Re: [PATCH] mm/gup: finish consolidating error handling

[Andrew Morton]

On Wed, 21 Nov 2018 00:14:02 -0800 john.hubbard@xxxxxxxxx wrote:

> Commit df06b37ffe5a4 ("mm/gup: cache dev_pagemap while pinning pages")
> attempted to operate on each page that get_user_pages had retrieved. In
> order to do that, it created a common exit point from the routine.
> However, one case was missed, which this patch fixes up.
> 
> Also, there was still an unnecessary shadow declaration (with a
> different type) of the "ret" variable, which this patch removes.
> 

What is the bug which this supposedly fixes and what is that bug's
user-visible impact?