block: convert to pos and nr_sectors accessors

With recent cleanups, there is no place where low level driver
directly manipulates request fields.  This means that the 'hard'
request fields always equal the !hard fields.  Convert all
rq->sectors, nr_sectors and current_nr_sectors references to
accessors.

While at it, drop superflous blk_rq_pos() < 0 test in swim.c.

[ Impact: use pos and nr_sectors accessors ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Tested-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Acked-by: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Acked-by: Mike Miller <mike.miller@hp.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Tim Waugh <tim@cyberelk.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Dario Ballabio <ballabio_dario@emc.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: unsik Kim <donari75@gmail.com>
Cc: Laurent Vivier <Laurent@lvivier.info>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 3fcb64b..70c4dd9 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -383,9 +383,9 @@
 	struct scsi_device *sdp = q->queuedata;
 	struct gendisk *disk = rq->rq_disk;
 	struct scsi_disk *sdkp;
-	sector_t block = rq->sector;
+	sector_t block = blk_rq_pos(rq);
 	sector_t threshold;
-	unsigned int this_count = rq->nr_sectors;
+	unsigned int this_count = blk_rq_sectors(rq);
 	int ret, host_dif;
 
 	if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
@@ -412,10 +412,10 @@
 					this_count));
 
 	if (!sdp || !scsi_device_online(sdp) ||
- 	    block + rq->nr_sectors > get_capacity(disk)) {
+	    block + blk_rq_sectors(rq) > get_capacity(disk)) {
 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
-						"Finishing %ld sectors\n",
-						rq->nr_sectors));
+						"Finishing %u sectors\n",
+						blk_rq_sectors(rq)));
 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
 						"Retry with 0x%p\n", SCpnt));
 		goto out;
@@ -462,7 +462,7 @@
 	 * for this.
 	 */
 	if (sdp->sector_size == 1024) {
-		if ((block & 1) || (rq->nr_sectors & 1)) {
+		if ((block & 1) || (blk_rq_sectors(rq) & 1)) {
 			scmd_printk(KERN_ERR, SCpnt,
 				    "Bad block number requested\n");
 			goto out;
@@ -472,7 +472,7 @@
 		}
 	}
 	if (sdp->sector_size == 2048) {
-		if ((block & 3) || (rq->nr_sectors & 3)) {
+		if ((block & 3) || (blk_rq_sectors(rq) & 3)) {
 			scmd_printk(KERN_ERR, SCpnt,
 				    "Bad block number requested\n");
 			goto out;
@@ -482,7 +482,7 @@
 		}
 	}
 	if (sdp->sector_size == 4096) {
-		if ((block & 7) || (rq->nr_sectors & 7)) {
+		if ((block & 7) || (blk_rq_sectors(rq) & 7)) {
 			scmd_printk(KERN_ERR, SCpnt,
 				    "Bad block number requested\n");
 			goto out;
@@ -511,10 +511,10 @@
 	}
 
 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
-					"%s %d/%ld 512 byte blocks.\n",
+					"%s %d/%u 512 byte blocks.\n",
 					(rq_data_dir(rq) == WRITE) ?
 					"writing" : "reading", this_count,
-					rq->nr_sectors));
+					blk_rq_sectors(rq)));
 
 	/* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
 	host_dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
@@ -970,8 +970,8 @@
 
 static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
 {
-	u64 start_lba = scmd->request->sector;
-	u64 end_lba = scmd->request->sector + (scsi_bufflen(scmd) / 512);
+	u64 start_lba = blk_rq_pos(scmd->request);
+	u64 end_lba = blk_rq_pos(scmd->request) + (scsi_bufflen(scmd) / 512);
 	u64 bad_lba;
 	int info_valid;