scsi: scsi_debug: Fix zone transition to full condition

When a write command to a sequential write required or sequential write
preferred zone result in the zone write pointer reaching the end of the
zone, the zone condition must be set to full AND the number of implicitly
or explicitly open zones updated to have a correct accounting for zone
resources. However, the function zbc_inc_wp() only sets the zone condition
to full without updating the open zone counters, resulting in a zone state
machine breakage.

Introduce the helper function zbc_set_zone_full() and use it in
zbc_inc_wp() to correctly transition zones to the full condition.

Link: https://lore.kernel.org/r/20220608011302.92061-1-damien.lemoal@opensource.wdc.com
Fixes: f0d1cf9 ("scsi: scsi_debug: Add ZBC zone commands")
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: Damien Le Moal

drivers/scsi/scsi_debug.c

@@ -2826,6 +2826,24 @@ static void zbc_open_zone(struct sdebug_dev_info *devip,
 	}
 }
 
+static inline void zbc_set_zone_full(struct sdebug_dev_info *devip,
+				     struct sdeb_zone_state *zsp)
+{
+	switch (zsp->z_cond) {
+	case ZC2_IMPLICIT_OPEN:
+		devip->nr_imp_open--;
+		break;
+	case ZC3_EXPLICIT_OPEN:
+		devip->nr_exp_open--;
+		break;
+	default:
+		WARN_ONCE(true, "Invalid zone %llu condition %x\n",
+			  zsp->z_start, zsp->z_cond);
+		break;
+	}
+	zsp->z_cond = ZC5_FULL;
+}
+
 static void zbc_inc_wp(struct sdebug_dev_info *devip,
 		       unsigned long long lba, unsigned int num)
 {
@@ -2838,7 +2856,7 @@ static void zbc_inc_wp(struct sdebug_dev_info *devip,
 	if (zsp->z_type == ZBC_ZTYPE_SWR) {
 		zsp->z_wp += num;
 		if (zsp->z_wp >= zend)
-			zsp->z_cond = ZC5_FULL;
+			zbc_set_zone_full(devip, zsp);
 		return;
 	}
 
@@ -2857,7 +2875,7 @@ static void zbc_inc_wp(struct sdebug_dev_info *devip,
 			n = num;
 		}
 		if (zsp->z_wp >= zend)
-			zsp->z_cond = ZC5_FULL;
+			zbc_set_zone_full(devip, zsp);
 
 		num -= n;
 		lba += n;