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Merge tag 'drm-fixes-2020-03-06-1' of git://anongit.freedesktop.org/drm/drm
[mirror_ubuntu-jammy-kernel.git] / fs / btrfs / file-item.c
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
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
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 *
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
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
151 /**
152 * btrfs_lookup_bio_sums - Look up checksums for a bio.
153 * @inode: inode that the bio is for.
154 * @bio: bio embedded in btrfs_io_bio.
155 * @offset: Unless (u64)-1, look up checksums for this offset in the file.
156 * If (u64)-1, use the page offsets from the bio instead.
157 * @dst: Buffer of size btrfs_super_csum_size() used to return checksum. If
158 * NULL, the checksum is returned in btrfs_io_bio(bio)->csum instead.
159 *
160 * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
161 */
162 blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
163 u64 offset, u8 *dst)
164 {
165 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
166 struct bio_vec bvec;
167 struct bvec_iter iter;
168 struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
169 struct btrfs_csum_item *item = NULL;
170 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
171 struct btrfs_path *path;
172 const bool page_offsets = (offset == (u64)-1);
173 u8 *csum;
174 u64 item_start_offset = 0;
175 u64 item_last_offset = 0;
176 u64 disk_bytenr;
177 u64 page_bytes_left;
178 u32 diff;
179 int nblocks;
180 int count = 0;
181 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
182
183 path = btrfs_alloc_path();
184 if (!path)
185 return BLK_STS_RESOURCE;
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 = kmalloc_array(nblocks, csum_size,
191 GFP_NOFS);
192 if (!btrfs_bio->csum) {
193 btrfs_free_path(path);
194 return BLK_STS_RESOURCE;
195 }
196 } else {
197 btrfs_bio->csum = btrfs_bio->csum_inline;
198 }
199 csum = btrfs_bio->csum;
200 } else {
201 csum = dst;
202 }
203
204 if (bio->bi_iter.bi_size > PAGE_SIZE * 8)
205 path->reada = READA_FORWARD;
206
207 /*
208 * the free space stuff is only read when it hasn't been
209 * updated in the current transaction. So, we can safely
210 * read from the commit root and sidestep a nasty deadlock
211 * between reading the free space cache and updating the csum tree.
212 */
213 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
214 path->search_commit_root = 1;
215 path->skip_locking = 1;
216 }
217
218 disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
219
220 bio_for_each_segment(bvec, bio, iter) {
221 page_bytes_left = bvec.bv_len;
222 if (count)
223 goto next;
224
225 if (page_offsets)
226 offset = page_offset(bvec.bv_page) + bvec.bv_offset;
227 count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
228 csum, nblocks);
229 if (count)
230 goto found;
231
232 if (!item || disk_bytenr < item_start_offset ||
233 disk_bytenr >= item_last_offset) {
234 struct btrfs_key found_key;
235 u32 item_size;
236
237 if (item)
238 btrfs_release_path(path);
239 item = btrfs_lookup_csum(NULL, fs_info->csum_root,
240 path, disk_bytenr, 0);
241 if (IS_ERR(item)) {
242 count = 1;
243 memset(csum, 0, csum_size);
244 if (BTRFS_I(inode)->root->root_key.objectid ==
245 BTRFS_DATA_RELOC_TREE_OBJECTID) {
246 set_extent_bits(io_tree, offset,
247 offset + fs_info->sectorsize - 1,
248 EXTENT_NODATASUM);
249 } else {
250 btrfs_info_rl(fs_info,
251 "no csum found for inode %llu start %llu",
252 btrfs_ino(BTRFS_I(inode)), offset);
253 }
254 item = NULL;
255 btrfs_release_path(path);
256 goto found;
257 }
258 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
259 path->slots[0]);
260
261 item_start_offset = found_key.offset;
262 item_size = btrfs_item_size_nr(path->nodes[0],
263 path->slots[0]);
264 item_last_offset = item_start_offset +
265 (item_size / csum_size) *
266 fs_info->sectorsize;
267 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
268 struct btrfs_csum_item);
269 }
270 /*
271 * this byte range must be able to fit inside
272 * a single leaf so it will also fit inside a u32
273 */
274 diff = disk_bytenr - item_start_offset;
275 diff = diff / fs_info->sectorsize;
276 diff = diff * csum_size;
277 count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >>
278 inode->i_sb->s_blocksize_bits);
279 read_extent_buffer(path->nodes[0], csum,
280 ((unsigned long)item) + diff,
281 csum_size * count);
282 found:
283 csum += count * csum_size;
284 nblocks -= count;
285 next:
286 while (count > 0) {
287 count--;
288 disk_bytenr += fs_info->sectorsize;
289 offset += fs_info->sectorsize;
290 page_bytes_left -= fs_info->sectorsize;
291 if (!page_bytes_left)
292 break; /* move to next bio */
293 }
294 }
295
296 WARN_ON_ONCE(count);
297 btrfs_free_path(path);
298 return BLK_STS_OK;
299 }
300
301 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
302 struct list_head *list, int search_commit)
303 {
304 struct btrfs_fs_info *fs_info = root->fs_info;
305 struct btrfs_key key;
306 struct btrfs_path *path;
307 struct extent_buffer *leaf;
308 struct btrfs_ordered_sum *sums;
309 struct btrfs_csum_item *item;
310 LIST_HEAD(tmplist);
311 unsigned long offset;
312 int ret;
313 size_t size;
314 u64 csum_end;
315 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
316
317 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
318 IS_ALIGNED(end + 1, fs_info->sectorsize));
319
320 path = btrfs_alloc_path();
321 if (!path)
322 return -ENOMEM;
323
324 if (search_commit) {
325 path->skip_locking = 1;
326 path->reada = READA_FORWARD;
327 path->search_commit_root = 1;
328 }
329
330 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
331 key.offset = start;
332 key.type = BTRFS_EXTENT_CSUM_KEY;
333
334 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
335 if (ret < 0)
336 goto fail;
337 if (ret > 0 && path->slots[0] > 0) {
338 leaf = path->nodes[0];
339 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
340 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
341 key.type == BTRFS_EXTENT_CSUM_KEY) {
342 offset = (start - key.offset) >>
343 fs_info->sb->s_blocksize_bits;
344 if (offset * csum_size <
345 btrfs_item_size_nr(leaf, path->slots[0] - 1))
346 path->slots[0]--;
347 }
348 }
349
350 while (start <= end) {
351 leaf = path->nodes[0];
352 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
353 ret = btrfs_next_leaf(root, path);
354 if (ret < 0)
355 goto fail;
356 if (ret > 0)
357 break;
358 leaf = path->nodes[0];
359 }
360
361 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
362 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
363 key.type != BTRFS_EXTENT_CSUM_KEY ||
364 key.offset > end)
365 break;
366
367 if (key.offset > start)
368 start = key.offset;
369
370 size = btrfs_item_size_nr(leaf, path->slots[0]);
371 csum_end = key.offset + (size / csum_size) * fs_info->sectorsize;
372 if (csum_end <= start) {
373 path->slots[0]++;
374 continue;
375 }
376
377 csum_end = min(csum_end, end + 1);
378 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
379 struct btrfs_csum_item);
380 while (start < csum_end) {
381 size = min_t(size_t, csum_end - start,
382 max_ordered_sum_bytes(fs_info, csum_size));
383 sums = kzalloc(btrfs_ordered_sum_size(fs_info, size),
384 GFP_NOFS);
385 if (!sums) {
386 ret = -ENOMEM;
387 goto fail;
388 }
389
390 sums->bytenr = start;
391 sums->len = (int)size;
392
393 offset = (start - key.offset) >>
394 fs_info->sb->s_blocksize_bits;
395 offset *= csum_size;
396 size >>= fs_info->sb->s_blocksize_bits;
397
398 read_extent_buffer(path->nodes[0],
399 sums->sums,
400 ((unsigned long)item) + offset,
401 csum_size * size);
402
403 start += fs_info->sectorsize * size;
404 list_add_tail(&sums->list, &tmplist);
405 }
406 path->slots[0]++;
407 }
408 ret = 0;
409 fail:
410 while (ret < 0 && !list_empty(&tmplist)) {
411 sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list);
412 list_del(&sums->list);
413 kfree(sums);
414 }
415 list_splice_tail(&tmplist, list);
416
417 btrfs_free_path(path);
418 return ret;
419 }
420
421 /*
422 * btrfs_csum_one_bio - Calculates checksums of the data contained inside a bio
423 * @inode: Owner of the data inside the bio
424 * @bio: Contains the data to be checksummed
425 * @file_start: offset in file this bio begins to describe
426 * @contig: Boolean. If true/1 means all bio vecs in this bio are
427 * contiguous and they begin at @file_start in the file. False/0
428 * means this bio can contains potentially discontigous bio vecs
429 * so the logical offset of each should be calculated separately.
430 */
431 blk_status_t btrfs_csum_one_bio(struct inode *inode, struct bio *bio,
432 u64 file_start, int contig)
433 {
434 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
435 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
436 struct btrfs_ordered_sum *sums;
437 struct btrfs_ordered_extent *ordered = NULL;
438 char *data;
439 struct bvec_iter iter;
440 struct bio_vec bvec;
441 int index;
442 int nr_sectors;
443 unsigned long total_bytes = 0;
444 unsigned long this_sum_bytes = 0;
445 int i;
446 u64 offset;
447 unsigned nofs_flag;
448 const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
449
450 nofs_flag = memalloc_nofs_save();
451 sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
452 GFP_KERNEL);
453 memalloc_nofs_restore(nofs_flag);
454
455 if (!sums)
456 return BLK_STS_RESOURCE;
457
458 sums->len = bio->bi_iter.bi_size;
459 INIT_LIST_HEAD(&sums->list);
460
461 if (contig)
462 offset = file_start;
463 else
464 offset = 0; /* shut up gcc */
465
466 sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
467 index = 0;
468
469 shash->tfm = fs_info->csum_shash;
470
471 bio_for_each_segment(bvec, bio, iter) {
472 if (!contig)
473 offset = page_offset(bvec.bv_page) + bvec.bv_offset;
474
475 if (!ordered) {
476 ordered = btrfs_lookup_ordered_extent(inode, offset);
477 BUG_ON(!ordered); /* Logic error */
478 }
479
480 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info,
481 bvec.bv_len + fs_info->sectorsize
482 - 1);
483
484 for (i = 0; i < nr_sectors; i++) {
485 if (offset >= ordered->file_offset + ordered->num_bytes ||
486 offset < ordered->file_offset) {
487 unsigned long bytes_left;
488
489 sums->len = this_sum_bytes;
490 this_sum_bytes = 0;
491 btrfs_add_ordered_sum(ordered, sums);
492 btrfs_put_ordered_extent(ordered);
493
494 bytes_left = bio->bi_iter.bi_size - total_bytes;
495
496 nofs_flag = memalloc_nofs_save();
497 sums = kvzalloc(btrfs_ordered_sum_size(fs_info,
498 bytes_left), GFP_KERNEL);
499 memalloc_nofs_restore(nofs_flag);
500 BUG_ON(!sums); /* -ENOMEM */
501 sums->len = bytes_left;
502 ordered = btrfs_lookup_ordered_extent(inode,
503 offset);
504 ASSERT(ordered); /* Logic error */
505 sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9)
506 + total_bytes;
507 index = 0;
508 }
509
510 crypto_shash_init(shash);
511 data = kmap_atomic(bvec.bv_page);
512 crypto_shash_update(shash, data + bvec.bv_offset
513 + (i * fs_info->sectorsize),
514 fs_info->sectorsize);
515 kunmap_atomic(data);
516 crypto_shash_final(shash, (char *)(sums->sums + index));
517 index += csum_size;
518 offset += fs_info->sectorsize;
519 this_sum_bytes += fs_info->sectorsize;
520 total_bytes += fs_info->sectorsize;
521 }
522
523 }
524 this_sum_bytes = 0;
525 btrfs_add_ordered_sum(ordered, sums);
526 btrfs_put_ordered_extent(ordered);
527 return 0;
528 }
529
530 /*
531 * helper function for csum removal, this expects the
532 * key to describe the csum pointed to by the path, and it expects
533 * the csum to overlap the range [bytenr, len]
534 *
535 * The csum should not be entirely contained in the range and the
536 * range should not be entirely contained in the csum.
537 *
538 * This calls btrfs_truncate_item with the correct args based on the
539 * overlap, and fixes up the key as required.
540 */
541 static noinline void truncate_one_csum(struct btrfs_fs_info *fs_info,
542 struct btrfs_path *path,
543 struct btrfs_key *key,
544 u64 bytenr, u64 len)
545 {
546 struct extent_buffer *leaf;
547 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
548 u64 csum_end;
549 u64 end_byte = bytenr + len;
550 u32 blocksize_bits = fs_info->sb->s_blocksize_bits;
551
552 leaf = path->nodes[0];
553 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
554 csum_end <<= fs_info->sb->s_blocksize_bits;
555 csum_end += key->offset;
556
557 if (key->offset < bytenr && csum_end <= end_byte) {
558 /*
559 * [ bytenr - len ]
560 * [ ]
561 * [csum ]
562 * A simple truncate off the end of the item
563 */
564 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
565 new_size *= csum_size;
566 btrfs_truncate_item(path, new_size, 1);
567 } else if (key->offset >= bytenr && csum_end > end_byte &&
568 end_byte > key->offset) {
569 /*
570 * [ bytenr - len ]
571 * [ ]
572 * [csum ]
573 * we need to truncate from the beginning of the csum
574 */
575 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
576 new_size *= csum_size;
577
578 btrfs_truncate_item(path, new_size, 0);
579
580 key->offset = end_byte;
581 btrfs_set_item_key_safe(fs_info, path, key);
582 } else {
583 BUG();
584 }
585 }
586
587 /*
588 * deletes the csum items from the csum tree for a given
589 * range of bytes.
590 */
591 int btrfs_del_csums(struct btrfs_trans_handle *trans,
592 struct btrfs_root *root, u64 bytenr, u64 len)
593 {
594 struct btrfs_fs_info *fs_info = trans->fs_info;
595 struct btrfs_path *path;
596 struct btrfs_key key;
597 u64 end_byte = bytenr + len;
598 u64 csum_end;
599 struct extent_buffer *leaf;
600 int ret;
601 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
602 int blocksize_bits = fs_info->sb->s_blocksize_bits;
603
604 ASSERT(root == fs_info->csum_root ||
605 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
606
607 path = btrfs_alloc_path();
608 if (!path)
609 return -ENOMEM;
610
611 while (1) {
612 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
613 key.offset = end_byte - 1;
614 key.type = BTRFS_EXTENT_CSUM_KEY;
615
616 path->leave_spinning = 1;
617 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
618 if (ret > 0) {
619 if (path->slots[0] == 0)
620 break;
621 path->slots[0]--;
622 } else if (ret < 0) {
623 break;
624 }
625
626 leaf = path->nodes[0];
627 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
628
629 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
630 key.type != BTRFS_EXTENT_CSUM_KEY) {
631 break;
632 }
633
634 if (key.offset >= end_byte)
635 break;
636
637 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
638 csum_end <<= blocksize_bits;
639 csum_end += key.offset;
640
641 /* this csum ends before we start, we're done */
642 if (csum_end <= bytenr)
643 break;
644
645 /* delete the entire item, it is inside our range */
646 if (key.offset >= bytenr && csum_end <= end_byte) {
647 int del_nr = 1;
648
649 /*
650 * Check how many csum items preceding this one in this
651 * leaf correspond to our range and then delete them all
652 * at once.
653 */
654 if (key.offset > bytenr && path->slots[0] > 0) {
655 int slot = path->slots[0] - 1;
656
657 while (slot >= 0) {
658 struct btrfs_key pk;
659
660 btrfs_item_key_to_cpu(leaf, &pk, slot);
661 if (pk.offset < bytenr ||
662 pk.type != BTRFS_EXTENT_CSUM_KEY ||
663 pk.objectid !=
664 BTRFS_EXTENT_CSUM_OBJECTID)
665 break;
666 path->slots[0] = slot;
667 del_nr++;
668 key.offset = pk.offset;
669 slot--;
670 }
671 }
672 ret = btrfs_del_items(trans, root, path,
673 path->slots[0], del_nr);
674 if (ret)
675 goto out;
676 if (key.offset == bytenr)
677 break;
678 } else if (key.offset < bytenr && csum_end > end_byte) {
679 unsigned long offset;
680 unsigned long shift_len;
681 unsigned long item_offset;
682 /*
683 * [ bytenr - len ]
684 * [csum ]
685 *
686 * Our bytes are in the middle of the csum,
687 * we need to split this item and insert a new one.
688 *
689 * But we can't drop the path because the
690 * csum could change, get removed, extended etc.
691 *
692 * The trick here is the max size of a csum item leaves
693 * enough room in the tree block for a single
694 * item header. So, we split the item in place,
695 * adding a new header pointing to the existing
696 * bytes. Then we loop around again and we have
697 * a nicely formed csum item that we can neatly
698 * truncate.
699 */
700 offset = (bytenr - key.offset) >> blocksize_bits;
701 offset *= csum_size;
702
703 shift_len = (len >> blocksize_bits) * csum_size;
704
705 item_offset = btrfs_item_ptr_offset(leaf,
706 path->slots[0]);
707
708 memzero_extent_buffer(leaf, item_offset + offset,
709 shift_len);
710 key.offset = bytenr;
711
712 /*
713 * btrfs_split_item returns -EAGAIN when the
714 * item changed size or key
715 */
716 ret = btrfs_split_item(trans, root, path, &key, offset);
717 if (ret && ret != -EAGAIN) {
718 btrfs_abort_transaction(trans, ret);
719 goto out;
720 }
721
722 key.offset = end_byte - 1;
723 } else {
724 truncate_one_csum(fs_info, path, &key, bytenr, len);
725 if (key.offset < bytenr)
726 break;
727 }
728 btrfs_release_path(path);
729 }
730 ret = 0;
731 out:
732 btrfs_free_path(path);
733 return ret;
734 }
735
736 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
737 struct btrfs_root *root,
738 struct btrfs_ordered_sum *sums)
739 {
740 struct btrfs_fs_info *fs_info = root->fs_info;
741 struct btrfs_key file_key;
742 struct btrfs_key found_key;
743 struct btrfs_path *path;
744 struct btrfs_csum_item *item;
745 struct btrfs_csum_item *item_end;
746 struct extent_buffer *leaf = NULL;
747 u64 next_offset;
748 u64 total_bytes = 0;
749 u64 csum_offset;
750 u64 bytenr;
751 u32 nritems;
752 u32 ins_size;
753 int index = 0;
754 int found_next;
755 int ret;
756 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
757
758 path = btrfs_alloc_path();
759 if (!path)
760 return -ENOMEM;
761 again:
762 next_offset = (u64)-1;
763 found_next = 0;
764 bytenr = sums->bytenr + total_bytes;
765 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
766 file_key.offset = bytenr;
767 file_key.type = BTRFS_EXTENT_CSUM_KEY;
768
769 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
770 if (!IS_ERR(item)) {
771 ret = 0;
772 leaf = path->nodes[0];
773 item_end = btrfs_item_ptr(leaf, path->slots[0],
774 struct btrfs_csum_item);
775 item_end = (struct btrfs_csum_item *)((char *)item_end +
776 btrfs_item_size_nr(leaf, path->slots[0]));
777 goto found;
778 }
779 ret = PTR_ERR(item);
780 if (ret != -EFBIG && ret != -ENOENT)
781 goto fail_unlock;
782
783 if (ret == -EFBIG) {
784 u32 item_size;
785 /* we found one, but it isn't big enough yet */
786 leaf = path->nodes[0];
787 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
788 if ((item_size / csum_size) >=
789 MAX_CSUM_ITEMS(fs_info, csum_size)) {
790 /* already at max size, make a new one */
791 goto insert;
792 }
793 } else {
794 int slot = path->slots[0] + 1;
795 /* we didn't find a csum item, insert one */
796 nritems = btrfs_header_nritems(path->nodes[0]);
797 if (!nritems || (path->slots[0] >= nritems - 1)) {
798 ret = btrfs_next_leaf(root, path);
799 if (ret == 1)
800 found_next = 1;
801 if (ret != 0)
802 goto insert;
803 slot = path->slots[0];
804 }
805 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
806 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
807 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
808 found_next = 1;
809 goto insert;
810 }
811 next_offset = found_key.offset;
812 found_next = 1;
813 goto insert;
814 }
815
816 /*
817 * at this point, we know the tree has an item, but it isn't big
818 * enough yet to put our csum in. Grow it
819 */
820 btrfs_release_path(path);
821 ret = btrfs_search_slot(trans, root, &file_key, path,
822 csum_size, 1);
823 if (ret < 0)
824 goto fail_unlock;
825
826 if (ret > 0) {
827 if (path->slots[0] == 0)
828 goto insert;
829 path->slots[0]--;
830 }
831
832 leaf = path->nodes[0];
833 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
834 csum_offset = (bytenr - found_key.offset) >>
835 fs_info->sb->s_blocksize_bits;
836
837 if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
838 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
839 csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
840 goto insert;
841 }
842
843 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
844 csum_size) {
845 int extend_nr;
846 u64 tmp;
847 u32 diff;
848 u32 free_space;
849
850 if (btrfs_leaf_free_space(leaf) <
851 sizeof(struct btrfs_item) + csum_size * 2)
852 goto insert;
853
854 free_space = btrfs_leaf_free_space(leaf) -
855 sizeof(struct btrfs_item) - csum_size;
856 tmp = sums->len - total_bytes;
857 tmp >>= fs_info->sb->s_blocksize_bits;
858 WARN_ON(tmp < 1);
859
860 extend_nr = max_t(int, 1, (int)tmp);
861 diff = (csum_offset + extend_nr) * csum_size;
862 diff = min(diff,
863 MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
864
865 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
866 diff = min(free_space, diff);
867 diff /= csum_size;
868 diff *= csum_size;
869
870 btrfs_extend_item(path, diff);
871 ret = 0;
872 goto csum;
873 }
874
875 insert:
876 btrfs_release_path(path);
877 csum_offset = 0;
878 if (found_next) {
879 u64 tmp;
880
881 tmp = sums->len - total_bytes;
882 tmp >>= fs_info->sb->s_blocksize_bits;
883 tmp = min(tmp, (next_offset - file_key.offset) >>
884 fs_info->sb->s_blocksize_bits);
885
886 tmp = max_t(u64, 1, tmp);
887 tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
888 ins_size = csum_size * tmp;
889 } else {
890 ins_size = csum_size;
891 }
892 path->leave_spinning = 1;
893 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
894 ins_size);
895 path->leave_spinning = 0;
896 if (ret < 0)
897 goto fail_unlock;
898 if (WARN_ON(ret != 0))
899 goto fail_unlock;
900 leaf = path->nodes[0];
901 csum:
902 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
903 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
904 btrfs_item_size_nr(leaf, path->slots[0]));
905 item = (struct btrfs_csum_item *)((unsigned char *)item +
906 csum_offset * csum_size);
907 found:
908 ins_size = (u32)(sums->len - total_bytes) >>
909 fs_info->sb->s_blocksize_bits;
910 ins_size *= csum_size;
911 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
912 ins_size);
913 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
914 ins_size);
915
916 index += ins_size;
917 ins_size /= csum_size;
918 total_bytes += ins_size * fs_info->sectorsize;
919
920 btrfs_mark_buffer_dirty(path->nodes[0]);
921 if (total_bytes < sums->len) {
922 btrfs_release_path(path);
923 cond_resched();
924 goto again;
925 }
926 out:
927 btrfs_free_path(path);
928 return ret;
929
930 fail_unlock:
931 goto out;
932 }
933
934 void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
935 const struct btrfs_path *path,
936 struct btrfs_file_extent_item *fi,
937 const bool new_inline,
938 struct extent_map *em)
939 {
940 struct btrfs_fs_info *fs_info = inode->root->fs_info;
941 struct btrfs_root *root = inode->root;
942 struct extent_buffer *leaf = path->nodes[0];
943 const int slot = path->slots[0];
944 struct btrfs_key key;
945 u64 extent_start, extent_end;
946 u64 bytenr;
947 u8 type = btrfs_file_extent_type(leaf, fi);
948 int compress_type = btrfs_file_extent_compression(leaf, fi);
949
950 btrfs_item_key_to_cpu(leaf, &key, slot);
951 extent_start = key.offset;
952
953 if (type == BTRFS_FILE_EXTENT_REG ||
954 type == BTRFS_FILE_EXTENT_PREALLOC) {
955 extent_end = extent_start +
956 btrfs_file_extent_num_bytes(leaf, fi);
957 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
958 size_t size;
959 size = btrfs_file_extent_ram_bytes(leaf, fi);
960 extent_end = ALIGN(extent_start + size,
961 fs_info->sectorsize);
962 }
963
964 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
965 if (type == BTRFS_FILE_EXTENT_REG ||
966 type == BTRFS_FILE_EXTENT_PREALLOC) {
967 em->start = extent_start;
968 em->len = extent_end - extent_start;
969 em->orig_start = extent_start -
970 btrfs_file_extent_offset(leaf, fi);
971 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
972 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
973 if (bytenr == 0) {
974 em->block_start = EXTENT_MAP_HOLE;
975 return;
976 }
977 if (compress_type != BTRFS_COMPRESS_NONE) {
978 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
979 em->compress_type = compress_type;
980 em->block_start = bytenr;
981 em->block_len = em->orig_block_len;
982 } else {
983 bytenr += btrfs_file_extent_offset(leaf, fi);
984 em->block_start = bytenr;
985 em->block_len = em->len;
986 if (type == BTRFS_FILE_EXTENT_PREALLOC)
987 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
988 }
989 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
990 em->block_start = EXTENT_MAP_INLINE;
991 em->start = extent_start;
992 em->len = extent_end - extent_start;
993 /*
994 * Initialize orig_start and block_len with the same values
995 * as in inode.c:btrfs_get_extent().
996 */
997 em->orig_start = EXTENT_MAP_HOLE;
998 em->block_len = (u64)-1;
999 if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) {
1000 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
1001 em->compress_type = compress_type;
1002 }
1003 } else {
1004 btrfs_err(fs_info,
1005 "unknown file extent item type %d, inode %llu, offset %llu, "
1006 "root %llu", type, btrfs_ino(inode), extent_start,
1007 root->root_key.objectid);
1008 }
1009 }
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