block: cleanup rq->data_len usages

With recent unification of fields, it's now guaranteed that
rq->data_len always equals blk_rq_bytes().  Convert all non-IDE direct
users to accessors.  IDE will be converted in a separate patch.

Boaz: spotted incorrect data_len/resid_len conversion in osd.

[ Impact: convert direct rq->data_len usages to blk_rq_bytes() ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: Darrick J. Wong <djwong@us.ibm.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/scsi/libsas/sas_host_smp.c b/drivers/scsi/libsas/sas_host_smp.c
index 89952ed..be9a951 100644
--- a/drivers/scsi/libsas/sas_host_smp.c
+++ b/drivers/scsi/libsas/sas_host_smp.c
@@ -137,21 +137,21 @@
 	int error = -EINVAL;
 
 	/* eight is the minimum size for request and response frames */
-	if (req->data_len < 8 || rsp->data_len < 8)
+	if (blk_rq_bytes(req) < 8 || blk_rq_bytes(rsp) < 8)
 		goto out;
 
-	if (bio_offset(req->bio) + req->data_len > PAGE_SIZE ||
-	    bio_offset(rsp->bio) + rsp->data_len > PAGE_SIZE) {
+	if (bio_offset(req->bio) + blk_rq_bytes(req) > PAGE_SIZE ||
+	    bio_offset(rsp->bio) + blk_rq_bytes(rsp) > PAGE_SIZE) {
 		shost_printk(KERN_ERR, shost,
 			"SMP request/response frame crosses page boundary");
 		goto out;
 	}
 
-	req_data = kzalloc(req->data_len, GFP_KERNEL);
+	req_data = kzalloc(blk_rq_bytes(req), GFP_KERNEL);
 
 	/* make sure frame can always be built ... we copy
 	 * back only the requested length */
-	resp_data = kzalloc(max(rsp->data_len, 128U), GFP_KERNEL);
+	resp_data = kzalloc(max(blk_rq_bytes(rsp), 128U), GFP_KERNEL);
 
 	if (!req_data || !resp_data) {
 		error = -ENOMEM;
@@ -160,7 +160,7 @@
 
 	local_irq_disable();
 	buf = kmap_atomic(bio_page(req->bio), KM_USER0) + bio_offset(req->bio);
-	memcpy(req_data, buf, req->data_len);
+	memcpy(req_data, buf, blk_rq_bytes(req));
 	kunmap_atomic(buf - bio_offset(req->bio), KM_USER0);
 	local_irq_enable();
 
@@ -176,8 +176,8 @@
 	resp_data[1] = req_data[1];
 	resp_data[2] = SMP_RESP_FUNC_UNK;
 
-	req->resid_len = req->data_len;
-	rsp->resid_len = rsp->data_len;
+	req->resid_len = blk_rq_bytes(req);
+	rsp->resid_len = blk_rq_bytes(rsp);
 
 	switch (req_data[1]) {
 	case SMP_REPORT_GENERAL:
@@ -264,7 +264,7 @@
 
 	local_irq_disable();
 	buf = kmap_atomic(bio_page(rsp->bio), KM_USER0) + bio_offset(rsp->bio);
-	memcpy(buf, resp_data, rsp->data_len);
+	memcpy(buf, resp_data, blk_rq_bytes(rsp));
 	flush_kernel_dcache_page(bio_page(rsp->bio));
 	kunmap_atomic(buf - bio_offset(rsp->bio), KM_USER0);
 	local_irq_enable();