From 48bf6beddf455b0cb605915081f3428960a6224e Mon Sep 17 00:00:00 2001 From: Bob Copeland Date: Mon, 13 Apr 2015 17:26:28 -0400 Subject: [PATCH] mac80211: introduce plink lock for plink fields The mesh plink code uses sta->lock to serialize access to the plink state fields between the peer link state machine and the peer link timer. Some paths (e.g. those involving mps_qos_null_tx()) unfortunately hold this spinlock across frame tx, which is soon to be disallowed. Add a new spinlock just for plink access. Signed-off-by: Bob Copeland Signed-off-by: Johannes Berg --- net/mac80211/mesh_plink.c | 37 ++++++++++++++++++++----------------- net/mac80211/sta_info.c | 1 + net/mac80211/sta_info.h | 5 ++++- 3 files changed, 25 insertions(+), 18 deletions(-) diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c index 60d737f..ac843fc 100644 --- a/net/mac80211/mesh_plink.c +++ b/net/mac80211/mesh_plink.c @@ -72,10 +72,11 @@ static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata, * * @sta: mesh peer link to restart * - * Locking: this function must be called holding sta->lock + * Locking: this function must be called holding sta->plink_lock */ static inline void mesh_plink_fsm_restart(struct sta_info *sta) { + lockdep_assert_held(&sta->plink_lock); sta->plink_state = NL80211_PLINK_LISTEN; sta->llid = sta->plid = sta->reason = 0; sta->plink_retries = 0; @@ -213,13 +214,15 @@ static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) * All mesh paths with this peer as next hop will be flushed * Returns beacon changed flag if the beacon content changed. * - * Locking: the caller must hold sta->lock + * Locking: the caller must hold sta->plink_lock */ static u32 __mesh_plink_deactivate(struct sta_info *sta) { struct ieee80211_sub_if_data *sdata = sta->sdata; u32 changed = 0; + lockdep_assert_held(&sta->plink_lock); + if (sta->plink_state == NL80211_PLINK_ESTAB) changed = mesh_plink_dec_estab_count(sdata); sta->plink_state = NL80211_PLINK_BLOCKED; @@ -244,13 +247,13 @@ u32 mesh_plink_deactivate(struct sta_info *sta) struct ieee80211_sub_if_data *sdata = sta->sdata; u32 changed; - spin_lock_bh(&sta->lock); + spin_lock_bh(&sta->plink_lock); changed = __mesh_plink_deactivate(sta); sta->reason = WLAN_REASON_MESH_PEER_CANCELED; mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, sta->sta.addr, sta->llid, sta->plid, sta->reason); - spin_unlock_bh(&sta->lock); + spin_unlock_bh(&sta->plink_lock); return changed; } @@ -387,7 +390,7 @@ static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, sband = local->hw.wiphy->bands[band]; rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates); - spin_lock_bh(&sta->lock); + spin_lock_bh(&sta->plink_lock); sta->last_rx = jiffies; /* rates and capabilities don't change during peering */ @@ -419,7 +422,7 @@ static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, else rate_control_rate_update(local, sband, sta, changed); out: - spin_unlock_bh(&sta->lock); + spin_unlock_bh(&sta->plink_lock); } static struct sta_info * @@ -552,7 +555,7 @@ static void mesh_plink_timer(unsigned long data) if (sta->sdata->local->quiescing) return; - spin_lock_bh(&sta->lock); + spin_lock_bh(&sta->plink_lock); /* If a timer fires just before a state transition on another CPU, * we may have already extended the timeout and changed state by the @@ -563,7 +566,7 @@ static void mesh_plink_timer(unsigned long data) mpl_dbg(sta->sdata, "Ignoring timer for %pM in state %s (timer adjusted)", sta->sta.addr, mplstates[sta->plink_state]); - spin_unlock_bh(&sta->lock); + spin_unlock_bh(&sta->plink_lock); return; } @@ -573,7 +576,7 @@ static void mesh_plink_timer(unsigned long data) mpl_dbg(sta->sdata, "Ignoring timer for %pM in state %s (timer deleted)", sta->sta.addr, mplstates[sta->plink_state]); - spin_unlock_bh(&sta->lock); + spin_unlock_bh(&sta->plink_lock); return; } @@ -619,7 +622,7 @@ static void mesh_plink_timer(unsigned long data) default: break; } - spin_unlock_bh(&sta->lock); + spin_unlock_bh(&sta->plink_lock); if (action) mesh_plink_frame_tx(sdata, action, sta->sta.addr, sta->llid, sta->plid, reason); @@ -674,16 +677,16 @@ u32 mesh_plink_open(struct sta_info *sta) if (!test_sta_flag(sta, WLAN_STA_AUTH)) return 0; - spin_lock_bh(&sta->lock); + spin_lock_bh(&sta->plink_lock); sta->llid = mesh_get_new_llid(sdata); if (sta->plink_state != NL80211_PLINK_LISTEN && sta->plink_state != NL80211_PLINK_BLOCKED) { - spin_unlock_bh(&sta->lock); + spin_unlock_bh(&sta->plink_lock); return 0; } sta->plink_state = NL80211_PLINK_OPN_SNT; mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); - spin_unlock_bh(&sta->lock); + spin_unlock_bh(&sta->plink_lock); mpl_dbg(sdata, "Mesh plink: starting establishment with %pM\n", sta->sta.addr); @@ -700,10 +703,10 @@ u32 mesh_plink_block(struct sta_info *sta) { u32 changed; - spin_lock_bh(&sta->lock); + spin_lock_bh(&sta->plink_lock); changed = __mesh_plink_deactivate(sta); sta->plink_state = NL80211_PLINK_BLOCKED; - spin_unlock_bh(&sta->lock); + spin_unlock_bh(&sta->plink_lock); return changed; } @@ -758,7 +761,7 @@ static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, mplstates[sta->plink_state], mplevents[event]); - spin_lock_bh(&sta->lock); + spin_lock_bh(&sta->plink_lock); switch (sta->plink_state) { case NL80211_PLINK_LISTEN: switch (event) { @@ -872,7 +875,7 @@ static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, */ break; } - spin_unlock_bh(&sta->lock); + spin_unlock_bh(&sta->plink_lock); if (action) { mesh_plink_frame_tx(sdata, action, sta->sta.addr, sta->llid, sta->plid, sta->reason); diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index 12971b7..53ab4bd 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -295,6 +295,7 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata, INIT_WORK(&sta->ampdu_mlme.work, ieee80211_ba_session_work); mutex_init(&sta->ampdu_mlme.mtx); #ifdef CONFIG_MAC80211_MESH + spin_lock_init(&sta->plink_lock); if (ieee80211_vif_is_mesh(&sdata->vif) && !sdata->u.mesh.user_mpm) init_timer(&sta->plink_timer); diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h index 5c164fb..40ad52e 100644 --- a/net/mac80211/sta_info.h +++ b/net/mac80211/sta_info.h @@ -299,6 +299,7 @@ struct sta_ampdu_mlme { * @tid_seq: per-TID sequence numbers for sending to this STA * @ampdu_mlme: A-MPDU state machine state * @timer_to_tid: identity mapping to ID timers + * @plink_lock: serialize access to plink fields * @llid: Local link ID * @plid: Peer link ID * @reason: Cancel reason on PLINK_HOLDING state @@ -422,9 +423,10 @@ struct sta_info { #ifdef CONFIG_MAC80211_MESH /* - * Mesh peer link attributes + * Mesh peer link attributes, protected by plink_lock. * TODO: move to a sub-structure that is referenced with pointer? */ + spinlock_t plink_lock; u16 llid; u16 plid; u16 reason; @@ -432,6 +434,7 @@ struct sta_info { enum nl80211_plink_state plink_state; u32 plink_timeout; struct timer_list plink_timer; + s64 t_offset; s64 t_offset_setpoint; /* mesh power save */ -- 2.7.4