This is a note to let you know that I've just added the patch titled
ipv4, ipv6: Use splice_eof() to flush
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:
ipv4-ipv6-use-splice_eof-to-flush.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 5611af5949dfd630156868ccdfe55a978083caf4
Author: David Howells <dhowells@xxxxxxxxxx>
Date: Wed Jun 7 19:19:13 2023 +0100
ipv4, ipv6: Use splice_eof() to flush
[ Upstream commit 1d7e4538a5463faa0b0e26a7a7b6bd68c7dfdd78 ]
Allow splice to undo the effects of MSG_MORE after prematurely ending a
splice/sendfile due to getting an EOF condition (->splice_read() returned
0) after splice had called sendmsg() with MSG_MORE set when the user didn't
set MSG_MORE.
For UDP, a pending packet will not be emitted if the socket is closed
before it is flushed; with this change, it be flushed by ->splice_eof().
For TCP, it's not clear that MSG_MORE is actually effective.
Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/CAHk-=wh=V579PDYvkpnTobCLGczbgxpMgGmmhqiTyE34Cpi5Gg@xxxxxxxxxxxxxx/
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
cc: Willem de Bruijn <willemdebruijn.kernel@xxxxxxxxx>
cc: David Ahern <dsahern@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/net/inet_common.h b/include/net/inet_common.h
index cec453c18f1d6..4673bbfd2811f 100644
--- a/include/net/inet_common.h
+++ b/include/net/inet_common.h
@@ -33,6 +33,7 @@ int inet_accept(struct socket *sock, struct socket *newsock, int flags,
bool kern);
int inet_send_prepare(struct sock *sk);
int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size);
+void inet_splice_eof(struct socket *sock);
ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
size_t size, int flags);
int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
diff --git a/include/net/tcp.h b/include/net/tcp.h
index c3d56b337f358..4c838f7290dd9 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -332,6 +332,7 @@ int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size);
int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *copied,
size_t size, struct ubuf_info *uarg);
+void tcp_splice_eof(struct socket *sock);
int tcp_sendpage(struct sock *sk, struct page *page, int offset, size_t size,
int flags);
int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset,
diff --git a/include/net/udp.h b/include/net/udp.h
index fee053bcd17c6..fa4cdbe55552c 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -269,6 +269,7 @@ int udp_get_port(struct sock *sk, unsigned short snum,
int udp_err(struct sk_buff *, u32);
int udp_abort(struct sock *sk, int err);
int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len);
+void udp_splice_eof(struct socket *sock);
int udp_push_pending_frames(struct sock *sk);
void udp_flush_pending_frames(struct sock *sk);
int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size);
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 5d379df90c826..347c3768df6e8 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -838,6 +838,21 @@ int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
}
EXPORT_SYMBOL(inet_sendmsg);
+void inet_splice_eof(struct socket *sock)
+{
+ const struct proto *prot;
+ struct sock *sk = sock->sk;
+
+ if (unlikely(inet_send_prepare(sk)))
+ return;
+
+ /* IPV6_ADDRFORM can change sk->sk_prot under us. */
+ prot = READ_ONCE(sk->sk_prot);
+ if (prot->splice_eof)
+ prot->splice_eof(sock);
+}
+EXPORT_SYMBOL_GPL(inet_splice_eof);
+
ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
size_t size, int flags)
{
@@ -1057,6 +1072,7 @@ const struct proto_ops inet_stream_ops = {
#ifdef CONFIG_MMU
.mmap = tcp_mmap,
#endif
+ .splice_eof = inet_splice_eof,
.sendpage = inet_sendpage,
.splice_read = tcp_splice_read,
.read_sock = tcp_read_sock,
@@ -1091,6 +1107,7 @@ const struct proto_ops inet_dgram_ops = {
.read_skb = udp_read_skb,
.recvmsg = inet_recvmsg,
.mmap = sock_no_mmap,
+ .splice_eof = inet_splice_eof,
.sendpage = inet_sendpage,
.set_peek_off = sk_set_peek_off,
#ifdef CONFIG_COMPAT
@@ -1122,6 +1139,7 @@ static const struct proto_ops inet_sockraw_ops = {
.sendmsg = inet_sendmsg,
.recvmsg = inet_recvmsg,
.mmap = sock_no_mmap,
+ .splice_eof = inet_splice_eof,
.sendpage = inet_sendpage,
#ifdef CONFIG_COMPAT
.compat_ioctl = inet_compat_ioctl,
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 3935451ad061e..0b7844a8d5711 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1492,6 +1492,22 @@ int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
}
EXPORT_SYMBOL(tcp_sendmsg);
+void tcp_splice_eof(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct tcp_sock *tp = tcp_sk(sk);
+ int mss_now, size_goal;
+
+ if (!tcp_write_queue_tail(sk))
+ return;
+
+ lock_sock(sk);
+ mss_now = tcp_send_mss(sk, &size_goal, 0);
+ tcp_push(sk, 0, mss_now, tp->nonagle, size_goal);
+ release_sock(sk);
+}
+EXPORT_SYMBOL_GPL(tcp_splice_eof);
+
/*
* Handle reading urgent data. BSD has very simple semantics for
* this, no blocking and very strange errors 8)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 7ebbbe561e402..be2c807eed15d 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -3067,6 +3067,7 @@ struct proto tcp_prot = {
.keepalive = tcp_set_keepalive,
.recvmsg = tcp_recvmsg,
.sendmsg = tcp_sendmsg,
+ .splice_eof = tcp_splice_eof,
.sendpage = tcp_sendpage,
.backlog_rcv = tcp_v4_do_rcv,
.release_cb = tcp_release_cb,
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index b49cb3df01bb4..e8dd2880ac9aa 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1332,6 +1332,21 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
}
EXPORT_SYMBOL(udp_sendmsg);
+void udp_splice_eof(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct udp_sock *up = udp_sk(sk);
+
+ if (!up->pending || READ_ONCE(up->corkflag))
+ return;
+
+ lock_sock(sk);
+ if (up->pending && !READ_ONCE(up->corkflag))
+ udp_push_pending_frames(sk);
+ release_sock(sk);
+}
+EXPORT_SYMBOL_GPL(udp_splice_eof);
+
int udp_sendpage(struct sock *sk, struct page *page, int offset,
size_t size, int flags)
{
@@ -2907,6 +2922,7 @@ struct proto udp_prot = {
.getsockopt = udp_getsockopt,
.sendmsg = udp_sendmsg,
.recvmsg = udp_recvmsg,
+ .splice_eof = udp_splice_eof,
.sendpage = udp_sendpage,
.release_cb = ip4_datagram_release_cb,
.hash = udp_lib_hash,
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index b5309ae87fd79..a2f29ca516000 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -711,6 +711,7 @@ const struct proto_ops inet6_stream_ops = {
#ifdef CONFIG_MMU
.mmap = tcp_mmap,
#endif
+ .splice_eof = inet_splice_eof,
.sendpage = inet_sendpage,
.sendmsg_locked = tcp_sendmsg_locked,
.sendpage_locked = tcp_sendpage_locked,
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 7be89dcfd5fc5..ba9a22db5805c 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -2158,6 +2158,7 @@ struct proto tcpv6_prot = {
.keepalive = tcp_set_keepalive,
.recvmsg = tcp_recvmsg,
.sendmsg = tcp_sendmsg,
+ .splice_eof = tcp_splice_eof,
.sendpage = tcp_sendpage,
.backlog_rcv = tcp_v6_do_rcv,
.release_cb = tcp_release_cb,
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 7f49f69226a21..2a65136dca773 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -1657,6 +1657,20 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
goto out;
}
+static void udpv6_splice_eof(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct udp_sock *up = udp_sk(sk);
+
+ if (!up->pending || READ_ONCE(up->corkflag))
+ return;
+
+ lock_sock(sk);
+ if (up->pending && !READ_ONCE(up->corkflag))
+ udp_v6_push_pending_frames(sk);
+ release_sock(sk);
+}
+
void udpv6_destroy_sock(struct sock *sk)
{
struct udp_sock *up = udp_sk(sk);
@@ -1768,6 +1782,7 @@ struct proto udpv6_prot = {
.getsockopt = udpv6_getsockopt,
.sendmsg = udpv6_sendmsg,
.recvmsg = udpv6_recvmsg,
+ .splice_eof = udpv6_splice_eof,
.release_cb = ip6_datagram_release_cb,
.hash = udp_lib_hash,
.unhash = udp_lib_unhash,
