From: Sepherosa Ziehau <sephe@dragonflybsd.org>
Date: Wed, 11 Apr 2012 03:23:39 +0000 (+0800)
Subject: tcp_input: Partly revert 98cb2337e1000153d84b64a5e9aabbecda8e8dbf
X-Git-Tag: v3.2.0~1161
X-Git-Url: http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/31ea9b1ec5820f58f17c8c156b84f057208df99d

tcp_input: Partly revert 98cb2337e1000153d84b64a5e9aabbecda8e8dbf

Since all TCP operations are carried in its own netisr thread, the
workaround/comment is no longer needed/applied; change it into
assertion instead.

The "snd_nxt < snd_una" should (hopefully) have been fixed by:
1ff9b7d322dc5a26f7173aa8c38ecb79da80e419
---

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 86b3265..d8c90fb 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -1985,16 +1985,10 @@ fastretransmit:
 				    tp->t_maxseg;
 				tcp_output(tp);
 
-				/*
-				 * Other acks may have been processed,
-				 * snd_nxt cannot be reset to a value less
-				 * then snd_una.
-				 */
 				if (SEQ_LT(oldsndnxt, oldsndmax)) {
-				    if (SEQ_GT(oldsndnxt, tp->snd_una))
+					KASSERT(SEQ_GEQ(oldsndnxt, tp->snd_una),
+					    ("snd_una moved in other threads"));
 					tp->snd_nxt = oldsndnxt;
-				    else
-					tp->snd_nxt = tp->snd_una;
 				}
 				tp->snd_cwnd = oldcwnd;
 				sent = tp->snd_max - oldsndmax;