On Tue, 2019-05-21 at 15:06 -0400, Chuck Lever wrote: > > On May 21, 2019, at 2:17 PM, Trond Myklebust < > > trondmy@xxxxxxxxxxxxxxx> wrote: > > > > On Tue, 2019-05-21 at 13:40 -0400, Chuck Lever wrote: > > > Hi Trond - > > > > > > > On May 21, 2019, at 8:46 AM, Trond Myklebust <trondmy@xxxxxxxxx > > > > > > > > > wrote: > > > > > > > > The following patchset adds support for the 'root_dir' > > > > configuration > > > > option for nfsd in nfs.conf. If a user sets this option to a > > > > valid > > > > directory path, then nfsd will act as if it is confined to a > > > > chroot > > > > jail based on that directory. All paths in /etc/exporfs and > > > > from > > > > exportfs are then resolved relative to that directory. > > > > > > What about files under /proc that mountd might access? I assume > > > these > > > pathnames are not affected. > > > > > That's why we have 2 threads. One thread is root jailed using > > chroot, > > and is used to talk to knfsd. The other thread is not root jailed > > (or > > at least not by root_dir) and so has full access to /etc, /proc, > > /var, > > ... > > > > > Aren't there also one or two other files that maintain export > > > state > > > like /var/lib/nfs/rmtab? Are those affected? > > > > See above. They are not affected. > > > > > IMHO it could be less confusing to administrators to make > > > root_dir an > > > [exportfs] option instead of a [mountd] option, if this is not a > > > true > > > chroot of mountd. > > > > It is neither. I made in a [nfsd] option, since it governs the way > > that > > both exportfs and mountd talk to nfsd. > > My point is not about implementation, it's about how this > functionality > is presented to administrators. > > In nfs.conf, [nfsd] looks like it controls what options are passed > via > rpc.nfsd. That still seems like a confusing admin interface. > > IMO admins won't care about who is talking to whom. They will care > about > how the export pathnames are interpreted. That seems like it belongs > squarely with the exportfs interface. > With the exportfs interface, yes. However it is not specific to the exportfs utility, so to me [exportfs] is more confusing than what exists now. OK, so what if we put it in [general] instead, and perhaps rename it "export_rootdir"? -- Trond Myklebust Linux NFS client maintainer, Hammerspace trond.myklebust@xxxxxxxxxxxxxxx
