Re: [PATCH 4/5] scsi_debug: support large non-fake virtual disk

[Douglas Gilbert <dougg@torque.net>]

FUJITA Tomonori wrote:
> Currently, the maximum amount of RAM that scsi_debug can allocate is
> 4GB. This patch increases it to 2TB; scsi_debug can allocates 2TB
> memory and export it as if it were 2TB scsi disk.
> 
> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
> Cc: Douglas Gilbert <dougg@torque.net>
> Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
> ---
>  drivers/scsi/scsi_debug.c |    6 +++---
>  1 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index c98559e..1b6a6d8 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -1949,7 +1949,7 @@ static void __init init_all_queued(void)
>  }
>  
>  static void __init sdebug_build_parts(unsigned char *ramp,
> -				      unsigned int store_size)
> +				      unsigned long store_size)
>  {
>  	struct partition * pp;
>  	int starts[SDEBUG_MAX_PARTS + 2];
> @@ -2476,14 +2476,14 @@ static void do_remove_driverfs_files(void)
>  
>  static int __init scsi_debug_init(void)
>  {
> -	unsigned int sz;
> +	unsigned long sz;
>  	int host_to_add;
>  	int k;
>  	int ret;
>  
>  	if (scsi_debug_dev_size_mb < 1)
>  		scsi_debug_dev_size_mb = 1;  /* force minimum 1 MB ramdisk */
> -	sz = (unsigned int)scsi_debug_dev_size_mb * 1048576;
> +	sz = (unsigned long)scsi_debug_dev_size_mb * 1048576;
>  	sdebug_store_sectors = sz / SECT_SIZE;
>  	sdebug_capacity = get_sdebug_capacity();
>  

Tomo,
Unsigned long is 32 bits on i386 (and 64 bits in the LP64
data model). Don't you want 64 bits in all cases? Either
unsigned long long, uint64_t or one of those crappy
kernel typedefs for 64 bits.

BTW I recently removed just about all the "unsigned long"
declarations out of sg3_utils due the uncertainty about the
size of "long".

Doug Gilbert