From 107c3044c4446f27627ed475cdc65f9b0b3f9bbf Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sun, 17 Sep 1995 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1995-09-17

---
 port/qio.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/port/qio.c b/port/qio.c
index 4a1239f60a6c18fb0609360a98969fdd3f93d810..e4974e8b62fdf1effe21bab87c2af888f8e288bc 100644
--- a/port/qio.c
+++ b/port/qio.c
@@ -412,11 +412,14 @@ qbread(Queue *q, int len)
 	nb = b;
 	if(n > len){
 		if((q->state&Qmsg) == 0){
+			iunlock(q);
+
 			n -= len;
 			b = allocb(n);
 			memmove(b->wp, nb->rp+len, n);
 			b->wp += n;
 
+			ilock(q);
 			b->next = q->bfirst;
 			if(q->bfirst == 0)
 				q->blast = b;