Re: [rfc] Ignore Fsync Calls in Laptop_Mode

[Dave Chinner <david@fromorbit.com>]

On Thu, May 19, 2011 at 03:34:46PM +0200, Dennis Jansen wrote:
> This is my first proper kernel code proposal so please bear with me!
> 
> =Summary for busy kernel hackers=
> Problem: laptop_mode wants to keep applications from waking the hard
> disks but fsync calls can "sneak through". (IMHO this is a bug.)
> 
> Proposed solution: Pretend the fsync was executed and successful.
> Insert two lines into the fsync and fdatasync calls in fs/sync.c:
> if (unlikely(laptop_mode))
>    return 0;

No, no, no, no, no, no, no, no, no, no.

There is _absolutely no justification_ for putting people's data at
risk like this.  If you want to do make fsync/fdatasync calls
no-ops, then go install libeatmydata on your systems. It's your
data, and you make the decision to risk it, not us.

And BTW, I just added your name to my "ignore fileystem/data
corruption bug reports from these people" list, because that's
exactly where you'll end up with if you follow this path.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com