On Wed 11-01-23 16:43:27, Jan Kara wrote:
> In data=journal mode, page should be dirtied only when it has buffers
> for checkpoint or it is writeably mapped. In the first case, we don't
> need to do anything special. In the second case, page was already added
> to the journal by ext4_page_mkwrite() and since transaction commit
> writeprotects mapped pages again, page should be writeable (and thus
> dirtied) only while it is part of the running transaction. So nothing
> needs to be done either. The only special case is when someone pins the
> page and uses this pin for modifying page data. So recognize this
> special case and only then mark the page as having data that needs
> adding to the journal.
>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
...
> static bool ext4_journalled_dirty_folio(struct address_space *mapping,
> struct folio *folio)
> {
> WARN_ON_ONCE(!folio_buffers(folio));
> - folio_set_checked(folio);
> + if (folio_may_be_dma_pinned(folio))
Bah, this should be folio_maybe_dma_pinned(). I had it there and that's
what I've tested with but before submission I was laboring whether I should
really keep this change or not, had it deleted for a while and then
restored the change, and while doing that I've introduced this bug. :-|
I'll resend with this bug fixed but before doing that I'll wait a few days
whether someone has more comments.
Honza
> + folio_set_checked(folio);
> return filemap_dirty_folio(mapping, folio);
> }
>
> --
> 2.35.3
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
