Patch "scsi: scsi_debug: Fix zone transition to full condition" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    scsi: scsi_debug: Fix zone transition to full condition

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     scsi-scsi_debug-fix-zone-transition-to-full-conditio.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 59b71585aa43d7b1cccbe080d7bb8961cdd002df
Author: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
Date:   Wed Jun 8 10:13:02 2022 +0900

    scsi: scsi_debug: Fix zone transition to full condition
    
    [ Upstream commit 566d3c57eb526f32951af15866086e236ce1fc8a ]
    
    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@xxxxxxxxxxxxxxxxxx
    Fixes: f0d1cf9378bd ("scsi: scsi_debug: Add ZBC zone commands")
    Reviewed-by: Niklas Cassel <niklas.cassel@xxxxxxx>
    Acked-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
    Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
    Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index cfeadd5f61f1..747e1cbb7ec9 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -2747,6 +2747,24 @@ 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)
 {
@@ -2759,7 +2777,7 @@ static void zbc_inc_wp(struct sdebug_dev_info *devip,
 	if (zsp->z_type == ZBC_ZONE_TYPE_SWR) {
 		zsp->z_wp += num;
 		if (zsp->z_wp >= zend)
-			zsp->z_cond = ZC5_FULL;
+			zbc_set_zone_full(devip, zsp);
 		return;
 	}
 
@@ -2778,7 +2796,7 @@ 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;