[lxc-devel] [PATCH 1/4] Automatic mounts: improvements for /proc and /sys

Christian Seiler christian at iwakd.de
Fri Sep 27 07:07:38 UTC 2013


Hi Serge,

> My 3.2, 3.8 and 3.11 kernels all behave the same:
>
> serge at sergeh1:~$ sudo mount -t tmpfs tmpfs /mnt
> serge at sergeh1:~$ sudo mount --bind /mnt /mnt2
> serge at sergeh1:~$ sudo mount -o remount,ro /mnt2
> serge at sergeh1:~$ sudo touch /mnt/a
> serge at sergeh1:~$ mount | grep /mnt
> tmpfs on /mnt type tmpfs (rw)
> /mnt on /mnt2 type none (ro,bind)

Oh, strange. Then maybe it's just the userns-patched 3.8 kernel
that was sent to this list a while back (it was an Ubuntu ppa,
I can't find the posting on the fly) that behaves differently.
Then maybe all of this is just a false alarm.

(The above commands produce two ro mounts in my test VM.)

(Although, I just also tested in on a Fedora 16 box with kernel
3.6.10 and with mount --make-rprivate / before executing your
commands and that also produced two ro mounts...)

Perhaps Ubuntu has a patch against standard upstream that
reverses the behaviour?

-- Christian





More information about the lxc-devel mailing list