Re: [PATCH 6/7] s390: dasd open counter.

[Andrew Morton <akpm@osdl.org>]

Heiko Carstens <heiko.carstens@de.ibm.com> wrote:
>
> From: Horst Hummel <horst.hummel@de.ibm.com>
> 
> The open_count is increased for every opener, that includes the
> blkdev_get in dasd_scan_partitions. This tampers the open_count
> in BIODASDINFO. Hide the internal open from user-space.
> 
> Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
> ---
> 
>  drivers/s390/block/dasd_ioctl.c |    9 ++++++++-
>  1 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff -urpN linux-2.6/drivers/s390/block/dasd_ioctl.c linux-2.6-patched/drivers/s390/block/dasd_ioctl.c
> --- linux-2.6/drivers/s390/block/dasd_ioctl.c	2006-01-18 17:25:49.000000000 +0100
> +++ linux-2.6-patched/drivers/s390/block/dasd_ioctl.c	2006-01-18 17:25:53.000000000 +0100
> @@ -421,8 +421,15 @@ dasd_ioctl_information(struct block_devi
>  	dasd_info->cu_model = cdev->id.cu_model;
>  	dasd_info->dev_type = cdev->id.dev_type;
>  	dasd_info->dev_model = cdev->id.dev_model;
> -	dasd_info->open_count = atomic_read(&device->open_count);
>  	dasd_info->status = device->state;
> +	/*
> +	 * The open_count is increased for every opener, that includes
> +	 * the blkdev_get in dasd_scan_partitions.
> +	 * This must be hidden from user-space.
> +	 */
> +	dasd_info->open_count = atomic_read(&device->open_count);
> +	if (!device->bdev)
> +		dasd_info->open_count++;

I'll change the above to atomic_inc().