| /* |
| * Copyright (C) 2010, Robin Rosenberg |
| * and other copyright owners as documented in the project's IP log. |
| * |
| * This program and the accompanying materials are made available |
| * under the terms of the Eclipse Distribution License v1.0 which |
| * accompanies this distribution, is reproduced below, and is |
| * available at http://www.eclipse.org/org/documents/edl-v10.php |
| * |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or |
| * without modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * - Neither the name of the Eclipse Foundation, Inc. nor the |
| * names of its contributors may be used to endorse or promote |
| * products derived from this software without specific prior |
| * written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
| * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| package org.eclipse.jgit.util; |
| |
| import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_CORE_SECTION; |
| import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_KEY_SUPPORTSATOMICFILECREATION; |
| |
| import java.io.BufferedReader; |
| import java.io.File; |
| import java.io.IOException; |
| import java.io.InputStreamReader; |
| import java.io.PrintStream; |
| import java.nio.charset.Charset; |
| import java.nio.file.FileAlreadyExistsException; |
| import java.nio.file.FileStore; |
| import java.nio.file.FileSystemException; |
| import java.nio.file.Files; |
| import java.nio.file.InvalidPathException; |
| import java.nio.file.Path; |
| import java.nio.file.Paths; |
| import java.nio.file.attribute.PosixFilePermission; |
| import java.text.MessageFormat; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Optional; |
| import java.util.Set; |
| import java.util.UUID; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| import org.eclipse.jgit.annotations.Nullable; |
| import org.eclipse.jgit.api.errors.JGitInternalException; |
| import org.eclipse.jgit.errors.CommandFailedException; |
| import org.eclipse.jgit.errors.ConfigInvalidException; |
| import org.eclipse.jgit.internal.JGitText; |
| import org.eclipse.jgit.lib.Constants; |
| import org.eclipse.jgit.lib.Repository; |
| import org.eclipse.jgit.lib.StoredConfig; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Base FS for POSIX based systems |
| * |
| * @since 3.0 |
| */ |
| public class FS_POSIX extends FS { |
| private final static Logger LOG = LoggerFactory.getLogger(FS_POSIX.class); |
| |
| private static final int DEFAULT_UMASK = 0022; |
| private volatile int umask = -1; |
| |
| private static final Map<FileStore, Boolean> CAN_HARD_LINK = new ConcurrentHashMap<>(); |
| |
| private volatile AtomicFileCreation supportsAtomicFileCreation = AtomicFileCreation.UNDEFINED; |
| |
| private enum AtomicFileCreation { |
| SUPPORTED, NOT_SUPPORTED, UNDEFINED |
| } |
| |
| /** |
| * Default constructor. |
| */ |
| protected FS_POSIX() { |
| } |
| |
| /** |
| * Constructor |
| * |
| * @param src |
| * FS to copy some settings from |
| */ |
| protected FS_POSIX(FS src) { |
| super(src); |
| if (src instanceof FS_POSIX) { |
| umask = ((FS_POSIX) src).umask; |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public FS newInstance() { |
| return new FS_POSIX(this); |
| } |
| |
| /** |
| * Set the umask, overriding any value observed from the shell. |
| * |
| * @param umask |
| * mask to apply when creating files. |
| * @since 4.0 |
| */ |
| public void setUmask(int umask) { |
| this.umask = umask; |
| } |
| |
| private int umask() { |
| int u = umask; |
| if (u == -1) { |
| u = readUmask(); |
| umask = u; |
| } |
| return u; |
| } |
| |
| /** @return mask returned from running {@code umask} command in shell. */ |
| private static int readUmask() { |
| try { |
| Process p = Runtime.getRuntime().exec( |
| new String[] { "sh", "-c", "umask" }, //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ |
| null, null); |
| try (BufferedReader lineRead = new BufferedReader( |
| new InputStreamReader(p.getInputStream(), Charset |
| .defaultCharset().name()))) { |
| if (p.waitFor() == 0) { |
| String s = lineRead.readLine(); |
| if (s != null && s.matches("0?\\d{3}")) { //$NON-NLS-1$ |
| return Integer.parseInt(s, 8); |
| } |
| } |
| return DEFAULT_UMASK; |
| } |
| } catch (Exception e) { |
| return DEFAULT_UMASK; |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected File discoverGitExe() { |
| String path = SystemReader.getInstance().getenv("PATH"); //$NON-NLS-1$ |
| File gitExe = searchPath(path, "git"); //$NON-NLS-1$ |
| |
| if (gitExe == null) { |
| if (SystemReader.getInstance().isMacOS()) { |
| if (searchPath(path, "bash") != null) { //$NON-NLS-1$ |
| // On MacOSX, PATH is shorter when Eclipse is launched from the |
| // Finder than from a terminal. Therefore try to launch bash as a |
| // login shell and search using that. |
| String w; |
| try { |
| w = readPipe(userHome(), |
| new String[]{"bash", "--login", "-c", "which git"}, // //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ |
| Charset.defaultCharset().name()); |
| } catch (CommandFailedException e) { |
| LOG.warn(e.getMessage()); |
| return null; |
| } |
| if (!StringUtils.isEmptyOrNull(w)) { |
| gitExe = new File(w); |
| } |
| } |
| } |
| } |
| |
| return gitExe; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean isCaseSensitive() { |
| return !SystemReader.getInstance().isMacOS(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean supportsExecute() { |
| return true; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean canExecute(File f) { |
| return FileUtils.canExecute(f); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean setExecute(File f, boolean canExecute) { |
| if (!isFile(f)) |
| return false; |
| if (!canExecute) |
| return f.setExecutable(false, false); |
| |
| try { |
| Path path = FileUtils.toPath(f); |
| Set<PosixFilePermission> pset = Files.getPosixFilePermissions(path); |
| |
| // owner (user) is always allowed to execute. |
| pset.add(PosixFilePermission.OWNER_EXECUTE); |
| |
| int mask = umask(); |
| apply(pset, mask, PosixFilePermission.GROUP_EXECUTE, 1 << 3); |
| apply(pset, mask, PosixFilePermission.OTHERS_EXECUTE, 1); |
| Files.setPosixFilePermissions(path, pset); |
| return true; |
| } catch (IOException e) { |
| // The interface doesn't allow to throw IOException |
| final boolean debug = Boolean.parseBoolean(SystemReader |
| .getInstance().getProperty("jgit.fs.debug")); //$NON-NLS-1$ |
| if (debug) |
| System.err.println(e); |
| return false; |
| } |
| } |
| |
| private static void apply(Set<PosixFilePermission> set, |
| int umask, PosixFilePermission perm, int test) { |
| if ((umask & test) == 0) { |
| // If bit is clear in umask, permission is allowed. |
| set.add(perm); |
| } else { |
| // If bit is set in umask, permission is denied. |
| set.remove(perm); |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public ProcessBuilder runInShell(String cmd, String[] args) { |
| List<String> argv = new ArrayList<>(4 + args.length); |
| argv.add("sh"); //$NON-NLS-1$ |
| argv.add("-c"); //$NON-NLS-1$ |
| argv.add(cmd + " \"$@\""); //$NON-NLS-1$ |
| argv.add(cmd); |
| argv.addAll(Arrays.asList(args)); |
| ProcessBuilder proc = new ProcessBuilder(); |
| proc.command(argv); |
| return proc; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public ProcessResult runHookIfPresent(Repository repository, String hookName, |
| String[] args, PrintStream outRedirect, PrintStream errRedirect, |
| String stdinArgs) throws JGitInternalException { |
| return internalRunHookIfPresent(repository, hookName, args, outRedirect, |
| errRedirect, stdinArgs); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean retryFailedLockFileCommit() { |
| return false; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean supportsSymlinks() { |
| return true; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void setHidden(File path, boolean hidden) throws IOException { |
| // no action on POSIX |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public Attributes getAttributes(File path) { |
| return FileUtils.getFileAttributesPosix(this, path); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public File normalize(File file) { |
| return FileUtils.normalize(file); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public String normalize(String name) { |
| return FileUtils.normalize(name); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public File findHook(Repository repository, String hookName) { |
| final File gitdir = repository.getDirectory(); |
| if (gitdir == null) { |
| return null; |
| } |
| final Path hookPath = gitdir.toPath().resolve(Constants.HOOKS) |
| .resolve(hookName); |
| if (Files.isExecutable(hookPath)) |
| return hookPath.toFile(); |
| return null; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean supportsAtomicCreateNewFile() { |
| if (supportsAtomicFileCreation == AtomicFileCreation.UNDEFINED) { |
| try { |
| StoredConfig config = SystemReader.getInstance().getUserConfig(); |
| String value = config.getString(CONFIG_CORE_SECTION, null, |
| CONFIG_KEY_SUPPORTSATOMICFILECREATION); |
| if (value != null) { |
| supportsAtomicFileCreation = StringUtils.toBoolean(value) |
| ? AtomicFileCreation.SUPPORTED |
| : AtomicFileCreation.NOT_SUPPORTED; |
| } else { |
| supportsAtomicFileCreation = AtomicFileCreation.SUPPORTED; |
| } |
| } catch (IOException | ConfigInvalidException e) { |
| LOG.warn(JGitText.get().assumeAtomicCreateNewFile, e); |
| supportsAtomicFileCreation = AtomicFileCreation.SUPPORTED; |
| } |
| } |
| return supportsAtomicFileCreation == AtomicFileCreation.SUPPORTED; |
| } |
| |
| @Override |
| @SuppressWarnings("boxing") |
| /** |
| * {@inheritDoc} |
| * <p> |
| * An implementation of the File#createNewFile() semantics which works also |
| * on NFS. If the config option |
| * {@code core.supportsAtomicCreateNewFile = true} (which is the default) |
| * then simply File#createNewFile() is called. |
| * |
| * But if {@code core.supportsAtomicCreateNewFile = false} then after |
| * successful creation of the lock file a hard link to that lock file is |
| * created and the attribute nlink of the lock file is checked to be 2. If |
| * multiple clients manage to create the same lock file nlink would be |
| * greater than 2 showing the error. |
| * |
| * @see "https://www.time-travellers.org/shane/papers/NFS_considered_harmful.html" |
| * |
| * @deprecated use {@link FS_POSIX#createNewFileAtomic(File)} instead |
| * @since 4.5 |
| */ |
| @Deprecated |
| public boolean createNewFile(File lock) throws IOException { |
| if (!lock.createNewFile()) { |
| return false; |
| } |
| if (supportsAtomicCreateNewFile()) { |
| return true; |
| } |
| Path lockPath = lock.toPath(); |
| Path link = null; |
| FileStore store = null; |
| try { |
| store = Files.getFileStore(lockPath); |
| } catch (SecurityException e) { |
| return true; |
| } |
| try { |
| Boolean canLink = CAN_HARD_LINK.computeIfAbsent(store, |
| s -> Boolean.TRUE); |
| if (Boolean.FALSE.equals(canLink)) { |
| return true; |
| } |
| link = Files.createLink( |
| Paths.get(lock.getAbsolutePath() + ".lnk"), //$NON-NLS-1$ |
| lockPath); |
| Integer nlink = (Integer) (Files.getAttribute(lockPath, |
| "unix:nlink")); //$NON-NLS-1$ |
| if (nlink > 2) { |
| LOG.warn(MessageFormat.format( |
| JGitText.get().failedAtomicFileCreation, lockPath, |
| nlink)); |
| return false; |
| } else if (nlink < 2) { |
| CAN_HARD_LINK.put(store, Boolean.FALSE); |
| } |
| return true; |
| } catch (UnsupportedOperationException | IllegalArgumentException e) { |
| CAN_HARD_LINK.put(store, Boolean.FALSE); |
| return true; |
| } finally { |
| if (link != null) { |
| Files.delete(link); |
| } |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| * <p> |
| * An implementation of the File#createNewFile() semantics which can create |
| * a unique file atomically also on NFS. If the config option |
| * {@code core.supportsAtomicCreateNewFile = true} (which is the default) |
| * then simply Files#createFile() is called. |
| * |
| * But if {@code core.supportsAtomicCreateNewFile = false} then after |
| * successful creation of the lock file a hard link to that lock file is |
| * created and the attribute nlink of the lock file is checked to be 2. If |
| * multiple clients manage to create the same lock file nlink would be |
| * greater than 2 showing the error. The hard link needs to be retained |
| * until the corresponding file is no longer needed in order to prevent that |
| * another process can create the same file concurrently using another NFS |
| * client which might not yet see the file due to caching. |
| * |
| * @see "https://www.time-travellers.org/shane/papers/NFS_considered_harmful.html" |
| * @param file |
| * the unique file to be created atomically |
| * @return LockToken this lock token must be held until the file is no |
| * longer needed |
| * @throws IOException |
| * @since 5.0 |
| */ |
| @Override |
| public LockToken createNewFileAtomic(File file) throws IOException { |
| Path path; |
| try { |
| path = file.toPath(); |
| Files.createFile(path); |
| } catch (FileAlreadyExistsException | InvalidPathException e) { |
| return token(false, null); |
| } |
| if (supportsAtomicCreateNewFile()) { |
| return token(true, null); |
| } |
| Path link = null; |
| FileStore store = null; |
| try { |
| store = Files.getFileStore(path); |
| } catch (SecurityException e) { |
| return token(true, null); |
| } |
| try { |
| Boolean canLink = CAN_HARD_LINK.computeIfAbsent(store, |
| s -> Boolean.TRUE); |
| if (Boolean.FALSE.equals(canLink)) { |
| return token(true, null); |
| } |
| link = Files.createLink(Paths.get(uniqueLinkPath(file)), path); |
| Integer nlink = (Integer) (Files.getAttribute(path, |
| "unix:nlink")); //$NON-NLS-1$ |
| if (nlink.intValue() > 2) { |
| LOG.warn(MessageFormat.format( |
| JGitText.get().failedAtomicFileCreation, path, nlink)); |
| return token(false, link); |
| } else if (nlink.intValue() < 2) { |
| CAN_HARD_LINK.put(store, Boolean.FALSE); |
| } |
| return token(true, link); |
| } catch (UnsupportedOperationException | IllegalArgumentException |
| | FileSystemException | SecurityException e) { |
| CAN_HARD_LINK.put(store, Boolean.FALSE); |
| return token(true, link); |
| } |
| } |
| |
| private static LockToken token(boolean created, @Nullable Path p) { |
| return ((p != null) && Files.exists(p)) |
| ? new LockToken(created, Optional.of(p)) |
| : new LockToken(created, Optional.empty()); |
| } |
| |
| private static String uniqueLinkPath(File file) { |
| UUID id = UUID.randomUUID(); |
| return file.getAbsolutePath() + "." //$NON-NLS-1$ |
| + Long.toHexString(id.getMostSignificantBits()) |
| + Long.toHexString(id.getLeastSignificantBits()); |
| } |
| } |