From: David Howells Subject: Re: Extended file stat: Splitting file- and fs-specific info? Date: Wed, 09 May 2012 10:21:14 +0100 Message-ID: <20170.1336555274@redhat.com> References: <20120509002420.GL5091@dastard> <20120419140558.17272.74360.stgit@warthog.procyon.org.uk> <16281.1336508382@redhat.com> Cc: dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, adilger-m1MBpc4rdrD3fQ9qLvQP4Q@public.gmane.org, bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org, smfrench-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, ben-/+tVBieCtBitmTQ+vhA3Yw@public.gmane.org, Trond.Myklebust-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org, roland-/Z5OmTQCD9xF6kxbq+BtvQ@public.gmane.org, jra-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org, bernd.schubert-mPn0NPGs4xGatNDF+KUbs4QuADTiUCJX@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, samba-technical-w/Ol4Ecudpl8XjKLYN78aQ@public.gmane.org, linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, libc-alpha-9JcytcrH/bA+uJoB2kUjGw@public.gmane.org To: Dave Chinner Return-path: In-Reply-To: <20120509002420.GL5091@dastard> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-ext4.vger.kernel.org Dave Chinner wrote: > I don't think we want to expose the inode generation numbers. It is > trivial to construct NFS file handles (usually just fsid, inode > number and generation) with that information and hence bypass > security checks to access files. I was asked for it by Bernd Schubert for userspace NFS servers and FUSE - maybe he can say what he wants it for. I also have a note that Jeremy Allison asked for it, but I can't find where or why, so that might be an error. It looks like FreeBSD do have an st_gen field in their stat struct, but it's only filled in for root. Maybe I could do something like that? David