scsi: ch: Have midlayer retry ch_do_scsi() UAs

This has ch_do_scsi() have the SCSI midlayer retry UAs instead of driving
them itself.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20240123002220.129141-12-michael.christie@oracle.com
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ch.c

@@ -185,17 +185,29 @@ static int
 ch_do_scsi(scsi_changer *ch, unsigned char *cmd, int cmd_len,
 	   void *buffer, unsigned int buflength, enum req_op op)
 {
-	int errno, retries = 0, timeout, result;
+	int errno = 0, timeout, result;
 	struct scsi_sense_hdr sshdr;
+	struct scsi_failure failure_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = 3,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
 		.sshdr = &sshdr,
+		.failures = &failures,
 	};
 
 	timeout = (cmd[0] == INITIALIZE_ELEMENT_STATUS)
 		? timeout_init : timeout_move;
 
- retry:
-	errno = 0;
 	result = scsi_execute_cmd(ch->device, cmd, op, buffer, buflength,
 				  timeout * HZ, MAX_RETRIES, &exec_args);
 	if (result < 0)
@@ -204,13 +216,6 @@ ch_do_scsi(scsi_changer *ch, unsigned char *cmd, int cmd_len,
 		if (debug)
 			scsi_print_sense_hdr(ch->device, ch->name, &sshdr);
 		errno = ch_find_errno(&sshdr);
-
-		switch(sshdr.sense_key) {
-		case UNIT_ATTENTION:
-			if (retries++ < 3)
-				goto retry;
-			break;
-		}
 	}
 	return errno;
 }