diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 3ba1df9..589850c 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2633,11 +2633,12 @@
 
 
 
-static int pkt_merge_bvec(struct request_queue *q, struct bio *bio, struct bio_vec *bvec)
+static int pkt_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
+			  struct bio_vec *bvec)
 {
 	struct pktcdvd_device *pd = q->queuedata;
-	sector_t zone = ZONE(bio->bi_sector, pd);
-	int used = ((bio->bi_sector - zone) << 9) + bio->bi_size;
+	sector_t zone = ZONE(bmd->bi_sector, pd);
+	int used = ((bmd->bi_sector - zone) << 9) + bmd->bi_size;
 	int remaining = (pd->settings.size << 9) - used;
 	int remaining2;
 
@@ -2645,7 +2646,7 @@
 	 * A bio <= PAGE_SIZE must be allowed. If it crosses a packet
 	 * boundary, pkt_make_request() will split the bio.
 	 */
-	remaining2 = PAGE_SIZE - bio->bi_size;
+	remaining2 = PAGE_SIZE - bmd->bi_size;
 	remaining = max(remaining, remaining2);
 
 	BUG_ON(remaining < 0);
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index 1074824..6a866d7 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -50,17 +50,19 @@
 /**
  *	linear_mergeable_bvec -- tell bio layer if two requests can be merged
  *	@q: request queue
- *	@bio: the buffer head that's been built up so far
+ *	@bvm: properties of new bio
  *	@biovec: the request that could be merged to it.
  *
  *	Return amount of bytes we can take at this offset
  */
-static int linear_mergeable_bvec(struct request_queue *q, struct bio *bio, struct bio_vec *biovec)
+static int linear_mergeable_bvec(struct request_queue *q,
+				 struct bvec_merge_data *bvm,
+				 struct bio_vec *biovec)
 {
 	mddev_t *mddev = q->queuedata;
 	dev_info_t *dev0;
-	unsigned long maxsectors, bio_sectors = bio->bi_size >> 9;
-	sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
+	unsigned long maxsectors, bio_sectors = bvm->bi_size >> 9;
+	sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
 
 	dev0 = which_dev(mddev, sector);
 	maxsectors = (dev0->size << 1) - (sector - (dev0->offset<<1));
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 914c04d..bcbb825 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -241,18 +241,20 @@
 /**
  *	raid0_mergeable_bvec -- tell bio layer if a two requests can be merged
  *	@q: request queue
- *	@bio: the buffer head that's been built up so far
+ *	@bvm: properties of new bio
  *	@biovec: the request that could be merged to it.
  *
  *	Return amount of bytes we can accept at this offset
  */
-static int raid0_mergeable_bvec(struct request_queue *q, struct bio *bio, struct bio_vec *biovec)
+static int raid0_mergeable_bvec(struct request_queue *q,
+				struct bvec_merge_data *bvm,
+				struct bio_vec *biovec)
 {
 	mddev_t *mddev = q->queuedata;
-	sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
+	sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
 	int max;
 	unsigned int chunk_sectors = mddev->chunk_size >> 9;
-	unsigned int bio_sectors = bio->bi_size >> 9;
+	unsigned int bio_sectors = bvm->bi_size >> 9;
 
 	max =  (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
 	if (max < 0) max = 0; /* bio_add cannot handle a negative return */
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index a71277b..22bb2b1 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -439,26 +439,27 @@
 /**
  *	raid10_mergeable_bvec -- tell bio layer if a two requests can be merged
  *	@q: request queue
- *	@bio: the buffer head that's been built up so far
+ *	@bvm: properties of new bio
  *	@biovec: the request that could be merged to it.
  *
  *	Return amount of bytes we can accept at this offset
  *      If near_copies == raid_disk, there are no striping issues,
  *      but in that case, the function isn't called at all.
  */
-static int raid10_mergeable_bvec(struct request_queue *q, struct bio *bio,
-				struct bio_vec *bio_vec)
+static int raid10_mergeable_bvec(struct request_queue *q,
+				 struct bvec_merge_data *bvm,
+				 struct bio_vec *biovec)
 {
 	mddev_t *mddev = q->queuedata;
-	sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
+	sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
 	int max;
 	unsigned int chunk_sectors = mddev->chunk_size >> 9;
-	unsigned int bio_sectors = bio->bi_size >> 9;
+	unsigned int bio_sectors = bvm->bi_size >> 9;
 
 	max =  (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
 	if (max < 0) max = 0; /* bio_add cannot handle a negative return */
-	if (max <= bio_vec->bv_len && bio_sectors == 0)
-		return bio_vec->bv_len;
+	if (max <= biovec->bv_len && bio_sectors == 0)
+		return biovec->bv_len;
 	else
 		return max;
 }
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 54c8ee2..9b00675 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3319,15 +3319,17 @@
 /* We want read requests to align with chunks where possible,
  * but write requests don't need to.
  */
-static int raid5_mergeable_bvec(struct request_queue *q, struct bio *bio, struct bio_vec *biovec)
+static int raid5_mergeable_bvec(struct request_queue *q,
+				struct bvec_merge_data *bvm,
+				struct bio_vec *biovec)
 {
 	mddev_t *mddev = q->queuedata;
-	sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
+	sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
 	int max;
 	unsigned int chunk_sectors = mddev->chunk_size >> 9;
-	unsigned int bio_sectors = bio->bi_size >> 9;
+	unsigned int bio_sectors = bvm->bi_size >> 9;
 
-	if (bio_data_dir(bio) == WRITE)
+	if ((bvm->bi_rw & 1) == WRITE)
 		return biovec->bv_len; /* always allow writes to be mergeable */
 
 	max =  (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
diff --git a/fs/bio.c b/fs/bio.c
index 7761c84..88322b0 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -325,10 +325,19 @@
 		if (page == prev->bv_page &&
 		    offset == prev->bv_offset + prev->bv_len) {
 			prev->bv_len += len;
-			if (q->merge_bvec_fn &&
-			    q->merge_bvec_fn(q, bio, prev) < len) {
-				prev->bv_len -= len;
-				return 0;
+
+			if (q->merge_bvec_fn) {
+				struct bvec_merge_data bvm = {
+					.bi_bdev = bio->bi_bdev,
+					.bi_sector = bio->bi_sector,
+					.bi_size = bio->bi_size,
+					.bi_rw = bio->bi_rw,
+				};
+
+				if (q->merge_bvec_fn(q, &bvm, prev) < len) {
+					prev->bv_len -= len;
+					return 0;
+				}
 			}
 
 			goto done;
@@ -369,11 +378,18 @@
 	 * queue to get further control
 	 */
 	if (q->merge_bvec_fn) {
+		struct bvec_merge_data bvm = {
+			.bi_bdev = bio->bi_bdev,
+			.bi_sector = bio->bi_sector,
+			.bi_size = bio->bi_size,
+			.bi_rw = bio->bi_rw,
+		};
+
 		/*
 		 * merge_bvec_fn() returns number of bytes it can accept
 		 * at this offset
 		 */
-		if (q->merge_bvec_fn(q, bio, bvec) < len) {
+		if (q->merge_bvec_fn(q, &bvm, bvec) < len) {
 			bvec->bv_page = NULL;
 			bvec->bv_len = 0;
 			bvec->bv_offset = 0;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 7ab8aca..ff9d0bd 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -254,7 +254,14 @@
 typedef void (unplug_fn) (struct request_queue *);
 
 struct bio_vec;
-typedef int (merge_bvec_fn) (struct request_queue *, struct bio *, struct bio_vec *);
+struct bvec_merge_data {
+	struct block_device *bi_bdev;
+	sector_t bi_sector;
+	unsigned bi_size;
+	unsigned long bi_rw;
+};
+typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
+			     struct bio_vec *);
 typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
 typedef void (softirq_done_fn)(struct request *);
 typedef int (dma_drain_needed_fn)(struct request *);