NFS: COPY handle ERR_OFFLOAD_DENIED

If server sends ERR_OFFLOAD_DENIED error, the client must fall
back on doing copy the normal way. Return ENOTSUPP to the vfs and
fallback to regular copy.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>

fs/nfs/nfs42proc.c

@@ -391,7 +391,8 @@ ssize_t nfs42_proc_copy(struct file *src, loff_t pos_src,
 			args.sync = true;
 			dst_exception.retry = 1;
 			continue;
-		} else if (err == -ESTALE &&
+		} else if ((err == -ESTALE ||
+				err == -NFS4ERR_OFFLOAD_DENIED) &&
 				!nfs42_files_from_same_server(src, dst)) {
 			nfs42_do_offload_cancel_async(src, &args.src_stateid);
 			err = -EOPNOTSUPP;