[PATCH v3 3/4] scsi: Convert SCSI errors to PR errors

[Mike Christie]

This converts the SCSI errors we commonly see during PR handling to PR_STS
errors or -Exyz errors. pr_ops callers can then handle scsi and nvme errors
without knowing the device types.

Signed-off-by: Mike Christie <michael.christie at oracle.com>
Reviewed-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Chaitanya Kulkarni <kch at nvidia.com>
---
 drivers/scsi/sd.c   | 35 ++++++++++++++++++++++++++++++++++-
 include/scsi/scsi.h |  1 +
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index eb76ba055021..bc60ec91dc8f 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1701,6 +1701,36 @@ static char sd_pr_type(enum pr_type type)
 	}
 };
 
+static int sd_scsi_to_pr_err(struct scsi_sense_hdr *sshdr, int result)
+{
+	switch (host_byte(result)) {
+	case DID_TRANSPORT_MARGINAL:
+	case DID_TRANSPORT_DISRUPTED:
+	case DID_BUS_BUSY:
+		return PR_STS_RETRY_PATH_FAILURE;
+	case DID_NO_CONNECT:
+		return PR_STS_PATH_FAILED;
+	case DID_TRANSPORT_FAILFAST:
+		return PR_STS_PATH_FAST_FAILED;
+	}
+
+	switch (status_byte(result)) {
+	case SAM_STAT_RESERVATION_CONFLICT:
+		return PR_STS_RESERVATION_CONFLICT;
+	case SAM_STAT_CHECK_CONDITION:
+		if (!scsi_sense_valid(sshdr))
+			return PR_STS_IOERR;
+
+		if (sshdr->sense_key == ILLEGAL_REQUEST &&
+		    (sshdr->asc == 0x26 || sshdr->asc == 0x24))
+			return -EINVAL;
+
+		fallthrough;
+	default:
+		return PR_STS_IOERR;
+	}
+}
+
 static int sd_pr_command(struct block_device *bdev, u8 sa,
 		u64 key, u64 sa_key, u8 type, u8 flags)
 {
@@ -1729,7 +1759,10 @@ static int sd_pr_command(struct block_device *bdev, u8 sa,
 		scsi_print_sense_hdr(sdev, NULL, &sshdr);
 	}
 
-	return result;
+	if (result <= 0)
+		return result;
+
+	return sd_scsi_to_pr_err(&sshdr, result);
 }
 
 static int sd_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index 3e46859774c8..ec093594ba53 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -121,6 +121,7 @@ enum scsi_disposition {
  *      msg_byte    (unused)
  *      host_byte   = set by low-level driver to indicate status.
  */
+#define status_byte(result) (result & 0xff)
 #define host_byte(result)   (((result) >> 16) & 0xff)
 
 #define sense_class(sense)  (((sense) >> 4) & 0x7)
-- 
2.25.1