The f_mountdrv forces mounted the partition.
FRESULT f_mountdrv ();
The f_mountdrv mounts a partition (initializes FATFS structure) and put it that can handle all file functions. This function should not be used except for recover FR_INCORRECT_DISK_CHANGE error because the file system is mounted(initialized) automatically in accordance with the necessity when any file function is called. To terminate use of the FatFs module, close all files and then the FATFS structure can be discarded. In this function, following process is executed.