[Devel] [PATCH hci-8.1 v9 04/10] dm-qcow2: complete wbd before ending the data qio

[Konstantin Khorenko]

I won't apply this version, please send v10 with the changes below.

On 10/28/26 16:06, Alexander Ivanov wrote:
> running in AIO completion context. revert_l_entries_update() then
> marks clusters unused and dirties R2 after the flush, and the change
> is never written back.

- Say what happens to that R2 page instead of "never written back".

The page is dirty and sits on slow_wb_batch_list. Preresume frees all
md pages in qcow2_free_md_pages_all(), which does not take them off
that list, so the slow writeback timer can later walk a freed page. If
the timer comes first, it writes the page after postsuspend, behind the
flush. Both are worse than a lost update, and the message should say
which one you are fixing.

-- 
Konstantin Khorenko,
Virtuozzo Linux Kernel Team