put iov_iter into msghdr

Note that the code _using_ ->msg_iter at that point will be very
unhappy with anything other than unshifted iovec-backed iov_iter.
We still need to convert users to proper primitives.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Author: Al Viro

crypto/algif_hash.c

@@ -42,7 +42,7 @@ static int hash_sendmsg(struct kiocb *unused, struct socket *sock,
 	struct alg_sock *ask = alg_sk(sk);
 	struct hash_ctx *ctx = ask->private;
 	unsigned long iovlen;
-	struct iovec *iov;
+	const struct iovec *iov;
 	long copied = 0;
 	int err;
 
@@ -58,7 +58,7 @@ static int hash_sendmsg(struct kiocb *unused, struct socket *sock,
 
 	ctx->more = 0;
 
-	for (iov = msg->msg_iov, iovlen = msg->msg_iovlen; iovlen > 0;
+	for (iov = msg->msg_iter.iov, iovlen = msg->msg_iter.nr_segs; iovlen > 0;
 	     iovlen--, iov++) {
 		unsigned long seglen = iov->iov_len;
 		char __user *from = iov->iov_base;

crypto/algif_skcipher.c

@@ -429,13 +429,13 @@ static int skcipher_recvmsg(struct kiocb *unused, struct socket *sock,
 	struct skcipher_sg_list *sgl;
 	struct scatterlist *sg;
 	unsigned long iovlen;
-	struct iovec *iov;
+	const struct iovec *iov;
 	int err = -EAGAIN;
 	int used;
 	long copied = 0;
 
 	lock_sock(sk);
-	for (iov = msg->msg_iov, iovlen = msg->msg_iovlen; iovlen > 0;
+	for (iov = msg->msg_iter.iov, iovlen = msg->msg_iter.nr_segs; iovlen > 0;
 	     iovlen--, iov++) {
 		unsigned long seglen = iov->iov_len;
 		char __user *from = iov->iov_base;

drivers/net/macvtap.c

@@ -1095,22 +1095,18 @@ 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);
-	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);
+	return macvtap_get_user(q, m, &m->msg_iter, m->msg_flags & MSG_DONTWAIT);
 }
 
 static int macvtap_recvmsg(struct kiocb *iocb, struct socket *sock,
 			   struct msghdr *m, size_t total_len,
 			   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;
-	iov_iter_init(&to, READ, m->msg_iov, m->msg_iovlen, total_len);
-	ret = macvtap_do_read(q, &to, flags & MSG_DONTWAIT);
+	ret = macvtap_do_read(q, &m->msg_iter, flags & MSG_DONTWAIT);
 	if (ret > total_len) {
 		m->msg_flags |= MSG_TRUNC;
 		ret = flags & MSG_TRUNC ? ret : total_len;

drivers/net/tun.c

@@ -1449,13 +1449,11 @@ static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
 	int ret;
 	struct tun_file *tfile = container_of(sock, struct tun_file, socket);
 	struct tun_struct *tun = __tun_get(tfile);
-	struct iov_iter from;
 
 	if (!tun)
 		return -EBADFD;
 
-	iov_iter_init(&from, WRITE, m->msg_iov, m->msg_iovlen, total_len);
-	ret = tun_get_user(tun, tfile, m->msg_control, &from,
+	ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter,
 			   m->msg_flags & MSG_DONTWAIT);
 	tun_put(tun);
 	return ret;
@@ -1467,7 +1465,6 @@ 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)
@@ -1482,8 +1479,7 @@ static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
 					 SOL_PACKET, TUN_TX_TIMESTAMP);
 		goto out;
 	}
-	iov_iter_init(&to, READ, m->msg_iov, m->msg_iovlen, total_len);
-	ret = tun_do_read(tun, tfile, &to, flags & MSG_DONTWAIT);
+	ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT);
 	if (ret > total_len) {
 		m->msg_flags |= MSG_TRUNC;
 		ret = flags & MSG_TRUNC ? ret : total_len;

drivers/vhost/net.c

@@ -342,7 +342,6 @@ static void handle_tx(struct vhost_net *net)
 		.msg_namelen = 0,
 		.msg_control = NULL,
 		.msg_controllen = 0,
-		.msg_iov = vq->iov,
 		.msg_flags = MSG_DONTWAIT,
 	};
 	size_t len, total_len = 0;
@@ -396,8 +395,8 @@ static void handle_tx(struct vhost_net *net)
 		}
 		/* Skip header. TODO: support TSO. */
 		s = move_iovec_hdr(vq->iov, nvq->hdr, hdr_size, out);
-		msg.msg_iovlen = out;
 		len = iov_length(vq->iov, out);
+		iov_iter_init(&msg.msg_iter, WRITE, vq->iov, out, len);
 		/* Sanity check */
 		if (!len) {
 			vq_err(vq, "Unexpected header len for TX: "
@@ -562,7 +561,6 @@ static void handle_rx(struct vhost_net *net)
 		.msg_namelen = 0,
 		.msg_control = NULL, /* FIXME: get and handle RX aux data. */
 		.msg_controllen = 0,
-		.msg_iov = vq->iov,
 		.msg_flags = MSG_DONTWAIT,
 	};
 	struct virtio_net_hdr_mrg_rxbuf hdr = {
@@ -600,7 +598,7 @@ static void handle_rx(struct vhost_net *net)
 			break;
 		/* On overrun, truncate and discard */
 		if (unlikely(headcount > UIO_MAXIOV)) {
-			msg.msg_iovlen = 1;
+			iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1);
 			err = sock->ops->recvmsg(NULL, sock, &msg,
 						 1, MSG_DONTWAIT | MSG_TRUNC);
 			pr_debug("Discarded rx packet: len %zd\n", sock_len);
@@ -626,7 +624,7 @@ static void handle_rx(struct vhost_net *net)
 			/* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
 			 * needed because recvmsg can modify msg_iov. */
 			copy_iovec_hdr(vq->iov, nvq->hdr, sock_hlen, in);
-		msg.msg_iovlen = in;
+		iov_iter_init(&msg.msg_iter, READ, vq->iov, in, sock_len);
 		err = sock->ops->recvmsg(NULL, sock, &msg,
 					 sock_len, MSG_DONTWAIT | MSG_TRUNC);
 		/* Userspace might have consumed the packet meanwhile:

fs/afs/rxrpc.c

@@ -306,8 +306,8 @@ static int afs_send_pages(struct afs_call *call, struct msghdr *msg,
 
 			_debug("- range %u-%u%s",
 			       offset, to, msg->msg_flags ? " [more]" : "");
-			msg->msg_iov = (struct iovec *) iov;
-			msg->msg_iovlen = 1;
+			iov_iter_init(&msg->msg_iter, WRITE,
+				      (struct iovec *) iov, 1, to - offset);
 
 			/* have to change the state *before* sending the last
 			 * packet as RxRPC might give us the reply before it
@@ -384,8 +384,8 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
 
 	msg.msg_name		= NULL;
 	msg.msg_namelen		= 0;
-	msg.msg_iov		= (struct iovec *) iov;
-	msg.msg_iovlen		= 1;
+	iov_iter_init(&msg.msg_iter, WRITE, (struct iovec *)iov, 1,
+		      call->request_size);
 	msg.msg_control		= NULL;
 	msg.msg_controllen	= 0;
 	msg.msg_flags		= (call->send_pages ? MSG_MORE : 0);
@@ -778,8 +778,7 @@ void afs_send_empty_reply(struct afs_call *call)
 	iov[0].iov_len		= 0;
 	msg.msg_name		= NULL;
 	msg.msg_namelen		= 0;
-	msg.msg_iov		= iov;
-	msg.msg_iovlen		= 0;
+	iov_iter_init(&msg.msg_iter, WRITE, iov, 0, 0);	/* WTF? */
 	msg.msg_control		= NULL;
 	msg.msg_controllen	= 0;
 	msg.msg_flags		= 0;
@@ -815,8 +814,7 @@ void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 	iov[0].iov_len		= len;
 	msg.msg_name		= NULL;
 	msg.msg_namelen		= 0;
-	msg.msg_iov		= iov;
-	msg.msg_iovlen		= 1;
+	iov_iter_init(&msg.msg_iter, WRITE, iov, 1, len);
 	msg.msg_control		= NULL;
 	msg.msg_controllen	= 0;
 	msg.msg_flags		= 0;

include/linux/skbuff.h

@@ -2646,22 +2646,24 @@ unsigned int datagram_poll(struct file *file, struct socket *sock,
 			   struct poll_table_struct *wait);
 int skb_copy_datagram_iovec(const struct sk_buff *from, int offset,
 			    struct iovec *to, int size);
+int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
+			   struct iov_iter *to, int size);
 static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
 					struct msghdr *msg, int size)
 {
-	return skb_copy_datagram_iovec(from, offset, msg->msg_iov, size);
+	/* XXX: stripping const */
+	return skb_copy_datagram_iovec(from, offset, (struct iovec *)msg->msg_iter.iov, size);
 }
 int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, int hlen,
 				     struct iovec *iov);
 static inline int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
 			    struct msghdr *msg)
 {
-	return skb_copy_and_csum_datagram_iovec(skb, hlen, msg->msg_iov);
+	/* XXX: stripping const */
+	return skb_copy_and_csum_datagram_iovec(skb, hlen, (struct iovec *)msg->msg_iter.iov);
 }
 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,
-			   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);
@@ -2689,12 +2691,14 @@ int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
 
 static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len)
 {
-	return memcpy_fromiovec(data, msg->msg_iov, len);
+	/* XXX: stripping const */
+	return memcpy_fromiovec(data, (struct iovec *)msg->msg_iter.iov, len);
 }
 
 static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len)
 {
-	return memcpy_toiovec(msg->msg_iov, data, len);
+	/* XXX: stripping const */
+	return memcpy_toiovec((struct iovec *)msg->msg_iter.iov, data, len);
 }
 
 struct skb_checksum_ops {

include/linux/socket.h

@@ -47,8 +47,7 @@ struct linger {
 struct msghdr {
 	void		*msg_name;	/* ptr to socket address structure */
 	int		msg_namelen;	/* size of socket address structure */
-	struct iovec	*msg_iov;	/* scatter/gather array */
-	__kernel_size_t	msg_iovlen;	/* # elements in msg_iov */
+	struct iov_iter	msg_iter;	/* data */
 	void		*msg_control;	/* ancillary data */
 	__kernel_size_t	msg_controllen;	/* ancillary data buffer length */
 	unsigned int	msg_flags;	/* flags on received message */

include/net/bluetooth/l2cap.h

@@ -911,7 +911,7 @@ static inline int l2cap_chan_no_memcpy_fromiovec(struct l2cap_chan *chan,
 	/* Following is safe since for compiler definitions of kvec and
 	 * iovec are identical, yielding the same in-core layout and alignment
 	 */
-	struct kvec *vec = (struct kvec *)msg->msg_iov;
+	struct kvec *vec = (struct kvec *)msg->msg_iter.iov;
 
 	while (len > 0) {
 		if (vec->iov_len) {

include/net/udplite.h

@@ -20,7 +20,8 @@ static __inline__ int udplite_getfrag(void *from, char *to, int  offset,
 				      int len, int odd, struct sk_buff *skb)
 {
 	struct msghdr *msg = from;
-	return memcpy_fromiovecend(to, msg->msg_iov, offset, len);
+	/* XXX: stripping const */
+	return memcpy_fromiovecend(to, (struct iovec *)msg->msg_iter.iov, offset, len);
 }
 
 /* Designate sk as UDP-Lite socket */