Re: [PATCH v2 01/12] fs-verity: add a documentation file

From: Matthew Wilcox
Date: Fri Dec 21 2018 - 10:54:00 EST

On Fri, Dec 21, 2018 at 10:47:14AM -0500, Theodore Y. Ts'o wrote:
> Linus --- we're going round and round, and I don't think this is
> really a technical dispute at this point, but rather an aesthetics
> one. Will you be willing to accept my pull request for a feature
> which is being shippped on millions of Android phones, has been out
> for review for months, and for which, if we *really* need to add
> uselessly complicated interface later, we can do that? It's always
> been the case for internal Kernel interfaces not to add code "just in
> case" it's useful, but rather when a user turns up. I argue we should
> be doing the same thing for user-space visible interfaces.

To look at it another way, this is an aesthetic dispute in which all those
who have offered opinions from outside Google -- myself, Dave Chinner &
Christoph all really dislike this interface. I'd be happy to discuss
alternative interfaces, particularly ones which allow for the current
internal implementation, but I think this interface is really bad.

In contrast to "we'll just fix it up later" (which usually applies
to in-kernel interfaces), we have a policy of not breaking userspace,
so accepting this interface means setting it in stone. We should get
it right.