situation with csum_and_copy_... API

index ac53a73..405dfdf 100644
@@ -1339,18 +1339,17 @@ done:
 }
 
 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
-			   const struct iovec *iv, unsigned long segs,
-			   ssize_t len, int noblock)
+			   struct iov_iter *to,
+			   int noblock)
 {
 	struct sk_buff *skb;
-	ssize_t ret = 0;
+	ssize_t ret;
 	int peeked, err, off = 0;
-	struct iov_iter iter;
 
 	tun_debug(KERN_INFO, tun, "tun_do_read\n");
 
-	if (!len)
-		return ret;
+	if (!iov_iter_count(to))
+		return 0;
 
 	if (tun->dev->reg_state != NETREG_REGISTERED)
 		return -EIO;

@@ -1359,37 +1358,27 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
 	skb = __skb_recv_datagram(tfile->socket.sk, noblock ? MSG_DONTWAIT : 0,
 				  &peeked, &off, &err);
 	if (!skb)
-		return ret;
+		return 0;
 
-	iov_iter_init(&iter, READ, iv, segs, len);
-	ret = tun_put_user(tun, tfile, skb, &iter);
+	ret = tun_put_user(tun, tfile, skb, to);
 	kfree_skb(skb);
 
 	return ret;
 }
 
-static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
-			    unsigned long count, loff_t pos)
+static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
 	struct file *file = iocb->ki_filp;
 	struct tun_file *tfile = file->private_data;
 	struct tun_struct *tun = __tun_get(tfile);
-	ssize_t len, ret;
+	ssize_t len = iov_iter_count(to), ret;
 
 	if (!tun)
 		return -EBADFD;
-	len = iov_length(iv, count);
-	if (len < 0) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	ret = tun_do_read(tun, tfile, iv, count, len,
-			  file->f_flags & O_NONBLOCK);
+	ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK);
 	ret = min_t(ssize_t, ret, len);
 	if (ret > 0)
 		iocb->ki_pos = ret;
-out:
 	tun_put(tun);
 	return ret;
 }

@@ -1471,6 +1460,7 @@ static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
 {
 	struct tun_file *tfile = container_of(sock, struct tun_file, socket);
 	struct tun_struct *tun = __tun_get(tfile);
+	struct iov_iter to;
 	int ret;
 
 	if (!tun)

@@ -1485,8 +1475,8 @@ static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
 					 SOL_PACKET, TUN_TX_TIMESTAMP);
 		goto out;
 	}
-	ret = tun_do_read(tun, tfile, m->msg_iov, m->msg_iovlen, total_len,
-			  flags & MSG_DONTWAIT);
+	iov_iter_init(&to, READ, m->msg_iov, m->msg_iovlen, total_len);
+	ret = tun_do_read(tun, tfile, &to, flags & MSG_DONTWAIT);
 	if (ret > total_len) {
 		m->msg_flags |= MSG_TRUNC;
 		ret = flags & MSG_TRUNC ? ret : total_len;

@@ -2242,8 +2232,8 @@ static int tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
 static const struct file_operations tun_fops = {
 	.owner	= THIS_MODULE,
 	.llseek = no_llseek,
-	.read  = do_sync_read,
-	.aio_read  = tun_chr_aio_read,
+	.read  = new_sync_read,
+	.read_iter  = tun_chr_read_iter,
 	.write = do_sync_write,
 	.aio_write = tun_chr_aio_write,
 	.poll	= tun_chr_poll,

index 42a80d3..8f80045 100644
@@ -831,64 +831,55 @@ done:
 }
 
 static ssize_t macvtap_do_read(struct macvtap_queue *q,
-			       const struct iovec *iv, unsigned long segs,
-			       unsigned long len,
+			       struct iov_iter *to,
 			       int noblock)
 {
 	DEFINE_WAIT(wait);
 	struct sk_buff *skb;
 	ssize_t ret = 0;
-	struct iov_iter iter;
 
-	while (len) {
+	if (!iov_iter_count(to))
+		return 0;
+
+	while (1) {
 		if (!noblock)
 			prepare_to_wait(sk_sleep(&q->sk), &wait,
 					TASK_INTERRUPTIBLE);
 
 		/* Read frames from the queue */
 		skb = skb_dequeue(&q->sk.sk_receive_queue);
-		if (!skb) {
-			if (noblock) {
-				ret = -EAGAIN;
-				break;
-			}
-			if (signal_pending(current)) {
-				ret = -ERESTARTSYS;
-				break;
-			}
-			/* Nothing to read, let's sleep */
-			schedule();
-			continue;
+		if (skb)
+			break;
+		if (noblock) {
+			ret = -EAGAIN;
+			break;
 		}
-		iov_iter_init(&iter, READ, iv, segs, len);
-		ret = macvtap_put_user(q, skb, &iter);
+		if (signal_pending(current)) {
+			ret = -ERESTARTSYS;
+			break;
+		}
+		/* Nothing to read, let's sleep */
+		schedule();
+	}
+	if (skb) {
+		ret = macvtap_put_user(q, skb, to);
 		kfree_skb(skb);
-		break;
 	}
-
 	if (!noblock)
 		finish_wait(sk_sleep(&q->sk), &wait);
 	return ret;
 }
 
-static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv,
-				unsigned long count, loff_t pos)
+static ssize_t macvtap_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
 	struct file *file = iocb->ki_filp;
 	struct macvtap_queue *q = file->private_data;
-	ssize_t len, ret = 0;
+	ssize_t len = iov_iter_count(to), ret;
 
-	len = iov_length(iv, count);
-	if (len < 0) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	ret = macvtap_do_read(q, iv, count, len, file->f_flags & O_NONBLOCK);
+	ret = macvtap_do_read(q, to, file->f_flags & O_NONBLOCK);
 	ret = min_t(ssize_t, ret, len);
 	if (ret > 0)
 		iocb->ki_pos = ret;
-out:
 	return ret;
 }
 

@@ -1089,7 +1080,8 @@ static const struct file_operations macvtap_fops = {
 	.owner		= THIS_MODULE,
 	.open		= macvtap_open,
 	.release	= macvtap_release,
-	.aio_read	= macvtap_aio_read,
+	.read		= new_sync_read,
+	.read_iter	= macvtap_read_iter,
 	.aio_write	= macvtap_aio_write,
 	.poll		= macvtap_poll,
 	.llseek		= no_llseek,

@@ -1112,11 +1104,12 @@ static int macvtap_recvmsg(struct kiocb *iocb, struct socket *sock,
 			   int flags)
 {
 	struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);
+	struct iov_iter to;
 	int ret;
 	if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
 		return -EINVAL;
-	ret = macvtap_do_read(q, m->msg_iov, m->msg_iovlen, total_len,
-			  flags & MSG_DONTWAIT);
+	iov_iter_init(&to, READ, m->msg_iov, m->msg_iovlen, total_len);
+	ret = macvtap_do_read(q, &to, flags & MSG_DONTWAIT);
 	if (ret > total_len) {
 		m->msg_flags |= MSG_TRUNC;
 		ret = flags & MSG_TRUNC ? ret : total_len;

index d048347..a01cd9a 100644
@@ -2659,10 +2659,13 @@ static inline int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
 int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset,
 				 const struct iovec *from, int from_offset,
 				 int len);
+int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
+				 struct iov_iter *from, int len);
 int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *frm,
 			   int offset, size_t count);
 int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
 			   struct iov_iter *to, int size);
+int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
 void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
 void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb);
 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);

128 lines not on this page · raw message

index 8f80045..22b4cf2 100644
@@ -640,12 +640,12 @@ static void macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
 
 /* Get packet from user space buffer */
 static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
-				const struct iovec *iv, unsigned long total_len,
-				size_t count, int noblock)
+				struct iov_iter *from, int noblock)
 {
 	int good_linear = SKB_MAX_HEAD(NET_IP_ALIGN);
 	struct sk_buff *skb;
 	struct macvlan_dev *vlan;
+	unsigned long total_len = iov_iter_count(from);
 	unsigned long len = total_len;
 	int err;
 	struct virtio_net_hdr vnet_hdr = { 0 };

@@ -653,6 +653,7 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 	int copylen = 0;
 	bool zerocopy = false;
 	size_t linear;
+	ssize_t n;
 
 	if (q->flags & IFF_VNET_HDR) {
 		vnet_hdr_len = q->vnet_hdr_sz;

@@ -662,10 +663,11 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 			goto err;
 		len -= vnet_hdr_len;
 
-		err = memcpy_fromiovecend((void *)&vnet_hdr, iv, 0,
-					   sizeof(vnet_hdr));
-		if (err < 0)
+		err = -EFAULT;
+		n = copy_from_iter(&vnet_hdr, sizeof(vnet_hdr), from);
+		if (n != sizeof(vnet_hdr))
 			goto err;
+		iov_iter_advance(from, vnet_hdr_len - sizeof(vnet_hdr));
 		if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
 		     vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
 							vnet_hdr.hdr_len)

@@ -680,17 +682,16 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 	if (unlikely(len < ETH_HLEN))
 		goto err;
 
-	err = -EMSGSIZE;
-	if (unlikely(count > UIO_MAXIOV))
-		goto err;
-
 	if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) {
+		struct iov_iter i;
+
 		copylen = vnet_hdr.hdr_len ? vnet_hdr.hdr_len : GOODCOPY_LEN;
 		if (copylen > good_linear)
 			copylen = good_linear;
 		linear = copylen;
-		if (iov_pages(iv, vnet_hdr_len + copylen, count)
-		    <= MAX_SKB_FRAGS)
+		i = *from;
+		iov_iter_advance(&i, copylen);
+		if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
 			zerocopy = true;
 	}
 

@@ -708,10 +709,9 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 		goto err;
 
 	if (zerocopy)
-		err = zerocopy_sg_from_iovec(skb, iv, vnet_hdr_len, count);
+		err = zerocopy_sg_from_iter(skb, from);
 	else {
-		err = skb_copy_datagram_from_iovec(skb, 0, iv, vnet_hdr_len,
-						   len);
+		err = skb_copy_datagram_from_iter(skb, 0, from, len);
 		if (!err && m && m->msg_control) {
 			struct ubuf_info *uarg = m->msg_control;
 			uarg->callback(uarg, false);

@@ -764,16 +764,12 @@ err:
 	return err;
 }
 
-static ssize_t macvtap_aio_write(struct kiocb *iocb, const struct iovec *iv,
-				 unsigned long count, loff_t pos)
+static ssize_t macvtap_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
 	struct file *file = iocb->ki_filp;
-	ssize_t result = -ENOLINK;
 	struct macvtap_queue *q = file->private_data;
 
-	result = macvtap_get_user(q, NULL, iv, iov_length(iv, count), count,
-				  file->f_flags & O_NONBLOCK);
-	return result;
+	return macvtap_get_user(q, NULL, from, file->f_flags & O_NONBLOCK);
 }
 
 /* Put packet to the user space buffer */

@@ -1081,8 +1077,9 @@ static const struct file_operations macvtap_fops = {
 	.open		= macvtap_open,
 	.release	= macvtap_release,
 	.read		= new_sync_read,
+	.write		= new_sync_write,
 	.read_iter	= macvtap_read_iter,
-	.aio_write	= macvtap_aio_write,
+	.write_iter	= macvtap_write_iter,
 	.poll		= macvtap_poll,
 	.llseek		= no_llseek,
 	.unlocked_ioctl	= macvtap_ioctl,

@@ -1095,8 +1092,9 @@ static int macvtap_sendmsg(struct kiocb *iocb, struct socket *sock,
 			   struct msghdr *m, size_t total_len)
 {
 	struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);
-	return macvtap_get_user(q, m, m->msg_iov, total_len, m->msg_iovlen,
-			    m->msg_flags & MSG_DONTWAIT);
+	struct iov_iter from;
+	iov_iter_init(&from, WRITE, m->msg_iov, m->msg_iovlen, total_len);
+	return macvtap_get_user(q, m, &from, m->msg_flags & MSG_DONTWAIT);
 }
 
 static int macvtap_recvmsg(struct kiocb *iocb, struct socket *sock,

126 lines not on this page · raw message

index a01cd9a..178cdbd 100644
@@ -2661,8 +2661,6 @@ int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset,
 				 int len);
 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
 				 struct iov_iter *from, int len);
-int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *frm,
-			   int offset, size_t count);
 int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
 			   struct iov_iter *to, int size);
 int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);

78 lines not on this page · raw message

index 178cdbd..7691ad5 100644
@@ -2656,9 +2656,6 @@ static inline int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
 {
 	return skb_copy_and_csum_datagram_iovec(skb, hlen, msg->msg_iov);
 }
-int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset,
-				 const struct iovec *from, int from_offset,
-				 int len);
 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
 				 struct iov_iter *from, int len);
 int skb_copy_datagram_iter(const struct sk_buff *from, int offset,

100 lines not on this page · raw message

index 108d7f3..dfb148e 100644
@@ -2408,6 +2408,10 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
 	unsigned short gso_type = 0;
 	int hlen, tlen;
 	int extra_len = 0;
+	struct iov_iter from;
+	ssize_t n;
+
+	iov_iter_init(&from, WRITE, msg->msg_iov, msg->msg_iovlen, len);
 
 	/*
 	 *	Get and verify the address.

@@ -2446,8 +2450,9 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
 
 		len -= vnet_hdr_len;
 
-		err = memcpy_from_msg((void *)&vnet_hdr, msg, vnet_hdr_len);
-		if (err < 0)
+		err = -EFAULT;
+		n = copy_from_iter(&vnet_hdr, vnet_hdr_len, &from);
+		if (n != vnet_hdr_len)
 			goto out_unlock;
 
 		if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&

@@ -2517,7 +2522,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
 	}
 
 	/* Returns -EFAULT on error */
-	err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
+	err = skb_copy_datagram_from_iter(skb, offset, &from, len);
 	if (err)
 		goto out_free;
 

index 5eee625..4450d62 100644
@@ -1459,6 +1459,9 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
 	struct scm_cookie tmp_scm;
 	int max_level;
 	int data_len = 0;
+	struct iov_iter from;
+
+	iov_iter_init(&from, WRITE, msg->msg_iov, msg->msg_iovlen, len);
 
 	if (NULL == siocb->scm)
 		siocb->scm = &tmp_scm;

@@ -1516,7 +1519,7 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
 	skb_put(skb, len - data_len);
 	skb->data_len = data_len;
 	skb->len = len;
-	err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov, 0, len);
+	err = skb_copy_datagram_from_iter(skb, 0, &from, len);
 	if (err)
 		goto out_free;
 

@@ -1638,6 +1641,9 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
 	bool fds_sent = false;
 	int max_level;
 	int data_len;
+	struct iov_iter from;
+
+	iov_iter_init(&from, WRITE, msg->msg_iov, msg->msg_iovlen, len);
 
 	if (NULL == siocb->scm)
 		siocb->scm = &tmp_scm;

@@ -1694,8 +1700,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
 		skb_put(skb, size - data_len);
 		skb->data_len = data_len;
 		skb->len = size;
-		err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov,
-						   sent, size);
+		err = skb_copy_datagram_from_iter(skb, 0, &from, size);
 		if (err) {
 			kfree_skb(skb);
 			goto out_err;

index 806e3b5..2bb2fcf 100644
@@ -531,7 +531,7 @@ struct sctp_datamsg {
 
 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
 					    struct sctp_sndrcvinfo *,
-					    struct msghdr *, int len);
+					    struct iov_iter *);
 void sctp_datamsg_free(struct sctp_datamsg *);
 void sctp_datamsg_put(struct sctp_datamsg *);
 void sctp_chunk_fail(struct sctp_chunk *, int error);

@@ -647,8 +647,8 @@ struct sctp_chunk {
 
 void sctp_chunk_hold(struct sctp_chunk *);
 void sctp_chunk_put(struct sctp_chunk *);
-int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
-			  struct iovec *data);
+int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
+			  struct iov_iter *from);
 void sctp_chunk_free(struct sctp_chunk *);
 void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
 struct sctp_chunk *sctp_chunkify(struct sk_buff *,

index 158701d..a338091 100644
@@ -164,7 +164,7 @@ static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chu
  */
 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
 					    struct sctp_sndrcvinfo *sinfo,
-					    struct msghdr *msgh, int msg_len)
+					    struct iov_iter *from)
 {
 	int max, whole, i, offset, over, err;
 	int len, first_len;

@@ -172,6 +172,7 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
 	struct sctp_chunk *chunk;
 	struct sctp_datamsg *msg;
 	struct list_head *pos, *temp;
+	size_t msg_len = iov_iter_count(from);
 	__u8 frag;
 
 	msg = sctp_datamsg_new(GFP_KERNEL);

@@ -279,12 +280,10 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
 			goto errout;
 		}
 
-		err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov);
+		err = sctp_user_addto_chunk(chunk, len, from);
 		if (err < 0)
 			goto errout_chunk_free;
 
-		offset += len;
-
 		/* Put the chunk->skb back into the form expected by send.  */
 		__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
 			   - (__u8 *)chunk->skb->data);

@@ -317,7 +316,7 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
 			goto errout;
 		}
 
-		err = sctp_user_addto_chunk(chunk, offset, over, msgh->msg_iov);
+		err = sctp_user_addto_chunk(chunk, over, from);
 
 		/* Put the chunk->skb back into the form expected by send.  */
 		__skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr

index e49bcce..e49e231 100644
@@ -1491,26 +1491,26 @@ static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
  * chunk is not big enough.
  * Returns a kernel err value.
  */
-int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
-			  struct iovec *data)
+int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
+			  struct iov_iter *from)
 {
-	__u8 *target;
-	int err = 0;
+	void *target;
+	ssize_t copied;
 
 	/* Make room in chunk for data.  */
 	target = skb_put(chunk->skb, len);
 
 	/* Copy data (whole iovec) into chunk */
-	if ((err = memcpy_fromiovecend(target, data, off, len)))
-		goto out;
+	copied = copy_from_iter(target, len, from);
+	if (copied != len)
+		return -EFAULT;
 
 	/* Adjust the chunk length field.  */
 	chunk->chunk_hdr->length =
 		htons(ntohs(chunk->chunk_hdr->length) + len);
 	chunk->chunk_end = skb_tail_pointer(chunk->skb);
 
-out:
-	return err;
+	return 0;
 }
 
 /* Helper function to assign a TSN if needed.  This assumes that both

index 85e0b65..0397ac9 100644
@@ -1609,6 +1609,9 @@ static int sctp_sendmsg(struct kiocb *iocb, struct sock *sk,
 	__u16 sinfo_flags = 0;
 	long timeo;
 	int err;
+	struct iov_iter from;
+
+	iov_iter_init(&from, WRITE, msg->msg_iov, msg->msg_iovlen, msg_len);
 
 	err = 0;
 	sp = sctp_sk(sk);

@@ -1947,7 +1950,7 @@ static int sctp_sendmsg(struct kiocb *iocb, struct sock *sk,
 	}
 
 	/* Break the message into multiple chunks of maximum size. */
-	datamsg = sctp_datamsg_from_user(asoc, sinfo, msg, msg_len);
+	datamsg = sctp_datamsg_from_user(asoc, sinfo, &from);
 	if (IS_ERR(datamsg)) {
 		err = PTR_ERR(datamsg);
 		goto out_free;

index e918091..2d4b2fa 100644
@@ -700,7 +700,7 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
  * tipc_sendmcast - send multicast message
  * @sock: socket structure
  * @seq: destination address
- * @iov: message data to send
+ * @msg: message to send
  * @dsz: total length of message data
  * @timeo: timeout to wait for wakeup
  *

@@ -708,7 +708,7 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
  * Returns the number of bytes sent on success, or errno
  */
 static int tipc_sendmcast(struct  socket *sock, struct tipc_name_seq *seq,
-			  struct iovec *iov, size_t dsz, long timeo)
+			  struct msghdr *msg, size_t dsz, long timeo)
 {
 	struct sock *sk = sock->sk;
 	struct tipc_msg *mhdr = &tipc_sk(sk)->phdr;

@@ -727,7 +727,7 @@ static int tipc_sendmcast(struct  socket *sock, struct tipc_name_seq *seq,
 
 new_mtu:
 	mtu = tipc_bclink_get_mtu();
-	rc = tipc_msg_build(mhdr, iov, 0, dsz, mtu, &buf);
+	rc = tipc_msg_build(mhdr, msg->msg_iov, 0, dsz, mtu, &buf);
 	if (unlikely(rc < 0))
 		return rc;
 

@@ -951,7 +951,7 @@ static int tipc_sendmsg(struct kiocb *iocb, struct socket *sock,
 	timeo = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT);
 
 	if (dest->addrtype == TIPC_ADDR_MCAST) {
-		rc = tipc_sendmcast(sock, seq, iov, dsz, timeo);
+		rc = tipc_sendmcast(sock, seq, m, dsz, timeo);
 		goto exit;
 	} else if (dest->addrtype == TIPC_ADDR_NAME) {
 		u32 type = dest->addr.name.name.type;

index ec18076..9155496 100644
@@ -162,14 +162,14 @@ err:
 /**
  * tipc_msg_build - create buffer chain containing specified header and data
  * @mhdr: Message header, to be prepended to data
- * @iov: User data
+ * @m: User message
  * @offset: Posision in iov to start copying from
  * @dsz: Total length of user data
  * @pktmax: Max packet size that can be used
  * @chain: Buffer or chain of buffers to be returned to caller
  * Returns message data size or errno: -ENOMEM, -EFAULT
  */
-int tipc_msg_build(struct tipc_msg *mhdr, struct iovec const *iov,
+int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
 		   int offset, int dsz, int pktmax , struct sk_buff **chain)
 {
 	int mhsz = msg_hdr_sz(mhdr);

@@ -194,7 +194,7 @@ int tipc_msg_build(struct tipc_msg *mhdr, struct iovec const *iov,
 		skb_copy_to_linear_data(buf, mhdr, mhsz);
 		pktpos = buf->data + mhsz;
 		TIPC_SKB_CB(buf)->chain_sz = 1;
-		if (!dsz || !memcpy_fromiovecend(pktpos, iov, offset, dsz))
+		if (!dsz || !memcpy_fromiovecend(pktpos, m->msg_iov, offset, dsz))
 			return dsz;
 		rc = -EFAULT;
 		goto error;

@@ -223,7 +223,7 @@ int tipc_msg_build(struct tipc_msg *mhdr, struct iovec const *iov,
 		if (drem < pktrem)
 			pktrem = drem;
 
-		if (memcpy_fromiovecend(pktpos, iov, offset, pktrem)) {
+		if (memcpy_fromiovecend(pktpos, m->msg_iov, offset, pktrem)) {
 			rc = -EFAULT;
 			goto error;
 		}

index 0ea7b69..d7d2ba2 100644
@@ -743,7 +743,7 @@ bool tipc_msg_bundle(struct sk_buff *bbuf, struct sk_buff *buf, u32 mtu);
 
 bool tipc_msg_make_bundle(struct sk_buff **buf, u32 mtu, u32 dnode);
 
-int tipc_msg_build(struct tipc_msg *mhdr, struct iovec const *iov,
+int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
 		   int offset, int dsz, int mtu , struct sk_buff **chain);
 
 struct sk_buff *tipc_msg_reassemble(struct sk_buff *chain);

index 2d4b2fa..b3415a7 100644
@@ -727,7 +727,7 @@ static int tipc_sendmcast(struct  socket *sock, struct tipc_name_seq *seq,
 
 new_mtu:
 	mtu = tipc_bclink_get_mtu();
-	rc = tipc_msg_build(mhdr, msg->msg_iov, 0, dsz, mtu, &buf);
+	rc = tipc_msg_build(mhdr, msg, 0, dsz, mtu, &buf);
 	if (unlikely(rc < 0))
 		return rc;
 

@@ -905,7 +905,6 @@ static int tipc_sendmsg(struct kiocb *iocb, struct socket *sock,
 	struct sock *sk = sock->sk;
 	struct tipc_sock *tsk = tipc_sk(sk);
 	struct tipc_msg *mhdr = &tsk->phdr;
-	struct iovec *iov = m->msg_iov;
 	u32 dnode, dport;
 	struct sk_buff *buf;
 	struct tipc_name_seq *seq = &dest->addr.nameseq;

@@ -982,7 +981,7 @@ static int tipc_sendmsg(struct kiocb *iocb, struct socket *sock,
 
 new_mtu:
 	mtu = tipc_node_get_mtu(dnode, tsk->ref);
-	rc = tipc_msg_build(mhdr, iov, 0, dsz, mtu, &buf);
+	rc = tipc_msg_build(mhdr, m, 0, dsz, mtu, &buf);
 	if (rc < 0)
 		goto exit;
 

@@ -1094,7 +1093,7 @@ static int tipc_send_stream(struct kiocb *iocb, struct socket *sock,
 next:
 	mtu = tsk->max_pkt;
 	send = min_t(uint, dsz - sent, TIPC_MAX_USER_MSG_SIZE);
-	rc = tipc_msg_build(mhdr, m->msg_iov, sent, send, mtu, &buf);
+	rc = tipc_msg_build(mhdr, m, sent, send, mtu, &buf);
 	if (unlikely(rc < 0))
 		goto exit;
 	do {

index 4282778..0d87674 100644
@@ -103,14 +103,14 @@ struct vsock_transport {
 	int (*dgram_dequeue)(struct kiocb *kiocb, struct vsock_sock *vsk,
 			     struct msghdr *msg, size_t len, int flags);
 	int (*dgram_enqueue)(struct vsock_sock *, struct sockaddr_vm *,
-			     struct iovec *, size_t len);
+			     struct msghdr *, size_t len);
 	bool (*dgram_allow)(u32 cid, u32 port);
 
 	/* STREAM. */
 	/* TODO: stream_bind() */
-	ssize_t (*stream_dequeue)(struct vsock_sock *, struct iovec *,
+	ssize_t (*stream_dequeue)(struct vsock_sock *, struct msghdr *,
 				  size_t len, int flags);
-	ssize_t (*stream_enqueue)(struct vsock_sock *, struct iovec *,
+	ssize_t (*stream_enqueue)(struct vsock_sock *, struct msghdr *,
 				  size_t len);
 	s64 (*stream_has_data)(struct vsock_sock *);
 	s64 (*stream_has_space)(struct vsock_sock *);

index 85d232b..1d0e39c 100644
@@ -1013,7 +1013,7 @@ static int vsock_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
 		goto out;
 	}
 
-	err = transport->dgram_enqueue(vsk, remote_addr, msg->msg_iov, len);
+	err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
 
 out:
 	release_sock(sk);

@@ -1617,7 +1617,7 @@ static int vsock_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
 		 */
 
 		written = transport->stream_enqueue(
-				vsk, msg->msg_iov,
+				vsk, msg,
 				len - total_written);
 		if (written < 0) {
 			err = -ENOMEM;

@@ -1739,7 +1739,7 @@ vsock_stream_recvmsg(struct kiocb *kiocb,
 				break;
 
 			read = transport->stream_dequeue(
-					vsk, msg->msg_iov,
+					vsk, msg,
 					len - copied, flags);
 			if (read < 0) {
 				err = -ENOMEM;

index a57ddef..c1c0389 100644
@@ -1697,7 +1697,7 @@ static int vmci_transport_dgram_bind(struct vsock_sock *vsk,
 static int vmci_transport_dgram_enqueue(
 	struct vsock_sock *vsk,
 	struct sockaddr_vm *remote_addr,
-	struct iovec *iov,
+	struct msghdr *msg,
 	size_t len)
 {
 	int err;

@@ -1714,7 +1714,7 @@ static int vmci_transport_dgram_enqueue(
 	if (!dg)
 		return -ENOMEM;
 
-	memcpy_fromiovec(VMCI_DG_PAYLOAD(dg), iov, len);
+	memcpy_from_msg(VMCI_DG_PAYLOAD(dg), msg, len);
 
 	dg->dst = vmci_make_handle(remote_addr->svm_cid,
 				   remote_addr->svm_port);

@@ -1835,22 +1835,22 @@ static int vmci_transport_connect(struct vsock_sock *vsk)
 
 static ssize_t vmci_transport_stream_dequeue(
 	struct vsock_sock *vsk,
-	struct iovec *iov,
+	struct msghdr *msg,
 	size_t len,
 	int flags)
 {
 	if (flags & MSG_PEEK)
-		return vmci_qpair_peekv(vmci_trans(vsk)->qpair, iov, len, 0);
+		return vmci_qpair_peekv(vmci_trans(vsk)->qpair, msg->msg_iov, len, 0);
 	else
-		return vmci_qpair_dequev(vmci_trans(vsk)->qpair, iov, len, 0);
+		return vmci_qpair_dequev(vmci_trans(vsk)->qpair, msg->msg_iov, len, 0);
 }
 
 static ssize_t vmci_transport_stream_enqueue(
 	struct vsock_sock *vsk,
-	struct iovec *iov,
+	struct msghdr *msg,
 	size_t len)
 {
-	return vmci_qpair_enquev(vmci_trans(vsk)->qpair, iov, len, 0);
+	return vmci_qpair_enquev(vmci_trans(vsk)->qpair, msg->msg_iov, len, 0);
 }
 
 static s64 vmci_transport_stream_has_data(struct vsock_sock *vsk)

index 9cd1cca..f591129 100644
@@ -570,15 +570,16 @@ int vcc_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 }
 
 int vcc_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
-		size_t total_len)
+		size_t size)
 {
 	struct sock *sk = sock->sk;
 	DEFINE_WAIT(wait);
 	struct atm_vcc *vcc;
 	struct sk_buff *skb;
 	int eff, error;
-	const void __user *buff;
-	int size;
+	struct iov_iter from;
+
+	iov_iter_init(&from, WRITE, m->msg_iov, m->msg_iovlen, size);
 
 	lock_sock(sk);
 	if (sock->state != SS_CONNECTED) {

@@ -589,12 +590,6 @@ int vcc_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
 		error = -EISCONN;
 		goto out;
 	}
-	if (m->msg_iovlen != 1) {
-		error = -ENOSYS; /* fix this later @@@ */
-		goto out;
-	}
-	buff = m->msg_iov->iov_base;
-	size = m->msg_iov->iov_len;
 	vcc = ATM_SD(sock);
 	if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
 	    test_bit(ATM_VF_CLOSE, &vcc->flags) ||

@@ -607,7 +602,7 @@ int vcc_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
 		error = 0;
 		goto out;
 	}
-	if (size < 0 || size > vcc->qos.txtp.max_sdu) {
+	if (size > vcc->qos.txtp.max_sdu) {
 		error = -EMSGSIZE;
 		goto out;
 	}

@@ -639,7 +634,7 @@ int vcc_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
 		goto out;
 	skb->dev = NULL; /* for paths shared with net_device interfaces */
 	ATM_SKB(skb)->atm_options = vcc->atm_options;
-	if (copy_from_user(skb_put(skb, size), buff, size)) {
+	if (copy_from_iter(skb_put(skb, size), size, &from) != size) {
 		kfree_skb(skb);
 		error = -EFAULT;
 		goto out;

index 7280ab8..c36d713 100644
@@ -316,8 +316,7 @@ int rds_ib_recv_alloc_caches(struct rds_ib_connection *ic);
 void rds_ib_recv_free_caches(struct rds_ib_connection *ic);
 void rds_ib_recv_refill(struct rds_connection *conn, int prefill);
 void rds_ib_inc_free(struct rds_incoming *inc);
-int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iovec *iov,
-			     size_t size);
+int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
 void rds_ib_recv_cq_comp_handler(struct ib_cq *cq, void *context);
 void rds_ib_recv_tasklet_fn(unsigned long data);
 void rds_ib_recv_init_ring(struct rds_ib_connection *ic);

index d67de45..1b981a4 100644
@@ -472,15 +472,12 @@ static struct list_head *rds_ib_recv_cache_get(struct rds_ib_refill_cache *cache
 	return head;
 }
 
-int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov,
-			    size_t size)
+int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
 {
 	struct rds_ib_incoming *ibinc;
 	struct rds_page_frag *frag;
-	struct iovec *iov = first_iov;
 	unsigned long to_copy;
 	unsigned long frag_off = 0;
-	unsigned long iov_off = 0;
 	int copied = 0;
 	int ret;
 	u32 len;

@@ -489,37 +486,25 @@ int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov,
 	frag = list_entry(ibinc->ii_frags.next, struct rds_page_frag, f_item);
 	len = be32_to_cpu(inc->i_hdr.h_len);
 
-	while (copied < size && copied < len) {
+	while (iov_iter_count(to) && copied < len) {
 		if (frag_off == RDS_FRAG_SIZE) {
 			frag = list_entry(frag->f_item.next,
 					  struct rds_page_frag, f_item);
 			frag_off = 0;
 		}
-		while (iov_off == iov->iov_len) {
-			iov_off = 0;
-			iov++;
-		}
-
-		to_copy = min(iov->iov_len - iov_off, RDS_FRAG_SIZE - frag_off);
-		to_copy = min_t(size_t, to_copy, size - copied);
+		to_copy = min_t(unsigned long, iov_iter_count(to),
+				RDS_FRAG_SIZE - frag_off);
 		to_copy = min_t(unsigned long, to_copy, len - copied);
 
-		rdsdebug("%lu bytes to user [%p, %zu] + %lu from frag "
-			 "[%p, %u] + %lu\n",
-			 to_copy, iov->iov_base, iov->iov_len, iov_off,
-			 sg_page(&frag->f_sg), frag->f_sg.offset, frag_off);
-
 		/* XXX needs + offset for multiple recvs per page */
-		ret = rds_page_copy_to_user(sg_page(&frag->f_sg),
-					    frag->f_sg.offset + frag_off,
-					    iov->iov_base + iov_off,
-					    to_copy);
-		if (ret) {
-			copied = ret;
-			break;
-		}
+		rds_stats_add(s_copy_to_user, to_copy);
+		ret = copy_page_to_iter(sg_page(&frag->f_sg),
+					frag->f_sg.offset + frag_off,
+					to_copy,
+					to);
+		if (ret != to_copy)
+			return -EFAULT;
 
-		iov_off += to_copy;
 		frag_off += to_copy;
 		copied += to_copy;
 	}

index 04ce3b1..cbe6674 100644
@@ -325,8 +325,7 @@ int rds_iw_recv(struct rds_connection *conn);
 int rds_iw_recv_refill(struct rds_connection *conn, gfp_t kptr_gfp,
 		       gfp_t page_gfp, int prefill);
 void rds_iw_inc_free(struct rds_incoming *inc);
-int rds_iw_inc_copy_to_user(struct rds_incoming *inc, struct iovec *iov,
-			     size_t size);
+int rds_iw_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
 void rds_iw_recv_cq_comp_handler(struct ib_cq *cq, void *context);
 void rds_iw_recv_tasklet_fn(unsigned long data);
 void rds_iw_recv_init_ring(struct rds_iw_connection *ic);

index aa8bf67..a66d179 100644
@@ -303,15 +303,12 @@ void rds_iw_inc_free(struct rds_incoming *inc)
 	BUG_ON(atomic_read(&rds_iw_allocation) < 0);
 }
 
-int rds_iw_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov,
-			    size_t size)
+int rds_iw_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
 {
 	struct rds_iw_incoming *iwinc;
 	struct rds_page_frag *frag;
-	struct iovec *iov = first_iov;
 	unsigned long to_copy;
 	unsigned long frag_off = 0;
-	unsigned long iov_off = 0;
 	int copied = 0;
 	int ret;
 	u32 len;

@@ -320,37 +317,25 @@ int rds_iw_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov,
 	frag = list_entry(iwinc->ii_frags.next, struct rds_page_frag, f_item);
 	len = be32_to_cpu(inc->i_hdr.h_len);
 
-	while (copied < size && copied < len) {
+	while (iov_iter_count(to) && copied < len) {
 		if (frag_off == RDS_FRAG_SIZE) {
 			frag = list_entry(frag->f_item.next,
 					  struct rds_page_frag, f_item);
 			frag_off = 0;
 		}
-		while (iov_off == iov->iov_len) {
-			iov_off = 0;
-			iov++;
-		}
-
-		to_copy = min(iov->iov_len - iov_off, RDS_FRAG_SIZE - frag_off);
-		to_copy = min_t(size_t, to_copy, size - copied);
+		to_copy = min_t(unsigned long, iov_iter_count(to),
+				RDS_FRAG_SIZE - frag_off);
 		to_copy = min_t(unsigned long, to_copy, len - copied);
 
-		rdsdebug("%lu bytes to user [%p, %zu] + %lu from frag "
-			 "[%p, %lu] + %lu\n",
-			 to_copy, iov->iov_base, iov->iov_len, iov_off,
-			 frag->f_page, frag->f_offset, frag_off);
-
 		/* XXX needs + offset for multiple recvs per page */
-		ret = rds_page_copy_to_user(frag->f_page,
-					    frag->f_offset + frag_off,
-					    iov->iov_base + iov_off,
-					    to_copy);
-		if (ret) {
-			copied = ret;
-			break;
-		}
+		rds_stats_add(s_copy_to_user, to_copy);
+		ret = copy_page_to_iter(frag->f_page,
+					frag->f_offset + frag_off,
+					to_copy,
+					to);
+		if (ret != to_copy)
+			return -EFAULT;
 
-		iov_off += to_copy;
 		frag_off += to_copy;
 		copied += to_copy;
 	}

index aba232f..7a546e0 100644
@@ -325,14 +325,11 @@ out:
 	return ret;
 }
 
-int rds_message_inc_copy_to_user(struct rds_incoming *inc,
-				 struct iovec *first_iov, size_t size)
+int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
 {
 	struct rds_message *rm;
-	struct iovec *iov;
 	struct scatterlist *sg;
 	unsigned long to_copy;
-	unsigned long iov_off;
 	unsigned long vec_off;
 	int copied;
 	int ret;

@@ -341,36 +338,20 @@ int rds_message_inc_copy_to_user(struct rds_incoming *inc,
 	rm = container_of(inc, struct rds_message, m_inc);
 	len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
 
-	iov = first_iov;
-	iov_off = 0;
 	sg = rm->data.op_sg;
 	vec_off = 0;
 	copied = 0;
 
-	while (copied < size && copied < len) {
-		while (iov_off == iov->iov_len) {
-			iov_off = 0;
-			iov++;
-		}
-
-		to_copy = min(iov->iov_len - iov_off, sg->length - vec_off);
-		to_copy = min_t(size_t, to_copy, size - copied);
+	while (iov_iter_count(to) && copied < len) {
+		to_copy = min(iov_iter_count(to), sg->length - vec_off);
 		to_copy = min_t(unsigned long, to_copy, len - copied);
 
-		rdsdebug("copying %lu bytes to user iov [%p, %zu] + %lu to "
-			 "sg [%p, %u, %u] + %lu\n",
-			 to_copy, iov->iov_base, iov->iov_len, iov_off,
-			 sg_page(sg), sg->offset, sg->length, vec_off);
-
-		ret = rds_page_copy_to_user(sg_page(sg), sg->offset + vec_off,
-					    iov->iov_base + iov_off,
-					    to_copy);
-		if (ret) {
-			copied = ret;
-			break;
-		}
+		rds_stats_add(s_copy_to_user, to_copy);
+		ret = copy_page_to_iter(sg_page(sg), sg->offset + vec_off,
+					to_copy, to);
+		if (ret != to_copy)
+			return -EFAULT;
 
-		iov_off += to_copy;
 		vec_off += to_copy;
 		copied += to_copy;
 

index 48f8ffc..b22dad9 100644
@@ -431,8 +431,7 @@ struct rds_transport {
 	int (*xmit_rdma)(struct rds_connection *conn, struct rm_rdma_op *op);
 	int (*xmit_atomic)(struct rds_connection *conn, struct rm_atomic_op *op);
 	int (*recv)(struct rds_connection *conn);
-	int (*inc_copy_to_user)(struct rds_incoming *inc, struct iovec *iov,
-				size_t size);
+	int (*inc_copy_to_user)(struct rds_incoming *inc, struct iov_iter *to);
 	void (*inc_free)(struct rds_incoming *inc);
 
 	int (*cm_handle_connect)(struct rdma_cm_id *cm_id,

@@ -667,8 +666,7 @@ int rds_message_add_extension(struct rds_header *hdr,
 int rds_message_next_extension(struct rds_header *hdr,
 			       unsigned int *pos, void *buf, unsigned int *buflen);
 int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset);
-int rds_message_inc_copy_to_user(struct rds_incoming *inc,
-				 struct iovec *first_iov, size_t size);
+int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
 void rds_message_inc_free(struct rds_incoming *inc);
 void rds_message_addref(struct rds_message *rm);
 void rds_message_put(struct rds_message *rm);

index bd82522..47d7b10 100644
@@ -404,6 +404,7 @@ int rds_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 	int ret = 0, nonblock = msg_flags & MSG_DONTWAIT;
 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
 	struct rds_incoming *inc = NULL;
+	struct iov_iter to;
 
 	/* udp_recvmsg()->sock_recvtimeo() gets away without locking too.. */
 	timeo = sock_rcvtimeo(sk, nonblock);

@@ -449,8 +450,8 @@ int rds_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 		rdsdebug("copying inc %p from %pI4:%u to user\n", inc,
 			 &inc->i_conn->c_faddr,
 			 ntohs(inc->i_hdr.h_sport));
-		ret = inc->i_conn->c_trans->inc_copy_to_user(inc, msg->msg_iov,
-							     size);
+		iov_iter_init(&to, READ, msg->msg_iov, msg->msg_iovlen, size);
+		ret = inc->i_conn->c_trans->inc_copy_to_user(inc, &to);
 		if (ret < 0)
 			break;
 

index 6563749..0dbdd37 100644
@@ -69,8 +69,7 @@ void rds_tcp_recv_exit(void);
 void rds_tcp_data_ready(struct sock *sk);
 int rds_tcp_recv(struct rds_connection *conn);
 void rds_tcp_inc_free(struct rds_incoming *inc);
-int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iovec *iov,
-			     size_t size);
+int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
 
 /* tcp_send.c */
 void rds_tcp_xmit_prepare(struct rds_connection *conn);

index 9ae6e0a..fbc5ef8 100644
@@ -59,50 +59,30 @@ void rds_tcp_inc_free(struct rds_incoming *inc)
 /*
  * this is pretty lame, but, whatever.
  */
-int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov,
-			     size_t size)
+int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
 {
 	struct rds_tcp_incoming *tinc;
-	struct iovec *iov, tmp;
 	struct sk_buff *skb;
-	unsigned long to_copy, skb_off;
 	int ret = 0;
 
-	if (size == 0)
+	if (!iov_iter_count(to))
 		goto out;
 
 	tinc = container_of(inc, struct rds_tcp_incoming, ti_inc);
-	iov = first_iov;
-	tmp = *iov;
 
 	skb_queue_walk(&tinc->ti_skb_list, skb) {
-		skb_off = 0;
-		while (skb_off < skb->len) {
-			while (tmp.iov_len == 0) {
-				iov++;
-				tmp = *iov;
-			}
-
-			to_copy = min(tmp.iov_len, size);
+		unsigned long to_copy, skb_off;
+		for (skb_off = 0; skb_off < skb->len; skb_off += to_copy) {
+			to_copy = iov_iter_count(to);
 			to_copy = min(to_copy, skb->len - skb_off);
 
-			rdsdebug("ret %d size %zu skb %p skb_off %lu "
-				 "skblen %d iov_base %p iov_len %zu cpy %lu\n",
-				 ret, size, skb, skb_off, skb->len,
-				 tmp.iov_base, tmp.iov_len, to_copy);
-
-			/* modifies tmp as it copies */
-			if (skb_copy_datagram_iovec(skb, skb_off, &tmp,
-						    to_copy)) {
-				ret = -EFAULT;
-				goto out;
-			}
+			if (skb_copy_datagram_iter(skb, skb_off, to, to_copy))
+				return -EFAULT;
 
 			rds_stats_add(s_copy_to_user, to_copy);
-			size -= to_copy;
 			ret += to_copy;
-			skb_off += to_copy;
-			if (size == 0)
+
+			if (!iov_iter_count(to))
 				goto out;
 		}
 	}

index 7a546e0..ff22022 100644
@@ -264,64 +264,46 @@ struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned in
 	return rm;
 }
 
-int rds_message_copy_from_user(struct rds_message *rm, struct iovec *first_iov,
-					       size_t total_len)
+int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from)
 {
 	unsigned long to_copy;
-	unsigned long iov_off;
 	unsigned long sg_off;
-	struct iovec *iov;
 	struct scatterlist *sg;
 	int ret = 0;
 
-	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
+	rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from));
 
 	/*
 	 * now allocate and copy in the data payload.
 	 */
 	sg = rm->data.op_sg;
-	iov = first_iov;
-	iov_off = 0;
 	sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
 
-	while (total_len) {
+	while (iov_iter_count(from)) {
 		if (!sg_page(sg)) {
-			ret = rds_page_remainder_alloc(sg, total_len,
+			ret = rds_page_remainder_alloc(sg, iov_iter_count(from),
 						       GFP_HIGHUSER);
 			if (ret)
-				goto out;
+				return ret;
 			rm->data.op_nents++;
 			sg_off = 0;
 		}
 
-		while (iov_off == iov->iov_len) {
-			iov_off = 0;
-			iov++;
-		}
-
-		to_copy = min(iov->iov_len - iov_off, sg->length - sg_off);
-		to_copy = min_t(size_t, to_copy, total_len);
-
-		rdsdebug("copying %lu bytes from user iov [%p, %zu] + %lu to "
-			 "sg [%p, %u, %u] + %lu\n",
-			 to_copy, iov->iov_base, iov->iov_len, iov_off,
-			 (void *)sg_page(sg), sg->offset, sg->length, sg_off);
+		to_copy = min_t(unsigned long, iov_iter_count(from),
+				sg->length - sg_off);
 
-		ret = rds_page_copy_from_user(sg_page(sg), sg->offset + sg_off,
-					      iov->iov_base + iov_off,
-					      to_copy);
-		if (ret)
-			goto out;
+		rds_stats_add(s_copy_from_user, to_copy);
+		ret = copy_page_from_iter(sg_page(sg), sg->offset + sg_off,
+					  to_copy, from);
+		if (ret != to_copy)
+			return -EFAULT;
 
-		iov_off += to_copy;
-		total_len -= to_copy;
 		sg_off += to_copy;
 
 		if (sg_off == sg->length)
 			sg++;
 	}
 
-out:
 	return ret;
 }
 

index b22dad9..c2a5eef 100644
@@ -656,8 +656,7 @@ rds_conn_connecting(struct rds_connection *conn)
 /* message.c */
 struct rds_message *rds_message_alloc(unsigned int nents, gfp_t gfp);
 struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents);
-int rds_message_copy_from_user(struct rds_message *rm, struct iovec *first_iov,
-					       size_t total_len);
+int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from);
 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len);
 void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
 				 __be16 dport, u64 seq);

index 0a64541..4de62ea 100644
@@ -934,7 +934,9 @@ int rds_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 	int queued = 0, allocated_mr = 0;
 	int nonblock = msg->msg_flags & MSG_DONTWAIT;
 	long timeo = sock_sndtimeo(sk, nonblock);
+	struct iov_iter from;
 
+	iov_iter_init(&from, WRITE, msg->msg_iov, msg->msg_iovlen, payload_len);
 	/* Mirror Linux UDP mirror of BSD error message compatibility */
 	/* XXX: Perhaps MSG_MORE someday */
 	if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_CMSG_COMPAT)) {

@@ -982,7 +984,7 @@ int rds_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 			ret = -ENOMEM;
 			goto out;
 		}
-		ret = rds_message_copy_from_user(rm, msg->msg_iov, payload_len);
+		ret = rds_message_copy_from_user(rm, &from);
 		if (ret)
 			goto out;
 	}