Re: [git patches] xfs and block fixes for virtually indexed arches

From: Linus Torvalds
Date: Thu Dec 17 2009 - 11:17:16 EST




On Thu, 17 Dec 2009, Kyle McMartin wrote:
>
> Linus, any word on these? I'd really love to get jejb and hch off
> my back. :)

I hate them.

I don't see what the point of allowing kernel virtual addresses in bio's
is. It's wrong. The fact that XFS does that sh*t is an XFS issue. Handle
it there.

Fix XFS. Or convince me with some really good arguments, and make sure
that Jens signs off on the cr*p too.

In other words, the thing I object to isn't even the new flushing thing,
it's this idiocy:

- save off virtual address:
..
bio->bi_private = data;
..

- do vmalloc_to_page:

+ if (is_vmalloc_addr(data)) {
+ flush_kernel_dcache_addr(data);
+ page = vmalloc_to_page(data);
+ } else
+ page = virt_to_page(data);

WTF? Why the hell should the block layer support this kind of absolute
crap? When has "use random kernel virtual address" ever been a valid thing
to do for IO?

Why aren't you doing this before you submit the vmalloc range for IO?

So no. Not a way in hell do I pull this for 33. And preferably never.

Linus
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