On Tue, 2008-05-06 at 23:50 +0200, Ivo van Doorn wrote:
> Since commit e38bad4766a110b61fa6038f10be16ced8c6cc38
> mac80211: make ieee80211_iterate_active_interfaces not need rtnl
> rt2500usb and rt73usb broke down due to attempting register access
> in atomic context (which is not possible for USB hardware).
>
> This patch restores ieee80211_iterate_active_interfaces() to use RTNL lock,
> and provides the non-RTNL version under a new name:
> ieee80211_iterate_active_interfaces_atomic()
>
> So far only rt2x00 uses ieee80211_iterate_active_interfaces(), and those
> drivers require the RTNL version of ieee80211_iterate_active_interfaces().
> Since they already call that function directly, this patch will automatically
> fix the USB rt2x00 drivers.
>
> v2: Rename ieee80211_iterate_active_interfaces_rtnl
>
> Signed-off-by: Ivo van Doorn <IvDoorn@xxxxxxxxx>
Acked-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Thanks for doing this.
> John, this is still 2.6.26 material. ;)
>
> diff --git a/include/net/mac80211.h b/include/net/mac80211.h
> index 7e75516..7d6de23 100644
> --- a/include/net/mac80211.h
> +++ b/include/net/mac80211.h
> @@ -1586,13 +1586,16 @@ void ieee80211_wake_queues(struct ieee80211_hw *hw);
> void ieee80211_scan_completed(struct ieee80211_hw *hw);
>
> /**
> - * ieee80211_iterate_active_interfaces - iterate active interfaces
> + * ieee80211_iterate_active_interfaces- iterate active interfaces
> *
> * This function iterates over the interfaces associated with a given
> * hardware that are currently active and calls the callback for them.
> + * This function allows the iterator function to sleep, when the iterator
> + * function is atomic @ieee80211_iterate_active_interfaces_atomic can
> + * be used.
> *
> * @hw: the hardware struct of which the interfaces should be iterated over
> - * @iterator: the iterator function to call, cannot sleep
> + * @iterator: the iterator function to call
> * @data: first argument of the iterator function
> */
> void ieee80211_iterate_active_interfaces(struct ieee80211_hw *hw,
> @@ -1601,6 +1604,24 @@ void ieee80211_iterate_active_interfaces(struct ieee80211_hw *hw,
> void *data);
>
> /**
> + * ieee80211_iterate_active_interfaces_atomic - iterate active interfaces
> + *
> + * This function iterates over the interfaces associated with a given
> + * hardware that are currently active and calls the callback for them.
> + * This function requires the iterator callback function to be atomic,
> + * if that is not desired, use @ieee80211_iterate_active_interfaces instead.
> + *
> + * @hw: the hardware struct of which the interfaces should be iterated over
> + * @iterator: the iterator function to call, cannot sleep
> + * @data: first argument of the iterator function
> + */
> +void ieee80211_iterate_active_interfaces_atomic(struct ieee80211_hw *hw,
> + void (*iterator)(void *data,
> + u8 *mac,
> + struct ieee80211_vif *vif),
> + void *data);
> +
> +/**
> * ieee80211_start_tx_ba_session - Start a tx Block Ack session.
> * @hw: pointer as obtained from ieee80211_alloc_hw().
> * @ra: receiver address of the BA session recipient
> diff --git a/net/mac80211/util.c b/net/mac80211/util.c
> index 74c48ef..2a8c0c5 100644
> --- a/net/mac80211/util.c
> +++ b/net/mac80211/util.c
> @@ -401,6 +401,41 @@ void ieee80211_iterate_active_interfaces(
> struct ieee80211_local *local = hw_to_local(hw);
> struct ieee80211_sub_if_data *sdata;
>
> + rtnl_lock();
> +
> + list_for_each_entry(sdata, &local->interfaces, list) {
> + switch (sdata->vif.type) {
> + case IEEE80211_IF_TYPE_INVALID:
> + case IEEE80211_IF_TYPE_MNTR:
> + case IEEE80211_IF_TYPE_VLAN:
> + continue;
> + case IEEE80211_IF_TYPE_AP:
> + case IEEE80211_IF_TYPE_STA:
> + case IEEE80211_IF_TYPE_IBSS:
> + case IEEE80211_IF_TYPE_WDS:
> + case IEEE80211_IF_TYPE_MESH_POINT:
> + break;
> + }
> + if (sdata->dev == local->mdev)
> + continue;
> + if (netif_running(sdata->dev))
> + iterator(data, sdata->dev->dev_addr,
> + &sdata->vif);
> + }
> +
> + rtnl_unlock();
> +}
> +EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);
> +
> +void ieee80211_iterate_active_interfaces_atomic(
> + struct ieee80211_hw *hw,
> + void (*iterator)(void *data, u8 *mac,
> + struct ieee80211_vif *vif),
> + void *data)
> +{
> + struct ieee80211_local *local = hw_to_local(hw);
> + struct ieee80211_sub_if_data *sdata;
> +
> rcu_read_lock();
>
> list_for_each_entry_rcu(sdata, &local->interfaces, list) {
> @@ -425,4 +460,4 @@ void ieee80211_iterate_active_interfaces(
>
> rcu_read_unlock();
> }
> -EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);
> +EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_atomic);
>
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