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Btrfs: cleanup unused arguments of btrfs_csum_data
[deliverable/linux.git] / fs / btrfs / file-item.c
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) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
29 sizeof(struct btrfs_item) * 2) / \
30 size) - 1))
31
32 #define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
33 PAGE_CACHE_SIZE))
34
35 #define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
36 sizeof(struct btrfs_ordered_sum)) / \
37 sizeof(struct btrfs_sector_sum) * \
38 (r)->sectorsize - (r)->sectorsize)
39
40 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
41 struct btrfs_root *root,
42 u64 objectid, u64 pos,
43 u64 disk_offset, u64 disk_num_bytes,
44 u64 num_bytes, u64 offset, u64 ram_bytes,
45 u8 compression, u8 encryption, u16 other_encoding)
46 {
47 int ret = 0;
48 struct btrfs_file_extent_item *item;
49 struct btrfs_key file_key;
50 struct btrfs_path *path;
51 struct extent_buffer *leaf;
52
53 path = btrfs_alloc_path();
54 if (!path)
55 return -ENOMEM;
56 file_key.objectid = objectid;
57 file_key.offset = pos;
58 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
59
60 path->leave_spinning = 1;
61 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
62 sizeof(*item));
63 if (ret < 0)
64 goto out;
65 BUG_ON(ret); /* Can't happen */
66 leaf = path->nodes[0];
67 item = btrfs_item_ptr(leaf, path->slots[0],
68 struct btrfs_file_extent_item);
69 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
70 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
71 btrfs_set_file_extent_offset(leaf, item, offset);
72 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
73 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
74 btrfs_set_file_extent_generation(leaf, item, trans->transid);
75 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
76 btrfs_set_file_extent_compression(leaf, item, compression);
77 btrfs_set_file_extent_encryption(leaf, item, encryption);
78 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
79
80 btrfs_mark_buffer_dirty(leaf);
81 out:
82 btrfs_free_path(path);
83 return ret;
84 }
85
86 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
87 struct btrfs_root *root,
88 struct btrfs_path *path,
89 u64 bytenr, int cow)
90 {
91 int ret;
92 struct btrfs_key file_key;
93 struct btrfs_key found_key;
94 struct btrfs_csum_item *item;
95 struct extent_buffer *leaf;
96 u64 csum_offset = 0;
97 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
98 int csums_in_item;
99
100 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
101 file_key.offset = bytenr;
102 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
103 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
104 if (ret < 0)
105 goto fail;
106 leaf = path->nodes[0];
107 if (ret > 0) {
108 ret = 1;
109 if (path->slots[0] == 0)
110 goto fail;
111 path->slots[0]--;
112 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
113 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
114 goto fail;
115
116 csum_offset = (bytenr - found_key.offset) >>
117 root->fs_info->sb->s_blocksize_bits;
118 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
119 csums_in_item /= csum_size;
120
121 if (csum_offset == csums_in_item) {
122 ret = -EFBIG;
123 goto fail;
124 } else if (csum_offset > csums_in_item) {
125 goto fail;
126 }
127 }
128 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
129 item = (struct btrfs_csum_item *)((unsigned char *)item +
130 csum_offset * csum_size);
131 return item;
132 fail:
133 if (ret > 0)
134 ret = -ENOENT;
135 return ERR_PTR(ret);
136 }
137
138 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
139 struct btrfs_root *root,
140 struct btrfs_path *path, u64 objectid,
141 u64 offset, int mod)
142 {
143 int ret;
144 struct btrfs_key file_key;
145 int ins_len = mod < 0 ? -1 : 0;
146 int cow = mod != 0;
147
148 file_key.objectid = objectid;
149 file_key.offset = offset;
150 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
151 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
152 return ret;
153 }
154
155 u64 btrfs_file_extent_length(struct btrfs_path *path)
156 {
157 int extent_type;
158 struct btrfs_file_extent_item *fi;
159 u64 len;
160
161 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
162 struct btrfs_file_extent_item);
163 extent_type = btrfs_file_extent_type(path->nodes[0], fi);
164
165 if (extent_type == BTRFS_FILE_EXTENT_REG ||
166 extent_type == BTRFS_FILE_EXTENT_PREALLOC)
167 len = btrfs_file_extent_num_bytes(path->nodes[0], fi);
168 else if (extent_type == BTRFS_FILE_EXTENT_INLINE)
169 len = btrfs_file_extent_inline_len(path->nodes[0], fi);
170 else
171 BUG();
172
173 return len;
174 }
175
176 static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
177 struct inode *inode, struct bio *bio,
178 u64 logical_offset, u32 *dst, int dio)
179 {
180 u32 sum;
181 struct bio_vec *bvec = bio->bi_io_vec;
182 int bio_index = 0;
183 u64 offset = 0;
184 u64 item_start_offset = 0;
185 u64 item_last_offset = 0;
186 u64 disk_bytenr;
187 u32 diff;
188 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
189 int ret;
190 struct btrfs_path *path;
191 struct btrfs_csum_item *item = NULL;
192 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
193
194 path = btrfs_alloc_path();
195 if (!path)
196 return -ENOMEM;
197 if (bio->bi_size > PAGE_CACHE_SIZE * 8)
198 path->reada = 2;
199
200 WARN_ON(bio->bi_vcnt <= 0);
201
202 /*
203 * the free space stuff is only read when it hasn't been
204 * updated in the current transaction. So, we can safely
205 * read from the commit root and sidestep a nasty deadlock
206 * between reading the free space cache and updating the csum tree.
207 */
208 if (btrfs_is_free_space_inode(inode)) {
209 path->search_commit_root = 1;
210 path->skip_locking = 1;
211 }
212
213 disk_bytenr = (u64)bio->bi_sector << 9;
214 if (dio)
215 offset = logical_offset;
216 while (bio_index < bio->bi_vcnt) {
217 if (!dio)
218 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
219 ret = btrfs_find_ordered_sum(inode, offset, disk_bytenr, &sum);
220 if (ret == 0)
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, root->fs_info->csum_root,
231 path, disk_bytenr, 0);
232 if (IS_ERR(item)) {
233 ret = PTR_ERR(item);
234 if (ret == -ENOENT || ret == -EFBIG)
235 ret = 0;
236 sum = 0;
237 if (BTRFS_I(inode)->root->root_key.objectid ==
238 BTRFS_DATA_RELOC_TREE_OBJECTID) {
239 set_extent_bits(io_tree, offset,
240 offset + bvec->bv_len - 1,
241 EXTENT_NODATASUM, GFP_NOFS);
242 } else {
243 printk(KERN_INFO "btrfs no csum found "
244 "for inode %llu start %llu\n",
245 (unsigned long long)
246 btrfs_ino(inode),
247 (unsigned long long)offset);
248 }
249 item = NULL;
250 btrfs_release_path(path);
251 goto found;
252 }
253 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
254 path->slots[0]);
255
256 item_start_offset = found_key.offset;
257 item_size = btrfs_item_size_nr(path->nodes[0],
258 path->slots[0]);
259 item_last_offset = item_start_offset +
260 (item_size / csum_size) *
261 root->sectorsize;
262 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
263 struct btrfs_csum_item);
264 }
265 /*
266 * this byte range must be able to fit inside
267 * a single leaf so it will also fit inside a u32
268 */
269 diff = disk_bytenr - item_start_offset;
270 diff = diff / root->sectorsize;
271 diff = diff * csum_size;
272
273 read_extent_buffer(path->nodes[0], &sum,
274 ((unsigned long)item) + diff,
275 csum_size);
276 found:
277 if (dst)
278 *dst++ = sum;
279 else
280 set_state_private(io_tree, offset, sum);
281 disk_bytenr += bvec->bv_len;
282 offset += bvec->bv_len;
283 bio_index++;
284 bvec++;
285 }
286 btrfs_free_path(path);
287 return 0;
288 }
289
290 int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
291 struct bio *bio, u32 *dst)
292 {
293 return __btrfs_lookup_bio_sums(root, inode, bio, 0, dst, 0);
294 }
295
296 int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
297 struct bio *bio, u64 offset)
298 {
299 return __btrfs_lookup_bio_sums(root, inode, bio, offset, NULL, 1);
300 }
301
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_key key;
306 struct btrfs_path *path;
307 struct extent_buffer *leaf;
308 struct btrfs_ordered_sum *sums;
309 struct btrfs_sector_sum *sector_sum;
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(root->fs_info->super_copy);
317
318 path = btrfs_alloc_path();
319 if (!path)
320 return -ENOMEM;
321
322 if (search_commit) {
323 path->skip_locking = 1;
324 path->reada = 2;
325 path->search_commit_root = 1;
326 }
327
328 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
329 key.offset = start;
330 key.type = BTRFS_EXTENT_CSUM_KEY;
331
332 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
333 if (ret < 0)
334 goto fail;
335 if (ret > 0 && path->slots[0] > 0) {
336 leaf = path->nodes[0];
337 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
338 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
339 key.type == BTRFS_EXTENT_CSUM_KEY) {
340 offset = (start - key.offset) >>
341 root->fs_info->sb->s_blocksize_bits;
342 if (offset * csum_size <
343 btrfs_item_size_nr(leaf, path->slots[0] - 1))
344 path->slots[0]--;
345 }
346 }
347
348 while (start <= end) {
349 leaf = path->nodes[0];
350 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
351 ret = btrfs_next_leaf(root, path);
352 if (ret < 0)
353 goto fail;
354 if (ret > 0)
355 break;
356 leaf = path->nodes[0];
357 }
358
359 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
360 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
361 key.type != BTRFS_EXTENT_CSUM_KEY)
362 break;
363
364 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
365 if (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) * root->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(root));
384 sums = kzalloc(btrfs_ordered_sum_size(root, size),
385 GFP_NOFS);
386 if (!sums) {
387 ret = -ENOMEM;
388 goto fail;
389 }
390
391 sector_sum = sums->sums;
392 sums->bytenr = start;
393 sums->len = size;
394
395 offset = (start - key.offset) >>
396 root->fs_info->sb->s_blocksize_bits;
397 offset *= csum_size;
398
399 while (size > 0) {
400 read_extent_buffer(path->nodes[0],
401 &sector_sum->sum,
402 ((unsigned long)item) +
403 offset, csum_size);
404 sector_sum->bytenr = start;
405
406 size -= root->sectorsize;
407 start += root->sectorsize;
408 offset += csum_size;
409 sector_sum++;
410 }
411 list_add_tail(&sums->list, &tmplist);
412 }
413 path->slots[0]++;
414 }
415 ret = 0;
416 fail:
417 while (ret < 0 && !list_empty(&tmplist)) {
418 sums = list_entry(&tmplist, struct btrfs_ordered_sum, list);
419 list_del(&sums->list);
420 kfree(sums);
421 }
422 list_splice_tail(&tmplist, list);
423
424 btrfs_free_path(path);
425 return ret;
426 }
427
428 int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
429 struct bio *bio, u64 file_start, int contig)
430 {
431 struct btrfs_ordered_sum *sums;
432 struct btrfs_sector_sum *sector_sum;
433 struct btrfs_ordered_extent *ordered;
434 char *data;
435 struct bio_vec *bvec = bio->bi_io_vec;
436 int bio_index = 0;
437 unsigned long total_bytes = 0;
438 unsigned long this_sum_bytes = 0;
439 u64 offset;
440 u64 disk_bytenr;
441
442 WARN_ON(bio->bi_vcnt <= 0);
443 sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
444 if (!sums)
445 return -ENOMEM;
446
447 sector_sum = sums->sums;
448 disk_bytenr = (u64)bio->bi_sector << 9;
449 sums->len = bio->bi_size;
450 INIT_LIST_HEAD(&sums->list);
451
452 if (contig)
453 offset = file_start;
454 else
455 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
456
457 ordered = btrfs_lookup_ordered_extent(inode, offset);
458 BUG_ON(!ordered); /* Logic error */
459 sums->bytenr = ordered->start;
460
461 while (bio_index < bio->bi_vcnt) {
462 if (!contig)
463 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
464
465 if (offset >= ordered->file_offset + ordered->len ||
466 offset < ordered->file_offset) {
467 unsigned long bytes_left;
468 sums->len = this_sum_bytes;
469 this_sum_bytes = 0;
470 btrfs_add_ordered_sum(inode, ordered, sums);
471 btrfs_put_ordered_extent(ordered);
472
473 bytes_left = bio->bi_size - total_bytes;
474
475 sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
476 GFP_NOFS);
477 BUG_ON(!sums); /* -ENOMEM */
478 sector_sum = sums->sums;
479 sums->len = bytes_left;
480 ordered = btrfs_lookup_ordered_extent(inode, offset);
481 BUG_ON(!ordered); /* Logic error */
482 sums->bytenr = ordered->start;
483 }
484
485 data = kmap_atomic(bvec->bv_page);
486 sector_sum->sum = ~(u32)0;
487 sector_sum->sum = btrfs_csum_data(data + bvec->bv_offset,
488 sector_sum->sum,
489 bvec->bv_len);
490 kunmap_atomic(data);
491 btrfs_csum_final(sector_sum->sum,
492 (char *)&sector_sum->sum);
493 sector_sum->bytenr = disk_bytenr;
494
495 sector_sum++;
496 bio_index++;
497 total_bytes += bvec->bv_len;
498 this_sum_bytes += bvec->bv_len;
499 disk_bytenr += bvec->bv_len;
500 offset += bvec->bv_len;
501 bvec++;
502 }
503 this_sum_bytes = 0;
504 btrfs_add_ordered_sum(inode, ordered, sums);
505 btrfs_put_ordered_extent(ordered);
506 return 0;
507 }
508
509 /*
510 * helper function for csum removal, this expects the
511 * key to describe the csum pointed to by the path, and it expects
512 * the csum to overlap the range [bytenr, len]
513 *
514 * The csum should not be entirely contained in the range and the
515 * range should not be entirely contained in the csum.
516 *
517 * This calls btrfs_truncate_item with the correct args based on the
518 * overlap, and fixes up the key as required.
519 */
520 static noinline void truncate_one_csum(struct btrfs_trans_handle *trans,
521 struct btrfs_root *root,
522 struct btrfs_path *path,
523 struct btrfs_key *key,
524 u64 bytenr, u64 len)
525 {
526 struct extent_buffer *leaf;
527 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
528 u64 csum_end;
529 u64 end_byte = bytenr + len;
530 u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
531
532 leaf = path->nodes[0];
533 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
534 csum_end <<= root->fs_info->sb->s_blocksize_bits;
535 csum_end += key->offset;
536
537 if (key->offset < bytenr && csum_end <= end_byte) {
538 /*
539 * [ bytenr - len ]
540 * [ ]
541 * [csum ]
542 * A simple truncate off the end of the item
543 */
544 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
545 new_size *= csum_size;
546 btrfs_truncate_item(trans, root, path, new_size, 1);
547 } else if (key->offset >= bytenr && csum_end > end_byte &&
548 end_byte > key->offset) {
549 /*
550 * [ bytenr - len ]
551 * [ ]
552 * [csum ]
553 * we need to truncate from the beginning of the csum
554 */
555 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
556 new_size *= csum_size;
557
558 btrfs_truncate_item(trans, root, path, new_size, 0);
559
560 key->offset = end_byte;
561 btrfs_set_item_key_safe(trans, root, path, key);
562 } else {
563 BUG();
564 }
565 }
566
567 /*
568 * deletes the csum items from the csum tree for a given
569 * range of bytes.
570 */
571 int btrfs_del_csums(struct btrfs_trans_handle *trans,
572 struct btrfs_root *root, u64 bytenr, u64 len)
573 {
574 struct btrfs_path *path;
575 struct btrfs_key key;
576 u64 end_byte = bytenr + len;
577 u64 csum_end;
578 struct extent_buffer *leaf;
579 int ret;
580 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
581 int blocksize_bits = root->fs_info->sb->s_blocksize_bits;
582
583 root = root->fs_info->csum_root;
584
585 path = btrfs_alloc_path();
586 if (!path)
587 return -ENOMEM;
588
589 while (1) {
590 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
591 key.offset = end_byte - 1;
592 key.type = BTRFS_EXTENT_CSUM_KEY;
593
594 path->leave_spinning = 1;
595 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
596 if (ret > 0) {
597 if (path->slots[0] == 0)
598 break;
599 path->slots[0]--;
600 } else if (ret < 0) {
601 break;
602 }
603
604 leaf = path->nodes[0];
605 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
606
607 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
608 key.type != BTRFS_EXTENT_CSUM_KEY) {
609 break;
610 }
611
612 if (key.offset >= end_byte)
613 break;
614
615 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
616 csum_end <<= blocksize_bits;
617 csum_end += key.offset;
618
619 /* this csum ends before we start, we're done */
620 if (csum_end <= bytenr)
621 break;
622
623 /* delete the entire item, it is inside our range */
624 if (key.offset >= bytenr && csum_end <= end_byte) {
625 ret = btrfs_del_item(trans, root, path);
626 if (ret)
627 goto out;
628 if (key.offset == bytenr)
629 break;
630 } else if (key.offset < bytenr && csum_end > end_byte) {
631 unsigned long offset;
632 unsigned long shift_len;
633 unsigned long item_offset;
634 /*
635 * [ bytenr - len ]
636 * [csum ]
637 *
638 * Our bytes are in the middle of the csum,
639 * we need to split this item and insert a new one.
640 *
641 * But we can't drop the path because the
642 * csum could change, get removed, extended etc.
643 *
644 * The trick here is the max size of a csum item leaves
645 * enough room in the tree block for a single
646 * item header. So, we split the item in place,
647 * adding a new header pointing to the existing
648 * bytes. Then we loop around again and we have
649 * a nicely formed csum item that we can neatly
650 * truncate.
651 */
652 offset = (bytenr - key.offset) >> blocksize_bits;
653 offset *= csum_size;
654
655 shift_len = (len >> blocksize_bits) * csum_size;
656
657 item_offset = btrfs_item_ptr_offset(leaf,
658 path->slots[0]);
659
660 memset_extent_buffer(leaf, 0, item_offset + offset,
661 shift_len);
662 key.offset = bytenr;
663
664 /*
665 * btrfs_split_item returns -EAGAIN when the
666 * item changed size or key
667 */
668 ret = btrfs_split_item(trans, root, path, &key, offset);
669 if (ret && ret != -EAGAIN) {
670 btrfs_abort_transaction(trans, root, ret);
671 goto out;
672 }
673
674 key.offset = end_byte - 1;
675 } else {
676 truncate_one_csum(trans, root, path, &key, bytenr, len);
677 if (key.offset < bytenr)
678 break;
679 }
680 btrfs_release_path(path);
681 }
682 ret = 0;
683 out:
684 btrfs_free_path(path);
685 return ret;
686 }
687
688 static u64 btrfs_sector_sum_left(struct btrfs_ordered_sum *sums,
689 struct btrfs_sector_sum *sector_sum,
690 u64 total_bytes, u64 sectorsize)
691 {
692 u64 tmp = sectorsize;
693 u64 next_sector = sector_sum->bytenr;
694 struct btrfs_sector_sum *next = sector_sum + 1;
695
696 while ((tmp + total_bytes) < sums->len) {
697 if (next_sector + sectorsize != next->bytenr)
698 break;
699 tmp += sectorsize;
700 next_sector = next->bytenr;
701 next++;
702 }
703 return tmp;
704 }
705
706 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
707 struct btrfs_root *root,
708 struct btrfs_ordered_sum *sums)
709 {
710 u64 bytenr;
711 int ret;
712 struct btrfs_key file_key;
713 struct btrfs_key found_key;
714 u64 next_offset;
715 u64 total_bytes = 0;
716 int found_next;
717 struct btrfs_path *path;
718 struct btrfs_csum_item *item;
719 struct btrfs_csum_item *item_end;
720 struct extent_buffer *leaf = NULL;
721 u64 csum_offset;
722 struct btrfs_sector_sum *sector_sum;
723 u32 nritems;
724 u32 ins_size;
725 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
726
727 path = btrfs_alloc_path();
728 if (!path)
729 return -ENOMEM;
730
731 sector_sum = sums->sums;
732 again:
733 next_offset = (u64)-1;
734 found_next = 0;
735 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
736 file_key.offset = sector_sum->bytenr;
737 bytenr = sector_sum->bytenr;
738 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
739
740 item = btrfs_lookup_csum(trans, root, path, sector_sum->bytenr, 1);
741 if (!IS_ERR(item)) {
742 leaf = path->nodes[0];
743 ret = 0;
744 goto found;
745 }
746 ret = PTR_ERR(item);
747 if (ret != -EFBIG && ret != -ENOENT)
748 goto fail_unlock;
749
750 if (ret == -EFBIG) {
751 u32 item_size;
752 /* we found one, but it isn't big enough yet */
753 leaf = path->nodes[0];
754 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
755 if ((item_size / csum_size) >=
756 MAX_CSUM_ITEMS(root, csum_size)) {
757 /* already at max size, make a new one */
758 goto insert;
759 }
760 } else {
761 int slot = path->slots[0] + 1;
762 /* we didn't find a csum item, insert one */
763 nritems = btrfs_header_nritems(path->nodes[0]);
764 if (path->slots[0] >= nritems - 1) {
765 ret = btrfs_next_leaf(root, path);
766 if (ret == 1)
767 found_next = 1;
768 if (ret != 0)
769 goto insert;
770 slot = 0;
771 }
772 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
773 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
774 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
775 found_next = 1;
776 goto insert;
777 }
778 next_offset = found_key.offset;
779 found_next = 1;
780 goto insert;
781 }
782
783 /*
784 * at this point, we know the tree has an item, but it isn't big
785 * enough yet to put our csum in. Grow it
786 */
787 btrfs_release_path(path);
788 ret = btrfs_search_slot(trans, root, &file_key, path,
789 csum_size, 1);
790 if (ret < 0)
791 goto fail_unlock;
792
793 if (ret > 0) {
794 if (path->slots[0] == 0)
795 goto insert;
796 path->slots[0]--;
797 }
798
799 leaf = path->nodes[0];
800 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
801 csum_offset = (bytenr - found_key.offset) >>
802 root->fs_info->sb->s_blocksize_bits;
803
804 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY ||
805 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
806 csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
807 goto insert;
808 }
809
810 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
811 csum_size) {
812 int extend_nr;
813 u64 tmp;
814 u32 diff;
815 u32 free_space;
816
817 if (btrfs_leaf_free_space(root, leaf) <
818 sizeof(struct btrfs_item) + csum_size * 2)
819 goto insert;
820
821 free_space = btrfs_leaf_free_space(root, leaf) -
822 sizeof(struct btrfs_item) - csum_size;
823 tmp = btrfs_sector_sum_left(sums, sector_sum, total_bytes,
824 root->sectorsize);
825 tmp >>= root->fs_info->sb->s_blocksize_bits;
826 WARN_ON(tmp < 1);
827
828 extend_nr = max_t(int, 1, (int)tmp);
829 diff = (csum_offset + extend_nr) * csum_size;
830 diff = min(diff, MAX_CSUM_ITEMS(root, csum_size) * csum_size);
831
832 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
833 diff = min(free_space, diff);
834 diff /= csum_size;
835 diff *= csum_size;
836
837 btrfs_extend_item(trans, root, path, diff);
838 goto csum;
839 }
840
841 insert:
842 btrfs_release_path(path);
843 csum_offset = 0;
844 if (found_next) {
845 u64 tmp;
846
847 tmp = btrfs_sector_sum_left(sums, sector_sum, total_bytes,
848 root->sectorsize);
849 tmp >>= root->fs_info->sb->s_blocksize_bits;
850 tmp = min(tmp, (next_offset - file_key.offset) >>
851 root->fs_info->sb->s_blocksize_bits);
852
853 tmp = max((u64)1, tmp);
854 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
855 ins_size = csum_size * tmp;
856 } else {
857 ins_size = csum_size;
858 }
859 path->leave_spinning = 1;
860 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
861 ins_size);
862 path->leave_spinning = 0;
863 if (ret < 0)
864 goto fail_unlock;
865 if (ret != 0) {
866 WARN_ON(1);
867 goto fail_unlock;
868 }
869 csum:
870 leaf = path->nodes[0];
871 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
872 ret = 0;
873 item = (struct btrfs_csum_item *)((unsigned char *)item +
874 csum_offset * csum_size);
875 found:
876 item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
877 item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
878 btrfs_item_size_nr(leaf, path->slots[0]));
879 next_sector:
880
881 write_extent_buffer(leaf, &sector_sum->sum, (unsigned long)item, csum_size);
882
883 total_bytes += root->sectorsize;
884 sector_sum++;
885 if (total_bytes < sums->len) {
886 item = (struct btrfs_csum_item *)((char *)item +
887 csum_size);
888 if (item < item_end && bytenr + PAGE_CACHE_SIZE ==
889 sector_sum->bytenr) {
890 bytenr = sector_sum->bytenr;
891 goto next_sector;
892 }
893 }
894
895 btrfs_mark_buffer_dirty(path->nodes[0]);
896 if (total_bytes < sums->len) {
897 btrfs_release_path(path);
898 cond_resched();
899 goto again;
900 }
901 out:
902 btrfs_free_path(path);
903 return ret;
904
905 fail_unlock:
906 goto out;
907 }
Linux kernel - Deliverables
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