The checksum conversion is still experimental and still does not convert
all filesystems correctly. Do not use on valuable data.
Previous implementation copied the UUID conversion which was not a good
base for the checksum conversion so it left out basically all trees
except extent and checksum.
This update adds the base for the required safety features:
- let the old csum tree intact until the full conversion is done (ie.
all data are still verifiable)
- add on-disk status tracking item, this should keep the from/to
checksum conversion, last generation to catch potential updates of the
underlying filesystem if conversion is interrupted and the filesystem
mounted
- convert most of the fundamental trees, the subvolumes, tree log and
relocation trees are not converted
- trees are converted in-place to avoid potentially running out of space
but this might be better done by transaction protection with a
temporary tree
Known issues:
- not all trees are converted
- not all checksums are correctly inserted into the new tree and reading
the files leads to EIO
Issue: #438
Signed-off-by: David Sterba <dsterba@suse.com>
9be33f558c