On 10/17, Chao Yu wrote:
> On 2018/10/16 11:10, Jaegeuk Kim wrote:
> > On 10/16, Chao Yu wrote:
> >> On 2018/10/16 7:08, Jaegeuk Kim wrote:
> >>> On 10/15, Chao Yu wrote:
> >>>> On 2018/10/11 5:22, Jaegeuk Kim wrote:
> >>>>> If we clear the cold data flag out of the writeback flow, we can
> >>>>> miscount
> >>>>> -1 by end_io.
> >>>>
> >>>> I didn't get it, which count do you mean?
> >>>
> >>> It's the number of dirty pages.
> >>>
> >>> Balancing F2FS Async:
> >>> - IO (CP: 1, Data: -1, Flush: ( 0 0 1), Discard: ( 0
> >>> 129304)) cmd: 0 undiscard: 0
>
> Better to add such info in commit message. :)
>
> >>>
> >>
> >> So I guess the race should be:
> >>
> >> GC thread: IRQ
> >> - move_data_page()
> >> - set_page_dirty()
> >> - clear_cold_data()
> >> - f2fs_write_end_io()
> >> - type = WB_DATA_TYPE(page);
> >> here, we get wrong type
> >> - dec_page_count(sbi, type);
> >> - f2fs_wait_on_page_writeback()
> >>
> >> How about relocate wait_writeback & set_page_dirty to avoid above race:
> >
> > Well, wait_on_stable_page() doesn't guarantee its end_io. So, I'm not sure
> > this is the only case.
>
> Yes, you're right, I missed that case.
>
> Can you use git-revert to generate the patch? so we can remain original
> commit info for better backward tracking.
>
> How do you think pick up original patch I submitted:
>
> https://lkml.org/lkml/2018/7/27/415
Seems that works.
Thanks,
>
> Thanks,
>
> >
> >>
> >> move_data_page()
> >>
> >> retry:
> >> f2fs_wait_on_page_writeback(page, DATA, true);
> >> set_page_dirty(page);
> >>
> >> Thanks,
> >>
> >>>>
> >>>> Thanks,
> >>>>
> >>>>>
> >>>>> Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
> >>>>> ---
> >>>>> fs/f2fs/data.c | 4 ----
> >>>>> 1 file changed, 4 deletions(-)
> >>>>>
> >>>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> >>>>> index 29a9d3b8f709..4102799b5558 100644
> >>>>> --- a/fs/f2fs/data.c
> >>>>> +++ b/fs/f2fs/data.c
> >>>>> @@ -2636,10 +2636,6 @@ static int f2fs_set_data_page_dirty(struct page
> >>>>> *page)
> >>>>> if (!PageUptodate(page))
> >>>>> SetPageUptodate(page);
> >>>>>
> >>>>> - /* don't remain PG_checked flag which was set during GC */
> >>>>> - if (is_cold_data(page))
> >>>>> - clear_cold_data(page);
> >>>>> -
> >>>>> if (f2fs_is_atomic_file(inode) &&
> >>>>> !f2fs_is_commit_atomic_write(inode)) {
> >>>>> if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
> >>>>> f2fs_register_inmem_page(inode, page);
> >>>>>
> >>>
> >>> .
> >>>
> >
> > .
> >
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