Re: [PATCH v3 56/68] afs: Handle len being extending over page end in write_begin/write_end

From: Linus Torvalds
Date: Thu Dec 16 2021 - 11:38:31 EST


On Thu, Dec 16, 2021 at 8:22 AM David Howells <dhowells@xxxxxxxxxx> wrote:
>
> With transparent huge pages, in the future, write_begin() and write_end()
> may be passed a length parameter that, in combination with the offset into
> the page, exceeds the length of that page. This allows
> grab_cache_page_write_begin() to better choose the size of THP to allocate.

I still think this is a fundamental bug in the caller. That
"explanation" is weak, and the whole concept smells like week-old fish
to me.

Linus