RDMA/uverbs: Factor out the add/get pattern into a helper

The next patch needs another copy of this, provide a simple helper to
reduce the coding. uapi_add_get_elm() returns an existing entry or adds a
new one.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

diff --git a/drivers/infiniband/core/uverbs_uapi.c b/drivers/infiniband/core/uverbs_uapi.c
index 67e8e96..cb35f18 100644 (file)
--- a/drivers/infiniband/core/uverbs_uapi.c
+++ b/drivers/infiniband/core/uverbs_uapi.c
@@ -26,6 +26,27 @@ static void *uapi_add_elm(struct uverbs_api *uapi, u32 key, size_t alloc_size)
        return elm;
 }
 
+static void *uapi_add_get_elm(struct uverbs_api *uapi, u32 key,
+                             size_t alloc_size, bool *exists)
+{
+       void *elm;
+
+       elm = uapi_add_elm(uapi, key, alloc_size);
+       if (!IS_ERR(elm)) {
+               *exists = false;
+               return elm;
+       }
+
+       if (elm != ERR_PTR(-EEXIST))
+               return elm;
+
+       elm = radix_tree_lookup(&uapi->radix, key);
+       if (WARN_ON(!elm))
+               return ERR_PTR(-EINVAL);
+       *exists = true;
+       return elm;
+}
+
 static int uapi_merge_method(struct uverbs_api *uapi,
                             struct uverbs_api_object *obj_elm, u32 obj_key,
                             const struct uverbs_method_def *method,
@@ -34,23 +55,21 @@ static int uapi_merge_method(struct uverbs_api *uapi,
        u32 method_key = obj_key | uapi_key_ioctl_method(method->id);
        struct uverbs_api_ioctl_method *method_elm;
        unsigned int i;
+       bool exists;
 
        if (!method->attrs)
                return 0;
 
-       method_elm = uapi_add_elm(uapi, method_key, sizeof(*method_elm));
-       if (IS_ERR(method_elm)) {
-               if (method_elm != ERR_PTR(-EEXIST))
-                       return PTR_ERR(method_elm);
-
+       method_elm = uapi_add_get_elm(uapi, method_key, sizeof(*method_elm),
+                                     &exists);
+       if (IS_ERR(method_elm))
+               return PTR_ERR(method_elm);
+       if (exists) {
                /*
                 * This occurs when a driver uses ADD_UVERBS_ATTRIBUTES_SIMPLE
                 */
                if (WARN_ON(method->handler))
                        return -EINVAL;
-               method_elm = radix_tree_lookup(&uapi->radix, method_key);
-               if (WARN_ON(!method_elm))
-                       return -EINVAL;
        } else {
                WARN_ON(!method->handler);
                rcu_assign_pointer(method_elm->handler, method->handler);
@@ -105,34 +124,29 @@ static int uapi_merge_obj_tree(struct uverbs_api *uapi,
        struct uverbs_api_object *obj_elm;
        unsigned int i;
        u32 obj_key;
+       bool exists;
        int rc;
 
        obj_key = uapi_key_obj(obj->id);
-       obj_elm = uapi_add_elm(uapi, obj_key, sizeof(*obj_elm));
-       if (IS_ERR(obj_elm)) {
-               if (obj_elm != ERR_PTR(-EEXIST))
-                       return PTR_ERR(obj_elm);
+       obj_elm = uapi_add_get_elm(uapi, obj_key, sizeof(*obj_elm), &exists);
+       if (IS_ERR(obj_elm))
+               return PTR_ERR(obj_elm);
 
-               /* This occurs when a driver uses ADD_UVERBS_METHODS */
-               if (WARN_ON(obj->type_attrs))
+       if (obj->type_attrs) {
+               if (WARN_ON(obj_elm->type_attrs))
                        return -EINVAL;
-               obj_elm = radix_tree_lookup(&uapi->radix, obj_key);
-               if (WARN_ON(!obj_elm))
-                       return -EINVAL;
-       } else {
+
                obj_elm->type_attrs = obj->type_attrs;
-               if (obj->type_attrs) {
-                       obj_elm->type_class = obj->type_attrs->type_class;
-                       /*
-                        * Today drivers are only permitted to use idr_class
-                        * types. They cannot use FD types because we
-                        * currently have no way to revoke the fops pointer
-                        * after device disassociation.
-                        */
-                       if (WARN_ON(is_driver && obj->type_attrs->type_class !=
-                                                        &uverbs_idr_class))
-                               return -EINVAL;
-               }
+               obj_elm->type_class = obj->type_attrs->type_class;
+               /*
+                * Today drivers are only permitted to use idr_class
+                * types. They cannot use FD types because we currently have
+                * no way to revoke the fops pointer after device
+                * disassociation.
+                */
+               if (WARN_ON(is_driver &&
+                           obj->type_attrs->type_class != &uverbs_idr_class))
+                       return -EINVAL;
        }
 
        if (!obj->methods)