Messages in this thread | | | Date | Sat, 24 Nov 2012 22:12:58 +0100 | Subject | Re: [PATCH 1/2] autofs4: allow autofs to work outside the initial PID namespace | From | Miklos Szeredi <> |
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On Sat, Nov 24, 2012 at 1:07 PM, Eric W. Biederman <ebiederm@xmission.com> wrote: > Ian Kent <raven@themaw.net> writes: > >> On Sat, 2012-11-24 at 10:23 +0800, Ian Kent wrote: >>> On Fri, 2012-11-23 at 15:30 +0100, Miklos Szeredi wrote:
>>> AFAICS autofs mounts mounted with MS_PRIVATE in the initial namespace do >>> propagate to the clone when it's created so I'm assuming subsequent >>> mounts would also. If these mounts are busy in some way they can't be >>> umounted in the clone unless "/" is marked private before attempting the >>> umount. >> >> This may sound stupid but if there something like, say, MS_NOPROPAGATE >> then the problem I see would pretty much just go away. No more need to >> umount existing mounts and container instances would be isolated. But, I >> guess, I'm not considering the possibility of cloned of processes as >> well .... if that makes sense, ;) > > Something is very weird is going on. MS_PRIVATE should be the > MS_NOPROPOGATE you are looking for. There is also MS_UNBINDABLE. > which is a stronger form of MS_PRIVATE and probably worth play with. >
MS_UNBINDABLE says: skip this mount when copying a mount tree, such as when the mount namespace is cloned.
If you set MS_UNBINDABLE on autofs mounts then they will simply not appear in a cloned namespace. Which sounds like a good idea, no?
Thanks, Miklos
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