[lxc-users] unpriviledged container failing to get an IP in Ubuntu 16

[Ivan Ogai]

Hello !

I sent this email yesterday to the list but I don't see it in the
archives.

https://lists.linuxcontainers.org/pipermail/lxc-users/2016-September/thread.html


Hello !

in a fresh Ubuntu 16.04 installation, when starting an unpriviledged container,
it gets no IP (lxc-ls --fancy in the host). dmesg last lines in the container
are:

[ 1743.140633] eth0: renamed from vethSLN6EBp
[ 1743.180001] IPv6: ADDRCONF(NETDEV_CHANGE): vethSLN6EB: link becomes ready
[ 1743.180205] lxcbr0: port 2(vethSLN6EB) entered forwarding state
[ 1743.180238] lxcbr0: port 2(vethSLN6EB) entered forwarding state
[ 1743.263802] cgroup: new mount options do not match the existing superblock, will be ignored
[ 1758.195512] lxcbr0: port 2(vethSLN6EB) entered forwarding state
[ 1920.142032] INFO: task systemd:6560 blocked for more than 120 seconds.
[ 1920.142038]       Not tainted 4.4.0-36-generic #55-Ubuntu
[ 1920.142039] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1920.142041] systemd         D ffff8803d6acbb58     0  6560   6548 0x00000100
[ 1920.142046]  ffff8803d6acbb58 ffff8803cfdb8dc0 ffff88042cf45280 ffff8803cfdb8dc0
[ 1920.142049]  ffff8803d6acc000 ffff880035672088 ffff880035672070 ffffffff00000000
[ 1920.142052]  fffffffe00000001 ffff8803d6acbb70 ffffffff81829ec5 ffff8803cfdb8dc0
[ 1920.142055] Call Trace:
[ 1920.142064]  [<ffffffff81829ec5>] schedule+0x35/0x80
[ 1920.142067]  [<ffffffff8182cb12>] rwsem_down_write_failed+0x202/0x350
[ 1920.142072]  [<ffffffff81288ff0>] ? kernfs_sop_show_options+0x40/0x40
[ 1920.142076]  [<ffffffff813ff853>] call_rwsem_down_write_failed+0x13/0x20
[ 1920.142078]  [<ffffffff8182c34d>] ? down_write+0x2d/0x40
[ 1920.142081]  [<ffffffff8120fb80>] grab_super+0x30/0xa0
[ 1920.142083]  [<ffffffff81210112>] sget_userns+0x152/0x450
[ 1920.142085]  [<ffffffff81289070>] ? kernfs_sop_show_path+0x50/0x50
[ 1920.142088]  [<ffffffff812892de>] kernfs_mount_ns+0x7e/0x230
[ 1920.142092]  [<ffffffff8111858b>] cgroup_mount+0x2eb/0x7f0
[ 1920.142094]  [<ffffffff812111d8>] mount_fs+0x38/0x160
[ 1920.142097]  [<ffffffff8122d1d7>] vfs_kern_mount+0x67/0x110
[ 1920.142100]  [<ffffffff8122f9a9>] do_mount+0x269/0xde0
[ 1920.142103]  [<ffffffff8123084f>] SyS_mount+0x9f/0x100
[ 1920.142106]  [<ffffffff8182dfb2>] entry_SYSCALL_64_fastpath+0x16/0x71

Trying to stop it in the host with "lxc-stop -n test" has no result. The
command never finishes. This one either:

    lxc-stop -n test --kill --nolock

No log is produced with:

    lxc-stop -n test --kill --nolock -o /tmp/log -l DEBUG

-- 
Ivan F. V. B.