Subject: Re: [vserver] fusermount -u fails
From: Herbert Poetzl <herbert@13thfloor.at>
Date: Tue, 2 Mar 2010 19:00:19 +0100

On Tue, Mar 02, 2010 at 12:02:16AM -0500, John A. Sullivan III wrote:
> Hello, all.  I'm struggling to get sshfs working in a vserver for use
> with X2Go (www.x2go.org).  I am running kernel 2.6.28.7 with
> vs2.3.0.36.7 on CentOS 5.4 with a Debian Lenny guest.  

I'd suggest to try with a more recent kernel, also
make sure that you have recent enough util-vserver
(i.e. not 0.30.215)

> I am able to mount the sshfs file system but I am not able to do an
> fusermount -u.
> It returns:

> fusermount: failed to clone namespace: Operation not permitted

strace -fF of the command in question might sched
some light on it ...

> Current ccapabilities are:
> SECURE_MOUNT
> SECURE_REMOUNT
> BINARY_MOUNT

> The user attempting to do the fusermount -u is a member of fuse group
> which has rw access to /dev/fuse.

> How do I get this to work?

> Just for kicks I tried adding the NAMESPACE ccapability but vserver
> complains Unknown ccap 'NAMESPACE' - not that I really understand what
> that capability would do :-(

> I tried setting setgid on fusermount; that didn't work.  Since it is
> already setuid, I thought I'd add the SETUID capability:
> vattribute --xid 40061 --bcap SETUID
> but got the same error.

> For kicks, I added SYS_ADMIN and received a different error:
> fusermount: failed to mark mounts slave: Invalid argument

sounds interesting ...

> Of course, I certainly don't want to grant SYS_ADMIN. Any help would
> be greatly appreciated. X2Go is working generally well in a vserver
> but it cannot clean up after itself if I don't solve this. 
> Thanks - John

best,
Herbert