gfs2: Fix glock shrinker

Merge Request Required Information

This MR contains a number of fixes, the most critical of which being 'gfs2: Fix "Make glock lru list scanning safer"', which fixes the glock shrinker that allows gfs2 to react to memory pressure.

Summary of Changes

Approved Development Ticket

JIRA: https://issues.redhat.com/browse/RHEL-32940 Signed-off-by: Andreas Gruenbacher agruenba@redhat.com