ViewFileSystem currently passes unqualified paths (no scheme or authority) to underlying FileSystems when doing a rename. DistributedFileSystem symlink support added in
HADOOP-9418 needs to qualify and check rename sources and destinations since cross-filesystem renames aren't supported, so this breaks in the following way
- Default FS URI is configured to viewfs://<viewfs>
- When doing a rename, ViewFileSystem checks to make sure both src and dst FileSystems are the same (which they are, both in same DFS), and then calls DistributedFileSystem#rename with unqualified "remainder" paths
- Since these paths are unqualified, DFS qualifies them with the default FS to check that it can do the rename. This turns it into viewfs://<viewfs>/<path>
- Since viewfs://<viewfs> is not the DFS's URI, DFS errors out the rename.