diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/java.base/linux/classes/sun/nio/fs/LinuxFileStore.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/java.base/linux/classes/sun/nio/fs/LinuxFileStore.java Tue Sep 12 19:03:39 2017 +0200 @@ -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 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); + } +}