package/kernel/mac80211/patches/312-mac80211-Use-rhltable-instead-of-rhashtable.patch

   1 From: Herbert Xu <herbert@gondor.apana.org.au>
   2 Date: Mon, 19 Sep 2016 19:00:10 +0800
   3 Subject: [PATCH] mac80211: Use rhltable instead of rhashtable
   4
   5 mac80211 currently uses rhashtable with insecure_elasticity set
   6 to true.  The latter is because of duplicate objects.  What's
   7 more, mac80211 walks the rhashtable chains by hand which is broken
   8 as rhashtable may contain multiple tables due to resizing or
   9 rehashing.
  10
  11 This patch fixes it by converting it to the newly added rhltable
  12 interface which is designed for use with duplicate objects.
  13
  14 With rhltable a lookup returns a list of objects instead of a
  15 single one.  This is then fed into the existing for_each_sta_info
  16 macro.
  17
  18 This patch also deletes the sta_addr_hash function since rhashtable
  19 defaults to jhash.
  20
  21 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  22 ---
  23
  24 --- a/net/mac80211/ieee80211_i.h
  25 +++ b/net/mac80211/ieee80211_i.h
  26 @@ -1233,7 +1233,7 @@ struct ieee80211_local {
  27         spinlock_t tim_lock;
  28         unsigned long num_sta;
  29         struct list_head sta_list;
  30 -       struct rhashtable sta_hash;
  31 +       struct rhltable sta_hash;
  32         struct timer_list sta_cleanup;
  33         int sta_generation;
  34
  35 --- a/net/mac80211/rx.c
  36 +++ b/net/mac80211/rx.c
  37 @@ -4004,7 +4004,7 @@ static void __ieee80211_rx_handle_packet
  38         __le16 fc;
  39         struct ieee80211_rx_data rx;
  40         struct ieee80211_sub_if_data *prev;
  41 -       struct rhash_head *tmp;
  42 +       struct rhlist_head *tmp;
  43         int err = 0;
  44
  45         fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
  46 @@ -4047,13 +4047,10 @@ static void __ieee80211_rx_handle_packet
  47                 goto out;
  48         } else if (ieee80211_is_data(fc)) {
  49                 struct sta_info *sta, *prev_sta;
  50 -               const struct bucket_table *tbl;
  51
  52                 prev_sta = NULL;
  53
  54 -               tbl = rht_dereference_rcu(local->sta_hash.tbl, &local->sta_hash);
  55 -
  56 -               for_each_sta_info(local, tbl, hdr->addr2, sta, tmp) {
  57 +               for_each_sta_info(local, hdr->addr2, sta, tmp) {
  58                         if (!prev_sta) {
  59                                 prev_sta = sta;
  60                                 continue;
  61 --- a/net/mac80211/sta_info.c
  62 +++ b/net/mac80211/sta_info.c
  63 @@ -67,12 +67,10 @@
  64
  65  static const struct rhashtable_params sta_rht_params = {
  66         .nelem_hint = 3, /* start small */
  67 -       .insecure_elasticity = true, /* Disable chain-length checks. */
  68         .automatic_shrinking = true,
  69         .head_offset = offsetof(struct sta_info, hash_node),
  70         .key_offset = offsetof(struct sta_info, addr),
  71         .key_len = ETH_ALEN,
  72 -       .hashfn = sta_addr_hash,
  73         .max_size = CPTCFG_MAC80211_STA_HASH_MAX_SIZE,
  74  };
  75
  76 @@ -80,8 +78,8 @@ static const struct rhashtable_params st
  77  static int sta_info_hash_del(struct ieee80211_local *local,
  78                              struct sta_info *sta)
  79  {
  80 -       return rhashtable_remove_fast(&local->sta_hash, &sta->hash_node,
  81 -                                     sta_rht_params);
  82 +       return rhltable_remove(&local->sta_hash, &sta->hash_node,
  83 +                              sta_rht_params);
  84  }
  85
  86  static void __cleanup_single_sta(struct sta_info *sta)
  87 @@ -157,19 +155,22 @@ static void cleanup_single_sta(struct st
  88         sta_info_free(local, sta);
  89  }
  90
  91 +struct rhlist_head *sta_info_hash_lookup(struct ieee80211_local *local,
  92 +                                        const u8 *addr)
  93 +{
  94 +       return rhltable_lookup(&local->sta_hash, addr, sta_rht_params);
  95 +}
  96 +
  97  /* protected by RCU */
  98  struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata,
  99                               const u8 *addr)
 100  {
 101         struct ieee80211_local *local = sdata->local;
 102 +       struct rhlist_head *tmp;
 103         struct sta_info *sta;
 104 -       struct rhash_head *tmp;
 105 -       const struct bucket_table *tbl;
 106
 107         rcu_read_lock();
 108 -       tbl = rht_dereference_rcu(local->sta_hash.tbl, &local->sta_hash);
 109 -
 110 -       for_each_sta_info(local, tbl, addr, sta, tmp) {
 111 +       for_each_sta_info(local, addr, sta, tmp) {
 112                 if (sta->sdata == sdata) {
 113                         rcu_read_unlock();
 114                         /* this is safe as the caller must already hold
 115 @@ -190,14 +191,11 @@ struct sta_info *sta_info_get_bss(struct
 116                                   const u8 *addr)
 117  {
 118         struct ieee80211_local *local = sdata->local;
 119 +       struct rhlist_head *tmp;
 120         struct sta_info *sta;
 121 -       struct rhash_head *tmp;
 122 -       const struct bucket_table *tbl;
 123
 124         rcu_read_lock();
 125 -       tbl = rht_dereference_rcu(local->sta_hash.tbl, &local->sta_hash);
 126 -
 127 -       for_each_sta_info(local, tbl, addr, sta, tmp) {
 128 +       for_each_sta_info(local, addr, sta, tmp) {
 129                 if (sta->sdata == sdata ||
 130                     (sta->sdata->bss && sta->sdata->bss == sdata->bss)) {
 131                         rcu_read_unlock();
 132 @@ -263,8 +261,8 @@ void sta_info_free(struct ieee80211_loca
 133  static int sta_info_hash_add(struct ieee80211_local *local,
 134                              struct sta_info *sta)
 135  {
 136 -       return rhashtable_insert_fast(&local->sta_hash, &sta->hash_node,
 137 -                                     sta_rht_params);
 138 +       return rhltable_insert(&local->sta_hash, &sta->hash_node,
 139 +                              sta_rht_params);
 140  }
 141
 142  static void sta_deliver_ps_frames(struct work_struct *wk)
 143 @@ -453,9 +451,9 @@ static int sta_info_insert_check(struct
 144                     is_multicast_ether_addr(sta->sta.addr)))
 145                 return -EINVAL;
 146
 147 -       /* Strictly speaking this isn't necessary as we hold the mutex, but
 148 -        * the rhashtable code can't really deal with that distinction. We
 149 -        * do require the mutex for correctness though.
 150 +       /* The RCU read lock is required by rhashtable due to
 151 +        * asynchronous resize/rehash.  We also require the mutex
 152 +        * for correctness.
 153          */
 154         rcu_read_lock();
 155         lockdep_assert_held(&sdata->local->sta_mtx);
 156 @@ -1043,16 +1041,11 @@ static void sta_info_cleanup(unsigned lo
 157                   round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL));
 158  }
 159
 160 -u32 sta_addr_hash(const void *key, u32 length, u32 seed)
 161 -{
 162 -       return jhash(key, ETH_ALEN, seed);
 163 -}
 164 -
 165  int sta_info_init(struct ieee80211_local *local)
 166  {
 167         int err;
 168
 169 -       err = rhashtable_init(&local->sta_hash, &sta_rht_params);
 170 +       err = rhltable_init(&local->sta_hash, &sta_rht_params);
 171         if (err)
 172                 return err;
 173
 174 @@ -1068,7 +1061,7 @@ int sta_info_init(struct ieee80211_local
 175  void sta_info_stop(struct ieee80211_local *local)
 176  {
 177         del_timer_sync(&local->sta_cleanup);
 178 -       rhashtable_destroy(&local->sta_hash);
 179 +       rhltable_destroy(&local->sta_hash);
 180  }
 181
 182
 183 @@ -1138,17 +1131,14 @@ struct ieee80211_sta *ieee80211_find_sta
 184                                                    const u8 *localaddr)
 185  {
 186         struct ieee80211_local *local = hw_to_local(hw);
 187 +       struct rhlist_head *tmp;
 188         struct sta_info *sta;
 189 -       struct rhash_head *tmp;
 190 -       const struct bucket_table *tbl;
 191 -
 192 -       tbl = rht_dereference_rcu(local->sta_hash.tbl, &local->sta_hash);
 193
 194         /*
 195          * Just return a random station if localaddr is NULL
 196          * ... first in list.
 197          */
 198 -       for_each_sta_info(local, tbl, addr, sta, tmp) {
 199 +       for_each_sta_info(local, addr, sta, tmp) {
 200                 if (localaddr &&
 201                     !ether_addr_equal(sta->sdata->vif.addr, localaddr))
 202                         continue;
 203 --- a/net/mac80211/sta_info.h
 204 +++ b/net/mac80211/sta_info.h
 205 @@ -455,7 +455,7 @@ struct sta_info {
 206         /* General information, mostly static */
 207         struct list_head list, free_list;
 208         struct rcu_head rcu_head;
 209 -       struct rhash_head hash_node;
 210 +       struct rhlist_head hash_node;
 211         u8 addr[ETH_ALEN];
 212         struct ieee80211_local *local;
 213         struct ieee80211_sub_if_data *sdata;
 214 @@ -638,6 +638,9 @@ rcu_dereference_protected_tid_tx(struct
 215   */
 216  #define STA_INFO_CLEANUP_INTERVAL (10 * HZ)
 217
 218 +struct rhlist_head *sta_info_hash_lookup(struct ieee80211_local *local,
 219 +                                        const u8 *addr);
 220 +
 221  /*
 222   * Get a STA info, must be under RCU read lock.
 223   */
 224 @@ -647,17 +650,9 @@ struct sta_info *sta_info_get(struct iee
 225  struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata,
 226                                   const u8 *addr);
 227
 228 -u32 sta_addr_hash(const void *key, u32 length, u32 seed);
 229 -
 230 -#define _sta_bucket_idx(_tbl, _a)                                      \
 231 -       rht_bucket_index(_tbl, sta_addr_hash(_a, ETH_ALEN, (_tbl)->hash_rnd))
 232 -
 233 -#define for_each_sta_info(local, tbl, _addr, _sta, _tmp)               \
 234 -       rht_for_each_entry_rcu(_sta, _tmp, tbl,                         \
 235 -                              _sta_bucket_idx(tbl, _addr),             \
 236 -                              hash_node)                               \
 237 -       /* compare address and run code only if it matches */           \
 238 -       if (ether_addr_equal(_sta->addr, (_addr)))
 239 +#define for_each_sta_info(local, _addr, _sta, _tmp)                    \
 240 +       rhl_for_each_entry_rcu(_sta, _tmp,                              \
 241 +                              sta_info_hash_lookup(local, _addr), hash_node)
 242
 243  /*
 244   * Get STA info by index, BROKEN!
 245 --- a/net/mac80211/status.c
 246 +++ b/net/mac80211/status.c
 247 @@ -759,8 +759,8 @@ void ieee80211_tx_status(struct ieee8021
 248         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 249         __le16 fc;
 250         struct ieee80211_supported_band *sband;
 251 +       struct rhlist_head *tmp;
 252         struct sta_info *sta;
 253 -       struct rhash_head *tmp;
 254         int retry_count;
 255         int rates_idx;
 256         bool send_to_cooked;
 257 @@ -768,7 +768,6 @@ void ieee80211_tx_status(struct ieee8021
 258         struct ieee80211_bar *bar;
 259         int shift = 0;
 260         int tid = IEEE80211_NUM_TIDS;
 261 -       const struct bucket_table *tbl;
 262
 263         rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
 264
 265 @@ -777,9 +776,7 @@ void ieee80211_tx_status(struct ieee8021
 266         sband = local->hw.wiphy->bands[info->band];
 267         fc = hdr->frame_control;
 268
 269 -       tbl = rht_dereference_rcu(local->sta_hash.tbl, &local->sta_hash);
 270 -
 271 -       for_each_sta_info(local, tbl, hdr->addr1, sta, tmp) {
 272 +       for_each_sta_info(local, hdr->addr1, sta, tmp) {
 273                 /* skip wrong virtual interface */
 274                 if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
 275                         continue;