From: "Matthew Wilcox (Oracle)" <wi...@infradead.org> Replae the func_lock with the internal XArray spinlock. Ensuring that nan_func is fully initialised before dropping the lock allows us to iterate the array while not holding the lock, avoiding the awkward dance in ieee80211_reconfig_nan().
Signed-off-by: Matthew Wilcox (Oracle) <wi...@infradead.org> --- net/mac80211/cfg.c | 57 ++++++++++++++------------------------ net/mac80211/ieee80211_i.h | 9 ++---- net/mac80211/iface.c | 16 +++++------ net/mac80211/util.c | 30 ++++---------------- 4 files changed, 37 insertions(+), 75 deletions(-) diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index 47d7670094a9..2ea45b7007db 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -266,7 +266,7 @@ static int ieee80211_add_nan_func(struct wiphy *wiphy, struct cfg80211_nan_func *nan_func) { struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev); - int ret; + int ret, id; if (sdata->vif.type != NL80211_IFTYPE_NAN) return -EOPNOTSUPP; @@ -274,27 +274,22 @@ static int ieee80211_add_nan_func(struct wiphy *wiphy, if (!ieee80211_sdata_running(sdata)) return -ENETDOWN; - spin_lock_bh(&sdata->u.nan.func_lock); - - ret = idr_alloc(&sdata->u.nan.function_inst_ids, - nan_func, 1, sdata->local->hw.max_nan_de_entries + 1, - GFP_ATOMIC); - spin_unlock_bh(&sdata->u.nan.func_lock); + xa_lock_bh(&sdata->u.nan.functions); + ret = __xa_alloc(&sdata->u.nan.functions, &id, nan_func, + XA_LIMIT(0, sdata->local->hw.max_nan_de_entries), + GFP_KERNEL); + if (ret == 0) + nan_func->instance_id = id; + xa_unlock_bh(&sdata->u.nan.functions); if (ret < 0) return ret; - nan_func->instance_id = ret; - WARN_ON(nan_func->instance_id == 0); ret = drv_add_nan_func(sdata->local, sdata, nan_func); - if (ret) { - spin_lock_bh(&sdata->u.nan.func_lock); - idr_remove(&sdata->u.nan.function_inst_ids, - nan_func->instance_id); - spin_unlock_bh(&sdata->u.nan.func_lock); - } + if (ret) + xa_erase_bh(&sdata->u.nan.functions, nan_func->instance_id); return ret; } @@ -304,11 +299,11 @@ ieee80211_find_nan_func_by_cookie(struct ieee80211_sub_if_data *sdata, u64 cookie) { struct cfg80211_nan_func *func; - int id; + unsigned long id; - lockdep_assert_held(&sdata->u.nan.func_lock); + lockdep_assert_held(&sdata->u.nan.functions.xa_lock); - idr_for_each_entry(&sdata->u.nan.function_inst_ids, func, id) { + xa_for_each(&sdata->u.nan.functions, id, func) { if (func->cookie == cookie) return func; } @@ -327,13 +322,13 @@ static void ieee80211_del_nan_func(struct wiphy *wiphy, !ieee80211_sdata_running(sdata)) return; - spin_lock_bh(&sdata->u.nan.func_lock); + xa_lock_bh(&sdata->u.nan.functions); func = ieee80211_find_nan_func_by_cookie(sdata, cookie); if (func) instance_id = func->instance_id; - spin_unlock_bh(&sdata->u.nan.func_lock); + xa_unlock_bh(&sdata->u.nan.functions); if (instance_id) drv_del_nan_func(sdata->local, sdata, instance_id); @@ -3766,19 +3761,11 @@ void ieee80211_nan_func_terminated(struct ieee80211_vif *vif, if (WARN_ON(vif->type != NL80211_IFTYPE_NAN)) return; - spin_lock_bh(&sdata->u.nan.func_lock); - - func = idr_find(&sdata->u.nan.function_inst_ids, inst_id); - if (WARN_ON(!func)) { - spin_unlock_bh(&sdata->u.nan.func_lock); + func = xa_erase_bh(&sdata->u.nan.functions, inst_id); + if (WARN_ON(!func)) return; - } cookie = func->cookie; - idr_remove(&sdata->u.nan.function_inst_ids, inst_id); - - spin_unlock_bh(&sdata->u.nan.func_lock); - cfg80211_free_nan_func(func); cfg80211_nan_func_terminated(ieee80211_vif_to_wdev(vif), inst_id, @@ -3796,16 +3783,14 @@ void ieee80211_nan_func_match(struct ieee80211_vif *vif, if (WARN_ON(vif->type != NL80211_IFTYPE_NAN)) return; - spin_lock_bh(&sdata->u.nan.func_lock); - - func = idr_find(&sdata->u.nan.function_inst_ids, match->inst_id); + xa_lock_bh(&sdata->u.nan.functions); + func = xa_load(&sdata->u.nan.functions, match->inst_id); if (WARN_ON(!func)) { - spin_unlock_bh(&sdata->u.nan.func_lock); + xa_unlock_bh(&sdata->u.nan.functions); return; } match->cookie = func->cookie; - - spin_unlock_bh(&sdata->u.nan.func_lock); + xa_unlock_bh(&sdata->u.nan.functions); cfg80211_nan_match(ieee80211_vif_to_wdev(vif), match, gfp); } diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index ade005892099..7be25939a6bf 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -23,7 +23,7 @@ #include <linux/spinlock.h> #include <linux/etherdevice.h> #include <linux/leds.h> -#include <linux/idr.h> +#include <linux/xarray.h> #include <linux/rhashtable.h> #include <net/ieee80211_radiotap.h> #include <net/cfg80211.h> @@ -862,14 +862,11 @@ struct ieee80211_if_mntr { * struct ieee80211_if_nan - NAN state * * @conf: current NAN configuration - * @func_ids: a bitmap of available instance_id's + * @functions: NAN function pointers */ struct ieee80211_if_nan { struct cfg80211_nan_conf conf; - - /* protects function_inst_ids */ - spinlock_t func_lock; - struct idr function_inst_ids; + struct xarray functions; }; struct ieee80211_sub_if_data { diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 8dc6580e1787..022e2eb6a46c 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -802,6 +802,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, struct cfg80211_chan_def chandef; bool cancel_scan; struct cfg80211_nan_func *func; + unsigned long index; clear_bit(SDATA_STATE_RUNNING, &sdata->state); @@ -961,15 +962,12 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, break; case NL80211_IFTYPE_NAN: /* clean all the functions */ - spin_lock_bh(&sdata->u.nan.func_lock); - - idr_for_each_entry(&sdata->u.nan.function_inst_ids, func, i) { - idr_remove(&sdata->u.nan.function_inst_ids, i); + xa_lock_bh(&sdata->u.nan.functions); + xa_for_each(&sdata->u.nan.functions, index, func) { + __xa_erase(&sdata->u.nan.functions, index); cfg80211_free_nan_func(func); } - idr_destroy(&sdata->u.nan.function_inst_ids); - - spin_unlock_bh(&sdata->u.nan.func_lock); + xa_unlock_bh(&sdata->u.nan.functions); break; case NL80211_IFTYPE_P2P_DEVICE: /* relies on synchronize_rcu() below */ @@ -1463,8 +1461,8 @@ static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata, sdata->vif.bss_conf.bssid = NULL; break; case NL80211_IFTYPE_NAN: - idr_init(&sdata->u.nan.function_inst_ids); - spin_lock_init(&sdata->u.nan.func_lock); + xa_init_flags(&sdata->u.nan.functions, + XA_FLAGS_ALLOC1 | XA_FLAGS_LOCK_BH); sdata->vif.bss_conf.bssid = sdata->vif.addr; break; case NL80211_IFTYPE_AP_VLAN: diff --git a/net/mac80211/util.c b/net/mac80211/util.c index 286c7ee35e63..4996a3c01205 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -2082,42 +2082,24 @@ static void ieee80211_reconfig_stations(struct ieee80211_sub_if_data *sdata) static int ieee80211_reconfig_nan(struct ieee80211_sub_if_data *sdata) { - struct cfg80211_nan_func *func, **funcs; - int res, id, i = 0; + struct cfg80211_nan_func *func; + unsigned long id; + int res; res = drv_start_nan(sdata->local, sdata, &sdata->u.nan.conf); if (WARN_ON(res)) return res; - funcs = kcalloc(sdata->local->hw.max_nan_de_entries + 1, - sizeof(*funcs), - GFP_KERNEL); - if (!funcs) - return -ENOMEM; - - /* Add all the functions: - * This is a little bit ugly. We need to call a potentially sleeping - * callback for each NAN function, so we can't hold the spinlock. - */ - spin_lock_bh(&sdata->u.nan.func_lock); - - idr_for_each_entry(&sdata->u.nan.function_inst_ids, func, id) - funcs[i++] = func; - - spin_unlock_bh(&sdata->u.nan.func_lock); - - for (i = 0; funcs[i]; i++) { - res = drv_add_nan_func(sdata->local, sdata, funcs[i]); + xa_for_each(&sdata->u.nan.functions, id, func) { + res = drv_add_nan_func(sdata->local, sdata, func); if (WARN_ON(res)) ieee80211_nan_func_terminated(&sdata->vif, - funcs[i]->instance_id, + func->instance_id, NL80211_NAN_FUNC_TERM_REASON_ERROR, GFP_KERNEL); } - kfree(funcs); - return 0; } -- 2.23.0.rc1