HADOOP-11130. NFS updateMaps OS check is reversed. Contributed by Brandon Li

(cherry picked from commit c88c6c57aa79e8a1f33d2e075491656f472c858b)

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -425,6 +425,8 @@ Release 2.6.0 - UNRELEASED
     HADOOP-1110. JavaKeystoreProvider should not report a key as created if it
     was not flushed to the backing file.
 
+    HADOOP-11130. NFS updateMaps OS check is reversed (brandonli)
+
     BREAKDOWN OF HDFS-6134 AND HADOOP-10150 SUBTASKS AND RELATED JIRAS
   
       HADOOP-10734. Implement high-performance secure random number sources.

hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/nfs/nfs3/IdUserGroup.java

@@ -45,8 +45,8 @@ public class IdUserGroup {
   private final static String OS = System.getProperty("os.name");
 
   /** Shell commands to get users and groups */
-  static final String LINUX_GET_ALL_USERS_CMD = "getent passwd | cut -d: -f1,3";
-  static final String LINUX_GET_ALL_GROUPS_CMD = "getent group | cut -d: -f1,3";
+  static final String GET_ALL_USERS_CMD = "getent passwd | cut -d: -f1,3";
+  static final String GET_ALL_GROUPS_CMD = "getent group | cut -d: -f1,3";
   static final String MAC_GET_ALL_USERS_CMD = "dscl . -list /Users UniqueID";
   static final String MAC_GET_ALL_GROUPS_CMD = "dscl . -list /Groups PrimaryGroupID";
 
@@ -223,16 +223,15 @@ public class IdUserGroup {
           + "' does not exist.");
     }
 
-    if (OS.startsWith("Linux")) {
-      updateMapInternal(uMap, "user", LINUX_GET_ALL_USERS_CMD, ":",
+    if (OS.startsWith("Mac")) {
+      updateMapInternal(uMap, "user", MAC_GET_ALL_USERS_CMD, "\\s+",
           staticMapping.uidMapping);
-      updateMapInternal(gMap, "group", LINUX_GET_ALL_GROUPS_CMD, ":",
+      updateMapInternal(gMap, "group", MAC_GET_ALL_GROUPS_CMD, "\\s+",
           staticMapping.gidMapping);
     } else {
-      // Mac
-      updateMapInternal(uMap, "user", MAC_GET_ALL_USERS_CMD, "\\s+",
+      updateMapInternal(uMap, "user", GET_ALL_USERS_CMD, ":",
           staticMapping.uidMapping);
-      updateMapInternal(gMap, "group", MAC_GET_ALL_GROUPS_CMD, "\\s+",
+      updateMapInternal(gMap, "group", GET_ALL_GROUPS_CMD, ":",
           staticMapping.gidMapping);
     }