[dm-devel] [PATCH] dm table: Fix zoned model check and zone sectors check

[Shin'ichiro Kawasaki]

Commit 24f6b6036c9e ("dm table: fix zoned iterate_devices based device
capability checks") triggered dm table load failure when dm-zoned device
is set up for zoned block devices and a regular device for cache.

The commit inverted logic of two callback functions for iterate_devices:
device_is_zoned_model() and device_matches_zone_sectors(). The logic of
device_is_zoned_model() was inverted then all destination devices of all
targets in dm table are required to have the expected zoned model. This
is fine for dm-linear, dm-flakey and dm-crypt on zoned block devices
since each target has only one destination device. However, this results
in failure for dm-zoned with regular cache device since that target has
both regular block device and zoned block devices.

As for device_matches_zone_sectors(), the commit inverted the logic to
require all zoned block devices in each target have the specified
zone_sectors. This check also fails for regular block device which does
not have zones.

To avoid the check failures, fix the zone model check and the zone
sectors check. For zone model check, invert the device_is_zoned_model()
logic again to require at least one destination device in one target has
the specified zoned model. For zone sectors check, skip the check if the
destination device is not a zoned block device. Also add comments and
improve error messages to clarify expectations to the two checks.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki at wdc.com>
Fixes: 24f6b6036c9e ("dm table: fix zoned iterate_devices based device capability checks")
---
 drivers/md/dm-table.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 95391f78b8d5..04b7a3978ef8 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1585,13 +1585,13 @@ bool dm_table_has_no_data_devices(struct dm_table *table)
 	return true;
 }
 
-static int device_not_zoned_model(struct dm_target *ti, struct dm_dev *dev,
-				  sector_t start, sector_t len, void *data)
+static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
+				 sector_t start, sector_t len, void *data)
 {
 	struct request_queue *q = bdev_get_queue(dev->bdev);
 	enum blk_zoned_model *zoned_model = data;
 
-	return blk_queue_zoned_model(q) != *zoned_model;
+	return blk_queue_zoned_model(q) == *zoned_model;
 }
 
 static bool dm_table_supports_zoned_model(struct dm_table *t,
@@ -1608,7 +1608,7 @@ static bool dm_table_supports_zoned_model(struct dm_table *t,
 			return false;
 
 		if (!ti->type->iterate_devices ||
-		    ti->type->iterate_devices(ti, device_not_zoned_model, &zoned_model))
+		    !ti->type->iterate_devices(ti, device_is_zoned_model, &zoned_model))
 			return false;
 	}
 
@@ -1621,9 +1621,18 @@ static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *
 	struct request_queue *q = bdev_get_queue(dev->bdev);
 	unsigned int *zone_sectors = data;
 
+	if (blk_queue_zoned_model(q) == BLK_ZONED_NONE)
+		return 0;
+
 	return blk_queue_zone_sectors(q) != *zone_sectors;
 }
 
+/*
+ * Check consistency of zoned model and zone sectors across all targets.
+ * For zoned model, at least one destination device used by each target shall
+ * have the zoned model. For zone sectors, if the destination device is a zoned
+ * block device, it shall have the specified zone_sectors.
+ */
 static int validate_hardware_zoned_model(struct dm_table *table,
 					 enum blk_zoned_model zoned_model,
 					 unsigned int zone_sectors)
@@ -1632,7 +1641,7 @@ static int validate_hardware_zoned_model(struct dm_table *table,
 		return 0;
 
 	if (!dm_table_supports_zoned_model(table, zoned_model)) {
-		DMERR("%s: zoned model is not consistent across all devices",
+		DMERR("%s: zoned model is not consistent across all targets",
 		      dm_device_name(table->md));
 		return -EINVAL;
 	}
@@ -1642,7 +1651,7 @@ static int validate_hardware_zoned_model(struct dm_table *table,
 		return -EINVAL;
 
 	if (dm_table_any_dev_attr(table, device_not_matches_zone_sectors, &zone_sectors)) {
-		DMERR("%s: zone sectors is not consistent across all devices",
+		DMERR("%s: zone sectors is not consistent across all zoned devices",
 		      dm_device_name(table->md));
 		return -EINVAL;
 	}
-- 
2.29.2