On 12/21/18 5:47 PM, Max Reitz wrote:
> By default, qemu-nbd binds to 0.0.0.0.  However, we then proceed to
> connect to "localhost".  Usually, this works out fine; but if this test
> is run concurrently, some other test function may have bound a different
> server to ::1 (on the same port -- you can bind different serves to the

s/serves/servers/

> same port, as long as one is on IPv4 and the other on IPv6).
> 
> So running qemu-nbd works, it can bind to 0.0.0.0:NBD_PORT.  But
> potentially a concurrent test has successfully taken [::1]:NBD_PORT.  In
> this case, trying to connect to "localhost" will lead us to the IPv6
> instance, where we do not want to end up.
> 
> Fix this by just binding to "localhost".  This will make qemu-nbd error
> out immediately and not give us cryptic errors later.
> 
> (Also, it will allow us to just try a different port as of a future
> patch.)
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  tests/qemu-iotests/147 | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org