On Mon, Dec 20, 2021 at 08:07:15AM +1100, NeilBrown wrote: > > Thanks for fixing swap-over-NFS! Looks like it passes all the > > swap-related xfstests except for generic/357 on NFS v4.2. This test > > checks that we get -EINVAL on a reflinked swapfile, but I'm not sure > > if there is a way to check for that on the client side but if you have > > any ideas it would be nice to get that test passing while you're at > > it! > > Thanks for testing!. > I think that testing that swap fails on a reflinked file is bogus. This > isn't an important part of the API, it is just an internal > implementation detail. > I certainly understand that it could be problematic implementing swap on > a reflinked file within XFS and it is perfectly acceptable to fail such > a request. But if one day someone decided to implement it - should that > be seen as a regression? Yes, there is really no fundamental reason not to support swap to reflinked files, especially for NFS. We'll need some kind of opt-in/out for this test.