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author | stephen hemminger <shemminger@vyatta.com> | 2010-02-22 07:57:19 +0000 |
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committer | David S. Miller <davem@davemloft.net> | 2010-02-22 15:45:56 -0800 |
commit | 7f6b9dbd5afbd966a82dcbafc5ed62305eb9d479 (patch) | |
tree | 7d6795317f67d79919df5bb6b52121ad94d8ff37 /net/key/af_key.c | |
parent | 808f5114a9206fee855117d416440e1071ab375c (diff) | |
download | linux-stable-7f6b9dbd5afbd966a82dcbafc5ed62305eb9d479.tar.gz linux-stable-7f6b9dbd5afbd966a82dcbafc5ed62305eb9d479.tar.bz2 linux-stable-7f6b9dbd5afbd966a82dcbafc5ed62305eb9d479.zip |
af_key: locking change
Get rid of custom locking that was using wait queue, lock, and atomic
to basically build a queued mutex. Use RCU for read side.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/key/af_key.c')
-rw-r--r-- | net/key/af_key.c | 76 |
1 files changed, 16 insertions, 60 deletions
diff --git a/net/key/af_key.c b/net/key/af_key.c index a20d2fa88db9..da2fe5f57619 100644 --- a/net/key/af_key.c +++ b/net/key/af_key.c @@ -41,9 +41,7 @@ struct netns_pfkey { struct hlist_head table; atomic_t socks_nr; }; -static DECLARE_WAIT_QUEUE_HEAD(pfkey_table_wait); -static DEFINE_RWLOCK(pfkey_table_lock); -static atomic_t pfkey_table_users = ATOMIC_INIT(0); +static DEFINE_MUTEX(pfkey_mutex); struct pfkey_sock { /* struct sock must be the first member of struct pfkey_sock */ @@ -108,50 +106,6 @@ static void pfkey_sock_destruct(struct sock *sk) atomic_dec(&net_pfkey->socks_nr); } -static void pfkey_table_grab(void) -{ - write_lock_bh(&pfkey_table_lock); - - if (atomic_read(&pfkey_table_users)) { - DECLARE_WAITQUEUE(wait, current); - - add_wait_queue_exclusive(&pfkey_table_wait, &wait); - for(;;) { - set_current_state(TASK_UNINTERRUPTIBLE); - if (atomic_read(&pfkey_table_users) == 0) - break; - write_unlock_bh(&pfkey_table_lock); - schedule(); - write_lock_bh(&pfkey_table_lock); - } - - __set_current_state(TASK_RUNNING); - remove_wait_queue(&pfkey_table_wait, &wait); - } -} - -static __inline__ void pfkey_table_ungrab(void) -{ - write_unlock_bh(&pfkey_table_lock); - wake_up(&pfkey_table_wait); -} - -static __inline__ void pfkey_lock_table(void) -{ - /* read_lock() synchronizes us to pfkey_table_grab */ - - read_lock(&pfkey_table_lock); - atomic_inc(&pfkey_table_users); - read_unlock(&pfkey_table_lock); -} - -static __inline__ void pfkey_unlock_table(void) -{ - if (atomic_dec_and_test(&pfkey_table_users)) - wake_up(&pfkey_table_wait); -} - - static const struct proto_ops pfkey_ops; static void pfkey_insert(struct sock *sk) @@ -159,16 +113,16 @@ static void pfkey_insert(struct sock *sk) struct net *net = sock_net(sk); struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id); - pfkey_table_grab(); - sk_add_node(sk, &net_pfkey->table); - pfkey_table_ungrab(); + mutex_lock(&pfkey_mutex); + sk_add_node_rcu(sk, &net_pfkey->table); + mutex_unlock(&pfkey_mutex); } static void pfkey_remove(struct sock *sk) { - pfkey_table_grab(); - sk_del_node_init(sk); - pfkey_table_ungrab(); + mutex_lock(&pfkey_mutex); + sk_del_node_init_rcu(sk); + mutex_unlock(&pfkey_mutex); } static struct proto key_proto = { @@ -223,6 +177,8 @@ static int pfkey_release(struct socket *sock) sock_orphan(sk); sock->sk = NULL; skb_queue_purge(&sk->sk_write_queue); + + synchronize_rcu(); sock_put(sk); return 0; @@ -277,8 +233,8 @@ static int pfkey_broadcast(struct sk_buff *skb, gfp_t allocation, if (!skb) return -ENOMEM; - pfkey_lock_table(); - sk_for_each(sk, node, &net_pfkey->table) { + rcu_read_lock(); + sk_for_each_rcu(sk, node, &net_pfkey->table) { struct pfkey_sock *pfk = pfkey_sk(sk); int err2; @@ -309,7 +265,7 @@ static int pfkey_broadcast(struct sk_buff *skb, gfp_t allocation, if ((broadcast_flags & BROADCAST_REGISTERED) && err) err = err2; } - pfkey_unlock_table(); + rcu_read_unlock(); if (one_sk != NULL) err = pfkey_broadcast_one(skb, &skb2, allocation, one_sk); @@ -3702,8 +3658,8 @@ static void *pfkey_seq_start(struct seq_file *f, loff_t *ppos) struct net *net = seq_file_net(f); struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id); - read_lock(&pfkey_table_lock); - return seq_hlist_start_head(&net_pfkey->table, *ppos); + rcu_read_lock(); + return seq_hlist_start_head_rcu(&net_pfkey->table, *ppos); } static void *pfkey_seq_next(struct seq_file *f, void *v, loff_t *ppos) @@ -3711,12 +3667,12 @@ static void *pfkey_seq_next(struct seq_file *f, void *v, loff_t *ppos) struct net *net = seq_file_net(f); struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id); - return seq_hlist_next(v, &net_pfkey->table, ppos); + return seq_hlist_next_rcu(v, &net_pfkey->table, ppos); } static void pfkey_seq_stop(struct seq_file *f, void *v) { - read_unlock(&pfkey_table_lock); + rcu_read_unlock(); } static const struct seq_operations pfkey_seq_ops = { |