Re: [PATCH] cciss: Fix warnings (and bug on 1TB discs)

[Matthew Wilcox <matthew@wil.cx>]

On Thu, Oct 19, 2006 at 09:23:36PM -0600, Matthew Wilcox wrote:
> CCISS was producing warnings about shifts being greater than the size
> of the type and pointers being of incompatible type.  Turns out this
> is because it's calling do_div on a 32-bit quantity.  Upon further
> investigation, the sector_t total_size is being assigned to an int,
> and then we're calling do_div on that int.  Obviously, sector_div is
> called for here, and I took the chance to refactor the code a little.

Oops, forgot:
Signed-off-by: Matthew Wilcox <matthew@wil.cx>

> diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
> index dcccaf2..bc66026 100644
> --- a/drivers/block/cciss.c
> +++ b/drivers/block/cciss.c
> @@ -1923,7 +1923,6 @@ static void cciss_geometry_inquiry(int c
>  {
>  	int return_code;
>  	unsigned long t;
> -	unsigned long rem;
>  
>  	memset(inq_buff, 0, sizeof(InquiryData_struct));
>  	if (withirq)
> @@ -1939,26 +1938,23 @@ static void cciss_geometry_inquiry(int c
>  			printk(KERN_WARNING
>  			       "cciss: reading geometry failed, volume "
>  			       "does not support reading geometry\n");
> -			drv->block_size = block_size;
> -			drv->nr_blocks = total_size;
>  			drv->heads = 255;
>  			drv->sectors = 32;	// Sectors per track
> -			t = drv->heads * drv->sectors;
> -			drv->cylinders = total_size;
> -			rem = do_div(drv->cylinders, t);
>  		} else {
> -			drv->block_size = block_size;
> -			drv->nr_blocks = total_size;
>  			drv->heads = inq_buff->data_byte[6];
>  			drv->sectors = inq_buff->data_byte[7];
>  			drv->cylinders = (inq_buff->data_byte[4] & 0xff) << 8;
>  			drv->cylinders += inq_buff->data_byte[5];
>  			drv->raid_level = inq_buff->data_byte[8];
> -			t = drv->heads * drv->sectors;
> -			if (t > 1) {
> -				drv->cylinders = total_size;
> -				rem = do_div(drv->cylinders, t);
> -			}
> +		}
> +		drv->block_size = block_size;
> +		drv->nr_blocks = total_size;
> +		t = drv->heads * drv->sectors;
> +		if (t > 1) {
> +			unsigned rem = sector_div(total_size, t);
> +			if (rem)
> +				total_size++;
> +			drv->cylinders = total_size;
>  		}
>  	} else {		/* Get geometry failed */
>  		printk(KERN_WARNING "cciss: reading geometry failed\n");
> -
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