On Tue, Aug 23, 2022, at 5:53 PM, Dave Chinner wrote:

THere's no definition of what consitutes an "inode change" and this
exposes internal filesystem implementation details (i.e. on disk
format behaviour) directly to userspace. That means when the
internal filesystem behaviour changes, userspace applications will
see changes in stat->ino_version changes and potentially break them.

As a userspace developer (ostree, etc. who is definitely interested in this functionality) I do agree with this concern; but a random drive by comment: would it be helpful to expose iversion (or other bits like this from the vfs) via e.g. debugfs to start?  I think that'd unblock writing fstests in the short term right?