mm.h: hardcode readahead to 2048Kb

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Added fsync on/off support.
fs: sync: enable fsync by default.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Reduce readahead from 2048 to 1024.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Enable pipe flag.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>