src/solaris/native/sun/nio/ch/FileDispatcherImpl.c

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this

@@ -21,10 +21,14 @@
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 
+#if defined(__linux__)
+#define _FILE_OFFSET_BITS 64
+#endif
+
 #include "jni.h"
 #include "jni_util.h"
 #include "jvm.h"
 #include "jlong.h"
 #include "sun_nio_ch_FileDispatcherImpl.h"

@@ -176,10 +180,34 @@
     return handle(env,
                   ftruncate64(fdval(env, fdo), size),
                   "Truncation failed");
 }
 
+JNIEXPORT jint JNICALL
+Java_sun_nio_ch_FileDispatcherImpl_allocate0(JNIEnv *env, jobject this,
+                                             jobject fdo, jlong size)
+{
+#if defined(__linux__)
+    /*
+     * On Linux, if the file size is being increased, then ftruncate64()
+     * will modify the metadata value of the size without actually allocating
+     * any blocks which can cause a SIGBUS error if the file is subsequently
+     * memory-mapped.
+     */
+    // Return on success or if errno is neither EOPNOTSUPP nor ENOSYS
+    int result = posix_fallocate(fdval(env, fdo), 0, size);
+    if (result == 0) {
+        return 0;
+    } else if (errno != EOPNOTSUPP && errno != ENOSYS) {
+        return handle(env, result, "Allocation failed");
+    }
+#endif
+    return handle(env,
+                  ftruncate64(fdval(env, fdo), size),
+                  "Truncation failed");
+}
+
 JNIEXPORT jlong JNICALL
 Java_sun_nio_ch_FileDispatcherImpl_size0(JNIEnv *env, jobject this, jobject fdo)
 {
     jint fd = fdval(env, fdo);
     struct stat64 fbuf;