Description

The f_sync() function performs the same process as f_close() function but the file is left opened and can continue read/write/seek operations to the file. This is suitable for the applications that open files for a long time in write mode, such as data logger. Performing f_sync() function of periodic or immediataly after f_write() function can minimize the risk of data loss due to a sudden blackout or an unintentional media removal. For more information, refer to application note.

However there is no sense in f_sync() function immediataly before f_close() function because it performs f_sync() function in it. In other words, the differnce between those functions is that the file object is invalidated or not.