net: sock_queue_err_skb() dont mess with sk_forward_alloc

commit b1faf5666438090a4dc4fceac8502edc7788b7e3 upstream.

Correct sk_forward_alloc handling for error_queue would need to use a
backlog of frames that softirq handler could not deliver because socket
is owned by user thread. Or extend backlog processing to be able to
process normal and error packets.

Another possibility is to not use mem charge for error queue, this is
what I implemented in this patch.

Note: this reverts commit 29030374
(net: fix sk_forward_alloc corruptions), since we dont need to lock
socket anymore.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: 单卫 <shanwei88@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/net/sock.h b/include/net/sock.h
index 9f96394f694e42dead181978ce59fdb6443df8fb..78adf52ca2785bc02341a1c3f75d95249d5f17e9 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1354,20 +1354,7 @@ extern void sk_stop_timer(struct sock *sk, struct timer_list* timer);
 
 extern int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
 
-static inline int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb)
-{
-       /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces
-          number of warnings when compiling with -W --ANK
-        */
-       if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
-           (unsigned)sk->sk_rcvbuf)
-               return -ENOMEM;
-       skb_set_owner_r(skb, sk);
-       skb_queue_tail(&sk->sk_error_queue, skb);
-       if (!sock_flag(sk, SOCK_DEAD))
-               sk->sk_data_ready(sk, skb->len);
-       return 0;
-}
+extern int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
 
 /*
  *     Recover an error report and clear atomically

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 50a85e31bf61e4af9e730140a167b3e9eaccb746..025f924cf78e738b942e9e96eb5c8f4862712f3e 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2977,6 +2977,34 @@ int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer)
 }
 EXPORT_SYMBOL_GPL(skb_cow_data);
 
+static void sock_rmem_free(struct sk_buff *skb)
+{
+       struct sock *sk = skb->sk;
+
+       atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
+}
+
+/*
+ * Note: We dont mem charge error packets (no sk_forward_alloc changes)
+ */
+int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb)
+{
+       if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
+           (unsigned)sk->sk_rcvbuf)
+               return -ENOMEM;
+
+       skb_orphan(skb);
+       skb->sk = sk;
+       skb->destructor = sock_rmem_free;
+       atomic_add(skb->truesize, &sk->sk_rmem_alloc);
+
+       skb_queue_tail(&sk->sk_error_queue, skb);
+       if (!sock_flag(sk, SOCK_DEAD))
+               sk->sk_data_ready(sk, skb->len);
+       return 0;
+}
+EXPORT_SYMBOL(sock_queue_err_skb);
+
 void skb_tstamp_tx(struct sk_buff *orig_skb,
                struct skb_shared_hwtstamps *hwtstamps)
 {
@@ -3009,9 +3037,7 @@ void skb_tstamp_tx(struct sk_buff *orig_skb,
        serr->ee.ee_errno = ENOMSG;
        serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
 
-       bh_lock_sock(sk);
        err = sock_queue_err_skb(sk, skb);
-       bh_unlock_sock(sk);
 
        if (err)
                kfree_skb(skb);

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 4a7fd783f9834a91130a2e198e639501a1f0c5b9..8e287707486591e0218efad46d5829aaa2f60c98 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -440,11 +440,9 @@ void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
        if (!inet->recverr) {
                if (!harderr || sk->sk_state != TCP_ESTABLISHED)
                        goto out;
-       } else {
-               bh_lock_sock(sk);
+       } else
                ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
-               bh_unlock_sock(sk);
-       }
+
        sk->sk_err = err;
        sk->sk_error_report(sk);
 out:

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 12d8791daf91fcee153ef122f93016aa350d46a5..9cc6289acaedb235ee93187ec95b8845d202f888 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -337,11 +337,9 @@ void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
        if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
                goto out;
 
-       if (np->recverr) {
-               bh_lock_sock(sk);
+       if (np->recverr)
                ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
-               bh_unlock_sock(sk);
-       }
+
        sk->sk_err = err;
        sk->sk_error_report(sk);
 out: