remove mapstructure from blockstorage,cdn,compute,db pkgs
diff --git a/openstack/compute/v2/extensions/diskconfig/results.go b/openstack/compute/v2/extensions/diskconfig/results.go
index b05c5b5..1957e12 100644
--- a/openstack/compute/v2/extensions/diskconfig/results.go
+++ b/openstack/compute/v2/extensions/diskconfig/results.go
@@ -1,60 +1,8 @@
 package diskconfig
 
-import (
-	"github.com/mitchellh/mapstructure"
-	"github.com/gophercloud/gophercloud"
-	"github.com/gophercloud/gophercloud/openstack/compute/v2/servers"
-	"github.com/gophercloud/gophercloud/pagination"
-)
+import "github.com/gophercloud/gophercloud/openstack/compute/v2/servers"
 
-func commonExtract(result gophercloud.Result) (*DiskConfig, error) {
-	var resp struct {
-		Server struct {
-			DiskConfig string `mapstructure:"OS-DCF:diskConfig"`
-		} `mapstructure:"server"`
-	}
-
-	err := mapstructure.Decode(result.Body, &resp)
-	if err != nil {
-		return nil, err
-	}
-
-	config := DiskConfig(resp.Server.DiskConfig)
-	return &config, nil
-}
-
-// ExtractGet returns the disk configuration from a servers.Get call.
-func ExtractGet(result servers.GetResult) (*DiskConfig, error) {
-	return commonExtract(result.Result)
-}
-
-// ExtractUpdate returns the disk configuration from a servers.Update call.
-func ExtractUpdate(result servers.UpdateResult) (*DiskConfig, error) {
-	return commonExtract(result.Result)
-}
-
-// ExtractRebuild returns the disk configuration from a servers.Rebuild call.
-func ExtractRebuild(result servers.RebuildResult) (*DiskConfig, error) {
-	return commonExtract(result.Result)
-}
-
-// ExtractDiskConfig returns the DiskConfig setting for a specific server acquired from an
-// servers.ExtractServers call, while iterating through a Pager.
-func ExtractDiskConfig(page pagination.Page, index int) (*DiskConfig, error) {
-	casted := page.(servers.ServerPage).Body
-
-	type server struct {
-		DiskConfig string `mapstructure:"OS-DCF:diskConfig"`
-	}
-	var response struct {
-		Servers []server `mapstructure:"servers"`
-	}
-
-	err := mapstructure.Decode(casted, &response)
-	if err != nil {
-		return nil, err
-	}
-
-	config := DiskConfig(response.Servers[index].DiskConfig)
-	return &config, nil
+type ServerWithDiskConfig struct {
+	servers.Server
+	DiskConfig DiskConfig `json:"OS-DCF:diskConfig"`
 }