diff options
| author | David Howells <dhowells@redhat.com> | 2023-06-07 19:19:13 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-06-08 19:40:30 -0700 |
| commit | 1d7e4538a5463faa0b0e26a7a7b6bd68c7dfdd78 (patch) | |
| tree | 0d539d1a13f203d607446b9163791db0ad7cab5c /net/ipv4/tcp.c | |
| parent | d4c1e80b0d1bacbbca5184f122b9893c5920c598 (diff) | |
ipv4, ipv6: Use splice_eof() to flush
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=V579PDYvkpnTobCLGczbgxpMgGmmhqiTyE34Cpi5Gg@mail.gmail.com/
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>
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 53b7751b68e1..09f03221a6f1 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1371,6 +1371,22 @@ 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) |