[PATCH 6.1 158/303] tcp_bpf: Inline do_tcp_sendpages as its now a wrapper around tcp_sendmsg

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Howells <[email protected]>

[ Upstream commit ebf2e8860eea66e2c4764316b80c6a5ee5f336ee ]

do_tcp_sendpages() is now just a small wrapper around tcp_sendmsg_locked(),
so inline it.  This is part of replacing ->sendpage() with a call to
sendmsg() with MSG_SPLICE_PAGES set.

Signed-off-by: David Howells <[email protected]>
cc: John Fastabend <[email protected]>
cc: Jakub Sitnicki <[email protected]>
cc: David Ahern <[email protected]>
cc: Jens Axboe <[email protected]>
cc: Matthew Wilcox <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Stable-dep-of: 007800408002 ("espintcp: use sk_msg_free_partial to fix partial send")
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 net/ipv4/tcp_bpf.c |   20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -92,11 +92,13 @@ static int tcp_bpf_push(struct sock *sk,
 {
 	bool apply = apply_bytes;
 	struct scatterlist *sge;
+	struct msghdr msghdr = { .msg_flags = flags | MSG_SPLICE_PAGES, };
 	struct page *page;
 	int size, ret = 0;
 	u32 off;
 
 	while (1) {
+		struct bio_vec bvec;
 		bool has_tx_ulp;
 
 		sge = sk_msg_elem(msg, msg->sg.start);
@@ -108,16 +110,18 @@ static int tcp_bpf_push(struct sock *sk,
 		tcp_rate_check_app_limited(sk);
 retry:
 		has_tx_ulp = tls_sw_has_ctx_tx(sk);
-		if (has_tx_ulp) {
-			flags |= MSG_SENDPAGE_NOPOLICY;
-			ret = kernel_sendpage_locked(sk,
-						     page, off, size, flags);
-		} else {
-			ret = do_tcp_sendpages(sk, page, off, size, flags);
-		}
+		if (has_tx_ulp)
+			msghdr.msg_flags |= MSG_SENDPAGE_NOPOLICY;
+
+		if (flags & MSG_SENDPAGE_NOTLAST)
+			msghdr.msg_flags |= MSG_MORE;
 
+		bvec_set_page(&bvec, page, size, off);
+		iov_iter_bvec(&msghdr.msg_iter, ITER_SOURCE, &bvec, 1, size);
+		ret = tcp_sendmsg_locked(sk, &msghdr, size);
 		if (ret <= 0)
 			return ret;
+
 		if (apply)
 			apply_bytes -= ret;
 		msg->sg.size -= ret;
@@ -501,7 +505,7 @@ static int tcp_bpf_sendmsg(struct sock *
 	long timeo;
 	int flags;
 
-	/* Don't let internal do_tcp_sendpages() flags through */
+	/* Don't let internal sendpage flags through */
 	flags = (msg->msg_flags & ~MSG_SENDPAGE_DECRYPTED);
 	flags |= MSG_NO_SHARED_FRAGS;