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
max_ordered_sum_bytes(struct btrfs_fs_info * fs_info,u16 csum_size)26 static 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
btrfs_insert_file_extent(struct btrfs_trans_handle * trans,struct btrfs_root * root,u64 objectid,u64 pos,u64 disk_offset,u64 disk_num_bytes,u64 num_bytes,u64 offset,u64 ram_bytes,u8 compression,u8 encryption,u16 other_encoding)34 int 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);
75 out:
76 btrfs_free_path(path);
77 return ret;
78 }
79
80 static struct btrfs_csum_item *
btrfs_lookup_csum(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,u64 bytenr,int cow)81 btrfs_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;
128 fail:
129 if (ret > 0)
130 ret = -ENOENT;
131 return ERR_PTR(ret);
132 }
133
btrfs_lookup_file_extent(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,u64 objectid,u64 offset,int mod)134 int 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
__btrfs_lookup_bio_sums(struct inode * inode,struct bio * bio,u64 logical_offset,u8 * dst,int dio)151 static 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);
273 found:
274 csum += count * csum_size;
275 nblocks -= count;
276 next:
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
btrfs_lookup_bio_sums(struct inode * inode,struct bio * bio,u8 * dst)291 blk_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
btrfs_lookup_bio_sums_dio(struct inode * inode,struct bio * bio,u64 offset)297 blk_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
btrfs_lookup_csums_range(struct btrfs_root * root,u64 start,u64 end,struct list_head * list,int search_commit)302 int 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;
410 fail:
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 */
btrfs_csum_one_bio(struct inode * inode,struct bio * bio,u64 file_start,int contig)432 blk_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 */
truncate_one_csum(struct btrfs_fs_info * fs_info,struct btrfs_path * path,struct btrfs_key * key,u64 bytenr,u64 len)542 static 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 */
btrfs_del_csums(struct btrfs_trans_handle * trans,struct btrfs_root * root,u64 bytenr,u64 len)592 int btrfs_del_csums(struct btrfs_trans_handle *trans,
593 struct btrfs_root *root, u64 bytenr, u64 len)
594 {
595 struct btrfs_fs_info *fs_info = trans->fs_info;
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 ASSERT(root == fs_info->csum_root ||
606 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
607
608 path = btrfs_alloc_path();
609 if (!path)
610 return -ENOMEM;
611
612 while (1) {
613 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
614 key.offset = end_byte - 1;
615 key.type = BTRFS_EXTENT_CSUM_KEY;
616
617 path->leave_spinning = 1;
618 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
619 if (ret > 0) {
620 if (path->slots[0] == 0)
621 break;
622 path->slots[0]--;
623 } else if (ret < 0) {
624 break;
625 }
626
627 leaf = path->nodes[0];
628 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
629
630 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
631 key.type != BTRFS_EXTENT_CSUM_KEY) {
632 break;
633 }
634
635 if (key.offset >= end_byte)
636 break;
637
638 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
639 csum_end <<= blocksize_bits;
640 csum_end += key.offset;
641
642 /* this csum ends before we start, we're done */
643 if (csum_end <= bytenr)
644 break;
645
646 /* delete the entire item, it is inside our range */
647 if (key.offset >= bytenr && csum_end <= end_byte) {
648 int del_nr = 1;
649
650 /*
651 * Check how many csum items preceding this one in this
652 * leaf correspond to our range and then delete them all
653 * at once.
654 */
655 if (key.offset > bytenr && path->slots[0] > 0) {
656 int slot = path->slots[0] - 1;
657
658 while (slot >= 0) {
659 struct btrfs_key pk;
660
661 btrfs_item_key_to_cpu(leaf, &pk, slot);
662 if (pk.offset < bytenr ||
663 pk.type != BTRFS_EXTENT_CSUM_KEY ||
664 pk.objectid !=
665 BTRFS_EXTENT_CSUM_OBJECTID)
666 break;
667 path->slots[0] = slot;
668 del_nr++;
669 key.offset = pk.offset;
670 slot--;
671 }
672 }
673 ret = btrfs_del_items(trans, root, path,
674 path->slots[0], del_nr);
675 if (ret)
676 goto out;
677 if (key.offset == bytenr)
678 break;
679 } else if (key.offset < bytenr && csum_end > end_byte) {
680 unsigned long offset;
681 unsigned long shift_len;
682 unsigned long item_offset;
683 /*
684 * [ bytenr - len ]
685 * [csum ]
686 *
687 * Our bytes are in the middle of the csum,
688 * we need to split this item and insert a new one.
689 *
690 * But we can't drop the path because the
691 * csum could change, get removed, extended etc.
692 *
693 * The trick here is the max size of a csum item leaves
694 * enough room in the tree block for a single
695 * item header. So, we split the item in place,
696 * adding a new header pointing to the existing
697 * bytes. Then we loop around again and we have
698 * a nicely formed csum item that we can neatly
699 * truncate.
700 */
701 offset = (bytenr - key.offset) >> blocksize_bits;
702 offset *= csum_size;
703
704 shift_len = (len >> blocksize_bits) * csum_size;
705
706 item_offset = btrfs_item_ptr_offset(leaf,
707 path->slots[0]);
708
709 memzero_extent_buffer(leaf, item_offset + offset,
710 shift_len);
711 key.offset = bytenr;
712
713 /*
714 * btrfs_split_item returns -EAGAIN when the
715 * item changed size or key
716 */
717 ret = btrfs_split_item(trans, root, path, &key, offset);
718 if (ret && ret != -EAGAIN) {
719 btrfs_abort_transaction(trans, ret);
720 goto out;
721 }
722
723 key.offset = end_byte - 1;
724 } else {
725 truncate_one_csum(fs_info, path, &key, bytenr, len);
726 if (key.offset < bytenr)
727 break;
728 }
729 btrfs_release_path(path);
730 }
731 ret = 0;
732 out:
733 btrfs_free_path(path);
734 return ret;
735 }
736
btrfs_csum_file_blocks(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_ordered_sum * sums)737 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
738 struct btrfs_root *root,
739 struct btrfs_ordered_sum *sums)
740 {
741 struct btrfs_fs_info *fs_info = root->fs_info;
742 struct btrfs_key file_key;
743 struct btrfs_key found_key;
744 struct btrfs_path *path;
745 struct btrfs_csum_item *item;
746 struct btrfs_csum_item *item_end;
747 struct extent_buffer *leaf = NULL;
748 u64 next_offset;
749 u64 total_bytes = 0;
750 u64 csum_offset;
751 u64 bytenr;
752 u32 nritems;
753 u32 ins_size;
754 int index = 0;
755 int found_next;
756 int ret;
757 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
758
759 path = btrfs_alloc_path();
760 if (!path)
761 return -ENOMEM;
762 again:
763 next_offset = (u64)-1;
764 found_next = 0;
765 bytenr = sums->bytenr + total_bytes;
766 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
767 file_key.offset = bytenr;
768 file_key.type = BTRFS_EXTENT_CSUM_KEY;
769
770 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
771 if (!IS_ERR(item)) {
772 ret = 0;
773 leaf = path->nodes[0];
774 item_end = btrfs_item_ptr(leaf, path->slots[0],
775 struct btrfs_csum_item);
776 item_end = (struct btrfs_csum_item *)((char *)item_end +
777 btrfs_item_size_nr(leaf, path->slots[0]));
778 goto found;
779 }
780 ret = PTR_ERR(item);
781 if (ret != -EFBIG && ret != -ENOENT)
782 goto fail_unlock;
783
784 if (ret == -EFBIG) {
785 u32 item_size;
786 /* we found one, but it isn't big enough yet */
787 leaf = path->nodes[0];
788 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
789 if ((item_size / csum_size) >=
790 MAX_CSUM_ITEMS(fs_info, csum_size)) {
791 /* already at max size, make a new one */
792 goto insert;
793 }
794 } else {
795 int slot = path->slots[0] + 1;
796 /* we didn't find a csum item, insert one */
797 nritems = btrfs_header_nritems(path->nodes[0]);
798 if (!nritems || (path->slots[0] >= nritems - 1)) {
799 ret = btrfs_next_leaf(root, path);
800 if (ret == 1)
801 found_next = 1;
802 if (ret != 0)
803 goto insert;
804 slot = path->slots[0];
805 }
806 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
807 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
808 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
809 found_next = 1;
810 goto insert;
811 }
812 next_offset = found_key.offset;
813 found_next = 1;
814 goto insert;
815 }
816
817 /*
818 * at this point, we know the tree has an item, but it isn't big
819 * enough yet to put our csum in. Grow it
820 */
821 btrfs_release_path(path);
822 ret = btrfs_search_slot(trans, root, &file_key, path,
823 csum_size, 1);
824 if (ret < 0)
825 goto fail_unlock;
826
827 if (ret > 0) {
828 if (path->slots[0] == 0)
829 goto insert;
830 path->slots[0]--;
831 }
832
833 leaf = path->nodes[0];
834 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
835 csum_offset = (bytenr - found_key.offset) >>
836 fs_info->sb->s_blocksize_bits;
837
838 if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
839 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
840 csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
841 goto insert;
842 }
843
844 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
845 csum_size) {
846 int extend_nr;
847 u64 tmp;
848 u32 diff;
849 u32 free_space;
850
851 if (btrfs_leaf_free_space(leaf) <
852 sizeof(struct btrfs_item) + csum_size * 2)
853 goto insert;
854
855 free_space = btrfs_leaf_free_space(leaf) -
856 sizeof(struct btrfs_item) - csum_size;
857 tmp = sums->len - total_bytes;
858 tmp >>= fs_info->sb->s_blocksize_bits;
859 WARN_ON(tmp < 1);
860
861 extend_nr = max_t(int, 1, (int)tmp);
862 diff = (csum_offset + extend_nr) * csum_size;
863 diff = min(diff,
864 MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
865
866 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
867 diff = min(free_space, diff);
868 diff /= csum_size;
869 diff *= csum_size;
870
871 btrfs_extend_item(path, diff);
872 ret = 0;
873 goto csum;
874 }
875
876 insert:
877 btrfs_release_path(path);
878 csum_offset = 0;
879 if (found_next) {
880 u64 tmp;
881
882 tmp = sums->len - total_bytes;
883 tmp >>= fs_info->sb->s_blocksize_bits;
884 tmp = min(tmp, (next_offset - file_key.offset) >>
885 fs_info->sb->s_blocksize_bits);
886
887 tmp = max_t(u64, 1, tmp);
888 tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
889 ins_size = csum_size * tmp;
890 } else {
891 ins_size = csum_size;
892 }
893 path->leave_spinning = 1;
894 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
895 ins_size);
896 path->leave_spinning = 0;
897 if (ret < 0)
898 goto fail_unlock;
899 if (WARN_ON(ret != 0))
900 goto fail_unlock;
901 leaf = path->nodes[0];
902 csum:
903 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
904 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
905 btrfs_item_size_nr(leaf, path->slots[0]));
906 item = (struct btrfs_csum_item *)((unsigned char *)item +
907 csum_offset * csum_size);
908 found:
909 ins_size = (u32)(sums->len - total_bytes) >>
910 fs_info->sb->s_blocksize_bits;
911 ins_size *= csum_size;
912 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
913 ins_size);
914 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
915 ins_size);
916
917 index += ins_size;
918 ins_size /= csum_size;
919 total_bytes += ins_size * fs_info->sectorsize;
920
921 btrfs_mark_buffer_dirty(path->nodes[0]);
922 if (total_bytes < sums->len) {
923 btrfs_release_path(path);
924 cond_resched();
925 goto again;
926 }
927 out:
928 btrfs_free_path(path);
929 return ret;
930
931 fail_unlock:
932 goto out;
933 }
934
btrfs_extent_item_to_extent_map(struct btrfs_inode * inode,const struct btrfs_path * path,struct btrfs_file_extent_item * fi,const bool new_inline,struct extent_map * em)935 void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
936 const struct btrfs_path *path,
937 struct btrfs_file_extent_item *fi,
938 const bool new_inline,
939 struct extent_map *em)
940 {
941 struct btrfs_fs_info *fs_info = inode->root->fs_info;
942 struct btrfs_root *root = inode->root;
943 struct extent_buffer *leaf = path->nodes[0];
944 const int slot = path->slots[0];
945 struct btrfs_key key;
946 u64 extent_start, extent_end;
947 u64 bytenr;
948 u8 type = btrfs_file_extent_type(leaf, fi);
949 int compress_type = btrfs_file_extent_compression(leaf, fi);
950
951 em->bdev = fs_info->fs_devices->latest_bdev;
952 btrfs_item_key_to_cpu(leaf, &key, slot);
953 extent_start = key.offset;
954
955 if (type == BTRFS_FILE_EXTENT_REG ||
956 type == BTRFS_FILE_EXTENT_PREALLOC) {
957 extent_end = extent_start +
958 btrfs_file_extent_num_bytes(leaf, fi);
959 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
960 size_t size;
961 size = btrfs_file_extent_ram_bytes(leaf, fi);
962 extent_end = ALIGN(extent_start + size,
963 fs_info->sectorsize);
964 }
965
966 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
967 if (type == BTRFS_FILE_EXTENT_REG ||
968 type == BTRFS_FILE_EXTENT_PREALLOC) {
969 em->start = extent_start;
970 em->len = extent_end - extent_start;
971 em->orig_start = extent_start -
972 btrfs_file_extent_offset(leaf, fi);
973 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
974 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
975 if (bytenr == 0) {
976 em->block_start = EXTENT_MAP_HOLE;
977 return;
978 }
979 if (compress_type != BTRFS_COMPRESS_NONE) {
980 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
981 em->compress_type = compress_type;
982 em->block_start = bytenr;
983 em->block_len = em->orig_block_len;
984 } else {
985 bytenr += btrfs_file_extent_offset(leaf, fi);
986 em->block_start = bytenr;
987 em->block_len = em->len;
988 if (type == BTRFS_FILE_EXTENT_PREALLOC)
989 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
990 }
991 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
992 em->block_start = EXTENT_MAP_INLINE;
993 em->start = extent_start;
994 em->len = extent_end - extent_start;
995 /*
996 * Initialize orig_start and block_len with the same values
997 * as in inode.c:btrfs_get_extent().
998 */
999 em->orig_start = EXTENT_MAP_HOLE;
1000 em->block_len = (u64)-1;
1001 if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) {
1002 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
1003 em->compress_type = compress_type;
1004 }
1005 } else {
1006 btrfs_err(fs_info,
1007 "unknown file extent item type %d, inode %llu, offset %llu, "
1008 "root %llu", type, btrfs_ino(inode), extent_start,
1009 root->root_key.objectid);
1010 }
1011 }
1012