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Btrfs: fix unblocked autodefraggers when remount
[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[16];
181 int len;
182 struct bio_vec *bvec = bio->bi_io_vec;
183 int bio_index = 0;
184 u64 offset = 0;
185 u64 item_start_offset = 0;
186 u64 item_last_offset = 0;
187 u64 disk_bytenr;
188 u32 diff;
189 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
190 int count;
191 struct btrfs_path *path;
192 struct btrfs_csum_item *item = NULL;
193 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
194
195 path = btrfs_alloc_path();
196 if (!path)
197 return -ENOMEM;
198 if (bio->bi_size > PAGE_CACHE_SIZE * 8)
199 path->reada = 2;
200
201 WARN_ON(bio->bi_vcnt <= 0);
202
203 /*
204 * the free space stuff is only read when it hasn't been
205 * updated in the current transaction. So, we can safely
206 * read from the commit root and sidestep a nasty deadlock
207 * between reading the free space cache and updating the csum tree.
208 */
209 if (btrfs_is_free_space_inode(inode)) {
210 path->search_commit_root = 1;
211 path->skip_locking = 1;
212 }
213
214 disk_bytenr = (u64)bio->bi_sector << 9;
215 if (dio)
216 offset = logical_offset;
217 while (bio_index < bio->bi_vcnt) {
218 len = min_t(int, ARRAY_SIZE(sum), bio->bi_vcnt - bio_index);
219 if (!dio)
220 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
221 count = btrfs_find_ordered_sum(inode, offset, disk_bytenr, sum,
222 len);
223 if (count)
224 goto found;
225
226 if (!item || disk_bytenr < item_start_offset ||
227 disk_bytenr >= item_last_offset) {
228 struct btrfs_key found_key;
229 u32 item_size;
230
231 if (item)
232 btrfs_release_path(path);
233 item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
234 path, disk_bytenr, 0);
235 if (IS_ERR(item)) {
236 count = 1;
237 sum[0] = 0;
238 if (BTRFS_I(inode)->root->root_key.objectid ==
239 BTRFS_DATA_RELOC_TREE_OBJECTID) {
240 set_extent_bits(io_tree, offset,
241 offset + bvec->bv_len - 1,
242 EXTENT_NODATASUM, GFP_NOFS);
243 } else {
244 printk(KERN_INFO "btrfs no csum found "
245 "for inode %llu start %llu\n",
246 (unsigned long long)
247 btrfs_ino(inode),
248 (unsigned long long)offset);
249 }
250 item = NULL;
251 btrfs_release_path(path);
252 goto found;
253 }
254 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
255 path->slots[0]);
256
257 item_start_offset = found_key.offset;
258 item_size = btrfs_item_size_nr(path->nodes[0],
259 path->slots[0]);
260 item_last_offset = item_start_offset +
261 (item_size / csum_size) *
262 root->sectorsize;
263 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
264 struct btrfs_csum_item);
265 }
266 /*
267 * this byte range must be able to fit inside
268 * a single leaf so it will also fit inside a u32
269 */
270 diff = disk_bytenr - item_start_offset;
271 diff = diff / root->sectorsize;
272 diff = diff * csum_size;
273 count = min_t(int, len, (item_last_offset - disk_bytenr) >>
274 inode->i_sb->s_blocksize_bits);
275 read_extent_buffer(path->nodes[0], sum,
276 ((unsigned long)item) + diff,
277 csum_size * count);
278 found:
279 if (dst) {
280 memcpy(dst, sum, count * csum_size);
281 dst += count;
282 } else {
283 if (dio)
284 extent_cache_csums_dio(io_tree, offset, sum,
285 count);
286 else
287 extent_cache_csums(io_tree, bio, bio_index, sum,
288 count);
289 }
290 while (count--) {
291 disk_bytenr += bvec->bv_len;
292 offset += bvec->bv_len;
293 bio_index++;
294 bvec++;
295 }
296 }
297 btrfs_free_path(path);
298 return 0;
299 }
300
301 int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
302 struct bio *bio, u32 *dst)
303 {
304 return __btrfs_lookup_bio_sums(root, inode, bio, 0, dst, 0);
305 }
306
307 int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
308 struct bio *bio, u64 offset)
309 {
310 return __btrfs_lookup_bio_sums(root, inode, bio, offset, NULL, 1);
311 }
312
313 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
314 struct list_head *list, int search_commit)
315 {
316 struct btrfs_key key;
317 struct btrfs_path *path;
318 struct extent_buffer *leaf;
319 struct btrfs_ordered_sum *sums;
320 struct btrfs_sector_sum *sector_sum;
321 struct btrfs_csum_item *item;
322 LIST_HEAD(tmplist);
323 unsigned long offset;
324 int ret;
325 size_t size;
326 u64 csum_end;
327 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
328
329 path = btrfs_alloc_path();
330 if (!path)
331 return -ENOMEM;
332
333 if (search_commit) {
334 path->skip_locking = 1;
335 path->reada = 2;
336 path->search_commit_root = 1;
337 }
338
339 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
340 key.offset = start;
341 key.type = BTRFS_EXTENT_CSUM_KEY;
342
343 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
344 if (ret < 0)
345 goto fail;
346 if (ret > 0 && path->slots[0] > 0) {
347 leaf = path->nodes[0];
348 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
349 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
350 key.type == BTRFS_EXTENT_CSUM_KEY) {
351 offset = (start - key.offset) >>
352 root->fs_info->sb->s_blocksize_bits;
353 if (offset * csum_size <
354 btrfs_item_size_nr(leaf, path->slots[0] - 1))
355 path->slots[0]--;
356 }
357 }
358
359 while (start <= end) {
360 leaf = path->nodes[0];
361 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
362 ret = btrfs_next_leaf(root, path);
363 if (ret < 0)
364 goto fail;
365 if (ret > 0)
366 break;
367 leaf = path->nodes[0];
368 }
369
370 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
371 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
372 key.type != BTRFS_EXTENT_CSUM_KEY ||
373 key.offset > end)
374 break;
375
376 if (key.offset > start)
377 start = key.offset;
378
379 size = btrfs_item_size_nr(leaf, path->slots[0]);
380 csum_end = key.offset + (size / csum_size) * root->sectorsize;
381 if (csum_end <= start) {
382 path->slots[0]++;
383 continue;
384 }
385
386 csum_end = min(csum_end, end + 1);
387 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
388 struct btrfs_csum_item);
389 while (start < csum_end) {
390 size = min_t(size_t, csum_end - start,
391 MAX_ORDERED_SUM_BYTES(root));
392 sums = kzalloc(btrfs_ordered_sum_size(root, size),
393 GFP_NOFS);
394 if (!sums) {
395 ret = -ENOMEM;
396 goto fail;
397 }
398
399 sector_sum = sums->sums;
400 sums->bytenr = start;
401 sums->len = size;
402
403 offset = (start - key.offset) >>
404 root->fs_info->sb->s_blocksize_bits;
405 offset *= csum_size;
406
407 while (size > 0) {
408 read_extent_buffer(path->nodes[0],
409 &sector_sum->sum,
410 ((unsigned long)item) +
411 offset, csum_size);
412 sector_sum->bytenr = start;
413
414 size -= root->sectorsize;
415 start += root->sectorsize;
416 offset += csum_size;
417 sector_sum++;
418 }
419 list_add_tail(&sums->list, &tmplist);
420 }
421 path->slots[0]++;
422 }
423 ret = 0;
424 fail:
425 while (ret < 0 && !list_empty(&tmplist)) {
426 sums = list_entry(&tmplist, struct btrfs_ordered_sum, list);
427 list_del(&sums->list);
428 kfree(sums);
429 }
430 list_splice_tail(&tmplist, list);
431
432 btrfs_free_path(path);
433 return ret;
434 }
435
436 int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
437 struct bio *bio, u64 file_start, int contig)
438 {
439 struct btrfs_ordered_sum *sums;
440 struct btrfs_sector_sum *sector_sum;
441 struct btrfs_ordered_extent *ordered;
442 char *data;
443 struct bio_vec *bvec = bio->bi_io_vec;
444 int bio_index = 0;
445 unsigned long total_bytes = 0;
446 unsigned long this_sum_bytes = 0;
447 u64 offset;
448 u64 disk_bytenr;
449
450 WARN_ON(bio->bi_vcnt <= 0);
451 sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
452 if (!sums)
453 return -ENOMEM;
454
455 sector_sum = sums->sums;
456 disk_bytenr = (u64)bio->bi_sector << 9;
457 sums->len = bio->bi_size;
458 INIT_LIST_HEAD(&sums->list);
459
460 if (contig)
461 offset = file_start;
462 else
463 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
464
465 ordered = btrfs_lookup_ordered_extent(inode, offset);
466 BUG_ON(!ordered); /* Logic error */
467 sums->bytenr = ordered->start;
468
469 while (bio_index < bio->bi_vcnt) {
470 if (!contig)
471 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
472
473 if (offset >= ordered->file_offset + ordered->len ||
474 offset < ordered->file_offset) {
475 unsigned long bytes_left;
476 sums->len = this_sum_bytes;
477 this_sum_bytes = 0;
478 btrfs_add_ordered_sum(inode, ordered, sums);
479 btrfs_put_ordered_extent(ordered);
480
481 bytes_left = bio->bi_size - total_bytes;
482
483 sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
484 GFP_NOFS);
485 BUG_ON(!sums); /* -ENOMEM */
486 sector_sum = sums->sums;
487 sums->len = bytes_left;
488 ordered = btrfs_lookup_ordered_extent(inode, offset);
489 BUG_ON(!ordered); /* Logic error */
490 sums->bytenr = ordered->start;
491 }
492
493 data = kmap_atomic(bvec->bv_page);
494 sector_sum->sum = ~(u32)0;
495 sector_sum->sum = btrfs_csum_data(data + bvec->bv_offset,
496 sector_sum->sum,
497 bvec->bv_len);
498 kunmap_atomic(data);
499 btrfs_csum_final(sector_sum->sum,
500 (char *)&sector_sum->sum);
501 sector_sum->bytenr = disk_bytenr;
502
503 sector_sum++;
504 bio_index++;
505 total_bytes += bvec->bv_len;
506 this_sum_bytes += bvec->bv_len;
507 disk_bytenr += bvec->bv_len;
508 offset += bvec->bv_len;
509 bvec++;
510 }
511 this_sum_bytes = 0;
512 btrfs_add_ordered_sum(inode, ordered, sums);
513 btrfs_put_ordered_extent(ordered);
514 return 0;
515 }
516
517 /*
518 * helper function for csum removal, this expects the
519 * key to describe the csum pointed to by the path, and it expects
520 * the csum to overlap the range [bytenr, len]
521 *
522 * The csum should not be entirely contained in the range and the
523 * range should not be entirely contained in the csum.
524 *
525 * This calls btrfs_truncate_item with the correct args based on the
526 * overlap, and fixes up the key as required.
527 */
528 static noinline void truncate_one_csum(struct btrfs_trans_handle *trans,
529 struct btrfs_root *root,
530 struct btrfs_path *path,
531 struct btrfs_key *key,
532 u64 bytenr, u64 len)
533 {
534 struct extent_buffer *leaf;
535 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
536 u64 csum_end;
537 u64 end_byte = bytenr + len;
538 u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
539
540 leaf = path->nodes[0];
541 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
542 csum_end <<= root->fs_info->sb->s_blocksize_bits;
543 csum_end += key->offset;
544
545 if (key->offset < bytenr && csum_end <= end_byte) {
546 /*
547 * [ bytenr - len ]
548 * [ ]
549 * [csum ]
550 * A simple truncate off the end of the item
551 */
552 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
553 new_size *= csum_size;
554 btrfs_truncate_item(trans, root, path, new_size, 1);
555 } else if (key->offset >= bytenr && csum_end > end_byte &&
556 end_byte > key->offset) {
557 /*
558 * [ bytenr - len ]
559 * [ ]
560 * [csum ]
561 * we need to truncate from the beginning of the csum
562 */
563 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
564 new_size *= csum_size;
565
566 btrfs_truncate_item(trans, root, path, new_size, 0);
567
568 key->offset = end_byte;
569 btrfs_set_item_key_safe(trans, root, path, key);
570 } else {
571 BUG();
572 }
573 }
574
575 /*
576 * deletes the csum items from the csum tree for a given
577 * range of bytes.
578 */
579 int btrfs_del_csums(struct btrfs_trans_handle *trans,
580 struct btrfs_root *root, u64 bytenr, u64 len)
581 {
582 struct btrfs_path *path;
583 struct btrfs_key key;
584 u64 end_byte = bytenr + len;
585 u64 csum_end;
586 struct extent_buffer *leaf;
587 int ret;
588 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
589 int blocksize_bits = root->fs_info->sb->s_blocksize_bits;
590
591 root = root->fs_info->csum_root;
592
593 path = btrfs_alloc_path();
594 if (!path)
595 return -ENOMEM;
596
597 while (1) {
598 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
599 key.offset = end_byte - 1;
600 key.type = BTRFS_EXTENT_CSUM_KEY;
601
602 path->leave_spinning = 1;
603 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
604 if (ret > 0) {
605 if (path->slots[0] == 0)
606 break;
607 path->slots[0]--;
608 } else if (ret < 0) {
609 break;
610 }
611
612 leaf = path->nodes[0];
613 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
614
615 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
616 key.type != BTRFS_EXTENT_CSUM_KEY) {
617 break;
618 }
619
620 if (key.offset >= end_byte)
621 break;
622
623 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
624 csum_end <<= blocksize_bits;
625 csum_end += key.offset;
626
627 /* this csum ends before we start, we're done */
628 if (csum_end <= bytenr)
629 break;
630
631 /* delete the entire item, it is inside our range */
632 if (key.offset >= bytenr && csum_end <= end_byte) {
633 ret = btrfs_del_item(trans, root, path);
634 if (ret)
635 goto out;
636 if (key.offset == bytenr)
637 break;
638 } else if (key.offset < bytenr && csum_end > end_byte) {
639 unsigned long offset;
640 unsigned long shift_len;
641 unsigned long item_offset;
642 /*
643 * [ bytenr - len ]
644 * [csum ]
645 *
646 * Our bytes are in the middle of the csum,
647 * we need to split this item and insert a new one.
648 *
649 * But we can't drop the path because the
650 * csum could change, get removed, extended etc.
651 *
652 * The trick here is the max size of a csum item leaves
653 * enough room in the tree block for a single
654 * item header. So, we split the item in place,
655 * adding a new header pointing to the existing
656 * bytes. Then we loop around again and we have
657 * a nicely formed csum item that we can neatly
658 * truncate.
659 */
660 offset = (bytenr - key.offset) >> blocksize_bits;
661 offset *= csum_size;
662
663 shift_len = (len >> blocksize_bits) * csum_size;
664
665 item_offset = btrfs_item_ptr_offset(leaf,
666 path->slots[0]);
667
668 memset_extent_buffer(leaf, 0, item_offset + offset,
669 shift_len);
670 key.offset = bytenr;
671
672 /*
673 * btrfs_split_item returns -EAGAIN when the
674 * item changed size or key
675 */
676 ret = btrfs_split_item(trans, root, path, &key, offset);
677 if (ret && ret != -EAGAIN) {
678 btrfs_abort_transaction(trans, root, ret);
679 goto out;
680 }
681
682 key.offset = end_byte - 1;
683 } else {
684 truncate_one_csum(trans, root, path, &key, bytenr, len);
685 if (key.offset < bytenr)
686 break;
687 }
688 btrfs_release_path(path);
689 }
690 ret = 0;
691 out:
692 btrfs_free_path(path);
693 return ret;
694 }
695
696 static u64 btrfs_sector_sum_left(struct btrfs_ordered_sum *sums,
697 struct btrfs_sector_sum *sector_sum,
698 u64 total_bytes, u64 sectorsize)
699 {
700 u64 tmp = sectorsize;
701 u64 next_sector = sector_sum->bytenr;
702 struct btrfs_sector_sum *next = sector_sum + 1;
703
704 while ((tmp + total_bytes) < sums->len) {
705 if (next_sector + sectorsize != next->bytenr)
706 break;
707 tmp += sectorsize;
708 next_sector = next->bytenr;
709 next++;
710 }
711 return tmp;
712 }
713
714 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
715 struct btrfs_root *root,
716 struct btrfs_ordered_sum *sums)
717 {
718 u64 bytenr;
719 int ret;
720 struct btrfs_key file_key;
721 struct btrfs_key found_key;
722 u64 next_offset;
723 u64 total_bytes = 0;
724 int found_next;
725 struct btrfs_path *path;
726 struct btrfs_csum_item *item;
727 struct btrfs_csum_item *item_end;
728 struct extent_buffer *leaf = NULL;
729 u64 csum_offset;
730 struct btrfs_sector_sum *sector_sum;
731 u32 nritems;
732 u32 ins_size;
733 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
734
735 path = btrfs_alloc_path();
736 if (!path)
737 return -ENOMEM;
738
739 sector_sum = sums->sums;
740 again:
741 next_offset = (u64)-1;
742 found_next = 0;
743 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
744 file_key.offset = sector_sum->bytenr;
745 bytenr = sector_sum->bytenr;
746 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
747
748 item = btrfs_lookup_csum(trans, root, path, sector_sum->bytenr, 1);
749 if (!IS_ERR(item)) {
750 leaf = path->nodes[0];
751 ret = 0;
752 goto found;
753 }
754 ret = PTR_ERR(item);
755 if (ret != -EFBIG && ret != -ENOENT)
756 goto fail_unlock;
757
758 if (ret == -EFBIG) {
759 u32 item_size;
760 /* we found one, but it isn't big enough yet */
761 leaf = path->nodes[0];
762 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
763 if ((item_size / csum_size) >=
764 MAX_CSUM_ITEMS(root, csum_size)) {
765 /* already at max size, make a new one */
766 goto insert;
767 }
768 } else {
769 int slot = path->slots[0] + 1;
770 /* we didn't find a csum item, insert one */
771 nritems = btrfs_header_nritems(path->nodes[0]);
772 if (path->slots[0] >= nritems - 1) {
773 ret = btrfs_next_leaf(root, path);
774 if (ret == 1)
775 found_next = 1;
776 if (ret != 0)
777 goto insert;
778 slot = 0;
779 }
780 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
781 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
782 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
783 found_next = 1;
784 goto insert;
785 }
786 next_offset = found_key.offset;
787 found_next = 1;
788 goto insert;
789 }
790
791 /*
792 * at this point, we know the tree has an item, but it isn't big
793 * enough yet to put our csum in. Grow it
794 */
795 btrfs_release_path(path);
796 ret = btrfs_search_slot(trans, root, &file_key, path,
797 csum_size, 1);
798 if (ret < 0)
799 goto fail_unlock;
800
801 if (ret > 0) {
802 if (path->slots[0] == 0)
803 goto insert;
804 path->slots[0]--;
805 }
806
807 leaf = path->nodes[0];
808 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
809 csum_offset = (bytenr - found_key.offset) >>
810 root->fs_info->sb->s_blocksize_bits;
811
812 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY ||
813 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
814 csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
815 goto insert;
816 }
817
818 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
819 csum_size) {
820 int extend_nr;
821 u64 tmp;
822 u32 diff;
823 u32 free_space;
824
825 if (btrfs_leaf_free_space(root, leaf) <
826 sizeof(struct btrfs_item) + csum_size * 2)
827 goto insert;
828
829 free_space = btrfs_leaf_free_space(root, leaf) -
830 sizeof(struct btrfs_item) - csum_size;
831 tmp = btrfs_sector_sum_left(sums, sector_sum, total_bytes,
832 root->sectorsize);
833 tmp >>= root->fs_info->sb->s_blocksize_bits;
834 WARN_ON(tmp < 1);
835
836 extend_nr = max_t(int, 1, (int)tmp);
837 diff = (csum_offset + extend_nr) * csum_size;
838 diff = min(diff, MAX_CSUM_ITEMS(root, csum_size) * csum_size);
839
840 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
841 diff = min(free_space, diff);
842 diff /= csum_size;
843 diff *= csum_size;
844
845 btrfs_extend_item(trans, root, path, diff);
846 goto csum;
847 }
848
849 insert:
850 btrfs_release_path(path);
851 csum_offset = 0;
852 if (found_next) {
853 u64 tmp;
854
855 tmp = btrfs_sector_sum_left(sums, sector_sum, total_bytes,
856 root->sectorsize);
857 tmp >>= root->fs_info->sb->s_blocksize_bits;
858 tmp = min(tmp, (next_offset - file_key.offset) >>
859 root->fs_info->sb->s_blocksize_bits);
860
861 tmp = max((u64)1, tmp);
862 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
863 ins_size = csum_size * tmp;
864 } else {
865 ins_size = csum_size;
866 }
867 path->leave_spinning = 1;
868 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
869 ins_size);
870 path->leave_spinning = 0;
871 if (ret < 0)
872 goto fail_unlock;
873 if (ret != 0) {
874 WARN_ON(1);
875 goto fail_unlock;
876 }
877 csum:
878 leaf = path->nodes[0];
879 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
880 ret = 0;
881 item = (struct btrfs_csum_item *)((unsigned char *)item +
882 csum_offset * csum_size);
883 found:
884 item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
885 item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
886 btrfs_item_size_nr(leaf, path->slots[0]));
887 next_sector:
888
889 write_extent_buffer(leaf, &sector_sum->sum, (unsigned long)item, csum_size);
890
891 total_bytes += root->sectorsize;
892 sector_sum++;
893 if (total_bytes < sums->len) {
894 item = (struct btrfs_csum_item *)((char *)item +
895 csum_size);
896 if (item < item_end && bytenr + PAGE_CACHE_SIZE ==
897 sector_sum->bytenr) {
898 bytenr = sector_sum->bytenr;
899 goto next_sector;
900 }
901 }
902
903 btrfs_mark_buffer_dirty(path->nodes[0]);
904 if (total_bytes < sums->len) {
905 btrfs_release_path(path);
906 cond_resched();
907 goto again;
908 }
909 out:
910 btrfs_free_path(path);
911 return ret;
912
913 fail_unlock:
914 goto out;
915 }
Linux kernel - Deliverables
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