tun: remove useless codes in tun_chr_aio_read() and tun_recvmsg()

By checking related codes, it is impossible that ret > len or total_len,
so we should remove some useless codes in both above functions.

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 3c5a8d8cde5077bc0c2d39d2f0aadc4e7d4a6231..bbb693512918e17a77e6a3ea06f9c875b6f17861 100644 (file)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1354,7 +1354,6 @@ static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
 
        ret = tun_do_read(tun, tfile, iv, len,
                          file->f_flags & O_NONBLOCK);
-       ret = min_t(ssize_t, ret, len);
        if (ret > 0)
                iocb->ki_pos = ret;
 out:
@@ -1455,10 +1454,6 @@ static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
        }
        ret = tun_do_read(tun, tfile, m->msg_iov, total_len,
                          flags & MSG_DONTWAIT);
-       if (ret > total_len) {
-               m->msg_flags |= MSG_TRUNC;
-               ret = flags & MSG_TRUNC ? ret : total_len;
-       }
 out:
        tun_put(tun);
        return ret;