hammerhead: Write read_ahead_kb on fs mount

Change-Id: I73f926979944c4fdfc77e4ee93c5cf0b73e2e3c2
Signed-off-by: Dan Trifan <jimsth@gmail.com>
hammerhead: Shorter down lock durations

Change-Id: I703421dd1f5c99f65213fe855cd4e5b96440d756
Signed-off-by: Dan Trifan <jimsth@gmail.com>
hammerhead: Reenable load based syncs

Change-Id: I7980558bcf4b1f166ced4177e39f5df7fe73dde6
Signed-off-by: Dan Trifan <jimsth@gmail.com>
Merge remote-tracking branch 'aicp/kitkat' into HEAD