From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: [PATCH] overlayfs: ignore empty NFSv4 ACLs in ext4 upperdir Date: Fri, 03 May 2019 09:04:17 +1000 Message-ID: <87woj831ce.fsf@notabene.neil.brown.name> References: <20161205151933.GA17517@fieldses.org> <20161205162559.GB17517@fieldses.org> <266c571f-e4e2-7c61-5ee2-8ece0c2d06e9@web.de> <20161206185806.GC31197@fieldses.org> <87bm0l4nra.fsf@notabene.neil.brown.name> <875zqt4igg.fsf@notabene.neil.brow n.name> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Miklos Szeredi , Andreas Gruenbacher Cc: Amir Goldstein , "J. Bruce Fields" , 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 --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On Thu, May 02 2019, Miklos Szeredi wrote: > On Thu, May 2, 2019 at 10:05 AM Andreas Gruenbacher = wrote: >> >> On Thu, 2 May 2019 at 05:57, NeilBrown wrote: >> > On Wed, May 01 2019, Amir Goldstein wrote: >> > > On Wed, May 1, 2019 at 10:03 PM NeilBrown wrote: >> > >> On Tue, Dec 06 2016, J. Bruce Fields wrote: >> > >> > On Tue, Dec 06, 2016 at 02:18:31PM +0100, Andreas Gruenbacher wro= te: >> > >> >> On Tue, Dec 6, 2016 at 11:08 AM, Miklos Szeredi wrote: >> > >> >> > On Tue, Dec 6, 2016 at 12:24 AM, Andreas Gr=C3=BCnbacher >> > >> >> > wrote: >> > >> >> >> 2016-12-06 0:19 GMT+01:00 Andreas Gr=C3=BCnbacher : >> > >> >> > >> > >> >> >>> It's not hard to come up with a heuristic that determines if= a >> > >> >> >>> system.nfs4_acl value is equivalent to a file mode, and to i= gnore the >> > >> >> >>> attribute in that case. (The file mode is transmitted in its= own >> > >> >> >>> attribute already, so actually converting .) That way, overl= ayfs could >> > >> >> >>> still fail copying up files that have an actual ACL. It's st= ill an >> > >> >> >>> ugly hack ... >> > >> >> >> >> > >> >> >> Actually, that kind of heuristic would make sense in the NFS = client >> > >> >> >> which could then hide the "system.nfs4_acl" attribute. >> >> I still think the nfs client could make this problem mostly go away by >> not exposing "system.nfs4_acl" xattrs when the acl is equivalent to >> the file mode. The richacl patches contain a workable abgorithm for >> that. The problem would remain for files that have an actual NFS4 ACL, >> which just cannot be mapped to a file mode or to POSIX ACLs in the >> general case, as well as for files that have a POSIX ACL. Mapping NFS4 >> ACL that used to be a POSIX ACL back to POSIX ACLs could be achieved >> in many cases as well, but the code would be quite messy. A better way >> seems to be to using a filesystem that doesn't support POSIX ACLs in >> the first place. Unfortunately, xfs doesn't allow turning off POSIX >> ACLs, for example. > > How about mounting NFSv4 with noacl? That should fix this issue, right? No. "noacl" only affect NFSv3 (and maybe v2) and it disables use of the NFSACL side-protocol. "noacl" has no effect on an NFSv4 mount. NeilBrown --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAlzLd3EACgkQOeye3VZi gbm7ShAAgFO2IV6B0rQjQjJRJNWPCq1/rOKOmOZtssw/B8rl1YZYnMKUeFtNgSuX KfAs6rK4sntvRkPnc/ObeZiXEQ3kLIqY9UQ8f7+u32eODZZUvJ8UjZTH6slVBpE3 IG2p6y35SRG0kS52l9AE1ktca+ZIGj4QyvBY1XgHZMG1hD/w3joUcoqWqMUofAqG hedTE7db4rPEiYiBLVdmu/VZ6b6fNanPxD+zuWfYUJEertsPYE42pLbZsofMJKmc KK4ijv1q33qhrgeZbj0vDGR0RQrSLgKgMa64xM6iYKBwLKuj6Q16gk7WgrMl+wMP hmcL+3DmhMErwxH+/C7tOlymyrU36kJLQ1GjndMCKRejdh6z8imZC9jbt6pesL9E DO09nblJ+NEuuvKitKtdnpcPuzMXoP7IM4p3xki9lRw5Cg87zcDlnPQI36x54y9d 4AFiqrKq8qvStl3ZlSLlyCou/UePbzlU3AAV+Pi3bT/o3/O/IgdwDmWqbS/hhJ+z 371LcGReYKVKyaEkCM9uYc9zuklmDkRGAPUyLyzRkR4061VpB9JlrsFoWlK41T1K 5jncgXLZDLmB8H+sXFwFYMFAkOA/0ZbHSGNIuKTetMlpXR2tEJ9GaPNtQmA1aV7k 14cQvKXpVwbY8z0+MTaPrW83lMpNCaLvMGj1lvOx5qjBFEeuVlk= =JMrR -----END PGP SIGNATURE----- --=-=-=--