Re: fsync in glib/gio

[Sven Herzberg <herzi gnome-de org>]

Am Montag, den 16.03.2009, 11:49 +0100 schrieb Alexander Larsson:
> On Mon, 2009-03-16 at 10:23 +0000, Michael Meeks wrote:
> > On Sun, 2009-03-15 at 10:19 +0100, Alexander Larsson wrote:
> > >  But there are milllions of lines of code that does the rename as
> > > atomic replace and the chances that anywhere near a majority of those
> > > are "fixed" is extremely slim. Therefore everyone should be aware of
> > > the broken filesystems that don't give data-before-metadata-on-rename
> > > guarantees so that sane people can stay away from them.
> > 
> > 	Out of interest, what distributions are shipping with ext4 configured
> > in this helpful "loose your data" mode ? can we not simply inject the
> > "go slower" patch into these ext4 distros [ since it won't affect their
> > performance quite as badly as everywhere else ], as a temporary
> > workaround; and then sit back and let the default glib behaviour be to
> > work well on all sane systems ? :-)
> 
> It seems both ubuntu and F11 will backport the ext4 fixes. However, even
> with these fixed there is risk for data loss on e.g. xfs, and even ext3
> if you configure it in data=writeback mode. There was also reports from
> nokia about it being unsafe on the flash file system they were using.

If "flash file system" is this one (they mention Nokia on the website -
2nd link):

http://www.linux-mtd.infradead.org/faq/ubifs.html#L_powercut
http://www.linux-mtd.infradead.org/doc/ubifs.html

This might be either not noticed by the developers or not an issue with
their file system.

Regards,
  Sven