The Connect method can be called between Schedule and lock. In that case, when
locked, the state is already set to CONNECTING of READY and the condition won't
be signaled anymore.
Read all directory entries into memory and close the struct nfsdir
before returning the StorageDirectoryReader instance. This is what
libnfs does, anyway.
Creating a NfsStorage sets its own export_name as the "base". Now
NfsFileReader can use this information to derive the export_name to be
mounted, instead of guessing. This solves the "too many connection"
problem on the NFS server while updating the database.
