Re: How does NILFS2 handle directory management

[Jiro SEKIBA <jir-hfpbi5WX9J54Eiagz67IpQ@public.gmane.org>]

Hi,

At Mon, 28 Sep 2009 00:10:49 +0200,
Reinoud Zandijk wrote:
> 
> Hi Ryusuke,
> 
> On Sat, Sep 26, 2009 at 10:16:34AM +0900, Ryusuke Konishi wrote:
> > > The Ext3 approach also is hacky and shoe-horned. How can it even see if the
> > > hash table is still OK? an Ext2 system could have radically reformed and
> > > reformatted the dirents.
> > 
> > One of the reason I see it as a candidate is that it keeps both
> > backward and forward compatibility.  And, we can see the applicable
> > code in front of our eyes.
> 
> Ext3 hash correctness detection thus works ONLY if the first entry is indeed
> recycled on a directory entry creation. If not, its pointing to garbage.....

When older code see that block, entire block has one virtual entry,
which is the first fake entry.  Rest of the block is seemed to be body of
the first entry.  So actually, there is only one entry on the block.
Therefore, that is the only case to be recycled.

thanks,

regards,
-- 
Jiro SEKIBA <jir-hfpbi5WX9J54Eiagz67IpQ@public.gmane.org>