[dm-devel] [PATCH 02/10] dm-table: Check device area zone alignment

[damien.lemoal at wdc.com]

From: Damien Le Moal <damien.lemoal at wdc.com>

If a target maps to a zoned block device, check that the device area is
aligned on zone boundaries to avoid problems with REQ_OP_ZONE_RESET
operations (resetting a partially mapped sequential zone would not be
possible). This also greatly facilitate the processing of zone report
with REQ_OP_ZONE_REPORT bios.

Signed-off-by: Damien Le Moal <damien.lemoal at wdc.com>
---
 drivers/md/dm-table.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 06d3b7b..6947f0f 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -339,6 +339,33 @@ static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
 		return 1;
 	}
 
+	/*
+	 * If the target is mapped to a zoned block device, check
+	 * that the device zones are not partially mapped.
+	 */
+	if (bdev_zoned_model(bdev) != BLK_ZONED_NONE) {
+		unsigned int zone_sectors = bdev_zone_sectors(bdev);
+
+		if (start & (zone_sectors - 1)) {
+			DMWARN("%s: start=%llu not aligned to h/w "
+			       "zone size %u of %s",
+			       dm_device_name(ti->table->md),
+			       (unsigned long long)start,
+			       zone_sectors, bdevname(bdev, b));
+			return 1;
+		}
+
+		if (start + len < dev_size &&
+		    len & (zone_sectors - 1)) {
+			DMWARN("%s: len=%llu not aligned to h/w "
+			       "zone size %u of %s",
+			       dm_device_name(ti->table->md),
+			       (unsigned long long)start,
+			       zone_sectors, bdevname(bdev, b));
+			return 1;
+		}
+	}
+
 	return 0;
 }
 
-- 
2.9.3

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