[PATCH] set request fastfail bit correctly

From Mike Christie <michaelc@cs.wisc.edu>

The first three bio and request flags are no longer identical.  The bio
barrier and rw flags are getting set in __make_request and get_request
respectively, and failfast is getting left out.

This sets the request's failfast flag in __make_request when the bio's
flag is set.

drivers/block/ll_rw_blk.c

@@ -2121,11 +2121,14 @@ static int __make_request(request_queue_t *q, struct bio *bio)
 		goto again;
 	}
 
+	req->flags |= REQ_CMD;
+
 	/*
-	 * first three bits are identical in rq->flags and bio->bi_rw,
-	 * see bio.h and blkdev.h
+	 * inherit FAILFAST from bio and don't stack up
+	 * retries for read ahead
 	 */
-	req->flags = (bio->bi_rw & 7) | REQ_CMD;
+	if (ra || test_bit(BIO_RW_FAILFAST, &bio->bi_rw))	
+		req->flags |= REQ_FAILFAST;
 
 	/*
 	 * REQ_BARRIER implies no merging, but lets make it explicit
@@ -2133,12 +2136,6 @@ static int __make_request(request_queue_t *q, struct bio *bio)
 	if (barrier)
 		req->flags |= (REQ_HARDBARRIER | REQ_NOMERGE);
 
-	/*
-	 * don't stack up retries for read ahead
-	 */
-	if (ra)
-		req->flags |= REQ_FAILFAST;
-
 	req->errors = 0;
 	req->hard_sector = req->sector = sector;
 	req->hard_nr_sectors = req->nr_sectors = nr_sectors;