null_blk: Add conventional zone configuration for zoned support

Allow the creation of conventional zones by adding the zone_nr_conv
configuration attribute. This new attribute is used only for zoned devices
and indicates the number of conventional zones to create. The default value
is 0. Since host-managed zoned block devices must always have at least one
sequential zone, if the value of zone_nr_conv is larger than or equal to
the total number of zones of the device nr_zones, zone_nr_conv is
automatically changed to nr_zones - 1.

Reviewed-by: Matias Bjorling <matias.bjorling@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Masato Suzuki <masato.suzuki@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 26 insertions, 1 deletions

diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
index c0b0e4a3fa8f..5d1c261a2cfd 100644
--- a/drivers/block/null_blk_zoned.c
+++ b/drivers/block/null_blk_zoned.c
@@ -29,7 +29,25 @@ int null_zone_init(struct nullb_device *dev)
 	if (!dev->zones)
 		return -ENOMEM;
 
-	for (i = 0; i < dev->nr_zones; i++) {
+	if (dev->zone_nr_conv >= dev->nr_zones) {
+		dev->zone_nr_conv = dev->nr_zones - 1;
+		pr_info("null_blk: changed the number of conventional zones to %u",
+			dev->zone_nr_conv);
+	}
+
+	for (i = 0; i <  dev->zone_nr_conv; i++) {
+		struct blk_zone *zone = &dev->zones[i];
+
+		zone->start = sector;
+		zone->len = dev->zone_size_sects;
+		zone->wp = zone->start + zone->len;
+		zone->type = BLK_ZONE_TYPE_CONVENTIONAL;
+		zone->cond = BLK_ZONE_COND_NOT_WP;
+
+		sector += dev->zone_size_sects;
+	}
+
+	for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
 		struct blk_zone *zone = &dev->zones[i];
 
 		zone->start = zone->wp = sector;
@@ -98,6 +116,8 @@ void null_zone_write(struct nullb_cmd *cmd, sector_t sector,
 		if (zone->wp == zone->start + zone->len)
 			zone->cond = BLK_ZONE_COND_FULL;
 		break;
+	case BLK_ZONE_COND_NOT_WP:
+		break;
 	default:
 		/* Invalid zone condition */
 		cmd->error = BLK_STS_IOERR;
@@ -111,6 +131,11 @@ void null_zone_reset(struct nullb_cmd *cmd, sector_t sector)
 	unsigned int zno = null_zone_no(dev, sector);
 	struct blk_zone *zone = &dev->zones[zno];
 
+	if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) {
+		cmd->error = BLK_STS_IOERR;
+		return;
+	}
+
 	zone->cond = BLK_ZONE_COND_EMPTY;
 	zone->wp = zone->start;
 }