[PATCH 3.16 167/245] scsi: sd: Clear sdkp->protection_type if disk is reformatted without PI

From: Ben Hutchings
Date: Thu Apr 23 2020 - 19:12:51 EST


3.16.83-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Xiang Chen <chenxiang66@xxxxxxxxxxxxx>

commit 465f4edaecc6c37f81349233e84d46246bcac11a upstream.

If an attached disk with protection information enabled is reformatted
to Type 0 the revalidation code does not clear the original protection
type and subsequent accesses will keep setting RDPROTECT/WRPROTECT.

Set the protection type to 0 if the disk reports PROT_EN=0 in READ
CAPACITY(16).

[mkp: commit desc]

Fixes: fe542396da73 ("[SCSI] sd: Ensure we correctly disable devices with unknown protection type")
Link: https://lore.kernel.org/r/1578532344-101668-1-git-send-email-chenxiang66@xxxxxxxxxxxxx
Signed-off-by: Xiang Chen <chenxiang66@xxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/scsi/sd.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1910,8 +1910,10 @@ static int sd_read_protection_type(struc
u8 type;
int ret = 0;

- if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
+ if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0) {
+ sdkp->protection_type = 0;
return ret;
+ }

type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */