Re: [PATCH 1/2] tomoyo: Convert get_user_pages*() to pin_user_pages*()

[John Hubbard]

On 11/7/20 1:04 AM, John Hubbard wrote:
> On 11/7/20 12:24 AM, Souptick Joarder wrote:
> > In 2019, we introduced pin_user_pages*() and now we are converting
> > get_user_pages*() to the new API as appropriate. [1] & [2] could
> > be referred for more information. This is case 5 as per document [1].
>
> It turns out that Case 5 can be implemented via a better pattern, as long
> as we're just dealing with a page at a time, briefly:
>
> lock_page()
> write to page's data
> unlock_page()
>
> ...which neatly synchronizes with writeback and other fs activities.

Ahem, I left out a key step: set_page_dirty()!

lock_page()
write to page's data
set_page_dirty()
unlock_page()


thanks,
--
John Hubbard
NVIDIA