Re: [PATCH 01/10] block: introduce blk_is_valid_logical_block_size

[Damien Le Moal <Damien.LeMoal@wdc.com>]

On 2020/07/21 19:53, Maxim Levitsky wrote:
> Kernel block layer has never supported logical block
> sizes less that SECTOR_SIZE nor larger that PAGE_SIZE.
> 
> Some drivers have runtime configurable block size,
> so it makes sense to have common helper for that.

...common helper to check the validity of the logical block size set by the driver.

("for that" does not refer to a clear action)

> 
> Signed-off-by: Maxim Levitsky  <mlevitsk@redhat.com>
> ---
>  block/blk-settings.c   | 18 ++++++++++++++++++
>  include/linux/blkdev.h |  1 +
>  2 files changed, 19 insertions(+)
> 
> diff --git a/block/blk-settings.c b/block/blk-settings.c
> index 9a2c23cd97007..3c4ef0d00c2bc 100644
> --- a/block/blk-settings.c
> +++ b/block/blk-settings.c
> @@ -311,6 +311,21 @@ void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
>  }
>  EXPORT_SYMBOL(blk_queue_max_segment_size);
>  
> +
> +/**
> + * blk_check_logical_block_size - check if logical block size is supported
> + * by the kernel
> + * @size:  the logical block size, in bytes
> + *
> + * Description:
> + *   This function checks if the block layers supports given block size
> + **/
> +bool blk_is_valid_logical_block_size(unsigned int size)
> +{
> +	return size >= SECTOR_SIZE && size <= PAGE_SIZE && !is_power_of_2(size);
> +}
> +EXPORT_SYMBOL(blk_is_valid_logical_block_size);
> +
>  /**
>   * blk_queue_logical_block_size - set logical block size for the queue
>   * @q:  the request queue for the device
> @@ -323,6 +338,8 @@ EXPORT_SYMBOL(blk_queue_max_segment_size);
>   **/
>  void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
>  {
> +	WARN_ON(!blk_is_valid_logical_block_size(size));
> +
>  	q->limits.logical_block_size = size;
>  
>  	if (q->limits.physical_block_size < size)
> @@ -330,6 +347,7 @@ void blk_queue_logical_block_size(struct request_queue *q, unsigned int size)
>  
>  	if (q->limits.io_min < q->limits.physical_block_size)
>  		q->limits.io_min = q->limits.physical_block_size;
> +

white line change.

>  }
>  EXPORT_SYMBOL(blk_queue_logical_block_size);
>  
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 57241417ff2f8..2ed3151397e41 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -1099,6 +1099,7 @@ extern void blk_queue_max_write_same_sectors(struct request_queue *q,
>  		unsigned int max_write_same_sectors);
>  extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q,
>  		unsigned int max_write_same_sectors);
> +extern bool blk_is_valid_logical_block_size(unsigned int size);
>  extern void blk_queue_logical_block_size(struct request_queue *, unsigned int);
>  extern void blk_queue_max_zone_append_sectors(struct request_queue *q,
>  		unsigned int max_zone_append_sectors);
> 


-- 
Damien Le Moal
Western Digital Research