From 9db56888ee9b958ee8384d665da0fb9dd640b94b Mon Sep 17 00:00:00 2001
From: John Birrell <jb@FreeBSD.org>
Date: Fri, 22 Feb 2002 04:26:54 +0000
Subject: [PATCH] Fix a bug where a short write to a non-blocking socket would
 leave the descriptor locked, causing other threads to hang if they happened
 to access the socket.

MFC after:	5 days
---
 lib/libc_r/uthread/uthread_sendfile.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/libc_r/uthread/uthread_sendfile.c b/lib/libc_r/uthread/uthread_sendfile.c
index 901d523abf8a..81dcf63283c5 100644
--- a/lib/libc_r/uthread/uthread_sendfile.c
+++ b/lib/libc_r/uthread/uthread_sendfile.c
@@ -139,8 +139,11 @@ _sendfile(int fd, int s, off_t offset, size_t nbytes, struct sf_hdtr *hdtr,
 			/*
 			 * If we're not blocking then return.
 			 */
-			if (!blocking)
+			if (!blocking) {
+				_FD_UNLOCK(s, FD_WRITE);
+				_FD_UNLOCK(fd, FD_READ);
 				goto SHORT_WRITE;
+			}
 
 			/*
 			 * Otherwise wait on the fd.