Re: [PATCH v2 1/5] zram: always chain bio to the parent in read_from_bdev_async

[Minchan Kim]

On Mon, Apr 03, 2023 at 03:22:17PM +0200, Pankaj Raghav wrote:
> zram_bvec_read() is called with the bio set to NULL only in
> writeback_store() function. When a writeback is triggered,
> zram_bvec_read() is called only if ZRAM_WB flag is not set. That will
> result only calling zram_read_from_zspool() in __zram_bvec_read().
> 
> rw_page callback used to call read_from_bdev_async with a NULL parent
> bio but that has been removed since commit 3222d8c2a7f8
> ("block: remove ->rw_page").
> 
> We can now safely always call bio_chain() as read_from_bdev_async() will
> be called with a parent bio set. A WARN_ON_ONCE is added if this function
> is called with parent set to NULL.
> 
> Signed-off-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
Acked-by: Minchan Kim <minchan@xxxxxxxxxx>

Thanks.