diff options
Diffstat (limited to 'fs/btrfs/file-item.c')
| -rw-r--r-- | fs/btrfs/file-item.c | 1001 |
1 files changed, 1001 insertions, 0 deletions
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c new file mode 100644 index 000000000..40db31b69 --- /dev/null +++ b/fs/btrfs/file-item.c @@ -0,0 +1,1001 @@ +// 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 "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)) + +#define MAX_ORDERED_SUM_BYTES(fs_info) ((PAGE_SIZE - \ + sizeof(struct btrfs_ordered_sum)) / \ + sizeof(u32) * (fs_info)->sectorsize) + +int btrfs_insert_file_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 objectid, u64 pos, + u64 disk_offset, u64 disk_num_bytes, + u64 num_bytes, u64 offset, u64 ram_bytes, + u8 compression, u8 encryption, u16 other_encoding) +{ + 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; + + path->leave_spinning = 1; + 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, disk_offset); + btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes); + btrfs_set_file_extent_offset(leaf, item, offset); + btrfs_set_file_extent_num_bytes(leaf, item, num_bytes); + btrfs_set_file_extent_ram_bytes(leaf, item, ram_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, compression); + btrfs_set_file_extent_encryption(leaf, item, encryption); + btrfs_set_file_extent_other_encoding(leaf, item, other_encoding); + + 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; + u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); + 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->sb->s_blocksize_bits; + csums_in_item = btrfs_item_size_nr(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) +{ + int ret; + 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; + ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow); + return ret; +} + +static void btrfs_io_bio_endio_readpage(struct btrfs_io_bio *bio, int err) +{ + kfree(bio->csum_allocated); +} + +static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, + u64 logical_offset, u32 *dst, int dio) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct bio_vec bvec; + struct bvec_iter iter; + struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); + struct btrfs_csum_item *item = NULL; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_path *path; + u8 *csum; + u64 offset = 0; + u64 item_start_offset = 0; + u64 item_last_offset = 0; + u64 disk_bytenr; + u64 page_bytes_left; + u32 diff; + int nblocks; + int count = 0; + u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); + + path = btrfs_alloc_path(); + if (!path) + return BLK_STS_RESOURCE; + + nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits; + if (!dst) { + if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) { + btrfs_bio->csum_allocated = kmalloc_array(nblocks, + csum_size, GFP_NOFS); + if (!btrfs_bio->csum_allocated) { + btrfs_free_path(path); + return BLK_STS_RESOURCE; + } + btrfs_bio->csum = btrfs_bio->csum_allocated; + btrfs_bio->end_io = btrfs_io_bio_endio_readpage; + } else { + btrfs_bio->csum = btrfs_bio->csum_inline; + } + csum = btrfs_bio->csum; + } else { + csum = (u8 *)dst; + } + + if (bio->bi_iter.bi_size > PAGE_SIZE * 8) + 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; + } + + disk_bytenr = (u64)bio->bi_iter.bi_sector << 9; + if (dio) + offset = logical_offset; + + bio_for_each_segment(bvec, bio, iter) { + page_bytes_left = bvec.bv_len; + if (count) + goto next; + + if (!dio) + offset = page_offset(bvec.bv_page) + bvec.bv_offset; + count = btrfs_find_ordered_sum(inode, offset, disk_bytenr, + (u32 *)csum, nblocks); + if (count) + goto found; + + if (!item || disk_bytenr < item_start_offset || + disk_bytenr >= item_last_offset) { + struct btrfs_key found_key; + u32 item_size; + + if (item) + btrfs_release_path(path); + item = btrfs_lookup_csum(NULL, fs_info->csum_root, + path, disk_bytenr, 0); + if (IS_ERR(item)) { + count = 1; + memset(csum, 0, csum_size); + if (BTRFS_I(inode)->root->root_key.objectid == + BTRFS_DATA_RELOC_TREE_OBJECTID) { + set_extent_bits(io_tree, offset, + offset + fs_info->sectorsize - 1, + EXTENT_NODATASUM); + } else { + btrfs_info_rl(fs_info, + "no csum found for inode %llu start %llu", + btrfs_ino(BTRFS_I(inode)), offset); + } + item = NULL; + btrfs_release_path(path); + goto found; + } + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + + item_start_offset = found_key.offset; + item_size = btrfs_item_size_nr(path->nodes[0], + path->slots[0]); + item_last_offset = item_start_offset + + (item_size / csum_size) * + fs_info->sectorsize; + item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_csum_item); + } + /* + * this byte range must be able to fit inside + * a single leaf so it will also fit inside a u32 + */ + diff = disk_bytenr - item_start_offset; + diff = diff / fs_info->sectorsize; + diff = diff * csum_size; + count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >> + inode->i_sb->s_blocksize_bits); + read_extent_buffer(path->nodes[0], csum, + ((unsigned long)item) + diff, + csum_size * count); +found: + csum += count * csum_size; + nblocks -= count; +next: + while (count > 0) { + count--; + disk_bytenr += fs_info->sectorsize; + offset += fs_info->sectorsize; + page_bytes_left -= fs_info->sectorsize; + if (!page_bytes_left) + break; /* move to next bio */ + } + } + + WARN_ON_ONCE(count); + btrfs_free_path(path); + return 0; +} + +blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u32 *dst) +{ + return __btrfs_lookup_bio_sums(inode, bio, 0, dst, 0); +} + +blk_status_t btrfs_lookup_bio_sums_dio(struct inode *inode, struct bio *bio, u64 offset) +{ + return __btrfs_lookup_bio_sums(inode, bio, offset, NULL, 1); +} + +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; + u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); + + 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->sb->s_blocksize_bits; + if (offset * csum_size < + btrfs_item_size_nr(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_nr(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)); + 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->sb->s_blocksize_bits; + offset *= csum_size; + size >>= fs_info->sb->s_blocksize_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; +} + +blk_status_t btrfs_csum_one_bio(struct inode *inode, struct bio *bio, + u64 file_start, int contig) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_ordered_sum *sums; + struct btrfs_ordered_extent *ordered = NULL; + char *data; + struct bvec_iter iter; + struct bio_vec bvec; + int index; + int nr_sectors; + unsigned long total_bytes = 0; + unsigned long this_sum_bytes = 0; + int i; + u64 offset; + + sums = kzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size), + GFP_NOFS); + if (!sums) + return BLK_STS_RESOURCE; + + sums->len = bio->bi_iter.bi_size; + INIT_LIST_HEAD(&sums->list); + + if (contig) + offset = file_start; + else + offset = 0; /* shut up gcc */ + + sums->bytenr = (u64)bio->bi_iter.bi_sector << 9; + index = 0; + + bio_for_each_segment(bvec, bio, iter) { + if (!contig) + offset = page_offset(bvec.bv_page) + bvec.bv_offset; + + if (!ordered) { + ordered = btrfs_lookup_ordered_extent(inode, offset); + BUG_ON(!ordered); /* Logic error */ + } + + data = kmap_atomic(bvec.bv_page); + + nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, + bvec.bv_len + fs_info->sectorsize + - 1); + + for (i = 0; i < nr_sectors; i++) { + if (offset >= ordered->file_offset + ordered->len || + offset < ordered->file_offset) { + unsigned long bytes_left; + + kunmap_atomic(data); + sums->len = this_sum_bytes; + this_sum_bytes = 0; + btrfs_add_ordered_sum(inode, ordered, sums); + btrfs_put_ordered_extent(ordered); + + bytes_left = bio->bi_iter.bi_size - total_bytes; + + sums = kzalloc(btrfs_ordered_sum_size(fs_info, bytes_left), + GFP_NOFS); + BUG_ON(!sums); /* -ENOMEM */ + sums->len = bytes_left; + ordered = btrfs_lookup_ordered_extent(inode, + offset); + ASSERT(ordered); /* Logic error */ + sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9) + + total_bytes; + index = 0; + + data = kmap_atomic(bvec.bv_page); + } + + sums->sums[index] = ~(u32)0; + sums->sums[index] + = btrfs_csum_data(data + bvec.bv_offset + + (i * fs_info->sectorsize), + sums->sums[index], + fs_info->sectorsize); + btrfs_csum_final(sums->sums[index], + (char *)(sums->sums + index)); + index++; + offset += fs_info->sectorsize; + this_sum_bytes += fs_info->sectorsize; + total_bytes += fs_info->sectorsize; + } + + kunmap_atomic(data); + } + this_sum_bytes = 0; + btrfs_add_ordered_sum(inode, 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; + u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); + u64 csum_end; + u64 end_byte = bytenr + len; + u32 blocksize_bits = fs_info->sb->s_blocksize_bits; + + leaf = path->nodes[0]; + csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size; + csum_end <<= fs_info->sb->s_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(fs_info, 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(fs_info, 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; + u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); + int blocksize_bits = fs_info->sb->s_blocksize_bits; + + ASSERT(root == fs_info->csum_root || + 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; + + path->leave_spinning = 1; + 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_nr(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; +} + +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 nritems; + u32 ins_size; + int index = 0; + int found_next; + int ret; + u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); + + 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_nr(leaf, path->slots[0])); + goto found; + } + ret = PTR_ERR(item); + if (ret != -EFBIG && ret != -ENOENT) + goto fail_unlock; + + 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_nr(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 { + int slot = path->slots[0] + 1; + /* we didn't find a csum item, insert one */ + nritems = btrfs_header_nritems(path->nodes[0]); + if (!nritems || (path->slots[0] >= nritems - 1)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) { + goto out; + } else if (ret > 0) { + found_next = 1; + goto insert; + } + 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) { + found_next = 1; + goto insert; + } + next_offset = found_key.offset; + found_next = 1; + goto insert; + } + + /* + * at this point, we know the tree has an item, but it isn't big + * enough yet to put our csum in. Grow it + */ + btrfs_release_path(path); + ret = btrfs_search_slot(trans, root, &file_key, path, + csum_size, 1); + if (ret < 0) + goto fail_unlock; + + 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->sb->s_blocksize_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; + } + + if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) / + csum_size) { + int extend_nr; + u64 tmp; + u32 diff; + u32 free_space; + + if (btrfs_leaf_free_space(fs_info, leaf) < + sizeof(struct btrfs_item) + csum_size * 2) + goto insert; + + free_space = btrfs_leaf_free_space(fs_info, leaf) - + sizeof(struct btrfs_item) - csum_size; + tmp = sums->len - total_bytes; + tmp >>= fs_info->sb->s_blocksize_bits; + WARN_ON(tmp < 1); + + extend_nr = max_t(int, 1, (int)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_nr(leaf, path->slots[0]); + diff = min(free_space, diff); + diff /= csum_size; + diff *= csum_size; + + btrfs_extend_item(fs_info, 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->sb->s_blocksize_bits; + tmp = min(tmp, (next_offset - file_key.offset) >> + fs_info->sb->s_blocksize_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; + } + path->leave_spinning = 1; + ret = btrfs_insert_empty_item(trans, root, path, &file_key, + ins_size); + path->leave_spinning = 0; + if (ret < 0) + goto fail_unlock; + if (WARN_ON(ret != 0)) + goto fail_unlock; + 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_nr(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->sb->s_blocksize_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); + + ins_size /= csum_size; + total_bytes += ins_size * fs_info->sectorsize; + index += ins_size; + + 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; + +fail_unlock: + goto out; +} + +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); + + em->bdev = fs_info->fs_devices->latest_bdev; + btrfs_item_key_to_cpu(leaf, &key, slot); + extent_start = key.offset; + + if (type == BTRFS_FILE_EXTENT_REG || + type == BTRFS_FILE_EXTENT_PREALLOC) { + extent_end = extent_start + + btrfs_file_extent_num_bytes(leaf, fi); + } else if (type == BTRFS_FILE_EXTENT_INLINE) { + size_t size; + size = btrfs_file_extent_ram_bytes(leaf, fi); + extent_end = ALIGN(extent_start + size, + fs_info->sectorsize); + } + + em->ram_bytes = btrfs_file_extent_ram_bytes(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); + } +} |