{macvtap,tun}_get_user(): switch to iov_iter

allows to switch macvtap and tun from ->aio_write() to ->write_iter()

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

1 files changed, 24 insertions, 20 deletions

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 405dfdf4f8c8..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;
@@ -1445,11 +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;
 }
@@ -2233,9 +2237,9 @@ static const struct file_operations tun_fops = {
         .owner  = THIS_MODULE,
         .llseek = no_llseek,
         .read  = new_sync_read,
+        .write = new_sync_write,
         .read_iter  = tun_chr_read_iter,
-        .write = do_sync_write,
-        .aio_write = tun_chr_aio_write,
+        .write_iter = tun_chr_write_iter,
         .poll   = tun_chr_poll,
         .unlocked_ioctl = tun_chr_ioctl,
 #ifdef CONFIG_COMPAT