Re: [PATCH RFC 1/2] xfs: return committed status from xfs_trans_roll()

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

On Tue, Jul 28, 2015 at 09:40:06AM -0400, Brian Foster wrote:
> > Hmmm - something I just noticed: if we only have one EFD per EFI,
> > why do we do we have that layer of extent counting before dropping
> > real references?
> > 
> 
> I wondered this myself, but hadn't made it deep enough to see if we used
> the reference count elsewhere.

Because the elders (no pun on Alex, sorry :)) didn't realize we

 a) don't even ever look at at the logged extents in EFD
 b) have a 1:1 relationship between EFIs and EFDs

I tried to sort some of that out about a year ago, but I didn't manage
to get far.
have just one.  Note that not having to log these