// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2007 Oracle. All rights reserved. */ #include #include #include #include #include #include #include "misc.h" #include "ctree.h" #include "disk-io.h" #include "transaction.h" #include "volumes.h" #include "print-tree.h" #include "compression.h" #define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \ sizeof(struct btrfs_item) * 2) / \ size) - 1)) #define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \ PAGE_SIZE)) /** * Set inode's size according to filesystem options * * @inode: inode we want to update the disk_i_size for * @new_i_size: i_size we want to set to, 0 if we use i_size * * With NO_HOLES set this simply sets the disk_is_size to whatever i_size_read() * returns as it is perfectly fine with a file that has holes without hole file * extent items. * * However without NO_HOLES we need to only return the area that is contiguous * from the 0 offset of the file. Otherwise we could end up adjust i_size up * to an extent that has a gap in between. * * Finally new_i_size should only be set in the case of truncate where we're not * ready to use i_size_read() as the limiter yet. */ void btrfs_inode_safe_disk_i_size_write(struct btrfs_inode *inode, u64 new_i_size) { struct btrfs_fs_info *fs_info = inode->root->fs_info; u64 start, end, i_size; int ret; i_size = new_i_size ?: i_size_read(&inode->vfs_inode); if (btrfs_fs_incompat(fs_info, NO_HOLES)) { inode->disk_i_size = i_size; return; } spin_lock(&inode->lock); ret = find_contiguous_extent_bit(&inode->file_extent_tree, 0, &start, &end, EXTENT_DIRTY); if (!ret && start == 0) i_size = min(i_size, end + 1); else i_size = 0; inode->disk_i_size = i_size; spin_unlock(&inode->lock); } /** * Mark range within a file as having a new extent inserted * * @inode: inode being modified * @start: start file offset of the file extent we've inserted * @len: logical length of the file extent item * * Call when we are inserting a new file extent where there was none before. * Does not need to call this in the case where we're replacing an existing file * extent, however if not sure it's fine to call this multiple times. * * The start and len must match the file extent item, so thus must be sectorsize * aligned. */ int btrfs_inode_set_file_extent_range(struct btrfs_inode *inode, u64 start, u64 len) { if (len == 0) return 0; ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize)); if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES)) return 0; return set_extent_bits(&inode->file_extent_tree, start, start + len - 1, EXTENT_DIRTY); } /** * Marks an inode range as not having a backing extent * * @inode: inode being modified * @start: start file offset of the file extent we've inserted * @len: logical length of the file extent item * * Called when we drop a file extent, for example when we truncate. Doesn't * need to be called for cases where we're replacing a file extent, like when * we've COWed a file extent. * * The start and len must match the file extent item, so thus must be sectorsize * aligned. */ int btrfs_inode_clear_file_extent_range(struct btrfs_inode *inode, u64 start, u64 len) { if (len == 0) return 0; ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize) || len == (u64)-1); if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES)) return 0; return clear_extent_bit(&inode->file_extent_tree, start, start + len - 1, EXTENT_DIRTY, 0, 0, NULL); } static inline u32 max_ordered_sum_bytes(struct btrfs_fs_info *fs_info, u16 csum_size) { u32 ncsums = (PAGE_SIZE - sizeof(struct btrfs_ordered_sum)) / csum_size; return ncsums * fs_info->sectorsize; } int btrfs_insert_hole_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid, u64 pos, u64 num_bytes) { int ret = 0; struct btrfs_file_extent_item *item; struct btrfs_key file_key; struct btrfs_path *path; struct extent_buffer *leaf; path = btrfs_alloc_path(); if (!path) return -ENOMEM; file_key.objectid = objectid; file_key.offset = pos; file_key.type = BTRFS_EXTENT_DATA_KEY; ret = btrfs_insert_empty_item(trans, root, path, &file_key, sizeof(*item)); if (ret < 0) goto out; BUG_ON(ret); /* Can't happen */ leaf = path->nodes[0]; item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_disk_bytenr(leaf, item, 0); btrfs_set_file_extent_disk_num_bytes(leaf, item, 0); btrfs_set_file_extent_offset(leaf, item, 0); btrfs_set_file_extent_num_bytes(leaf, item, num_bytes); btrfs_set_file_extent_ram_bytes(leaf, item, num_bytes); btrfs_set_file_extent_generation(leaf, item, trans->transid); btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG); btrfs_set_file_extent_compression(leaf, item, 0); btrfs_set_file_extent_encryption(leaf, item, 0); btrfs_set_file_extent_other_encoding(leaf, item, 0); btrfs_mark_buffer_dirty(leaf); out: btrfs_free_path(path); return ret; } static struct btrfs_csum_item * btrfs_lookup_csum(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 bytenr, int cow) { struct btrfs_fs_info *fs_info = root->fs_info; int ret; struct btrfs_key file_key; struct btrfs_key found_key; struct btrfs_csum_item *item; struct extent_buffer *leaf; u64 csum_offset = 0; const u32 csum_size = fs_info->csum_size; int csums_in_item; file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; file_key.offset = bytenr; file_key.type = BTRFS_EXTENT_CSUM_KEY; ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow); if (ret < 0) goto fail; leaf = path->nodes[0]; if (ret > 0) { ret = 1; if (path->slots[0] == 0) goto fail; path->slots[0]--; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.type != BTRFS_EXTENT_CSUM_KEY) goto fail; csum_offset = (bytenr - found_key.offset) >> fs_info->sectorsize_bits; csums_in_item = btrfs_item_size(leaf, path->slots[0]); csums_in_item /= csum_size; if (csum_offset == csums_in_item) { ret = -EFBIG; goto fail; } else if (csum_offset > csums_in_item) { goto fail; } } item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item); item = (struct btrfs_csum_item *)((unsigned char *)item + csum_offset * csum_size); return item; fail: if (ret > 0) ret = -ENOENT; return ERR_PTR(ret); } int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 objectid, u64 offset, int mod) { struct btrfs_key file_key; int ins_len = mod < 0 ? -1 : 0; int cow = mod != 0; file_key.objectid = objectid; file_key.offset = offset; file_key.type = BTRFS_EXTENT_DATA_KEY; return btrfs_search_slot(trans, root, &file_key, path, ins_len, cow); } /* * Find checksums for logical bytenr range [disk_bytenr, disk_bytenr + len) and * estore the result to @dst. * * Return >0 for the number of sectors we found. * Return 0 for the range [disk_bytenr, disk_bytenr + sectorsize) has no csum * for it. Caller may want to try next sector until one range is hit. * Return <0 for fatal error. */ static int search_csum_tree(struct btrfs_fs_info *fs_info, struct btrfs_path *path, u64 disk_bytenr, u64 len, u8 *dst) { struct btrfs_root *csum_root; struct btrfs_csum_item *item = NULL; struct btrfs_key key; const u32 sectorsize = fs_info->sectorsize; const u32 csum_size = fs_info->csum_size; u32 itemsize; int ret; u64 csum_start; u64 csum_len; ASSERT(IS_ALIGNED(disk_bytenr, sectorsize) && IS_ALIGNED(len, sectorsize)); /* Check if the current csum item covers disk_bytenr */ if (path->nodes[0]) { item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_csum_item); btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); itemsize = btrfs_item_size(path->nodes[0], path->slots[0]); csum_start = key.offset; csum_len = (itemsize / csum_size) * sectorsize; if (in_range(disk_bytenr, csum_start, csum_len)) goto found; } /* Current item doesn't contain the desired range, search again */ btrfs_release_path(path); csum_root = btrfs_csum_root(fs_info, disk_bytenr); item = btrfs_lookup_csum(NULL, csum_root, path, disk_bytenr, 0); if (IS_ERR(item)) { ret = PTR_ERR(item); goto out; } btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); itemsize = btrfs_item_size(path->nodes[0], path->slots[0]); csum_start = key.offset; csum_len = (itemsize / csum_size) * sectorsize; ASSERT(in_range(disk_bytenr, csum_start, csum_len)); found: ret = (min(csum_start + csum_len, disk_bytenr + len) - disk_bytenr) >> fs_info->sectorsize_bits; read_extent_buffer(path->nodes[0], dst, (unsigned long)item, ret * csum_size); out: if (ret == -ENOENT || ret == -EFBIG) ret = 0; return ret; } /* * Locate the file_offset of @cur_disk_bytenr of a @bio. * * Bio of btrfs represents read range of * [bi_sector << 9, bi_sector << 9 + bi_size). * Knowing this, we can iterate through each bvec to locate the page belong to * @cur_disk_bytenr and get the file offset. * * @inode is used to determine if the bvec page really belongs to @inode. * * Return 0 if we can't find the file offset * Return >0 if we find the file offset and restore it to @file_offset_ret */ static int search_file_offset_in_bio(struct bio *bio, struct inode *inode, u64 disk_bytenr, u64 *file_offset_ret) { struct bvec_iter iter; struct bio_vec bvec; u64 cur = bio->bi_iter.bi_sector << SECTOR_SHIFT; int ret = 0; bio_for_each_segment(bvec, bio, iter) { struct page *page = bvec.bv_page; if (cur > disk_bytenr) break; if (cur + bvec.bv_len <= disk_bytenr) { cur += bvec.bv_len; continue; } ASSERT(in_range(disk_bytenr, cur, bvec.bv_len)); if (page->mapping && page->mapping->host && page->mapping->host == inode) { ret = 1; *file_offset_ret = page_offset(page) + bvec.bv_offset + disk_bytenr - cur; break; } } return ret; } /** * Lookup the checksum for the read bio in csum tree. * * @inode: inode that the bio is for. * @bio: bio to look up. * @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return * checksum (nblocks = bio->bi_iter.bi_size / fs_info->sectorsize). If * NULL, the checksum buffer is allocated and returned in * btrfs_bio(bio)->csum instead. * * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise. */ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst) { struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct btrfs_bio *bbio = NULL; struct btrfs_path *path; const u32 sectorsize = fs_info->sectorsize; const u32 csum_size = fs_info->csum_size; u32 orig_len = bio->bi_iter.bi_size; u64 orig_disk_bytenr = bio->bi_iter.bi_sector << SECTOR_SHIFT; u64 cur_disk_bytenr; u8 *csum; const unsigned int nblocks = orig_len >> fs_info->sectorsize_bits; int count = 0; blk_status_t ret = BLK_STS_OK; if ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) || test_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state)) return BLK_STS_OK; /* * This function is only called for read bio. * * This means two things: * - All our csums should only be in csum tree * No ordered extents csums, as ordered extents are only for write * path. * - No need to bother any other info from bvec * Since we're looking up csums, the only important info is the * disk_bytenr and the length, which can be extracted from bi_iter * directly. */ ASSERT(bio_op(bio) == REQ_OP_READ); path = btrfs_alloc_path(); if (!path) return BLK_STS_RESOURCE; if (!dst) { bbio = btrfs_bio(bio); if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) { bbio->csum = kmalloc_array(nblocks, csum_size, GFP_NOFS); if (!bbio->csum) { btrfs_free_path(path); return BLK_STS_RESOURCE; } } else { bbio->csum = bbio->csum_inline; } csum = bbio->csum; } else { csum = dst; } /* * If requested number of sectors is larger than one leaf can contain, * kick the readahead for csum tree. */ if (nblocks > fs_info->csums_per_leaf) path->reada = READA_FORWARD; /* * the free space stuff is only read when it hasn't been * updated in the current transaction. So, we can safely * read from the commit root and sidestep a nasty deadlock * between reading the free space cache and updating the csum tree. */ if (btrfs_is_free_space_inode(BTRFS_I(inode))) { path->search_commit_root = 1; path->skip_locking = 1; } for (cur_disk_bytenr = orig_disk_bytenr; cur_disk_bytenr < orig_disk_bytenr + orig_len; cur_disk_bytenr += (count * sectorsize)) { u64 search_len = orig_disk_bytenr + orig_len - cur_disk_bytenr; unsigned int sector_offset; u8 *csum_dst; /* * Although both cur_disk_bytenr and orig_disk_bytenr is u64, * we're calculating the offset to the bio start. * * Bio size is limited to UINT_MAX, thus unsigned int is large * enough to contain the raw result, not to mention the right * shifted result. */ ASSERT(cur_disk_bytenr - orig_disk_bytenr < UINT_MAX); sector_offset = (cur_disk_bytenr - orig_disk_bytenr) >> fs_info->sectorsize_bits; csum_dst = csum + sector_offset * csum_size; count = search_csum_tree(fs_info, path, cur_disk_bytenr, search_len, csum_dst); if (count < 0) { ret = errno_to_blk_status(count); if (bbio) btrfs_bio_free_csum(bbio); break; } /* * We didn't find a csum for this range. We need to make sure * we complain loudly about this, because we are not NODATASUM. * * However for the DATA_RELOC inode we could potentially be * relocating data extents for a NODATASUM inode, so the inode * itself won't be marked with NODATASUM, but the extent we're * copying is in fact NODATASUM. If we don't find a csum we * assume this is the case. */ if (count == 0) { memset(csum_dst, 0, csum_size); count = 1; if (BTRFS_I(inode)->root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) { u64 file_offset; int ret; ret = search_file_offset_in_bio(bio, inode, cur_disk_bytenr, &file_offset); if (ret) set_extent_bits(io_tree, file_offset, file_offset + sectorsize - 1, EXTENT_NODATASUM); } else { btrfs_warn_rl(fs_info, "csum hole found for disk bytenr range [%llu, %llu)", cur_disk_bytenr, cur_disk_bytenr + sectorsize); } } } btrfs_free_path(path); return ret; } int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end, struct list_head *list, int search_commit) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_key key; struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_ordered_sum *sums; struct btrfs_csum_item *item; LIST_HEAD(tmplist); unsigned long offset; int ret; size_t size; u64 csum_end; const u32 csum_size = fs_info->csum_size; ASSERT(IS_ALIGNED(start, fs_info->sectorsize) && IS_ALIGNED(end + 1, fs_info->sectorsize)); path = btrfs_alloc_path(); if (!path) return -ENOMEM; if (search_commit) { path->skip_locking = 1; path->reada = READA_FORWARD; path->search_commit_root = 1; } key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; key.offset = start; key.type = BTRFS_EXTENT_CSUM_KEY; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto fail; if (ret > 0 && path->slots[0] > 0) { leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1); if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID && key.type == BTRFS_EXTENT_CSUM_KEY) { offset = (start - key.offset) >> fs_info->sectorsize_bits; if (offset * csum_size < btrfs_item_size(leaf, path->slots[0] - 1)) path->slots[0]--; } } while (start <= end) { leaf = path->nodes[0]; if (path->slots[0] >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) goto fail; if (ret > 0) break; leaf = path->nodes[0]; } btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || key.type != BTRFS_EXTENT_CSUM_KEY || key.offset > end) break; if (key.offset > start) start = key.offset; size = btrfs_item_size(leaf, path->slots[0]); csum_end = key.offset + (size / csum_size) * fs_info->sectorsize; if (csum_end <= start) { path->slots[0]++; continue; } csum_end = min(csum_end, end + 1); item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_csum_item); while (start < csum_end) { size = min_t(size_t, csum_end - start, max_ordered_sum_bytes(fs_info, csum_size)); sums = kzalloc(btrfs_ordered_sum_size(fs_info, size), GFP_NOFS); if (!sums) { ret = -ENOMEM; goto fail; } sums->bytenr = start; sums->len = (int)size; offset = (start - key.offset) >> fs_info->sectorsize_bits; offset *= csum_size; size >>= fs_info->sectorsize_bits; read_extent_buffer(path->nodes[0], sums->sums, ((unsigned long)item) + offset, csum_size * size); start += fs_info->sectorsize * size; list_add_tail(&sums->list, &tmplist); } path->slots[0]++; } ret = 0; fail: while (ret < 0 && !list_empty(&tmplist)) { sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list); list_del(&sums->list); kfree(sums); } list_splice_tail(&tmplist, list); btrfs_free_path(path); return ret; } /** * Calculate checksums of the data contained inside a bio * * @inode: Owner of the data inside the bio * @bio: Contains the data to be checksummed * @offset: If (u64)-1, @bio may contain discontiguous bio vecs, so the * file offsets are determined from the page offsets in the bio. * Otherwise, this is the starting file offset of the bio vecs in * @bio, which must be contiguous. * @one_ordered: If true, @bio only refers to one ordered extent. */ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio, u64 offset, bool one_ordered) { struct btrfs_fs_info *fs_info = inode->root->fs_info; SHASH_DESC_ON_STACK(shash, fs_info->csum_shash); struct btrfs_ordered_sum *sums; struct btrfs_ordered_extent *ordered = NULL; const bool use_page_offsets = (offset == (u64)-1); char *data; struct bvec_iter iter; struct bio_vec bvec; int index; unsigned int blockcount; unsigned long total_bytes = 0; unsigned long this_sum_bytes = 0; int i; unsigned nofs_flag; nofs_flag = memalloc_nofs_save(); sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size), GFP_KERNEL); memalloc_nofs_restore(nofs_flag); if (!sums) return BLK_STS_RESOURCE; sums->len = bio->bi_iter.bi_size; INIT_LIST_HEAD(&sums->list); sums->bytenr = bio->bi_iter.bi_sector << 9; index = 0; shash->tfm = fs_info->csum_shash; bio_for_each_segment(bvec, bio, iter) { if (use_page_offsets) offset = page_offset(bvec.bv_page) + bvec.bv_offset; if (!ordered) { ordered = btrfs_lookup_ordered_extent(inode, offset); /* * The bio range is not covered by any ordered extent, * must be a code logic error. */ if (unlikely(!ordered)) { WARN(1, KERN_WARNING "no ordered extent for root %llu ino %llu offset %llu\n", inode->root->root_key.objectid, btrfs_ino(inode), offset); kvfree(sums); return BLK_STS_IOERR; } } blockcount = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len + fs_info->sectorsize - 1); for (i = 0; i < blockcount; i++) { if (!one_ordered && !in_range(offset, ordered->file_offset, ordered->num_bytes)) { unsigned long bytes_left; sums->len = this_sum_bytes; this_sum_bytes = 0; btrfs_add_ordered_sum(ordered, sums); btrfs_put_ordered_extent(ordered); bytes_left = bio->bi_iter.bi_size - total_bytes; nofs_flag = memalloc_nofs_save(); sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bytes_left), GFP_KERNEL); memalloc_nofs_restore(nofs_flag); BUG_ON(!sums); /* -ENOMEM */ sums->len = bytes_left; ordered = btrfs_lookup_ordered_extent(inode, offset); ASSERT(ordered); /* Logic error */ sums->bytenr = (bio->bi_iter.bi_sector << 9) + total_bytes; index = 0; } data = bvec_kmap_local(&bvec); crypto_shash_digest(shash, data + (i * fs_info->sectorsize), fs_info->sectorsize, sums->sums + index); kunmap_local(data); index += fs_info->csum_size; offset += fs_info->sectorsize; this_sum_bytes += fs_info->sectorsize; total_bytes += fs_info->sectorsize; } } this_sum_bytes = 0; btrfs_add_ordered_sum(ordered, sums); btrfs_put_ordered_extent(ordered); return 0; } /* * helper function for csum removal, this expects the * key to describe the csum pointed to by the path, and it expects * the csum to overlap the range [bytenr, len] * * The csum should not be entirely contained in the range and the * range should not be entirely contained in the csum. * * This calls btrfs_truncate_item with the correct args based on the * overlap, and fixes up the key as required. */ static noinline void truncate_one_csum(struct btrfs_fs_info *fs_info, struct btrfs_path *path, struct btrfs_key *key, u64 bytenr, u64 len) { struct extent_buffer *leaf; const u32 csum_size = fs_info->csum_size; u64 csum_end; u64 end_byte = bytenr + len; u32 blocksize_bits = fs_info->sectorsize_bits; leaf = path->nodes[0]; csum_end = btrfs_item_size(leaf, path->slots[0]) / csum_size; csum_end <<= blocksize_bits; csum_end += key->offset; if (key->offset < bytenr && csum_end <= end_byte) { /* * [ bytenr - len ] * [ ] * [csum ] * A simple truncate off the end of the item */ u32 new_size = (bytenr - key->offset) >> blocksize_bits; new_size *= csum_size; btrfs_truncate_item(path, new_size, 1); } else if (key->offset >= bytenr && csum_end > end_byte && end_byte > key->offset) { /* * [ bytenr - len ] * [ ] * [csum ] * we need to truncate from the beginning of the csum */ u32 new_size = (csum_end - end_byte) >> blocksize_bits; new_size *= csum_size; btrfs_truncate_item(path, new_size, 0); key->offset = end_byte; btrfs_set_item_key_safe(fs_info, path, key); } else { BUG(); } } /* * deletes the csum items from the csum tree for a given * range of bytes. */ int btrfs_del_csums(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 len) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_path *path; struct btrfs_key key; u64 end_byte = bytenr + len; u64 csum_end; struct extent_buffer *leaf; int ret = 0; const u32 csum_size = fs_info->csum_size; u32 blocksize_bits = fs_info->sectorsize_bits; ASSERT(root->root_key.objectid == BTRFS_CSUM_TREE_OBJECTID || root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID); path = btrfs_alloc_path(); if (!path) return -ENOMEM; while (1) { key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; key.offset = end_byte - 1; key.type = BTRFS_EXTENT_CSUM_KEY; ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret > 0) { ret = 0; if (path->slots[0] == 0) break; path->slots[0]--; } else if (ret < 0) { break; } leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || key.type != BTRFS_EXTENT_CSUM_KEY) { break; } if (key.offset >= end_byte) break; csum_end = btrfs_item_size(leaf, path->slots[0]) / csum_size; csum_end <<= blocksize_bits; csum_end += key.offset; /* this csum ends before we start, we're done */ if (csum_end <= bytenr) break; /* delete the entire item, it is inside our range */ if (key.offset >= bytenr && csum_end <= end_byte) { int del_nr = 1; /* * Check how many csum items preceding this one in this * leaf correspond to our range and then delete them all * at once. */ if (key.offset > bytenr && path->slots[0] > 0) { int slot = path->slots[0] - 1; while (slot >= 0) { struct btrfs_key pk; btrfs_item_key_to_cpu(leaf, &pk, slot); if (pk.offset < bytenr || pk.type != BTRFS_EXTENT_CSUM_KEY || pk.objectid != BTRFS_EXTENT_CSUM_OBJECTID) break; path->slots[0] = slot; del_nr++; key.offset = pk.offset; slot--; } } ret = btrfs_del_items(trans, root, path, path->slots[0], del_nr); if (ret) break; if (key.offset == bytenr) break; } else if (key.offset < bytenr && csum_end > end_byte) { unsigned long offset; unsigned long shift_len; unsigned long item_offset; /* * [ bytenr - len ] * [csum ] * * Our bytes are in the middle of the csum, * we need to split this item and insert a new one. * * But we can't drop the path because the * csum could change, get removed, extended etc. * * The trick here is the max size of a csum item leaves * enough room in the tree block for a single * item header. So, we split the item in place, * adding a new header pointing to the existing * bytes. Then we loop around again and we have * a nicely formed csum item that we can neatly * truncate. */ offset = (bytenr - key.offset) >> blocksize_bits; offset *= csum_size; shift_len = (len >> blocksize_bits) * csum_size; item_offset = btrfs_item_ptr_offset(leaf, path->slots[0]); memzero_extent_buffer(leaf, item_offset + offset, shift_len); key.offset = bytenr; /* * btrfs_split_item returns -EAGAIN when the * item changed size or key */ ret = btrfs_split_item(trans, root, path, &key, offset); if (ret && ret != -EAGAIN) { btrfs_abort_transaction(trans, ret); break; } ret = 0; key.offset = end_byte - 1; } else { truncate_one_csum(fs_info, path, &key, bytenr, len); if (key.offset < bytenr) break; } btrfs_release_path(path); } btrfs_free_path(path); return ret; } static int find_next_csum_offset(struct btrfs_root *root, struct btrfs_path *path, u64 *next_offset) { const u32 nritems = btrfs_header_nritems(path->nodes[0]); struct btrfs_key found_key; int slot = path->slots[0] + 1; int ret; if (nritems == 0 || slot >= nritems) { ret = btrfs_next_leaf(root, path); if (ret < 0) { return ret; } else if (ret > 0) { *next_offset = (u64)-1; return 0; } slot = path->slots[0]; } btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot); if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || found_key.type != BTRFS_EXTENT_CSUM_KEY) *next_offset = (u64)-1; else *next_offset = found_key.offset; return 0; } int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_ordered_sum *sums) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_key file_key; struct btrfs_key found_key; struct btrfs_path *path; struct btrfs_csum_item *item; struct btrfs_csum_item *item_end; struct extent_buffer *leaf = NULL; u64 next_offset; u64 total_bytes = 0; u64 csum_offset; u64 bytenr; u32 ins_size; int index = 0; int found_next; int ret; const u32 csum_size = fs_info->csum_size; path = btrfs_alloc_path(); if (!path) return -ENOMEM; again: next_offset = (u64)-1; found_next = 0; bytenr = sums->bytenr + total_bytes; file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; file_key.offset = bytenr; file_key.type = BTRFS_EXTENT_CSUM_KEY; item = btrfs_lookup_csum(trans, root, path, bytenr, 1); if (!IS_ERR(item)) { ret = 0; leaf = path->nodes[0]; item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item); item_end = (struct btrfs_csum_item *)((char *)item_end + btrfs_item_size(leaf, path->slots[0])); goto found; } ret = PTR_ERR(item); if (ret != -EFBIG && ret != -ENOENT) goto out; if (ret == -EFBIG) { u32 item_size; /* we found one, but it isn't big enough yet */ leaf = path->nodes[0]; item_size = btrfs_item_size(leaf, path->slots[0]); if ((item_size / csum_size) >= MAX_CSUM_ITEMS(fs_info, csum_size)) { /* already at max size, make a new one */ goto insert; } } else { /* We didn't find a csum item, insert one. */ ret = find_next_csum_offset(root, path, &next_offset); if (ret < 0) goto out; found_next = 1; goto insert; } /* * At this point, we know the tree has a checksum item that ends at an * offset matching the start of the checksum range we want to insert. * We try to extend that item as much as possible and then add as many * checksums to it as they fit. * * First check if the leaf has enough free space for at least one * checksum. If it has go directly to the item extension code, otherwise * release the path and do a search for insertion before the extension. */ if (btrfs_leaf_free_space(leaf) >= csum_size) { btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); csum_offset = (bytenr - found_key.offset) >> fs_info->sectorsize_bits; goto extend_csum; } btrfs_release_path(path); path->search_for_extension = 1; ret = btrfs_search_slot(trans, root, &file_key, path, csum_size, 1); path->search_for_extension = 0; if (ret < 0) goto out; if (ret > 0) { if (path->slots[0] == 0) goto insert; path->slots[0]--; } leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); csum_offset = (bytenr - found_key.offset) >> fs_info->sectorsize_bits; if (found_key.type != BTRFS_EXTENT_CSUM_KEY || found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) { goto insert; } extend_csum: if (csum_offset == btrfs_item_size(leaf, path->slots[0]) / csum_size) { int extend_nr; u64 tmp; u32 diff; tmp = sums->len - total_bytes; tmp >>= fs_info->sectorsize_bits; WARN_ON(tmp < 1); extend_nr = max_t(int, 1, tmp); /* * A log tree can already have checksum items with a subset of * the checksums we are trying to log. This can happen after * doing a sequence of partial writes into prealloc extents and * fsyncs in between, with a full fsync logging a larger subrange * of an extent for which a previous fast fsync logged a smaller * subrange. And this happens in particular due to merging file * extent items when we complete an ordered extent for a range * covered by a prealloc extent - this is done at * btrfs_mark_extent_written(). * * So if we try to extend the previous checksum item, which has * a range that ends at the start of the range we want to insert, * make sure we don't extend beyond the start offset of the next * checksum item. If we are at the last item in the leaf, then * forget the optimization of extending and add a new checksum * item - it is not worth the complexity of releasing the path, * getting the first key for the next leaf, repeat the btree * search, etc, because log trees are temporary anyway and it * would only save a few bytes of leaf space. */ if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { if (path->slots[0] + 1 >= btrfs_header_nritems(path->nodes[0])) { ret = find_next_csum_offset(root, path, &next_offset); if (ret < 0) goto out; found_next = 1; goto insert; } ret = find_next_csum_offset(root, path, &next_offset); if (ret < 0) goto out; tmp = (next_offset - bytenr) >> fs_info->sectorsize_bits; if (tmp <= INT_MAX) extend_nr = min_t(int, extend_nr, tmp); } diff = (csum_offset + extend_nr) * csum_size; diff = min(diff, MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size); diff = diff - btrfs_item_size(leaf, path->slots[0]); diff = min_t(u32, btrfs_leaf_free_space(leaf), diff); diff /= csum_size; diff *= csum_size; btrfs_extend_item(path, diff); ret = 0; goto csum; } insert: btrfs_release_path(path); csum_offset = 0; if (found_next) { u64 tmp; tmp = sums->len - total_bytes; tmp >>= fs_info->sectorsize_bits; tmp = min(tmp, (next_offset - file_key.offset) >> fs_info->sectorsize_bits); tmp = max_t(u64, 1, tmp); tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size)); ins_size = csum_size * tmp; } else { ins_size = csum_size; } ret = btrfs_insert_empty_item(trans, root, path, &file_key, ins_size); if (ret < 0) goto out; if (WARN_ON(ret != 0)) goto out; leaf = path->nodes[0]; csum: item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item); item_end = (struct btrfs_csum_item *)((unsigned char *)item + btrfs_item_size(leaf, path->slots[0])); item = (struct btrfs_csum_item *)((unsigned char *)item + csum_offset * csum_size); found: ins_size = (u32)(sums->len - total_bytes) >> fs_info->sectorsize_bits; ins_size *= csum_size; ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item, ins_size); write_extent_buffer(leaf, sums->sums + index, (unsigned long)item, ins_size); index += ins_size; ins_size /= csum_size; total_bytes += ins_size * fs_info->sectorsize; btrfs_mark_buffer_dirty(path->nodes[0]); if (total_bytes < sums->len) { btrfs_release_path(path); cond_resched(); goto again; } out: btrfs_free_path(path); return ret; } void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode, const struct btrfs_path *path, struct btrfs_file_extent_item *fi, const bool new_inline, struct extent_map *em) { struct btrfs_fs_info *fs_info = inode->root->fs_info; struct btrfs_root *root = inode->root; struct extent_buffer *leaf = path->nodes[0]; const int slot = path->slots[0]; struct btrfs_key key; u64 extent_start, extent_end; u64 bytenr; u8 type = btrfs_file_extent_type(leaf, fi); int compress_type = btrfs_file_extent_compression(leaf, fi); btrfs_item_key_to_cpu(leaf, &key, slot); extent_start = key.offset; extent_end = btrfs_file_extent_end(path); em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); em->generation = btrfs_file_extent_generation(leaf, fi); if (type == BTRFS_FILE_EXTENT_REG || type == BTRFS_FILE_EXTENT_PREALLOC) { em->start = extent_start; em->len = extent_end - extent_start; em->orig_start = extent_start - btrfs_file_extent_offset(leaf, fi); em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi); bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); if (bytenr == 0) { em->block_start = EXTENT_MAP_HOLE; return; } if (compress_type != BTRFS_COMPRESS_NONE) { set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); em->compress_type = compress_type; em->block_start = bytenr; em->block_len = em->orig_block_len; } else { bytenr += btrfs_file_extent_offset(leaf, fi); em->block_start = bytenr; em->block_len = em->len; if (type == BTRFS_FILE_EXTENT_PREALLOC) set_bit(EXTENT_FLAG_PREALLOC, &em->flags); } } else if (type == BTRFS_FILE_EXTENT_INLINE) { em->block_start = EXTENT_MAP_INLINE; em->start = extent_start; em->len = extent_end - extent_start; /* * Initialize orig_start and block_len with the same values * as in inode.c:btrfs_get_extent(). */ em->orig_start = EXTENT_MAP_HOLE; em->block_len = (u64)-1; if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) { set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); em->compress_type = compress_type; } } else { btrfs_err(fs_info, "unknown file extent item type %d, inode %llu, offset %llu, " "root %llu", type, btrfs_ino(inode), extent_start, root->root_key.objectid); } } /* * Returns the end offset (non inclusive) of the file extent item the given path * points to. If it points to an inline extent, the returned offset is rounded * up to the sector size. */ u64 btrfs_file_extent_end(const struct btrfs_path *path) { const struct extent_buffer *leaf = path->nodes[0]; const int slot = path->slots[0]; struct btrfs_file_extent_item *fi; struct btrfs_key key; u64 end; btrfs_item_key_to_cpu(leaf, &key, slot); ASSERT(key.type == BTRFS_EXTENT_DATA_KEY); fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) { end = btrfs_file_extent_ram_bytes(leaf, fi); end = ALIGN(key.offset + end, leaf->fs_info->sectorsize); } else { end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); } return end; }