cmd,rawdb: avoid extend Tail method in chainfreezer which make db ins…

…pect failed in chain freezer (#627)

core/rawdb/ancient_utils.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/log"
 )
 
 type tableSize struct {
@@ -89,6 +90,10 @@ func inspectFreezers(db ethdb.Database) ([]freezerInfo, error) {
 			infos = append(infos, info)
 
 		case stateFreezerName:
+			if ReadStateScheme(db) != PathScheme {
+				log.Info("Skip inspecting state freezer", "reason", "state freezer is supported for PathScheme only")
+				continue
+			}
 			datadir, err := db.AncientDatadir()
 			if err != nil {
 				return nil, err

core/rawdb/chain_freezer.go

@@ -73,11 +73,6 @@ func (f *chainFreezer) Close() error {
 	return err
 }
 
-// Tail returns an error as we don't have a backing chain freezer.
-func (f *chainFreezer) Tail() (uint64, error) {
-	return 0, errNotSupported
-}
-
 // freeze is a background thread that periodically checks the blockchain for any
 // import progress and moves ancient data from the fast database into the freezer.
 //