Re: [PATCH] zram: correct offset usage in zram_bio_discard

[Sergey Senozhatsky <sergey.senozhatsky@gmail.com>]

On (04/22/14 11:14), Weijie Yang wrote:
> 
> we want to skip the logical block which is partially covered by
> the discard bio, so check the remaining size and subtract it if
> there is a need to goto the next logical block.
> 

looks sane.

	-ss

> This patch corrects the offset usage in zram_bio_discard.
> 
> Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
> ---
>  drivers/block/zram/zram_drv.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index 9849b52..48eccb3 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -572,10 +572,10 @@ static void zram_bio_discard(struct zram *zram, u32 index,
>  	 * skipping this logical block is appropriate here.
>  	 */
>  	if (offset) {
> -		if (n < offset)
> +		if (n <= (PAGE_SIZE - offset))
>  			return;
>  
> -		n -= offset;
> +		n -= (PAGE_SIZE - offset);
>  		index++;
>  	}
>  
> -- 
> 1.7.10.4
> 
>