From e38bad4766a110b61fa6038f10be16ced8c6cc38 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 28 Nov 2007 10:55:32 +0100 Subject: [PATCH] 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 --- include/net/mac80211.h | 3 +-- net/mac80211/util.c | 7 ++++--- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 1470e1b886f0..4cc5b1c8a4f1 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 5227c16f113e..7b278e9aa1a4 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);