From 4a6187008f1ac3db2e221b3b21151f4d72fa8821 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 28 May 2026 15:02:08 +1000 Subject: tcp_splice: Improve EOF exit condition for the loop In tcp_splice_forward() we exit the forwarding loop if we have an EOF on the read side. However, this potentially leaves data in the pipe, even if the write side hasn't yet blocked. It's not clear to me whether this could leave data indefinitely in the pipe with no events to keep it moving, but it's not clear to me that it couldn't either. Stay in the loop until either the write side blocks or we've emptied the pipe. Secondly, this test is after several tests on how much we wrote which might also cause a retry. However, if we've reached EOF and the pipe is empty, there's nothing more to do, regardless of how much we wrote, so we should exit, regardless of those conditions. So move this exit test above the retry conditions. Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- tcp_splice.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/tcp_splice.c b/tcp_splice.c index 25e5d09..943dc21 100644 --- a/tcp_splice.c +++ b/tcp_splice.c @@ -543,15 +543,16 @@ retry: break; } + if (conn->events & FIN_RCVD(fromsidei) && + !conn->pending[fromsidei]) + break; + if (never_read && written == (long)(c->tcp.pipe_size)) goto retry; if (!never_read && written > 0 && written < conn->pending[fromsidei]) goto retry; - - if (conn->events & FIN_RCVD(fromsidei)) - break; } if (!conn->pending[fromsidei] && -- cgit v1.2.3