[CRIU] dump failure msgs

[Andrey Wagin]

2014-03-20 11:44 GMT+04:00 riya khanna <riyakhanna1983 at gmail.com>:
> Hi Andrey, Pavel,
>
> I applied nested mountains patch. Now the error I get is this:
>
> (00.285979) Collecting root for process 95
>
> (00.286310) Error (mount.c:1683): The root task has another root than mntns:
> /rootfs
>
>
> It is printed from mntns_collect_root:
>
>        if (ret != 1 || path[0] != '/') {
>
>                 pr_err("The root task has another root than mntns: %s\n",
> path);
>
>                 close_pid_proc();
>
>                 return -1;
>
>         }
>
>
> How can I fix this error? The erroneous "path" printed out is
> "/home/riya/container/rootfs", which contains the roots for the container.

Which LXC version do you use? I saw this error, when I was using
lxc-0.9.0-2.fc20.x86_64. In this version lxc calls chroot before
pivot_root. This problem was fixed by
https://github.com/lxc/lxc/commit/b7f954bbddc50844e5ea3f7e72170173f5cecfb7.
Pls check that you have this commit.

Could you show some info for the container's init process?
cat /proc/PID/mountinfo
ls -l /proc/PID/
ls -l /proc/PID/fd/

Thanks.

>
> Thanks,
>
> Riya
>
>
> On Wed, Mar 12, 2014 at 6:04 AM, Pavel Emelyanov <xemul at parallels.com>
> wrote:
>>
>> On 03/12/2014 10:21 AM, riya khanna wrote:
>> > Thanks Pavel!
>> >
>> > Quick question: could you briefly explain the concept of nested mount
>> > namespaces to me?
>>
>> Sure. The systemd spawns services with CLONE_NEWNS clone() flag, which
>> results in
>> services seeing their own mount points.
>>
>> You can read man mount about propagations for more details.
>>
>> > or perhaps direct me to an article that gives the overview.
>> >
>> > Thanks for your time!
>> >
>> > -Riya
>> >
>> >
>> > On Tue, Mar 11, 2014 at 10:36 AM, Pavel Emelyanov <xemul at parallels.com
>> > <mailto:xemul at parallels.com>> wrote:
>> >
>> >     On 03/11/2014 10:19 AM, riya khanna wrote:
>> >     > Any inputs on how to fix this? Pavel?
>> >
>> >     Yup, sorry for late response. It's nested mount namespaces support
>> > we're
>> >     currently working on. You can check the Andrey's patches on the list
>> >     titled "[PATCH 00/13] Restore nested mount namespaces (v2)".
>> >
>> >     Thanks,
>> >     Pavel
>> >
>> >     >
>> >     > On Sun, Mar 9, 2014 at 4:26 PM, riya khanna
>> > <riyakhanna1983 at gmail.com <mailto:riyakhanna1983 at gmail.com>
>> > <mailto:riyakhanna1983 at gmail.com <mailto:riyakhanna1983 at gmail.com>>> wrote:
>> >     >
>> >     >     I'm trying to dump a container and I see the following errors:
>> >     >
>> >     >     (00.238188) pid = 333 getpid() = 1975
>> >     >
>> >     >     (00.238256) pid = 333 root_item->pid.real = 84
>> >     >
>> >     >     (00.238353) Error (namespaces.c:159): Can't dump nested mnt
>> > namespace for 333
>> >     >
>> >     >     (00.238432) Error (namespaces.c:355): Can't make mntns id
>> >     >
>> >     >
>> >     >     This is the output of ps
>> >     >
>> >     >        84 pts/0    S+     0:05 /sbin/init
>> >     >
>> >     >       333 pts/0    Sl     0:09 /bin/server
>> >     >
>> >     >
>> >     >     What could be wrong here?
>> >     >
>> >     >     On Sat, Jan 18, 2014 at 11:46 AM, Pavel Emelyanov
>> > <xemul at parallels.com <mailto:xemul at parallels.com>
>> > <mailto:xemul at parallels.com <mailto:xemul at parallels.com>>> wrote:
>> >     >
>> >     >         On 01/18/2014 08:26 AM, riya khanna wrote:
>> >     >         > Hi,
>> >     >         >
>> >     >         > What could be interpreted by each of these error msgs
>> > below:
>> >     >         >
>> >     >         > err msg 1:
>> >     >         >
>> >     >         > (00.580627) Error (proc_parse.c:312): Can't handle
>> > non-regular mapping on 221's map 3069145088 <tel:3069145088> <tel:3069145088
>> > <tel:3069145088>>
>> >     >
>> >     >         The task with pid 221 has a mapping of some device. You
>> > can check it via /proc.
>> >     >
>> >     >         >
>> >     >         > (00.580791) Error (cr-dump.c:1413): Collect mappings
>> > (pid: 221) failed with -1
>> >     >
>> >     >         This is a propagation of the above error through the
>> > CRIU's calls.
>> >     >
>> >     >         >
>> >     >         > err msg 2:
>> >     >         >
>> >     >         > Error (files.c:245): Can't dump file 3 of that type
>> > [20666] (chr 10:14)
>> >     >
>> >     >         The program you're dumping opened character device with
>> > major:minor == 10:14.
>> >     >         This is some misc device..
>> >     >
>> >     >         > Thanks,
>> >     >         >
>> >     >         > Riya
>> >     >         >
>> >     >         >
>> >     >         >
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>> >     >         >
>> >     >
>> >     >
>> >     >
>> >     >
>> >
>> >
>> >
>>
>>
>