[Cluster-devel] [PATCH] Move struct gfs2_rgrp_lvb out of gfs2_ondisk.h

[Bob Peterson <rpeterso@redhat.com>]

----- Original Message -----
> Hi,
> 
> On 15/01/2020 09:24, Andreas Gruenbacher wrote:
> > On Wed, Jan 15, 2020 at 9:58 AM Steven Whitehouse <swhiteho@redhat.com>
> > wrote:
> >> On 15/01/2020 08:49, Andreas Gruenbacher wrote:
> >>> There's no point in sharing the internal structure of lock value blocks
> >>> with user space.
> >> The reason that is in ondisk is that changing that structure is
> >> something that needs to follow the same rules as changing the on disk
> >> structures. So it is there as a reminder of that,
> > I can see a point in that. The reason I've posted this is because Bob
> > was complaining that changes to include/uapi/linux/gfs2_ondisk.h break
> > his out-of-tree module build process. (One of the patches I'm working
> > on adds an inode LVB.) The same would be true of on-disk format
> > changes as well of course, and those definitely need to be shared with
> > user space. I'm not usually building gfs2 out of tree, so I'm
> > indifferent to this change.
> >
> > Thanks,
> > Andreas
> >
> Why would we need to be able to build gfs2 (at least I assume it is
> gfs2) out of tree anyway?
> 
> Steve.

Simply for productivity. The difference is this procedure, which literally takes 10 seconds,
if done simultaneously on all nodes using something like cssh:

make -C /usr/src/kernels/4.18.0-165.el8.x86_64 modules M=$PWD
rmmod gfs2
insmod gfs2.ko

Compared to a procedure like this, which takes at least 30 minutes:

make (a new kernel .src.rpm)
scp or rsync the .src.rpm to a build machine
cd ~/rpmbuild/
rpm --force -i --nodeps /home/bob/*kernel-4.18.0*.src.rpm &> /dev/null
echo $?
rpmbuild --target=x86_64 -ba SPECS/kernel.spec
( -or- submit a "real" kernel build)
then wait for the kernel build
Pull down all necessary kernel rpms
scp <those rpms> to all the nodes in the cluster
rpm --force -i --nodeps <those rpms>
/sbin/reboot all the nodes in the cluster
wait for all the nodes to reboot, the cluster to stabilize, etc.

Regards,

Bob Peterson
Red Hat File Systems