DefaultFileSystemMaster#listStatus throws 'Path is no longer valid, possibly due to a concurrent delete.'When concurrent deletion occurs.

Suppose the directory /path has many files.

/path
/file_1
/file_2
/file_3
....
/file_1000000

The order of events is like this.

1. Client A calls FileSystem.listStatus("/path")
2. Client B calls FileSystem.delete("/path/file_1000000") successfully.
3. Client A gets an exception