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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#include <linux/bio.h>
7#include <linux/slab.h>
8#include <linux/pagemap.h>
9#include <linux/highmem.h>
10#include <linux/sched/mm.h>
11#include <crypto/hash.h>
12#include "ctree.h"
13#include "disk-io.h"
14#include "transaction.h"
15#include "volumes.h"
16#include "print-tree.h"
17#include "compression.h"
18
19#define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
20 sizeof(struct btrfs_item) * 2) / \
21 size) - 1))
22
23#define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
24 PAGE_SIZE))
25
26static inline u32 max_ordered_sum_bytes(struct btrfs_fs_info *fs_info,
27 u16 csum_size)
28{
29 u32 ncsums = (PAGE_SIZE - sizeof(struct btrfs_ordered_sum)) / csum_size;
30
31 return ncsums * fs_info->sectorsize;
32}
33
34int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
35 struct btrfs_root *root,
36 u64 objectid, u64 pos,
37 u64 disk_offset, u64 disk_num_bytes,
38 u64 num_bytes, u64 offset, u64 ram_bytes,
39 u8 compression, u8 encryption, u16 other_encoding)
40{
41 int ret = 0;
42 struct btrfs_file_extent_item *item;
43 struct btrfs_key file_key;
44 struct btrfs_path *path;
45 struct extent_buffer *leaf;
46
47 path = btrfs_alloc_path();
48 if (!path)
49 return -ENOMEM;
50 file_key.objectid = objectid;
51 file_key.offset = pos;
52 file_key.type = BTRFS_EXTENT_DATA_KEY;
53
54 path->leave_spinning = 1;
55 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
56 sizeof(*item));
57 if (ret < 0)
58 goto out;
59 BUG_ON(ret); /* Can't happen */
60 leaf = path->nodes[0];
61 item = btrfs_item_ptr(leaf, path->slots[0],
62 struct btrfs_file_extent_item);
63 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
64 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
65 btrfs_set_file_extent_offset(leaf, item, offset);
66 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
67 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
68 btrfs_set_file_extent_generation(leaf, item, trans->transid);
69 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
70 btrfs_set_file_extent_compression(leaf, item, compression);
71 btrfs_set_file_extent_encryption(leaf, item, encryption);
72 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
73
74 btrfs_mark_buffer_dirty(leaf);
75out:
76 btrfs_free_path(path);
77 return ret;
78}
79
80static struct btrfs_csum_item *
81btrfs_lookup_csum(struct btrfs_trans_handle *trans,
82 struct btrfs_root *root,
83 struct btrfs_path *path,
84 u64 bytenr, int cow)
85{
86 struct btrfs_fs_info *fs_info = root->fs_info;
87 int ret;
88 struct btrfs_key file_key;
89 struct btrfs_key found_key;
90 struct btrfs_csum_item *item;
91 struct extent_buffer *leaf;
92 u64 csum_offset = 0;
93 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
94 int csums_in_item;
95
96 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
97 file_key.offset = bytenr;
98 file_key.type = BTRFS_EXTENT_CSUM_KEY;
99 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
100 if (ret < 0)
101 goto fail;
102 leaf = path->nodes[0];
103 if (ret > 0) {
104 ret = 1;
105 if (path->slots[0] == 0)
106 goto fail;
107 path->slots[0]--;
108 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
109 if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
110 goto fail;
111
112 csum_offset = (bytenr - found_key.offset) >>
113 fs_info->sb->s_blocksize_bits;
114 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
115 csums_in_item /= csum_size;
116
117 if (csum_offset == csums_in_item) {
118 ret = -EFBIG;
119 goto fail;
120 } else if (csum_offset > csums_in_item) {
121 goto fail;
122 }
123 }
124 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
125 item = (struct btrfs_csum_item *)((unsigned char *)item +
126 csum_offset * csum_size);
127 return item;
128fail:
129 if (ret > 0)
130 ret = -ENOENT;
131 return ERR_PTR(ret);
132}
133
134int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
135 struct btrfs_root *root,
136 struct btrfs_path *path, u64 objectid,
137 u64 offset, int mod)
138{
139 int ret;
140 struct btrfs_key file_key;
141 int ins_len = mod < 0 ? -1 : 0;
142 int cow = mod != 0;
143
144 file_key.objectid = objectid;
145 file_key.offset = offset;
146 file_key.type = BTRFS_EXTENT_DATA_KEY;
147 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
148 return ret;
149}
150
151static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
152 u64 logical_offset, u8 *dst, int dio)
153{
154 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
155 struct bio_vec bvec;
156 struct bvec_iter iter;
157 struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
158 struct btrfs_csum_item *item = NULL;
159 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
160 struct btrfs_path *path;
161 u8 *csum;
162 u64 offset = 0;
163 u64 item_start_offset = 0;
164 u64 item_last_offset = 0;
165 u64 disk_bytenr;
166 u64 page_bytes_left;
167 u32 diff;
168 int nblocks;
169 int count = 0;
170 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
171
172 path = btrfs_alloc_path();
173 if (!path)
174 return BLK_STS_RESOURCE;
175
176 nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits;
177 if (!dst) {
178 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
179 btrfs_bio->csum = kmalloc_array(nblocks, csum_size,
180 GFP_NOFS);
181 if (!btrfs_bio->csum) {
182 btrfs_free_path(path);
183 return BLK_STS_RESOURCE;
184 }
185 } else {
186 btrfs_bio->csum = btrfs_bio->csum_inline;
187 }
188 csum = btrfs_bio->csum;
189 } else {
190 csum = dst;
191 }
192
193 if (bio->bi_iter.bi_size > PAGE_SIZE * 8)
194 path->reada = READA_FORWARD;
195
196 /*
197 * the free space stuff is only read when it hasn't been
198 * updated in the current transaction. So, we can safely
199 * read from the commit root and sidestep a nasty deadlock
200 * between reading the free space cache and updating the csum tree.
201 */
202 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
203 path->search_commit_root = 1;
204 path->skip_locking = 1;
205 }
206
207 disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
208 if (dio)
209 offset = logical_offset;
210
211 bio_for_each_segment(bvec, bio, iter) {
212 page_bytes_left = bvec.bv_len;
213 if (count)
214 goto next;
215
216 if (!dio)
217 offset = page_offset(bvec.bv_page) + bvec.bv_offset;
218 count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
219 csum, nblocks);
220 if (count)
221 goto found;
222
223 if (!item || disk_bytenr < item_start_offset ||
224 disk_bytenr >= item_last_offset) {
225 struct btrfs_key found_key;
226 u32 item_size;
227
228 if (item)
229 btrfs_release_path(path);
230 item = btrfs_lookup_csum(NULL, fs_info->csum_root,
231 path, disk_bytenr, 0);
232 if (IS_ERR(item)) {
233 count = 1;
234 memset(csum, 0, csum_size);
235 if (BTRFS_I(inode)->root->root_key.objectid ==
236 BTRFS_DATA_RELOC_TREE_OBJECTID) {
237 set_extent_bits(io_tree, offset,
238 offset + fs_info->sectorsize - 1,
239 EXTENT_NODATASUM);
240 } else {
241 btrfs_info_rl(fs_info,
242 "no csum found for inode %llu start %llu",
243 btrfs_ino(BTRFS_I(inode)), offset);
244 }
245 item = NULL;
246 btrfs_release_path(path);
247 goto found;
248 }
249 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
250 path->slots[0]);
251
252 item_start_offset = found_key.offset;
253 item_size = btrfs_item_size_nr(path->nodes[0],
254 path->slots[0]);
255 item_last_offset = item_start_offset +
256 (item_size / csum_size) *
257 fs_info->sectorsize;
258 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
259 struct btrfs_csum_item);
260 }
261 /*
262 * this byte range must be able to fit inside
263 * a single leaf so it will also fit inside a u32
264 */
265 diff = disk_bytenr - item_start_offset;
266 diff = diff / fs_info->sectorsize;
267 diff = diff * csum_size;
268 count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >>
269 inode->i_sb->s_blocksize_bits);
270 read_extent_buffer(path->nodes[0], csum,
271 ((unsigned long)item) + diff,
272 csum_size * count);
273found:
274 csum += count * csum_size;
275 nblocks -= count;
276next:
277 while (count--) {
278 disk_bytenr += fs_info->sectorsize;
279 offset += fs_info->sectorsize;
280 page_bytes_left -= fs_info->sectorsize;
281 if (!page_bytes_left)
282 break; /* move to next bio */
283 }
284 }
285
286 WARN_ON_ONCE(count);
287 btrfs_free_path(path);
288 return 0;
289}
290
291blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
292 u8 *dst)
293{
294 return __btrfs_lookup_bio_sums(inode, bio, 0, dst, 0);
295}
296
297blk_status_t btrfs_lookup_bio_sums_dio(struct inode *inode, struct bio *bio, u64 offset)
298{
299 return __btrfs_lookup_bio_sums(inode, bio, offset, NULL, 1);
300}
301
302int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
303 struct list_head *list, int search_commit)
304{
305 struct btrfs_fs_info *fs_info = root->fs_info;
306 struct btrfs_key key;
307 struct btrfs_path *path;
308 struct extent_buffer *leaf;
309 struct btrfs_ordered_sum *sums;
310 struct btrfs_csum_item *item;
311 LIST_HEAD(tmplist);
312 unsigned long offset;
313 int ret;
314 size_t size;
315 u64 csum_end;
316 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
317
318 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
319 IS_ALIGNED(end + 1, fs_info->sectorsize));
320
321 path = btrfs_alloc_path();
322 if (!path)
323 return -ENOMEM;
324
325 if (search_commit) {
326 path->skip_locking = 1;
327 path->reada = READA_FORWARD;
328 path->search_commit_root = 1;
329 }
330
331 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
332 key.offset = start;
333 key.type = BTRFS_EXTENT_CSUM_KEY;
334
335 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
336 if (ret < 0)
337 goto fail;
338 if (ret > 0 && path->slots[0] > 0) {
339 leaf = path->nodes[0];
340 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
341 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
342 key.type == BTRFS_EXTENT_CSUM_KEY) {
343 offset = (start - key.offset) >>
344 fs_info->sb->s_blocksize_bits;
345 if (offset * csum_size <
346 btrfs_item_size_nr(leaf, path->slots[0] - 1))
347 path->slots[0]--;
348 }
349 }
350
351 while (start <= end) {
352 leaf = path->nodes[0];
353 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
354 ret = btrfs_next_leaf(root, path);
355 if (ret < 0)
356 goto fail;
357 if (ret > 0)
358 break;
359 leaf = path->nodes[0];
360 }
361
362 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
363 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
364 key.type != BTRFS_EXTENT_CSUM_KEY ||
365 key.offset > end)
366 break;
367
368 if (key.offset > start)
369 start = key.offset;
370
371 size = btrfs_item_size_nr(leaf, path->slots[0]);
372 csum_end = key.offset + (size / csum_size) * fs_info->sectorsize;
373 if (csum_end <= start) {
374 path->slots[0]++;
375 continue;
376 }
377
378 csum_end = min(csum_end, end + 1);
379 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
380 struct btrfs_csum_item);
381 while (start < csum_end) {
382 size = min_t(size_t, csum_end - start,
383 max_ordered_sum_bytes(fs_info, csum_size));
384 sums = kzalloc(btrfs_ordered_sum_size(fs_info, size),
385 GFP_NOFS);
386 if (!sums) {
387 ret = -ENOMEM;
388 goto fail;
389 }
390
391 sums->bytenr = start;
392 sums->len = (int)size;
393
394 offset = (start - key.offset) >>
395 fs_info->sb->s_blocksize_bits;
396 offset *= csum_size;
397 size >>= fs_info->sb->s_blocksize_bits;
398
399 read_extent_buffer(path->nodes[0],
400 sums->sums,
401 ((unsigned long)item) + offset,
402 csum_size * size);
403
404 start += fs_info->sectorsize * size;
405 list_add_tail(&sums->list, &tmplist);
406 }
407 path->slots[0]++;
408 }
409 ret = 0;
410fail:
411 while (ret < 0 && !list_empty(&tmplist)) {
412 sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list);
413 list_del(&sums->list);
414 kfree(sums);
415 }
416 list_splice_tail(&tmplist, list);
417
418 btrfs_free_path(path);
419 return ret;
420}
421
422/*
423 * btrfs_csum_one_bio - Calculates checksums of the data contained inside a bio
424 * @inode: Owner of the data inside the bio
425 * @bio: Contains the data to be checksummed
426 * @file_start: offset in file this bio begins to describe
427 * @contig: Boolean. If true/1 means all bio vecs in this bio are
428 * contiguous and they begin at @file_start in the file. False/0
429 * means this bio can contains potentially discontigous bio vecs
430 * so the logical offset of each should be calculated separately.
431 */
432blk_status_t btrfs_csum_one_bio(struct inode *inode, struct bio *bio,
433 u64 file_start, int contig)
434{
435 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
436 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
437 struct btrfs_ordered_sum *sums;
438 struct btrfs_ordered_extent *ordered = NULL;
439 char *data;
440 struct bvec_iter iter;
441 struct bio_vec bvec;
442 int index;
443 int nr_sectors;
444 unsigned long total_bytes = 0;
445 unsigned long this_sum_bytes = 0;
446 int i;
447 u64 offset;
448 unsigned nofs_flag;
449 const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
450
451 nofs_flag = memalloc_nofs_save();
452 sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
453 GFP_KERNEL);
454 memalloc_nofs_restore(nofs_flag);
455
456 if (!sums)
457 return BLK_STS_RESOURCE;
458
459 sums->len = bio->bi_iter.bi_size;
460 INIT_LIST_HEAD(&sums->list);
461
462 if (contig)
463 offset = file_start;
464 else
465 offset = 0; /* shut up gcc */
466
467 sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
468 index = 0;
469
470 shash->tfm = fs_info->csum_shash;
471
472 bio_for_each_segment(bvec, bio, iter) {
473 if (!contig)
474 offset = page_offset(bvec.bv_page) + bvec.bv_offset;
475
476 if (!ordered) {
477 ordered = btrfs_lookup_ordered_extent(inode, offset);
478 BUG_ON(!ordered); /* Logic error */
479 }
480
481 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info,
482 bvec.bv_len + fs_info->sectorsize
483 - 1);
484
485 for (i = 0; i < nr_sectors; i++) {
486 if (offset >= ordered->file_offset + ordered->len ||
487 offset < ordered->file_offset) {
488 unsigned long bytes_left;
489
490 sums->len = this_sum_bytes;
491 this_sum_bytes = 0;
492 btrfs_add_ordered_sum(ordered, sums);
493 btrfs_put_ordered_extent(ordered);
494
495 bytes_left = bio->bi_iter.bi_size - total_bytes;
496
497 nofs_flag = memalloc_nofs_save();
498 sums = kvzalloc(btrfs_ordered_sum_size(fs_info,
499 bytes_left), GFP_KERNEL);
500 memalloc_nofs_restore(nofs_flag);
501 BUG_ON(!sums); /* -ENOMEM */
502 sums->len = bytes_left;
503 ordered = btrfs_lookup_ordered_extent(inode,
504 offset);
505 ASSERT(ordered); /* Logic error */
506 sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9)
507 + total_bytes;
508 index = 0;
509 }
510
511 crypto_shash_init(shash);
512 data = kmap_atomic(bvec.bv_page);
513 crypto_shash_update(shash, data + bvec.bv_offset
514 + (i * fs_info->sectorsize),
515 fs_info->sectorsize);
516 kunmap_atomic(data);
517 crypto_shash_final(shash, (char *)(sums->sums + index));
518 index += csum_size;
519 offset += fs_info->sectorsize;
520 this_sum_bytes += fs_info->sectorsize;
521 total_bytes += fs_info->sectorsize;
522 }
523
524 }
525 this_sum_bytes = 0;
526 btrfs_add_ordered_sum(ordered, sums);
527 btrfs_put_ordered_extent(ordered);
528 return 0;
529}
530
531/*
532 * helper function for csum removal, this expects the
533 * key to describe the csum pointed to by the path, and it expects
534 * the csum to overlap the range [bytenr, len]
535 *
536 * The csum should not be entirely contained in the range and the
537 * range should not be entirely contained in the csum.
538 *
539 * This calls btrfs_truncate_item with the correct args based on the
540 * overlap, and fixes up the key as required.
541 */
542static noinline void truncate_one_csum(struct btrfs_fs_info *fs_info,
543 struct btrfs_path *path,
544 struct btrfs_key *key,
545 u64 bytenr, u64 len)
546{
547 struct extent_buffer *leaf;
548 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
549 u64 csum_end;
550 u64 end_byte = bytenr + len;
551 u32 blocksize_bits = fs_info->sb->s_blocksize_bits;
552
553 leaf = path->nodes[0];
554 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
555 csum_end <<= fs_info->sb->s_blocksize_bits;
556 csum_end += key->offset;
557
558 if (key->offset < bytenr && csum_end <= end_byte) {
559 /*
560 * [ bytenr - len ]
561 * [ ]
562 * [csum ]
563 * A simple truncate off the end of the item
564 */
565 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
566 new_size *= csum_size;
567 btrfs_truncate_item(path, new_size, 1);
568 } else if (key->offset >= bytenr && csum_end > end_byte &&
569 end_byte > key->offset) {
570 /*
571 * [ bytenr - len ]
572 * [ ]
573 * [csum ]
574 * we need to truncate from the beginning of the csum
575 */
576 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
577 new_size *= csum_size;
578
579 btrfs_truncate_item(path, new_size, 0);
580
581 key->offset = end_byte;
582 btrfs_set_item_key_safe(fs_info, path, key);
583 } else {
584 BUG();
585 }
586}
587
588/*
589 * deletes the csum items from the csum tree for a given
590 * range of bytes.
591 */
592int btrfs_del_csums(struct btrfs_trans_handle *trans,
593 struct btrfs_fs_info *fs_info, u64 bytenr, u64 len)
594{
595 struct btrfs_root *root = fs_info->csum_root;
596 struct btrfs_path *path;
597 struct btrfs_key key;
598 u64 end_byte = bytenr + len;
599 u64 csum_end;
600 struct extent_buffer *leaf;
601 int ret;
602 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
603 int blocksize_bits = fs_info->sb->s_blocksize_bits;
604
605 path = btrfs_alloc_path();
606 if (!path)
607 return -ENOMEM;
608
609 while (1) {
610 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
611 key.offset = end_byte - 1;
612 key.type = BTRFS_EXTENT_CSUM_KEY;
613
614 path->leave_spinning = 1;
615 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
616 if (ret > 0) {
617 if (path->slots[0] == 0)
618 break;
619 path->slots[0]--;
620 } else if (ret < 0) {
621 break;
622 }
623
624 leaf = path->nodes[0];
625 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
626
627 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
628 key.type != BTRFS_EXTENT_CSUM_KEY) {
629 break;
630 }
631
632 if (key.offset >= end_byte)
633 break;
634
635 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
636 csum_end <<= blocksize_bits;
637 csum_end += key.offset;
638
639 /* this csum ends before we start, we're done */
640 if (csum_end <= bytenr)
641 break;
642
643 /* delete the entire item, it is inside our range */
644 if (key.offset >= bytenr && csum_end <= end_byte) {
645 int del_nr = 1;
646
647 /*
648 * Check how many csum items preceding this one in this
649 * leaf correspond to our range and then delete them all
650 * at once.
651 */
652 if (key.offset > bytenr && path->slots[0] > 0) {
653 int slot = path->slots[0] - 1;
654
655 while (slot >= 0) {
656 struct btrfs_key pk;
657
658 btrfs_item_key_to_cpu(leaf, &pk, slot);
659 if (pk.offset < bytenr ||
660 pk.type != BTRFS_EXTENT_CSUM_KEY ||
661 pk.objectid !=
662 BTRFS_EXTENT_CSUM_OBJECTID)
663 break;
664 path->slots[0] = slot;
665 del_nr++;
666 key.offset = pk.offset;
667 slot--;
668 }
669 }
670 ret = btrfs_del_items(trans, root, path,
671 path->slots[0], del_nr);
672 if (ret)
673 goto out;
674 if (key.offset == bytenr)
675 break;
676 } else if (key.offset < bytenr && csum_end > end_byte) {
677 unsigned long offset;
678 unsigned long shift_len;
679 unsigned long item_offset;
680 /*
681 * [ bytenr - len ]
682 * [csum ]
683 *
684 * Our bytes are in the middle of the csum,
685 * we need to split this item and insert a new one.
686 *
687 * But we can't drop the path because the
688 * csum could change, get removed, extended etc.
689 *
690 * The trick here is the max size of a csum item leaves
691 * enough room in the tree block for a single
692 * item header. So, we split the item in place,
693 * adding a new header pointing to the existing
694 * bytes. Then we loop around again and we have
695 * a nicely formed csum item that we can neatly
696 * truncate.
697 */
698 offset = (bytenr - key.offset) >> blocksize_bits;
699 offset *= csum_size;
700
701 shift_len = (len >> blocksize_bits) * csum_size;
702
703 item_offset = btrfs_item_ptr_offset(leaf,
704 path->slots[0]);
705
706 memzero_extent_buffer(leaf, item_offset + offset,
707 shift_len);
708 key.offset = bytenr;
709
710 /*
711 * btrfs_split_item returns -EAGAIN when the
712 * item changed size or key
713 */
714 ret = btrfs_split_item(trans, root, path, &key, offset);
715 if (ret && ret != -EAGAIN) {
716 btrfs_abort_transaction(trans, ret);
717 goto out;
718 }
719
720 key.offset = end_byte - 1;
721 } else {
722 truncate_one_csum(fs_info, path, &key, bytenr, len);
723 if (key.offset < bytenr)
724 break;
725 }
726 btrfs_release_path(path);
727 }
728 ret = 0;
729out:
730 btrfs_free_path(path);
731 return ret;
732}
733
734int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
735 struct btrfs_root *root,
736 struct btrfs_ordered_sum *sums)
737{
738 struct btrfs_fs_info *fs_info = root->fs_info;
739 struct btrfs_key file_key;
740 struct btrfs_key found_key;
741 struct btrfs_path *path;
742 struct btrfs_csum_item *item;
743 struct btrfs_csum_item *item_end;
744 struct extent_buffer *leaf = NULL;
745 u64 next_offset;
746 u64 total_bytes = 0;
747 u64 csum_offset;
748 u64 bytenr;
749 u32 nritems;
750 u32 ins_size;
751 int index = 0;
752 int found_next;
753 int ret;
754 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
755
756 path = btrfs_alloc_path();
757 if (!path)
758 return -ENOMEM;
759again:
760 next_offset = (u64)-1;
761 found_next = 0;
762 bytenr = sums->bytenr + total_bytes;
763 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
764 file_key.offset = bytenr;
765 file_key.type = BTRFS_EXTENT_CSUM_KEY;
766
767 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
768 if (!IS_ERR(item)) {
769 ret = 0;
770 leaf = path->nodes[0];
771 item_end = btrfs_item_ptr(leaf, path->slots[0],
772 struct btrfs_csum_item);
773 item_end = (struct btrfs_csum_item *)((char *)item_end +
774 btrfs_item_size_nr(leaf, path->slots[0]));
775 goto found;
776 }
777 ret = PTR_ERR(item);
778 if (ret != -EFBIG && ret != -ENOENT)
779 goto fail_unlock;
780
781 if (ret == -EFBIG) {
782 u32 item_size;
783 /* we found one, but it isn't big enough yet */
784 leaf = path->nodes[0];
785 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
786 if ((item_size / csum_size) >=
787 MAX_CSUM_ITEMS(fs_info, csum_size)) {
788 /* already at max size, make a new one */
789 goto insert;
790 }
791 } else {
792 int slot = path->slots[0] + 1;
793 /* we didn't find a csum item, insert one */
794 nritems = btrfs_header_nritems(path->nodes[0]);
795 if (!nritems || (path->slots[0] >= nritems - 1)) {
796 ret = btrfs_next_leaf(root, path);
797 if (ret == 1)
798 found_next = 1;
799 if (ret != 0)
800 goto insert;
801 slot = path->slots[0];
802 }
803 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
804 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
805 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
806 found_next = 1;
807 goto insert;
808 }
809 next_offset = found_key.offset;
810 found_next = 1;
811 goto insert;
812 }
813
814 /*
815 * at this point, we know the tree has an item, but it isn't big
816 * enough yet to put our csum in. Grow it
817 */
818 btrfs_release_path(path);
819 ret = btrfs_search_slot(trans, root, &file_key, path,
820 csum_size, 1);
821 if (ret < 0)
822 goto fail_unlock;
823
824 if (ret > 0) {
825 if (path->slots[0] == 0)
826 goto insert;
827 path->slots[0]--;
828 }
829
830 leaf = path->nodes[0];
831 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
832 csum_offset = (bytenr - found_key.offset) >>
833 fs_info->sb->s_blocksize_bits;
834
835 if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
836 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
837 csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
838 goto insert;
839 }
840
841 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
842 csum_size) {
843 int extend_nr;
844 u64 tmp;
845 u32 diff;
846 u32 free_space;
847
848 if (btrfs_leaf_free_space(leaf) <
849 sizeof(struct btrfs_item) + csum_size * 2)
850 goto insert;
851
852 free_space = btrfs_leaf_free_space(leaf) -
853 sizeof(struct btrfs_item) - csum_size;
854 tmp = sums->len - total_bytes;
855 tmp >>= fs_info->sb->s_blocksize_bits;
856 WARN_ON(tmp < 1);
857
858 extend_nr = max_t(int, 1, (int)tmp);
859 diff = (csum_offset + extend_nr) * csum_size;
860 diff = min(diff,
861 MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
862
863 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
864 diff = min(free_space, diff);
865 diff /= csum_size;
866 diff *= csum_size;
867
868 btrfs_extend_item(path, diff);
869 ret = 0;
870 goto csum;
871 }
872
873insert:
874 btrfs_release_path(path);
875 csum_offset = 0;
876 if (found_next) {
877 u64 tmp;
878
879 tmp = sums->len - total_bytes;
880 tmp >>= fs_info->sb->s_blocksize_bits;
881 tmp = min(tmp, (next_offset - file_key.offset) >>
882 fs_info->sb->s_blocksize_bits);
883
884 tmp = max_t(u64, 1, tmp);
885 tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
886 ins_size = csum_size * tmp;
887 } else {
888 ins_size = csum_size;
889 }
890 path->leave_spinning = 1;
891 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
892 ins_size);
893 path->leave_spinning = 0;
894 if (ret < 0)
895 goto fail_unlock;
896 if (WARN_ON(ret != 0))
897 goto fail_unlock;
898 leaf = path->nodes[0];
899csum:
900 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
901 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
902 btrfs_item_size_nr(leaf, path->slots[0]));
903 item = (struct btrfs_csum_item *)((unsigned char *)item +
904 csum_offset * csum_size);
905found:
906 ins_size = (u32)(sums->len - total_bytes) >>
907 fs_info->sb->s_blocksize_bits;
908 ins_size *= csum_size;
909 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
910 ins_size);
911 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
912 ins_size);
913
914 index += ins_size;
915 ins_size /= csum_size;
916 total_bytes += ins_size * fs_info->sectorsize;
917
918 btrfs_mark_buffer_dirty(path->nodes[0]);
919 if (total_bytes < sums->len) {
920 btrfs_release_path(path);
921 cond_resched();
922 goto again;
923 }
924out:
925 btrfs_free_path(path);
926 return ret;
927
928fail_unlock:
929 goto out;
930}
931
932void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
933 const struct btrfs_path *path,
934 struct btrfs_file_extent_item *fi,
935 const bool new_inline,
936 struct extent_map *em)
937{
938 struct btrfs_fs_info *fs_info = inode->root->fs_info;
939 struct btrfs_root *root = inode->root;
940 struct extent_buffer *leaf = path->nodes[0];
941 const int slot = path->slots[0];
942 struct btrfs_key key;
943 u64 extent_start, extent_end;
944 u64 bytenr;
945 u8 type = btrfs_file_extent_type(leaf, fi);
946 int compress_type = btrfs_file_extent_compression(leaf, fi);
947
948 em->bdev = fs_info->fs_devices->latest_bdev;
949 btrfs_item_key_to_cpu(leaf, &key, slot);
950 extent_start = key.offset;
951
952 if (type == BTRFS_FILE_EXTENT_REG ||
953 type == BTRFS_FILE_EXTENT_PREALLOC) {
954 extent_end = extent_start +
955 btrfs_file_extent_num_bytes(leaf, fi);
956 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
957 size_t size;
958 size = btrfs_file_extent_ram_bytes(leaf, fi);
959 extent_end = ALIGN(extent_start + size,
960 fs_info->sectorsize);
961 }
962
963 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
964 if (type == BTRFS_FILE_EXTENT_REG ||
965 type == BTRFS_FILE_EXTENT_PREALLOC) {
966 em->start = extent_start;
967 em->len = extent_end - extent_start;
968 em->orig_start = extent_start -
969 btrfs_file_extent_offset(leaf, fi);
970 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
971 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
972 if (bytenr == 0) {
973 em->block_start = EXTENT_MAP_HOLE;
974 return;
975 }
976 if (compress_type != BTRFS_COMPRESS_NONE) {
977 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
978 em->compress_type = compress_type;
979 em->block_start = bytenr;
980 em->block_len = em->orig_block_len;
981 } else {
982 bytenr += btrfs_file_extent_offset(leaf, fi);
983 em->block_start = bytenr;
984 em->block_len = em->len;
985 if (type == BTRFS_FILE_EXTENT_PREALLOC)
986 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
987 }
988 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
989 em->block_start = EXTENT_MAP_INLINE;
990 em->start = extent_start;
991 em->len = extent_end - extent_start;
992 /*
993 * Initialize orig_start and block_len with the same values
994 * as in inode.c:btrfs_get_extent().
995 */
996 em->orig_start = EXTENT_MAP_HOLE;
997 em->block_len = (u64)-1;
998 if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) {
999 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
1000 em->compress_type = compress_type;
1001 }
1002 } else {
1003 btrfs_err(fs_info,
1004 "unknown file extent item type %d, inode %llu, offset %llu, "
1005 "root %llu", type, btrfs_ino(inode), extent_start,
1006 root->root_key.objectid);
1007 }
1008}
1/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/bio.h>
20#include <linux/slab.h>
21#include <linux/pagemap.h>
22#include <linux/highmem.h>
23#include "ctree.h"
24#include "disk-io.h"
25#include "transaction.h"
26#include "print-tree.h"
27
28#define MAX_CSUM_ITEMS(r, size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
29 sizeof(struct btrfs_item) * 2) / \
30 size) - 1))
31
32#define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
33 sizeof(struct btrfs_ordered_sum)) / \
34 sizeof(struct btrfs_sector_sum) * \
35 (r)->sectorsize - (r)->sectorsize)
36
37int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
38 struct btrfs_root *root,
39 u64 objectid, u64 pos,
40 u64 disk_offset, u64 disk_num_bytes,
41 u64 num_bytes, u64 offset, u64 ram_bytes,
42 u8 compression, u8 encryption, u16 other_encoding)
43{
44 int ret = 0;
45 struct btrfs_file_extent_item *item;
46 struct btrfs_key file_key;
47 struct btrfs_path *path;
48 struct extent_buffer *leaf;
49
50 path = btrfs_alloc_path();
51 if (!path)
52 return -ENOMEM;
53 file_key.objectid = objectid;
54 file_key.offset = pos;
55 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
56
57 path->leave_spinning = 1;
58 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
59 sizeof(*item));
60 if (ret < 0)
61 goto out;
62 BUG_ON(ret);
63 leaf = path->nodes[0];
64 item = btrfs_item_ptr(leaf, path->slots[0],
65 struct btrfs_file_extent_item);
66 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
67 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
68 btrfs_set_file_extent_offset(leaf, item, offset);
69 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
70 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
71 btrfs_set_file_extent_generation(leaf, item, trans->transid);
72 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
73 btrfs_set_file_extent_compression(leaf, item, compression);
74 btrfs_set_file_extent_encryption(leaf, item, encryption);
75 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
76
77 btrfs_mark_buffer_dirty(leaf);
78out:
79 btrfs_free_path(path);
80 return ret;
81}
82
83struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
84 struct btrfs_root *root,
85 struct btrfs_path *path,
86 u64 bytenr, int cow)
87{
88 int ret;
89 struct btrfs_key file_key;
90 struct btrfs_key found_key;
91 struct btrfs_csum_item *item;
92 struct extent_buffer *leaf;
93 u64 csum_offset = 0;
94 u16 csum_size =
95 btrfs_super_csum_size(&root->fs_info->super_copy);
96 int csums_in_item;
97
98 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
99 file_key.offset = bytenr;
100 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
101 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
102 if (ret < 0)
103 goto fail;
104 leaf = path->nodes[0];
105 if (ret > 0) {
106 ret = 1;
107 if (path->slots[0] == 0)
108 goto fail;
109 path->slots[0]--;
110 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
111 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
112 goto fail;
113
114 csum_offset = (bytenr - found_key.offset) >>
115 root->fs_info->sb->s_blocksize_bits;
116 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
117 csums_in_item /= csum_size;
118
119 if (csum_offset >= csums_in_item) {
120 ret = -EFBIG;
121 goto fail;
122 }
123 }
124 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
125 item = (struct btrfs_csum_item *)((unsigned char *)item +
126 csum_offset * csum_size);
127 return item;
128fail:
129 if (ret > 0)
130 ret = -ENOENT;
131 return ERR_PTR(ret);
132}
133
134
135int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
136 struct btrfs_root *root,
137 struct btrfs_path *path, u64 objectid,
138 u64 offset, int mod)
139{
140 int ret;
141 struct btrfs_key file_key;
142 int ins_len = mod < 0 ? -1 : 0;
143 int cow = mod != 0;
144
145 file_key.objectid = objectid;
146 file_key.offset = offset;
147 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
148 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
149 return ret;
150}
151
152
153static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
154 struct inode *inode, struct bio *bio,
155 u64 logical_offset, u32 *dst, int dio)
156{
157 u32 sum;
158 struct bio_vec *bvec = bio->bi_io_vec;
159 int bio_index = 0;
160 u64 offset = 0;
161 u64 item_start_offset = 0;
162 u64 item_last_offset = 0;
163 u64 disk_bytenr;
164 u32 diff;
165 u16 csum_size =
166 btrfs_super_csum_size(&root->fs_info->super_copy);
167 int ret;
168 struct btrfs_path *path;
169 struct btrfs_csum_item *item = NULL;
170 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
171
172 path = btrfs_alloc_path();
173 if (!path)
174 return -ENOMEM;
175 if (bio->bi_size > PAGE_CACHE_SIZE * 8)
176 path->reada = 2;
177
178 WARN_ON(bio->bi_vcnt <= 0);
179
180 /*
181 * the free space stuff is only read when it hasn't been
182 * updated in the current transaction. So, we can safely
183 * read from the commit root and sidestep a nasty deadlock
184 * between reading the free space cache and updating the csum tree.
185 */
186 if (btrfs_is_free_space_inode(root, inode)) {
187 path->search_commit_root = 1;
188 path->skip_locking = 1;
189 }
190
191 disk_bytenr = (u64)bio->bi_sector << 9;
192 if (dio)
193 offset = logical_offset;
194 while (bio_index < bio->bi_vcnt) {
195 if (!dio)
196 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
197 ret = btrfs_find_ordered_sum(inode, offset, disk_bytenr, &sum);
198 if (ret == 0)
199 goto found;
200
201 if (!item || disk_bytenr < item_start_offset ||
202 disk_bytenr >= item_last_offset) {
203 struct btrfs_key found_key;
204 u32 item_size;
205
206 if (item)
207 btrfs_release_path(path);
208 item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
209 path, disk_bytenr, 0);
210 if (IS_ERR(item)) {
211 ret = PTR_ERR(item);
212 if (ret == -ENOENT || ret == -EFBIG)
213 ret = 0;
214 sum = 0;
215 if (BTRFS_I(inode)->root->root_key.objectid ==
216 BTRFS_DATA_RELOC_TREE_OBJECTID) {
217 set_extent_bits(io_tree, offset,
218 offset + bvec->bv_len - 1,
219 EXTENT_NODATASUM, GFP_NOFS);
220 } else {
221 printk(KERN_INFO "btrfs no csum found "
222 "for inode %llu start %llu\n",
223 (unsigned long long)
224 btrfs_ino(inode),
225 (unsigned long long)offset);
226 }
227 item = NULL;
228 btrfs_release_path(path);
229 goto found;
230 }
231 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
232 path->slots[0]);
233
234 item_start_offset = found_key.offset;
235 item_size = btrfs_item_size_nr(path->nodes[0],
236 path->slots[0]);
237 item_last_offset = item_start_offset +
238 (item_size / csum_size) *
239 root->sectorsize;
240 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
241 struct btrfs_csum_item);
242 }
243 /*
244 * this byte range must be able to fit inside
245 * a single leaf so it will also fit inside a u32
246 */
247 diff = disk_bytenr - item_start_offset;
248 diff = diff / root->sectorsize;
249 diff = diff * csum_size;
250
251 read_extent_buffer(path->nodes[0], &sum,
252 ((unsigned long)item) + diff,
253 csum_size);
254found:
255 if (dst)
256 *dst++ = sum;
257 else
258 set_state_private(io_tree, offset, sum);
259 disk_bytenr += bvec->bv_len;
260 offset += bvec->bv_len;
261 bio_index++;
262 bvec++;
263 }
264 btrfs_free_path(path);
265 return 0;
266}
267
268int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
269 struct bio *bio, u32 *dst)
270{
271 return __btrfs_lookup_bio_sums(root, inode, bio, 0, dst, 0);
272}
273
274int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
275 struct bio *bio, u64 offset, u32 *dst)
276{
277 return __btrfs_lookup_bio_sums(root, inode, bio, offset, dst, 1);
278}
279
280int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
281 struct list_head *list, int search_commit)
282{
283 struct btrfs_key key;
284 struct btrfs_path *path;
285 struct extent_buffer *leaf;
286 struct btrfs_ordered_sum *sums;
287 struct btrfs_sector_sum *sector_sum;
288 struct btrfs_csum_item *item;
289 unsigned long offset;
290 int ret;
291 size_t size;
292 u64 csum_end;
293 u16 csum_size = btrfs_super_csum_size(&root->fs_info->super_copy);
294
295 path = btrfs_alloc_path();
296 if (!path)
297 return -ENOMEM;
298
299 if (search_commit) {
300 path->skip_locking = 1;
301 path->reada = 2;
302 path->search_commit_root = 1;
303 }
304
305 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
306 key.offset = start;
307 key.type = BTRFS_EXTENT_CSUM_KEY;
308
309 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
310 if (ret < 0)
311 goto fail;
312 if (ret > 0 && path->slots[0] > 0) {
313 leaf = path->nodes[0];
314 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
315 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
316 key.type == BTRFS_EXTENT_CSUM_KEY) {
317 offset = (start - key.offset) >>
318 root->fs_info->sb->s_blocksize_bits;
319 if (offset * csum_size <
320 btrfs_item_size_nr(leaf, path->slots[0] - 1))
321 path->slots[0]--;
322 }
323 }
324
325 while (start <= end) {
326 leaf = path->nodes[0];
327 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
328 ret = btrfs_next_leaf(root, path);
329 if (ret < 0)
330 goto fail;
331 if (ret > 0)
332 break;
333 leaf = path->nodes[0];
334 }
335
336 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
337 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
338 key.type != BTRFS_EXTENT_CSUM_KEY)
339 break;
340
341 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
342 if (key.offset > end)
343 break;
344
345 if (key.offset > start)
346 start = key.offset;
347
348 size = btrfs_item_size_nr(leaf, path->slots[0]);
349 csum_end = key.offset + (size / csum_size) * root->sectorsize;
350 if (csum_end <= start) {
351 path->slots[0]++;
352 continue;
353 }
354
355 csum_end = min(csum_end, end + 1);
356 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
357 struct btrfs_csum_item);
358 while (start < csum_end) {
359 size = min_t(size_t, csum_end - start,
360 MAX_ORDERED_SUM_BYTES(root));
361 sums = kzalloc(btrfs_ordered_sum_size(root, size),
362 GFP_NOFS);
363 BUG_ON(!sums);
364
365 sector_sum = sums->sums;
366 sums->bytenr = start;
367 sums->len = size;
368
369 offset = (start - key.offset) >>
370 root->fs_info->sb->s_blocksize_bits;
371 offset *= csum_size;
372
373 while (size > 0) {
374 read_extent_buffer(path->nodes[0],
375 §or_sum->sum,
376 ((unsigned long)item) +
377 offset, csum_size);
378 sector_sum->bytenr = start;
379
380 size -= root->sectorsize;
381 start += root->sectorsize;
382 offset += csum_size;
383 sector_sum++;
384 }
385 list_add_tail(&sums->list, list);
386 }
387 path->slots[0]++;
388 }
389 ret = 0;
390fail:
391 btrfs_free_path(path);
392 return ret;
393}
394
395int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
396 struct bio *bio, u64 file_start, int contig)
397{
398 struct btrfs_ordered_sum *sums;
399 struct btrfs_sector_sum *sector_sum;
400 struct btrfs_ordered_extent *ordered;
401 char *data;
402 struct bio_vec *bvec = bio->bi_io_vec;
403 int bio_index = 0;
404 unsigned long total_bytes = 0;
405 unsigned long this_sum_bytes = 0;
406 u64 offset;
407 u64 disk_bytenr;
408
409 WARN_ON(bio->bi_vcnt <= 0);
410 sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
411 if (!sums)
412 return -ENOMEM;
413
414 sector_sum = sums->sums;
415 disk_bytenr = (u64)bio->bi_sector << 9;
416 sums->len = bio->bi_size;
417 INIT_LIST_HEAD(&sums->list);
418
419 if (contig)
420 offset = file_start;
421 else
422 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
423
424 ordered = btrfs_lookup_ordered_extent(inode, offset);
425 BUG_ON(!ordered);
426 sums->bytenr = ordered->start;
427
428 while (bio_index < bio->bi_vcnt) {
429 if (!contig)
430 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
431
432 if (!contig && (offset >= ordered->file_offset + ordered->len ||
433 offset < ordered->file_offset)) {
434 unsigned long bytes_left;
435 sums->len = this_sum_bytes;
436 this_sum_bytes = 0;
437 btrfs_add_ordered_sum(inode, ordered, sums);
438 btrfs_put_ordered_extent(ordered);
439
440 bytes_left = bio->bi_size - total_bytes;
441
442 sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
443 GFP_NOFS);
444 BUG_ON(!sums);
445 sector_sum = sums->sums;
446 sums->len = bytes_left;
447 ordered = btrfs_lookup_ordered_extent(inode, offset);
448 BUG_ON(!ordered);
449 sums->bytenr = ordered->start;
450 }
451
452 data = kmap_atomic(bvec->bv_page, KM_USER0);
453 sector_sum->sum = ~(u32)0;
454 sector_sum->sum = btrfs_csum_data(root,
455 data + bvec->bv_offset,
456 sector_sum->sum,
457 bvec->bv_len);
458 kunmap_atomic(data, KM_USER0);
459 btrfs_csum_final(sector_sum->sum,
460 (char *)§or_sum->sum);
461 sector_sum->bytenr = disk_bytenr;
462
463 sector_sum++;
464 bio_index++;
465 total_bytes += bvec->bv_len;
466 this_sum_bytes += bvec->bv_len;
467 disk_bytenr += bvec->bv_len;
468 offset += bvec->bv_len;
469 bvec++;
470 }
471 this_sum_bytes = 0;
472 btrfs_add_ordered_sum(inode, ordered, sums);
473 btrfs_put_ordered_extent(ordered);
474 return 0;
475}
476
477/*
478 * helper function for csum removal, this expects the
479 * key to describe the csum pointed to by the path, and it expects
480 * the csum to overlap the range [bytenr, len]
481 *
482 * The csum should not be entirely contained in the range and the
483 * range should not be entirely contained in the csum.
484 *
485 * This calls btrfs_truncate_item with the correct args based on the
486 * overlap, and fixes up the key as required.
487 */
488static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
489 struct btrfs_root *root,
490 struct btrfs_path *path,
491 struct btrfs_key *key,
492 u64 bytenr, u64 len)
493{
494 struct extent_buffer *leaf;
495 u16 csum_size =
496 btrfs_super_csum_size(&root->fs_info->super_copy);
497 u64 csum_end;
498 u64 end_byte = bytenr + len;
499 u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
500 int ret;
501
502 leaf = path->nodes[0];
503 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
504 csum_end <<= root->fs_info->sb->s_blocksize_bits;
505 csum_end += key->offset;
506
507 if (key->offset < bytenr && csum_end <= end_byte) {
508 /*
509 * [ bytenr - len ]
510 * [ ]
511 * [csum ]
512 * A simple truncate off the end of the item
513 */
514 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
515 new_size *= csum_size;
516 ret = btrfs_truncate_item(trans, root, path, new_size, 1);
517 } else if (key->offset >= bytenr && csum_end > end_byte &&
518 end_byte > key->offset) {
519 /*
520 * [ bytenr - len ]
521 * [ ]
522 * [csum ]
523 * we need to truncate from the beginning of the csum
524 */
525 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
526 new_size *= csum_size;
527
528 ret = btrfs_truncate_item(trans, root, path, new_size, 0);
529
530 key->offset = end_byte;
531 ret = btrfs_set_item_key_safe(trans, root, path, key);
532 BUG_ON(ret);
533 } else {
534 BUG();
535 }
536 return 0;
537}
538
539/*
540 * deletes the csum items from the csum tree for a given
541 * range of bytes.
542 */
543int btrfs_del_csums(struct btrfs_trans_handle *trans,
544 struct btrfs_root *root, u64 bytenr, u64 len)
545{
546 struct btrfs_path *path;
547 struct btrfs_key key;
548 u64 end_byte = bytenr + len;
549 u64 csum_end;
550 struct extent_buffer *leaf;
551 int ret;
552 u16 csum_size =
553 btrfs_super_csum_size(&root->fs_info->super_copy);
554 int blocksize_bits = root->fs_info->sb->s_blocksize_bits;
555
556 root = root->fs_info->csum_root;
557
558 path = btrfs_alloc_path();
559 if (!path)
560 return -ENOMEM;
561
562 while (1) {
563 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
564 key.offset = end_byte - 1;
565 key.type = BTRFS_EXTENT_CSUM_KEY;
566
567 path->leave_spinning = 1;
568 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
569 if (ret > 0) {
570 if (path->slots[0] == 0)
571 break;
572 path->slots[0]--;
573 } else if (ret < 0) {
574 break;
575 }
576
577 leaf = path->nodes[0];
578 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
579
580 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
581 key.type != BTRFS_EXTENT_CSUM_KEY) {
582 break;
583 }
584
585 if (key.offset >= end_byte)
586 break;
587
588 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
589 csum_end <<= blocksize_bits;
590 csum_end += key.offset;
591
592 /* this csum ends before we start, we're done */
593 if (csum_end <= bytenr)
594 break;
595
596 /* delete the entire item, it is inside our range */
597 if (key.offset >= bytenr && csum_end <= end_byte) {
598 ret = btrfs_del_item(trans, root, path);
599 if (ret)
600 goto out;
601 if (key.offset == bytenr)
602 break;
603 } else if (key.offset < bytenr && csum_end > end_byte) {
604 unsigned long offset;
605 unsigned long shift_len;
606 unsigned long item_offset;
607 /*
608 * [ bytenr - len ]
609 * [csum ]
610 *
611 * Our bytes are in the middle of the csum,
612 * we need to split this item and insert a new one.
613 *
614 * But we can't drop the path because the
615 * csum could change, get removed, extended etc.
616 *
617 * The trick here is the max size of a csum item leaves
618 * enough room in the tree block for a single
619 * item header. So, we split the item in place,
620 * adding a new header pointing to the existing
621 * bytes. Then we loop around again and we have
622 * a nicely formed csum item that we can neatly
623 * truncate.
624 */
625 offset = (bytenr - key.offset) >> blocksize_bits;
626 offset *= csum_size;
627
628 shift_len = (len >> blocksize_bits) * csum_size;
629
630 item_offset = btrfs_item_ptr_offset(leaf,
631 path->slots[0]);
632
633 memset_extent_buffer(leaf, 0, item_offset + offset,
634 shift_len);
635 key.offset = bytenr;
636
637 /*
638 * btrfs_split_item returns -EAGAIN when the
639 * item changed size or key
640 */
641 ret = btrfs_split_item(trans, root, path, &key, offset);
642 BUG_ON(ret && ret != -EAGAIN);
643
644 key.offset = end_byte - 1;
645 } else {
646 ret = truncate_one_csum(trans, root, path,
647 &key, bytenr, len);
648 BUG_ON(ret);
649 if (key.offset < bytenr)
650 break;
651 }
652 btrfs_release_path(path);
653 }
654 ret = 0;
655out:
656 btrfs_free_path(path);
657 return ret;
658}
659
660int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
661 struct btrfs_root *root,
662 struct btrfs_ordered_sum *sums)
663{
664 u64 bytenr;
665 int ret;
666 struct btrfs_key file_key;
667 struct btrfs_key found_key;
668 u64 next_offset;
669 u64 total_bytes = 0;
670 int found_next;
671 struct btrfs_path *path;
672 struct btrfs_csum_item *item;
673 struct btrfs_csum_item *item_end;
674 struct extent_buffer *leaf = NULL;
675 u64 csum_offset;
676 struct btrfs_sector_sum *sector_sum;
677 u32 nritems;
678 u32 ins_size;
679 u16 csum_size =
680 btrfs_super_csum_size(&root->fs_info->super_copy);
681
682 path = btrfs_alloc_path();
683 if (!path)
684 return -ENOMEM;
685
686 sector_sum = sums->sums;
687again:
688 next_offset = (u64)-1;
689 found_next = 0;
690 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
691 file_key.offset = sector_sum->bytenr;
692 bytenr = sector_sum->bytenr;
693 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
694
695 item = btrfs_lookup_csum(trans, root, path, sector_sum->bytenr, 1);
696 if (!IS_ERR(item)) {
697 leaf = path->nodes[0];
698 ret = 0;
699 goto found;
700 }
701 ret = PTR_ERR(item);
702 if (ret != -EFBIG && ret != -ENOENT)
703 goto fail_unlock;
704
705 if (ret == -EFBIG) {
706 u32 item_size;
707 /* we found one, but it isn't big enough yet */
708 leaf = path->nodes[0];
709 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
710 if ((item_size / csum_size) >=
711 MAX_CSUM_ITEMS(root, csum_size)) {
712 /* already at max size, make a new one */
713 goto insert;
714 }
715 } else {
716 int slot = path->slots[0] + 1;
717 /* we didn't find a csum item, insert one */
718 nritems = btrfs_header_nritems(path->nodes[0]);
719 if (path->slots[0] >= nritems - 1) {
720 ret = btrfs_next_leaf(root, path);
721 if (ret == 1)
722 found_next = 1;
723 if (ret != 0)
724 goto insert;
725 slot = 0;
726 }
727 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
728 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
729 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
730 found_next = 1;
731 goto insert;
732 }
733 next_offset = found_key.offset;
734 found_next = 1;
735 goto insert;
736 }
737
738 /*
739 * at this point, we know the tree has an item, but it isn't big
740 * enough yet to put our csum in. Grow it
741 */
742 btrfs_release_path(path);
743 ret = btrfs_search_slot(trans, root, &file_key, path,
744 csum_size, 1);
745 if (ret < 0)
746 goto fail_unlock;
747
748 if (ret > 0) {
749 if (path->slots[0] == 0)
750 goto insert;
751 path->slots[0]--;
752 }
753
754 leaf = path->nodes[0];
755 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
756 csum_offset = (bytenr - found_key.offset) >>
757 root->fs_info->sb->s_blocksize_bits;
758
759 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY ||
760 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
761 csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
762 goto insert;
763 }
764
765 if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
766 csum_size) {
767 u32 diff = (csum_offset + 1) * csum_size;
768
769 /*
770 * is the item big enough already? we dropped our lock
771 * before and need to recheck
772 */
773 if (diff < btrfs_item_size_nr(leaf, path->slots[0]))
774 goto csum;
775
776 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
777 if (diff != csum_size)
778 goto insert;
779
780 ret = btrfs_extend_item(trans, root, path, diff);
781 goto csum;
782 }
783
784insert:
785 btrfs_release_path(path);
786 csum_offset = 0;
787 if (found_next) {
788 u64 tmp = total_bytes + root->sectorsize;
789 u64 next_sector = sector_sum->bytenr;
790 struct btrfs_sector_sum *next = sector_sum + 1;
791
792 while (tmp < sums->len) {
793 if (next_sector + root->sectorsize != next->bytenr)
794 break;
795 tmp += root->sectorsize;
796 next_sector = next->bytenr;
797 next++;
798 }
799 tmp = min(tmp, next_offset - file_key.offset);
800 tmp >>= root->fs_info->sb->s_blocksize_bits;
801 tmp = max((u64)1, tmp);
802 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
803 ins_size = csum_size * tmp;
804 } else {
805 ins_size = csum_size;
806 }
807 path->leave_spinning = 1;
808 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
809 ins_size);
810 path->leave_spinning = 0;
811 if (ret < 0)
812 goto fail_unlock;
813 if (ret != 0) {
814 WARN_ON(1);
815 goto fail_unlock;
816 }
817csum:
818 leaf = path->nodes[0];
819 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
820 ret = 0;
821 item = (struct btrfs_csum_item *)((unsigned char *)item +
822 csum_offset * csum_size);
823found:
824 item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
825 item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
826 btrfs_item_size_nr(leaf, path->slots[0]));
827next_sector:
828
829 write_extent_buffer(leaf, §or_sum->sum, (unsigned long)item, csum_size);
830
831 total_bytes += root->sectorsize;
832 sector_sum++;
833 if (total_bytes < sums->len) {
834 item = (struct btrfs_csum_item *)((char *)item +
835 csum_size);
836 if (item < item_end && bytenr + PAGE_CACHE_SIZE ==
837 sector_sum->bytenr) {
838 bytenr = sector_sum->bytenr;
839 goto next_sector;
840 }
841 }
842
843 btrfs_mark_buffer_dirty(path->nodes[0]);
844 if (total_bytes < sums->len) {
845 btrfs_release_path(path);
846 cond_resched();
847 goto again;
848 }
849out:
850 btrfs_free_path(path);
851 return ret;
852
853fail_unlock:
854 goto out;
855}