On Sun, Feb 02, 2025 at 10:26:28AM -0500, Theodore Ts'o wrote: > Well, in the past I attempted to land a "local" file system type that > could be used for file systems that were available via docker (and so > there was no block device to mount and unmount). This was useful for > testing gVisor[1] and could also be used for testing Windows Subsystem > for Linux v1. As I recall, either Dave or Cristoph objected, even > though the diffstat was +73, -4 lines in common/rc. Yes, xfstests should just support upstream code. Even for things where we through it would get upstream ASAP like the XFS rtrmap/reflink/metadir work (which finally did get upstream now) having the half-finished support in xfstests without actually landing the rest caused more than enough problems. Something like lustre that has historically been a complete trainwreck and where I have strong doubts that the maintainers get their act together is even worse.