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

[Damien Le Moal]

On 2020/07/21 20:09, Maxim Levitsky wrote:
> On Tue, 2020-07-21 at 11:05 +0000, Damien Le Moal wrote:
>> 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.
> Agree, will fix.
>>
>> ("for that" does not refer to a clear action)
>>
>>> Signed-off-by: Maxim Levitsky  <mlevitsk@xxxxxxxxxx>
>>> ---
>>>  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);
> Note here a typo, made in last minute change which I didn't test.
> It should be without '!'

Oh ! Indeed. I missed that.

> 
> Best regards,
> 	Maxim Levitsky
> 
>>> +}
>>> +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