Re: [PATCH 7/7] rbd: create rbd_refresh_header()

[Josh Durgin <josh.durgin@inktank.com>]

On 07/26/2012 12:09 PM, Alex Elder wrote:
> Create a simple helper that handles the common case of calling
> __rbd_refresh_header() while holding the ctl_mutex.
>
> Signed-off-by: Alex Elder <elder@inktank.com>

Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

> ---
>   drivers/block/rbd.c |   25 +++++++++++++++----------
>   1 file changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index 31be4ca..94d0745 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -240,7 +240,7 @@ static void rbd_put_dev(struct rbd_device *rbd_dev)
>   	put_device(&rbd_dev->dev);
>   }
>
> -static int __rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver);
> +static int rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver);
>
>   static int rbd_open(struct block_device *bdev, fmode_t mode)
>   {
> @@ -1222,9 +1222,7 @@ static void rbd_watch_cb(u64 ver, u64 notify_id,
> u8 opcode, void *data)
>
>   	dout("rbd_watch_cb %s notify_id=%lld opcode=%d\n",
>   		rbd_dev->header_name, notify_id, (int) opcode);
> -	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
> -	rc = __rbd_refresh_header(rbd_dev, &hver);
> -	mutex_unlock(&ctl_mutex);
> +	rc = rbd_refresh_header(rbd_dev, &hver);
>   	if (rc)
>   		pr_warning(RBD_DRV_NAME "%d got notification but failed to "
>   			   " update snaps: %d\n", rbd_dev->major, rc);
> @@ -1746,6 +1744,17 @@ static int __rbd_refresh_header(struct rbd_device
> *rbd_dev, u64 *hver)
>   	return ret;
>   }
>
> +static int rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver)
> +{
> +	int ret;
> +
> +	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
> +	ret = __rbd_refresh_header(rbd_dev, hver);
> +	mutex_unlock(&ctl_mutex);
> +
> +	return ret;
> +}
> +
>   static int rbd_init_disk(struct rbd_device *rbd_dev)
>   {
>   	struct gendisk *disk;
> @@ -1899,9 +1908,7 @@ static ssize_t rbd_image_refresh(struct device *dev,
>   	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
>   	int ret;
>
> -	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
> -	ret = __rbd_refresh_header(rbd_dev, NULL);
> -	mutex_unlock(&ctl_mutex);
> +	ret = rbd_refresh_header(rbd_dev, NULL);
>
>   	return ret < 0 ? ret : size;
>   }
> @@ -2191,9 +2198,7 @@ static int rbd_init_watch_dev(struct rbd_device
> *rbd_dev)
>   	do {
>   		ret = rbd_req_sync_watch(rbd_dev);
>   		if (ret == -ERANGE) {
> -			mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
> -			rc = __rbd_refresh_header(rbd_dev, NULL);
> -			mutex_unlock(&ctl_mutex);
> +			rc = rbd_refresh_header(rbd_dev, NULL);
>   			if (rc < 0)
>   				return rc;
>   		}
>