mirrors/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2025-11-04 02:30:34 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

tcp: relax listening_hash operations

Browse source 
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>
This commit is contained in:
Eric Dumazet 2016-10-19 21:24:58 -07:00 committed by David S. Miller
parent 25c07e2c5e
commit 9652dc2eb9
2 changed files with 7 additions and 15 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

16
net/ipv4/inet_diag.c
View file

@ -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;

6
net/ipv4/tcp_ipv4.c
View file

@ -1893,7 +1893,7 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
if (!sk) {
get_head:
ilb = &tcp_hashinfo.listening_hash[st->bucket];
spin_lock_bh(&ilb->lock);
spin_lock(&ilb->lock);
sk = sk_head(&ilb->head);
st->offset = 0;
goto get_sk;
@ -1911,7 +1911,7 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
return sk;
icsk = inet_csk(sk);
}
spin_unlock_bh(&ilb->lock);
spin_unlock(&ilb->lock);
st->offset = 0;
if (++st->bucket < INET_LHTABLE_SIZE)
goto get_head;
@ -2119,7 +2119,7 @@ static void tcp_seq_stop(struct seq_file *seq, void *v)
switch (st->state) {
case TCP_SEQ_STATE_LISTENING:
if (v != SEQ_START_TOKEN)
spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock);
spin_unlock(&tcp_hashinfo.listening_hash[st->bucket].lock);
break;
case TCP_SEQ_STATE_ESTABLISHED:
if (v)