6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Howells dhowells@redhat.com
[ 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@linux-foundation.org Link: https://lore.kernel.org/r/CAHk-=wh=V579PDYvkpnTobCLGczbgxpMgGmmhqiTyE34Cpi5G... Signed-off-by: David Howells dhowells@redhat.com cc: Kuniyuki Iwashima kuniyu@amazon.com cc: Willem de Bruijn willemdebruijn.kernel@gmail.com cc: David Ahern dsahern@kernel.org cc: Jens Axboe axboe@kernel.dk cc: Matthew Wilcox willy@infradead.org Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: a0002127cd74 ("udp: move udp->no_check6_tx to udp->udp_flags") Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/inet_common.h | 1 + include/net/tcp.h | 1 + include/net/udp.h | 1 + net/ipv4/af_inet.c | 18 ++++++++++++++++++ net/ipv4/tcp.c | 16 ++++++++++++++++ net/ipv4/tcp_ipv4.c | 1 + net/ipv4/udp.c | 16 ++++++++++++++++ net/ipv6/af_inet6.c | 1 + net/ipv6/tcp_ipv6.c | 1 + net/ipv6/udp.c | 15 +++++++++++++++ 10 files changed, 71 insertions(+)
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,