[PATCH 03/17] blktrans: track open and close calls.

[Ricard Wanderlof]

On Sat, 30 Jan 2010, Maxim Levitsky wrote:

> This patch adds tracking for open and close calls.
> Now trans ->open and ->release are never called twise in a row
> ->release is also called once before mtd device disappers
> ...

> --- a/drivers/mtd/mtd_blkdevs.c
> +++ b/drivers/mtd/mtd_blkdevs.c
> @@ -128,6 +128,9 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode)
> 	if (!get_mtd_device(NULL, dev->mtd->index))
> 		goto out;
>
> +	if (dev->open++)
> +		goto out;
> +
> 	if (!try_module_get(tr->owner))
> 		goto out_tr;
>
> @@ -153,6 +156,10 @@ static int blktrans_release(struct gendisk *disk, fmode_t mode)
> 	struct mtd_blktrans_ops *tr = dev->tr;
> 	int ret = 0;
>
> +	dev->open--;
> +	if (dev->open)
> +		return 0;
> +

Just a very minor quibble: if you use if (dev->open++) in one function, 
why not use if (--dev->open) in the other? Or separate the 
increment/decrement from the test, depending on you style preferences.

/Ricard
-- 
Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
Phone +46 46 272 2016                           Fax +46 46 13 61 30