Commit f5e50cd0 authored by Javier Cardona's avatar Javier Cardona Committed by John W. Linville
Browse files

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: default avatarJavier Cardona <javier@cozybit.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent ece1a2e7

net/mac80211/mesh.h

+3 −1
Original line number Diff line number Diff line
@@ -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

 *

 *

net/mac80211/mesh_pathtbl.c

+4 −10
Original line number Diff line number Diff line
@@ -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();

}