From 2a8875e73ffb18165ceb245f99c2ccad77378051 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 8 Dec 2009 20:19:53 -0800 Subject: [PATCH] tcp: documents timewait refcnt tricks Adds kerneldoc for inet_twsk_unhash() & inet_twsk_bind_unhash(). With help from Randy Dunlap. Suggested-by: Evgeniy Polyakov Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/inet_timewait_sock.c | 38 ++++++++++++++++++++++++-------------- 1 file changed, 24 insertions(+), 14 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c index bf4b1e2a430..cc94cc2d8b2 100644 --- a/net/ipv4/inet_timewait_sock.c +++ b/net/ipv4/inet_timewait_sock.c @@ -15,9 +15,13 @@ #include -/* - * unhash a timewait socket from established hash - * lock must be hold by caller +/** + * inet_twsk_unhash - unhash a timewait socket from established hash + * @tw: timewait socket + * + * unhash a timewait socket from established hash, if hashed. + * ehash lock must be held by caller. + * Returns 1 if caller should call inet_twsk_put() after lock release. */ int inet_twsk_unhash(struct inet_timewait_sock *tw) { @@ -26,12 +30,21 @@ int inet_twsk_unhash(struct inet_timewait_sock *tw) hlist_nulls_del_rcu(&tw->tw_node); sk_nulls_node_init(&tw->tw_node); + /* + * We cannot call inet_twsk_put() ourself under lock, + * caller must call it for us. + */ return 1; } -/* - * unhash a timewait socket from bind hash - * lock must be hold by caller +/** + * inet_twsk_bind_unhash - unhash a timewait socket from bind hash + * @tw: timewait socket + * @hashinfo: hashinfo pointer + * + * unhash a timewait socket from bind hash, if hashed. + * bind hash lock must be held by caller. + * Returns 1 if caller should call inet_twsk_put() after lock release. */ int inet_twsk_bind_unhash(struct inet_timewait_sock *tw, struct inet_hashinfo *hashinfo) @@ -44,6 +57,10 @@ int inet_twsk_bind_unhash(struct inet_timewait_sock *tw, __hlist_del(&tw->tw_bind_node); tw->tw_tb = NULL; inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb); + /* + * We cannot call inet_twsk_put() ourself under lock, + * caller must call it for us. + */ return 1; } @@ -139,7 +156,7 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk, /* * Notes : - * - We initially set tw_refcnt to 0 in inet_twsk_alloc() + * - We initially set tw_refcnt to 0 in inet_twsk_alloc() * - We add one reference for the bhash link * - We add one reference for the ehash link * - We want this refcnt update done before allowing other @@ -149,7 +166,6 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk, spin_unlock(lock); } - EXPORT_SYMBOL_GPL(__inet_twsk_hashdance); struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int state) @@ -190,7 +206,6 @@ struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int stat return tw; } - EXPORT_SYMBOL_GPL(inet_twsk_alloc); /* Returns non-zero if quota exceeded. */ @@ -269,7 +284,6 @@ void inet_twdr_hangman(unsigned long data) out: spin_unlock(&twdr->death_lock); } - EXPORT_SYMBOL_GPL(inet_twdr_hangman); void inet_twdr_twkill_work(struct work_struct *work) @@ -300,7 +314,6 @@ void inet_twdr_twkill_work(struct work_struct *work) spin_unlock_bh(&twdr->death_lock); } } - EXPORT_SYMBOL_GPL(inet_twdr_twkill_work); /* These are always called from BH context. See callers in @@ -320,7 +333,6 @@ void inet_twsk_deschedule(struct inet_timewait_sock *tw, spin_unlock(&twdr->death_lock); __inet_twsk_kill(tw, twdr->hashinfo); } - EXPORT_SYMBOL(inet_twsk_deschedule); void inet_twsk_schedule(struct inet_timewait_sock *tw, @@ -401,7 +413,6 @@ void inet_twsk_schedule(struct inet_timewait_sock *tw, mod_timer(&twdr->tw_timer, jiffies + twdr->period); spin_unlock(&twdr->death_lock); } - EXPORT_SYMBOL_GPL(inet_twsk_schedule); void inet_twdr_twcal_tick(unsigned long data) @@ -462,7 +473,6 @@ out: #endif spin_unlock(&twdr->death_lock); } - EXPORT_SYMBOL_GPL(inet_twdr_twcal_tick); void inet_twsk_purge(struct inet_hashinfo *hashinfo, -- cgit v1.2.3-70-g09d2