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authorDavid Howells <dhowells@redhat.com>2023-06-07 21:19:13 +0300
committerJakub Kicinski <kuba@kernel.org>2023-06-09 05:40:30 +0300
commit1d7e4538a5463faa0b0e26a7a7b6bd68c7dfdd78 (patch)
tree0d539d1a13f203d607446b9163791db0ad7cab5c /net/ipv4/udp.c
parentd4c1e80b0d1bacbbca5184f122b9893c5920c598 (diff)
downloadlinux-1d7e4538a5463faa0b0e26a7a7b6bd68c7dfdd78.tar.xz
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/udp.c')
-rw-r--r--net/ipv4/udp.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index fd3dae081f3a..df5e407286d7 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1324,6 +1324,21 @@ do_confirm:
}
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)
{
@@ -2918,6 +2933,7 @@ 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,