switch memcpy_to_msg() and skb_copy{,_and_csum}_datagram_msg() to primitives
... making both non-draining. That means that tcp_recvmsg() becomes
non-draining. And _that_ would break iscsit_do_rx_data() unless we
a) make sure tcp_recvmsg() is uniformly non-draining (it is)
b) make sure it copes with arbitrary (including shifted)
iov_iter (it does, all it uses is iov_iter primitives)
c) make iscsit_do_rx_data() initialize ->msg_iter only once.
Fortunately, (c) is doable with minimal work and we are rid of one
the two places where kernel send/recvmsg users would be unhappy with
non-draining behaviour.
Actually, that makes all but one of ->recvmsg() instances iov_iter-clean.
The exception is skcipher_recvmsg() and it also isn't hard to convert
to primitives (iov_iter_get_pages() is needed there). That'll wait
a bit - there's some interplay with ->sendmsg() path for that one.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 52cf1bd..4902f2d 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2651,17 +2651,10 @@
static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
struct msghdr *msg, int size)
{
- /* XXX: stripping const */
- return skb_copy_datagram_iovec(from, offset, (struct iovec *)msg->msg_iter.iov, size);
+ return skb_copy_datagram_iter(from, offset, &msg->msg_iter, 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)
-{
- /* XXX: stripping const */
- return skb_copy_and_csum_datagram_iovec(skb, hlen, (struct iovec *)msg->msg_iter.iov);
-}
+int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
+ struct msghdr *msg);
int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
struct iov_iter *from, int len);
int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
@@ -2697,8 +2690,7 @@
static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len)
{
- /* XXX: stripping const */
- return memcpy_toiovec((struct iovec *)msg->msg_iter.iov, data, len);
+ return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT;
}
struct skb_checksum_ops {