pkt_sched: Fix gen_estimator locks

While passing a qdisc root lock to gen_new_estimator() and
gen_replace_estimator() dev could be deactivated or even before
grafting proper root qdisc as qdisc_sleeping (e.g. qdisc_create), so
using qdisc_root_lock() is not enough. This patch adds
qdisc_root_sleeping_lock() for this, plus additional checks, where
necessary.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index b1d2cfe..ef8a7e2 100644 (file)
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -217,6 +217,14 @@ static inline spinlock_t *qdisc_root_lock(struct Qdisc *qdisc)
        return qdisc_lock(root);
 }
 
+static inline spinlock_t *qdisc_root_sleeping_lock(struct Qdisc *qdisc)
+{
+       struct Qdisc *root = qdisc_root_sleeping(qdisc);
+
+       ASSERT_RTNL();
+       return qdisc_lock(root);
+}
+
 static inline struct net_device *qdisc_dev(struct Qdisc *qdisc)
 {
        return qdisc->dev_queue->dev;

diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index ad9cda1..506b709 100644 (file)
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -830,9 +830,16 @@ qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
                        sch->stab = stab;
                }
                if (tca[TCA_RATE]) {
+                       spinlock_t *root_lock;
+
+                       if ((sch->parent != TC_H_ROOT) &&
+                           !(sch->flags & TCQ_F_INGRESS))
+                               root_lock = qdisc_root_sleeping_lock(sch);
+                       else
+                               root_lock = qdisc_lock(sch);
+
                        err = gen_new_estimator(&sch->bstats, &sch->rate_est,
-                                               qdisc_root_lock(sch),
-                                               tca[TCA_RATE]);
+                                               root_lock, tca[TCA_RATE]);
                        if (err) {
                                /*
                                 * Any broken qdiscs that would require
@@ -884,7 +891,8 @@ static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
 
        if (tca[TCA_RATE])
                gen_replace_estimator(&sch->bstats, &sch->rate_est,
-                                     qdisc_root_lock(sch), tca[TCA_RATE]);
+                                     qdisc_root_sleeping_lock(sch),
+                                     tca[TCA_RATE]);
        return 0;
 }
 

diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 8fa90d6..9b720ad 100644 (file)
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -1839,7 +1839,7 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **t
 
                if (tca[TCA_RATE])
                        gen_replace_estimator(&cl->bstats, &cl->rate_est,
-                                             qdisc_root_lock(sch),
+                                             qdisc_root_sleeping_lock(sch),
                                              tca[TCA_RATE]);
                return 0;
        }
@@ -1930,7 +1930,7 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **t
 
        if (tca[TCA_RATE])
                gen_new_estimator(&cl->bstats, &cl->rate_est,
-                                 qdisc_root_lock(sch), tca[TCA_RATE]);
+                                 qdisc_root_sleeping_lock(sch), tca[TCA_RATE]);
 
        *arg = (unsigned long)cl;
        return 0;

diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index c2b8d9c..c1e77da 100644 (file)
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1045,7 +1045,7 @@ hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 
                if (tca[TCA_RATE])
                        gen_replace_estimator(&cl->bstats, &cl->rate_est,
-                                             qdisc_root_lock(sch),
+                                             qdisc_root_sleeping_lock(sch),
                                              tca[TCA_RATE]);
                return 0;
        }
@@ -1104,7 +1104,7 @@ hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 
        if (tca[TCA_RATE])
                gen_new_estimator(&cl->bstats, &cl->rate_est,
-                                 qdisc_root_lock(sch), tca[TCA_RATE]);
+                                 qdisc_root_sleeping_lock(sch), tca[TCA_RATE]);
        *arg = (unsigned long)cl;
        return 0;
 }

diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 0df0df2..97d4761 100644 (file)
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1372,7 +1372,7 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
                        goto failure;
 
                gen_new_estimator(&cl->bstats, &cl->rate_est,
-                                 qdisc_root_lock(sch),
+                                 qdisc_root_sleeping_lock(sch),
                                  tca[TCA_RATE] ? : &est.nla);
                cl->refcnt = 1;
                cl->children = 0;
@@ -1427,7 +1427,7 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
        } else {
                if (tca[TCA_RATE])
                        gen_replace_estimator(&cl->bstats, &cl->rate_est,
-                                             qdisc_root_lock(sch),
+                                             qdisc_root_sleeping_lock(sch),
                                              tca[TCA_RATE]);
                sch_tree_lock(sch);
        }