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| author |   John Fastabend <john.fastabend@gmail.com> | 2014-09-12 20:04:52 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2014-09-13 12:30:25 -0400 |
| commit | 46e5da40aec256155cfedee96dd21a75da941f2c (patch) | |
| tree | cc3986c52025d252c2a063053692595e60c80e13 /include/net/sch_generic.h | |
| parent | sunvnet: Avoid sending superfluous LDC messages. (diff) | |
| download | linux-dev-46e5da40aec256155cfedee96dd21a75da941f2c.tar.xz linux-dev-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.h | 21 |
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; |