[PATCH v8 0/4] Fix DM zone resource limits stacking

[Damien Le Moal <dlemoal@kernel.org>]

This is the updated patch 4/4 of the series "Zone write plugging and DM
zone fixes". This patch fixes DM zone resource limits stacking (max open
zones and max active zones limits). Patch 1 is new and is added to help
catch problems and eventual regressions of the handling of these limits.

Changes from v7:
 - Moved v7 changes mistakenly added to patch 4 to patch 3 where they
   belong.

Changes from v6:
 - Modified patch 3 as suggested by Niklas (moved the increment of
   zlim->mapped_nr_seq_zones after handling zc.target_nr_seq_zones == 0)
 - Rebased on rc3
 - Added review tags
 
Changes from v5:
 - Corrected typo in comment in patch 2
 - Simplyfied patch 3 by removing the function dm_set_zone_resources()
   and integrating its code directly in dm_set_zone_restrictions().
 - Added review tags

Changes from v4:
 - Fixed a typo in a comment in patch 1
 - Added patch 2 and changed patch 3 accordingly
 - Added review tags

Changes from v3:
 - Modify patch 1 to always check the zone resource limits values in
   disk_update_zone_resources(), including for DM devices that do not
   use zone write plugging. Simplify patch 2 accordingly by removing the
   same check and adjustment of the zone resource limits.
 - Added patch 3

Changes from v2:
 - Modify patch 1 to return an error for the case where the max open
   zones limit is greater than the max active zones limit.
 - Modify patch 2 to avoid duplicated actions on the limits and to
   remove warnings for unusual zone limits.

Changes from v1:
 - Added patch 1
 - Modified patch 2 to not cap the limits for a target with the number
   of sequential zones mapped but rather to use the device limits as is
   when more zones than the limits are mapped and 0 otherwise (no
   limits).

Damien Le Moal (4):
  block: Improve checks on zone resource limits
  dm: Call dm_revalidate_zones() after setting the queue limits
  dm: Improve zone resource limits handling
  dm: Remove unused macro DM_ZONE_INVALID_WP_OFST

 block/blk-settings.c  |   8 ++
 block/blk-zoned.c     |  20 ++++-
 drivers/md/dm-table.c |  15 +++-
 drivers/md/dm-zone.c  | 205 ++++++++++++++++++++++++++++++++----------
 drivers/md/dm.h       |   1 +
 5 files changed, 195 insertions(+), 54 deletions(-)

-- 
2.45.2