Re: [PATCH v4 09/25] iomap: issue readahead for fsverity merkle tree

["Darrick J. Wong" <djwong@kernel.org>]

On Mon, Mar 09, 2026 at 08:23:24PM +0100, Andrey Albershteyn wrote:
> Issue reading of fsverity merkle tree on the fsverity inodes. This way
> metadata will be available at I/O completion time.
> 
> Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
> ---
>  fs/iomap/buffered-io.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index a335a18c307f..1d9481f00b41 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -593,6 +593,9 @@ void iomap_read_folio(const struct iomap_ops *ops,
>  
>  	if (iter.pos < i_size_read(iter.inode))
>  		ctx->vi = fsverity_get_info(iter.inode);
> +	if (ctx->vi)
> +		fsverity_readahead(ctx->vi, folio->index,
> +				   folio_nr_pages(folio));

Initiating merkle tree readahead before you start reading in the data
folios?  Ok, sounds reasonable, though the old-habits disk-using part
of my brain thinks "should we be allocating the merkle tree *before* the
data blocks?" to improve read bandwidth usage :P

Anyway we can sort through that later so
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

>  
>  	while ((ret = iomap_iter(&iter, ops)) > 0)
>  		iter.status = iomap_read_folio_iter(&iter, ctx,
> -- 
> 2.51.2
> 
>