linux-unionfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Carl Karsten <carl@nextdayvideo.com>
To: Amir Goldstein <amir73il@gmail.com>
Cc: overlayfs <linux-unionfs@vger.kernel.org>
Subject: Re: nfs server serving ... wrong mount?
Date: Thu, 21 Oct 2021 03:10:06 -0500	[thread overview]
Message-ID: <CADmzSSg5AZE61KMmUkrUMGVN=db4Q8kpB4vVuALzaN2uwg89rQ@mail.gmail.com> (raw)
In-Reply-To: <CAOQ4uxgN50djKrqE4FYhC0pNpHdp5HDyQcSQX4+dHqOYp_NY6A@mail.gmail.com>

ah, non-disk filesystem is the problem.  thanks.

I had switched the mounts to use ..../base and everything was fine, so
I figured overlayfs was mucking something up.

I'm glad you enjoying my riddles :)

On Thu, Oct 21, 2021 at 2:09 AM Amir Goldstein <amir73il@gmail.com> wrote:
>
> On Thu, Oct 21, 2021 at 12:51 AM Carl Karsten <carl@nextdayvideo.com> wrote:
> >
> > I have 2 overlayfs monts.
> >
> > I can nfs export one or the other fine, but not both at the same time,
> > the client gets the wrong files.
>
> Hi Carl,
>
> Thanks for the daily overlayfs riddles ;-)
>
> This is not an overlayfs issue. It's nfs exports configuration issue.
> Please read the documentation of fsid export option.
> Disk filesystems have uuid so they don't need explicit identification.
> Overlayfs does not have a stable UUID.
>
> >
> > server hosthame negk bullseye ext4
> > client twist ubuntu
> >
> > juser@negk:~$ cat /etc/exports
> > # /srv/nfs/rpi/buster/boot/merged *(ro,sync,no_subtree_check,no_root_squash)
> > /srv/nfs/rpi/buster/root/merged *(ro,sync,no_subtree_check,no_root_squash)
>
> In this case, "root" is auto assigned fsid 1
>
> >
> > juser@negk:~$ ls /srv/nfs/rpi/buster/boot/merged
> > bcm2708-rpi-b.dtb       bcm2710-rpi-3-b-plus.dtb  fixup4cd.dat
> > kernel7.img       start4.elf
> > (snip)
> >
> > juser@negk:~$ ls /srv/nfs/rpi/buster/root/merged
> > bin  boot  dev  etc  home  lib  lost+found  media  mnt  opt  proc
> > root  run  sbin  srv  sys  tmp  usr  var
> >
> > carl@twist:~/mnt$ sudo mount -t nfs negk:/srv/nfs/rpi/buster/root/merged nfs
> > carl@twist:~/mnt$ ls nfs
> > bin  boot  dev  etc  home  lib  lost+found  media  mnt  opt  proc
> > root  run  sbin  srv  sys  tmp  usr  var
> > carl@twist:~/mnt$ sudo umount nfs
> >
> > # enable root in negk exports...
>
> I think you meant enable "boot"
> and is that case "boot" gets assigned fsid 1 and "root" gets reassigned fsid 2
>
> >
> > carl@twist:~/mnt$ sudo mount -t nfs negk:/srv/nfs/rpi/buster/root/merged nfs
> > carl@twist:~/mnt$ ls nfs
> > bcm2708-rpi-b.dtb       bcm2710-rpi-3-b-plus.dtb  fixup4cd.dat
> > kernel7.img       start4.elf
> > (snip)
> >
>
> It is a bit surprising to me that you get the wrong export after a clean mount,
> but it doesn't change the core configuration issue.
>
> Perhaps nfs client has some fsid cache or you have a deferred umount in
> the system of negk:/srv/nfs/rpi/buster/root/merged (e.g. due to spawned mount
> ns or something) and then the "new" nfs mount uses the old resolved fsid 1.
>
> In any case, when exporting more than one non-disk filesystem, you should
> use explicit fsid.
>
> Thanks,
> Amir.



-- 
Carl K

      reply	other threads:[~2021-10-21  8:10 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-20 21:50 nfs server serving ... wrong mount? Carl Karsten
2021-10-21  7:09 ` Amir Goldstein
2021-10-21  8:10   ` Carl Karsten [this message]

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='CADmzSSg5AZE61KMmUkrUMGVN=db4Q8kpB4vVuALzaN2uwg89rQ@mail.gmail.com' \
    --to=carl@nextdayvideo.com \
    --cc=amir73il@gmail.com \
    --cc=linux-unionfs@vger.kernel.org \
    /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).