| Message ID | 20230331160914.1608208-4-dhowells@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | splice, net: Replace sendpage with sendmsg(MSG_SPLICE_PAGES) | expand |
David Howells wrote: > 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 and recvmsg syscalls on entry. nit: comment not longer matches implementation: recvmsg > 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@redhat.com> > cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com> > cc: "David S. Miller" <davem@davemloft.net> > cc: Eric Dumazet <edumazet@google.com> > cc: Jakub Kicinski <kuba@kernel.org> > cc: Paolo Abeni <pabeni@redhat.com> > cc: Jens Axboe <axboe@kernel.dk> > cc: Matthew Wilcox <willy@infradead.org> > cc: netdev@vger.kernel.org Aside from that Reviewed-by: Willem de Bruijn <willemb@google.com>
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/net/socket.c b/net/socket.c index 6bae8ce7059e..0c39ce57d603 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2139,6 +2139,7 @@ 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; @@ -2486,6 +2487,7 @@ static int ____sys_sendmsg(struct socket *sock, struct msghdr *msg_sys, } msg_sys->msg_flags = flags; + flags &= ~MSG_INTERNAL_SENDMSG_FLAGS; if (sock->file->f_flags & O_NONBLOCK) msg_sys->msg_flags |= MSG_DONTWAIT; /*
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 and recvmsg 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@redhat.com> cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> cc: netdev@vger.kernel.org --- include/linux/socket.h | 3 +++ net/socket.c | 2 ++ 2 files changed, 5 insertions(+)