From: Johannes Berg Date: Wed, 28 Nov 2007 09:55:32 +0000 (+0100) Subject: mac80211: make ieee80211_iterate_active_interfaces not need rtnl X-Git-Tag: v2.6.25-rc1~1162^2~1302 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=e38bad4766a110b61fa6038f10be16ced8c6cc38;p=linux-2.6-omap-h63xx.git mac80211: make ieee80211_iterate_active_interfaces not need rtnl Interface iteration in mac80211 can be done without holding any locks because I converted it to RCU. Initially, I thought this wouldn't be needed for ieee80211_iterate_active_interfaces but it's turning out that multi-BSS AP support can be much simpler in a driver if ieee80211_iterate_active_interfaces can be called without holding locks. This converts it to use RCU, it adds a requirement that the callback it invokes cannot sleep. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville Signed-off-by: David S. Miller --- diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 1470e1b886f..4cc5b1c8a4f 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -1411,10 +1411,9 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw); * * This function iterates over the interfaces associated with a given * hardware that are currently active and calls the callback for them. - * Must be called under RTNL. * * @hw: the hardware struct of which the interfaces should be iterated over - * @iterator: the iterator function to call + * @iterator: the iterator function to call, cannot sleep * @data: first argument of the iterator function */ void ieee80211_iterate_active_interfaces(struct ieee80211_hw *hw, diff --git a/net/mac80211/util.c b/net/mac80211/util.c index 5227c16f113..7b278e9aa1a 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -482,10 +482,9 @@ void ieee80211_iterate_active_interfaces(struct ieee80211_hw *hw, struct ieee80211_local *local = hw_to_local(hw); struct ieee80211_sub_if_data *sdata; - ASSERT_RTNL(); + rcu_read_lock(); - /* we hold the RTNL here so can safely walk the list */ - list_for_each_entry(sdata, &local->interfaces, list) { + list_for_each_entry_rcu(sdata, &local->interfaces, list) { switch (sdata->type) { case IEEE80211_IF_TYPE_INVALID: case IEEE80211_IF_TYPE_MNTR: @@ -503,5 +502,7 @@ void ieee80211_iterate_active_interfaces(struct ieee80211_hw *hw, iterator(data, sdata->dev->dev_addr, sdata->dev->ifindex); } + + rcu_read_unlock(); } EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);