[PATCH 2/3] Add RCU versions of socket hlist handling
From: Corey Minyard <hidden>
Date: 2008-10-06 19:46:50
Also in:
lkml
Subsystem:
networking [general], networking [sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds
Add RCU version of some of the socket hlist handlers, getting ready for changing the UDP hash lock to RCU. Signed-off-by: Corey Minyard <redacted> --- include/net/sock.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 50 insertions(+), 0 deletions(-)
diff --git a/include/net/sock.h b/include/net/sock.h
index 06c5259..6cd39e5 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h@@ -42,6 +42,7 @@ #include <linux/kernel.h> #include <linux/list.h> +#include <linux/rculist.h> #include <linux/timer.h> #include <linux/cache.h> #include <linux/module.h>
@@ -294,12 +295,24 @@ static inline struct sock *sk_head(const struct hlist_head *head) return hlist_empty(head) ? NULL : __sk_head(head); } +static inline struct sock *sk_head_rcu(const struct hlist_head *head) +{ + struct hlist_node *first = rcu_dereference(head->first); + return first ? hlist_entry(first, struct sock, sk_node) : NULL; +} + static inline struct sock *sk_next(const struct sock *sk) { return sk->sk_node.next ? hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL; } +static inline struct sock *sk_next_rcu(const struct sock *sk) +{ + struct hlist_node *next = rcu_dereference(sk->sk_node.next); + return next ? hlist_entry(next, struct sock, sk_node) : NULL; +} + static inline int sk_unhashed(const struct sock *sk) { return hlist_unhashed(&sk->sk_node);
@@ -361,6 +374,27 @@ static __inline__ int sk_del_node_init(struct sock *sk) return rc; } +static inline int __sk_del_node_init_rcu(struct sock *sk) +{ + if (sk_hashed(sk)) { + hlist_del_init_rcu(&sk->sk_node); + return 1; + } + return 0; +} + +static inline int sk_del_node_init_rcu(struct sock *sk) +{ + int rc = __sk_del_node_init_rcu(sk); + + if (rc) { + /* paranoid for a while -acme */ + WARN_ON(atomic_read(&sk->sk_refcnt) == 1); + __sock_put(sk); + } + return rc; +} + static __inline__ void __sk_add_node(struct sock *sk, struct hlist_head *list) { hlist_add_head(&sk->sk_node, list);
@@ -372,6 +406,17 @@ static __inline__ void sk_add_node(struct sock *sk, struct hlist_head *list) __sk_add_node(sk, list); } +static inline void __sk_add_node_rcu(struct sock *sk, struct hlist_head *list) +{ + hlist_add_head_rcu(&sk->sk_node, list); +} + +static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list) +{ + sock_hold(sk); + __sk_add_node_rcu(sk, list); +} + static __inline__ void __sk_del_bind_node(struct sock *sk) { __hlist_del(&sk->sk_bind_node);
@@ -385,9 +430,14 @@ static __inline__ void sk_add_bind_node(struct sock *sk, #define sk_for_each(__sk, node, list) \ hlist_for_each_entry(__sk, node, list, sk_node) +#define sk_for_each_rcu(__sk, node, list) \ + hlist_for_each_entry_rcu(__sk, node, list, sk_node) #define sk_for_each_from(__sk, node) \ if (__sk && ({ node = &(__sk)->sk_node; 1; })) \ hlist_for_each_entry_from(__sk, node, sk_node) +#define sk_for_each_from_rcu(__sk, node) \ + if (__sk && ({ node = &(__sk)->sk_node; 1; })) \ + hlist_for_each_entry_from_rcu(__sk, node, sk_node) #define sk_for_each_continue(__sk, node) \ if (__sk && ({ node = &(__sk)->sk_node; 1; })) \ hlist_for_each_entry_continue(__sk, node, sk_node)
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1.5.6.5