Re: [PATCH 1/9] iomap: Fix misplaced page flushing

From: Darrick J. Wong
Date: Tue Aug 25 2020 - 16:48:11 EST


On Mon, Aug 24, 2020 at 03:55:02PM +0100, Matthew Wilcox (Oracle) wrote:
> If iomap_unshare_actor() unshares to an inline iomap, the page was
> not being flushed. block_write_end() and __iomap_write_end() already
> contain flushes, so adding it to iomap_write_end_inline() seems like
> the best place. That means we can remove it from iomap_write_actor().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>

Seems reasonable to me...
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>

--D

> ---
> fs/iomap/buffered-io.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index bcfc288dba3f..cffd575e57b6 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -715,6 +715,7 @@ iomap_write_end_inline(struct inode *inode, struct page *page,
> {
> void *addr;
>
> + flush_dcache_page(page);
> WARN_ON_ONCE(!PageUptodate(page));
> BUG_ON(pos + copied > PAGE_SIZE - offset_in_page(iomap->inline_data));
>
> @@ -811,8 +812,6 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
>
> copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes);
>
> - flush_dcache_page(page);
> -
> status = iomap_write_end(inode, pos, bytes, copied, page, iomap,
> srcmap);
> if (unlikely(status < 0))
> --
> 2.28.0
>