[lxc-devel] Regression in kernel support after preserve_ns change (affects master and 1.1 branch)

[Wolfgang Bumiller]

> On November 17, 2015 at 5:19 PM Stéphane Graber <stgraber at ubuntu.com> wrote:
> 
> Hello,
> 
> We just got a report when testing 1.1.5 for inclusion in Ubuntu that the
> preserve_ns change that was made recently is breaking on kernels higher
> than 3.2 and lower than 3.8.
> 
> Specifically kernels that do have /proc/self/ns but do not have entries
> in there for all the namespaces which can be cloned/unshared.
> 
> Rather than only skipping preserve_ns when /proc/self/ns doesn't exist,
> it should be skipped if /proc/self/ns doesn't exist AND if ANY of the
> /proc/self/ns/<namespace> entries are missing.
> 
> Anyone interested in sending a patch?

Can work on that tomorrow or thursday.
Why would this particular change cause breakage though? It had been used in the
same function before attaching already. Guess I'll have to get my hands on such
an ancient kernel...