tcp: relax listening_hash operations
softirq handlers use RCU protection to lookup listeners,
and write operations all happen from process context.
We do not need to block BH for dump operations.
Also SYN_RECV since request sockets are stored in the ehash table :
1) inet_diag_dump_icsk() no longer need to clear
cb->args[3] and cb->args[4] that were used as cursors while
iterating the old per listener hash table.
2) Also factorize a test : No need to scan listening_hash[]
if r->id.idiag_dport is not zero.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index e4d16fc..0a1d4a8 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -863,7 +863,7 @@ void inet_diag_dump_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *skb,
s_num = num = cb->args[2];
if (cb->args[0] == 0) {
- if (!(idiag_states & TCPF_LISTEN))
+ if (!(idiag_states & TCPF_LISTEN) || r->id.idiag_dport)
goto skip_listen_ht;
for (i = s_i; i < INET_LHTABLE_SIZE; i++) {
@@ -872,7 +872,7 @@ void inet_diag_dump_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *skb,
num = 0;
ilb = &hashinfo->listening_hash[i];
- spin_lock_bh(&ilb->lock);
+ spin_lock(&ilb->lock);
sk_for_each(sk, &ilb->head) {
struct inet_sock *inet = inet_sk(sk);
@@ -892,26 +892,18 @@ void inet_diag_dump_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *skb,
r->id.idiag_sport)
goto next_listen;
- if (r->id.idiag_dport ||
- cb->args[3] > 0)
- goto next_listen;
-
if (inet_csk_diag_dump(sk, skb, cb, r,
bc, net_admin) < 0) {
- spin_unlock_bh(&ilb->lock);
+ spin_unlock(&ilb->lock);
goto done;
}
next_listen:
- cb->args[3] = 0;
- cb->args[4] = 0;
++num;
}
- spin_unlock_bh(&ilb->lock);
+ spin_unlock(&ilb->lock);
s_num = 0;
- cb->args[3] = 0;
- cb->args[4] = 0;
}
skip_listen_ht:
cb->args[0] = 1;