diff --git a/block/as-iosched.c b/block/as-iosched.c
index 631f6f44460a..c48fa670d221 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -17,9 +17,6 @@
 #include <linux/rbtree.h>
 #include <linux/interrupt.h>
 
-#define REQ_SYNC	1
-#define REQ_ASYNC	0
-
 /*
  * See Documentation/block/as-iosched.txt
  */
@@ -93,7 +90,7 @@ struct as_data {
 	struct list_head fifo_list[2];
 
 	struct request *next_rq[2];	/* next in sort order */
-	sector_t last_sector[2];	/* last REQ_SYNC & REQ_ASYNC sectors */
+	sector_t last_sector[2];	/* last SYNC & ASYNC sectors */
 
 	unsigned long exit_prob;	/* probability a task will exit while
 					   being waited on */
@@ -109,7 +106,7 @@ struct as_data {
 	unsigned long last_check_fifo[2];
 	int changed_batch;		/* 1: waiting for old batch to end */
 	int new_batch;			/* 1: waiting on first read complete */
-	int batch_data_dir;		/* current batch REQ_SYNC / REQ_ASYNC */
+	int batch_data_dir;		/* current batch SYNC / ASYNC */
 	int write_batch_count;		/* max # of reqs in a write batch */
 	int current_write_count;	/* how many requests left this batch */
 	int write_batch_idled;		/* has the write batch gone idle? */
@@ -554,7 +551,7 @@ static void as_update_iohist(struct as_data *ad, struct as_io_context *aic,
 	if (aic == NULL)
 		return;
 
-	if (data_dir == REQ_SYNC) {
+	if (data_dir == BLK_RW_SYNC) {
 		unsigned long in_flight = atomic_read(&aic->nr_queued)
 					+ atomic_read(&aic->nr_dispatched);
 		spin_lock(&aic->lock);
@@ -811,7 +808,7 @@ static void as_update_rq(struct as_data *ad, struct request *rq)
  */
 static void update_write_batch(struct as_data *ad)
 {
-	unsigned long batch = ad->batch_expire[REQ_ASYNC];
+	unsigned long batch = ad->batch_expire[BLK_RW_ASYNC];
 	long write_time;
 
 	write_time = (jiffies - ad->current_batch_expires) + batch;
@@ -855,7 +852,7 @@ static void as_completed_request(struct request_queue *q, struct request *rq)
 		kblockd_schedule_work(q, &ad->antic_work);
 		ad->changed_batch = 0;
 
-		if (ad->batch_data_dir == REQ_SYNC)
+		if (ad->batch_data_dir == BLK_RW_SYNC)
 			ad->new_batch = 1;
 	}
 	WARN_ON(ad->nr_dispatched == 0);
@@ -869,7 +866,7 @@ static void as_completed_request(struct request_queue *q, struct request *rq)
 	if (ad->new_batch && ad->batch_data_dir == rq_is_sync(rq)) {
 		update_write_batch(ad);
 		ad->current_batch_expires = jiffies +
-				ad->batch_expire[REQ_SYNC];
+				ad->batch_expire[BLK_RW_SYNC];
 		ad->new_batch = 0;
 	}
 
@@ -960,7 +957,7 @@ static inline int as_batch_expired(struct as_data *ad)
 	if (ad->changed_batch || ad->new_batch)
 		return 0;
 
-	if (ad->batch_data_dir == REQ_SYNC)
+	if (ad->batch_data_dir == BLK_RW_SYNC)
 		/* TODO! add a check so a complete fifo gets written? */
 		return time_after(jiffies, ad->current_batch_expires);
 
@@ -986,7 +983,7 @@ static void as_move_to_dispatch(struct as_data *ad, struct request *rq)
 	 */
 	ad->last_sector[data_dir] = rq->sector + rq->nr_sectors;
 
-	if (data_dir == REQ_SYNC) {
+	if (data_dir == BLK_RW_SYNC) {
 		struct io_context *ioc = RQ_IOC(rq);
 		/* In case we have to anticipate after this */
 		copy_io_context(&ad->io_context, &ioc);
@@ -1025,41 +1022,41 @@ static void as_move_to_dispatch(struct as_data *ad, struct request *rq)
 static int as_dispatch_request(struct request_queue *q, int force)
 {
 	struct as_data *ad = q->elevator->elevator_data;
-	const int reads = !list_empty(&ad->fifo_list[REQ_SYNC]);
-	const int writes = !list_empty(&ad->fifo_list[REQ_ASYNC]);
+	const int reads = !list_empty(&ad->fifo_list[BLK_RW_SYNC]);
+	const int writes = !list_empty(&ad->fifo_list[BLK_RW_ASYNC]);
 	struct request *rq;
 
 	if (unlikely(force)) {
 		/*
 		 * Forced dispatch, accounting is useless.  Reset
 		 * accounting states and dump fifo_lists.  Note that
-		 * batch_data_dir is reset to REQ_SYNC to avoid
+		 * batch_data_dir is reset to BLK_RW_SYNC to avoid
 		 * screwing write batch accounting as write batch
 		 * accounting occurs on W->R transition.
 		 */
 		int dispatched = 0;
 
-		ad->batch_data_dir = REQ_SYNC;
+		ad->batch_data_dir = BLK_RW_SYNC;
 		ad->changed_batch = 0;
 		ad->new_batch = 0;
 
-		while (ad->next_rq[REQ_SYNC]) {
-			as_move_to_dispatch(ad, ad->next_rq[REQ_SYNC]);
+		while (ad->next_rq[BLK_RW_SYNC]) {
+			as_move_to_dispatch(ad, ad->next_rq[BLK_RW_SYNC]);
 			dispatched++;
 		}
-		ad->last_check_fifo[REQ_SYNC] = jiffies;
+		ad->last_check_fifo[BLK_RW_SYNC] = jiffies;
 
-		while (ad->next_rq[REQ_ASYNC]) {
-			as_move_to_dispatch(ad, ad->next_rq[REQ_ASYNC]);
+		while (ad->next_rq[BLK_RW_ASYNC]) {
+			as_move_to_dispatch(ad, ad->next_rq[BLK_RW_ASYNC]);
 			dispatched++;
 		}
-		ad->last_check_fifo[REQ_ASYNC] = jiffies;
+		ad->last_check_fifo[BLK_RW_ASYNC] = jiffies;
 
 		return dispatched;
 	}
 
 	/* Signal that the write batch was uncontended, so we can't time it */
-	if (ad->batch_data_dir == REQ_ASYNC && !reads) {
+	if (ad->batch_data_dir == BLK_RW_ASYNC && !reads) {
 		if (ad->current_write_count == 0 || !writes)
 			ad->write_batch_idled = 1;
 	}
@@ -1076,8 +1073,8 @@ static int as_dispatch_request(struct request_queue *q, int force)
 		 */
 		rq = ad->next_rq[ad->batch_data_dir];
 
-		if (ad->batch_data_dir == REQ_SYNC && ad->antic_expire) {
-			if (as_fifo_expired(ad, REQ_SYNC))
+		if (ad->batch_data_dir == BLK_RW_SYNC && ad->antic_expire) {
+			if (as_fifo_expired(ad, BLK_RW_SYNC))
 				goto fifo_expired;
 
 			if (as_can_anticipate(ad, rq)) {
@@ -1090,7 +1087,7 @@ static int as_dispatch_request(struct request_queue *q, int force)
 			/* we have a "next request" */
 			if (reads && !writes)
 				ad->current_batch_expires =
-					jiffies + ad->batch_expire[REQ_SYNC];
+					jiffies + ad->batch_expire[BLK_RW_SYNC];
 			goto dispatch_request;
 		}
 	}
@@ -1101,20 +1098,20 @@ static int as_dispatch_request(struct request_queue *q, int force)
 	 */
 
 	if (reads) {
-		BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[REQ_SYNC]));
+		BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[BLK_RW_SYNC]));
 
-		if (writes && ad->batch_data_dir == REQ_SYNC)
+		if (writes && ad->batch_data_dir == BLK_RW_SYNC)
 			/*
 			 * Last batch was a read, switch to writes
 			 */
 			goto dispatch_writes;
 
-		if (ad->batch_data_dir == REQ_ASYNC) {
+		if (ad->batch_data_dir == BLK_RW_ASYNC) {
 			WARN_ON(ad->new_batch);
 			ad->changed_batch = 1;
 		}
-		ad->batch_data_dir = REQ_SYNC;
-		rq = rq_entry_fifo(ad->fifo_list[REQ_SYNC].next);
+		ad->batch_data_dir = BLK_RW_SYNC;
+		rq = rq_entry_fifo(ad->fifo_list[BLK_RW_SYNC].next);
 		ad->last_check_fifo[ad->batch_data_dir] = jiffies;
 		goto dispatch_request;
 	}
@@ -1125,9 +1122,9 @@ static int as_dispatch_request(struct request_queue *q, int force)
 
 	if (writes) {
 dispatch_writes:
-		BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[REQ_ASYNC]));
+		BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[BLK_RW_ASYNC]));
 
-		if (ad->batch_data_dir == REQ_SYNC) {
+		if (ad->batch_data_dir == BLK_RW_SYNC) {
 			ad->changed_batch = 1;
 
 			/*
@@ -1137,11 +1134,11 @@ static int as_dispatch_request(struct request_queue *q, int force)
 			 */
 			ad->new_batch = 0;
 		}
-		ad->batch_data_dir = REQ_ASYNC;
+		ad->batch_data_dir = BLK_RW_ASYNC;
 		ad->current_write_count = ad->write_batch_count;
 		ad->write_batch_idled = 0;
-		rq = rq_entry_fifo(ad->fifo_list[REQ_ASYNC].next);
-		ad->last_check_fifo[REQ_ASYNC] = jiffies;
+		rq = rq_entry_fifo(ad->fifo_list[BLK_RW_ASYNC].next);
+		ad->last_check_fifo[BLK_RW_ASYNC] = jiffies;
 		goto dispatch_request;
 	}
 
@@ -1164,9 +1161,9 @@ static int as_dispatch_request(struct request_queue *q, int force)
 		if (ad->nr_dispatched)
 			return 0;
 
-		if (ad->batch_data_dir == REQ_ASYNC)
+		if (ad->batch_data_dir == BLK_RW_ASYNC)
 			ad->current_batch_expires = jiffies +
-					ad->batch_expire[REQ_ASYNC];
+					ad->batch_expire[BLK_RW_ASYNC];
 		else
 			ad->new_batch = 1;
 
@@ -1238,8 +1235,8 @@ static int as_queue_empty(struct request_queue *q)
 {
 	struct as_data *ad = q->elevator->elevator_data;
 
-	return list_empty(&ad->fifo_list[REQ_ASYNC])
-		&& list_empty(&ad->fifo_list[REQ_SYNC]);
+	return list_empty(&ad->fifo_list[BLK_RW_ASYNC])
+		&& list_empty(&ad->fifo_list[BLK_RW_SYNC]);
 }
 
 static int
@@ -1346,8 +1343,8 @@ static void as_exit_queue(struct elevator_queue *e)
 	del_timer_sync(&ad->antic_timer);
 	cancel_work_sync(&ad->antic_work);
 
-	BUG_ON(!list_empty(&ad->fifo_list[REQ_SYNC]));
-	BUG_ON(!list_empty(&ad->fifo_list[REQ_ASYNC]));
+	BUG_ON(!list_empty(&ad->fifo_list[BLK_RW_SYNC]));
+	BUG_ON(!list_empty(&ad->fifo_list[BLK_RW_ASYNC]));
 
 	put_io_context(ad->io_context);
 	kfree(ad);
@@ -1372,18 +1369,18 @@ static void *as_init_queue(struct request_queue *q)
 	init_timer(&ad->antic_timer);
 	INIT_WORK(&ad->antic_work, as_work_handler);
 
-	INIT_LIST_HEAD(&ad->fifo_list[REQ_SYNC]);
-	INIT_LIST_HEAD(&ad->fifo_list[REQ_ASYNC]);
-	ad->sort_list[REQ_SYNC] = RB_ROOT;
-	ad->sort_list[REQ_ASYNC] = RB_ROOT;
-	ad->fifo_expire[REQ_SYNC] = default_read_expire;
-	ad->fifo_expire[REQ_ASYNC] = default_write_expire;
+	INIT_LIST_HEAD(&ad->fifo_list[BLK_RW_SYNC]);
+	INIT_LIST_HEAD(&ad->fifo_list[BLK_RW_ASYNC]);
+	ad->sort_list[BLK_RW_SYNC] = RB_ROOT;
+	ad->sort_list[BLK_RW_ASYNC] = RB_ROOT;
+	ad->fifo_expire[BLK_RW_SYNC] = default_read_expire;
+	ad->fifo_expire[BLK_RW_ASYNC] = default_write_expire;
 	ad->antic_expire = default_antic_expire;
-	ad->batch_expire[REQ_SYNC] = default_read_batch_expire;
-	ad->batch_expire[REQ_ASYNC] = default_write_batch_expire;
+	ad->batch_expire[BLK_RW_SYNC] = default_read_batch_expire;
+	ad->batch_expire[BLK_RW_ASYNC] = default_write_batch_expire;
 
-	ad->current_batch_expires = jiffies + ad->batch_expire[REQ_SYNC];
-	ad->write_batch_count = ad->batch_expire[REQ_ASYNC] / 10;
+	ad->current_batch_expires = jiffies + ad->batch_expire[BLK_RW_SYNC];
+	ad->write_batch_count = ad->batch_expire[BLK_RW_ASYNC] / 10;
 	if (ad->write_batch_count < 2)
 		ad->write_batch_count = 2;
 
@@ -1432,11 +1429,11 @@ static ssize_t __FUNC(struct elevator_queue *e, char *page)	\
 	struct as_data *ad = e->elevator_data;			\
 	return as_var_show(jiffies_to_msecs((__VAR)), (page));	\
 }
-SHOW_FUNCTION(as_read_expire_show, ad->fifo_expire[REQ_SYNC]);
-SHOW_FUNCTION(as_write_expire_show, ad->fifo_expire[REQ_ASYNC]);
+SHOW_FUNCTION(as_read_expire_show, ad->fifo_expire[BLK_RW_SYNC]);
+SHOW_FUNCTION(as_write_expire_show, ad->fifo_expire[BLK_RW_ASYNC]);
 SHOW_FUNCTION(as_antic_expire_show, ad->antic_expire);
-SHOW_FUNCTION(as_read_batch_expire_show, ad->batch_expire[REQ_SYNC]);
-SHOW_FUNCTION(as_write_batch_expire_show, ad->batch_expire[REQ_ASYNC]);
+SHOW_FUNCTION(as_read_batch_expire_show, ad->batch_expire[BLK_RW_SYNC]);
+SHOW_FUNCTION(as_write_batch_expire_show, ad->batch_expire[BLK_RW_ASYNC]);
 #undef SHOW_FUNCTION
 
 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX)				\
@@ -1451,13 +1448,14 @@ static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)
 	*(__PTR) = msecs_to_jiffies(*(__PTR));				\
 	return ret;							\
 }
-STORE_FUNCTION(as_read_expire_store, &ad->fifo_expire[REQ_SYNC], 0, INT_MAX);
-STORE_FUNCTION(as_write_expire_store, &ad->fifo_expire[REQ_ASYNC], 0, INT_MAX);
+STORE_FUNCTION(as_read_expire_store, &ad->fifo_expire[BLK_RW_SYNC], 0, INT_MAX);
+STORE_FUNCTION(as_write_expire_store,
+			&ad->fifo_expire[BLK_RW_ASYNC], 0, INT_MAX);
 STORE_FUNCTION(as_antic_expire_store, &ad->antic_expire, 0, INT_MAX);
 STORE_FUNCTION(as_read_batch_expire_store,
-			&ad->batch_expire[REQ_SYNC], 0, INT_MAX);
+			&ad->batch_expire[BLK_RW_SYNC], 0, INT_MAX);
 STORE_FUNCTION(as_write_batch_expire_store,
-			&ad->batch_expire[REQ_ASYNC], 0, INT_MAX);
+			&ad->batch_expire[BLK_RW_ASYNC], 0, INT_MAX);
 #undef STORE_FUNCTION
 
 #define AS_ATTR(name) \