drbd/0021-compat-sock-Remove-sendpage-in-favour-of-sendmsg-MSG.patch

From a000a5577210929ca808fe19719186cb7e917f44 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Moritz=20WanzenBug=20Wanzenb=C3=B6ck?=
 <moritz.wanzenboeck@linbit.com>
Date: Wed, 13 Sep 2023 13:30:57 +0200
Subject: [PATCH] compat: sock: Remove ->sendpage*() in favour of
 sendmsg(MSG_SPLICE_PAGES)

See also upstream Linux kernel commits
dc97391e6610 ("sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)")
eeac7405c735 ("drbd: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage()")
4b9c2edaf728 ("drbd: swap bvec_set_page len and offset")

Original message:

Remove ->sendpage() and ->sendpage_locked().  sendmsg() with
MSG_SPLICE_PAGES should be used instead.  This allows multiple pages and
multipage folios to be passed through.
---
 .../cocci/msg_splice_pages__no_present.cocci     | 16 ++++++++++++++++
 drbd/drbd-kernel-compat/gen_patch_names.c        |  3 +++
 .../tests/have_msg_splice_pages.c                |  7 +++++++
 drbd/drbd_transport_tcp.c                        |  8 ++++++--
 4 files changed, 32 insertions(+), 2 deletions(-)
 create mode 100644 drbd/drbd-kernel-compat/cocci/msg_splice_pages__no_present.cocci
 create mode 100644 drbd/drbd-kernel-compat/tests/have_msg_splice_pages.c

diff --git a/drbd/drbd-kernel-compat/cocci/msg_splice_pages__no_present.cocci b/drbd/drbd-kernel-compat/cocci/msg_splice_pages__no_present.cocci
new file mode 100644
index 000000000000..0fdf77e43737
--- /dev/null
+++ b/drbd/drbd-kernel-compat/cocci/msg_splice_pages__no_present.cocci
@@ -0,0 +1,16 @@
+@@
+expression flags;
+@@
+  flags
+- | MSG_SPLICE_PAGES
+
+@@
+identifier bvec, page, len, offset, msg, socket;
+@@
+- struct bio_vec bvec;
+  ...
+  int sent;
+- bvec_set_page(&bvec, page, len, offset);
+- iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, len);
+- sent = sock_sendmsg(socket, &msg);
++ sent = socket->ops->sendpage(socket, page, offset, len, msg.msg_flags);
diff --git a/drbd/drbd-kernel-compat/gen_patch_names.c b/drbd/drbd-kernel-compat/gen_patch_names.c
index 608be8b4f099..6a96c5b89f11 100644
--- a/drbd/drbd-kernel-compat/gen_patch_names.c
+++ b/drbd/drbd-kernel-compat/gen_patch_names.c
@@ -127,6 +127,9 @@ int main(int argc, char **argv)
 	patch(1, "bvec_kmap_local", true, false,
 	      COMPAT_HAVE_BVEC_KMAP_LOCAL, "present");
 
+	patch(1, "msg_splice_pages", true, false,
+	      COMPAT_HAVE_MSG_SPLICE_PAGES, "present");
+
 	patch(1, "struct_bvec_iter", true, false,
 	      COMPAT_HAVE_STRUCT_BVEC_ITER, "present");
 
diff --git a/drbd/drbd-kernel-compat/tests/have_msg_splice_pages.c b/drbd/drbd-kernel-compat/tests/have_msg_splice_pages.c
new file mode 100644
index 000000000000..0bb23ef6d39a
--- /dev/null
+++ b/drbd/drbd-kernel-compat/tests/have_msg_splice_pages.c
@@ -0,0 +1,7 @@
+/* { "version": "v6.5-rc1", "commit": "dc97391e661009eab46783030d2404c9b6e6f2e7", "comment": "sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)", "author": "David Howells <dhowells@redhat.com>", "date": "Fri Jun 23 23:55:12 2023 +0100" } */
+#include <linux/net.h>
+
+int foo(void)
+{
+	return MSG_SPLICE_PAGES;
+}
diff --git a/drbd/drbd_transport_tcp.c b/drbd/drbd_transport_tcp.c
index ca60833f73d7..5dcba50dd0eb 100644
--- a/drbd/drbd_transport_tcp.c
+++ b/drbd/drbd_transport_tcp.c
@@ -1193,18 +1193,22 @@ static int dtt_send_page(struct drbd_transport *transport, enum drbd_stream stre
 	struct drbd_tcp_transport *tcp_transport =
 		container_of(transport, struct drbd_tcp_transport, transport);
 	struct socket *socket = tcp_transport->stream[stream];
+	struct msghdr msg = { .msg_flags = msg_flags | MSG_NOSIGNAL | MSG_SPLICE_PAGES };
+	struct bio_vec bvec;
 	int len = size;
 	int err = -EIO;
 
 	if (!socket)
 		return -ENOTCONN;
 
-	msg_flags |= MSG_NOSIGNAL;
 	dtt_update_congested(tcp_transport);
 	do {
 		int sent;
 
-		sent = socket->ops->sendpage(socket, page, offset, len, msg_flags);
+		bvec_set_page(&bvec, page, len, offset);
+		iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, len);
+
+		sent = sock_sendmsg(socket, &msg);
 		if (sent <= 0) {
 			if (sent == -EAGAIN) {
 				if (drbd_stream_send_timed_out(transport, stream))
-- 
2.42.1