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authorPavel Begunkov <asml.silence@gmail.com>2023-05-15 17:06:37 +0100
committerDavid S. Miller <davem@davemloft.net>2023-05-17 08:37:55 +0100
commita7533584728d366f11b210d0e8a2fad03109c669 (patch)
treeea527346b81a27e1bd3d80a2ea1ff207034e51b4 /net/ipv4/tcp.c
parenteea96a3e2c909a055005ac65dde356b36cabc4ed (diff)
net/tcp: optimise io_uring zc ubuf refcounting
io_uring keeps a reference to ubuf_info during submission, so if tcp_sendmsg_locked() sees msghdr::msg_ubuf in can be sure the buffer will be kept alive and doesn't need to additionally pin it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp.c')
-rw-r--r--net/ipv4/tcp.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 40f591f7fce1..3d18e295bb2f 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1231,7 +1231,6 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
if ((flags & MSG_ZEROCOPY) && size) {
if (msg->msg_ubuf) {
uarg = msg->msg_ubuf;
- net_zcopy_get(uarg);
zc = sk->sk_route_caps & NETIF_F_SG;
} else if (sock_flag(sk, SOCK_ZEROCOPY)) {
skb = tcp_write_queue_tail(sk);
@@ -1458,7 +1457,9 @@ out:
tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
}
out_nopush:
- net_zcopy_put(uarg);
+ /* msg->msg_ubuf is pinned by the caller so we don't take extra refs */
+ if (uarg && !msg->msg_ubuf)
+ net_zcopy_put(uarg);
return copied + copied_syn;
do_error:
@@ -1467,7 +1468,9 @@ do_error:
if (copied + copied_syn)
goto out;
out_err:
- net_zcopy_put_abort(uarg, true);
+ /* msg->msg_ubuf is pinned by the caller so we don't take extra refs */
+ if (uarg && !msg->msg_ubuf)
+ net_zcopy_put_abort(uarg, true);
err = sk_stream_error(sk, flags, err);
/* make sure we wake any epoll edge trigger waiter */
if (unlikely(tcp_rtx_and_write_queues_empty(sk) && err == -EAGAIN)) {