Re: [PATCH] iomap: Set all uptodate bits for an Uptodate page

[Sedat Dilek <sedat.dilek@gmail.com>]

On Fri, Sep 25, 2020 at 12:44 PM Sedat Dilek <sedat.dilek@gmail.com> wrote:
>
> On Fri, Sep 25, 2020 at 1:57 AM Matthew Wilcox <willy@infradead.org> wrote:
> >
> > On Thu, Sep 24, 2020 at 10:04:40PM +0200, Sedat Dilek wrote:
> > > On Thu, Sep 24, 2020 at 10:02 PM Matthew Wilcox <willy@infradead.org> wrote:
> > > >
> > > > On Thu, Sep 24, 2020 at 09:54:36PM +0200, Sedat Dilek wrote:
> > > > > You are named in "mm: fix misplaced unlock_page in do_wp_page()".
> > > > > Is this here a different issue?
> > > >
> > > > Yes, completely different.  That bug is one Linus introduced in this
> > > > cycle; the bug that this patch fixes was introduced a couple of years
> > > > ago, and we only noticed now because I added an assertion to -next.
> > > > Maybe I should add the assertion for 5.9 too.
> > >
> > > Can you point me to this "assertion"?
> > > Thanks.
> >
> > Here's the version against 5.8
> >
> > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> > index 810f7dae11d9..b421e4efc4bd 100644
> > --- a/fs/iomap/buffered-io.c
> > +++ b/fs/iomap/buffered-io.c
> > @@ -70,11 +70,15 @@ static void
> >  iomap_page_release(struct page *page)
> >  {
> >         struct iomap_page *iop = detach_page_private(page);
> > +       unsigned int nr_blocks = PAGE_SIZE / i_blocksize(page->mapping->host);
> >
> >         if (!iop)
> >                 return;
> >         WARN_ON_ONCE(atomic_read(&iop->read_count));
> >         WARN_ON_ONCE(atomic_read(&iop->write_count));
> > +       WARN_ON_ONCE(bitmap_full(iop->uptodate, nr_blocks) !=
> > +                       PageUptodate(page));
> > +
>
> Are you sure this is "bitmap_full()" or should it be "bitmap_f*i*ll()"?
>
> Both are available in include/linux/bitmap.h.
>

OK, I checked linux-next (next-20200925) and iomap_page_release() (see
[1] and [2]).
Cut-N-Paste is malformatting here in Gmail, so I add the links below.

I also looked into __gfs2_readpage() in fs/gfs2/aops.c:

if (i_blocksize(page->mapping->host) == PAGE_SIZE &&
    !page_has_buffers(page)) {
           error = iomap_readpage(page, &gfs2_iomap_ops);

Thanks.

- Sedat -

[1] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/fs/iomap/buffered-io.c?h=next-20200925#n67
[2] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/fs/iomap/buffered-io.c?h=next-20200925#n77
[3] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/fs/gfs2/aops.c?h=next-20200925#n471



>
> >         kfree(iop);
> >  }
> >