block: Make most scsi_req_init() calls implicit

Instead of explicitly calling scsi_req_init() after blk_get_request(),
call that function from inside blk_get_request(). Add an
.initialize_rq_fn() callback function to the block drivers that need
it. Merge the IDE .init_rq_fn() function into .initialize_rq_fn()
because it is too small to keep it as a separate function. Keep the
scsi_req_init() call in ide_prep_sense() because it follows a
blk_rq_init() call.

References: commit 82ed4db499 ("block: split scsi_request out of struct request")
Signed-off-by: Bart Van Assche <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Hannes Reinecke <[email protected]>
Cc: Omar Sandoval <[email protected]>
Cc: Nicholas Bellinger <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

drivers/scsi/osd/osd_initiator.c

@@ -1574,7 +1574,6 @@ static struct request *_make_request(struct request_queue *q, bool has_write,
 			flags);
 	if (IS_ERR(req))
 		return req;
-	scsi_req_init(req);
 
 	for_each_bio(bio) {
 		struct bio *bounce_bio = bio;
@@ -1619,7 +1618,6 @@ static int _init_blk_request(struct osd_request *or,
 				ret = PTR_ERR(req);
 				goto out;
 			}
-			scsi_req_init(req);
 			or->in.req = or->request->next_rq = req;
 		}
 	} else if (has_in)

drivers/scsi/osst.c

@@ -373,7 +373,6 @@ static int osst_execute(struct osst_request *SRpnt, const unsigned char *cmd,
 		return DRIVER_ERROR << 24;
 
 	rq = scsi_req(req);
-	scsi_req_init(req);
 	req->rq_flags |= RQF_QUIET;
 
 	SRpnt->bio = NULL;

drivers/scsi/scsi_error.c

@@ -1903,7 +1903,6 @@ static void scsi_eh_lock_door(struct scsi_device *sdev)
 	if (IS_ERR(req))
 		return;
 	rq = scsi_req(req);
-	scsi_req_init(req);
 
 	rq->cmd[0] = ALLOW_MEDIUM_REMOVAL;
 	rq->cmd[1] = 0;

drivers/scsi/scsi_lib.c

@@ -250,7 +250,6 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 	if (IS_ERR(req))
 		return ret;
 	rq = scsi_req(req);
-	scsi_req_init(req);
 
 	if (bufflen &&	blk_rq_map_kern(sdev->request_queue, req,
 					buffer, bufflen, __GFP_RECLAIM))
@@ -1117,6 +1116,18 @@ err_exit:
 }
 EXPORT_SYMBOL(scsi_init_io);
 
+/**
+ * scsi_initialize_rq - initialize struct scsi_cmnd.req
+ *
+ * Called from inside blk_get_request().
+ */
+void scsi_initialize_rq(struct request *rq)
+{
+	scsi_req_init(rq);
+}
+EXPORT_SYMBOL(scsi_initialize_rq);
+
+/* Called after a request has been started. */
 void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
 {
 	void *buf = cmd->sense_buffer;
@@ -2124,6 +2135,7 @@ struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
 	q->request_fn = scsi_request_fn;
 	q->init_rq_fn = scsi_init_rq;
 	q->exit_rq_fn = scsi_exit_rq;
+	q->initialize_rq_fn = scsi_initialize_rq;
 
 	if (blk_init_allocated_queue(q) < 0) {
 		blk_cleanup_queue(q);
@@ -2148,6 +2160,7 @@ static const struct blk_mq_ops scsi_mq_ops = {
 #endif
 	.init_request	= scsi_init_request,
 	.exit_request	= scsi_exit_request,
+	.initialize_rq_fn = scsi_initialize_rq,
 	.map_queues	= scsi_map_queues,
 };
 

drivers/scsi/scsi_transport_sas.c

@@ -33,6 +33,7 @@
 #include <linux/bsg.h>
 
 #include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_request.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_host.h>
@@ -230,6 +231,7 @@ static int sas_bsg_initialize(struct Scsi_Host *shost, struct sas_rphy *rphy)
 	q = blk_alloc_queue(GFP_KERNEL);
 	if (!q)
 		return -ENOMEM;
+	q->initialize_rq_fn = scsi_initialize_rq;
 	q->cmd_size = sizeof(struct scsi_request);
 
 	if (rphy) {

drivers/scsi/sg.c

@@ -1732,8 +1732,6 @@ sg_start_req(Sg_request *srp, unsigned char *cmd)
 	}
 	req = scsi_req(rq);
 
-	scsi_req_init(rq);
-
 	if (hp->cmd_len > BLK_MAX_CDB)
 		req->cmd = long_cmdp;
 	memcpy(req->cmd, cmd, hp->cmd_len);

drivers/scsi/st.c

@@ -549,7 +549,6 @@ static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 	if (IS_ERR(req))
 		return DRIVER_ERROR << 24;
 	rq = scsi_req(req);
-	scsi_req_init(req);
 	req->rq_flags |= RQF_QUIET;
 
 	mdata->null_mapped = 1;