06961c487a
The block core (bio_split_discard) will already split discards based on the 'discard_granularity' and 'max_discard_sectors' queue_limits. But the DM thin target also needs to ensure that it doesn't receive a discard that spans a 'max_discard_sectors' boundary. Introduce a dm_target 'max_discard_granularity' flag that if set will cause DM core to split discard bios relative to 'max_discard_sectors'. This treats 'discard_granularity' as a "min_discard_granularity" and 'max_discard_sectors' as a "max_discard_granularity". Requested-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>