[Devel] [PATCH] Clean proto_(un)register from in-code ifdefs

[Pavel Emelyanov]

The struct proto has the per-cpu "inuse" counter, which is handled
with a special care. All the handling code hides under the ifdef 
CONFIG_SMP and it introduces some code duplication and makes it 
look worse than it could.

Clean this.

Signed-off-by: Pavel Emelyanov <xemul at openvz.org>

---

diff --git a/net/core/sock.c b/net/core/sock.c
index e077f26..8fc2f84 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1819,23 +1819,48 @@ static int inuse_get(const struct proto *prot)
 		res += per_cpu_ptr(prot->inuse_ptr, cpu)[0];
 	return res;
 }
-#endif
 
-int proto_register(struct proto *prot, int alloc_slab)
+static int inuse_init(struct proto *prot)
 {
-	char *request_sock_slab_name = NULL;
-	char *timewait_sock_slab_name;
-	int rc = -ENOBUFS;
-
-#ifdef CONFIG_SMP
 	if (!prot->inuse_getval || !prot->inuse_add) {
 		prot->inuse_ptr = alloc_percpu(int);
 		if (prot->inuse_ptr == NULL)
-			goto out;
+			return -ENOBUFS;
+
 		prot->inuse_getval = inuse_get;
 		prot->inuse_add = inuse_add;
 	}
+	return 0;
+}
+
+static void inuse_fini(struct proto *prot)
+{
+	if (prot->inuse_ptr != NULL) {
+		free_percpu(prot->inuse_ptr);
+		prot->inuse_ptr = NULL;
+		prot->inuse_getval = NULL;
+		prot->inuse_add = NULL;
+	}
+}
+#else
+static inline int inuse_init(struct proto *prot)
+{
+	return 0;
+}
+
+static inline void inuse_fini(struct proto *prot)
+{
+}
 #endif
+
+int proto_register(struct proto *prot, int alloc_slab)
+{
+	char *request_sock_slab_name = NULL;
+	char *timewait_sock_slab_name;
+
+	if (inuse_init(prot))
+		goto out;
+
 	if (alloc_slab) {
 		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
 					       SLAB_HWCACHE_ALIGN, NULL);
@@ -1887,9 +1912,8 @@ int proto_register(struct proto *prot, int alloc_slab)
 	write_lock(&proto_list_lock);
 	list_add(&prot->node, &proto_list);
 	write_unlock(&proto_list_lock);
-	rc = 0;
-out:
-	return rc;
+	return 0;
+
 out_free_timewait_sock_slab_name:
 	kfree(timewait_sock_slab_name);
 out_free_request_sock_slab:
@@ -1903,15 +1927,9 @@ out_free_sock_slab:
 	kmem_cache_destroy(prot->slab);
 	prot->slab = NULL;
 out_free_inuse:
-#ifdef CONFIG_SMP
-	if (prot->inuse_ptr != NULL) {
-		free_percpu(prot->inuse_ptr);
-		prot->inuse_ptr = NULL;
-		prot->inuse_getval = NULL;
-		prot->inuse_add = NULL;
-	}
-#endif
-	goto out;
+	inuse_fini(prot);
+out:
+	return -ENOBUFS;
 }
 
 EXPORT_SYMBOL(proto_register);
@@ -1922,14 +1940,7 @@ void proto_unregister(struct proto *prot)
 	list_del(&prot->node);
 	write_unlock(&proto_list_lock);
 
-#ifdef CONFIG_SMP
-	if (prot->inuse_ptr != NULL) {
-		free_percpu(prot->inuse_ptr);
-		prot->inuse_ptr = NULL;
-		prot->inuse_getval = NULL;
-		prot->inuse_add = NULL;
-	}
-#endif
+	inuse_fini(prot);
 	if (prot->slab != NULL) {
 		kmem_cache_destroy(prot->slab);
 		prot->slab = NULL;