From mboxrd@z Thu Jan 1 00:00:00 1970 From: Trond Myklebust Subject: Re: [PATCH 0/7] Permit filesystem local caching and NFS superblock sharing [try #13] Date: Wed, 06 Sep 2006 08:46:53 -0400 Message-ID: <1157546813.5541.8.camel@lade.trondhjem.org> References: <1157518718.3066.22.camel@raven.themaw.net> <1157458817.4133.29.camel@raven.themaw.net> <1157451611.4133.22.camel@raven.themaw.net> <1157436412.3915.26.camel@raven.themaw.net> <20060901195009.187af603.akpm@osdl.org> <20060831102127.8fb9a24b.akpm@osdl.org> <20060830135503.98f57ff3.akpm@osdl.org> <20060830125239.6504d71a.akpm@osdl.org> <20060830193153.12446.24095.stgit@warthog.cambridge.redhat.com> <27414.1156970238@warthog.cambridge.redhat.com> <9849.1157018310@warthog.cambridge.redhat.com> <9534.1157116114@warthog.cambridge.redhat.com> <20060901093451.87aa486d.akpm@osdl.org> <1157130044.5632.87.camel@localhost> <28945.1157370732@warthog.cambridge.redhat.com> <1157376295.3240.13.camel@raven.themaw.net> <1157421445.5510.13.camel@localhost> <1157424937.3002.4.camel@raven.themaw.net> <1157428241.5510.72.camel@localhost> <1157429030.3915.8.camel@raven.themaw.net> <1157432039.32412.37.camel@localhost> <3698.1157449249@warthog.cambridge.redhat.com> <4987.1157452656@war! thog.cambridge.redhat.com> <11346.1157463522@warthog.cambridge.redhat.com> <8912.1157536306@warthog.cambridge.redhat.com> Reply-To: Linux filesystem caching discussion list Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Andrew Morton , nfsv4@linux-nfs.org, linux-kernel@vger.kernel.org, torvalds@osdl.org, linux-cachefs@redhat.com, linux-fsdevel@vger.kernel.org, Ian Kent Return-path: To: David Howells In-Reply-To: <8912.1157536306@warthog.cambridge.redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-cachefs-bounces@redhat.com Errors-To: linux-cachefs-bounces@redhat.com List-Id: linux-fsdevel.vger.kernel.org On Wed, 2006-09-06 at 10:51 +0100, David Howells wrote: > Ian Kent wrote: > > > > Not if you've already caused the NFS filesystem to create a "dummy" dentry > > > that's a directory because you couldn't see that what that name > > > corresponds to on the server is actually a symlink. > > > > Shouldn't stat tell me if this is a symlink? > > You may not be able to find out from the server what it is you're trying to > deal with because you may not have permission to do so, or because whatever it > is may not be exported. The first may be the trickiest to deal with because > the MOUNT service for NFS2 and NFS3 can jump you over bits of the path you > can't otherwise access. > > The problem actually comes when the conditions on the server change; perhaps an > intermediate directory is made accessible on the server and suddenly the client > can see inside of it. It may then find out that what it had assumed to be > directories, and what it had set dummy directory dentries up for, aren't. It really doesn't matter whether there is a symlink or not. automounters should _not_ be trying to create directories on any filesystem other than the autofs filesystem itself.