diff --git a/block/blktrace.c b/block/blktrace.c
index 92925e7d9e6cb98af23ac11f6b1dfc1d3f4244f9..b8c0702777ff4e1bb2557567a7aa7f6d987bb6eb 100644
--- a/block/blktrace.c
+++ b/block/blktrace.c
@@ -69,7 +69,7 @@ static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK
 /*
  * Bio action bits of interest
  */
-static u32 bio_act[3] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_ACT(BLK_TC_SYNC) };
+static u32 bio_act[5] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_ACT(BLK_TC_SYNC), 0, BLK_TC_ACT(BLK_TC_AHEAD) };
 
 /*
  * More could be added as needed, taking care to increment the decrementer
@@ -79,6 +79,8 @@ static u32 bio_act[3] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_AC
 	(((rw) & (1 << BIO_RW_BARRIER)) >> (BIO_RW_BARRIER - 0))
 #define trace_sync_bit(rw)	\
 	(((rw) & (1 << BIO_RW_SYNC)) >> (BIO_RW_SYNC - 1))
+#define trace_ahead_bit(rw)	\
+	(((rw) & (1 << BIO_RW_AHEAD)) << (BIO_RW_AHEAD - 0))
 
 /*
  * The worker for the various blk_add_trace*() types. Fills out a
@@ -100,6 +102,7 @@ void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
 	what |= ddir_act[rw & WRITE];
 	what |= bio_act[trace_barrier_bit(rw)];
 	what |= bio_act[trace_sync_bit(rw)];
+	what |= bio_act[trace_ahead_bit(rw)];
 
 	pid = tsk->pid;
 	if (unlikely(act_log_check(bt, what, sector, pid)))
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index ab17c7224bb67677325196c2dd2724aa55508619..61d6b3c65b6697105a432378ba452a86ebc346bf 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -3491,8 +3491,8 @@ EXPORT_SYMBOL(end_request);
 
 void blk_rq_bio_prep(request_queue_t *q, struct request *rq, struct bio *bio)
 {
-	/* first three bits are identical in rq->flags and bio->bi_rw */
-	rq->flags |= (bio->bi_rw & 7);
+	/* first two bits are identical in rq->flags and bio->bi_rw */
+	rq->flags |= (bio->bi_rw & 3);
 
 	rq->nr_phys_segments = bio_phys_segments(q, bio);
 	rq->nr_hw_segments = bio_hw_segments(q, bio);
diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index a7e8cef73d1552589bb8f86b71dcf570b06bcd02..7520cc1ff9e2b9d3947f3cb1ace868b329394555 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -11,7 +11,7 @@ enum blktrace_cat {
 	BLK_TC_READ	= 1 << 0,	/* reads */
 	BLK_TC_WRITE	= 1 << 1,	/* writes */
 	BLK_TC_BARRIER	= 1 << 2,	/* barrier */
-	BLK_TC_SYNC	= 1 << 3,	/* barrier */
+	BLK_TC_SYNC	= 1 << 3,	/* sync IO */
 	BLK_TC_QUEUE	= 1 << 4,	/* queueing/merging */
 	BLK_TC_REQUEUE	= 1 << 5,	/* requeueing */
 	BLK_TC_ISSUE	= 1 << 6,	/* issue */
@@ -19,6 +19,7 @@ enum blktrace_cat {
 	BLK_TC_FS	= 1 << 8,	/* fs requests */
 	BLK_TC_PC	= 1 << 9,	/* pc requests */
 	BLK_TC_NOTIFY	= 1 << 10,	/* special message */
+	BLK_TC_AHEAD	= 1 << 11,	/* readahead */
 
 	BLK_TC_END	= 1 << 15,	/* only 16-bits, reminder */
 };
@@ -147,7 +148,7 @@ static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 				    u32 what)
 {
 	struct blk_trace *bt = q->blk_trace;
-	int rw = rq->flags & 0x07;
+	int rw = rq->flags & 0x03;
 
 	if (likely(!bt))
 		return;