2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
19 #include <linux/bio.h>
20 #include <linux/slab.h>
21 #include <linux/pagemap.h>
22 #include <linux/highmem.h>
25 #include "transaction.h"
26 #include "print-tree.h"
28 #define MAX_CSUM_ITEMS(r, size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
29 sizeof(struct btrfs_item) * 2) / \
32 #define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
33 sizeof(struct btrfs_ordered_sum)) / \
34 sizeof(struct btrfs_sector_sum) * \
35 (r)->sectorsize - (r)->sectorsize)
37 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
38 struct btrfs_root *root,
39 u64 objectid, u64 pos,
40 u64 disk_offset, u64 disk_num_bytes,
41 u64 num_bytes, u64 offset, u64 ram_bytes,
42 u8 compression, u8 encryption, u16 other_encoding)
45 struct btrfs_file_extent_item *item;
46 struct btrfs_key file_key;
47 struct btrfs_path *path;
48 struct extent_buffer *leaf;
50 path = btrfs_alloc_path();
53 file_key.objectid = objectid;
54 file_key.offset = pos;
55 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
57 path->leave_spinning = 1;
58 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
63 leaf = path->nodes[0];
64 item = btrfs_item_ptr(leaf, path->slots[0],
65 struct btrfs_file_extent_item);
66 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
67 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
68 btrfs_set_file_extent_offset(leaf, item, offset);
69 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
70 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
71 btrfs_set_file_extent_generation(leaf, item, trans->transid);
72 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
73 btrfs_set_file_extent_compression(leaf, item, compression);
74 btrfs_set_file_extent_encryption(leaf, item, encryption);
75 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
77 btrfs_mark_buffer_dirty(leaf);
79 btrfs_free_path(path);
83 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
84 struct btrfs_root *root,
85 struct btrfs_path *path,
89 struct btrfs_key file_key;
90 struct btrfs_key found_key;
91 struct btrfs_csum_item *item;
92 struct extent_buffer *leaf;
95 btrfs_super_csum_size(&root->fs_info->super_copy);
98 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
99 file_key.offset = bytenr;
100 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
101 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
104 leaf = path->nodes[0];
107 if (path->slots[0] == 0)
110 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
111 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
114 csum_offset = (bytenr - found_key.offset) >>
115 root->fs_info->sb->s_blocksize_bits;
116 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
117 csums_in_item /= csum_size;
119 if (csum_offset >= csums_in_item) {
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);
135 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
136 struct btrfs_root *root,
137 struct btrfs_path *path, u64 objectid,
141 struct btrfs_key file_key;
142 int ins_len = mod < 0 ? -1 : 0;
145 file_key.objectid = objectid;
146 file_key.offset = offset;
147 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
148 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
153 static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
154 struct inode *inode, struct bio *bio,
155 u64 logical_offset, u32 *dst, int dio)
158 struct bio_vec *bvec = bio->bi_io_vec;
161 u64 item_start_offset = 0;
162 u64 item_last_offset = 0;
166 btrfs_super_csum_size(&root->fs_info->super_copy);
168 struct btrfs_path *path;
169 struct btrfs_csum_item *item = NULL;
170 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
172 path = btrfs_alloc_path();
173 if (bio->bi_size > PAGE_CACHE_SIZE * 8)
176 WARN_ON(bio->bi_vcnt <= 0);
178 disk_bytenr = (u64)bio->bi_sector << 9;
180 offset = logical_offset;
181 while (bio_index < bio->bi_vcnt) {
183 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
184 ret = btrfs_find_ordered_sum(inode, offset, disk_bytenr, &sum);
188 if (!item || disk_bytenr < item_start_offset ||
189 disk_bytenr >= item_last_offset) {
190 struct btrfs_key found_key;
194 btrfs_release_path(root, path);
195 item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
196 path, disk_bytenr, 0);
199 if (ret == -ENOENT || ret == -EFBIG)
202 if (BTRFS_I(inode)->root->root_key.objectid ==
203 BTRFS_DATA_RELOC_TREE_OBJECTID) {
204 set_extent_bits(io_tree, offset,
205 offset + bvec->bv_len - 1,
206 EXTENT_NODATASUM, GFP_NOFS);
208 printk(KERN_INFO "btrfs no csum found "
209 "for inode %lu start %llu\n",
211 (unsigned long long)offset);
214 btrfs_release_path(root, path);
217 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
220 item_start_offset = found_key.offset;
221 item_size = btrfs_item_size_nr(path->nodes[0],
223 item_last_offset = item_start_offset +
224 (item_size / csum_size) *
226 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
227 struct btrfs_csum_item);
230 * this byte range must be able to fit inside
231 * a single leaf so it will also fit inside a u32
233 diff = disk_bytenr - item_start_offset;
234 diff = diff / root->sectorsize;
235 diff = diff * csum_size;
237 read_extent_buffer(path->nodes[0], &sum,
238 ((unsigned long)item) + diff,
244 set_state_private(io_tree, offset, sum);
245 disk_bytenr += bvec->bv_len;
246 offset += bvec->bv_len;
250 btrfs_free_path(path);
254 int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
255 struct bio *bio, u32 *dst)
257 return __btrfs_lookup_bio_sums(root, inode, bio, 0, dst, 0);
260 int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
261 struct bio *bio, u64 offset, u32 *dst)
263 return __btrfs_lookup_bio_sums(root, inode, bio, offset, dst, 1);
266 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
267 struct list_head *list)
269 struct btrfs_key key;
270 struct btrfs_path *path;
271 struct extent_buffer *leaf;
272 struct btrfs_ordered_sum *sums;
273 struct btrfs_sector_sum *sector_sum;
274 struct btrfs_csum_item *item;
275 unsigned long offset;
279 u16 csum_size = btrfs_super_csum_size(&root->fs_info->super_copy);
281 path = btrfs_alloc_path();
284 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
286 key.type = BTRFS_EXTENT_CSUM_KEY;
288 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
291 if (ret > 0 && path->slots[0] > 0) {
292 leaf = path->nodes[0];
293 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
294 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
295 key.type == BTRFS_EXTENT_CSUM_KEY) {
296 offset = (start - key.offset) >>
297 root->fs_info->sb->s_blocksize_bits;
298 if (offset * csum_size <
299 btrfs_item_size_nr(leaf, path->slots[0] - 1))
304 while (start <= end) {
305 leaf = path->nodes[0];
306 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
307 ret = btrfs_next_leaf(root, path);
312 leaf = path->nodes[0];
315 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
316 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
317 key.type != BTRFS_EXTENT_CSUM_KEY)
320 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
321 if (key.offset > end)
324 if (key.offset > start)
327 size = btrfs_item_size_nr(leaf, path->slots[0]);
328 csum_end = key.offset + (size / csum_size) * root->sectorsize;
329 if (csum_end <= start) {
334 csum_end = min(csum_end, end + 1);
335 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
336 struct btrfs_csum_item);
337 while (start < csum_end) {
338 size = min_t(size_t, csum_end - start,
339 MAX_ORDERED_SUM_BYTES(root));
340 sums = kzalloc(btrfs_ordered_sum_size(root, size),
344 sector_sum = sums->sums;
345 sums->bytenr = start;
348 offset = (start - key.offset) >>
349 root->fs_info->sb->s_blocksize_bits;
353 read_extent_buffer(path->nodes[0],
355 ((unsigned long)item) +
357 sector_sum->bytenr = start;
359 size -= root->sectorsize;
360 start += root->sectorsize;
364 list_add_tail(&sums->list, list);
370 btrfs_free_path(path);
374 int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
375 struct bio *bio, u64 file_start, int contig)
377 struct btrfs_ordered_sum *sums;
378 struct btrfs_sector_sum *sector_sum;
379 struct btrfs_ordered_extent *ordered;
381 struct bio_vec *bvec = bio->bi_io_vec;
383 unsigned long total_bytes = 0;
384 unsigned long this_sum_bytes = 0;
388 WARN_ON(bio->bi_vcnt <= 0);
389 sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
393 sector_sum = sums->sums;
394 disk_bytenr = (u64)bio->bi_sector << 9;
395 sums->len = bio->bi_size;
396 INIT_LIST_HEAD(&sums->list);
401 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
403 ordered = btrfs_lookup_ordered_extent(inode, offset);
405 sums->bytenr = ordered->start;
407 while (bio_index < bio->bi_vcnt) {
409 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
411 if (!contig && (offset >= ordered->file_offset + ordered->len ||
412 offset < ordered->file_offset)) {
413 unsigned long bytes_left;
414 sums->len = this_sum_bytes;
416 btrfs_add_ordered_sum(inode, ordered, sums);
417 btrfs_put_ordered_extent(ordered);
419 bytes_left = bio->bi_size - total_bytes;
421 sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
424 sector_sum = sums->sums;
425 sums->len = bytes_left;
426 ordered = btrfs_lookup_ordered_extent(inode, offset);
428 sums->bytenr = ordered->start;
431 data = kmap_atomic(bvec->bv_page, KM_USER0);
432 sector_sum->sum = ~(u32)0;
433 sector_sum->sum = btrfs_csum_data(root,
434 data + bvec->bv_offset,
437 kunmap_atomic(data, KM_USER0);
438 btrfs_csum_final(sector_sum->sum,
439 (char *)§or_sum->sum);
440 sector_sum->bytenr = disk_bytenr;
444 total_bytes += bvec->bv_len;
445 this_sum_bytes += bvec->bv_len;
446 disk_bytenr += bvec->bv_len;
447 offset += bvec->bv_len;
451 btrfs_add_ordered_sum(inode, ordered, sums);
452 btrfs_put_ordered_extent(ordered);
457 * helper function for csum removal, this expects the
458 * key to describe the csum pointed to by the path, and it expects
459 * the csum to overlap the range [bytenr, len]
461 * The csum should not be entirely contained in the range and the
462 * range should not be entirely contained in the csum.
464 * This calls btrfs_truncate_item with the correct args based on the
465 * overlap, and fixes up the key as required.
467 static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
468 struct btrfs_root *root,
469 struct btrfs_path *path,
470 struct btrfs_key *key,
473 struct extent_buffer *leaf;
475 btrfs_super_csum_size(&root->fs_info->super_copy);
477 u64 end_byte = bytenr + len;
478 u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
481 leaf = path->nodes[0];
482 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
483 csum_end <<= root->fs_info->sb->s_blocksize_bits;
484 csum_end += key->offset;
486 if (key->offset < bytenr && csum_end <= end_byte) {
491 * A simple truncate off the end of the item
493 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
494 new_size *= csum_size;
495 ret = btrfs_truncate_item(trans, root, path, new_size, 1);
497 } else if (key->offset >= bytenr && csum_end > end_byte &&
498 end_byte > key->offset) {
503 * we need to truncate from the beginning of the csum
505 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
506 new_size *= csum_size;
508 ret = btrfs_truncate_item(trans, root, path, new_size, 0);
511 key->offset = end_byte;
512 ret = btrfs_set_item_key_safe(trans, root, path, key);
521 * deletes the csum items from the csum tree for a given
524 int btrfs_del_csums(struct btrfs_trans_handle *trans,
525 struct btrfs_root *root, u64 bytenr, u64 len)
527 struct btrfs_path *path;
528 struct btrfs_key key;
529 u64 end_byte = bytenr + len;
531 struct extent_buffer *leaf;
534 btrfs_super_csum_size(&root->fs_info->super_copy);
535 int blocksize_bits = root->fs_info->sb->s_blocksize_bits;
537 root = root->fs_info->csum_root;
539 path = btrfs_alloc_path();
544 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
545 key.offset = end_byte - 1;
546 key.type = BTRFS_EXTENT_CSUM_KEY;
548 path->leave_spinning = 1;
549 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
551 if (path->slots[0] == 0)
554 } else if (ret < 0) {
558 leaf = path->nodes[0];
559 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
561 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
562 key.type != BTRFS_EXTENT_CSUM_KEY) {
566 if (key.offset >= end_byte)
569 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
570 csum_end <<= blocksize_bits;
571 csum_end += key.offset;
573 /* this csum ends before we start, we're done */
574 if (csum_end <= bytenr)
577 /* delete the entire item, it is inside our range */
578 if (key.offset >= bytenr && csum_end <= end_byte) {
579 ret = btrfs_del_item(trans, root, path);
581 if (key.offset == bytenr)
583 } else if (key.offset < bytenr && csum_end > end_byte) {
584 unsigned long offset;
585 unsigned long shift_len;
586 unsigned long item_offset;
591 * Our bytes are in the middle of the csum,
592 * we need to split this item and insert a new one.
594 * But we can't drop the path because the
595 * csum could change, get removed, extended etc.
597 * The trick here is the max size of a csum item leaves
598 * enough room in the tree block for a single
599 * item header. So, we split the item in place,
600 * adding a new header pointing to the existing
601 * bytes. Then we loop around again and we have
602 * a nicely formed csum item that we can neatly
605 offset = (bytenr - key.offset) >> blocksize_bits;
608 shift_len = (len >> blocksize_bits) * csum_size;
610 item_offset = btrfs_item_ptr_offset(leaf,
613 memset_extent_buffer(leaf, 0, item_offset + offset,
618 * btrfs_split_item returns -EAGAIN when the
619 * item changed size or key
621 ret = btrfs_split_item(trans, root, path, &key, offset);
622 BUG_ON(ret && ret != -EAGAIN);
624 key.offset = end_byte - 1;
626 ret = truncate_one_csum(trans, root, path,
629 if (key.offset < bytenr)
632 btrfs_release_path(root, path);
635 btrfs_free_path(path);
639 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
640 struct btrfs_root *root,
641 struct btrfs_ordered_sum *sums)
645 struct btrfs_key file_key;
646 struct btrfs_key found_key;
650 struct btrfs_path *path;
651 struct btrfs_csum_item *item;
652 struct btrfs_csum_item *item_end;
653 struct extent_buffer *leaf = NULL;
655 struct btrfs_sector_sum *sector_sum;
660 unsigned long map_len;
661 unsigned long map_start;
663 btrfs_super_csum_size(&root->fs_info->super_copy);
665 path = btrfs_alloc_path();
667 sector_sum = sums->sums;
669 next_offset = (u64)-1;
671 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
672 file_key.offset = sector_sum->bytenr;
673 bytenr = sector_sum->bytenr;
674 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
676 item = btrfs_lookup_csum(trans, root, path, sector_sum->bytenr, 1);
678 leaf = path->nodes[0];
683 if (ret != -EFBIG && ret != -ENOENT)
688 /* we found one, but it isn't big enough yet */
689 leaf = path->nodes[0];
690 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
691 if ((item_size / csum_size) >=
692 MAX_CSUM_ITEMS(root, csum_size)) {
693 /* already at max size, make a new one */
697 int slot = path->slots[0] + 1;
698 /* we didn't find a csum item, insert one */
699 nritems = btrfs_header_nritems(path->nodes[0]);
700 if (path->slots[0] >= nritems - 1) {
701 ret = btrfs_next_leaf(root, path);
708 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
709 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
710 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
714 next_offset = found_key.offset;
720 * at this point, we know the tree has an item, but it isn't big
721 * enough yet to put our csum in. Grow it
723 btrfs_release_path(root, path);
724 ret = btrfs_search_slot(trans, root, &file_key, path,
730 if (path->slots[0] == 0)
735 leaf = path->nodes[0];
736 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
737 csum_offset = (bytenr - found_key.offset) >>
738 root->fs_info->sb->s_blocksize_bits;
740 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY ||
741 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
742 csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
746 if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
748 u32 diff = (csum_offset + 1) * csum_size;
751 * is the item big enough already? we dropped our lock
752 * before and need to recheck
754 if (diff < btrfs_item_size_nr(leaf, path->slots[0]))
757 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
758 if (diff != csum_size)
761 ret = btrfs_extend_item(trans, root, path, diff);
767 btrfs_release_path(root, path);
770 u64 tmp = total_bytes + root->sectorsize;
771 u64 next_sector = sector_sum->bytenr;
772 struct btrfs_sector_sum *next = sector_sum + 1;
774 while (tmp < sums->len) {
775 if (next_sector + root->sectorsize != next->bytenr)
777 tmp += root->sectorsize;
778 next_sector = next->bytenr;
781 tmp = min(tmp, next_offset - file_key.offset);
782 tmp >>= root->fs_info->sb->s_blocksize_bits;
783 tmp = max((u64)1, tmp);
784 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
785 ins_size = csum_size * tmp;
787 ins_size = csum_size;
789 path->leave_spinning = 1;
790 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
792 path->leave_spinning = 0;
800 leaf = path->nodes[0];
801 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
803 item = (struct btrfs_csum_item *)((unsigned char *)item +
804 csum_offset * csum_size);
806 item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
807 item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
808 btrfs_item_size_nr(leaf, path->slots[0]));
813 (unsigned long)item + csum_size >= map_start + map_len) {
817 unmap_extent_buffer(leaf, eb_token, KM_USER1);
819 err = map_private_extent_buffer(leaf, (unsigned long)item,
822 &map_start, &map_len, KM_USER1);
827 memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
828 §or_sum->sum, csum_size);
830 write_extent_buffer(leaf, §or_sum->sum,
831 (unsigned long)item, csum_size);
834 total_bytes += root->sectorsize;
836 if (total_bytes < sums->len) {
837 item = (struct btrfs_csum_item *)((char *)item +
839 if (item < item_end && bytenr + PAGE_CACHE_SIZE ==
840 sector_sum->bytenr) {
841 bytenr = sector_sum->bytenr;
846 unmap_extent_buffer(leaf, eb_token, KM_USER1);
849 btrfs_mark_buffer_dirty(path->nodes[0]);
850 if (total_bytes < sums->len) {
851 btrfs_release_path(root, path);
856 btrfs_free_path(path);