)

// Fdatasync - fdatasync() is similar to fsync(), but does not flush modified metadata
// unless that metadata is needed in order to allow a subsequent data retrieval
// to  be  correctly  handled.   For example, changes to st_atime or st_mtime
// (respectively, time of last access and time of last modification; see inode(7))
// do not require flushing because they are not necessary for a subsequent data