count directories in estimate msdos blocksize is 2048 round_to_blocksize rounds 0 -> blocksize pass graft to estimate_size so we don't repeat overhead
This contains simple functions for creating disk images: mkcpio, mksquashfs, mkdosimg, mkext4img, mkbtrfsimg And the helper functions they use: truncate, loop_{attach,detach}, dm_{attach,detach}, mount/umount, estimate_size, roundup, cpio_copytree