YARN-2701. Potential race condition in startLocalizer when using LinuxContainerExecutor. Contributed by Xuan Gong

hadoop-yarn-project/CHANGES.txt

@@ -699,6 +699,9 @@ Release 2.6.0 - UNRELEASED
     YARN-2588. Standby RM fails to transitionToActive if previous
     transitionToActive failed with ZK exception. (Rohith Sharmaks via jianhe)
 
+    YARN-2701. Potential race condition in startLocalizer when using
+    LinuxContainerExecutor. (Xuan Gong via jianhe)
+
 Release 2.5.1 - 2014-09-05
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/LinuxContainerExecutor.java

@@ -18,6 +18,7 @@
 
 package org.apache.hadoop.yarn.server.nodemanager;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Optional;
 
 import java.io.File;
@@ -220,7 +221,7 @@ public class LinuxContainerExecutor extends ContainerExecutor {
     if (javaLibPath != null) {
       command.add("-Djava.library.path=" + javaLibPath);
     }
-    ContainerLocalizer.buildMainArgs(command, user, appId, locId, nmAddr, localDirs);
+    buildMainArgs(command, user, appId, locId, nmAddr, localDirs);
     String[] commandArray = command.toArray(new String[command.size()]);
     ShellCommandExecutor shExec = new ShellCommandExecutor(commandArray);
     if (LOG.isDebugEnabled()) {
@@ -241,6 +242,13 @@ public class LinuxContainerExecutor extends ContainerExecutor {
     }
   }
 
+  @VisibleForTesting
+  public void buildMainArgs(List<String> command, String user, String appId,
+      String locId, InetSocketAddress nmAddr, List<String> localDirs) {
+    ContainerLocalizer.buildMainArgs(command, user, appId, locId, nmAddr,
+      localDirs);
+  }
+
   @Override
   public int launchContainer(Container container,
       Path nmPrivateCotainerScriptPath, Path nmPrivateTokensPath,

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/native/container-executor/impl/container-executor.c

@@ -451,59 +451,39 @@ char *get_tmp_directory(const char *work_dir) {
  * with the desired permissions.
  */
 int mkdirs(const char* path, mode_t perm) {
-  struct stat sb;
-  char * npath;
-  char * p;
-  if (stat(path, &sb) == 0) {
-    if (S_ISDIR (sb.st_mode)) {
-      return 0;
-    } else {
-      fprintf(LOGFILE, "Path %s is file not dir\n", path);
-      return -1;
-    }
-  }
-  npath = strdup(path);
-  if (npath == NULL) {
-    fprintf(LOGFILE, "Not enough memory to copy path string");
+  char *buffer = strdup(path);
+  char *token;
+  int cwd = open("/", O_RDONLY);
+  if (cwd == -1) {
+    fprintf(LOGFILE, "Can't open / in %s - %s\n", path, strerror(errno));
+    free(buffer);
     return -1;
   }
-  /* Skip leading slashes. */
-  p = npath;
-  while (*p == '/') {
-    p++;
-  }
-
-  while (NULL != (p = strchr(p, '/'))) {
-    *p = '\0';
-    if (stat(npath, &sb) != 0) {
-      if (mkdir(npath, perm) != 0) {
-        fprintf(LOGFILE, "Can't create directory %s in %s - %s\n", npath,
-                path, strerror(errno));
-        free(npath);
-        return -1;
+  for(token = strtok(buffer, "/"); token != NULL; token = strtok(NULL, "/")) {
+    if (mkdirat(cwd, token, perm) != 0) {
+      if (errno != EEXIST) {
+	    fprintf(LOGFILE, "Can't create directory %s in %s - %s\n",
+			    token, path, strerror(errno));
+	    close(cwd);
+	    free(buffer);
+	    return -1;
       }
-    } else if (!S_ISDIR (sb.st_mode)) {
-      fprintf(LOGFILE, "Path %s is file not dir\n", npath);
-      free(npath);
+    }
+    int new_dir = openat(cwd, token, O_RDONLY);
+    close(cwd);
+    cwd = new_dir;
+    if (cwd == -1) {
+      fprintf(LOGFILE, "Can't open %s in %s - %s\n", token, path,
+		      strerror(errno));
+      free(buffer);
       return -1;
     }
-    *p++ = '/'; /* restore slash */
-    while (*p == '/')
-      p++;
   }
-
-  /* Create the final directory component. */
-  if (mkdir(npath, perm) != 0) {
-    fprintf(LOGFILE, "Can't create directory %s - %s\n", npath,
-            strerror(errno));
-    free(npath);
-    return -1;
-  }
-  free(npath);
+  free(buffer);
+  close(cwd);
   return 0;
 }
 
-
 /**
  * Function to prepare the container directories.
  * It creates the container work and log directories.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/TestLinuxContainerExecutor.java

@@ -18,6 +18,8 @@
 
 package org.apache.hadoop.yarn.server.nodemanager;
 
+import static org.apache.hadoop.fs.CreateFlag.CREATE;
+import static org.apache.hadoop.fs.CreateFlag.OVERWRITE;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
@@ -29,8 +31,11 @@ import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.PrintWriter;
+import java.net.InetSocketAddress;
+import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 
 import org.junit.Assert;
@@ -52,6 +57,8 @@ import org.apache.hadoop.yarn.api.records.Resource;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.server.nodemanager.ContainerExecutor.Signal;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.container.Container;
+import org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ContainerLocalizer;
+import org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ResourceLocalizationService;
 import org.apache.hadoop.yarn.server.nodemanager.util.LCEResourcesHandler;
 import org.junit.After;
 import org.junit.Before;
@@ -108,10 +115,12 @@ public class TestLinuxContainerExecutor {
   private LinuxContainerExecutor exec = null;
   private String appSubmitter = null;
   private LocalDirsHandlerService dirsHandler;
+  private Configuration conf;
+  private FileContext files;
 
   @Before
   public void setup() throws Exception {
-    FileContext files = FileContext.getLocalFSFileContext();
+    files = FileContext.getLocalFSFileContext();
     Path workSpacePath = new Path(workSpace.getAbsolutePath());
     files.mkdir(workSpacePath, null, true);
     FileUtil.chmod(workSpace.getAbsolutePath(), "777");
@@ -123,7 +132,11 @@ public class TestLinuxContainerExecutor {
         new FsPermission("777"), false);
     String exec_path = System.getProperty("container-executor.path");
     if(exec_path != null && !exec_path.isEmpty()) {
-      Configuration conf = new Configuration(false);
+      conf = new Configuration(false);
+      conf.setClass("fs.AbstractFileSystem.file.impl",
+        org.apache.hadoop.fs.local.LocalFs.class,
+        org.apache.hadoop.fs.AbstractFileSystem.class);
+      conf.set(YarnConfiguration.NM_NONSECURE_MODE_LOCAL_USER_KEY, "xuan");
       LOG.info("Setting "+YarnConfiguration.NM_LINUX_CONTAINER_EXECUTOR_PATH
           +"="+exec_path);
       conf.set(YarnConfiguration.NM_LINUX_CONTAINER_EXECUTOR_PATH, exec_path);
@@ -212,6 +225,59 @@ public class TestLinuxContainerExecutor {
         dirsHandler.getLogDirs());
   }
   
+  @Test
+  public void testContainerLocalizer() throws Exception {
+    if (!shouldRun()) {
+      return;
+    }
+    List<String> localDirs = dirsHandler.getLocalDirs();
+    List<String> logDirs = dirsHandler.getLogDirs();
+    for (String localDir : localDirs) {
+      Path userDir =
+          new Path(localDir, ContainerLocalizer.USERCACHE);
+      files.mkdir(userDir, new FsPermission("777"), false);
+      // $local/filecache
+      Path fileDir =
+          new Path(localDir, ContainerLocalizer.FILECACHE);
+      files.mkdir(fileDir, new FsPermission("777"), false);
+    }
+    String locId = "container_01_01";
+    Path nmPrivateContainerTokensPath =
+        dirsHandler.getLocalPathForWrite(
+            ResourceLocalizationService.NM_PRIVATE_DIR + Path.SEPARATOR
+              + String.format(ContainerLocalizer.TOKEN_FILE_NAME_FMT,
+                  locId));
+    files.create(nmPrivateContainerTokensPath, EnumSet.of(CREATE, OVERWRITE));
+    Configuration config = new YarnConfiguration(conf);
+    InetSocketAddress nmAddr = config.getSocketAddr(
+      YarnConfiguration.NM_BIND_HOST,
+      YarnConfiguration.NM_LOCALIZER_ADDRESS,
+      YarnConfiguration.DEFAULT_NM_LOCALIZER_ADDRESS,
+      YarnConfiguration.DEFAULT_NM_LOCALIZER_PORT);
+    String appId = "application_01_01";
+    exec = new LinuxContainerExecutor() {
+      @Override
+      public void buildMainArgs(List<String> command, String user, String appId,
+          String locId, InetSocketAddress nmAddr, List<String> localDirs) {
+        MockContainerLocalizer.buildMainArgs(command, user, appId, locId, nmAddr,
+          localDirs);
+      }
+    };
+    exec.setConf(conf);
+
+    exec.startLocalizer(nmPrivateContainerTokensPath, nmAddr, appSubmitter,
+      appId, locId, localDirs, logDirs);
+
+    String locId2 = "container_01_02";
+    Path nmPrivateContainerTokensPath2 =
+        dirsHandler
+          .getLocalPathForWrite(ResourceLocalizationService.NM_PRIVATE_DIR
+              + Path.SEPARATOR
+              + String.format(ContainerLocalizer.TOKEN_FILE_NAME_FMT, locId2));
+    files.create(nmPrivateContainerTokensPath2, EnumSet.of(CREATE, OVERWRITE));
+    exec.startLocalizer(nmPrivateContainerTokensPath2, nmAddr, appSubmitter,
+      appId, locId2, localDirs, logDirs);
+  }
   
   @Test
   public void testContainerLaunch() throws IOException {