Re: [PATCH v9 06/10] iomap: fix iomap_dio_zero() for fs bs > system page size

Dave Chinner
2024-07-08T22:18:15Z

On Thu, Jul 04, 2024 at 11:23:16AM +0000, Pankaj Raghav (Samsung) wrote:
> From: Pankaj Raghav <p.raghav@samsung.com>
>
> iomap_dio_zero() will pad a fs block with zeroes if the direct IO size
> < fs block size. iomap_dio_zero() has an implicit assumption that fs block
> size < page_size. This is true for most filesystems at the moment.
>
> If the block size > page size, this will send the contents of the page
> next to zero page(as len > PAGE_SIZE) to the underlying block device,
> causing FS corruption.
>
> iomap is a generic infrastructure and it should not make any assumptions
> about the fs block size and the page size of the system.
>
> Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
> ---
> fs/iomap/buffered-io.c | 4 ++--
> fs/iomap/direct-io.c | 45 ++++++++++++++++++++++++++++++++++++------
> 2 files changed, 41 insertions(+), 8 deletions(-)

Looks fine.

Reviewed-by: Dave Chinner <dchinner@redhat.com>

--
Dave Chinner
david@fromorbit.com