[dm-devel] [PATCH v3] dm zoned: Silence a static checker warning

[Damien Le Moal]

On 2019/04/10 17:13, Dan Carpenter wrote:
> My static checker complains about this line from dmz_get_zoned_device()
> 
> 	aligned_capacity = dev->capacity & ~(blk_queue_zone_sectors(q) - 1);
> 
> The problem is that "aligned_capacity" and "dev->capacity" are sector_t
> type (which is a u64 under most configs) but blk_queue_zone_sectors(q)
> returns a u32 so the higher 32 bits in aligned_capacity are cleared to
> zero.  This patch adds a cast to address the issue.
> 
> Fixes: 114e025968b5 ("dm zoned: ignore last smaller runt zone")
> Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
> ---
> v2: The v1 patch declared blk_queue_zone_sectors() as sector_t but the
>     v2 cast added a cast to u64.
> v3: Cast it to sector_t instead
> 
>  drivers/md/dm-zoned-target.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c
> index 8865c1709e16..51d029bbb740 100644
> --- a/drivers/md/dm-zoned-target.c
> +++ b/drivers/md/dm-zoned-target.c
> @@ -643,7 +643,8 @@ static int dmz_get_zoned_device(struct dm_target *ti, char *path)
>  
>  	q = bdev_get_queue(dev->bdev);
>  	dev->capacity = i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT;
> -	aligned_capacity = dev->capacity & ~(blk_queue_zone_sectors(q) - 1);
> +	aligned_capacity = dev->capacity &
> +				~((sector_t)blk_queue_zone_sectors(q) - 1);
>  	if (ti->begin ||
>  	    ((ti->len != dev->capacity) && (ti->len != aligned_capacity))) {
>  		ti->error = "Partial mapping not supported";
> 

Thanks for fixing this !

Reviewed-by: Damien Le Moal <damien.lemoal at wdc.com>

-- 
Damien Le Moal
Western Digital Research