Commit 2a8875e7 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller

[PATCH] tcp: documents timewait refcnt tricks

Adds kerneldoc for inet_twsk_unhash() & inet_twsk_bind_unhash().

With help from Randy Dunlap.
Suggested-by: default avatarEvgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3cdaedae
...@@ -15,9 +15,13 @@ ...@@ -15,9 +15,13 @@
#include <net/ip.h> #include <net/ip.h>
/* /**
* unhash a timewait socket from established hash * inet_twsk_unhash - unhash a timewait socket from established hash
* lock must be hold by caller * @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) int inet_twsk_unhash(struct inet_timewait_sock *tw)
{ {
...@@ -26,12 +30,21 @@ 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); hlist_nulls_del_rcu(&tw->tw_node);
sk_nulls_node_init(&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; return 1;
} }
/* /**
* unhash a timewait socket from bind hash * inet_twsk_bind_unhash - unhash a timewait socket from bind hash
* lock must be hold by caller * @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, int inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
struct inet_hashinfo *hashinfo) struct inet_hashinfo *hashinfo)
...@@ -44,6 +57,10 @@ int inet_twsk_bind_unhash(struct inet_timewait_sock *tw, ...@@ -44,6 +57,10 @@ int inet_twsk_bind_unhash(struct inet_timewait_sock *tw,
__hlist_del(&tw->tw_bind_node); __hlist_del(&tw->tw_bind_node);
tw->tw_tb = NULL; tw->tw_tb = NULL;
inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb); 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; return 1;
} }
...@@ -139,7 +156,7 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk, ...@@ -139,7 +156,7 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
/* /*
* Notes : * 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 bhash link
* - We add one reference for the ehash link * - We add one reference for the ehash link
* - We want this refcnt update done before allowing other * - 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, ...@@ -149,7 +166,6 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
spin_unlock(lock); spin_unlock(lock);
} }
EXPORT_SYMBOL_GPL(__inet_twsk_hashdance); EXPORT_SYMBOL_GPL(__inet_twsk_hashdance);
struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int state) 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 ...@@ -190,7 +206,6 @@ struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int stat
return tw; return tw;
} }
EXPORT_SYMBOL_GPL(inet_twsk_alloc); EXPORT_SYMBOL_GPL(inet_twsk_alloc);
/* Returns non-zero if quota exceeded. */ /* Returns non-zero if quota exceeded. */
...@@ -269,7 +284,6 @@ void inet_twdr_hangman(unsigned long data) ...@@ -269,7 +284,6 @@ void inet_twdr_hangman(unsigned long data)
out: out:
spin_unlock(&twdr->death_lock); spin_unlock(&twdr->death_lock);
} }
EXPORT_SYMBOL_GPL(inet_twdr_hangman); EXPORT_SYMBOL_GPL(inet_twdr_hangman);
void inet_twdr_twkill_work(struct work_struct *work) void inet_twdr_twkill_work(struct work_struct *work)
...@@ -300,7 +314,6 @@ 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); spin_unlock_bh(&twdr->death_lock);
} }
} }
EXPORT_SYMBOL_GPL(inet_twdr_twkill_work); EXPORT_SYMBOL_GPL(inet_twdr_twkill_work);
/* These are always called from BH context. See callers in /* These are always called from BH context. See callers in
...@@ -320,7 +333,6 @@ void inet_twsk_deschedule(struct inet_timewait_sock *tw, ...@@ -320,7 +333,6 @@ void inet_twsk_deschedule(struct inet_timewait_sock *tw,
spin_unlock(&twdr->death_lock); spin_unlock(&twdr->death_lock);
__inet_twsk_kill(tw, twdr->hashinfo); __inet_twsk_kill(tw, twdr->hashinfo);
} }
EXPORT_SYMBOL(inet_twsk_deschedule); EXPORT_SYMBOL(inet_twsk_deschedule);
void inet_twsk_schedule(struct inet_timewait_sock *tw, void inet_twsk_schedule(struct inet_timewait_sock *tw,
...@@ -401,7 +413,6 @@ 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); mod_timer(&twdr->tw_timer, jiffies + twdr->period);
spin_unlock(&twdr->death_lock); spin_unlock(&twdr->death_lock);
} }
EXPORT_SYMBOL_GPL(inet_twsk_schedule); EXPORT_SYMBOL_GPL(inet_twsk_schedule);
void inet_twdr_twcal_tick(unsigned long data) void inet_twdr_twcal_tick(unsigned long data)
...@@ -462,7 +473,6 @@ void inet_twdr_twcal_tick(unsigned long data) ...@@ -462,7 +473,6 @@ void inet_twdr_twcal_tick(unsigned long data)
#endif #endif
spin_unlock(&twdr->death_lock); spin_unlock(&twdr->death_lock);
} }
EXPORT_SYMBOL_GPL(inet_twdr_twcal_tick); EXPORT_SYMBOL_GPL(inet_twdr_twcal_tick);
void inet_twsk_purge(struct inet_hashinfo *hashinfo, void inet_twsk_purge(struct inet_hashinfo *hashinfo,
......
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