Re: [PATCH 1/9] rbd: introduce rbd_is_snap()

[Dongsheng Yang <dongsheng.yang@xxxxxxxxxxxx>]

On 11/18/2019 09:38 PM, Ilya Dryomov wrote:
> Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Reviewed-by: Dongsheng Yang <dongsheng.yang@xxxxxxxxxxxx>
> ---
>   drivers/block/rbd.c | 21 +++++++++++++--------
>   1 file changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index 2aaa56e4cec9..cf2a7d094890 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -514,6 +514,11 @@ static int minor_to_rbd_dev_id(int minor)
>   	return minor >> RBD_SINGLE_MAJOR_PART_SHIFT;
>   }
>   
> +static bool rbd_is_snap(struct rbd_device *rbd_dev)
> +{
> +	return rbd_dev->spec->snap_id != CEPH_NOSNAP;
> +}
> +
>   static bool __rbd_is_lock_owner(struct rbd_device *rbd_dev)
>   {
>   	lockdep_assert_held(&rbd_dev->lock_rwsem);
> @@ -696,7 +701,7 @@ static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
>   		return -EFAULT;
>   
>   	/* Snapshots can't be marked read-write */
> -	if (rbd_dev->spec->snap_id != CEPH_NOSNAP && !ro)
> +	if (rbd_is_snap(rbd_dev) && !ro)
>   		return -EROFS;
>   
>   	/* Let blkdev_roset() handle it */
> @@ -3538,7 +3543,7 @@ static bool need_exclusive_lock(struct rbd_img_request *img_req)
>   	if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK))
>   		return false;
>   
> -	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
> +	if (rbd_is_snap(rbd_dev))
>   		return false;
>   
>   	rbd_assert(!test_bit(IMG_REQ_CHILD, &img_req->flags));
> @@ -4809,7 +4814,7 @@ static void rbd_queue_workfn(struct work_struct *work)
>   		goto err_rq;
>   	}
>   
> -	if (op_type != OBJ_OP_READ && rbd_dev->spec->snap_id != CEPH_NOSNAP) {
> +	if (op_type != OBJ_OP_READ && rbd_is_snap(rbd_dev)) {
>   		rbd_warn(rbd_dev, "%s on read-only snapshot",
>   			 obj_op_name(op_type));
>   		result = -EIO;
> @@ -4824,7 +4829,7 @@ static void rbd_queue_workfn(struct work_struct *work)
>   	 */
>   	if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) {
>   		dout("request for non-existent snapshot");
> -		rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);
> +		rbd_assert(rbd_is_snap(rbd_dev));
>   		result = -ENXIO;
>   		goto err_rq;
>   	}
> @@ -5067,7 +5072,7 @@ static int rbd_dev_refresh(struct rbd_device *rbd_dev)
>   			goto out;
>   	}
>   
> -	if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
> +	if (!rbd_is_snap(rbd_dev)) {
>   		rbd_dev->mapping.size = rbd_dev->header.image_size;
>   	} else {
>   		/* validate mapped snapshot's EXISTS flag */
> @@ -6656,7 +6661,7 @@ static int rbd_add_acquire_lock(struct rbd_device *rbd_dev)
>   		return -EINVAL;
>   	}
>   
> -	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
> +	if (rbd_is_snap(rbd_dev))
>   		return 0;
>   
>   	rbd_assert(!rbd_is_lock_owner(rbd_dev));
> @@ -7027,7 +7032,7 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
>   	if (ret)
>   		goto err_out_probe;
>   
> -	if (rbd_dev->spec->snap_id != CEPH_NOSNAP &&
> +	if (rbd_is_snap(rbd_dev) &&
>   	    (rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP)) {
>   		ret = rbd_object_map_load(rbd_dev);
>   		if (ret)
> @@ -7116,7 +7121,7 @@ static ssize_t do_rbd_add(struct bus_type *bus,
>   	}
>   
>   	/* If we are mapping a snapshot it must be marked read-only */
> -	if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
> +	if (rbd_is_snap(rbd_dev))
>   		rbd_dev->opts->read_only = true;
>   
>   	if (rbd_dev->opts->alloc_size > rbd_dev->layout.object_size) {