[lxc-devel] A question about chroot_into_slave()

[Andrey Wagin]

2014-10-03 22:30 GMT+04:00 Serge Hallyn <serge.hallyn at ubuntu.com>:
>> root at ubuntu:~# uname -a
>> Linux ubuntu 3.13.0-30-generic #54-Ubuntu SMP Mon Jun 9 22:45:01 UTC
>> 2014 x86_64 x86_64 x86_64 GNU/Linux
>> root at ubuntu:~# cat /etc/lsb-release
>> DISTRIB_ID=Ubuntu
>> DISTRIB_RELEASE=14.04
>> DISTRIB_CODENAME=trusty
>> DISTRIB_DESCRIPTION="Ubuntu 14.04.1 LTS"
>
> A-ha.  I was trying in 14.10 with no success.  In 14.04, I can reproduce
> this.  I've opened https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1377267
> about this issue.  The bug has links to two sets of testscripts to make this
> easier to reproduce.

I installed 14.10 to investigate how the problem was fixed there.

I found one interesting thing. chroot work differently on 14.10. and 14.04.

Here is output for 14.10
root at ubuntu:/home/avagin/test# strace -fo log bash cis.maintest
...
TEST GOOD for /home/avagin/test/centos

root at ubuntu:/home/avagin/test# cat log | grep '^[0-9]*\s*chroot'
1964  chroot("waterbuffalo")            = 0
1964  chroot(".")                       = 0
1978  chroot("waterbuffalo")            = 0
1978  chroot(".")                       = 0

And the same for 14.04
root at ubuntu:/home/avagin/test# strace -fo log bash cis.maintest
...
TEST BAD for /home/avagin/test/centos
root at ubuntu:/home/avagin/test# cat log | grep '^[0-9]*\s*chroot'
3249  chroot("/mnt/root")               = 0
3254  chroot("waterbuffalo")            = 0
3254  chroot(".")                       = 0
3262  chroot("/mnt/root")               = 0
3267  chroot("waterbuffalo")            = 0
3267  chroot(".")                       = 0

Do you see difference? chroot("/mnt/root") isn't called in the first
example. So I think the origin problem exists in 14.10 too.

Thanks,
Andrew
>
> -serge