[PATCH v4 31/36] scsi: sd: Have sd_pr_command retry UAs

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

It's common to get a UA when doing PR commands. It could be due to a
target restarting, transport level relogin or other PR commands like a
release causing it. The upper layers don't get the sense and in some cases
have no idea if it's a SCSI device, so this has the sd layer retry.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
---
 drivers/scsi/sd.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index c0c29b948476..d19e2d20ad91 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1723,6 +1723,16 @@ static int sd_pr_command(struct block_device *bdev, u8 sa,
 	int result;
 	u8 cmd[16] = { 0, };
 	u8 data[24] = { 0, };
+	struct scsi_failure failures[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = 5,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{},
+	};
 
 	cmd[0] = PERSISTENT_RESERVE_OUT;
 	cmd[1] = sa;
@@ -1741,7 +1751,8 @@ static int sd_pr_command(struct block_device *bdev, u8 sa,
 					.buf_len = sizeof(data),
 					.sshdr = &sshdr,
 					.timeout = SD_TIMEOUT,
-					.retries = sdkp->max_retries }));
+					.retries = sdkp->max_retries,
+					.failures = failures }));
 
 	if (scsi_status_is_check_condition(result) &&
 	    scsi_sense_valid(&sshdr)) {
-- 
2.25.1