From 872e397d62a67843ea09cf6641819cb1a7e5ee98 Mon Sep 17 00:00:00 2001 From: pengdonglin Date: Tue, 16 Sep 2025 12:47:31 +0800 Subject: [PATCH] wifi: mac80211: Remove redundant rcu_read_lock/unlock() in spin_lock Since commit a8bb74acd8efe ("rcu: Consolidate RCU-sched update-side function definitions") there is no difference between rcu_read_lock(), rcu_read_lock_bh() and rcu_read_lock_sched() in terms of RCU read section and the relevant grace period. That means that spin_lock(), which implies rcu_read_lock_sched(), also implies rcu_read_lock(). There is no need no explicitly start a RCU read section if one has already been started implicitly by spin_lock(). Simplify the code and remove the inner rcu_read_lock() invocation. Cc: Johannes Berg Signed-off-by: pengdonglin Signed-off-by: pengdonglin Link: https://patch.msgid.link/20250916044735.2316171-11-dolinux.peng@gmail.com Signed-off-by: Johannes Berg --- net/mac80211/cfg.c | 2 -- net/mac80211/debugfs.c | 2 -- net/mac80211/debugfs_netdev.c | 2 -- net/mac80211/debugfs_sta.c | 2 -- net/mac80211/sta_info.c | 2 -- 5 files changed, 10 deletions(-) diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index da15ccfcf4a2a..d9aca1c3c097e 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -4935,7 +4935,6 @@ static int ieee80211_get_txq_stats(struct wiphy *wiphy, int ret = 0; spin_lock_bh(&local->fq.lock); - rcu_read_lock(); if (wdev) { sdata = IEEE80211_WDEV_TO_SUB_IF(wdev); @@ -4961,7 +4960,6 @@ static int ieee80211_get_txq_stats(struct wiphy *wiphy, } out: - rcu_read_unlock(); spin_unlock_bh(&local->fq.lock); return ret; diff --git a/net/mac80211/debugfs.c b/net/mac80211/debugfs.c index e8b78ec682da8..82099f4cedbe0 100644 --- a/net/mac80211/debugfs.c +++ b/net/mac80211/debugfs.c @@ -82,7 +82,6 @@ static ssize_t aqm_read(struct file *file, int len = 0; spin_lock_bh(&local->fq.lock); - rcu_read_lock(); len = scnprintf(buf, sizeof(buf), "access name value\n" @@ -105,7 +104,6 @@ static ssize_t aqm_read(struct file *file, fq->limit, fq->quantum); - rcu_read_unlock(); spin_unlock_bh(&local->fq.lock); return simple_read_from_buffer(user_buf, count, ppos, diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c index 1dac78271045a..30a5a978a678c 100644 --- a/net/mac80211/debugfs_netdev.c +++ b/net/mac80211/debugfs_netdev.c @@ -625,7 +625,6 @@ static ssize_t ieee80211_if_fmt_aqm( txqi = to_txq_info(sdata->vif.txq); spin_lock_bh(&local->fq.lock); - rcu_read_lock(); len = scnprintf(buf, buflen, @@ -642,7 +641,6 @@ static ssize_t ieee80211_if_fmt_aqm( txqi->tin.tx_bytes, txqi->tin.tx_packets); - rcu_read_unlock(); spin_unlock_bh(&local->fq.lock); return len; diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c index 49061bd4151bc..ef75255d47d5a 100644 --- a/net/mac80211/debugfs_sta.c +++ b/net/mac80211/debugfs_sta.c @@ -148,7 +148,6 @@ static ssize_t sta_aqm_read(struct file *file, char __user *userbuf, return -ENOMEM; spin_lock_bh(&local->fq.lock); - rcu_read_lock(); p += scnprintf(p, bufsz + buf - p, @@ -178,7 +177,6 @@ static ssize_t sta_aqm_read(struct file *file, char __user *userbuf, test_bit(IEEE80211_TXQ_DIRTY, &txqi->flags) ? " DIRTY" : ""); } - rcu_read_unlock(); spin_unlock_bh(&local->fq.lock); rv = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf); diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index 1bd75e0375a02..f4d3b67fda062 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -2637,13 +2637,11 @@ static void sta_set_tidstats(struct sta_info *sta, if (link_id < 0 && tid < IEEE80211_NUM_TIDS) { spin_lock_bh(&local->fq.lock); - rcu_read_lock(); tidstats->filled |= BIT(NL80211_TID_STATS_TXQ_STATS); ieee80211_fill_txq_stats(&tidstats->txq_stats, to_txq_info(sta->sta.txq[tid])); - rcu_read_unlock(); spin_unlock_bh(&local->fq.lock); } } -- 2.47.3