From: "bfields@fieldses.org" <bfields@fieldses.org>
To: Trond Myklebust <trondmy@hammerspace.com>
Cc: "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
"Anna.Schumaker@netapp.com" <Anna.Schumaker@netapp.com>
Subject: Re: [PATCH 6/9] NFSv4: Convert the NFS client idmapper to use the container user namespace
Date: Thu, 25 Apr 2019 12:45:00 -0400 [thread overview]
Message-ID: <20190425164500.GA9015@fieldses.org> (raw)
In-Reply-To: <e3553fd56047430f171a3c285150b56d5fc69ccd.camel@hammerspace.com>
On Thu, Apr 25, 2019 at 04:40:18PM +0000, Trond Myklebust wrote:
> On Thu, 2019-04-25 at 11:33 -0400, bfields@fieldses.org wrote:
> > On Thu, Apr 25, 2019 at 03:00:22PM +0000, Trond Myklebust wrote:
> > > The assumption is that if you have enough privileges to mount a
> > > filesystem using the NFS client, then you would also have enough
> > > privileges to run a userspace client, so there is little point in
> > > restricting the NFS client.
> > >
> > > So the guiding principle is that a NFS client mount that is started
> > > in
> > > a container should behave as if it were started by a process in a
> > > "real
> > > VM". That means that the root uid/gid in the container maps to a
> > > root
> > > uid/gid on the wire.
> > > Ditto, if there is a need to run the idmapper in the container,
> > > then
> > > the expectation is that processes running as 'user' with uid 'u',
> > > will
> > > see their creds mapped correctly by the idmapper. Again, that's
> > > what
> > > you would see if the process were running in a VM instead of a
> > > container.
> > >
> > > Does that all make sense?
> >
> > Yes, thanks!
> >
> > I thought there was a problem that the idmapper depended on
> > keyring usermodehelper calls that it was hard to pass namespace
> > information to. Did that get fixed and I missed it or or forgot?
>
> No, you are correct, and so we assume the container is using rpc.idmapd
> (and rpc.gssd) if it is running NFSv4 with RPCSEC_GSS.
>
> If the keyring upcall gets fixed, then we may allow it to be used in
> future kernels.
OK, got it. Is there anything we lose by using idmapd? (IDMAP_NAMESZ
might be a limitation?)
--b.
next prev parent reply other threads:[~2019-04-25 16:45 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-24 21:46 [PATCH 0/9] Client container fixes Trond Myklebust
2019-04-24 21:46 ` [PATCH 1/9] SUNRPC: Cache cred of process creating the rpc_client Trond Myklebust
2019-04-24 21:46 ` [PATCH 2/9] NFS: Store the credential of the mount process in the nfs_server Trond Myklebust
2019-04-24 21:46 ` [PATCH 3/9] SUNRPC: Use the client user namespace when encoding creds Trond Myklebust
2019-04-24 21:46 ` [PATCH 4/9] SUNRPC: Use namespace of listening daemon in the client AUTH_GSS upcall Trond Myklebust
2019-04-24 21:46 ` [PATCH 5/9] NFS: Convert NFSv3 to use the container user namespace Trond Myklebust
2019-04-24 21:46 ` [PATCH 6/9] NFSv4: Convert the NFS client idmapper " Trond Myklebust
2019-04-24 21:46 ` [PATCH 7/9] NFS: Convert NFSv2 " Trond Myklebust
2019-04-24 21:46 ` [PATCH 8/9] NFS: When mounting, don't share filesystems between different user namespaces Trond Myklebust
2019-04-24 21:46 ` [PATCH 9/9] lockd: Store the lockd client credential in struct nlm_host Trond Myklebust
2019-04-25 14:32 ` [PATCH 6/9] NFSv4: Convert the NFS client idmapper to use the container user namespace J. Bruce Fields
2019-04-25 15:00 ` Trond Myklebust
2019-04-25 15:33 ` bfields
2019-04-25 16:40 ` Trond Myklebust
2019-04-25 16:45 ` bfields [this message]
2019-04-25 16:48 ` Trond Myklebust
2019-04-25 20:16 ` bfields
2019-06-14 18:52 ` [PATCH 1/9] SUNRPC: Cache cred of process creating the rpc_client Ido Schimmel
2019-06-20 12:33 ` Ido Schimmel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190425164500.GA9015@fieldses.org \
--to=bfields@fieldses.org \
--cc=Anna.Schumaker@netapp.com \
--cc=linux-nfs@vger.kernel.org \
--cc=trondmy@hammerspace.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).