[lxc-users] CRIU with lxc.network.type empty fails

[Tycho Andersen]

Hi Dietmar,

On Wed, Aug 12, 2015 at 08:22:14AM +0200, Dietmar Maurer wrote:
> > > What container images from https://images.linuxcontainers.org/ are 
> > > known to work with CRIU?
> > 
> > I've tested with all the Ubuntu releases (not including wily, which
> > isn't tagged yet), but not anything else. There are a few known bugs
> > related to lxcfs that I haven't had time to track down, but if you
> > e.g. use trusty without lxcfs I'm not aware of any bugs at the moment.
> > I'm sure they exist, though, so feedback is definitely appreciated!
> 
> I still use lxcfs for my tests, and I get the same errors 
> with ubuntu 15.04 (vivid):
> 
> ...
> (00.124385) fsnotify: wd: wd 0x00000002 s_dev 0x00700000 i_ino 0x
>            1823 mask 0x0800afce
> (00.124387) fsnotify: 	[fhandle] bytes 0x00000008 type 0x00000001 __handle
> 0x186df32600001823:0x0000000000000000
> (00.124388) fsnotify: Opening fhandle 700000:186df32600001823...
> (00.124392) Path `/' resolved to `./' mountpoint
> (00.124397) fsnotify: 	Handle 0x700000:0x1823 is openable
> (00.124399) Warn  (fsnotify.c:188): fsnotify: 	Handle 0x700000:0x1823 cannot be
> opened
> (00.124400) irmap: Resolving 700:1823 path
> (00.124407) irmap: Scanning /etc hint
> (00.124423) irmap: Scanning /var/spool hint
> (00.124426) irmap: Scanning /lib/udev hint
> (00.124427) irmap: Scanning /. hint
> (00.124428) irmap: Scanning /no-such-path hint
> (00.124429) irmap: Refresh stat for /no-such-path
> (00.124436) Error (irmap.c:81): irmap: Can't stat /no-such-path: No such file or
> directory
> (00.124438) Error (fsnotify.c:191): fsnotify: 	Can't dump that handle
> (00.124445) ----------------------------------------
> (00.124446) Error (cr-dump.c:1255): Dump files (pid: 3220) failed with -1

Hmm, I've not seen this on vivid. Can you describe how to reproduce it
and I'll take a look?

> with ubuntu 14.04 I get this:
> 
> ...
> (00.003608) autodetected external mount /sys/fs/pstore/ for ./sys/fs/pstore
> (00.003610) autodetected external mount /sys/kernel/security/ for
> ./sys/kernel/security
> (00.003611) autodetected external mount /sys/kernel/debug/ for
> ./sys/kernel/debug
> (00.003613) autodetected external mount /sys/fs/fuse/connections/ for
> ./sys/fs/fuse/connections
> (00.003620) Error (mount.c:680): FS mnt ./sys/kernel/debug/tracing dev 0x9 root
> / unsupported id 130
> ...
> (00.003719) Error (cr-dump.c:1618): Dumping FAILED.
> 
> (using latest ubuntu 4.1 kernel)
> 
> I guess this is related to lxcfs?

Not quite, can you show /proc/<container init pid>/mountinfo? I think
this should be autodetected by criu the same way the other mounts are,
but apparently it is not.

Tycho