[PATCH] scsi_get_request_dev() cleanup

	_Now_ we can clean the scsi_get_request_dev() up.  Indeed, for
any SCSI request we either have ->rq_dev == NODEV and ->rq_disk == NULL
or ->rq_disk->private_data points to address of template in question.
IOW, scsi_get_request_dev() becomes simply
{
	struct gendisk *p = req->rq_disk;
	return p ? *(struct Scsi_Device_Template **)p->private_data : NULL;
}
and that allows to kill ->max_major, ->min_major and ->major in
Scsi_Device_Template, along with the last non-trivial use of ->rq_dev.

drivers/scsi/hosts.h

@@ -560,9 +560,6 @@ struct Scsi_Device_Template
     const char * tag;
     struct module * module;	  /* Used for loadable modules */
     unsigned char scsi_type;
-    unsigned int major;
-    unsigned int min_major;      /* Minimum major in range. */ 
-    unsigned int max_major;      /* Maximum major in range. */
     unsigned int nr_dev;	  /* Number currently attached */
     unsigned int dev_noticed;	  /* Number of devices detected. */
     unsigned int dev_max;	  /* Current size of arrays */

drivers/scsi/ide-scsi.c

@@ -760,9 +760,13 @@ static inline struct bio *idescsi_dma_bio(ide_drive_t *drive, idescsi_pc_t *pc)
 static inline int should_transform(ide_drive_t *drive, Scsi_Cmnd *cmd)
 {
 	idescsi_scsi_t *scsi = drive->driver_data;
+	struct gendisk *disk = cmd->request->rq_disk;
 
-	if (major(cmd->request->rq_dev) == SCSI_GENERIC_MAJOR)
-		return test_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
+	if (disk) {
+		struct Scsi_Device_Template **p = disk->private_data;
+		if (strcmp((*p)->tag, "sg") == 0)
+			return test_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
+	}
 	return test_bit(IDESCSI_TRANSFORM, &scsi->transform);
 }
 

drivers/scsi/osst.c

@@ -162,7 +162,6 @@ struct Scsi_Device_Template osst_template =
        name:		"OnStream tape",
        tag:		"osst",
        scsi_type:	TYPE_TAPE,
-       major:		OSST_MAJOR,
        detect:		osst_detect,
        init:		osst_init,
        attach:		osst_attach,

drivers/scsi/scsi_lib.c

@@ -635,7 +635,7 @@ void scsi_io_completion(Scsi_Cmnd * SCpnt, int good_sectors,
 			break;
 		case NOT_READY:
 			printk(KERN_INFO "Device %s not ready.\n",
-			       kdevname(req->rq_dev));
+			       req->rq_disk ? req->rq_disk->disk_name : "");
 			SCpnt = scsi_end_request(SCpnt, 0, this_count);
 			return;
 			break;
@@ -703,36 +703,8 @@ void scsi_io_completion(Scsi_Cmnd * SCpnt, int good_sectors,
  */
 struct Scsi_Device_Template *scsi_get_request_dev(struct request *req)
 {
-	struct Scsi_Device_Template *spnt;
-	kdev_t dev = req->rq_dev;
-	int major = major(dev);
-
-	for (spnt = scsi_devicelist; spnt; spnt = spnt->next) {
-		/*
-		 * Search for a block device driver that supports this
-		 * major.
-		 */
-		if (spnt->blk && spnt->major == major) {
-			return spnt;
-		}
-		/*
-		 * I am still not entirely satisfied with this solution,
-		 * but it is good enough for now.  Disks have a number of
-		 * major numbers associated with them, the primary
-		 * 8, which we test above, and a secondary range of 7
-		 * different consecutive major numbers.   If this ever
-		 * becomes insufficient, then we could add another function
-		 * to the structure, and generalize this completely.
-		 */
-		if( spnt->min_major != 0 
-		    && spnt->max_major != 0
-		    && major >= spnt->min_major
-		    && major <= spnt->max_major )
-		{
-			return spnt;
-		}
-	}
-	return NULL;
+	struct gendisk *p = req->rq_disk;
+	return p ? *(struct Scsi_Device_Template **)p->private_data : NULL;
 }
 
 /*

drivers/scsi/sd.c

@@ -106,9 +106,6 @@ static struct Scsi_Device_Template sd_template = {
 	.name		= "disk",
 	.tag		= "sd",
 	.scsi_type	= TYPE_DISK,
-	.major		= SCSI_DISK0_MAJOR,
-	.min_major	= SCSI_DISK1_MAJOR,
-	.max_major	= SCSI_DISK7_MAJOR,
 	.blk		= 1,
 	.detect		= sd_detect,
 	.attach		= sd_attach,

drivers/scsi/sg.c

@@ -125,7 +125,6 @@ static struct Scsi_Device_Template sg_template = {
 	.name = "generic",
 	.tag = "sg",
 	.scsi_type = 0xff,
-	.major = SCSI_GENERIC_MAJOR,
 	.detect = sg_detect,
 	.init = sg_init,
 	.attach = sg_attach,

drivers/scsi/sr.c

@@ -77,7 +77,6 @@ static struct Scsi_Device_Template sr_template = {
 	.name		= "cdrom",
 	.tag		= "sr",
 	.scsi_type	= TYPE_ROM,
-	.major		= SCSI_CDROM_MAJOR,
 	.blk		= 1,
 	.detect		= sr_detect,
 	.init		= sr_init,

drivers/scsi/st.c

@@ -175,7 +175,6 @@ static struct Scsi_Device_Template st_template = {
 	.name =		"tape", 
 	.tag =		"st", 
 	.scsi_type =	TYPE_TAPE,
-	.major =	SCSI_TAPE_MAJOR, 
 	.detect =	st_detect, 
 	.attach =	st_attach, 
 	.detach =	st_detach