Hard link to root-owned file now fails (since Fedora 19)

[Richard W.M. Jones]

On Tue, Jul 16, 2013 at 01:07:40PM +0100, Bryn M. Reeves wrote:
> On 07/16/2013 12:41 PM, Colin Walters wrote:
> > On Tue, 2013-07-16 at 10:42 +0100, Richard W.M. Jones wrote:
> > 
> >> FWIW this change caused a segfault in OpenStack 
> > 
> > This phrase is very dramatic.  I'd say "triggered a double free in an
> > untested libguestfs error path" is more accurate and less dramatic.
> 
> Or: uncovered a pre-existing bug that could then be addressed..
> 
> Not sure how that is a bad thing.

Changed the kernel interface, exposing a bug, but it certainly did
cause a segfault.

The other part of this is we're going to have to rewrite some
perfectly working code to fit this new assumption.  I'm not even sure
how to do that because we want the atomic behaviour of hard links, and
we want to have qemu running as a different user (for security, oh the
irony), so there's no other obvious way to code it.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
libguestfs lets you edit virtual machines.  Supports shell scripting,
bindings from many languages.  http://libguestfs.org