diff options
| -rw-r--r-- | net/netlink/af_netlink.c | 32 | ||||
| -rw-r--r-- | net/netlink/af_netlink.h | 1 |
2 files changed, 17 insertions, 16 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 738c3bfaa564..298e1df7132a 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -97,12 +97,12 @@ static int netlink_dump(struct sock *sk); static void netlink_skb_destructor(struct sk_buff *skb); /* nl_table locking explained: - * Lookup and traversal are protected with nl_sk_hash_lock or nl_table_lock - * combined with an RCU read-side lock. Insertion and removal are protected - * with nl_sk_hash_lock while using RCU list modification primitives and may - * run in parallel to nl_table_lock protected lookups. Destruction of the - * Netlink socket may only occur *after* nl_table_lock has been acquired - * either during or after the socket has been removed from the list. + * Lookup and traversal are protected with an RCU read-side lock. Insertion + * and removal are protected with nl_sk_hash_lock while using RCU list + * modification primitives and may run in parallel to RCU protected lookups. + * Destruction of the Netlink socket may only occur *after* nl_table_lock has + * been acquired * either during or after the socket has been removed from + * the list and after an RCU grace period. */ DEFINE_RWLOCK(nl_table_lock); EXPORT_SYMBOL_GPL(nl_table_lock); @@ -1003,13 +1003,11 @@ static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) struct netlink_table *table = &nl_table[protocol]; struct sock *sk; - read_lock(&nl_table_lock); rcu_read_lock(); sk = __netlink_lookup(table, portid, net); if (sk) sock_hold(sk); rcu_read_unlock(); - read_unlock(&nl_table_lock); return sk; } @@ -1183,6 +1181,13 @@ out_module: goto out; } +static void deferred_put_nlk_sk(struct rcu_head *head) +{ + struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu); + + sock_put(&nlk->sk); +} + static int netlink_release(struct socket *sock) { struct sock *sk = sock->sk; @@ -1248,7 +1253,7 @@ static int netlink_release(struct socket *sock) local_bh_disable(); sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); local_bh_enable(); - sock_put(sk); + call_rcu(&nlk->rcu, deferred_put_nlk_sk); return 0; } @@ -1263,7 +1268,6 @@ static int netlink_autobind(struct socket *sock) retry: cond_resched(); - netlink_table_grab(); rcu_read_lock(); if (__netlink_lookup(table, portid, net)) { /* Bind collision, search negative portid values. */ @@ -1271,11 +1275,9 @@ retry: if (rover > -4097) rover = -4097; rcu_read_unlock(); - netlink_table_ungrab(); goto retry; } rcu_read_unlock(); - netlink_table_ungrab(); err = netlink_insert(sk, net, portid); if (err == -EADDRINUSE) @@ -2910,9 +2912,8 @@ static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) } static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) - __acquires(nl_table_lock) __acquires(RCU) + __acquires(RCU) { - read_lock(&nl_table_lock); rcu_read_lock(); return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; } @@ -2964,10 +2965,9 @@ static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) } static void netlink_seq_stop(struct seq_file *seq, void *v) - __releases(RCU) __releases(nl_table_lock) + __releases(RCU) { rcu_read_unlock(); - read_unlock(&nl_table_lock); } diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h index f123a88496f8..fd96fa76202a 100644 --- a/net/netlink/af_netlink.h +++ b/net/netlink/af_netlink.h @@ -50,6 +50,7 @@ struct netlink_sock { #endif /* CONFIG_NETLINK_MMAP */ struct rhash_head node; + struct rcu_head rcu; }; static inline struct netlink_sock *nlk_sk(struct sock *sk) |