[ovs-dev] [PATCH ] debian: place kernel module to satisfy depmod search.

[Ben Pfaff]

On Wed, Oct 14, 2015 at 03:28:24PM -0700, Joe Stringer wrote:
> On 14 October 2015 at 15:21, Ben Pfaff <blp at nicira.com> wrote:
> > On Tue, Oct 06, 2015 at 04:35:32PM -0700, Saurabh Mohan wrote:
> >> On Ubuntu depmod's search priority is configured in /etc/depmod to be
> >> updates and then the kernel built-in directory.
> >> $ cat /etc/depmod.d/ubuntu.conf
> >> search updates ubuntu built-in
> >>
> >> Thus change the placement of openvswitch.ko under updates/ not kernel/updates.
> >>
> >> Signed-off-by: Saurabh Mohan <saurabh at cplanenetworks.com>
> >
> > This appears to be correct, but I'm confused about how this could have
> > not been noticed for years.  Did something change recently?
> 
> We recently changed it from kernel/ to kernel/updates (prior to v2.4
> release), and the commit message suggests it was previously
> nondeterministic:
> 
> commit b519432205c36bda5c7331f77a49eaaa919967ad
> Author: Ansis Atteka <aatteka at nicira.com>
> Date:   Tue May 26 16:49:49 2015 -0700
> 
>     debian: install openvswitch kernel module under "updates" directory
> 
>     This patch fixes a bug where "modprobe openvswitch" command on Ubuntu
>     distribution would have sometimes tried to load OVS kernel module that
>     shipped together with Linux Kernel, even though one had also installed
>     OVS datapath debian package created with module-assistant.  Because of
>     this issue force-reload-kmod command occasionally malfunctioned and
>     failed to load the right kernel module.
> 
>     This bug happened *occasionally* because the default Ubuntu depmod
>     configuration in /etc/depmod.d/ubuntu.conf is set to look for kernel
>     modules first in "updates" directory, then in "ubuntu" directory and
>     then in other directories.  If there were two openvswitch.ko modules
>     in "other directories", then modprobe would have loaded kernel
>     module that was nondeterministically listed first by file system.

OK, I understand why it was nondeterministic before, but where does
kernel/updates come in then, since it seems to be different from and not
as high-priority as "updates"?  Does anyone know?

Thanks,

Ben.