From f5e50cd0757cc97cd1caded0d3f07ff09b5319e4 Mon Sep 17 00:00:00 2001 From: Javier Cardona Date: Mon, 29 Aug 2011 13:23:05 -0700 Subject: [PATCH] mac80211: Improve mpath state locking No need to take the mpath state lock when an mpath is removed. Also, no need checking the lock when reading mpath flags. Signed-off-by: Javier Cardona Signed-off-by: John W. Linville --- net/mac80211/mesh.h | 4 +++- net/mac80211/mesh_pathtbl.c | 14 ++++---------- 2 files changed, 7 insertions(+), 11 deletions(-) diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h index 57a2ad021bee..7118e8e8855c 100644 --- a/net/mac80211/mesh.h +++ b/net/mac80211/mesh.h @@ -80,7 +80,9 @@ enum mesh_deferred_task_flags { * retry * @discovery_retries: number of discovery retries * @flags: mesh path flags, as specified on &enum mesh_path_flags - * @state_lock: mesh path state lock + * @state_lock: mesh path state lock used to protect changes to the + * mpath itself. No need to take this lock when adding or removing + * an mpath to a hash bucket on a path table. * @is_gate: the destination station of this path is a mesh gate * * diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c index d07279911a0c..618f84148a75 100644 --- a/net/mac80211/mesh_pathtbl.c +++ b/net/mac80211/mesh_pathtbl.c @@ -776,18 +776,17 @@ void mesh_plink_broken(struct sta_info *sta) tbl = rcu_dereference(mesh_paths); for_each_mesh_entry(tbl, p, node, i) { mpath = node->mpath; - spin_lock_bh(&mpath->state_lock); if (rcu_dereference(mpath->next_hop) == sta && mpath->flags & MESH_PATH_ACTIVE && !(mpath->flags & MESH_PATH_FIXED)) { + spin_lock_bh(&mpath->state_lock); mpath->flags &= ~MESH_PATH_ACTIVE; ++mpath->sn; spin_unlock_bh(&mpath->state_lock); mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl, mpath->dst, cpu_to_le32(mpath->sn), reason, bcast, sdata); - } else - spin_unlock_bh(&mpath->state_lock); + } } rcu_read_unlock(); } @@ -866,7 +865,7 @@ static void mpp_path_flush(struct ieee80211_sub_if_data *sdata) if (mpath->sdata != sdata) continue; spin_lock_bh(&tbl->hashwlock[i]); - spin_lock_bh(&mpath->state_lock); + hlist_del_rcu(&node->list); call_rcu(&node->rcu, mesh_path_node_reclaim); atomic_dec(&tbl->entries); spin_unlock_bh(&tbl->hashwlock[i]); @@ -1160,15 +1159,10 @@ void mesh_path_expire(struct ieee80211_sub_if_data *sdata) if (node->mpath->sdata != sdata) continue; mpath = node->mpath; - spin_lock_bh(&mpath->state_lock); if ((!(mpath->flags & MESH_PATH_RESOLVING)) && (!(mpath->flags & MESH_PATH_FIXED)) && - time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE)) { - spin_unlock_bh(&mpath->state_lock); + time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE)) mesh_path_del(mpath->dst, mpath->sdata); - } else - spin_unlock_bh(&mpath->state_lock); - } rcu_read_unlock(); }