From a similar answer by jlp at Server Fault:
I don't believe it is possible to extract the block level checksums from a ZFS filesystem, but since the checksums are at the block level, not the file level, it probably wouldn't help you anyway.
Meaning: checksums are not created per file by btrfs.
It is mentioned
that there is a patch to add a functionality to the inspect-internal subcommand:
btrfs inspect-internal dump-csums
This dumps – for all blocks being occupied by a given file – the block checksums. Plural, unless the file fits into one block.
