1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2007 Oracle. All rights reserved.
7 #include <linux/slab.h>
8 #include <linux/pagemap.h>
9 #include <linux/highmem.h>
10 #include <linux/sched/mm.h>
11 #include <crypto/hash.h>
14 #include "transaction.h"
16 #include "print-tree.h"
17 #include "compression.h"
19 #define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
20 sizeof(struct btrfs_item) * 2) / \
23 #define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
27 * @inode - the inode we want to update the disk_i_size for
28 * @new_i_size - the i_size we want to set to, 0 if we use i_size
30 * With NO_HOLES set this simply sets the disk_is_size to whatever i_size_read()
31 * returns as it is perfectly fine with a file that has holes without hole file
34 * However without NO_HOLES we need to only return the area that is contiguous
35 * from the 0 offset of the file. Otherwise we could end up adjust i_size up
36 * to an extent that has a gap in between.
38 * Finally new_i_size should only be set in the case of truncate where we're not
39 * ready to use i_size_read() as the limiter yet.
41 void btrfs_inode_safe_disk_i_size_write(struct inode *inode, u64 new_i_size)
43 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
44 u64 start, end, i_size;
47 i_size = new_i_size ?: i_size_read(inode);
48 if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
49 BTRFS_I(inode)->disk_i_size = i_size;
53 spin_lock(&BTRFS_I(inode)->lock);
54 ret = find_contiguous_extent_bit(&BTRFS_I(inode)->file_extent_tree, 0,
55 &start, &end, EXTENT_DIRTY);
56 if (!ret && start == 0)
57 i_size = min(i_size, end + 1);
60 BTRFS_I(inode)->disk_i_size = i_size;
61 spin_unlock(&BTRFS_I(inode)->lock);
65 * @inode - the inode we're modifying
66 * @start - the start file offset of the file extent we've inserted
67 * @len - the logical length of the file extent item
69 * Call when we are inserting a new file extent where there was none before.
70 * Does not need to call this in the case where we're replacing an existing file
71 * extent, however if not sure it's fine to call this multiple times.
73 * The start and len must match the file extent item, so thus must be sectorsize
76 int btrfs_inode_set_file_extent_range(struct btrfs_inode *inode, u64 start,
82 ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize));
84 if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES))
86 return set_extent_bits(&inode->file_extent_tree, start, start + len - 1,
91 * @inode - the inode we're modifying
92 * @start - the start file offset of the file extent we've inserted
93 * @len - the logical length of the file extent item
95 * Called when we drop a file extent, for example when we truncate. Doesn't
96 * need to be called for cases where we're replacing a file extent, like when
97 * we've COWed a file extent.
99 * The start and len must match the file extent item, so thus must be sectorsize
102 int btrfs_inode_clear_file_extent_range(struct btrfs_inode *inode, u64 start,
108 ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize) ||
111 if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES))
113 return clear_extent_bit(&inode->file_extent_tree, start,
114 start + len - 1, EXTENT_DIRTY, 0, 0, NULL);
117 static inline u32 max_ordered_sum_bytes(struct btrfs_fs_info *fs_info,
120 u32 ncsums = (PAGE_SIZE - sizeof(struct btrfs_ordered_sum)) / csum_size;
122 return ncsums * fs_info->sectorsize;
125 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
126 struct btrfs_root *root,
127 u64 objectid, u64 pos,
128 u64 disk_offset, u64 disk_num_bytes,
129 u64 num_bytes, u64 offset, u64 ram_bytes,
130 u8 compression, u8 encryption, u16 other_encoding)
133 struct btrfs_file_extent_item *item;
134 struct btrfs_key file_key;
135 struct btrfs_path *path;
136 struct extent_buffer *leaf;
138 path = btrfs_alloc_path();
141 file_key.objectid = objectid;
142 file_key.offset = pos;
143 file_key.type = BTRFS_EXTENT_DATA_KEY;
145 path->leave_spinning = 1;
146 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
150 BUG_ON(ret); /* Can't happen */
151 leaf = path->nodes[0];
152 item = btrfs_item_ptr(leaf, path->slots[0],
153 struct btrfs_file_extent_item);
154 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
155 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
156 btrfs_set_file_extent_offset(leaf, item, offset);
157 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
158 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
159 btrfs_set_file_extent_generation(leaf, item, trans->transid);
160 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
161 btrfs_set_file_extent_compression(leaf, item, compression);
162 btrfs_set_file_extent_encryption(leaf, item, encryption);
163 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
165 btrfs_mark_buffer_dirty(leaf);
167 btrfs_free_path(path);
171 static struct btrfs_csum_item *
172 btrfs_lookup_csum(struct btrfs_trans_handle *trans,
173 struct btrfs_root *root,
174 struct btrfs_path *path,
177 struct btrfs_fs_info *fs_info = root->fs_info;
179 struct btrfs_key file_key;
180 struct btrfs_key found_key;
181 struct btrfs_csum_item *item;
182 struct extent_buffer *leaf;
184 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
187 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
188 file_key.offset = bytenr;
189 file_key.type = BTRFS_EXTENT_CSUM_KEY;
190 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
193 leaf = path->nodes[0];
196 if (path->slots[0] == 0)
199 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
200 if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
203 csum_offset = (bytenr - found_key.offset) >>
204 fs_info->sb->s_blocksize_bits;
205 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
206 csums_in_item /= csum_size;
208 if (csum_offset == csums_in_item) {
211 } else if (csum_offset > csums_in_item) {
215 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
216 item = (struct btrfs_csum_item *)((unsigned char *)item +
217 csum_offset * csum_size);
225 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
226 struct btrfs_root *root,
227 struct btrfs_path *path, u64 objectid,
231 struct btrfs_key file_key;
232 int ins_len = mod < 0 ? -1 : 0;
235 file_key.objectid = objectid;
236 file_key.offset = offset;
237 file_key.type = BTRFS_EXTENT_DATA_KEY;
238 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
243 * btrfs_lookup_bio_sums - Look up checksums for a bio.
244 * @inode: inode that the bio is for.
245 * @bio: bio to look up.
246 * @offset: Unless (u64)-1, look up checksums for this offset in the file.
247 * If (u64)-1, use the page offsets from the bio instead.
248 * @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return
249 * checksum (nblocks = bio->bi_iter.bi_size / fs_info->sectorsize). If
250 * NULL, the checksum buffer is allocated and returned in
251 * btrfs_io_bio(bio)->csum instead.
253 * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
255 blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
258 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
260 struct bvec_iter iter;
261 struct btrfs_csum_item *item = NULL;
262 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
263 struct btrfs_path *path;
264 const bool page_offsets = (offset == (u64)-1);
266 u64 item_start_offset = 0;
267 u64 item_last_offset = 0;
273 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
275 path = btrfs_alloc_path();
277 return BLK_STS_RESOURCE;
279 nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits;
281 struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
283 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
284 btrfs_bio->csum = kmalloc_array(nblocks, csum_size,
286 if (!btrfs_bio->csum) {
287 btrfs_free_path(path);
288 return BLK_STS_RESOURCE;
291 btrfs_bio->csum = btrfs_bio->csum_inline;
293 csum = btrfs_bio->csum;
298 if (bio->bi_iter.bi_size > PAGE_SIZE * 8)
299 path->reada = READA_FORWARD;
302 * the free space stuff is only read when it hasn't been
303 * updated in the current transaction. So, we can safely
304 * read from the commit root and sidestep a nasty deadlock
305 * between reading the free space cache and updating the csum tree.
307 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
308 path->search_commit_root = 1;
309 path->skip_locking = 1;
312 disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
314 bio_for_each_segment(bvec, bio, iter) {
315 page_bytes_left = bvec.bv_len;
320 offset = page_offset(bvec.bv_page) + bvec.bv_offset;
321 count = btrfs_find_ordered_sum(BTRFS_I(inode), offset,
322 disk_bytenr, csum, nblocks);
326 if (!item || disk_bytenr < item_start_offset ||
327 disk_bytenr >= item_last_offset) {
328 struct btrfs_key found_key;
332 btrfs_release_path(path);
333 item = btrfs_lookup_csum(NULL, fs_info->csum_root,
334 path, disk_bytenr, 0);
337 memset(csum, 0, csum_size);
338 if (BTRFS_I(inode)->root->root_key.objectid ==
339 BTRFS_DATA_RELOC_TREE_OBJECTID) {
340 set_extent_bits(io_tree, offset,
341 offset + fs_info->sectorsize - 1,
344 btrfs_info_rl(fs_info,
345 "no csum found for inode %llu start %llu",
346 btrfs_ino(BTRFS_I(inode)), offset);
349 btrfs_release_path(path);
352 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
355 item_start_offset = found_key.offset;
356 item_size = btrfs_item_size_nr(path->nodes[0],
358 item_last_offset = item_start_offset +
359 (item_size / csum_size) *
361 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
362 struct btrfs_csum_item);
365 * this byte range must be able to fit inside
366 * a single leaf so it will also fit inside a u32
368 diff = disk_bytenr - item_start_offset;
369 diff = diff / fs_info->sectorsize;
370 diff = diff * csum_size;
371 count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >>
372 inode->i_sb->s_blocksize_bits);
373 read_extent_buffer(path->nodes[0], csum,
374 ((unsigned long)item) + diff,
377 csum += count * csum_size;
382 disk_bytenr += fs_info->sectorsize;
383 offset += fs_info->sectorsize;
384 page_bytes_left -= fs_info->sectorsize;
385 if (!page_bytes_left)
386 break; /* move to next bio */
391 btrfs_free_path(path);
395 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
396 struct list_head *list, int search_commit)
398 struct btrfs_fs_info *fs_info = root->fs_info;
399 struct btrfs_key key;
400 struct btrfs_path *path;
401 struct extent_buffer *leaf;
402 struct btrfs_ordered_sum *sums;
403 struct btrfs_csum_item *item;
405 unsigned long offset;
409 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
411 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
412 IS_ALIGNED(end + 1, fs_info->sectorsize));
414 path = btrfs_alloc_path();
419 path->skip_locking = 1;
420 path->reada = READA_FORWARD;
421 path->search_commit_root = 1;
424 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
426 key.type = BTRFS_EXTENT_CSUM_KEY;
428 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
431 if (ret > 0 && path->slots[0] > 0) {
432 leaf = path->nodes[0];
433 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
434 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
435 key.type == BTRFS_EXTENT_CSUM_KEY) {
436 offset = (start - key.offset) >>
437 fs_info->sb->s_blocksize_bits;
438 if (offset * csum_size <
439 btrfs_item_size_nr(leaf, path->slots[0] - 1))
444 while (start <= end) {
445 leaf = path->nodes[0];
446 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
447 ret = btrfs_next_leaf(root, path);
452 leaf = path->nodes[0];
455 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
456 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
457 key.type != BTRFS_EXTENT_CSUM_KEY ||
461 if (key.offset > start)
464 size = btrfs_item_size_nr(leaf, path->slots[0]);
465 csum_end = key.offset + (size / csum_size) * fs_info->sectorsize;
466 if (csum_end <= start) {
471 csum_end = min(csum_end, end + 1);
472 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
473 struct btrfs_csum_item);
474 while (start < csum_end) {
475 size = min_t(size_t, csum_end - start,
476 max_ordered_sum_bytes(fs_info, csum_size));
477 sums = kzalloc(btrfs_ordered_sum_size(fs_info, size),
484 sums->bytenr = start;
485 sums->len = (int)size;
487 offset = (start - key.offset) >>
488 fs_info->sb->s_blocksize_bits;
490 size >>= fs_info->sb->s_blocksize_bits;
492 read_extent_buffer(path->nodes[0],
494 ((unsigned long)item) + offset,
497 start += fs_info->sectorsize * size;
498 list_add_tail(&sums->list, &tmplist);
504 while (ret < 0 && !list_empty(&tmplist)) {
505 sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list);
506 list_del(&sums->list);
509 list_splice_tail(&tmplist, list);
511 btrfs_free_path(path);
516 * btrfs_csum_one_bio - Calculates checksums of the data contained inside a bio
517 * @inode: Owner of the data inside the bio
518 * @bio: Contains the data to be checksummed
519 * @file_start: offset in file this bio begins to describe
520 * @contig: Boolean. If true/1 means all bio vecs in this bio are
521 * contiguous and they begin at @file_start in the file. False/0
522 * means this bio can contains potentially discontigous bio vecs
523 * so the logical offset of each should be calculated separately.
525 blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
526 u64 file_start, int contig)
528 struct btrfs_fs_info *fs_info = inode->root->fs_info;
529 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
530 struct btrfs_ordered_sum *sums;
531 struct btrfs_ordered_extent *ordered = NULL;
533 struct bvec_iter iter;
537 unsigned long total_bytes = 0;
538 unsigned long this_sum_bytes = 0;
542 const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
544 nofs_flag = memalloc_nofs_save();
545 sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
547 memalloc_nofs_restore(nofs_flag);
550 return BLK_STS_RESOURCE;
552 sums->len = bio->bi_iter.bi_size;
553 INIT_LIST_HEAD(&sums->list);
558 offset = 0; /* shut up gcc */
560 sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
563 shash->tfm = fs_info->csum_shash;
565 bio_for_each_segment(bvec, bio, iter) {
567 offset = page_offset(bvec.bv_page) + bvec.bv_offset;
570 ordered = btrfs_lookup_ordered_extent(inode, offset);
572 * The bio range is not covered by any ordered extent,
573 * must be a code logic error.
575 if (unlikely(!ordered)) {
577 "no ordered extent for root %llu ino %llu offset %llu\n",
578 inode->root->root_key.objectid,
579 btrfs_ino(inode), offset);
581 return BLK_STS_IOERR;
585 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info,
586 bvec.bv_len + fs_info->sectorsize
589 for (i = 0; i < nr_sectors; i++) {
590 if (offset >= ordered->file_offset + ordered->num_bytes ||
591 offset < ordered->file_offset) {
592 unsigned long bytes_left;
594 sums->len = this_sum_bytes;
596 btrfs_add_ordered_sum(ordered, sums);
597 btrfs_put_ordered_extent(ordered);
599 bytes_left = bio->bi_iter.bi_size - total_bytes;
601 nofs_flag = memalloc_nofs_save();
602 sums = kvzalloc(btrfs_ordered_sum_size(fs_info,
603 bytes_left), GFP_KERNEL);
604 memalloc_nofs_restore(nofs_flag);
606 return BLK_STS_RESOURCE;
608 sums->len = bytes_left;
609 ordered = btrfs_lookup_ordered_extent(inode,
611 ASSERT(ordered); /* Logic error */
612 sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9)
617 data = kmap_atomic(bvec.bv_page);
618 crypto_shash_digest(shash, data + bvec.bv_offset
619 + (i * fs_info->sectorsize),
624 offset += fs_info->sectorsize;
625 this_sum_bytes += fs_info->sectorsize;
626 total_bytes += fs_info->sectorsize;
631 btrfs_add_ordered_sum(ordered, sums);
632 btrfs_put_ordered_extent(ordered);
637 * helper function for csum removal, this expects the
638 * key to describe the csum pointed to by the path, and it expects
639 * the csum to overlap the range [bytenr, len]
641 * The csum should not be entirely contained in the range and the
642 * range should not be entirely contained in the csum.
644 * This calls btrfs_truncate_item with the correct args based on the
645 * overlap, and fixes up the key as required.
647 static noinline void truncate_one_csum(struct btrfs_fs_info *fs_info,
648 struct btrfs_path *path,
649 struct btrfs_key *key,
652 struct extent_buffer *leaf;
653 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
655 u64 end_byte = bytenr + len;
656 u32 blocksize_bits = fs_info->sb->s_blocksize_bits;
658 leaf = path->nodes[0];
659 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
660 csum_end <<= fs_info->sb->s_blocksize_bits;
661 csum_end += key->offset;
663 if (key->offset < bytenr && csum_end <= end_byte) {
668 * A simple truncate off the end of the item
670 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
671 new_size *= csum_size;
672 btrfs_truncate_item(path, new_size, 1);
673 } else if (key->offset >= bytenr && csum_end > end_byte &&
674 end_byte > key->offset) {
679 * we need to truncate from the beginning of the csum
681 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
682 new_size *= csum_size;
684 btrfs_truncate_item(path, new_size, 0);
686 key->offset = end_byte;
687 btrfs_set_item_key_safe(fs_info, path, key);
694 * deletes the csum items from the csum tree for a given
697 int btrfs_del_csums(struct btrfs_trans_handle *trans,
698 struct btrfs_root *root, u64 bytenr, u64 len)
700 struct btrfs_fs_info *fs_info = trans->fs_info;
701 struct btrfs_path *path;
702 struct btrfs_key key;
703 u64 end_byte = bytenr + len;
705 struct extent_buffer *leaf;
707 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
708 int blocksize_bits = fs_info->sb->s_blocksize_bits;
710 ASSERT(root == fs_info->csum_root ||
711 root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
713 path = btrfs_alloc_path();
718 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
719 key.offset = end_byte - 1;
720 key.type = BTRFS_EXTENT_CSUM_KEY;
722 path->leave_spinning = 1;
723 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
726 if (path->slots[0] == 0)
729 } else if (ret < 0) {
733 leaf = path->nodes[0];
734 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
736 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
737 key.type != BTRFS_EXTENT_CSUM_KEY) {
741 if (key.offset >= end_byte)
744 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
745 csum_end <<= blocksize_bits;
746 csum_end += key.offset;
748 /* this csum ends before we start, we're done */
749 if (csum_end <= bytenr)
752 /* delete the entire item, it is inside our range */
753 if (key.offset >= bytenr && csum_end <= end_byte) {
757 * Check how many csum items preceding this one in this
758 * leaf correspond to our range and then delete them all
761 if (key.offset > bytenr && path->slots[0] > 0) {
762 int slot = path->slots[0] - 1;
767 btrfs_item_key_to_cpu(leaf, &pk, slot);
768 if (pk.offset < bytenr ||
769 pk.type != BTRFS_EXTENT_CSUM_KEY ||
771 BTRFS_EXTENT_CSUM_OBJECTID)
773 path->slots[0] = slot;
775 key.offset = pk.offset;
779 ret = btrfs_del_items(trans, root, path,
780 path->slots[0], del_nr);
783 if (key.offset == bytenr)
785 } else if (key.offset < bytenr && csum_end > end_byte) {
786 unsigned long offset;
787 unsigned long shift_len;
788 unsigned long item_offset;
793 * Our bytes are in the middle of the csum,
794 * we need to split this item and insert a new one.
796 * But we can't drop the path because the
797 * csum could change, get removed, extended etc.
799 * The trick here is the max size of a csum item leaves
800 * enough room in the tree block for a single
801 * item header. So, we split the item in place,
802 * adding a new header pointing to the existing
803 * bytes. Then we loop around again and we have
804 * a nicely formed csum item that we can neatly
807 offset = (bytenr - key.offset) >> blocksize_bits;
810 shift_len = (len >> blocksize_bits) * csum_size;
812 item_offset = btrfs_item_ptr_offset(leaf,
815 memzero_extent_buffer(leaf, item_offset + offset,
820 * btrfs_split_item returns -EAGAIN when the
821 * item changed size or key
823 ret = btrfs_split_item(trans, root, path, &key, offset);
824 if (ret && ret != -EAGAIN) {
825 btrfs_abort_transaction(trans, ret);
830 key.offset = end_byte - 1;
832 truncate_one_csum(fs_info, path, &key, bytenr, len);
833 if (key.offset < bytenr)
836 btrfs_release_path(path);
838 btrfs_free_path(path);
842 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
843 struct btrfs_root *root,
844 struct btrfs_ordered_sum *sums)
846 struct btrfs_fs_info *fs_info = root->fs_info;
847 struct btrfs_key file_key;
848 struct btrfs_key found_key;
849 struct btrfs_path *path;
850 struct btrfs_csum_item *item;
851 struct btrfs_csum_item *item_end;
852 struct extent_buffer *leaf = NULL;
862 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
864 path = btrfs_alloc_path();
868 next_offset = (u64)-1;
870 bytenr = sums->bytenr + total_bytes;
871 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
872 file_key.offset = bytenr;
873 file_key.type = BTRFS_EXTENT_CSUM_KEY;
875 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
878 leaf = path->nodes[0];
879 item_end = btrfs_item_ptr(leaf, path->slots[0],
880 struct btrfs_csum_item);
881 item_end = (struct btrfs_csum_item *)((char *)item_end +
882 btrfs_item_size_nr(leaf, path->slots[0]));
886 if (ret != -EFBIG && ret != -ENOENT)
891 /* we found one, but it isn't big enough yet */
892 leaf = path->nodes[0];
893 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
894 if ((item_size / csum_size) >=
895 MAX_CSUM_ITEMS(fs_info, csum_size)) {
896 /* already at max size, make a new one */
900 int slot = path->slots[0] + 1;
901 /* we didn't find a csum item, insert one */
902 nritems = btrfs_header_nritems(path->nodes[0]);
903 if (!nritems || (path->slots[0] >= nritems - 1)) {
904 ret = btrfs_next_leaf(root, path);
907 } else if (ret > 0) {
911 slot = path->slots[0];
913 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
914 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
915 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
919 next_offset = found_key.offset;
925 * At this point, we know the tree has a checksum item that ends at an
926 * offset matching the start of the checksum range we want to insert.
927 * We try to extend that item as much as possible and then add as many
928 * checksums to it as they fit.
930 * First check if the leaf has enough free space for at least one
931 * checksum. If it has go directly to the item extension code, otherwise
932 * release the path and do a search for insertion before the extension.
934 if (btrfs_leaf_free_space(leaf) >= csum_size) {
935 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
936 csum_offset = (bytenr - found_key.offset) >>
937 fs_info->sb->s_blocksize_bits;
941 btrfs_release_path(path);
942 ret = btrfs_search_slot(trans, root, &file_key, path,
948 if (path->slots[0] == 0)
953 leaf = path->nodes[0];
954 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
955 csum_offset = (bytenr - found_key.offset) >>
956 fs_info->sb->s_blocksize_bits;
958 if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
959 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
960 csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
965 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
971 tmp = sums->len - total_bytes;
972 tmp >>= fs_info->sb->s_blocksize_bits;
975 extend_nr = max_t(int, 1, (int)tmp);
976 diff = (csum_offset + extend_nr) * csum_size;
978 MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
980 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
981 diff = min_t(u32, btrfs_leaf_free_space(leaf), diff);
985 btrfs_extend_item(path, diff);
991 btrfs_release_path(path);
996 tmp = sums->len - total_bytes;
997 tmp >>= fs_info->sb->s_blocksize_bits;
998 tmp = min(tmp, (next_offset - file_key.offset) >>
999 fs_info->sb->s_blocksize_bits);
1001 tmp = max_t(u64, 1, tmp);
1002 tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
1003 ins_size = csum_size * tmp;
1005 ins_size = csum_size;
1007 path->leave_spinning = 1;
1008 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
1010 path->leave_spinning = 0;
1013 if (WARN_ON(ret != 0))
1015 leaf = path->nodes[0];
1017 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
1018 item_end = (struct btrfs_csum_item *)((unsigned char *)item +
1019 btrfs_item_size_nr(leaf, path->slots[0]));
1020 item = (struct btrfs_csum_item *)((unsigned char *)item +
1021 csum_offset * csum_size);
1023 ins_size = (u32)(sums->len - total_bytes) >>
1024 fs_info->sb->s_blocksize_bits;
1025 ins_size *= csum_size;
1026 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
1028 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
1032 ins_size /= csum_size;
1033 total_bytes += ins_size * fs_info->sectorsize;
1035 btrfs_mark_buffer_dirty(path->nodes[0]);
1036 if (total_bytes < sums->len) {
1037 btrfs_release_path(path);
1042 btrfs_free_path(path);
1046 void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
1047 const struct btrfs_path *path,
1048 struct btrfs_file_extent_item *fi,
1049 const bool new_inline,
1050 struct extent_map *em)
1052 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1053 struct btrfs_root *root = inode->root;
1054 struct extent_buffer *leaf = path->nodes[0];
1055 const int slot = path->slots[0];
1056 struct btrfs_key key;
1057 u64 extent_start, extent_end;
1059 u8 type = btrfs_file_extent_type(leaf, fi);
1060 int compress_type = btrfs_file_extent_compression(leaf, fi);
1062 btrfs_item_key_to_cpu(leaf, &key, slot);
1063 extent_start = key.offset;
1064 extent_end = btrfs_file_extent_end(path);
1065 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1066 if (type == BTRFS_FILE_EXTENT_REG ||
1067 type == BTRFS_FILE_EXTENT_PREALLOC) {
1068 em->start = extent_start;
1069 em->len = extent_end - extent_start;
1070 em->orig_start = extent_start -
1071 btrfs_file_extent_offset(leaf, fi);
1072 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
1073 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1075 em->block_start = EXTENT_MAP_HOLE;
1078 if (compress_type != BTRFS_COMPRESS_NONE) {
1079 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
1080 em->compress_type = compress_type;
1081 em->block_start = bytenr;
1082 em->block_len = em->orig_block_len;
1084 bytenr += btrfs_file_extent_offset(leaf, fi);
1085 em->block_start = bytenr;
1086 em->block_len = em->len;
1087 if (type == BTRFS_FILE_EXTENT_PREALLOC)
1088 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
1090 } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1091 em->block_start = EXTENT_MAP_INLINE;
1092 em->start = extent_start;
1093 em->len = extent_end - extent_start;
1095 * Initialize orig_start and block_len with the same values
1096 * as in inode.c:btrfs_get_extent().
1098 em->orig_start = EXTENT_MAP_HOLE;
1099 em->block_len = (u64)-1;
1100 if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) {
1101 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
1102 em->compress_type = compress_type;
1106 "unknown file extent item type %d, inode %llu, offset %llu, "
1107 "root %llu", type, btrfs_ino(inode), extent_start,
1108 root->root_key.objectid);
1113 * Returns the end offset (non inclusive) of the file extent item the given path
1114 * points to. If it points to an inline extent, the returned offset is rounded
1115 * up to the sector size.
1117 u64 btrfs_file_extent_end(const struct btrfs_path *path)
1119 const struct extent_buffer *leaf = path->nodes[0];
1120 const int slot = path->slots[0];
1121 struct btrfs_file_extent_item *fi;
1122 struct btrfs_key key;
1125 btrfs_item_key_to_cpu(leaf, &key, slot);
1126 ASSERT(key.type == BTRFS_EXTENT_DATA_KEY);
1127 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1129 if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
1130 end = btrfs_file_extent_ram_bytes(leaf, fi);
1131 end = ALIGN(key.offset + end, leaf->fs_info->sectorsize);
1133 end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);