* Jeff Layton: > To do this we'd need 2 64-bit fields in the on-disk and in-memory > superblocks for ext4, xfs and btrfs. On the first mount after a crash, > the filesystem would need to bump s_version_max by the significant > increment (2^40 bits or whatever). On a "clean" mount, it wouldn't need > to do that. > > Would there be a way to ensure that the new s_version_max value has made > it to disk? Bumping it by a large value and hoping for the best might be > ok for most cases, but there are always outliers, so it might be > worthwhile to make an i_version increment wait on that if necessary. How common are unclean shutdowns in practice? Do ex64/XFS/btrfs keep counters in the superblocks for journal replays that can be read easily? Several useful i_version applications could be negatively impacted by frequent i_version invalidation. Thanks, Florian