summaryrefslogtreecommitdiffstats
path: root/include/net/sch_generic.h
diff options
context:
space:
mode:
authorJohn Fastabend2014-09-13 05:04:52 +0200
committerDavid S. Miller2014-09-13 18:30:25 +0200
commit46e5da40aec256155cfedee96dd21a75da941f2c (patch)
treecc3986c52025d252c2a063053692595e60c80e13 /include/net/sch_generic.h
parentsunvnet: Avoid sending superfluous LDC messages. (diff)
downloadkernel-qcow2-linux-46e5da40aec256155cfedee96dd21a75da941f2c.tar.gz
kernel-qcow2-linux-46e5da40aec256155cfedee96dd21a75da941f2c.tar.xz
kernel-qcow2-linux-46e5da40aec256155cfedee96dd21a75da941f2c.zip
net: qdisc: use rcu prefix and silence sparse warnings
Add __rcu notation to qdisc handling by doing this we can make smatch output more legible. And anyways some of the cases should be using rcu_dereference() see qdisc_all_tx_empty(), qdisc_tx_chainging(), and so on. Also *wake_queue() API is commonly called from driver timer routines without rcu lock or rtnl lock. So I added rcu_read_lock() blocks around netif_wake_subqueue and netif_tx_wake_queue. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/sch_generic.h')
-rw-r--r--include/net/sch_generic.h21
1 files changed, 15 insertions, 6 deletions
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index a3cfb8ebeb53..56838ab29b42 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -259,7 +259,9 @@ static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
{
- return qdisc->dev_queue->qdisc;
+ struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
+
+ return q;
}
static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
@@ -384,7 +386,7 @@ static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
struct Qdisc *qdisc;
for (; i < dev->num_tx_queues; i++) {
- qdisc = netdev_get_tx_queue(dev, i)->qdisc;
+ qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
if (qdisc) {
spin_lock_bh(qdisc_lock(qdisc));
qdisc_reset(qdisc);
@@ -402,13 +404,18 @@ static inline void qdisc_reset_all_tx(struct net_device *dev)
static inline bool qdisc_all_tx_empty(const struct net_device *dev)
{
unsigned int i;
+
+ rcu_read_lock();
for (i = 0; i < dev->num_tx_queues; i++) {
struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
- const struct Qdisc *q = txq->qdisc;
+ const struct Qdisc *q = rcu_dereference(txq->qdisc);
- if (q->q.qlen)
+ if (q->q.qlen) {
+ rcu_read_unlock();
return false;
+ }
}
+ rcu_read_unlock();
return true;
}
@@ -416,9 +423,10 @@ static inline bool qdisc_all_tx_empty(const struct net_device *dev)
static inline bool qdisc_tx_changing(const struct net_device *dev)
{
unsigned int i;
+
for (i = 0; i < dev->num_tx_queues; i++) {
struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
- if (txq->qdisc != txq->qdisc_sleeping)
+ if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
return true;
}
return false;
@@ -428,9 +436,10 @@ static inline bool qdisc_tx_changing(const struct net_device *dev)
static inline bool qdisc_tx_is_noop(const struct net_device *dev)
{
unsigned int i;
+
for (i = 0; i < dev->num_tx_queues; i++) {
struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
- if (txq->qdisc != &noop_qdisc)
+ if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
return false;
}
return true;