diff --git a/include/spdk/bdev.h b/include/spdk/bdev.h
index e152d345a..27e00071b 100644
--- a/include/spdk/bdev.h
+++ b/include/spdk/bdev.h
@@ -189,17 +189,11 @@ struct spdk_bdev_io {
 			/** The unaligned rbuf originally allocated. */
 			void *buf_unaligned;
 
-			/** For basic read case, use our own iovec element. */
-			struct iovec iov;
+			/** For single buffer cases, pointer to the aligned data buffer.  */
+			void *buf;
 
-			/** For SG buffer cases, array of iovecs to transfer. */
-			struct iovec *iovs;
-
-			/** For SG buffer cases, number of iovecs in iovec array. */
-			int iovcnt;
-
-			/** For SG buffer cases, total size of data to be transferred. */
-			size_t len;
+			/** For single buffer cases, size of the data buffer. */
+			uint64_t nbytes;
 
 			/** Starting offset (in bytes) of the blockdev for this I/O. */
 			uint64_t offset;
@@ -285,11 +279,6 @@ bool spdk_bdev_io_type_supported(struct spdk_bdev *bdev, enum spdk_bdev_io_type
 struct spdk_bdev_io *spdk_bdev_read(struct spdk_bdev *bdev, struct spdk_io_channel *ch,
 				    void *buf, uint64_t offset, uint64_t nbytes,
 				    spdk_bdev_io_completion_cb cb, void *cb_arg);
-struct spdk_bdev_io *
-spdk_bdev_readv(struct spdk_bdev *bdev, struct spdk_io_channel *ch,
-		struct iovec *iov, int iovcnt,
-		uint64_t offset, uint64_t nbytes,
-		spdk_bdev_io_completion_cb cb, void *cb_arg);
 struct spdk_bdev_io *spdk_bdev_write(struct spdk_bdev *bdev, struct spdk_io_channel *ch,
 				     void *buf, uint64_t offset, uint64_t nbytes,
 				     spdk_bdev_io_completion_cb cb, void *cb_arg);
diff --git a/lib/bdev/aio/blockdev_aio.c b/lib/bdev/aio/blockdev_aio.c
index 570644037..b871e5300 100644
--- a/lib/bdev/aio/blockdev_aio.c
+++ b/lib/bdev/aio/blockdev_aio.c
@@ -98,9 +98,8 @@ blockdev_aio_close(struct file_disk *disk)
 }
 
 static int64_t
-blockdev_aio_readv(struct file_disk *fdisk, struct spdk_io_channel *ch,
-		   struct blockdev_aio_task *aio_task,
-		   struct iovec *iov, int iovcnt, uint64_t nbytes, uint64_t offset)
+blockdev_aio_read(struct file_disk *fdisk, struct spdk_io_channel *ch,
+		  struct blockdev_aio_task *aio_task, void *buf, uint64_t nbytes, uint64_t offset)
 {
 	struct iocb *iocb = &aio_task->iocb;
 	struct blockdev_aio_io_channel *aio_ch = spdk_io_channel_get_ctx(ch);
@@ -108,15 +107,15 @@ blockdev_aio_readv(struct file_disk *fdisk, struct spdk_io_channel *ch,
 
 	iocb->aio_fildes = fdisk->fd;
 	iocb->aio_reqprio = 0;
-	iocb->aio_lio_opcode = IO_CMD_PREADV;
-	iocb->u.v.vec = iov;
-	iocb->u.v.nr = iovcnt;
-	iocb->u.v.offset = offset;
+	iocb->aio_lio_opcode = IO_CMD_PREAD;
+	iocb->u.c.buf = buf;
+	iocb->u.c.nbytes = nbytes;
+	iocb->u.c.offset = offset;
 	iocb->data = aio_task;
 	aio_task->len = nbytes;
 
-	SPDK_TRACELOG(SPDK_TRACE_AIO, "read %d iovs size %lu to off: %#lx\n",
-		      iovcnt, nbytes, offset);
+	SPDK_TRACELOG(SPDK_TRACE_AIO, "read from %p of size %lu to off: %#lx\n",
+		      buf, nbytes, offset);
 
 	rc = io_submit(aio_ch->io_ctx, 1, &iocb);
 	if (rc < 0) {
@@ -246,13 +245,12 @@ static void blockdev_aio_get_rbuf_cb(struct spdk_bdev_io *bdev_io)
 {
 	int ret = 0;
 
-	ret = blockdev_aio_readv((struct file_disk *)bdev_io->ctx,
-				 bdev_io->ch,
-				 (struct blockdev_aio_task *)bdev_io->driver_ctx,
-				 bdev_io->u.read.iovs,
-				 bdev_io->u.read.iovcnt,
-				 bdev_io->u.read.offset,
-				 bdev_io->u.read.len);
+	ret = blockdev_aio_read((struct file_disk *)bdev_io->ctx,
+				bdev_io->ch,
+				(struct blockdev_aio_task *)bdev_io->driver_ctx,
+				bdev_io->u.read.buf,
+				bdev_io->u.read.nbytes,
+				bdev_io->u.read.offset);
 
 	if (ret < 0) {
 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
diff --git a/lib/bdev/bdev.c b/lib/bdev/bdev.c
index e0db48f0c..7c7056525 100644
--- a/lib/bdev/bdev.c
+++ b/lib/bdev/bdev.c
@@ -113,11 +113,8 @@ spdk_bdev_io_set_rbuf(struct spdk_bdev_io *bdev_io, void *buf)
 {
 	assert(bdev_io->get_rbuf_cb != NULL);
 	assert(buf != NULL);
-	assert(bdev_io->u.read.iovs != NULL);
-
 	bdev_io->u.read.buf_unaligned = buf;
-	bdev_io->u.read.iovs[0].iov_base = (void *)((unsigned long)((char *)buf + 512) & ~511UL);
-	bdev_io->u.read.iovs[0].iov_len = bdev_io->u.read.len;
+	bdev_io->u.read.buf = (void *)((unsigned long)((char *)buf + 512) & ~511UL);
 	bdev_io->u.read.put_rbuf = true;
 	bdev_io->get_rbuf_cb(bdev_io);
 }
@@ -131,9 +128,7 @@ spdk_bdev_io_put_rbuf(struct spdk_bdev_io *bdev_io)
 	need_rbuf_tailq_t *tailq;
 	uint64_t length;
 
-	assert(bdev_io->u.read.iovcnt == 1);
-
-	length = bdev_io->u.read.len;
+	length = bdev_io->u.read.nbytes;
 	buf = bdev_io->u.read.buf_unaligned;
 
 	if (length <= SPDK_BDEV_SMALL_RBUF_MAX_SIZE) {
@@ -366,7 +361,7 @@ spdk_bdev_put_io(struct spdk_bdev_io *bdev_io)
 static void
 _spdk_bdev_io_get_rbuf(struct spdk_bdev_io *bdev_io)
 {
-	uint64_t len = bdev_io->u.read.len;
+	uint64_t len = bdev_io->u.read.nbytes;
 	struct rte_mempool *pool;
 	need_rbuf_tailq_t *tailq;
 	int rc;
@@ -549,62 +544,9 @@ spdk_bdev_read(struct spdk_bdev *bdev, struct spdk_io_channel *ch,
 
 	bdev_io->ch = ch;
 	bdev_io->type = SPDK_BDEV_IO_TYPE_READ;
-	bdev_io->u.read.iov.iov_base = buf;
-	bdev_io->u.read.iov.iov_len = nbytes;
-	bdev_io->u.read.iovs = &bdev_io->u.read.iov;
-	bdev_io->u.read.iovcnt = 1;
-	bdev_io->u.read.len = nbytes;
+	bdev_io->u.read.buf = buf;
+	bdev_io->u.read.nbytes = nbytes;
 	bdev_io->u.read.offset = offset;
-	bdev_io->u.read.put_rbuf = false;
-	spdk_bdev_io_init(bdev_io, bdev, cb_arg, cb);
-
-	rc = spdk_bdev_io_submit(bdev_io);
-	if (rc < 0) {
-		spdk_bdev_put_io(bdev_io);
-		return NULL;
-	}
-
-	return bdev_io;
-}
-
-struct spdk_bdev_io *
-spdk_bdev_readv(struct spdk_bdev *bdev, struct spdk_io_channel *ch,
-		struct iovec *iov, int iovcnt,
-		uint64_t offset, uint64_t nbytes,
-		spdk_bdev_io_completion_cb cb, void *cb_arg)
-{
-	struct spdk_bdev_io *bdev_io;
-	int rc;
-
-	/* Return failure if nbytes is not a multiple of bdev->blocklen */
-	if (nbytes % bdev->blocklen) {
-		return NULL;
-	}
-
-	/* Return failure if offset + nbytes is less than offset; indicates there
-	 * has been an overflow and hence the offset has been wrapped around */
-	if ((offset + nbytes) < offset) {
-		return NULL;
-	}
-
-	/* Return failure if offset + nbytes exceeds the size of the blockdev */
-	if ((offset + nbytes) > (bdev->blockcnt * bdev->blocklen)) {
-		return NULL;
-	}
-
-	bdev_io = spdk_bdev_get_io();
-	if (!bdev_io) {
-		SPDK_ERRLOG("spdk_bdev_io memory allocation failed duing read\n");
-		return NULL;
-	}
-
-	bdev_io->ch = ch;
-	bdev_io->type = SPDK_BDEV_IO_TYPE_READ;
-	bdev_io->u.read.iovs = iov;
-	bdev_io->u.read.iovcnt = iovcnt;
-	bdev_io->u.read.len = nbytes;
-	bdev_io->u.read.offset = offset;
-	bdev_io->u.read.put_rbuf = false;
 	spdk_bdev_io_init(bdev_io, bdev, cb_arg, cb);
 
 	rc = spdk_bdev_io_submit(bdev_io);
@@ -891,9 +833,8 @@ void
 spdk_bdev_io_get_rbuf(struct spdk_bdev_io *bdev_io, spdk_bdev_io_get_rbuf_cb cb)
 {
 	assert(cb != NULL);
-	assert(bdev_io->u.read.iovs != NULL);
 
-	if (bdev_io->u.read.iovs[0].iov_base == NULL) {
+	if (bdev_io->u.read.buf == NULL) {
 		bdev_io->get_rbuf_cb = cb;
 		_spdk_bdev_io_get_rbuf(bdev_io);
 	} else {
diff --git a/lib/bdev/malloc/blockdev_malloc.c b/lib/bdev/malloc/blockdev_malloc.c
index deac05b7d..86c5c6701 100644
--- a/lib/bdev/malloc/blockdev_malloc.c
+++ b/lib/bdev/malloc/blockdev_malloc.c
@@ -70,11 +70,6 @@ malloc_done(void *ref, int status)
 	spdk_bdev_io_complete(spdk_bdev_io_from_ctx(cp_task), bdev_status);
 }
 
-static void
-malloc_iov_done_nop(void *ref, int status)
-{
-}
-
 static struct malloc_disk *g_malloc_disk_head = NULL;
 
 int malloc_disk_count = 0;
@@ -125,58 +120,16 @@ blockdev_malloc_destruct(struct spdk_bdev *bdev)
 	return 0;
 }
 
-static int
-blockdev_malloc_check_iov_len(struct iovec *iovs, int iovcnt, size_t nbytes)
-{
-	int i;
-
-	for (i = 0; nbytes && i < iovcnt; i++) {
-		if (nbytes < iovs[i].iov_len)
-			break;
-
-		nbytes -= iovs[i].iov_len;
-	}
-
-	/* IO len must be equal to total len of all buffers */
-	return nbytes != 0 || iovcnt != i;
-}
-
 static int64_t
-blockdev_malloc_readv(struct malloc_disk *mdisk, struct spdk_io_channel *ch,
-		      struct copy_task *copy_req,
-		      struct iovec *iov, int iovcnt, size_t len, uint64_t offset)
+blockdev_malloc_read(struct malloc_disk *mdisk, struct spdk_io_channel *ch,
+		     struct copy_task *copy_req,
+		     void *buf, uint64_t nbytes, uint64_t offset)
 {
-	int64_t res = 0;
-	copy_completion_cb completion_cb = malloc_iov_done_nop;
-	void *src = mdisk->malloc_buf + offset;
-	int i;
+	SPDK_TRACELOG(SPDK_TRACE_MALLOC, "read %lu bytes from offset %#lx to %p\n",
+		      nbytes, offset, buf);
 
-	if (blockdev_malloc_check_iov_len(iov, iovcnt, len))
-		return -1;
-
-	SPDK_TRACELOG(SPDK_TRACE_MALLOC, "read %lu bytes from offset %#lx\n",
-		      len, offset);
-
-	for (i = 0; i < iovcnt; i++) {
-		/*
-		 * The copy engine will complete all copy operations in order, so
-		 * use a nop callback for the all iov completions before the last one.
-		 * Then when the last iov is completed, we will actually complete the
-		 * bdev operation back to the caller.
-		 */
-		if (len == iov[i].iov_len)
-			completion_cb = malloc_done;
-
-		res = spdk_copy_submit(copy_req, ch, iov[i].iov_base,
-				       src, iov[i].iov_len, completion_cb);
-		if (res)
-			break;
-
-		src += iov[i].iov_len;
-		len -= iov[i].iov_len;
-	}
-
-	return res;
+	return spdk_copy_submit(copy_req, ch, buf, mdisk->malloc_buf + offset,
+				nbytes, malloc_done);
 }
 
 static int64_t
@@ -184,37 +137,14 @@ blockdev_malloc_writev(struct malloc_disk *mdisk, struct spdk_io_channel *ch,
 		       struct copy_task *copy_req,
 		       struct iovec *iov, int iovcnt, size_t len, uint64_t offset)
 {
-	int64_t res = 0;
-	copy_completion_cb completion_cb = malloc_iov_done_nop;
-	void *dst = mdisk->malloc_buf + offset;
-	int i;
-
-	if (blockdev_malloc_check_iov_len(iov, iovcnt, len))
+	if ((iovcnt != 1) || (iov->iov_len != len))
 		return -1;
 
-	SPDK_TRACELOG(SPDK_TRACE_MALLOC, "wrote %lu bytes to offset %#lx\n",
-		      len, offset);
+	SPDK_TRACELOG(SPDK_TRACE_MALLOC, "wrote %lu bytes to offset %#lx from %p\n",
+		      iov->iov_len, offset, iov->iov_base);
 
-	for (i = 0; i < iovcnt; i++) {
-		/*
-		 * The copy engine will complete all copy operations in order, so
-		 * use a nop callback for the all iov completions before the last one.
-		 * Then when the last iov is completed, we will actually complete the
-		 * bdev operation back to the caller.
-		 */
-		if (len == iov[i].iov_len)
-			completion_cb = malloc_done;
-
-		res = spdk_copy_submit(copy_req, ch, dst, iov[i].iov_base,
-				       iov[i].iov_len, completion_cb);
-		if (res)
-			break;
-
-		dst += iov[i].iov_len;
-		len -= iov[i].iov_len;
-	}
-
-	return res;
+	return spdk_copy_submit(copy_req, ch, mdisk->malloc_buf + offset,
+				iov->iov_base, len, malloc_done);
 }
 
 static int
@@ -268,25 +198,20 @@ static int _blockdev_malloc_submit_request(struct spdk_bdev_io *bdev_io)
 {
 	switch (bdev_io->type) {
 	case SPDK_BDEV_IO_TYPE_READ:
-		if (bdev_io->u.read.iovs[0].iov_base == NULL) {
-			assert(bdev_io->u.read.iovcnt == 1);
-			bdev_io->u.read.iovs[0].iov_base =
-				((struct malloc_disk *)bdev_io->ctx)->malloc_buf +
-				bdev_io->u.read.offset;
-			bdev_io->u.read.iovs[0].iov_len = bdev_io->u.read.len;
-			bdev_io->u.read.put_rbuf = false;
+		if (bdev_io->u.read.buf == NULL) {
+			bdev_io->u.read.buf = ((struct malloc_disk *)bdev_io->ctx)->malloc_buf +
+					      bdev_io->u.read.offset;
 			spdk_bdev_io_complete(spdk_bdev_io_from_ctx(bdev_io->driver_ctx),
 					      SPDK_BDEV_IO_STATUS_SUCCESS);
 			return 0;
 		}
 
-		return blockdev_malloc_readv((struct malloc_disk *)bdev_io->ctx,
-					     bdev_io->ch,
-					     (struct copy_task *)bdev_io->driver_ctx,
-					     bdev_io->u.read.iovs,
-					     bdev_io->u.read.iovcnt,
-					     bdev_io->u.read.len,
-					     bdev_io->u.read.offset);
+		return blockdev_malloc_read((struct malloc_disk *)bdev_io->ctx,
+					    bdev_io->ch,
+					    (struct copy_task *)bdev_io->driver_ctx,
+					    bdev_io->u.read.buf,
+					    bdev_io->u.read.nbytes,
+					    bdev_io->u.read.offset);
 
 	case SPDK_BDEV_IO_TYPE_WRITE:
 		return blockdev_malloc_writev((struct malloc_disk *)bdev_io->ctx,
diff --git a/lib/bdev/nvme/blockdev_nvme.c b/lib/bdev/nvme/blockdev_nvme.c
index 4c203dfeb..d78498a34 100644
--- a/lib/bdev/nvme/blockdev_nvme.c
+++ b/lib/bdev/nvme/blockdev_nvme.c
@@ -89,17 +89,7 @@ struct nvme_io_channel {
 
 #define NVME_DEFAULT_MAX_UNMAP_BDESC_COUNT	1
 struct nvme_blockio {
-	/** array of iovecs to transfer. */
-	struct iovec *iovs;
-
-	/** Number of iovecs in iovs array. */
-	int iovcnt;
-
-	/** Current iovec position. */
-	int iovpos;
-
-	/** Offset in current iovec. */
-	uint32_t iov_offset;
+	int	reserved;
 };
 
 enum data_direction {
@@ -131,10 +121,9 @@ static void nvme_ctrlr_initialize_blockdevs(struct spdk_nvme_ctrlr *ctrlr,
 		int bdev_per_ns, int ctrlr_id);
 static int nvme_library_init(void);
 static void nvme_library_fini(void);
-static int nvme_queue_cmd(struct nvme_blockdev *bdev, struct spdk_nvme_qpair *qpair,
-			  struct nvme_blockio *bio,
-			  int direction, struct iovec *iov, int iovcnt, uint64_t nbytes,
-			  uint64_t offset);
+int nvme_queue_cmd(struct nvme_blockdev *bdev, struct spdk_nvme_qpair *qpair,
+		   struct nvme_blockio *bio,
+		   int direction, void *buf, uint64_t nbytes, uint64_t offset);
 
 static int
 nvme_get_ctx_size(void)
@@ -146,18 +135,17 @@ SPDK_BDEV_MODULE_REGISTER(nvme_library_init, NULL, blockdev_nvme_get_spdk_runnin
 			  nvme_get_ctx_size)
 
 static int64_t
-blockdev_nvme_readv(struct nvme_blockdev *nbdev, struct spdk_io_channel *ch,
-		    struct nvme_blockio *bio,
-		    struct iovec *iov, int iovcnt, uint64_t nbytes, uint64_t offset)
+blockdev_nvme_read(struct nvme_blockdev *nbdev, struct spdk_io_channel *ch,
+		   struct nvme_blockio *bio,
+		   void *buf, uint64_t nbytes, uint64_t offset)
 {
 	struct nvme_io_channel *nvme_ch = spdk_io_channel_get_ctx(ch);
 	int64_t rc;
 
-	SPDK_TRACELOG(SPDK_TRACE_BDEV_NVME, "read %lu bytes with offset %#lx\n",
-		      nbytes, offset);
+	SPDK_TRACELOG(SPDK_TRACE_BDEV_NVME, "read %lu bytes with offset %#lx to %p\n",
+		      nbytes, offset, buf);
 
-	rc = nvme_queue_cmd(nbdev, nvme_ch->qpair, bio, BDEV_DISK_READ,
-			    iov, iovcnt, nbytes, offset);
+	rc = nvme_queue_cmd(nbdev, nvme_ch->qpair, bio, BDEV_DISK_READ, buf, nbytes, offset);
 	if (rc < 0)
 		return -1;
 
@@ -172,15 +160,18 @@ blockdev_nvme_writev(struct nvme_blockdev *nbdev, struct spdk_io_channel *ch,
 	struct nvme_io_channel *nvme_ch = spdk_io_channel_get_ctx(ch);
 	int64_t rc;
 
-	SPDK_TRACELOG(SPDK_TRACE_BDEV_NVME, "write %lu bytes with offset %#lx\n",
-		      len, offset);
+	if ((iovcnt != 1) || (iov->iov_len != len))
+		return -1;
 
-	rc = nvme_queue_cmd(nbdev, nvme_ch->qpair, bio, BDEV_DISK_WRITE,
-			    iov, iovcnt, len, offset);
+	SPDK_TRACELOG(SPDK_TRACE_BDEV_NVME, "write %lu bytes with offset %#lx from %p\n",
+		      iov->iov_len, offset, iov->iov_base);
+
+	rc = nvme_queue_cmd(nbdev, nvme_ch->qpair, bio, BDEV_DISK_WRITE, (void *)iov->iov_base,
+			    iov->iov_len, offset);
 	if (rc < 0)
 		return -1;
 
-	return len;
+	return iov->iov_len;
 }
 
 static void
@@ -232,13 +223,12 @@ static void blockdev_nvme_get_rbuf_cb(struct spdk_bdev_io *bdev_io)
 {
 	int ret;
 
-	ret = blockdev_nvme_readv((struct nvme_blockdev *)bdev_io->ctx,
-				  bdev_io->ch,
-				  (struct nvme_blockio *)bdev_io->driver_ctx,
-				  bdev_io->u.read.iovs,
-				  bdev_io->u.read.iovcnt,
-				  bdev_io->u.read.len,
-				  bdev_io->u.read.offset);
+	ret = blockdev_nvme_read((struct nvme_blockdev *)bdev_io->ctx,
+				 bdev_io->ch,
+				 (struct nvme_blockio *)bdev_io->driver_ctx,
+				 bdev_io->u.read.buf,
+				 bdev_io->u.read.nbytes,
+				 bdev_io->u.read.offset);
 
 	if (ret < 0) {
 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
@@ -618,51 +608,10 @@ queued_done(void *ref, const struct spdk_nvme_cpl *cpl)
 	spdk_bdev_io_complete(spdk_bdev_io_from_ctx(bio), status);
 }
 
-static void
-queued_reset_sgl(void *ref, uint32_t sgl_offset)
-{
-	struct nvme_blockio *bio = ref;
-	struct iovec *iov;
-
-	bio->iov_offset = sgl_offset;
-	for (bio->iovpos = 0; bio->iovpos < bio->iovcnt; bio->iovpos++) {
-		iov = &bio->iovs[bio->iovpos];
-		if (bio->iov_offset < iov->iov_len)
-			break;
-
-		bio->iov_offset -= iov->iov_len;
-	}
-}
-
-static int
-queued_next_sge(void *ref, uint64_t *address, uint32_t *length)
-{
-	struct nvme_blockio *bio = ref;
-	struct iovec *iov;
-
-	assert(bio->iovpos < bio->iovcnt);
-
-	iov = &bio->iovs[bio->iovpos];
-	bio->iovpos++;
-
-	*address = spdk_vtophys(iov->iov_base);
-	*length = iov->iov_len;
-
-	if (bio->iov_offset) {
-		assert(bio->iov_offset <= iov->iov_len);
-		*address += bio->iov_offset;
-		*length -= bio->iov_offset;
-		bio->iov_offset = 0;
-	}
-
-	return 0;
-}
-
 int
 nvme_queue_cmd(struct nvme_blockdev *bdev, struct spdk_nvme_qpair *qpair,
 	       struct nvme_blockio *bio,
-	       int direction, struct iovec *iov, int iovcnt, uint64_t nbytes,
-	       uint64_t offset)
+	       int direction, void *buf, uint64_t nbytes, uint64_t offset)
 {
 	uint32_t ss = spdk_nvme_ns_get_sector_size(bdev->ns);
 	uint32_t lba_count;
@@ -678,19 +627,12 @@ nvme_queue_cmd(struct nvme_blockdev *bdev, struct spdk_nvme_qpair *qpair,
 
 	lba_count = nbytes / ss;
 
-	bio->iovs = iov;
-	bio->iovcnt = iovcnt;
-	bio->iovpos = 0;
-	bio->iov_offset = 0;
-
 	if (direction == BDEV_DISK_READ) {
-		rc = spdk_nvme_ns_cmd_readv(bdev->ns, qpair, next_lba,
-					    lba_count, queued_done, bio, 0,
-					    queued_reset_sgl, queued_next_sge);
+		rc = spdk_nvme_ns_cmd_read(bdev->ns, qpair, buf, next_lba,
+					   lba_count, queued_done, bio, 0);
 	} else {
-		rc = spdk_nvme_ns_cmd_writev(bdev->ns, qpair, next_lba,
-					     lba_count, queued_done, bio, 0,
-					     queued_reset_sgl, queued_next_sge);
+		rc = spdk_nvme_ns_cmd_write(bdev->ns, qpair, buf, next_lba,
+					    lba_count, queued_done, bio, 0);
 	}
 
 	if (rc != 0) {
diff --git a/lib/bdev/rbd/blockdev_rbd.c b/lib/bdev/rbd/blockdev_rbd.c
index 5ee52d7f3..061be4a97 100644
--- a/lib/bdev/rbd/blockdev_rbd.c
+++ b/lib/bdev/rbd/blockdev_rbd.c
@@ -250,20 +250,17 @@ SPDK_BDEV_MODULE_REGISTER(blockdev_rbd_library_init, blockdev_rbd_library_fini,
 			  blockdev_rbd_get_ctx_size)
 
 static int64_t
-blockdev_rbd_readv(struct blockdev_rbd *disk, struct spdk_io_channel *ch,
-		   struct blockdev_rbd_io *cmd, struct iovec *iov,
-		   int iovcnt, size_t len, uint64_t offset)
+blockdev_rbd_read(struct blockdev_rbd *disk, struct spdk_io_channel *ch,
+		  struct blockdev_rbd_io *cmd, void *buf, size_t nbytes,
+		  uint64_t offset)
 {
 	struct blockdev_rbd_io_channel *rbdio_ch = spdk_io_channel_get_ctx(ch);
 
-	if (iovcnt != 1 || iov->iov_len != len)
-		return -1;
-
 	cmd->ch = rbdio_ch;
 	cmd->direction = BLOCKDEV_RBD_READ;
-	cmd->len = len;
+	cmd->len = nbytes;
 
-	return blockdev_rbd_start_aio(rbdio_ch->image, cmd, iov->iov_base, offset, len);
+	return blockdev_rbd_start_aio(rbdio_ch->image, cmd, buf, offset, nbytes);
 }
 
 static int64_t
@@ -292,13 +289,12 @@ static void blockdev_rbd_get_rbuf_cb(struct spdk_bdev_io *bdev_io)
 {
 	int ret;
 
-	ret = blockdev_rbd_readv(bdev_io->ctx,
-				 bdev_io->ch,
-				 (struct blockdev_rbd_io *)bdev_io->driver_ctx,
-				 bdev_io->u.read.iovs,
-				 bdev_io->u.read.iovcnt,
-				 bdev_io->u.read.len,
-				 bdev_io->u.read.offset);
+	ret = blockdev_rbd_read(bdev_io->ctx,
+				bdev_io->ch,
+				(struct blockdev_rbd_io *)bdev_io->driver_ctx,
+				bdev_io->u.read.buf,
+				bdev_io->u.read.nbytes,
+				bdev_io->u.read.offset);
 
 	if (ret != 0) {
 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
diff --git a/lib/scsi/scsi_bdev.c b/lib/scsi/scsi_bdev.c
index 4533f844d..e4651b564 100644
--- a/lib/scsi/scsi_bdev.c
+++ b/lib/scsi/scsi_bdev.c
@@ -1302,7 +1302,7 @@ spdk_bdev_scsi_task_complete(spdk_event_t event)
 	}
 
 	if (bdev_io->type == SPDK_BDEV_IO_TYPE_READ) {
-		task->rbuf = bdev_io->u.read.iovs[0].iov_base;
+		task->rbuf = bdev_io->u.read.buf;
 	}
 
 	spdk_scsi_lun_complete_task(task->lun, task);
diff --git a/test/lib/bdev/bdevperf/bdevperf.c b/test/lib/bdev/bdevperf/bdevperf.c
index a253367a9..454e47a71 100644
--- a/test/lib/bdev/bdevperf/bdevperf.c
+++ b/test/lib/bdev/bdevperf/bdevperf.c
@@ -195,8 +195,7 @@ bdevperf_complete(spdk_event_t event)
 		target->is_draining = true;
 		g_run_failed = true;
 	} else if (g_verify || g_reset || g_unmap) {
-		assert(bdev_io->u.read.iovcnt == 1);
-		if (memcmp(task->buf, bdev_io->u.read.iov.iov_base, g_io_size) != 0) {
+		if (memcmp(task->buf, bdev_io->u.read.buf, g_io_size) != 0) {
 			printf("Buffer mismatch! Disk Offset: %lu\n", bdev_io->u.read.offset);
 			target->is_draining = true;
 			g_run_failed = true;