2010-06-03 20:04:27

by Daniel Lezcano

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Subject: mount namespace : who mounted what ?

Hi all,

I was wondering, in a new mount namespace, if it is possible to know
which mount points were inherited and which were mounted in a new
namespace ?

I looked at /proc/<pid>/mountinfo and investigated a bit on the mount
id, but this one is not reliable as it changes in the new namespace. The
/proc/<pid>/mounts file shows all the mount points visible for the
process inherited or not.

Any ideas ?

Thanks
-- Daniel


2010-06-04 04:02:00

by Al Viro

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Subject: Re: mount namespace : who mounted what ?

On Thu, Jun 03, 2010 at 10:04:13PM +0200, Daniel Lezcano wrote:
> Hi all,
>
> I was wondering, in a new mount namespace, if it is possible to know
> which mount points were inherited and which were mounted in a new
> namespace ?
>
> I looked at /proc/<pid>/mountinfo and investigated a bit on the
> mount id, but this one is not reliable as it changes in the new
> namespace. The /proc/<pid>/mounts file shows all the mount points
> visible for the process inherited or not.

No more than "had it been this process that mmaped that area or was it
inherited from the parent?"

2010-06-04 10:14:12

by Daniel Lezcano

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Subject: Re: mount namespace : who mounted what ?

On 06/04/2010 06:01 AM, Al Viro wrote:
> On Thu, Jun 03, 2010 at 10:04:13PM +0200, Daniel Lezcano wrote:
>
>> Hi all,
>>
>> I was wondering, in a new mount namespace, if it is possible to know
>> which mount points were inherited and which were mounted in a new
>> namespace ?
>>
>> I looked at /proc/<pid>/mountinfo and investigated a bit on the
>> mount id, but this one is not reliable as it changes in the new
>> namespace. The /proc/<pid>/mounts file shows all the mount points
>> visible for the process inherited or not.
>>
> No more than "had it been this process that mmaped that area or was it
> inherited from the parent?"
>

Ok, thanks.

I thought it may be interessting to add this information in the procfs
(eg. /proc/<pid>/mountprivate) but wrt your remark that should have no
sense as, to be consistent, we should do the same for all kind of
inherited resources.