Re: [GIT PULL] Squashfs pull request for 2.6.29

[Ingo Molnar <mingo@elte.hu>]

* Jörn Engel <joern@logfs.org> wrote:

> On Fri, 9 January 2009 11:37:39 -0800, David Brown wrote:
> > On Fri, Jan 09, 2009 at 05:54:22PM +0100, Jörn Engel wrote:
> > >
> > > In general, filesystems and ABI changes are special because stupid 
> > > mistakes are eternal.  If some device driver has a bug, you can fix 
> > > it, reboot and be done with it.  Not so with filesystems.
> > 
> > Squashfs is readonly from the kernel.  The images are created with 
> > userspace tools.
> 
> While true, it doesn't make a difference.  If, for example, your 
> structures members are not naturally aligned, you take a performance hit 
> for no good reason.  Simply moving fields around would make the code go 
> faster.  But the format is fixed and prevents you from making this 
> change.
> 
> You have to get those things right from the beginning or pay for your 
> mistakes everafter.  In general (and I stress "In general") filesystems 
> want more review than ordinary device drivers.  And just to stress that 
> again, this is not an argument against merging squashfs now.

What does a performance hit have to do with an ABI? Absolutely nothing - 
if such a bug is noticed it is fixed, that's it. Your argument does not 
parse and makes absolutely zero technical sense.

Your "ABI is forever" objection against a _read only_ filesystem is a 
newbie mistake worthy of cookie file inclusion - i had a real good laugh 
when i read it ;-)

	Ingo
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