This is just wasted time, we've already found a tb that doesn't have a bind
conflict, and we don't drop the head lock so scanning again isn't going to give
us a different answer. Instead move the tb->reuse setting logic outside of the
found_tb path and put it in the success: path. Then make it so that we don't
goto again if we find a bind conflict in the found_tb path as we won't reach
this anymore when we are scanning for an ephemeral port.
Signed-off-by: Josef Bacik <jba...@fb.com>
---
net/ipv4/inet_connection_sock.c | 39 ++++++++++++++++++---------------------
1 file changed, 18 insertions(+), 21 deletions(-)
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 1a1a94bd..fc9bfe1 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -92,7 +92,7 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
{
bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;
- int ret = 1, attempts = 5, port = snum;
+ int ret = 1, port = snum;
struct inet_bind_hashbucket *head;
struct net *net = sock_net(sk);
int i, low, high, attempt_half;
@@ -100,6 +100,7 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
kuid_t uid = sock_i_uid(sk);
u32 remaining, offset;
bool reuseport_ok = !!snum;
+ bool empty_tb = true;
if (port) {
head = &hinfo->bhash[inet_bhashfn(net, port,
@@ -111,7 +112,6 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
goto tb_not_found;
}
-again:
attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0;
other_half_scan:
inet_get_local_port_range(net, &low, &high);
@@ -148,8 +148,12 @@ other_parity_scan:
spin_lock_bh(&head->lock);
inet_bind_bucket_for_each(tb, &head->chain)
if (net_eq(ib_net(tb), net) && tb->port == port) {
- if (!inet_csk_bind_conflict(sk, tb, false,
reuseport_ok))
- goto tb_found;
+ if (hlist_empty(&tb->owners))
+ goto success;
+ if (!inet_csk_bind_conflict(sk, tb, false,
reuseport_ok)) {
+ empty_tb = false;
+ goto success;
+ }
goto next_port;
}
goto tb_not_found;
@@ -184,23 +188,12 @@ tb_found:
!rcu_access_pointer(sk->sk_reuseport_cb) &&
sk->sk_reuseport && uid_eq(tb->fastuid, uid)))
goto success;
- if (inet_csk_bind_conflict(sk, tb, true, reuseport_ok)) {
- if ((reuse ||
- (tb->fastreuseport > 0 &&
- sk->sk_reuseport &&
- !rcu_access_pointer(sk->sk_reuseport_cb) &&
- uid_eq(tb->fastuid, uid))) && !snum &&
- --attempts >= 0) {
- spin_unlock_bh(&head->lock);
- goto again;
- }
+ if (inet_csk_bind_conflict(sk, tb, true, reuseport_ok))
goto fail_unlock;
- }
- if (!reuse)
- tb->fastreuse = 0;
- if (!sk->sk_reuseport || !uid_eq(tb->fastuid, uid))
- tb->fastreuseport = 0;
- } else {
+ empty_tb = false;
+ }
+success:
+ if (empty_tb) {
tb->fastreuse = reuse;
if (sk->sk_reuseport) {
tb->fastreuseport = 1;
@@ -208,8 +201,12 @@ tb_found:
} else {
tb->fastreuseport = 0;
}
+ } else {
+ if (!reuse)
+ tb->fastreuse = 0;
+ if (!sk->sk_reuseport || !uid_eq(tb->fastuid, uid))
+ tb->fastreuseport = 0;
}
-success:
if (!inet_csk(sk)->icsk_bind_hash)
inet_bind_hash(sk, tb, port);
WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
--
2.9.3
