HDFS-13729. Fix broken links to RBF documentation. Contributed by Gabor Bota.

(cherry picked from commit 418cc7f3aeabedc57c94aa9d4c4248c1476ac90e)

hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSCommands.md

@@ -416,7 +416,7 @@ Runs a HDFS dfsadmin client.
 
 Usage: `hdfs dfsrouter`
 
-Runs the DFS router. See [Router](./HDFSRouterFederation.html#Router) for more info.
+Runs the DFS router. See [Router](../hadoop-hdfs-rbf/HDFSRouterFederation.html#Router) for more info.
 
 ### `dfsrouteradmin`
 
@@ -441,7 +441,7 @@ Usage:
 | `-nameservice` `disable` `enable` *nameservice* | Disable/enable  a name service from the federation. If disabled, requests will not go to that name service. |
 | `-getDisabledNameservices` | Get the name services that are disabled in the federation. |
 
-The commands for managing Router-based federation. See [Mount table management](./HDFSRouterFederation.html#Mount_table_management) for more info.
+The commands for managing Router-based federation. See [Mount table management](../hadoop-hdfs-rbf/HDFSRouterFederation.html#Mount_table_management) for more info.
 
 ### `diskbalancer`
 

hadoop-project/src/site/markdown/index.md.vm

@@ -225,7 +225,7 @@ cluster for existing HDFS clients.
 
 See [HDFS-10467](https://issues.apache.org/jira/browse/HDFS-10467) and the
 HDFS Router-based Federation
-[documentation](./hadoop-project-dist/hadoop-hdfs/HDFSRouterFederation.html) for
+[documentation](./hadoop-project-dist/hadoop-hdfs-rbf/HDFSRouterFederation.html) for
 more details.
 
 API-based configuration of Capacity Scheduler queue configuration