On Thu, Sep 24, 2020 at 5:15 PM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:
>
> On Thu, Sep 24, 2020 at 05:08:03PM +0200, Sedat Dilek wrote:
> > On Thu, Sep 24, 2020 at 2:58 PM Matthew Wilcox (Oracle)
> > <willy@xxxxxxxxxxxxx> wrote:
> > >
> > > For filesystems with block size < page size, we need to set all the
> > > per-block uptodate bits if the page was already uptodate at the time
> > > we create the per-block metadata. This can happen if the page is
> > > invalidated (eg by a write to drop_caches) but ultimately not removed
> > > from the page cache.
> > >
> > > This is a data corruption issue as page writeback skips blocks which
> > > are marked !uptodate.
> > >
> > > Fixes: 9dc55f1389f9 ("iomap: add support for sub-pagesize buffered I/O without buffer heads")
> >
> > This commit is also in Linux v5.9-rc6+ but does not cleanly apply.
> > Against which Git tree is this patch?
> > When Linux v5.9-rc6+ is affected, do you have a backport?
>
> This applies to v5.8. I'll happily backport this for any other kernel
> versions.
>
> From 51f85a97ccdd7071e5f95b2ac4e41c12bf4d4176 Mon Sep 17 00:00:00 2001
> From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
> Date: Thu, 24 Sep 2020 08:44:56 -0400
> Subject: [PATCH] iomap: Set all uptodate bits for an Uptodate page
>
> For filesystems with block size < page size, we need to set all the
> per-block uptodate bits if the page was already uptodate at the time
> we create the per-block metadata. This can happen if the page is
> invalidated (eg by a write to drop_caches) but ultimately not removed
> from the page cache.
>
> This is a data corruption issue as page writeback skips blocks which
> are marked !uptodate.
>
> Fixes: 9dc55f1389f9 ("iomap: add support for sub-pagesize buffered I/O without buffer heads")
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Reported-by: Qian Cai <cai@xxxxxxxxxx>
> Cc: Brian Foster <bfoster@xxxxxxxxxx>
> ---
> fs/iomap/buffered-io.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index bcfc288dba3f..810f7dae11d9 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -53,7 +53,10 @@ iomap_page_create(struct inode *inode, struct page *page)
> atomic_set(&iop->read_count, 0);
> atomic_set(&iop->write_count, 0);
> spin_lock_init(&iop->uptodate_lock);
> - bitmap_zero(iop->uptodate, PAGE_SIZE / SECTOR_SIZE);
> + if (PageUptodate(page))
> + bitmap_fill(iop->uptodate, PAGE_SIZE / SECTOR_SIZE);
> + else
> + bitmap_zero(iop->uptodate, PAGE_SIZE / SECTOR_SIZE);
>
> /*
> * migrate_page_move_mapping() assumes that pages with private data have
> --
> 2.28.0
>
Great and thanks.
Can you send out a seperate patch and label it with "PATCH v5.9"?
I run:
$ git format-patch -1 --subject-prefix="PATCH v5.9" --signoff
Normally, I catch patches from any patchwork URL in mbox format.
Thanks.
- Sedat -
[1] https://patchwork.kernel.org/project/linux-fsdevel/list/
[2] https://patchwork.kernel.org/patch/11797229/ <--- XXX: [ PATCH v5.8 ]
