net: dev_add_pack() & __dev_remove_pack() changes

Add a small helper ptype_head() to get the head to manipulate

dev_add_pack() & __dev_remove_pack() can use a spinlock without
blocking BH, since softirq use RCU, and these functions are run from
process context only.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 17 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index d8c43e73f0b7..efd318db11ab 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -371,6 +371,14 @@ static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
  *                                                      --ANK (980803)
  */
 
+static inline struct list_head *ptype_head(const struct packet_type *pt)
+{
+        if (pt->type == htons(ETH_P_ALL))
+                return &ptype_all;
+        else
+                return &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
+}
+
 /**
  *      dev_add_pack - add packet handler
  *      @pt: packet type declaration
@@ -386,16 +394,11 @@ static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
 
 void dev_add_pack(struct packet_type *pt)
 {
-        int hash;
+        struct list_head *head = ptype_head(pt);
 
-        spin_lock_bh(&ptype_lock);
-        if (pt->type == htons(ETH_P_ALL))
-                list_add_rcu(&pt->list, &ptype_all);
-        else {
-                hash = ntohs(pt->type) & PTYPE_HASH_MASK;
-                list_add_rcu(&pt->list, &ptype_base[hash]);
-        }
-        spin_unlock_bh(&ptype_lock);
+        spin_lock(&ptype_lock);
+        list_add_rcu(&pt->list, head);
+        spin_unlock(&ptype_lock);
 }
 EXPORT_SYMBOL(dev_add_pack);
 
@@ -414,15 +417,10 @@ EXPORT_SYMBOL(dev_add_pack);
  */
 void __dev_remove_pack(struct packet_type *pt)
 {
-        struct list_head *head;
+        struct list_head *head = ptype_head(pt);
         struct packet_type *pt1;
 
-        spin_lock_bh(&ptype_lock);
-
-        if (pt->type == htons(ETH_P_ALL))
-                head = &ptype_all;
-        else
-                head = &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
+        spin_lock(&ptype_lock);
 
         list_for_each_entry(pt1, head, list) {
                 if (pt == pt1) {
@@ -433,7 +431,7 @@ void __dev_remove_pack(struct packet_type *pt)
 
         printk(KERN_WARNING "dev_remove_pack: %p not found.\n", pt);
 out:
-        spin_unlock_bh(&ptype_lock);
+        spin_unlock(&ptype_lock);
 }
 EXPORT_SYMBOL(__dev_remove_pack);