Re: fsync in glib/gio

[Mathias Hasselmann <mathias hasselmann gmx de>]

Am Freitag, den 13.03.2009, 12:18 +0100 schrieb Sven Neumann:
> Hi,
> 
> On Fri, 2009-03-13 at 08:38 +0100, Alexander Larsson wrote:
> 
> > If you want to you can make all i/o sync by mounting it as such. But
> > thats of course really slow. Generally the gio file write operations are
> > used for saving files, and people sort of expect that when save returns
> > the file is ok on disk. 
> 
> Do they?? Doing file I/O asynchronously is a feature, in particular for
> laptop users. It improves I/O performance and it saves power. Of course
> it's a risk and may result in data loss under certain rare
> circumstances. But it's a risk that people are willing to take. Please
> do not ruin this by implicitly enforcing fsync.

I think you don't understand the problem.

Other file systems but ext3 in order=data mode are that brain dead and
broken, that they lose __both__ the old and new document on power loss!
This is __not__ acceptable, in no way.

Maybe the time kernel hackers will realize some day, that they lost any
sense for real world applications and over-optimized their file systems
for write performance benchmarks. Well, but until this happens we have
to suffer from fsync().

Really, loosing both versions of files really isn't an option.

Ciao,
Mathias
-- 
Mathias Hasselmann <mathias hasselmann gmx de>
Personal Blog: http://taschenorakel.de/mathias/
Openismus GmbH: http://www.openismus.com/