1346 struct btrfs_key key;
1347 u64 end;
1348
1349 btrfs_item_key_to_cpu(leaf, &key, slot);
1350 ASSERT(key.type == BTRFS_EXTENT_DATA_KEY);
1351 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1352
1353 if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE)
1354 end = leaf->fs_info->sectorsize;
1355 else
1356 end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1357
1358 return end;
1359}
1/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/bio.h>
20#include <linux/slab.h>
21#include <linux/pagemap.h>
22#include <linux/highmem.h>
23#include "ctree.h"
24#include "disk-io.h"
25#include "transaction.h"
26#include "volumes.h"
27#include "print-tree.h"
28#include "compression.h"
29
30#define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
31 sizeof(struct btrfs_item) * 2) / \
32 size) - 1))
33
34#define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
35 PAGE_SIZE))
36
37#define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
38 sizeof(struct btrfs_ordered_sum)) / \
39 sizeof(u32) * (r)->sectorsize)
40
41int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
42 struct btrfs_root *root,
43 u64 objectid, u64 pos,
44 u64 disk_offset, u64 disk_num_bytes,
45 u64 num_bytes, u64 offset, u64 ram_bytes,
46 u8 compression, u8 encryption, u16 other_encoding)
47{
48 int ret = 0;
49 struct btrfs_file_extent_item *item;
50 struct btrfs_key file_key;
51 struct btrfs_path *path;
52 struct extent_buffer *leaf;
53
54 path = btrfs_alloc_path();
55 if (!path)
56 return -ENOMEM;
57 file_key.objectid = objectid;
58 file_key.offset = pos;
59 file_key.type = BTRFS_EXTENT_DATA_KEY;
60
61 path->leave_spinning = 1;
62 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
63 sizeof(*item));
64 if (ret < 0)
65 goto out;
66 BUG_ON(ret); /* Can't happen */
67 leaf = path->nodes[0];
68 item = btrfs_item_ptr(leaf, path->slots[0],
69 struct btrfs_file_extent_item);
70 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
71 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
72 btrfs_set_file_extent_offset(leaf, item, offset);
73 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
74 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
75 btrfs_set_file_extent_generation(leaf, item, trans->transid);
76 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
77 btrfs_set_file_extent_compression(leaf, item, compression);
78 btrfs_set_file_extent_encryption(leaf, item, encryption);
79 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
80
81 btrfs_mark_buffer_dirty(leaf);
82out:
83 btrfs_free_path(path);
84 return ret;
85}
86
87static struct btrfs_csum_item *
88btrfs_lookup_csum(struct btrfs_trans_handle *trans,
89 struct btrfs_root *root,
90 struct btrfs_path *path,
91 u64 bytenr, int cow)
92{
93 int ret;
94 struct btrfs_key file_key;
95 struct btrfs_key found_key;
96 struct btrfs_csum_item *item;
97 struct extent_buffer *leaf;
98 u64 csum_offset = 0;
99 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
100 int csums_in_item;
101
102 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
103 file_key.offset = bytenr;
104 file_key.type = BTRFS_EXTENT_CSUM_KEY;
105 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
106 if (ret < 0)
107 goto fail;
108 leaf = path->nodes[0];
109 if (ret > 0) {
110 ret = 1;
111 if (path->slots[0] == 0)
112 goto fail;
113 path->slots[0]--;
114 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
115 if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
116 goto fail;
117
118 csum_offset = (bytenr - found_key.offset) >>
119 root->fs_info->sb->s_blocksize_bits;
120 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
121 csums_in_item /= csum_size;
122
123 if (csum_offset == csums_in_item) {
124 ret = -EFBIG;
125 goto fail;
126 } else if (csum_offset > csums_in_item) {
127 goto fail;
128 }
129 }
130 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
131 item = (struct btrfs_csum_item *)((unsigned char *)item +
132 csum_offset * csum_size);
133 return item;
134fail:
135 if (ret > 0)
136 ret = -ENOENT;
137 return ERR_PTR(ret);
138}
139
140int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
141 struct btrfs_root *root,
142 struct btrfs_path *path, u64 objectid,
143 u64 offset, int mod)
144{
145 int ret;
146 struct btrfs_key file_key;
147 int ins_len = mod < 0 ? -1 : 0;
148 int cow = mod != 0;
149
150 file_key.objectid = objectid;
151 file_key.offset = offset;
152 file_key.type = BTRFS_EXTENT_DATA_KEY;
153 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
154 return ret;
155}
156
157static void btrfs_io_bio_endio_readpage(struct btrfs_io_bio *bio, int err)
158{
159 kfree(bio->csum_allocated);
160}
161
162static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
163 struct inode *inode, struct bio *bio,
164 u64 logical_offset, u32 *dst, int dio)
165{
166 struct bio_vec *bvec = bio->bi_io_vec;
167 struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
168 struct btrfs_csum_item *item = NULL;
169 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
170 struct btrfs_path *path;
171 u8 *csum;
172 u64 offset = 0;
173 u64 item_start_offset = 0;
174 u64 item_last_offset = 0;
175 u64 disk_bytenr;
176 u64 page_bytes_left;
177 u32 diff;
178 int nblocks;
179 int bio_index = 0;
180 int count;
181 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
182
183 path = btrfs_alloc_path();
184 if (!path)
185 return -ENOMEM;
186
187 nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits;
188 if (!dst) {
189 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
190 btrfs_bio->csum_allocated = kmalloc_array(nblocks,
191 csum_size, GFP_NOFS);
192 if (!btrfs_bio->csum_allocated) {
193 btrfs_free_path(path);
194 return -ENOMEM;
195 }
196 btrfs_bio->csum = btrfs_bio->csum_allocated;
197 btrfs_bio->end_io = btrfs_io_bio_endio_readpage;
198 } else {
199 btrfs_bio->csum = btrfs_bio->csum_inline;
200 }
201 csum = btrfs_bio->csum;
202 } else {
203 csum = (u8 *)dst;
204 }
205
206 if (bio->bi_iter.bi_size > PAGE_SIZE * 8)
207 path->reada = READA_FORWARD;
208
209 WARN_ON(bio->bi_vcnt <= 0);
210
211 /*
212 * the free space stuff is only read when it hasn't been
213 * updated in the current transaction. So, we can safely
214 * read from the commit root and sidestep a nasty deadlock
215 * between reading the free space cache and updating the csum tree.
216 */
217 if (btrfs_is_free_space_inode(inode)) {
218 path->search_commit_root = 1;
219 path->skip_locking = 1;
220 }
221
222 disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
223 if (dio)
224 offset = logical_offset;
225
226 page_bytes_left = bvec->bv_len;
227 while (bio_index < bio->bi_vcnt) {
228 if (!dio)
229 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
230 count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
231 (u32 *)csum, nblocks);
232 if (count)
233 goto found;
234
235 if (!item || disk_bytenr < item_start_offset ||
236 disk_bytenr >= item_last_offset) {
237 struct btrfs_key found_key;
238 u32 item_size;
239
240 if (item)
241 btrfs_release_path(path);
242 item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
243 path, disk_bytenr, 0);
244 if (IS_ERR(item)) {
245 count = 1;
246 memset(csum, 0, csum_size);
247 if (BTRFS_I(inode)->root->root_key.objectid ==
248 BTRFS_DATA_RELOC_TREE_OBJECTID) {
249 set_extent_bits(io_tree, offset,
250 offset + root->sectorsize - 1,
251 EXTENT_NODATASUM, GFP_NOFS);
252 } else {
253 btrfs_info(BTRFS_I(inode)->root->fs_info,
254 "no csum found for inode %llu start %llu",
255 btrfs_ino(inode), offset);
256 }
257 item = NULL;
258 btrfs_release_path(path);
259 goto found;
260 }
261 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
262 path->slots[0]);
263
264 item_start_offset = found_key.offset;
265 item_size = btrfs_item_size_nr(path->nodes[0],
266 path->slots[0]);
267 item_last_offset = item_start_offset +
268 (item_size / csum_size) *
269 root->sectorsize;
270 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
271 struct btrfs_csum_item);
272 }
273 /*
274 * this byte range must be able to fit inside
275 * a single leaf so it will also fit inside a u32
276 */
277 diff = disk_bytenr - item_start_offset;
278 diff = diff / root->sectorsize;
279 diff = diff * csum_size;
280 count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >>
281 inode->i_sb->s_blocksize_bits);
282 read_extent_buffer(path->nodes[0], csum,
283 ((unsigned long)item) + diff,
284 csum_size * count);
285found:
286 csum += count * csum_size;
287 nblocks -= count;
288
289 while (count--) {
290 disk_bytenr += root->sectorsize;
291 offset += root->sectorsize;
292 page_bytes_left -= root->sectorsize;
293 if (!page_bytes_left) {
294 bio_index++;
295 /*
296 * make sure we're still inside the
297 * bio before we update page_bytes_left
298 */
299 if (bio_index >= bio->bi_vcnt) {
300 WARN_ON_ONCE(count);
301 goto done;
302 }
303 bvec++;
304 page_bytes_left = bvec->bv_len;
305 }
306
307 }
308 }
309
310done:
311 btrfs_free_path(path);
312 return 0;
313}
314
315int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
316 struct bio *bio, u32 *dst)
317{
318 return __btrfs_lookup_bio_sums(root, inode, bio, 0, dst, 0);
319}
320
321int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
322 struct bio *bio, u64 offset)
323{
324 return __btrfs_lookup_bio_sums(root, inode, bio, offset, NULL, 1);
325}
326
327int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
328 struct list_head *list, int search_commit)
329{
330 struct btrfs_key key;
331 struct btrfs_path *path;
332 struct extent_buffer *leaf;
333 struct btrfs_ordered_sum *sums;
334 struct btrfs_csum_item *item;
335 LIST_HEAD(tmplist);
336 unsigned long offset;
337 int ret;
338 size_t size;
339 u64 csum_end;
340 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
341
342 ASSERT(IS_ALIGNED(start, root->sectorsize) &&
343 IS_ALIGNED(end + 1, root->sectorsize));
344
345 path = btrfs_alloc_path();
346 if (!path)
347 return -ENOMEM;
348
349 if (search_commit) {
350 path->skip_locking = 1;
351 path->reada = READA_FORWARD;
352 path->search_commit_root = 1;
353 }
354
355 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
356 key.offset = start;
357 key.type = BTRFS_EXTENT_CSUM_KEY;
358
359 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
360 if (ret < 0)
361 goto fail;
362 if (ret > 0 && path->slots[0] > 0) {
363 leaf = path->nodes[0];
364 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
365 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
366 key.type == BTRFS_EXTENT_CSUM_KEY) {
367 offset = (start - key.offset) >>
368 root->fs_info->sb->s_blocksize_bits;
369 if (offset * csum_size <
370 btrfs_item_size_nr(leaf, path->slots[0] - 1))
371 path->slots[0]--;
372 }
373 }
374
375 while (start <= end) {
376 leaf = path->nodes[0];
377 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
378 ret = btrfs_next_leaf(root, path);
379 if (ret < 0)
380 goto fail;
381 if (ret > 0)
382 break;
383 leaf = path->nodes[0];
384 }
385
386 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
387 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
388 key.type != BTRFS_EXTENT_CSUM_KEY ||
389 key.offset > end)
390 break;
391
392 if (key.offset > start)
393 start = key.offset;
394
395 size = btrfs_item_size_nr(leaf, path->slots[0]);
396 csum_end = key.offset + (size / csum_size) * root->sectorsize;
397 if (csum_end <= start) {
398 path->slots[0]++;
399 continue;
400 }
401
402 csum_end = min(csum_end, end + 1);
403 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
404 struct btrfs_csum_item);
405 while (start < csum_end) {
406 size = min_t(size_t, csum_end - start,
407 MAX_ORDERED_SUM_BYTES(root));
408 sums = kzalloc(btrfs_ordered_sum_size(root, size),
409 GFP_NOFS);
410 if (!sums) {
411 ret = -ENOMEM;
412 goto fail;
413 }
414
415 sums->bytenr = start;
416 sums->len = (int)size;
417
418 offset = (start - key.offset) >>
419 root->fs_info->sb->s_blocksize_bits;
420 offset *= csum_size;
421 size >>= root->fs_info->sb->s_blocksize_bits;
422
423 read_extent_buffer(path->nodes[0],
424 sums->sums,
425 ((unsigned long)item) + offset,
426 csum_size * size);
427
428 start += root->sectorsize * size;
429 list_add_tail(&sums->list, &tmplist);
430 }
431 path->slots[0]++;
432 }
433 ret = 0;
434fail:
435 while (ret < 0 && !list_empty(&tmplist)) {
436 sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list);
437 list_del(&sums->list);
438 kfree(sums);
439 }
440 list_splice_tail(&tmplist, list);
441
442 btrfs_free_path(path);
443 return ret;
444}
445
446int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
447 struct bio *bio, u64 file_start, int contig)
448{
449 struct btrfs_ordered_sum *sums;
450 struct btrfs_ordered_extent *ordered;
451 char *data;
452 struct bio_vec *bvec = bio->bi_io_vec;
453 int bio_index = 0;
454 int index;
455 int nr_sectors;
456 int i;
457 unsigned long total_bytes = 0;
458 unsigned long this_sum_bytes = 0;
459 u64 offset;
460
461 WARN_ON(bio->bi_vcnt <= 0);
462 sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_iter.bi_size),
463 GFP_NOFS);
464 if (!sums)
465 return -ENOMEM;
466
467 sums->len = bio->bi_iter.bi_size;
468 INIT_LIST_HEAD(&sums->list);
469
470 if (contig)
471 offset = file_start;
472 else
473 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
474
475 ordered = btrfs_lookup_ordered_extent(inode, offset);
476 BUG_ON(!ordered); /* Logic error */
477 sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
478 index = 0;
479
480 while (bio_index < bio->bi_vcnt) {
481 if (!contig)
482 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
483
484 data = kmap_atomic(bvec->bv_page);
485
486 nr_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info,
487 bvec->bv_len + root->sectorsize
488 - 1);
489
490 for (i = 0; i < nr_sectors; i++) {
491 if (offset >= ordered->file_offset + ordered->len ||
492 offset < ordered->file_offset) {
493 unsigned long bytes_left;
494
495 kunmap_atomic(data);
496 sums->len = this_sum_bytes;
497 this_sum_bytes = 0;
498 btrfs_add_ordered_sum(inode, ordered, sums);
499 btrfs_put_ordered_extent(ordered);
500
501 bytes_left = bio->bi_iter.bi_size - total_bytes;
502
503 sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
504 GFP_NOFS);
505 BUG_ON(!sums); /* -ENOMEM */
506 sums->len = bytes_left;
507 ordered = btrfs_lookup_ordered_extent(inode,
508 offset);
509 ASSERT(ordered); /* Logic error */
510 sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9)
511 + total_bytes;
512 index = 0;
513
514 data = kmap_atomic(bvec->bv_page);
515 }
516
517 sums->sums[index] = ~(u32)0;
518 sums->sums[index]
519 = btrfs_csum_data(data + bvec->bv_offset
520 + (i * root->sectorsize),
521 sums->sums[index],
522 root->sectorsize);
523 btrfs_csum_final(sums->sums[index],
524 (char *)(sums->sums + index));
525 index++;
526 offset += root->sectorsize;
527 this_sum_bytes += root->sectorsize;
528 total_bytes += root->sectorsize;
529 }
530
531 kunmap_atomic(data);
532
533 bio_index++;
534 bvec++;
535 }
536 this_sum_bytes = 0;
537 btrfs_add_ordered_sum(inode, ordered, sums);
538 btrfs_put_ordered_extent(ordered);
539 return 0;
540}
541
542/*
543 * helper function for csum removal, this expects the
544 * key to describe the csum pointed to by the path, and it expects
545 * the csum to overlap the range [bytenr, len]
546 *
547 * The csum should not be entirely contained in the range and the
548 * range should not be entirely contained in the csum.
549 *
550 * This calls btrfs_truncate_item with the correct args based on the
551 * overlap, and fixes up the key as required.
552 */
553static noinline void truncate_one_csum(struct btrfs_root *root,
554 struct btrfs_path *path,
555 struct btrfs_key *key,
556 u64 bytenr, u64 len)
557{
558 struct extent_buffer *leaf;
559 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
560 u64 csum_end;
561 u64 end_byte = bytenr + len;
562 u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
563
564 leaf = path->nodes[0];
565 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
566 csum_end <<= root->fs_info->sb->s_blocksize_bits;
567 csum_end += key->offset;
568
569 if (key->offset < bytenr && csum_end <= end_byte) {
570 /*
571 * [ bytenr - len ]
572 * [ ]
573 * [csum ]
574 * A simple truncate off the end of the item
575 */
576 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
577 new_size *= csum_size;
578 btrfs_truncate_item(root, path, new_size, 1);
579 } else if (key->offset >= bytenr && csum_end > end_byte &&
580 end_byte > key->offset) {
581 /*
582 * [ bytenr - len ]
583 * [ ]
584 * [csum ]
585 * we need to truncate from the beginning of the csum
586 */
587 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
588 new_size *= csum_size;
589
590 btrfs_truncate_item(root, path, new_size, 0);
591
592 key->offset = end_byte;
593 btrfs_set_item_key_safe(root->fs_info, path, key);
594 } else {
595 BUG();
596 }
597}
598
599/*
600 * deletes the csum items from the csum tree for a given
601 * range of bytes.
602 */
603int btrfs_del_csums(struct btrfs_trans_handle *trans,
604 struct btrfs_root *root, u64 bytenr, u64 len)
605{
606 struct btrfs_path *path;
607 struct btrfs_key key;
608 u64 end_byte = bytenr + len;
609 u64 csum_end;
610 struct extent_buffer *leaf;
611 int ret;
612 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
613 int blocksize_bits = root->fs_info->sb->s_blocksize_bits;
614
615 root = root->fs_info->csum_root;
616
617 path = btrfs_alloc_path();
618 if (!path)
619 return -ENOMEM;
620
621 while (1) {
622 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
623 key.offset = end_byte - 1;
624 key.type = BTRFS_EXTENT_CSUM_KEY;
625
626 path->leave_spinning = 1;
627 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
628 if (ret > 0) {
629 if (path->slots[0] == 0)
630 break;
631 path->slots[0]--;
632 } else if (ret < 0) {
633 break;
634 }
635
636 leaf = path->nodes[0];
637 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
638
639 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
640 key.type != BTRFS_EXTENT_CSUM_KEY) {
641 break;
642 }
643
644 if (key.offset >= end_byte)
645 break;
646
647 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
648 csum_end <<= blocksize_bits;
649 csum_end += key.offset;
650
651 /* this csum ends before we start, we're done */
652 if (csum_end <= bytenr)
653 break;
654
655 /* delete the entire item, it is inside our range */
656 if (key.offset >= bytenr && csum_end <= end_byte) {
657 ret = btrfs_del_item(trans, root, path);
658 if (ret)
659 goto out;
660 if (key.offset == bytenr)
661 break;
662 } else if (key.offset < bytenr && csum_end > end_byte) {
663 unsigned long offset;
664 unsigned long shift_len;
665 unsigned long item_offset;
666 /*
667 * [ bytenr - len ]
668 * [csum ]
669 *
670 * Our bytes are in the middle of the csum,
671 * we need to split this item and insert a new one.
672 *
673 * But we can't drop the path because the
674 * csum could change, get removed, extended etc.
675 *
676 * The trick here is the max size of a csum item leaves
677 * enough room in the tree block for a single
678 * item header. So, we split the item in place,
679 * adding a new header pointing to the existing
680 * bytes. Then we loop around again and we have
681 * a nicely formed csum item that we can neatly
682 * truncate.
683 */
684 offset = (bytenr - key.offset) >> blocksize_bits;
685 offset *= csum_size;
686
687 shift_len = (len >> blocksize_bits) * csum_size;
688
689 item_offset = btrfs_item_ptr_offset(leaf,
690 path->slots[0]);
691
692 memset_extent_buffer(leaf, 0, item_offset + offset,
693 shift_len);
694 key.offset = bytenr;
695
696 /*
697 * btrfs_split_item returns -EAGAIN when the
698 * item changed size or key
699 */
700 ret = btrfs_split_item(trans, root, path, &key, offset);
701 if (ret && ret != -EAGAIN) {
702 btrfs_abort_transaction(trans, root, ret);
703 goto out;
704 }
705
706 key.offset = end_byte - 1;
707 } else {
708 truncate_one_csum(root, path, &key, bytenr, len);
709 if (key.offset < bytenr)
710 break;
711 }
712 btrfs_release_path(path);
713 }
714 ret = 0;
715out:
716 btrfs_free_path(path);
717 return ret;
718}
719
720int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
721 struct btrfs_root *root,
722 struct btrfs_ordered_sum *sums)
723{
724 struct btrfs_key file_key;
725 struct btrfs_key found_key;
726 struct btrfs_path *path;
727 struct btrfs_csum_item *item;
728 struct btrfs_csum_item *item_end;
729 struct extent_buffer *leaf = NULL;
730 u64 next_offset;
731 u64 total_bytes = 0;
732 u64 csum_offset;
733 u64 bytenr;
734 u32 nritems;
735 u32 ins_size;
736 int index = 0;
737 int found_next;
738 int ret;
739 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
740
741 path = btrfs_alloc_path();
742 if (!path)
743 return -ENOMEM;
744again:
745 next_offset = (u64)-1;
746 found_next = 0;
747 bytenr = sums->bytenr + total_bytes;
748 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
749 file_key.offset = bytenr;
750 file_key.type = BTRFS_EXTENT_CSUM_KEY;
751
752 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
753 if (!IS_ERR(item)) {
754 ret = 0;
755 leaf = path->nodes[0];
756 item_end = btrfs_item_ptr(leaf, path->slots[0],
757 struct btrfs_csum_item);
758 item_end = (struct btrfs_csum_item *)((char *)item_end +
759 btrfs_item_size_nr(leaf, path->slots[0]));
760 goto found;
761 }
762 ret = PTR_ERR(item);
763 if (ret != -EFBIG && ret != -ENOENT)
764 goto fail_unlock;
765
766 if (ret == -EFBIG) {
767 u32 item_size;
768 /* we found one, but it isn't big enough yet */
769 leaf = path->nodes[0];
770 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
771 if ((item_size / csum_size) >=
772 MAX_CSUM_ITEMS(root, csum_size)) {
773 /* already at max size, make a new one */
774 goto insert;
775 }
776 } else {
777 int slot = path->slots[0] + 1;
778 /* we didn't find a csum item, insert one */
779 nritems = btrfs_header_nritems(path->nodes[0]);
780 if (!nritems || (path->slots[0] >= nritems - 1)) {
781 ret = btrfs_next_leaf(root, path);
782 if (ret == 1)
783 found_next = 1;
784 if (ret != 0)
785 goto insert;
786 slot = path->slots[0];
787 }
788 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
789 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
790 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
791 found_next = 1;
792 goto insert;
793 }
794 next_offset = found_key.offset;
795 found_next = 1;
796 goto insert;
797 }
798
799 /*
800 * at this point, we know the tree has an item, but it isn't big
801 * enough yet to put our csum in. Grow it
802 */
803 btrfs_release_path(path);
804 ret = btrfs_search_slot(trans, root, &file_key, path,
805 csum_size, 1);
806 if (ret < 0)
807 goto fail_unlock;
808
809 if (ret > 0) {
810 if (path->slots[0] == 0)
811 goto insert;
812 path->slots[0]--;
813 }
814
815 leaf = path->nodes[0];
816 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
817 csum_offset = (bytenr - found_key.offset) >>
818 root->fs_info->sb->s_blocksize_bits;
819
820 if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
821 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
822 csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
823 goto insert;
824 }
825
826 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
827 csum_size) {
828 int extend_nr;
829 u64 tmp;
830 u32 diff;
831 u32 free_space;
832
833 if (btrfs_leaf_free_space(root, leaf) <
834 sizeof(struct btrfs_item) + csum_size * 2)
835 goto insert;
836
837 free_space = btrfs_leaf_free_space(root, leaf) -
838 sizeof(struct btrfs_item) - csum_size;
839 tmp = sums->len - total_bytes;
840 tmp >>= root->fs_info->sb->s_blocksize_bits;
841 WARN_ON(tmp < 1);
842
843 extend_nr = max_t(int, 1, (int)tmp);
844 diff = (csum_offset + extend_nr) * csum_size;
845 diff = min(diff, MAX_CSUM_ITEMS(root, csum_size) * csum_size);
846
847 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
848 diff = min(free_space, diff);
849 diff /= csum_size;
850 diff *= csum_size;
851
852 btrfs_extend_item(root, path, diff);
853 ret = 0;
854 goto csum;
855 }
856
857insert:
858 btrfs_release_path(path);
859 csum_offset = 0;
860 if (found_next) {
861 u64 tmp;
862
863 tmp = sums->len - total_bytes;
864 tmp >>= root->fs_info->sb->s_blocksize_bits;
865 tmp = min(tmp, (next_offset - file_key.offset) >>
866 root->fs_info->sb->s_blocksize_bits);
867
868 tmp = max((u64)1, tmp);
869 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
870 ins_size = csum_size * tmp;
871 } else {
872 ins_size = csum_size;
873 }
874 path->leave_spinning = 1;
875 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
876 ins_size);
877 path->leave_spinning = 0;
878 if (ret < 0)
879 goto fail_unlock;
880 if (WARN_ON(ret != 0))
881 goto fail_unlock;
882 leaf = path->nodes[0];
883csum:
884 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
885 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
886 btrfs_item_size_nr(leaf, path->slots[0]));
887 item = (struct btrfs_csum_item *)((unsigned char *)item +
888 csum_offset * csum_size);
889found:
890 ins_size = (u32)(sums->len - total_bytes) >>
891 root->fs_info->sb->s_blocksize_bits;
892 ins_size *= csum_size;
893 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
894 ins_size);
895 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
896 ins_size);
897
898 ins_size /= csum_size;
899 total_bytes += ins_size * root->sectorsize;
900 index += ins_size;
901
902 btrfs_mark_buffer_dirty(path->nodes[0]);
903 if (total_bytes < sums->len) {
904 btrfs_release_path(path);
905 cond_resched();
906 goto again;
907 }
908out:
909 btrfs_free_path(path);
910 return ret;
911
912fail_unlock:
913 goto out;
914}
915
916void btrfs_extent_item_to_extent_map(struct inode *inode,
917 const struct btrfs_path *path,
918 struct btrfs_file_extent_item *fi,
919 const bool new_inline,
920 struct extent_map *em)
921{
922 struct btrfs_root *root = BTRFS_I(inode)->root;
923 struct extent_buffer *leaf = path->nodes[0];
924 const int slot = path->slots[0];
925 struct btrfs_key key;
926 u64 extent_start, extent_end;
927 u64 bytenr;
928 u8 type = btrfs_file_extent_type(leaf, fi);
929 int compress_type = btrfs_file_extent_compression(leaf, fi);
930
931 em->bdev = root->fs_info->fs_devices->latest_bdev;
932 btrfs_item_key_to_cpu(leaf, &key, slot);
933 extent_start = key.offset;
934
935 if (type == BTRFS_FILE_EXTENT_REG ||
936 type == BTRFS_FILE_EXTENT_PREALLOC) {
937 extent_end = extent_start +
938 btrfs_file_extent_num_bytes(leaf, fi);
939 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
940 size_t size;
941 size = btrfs_file_extent_inline_len(leaf, slot, fi);
942 extent_end = ALIGN(extent_start + size, root->sectorsize);
943 }
944
945 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
946 if (type == BTRFS_FILE_EXTENT_REG ||
947 type == BTRFS_FILE_EXTENT_PREALLOC) {
948 em->start = extent_start;
949 em->len = extent_end - extent_start;
950 em->orig_start = extent_start -
951 btrfs_file_extent_offset(leaf, fi);
952 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
953 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
954 if (bytenr == 0) {
955 em->block_start = EXTENT_MAP_HOLE;
956 return;
957 }
958 if (compress_type != BTRFS_COMPRESS_NONE) {
959 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
960 em->compress_type = compress_type;
961 em->block_start = bytenr;
962 em->block_len = em->orig_block_len;
963 } else {
964 bytenr += btrfs_file_extent_offset(leaf, fi);
965 em->block_start = bytenr;
966 em->block_len = em->len;
967 if (type == BTRFS_FILE_EXTENT_PREALLOC)
968 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
969 }
970 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
971 em->block_start = EXTENT_MAP_INLINE;
972 em->start = extent_start;
973 em->len = extent_end - extent_start;
974 /*
975 * Initialize orig_start and block_len with the same values
976 * as in inode.c:btrfs_get_extent().
977 */
978 em->orig_start = EXTENT_MAP_HOLE;
979 em->block_len = (u64)-1;
980 if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) {
981 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
982 em->compress_type = compress_type;
983 }
984 } else {
985 btrfs_err(root->fs_info,
986 "unknown file extent item type %d, inode %llu, offset %llu, root %llu",
987 type, btrfs_ino(inode), extent_start,
988 root->root_key.objectid);
989 }
990}