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

Matthew Wilcox
2006-10-20T03:27:57Z

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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