[libvirt] [PATCH] LXC: make sure fuse thread start to run before we do clone

[Daniel P. Berrange]

On Wed, Nov 13, 2013 at 11:33:46AM -0700, Eric Blake wrote:
> On 11/13/2013 11:16 AM, Rich Felker wrote:
> 
> >> We are not using clone() in a manner that is strictly equivalent
> >> to fork(). Libvirt is using clone() to create Linux containers
> >> with new namespaces. eg we do 
> >>
> >>   clone(CLONE_NEWPID|CLONE_NEWNS|CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWUSER|CLONE_NEWNET|SIGCHLD)
> > 
> > Understood. I still call this a fork-like manner since it's not
> > sharing VM or using CLONE_THREAD and using the default signal of
> > SIGCHLD. BTW is there a reason to prefer this usage over regular fork
> > followed by unshare()?
> 
> Yes.  Per 'man 2 unshare', CLONE_NEWPID is not supported with unshare(),
> yet we require our child to have pid 1 in its new pid namespace.

Yeah, I also wish we could use unshare() instead of clone(), but the
CLONE_NEWPID design limitation is a blocker for that.

Daniel
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