public inbox for [email protected]
 help / color / mirror / Atom feed
* [PATCH net-next v10 01/16] net: Declare MSG_SPLICE_PAGES internal sendmsg() flag
       [not found] <[email protected]>
@ 2023-05-22 12:11 ` David Howells
  0 siblings, 0 replies; only message in thread
From: David Howells @ 2023-05-22 12:11 UTC (permalink / raw)
  To: netdev
  Cc: David Howells, David S. Miller, Eric Dumazet, Jakub Kicinski,
	Paolo Abeni, Willem de Bruijn, David Ahern, Matthew Wilcox,
	Al Viro, Christoph Hellwig, Jens Axboe, Jeff Layton,
	Christian Brauner, Chuck Lever III, Linus Torvalds,
	linux-fsdevel, linux-kernel, linux-mm, Willem de Bruijn,
	io-uring

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 <[email protected]>
Reviewed-by: Willem de Bruijn <[email protected]>
cc: "David S. Miller" <[email protected]>
cc: Eric Dumazet <[email protected]>
cc: Jakub Kicinski <[email protected]>
cc: Paolo Abeni <[email protected]>
cc: Jens Axboe <[email protected]>
cc: Matthew Wilcox <[email protected]>
cc: [email protected]
cc: [email protected]
---

Notes:
    ver #7)
     - In ____sys_sendmsg(), clear internal flags before setting msg_flags.
     - Clear internal flags in uring io_send{,_zc}().

 include/linux/socket.h | 3 +++
 io_uring/net.c         | 2 ++
 net/socket.c           | 2 ++
 3 files changed, 7 insertions(+)

diff --git a/include/linux/socket.h b/include/linux/socket.h
index 13c3a237b9c9..bd1cc3238851 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -327,6 +327,7 @@ 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
@@ -337,6 +338,8 @@ 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 89e839013837..f7cbb3c7a575 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) {
@@ -1136,6 +1137,7 @@ 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 b7e01d0fe082..3df96e9ba4e2 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2138,6 +2138,7 @@ 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;
@@ -2483,6 +2484,7 @@ 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)


^ permalink raw reply related	[flat|nested] only message in thread

only message in thread, other threads:[~2023-05-22 12:12 UTC | newest]

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <[email protected]>
2023-05-22 12:11 ` [PATCH net-next v10 01/16] net: Declare MSG_SPLICE_PAGES internal sendmsg() flag David Howells

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox