mac80211: split sta_info_add
sta_info_add() has two functions: allocating a station info
structure and inserting it into the hash table/list. Splitting
these two functions allows allocating with GFP_KERNEL in many
places instead of GFP_ATOMIC which is now required by the RCU
protection. Additionally, in many places RCU protection is now
no longer needed at all because between sta_info_alloc() and
sta_info_insert() the caller owns the structure.
This fixes a few race conditions with setting initial flags
and similar, but not all (see comments in ieee80211_sta.c and
cfg.c). More documentation on the existing races will be in
a follow-up patch.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
index c2b8050..85cb75d 100644
--- a/net/mac80211/mesh_plink.c
+++ b/net/mac80211/mesh_plink.c
@@ -89,44 +89,41 @@
}
/**
- * mesh_plink_add - allocate and add a new mesh peer link
+ * mesh_plink_alloc - allocate a new mesh peer link
*
+ * @sdata: local mesh interface
* @hw_addr: hardware address (ETH_ALEN length)
* @rates: rates the mesh peer supports
- * @dev: local mesh interface
*
* The initial state of the new plink is set to LISTEN
*
- * Returns: non-NULL on success, ERR_PTR() on error.
+ * Returns: NULL on error.
*/
-struct sta_info *mesh_plink_add(u8 *hw_addr, u64 rates,
- struct ieee80211_sub_if_data *sdata)
+struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
+ u8 *hw_addr, u64 rates, gfp_t gfp)
{
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
if (compare_ether_addr(hw_addr, sdata->dev->dev_addr) == 0)
/* never add ourselves as neighbours */
- return ERR_PTR(-EINVAL);
+ return NULL;
if (is_multicast_ether_addr(hw_addr))
- return ERR_PTR(-EINVAL);
+ return NULL;
if (local->num_sta >= MESH_MAX_PLINKS)
- return ERR_PTR(-ENOSPC);
+ return NULL;
- sta = sta_info_add(sdata, hw_addr);
- if (IS_ERR(sta))
- return sta;
+ sta = sta_info_alloc(sdata, hw_addr, gfp);
+ if (!sta)
+ return NULL;
sta->plink_state = LISTEN;
spin_lock_init(&sta->plink_lock);
init_timer(&sta->plink_timer);
sta->flags |= WLAN_STA_AUTHORIZED;
sta->supp_rates[local->hw.conf.channel->band] = rates;
- rate_control_rate_init(sta, local);
-
- mesh_accept_plinks_update(sdata);
return sta;
}
@@ -252,8 +249,13 @@
sta = sta_info_get(local, hw_addr);
if (!sta) {
- sta = mesh_plink_add(hw_addr, rates, sdata);
- if (IS_ERR(sta)) {
+ sta = mesh_plink_alloc(sdata, hw_addr, rates, GFP_ATOMIC);
+ if (!sta) {
+ rcu_read_unlock();
+ return;
+ }
+ if (sta_info_insert(sta)) {
+ sta_info_destroy(sta);
rcu_read_unlock();
return;
}
@@ -516,12 +518,17 @@
}
rates = ieee80211_sta_get_rates(local, &elems, rx_status->band);
- sta = mesh_plink_add(mgmt->sa, rates, sdata);
- if (IS_ERR(sta)) {
+ sta = mesh_plink_alloc(sdata, mgmt->sa, rates, GFP_ATOMIC);
+ if (!sta) {
mpl_dbg("Mesh plink error: plink table full\n");
rcu_read_unlock();
return;
}
+ if (sta_info_insert(sta)) {
+ sta_info_destroy(sta);
+ rcu_read_unlock();
+ return;
+ }
event = OPN_ACPT;
spin_lock_bh(&sta->plink_lock);
} else {
