bpf, sockmap: Reschedule is now done through backlog

[ Upstream commit bce22552f92ea7c577f49839b8e8f7d29afaf880 ]

Now that the backlog manages the reschedule() logic correctly we can drop
the partial fix to reschedule from recvmsg hook.

Rescheduling on recvmsg hook was added to address a corner case where we
still had data in the backlog state but had nothing to kick it and
reschedule the backlog worker to run and finish copying data out of the
state. This had a couple limitations, first it required user space to
kick it introducing an unnecessary EBUSY and retry. Second it only
handled the ingress case and egress redirects would still be hung.

With the correct fix, pushing the reschedule logic down to where the
enomem error occurs we can drop this fix.

Fixes: bec217197b412 ("skmsg: Schedule psock work if the cached skb exists on the psock")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230523025618.113937-4-john.fastabend@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 6a9b794861f3f4ba900660112d5a6f44d211b8b8..2dfb6e31e8d0487c96414e104896fe5acca0dd56 100644 (file)
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -480,8 +480,6 @@ int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg,
                msg_rx = sk_psock_peek_msg(psock);
        }
 out:
-       if (psock->work_state.skb && copied > 0)
-               schedule_delayed_work(&psock->work, 0);
        return copied;
 }
 EXPORT_SYMBOL_GPL(sk_msg_recvmsg);