Return-Path: Received: from mx2.suse.de ([195.135.220.15]:49202 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754406AbdKIVGY (ORCPT ); Thu, 9 Nov 2017 16:06:24 -0500 From: NeilBrown To: Jeff Layton , Ian Kent , Latchesar Ionkov , Eric Van Hensbergen , Al Viro , Ron Minnich , Trond Myklebust Date: Fri, 10 Nov 2017 08:06:09 +1100 Cc: linux-nfs@vger.kernel.org, autofs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, v9fs-developer@lists.sourceforge.net, Linus Torvalds Subject: Re: [PATCH 0/3] VFS: name lookup improvements. In-Reply-To: <1510230754.29194.6.camel@redhat.com> References: <151021179901.22743.15252956909042161062.stgit@noble> <1510230754.29194.6.camel@redhat.com> Message-ID: <87a7zvf9ha.fsf@notabene.neil.brown.name> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: linux-nfs-owner@vger.kernel.org List-ID: --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Thu, Nov 09 2017, Jeff Layton wrote: > On Thu, 2017-11-09 at 18:20 +1100, NeilBrown wrote: >> These three patches address two issues: d_weak_revalidate and >> path_mountpoint lookups. >>=20 >> The former is poorly defined and doesn't actually do the one thing >> that it would be useful for it to do. So the nfs implemention >> is improved, the 9p one discarded, and the documentation clarified. >>=20 >> Given this change and recent change to follow_automount() the >> mountpoint path lookup functions are no longer needed. The regular >> path look functions are quite sufficient. >> The second two patches remove this with detailed explanation of why >> it is OK. >>=20 >> Thanks, >> NeilBrown >>=20 >>=20 >> --- >>=20 >> NeilBrown (3): >> VFS/nfs/9p: revise meaning of d_weak_invalidate. >> VFS: remove user_path_mountpoint_at() >> VFS / autofs4: remove kern_path_mountpoint() >>=20 >>=20 >> Documentation/filesystems/porting | 5 + >> Documentation/filesystems/vfs.txt | 11 +-- >> fs/9p/vfs_dentry.c | 1=20 >> fs/autofs4/dev-ioctl.c | 5 - >> fs/internal.h | 1=20 >> fs/namei.c | 150 ------------------------------= ------- >> fs/namespace.c | 2=20 >> fs/nfs/dir.c | 60 ++------------- >> include/linux/namei.h | 1=20 >> 9 files changed, 24 insertions(+), 212 deletions(-) >>=20 >> -- >> Signature >>=20 > > I love that diffstat and I think the patches and the logic behind them > look reasonable. I'm the one that added d_weak_revalidate and while it > did fix a problem at the time, it has always seemed a bit of an odd > d_op. > > Your patch does make me wonder if we should consider merging > d_weak_revalidate and d_revalidate back together, and simply require all > the d_revalidate ops vet the flags more thoroughly. This boils down to adding if (flags & LOOKUP_JUMPED) return 1; to the front of almost every d_revalidate function. I'm probably in favour of that, but it isn't an obvious win. I can certainly offer it as a follow-on patch so we can see exactly the impact. Thanks, NeilBrown --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAloEw0MACgkQOeye3VZi gbmyGg/+OcpR/hHDyiO5Mtlpf07nrrERcoK6jXdQI83xawiL73Ewu71kWPvzuL2o 5jvumq+W3eK1qJKjYB7IcfrNIaRTv+LHVkUk50Yjs1YyzsXmsyIKc7jYdLPAlEEQ AHAWdsGnuOIrEzRxAkdh9Rvef1vnmJdNicnAV9G7fKcpws5y0T/KKmEZH5emBaU4 JEWA2M7EcSM6KUa/cWgUNFRRtqh0GamF/OmKQE8+cDvO3T/sl+pmDc+yoUBKd6w4 8BNq46KoeYLTI7Q+sjoVuYAVSbVO0yoDxnUzVwrJHyoaHoyStZvtuuSzHhUqzyIg LOQdwNbryuY8sn/NNntSdu79ypL+mkVyo8GwJlnLWjmOMAwQOXyoW73h2s9bwdBm JVqPPjroei/HAZ7Uafh9c9dLYCB1mIqWZDmXAKtyQQv/tG1WHdU6W0KBRzmzxKht msgHPmsYTEK0MEXX/OIZ0X+Xf5xojzSZ1dK60nAntB0GcwSFUFcV/aePu9s7RRcd FoigaDWbyilqlh7LadY6Mxbc1oJFCwRJSaCQsYYwaFH0TBee27Nx3LFiLxnCVI/U qcN6nV7gRvyVcJ0qs4FPIDQovaZgpRN9SKGhVMKYcS4TxOAHjFJ5FoQ016caIZPN mX+rz6aQNajnwaC+aAhhitLchZUvG0AmjOX3y7GuRDpuqUZTvpE= =eOBf -----END PGP SIGNATURE----- --=-=-=--