>From ZBC-1:
* RC BASIS = 0: The RETURNED LOGICAL BLOCK ADDRESS field indicates the
highest LBA of a contiguous range of zones that are not sequential write
required zones starting with the first zone.
* RC BASIS = 1: The RETURNED LOGICAL BLOCK ADDRESS field indicates the LBA
of the last logical block on the logical unit.
The current scsi_debug READ CAPACITY response does not comply with the above
if there are one or more sequential write required zones. SCSI initiators
need a way to retrieve the largest valid LBA from SCSI devices. Reporting
the largest valid LBA if there are one or more sequential zones requires to
set the RC BASIS field in the READ CAPACITY response to one. Hence this
patch.
Cc: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
Cc: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
Suggested-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
Changes between v2 and v3: elaborated the comment added by this patch.
Changes between v1 and v2: simplified this patch as suggested by Damien.
drivers/scsi/scsi_debug.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 697fc57bc711..629853662b82 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -1899,6 +1899,13 @@ static int resp_readcap16(struct scsi_cmnd *scp,
arr[14] |= 0x40;
}
+ /*
+ * Since the scsi_debug READ CAPACITY implementation always reports the
+ * total disk capacity, set RC BASIS = 1 for host-managed ZBC devices.
+ */
+ if (devip->zmodel == BLK_ZONED_HM)
+ arr[12] |= 1 << 4;
+
arr[15] = sdebug_lowest_aligned & 0xff;
if (have_dif_prot) {
