Re: [PATCH] scsi/sd: Fix capacity output to show MB/GB/TB/...

Simon Arlott
2008-08-31T15:09:00Z

On 31/08/08 02:59, James Bottomley wrote:
> On Sat, 2008-08-30 at 22:03 +0100, Simon Arlott wrote:
>> The capacity printk'd in bytes is divided by 1000000,
>> whereas 1048576 would be more consistent with the rest
>> of the OS and disk-related utilities ('df' etc.).
>>
>> This change replaces the (sz - (sz/625 - 974))/1950
>> calculation with a simple right shift to output with
>> five significant digits the capacity in KB, MB, GB, TB,
>> PB, or EB. Anything beyond this becomes too large...
>
> Well, still needs to be dividing by 1000 not 1024 for SCSI and ATA.
> However, I'm afraid it needs to be a bit more sophisticated: for
> instance, under these calculations, a 1.75TB disk will show up as 1TB.
> Thus, I think we need to print the capacity to 3 significant figures to
> cope with this case.

Actually it'll show up as 1629GB, as my patch shows up to 5 digits
(not five significant digits, which would require outputting a
non-integer value).

Isn't outputting "1.75" unnecessarily complicated, and "1750" would
work better?

--
Simon Arlott