8187443: Forest Consolidation: Move files to unified layout

Reviewed-by: darcy, ihse

src/java.base/linux/classes/sun/nio/fs/LinuxFileStore.java

@@ -0,0 +1,161 @@
+/*
+ * Copyright (c) 2008, 2015, 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
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * 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.
+ */
+
+package sun.nio.fs;
+
+import java.nio.file.attribute.*;
+import java.util.*;
+import java.io.IOException;
+
+/**
+ * Linux implementation of FileStore
+ */
+
+class LinuxFileStore
+    extends UnixFileStore
+{
+    // used when checking if extended attributes are enabled or not
+    private volatile boolean xattrChecked;
+    private volatile boolean xattrEnabled;
+
+    LinuxFileStore(UnixPath file) throws IOException {
+        super(file);
+    }
+
+    LinuxFileStore(UnixFileSystem fs, UnixMountEntry entry) throws IOException {
+        super(fs, entry);
+    }
+
+    /**
+     * Finds, and returns, the mount entry for the file system where the file
+     * resides.
+     */
+    @Override
+    UnixMountEntry findMountEntry() throws IOException {
+        LinuxFileSystem fs = (LinuxFileSystem)file().getFileSystem();
+
+        // step 1: get realpath
+        UnixPath path = null;
+        try {
+            byte[] rp = UnixNativeDispatcher.realpath(file());
+            path = new UnixPath(fs, rp);
+        } catch (UnixException x) {
+            x.rethrowAsIOException(file());
+        }
+
+        // step 2: find mount point
+        UnixPath parent = path.getParent();
+        while (parent != null) {
+            UnixFileAttributes attrs = null;
+            try {
+                attrs = UnixFileAttributes.get(parent, true);
+            } catch (UnixException x) {
+                x.rethrowAsIOException(parent);
+            }
+            if (attrs.dev() != dev())
+                break;
+            path = parent;
+            parent = parent.getParent();
+        }
+
+        // step 3: lookup mounted file systems (use /proc/mounts to ensure we
+        // find the file system even when not in /etc/mtab)
+        byte[] dir = path.asByteArray();
+        for (UnixMountEntry entry: fs.getMountEntries("/proc/mounts")) {
+            if (Arrays.equals(dir, entry.dir()))
+                return entry;
+        }
+
+        throw new IOException("Mount point not found");
+    }
+
+    // returns true if extended attributes enabled on file system where given
+    // file resides, returns false if disabled or unable to determine.
+    private boolean isExtendedAttributesEnabled(UnixPath path) {
+        int fd = -1;
+        try {
+            fd = path.openForAttributeAccess(false);
+
+            // fgetxattr returns size if called with size==0
+            byte[] name = Util.toBytes("user.java");
+            LinuxNativeDispatcher.fgetxattr(fd, name, 0L, 0);
+            return true;
+        } catch (UnixException e) {
+            // attribute does not exist
+            if (e.errno() == UnixConstants.ENODATA)
+                return true;
+        } finally {
+            UnixNativeDispatcher.close(fd);
+        }
+        return false;
+    }
+
+    @Override
+    public boolean supportsFileAttributeView(Class<? extends FileAttributeView> type) {
+        // support DosFileAttributeView and UserDefinedAttributeView if extended
+        // attributes enabled
+        if (type == DosFileAttributeView.class ||
+            type == UserDefinedFileAttributeView.class)
+        {
+            // lookup fstypes.properties
+            FeatureStatus status = checkIfFeaturePresent("user_xattr");
+            if (status == FeatureStatus.PRESENT)
+                return true;
+            if (status == FeatureStatus.NOT_PRESENT)
+                return false;
+
+            // if file system is mounted with user_xattr option then assume
+            // extended attributes are enabled
+            if ((entry().hasOption("user_xattr")))
+                return true;
+
+            // user_xattr option not present but we special-case ext3/4 as we
+            // know that extended attributes are not enabled by default.
+            if (entry().fstype().equals("ext3") || entry().fstype().equals("ext4"))
+                return false;
+
+            // not ext3/4 so probe mount point
+            if (!xattrChecked) {
+                UnixPath dir = new UnixPath(file().getFileSystem(), entry().dir());
+                xattrEnabled = isExtendedAttributesEnabled(dir);
+                xattrChecked = true;
+            }
+            return xattrEnabled;
+        }
+        // POSIX attributes not supported on FAT
+        if (type == PosixFileAttributeView.class && entry().fstype().equals("vfat"))
+            return false;
+        return super.supportsFileAttributeView(type);
+    }
+
+    @Override
+    public boolean supportsFileAttributeView(String name) {
+        if (name.equals("dos"))
+            return supportsFileAttributeView(DosFileAttributeView.class);
+        if (name.equals("user"))
+            return supportsFileAttributeView(UserDefinedFileAttributeView.class);
+        return super.supportsFileAttributeView(name);
+    }
+}