nfsv42: initial support for intra-server copy

Motivation:
the newer libc make use of copy_file_range function, that directly
mapped to NFSv4.2 COPY request.

Modification:
Add initial implementation on OperationCOPY that synchronously copies
the data between two open files.

Result:
initial step to support intra-server copy.

Acked-by: Paul Millar
Target: master

core/src/main/java/org/dcache/nfs/v4/MDSOperationExecutor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009 - 2020 Deutsches Elektronen-Synchroton,
+ * Copyright (c) 2009 - 2021 Deutsches Elektronen-Synchroton,
  * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY
  *
  * This library is free software; you can redistribute it and/or modify
@@ -159,8 +159,9 @@ protected AbstractNFSv4Operation getOperation(nfs_argop4 op) {
                 return new OperationLISTXATTRS(op);
             case nfs_opnum4.OP_REMOVEXATTR:
                 return new OperationREMOVEXATTR(op);
-            case nfs_opnum4.OP_ALLOCATE:
             case nfs_opnum4.OP_COPY:
+                return new OperationCOPY(op);
+            case nfs_opnum4.OP_ALLOCATE:
             case nfs_opnum4.OP_COPY_NOTIFY:
             case nfs_opnum4.OP_DEALLOCATE:
             case nfs_opnum4.OP_IO_ADVISE:

core/src/main/java/org/dcache/nfs/v4/OperationCOPY.java

@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2021 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
+ * License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this program (see the file COPYING.LIB for more
+ * details); if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+package org.dcache.nfs.v4;
+
+import java.io.IOException;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+
+import com.google.common.annotations.Beta;
+import com.google.common.util.concurrent.Uninterruptibles;
+import org.dcache.nfs.ChimeraNFSException;
+import org.dcache.nfs.nfsstat;
+import org.dcache.nfs.status.NotSuppException;
+import org.dcache.nfs.status.OpenModeException;
+import org.dcache.nfs.v4.xdr.COPY4res;
+import org.dcache.nfs.v4.xdr.COPY4resok;
+import org.dcache.nfs.v4.xdr.copy_requirements4;
+import org.dcache.nfs.v4.xdr.length4;
+import org.dcache.nfs.v4.xdr.nfs4_prot;
+import org.dcache.nfs.v4.xdr.nfs_argop4;
+import org.dcache.nfs.v4.xdr.nfs_opnum4;
+import org.dcache.nfs.v4.xdr.nfs_resop4;
+import org.dcache.nfs.v4.xdr.stable_how4;
+import org.dcache.nfs.v4.xdr.stateid4;
+import org.dcache.nfs.v4.xdr.write_response4;
+import org.dcache.nfs.vfs.Inode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Beta
+/**
+ * NFSv4.2 operations that handles server side copy as specified in rfc7862#section-4.
+ */
+public class OperationCOPY extends AbstractNFSv4Operation {
+
+    private final static Logger LOGGER = LoggerFactory.getLogger(OperationCOPY.class);
+
+    public OperationCOPY(nfs_argop4 args) {
+        super(args, nfs_opnum4.OP_COPY);
+    }
+
+    @Override
+    public void process(CompoundContext context, nfs_resop4 result) throws ChimeraNFSException, IOException {
+
+        final COPY4res res =  result.opcopy;
+
+        // inter server copy is not supported
+        if (_args.opcopy.ca_source_server.length > 0) {
+            throw new NotSuppException("Inter-server copy is not supported");
+        }
+
+        // only synchronous mode is supported (for now)
+        if (!_args.opcopy.ca_consecutive || !_args.opcopy.ca_synchronous) {
+            throw new NotSuppException();
+        }
+
+        Inode srcInode = context.savedInode();
+        Inode dstInode = context.currentInode();
+
+        long srcPos = _args.opcopy.ca_src_offset.value;
+        long dstPos = _args.opcopy.ca_dst_offset.value;
+        long len = _args.opcopy.ca_count.value;
+
+        NFS4Client client = context.getSession().getClient();
+
+        int srcAccess = context.getStateHandler().getFileTracker().getShareAccess(client, srcInode, _args.opcopy.ca_src_stateid);
+        int dstAccess = context.getStateHandler().getFileTracker().getShareAccess(client, dstInode, _args.opcopy.ca_dst_stateid);
+
+        if ((srcAccess & nfs4_prot.OPEN4_SHARE_ACCESS_READ) == 0) {
+            throw new OpenModeException("Invalid source inode open mode (required read)");
+        }
+
+        if ((dstAccess & nfs4_prot.OPEN4_SHARE_ACCESS_WRITE) == 0) {
+            throw new OpenModeException("Invalid destination inode open mode (required write)");
+        }
+
+        Future<Long> copyFuture = context.getFs().copyFileRange(srcInode, srcPos, dstInode, dstPos, len);
+
+        try {
+            long n = Uninterruptibles.getUninterruptibly(copyFuture);
+
+            res.cr_resok4 = new COPY4resok();
+            res.cr_resok4.cr_response = new write_response4();
+            res.cr_resok4.cr_response.wr_callback_id = new stateid4[0];
+            res.cr_resok4.cr_response.wr_committed = stable_how4.FILE_SYNC4;
+            res.cr_resok4.cr_response.wr_count = new length4(n);
+            res.cr_resok4.cr_response.wr_writeverf = context.getRebootVerifier();
+
+            res.cr_resok4.cr_requirements = new copy_requirements4();
+            res.cr_resok4.cr_requirements.cr_consecutive = true;
+            res.cr_resok4.cr_requirements.cr_synchronous = true;
+
+            res.cr_status = nfsstat.NFS_OK;
+        } catch (ExecutionException e) {
+            Throwable cause = e.getCause();
+            if (cause instanceof ChimeraNFSException) {
+                res.cr_status = ((ChimeraNFSException) cause).getStatus();
+            } else {
+                LOGGER.warn("Unexpected error during copyFileRange", e);
+                res.cr_status = nfsstat.NFSERR_IO;
+            }
+        }
+    }
+}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009 - 2020 Deutsches Elektronen-Synchroton,
+ * Copyright (c) 2009 - 2021 Deutsches Elektronen-Synchroton,
  * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY
  *
  * This library is free software; you can redistribute it and/or modify
@@ -21,6 +21,7 @@
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.util.concurrent.CompletableFuture;
 import javax.security.auth.Subject;
 import org.dcache.nfs.v4.NfsIdMapping;
 import org.dcache.nfs.v4.xdr.nfsace4;
@@ -200,4 +201,9 @@ public String[] listXattrs(Inode inode) throws IOException {
     public void removeXattr(Inode inode, String attr) throws IOException {
         delegate().removeXattr(inode, attr);
     }
+
+    @Override
+    public CompletableFuture<Long> copyFileRange(Inode src, long srcPos, Inode dst, long dstPos, long len) {
+        return delegate().copyFileRange(src, srcPos, dst, dstPos, len);
+    }
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009 - 2020 Deutsches Elektronen-Synchroton,
+ * Copyright (c) 2009 - 2021 Deutsches Elektronen-Synchroton,
  * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY
  *
  * This library is free software; you can redistribute it and/or modify
@@ -21,7 +21,10 @@
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.util.concurrent.CompletableFuture;
 import javax.security.auth.Subject;
+
+import com.google.common.annotations.Beta;
 import org.dcache.nfs.status.NotSuppException;
 import org.dcache.nfs.v4.NfsIdMapping;
 import org.dcache.nfs.v4.xdr.nfsace4;
@@ -501,4 +504,20 @@ default void removeXattr(Inode inode, String attr) throws IOException {
         throw new NotSuppException();
     }
 
+    /**
+     * Performs an in-filesystem copy between two open files. The result of the successfully completed {@link CompletableFuture}
+     * corresponds to the number of copied bytes. If {@code copyFileRange} operation fails, the returned CompletableFuture
+     * with complete exceptionally with corresponding error.
+     * @param src inode of the source file.
+     * @param srcPos starting position in the source file.
+     * @param dst inode of the destination file.
+     * @param dstPos starting position in the destination file.
+     * @param len number of bytes to copy.
+     * @return a {@link CompletableFuture} representing pending completion of the copy request
+     * @since 0.23
+     */
+    @Beta
+    default CompletableFuture<Long> copyFileRange(Inode src, long srcPos, Inode dst, long dstPos, long len) {
+        return CompletableFuture.failedFuture(new NotSuppException());
+    }
 }