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

Damien Le Moal
2020-07-21T11:06:04Z

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