-static int custom_alloc_extent(struct btrfs_root *root, u64 num_bytes,
- u64 hint_byte, struct btrfs_key *ins)
-{
- u64 start;
- u64 end;
- u64 last = hint_byte;
- int ret;
- int wrapped = 0;
- struct btrfs_block_group_cache *cache;
-
- while (1) {
- ret = find_first_extent_bit(&root->fs_info->free_space_cache,
- last, &start, &end, EXTENT_DIRTY);
- if (ret) {
- if (wrapped++ == 0) {
- last = 0;
- continue;
- } else {
- goto fail;
- }
- }
-
- start = max(last, start);
- last = end + 1;
- if (last - start < num_bytes)
- continue;
-
- last = start + num_bytes;
- if (test_range_bit(&root->fs_info->pinned_extents,
- start, last - 1, EXTENT_DIRTY, 0))
- continue;
-
- cache = btrfs_lookup_block_group(root->fs_info, start);
- BUG_ON(!cache);
- if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM ||
- last > cache->key.objectid + cache->key.offset) {
- last = cache->key.objectid + cache->key.offset;
- continue;
- }
-
- if (cache->flags & (BTRFS_BLOCK_GROUP_SYSTEM |
- BTRFS_BLOCK_GROUP_METADATA)) {
- last = cache->key.objectid + cache->key.offset;
- continue;
- }
-
- clear_extent_dirty(&root->fs_info->free_space_cache,
- start, start + num_bytes - 1, 0);
-
- ins->objectid = start;
- ins->offset = num_bytes;
- ins->type = BTRFS_EXTENT_ITEM_KEY;
- return 0;
- }
-fail:
- fprintf(stderr, "not enough free space\n");
- return -ENOSPC;
-}
-
-static int record_file_extent(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, u64 objectid,
- struct btrfs_inode_item *inode,
- u64 file_pos, u64 disk_bytenr,
- u64 num_bytes)
-{
- int ret;
- struct btrfs_fs_info *info = root->fs_info;
- struct btrfs_root *extent_root = info->extent_root;
- struct extent_buffer *leaf;
- struct btrfs_file_extent_item *fi;
- struct btrfs_key ins_key;
- struct btrfs_path path;
- struct btrfs_extent_item *ei;
-
- btrfs_init_path(&path);
-
- ins_key.objectid = objectid;
- ins_key.offset = 0;
- btrfs_set_key_type(&ins_key, BTRFS_EXTENT_DATA_KEY);
- ret = btrfs_insert_empty_item(trans, root, &path, &ins_key,
- sizeof(*fi));
- if (ret)
- goto fail;
- leaf = path.nodes[0];
- fi = btrfs_item_ptr(leaf, path.slots[0],
- struct btrfs_file_extent_item);
- btrfs_set_file_extent_generation(leaf, fi, trans->transid);
- btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG);
- btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
- btrfs_set_file_extent_disk_num_bytes(leaf, fi, num_bytes);
- btrfs_set_file_extent_offset(leaf, fi, 0);
- btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
- btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
- btrfs_set_file_extent_compression(leaf, fi, 0);
- btrfs_set_file_extent_encryption(leaf, fi, 0);
- btrfs_set_file_extent_other_encoding(leaf, fi, 0);
- btrfs_mark_buffer_dirty(leaf);
-
- btrfs_release_path(root, &path);
-
- ins_key.objectid = disk_bytenr;
- ins_key.offset = num_bytes;
- ins_key.type = BTRFS_EXTENT_ITEM_KEY;
-
- ret = btrfs_insert_empty_item(trans, extent_root, &path,
- &ins_key, sizeof(*ei));
- if (ret == 0) {
- leaf = path.nodes[0];
- ei = btrfs_item_ptr(leaf, path.slots[0],
- struct btrfs_extent_item);
-
- btrfs_set_extent_refs(leaf, ei, 0);
- btrfs_set_extent_generation(leaf, ei, trans->transid);
- btrfs_set_extent_flags(leaf, ei, BTRFS_EXTENT_FLAG_DATA);
-
- btrfs_mark_buffer_dirty(leaf);
- ret = btrfs_update_block_group(trans, root, disk_bytenr,
- num_bytes, 1, 0);
- if (ret)
- goto fail;
- } else if (ret != -EEXIST) {
- goto fail;
- }
-
- ret = btrfs_inc_extent_ref(trans, root, disk_bytenr, num_bytes, 0,
- root->root_key.objectid,
- objectid, 0);
-fail:
- btrfs_release_path(root, &path);
- return ret;
-}