sync_file_range is different to fsync, fdatasync and O_DSYNC in that it does not flush the disk write cache (whereas the latter explicitly do on newer kernels):

sync_file_range is different to fsync, fdatasync and O_DSYNC in that it does not flush the disk write cache (whereas the latter explicitly do on newer kernels): https://linux.die.net/man/2/sync_file_range https://linux.die.net/man/2/sync_file_range: This system call does not flush disk write caches and thus does not provide any data integrity on systems with volatile disk write caches.