In the time since the mesh path table was implemented as an
RCU-traversable, dynamically growing hash table, a generic RCU
hashtable implementation was added to the kernel.

Switch the mesh path table over to rhashtable to remove some code
and also gain some features like automatic shrinking.

Cc: Thomas Graf <tg...@suug.ch>
Cc: netdev@vger.kernel.org
Signed-off-by: Bob Copeland <m...@bobcopeland.com>
---
 net/mac80211/ieee80211_i.h  |  11 +-
 net/mac80211/mesh.c         |   6 -
 net/mac80211/mesh.h         |  31 +-
 net/mac80211/mesh_pathtbl.c | 786 ++++++++++++++------------------------------
 4 files changed, 259 insertions(+), 575 deletions(-)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index db7f0dbebc4b..c8945e2d8a86 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -697,17 +697,10 @@ struct ieee80211_if_mesh {
        /* offset from skb->data while building IE */
        int meshconf_offset;
 
-       struct mesh_table __rcu *mesh_paths;
-       struct mesh_table __rcu *mpp_paths; /* Store paths for MPP&MAP */
+       struct mesh_table *mesh_paths;
+       struct mesh_table *mpp_paths; /* Store paths for MPP&MAP */
        int mesh_paths_generation;
        int mpp_paths_generation;
-
-       /* Protects assignment of the mesh_paths/mpp_paths table
-        * pointer for resize against reading it for add/delete
-        * of individual paths.  Pure readers (lookups) just use
-        * RCU.
-        */
-       rwlock_t pathtbl_resize_lock;
 };
 
 #ifdef CONFIG_MAC80211_MESH
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index c92af2a7714d..a216c439b6f2 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -1347,12 +1347,6 @@ void ieee80211_mesh_work(struct ieee80211_sub_if_data 
*sdata)
                       ifmsh->last_preq + 
msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
                mesh_path_start_discovery(sdata);
 
-       if (test_and_clear_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags))
-               mesh_mpath_table_grow(sdata);
-
-       if (test_and_clear_bit(MESH_WORK_GROW_MPP_TABLE, &ifmsh->wrkq_flags))
-               mesh_mpp_table_grow(sdata);
-
        if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
                ieee80211_mesh_housekeeping(sdata);
 
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index f3cc3917e048..cc6854db156e 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -51,10 +51,6 @@ enum mesh_path_flags {
  *
  *
  * @MESH_WORK_HOUSEKEEPING: run the periodic mesh housekeeping tasks
- * @MESH_WORK_GROW_MPATH_TABLE: the mesh path table is full and needs
- * to grow.
- * @MESH_WORK_GROW_MPP_TABLE: the mesh portals table is full and needs to
- * grow
  * @MESH_WORK_ROOT: the mesh root station needs to send a frame
  * @MESH_WORK_DRIFT_ADJUST: time to compensate for clock drift relative to 
other
  * mesh nodes
@@ -62,8 +58,6 @@ enum mesh_path_flags {
  */
 enum mesh_deferred_task_flags {
        MESH_WORK_HOUSEKEEPING,
-       MESH_WORK_GROW_MPATH_TABLE,
-       MESH_WORK_GROW_MPP_TABLE,
        MESH_WORK_ROOT,
        MESH_WORK_DRIFT_ADJUST,
        MESH_WORK_MBSS_CHANGED,
@@ -105,6 +99,7 @@ enum mesh_deferred_task_flags {
 struct mesh_path {
        u8 dst[ETH_ALEN];
        u8 mpp[ETH_ALEN];       /* used for MPP or MAP */
+       struct rhash_head rhash;
        struct hlist_node gate_list;
        struct ieee80211_sub_if_data *sdata;
        struct sta_info __rcu *next_hop;
@@ -129,34 +124,17 @@ struct mesh_path {
 /**
  * struct mesh_table
  *
- * @hash_buckets: array of hash buckets of the table
- * @hashwlock: array of locks to protect write operations, one per bucket
- * @hash_mask: 2^size_order - 1, used to compute hash idx
- * @hash_rnd: random value used for hash computations
  * @entries: number of entries in the table
- * @free_node: function to free nodes of the table
- * @copy_node: function to copy nodes of the table
- * @size_order: determines size of the table, there will be 2^size_order hash
- *     buckets
  * @known_gates: list of known mesh gates and their mpaths by the station. The
  * gate's mpath may or may not be resolved and active.
- *
- * rcu_head: RCU head to free the table
+ * @rhash: the rhashtable containing struct mesh_paths, keyed by dest addr
  */
 struct mesh_table {
-       /* Number of buckets will be 2^N */
-       struct hlist_head *hash_buckets;
-       spinlock_t *hashwlock;          /* One per bucket, for add/del */
-       unsigned int hash_mask;         /* (2^size_order) - 1 */
-       __u32 hash_rnd;                 /* Used for hash generation */
        atomic_t entries;               /* Up to MAX_MESH_NEIGHBOURS */
-       void (*free_node) (struct hlist_node *p, bool free_leafs);
-       int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
-       int size_order;
        struct hlist_head *known_gates;
        spinlock_t gates_lock;
 
-       struct rcu_head rcu_head;
+       struct rhashtable rhead;
 };
 
 /* Recent multicast cache */
@@ -300,9 +278,6 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data 
*sdata,
 void mesh_sta_cleanup(struct sta_info *sta);
 
 /* Private interfaces */
-/* Mesh tables */
-void mesh_mpath_table_grow(struct ieee80211_sub_if_data *sdata);
-void mesh_mpp_table_grow(struct ieee80211_sub_if_data *sdata);
 /* Mesh paths */
 int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata,
                       u8 ttl, const u8 *target, u32 target_sn,
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index e4daf4b94eaf..7455397f8c3b 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -18,11 +18,20 @@
 #include "ieee80211_i.h"
 #include "mesh.h"
 
-/* There will be initially 2^INIT_PATHS_SIZE_ORDER buckets */
-#define INIT_PATHS_SIZE_ORDER  2
+static u32 mesh_table_hash(const void *addr, u32 len, u32 seed)
+{
+       /* Use last four bytes of hw addr as hash index */
+       return jhash_1word(*(u32 *)(addr+2), seed);
+}
 
-/* Keep the mean chain length below this constant */
-#define MEAN_CHAIN_LEN         2
+static const struct rhashtable_params mesh_rht_params = {
+       .nelem_hint = 2,
+       .automatic_shrinking = true,
+       .key_len = ETH_ALEN,
+       .key_offset = offsetof(struct mesh_path, dst),
+       .head_offset = offsetof(struct mesh_path, rhash),
+       .hashfn = mesh_table_hash,
+};
 
 static inline bool mpath_expired(struct mesh_path *mpath)
 {
@@ -31,157 +40,47 @@ static inline bool mpath_expired(struct mesh_path *mpath)
               !(mpath->flags & MESH_PATH_FIXED);
 }
 
-struct mpath_node {
-       struct hlist_node list;
-       struct rcu_head rcu;
-       /* This indirection allows two different tables to point to the same
-        * mesh_path structure, useful when resizing
-        */
-       struct mesh_path *mpath;
-};
-
-static inline struct mesh_table *resize_dereference_paths(
-       struct ieee80211_sub_if_data *sdata,
-       struct mesh_table __rcu *table)
+static void mesh_path_reclaim(struct rcu_head *rp)
 {
-       return rcu_dereference_protected(table,
-               lockdep_is_held(&sdata->u.mesh.pathtbl_resize_lock));
-}
+       struct mesh_path *mpath = container_of(rp, struct mesh_path, rcu);
 
-static inline struct mesh_table *resize_dereference_mesh_paths(
-               struct ieee80211_sub_if_data *sdata)
-{
-       return resize_dereference_paths(sdata, sdata->u.mesh.mesh_paths);
+       del_timer_sync(&mpath->timer);
+       kfree(mpath);
 }
 
-static inline struct mesh_table *resize_dereference_mpp_paths(
-               struct ieee80211_sub_if_data *sdata)
+static void mesh_path_rht_free(void *ptr, void *unused_arg)
 {
-       return resize_dereference_paths(sdata, sdata->u.mesh.mpp_paths);
+       struct mesh_path *mpath = ptr;
+       call_rcu(&mpath->rcu, mesh_path_reclaim);
 }
 
-/*
- * CAREFUL -- "tbl" must not be an expression,
- * in particular not an rcu_dereference(), since
- * it's used twice. So it is illegal to do
- *     for_each_mesh_entry(rcu_dereference(...), ...)
- */
-#define for_each_mesh_entry(tbl, node, i) \
-       for (i = 0; i <= tbl->hash_mask; i++) \
-               hlist_for_each_entry_rcu(node, &tbl->hash_buckets[i], list)
-
-
-static struct mesh_table *mesh_table_alloc(int size_order)
+static struct mesh_table *mesh_table_alloc(void)
 {
-       int i;
        struct mesh_table *newtbl;
 
        newtbl = kmalloc(sizeof(struct mesh_table), GFP_ATOMIC);
        if (!newtbl)
                return NULL;
 
-       newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) *
-                       (1 << size_order), GFP_ATOMIC);
-
-       if (!newtbl->hash_buckets) {
+       newtbl->known_gates = kzalloc(sizeof(struct hlist_head), GFP_ATOMIC);
+       if (!newtbl->known_gates) {
                kfree(newtbl);
                return NULL;
        }
-
-       newtbl->hashwlock = kmalloc(sizeof(spinlock_t) *
-                       (1 << size_order), GFP_ATOMIC);
-       if (!newtbl->hashwlock) {
-               kfree(newtbl->hash_buckets);
-               kfree(newtbl);
-               return NULL;
-       }
-
-       newtbl->size_order = size_order;
-       newtbl->hash_mask = (1 << size_order) - 1;
+       INIT_HLIST_HEAD(newtbl->known_gates);
        atomic_set(&newtbl->entries,  0);
-       get_random_bytes(&newtbl->hash_rnd,
-                       sizeof(newtbl->hash_rnd));
-       for (i = 0; i <= newtbl->hash_mask; i++)
-               spin_lock_init(&newtbl->hashwlock[i]);
        spin_lock_init(&newtbl->gates_lock);
 
        return newtbl;
 }
 
-static void __mesh_table_free(struct mesh_table *tbl)
+static void mesh_table_free(struct mesh_table *tbl)
 {
-       kfree(tbl->hash_buckets);
-       kfree(tbl->hashwlock);
+       rhashtable_free_and_destroy(&tbl->rhead,
+                                   mesh_path_rht_free, NULL);
        kfree(tbl);
 }
 
-static void mesh_table_free(struct mesh_table *tbl, bool free_leafs)
-{
-       struct hlist_head *mesh_hash;
-       struct hlist_node *p, *q;
-       struct mesh_path *gate;
-       int i;
-
-       mesh_hash = tbl->hash_buckets;
-       if (free_leafs) {
-               spin_lock_bh(&tbl->gates_lock);
-               hlist_for_each_entry_safe(gate, q,
-                                         tbl->known_gates, gate_list)
-                       hlist_del(&gate->gate_list);
-               kfree(tbl->known_gates);
-               spin_unlock_bh(&tbl->gates_lock);
-       }
-       for (i = 0; i <= tbl->hash_mask; i++) {
-               spin_lock_bh(&tbl->hashwlock[i]);
-               hlist_for_each_safe(p, q, &mesh_hash[i]) {
-                       tbl->free_node(p, free_leafs);
-                       atomic_dec(&tbl->entries);
-               }
-               spin_unlock_bh(&tbl->hashwlock[i]);
-       }
-
-       __mesh_table_free(tbl);
-}
-
-static int mesh_table_grow(struct mesh_table *oldtbl,
-                          struct mesh_table *newtbl)
-{
-       struct hlist_head *oldhash;
-       struct hlist_node *p, *q;
-       int i;
-
-       if (atomic_read(&oldtbl->entries)
-                       < MEAN_CHAIN_LEN * (oldtbl->hash_mask + 1))
-               return -EAGAIN;
-
-       newtbl->free_node = oldtbl->free_node;
-       newtbl->copy_node = oldtbl->copy_node;
-       newtbl->known_gates = oldtbl->known_gates;
-       atomic_set(&newtbl->entries, atomic_read(&oldtbl->entries));
-
-       oldhash = oldtbl->hash_buckets;
-       for (i = 0; i <= oldtbl->hash_mask; i++)
-               hlist_for_each(p, &oldhash[i])
-                       if (oldtbl->copy_node(p, newtbl) < 0)
-                               goto errcopy;
-
-       return 0;
-
-errcopy:
-       for (i = 0; i <= newtbl->hash_mask; i++) {
-               hlist_for_each_safe(p, q, &newtbl->hash_buckets[i])
-                       oldtbl->free_node(p, 0);
-       }
-       return -ENOMEM;
-}
-
-static u32 mesh_table_hash(const u8 *addr, struct mesh_table *tbl)
-{
-       /* Use last four bytes of hw addr as hash index */
-       return jhash_1word(*(u32 *)(addr+2), tbl->hash_rnd) & tbl->hash_mask;
-}
-
-
 /**
  *
  * mesh_path_assign_nexthop - update mesh path next hop
@@ -324,22 +223,15 @@ static struct mesh_path *mpath_lookup(struct mesh_table 
*tbl, const u8 *dst,
                                      struct ieee80211_sub_if_data *sdata)
 {
        struct mesh_path *mpath;
-       struct hlist_head *bucket;
-       struct mpath_node *node;
-
-       bucket = &tbl->hash_buckets[mesh_table_hash(dst, tbl)];
-       hlist_for_each_entry_rcu(node, bucket, list) {
-               mpath = node->mpath;
-               if (ether_addr_equal(dst, mpath->dst)) {
-                       if (mpath_expired(mpath)) {
-                               spin_lock_bh(&mpath->state_lock);
-                               mpath->flags &= ~MESH_PATH_ACTIVE;
-                               spin_unlock_bh(&mpath->state_lock);
-                       }
-                       return mpath;
-               }
+
+       mpath = rhashtable_lookup_fast(&tbl->rhead, dst, mesh_rht_params);
+
+       if (mpath && mpath_expired(mpath)) {
+               spin_lock_bh(&mpath->state_lock);
+               mpath->flags &= ~MESH_PATH_ACTIVE;
+               spin_unlock_bh(&mpath->state_lock);
        }
-       return NULL;
+       return mpath;
 }
 
 /**
@@ -354,17 +246,52 @@ static struct mesh_path *mpath_lookup(struct mesh_table 
*tbl, const u8 *dst,
 struct mesh_path *
 mesh_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
 {
-       return mpath_lookup(rcu_dereference(sdata->u.mesh.mesh_paths), dst,
-                           sdata);
+       return mpath_lookup(sdata->u.mesh.mesh_paths, dst, sdata);
 }
 
 struct mesh_path *
 mpp_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
 {
-       return mpath_lookup(rcu_dereference(sdata->u.mesh.mpp_paths), dst,
-                           sdata);
+       return mpath_lookup(sdata->u.mesh.mpp_paths, dst, sdata);
 }
 
+static struct mesh_path *
+__mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
+{
+       int i = 0, ret;
+       struct mesh_path *mpath = NULL;
+       struct rhashtable_iter iter;
+
+       ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
+       if (ret)
+               return NULL;
+
+       ret = rhashtable_walk_start(&iter);
+       if (ret && ret != -EAGAIN)
+               goto err;
+
+       while ((mpath = rhashtable_walk_next(&iter))) {
+               if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
+                       continue;
+               if (IS_ERR(mpath))
+                       break;
+               if (i++ == idx)
+                       break;
+       }
+err:
+       rhashtable_walk_stop(&iter);
+       rhashtable_walk_exit(&iter);
+
+       if (IS_ERR(mpath) || !mpath)
+               return NULL;
+
+       if (mpath_expired(mpath)) {
+               spin_lock_bh(&mpath->state_lock);
+               mpath->flags &= ~MESH_PATH_ACTIVE;
+               spin_unlock_bh(&mpath->state_lock);
+       }
+       return mpath;
+}
 
 /**
  * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
@@ -378,23 +305,7 @@ mpp_path_lookup(struct ieee80211_sub_if_data *sdata, const 
u8 *dst)
 struct mesh_path *
 mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
 {
-       struct mesh_table *tbl = rcu_dereference(sdata->u.mesh.mesh_paths);
-       struct mpath_node *node;
-       int i;
-       int j = 0;
-
-       for_each_mesh_entry(tbl, node, i) {
-               if (j++ == idx) {
-                       if (mpath_expired(node->mpath)) {
-                               spin_lock_bh(&node->mpath->state_lock);
-                               node->mpath->flags &= ~MESH_PATH_ACTIVE;
-                               spin_unlock_bh(&node->mpath->state_lock);
-                       }
-                       return node->mpath;
-               }
-       }
-
-       return NULL;
+       return __mesh_path_lookup_by_idx(sdata->u.mesh.mesh_paths, idx);
 }
 
 /**
@@ -409,17 +320,7 @@ mesh_path_lookup_by_idx(struct ieee80211_sub_if_data 
*sdata, int idx)
 struct mesh_path *
 mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
 {
-       struct mesh_table *tbl = rcu_dereference(sdata->u.mesh.mpp_paths);
-       struct mpath_node *node;
-       int i;
-       int j = 0;
-
-       for_each_mesh_entry(tbl, node, i) {
-               if (j++ == idx)
-                       return node->mpath;
-       }
-
-       return NULL;
+       return __mesh_path_lookup_by_idx(sdata->u.mesh.mpp_paths, idx);
 }
 
 /**
@@ -432,7 +333,7 @@ int mesh_path_add_gate(struct mesh_path *mpath)
        int err;
 
        rcu_read_lock();
-       tbl = rcu_dereference(mpath->sdata->u.mesh.mesh_paths);
+       tbl = mpath->sdata->u.mesh.mesh_paths;
 
        spin_lock_bh(&mpath->state_lock);
        if (mpath->is_gate) {
@@ -526,15 +427,9 @@ struct mesh_path *mesh_path_new(struct 
ieee80211_sub_if_data *sdata,
 struct mesh_path *mesh_path_add(struct ieee80211_sub_if_data *sdata,
                                const u8 *dst)
 {
-       struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
-       struct ieee80211_local *local = sdata->local;
        struct mesh_table *tbl;
        struct mesh_path *mpath, *new_mpath;
-       struct mpath_node *node, *new_node;
-       struct hlist_head *bucket;
-       int grow = 0;
-       int err;
-       u32 hash_idx;
+       int ret;
 
        if (ether_addr_equal(dst, sdata->vif.addr))
                /* never add ourselves as neighbours */
@@ -546,116 +441,44 @@ struct mesh_path *mesh_path_add(struct 
ieee80211_sub_if_data *sdata,
        if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0)
                return ERR_PTR(-ENOSPC);
 
-       read_lock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       tbl = resize_dereference_mesh_paths(sdata);
-
-       hash_idx = mesh_table_hash(dst, tbl);
-       bucket = &tbl->hash_buckets[hash_idx];
-
-       spin_lock(&tbl->hashwlock[hash_idx]);
-
-       hlist_for_each_entry(node, bucket, list) {
-               mpath = node->mpath;
-               if (ether_addr_equal(dst, mpath->dst))
-                       goto found;
-       }
-
-       err = -ENOMEM;
        new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
        if (!new_mpath)
-               goto err_path_alloc;
-
-       new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
-       if (!new_node)
-               goto err_node_alloc;
-
-       new_node->mpath = new_mpath;
-       hlist_add_head_rcu(&new_node->list, bucket);
-       if (atomic_inc_return(&tbl->entries) >=
-           MEAN_CHAIN_LEN * (tbl->hash_mask + 1))
-               grow = 1;
-
-       sdata->u.mesh.mesh_paths_generation++;
-
-       if (grow) {
-               set_bit(MESH_WORK_GROW_MPATH_TABLE,  &ifmsh->wrkq_flags);
-               ieee80211_queue_work(&local->hw, &sdata->work);
-       }
-       mpath = new_mpath;
-found:
-       spin_unlock(&tbl->hashwlock[hash_idx]);
-       read_unlock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       return mpath;
-
-err_node_alloc:
-       kfree(new_mpath);
-err_path_alloc:
-       atomic_dec(&sdata->u.mesh.mpaths);
-       spin_unlock(&tbl->hashwlock[hash_idx]);
-       read_unlock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       return ERR_PTR(err);
-}
-
-static void mesh_table_free_rcu(struct rcu_head *rcu)
-{
-       struct mesh_table *tbl = container_of(rcu, struct mesh_table, rcu_head);
-
-       mesh_table_free(tbl, false);
-}
-
-void mesh_mpath_table_grow(struct ieee80211_sub_if_data *sdata)
-{
-       struct mesh_table *oldtbl, *newtbl;
+               return ERR_PTR(-ENOMEM);
 
-       write_lock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       oldtbl = resize_dereference_mesh_paths(sdata);
-       newtbl = mesh_table_alloc(oldtbl->size_order + 1);
-       if (!newtbl)
-               goto out;
-       if (mesh_table_grow(oldtbl, newtbl) < 0) {
-               __mesh_table_free(newtbl);
-               goto out;
-       }
-       rcu_assign_pointer(sdata->u.mesh.mesh_paths, newtbl);
+       tbl = sdata->u.mesh.mesh_paths;
+       do {
+               ret = rhashtable_lookup_insert_fast(&tbl->rhead,
+                                                   &new_mpath->rhash,
+                                                   mesh_rht_params);
 
-       call_rcu(&oldtbl->rcu_head, mesh_table_free_rcu);
+               if (ret == -EEXIST)
+                       mpath = rhashtable_lookup_fast(&tbl->rhead,
+                                                      dst,
+                                                      mesh_rht_params);
 
- out:
-       write_unlock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-}
+       } while (unlikely(ret == -EEXIST && !mpath));
 
-void mesh_mpp_table_grow(struct ieee80211_sub_if_data *sdata)
-{
-       struct mesh_table *oldtbl, *newtbl;
+       if (ret && ret != -EEXIST)
+               return ERR_PTR(ret);
 
-       write_lock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       oldtbl = resize_dereference_mpp_paths(sdata);
-       newtbl = mesh_table_alloc(oldtbl->size_order + 1);
-       if (!newtbl)
-               goto out;
-       if (mesh_table_grow(oldtbl, newtbl) < 0) {
-               __mesh_table_free(newtbl);
-               goto out;
+       /* At this point either new_mpath was added, or we found a
+        * matching entry already in the table; in the latter case
+        * free the unnecessary new entry.
+        */
+       if (ret == -EEXIST) {
+               kfree(new_mpath);
+               new_mpath = mpath;
        }
-       rcu_assign_pointer(sdata->u.mesh.mpp_paths, newtbl);
-       call_rcu(&oldtbl->rcu_head, mesh_table_free_rcu);
-
- out:
-       write_unlock_bh(&sdata->u.mesh.pathtbl_resize_lock);
+       sdata->u.mesh.mesh_paths_generation++;
+       return new_mpath;
 }
 
 int mpp_path_add(struct ieee80211_sub_if_data *sdata,
                 const u8 *dst, const u8 *mpp)
 {
-       struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
-       struct ieee80211_local *local = sdata->local;
        struct mesh_table *tbl;
-       struct mesh_path *mpath, *new_mpath;
-       struct mpath_node *node, *new_node;
-       struct hlist_head *bucket;
-       int grow = 0;
-       int err = 0;
-       u32 hash_idx;
+       struct mesh_path *new_mpath;
+       int ret;
 
        if (ether_addr_equal(dst, sdata->vif.addr))
                /* never add ourselves as neighbours */
@@ -664,56 +487,19 @@ int mpp_path_add(struct ieee80211_sub_if_data *sdata,
        if (is_multicast_ether_addr(dst))
                return -ENOTSUPP;
 
-       err = -ENOMEM;
        new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
-       if (!new_mpath)
-               goto err_path_alloc;
 
-       new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
-       if (!new_node)
-               goto err_node_alloc;
+       if (!new_mpath)
+               return -ENOMEM;
 
        memcpy(new_mpath->mpp, mpp, ETH_ALEN);
-       new_node->mpath = new_mpath;
-       read_lock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       tbl = resize_dereference_mpp_paths(sdata);
-
-       hash_idx = mesh_table_hash(dst, tbl);
-       bucket = &tbl->hash_buckets[hash_idx];
-
-       spin_lock(&tbl->hashwlock[hash_idx]);
-
-       err = -EEXIST;
-       hlist_for_each_entry(node, bucket, list) {
-               mpath = node->mpath;
-               if (ether_addr_equal(dst, mpath->dst))
-                       goto err_exists;
-       }
-
-       hlist_add_head_rcu(&new_node->list, bucket);
-       if (atomic_inc_return(&tbl->entries) >=
-           MEAN_CHAIN_LEN * (tbl->hash_mask + 1))
-               grow = 1;
-
-       spin_unlock(&tbl->hashwlock[hash_idx]);
-       read_unlock_bh(&sdata->u.mesh.pathtbl_resize_lock);
+       tbl = sdata->u.mesh.mpp_paths;
+       ret = rhashtable_lookup_insert_fast(&tbl->rhead,
+                                           &new_mpath->rhash,
+                                           mesh_rht_params);
 
        sdata->u.mesh.mpp_paths_generation++;
-
-       if (grow) {
-               set_bit(MESH_WORK_GROW_MPP_TABLE,  &ifmsh->wrkq_flags);
-               ieee80211_queue_work(&local->hw, &sdata->work);
-       }
-       return 0;
-
-err_exists:
-       spin_unlock(&tbl->hashwlock[hash_idx]);
-       read_unlock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       kfree(new_node);
-err_node_alloc:
-       kfree(new_mpath);
-err_path_alloc:
-       return err;
+       return ret;
 }
 
 
@@ -727,17 +513,26 @@ err_path_alloc:
  */
 void mesh_plink_broken(struct sta_info *sta)
 {
-       struct mesh_table *tbl;
+       struct ieee80211_sub_if_data *sdata = sta->sdata;
+       struct mesh_table *tbl = sdata->u.mesh.mesh_paths;
        static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
        struct mesh_path *mpath;
-       struct mpath_node *node;
-       struct ieee80211_sub_if_data *sdata = sta->sdata;
-       int i;
+       struct rhashtable_iter iter;
+       int ret;
 
-       rcu_read_lock();
-       tbl = rcu_dereference(sdata->u.mesh.mesh_paths);
-       for_each_mesh_entry(tbl, node, i) {
-               mpath = node->mpath;
+       ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
+       if (ret)
+               return;
+
+       ret = rhashtable_walk_start(&iter);
+       if (ret && ret != -EAGAIN)
+               goto out;
+
+       while ((mpath = rhashtable_walk_next(&iter))) {
+               if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
+                       continue;
+               if (IS_ERR(mpath))
+                       break;
                if (rcu_access_pointer(mpath->next_hop) == sta &&
                    mpath->flags & MESH_PATH_ACTIVE &&
                    !(mpath->flags & MESH_PATH_FIXED)) {
@@ -751,30 +546,20 @@ void mesh_plink_broken(struct sta_info *sta)
                                WLAN_REASON_MESH_PATH_DEST_UNREACHABLE, bcast);
                }
        }
-       rcu_read_unlock();
-}
-
-static void mesh_path_node_reclaim(struct rcu_head *rp)
-{
-       struct mpath_node *node = container_of(rp, struct mpath_node, rcu);
-
-       del_timer_sync(&node->mpath->timer);
-       kfree(node->mpath);
-       kfree(node);
+out:
+       rhashtable_walk_stop(&iter);
+       rhashtable_walk_exit(&iter);
 }
 
-/* needs to be called with the corresponding hashwlock taken */
-static void __mesh_path_del(struct mesh_table *tbl, struct mpath_node *node)
+static void __mesh_path_del(struct mesh_table *tbl, struct mesh_path *mpath)
 {
-       struct mesh_path *mpath = node->mpath;
-       struct ieee80211_sub_if_data *sdata = node->mpath->sdata;
+       struct ieee80211_sub_if_data *sdata = mpath->sdata;
 
+       rhashtable_remove_fast(&tbl->rhead, &mpath->rhash, mesh_rht_params);
        spin_lock_bh(&mpath->state_lock);
        mpath->flags |= MESH_PATH_RESOLVING;
-       if (mpath->is_gate)
-               mesh_gate_del(tbl, mpath);
-       hlist_del_rcu(&node->list);
-       call_rcu(&node->rcu, mesh_path_node_reclaim);
+       mesh_gate_del(tbl, mpath);
+       call_rcu(&mpath->rcu, mesh_path_reclaim);
        spin_unlock_bh(&mpath->state_lock);
        atomic_dec(&sdata->u.mesh.mpaths);
        atomic_dec(&tbl->entries);
@@ -794,63 +579,87 @@ static void __mesh_path_del(struct mesh_table *tbl, 
struct mpath_node *node)
 void mesh_path_flush_by_nexthop(struct sta_info *sta)
 {
        struct ieee80211_sub_if_data *sdata = sta->sdata;
-       struct mesh_table *tbl;
+       struct mesh_table *tbl = sdata->u.mesh.mesh_paths;
        struct mesh_path *mpath;
-       struct mpath_node *node;
-       int i;
+       struct rhashtable_iter iter;
+       int ret;
 
-       rcu_read_lock();
-       read_lock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       tbl = resize_dereference_mesh_paths(sdata);
-       for_each_mesh_entry(tbl, node, i) {
-               mpath = node->mpath;
-               if (rcu_access_pointer(mpath->next_hop) == sta) {
-                       spin_lock(&tbl->hashwlock[i]);
-                       __mesh_path_del(tbl, node);
-                       spin_unlock(&tbl->hashwlock[i]);
-               }
+       ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
+       if (ret)
+               return;
+
+       ret = rhashtable_walk_start(&iter);
+       if (ret && ret != -EAGAIN)
+               goto out;
+
+       while ((mpath = rhashtable_walk_next(&iter))) {
+               if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
+                       continue;
+               if (IS_ERR(mpath))
+                       break;
+
+               if (rcu_access_pointer(mpath->next_hop) == sta)
+                       __mesh_path_del(tbl, mpath);
        }
-       read_unlock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       rcu_read_unlock();
+out:
+       rhashtable_walk_stop(&iter);
+       rhashtable_walk_exit(&iter);
 }
 
 static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata,
                               const u8 *proxy)
 {
-       struct mesh_table *tbl;
-       struct mesh_path *mpp;
-       struct mpath_node *node;
-       int i;
+       struct mesh_table *tbl = sdata->u.mesh.mpp_paths;
+       struct mesh_path *mpath;
+       struct rhashtable_iter iter;
+       int ret;
 
-       rcu_read_lock();
-       read_lock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       tbl = resize_dereference_mpp_paths(sdata);
-       for_each_mesh_entry(tbl, node, i) {
-               mpp = node->mpath;
-               if (ether_addr_equal(mpp->mpp, proxy)) {
-                       spin_lock(&tbl->hashwlock[i]);
-                       __mesh_path_del(tbl, node);
-                       spin_unlock(&tbl->hashwlock[i]);
-               }
+       ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
+       if (ret)
+               return;
+
+       ret = rhashtable_walk_start(&iter);
+       if (ret && ret != -EAGAIN)
+               goto out;
+
+       while ((mpath = rhashtable_walk_next(&iter))) {
+               if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
+                       continue;
+               if (IS_ERR(mpath))
+                       break;
+
+               if (ether_addr_equal(mpath->mpp, proxy))
+                       __mesh_path_del(tbl, mpath);
        }
-       read_unlock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       rcu_read_unlock();
+out:
+       rhashtable_walk_stop(&iter);
+       rhashtable_walk_exit(&iter);
 }
 
-static void table_flush_by_iface(struct mesh_table *tbl,
-                                struct ieee80211_sub_if_data *sdata)
+static void table_flush_by_iface(struct mesh_table *tbl)
 {
        struct mesh_path *mpath;
-       struct mpath_node *node;
-       int i;
-
-       WARN_ON(!rcu_read_lock_held());
-       for_each_mesh_entry(tbl, node, i) {
-               mpath = node->mpath;
-               spin_lock_bh(&tbl->hashwlock[i]);
-               __mesh_path_del(tbl, node);
-               spin_unlock_bh(&tbl->hashwlock[i]);
+       struct rhashtable_iter iter;
+       int ret;
+
+       ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
+       if (ret)
+               return;
+
+       ret = rhashtable_walk_start(&iter);
+       if (ret && ret != -EAGAIN)
+               goto out;
+
+       while ((mpath = rhashtable_walk_next(&iter))) {
+               if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
+                       continue;
+               if (IS_ERR(mpath))
+                       break;
+               __mesh_path_del(tbl, mpath);
        }
+out:
+       rhashtable_walk_stop(&iter);
+       rhashtable_walk_exit(&iter);
 }
 
 /**
@@ -863,16 +672,8 @@ static void table_flush_by_iface(struct mesh_table *tbl,
  */
 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
 {
-       struct mesh_table *tbl;
-
-       rcu_read_lock();
-       read_lock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       tbl = resize_dereference_mesh_paths(sdata);
-       table_flush_by_iface(tbl, sdata);
-       tbl = resize_dereference_mpp_paths(sdata);
-       table_flush_by_iface(tbl, sdata);
-       read_unlock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       rcu_read_unlock();
+       table_flush_by_iface(sdata->u.mesh.mesh_paths);
+       table_flush_by_iface(sdata->u.mesh.mpp_paths);
 }
 
 /**
@@ -884,36 +685,25 @@ void mesh_path_flush_by_iface(struct 
ieee80211_sub_if_data *sdata)
  *
  * Returns: 0 if successful
  */
-static int table_path_del(struct mesh_table __rcu *rcu_tbl,
+static int table_path_del(struct mesh_table *tbl,
                          struct ieee80211_sub_if_data *sdata,
                          const u8 *addr)
 {
-       struct mesh_table *tbl;
        struct mesh_path *mpath;
-       struct mpath_node *node;
-       struct hlist_head *bucket;
-       int hash_idx;
-       int err = 0;
-
-       tbl = resize_dereference_paths(sdata, rcu_tbl);
-       hash_idx = mesh_table_hash(addr, tbl);
-       bucket = &tbl->hash_buckets[hash_idx];
-
-       spin_lock(&tbl->hashwlock[hash_idx]);
-       hlist_for_each_entry(node, bucket, list) {
-               mpath = node->mpath;
-               if (ether_addr_equal(addr, mpath->dst)) {
-                       __mesh_path_del(tbl, node);
-                       goto enddel;
-               }
+
+       rcu_read_lock();
+       mpath = rhashtable_lookup_fast(&tbl->rhead, addr, mesh_rht_params);
+       if (!mpath) {
+               rcu_read_unlock();
+               return -ENXIO;
        }
 
-       err = -ENXIO;
-enddel:
-       spin_unlock(&tbl->hashwlock[hash_idx]);
-       return err;
+       __mesh_path_del(tbl, mpath);
+       rcu_read_unlock();
+       return 0;
 }
 
+
 /**
  * mesh_path_del - delete a mesh path from the table
  *
@@ -924,36 +714,13 @@ enddel:
  */
 int mesh_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr)
 {
-       int err = 0;
+       int err;
 
        /* flush relevant mpp entries first */
        mpp_flush_by_proxy(sdata, addr);
 
-       read_lock_bh(&sdata->u.mesh.pathtbl_resize_lock);
        err = table_path_del(sdata->u.mesh.mesh_paths, sdata, addr);
        sdata->u.mesh.mesh_paths_generation++;
-       read_unlock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-
-       return err;
-}
-
-/**
- * mpp_path_del - delete a mesh proxy path from the table
- *
- * @addr: addr address (ETH_ALEN length)
- * @sdata: local subif
- *
- * Returns: 0 if successful
- */
-static int mpp_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr)
-{
-       int err = 0;
-
-       read_lock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-       err = table_path_del(sdata->u.mesh.mpp_paths, sdata, addr);
-       sdata->u.mesh.mpp_paths_generation++;
-       read_unlock_bh(&sdata->u.mesh.pathtbl_resize_lock);
-
        return err;
 }
 
@@ -987,18 +754,17 @@ int mesh_path_send_to_gates(struct mesh_path *mpath)
        struct ieee80211_sub_if_data *sdata = mpath->sdata;
        struct mesh_table *tbl;
        struct mesh_path *from_mpath = mpath;
-       struct mesh_path *gate = NULL;
+       struct mesh_path *gate;
        bool copy = false;
        struct hlist_head *known_gates;
 
-       rcu_read_lock();
-       tbl = rcu_dereference(sdata->u.mesh.mesh_paths);
+       tbl = sdata->u.mesh.mesh_paths;
        known_gates = tbl->known_gates;
-       rcu_read_unlock();
 
        if (!known_gates)
                return -EHOSTUNREACH;
 
+       rcu_read_lock();
        hlist_for_each_entry_rcu(gate, known_gates, gate_list) {
                if (gate->flags & MESH_PATH_ACTIVE) {
                        mpath_dbg(sdata, "Forwarding to %pM\n", gate->dst);
@@ -1016,6 +782,7 @@ int mesh_path_send_to_gates(struct mesh_path *mpath)
                mpath_dbg(sdata, "Sending to %pM\n", gate->dst);
                mesh_path_tx_pending(gate);
        }
+       rcu_read_unlock();
 
        return (from_mpath == mpath) ? -EHOSTUNREACH : 0;
 }
@@ -1072,118 +839,73 @@ void mesh_path_fix_nexthop(struct mesh_path *mpath, 
struct sta_info *next_hop)
        mesh_path_tx_pending(mpath);
 }
 
-static void mesh_path_node_free(struct hlist_node *p, bool free_leafs)
-{
-       struct mesh_path *mpath;
-       struct mpath_node *node = hlist_entry(p, struct mpath_node, list);
-       mpath = node->mpath;
-       hlist_del_rcu(p);
-       if (free_leafs) {
-               del_timer_sync(&mpath->timer);
-               kfree(mpath);
-       }
-       kfree(node);
-}
-
-static int mesh_path_node_copy(struct hlist_node *p, struct mesh_table *newtbl)
-{
-       struct mesh_path *mpath;
-       struct mpath_node *node, *new_node;
-       u32 hash_idx;
-
-       new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
-       if (new_node == NULL)
-               return -ENOMEM;
-
-       node = hlist_entry(p, struct mpath_node, list);
-       mpath = node->mpath;
-       new_node->mpath = mpath;
-       hash_idx = mesh_table_hash(mpath->dst, newtbl);
-       hlist_add_head(&new_node->list,
-                       &newtbl->hash_buckets[hash_idx]);
-       return 0;
-}
-
 int mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata)
 {
        struct mesh_table *tbl_path, *tbl_mpp;
        int ret;
 
-       tbl_path = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
+       tbl_path = mesh_table_alloc();
        if (!tbl_path)
                return -ENOMEM;
-       tbl_path->free_node = &mesh_path_node_free;
-       tbl_path->copy_node = &mesh_path_node_copy;
-       tbl_path->known_gates = kzalloc(sizeof(struct hlist_head), GFP_ATOMIC);
-       if (!tbl_path->known_gates) {
-               ret = -ENOMEM;
-               goto free_path;
-       }
-       INIT_HLIST_HEAD(tbl_path->known_gates);
 
-
-       tbl_mpp = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
+       tbl_mpp = mesh_table_alloc();
        if (!tbl_mpp) {
                ret = -ENOMEM;
                goto free_path;
        }
-       tbl_mpp->free_node = &mesh_path_node_free;
-       tbl_mpp->copy_node = &mesh_path_node_copy;
-       tbl_mpp->known_gates = kzalloc(sizeof(struct hlist_head), GFP_ATOMIC);
-       if (!tbl_mpp->known_gates) {
-               ret = -ENOMEM;
-               goto free_mpp;
-       }
-       INIT_HLIST_HEAD(tbl_mpp->known_gates);
 
-       rwlock_init(&sdata->u.mesh.pathtbl_resize_lock);
+       rhashtable_init(&tbl_path->rhead, &mesh_rht_params);
+       rhashtable_init(&tbl_mpp->rhead, &mesh_rht_params);
 
-       /* Need no locking since this is during init */
-       RCU_INIT_POINTER(sdata->u.mesh.mesh_paths, tbl_path);
-       RCU_INIT_POINTER(sdata->u.mesh.mpp_paths, tbl_mpp);
+       sdata->u.mesh.mesh_paths = tbl_path;
+       sdata->u.mesh.mpp_paths = tbl_mpp;
 
        return 0;
 
-free_mpp:
-       mesh_table_free(tbl_mpp, true);
 free_path:
-       mesh_table_free(tbl_path, true);
+       mesh_table_free(tbl_path);
        return ret;
 }
 
-void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
+static
+void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata,
+                         struct mesh_table *tbl)
 {
-       struct mesh_table *tbl;
        struct mesh_path *mpath;
-       struct mpath_node *node;
-       int i;
+       struct rhashtable_iter iter;
+       int ret;
 
-       rcu_read_lock();
-       tbl = rcu_dereference(sdata->u.mesh.mesh_paths);
-       for_each_mesh_entry(tbl, node, i) {
-               mpath = node->mpath;
+       ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_KERNEL);
+       if (ret)
+               return;
+
+       ret = rhashtable_walk_start(&iter);
+       if (ret && ret != -EAGAIN)
+               goto out;
+
+       while ((mpath = rhashtable_walk_next(&iter))) {
+               if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
+                       continue;
+               if (IS_ERR(mpath))
+                       break;
                if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
                    (!(mpath->flags & MESH_PATH_FIXED)) &&
                     time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
-                       mesh_path_del(sdata, mpath->dst);
-       }
-
-       tbl = rcu_dereference(sdata->u.mesh.mpp_paths);
-       for_each_mesh_entry(tbl, node, i) {
-               mpath = node->mpath;
-               if ((!(mpath->flags & MESH_PATH_FIXED)) &&
-                   time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
-                       mpp_path_del(sdata, mpath->dst);
+                       __mesh_path_del(tbl, mpath);
        }
+out:
+       rhashtable_walk_stop(&iter);
+       rhashtable_walk_exit(&iter);
+}
 
-       rcu_read_unlock();
+void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
+{
+       mesh_path_tbl_expire(sdata, sdata->u.mesh.mesh_paths);
+       mesh_path_tbl_expire(sdata, sdata->u.mesh.mpp_paths);
 }
 
 void mesh_pathtbl_unregister(struct ieee80211_sub_if_data *sdata)
 {
-       /* no need for locking during exit path */
-       mesh_table_free(rcu_dereference_protected(sdata->u.mesh.mesh_paths, 1),
-                       true);
-       mesh_table_free(rcu_dereference_protected(sdata->u.mesh.mpp_paths, 1),
-                       true);
+       mesh_table_free(sdata->u.mesh.mesh_paths);
+       mesh_table_free(sdata->u.mesh.mpp_paths);
 }
-- 
2.6.1

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