Currently when connected to a replica set and using MongoGridFSFileInfo or MongoGridFSStream with a ReadPreference other than Primary the reads can be distributed over different secondaries, possibly leading to inconsistent results if the different secondaries have different replication lags.

Instead, MongoGridFSFileInfo and MongoGridFSStream should be bound to a specific secondary, so that all operations performed within the scope of the object go to the same secondary.