Re: [PATCH 00/18 V2] Repair SWAP-over-NFS

On Mon, Dec 20, 2021 at 08:07:15AM +1100, NeilBrown wrote:

quoted

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.