?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Linux 3.17-rc2
[linux/fpc-iii.git] / fs / btrfs / file-item.c
blob54c84daec9b515f73f8f1178a1e4ea9485d20e3f
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 "volumes.h"
27 #include "print-tree.h"
28
29 #define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
30 sizeof(struct btrfs_item) * 2) / \
31 size) - 1))
32
33 #define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
34 PAGE_CACHE_SIZE))
35
36 #define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
37 sizeof(struct btrfs_ordered_sum)) / \
38 sizeof(u32) * (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 static struct btrfs_csum_item *
87 btrfs_lookup_csum(struct btrfs_trans_handle *trans,
88 struct btrfs_root *root,
89 struct btrfs_path *path,
90 u64 bytenr, int cow)
91 {
92 int ret;
93 struct btrfs_key file_key;
94 struct btrfs_key found_key;
95 struct btrfs_csum_item *item;
96 struct extent_buffer *leaf;
97 u64 csum_offset = 0;
98 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
99 int csums_in_item;
100
101 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
102 file_key.offset = bytenr;
103 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
104 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
105 if (ret < 0)
106 goto fail;
107 leaf = path->nodes[0];
108 if (ret > 0) {
109 ret = 1;
110 if (path->slots[0] == 0)
111 goto fail;
112 path->slots[0]--;
113 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
114 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
115 goto fail;
116
117 csum_offset = (bytenr - found_key.offset) >>
118 root->fs_info->sb->s_blocksize_bits;
119 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
120 csums_in_item /= csum_size;
121
122 if (csum_offset == csums_in_item) {
123 ret = -EFBIG;
124 goto fail;
125 } else if (csum_offset > csums_in_item) {
126 goto fail;
127 }
128 }
129 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
130 item = (struct btrfs_csum_item *)((unsigned char *)item +
131 csum_offset * csum_size);
132 return item;
133 fail:
134 if (ret > 0)
135 ret = -ENOENT;
136 return ERR_PTR(ret);
137 }
138
139 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
140 struct btrfs_root *root,
141 struct btrfs_path *path, u64 objectid,
142 u64 offset, int mod)
143 {
144 int ret;
145 struct btrfs_key file_key;
146 int ins_len = mod < 0 ? -1 : 0;
147 int cow = mod != 0;
148
149 file_key.objectid = objectid;
150 file_key.offset = offset;
151 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
152 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
153 return ret;
154 }
155
156 static void btrfs_io_bio_endio_readpage(struct btrfs_io_bio *bio, int err)
157 {
158 kfree(bio->csum_allocated);
159 }
160
161 static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
162 struct inode *inode, struct bio *bio,
163 u64 logical_offset, u32 *dst, int dio)
164 {
165 struct bio_vec *bvec = bio->bi_io_vec;
166 struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
167 struct btrfs_csum_item *item = NULL;
168 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
169 struct btrfs_path *path;
170 u8 *csum;
171 u64 offset = 0;
172 u64 item_start_offset = 0;
173 u64 item_last_offset = 0;
174 u64 disk_bytenr;
175 u32 diff;
176 int nblocks;
177 int bio_index = 0;
178 int count;
179 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
180
181 path = btrfs_alloc_path();
182 if (!path)
183 return -ENOMEM;
184
185 nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits;
186 if (!dst) {
187 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
188 btrfs_bio->csum_allocated = kmalloc(nblocks * csum_size,
189 GFP_NOFS);
190 if (!btrfs_bio->csum_allocated) {
191 btrfs_free_path(path);
192 return -ENOMEM;
193 }
194 btrfs_bio->csum = btrfs_bio->csum_allocated;
195 btrfs_bio->end_io = btrfs_io_bio_endio_readpage;
196 } else {
197 btrfs_bio->csum = btrfs_bio->csum_inline;
198 }
199 csum = btrfs_bio->csum;
200 } else {
201 csum = (u8 *)dst;
202 }
203
204 if (bio->bi_iter.bi_size > PAGE_CACHE_SIZE * 8)
205 path->reada = 2;
206
207 WARN_ON(bio->bi_vcnt <= 0);
208
209 /*
210 * the free space stuff is only read when it hasn't been
211 * updated in the current transaction. So, we can safely
212 * read from the commit root and sidestep a nasty deadlock
213 * between reading the free space cache and updating the csum tree.
214 */
215 if (btrfs_is_free_space_inode(inode)) {
216 path->search_commit_root = 1;
217 path->skip_locking = 1;
218 }
219
220 disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
221 if (dio)
222 offset = logical_offset;
223 while (bio_index < bio->bi_vcnt) {
224 if (!dio)
225 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
226 count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
227 (u32 *)csum, nblocks);
228 if (count)
229 goto found;
230
231 if (!item || disk_bytenr < item_start_offset ||
232 disk_bytenr >= item_last_offset) {
233 struct btrfs_key found_key;
234 u32 item_size;
235
236 if (item)
237 btrfs_release_path(path);
238 item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
239 path, disk_bytenr, 0);
240 if (IS_ERR(item)) {
241 count = 1;
242 memset(csum, 0, csum_size);
243 if (BTRFS_I(inode)->root->root_key.objectid ==
244 BTRFS_DATA_RELOC_TREE_OBJECTID) {
245 set_extent_bits(io_tree, offset,
246 offset + bvec->bv_len - 1,
247 EXTENT_NODATASUM, GFP_NOFS);
248 } else {
249 btrfs_info(BTRFS_I(inode)->root->fs_info,
250 "no csum found for inode %llu start %llu",
251 btrfs_ino(inode), offset);
252 }
253 item = NULL;
254 btrfs_release_path(path);
255 goto found;
256 }
257 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
258 path->slots[0]);
259
260 item_start_offset = found_key.offset;
261 item_size = btrfs_item_size_nr(path->nodes[0],
262 path->slots[0]);
263 item_last_offset = item_start_offset +
264 (item_size / csum_size) *
265 root->sectorsize;
266 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
267 struct btrfs_csum_item);
268 }
269 /*
270 * this byte range must be able to fit inside
271 * a single leaf so it will also fit inside a u32
272 */
273 diff = disk_bytenr - item_start_offset;
274 diff = diff / root->sectorsize;
275 diff = diff * csum_size;
276 count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >>
277 inode->i_sb->s_blocksize_bits);
278 read_extent_buffer(path->nodes[0], csum,
279 ((unsigned long)item) + diff,
280 csum_size * count);
281 found:
282 csum += count * csum_size;
283 nblocks -= count;
284 bio_index += count;
285 while (count--) {
286 disk_bytenr += bvec->bv_len;
287 offset += bvec->bv_len;
288 bvec++;
289 }
290 }
291 btrfs_free_path(path);
292 return 0;
293 }
294
295 int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
296 struct bio *bio, u32 *dst)
297 {
298 return __btrfs_lookup_bio_sums(root, inode, bio, 0, dst, 0);
299 }
300
301 int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
302 struct btrfs_dio_private *dip, struct bio *bio,
303 u64 offset)
304 {
305 int len = (bio->bi_iter.bi_sector << 9) - dip->disk_bytenr;
306 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
307 int ret;
308
309 len >>= inode->i_sb->s_blocksize_bits;
310 len *= csum_size;
311
312 ret = __btrfs_lookup_bio_sums(root, inode, bio, offset,
313 (u32 *)(dip->csum + len), 1);
314 return ret;
315 }
316
317 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
318 struct list_head *list, int search_commit)
319 {
320 struct btrfs_key key;
321 struct btrfs_path *path;
322 struct extent_buffer *leaf;
323 struct btrfs_ordered_sum *sums;
324 struct btrfs_csum_item *item;
325 LIST_HEAD(tmplist);
326 unsigned long offset;
327 int ret;
328 size_t size;
329 u64 csum_end;
330 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
331
332 ASSERT(start == ALIGN(start, root->sectorsize) &&
333 (end + 1) == ALIGN(end + 1, root->sectorsize));
334
335 path = btrfs_alloc_path();
336 if (!path)
337 return -ENOMEM;
338
339 if (search_commit) {
340 path->skip_locking = 1;
341 path->reada = 2;
342 path->search_commit_root = 1;
343 }
344
345 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
346 key.offset = start;
347 key.type = BTRFS_EXTENT_CSUM_KEY;
348
349 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
350 if (ret < 0)
351 goto fail;
352 if (ret > 0 && path->slots[0] > 0) {
353 leaf = path->nodes[0];
354 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
355 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
356 key.type == BTRFS_EXTENT_CSUM_KEY) {
357 offset = (start - key.offset) >>
358 root->fs_info->sb->s_blocksize_bits;
359 if (offset * csum_size <
360 btrfs_item_size_nr(leaf, path->slots[0] - 1))
361 path->slots[0]--;
362 }
363 }
364
365 while (start <= end) {
366 leaf = path->nodes[0];
367 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
368 ret = btrfs_next_leaf(root, path);
369 if (ret < 0)
370 goto fail;
371 if (ret > 0)
372 break;
373 leaf = path->nodes[0];
374 }
375
376 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
377 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
378 key.type != BTRFS_EXTENT_CSUM_KEY ||
379 key.offset > end)
380 break;
381
382 if (key.offset > start)
383 start = key.offset;
384
385 size = btrfs_item_size_nr(leaf, path->slots[0]);
386 csum_end = key.offset + (size / csum_size) * root->sectorsize;
387 if (csum_end <= start) {
388 path->slots[0]++;
389 continue;
390 }
391
392 csum_end = min(csum_end, end + 1);
393 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
394 struct btrfs_csum_item);
395 while (start < csum_end) {
396 size = min_t(size_t, csum_end - start,
397 MAX_ORDERED_SUM_BYTES(root));
398 sums = kzalloc(btrfs_ordered_sum_size(root, size),
399 GFP_NOFS);
400 if (!sums) {
401 ret = -ENOMEM;
402 goto fail;
403 }
404
405 sums->bytenr = start;
406 sums->len = (int)size;
407
408 offset = (start - key.offset) >>
409 root->fs_info->sb->s_blocksize_bits;
410 offset *= csum_size;
411 size >>= root->fs_info->sb->s_blocksize_bits;
412
413 read_extent_buffer(path->nodes[0],
414 sums->sums,
415 ((unsigned long)item) + offset,
416 csum_size * size);
417
418 start += root->sectorsize * size;
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_ordered_extent *ordered;
441 char *data;
442 struct bio_vec *bvec = bio->bi_io_vec;
443 int bio_index = 0;
444 int index;
445 unsigned long total_bytes = 0;
446 unsigned long this_sum_bytes = 0;
447 u64 offset;
448
449 WARN_ON(bio->bi_vcnt <= 0);
450 sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_iter.bi_size),
451 GFP_NOFS);
452 if (!sums)
453 return -ENOMEM;
454
455 sums->len = bio->bi_iter.bi_size;
456 INIT_LIST_HEAD(&sums->list);
457
458 if (contig)
459 offset = file_start;
460 else
461 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
462
463 ordered = btrfs_lookup_ordered_extent(inode, offset);
464 BUG_ON(!ordered); /* Logic error */
465 sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
466 index = 0;
467
468 while (bio_index < bio->bi_vcnt) {
469 if (!contig)
470 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
471
472 if (offset >= ordered->file_offset + ordered->len ||
473 offset < ordered->file_offset) {
474 unsigned long bytes_left;
475 sums->len = this_sum_bytes;
476 this_sum_bytes = 0;
477 btrfs_add_ordered_sum(inode, ordered, sums);
478 btrfs_put_ordered_extent(ordered);
479
480 bytes_left = bio->bi_iter.bi_size - total_bytes;
481
482 sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
483 GFP_NOFS);
484 BUG_ON(!sums); /* -ENOMEM */
485 sums->len = bytes_left;
486 ordered = btrfs_lookup_ordered_extent(inode, offset);
487 BUG_ON(!ordered); /* Logic error */
488 sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9) +
489 total_bytes;
490 index = 0;
491 }
492
493 data = kmap_atomic(bvec->bv_page);
494 sums->sums[index] = ~(u32)0;
495 sums->sums[index] = btrfs_csum_data(data + bvec->bv_offset,
496 sums->sums[index],
497 bvec->bv_len);
498 kunmap_atomic(data);
499 btrfs_csum_final(sums->sums[index],
500 (char *)(sums->sums + index));
501
502 bio_index++;
503 index++;
504 total_bytes += bvec->bv_len;
505 this_sum_bytes += bvec->bv_len;
506 offset += bvec->bv_len;
507 bvec++;
508 }
509 this_sum_bytes = 0;
510 btrfs_add_ordered_sum(inode, ordered, sums);
511 btrfs_put_ordered_extent(ordered);
512 return 0;
513 }
514
515 /*
516 * helper function for csum removal, this expects the
517 * key to describe the csum pointed to by the path, and it expects
518 * the csum to overlap the range [bytenr, len]
519 *
520 * The csum should not be entirely contained in the range and the
521 * range should not be entirely contained in the csum.
522 *
523 * This calls btrfs_truncate_item with the correct args based on the
524 * overlap, and fixes up the key as required.
525 */
526 static noinline void truncate_one_csum(struct btrfs_root *root,
527 struct btrfs_path *path,
528 struct btrfs_key *key,
529 u64 bytenr, u64 len)
530 {
531 struct extent_buffer *leaf;
532 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
533 u64 csum_end;
534 u64 end_byte = bytenr + len;
535 u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
536
537 leaf = path->nodes[0];
538 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
539 csum_end <<= root->fs_info->sb->s_blocksize_bits;
540 csum_end += key->offset;
541
542 if (key->offset < bytenr && csum_end <= end_byte) {
543 /*
544 * [ bytenr - len ]
545 * [ ]
546 * [csum ]
547 * A simple truncate off the end of the item
548 */
549 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
550 new_size *= csum_size;
551 btrfs_truncate_item(root, path, new_size, 1);
552 } else if (key->offset >= bytenr && csum_end > end_byte &&
553 end_byte > key->offset) {
554 /*
555 * [ bytenr - len ]
556 * [ ]
557 * [csum ]
558 * we need to truncate from the beginning of the csum
559 */
560 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
561 new_size *= csum_size;
562
563 btrfs_truncate_item(root, path, new_size, 0);
564
565 key->offset = end_byte;
566 btrfs_set_item_key_safe(root, path, key);
567 } else {
568 BUG();
569 }
570 }
571
572 /*
573 * deletes the csum items from the csum tree for a given
574 * range of bytes.
575 */
576 int btrfs_del_csums(struct btrfs_trans_handle *trans,
577 struct btrfs_root *root, u64 bytenr, u64 len)
578 {
579 struct btrfs_path *path;
580 struct btrfs_key key;
581 u64 end_byte = bytenr + len;
582 u64 csum_end;
583 struct extent_buffer *leaf;
584 int ret;
585 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
586 int blocksize_bits = root->fs_info->sb->s_blocksize_bits;
587
588 root = root->fs_info->csum_root;
589
590 path = btrfs_alloc_path();
591 if (!path)
592 return -ENOMEM;
593
594 while (1) {
595 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
596 key.offset = end_byte - 1;
597 key.type = BTRFS_EXTENT_CSUM_KEY;
598
599 path->leave_spinning = 1;
600 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
601 if (ret > 0) {
602 if (path->slots[0] == 0)
603 break;
604 path->slots[0]--;
605 } else if (ret < 0) {
606 break;
607 }
608
609 leaf = path->nodes[0];
610 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
611
612 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
613 key.type != BTRFS_EXTENT_CSUM_KEY) {
614 break;
615 }
616
617 if (key.offset >= end_byte)
618 break;
619
620 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
621 csum_end <<= blocksize_bits;
622 csum_end += key.offset;
623
624 /* this csum ends before we start, we're done */
625 if (csum_end <= bytenr)
626 break;
627
628 /* delete the entire item, it is inside our range */
629 if (key.offset >= bytenr && csum_end <= end_byte) {
630 ret = btrfs_del_item(trans, root, path);
631 if (ret)
632 goto out;
633 if (key.offset == bytenr)
634 break;
635 } else if (key.offset < bytenr && csum_end > end_byte) {
636 unsigned long offset;
637 unsigned long shift_len;
638 unsigned long item_offset;
639 /*
640 * [ bytenr - len ]
641 * [csum ]
642 *
643 * Our bytes are in the middle of the csum,
644 * we need to split this item and insert a new one.
645 *
646 * But we can't drop the path because the
647 * csum could change, get removed, extended etc.
648 *
649 * The trick here is the max size of a csum item leaves
650 * enough room in the tree block for a single
651 * item header. So, we split the item in place,
652 * adding a new header pointing to the existing
653 * bytes. Then we loop around again and we have
654 * a nicely formed csum item that we can neatly
655 * truncate.
656 */
657 offset = (bytenr - key.offset) >> blocksize_bits;
658 offset *= csum_size;
659
660 shift_len = (len >> blocksize_bits) * csum_size;
661
662 item_offset = btrfs_item_ptr_offset(leaf,
663 path->slots[0]);
664
665 memset_extent_buffer(leaf, 0, item_offset + offset,
666 shift_len);
667 key.offset = bytenr;
668
669 /*
670 * btrfs_split_item returns -EAGAIN when the
671 * item changed size or key
672 */
673 ret = btrfs_split_item(trans, root, path, &key, offset);
674 if (ret && ret != -EAGAIN) {
675 btrfs_abort_transaction(trans, root, ret);
676 goto out;
677 }
678
679 key.offset = end_byte - 1;
680 } else {
681 truncate_one_csum(root, path, &key, bytenr, len);
682 if (key.offset < bytenr)
683 break;
684 }
685 btrfs_release_path(path);
686 }
687 ret = 0;
688 out:
689 btrfs_free_path(path);
690 return ret;
691 }
692
693 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
694 struct btrfs_root *root,
695 struct btrfs_ordered_sum *sums)
696 {
697 struct btrfs_key file_key;
698 struct btrfs_key found_key;
699 struct btrfs_path *path;
700 struct btrfs_csum_item *item;
701 struct btrfs_csum_item *item_end;
702 struct extent_buffer *leaf = NULL;
703 u64 next_offset;
704 u64 total_bytes = 0;
705 u64 csum_offset;
706 u64 bytenr;
707 u32 nritems;
708 u32 ins_size;
709 int index = 0;
710 int found_next;
711 int ret;
712 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
713
714 path = btrfs_alloc_path();
715 if (!path)
716 return -ENOMEM;
717 again:
718 next_offset = (u64)-1;
719 found_next = 0;
720 bytenr = sums->bytenr + total_bytes;
721 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
722 file_key.offset = bytenr;
723 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
724
725 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
726 if (!IS_ERR(item)) {
727 ret = 0;
728 leaf = path->nodes[0];
729 item_end = btrfs_item_ptr(leaf, path->slots[0],
730 struct btrfs_csum_item);
731 item_end = (struct btrfs_csum_item *)((char *)item_end +
732 btrfs_item_size_nr(leaf, path->slots[0]));
733 goto found;
734 }
735 ret = PTR_ERR(item);
736 if (ret != -EFBIG && ret != -ENOENT)
737 goto fail_unlock;
738
739 if (ret == -EFBIG) {
740 u32 item_size;
741 /* we found one, but it isn't big enough yet */
742 leaf = path->nodes[0];
743 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
744 if ((item_size / csum_size) >=
745 MAX_CSUM_ITEMS(root, csum_size)) {
746 /* already at max size, make a new one */
747 goto insert;
748 }
749 } else {
750 int slot = path->slots[0] + 1;
751 /* we didn't find a csum item, insert one */
752 nritems = btrfs_header_nritems(path->nodes[0]);
753 if (!nritems || (path->slots[0] >= nritems - 1)) {
754 ret = btrfs_next_leaf(root, path);
755 if (ret == 1)
756 found_next = 1;
757 if (ret != 0)
758 goto insert;
759 slot = path->slots[0];
760 }
761 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
762 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
763 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
764 found_next = 1;
765 goto insert;
766 }
767 next_offset = found_key.offset;
768 found_next = 1;
769 goto insert;
770 }
771
772 /*
773 * at this point, we know the tree has an item, but it isn't big
774 * enough yet to put our csum in. Grow it
775 */
776 btrfs_release_path(path);
777 ret = btrfs_search_slot(trans, root, &file_key, path,
778 csum_size, 1);
779 if (ret < 0)
780 goto fail_unlock;
781
782 if (ret > 0) {
783 if (path->slots[0] == 0)
784 goto insert;
785 path->slots[0]--;
786 }
787
788 leaf = path->nodes[0];
789 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
790 csum_offset = (bytenr - found_key.offset) >>
791 root->fs_info->sb->s_blocksize_bits;
792
793 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY ||
794 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
795 csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
796 goto insert;
797 }
798
799 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
800 csum_size) {
801 int extend_nr;
802 u64 tmp;
803 u32 diff;
804 u32 free_space;
805
806 if (btrfs_leaf_free_space(root, leaf) <
807 sizeof(struct btrfs_item) + csum_size * 2)
808 goto insert;
809
810 free_space = btrfs_leaf_free_space(root, leaf) -
811 sizeof(struct btrfs_item) - csum_size;
812 tmp = sums->len - total_bytes;
813 tmp >>= root->fs_info->sb->s_blocksize_bits;
814 WARN_ON(tmp < 1);
815
816 extend_nr = max_t(int, 1, (int)tmp);
817 diff = (csum_offset + extend_nr) * csum_size;
818 diff = min(diff, MAX_CSUM_ITEMS(root, csum_size) * csum_size);
819
820 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
821 diff = min(free_space, diff);
822 diff /= csum_size;
823 diff *= csum_size;
824
825 btrfs_extend_item(root, path, diff);
826 ret = 0;
827 goto csum;
828 }
829
830 insert:
831 btrfs_release_path(path);
832 csum_offset = 0;
833 if (found_next) {
834 u64 tmp;
835
836 tmp = sums->len - total_bytes;
837 tmp >>= root->fs_info->sb->s_blocksize_bits;
838 tmp = min(tmp, (next_offset - file_key.offset) >>
839 root->fs_info->sb->s_blocksize_bits);
840
841 tmp = max((u64)1, tmp);
842 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
843 ins_size = csum_size * tmp;
844 } else {
845 ins_size = csum_size;
846 }
847 path->leave_spinning = 1;
848 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
849 ins_size);
850 path->leave_spinning = 0;
851 if (ret < 0)
852 goto fail_unlock;
853 if (WARN_ON(ret != 0))
854 goto fail_unlock;
855 leaf = path->nodes[0];
856 csum:
857 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
858 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
859 btrfs_item_size_nr(leaf, path->slots[0]));
860 item = (struct btrfs_csum_item *)((unsigned char *)item +
861 csum_offset * csum_size);
862 found:
863 ins_size = (u32)(sums->len - total_bytes) >>
864 root->fs_info->sb->s_blocksize_bits;
865 ins_size *= csum_size;
866 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
867 ins_size);
868 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
869 ins_size);
870
871 ins_size /= csum_size;
872 total_bytes += ins_size * root->sectorsize;
873 index += ins_size;
874
875 btrfs_mark_buffer_dirty(path->nodes[0]);
876 if (total_bytes < sums->len) {
877 btrfs_release_path(path);
878 cond_resched();
879 goto again;
880 }
881 out:
882 btrfs_free_path(path);
883 return ret;
884
885 fail_unlock:
886 goto out;
887 }
888
889 void btrfs_extent_item_to_extent_map(struct inode *inode,
890 const struct btrfs_path *path,
891 struct btrfs_file_extent_item *fi,
892 const bool new_inline,
893 struct extent_map *em)
894 {
895 struct btrfs_root *root = BTRFS_I(inode)->root;
896 struct extent_buffer *leaf = path->nodes[0];
897 const int slot = path->slots[0];
898 struct btrfs_key key;
899 u64 extent_start, extent_end;
900 u64 bytenr;
901 u8 type = btrfs_file_extent_type(leaf, fi);
902 int compress_type = btrfs_file_extent_compression(leaf, fi);
903
904 em->bdev = root->fs_info->fs_devices->latest_bdev;
905 btrfs_item_key_to_cpu(leaf, &key, slot);
906 extent_start = key.offset;
907
908 if (type == BTRFS_FILE_EXTENT_REG ||
909 type == BTRFS_FILE_EXTENT_PREALLOC) {
910 extent_end = extent_start +
911 btrfs_file_extent_num_bytes(leaf, fi);
912 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
913 size_t size;
914 size = btrfs_file_extent_inline_len(leaf, slot, fi);
915 extent_end = ALIGN(extent_start + size, root->sectorsize);
916 }
917
918 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
919 if (type == BTRFS_FILE_EXTENT_REG ||
920 type == BTRFS_FILE_EXTENT_PREALLOC) {
921 em->start = extent_start;
922 em->len = extent_end - extent_start;
923 em->orig_start = extent_start -
924 btrfs_file_extent_offset(leaf, fi);
925 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
926 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
927 if (bytenr == 0) {
928 em->block_start = EXTENT_MAP_HOLE;
929 return;
930 }
931 if (compress_type != BTRFS_COMPRESS_NONE) {
932 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
933 em->compress_type = compress_type;
934 em->block_start = bytenr;
935 em->block_len = em->orig_block_len;
936 } else {
937 bytenr += btrfs_file_extent_offset(leaf, fi);
938 em->block_start = bytenr;
939 em->block_len = em->len;
940 if (type == BTRFS_FILE_EXTENT_PREALLOC)
941 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
942 }
943 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
944 em->block_start = EXTENT_MAP_INLINE;
945 em->start = extent_start;
946 em->len = extent_end - extent_start;
947 /*
948 * Initialize orig_start and block_len with the same values
949 * as in inode.c:btrfs_get_extent().
950 */
951 em->orig_start = EXTENT_MAP_HOLE;
952 em->block_len = (u64)-1;
953 if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) {
954 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
955 em->compress_type = compress_type;
956 }
957 } else {
958 btrfs_err(root->fs_info,
959 "unknown file extent item type %d, inode %llu, offset %llu, root %llu",
960 type, btrfs_ino(inode), extent_start,
961 root->root_key.objectid);
962 }
963 }
Linux with added FPC-III support