btrfs_header
uint8* base = (uint8*)fNode + sizeof(btrfs_header);
return fVolume->BlockSize() - SpaceUsed() - sizeof(btrfs_header);
memcpy(fNode, origin->fNode, sizeof(btrfs_header));
uint8* base = (uint8*)fNode + sizeof(btrfs_header);
upperLimit = fVolume->BlockSize() - sizeof(btrfs_header);
btrfs_header header;
sizeof(btrfs_header));
btrfs_header header;