diff mbox series

[09/15] scsi: scsi_debug: Improve RDPROTECT/WRPROTECT handling

Message ID 20210609033929.3815-10-martin.petersen@oracle.com
State New
Headers show
Series Subject: Protection information and block size cleanup | expand

Commit Message

Martin K. Petersen June 9, 2021, 3:39 a.m. UTC
It is useful for testing purposes to be able to inject errors by
writing bad protection information to media with checking disabled and
then attempting to read it back. Extend scsi_debug's PI verification
logic to give the driver feature parity with commercially available
drives. Almost all devices with PI capability support RDPROTECT and
WRPROTECT values of 0, 1, and 3.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---
 drivers/scsi/scsi_debug.c | 90 +++++++++++++++++++++++++++++----------
 1 file changed, 67 insertions(+), 23 deletions(-)

Comments

Douglas Gilbert June 14, 2021, 10:07 p.m. UTC | #1
On 2021-06-08 11:39 p.m., Martin K. Petersen wrote:
> It is useful for testing purposes to be able to inject errors by

> writing bad protection information to media with checking disabled and

> then attempting to read it back. Extend scsi_debug's PI verification

> logic to give the driver feature parity with commercially available

> drives. Almost all devices with PI capability support RDPROTECT and

> WRPROTECT values of 0, 1, and 3.

> 

> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>


Reviewed-by: Douglas Gilbert <dgilbert@interlog.com>
diff mbox series

Patch

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 9033ab4911ba..25112b15ab14 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -3076,6 +3076,7 @@  static void dif_copy_prot(struct scsi_cmnd *scp, sector_t sector,
 static int prot_verify_read(struct scsi_cmnd *scp, sector_t start_sec,
 			    unsigned int sectors, u32 ei_lba)
 {
+	int ret = 0;
 	unsigned int i;
 	sector_t sector;
 	struct sdeb_store_info *sip = devip2sip((struct sdebug_dev_info *)
@@ -3083,26 +3084,33 @@  static int prot_verify_read(struct scsi_cmnd *scp, sector_t start_sec,
 	struct t10_pi_tuple *sdt;
 
 	for (i = 0; i < sectors; i++, ei_lba++) {
-		int ret;
-
 		sector = start_sec + i;
 		sdt = dif_store(sip, sector);
 
 		if (sdt->app_tag == cpu_to_be16(0xffff))
 			continue;
 
-		ret = dif_verify(sdt, lba2fake_store(sip, sector), sector,
-				 ei_lba);
-		if (ret) {
-			dif_errors++;
-			return ret;
+		/*
+		 * Because scsi_debug acts as both initiator and
+		 * target we proceed to verify the PI even if
+		 * RDPROTECT=3. This is done so the "initiator" knows
+		 * which type of error to return. Otherwise we would
+		 * have to iterate over the PI twice.
+		 */
+		if (scp->cmnd[1] >> 5) { /* RDPROTECT */
+			ret = dif_verify(sdt, lba2fake_store(sip, sector),
+					 sector, ei_lba);
+			if (ret) {
+				dif_errors++;
+				break;
+			}
 		}
 	}
 
 	dif_copy_prot(scp, start_sec, sectors, true);
 	dix_reads++;
 
-	return 0;
+	return ret;
 }
 
 static int resp_read_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
@@ -3196,12 +3204,29 @@  static int resp_read_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 
 	/* DIX + T10 DIF */
 	if (unlikely(sdebug_dix && scsi_prot_sg_count(scp))) {
-		int prot_ret = prot_verify_read(scp, lba, num, ei_lba);
-
-		if (prot_ret) {
-			read_unlock(macc_lckp);
-			mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, prot_ret);
-			return illegal_condition_result;
+		switch (prot_verify_read(scp, lba, num, ei_lba)) {
+		case 1: /* Guard tag error */
+			if (cmd[1] >> 5 != 3) { /* RDPROTECT != 3 */
+				read_unlock(macc_lckp);
+				mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 1);
+				return check_condition_result;
+			} else if (scp->prot_flags & SCSI_PROT_GUARD_CHECK) {
+				read_unlock(macc_lckp);
+				mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 1);
+				return illegal_condition_result;
+			}
+			break;
+		case 3: /* Reference tag error */
+			if (cmd[1] >> 5 != 3) { /* RDPROTECT != 3 */
+				read_unlock(macc_lckp);
+				mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 3);
+				return check_condition_result;
+			} else if (scp->prot_flags & SCSI_PROT_REF_CHECK) {
+				read_unlock(macc_lckp);
+				mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 3);
+				return illegal_condition_result;
+			}
+			break;
 		}
 	}
 
@@ -3277,9 +3302,11 @@  static int prot_verify_write(struct scsi_cmnd *SCpnt, sector_t start_sec,
 			sdt = piter.addr + ppage_offset;
 			daddr = diter.addr + dpage_offset;
 
-			ret = dif_verify(sdt, daddr, sector, ei_lba);
-			if (ret)
-				goto out;
+			if (SCpnt->cmnd[1] >> 5 != 3) { /* WRPROTECT */
+				ret = dif_verify(sdt, daddr, sector, ei_lba);
+				if (ret)
+					goto out;
+			}
 
 			sector++;
 			ei_lba++;
@@ -3456,12 +3483,29 @@  static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 
 	/* DIX + T10 DIF */
 	if (unlikely(sdebug_dix && scsi_prot_sg_count(scp))) {
-		int prot_ret = prot_verify_write(scp, lba, num, ei_lba);
-
-		if (prot_ret) {
-			write_unlock(macc_lckp);
-			mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, prot_ret);
-			return illegal_condition_result;
+		switch (prot_verify_write(scp, lba, num, ei_lba)) {
+		case 1: /* Guard tag error */
+			if (scp->prot_flags & SCSI_PROT_GUARD_CHECK) {
+				write_unlock(macc_lckp);
+				mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 1);
+				return illegal_condition_result;
+			} else if (scp->cmnd[1] >> 5 != 3) { /* WRPROTECT != 3 */
+				write_unlock(macc_lckp);
+				mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 1);
+				return check_condition_result;
+			}
+			break;
+		case 3: /* Reference tag error */
+			if (scp->prot_flags & SCSI_PROT_REF_CHECK) {
+				write_unlock(macc_lckp);
+				mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 3);
+				return illegal_condition_result;
+			} else if (scp->cmnd[1] >> 5 != 3) { /* WRPROTECT != 3 */
+				write_unlock(macc_lckp);
+				mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 3);
+				return check_condition_result;
+			}
+			break;
 		}
 	}