-/*
- Controls ongoing disk read-ahead operations during boot-up. The argument
- must be a string, and either "cancel", "done" or "noreplay".
-
- cancel = terminate read-ahead data collection, drop collected information
- done = terminate read-ahead data collection, keep collected information
- noreplay = terminate read-ahead replay
-*/
-int sd_readahead(const char *action);
-