scsi: set ->scsi_done before calling scsi_dispatch_cmd

The blk-mq code path will set this to a different function, so make the
code simpler by setting it up in a legacy-request specific place.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>

drivers/scsi/scsi.c

@@ -72,8 +72,6 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/scsi.h>
 
-static void scsi_done(struct scsi_cmnd *cmd);
-
 /*
  * Definitions and constants.
  */
@@ -693,8 +691,6 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 	}
 
 	trace_scsi_dispatch_cmd_start(cmd);
-
-	cmd->scsi_done = scsi_done;
 	rtn = host->hostt->queuecommand(host, cmd);
 	if (rtn) {
 		trace_scsi_dispatch_cmd_error(cmd, rtn);
@@ -708,27 +704,10 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 
 	return rtn;
  done:
-	scsi_done(cmd);
+	cmd->scsi_done(cmd);
 	return 0;
 }
 
-/**
- * scsi_done - Invoke completion on finished SCSI command.
- * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
- * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
- *
- * Description: This function is the mid-level's (SCSI Core) interrupt routine,
- * which regains ownership of the SCSI command (de facto) from a LLDD, and
- * calls blk_complete_request() for further processing.
- *
- * This function is interrupt context safe.
- */
-static void scsi_done(struct scsi_cmnd *cmd)
-{
-	trace_scsi_dispatch_cmd_done(cmd);
-	blk_complete_request(cmd->request);
-}
-
 /**
  * scsi_finish_command - cleanup and pass command back to upper layer
  * @cmd: the command

drivers/scsi/scsi_lib.c

@@ -29,6 +29,8 @@
 #include <scsi/scsi_eh.h>
 #include <scsi/scsi_host.h>
 
+#include <trace/events/scsi.h>
+
 #include "scsi_priv.h"
 #include "scsi_logging.h"
 
@@ -1454,6 +1456,23 @@ static void scsi_softirq_done(struct request *rq)
 	}
 }
 
+/**
+ * scsi_done - Invoke completion on finished SCSI command.
+ * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
+ * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
+ *
+ * Description: This function is the mid-level's (SCSI Core) interrupt routine,
+ * which regains ownership of the SCSI command (de facto) from a LLDD, and
+ * calls blk_complete_request() for further processing.
+ *
+ * This function is interrupt context safe.
+ */
+static void scsi_done(struct scsi_cmnd *cmd)
+{
+	trace_scsi_dispatch_cmd_done(cmd);
+	blk_complete_request(cmd->request);
+}
+
 /*
  * Function:    scsi_request_fn()
  *
@@ -1556,6 +1575,7 @@ static void scsi_request_fn(struct request_queue *q)
 		/*
 		 * Dispatch the command to the low-level driver.
 		 */
+		cmd->scsi_done = scsi_done;
 		rtn = scsi_dispatch_cmd(cmd);
 		if (rtn) {
 			scsi_queue_insert(cmd, rtn);