// (st_size, as made by say ftruncate(2)), would require a metadata flush.
//
// The aim of fdatasync() is to reduce disk activity for applications that
// do not require all metadata to be synchronized with the disk.
func Fdatasync(f *os.File) error {
	return syscall.Fdatasync(int(f.Fd()))
}

// FadviseDontNeed invalidates page-cache
func FadviseDontNeed(f *os.File) error {

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package disk

import (
	"os"
	"syscall"
)

// Fdatasync is fsync on freebsd/darwin
func Fdatasync(f *os.File) error {
	return syscall.Fsync(int(f.Fd()))
}

// FadviseDontNeed is a no-op
func FadviseDontNeed(f *os.File) error {
	return nil

//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package disk

import (
	"os"
)

// Fdatasync is a no-op
func Fdatasync(f *os.File) error {
	return nil
}

// FadviseDontNeed is a no-op
func FadviseDontNeed(f *os.File) error {
	return nil

**In our tests we also found ext4 does not honor POSIX O_DIRECT/Fdatasync semantics, ext4 trades performance for consistency guarantees. Please avoid ext4 in your setup.**