Re: [PATCH 4.19.y] iomap: Set all uptodate bits for an Uptodate page

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Nov 16, 2023 at 02:40:10PM +0800, zhangshida wrote:
> From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> 
> commit 4595a298d5563cf76c1d852970f162051fd1a7a6 upstream.
> 
> 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@infradead.org>
> Reported-by: Qian Cai <cai@redhat.com>
> Cc: Brian Foster <bfoster@redhat.com>
> Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Shida Zhang <zhangshida@kylinos.cn>
> ---
>  fs/iomap.c | 3 +++
>  1 file changed, 3 insertions(+)

Now queued up, thanks.

greg k-h