diff options
| -rw-r--r-- | net/mac80211/mesh_pathtbl.c | 70 |
1 files changed, 28 insertions, 42 deletions
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c index 7797f55eec46..a66a2cab8d34 100644 --- a/net/mac80211/mesh_pathtbl.c +++ b/net/mac80211/mesh_pathtbl.c @@ -48,10 +48,10 @@ static struct mesh_table __rcu *mpp_paths; /* Store paths for MPP&MAP */ int mesh_paths_generation; /* This lock will have the grow table function as writer and add / delete nodes - * as readers. When reading the table (i.e. doing lookups) we are well protected - * by RCU. We need to take this lock when modying the number of buckets - * on one of the path tables but we don't need to if adding or removing mpaths - * from hash buckets. + * as readers. RCU provides sufficient protection only when reading the table + * (i.e. doing lookups). Adding or adding or removing nodes requires we take + * the read lock or we risk operating on an old table. The write lock is only + * needed when modifying the number of buckets a table. */ static DEFINE_RWLOCK(pathtbl_resize_lock); @@ -335,25 +335,14 @@ static void mesh_path_move_to_queue(struct mesh_path *gate_mpath, } -/** - * mesh_path_lookup - look up a path in the mesh path table - * @dst: hardware address (ETH_ALEN length) of destination - * @sdata: local subif - * - * Returns: pointer to the mesh path structure, or NULL if not found - * - * Locking: must be called within a read rcu section. - */ -struct mesh_path *mesh_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata) +static struct mesh_path *path_lookup(struct mesh_table *tbl, u8 *dst, + struct ieee80211_sub_if_data *sdata) { struct mesh_path *mpath; struct hlist_node *n; struct hlist_head *bucket; - struct mesh_table *tbl; struct mpath_node *node; - tbl = rcu_dereference(mesh_paths); - bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)]; hlist_for_each_entry_rcu(node, n, bucket, list) { mpath = node->mpath; @@ -370,30 +359,23 @@ struct mesh_path *mesh_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata) return NULL; } -struct mesh_path *mpp_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata) +/** + * mesh_path_lookup - look up a path in the mesh path table + * @dst: hardware address (ETH_ALEN length) of destination + * @sdata: local subif + * + * Returns: pointer to the mesh path structure, or NULL if not found + * + * Locking: must be called within a read rcu section. + */ +struct mesh_path *mesh_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata) { - struct mesh_path *mpath; - struct hlist_node *n; - struct hlist_head *bucket; - struct mesh_table *tbl; - struct mpath_node *node; - - tbl = rcu_dereference(mpp_paths); + return path_lookup(rcu_dereference(mesh_paths), dst, sdata); +} - bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)]; - hlist_for_each_entry_rcu(node, n, bucket, list) { - mpath = node->mpath; - if (mpath->sdata == sdata && - memcmp(dst, mpath->dst, ETH_ALEN) == 0) { - if (MPATH_EXPIRED(mpath)) { - spin_lock_bh(&mpath->state_lock); - mpath->flags &= ~MESH_PATH_ACTIVE; - spin_unlock_bh(&mpath->state_lock); - } - return mpath; - } - } - return NULL; +struct mesh_path *mpp_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata) +{ + return path_lookup(rcu_dereference(mpp_paths), dst, sdata); } @@ -836,7 +818,8 @@ void mesh_path_flush_by_nexthop(struct sta_info *sta) int i; rcu_read_lock(); - tbl = rcu_dereference(mesh_paths); + read_lock_bh(&pathtbl_resize_lock); + tbl = resize_dereference_mesh_paths(); for_each_mesh_entry(tbl, p, node, i) { mpath = node->mpath; if (rcu_dereference(mpath->next_hop) == sta) { @@ -845,6 +828,7 @@ void mesh_path_flush_by_nexthop(struct sta_info *sta) spin_unlock_bh(&tbl->hashwlock[i]); } } + read_unlock_bh(&pathtbl_resize_lock); rcu_read_unlock(); } @@ -880,10 +864,12 @@ void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata) struct mesh_table *tbl; rcu_read_lock(); - tbl = rcu_dereference(mesh_paths); + read_lock_bh(&pathtbl_resize_lock); + tbl = resize_dereference_mesh_paths(); table_flush_by_iface(tbl, sdata); - tbl = rcu_dereference(mpp_paths); + tbl = resize_dereference_mpp_paths(); table_flush_by_iface(tbl, sdata); + read_unlock_bh(&pathtbl_resize_lock); rcu_read_unlock(); } |