Re: [GIT PULL] Block fixes for 4.5-final

[Linus Torvalds]

On Thu, Mar 3, 2016 at 1:11 PM, Jens Axboe <axboe@xxxxxx> wrote:
>
> It does fix a regression - the change is that NVMe now uses the block layer
> for these types of requests, and they don't have to adhere to the regular fs
> limits of sizing. Hence we broke real use cases, of (for instance) pulling
> logs off devices. Both of the referenced commits were added yesterday, not
> today. And they should have been folded, but I had already committed the
> first one. I don't think that should preclude doing it much cleaner than the
> first one.

Why does this affect only NVMe, and not all the other drivers that
have been around forever?  What is that magical case that breaks?
Details, please.

> Fair enough, I can boil it down somewhat. But honestly, the only stuff I'd
> feel comfortable pulling out now would be the lightnvm changes which aren't
> that critical due to the user base, though that's also why it would be fine
> to shove it in now. And the cgroup writeback enable, which can wait. The two
> commits referenced above could be folded, but they'd still be in the new
> pull request.
>
> So let me know if you want that, or we can proceed with the current branch,
> because most of it should really go in as-is.

I basically want for every commit an explanation of why it's so
critical by now. I want to make you have to *think* and explain before
you send stuff at this stage, and I want to understand why each commit
is so important.

Because really, this has been going on far too long, and this pull
request looked singularly pointless.

No way do I want things like cgroup writeback changes outside the
merge window, for example, unless it's a major performance regression
(with numbers) or something like that.

No way do I want any lightnvm stuff.

No way do I want big "cleanup" patches.

               Linus