On Thu, Mar 21, 2024 at 02:28:23PM -0700, Christoph Hellwig wrote: > On Wed, Mar 20, 2024 at 07:40:05PM -0700, Darrick J. Wong wrote: > > > Well xfs_verity.c could just zlib/zstd/whatever compress the contents > > > and see if that helps. We only need a ~2% compression to shrink to a > > > single 4k block, a ~1% reduction for 64k blocks, or a 6% reduction for > > > 1k blocks. > > > > ...or we just turn off the attr remote header for XFS_ATTR_VERITY merkle > > tree block values and XOR i_ino, merkle_pos, and the fs uuid into the > > first 32 bytes. > > That does sound much better than wasting the space or crazy compression > schemes. It turns out that merkle tree blocks are nearly "random" data, which means that my experiments with creating fsverity files and trying to compress merkle tree blocks actually made it *bigger*. No zlib for us! --D
