[PATCH]: Adjust qlen when grafting in multiple qdiscs

[Patrick McHardy <kaber@xxxxxxxxx>]

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      kaber@xxxxxxxxx 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;