Messages in this thread | | | From | (Eric W. Biederman) | Date | Sun, 24 Jul 2016 00:10:21 -0500 | Subject | Re: [PATCH 0/5 RFC] Add an interface to discover relationships between namespaces |
| |
Andrey Vagin <avagin@openvz.org> writes:
> Hello, > > I forgot to add --cc-cover for git send-email, so everyone who is in > Cc got only a cover letter. All messages were sent in mail lists. > > Sorry for inconvenience.
Mostly the code looked sensible. But I had a couple of issues. Resend this in September (when the merge window is closed and I am back from vacation) and I will give this a thorough review and get this merged. Or possibly next week if Linus releases another -rc
> On Thu, Jul 14, 2016 at 11:20 AM, Andrey Vagin <avagin@openvz.org> wrote: >> Each namespace has an owning user namespace and now there is not way >> to discover these relationships. >> >> Pid and user namepaces are hierarchical. There is no way to discover >> parent-child relationships too. >> >> Why we may want to know relationships between namespaces? >> >> One use would be visualization, in order to understand the running system. >> Another would be to answer the question: what capability does process X have to >> perform operations on a resource governed by namespace Y? >> >> One more use-case (which usually called abnormal) is checkpoint/restart. >> In CRIU we age going to dump and restore nested namespaces. >> >> There [1] was a discussion about which interface to choose to determing >> relationships between namespaces. >> >> Eric suggested to add two ioctl-s [2]: >>> Grumble, Grumble. I think this may actually a case for creating ioctls >>> for these two cases. Now that random nsfs file descriptors are bind >>> mountable the original reason for using proc files is not as pressing. >>> >>> One ioctl for the user namespace that owns a file descriptor. >>> One ioctl for the parent namespace of a namespace file descriptor. >> >> Here is an implementaions of these ioctl-s. >> >> [1] https://lkml.org/lkml/2016/7/6/158 >> [2] https://lkml.org/lkml/2016/7/9/101 >> >> Cc: "Eric W. Biederman" <ebiederm@xmission.com> >> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> >> Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> >> Cc: "W. Trevor King" <wking@tremily.us> >> Cc: Alexander Viro <viro@zeniv.linux.org.uk> >> Cc: Serge Hallyn <serge.hallyn@canonical.com>
Eric
| |