diff options
Diffstat (limited to 'fs/btrfs/file-item.c')
| -rw-r--r-- | fs/btrfs/file-item.c | 1304 |
1 files changed, 1304 insertions, 0 deletions
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c new file mode 100644 index 000000000..14478da87 --- /dev/null +++ b/fs/btrfs/file-item.c @@ -0,0 +1,1304 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2007 Oracle. All rights reserved. + */ + +#include <linux/bio.h> +#include <linux/slab.h> +#include <linux/pagemap.h> +#include <linux/highmem.h> +#include <linux/sched/mm.h> +#include <crypto/hash.h> +#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; + + spin_lock(&inode->lock); + 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; + goto out_unlock; + } + + 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; +out_unlock: + 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, 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; +} + +/* + * Calculate the total size needed to allocate for an ordered sum structure + * spanning @bytes in the file. + */ +static int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info, unsigned long bytes) +{ + int num_sectors = (int)DIV_ROUND_UP(bytes, fs_info->sectorsize); + + return sizeof(struct btrfs_ordered_sum) + num_sectors * fs_info->csum_size; +} + +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, + bool nowait) +{ + 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; + + path->nowait = nowait; + 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 = 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); + if (!sums) + return BLK_STS_RESOURCE; + + 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; +} |