Re: [PATCH] fs: ext4: inode->i_generation not assigned 0.

From: J. Bruce Fields
Date: Wed Jul 05 2017 - 22:39:53 EST


On Thu, Jul 06, 2017 at 11:08:27AM +1000, NeilBrown wrote:
> On Wed, Jul 05 2017, J. Bruce Fields wrote:
>
> > On Wed, Jul 05, 2017 at 12:19:33PM -0700, Darrick J. Wong wrote:
> >> So, what's the probability that there are clients out there that started
> >> talking to a 2.2-based knfsd and will now want to talk to a modern 4.13
> >> kernel seventeen years later?
> >
> > I think it's unlikely enough that we could drop that code;

Wow, that was a terrible sentence. What I meant was: I think it's
unlikely that such a client exists, therefore I'm OK with dropping that
code.

Anyway:

> cc'ing Neil
> > in case we overlooked anything.
>
> While I remain a fan of maintaining forward/backward compatibility as
> much as possible, 15 years is probably more than I can realistically
> hope for.
> As you say, a generation number of '0' is only special when old-style
> file handles are used, with the "subtree_check" export option. They are
> unlikely to have been used recently.
...
> But for the main point of your question: I see no problem with removing
> nfs_fhbase_old and related code, and that includes the special handling
> of generation number zero.

So, we agree, OK.

I dunno if this is actually urgent. But it'd be nice to clean out.

--b.