staging: zcache: cleanup the code between tmem_obj_init and tmem_obj_find

tmem_obj_find and insertion tmem-obj have the some logic, we can integrate
the code

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 33 insertions, 30 deletions

diff --git a/drivers/staging/zcache/tmem.c b/drivers/staging/zcache/tmem.c
index 1ca66ea9b28..eaa90213457 100644
--- a/drivers/staging/zcache/tmem.c
+++ b/drivers/staging/zcache/tmem.c
@@ -72,33 +72,49 @@ void tmem_register_pamops(struct tmem_pamops *m)
  * the hashbucket lock must be held.
  */
 
-/* searches for object==oid in pool, returns locked object if found */
-static struct tmem_obj *tmem_obj_find(struct tmem_hashbucket *hb,
-                                        struct tmem_oid *oidp)
+static struct tmem_obj
+*__tmem_obj_find(struct tmem_hashbucket*hb, struct tmem_oid *oidp,
+                 struct rb_node **parent, struct rb_node ***link)
 {
-        struct rb_node *rbnode;
-        struct tmem_obj *obj;
-
-        rbnode = hb->obj_rb_root.rb_node;
-        while (rbnode) {
-                BUG_ON(RB_EMPTY_NODE(rbnode));
-                obj = rb_entry(rbnode, struct tmem_obj, rb_tree_node);
+        struct rb_node *_parent = NULL, **rbnode;
+        struct tmem_obj *obj = NULL;
+
+        rbnode = &hb->obj_rb_root.rb_node;
+        while (*rbnode) {
+                BUG_ON(RB_EMPTY_NODE(*rbnode));
+                _parent = *rbnode;
+                obj = rb_entry(*rbnode, struct tmem_obj,
+                               rb_tree_node);
                 switch (tmem_oid_compare(oidp, &obj->oid)) {
                 case 0: /* equal */
                         goto out;
                 case -1:
-                        rbnode = rbnode->rb_left;
+                        rbnode = &(*rbnode)->rb_left;
                         break;
                 case 1:
-                        rbnode = rbnode->rb_right;
+                        rbnode = &(*rbnode)->rb_right;
                         break;
                 }
         }
+
+        if (parent)
+                *parent = _parent;
+        if (link)
+                *link = rbnode;
+
         obj = NULL;
 out:
         return obj;
 }
 
+
+/* searches for object==oid in pool, returns locked object if found */
+static struct tmem_obj *tmem_obj_find(struct tmem_hashbucket *hb,
+                                        struct tmem_oid *oidp)
+{
+        return __tmem_obj_find(hb, oidp, NULL, NULL);
+}
+
 static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *);
 
 /* free an object that has no more pampds in it */
@@ -131,8 +147,7 @@ static void tmem_obj_init(struct tmem_obj *obj, struct tmem_hashbucket *hb,
                                         struct tmem_oid *oidp)
 {
         struct rb_root *root = &hb->obj_rb_root;
-        struct rb_node **new = &(root->rb_node), *parent = NULL;
-        struct tmem_obj *this;
+        struct rb_node **new = NULL, *parent = NULL;
 
         BUG_ON(pool == NULL);
         atomic_inc(&pool->obj_count);
@@ -144,22 +159,10 @@ static void tmem_obj_init(struct tmem_obj *obj, struct tmem_hashbucket *hb,
         obj->pampd_count = 0;
         (*tmem_pamops.new_obj)(obj);
         SET_SENTINEL(obj, OBJ);
-        while (*new) {
-                BUG_ON(RB_EMPTY_NODE(*new));
-                this = rb_entry(*new, struct tmem_obj, rb_tree_node);
-                parent = *new;
-                switch (tmem_oid_compare(oidp, &this->oid)) {
-                case 0:
-                        BUG(); /* already present; should never happen! */
-                        break;
-                case -1:
-                        new = &(*new)->rb_left;
-                        break;
-                case 1:
-                        new = &(*new)->rb_right;
-                        break;
-                }
-        }
+
+        if (__tmem_obj_find(hb, oidp, &parent, &new))
+                BUG();
+
         rb_link_node(&obj->rb_tree_node, parent, new);
         rb_insert_color(&obj->rb_tree_node, root);
 }