Re: [RFC][PATCH] cifs: Fix cifs_writepages_region()

[Linus Torvalds]

On Fri, Feb 24, 2023 at 12:14 PM David Howells <dhowells@xxxxxxxxxx> wrote:
>
> Then why do we have to wait for PG_writeback to complete?

At least for PG_writeback, it's about "the _previous_ dirty write is
still under way, but - since PG_dirty is set again - the page has been
dirtied since".

So we have to start _another_ writeback, because while the current
writeback *might* have written the updated data, that is not at all
certain or clear.

I'm not sure what the fscache rules are.

                Linus