Bug 1199554

Summary:	Mount in different namespaces.
Product:	[Fedora] Fedora	Reporter:	Daniel Walsh <dwalsh>
Component:	util-linux	Assignee:	Karel Zak <kzak>
Status:	CLOSED UPSTREAM	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	23	CC:	dwalsh, hchen, jonathan, jsafrane, kzak, sct, steved, walters
Target Milestone:	---
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-08-13 09:43:22 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1199563

Description Daniel Walsh 2015-03-06 15:43:06 UTC

Currently we have a problem with executing mount from one namespace to affect a different namespace.

The use case we are working towards is to allow a container application like gluster/cephs/nfs-utils to be run within a container in its own namespace.  Then allow the mount command to mount file systems in the hosts (primary) mnt namespaces.  

We would like to see a command like

mount --namespace=/proc/$n/ns/mnt

The critical point here is that the mount command would have to load all of its libraries and potentially helper routines before switching namespace.

Comment 1 hchen 2015-03-06 15:50:58 UTC

This option should also be passed to any mount helpers (mount.nfs, mount.glusterfs, mount.ceph, etc) so the filesystem specific mounter will pick up this option and switch to the proper namespace by calling setns(2). 

An implementation of calling setns(2) in util-linux can be found at 
https://lists.projectatomic.io/projectatomic-archives/atomic-devel/2015-February/msg00064.html

A validation of calling setns(2) in mount helpers can be found in the prototype at https://github.com/rootfs/install-glusterfs-on-fc21/. The test description can be found in the README.md file.

Comment 2 Karel Zak 2015-05-06 10:08:29 UTC

(In reply to hchen from comment #1)
> This option should also be passed to any mount helpers (mount.nfs,
> mount.glusterfs, mount.ceph, etc) so the filesystem specific mounter will
> pick up this option and switch to the proper namespace by calling setns(2). 
> 
> An implementation of calling setns(2) in util-linux can be found at 
> https://lists.projectatomic.io/projectatomic-archives/atomic-devel/2015-
> February/msg00064.html

I have doubts the patch is correct. It forces mount(8) to set a new namespace *always* when --namespace is specified. It means that it will search for /etc/fstab in the namespace and it will execute /sbin/mount.<type> helpers with in the namespace. (So you need all libs for the helpers, etc.) 

Is it expected behaviour? If yes, the we don't have to export --namespace into mount.<type> helpers, because the helpers will be already in the namespace.


I guess the wanted behaviour is to use setns(2) only in the final mount code when all libs are already linked to the memory and exec() is no more expected.

Comment 3 Jan Kurik 2015-07-15 14:26:17 UTC

This bug appears to have been reported against 'rawhide' during the Fedora 23 development cycle.
Changing version to '23'.

(As we did not run this process for some time, it could affect also pre-Fedora 23 development
cycle bugs. We are very sorry. It will help us with cleanup during Fedora 23 End Of Life. Thank you.)

More information and reason for this action is here:
https://fedoraproject.org/wiki/BugZappers/HouseKeeping/Fedora23

Comment 4 Karel Zak 2015-08-13 09:43:22 UTC

This has to be implemented on upstream level, so I have added this request to upstream TODO file. We will see... closing for fedora..

Comment 5 Red Hat Bugzilla 2023-09-14 02:55:47 UTC

The needinfo request[s] on this closed bug have been removed as they have been unresolved for 1000 days