[RFC 01/10] net: pass ubuf to custom sg_from_iter callbacks

[Pavel Begunkov <asml.silence@gmail.com>]

ubuf_info and callbacks for chunking zerocopy iterators into skbs comes
in pairs in msghdr, and in the future the callback will need to know
which ubuf_info it was called with. We can't derive it from the skb as
some paths set it after the call, so pass it in.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 include/linux/socket.h | 2 +-
 io_uring/net.c         | 8 ++++----
 net/core/datagram.c    | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/linux/socket.h b/include/linux/socket.h
index 2a8d7b14f1d1..5ae24847f5c4 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -90,7 +90,7 @@ struct msghdr {
 	unsigned int	msg_flags;	/* flags on received message */
 	__kernel_size_t	msg_controllen;	/* ancillary data buffer length */
 	struct ubuf_info *msg_ubuf;
-	int (*sg_from_iter)(struct sk_buff *skb,
+	int (*sg_from_iter)(struct sk_buff *skb, struct ubuf_info *ubuf,
 			    struct iov_iter *from, size_t length);
 };
 
diff --git a/io_uring/net.c b/io_uring/net.c
index 00a7df803b99..cf273d6f02b1 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -116,9 +116,9 @@ struct io_recvzc {
 	struct io_zcrx_ifq		*ifq;
 };
 
-static int io_sg_from_iter_iovec(struct sk_buff *skb,
+static int io_sg_from_iter_iovec(struct sk_buff *skb, struct ubuf_info *ubuf,
 				 struct iov_iter *from, size_t length);
-static int io_sg_from_iter(struct sk_buff *skb,
+static int io_sg_from_iter(struct sk_buff *skb, struct ubuf_info *ubuf,
 			   struct iov_iter *from, size_t length);
 
 int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
@@ -1447,14 +1447,14 @@ int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	return 0;
 }
 
-static int io_sg_from_iter_iovec(struct sk_buff *skb,
+static int io_sg_from_iter_iovec(struct sk_buff *skb, struct ubuf_info *ubuf,
 				 struct iov_iter *from, size_t length)
 {
 	skb_zcopy_downgrade_managed(skb);
 	return zerocopy_fill_skb_from_iter(skb, from, length);
 }
 
-static int io_sg_from_iter(struct sk_buff *skb,
+static int io_sg_from_iter(struct sk_buff *skb, struct ubuf_info *ubuf,
 			   struct iov_iter *from, size_t length)
 {
 	struct skb_shared_info *shinfo = skb_shinfo(skb);
diff --git a/net/core/datagram.c b/net/core/datagram.c
index c285c6465923..f15886f40efc 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -753,7 +753,7 @@ int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk,
 	int ret;
 
 	if (msg && msg->msg_ubuf && msg->sg_from_iter)
-		ret = msg->sg_from_iter(skb, from, length);
+		ret = msg->sg_from_iter(skb, msg->msg_ubuf, from, length);
 	else if (binding)
 		ret = zerocopy_fill_skb_from_devmem(skb, from, length, binding);
 	else
-- 
2.54.0