nfs: drop support v0 file handles

Motivation:
as the initial nfs file handles didn't include schema version, the
FileHandle class was adopted to decode unversioned handles. The
workaround was introduced to avoid client reboot on server update.
That was in 2012...

Modification:
Drop support for v0 file handle decoding as it not needed anymore.

Result:
Less dead code.

Acked-by: Karen Hoyos
Target: master

Author: kofemann

core/src/main/java/org/dcache/nfs/vfs/FileHandle.java

@@ -1,4 +1,7 @@
 /*
+ * Copyright (c) 2012 - 2025 Deutsches Elektronen-Synchroton,
+ * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY
+ *
  * This library is free software; you can redistribute it and/or modify
  * it under the terms of the GNU Library General Public License as
  * published by the Free Software Foundation; either version 2 of the
@@ -40,8 +43,6 @@ public class FileHandle {
     private final static int VERSION = 1;
     private final static int MAGIC = 0xCAFFEE;
     private final static byte[] EMPTY_FH = new byte[0];
-    private final static byte[] FH_V0_REG = new byte[] {0x30, 0x3a};
-    private final static byte[] FH_V0_PFS = new byte[] {0x32, 0x35, 0x35, 0x3a};
 
     private final int version;
     private final int magic;
@@ -69,43 +70,22 @@ public FileHandle(byte[] bytes) {
 
         int magic_version = b.getInt();
         int geussVersion = (magic_version & 0xFF000000) >>> 24;
-        if (geussVersion == VERSION) {
-            version = geussVersion;
-            magic = magic_version & 0x00FFFFFF;
-            if (magic != MAGIC) {
-                throw new IllegalArgumentException("Bad magic number");
-            }
-
-            generation = b.getInt();
-            exportIdx = b.getInt();
-            type = (int) b.get();
-            int olen = (int) b.get();
-            fs_opaque = new byte[olen];
-            b.get(fs_opaque);
-
-        } else if (arrayEquals(bytes, FH_V0_REG, FH_V0_REG.length)
-                || arrayEquals(bytes, FH_V0_PFS, FH_V0_PFS.length)) {
-            magic = MAGIC;
-            generation = 0;
-            type = bytes[1] == FH_V0_REG[1] ? 0 : 1;
-            if (type == 1) {
-                /*
-                 * convert pseudo inode into real one: '255:' => '0:' NOTICE: the converted handle will present himself
-                 * as version 1
-                 */
-                version = 1;
-                exportIdx = 0;
-                fs_opaque = new byte[bytes.length - 2];
-                System.arraycopy(bytes, 2, fs_opaque, 0, fs_opaque.length);
-                fs_opaque[0] = 0x30;
-            } else {
-                version = 0;
-                exportIdx = -1;
-                fs_opaque = bytes;
-            }
-        } else {
+        if (geussVersion != VERSION) {
             throw new IllegalArgumentException("Unsupported version: " + geussVersion);
         }
+
+        version = geussVersion;
+        magic = magic_version & 0x00FFFFFF;
+        if (magic != MAGIC) {
+            throw new IllegalArgumentException("Bad magic number");
+        }
+
+        generation = b.getInt();
+        exportIdx = b.getInt();
+        type = (int) b.get();
+        int olen = (int) b.get();
+        fs_opaque = new byte[olen];
+        b.get(fs_opaque);
     }
 
     public int getVersion() {
@@ -152,17 +132,6 @@ public String toString() {
         return BaseEncoding.base16().lowerCase().encode(this.bytes());
     }
 
-    private static boolean arrayEquals(byte[] a1, byte[] a2, int len) {
-        if (a1.length < len || a2.length < len)
-            return false;
-        for (int i = 0; i < len; i++) {
-            if (a1[i] != a2[i]) {
-                return false;
-            }
-        }
-        return true;
-    }
-
     public static class FileHandleBuilder {
         private int version = VERSION;
         private int magic = MAGIC;

core/src/test/java/org/dcache/nfs/vfs/FileHandleTest.java

@@ -76,37 +76,4 @@ public void testBuilder() {
                 "01caffee00000000ea15b996002e303a494e4f44453a3030303043333732333331373433393234353645423833453434383434453844323844363a30"),
                 fh.bytes());
     }
-
-    @Test
-    public void testValidHandleV0Regular() {
-        String oldId = "0:INODE:0000C37233174392456EB83E44844E8D28D6:0";
-
-        byte[] bytes = oldId.getBytes(US_ASCII);
-        FileHandle fh = new FileHandle(bytes);
-
-        assertEquals(0, fh.getVersion());
-        assertEquals(0xCAFFEE, fh.getMagic());
-        assertEquals(0, fh.getGeneration());
-        byte[] opaque = fh.getFsOpaque();
-        assertEquals(-1, fh.getExportIdx());
-        assertEquals(0, fh.getType());
-        assertEquals(oldId, new String(opaque, US_ASCII));
-    }
-
-    @Test
-    public void testValidHandleV0Pseudo() {
-        String oldIdPseudo = "255:INODE:0000C37233174392456EB83E44844E8D28D6:0";
-        String oldIdReg = "0:INODE:0000C37233174392456EB83E44844E8D28D6:0";
-
-        byte[] bytes = oldIdPseudo.getBytes(US_ASCII);
-        FileHandle fh = new FileHandle(bytes);
-
-        assertEquals(1, fh.getVersion());
-        assertEquals(0xCAFFEE, fh.getMagic());
-        assertEquals(0, fh.getGeneration());
-        byte[] opaque = fh.getFsOpaque();
-        assertEquals(0, fh.getExportIdx());
-        assertEquals(1, fh.getType());
-        assertEquals(oldIdReg, new String(opaque, US_ASCII));
-    }
 }