On 2019/04/10 15:10, 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) but blk_queue_zone_sectors(q) returns a u32 so the
> higher 32 bits in aligned_capacity are always cleared to zero.
>
> Declaring blk_queue_zone_sectors() as a sector_t addresses this warning
> and it feels intuitive based on the function name. I updated
> bdev_zone_sectors() as well just to be consistent.
>
> Fixes: 114e025968b5 ("dm zoned: ignore last smaller runt zone")
> Signed-off-by: Dan Carpenter <[email protected]>
> ---
> Please review this one extra carefully. I'm not positive it's correct.
>
> include/linux/blkdev.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 4b85dc066264..1785a7f506be 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -670,7 +670,7 @@ static inline bool blk_queue_is_zoned(struct
> request_queue *q)
> }
> }
>
> -static inline unsigned int blk_queue_zone_sectors(struct request_queue *q)
> +static inline sector_t blk_queue_zone_sectors(struct request_queue *q)
> {
> return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
> }
> @@ -1419,7 +1419,7 @@ static inline bool bdev_is_zoned(struct block_device
> *bdev)
> return false;
> }
>
> -static inline unsigned int bdev_zone_sectors(struct block_device *bdev)
> +static inline sector_t bdev_zone_sectors(struct block_device *bdev)
> {
> struct request_queue *q = bdev_get_queue(bdev);
Indeed, using sector_t instead of unsigned int is more intuitive and changing to
sector_t matches the 64bits zone length in struct blk_zone too, so no problem on
this front.
However, q->limits.chunk_sectors is an unsigned int, which is why I used that
type, to reflect the fact that even though the API allows values larger than 4G
sectors, the handling through the queue limits truncates that to at most 4G-1
sectors. Furthermore, the unsigned int type is used wherever
blk_queue_zone_sectors() and bdev_zone_sectors() are called (block/ioctl.c,
block/blk-zoned.c, f2fs, etc). That needs in depth checking.
I would rather keep the unsigned int since the queue limits will give only 32
bit values anyway. What about a cast for the aligned capacity line ? Something
like:
aligned_capacity = dev->capacity & ~((u64)blk_queue_zone_sectors(q) - 1);
Would that make your checker happy ?
--
Damien Le Moal
Western Digital Research
