Merge branch 'for-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

More work from Al Viro to move away from modifying iovecs
by using iov_iter instead.

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 89 insertions, 104 deletions

diff --git a/drivers/isdn/mISDN/socket.c b/drivers/isdn/mISDN/socket.c
index dcbd8589f0c4..84b35925ee4d 100644
--- a/drivers/isdn/mISDN/socket.c
+++ b/drivers/isdn/mISDN/socket.c
@@ -203,7 +203,7 @@ mISDN_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
 	if (!skb)
 		goto done;
 
-	if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
+	if (memcpy_from_msg(skb_put(skb, len), msg, len)) {
 		err = -EFAULT;
 		goto done;
 	}
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 42a80d3de839..22b4cf2fa108 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -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 */
@@ -831,64 +827,55 @@ 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;
+		}
+		if (signal_pending(current)) {
+			ret = -ERESTARTSYS;
+			break;
 		}
-		iov_iter_init(&iter, READ, iv, segs, len);
-		ret = macvtap_put_user(q, skb, &iter);
+		/* 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;
-
-	len = iov_length(iv, count);
-	if (len < 0) {
-		ret = -EINVAL;
-		goto out;
-	}
+	ssize_t len = iov_iter_count(to), ret;
 
-	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;
 }
 
@@ -1089,8 +1076,10 @@ static const struct file_operations macvtap_fops = {
 	.owner		= THIS_MODULE,
 	.open		= macvtap_open,
 	.release	= macvtap_release,
-	.aio_read	= macvtap_aio_read,
-	.aio_write	= macvtap_aio_write,
+	.read		= new_sync_read,
+	.write		= new_sync_write,
+	.read_iter	= macvtap_read_iter,
+	.write_iter	= macvtap_write_iter,
 	.poll		= macvtap_poll,
 	.llseek		= no_llseek,
 	.unlocked_ioctl	= macvtap_ioctl,
@@ -1103,8 +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,
@@ -1112,11 +1102,12 @@ 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;
diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c
index 443cbbf5c55f..d2408a5e43a6 100644
--- a/drivers/net/ppp/pppoe.c
+++ b/drivers/net/ppp/pppoe.c
@@ -869,7 +869,7 @@ static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock,
 	ph = (struct pppoe_hdr *)skb_put(skb, total_len + sizeof(struct pppoe_hdr));
 	start = (char *)&ph->tag[0];
 
-	error = memcpy_fromiovec(start, m->msg_iov, total_len);
+	error = memcpy_from_msg(start, m, total_len);
 	if (error < 0) {
 		kfree_skb(skb);
 		goto end;
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index ac53a7316ecd..4b743c612624 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1012,28 +1012,29 @@ static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
 
 /* Get packet from user space buffer */
 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
-			    void *msg_control, const struct iovec *iv,
-			    size_t total_len, size_t count, int noblock)
+			    void *msg_control, struct iov_iter *from,
+			    int noblock)
 {
 	struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
 	struct sk_buff *skb;
+	size_t total_len = iov_iter_count(from);
 	size_t len = total_len, align = NET_SKB_PAD, linear;
 	struct virtio_net_hdr gso = { 0 };
 	int good_linear;
-	int offset = 0;
 	int copylen;
 	bool zerocopy = false;
 	int err;
 	u32 rxhash;
+	ssize_t n;
 
 	if (!(tun->flags & TUN_NO_PI)) {
 		if (len < sizeof(pi))
 			return -EINVAL;
 		len -= sizeof(pi);
 
-		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
+		n = copy_from_iter(&pi, sizeof(pi), from);
+		if (n != sizeof(pi))
 			return -EFAULT;
-		offset += sizeof(pi);
 	}
 
 	if (tun->flags & TUN_VNET_HDR) {
@@ -1041,7 +1042,8 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 			return -EINVAL;
 		len -= tun->vnet_hdr_sz;
 
-		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
+		n = copy_from_iter(&gso, sizeof(gso), from);
+		if (n != sizeof(gso))
 			return -EFAULT;
 
 		if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
@@ -1050,7 +1052,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 
 		if (gso.hdr_len > len)
 			return -EINVAL;
-		offset += tun->vnet_hdr_sz;
+		iov_iter_advance(from, tun->vnet_hdr_sz);
 	}
 
 	if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
@@ -1063,6 +1065,8 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 	good_linear = SKB_MAX_HEAD(align);
 
 	if (msg_control) {
+		struct iov_iter i = *from;
+
 		/* There are 256 bytes to be copied in skb, so there is
 		 * enough room for skb expand head in case it is used.
 		 * The rest of the buffer is mapped from userspace.
@@ -1071,7 +1075,8 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 		if (copylen > good_linear)
 			copylen = good_linear;
 		linear = copylen;
-		if (iov_pages(iv, offset + copylen, count) <= MAX_SKB_FRAGS)
+		iov_iter_advance(&i, copylen);
+		if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
 			zerocopy = true;
 	}
 
@@ -1091,9 +1096,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 	}
 
 	if (zerocopy)
-		err = zerocopy_sg_from_iovec(skb, iv, offset, count);
+		err = zerocopy_sg_from_iter(skb, from);
 	else {
-		err = skb_copy_datagram_from_iovec(skb, 0, iv, offset, len);
+		err = skb_copy_datagram_from_iter(skb, 0, from, len);
 		if (!err && msg_control) {
 			struct ubuf_info *uarg = msg_control;
 			uarg->callback(uarg, false);
@@ -1207,8 +1212,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 	return total_len;
 }
 
-static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
-			      unsigned long count, loff_t pos)
+static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
 	struct file *file = iocb->ki_filp;
 	struct tun_struct *tun = tun_get(file);
@@ -1218,10 +1222,7 @@ static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 	if (!tun)
 		return -EBADFD;
 
-	tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
-
-	result = tun_get_user(tun, tfile, NULL, iv, iov_length(iv, count),
-			      count, file->f_flags & O_NONBLOCK);
+	result = tun_get_user(tun, tfile, NULL, from, file->f_flags & O_NONBLOCK);
 
 	tun_put(tun);
 	return result;
@@ -1339,18 +1340,17 @@ 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 +1359,27 @@ 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;
 }
@@ -1456,11 +1446,14 @@ 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;
-	ret = tun_get_user(tun, tfile, m->msg_control, m->msg_iov, total_len,
-			   m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
+
+	iov_iter_init(&from, WRITE, m->msg_iov, m->msg_iovlen, total_len);
+	ret = tun_get_user(tun, tfile, m->msg_control, &from,
+			   m->msg_flags & MSG_DONTWAIT);
 	tun_put(tun);
 	return ret;
 }
@@ -1471,6 +1464,7 @@ 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 +1479,8 @@ 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;
@@ -2242,10 +2236,10 @@ 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,
-	.write = do_sync_write,
-	.aio_write = tun_chr_aio_write,
+	.read  = new_sync_read,
+	.write = new_sync_write,
+	.read_iter  = tun_chr_read_iter,
+	.write_iter = tun_chr_write_iter,
 	.poll	= tun_chr_poll,
 	.unlocked_ioctl	= tun_chr_ioctl,
 #ifdef CONFIG_COMPAT