This is a note to let you know that I've just added the patch titled
net: Declare MSG_SPLICE_PAGES internal sendmsg() flag
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-declare-msg_splice_pages-internal-sendmsg-flag.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 75dffd6df5e444bb377e400ba3e8acf49ca982d3
Author: David Howells <dhowells@xxxxxxxxxx>
Date: Mon May 22 13:11:10 2023 +0100
net: Declare MSG_SPLICE_PAGES internal sendmsg() flag
[ Upstream commit b841b901c452d92610f739a36e54978453528876 ]
Declare MSG_SPLICE_PAGES, an internal sendmsg() flag, that hints to a
network protocol that it should splice pages from the source iterator
rather than copying the data if it can. This flag is added to a list that
is cleared by sendmsg syscalls on entry.
This is intended as a replacement for the ->sendpage() op, allowing a way
to splice in several multipage folios in one go.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Reviewed-by: Willem de Bruijn <willemb@xxxxxxxxxx>
cc: Jens Axboe <axboe@xxxxxxxxx>
cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Stable-dep-of: a0002127cd74 ("udp: move udp->no_check6_tx to udp->udp_flags")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/linux/socket.h b/include/linux/socket.h
index 1db29aab8f9c3..b3c58042bd254 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -324,6 +324,7 @@ struct ucred {
*/
#define MSG_ZEROCOPY 0x4000000 /* Use user data in kernel path */
+#define MSG_SPLICE_PAGES 0x8000000 /* Splice the pages from the iterator in sendmsg() */
#define MSG_FASTOPEN 0x20000000 /* Send data in TCP SYN */
#define MSG_CMSG_CLOEXEC 0x40000000 /* Set close_on_exec for file
descriptor received through
@@ -334,6 +335,8 @@ struct ucred {
#define MSG_CMSG_COMPAT 0 /* We never have 32 bit fixups */
#endif
+/* Flags to be cleared on entry by sendmsg and sendmmsg syscalls */
+#define MSG_INTERNAL_SENDMSG_FLAGS (MSG_SPLICE_PAGES)
/* Setsockoptions(2) level. Thanks to BSD these must match IPPROTO_xxx */
#define SOL_IP 0
diff --git a/io_uring/net.c b/io_uring/net.c
index 57c626cb4d1a5..67f09a40bcb21 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -389,6 +389,7 @@ int io_send(struct io_kiocb *req, unsigned int issue_flags)
if (flags & MSG_WAITALL)
min_ret = iov_iter_count(&msg.msg_iter);
+ flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
msg.msg_flags = flags;
ret = sock_sendmsg(sock, &msg);
if (ret < min_ret) {
@@ -1137,6 +1138,7 @@ int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
msg_flags |= MSG_DONTWAIT;
if (msg_flags & MSG_WAITALL)
min_ret = iov_iter_count(&msg.msg_iter);
+ msg_flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
msg.msg_flags = msg_flags;
msg.msg_ubuf = &io_notif_to_data(zc->notif)->uarg;
diff --git a/net/socket.c b/net/socket.c
index 0104617b440dc..6f39f7b0cc85c 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2131,6 +2131,7 @@ int __sys_sendto(int fd, void __user *buff, size_t len, unsigned int flags,
msg.msg_name = (struct sockaddr *)&address;
msg.msg_namelen = addr_len;
}
+ flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
if (sock->file->f_flags & O_NONBLOCK)
flags |= MSG_DONTWAIT;
msg.msg_flags = flags;
@@ -2482,6 +2483,7 @@ static int ____sys_sendmsg(struct socket *sock, struct msghdr *msg_sys,
msg_sys->msg_control = ctl_buf;
msg_sys->msg_control_is_user = false;
}
+ flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
msg_sys->msg_flags = flags;
if (sock->file->f_flags & O_NONBLOCK)
