Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753247AbaA3Opt (ORCPT ); Thu, 30 Jan 2014 09:45:49 -0500 Received: from mail-ig0-f182.google.com ([209.85.213.182]:63156 "EHLO mail-ig0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753084AbaA3Opr convert rfc822-to-8bit (ORCPT ); Thu, 30 Jan 2014 09:45:47 -0500 Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 7.1 \(1827\)) Subject: Re: NFS client broken in Linus' tip From: Trond Myklebust In-Reply-To: <20140130143054.GY15937@n2100.arm.linux.org.uk> Date: Thu, 30 Jan 2014 09:45:44 -0500 Cc: linuxnfs , Christoph Hellwig , Viro Alexander , linux-arm-kernel@lists.infradead.org, Linux Kernel Mailing List Content-Transfer-Encoding: 8BIT Message-Id: <88DBB0A6-218A-40C5-94EA-295406E5E20E@primarydata.com> References: <20140130140834.GW15937@n2100.arm.linux.org.uk> <960A8F94-BDD4-4ED0-95EC-0D71D4AC27E7@primarydata.com> <20140130143054.GY15937@n2100.arm.linux.org.uk> To: Russell King - ARM Linux X-Mailer: Apple Mail (2.1827) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Jan 30, 2014, at 9:30, Russell King - ARM Linux wrote: > On Thu, Jan 30, 2014 at 09:17:00AM -0500, Trond Myklebust wrote: >> >> On Jan 30, 2014, at 9:08, Russell King - ARM Linux wrote: >> >>> I just booted Linus' tip (plus a few other patches to imx-drm and imx >>> code), and stumbled into this interesting scenario: >>> >>> # touch test >>> touch: cannot touch `test': Operation not supported >>> >>> I also tried mkdir and mknod, all result in the same error. Hard and >>> symlinks links are creatable. >>> >>> However, I can chmod existing files and rename them. Files can also be >>> deleted, and the combination of this has left me without a /etc/mtab ! >>> >>> The machine is a iMX6 based ARM, running root-nfs, which was mounted via >>> ubuntu's initramfs (so not using the kernel's built-in root-nfs.) >>> >>> /proc/mounts for the root mount gives: >>> 192.168.1.123:/var/boot/ci / nfs rw,relatime,vers=3,rsize=65536,wsize=65536,namlen=255,hard,nolock,proto=tcp,port=2049,timeo=7,retrans=10,sec=sys,local_lock=all,addr=192.168.1.123 0 0 >>> >>> CONFIG_NFS_FS=y >>> CONFIG_NFS_V2=y >>> CONFIG_NFS_V3=y >>> CONFIG_NFS_V3_ACL=y >>> CONFIG_NFS_V4=y >>> # CONFIG_NFS_SWAP is not set >>> # CONFIG_NFS_V4_1 is not set >>> CONFIG_ROOT_NFS=y >>> # CONFIG_NFS_USE_LEGACY_DNS is not set >>> CONFIG_NFS_USE_KERNEL_DNS=y >>> # CONFIG_NFSD is not set >>> CONFIG_LOCKD=y >>> CONFIG_LOCKD_V4=y >>> CONFIG_NFS_ACL_SUPPORT=y >>> CONFIG_NFS_COMMON=y >>> CONFIG_SUNRPC=y >>> CONFIG_SUNRPC_GSS=y >>> >>> tcpdumping, I see: >>> >>> 13:59:51.713523 IP 192.168.1.252.1341245608 > 192.168.1.123.2049: 132 lookup fh Unknown/010007011040840000000000CC238FC8FBA0475D9D9F8356B4C44166CDC38700 "test" >>> 13:59:51.714345 IP 192.168.1.123.2049 > 192.168.1.252.1341245608: reply ok 120 lookup ERROR: No such file or directory >>> 13:59:51.751303 IP 192.168.1.252.797 > 192.168.1.123.nfs: . ack 3381 win 2625 >>> >>> which is the only NFS packet(s) I see which mention "test". >>> >>> and stracing touch: >>> >>> open("test", O_WRONLY|O_CREAT|O_NOCTTY|O_NONBLOCK|O_LARGEFILE, 0666) = -1 EOPNOTSUPP (Operation not supported) >>> utimensat(AT_FDCWD, "test", NULL, 0) = -1 ENOENT (No such file or directory) >>> write(2, "touch: ", 7touch: ) = 7 >>> write(2, "cannot touch `test'", 19cannot touch `test') = 19 >>> write(2, ": Operation not supported", 25: Operation not supported) = 25 >>> write(2, "\n", 1 >>> ) = 1 >>> >>> I think it's down to this: >>> >>> commit 013cdf1088d7235da9477a2375654921d9b9ba9f >>> Author: Christoph Hellwig >>> Date: Fri Dec 20 05:16:53 2013 -0800 >>> >>> nfs: use generic posix ACL infrastructure for v3 Posix ACLs >>> >>> This causes a small behaviour change in that we don't bother to set >>> ACLs on file creation if the mode bit can express the access permissions >>> fully, and thus behaving identical to local filesystems. >>> >>> Signed-off-by: Christoph Hellwig >>> Signed-off-by: Al Viro >>> >>> which adds: >>> >>> + status = posix_acl_create(dir, &sattr->ia_mode, &default_acl, &acl); >>> + if (status) >>> + goto out; >> >> Right, this should clearly not cause nfs4_proc_create to fail if it >> returns EOPNOTSUPP. > > NFS3 :) Sorry. I fat fingered that one. I intended to write nfs3_... >>> into nfs3_proc_create(), but this ends up calling down into nfs3_get_acl(), >>> which does this: >>> >>> if (!nfs_server_capable(inode, NFS_CAP_ACLS)) >>> return ERR_PTR(-EOPNOTSUPP); >> >> Just for completeness sake: is the server you were running against supposed to support POSIX acls? > > The server is an old 3.1.8 kernel with this NFS config: > > CONFIG_NFS_FS=m > CONFIG_NFS_V3=y > # CONFIG_NFS_V3_ACL is not set > # CONFIG_NFS_V4 is not set > # CONFIG_NFS_FSCACHE is not set > CONFIG_NFSD=m > CONFIG_NFSD_V3=y > # CONFIG_NFSD_V3_ACL is not set > # CONFIG_NFSD_V4 is not set > CONFIG_LOCKD=m > CONFIG_LOCKD_V4=y > CONFIG_NFS_COMMON=y > > which has worked fine with NFS clients for the last 1800 odd days... until > now. > OK. I?m guessing that you?re hitting the auto-probing code further down in nfs3_get_acl(), which also returns EOPNOTSUPP in those cases. Those probably need to return NULL too, then? However, there seems to be an inconsistency in the whole API here: posix_acl_create() and posix_acl_chmod() seem to want to return ?0? both when acls are not supported and when they are not set, however posix_acl_xattr_get() wants to return EOPNOTSUPP in the first case, and ENODATA in the second. How is the filesystem supposed to know what to return? -- Trond Myklebust Linux NFS client maintainer -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/