Re: [PATCH V3 0/6] namespaces: log namespaces per task

Michael Kerrisk (man-pages)
2014-05-26T19:13:21Z

Hi Richard

On Mon, May 26, 2014 at 6:58 PM, Richard Guy Briggs <rgb@redhat.com> wrote:
> On 14/05/22, Michael Kerrisk wrote:
>> Richard,
>
> Hi Michael,
>
>> On Tue, May 20, 2014 at 3:12 PM, Richard Guy Briggs <rgb@redhat.com> wrote:
>> > The purpose is to track namespaces in use by logged processes from the
>> > perspective of init_*_ns.
>> >
>> > 1/6 defines a function to generate them and assigns them.
>> >
>> > Use a serial number per namespace (unique across one boot of one kernel)
>> > instead of the inode number (which is claimed to have had the right to change
>> > reserved and is not necessarily unique if there is more than one proc fs). It
>> > could be argued that the inode numbers have now become a defacto interface and
>> > can't change now, but I'm proposing this approach to see if this helps address
>> > some of the objections to the earlier patchset.
>> >
>> > 2/6 adds access functions to get to the serial numbers in a similar way to
>> > inode access for namespace proc operations.
>> >
>> > 3/6 implements, as suggested by Serge Hallyn, making these serial numbers
>> > available in /proc/self/ns/{ipc,mnt,net,pid,user,uts}_snum. I chose "snum"
>> > instead of "seq" for consistency with inum and there are a number of other uses
>> > of "seq" in the namespace code.
>> >
>> > 4/6 exposes proc's ns entries structure which lists a number of useful
>> > operations per namespace type for other subsystems to use.
>>
>> Since the 3 and 4 change the ABI, please CC iterations of this patch
>> series to linux-api@vger.kernel.org, as per Documentation/SubmitChecklist.
>
> Neither patch 3/6 nor 4/6 changes the syscall interface.

(Agreed.)

> Patch 3/6 adds /proc/<pid>/ns/ entries, which looks more like #16 in
> that document (for which /proc/<pid>/ns/<nstype> was never added).

But, that's a change to the surface that the kernel exposes to user
space, right? If so, it is best CCed to linux-api.

Thanks,

Michael