{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>

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 8f80045..22b4cf2 100644 (file)
--- 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 */
@@ -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,

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 405dfdf..4b743c6 100644 (file)
--- 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