7 files changed, 55 insertions, 48 deletions

diff --git a/kernel/audit.c b/kernel/audit.c
index 0f84dd7af2c8..ac26d4d960d3 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -427,7 +427,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 /* Get message from skb (based on rtnetlink_rcv_skb).  Each message is
  * processed by audit_receive_msg.  Malformed skbs with wrong length are
  * discarded silently.  */
-static int audit_receive_skb(struct sk_buff *skb)
+static void audit_receive_skb(struct sk_buff *skb)
 {
         int             err;
         struct nlmsghdr *nlh;
@@ -436,7 +436,7 @@ static int audit_receive_skb(struct sk_buff *skb)
         while (skb->len >= NLMSG_SPACE(0)) {
                 nlh = (struct nlmsghdr *)skb->data;
                 if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
-                        return 0;
+                        return;
                 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
                 if (rlen > skb->len)
                         rlen = skb->len;
@@ -446,23 +446,20 @@ static int audit_receive_skb(struct sk_buff *skb)
                         netlink_ack(skb, nlh, 0);
                 skb_pull(skb, rlen);
         }
-        return 0;
 }
 
 /* Receive messages from netlink socket. */
 static void audit_receive(struct sock *sk, int length)
 {
         struct sk_buff  *skb;
+        unsigned int qlen;
 
-        if (down_trylock(&audit_netlink_sem))
-                return;
+        down(&audit_netlink_sem);
 
-                                /* FIXME: this must not cause starvation */
-        while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
-                if (audit_receive_skb(skb) && skb->len)
-                        skb_queue_head(&sk->sk_receive_queue, skb);
-                else
-                        kfree_skb(skb);
+        for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
+                skb = skb_dequeue(&sk->sk_receive_queue);
+                audit_receive_skb(skb);
+                kfree_skb(skb);
         }
         up(&audit_netlink_sem);
 }
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 5fb70cfa1085..6e1ab1e34b2e 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -609,26 +609,31 @@ static inline int rtnetlink_rcv_skb(struct sk_buff *skb)
 
 /*
  *  rtnetlink input queue processing routine:
- *      - try to acquire shared lock. If it is failed, defer processing.
+ *      - process as much as there was in the queue upon entry.
  *      - feed skbs to rtnetlink_rcv_skb, until it refuse a message,
- *        that will occur, when a dump started and/or acquisition of
- *        exclusive lock failed.
+ *        that will occur, when a dump started.
  */
 
 static void rtnetlink_rcv(struct sock *sk, int len)
 {
+        unsigned int qlen = skb_queue_len(&sk->sk_receive_queue);
+
         do {
                 struct sk_buff *skb;
 
-                if (rtnl_shlock_nowait())
-                        return;
+                rtnl_lock();
+
+                if (qlen > skb_queue_len(&sk->sk_receive_queue))
+                        qlen = skb_queue_len(&sk->sk_receive_queue);
 
-                while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
+                while (qlen--) {
+                        skb = skb_dequeue(&sk->sk_receive_queue);
                         if (rtnetlink_rcv_skb(skb)) {
-                                if (skb->len)
+                                if (skb->len) {
                                         skb_queue_head(&sk->sk_receive_queue,
                                                        skb);
-                                else
+                                        qlen++;
+                                } else
                                         kfree_skb(skb);
                                 break;
                         }
@@ -638,7 +643,7 @@ static void rtnetlink_rcv(struct sock *sk, int len)
                 up(&rtnl_sem);
 
                 netdev_run_todo();
-        } while (rtnl && rtnl->sk_receive_queue.qlen);
+        } while (qlen);
 }
 
 static struct rtnetlink_link link_rtnetlink_table[RTM_NR_MSGTYPES] =
diff --git a/net/decnet/netfilter/dn_rtmsg.c b/net/decnet/netfilter/dn_rtmsg.c
index f86a6259fd12..101ddef9ba9a 100644
--- a/net/decnet/netfilter/dn_rtmsg.c
+++ b/net/decnet/netfilter/dn_rtmsg.c
@@ -119,8 +119,9 @@ static inline void dnrmg_receive_user_skb(struct sk_buff *skb)
 static void dnrmg_receive_user_sk(struct sock *sk, int len)
 {
         struct sk_buff *skb;
+        unsigned int qlen = skb_queue_len(&sk->sk_receive_queue);
 
-        while((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
+        while (qlen-- && (skb = skb_dequeue(&sk->sk_receive_queue))) {
                 dnrmg_receive_user_skb(skb);
                 kfree_skb(skb);
         }
diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
index 9e40dffc204f..e5746b674413 100644
--- a/net/ipv4/netfilter/ip_queue.c
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -546,20 +546,18 @@ ipq_rcv_skb(struct sk_buff *skb)
 static void
 ipq_rcv_sk(struct sock *sk, int len)
 {
-        do {
-                struct sk_buff *skb;
+        struct sk_buff *skb;
+        unsigned int qlen;
 
-                if (down_trylock(&ipqnl_sem))
-                        return;
+        down(&ipqnl_sem);
                         
-                while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
-                        ipq_rcv_skb(skb);
-                        kfree_skb(skb);
-                }
+        for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
+                skb = skb_dequeue(&sk->sk_receive_queue);
+                ipq_rcv_skb(skb);
+                kfree_skb(skb);
+        }
                 
-                up(&ipqnl_sem);
-
-        } while (ipqnl && ipqnl->sk_receive_queue.qlen);
+        up(&ipqnl_sem);
 }
 
 static int
diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
index 313c1408da33..8faa8948f75c 100644
--- a/net/ipv4/tcp_diag.c
+++ b/net/ipv4/tcp_diag.c
@@ -777,8 +777,9 @@ static inline void tcpdiag_rcv_skb(struct sk_buff *skb)
 static void tcpdiag_rcv(struct sock *sk, int len)
 {
         struct sk_buff *skb;
+        unsigned int qlen = skb_queue_len(&sk->sk_receive_queue);
 
-        while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
+        while (qlen-- && (skb = skb_dequeue(&sk->sk_receive_queue))) {
                 tcpdiag_rcv_skb(skb);
                 kfree_skb(skb);
         }
diff --git a/net/ipv6/netfilter/ip6_queue.c b/net/ipv6/netfilter/ip6_queue.c
index c54830b89593..750943e2d34e 100644
--- a/net/ipv6/netfilter/ip6_queue.c
+++ b/net/ipv6/netfilter/ip6_queue.c
@@ -549,20 +549,18 @@ ipq_rcv_skb(struct sk_buff *skb)
 static void
 ipq_rcv_sk(struct sock *sk, int len)
 {
-        do {
-                struct sk_buff *skb;
+        struct sk_buff *skb;
+        unsigned int qlen;
 
-                if (down_trylock(&ipqnl_sem))
-                        return;
+        down(&ipqnl_sem);
                         
-                while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
-                        ipq_rcv_skb(skb);
-                        kfree_skb(skb);
-                }
+        for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
+                skb = skb_dequeue(&sk->sk_receive_queue);
+                ipq_rcv_skb(skb);
+                kfree_skb(skb);
+        }
                 
-                up(&ipqnl_sem);
-
-        } while (ipqnl && ipqnl->sk_receive_queue.qlen);
+        up(&ipqnl_sem);
 }
 
 static int
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 52b5843937c5..dab112f1dd8a 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1008,17 +1008,24 @@ static int xfrm_user_rcv_skb(struct sk_buff *skb)
 
 static void xfrm_netlink_rcv(struct sock *sk, int len)
 {
+        unsigned int qlen = skb_queue_len(&sk->sk_receive_queue);
+
         do {
                 struct sk_buff *skb;
 
                 down(&xfrm_cfg_sem);
 
-                while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
+                if (qlen > skb_queue_len(&sk->sk_receive_queue))
+                        qlen = skb_queue_len(&sk->sk_receive_queue);
+
+                while (qlen--) {
+                        skb = skb_dequeue(&sk->sk_receive_queue);
                         if (xfrm_user_rcv_skb(skb)) {
-                                if (skb->len)
+                                if (skb->len) {
                                         skb_queue_head(&sk->sk_receive_queue,
                                                        skb);
-                                else
+                                        qlen++;
+                                } else
                                         kfree_skb(skb);
                                 break;
                         }
@@ -1027,7 +1034,7 @@ static void xfrm_netlink_rcv(struct sock *sk, int len)
 
                 up(&xfrm_cfg_sem);
 
-        } while (xfrm_nl && xfrm_nl->sk_receive_queue.qlen);
+        } while (qlen);
 }
 
 static int build_expire(struct sk_buff *skb, struct xfrm_state *x, int hard)