Subject: [PATCH]: Adjust qlen when grafting in multiple qdiscs

From: Patrick McHardy <[email-masked]>
Date: Thu, 13 Nov 2003 15:47:06 +0100

Hi Dave,

multiple qdiscs fail to adjust sch->q.qlen after grafting when the
old qdisc is non-empty. This permanently damages the counter.
TBF additionally needs to adjust stats.backlog.

Best regards,
Patrick

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
#	           ChangeSet	1.1427  -> 1.1428 
#	 net/sched/sch_tbf.c	1.10    -> 1.11   
#	 net/sched/sch_cbq.c	1.13    -> 1.14   
#	net/sched/sch_dsmark.c	1.10    -> 1.11   
#	net/sched/sch_prio.c	1.9     -> 1.10   
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 03/11/12	[email-masked]	1.1428
# Adjust qlen when grafting in multiple qdiscs
# --------------------------------------------
#
diff -Nru a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
--- a/net/sched/sch_cbq.c	Thu Nov 13 14:57:07 2003
+++ b/net/sched/sch_cbq.c	Thu Nov 13 14:57:07 2003
@@ -1670,6 +1670,7 @@
 		sch_tree_lock(sch);
 		*old = cl->q;
 		cl->q = new;
+		sch->q.qlen -= (*old)->q.qlen;
 		qdisc_reset(*old);
 		sch_tree_unlock(sch);
 
diff -Nru a/net/sched/sch_dsmark.c b/net/sched/sch_dsmark.c
--- a/net/sched/sch_dsmark.c	Thu Nov 13 14:57:07 2003
+++ b/net/sched/sch_dsmark.c	Thu Nov 13 14:57:07 2003
@@ -75,8 +75,10 @@
 		new = &noop_qdisc;
 	sch_tree_lock(sch);
 	*old = xchg(&p->q,new);
-	if (*old)
+	if (*old) {
+		sch->q.qlen -= (*old)->q.qlen;
 		qdisc_reset(*old);
+	}
 	sch_tree_unlock(sch); /* @@@ move up ? */
         return 0;
 }
diff -Nru a/net/sched/sch_prio.c b/net/sched/sch_prio.c
--- a/net/sched/sch_prio.c	Thu Nov 13 14:57:07 2003
+++ b/net/sched/sch_prio.c	Thu Nov 13 14:57:07 2003
@@ -266,6 +266,7 @@
 	sch_tree_lock(sch);
 	*old = q->queues[band];
 	q->queues[band] = new;
+	sch->q.qlen -= (*old)->q.qlen;
 	qdisc_reset(*old);
 	sch_tree_unlock(sch);
 
diff -Nru a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c
--- a/net/sched/sch_tbf.c	Thu Nov 13 14:57:07 2003
+++ b/net/sched/sch_tbf.c	Thu Nov 13 14:57:07 2003
@@ -455,6 +455,8 @@
 	sch_tree_lock(sch);	
 	*old = xchg(&q->qdisc, new);
 	qdisc_reset(*old);
+	sch->q.qlen = 0;
+	sch->stats.backlog = 0;
 	sch_tree_unlock(sch);
 	
 	return 0;