[XFRM]: Eliminate refcounting confusion by creating __xfrm_state_put().

We often just do an atomic_dec(&x->refcnt) on an xfrm_state object
because we know there is more than 1 reference remaining and thus
we can elide the heavier xfrm_state_put() call.

Do this behind an inline function called __xfrm_state_put() so that is
more obvious and also to allow us to more cleanly add refcount
debugging later.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 11 insertions, 6 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index d6111a2f0a2..004e645f3e1 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -403,6 +403,11 @@ unsigned xfrm_spi_hash(xfrm_address_t *addr, u32 spi, u8 proto, unsigned short f
 
 extern void __xfrm_state_destroy(struct xfrm_state *);
 
+static inline void __xfrm_state_put(struct xfrm_state *x)
+{
+        atomic_dec(&x->refcnt);
+}
+
 static inline void xfrm_state_put(struct xfrm_state *x)
 {
         if (atomic_dec_and_test(&x->refcnt))
diff --git a/net/key/af_key.c b/net/key/af_key.c
index ae86d237a45..b2d4d1dd211 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1423,7 +1423,7 @@ static int pfkey_add(struct sock *sk, struct sk_buff *skb, struct sadb_msg *hdr,
 
         if (err < 0) {
                 x->km.state = XFRM_STATE_DEAD;
-                xfrm_state_put(x);
+                __xfrm_state_put(x);
                 goto out;
         }
 
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index e12d0be5f97..c656cbaf35e 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -220,14 +220,14 @@ static int __xfrm_state_delete(struct xfrm_state *x)
                 x->km.state = XFRM_STATE_DEAD;
                 spin_lock(&xfrm_state_lock);
                 list_del(&x->bydst);
-                atomic_dec(&x->refcnt);
+                __xfrm_state_put(x);
                 if (x->id.spi) {
                         list_del(&x->byspi);
-                        atomic_dec(&x->refcnt);
+                        __xfrm_state_put(x);
                 }
                 spin_unlock(&xfrm_state_lock);
                 if (del_timer(&x->timer))
-                        atomic_dec(&x->refcnt);
+                        __xfrm_state_put(x);
 
                 /* The number two in this test is the reference
                  * mentioned in the comment below plus the reference
@@ -243,7 +243,7 @@ static int __xfrm_state_delete(struct xfrm_state *x)
                  * The xfrm_state_alloc call gives a reference, and that
                  * is what we are dropping here.
                  */
-                atomic_dec(&x->refcnt);
+                __xfrm_state_put(x);
                 err = 0;
         }
 
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index ac87a09ba83..7de17559249 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -345,7 +345,7 @@ static int xfrm_add_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
 
         if (err < 0) {
                 x->km.state = XFRM_STATE_DEAD;
-                xfrm_state_put(x);
+                __xfrm_state_put(x);
                 goto out;
         }