[PATCH v11 04/34] scsi: Have scsi-ml retry scsi_probe_lun errors

[Mike Christie <michael.christie@oracle.com>]

This has scsi_probe_lun ask scsi-ml to retry UAs instead of driving them
itself.

There is one behavior change with this patch. We used to get a total of
3 retries for both UAs we were checking for. We now get 3 retries for
each.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_scan.c | 42 +++++++++++++++++++++++-----------------
 1 file changed, 24 insertions(+), 18 deletions(-)

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 52014b2d39e1..0accd2f0f295 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -647,10 +647,29 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
 	int first_inquiry_len, try_inquiry_len, next_inquiry_len;
 	int response_len = 0;
 	int pass, count, result, resid;
-	struct scsi_sense_hdr sshdr;
+	/*
+	 * not-ready to ready transition [asc/ascq=0x28/0x0] or power-on,
+	 * reset [asc/ascq=0x29/0x0], continue. INQUIRY should not yield
+	 * UNIT_ATTENTION but many buggy devices do so anyway.
+	 */
+	struct scsi_failure failures[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x28,
+			.allowed = 3,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x29,
+			.allowed = 3,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
 	const struct scsi_exec_args exec_args = {
-		.sshdr = &sshdr,
 		.resid = &resid,
+		.failures = failures,
 	};
 
 	*bflags = 0;
@@ -668,6 +687,8 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
 				pass, try_inquiry_len));
 
 	/* Each pass gets up to three chances to ignore Unit Attention */
+	scsi_reset_failures(failures);
+
 	for (count = 0; count < 3; ++count) {
 		memset(scsi_cmd, 0, 6);
 		scsi_cmd[0] = INQUIRY;
@@ -684,22 +705,7 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
 				"scsi scan: INQUIRY %s with code 0x%x\n",
 				result ? "failed" : "successful", result));
 
-		if (result > 0) {
-			/*
-			 * not-ready to ready transition [asc/ascq=0x28/0x0]
-			 * or power-on, reset [asc/ascq=0x29/0x0], continue.
-			 * INQUIRY should not yield UNIT_ATTENTION
-			 * but many buggy devices do so anyway. 
-			 */
-			if (scsi_status_is_check_condition(result) &&
-			    scsi_sense_valid(&sshdr)) {
-				if ((sshdr.sense_key == UNIT_ATTENTION) &&
-				    ((sshdr.asc == 0x28) ||
-				     (sshdr.asc == 0x29)) &&
-				    (sshdr.ascq == 0))
-					continue;
-			}
-		} else if (result == 0) {
+		if (result == 0) {
 			/*
 			 * if nothing was transferred, we try
 			 * again. It's a workaround for some USB
-- 
2.34.1