[SOCK]: Add some notes about per-bind-bucket sock lookup.

I was asked about "why don't we perform a sk_net filtering in
bind_conflict calls, like we do in other sock lookup places"
for a couple of times.

Can we please add a comment about why we do not need one?

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 8d70cfb..828ea21 100644 (file)
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -55,6 +55,13 @@ int inet_csk_bind_conflict(const struct sock *sk,
        struct hlist_node *node;
        int reuse = sk->sk_reuse;
 
+       /*
+        * Unlike other sk lookup places we do not check
+        * for sk_net here, since _all_ the socks listed
+        * in tb->owners list belong to the same net - the
+        * one this bucket belongs to.
+        */
+
        sk_for_each_bound(sk2, node, &tb->owners) {
                if (sk != sk2 &&
                    !inet_v6_ipv6only(sk2) &&

diff --git a/net/ipv6/inet6_connection_sock.c b/net/ipv6/inet6_connection_sock.c
index 78de42a..87801cc 100644 (file)
--- a/net/ipv6/inet6_connection_sock.c
+++ b/net/ipv6/inet6_connection_sock.c
@@ -33,6 +33,10 @@ int inet6_csk_bind_conflict(const struct sock *sk,
        const struct hlist_node *node;
 
        /* We must walk the whole port owner list in this case. -DaveM */
+       /*
+        * See comment in inet_csk_bind_conflict about sock lookup
+        * vs net namespaces issues.
+        */
        sk_for_each_bound(sk2, node, &tb->owners) {
                if (sk != sk2 &&
                    (!sk->sk_bound_dev_if ||