On Tue, May 07, 2019 at 10:24:58AM +1000, NeilBrown wrote: > Interesting perspective .... though doesn't NFSv4 explicitly allow > client-side ACL enforcement in the case of delegations? Not really. What you're probably thinking of is the single ACE that the server can return on granting a delegation, that tells the client it can skip the ACCESS check for users matching that ACE. It's unclear how useful that is. It's currently unused by the Linux client and server. > Not sure how relevant that is.... > > It seems to me we have two options: > 1/ declare the NFSv4 doesn't work as a lower layer for overlayfs and > recommend people use NFSv3, or > 2/ Modify overlayfs to work with NFSv4 by ignoring nfsv4 ACLs either > 2a/ always - and ignore all other acls and probably all system. xattrs, > or > 2b/ based on a mount option that might be > 2bi/ general "noacl" or might be > 2bii/ explicit "noxattr=system.nfs4acl" > > I think that continuing to discuss the miniature of the options isn't > going to help. No solution is perfect - we just need to clearly > document the implications of whatever we come up with. > > I lean towards 2a, but I be happy with with any '2' and '1' won't kill > me. I guess I'd also lean towards 2a. I don't think it applies to posix acls, as overlayfs is capable of copying those up and evaluating them on its own. --b. > > Do we have a vote? Or does someone make an executive decision?? > > NeilBrown