[libvirt-users] libvirt 1.0.3 Vs 1.0.4 / cgroup devices

[Mohamed Larabi]

Hi Daniel,

knowing that the /dev/random (c 1:8 rwm) device is assigned to the containers, the problem is :
      - with libvirt 1.0.3: inside the container, I can do rm -f /dev/random; mknod /dev/random c 1 8 (which works fine)
      - with libvirt 1.0.4: rm -f /dev/random; mknod /dev/random c 1 8 is not working (mknod: `random': Operation not permitted)

why is it allowed in 1.0.3 and not in 1.0.4 ?

Thanks

Mohamed

----- Mail original -----
> De: "Daniel P. Berrange" <berrange at redhat.com>
> À: "Mohamed Larabi" <mohamed.larabi at inria.fr>
> Cc: libvirt-users at redhat.com
> Envoyé: Jeudi 18 Avril 2013 11:22:17
> Objet: Re: [libvirt-users] libvirt 1.0.3 Vs 1.0.4 / cgroup devices
> 
> On Thu, Apr 18, 2013 at 11:11:21AM +0200, Mohamed Larabi wrote:
> > Hi there,
> > 
> > 
> > I am using libvirt with lxc to create fedora 16 & 18 containers on
> > fedora 18 host.
> > 
> > 
> > first I did the setup with libvirt 1.0.3 and everything worked
> > fine, then after upgrading to libvirt 1.0.4, I could not create
> > character device on the guests :
> > 
> > 
> > Test on the guest1 :
> > 
> > 
> > # ls -l /dev
> > total 0
> > lrwxrwxrwx. 1 root root 10 Apr 17 21:18 console -> /dev/pts/0
> > lrwxrwxrwx. 1 root root 11 Apr 17 21:18 core -> /proc/kcore
> > lrwxrwxrwx. 1 root root 13 Apr 17 21:18 fd -> /proc/self/fd
> > crw-rw-rw-. 1 root root 1, 7 Apr 17 21:18 full
> > drwxr-xr-x. 2 root root 0 Apr 17 21:18 hugepages
> > prw-------. 1 root root 0 Apr 17 21:18 initctl
> > srw-rw-rw-. 1 root root 0 Apr 17 21:18 log
> > drwxrwxrwt. 2 root root 40 Apr 17 21:18 mqueue
> > crw-rw-rw-. 1 root root 1, 3 Apr 17 21:18 null
> > crw-rw-rw-. 1 root root 5, 2 Apr 18 10:31 ptmx
> > drwxr-xr-x. 2 root root 0 Apr 17 21:18 pts
> > crw-r--r--. 1 root root 1, 8 Apr 17 21:19 random
> > drwxrwxrwt. 2 root root 40 Apr 17 21:18 shm
> > lrwxrwxrwx. 1 root root 15 Apr 17 21:18 stderr -> /proc/self/fd/2
> > lrwxrwxrwx. 1 root root 15 Apr 17 21:18 stdin -> /proc/self/fd/0
> > lrwxrwxrwx. 1 root root 15 Apr 17 21:18 stdout -> /proc/self/fd/1
> > lrwxrwxrwx. 1 root root 10 Apr 17 21:18 tty1 -> /dev/pts/0
> > crw-rw-rw-. 1 root root 1, 9 Apr 17 21:18 urandom
> > crw-rw-rw-. 1 root root 1, 5 Apr 17 21:18 zero
> > 
> > 
> > # rm -f /dev/random (successful)
> > 
> > 
> > # mknod random c 1 8
> > mknod: `random': Operation not permitted
> 
> Libvirt does not allow the 'mknod' capability within containers.
> Any devices that have been assigned to the container will have
> device nodes pre-created in /dev by libvirt itself.
> 
> Daniel
> --
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