Bug#930238: unblock: zfs-linux/0.7.12-2+deb10u1 [t-p-u]

[Philipp Kern <pkern@debian.org>]

On 2019-06-15 11:04, Paul Gevers wrote:
> On 14-06-2019 12:50, Aron Xu wrote:
> > I have tested the package in a virtual machine on amd64 for
> > linux/4.19.37-3 (buster) and a locally built updated linux kernel that
> > breaks zfs-linux/0.7.12-2. The dkms package builds fine with both of
> > the versions and zpool create/export/import works fine. Therefore,
> > please unblock the t-p-u update for buster, thanks.
>
> I am probably asking a very stupid question, but ...
>
> The changes in the patch are in the source code. Do these dkms package
> work is such a way that the binaries are compiled every time that a
> kernel gets updated? I.e. a change in the source that checks for the
> kernel version actually results in a binary that works for that source?

The whole point of dkms is to make sure that kernel modules available as 
source are made available to all installed kernels. So as long as the 
ABI version of the kernel changes (in Ubuntu with every upload, for us 
much more rarely) the module is recompiled. The corollary here is that 
it is not recompiled if the ABI version did not change because the 
module is assumed to still be compatible.

(Our kernel maintainers also regularly ignore certain ABI changes they 
do not consider to actually be part of the ABI they support.)

Kind regards
Philipp Kern