Return-Path: linux-nfs-owner@vger.kernel.org Received: from gw-1.arm.linux.org.uk ([78.32.30.217]:55976 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752454AbaBCUZh (ORCPT ); Mon, 3 Feb 2014 15:25:37 -0500 Date: Mon, 3 Feb 2014 20:25:21 +0000 From: Russell King - ARM Linux To: Trond Myklebust Cc: Christoph Hellwig , linuxnfs , Linux Kernel Mailing List , Viro Alexander , Christoph Hellwig , linux-arm-kernel@lists.infradead.org Subject: Re: NFS client broken in Linus' tip Message-ID: <20140203202521.GM26684@n2100.arm.linux.org.uk> References: <20140130141405.GA23985@infradead.org> <20140130142752.GX15937@n2100.arm.linux.org.uk> <20140130143208.GB9573@infradead.org> <20140130153812.GA15937@n2100.arm.linux.org.uk> <1391201970.6978.1.camel@leira.trondhjem.org> <20140203080325.GB806@infradead.org> <85AAFCF5-60EE-42E5-B103-37A4613C5947@primarydata.com> <20140203145759.GA30263@infradead.org> <3003D7E5-93F8-4B32-ACDB-07ED3F6CE70D@primarydata.com> <1391458935.17089.1.camel@leira.trondhjem.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <1391458935.17089.1.camel@leira.trondhjem.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mon, Feb 03, 2014 at 03:22:15PM -0500, Trond Myklebust wrote: > On Mon, 2014-02-03 at 10:45 -0500, Trond Myklebust wrote: > > On Feb 3, 2014, at 9:57, Christoph Hellwig wrote: > > > > > On Mon, Feb 03, 2014 at 09:17:30AM -0500, Trond Myklebust wrote: > > >> As I said above, that causes posix_acl_xattr_get() to return the wrong answer (ENODATA instead of EOPNOTSUPP). > > > > > > Is it really the wrong answer? How does userspace care wether this > > > server doesn't support ACLs at all or none is set? The resulting > > > behavior is the same. > > > > It will certainly cause acl_get_file() to behave differently than previously. I’ve no idea how that will affect applications, though. > > > > > If there's a good reason to care we might have to go with your patch, > > > but if we can avoid it I'd prefer to keep things simple. > > > > One alternative is to simply wrap posix_acl_xattr_get() in fs/nfs/nfs3acl.c, and have it check the value of nfs_server_capable(inode, NFS_CAP_ACLS) before returning ENODATA. That’s rather ugly too... > > FWIW, here is the alternative patch. I've tested it, and it seems to > work. Thanks. As there's now two fixes, which would you like me to test? One comment on this patch though: > +static int > +nfs_posix_acl_xattr_get(struct dentry *dentry, const char *name, > + void *value, size_t size, int type) > +{ > + int ret; > + > + ret = posix_acl_xattr_get(dentry, name, value, size, type); > + /* > + * This check is needed to override the ENODATA error that > + * posix_acl_xattr_get will return if the acl probe fails. > + */ > + if (!nfs_server_capable(dentry->d_inode, NFS_CAP_ACLS)) > + ret = -EOPNOTSUPP; I'm not familiar with this code, but the above looks slightly weird, and a little suspicious - especially with the lack of blank line before the comment. Is the above actually intended? -- FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad. Estimate before purchase was "up to 13.2Mbit".