From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J. Bruce Fields" Subject: Re: [PATCH] overlayfs: ignore empty NFSv4 ACLs in ext4 upperdir Date: Fri, 10 May 2019 16:09:41 -0400 Message-ID: <20190510200941.GB5349@fieldses.org> References: <266c571f-e4e2-7c61-5ee2-8ece0c2d06e9@web.de> <20161206185806.GC31197@fieldses.org> <87bm0l4nra.fsf@notabene.neil.brown.name> <20190503153531.GJ12608@fieldses.org> <87woj3157p.fsf@notabene.neil.brown.name> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <87woj3157p.fsf@notabene.neil.brown.name> Sender: linux-kernel-owner@vger.kernel.org To: NeilBrown Cc: Andreas Gruenbacher , Miklos Szeredi , Andreas =?utf-8?Q?Gr=C3=BCnbacher?= , Patrick Plagwitz , "linux-unionfs@vger.kernel.org" , Linux NFS list , Linux FS-devel Mailing List , Linux Kernel Mailing List List-Id: linux-unionfs@vger.kernel.org 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