Re: [PATCH 13/16] rbd: rename some fields in struct rbd_dev

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

On 07/11/2012 07:02 AM, Alex Elder wrote:
> An rbd image is not a single object, but a logical construct made up
> of an aggregation of objects.
>
> Rename some fields in struct rbd_dev, in hopes of reinforcing this.
>      obj         -->  image_name
>      obj_len     -->  image_name_len

As mentioned before, this can be turned into a local variable instead.

>      obj_md_name -->  header_name
>
> Also rename a related symbol name:
>      RBD_MAX_MD_NAME_LEN -->  RBD_MAX_HEADER_NAME_LEN

Looks like this got removed in patch 9.

>
> Signed-off-by: Alex Elder<elder@inktank.com>
> ---
>   drivers/block/rbd.c |   53
> ++++++++++++++++++++++++++-------------------------
>   1 files changed, 27 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index c38246b..14e675c 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -161,9 +161,9 @@ struct rbd_device {
>   	spinlock_t		lock;		/* queue lock */
>
>   	struct rbd_image_header	header;
> -	char			*obj; /* rbd image name */
> -	size_t			obj_len;
> -	char			*obj_md_name; /* hdr nm. */
> +	char			*image_name;
> +	size_t			image_name_len;
> +	char			*header_name;
>   	int			pool_id;
>
>   	struct ceph_osd_event   *watch_event;
> @@ -1224,8 +1224,8 @@ static void rbd_watch_cb(u64 ver, u64 notify_id,
> u8 opcode, void *data)
>   	if (!rbd_dev)
>   		return;
>
> -	dout("rbd_watch_cb %s notify_id=%lld opcode=%d\n", rbd_dev->obj_md_name,
> -		notify_id, (int)opcode);
> +	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);
>   	mutex_unlock(&ctl_mutex);
> @@ -1233,7 +1233,7 @@ static void rbd_watch_cb(u64 ver, u64 notify_id,
> u8 opcode, void *data)
>   		pr_warning(RBD_DRV_NAME "%d got notification but failed to "
>   			   " update snaps: %d\n", rbd_dev->major, rc);
>
> -	rbd_req_sync_notify_ack(rbd_dev, ver, notify_id, rbd_dev->obj_md_name);
> +	rbd_req_sync_notify_ack(rbd_dev, ver, notify_id, rbd_dev->header_name);
>   }
>
>   /*
> @@ -1321,7 +1321,7 @@ static void rbd_notify_cb(u64 ver, u64 notify_id,
> u8 opcode, void *data)
>   		return;
>
>   	dout("rbd_notify_cb %s notify_id=%lld opcode=%d\n",
> -				rbd_dev->obj_md_name,
> +				rbd_dev->header_name,
>   		notify_id, (int)opcode);
>   }
>
> @@ -1599,7 +1599,7 @@ static int rbd_read_header(struct rbd_device *rbd_dev,
>
>   		rc = rbd_req_sync_read(rbd_dev,
>   				       NULL, CEPH_NOSNAP,
> -				       rbd_dev->obj_md_name,
> +				       rbd_dev->header_name,
>   				       0, len,
>   				       (char *)dh,&ver);
>   		if (rc<  0)
> @@ -1609,7 +1609,8 @@ static int rbd_read_header(struct rbd_device *rbd_dev,
>   		if (rc<  0) {
>   			if (rc == -ENXIO)
>   				pr_warning("unrecognized header format"
> -					   " for image %s", rbd_dev->obj);
> +					   " for image %s\n",
> +					   rbd_dev->image_name);
>   			goto out_dh;
>   		}
>
> @@ -1665,7 +1666,7 @@ static int rbd_header_add_snap(struct rbd_device
> *rbd_dev,
>   	ceph_encode_string_safe(&p, e, snap_name, name_len, bad);
>   	ceph_encode_64_safe(&p, e, new_snapid, bad);
>
> -	ret = rbd_req_sync_exec(rbd_dev, rbd_dev->obj_md_name,
> +	ret = rbd_req_sync_exec(rbd_dev, rbd_dev->header_name,
>   				"rbd", "snap_add",
>   				data, p - data,&ver);
>
> @@ -1862,7 +1863,7 @@ static ssize_t rbd_name_show(struct device *dev,
>   {
>   	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
>
> -	return sprintf(buf, "%s\n", rbd_dev->obj);
> +	return sprintf(buf, "%s\n", rbd_dev->image_name);
>   }
>
>   static ssize_t rbd_snap_show(struct device *dev,
> @@ -2164,7 +2165,7 @@ static int rbd_init_watch_dev(struct rbd_device
> *rbd_dev)
>   	int ret, rc;
>
>   	do {
> -		ret = rbd_req_sync_watch(rbd_dev, rbd_dev->obj_md_name,
> +		ret = rbd_req_sync_watch(rbd_dev, rbd_dev->header_name,
>   					 rbd_dev->header.obj_version);
>   		if (ret == -ERANGE) {
>   			mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
> @@ -2327,7 +2328,7 @@ static inline char *dup_token(const char **buf,
> size_t *lenp)
>   }
>
>   /*
> - * This fills in the obj, obj_len, snap_name, rbd_dev, rbd_md_name,
> + * This fills in the image, image_len, snap_name, rbd_dev, header_name,
>    * and name fields of the given rbd_dev, based on the list of
>    * monitor addresses and other options provided via /sys/bus/rbd/add.
>    *
> @@ -2368,18 +2369,18 @@ static char *rbd_add_parse_args(struct
> rbd_device *rbd_dev,
>   	if (!pool_name)
>   		goto out_err;
>
> -	rbd_dev->obj = dup_token(&buf,&rbd_dev->obj_len);
> -	if (!rbd_dev->obj)
> +	rbd_dev->image_name = dup_token(&buf,&rbd_dev->image_name_len);
> +	if (!rbd_dev->image_name)
>   		goto out_err;
>
>   	/* Create the name of the header object */
>
> -	rbd_dev->obj_md_name = kmalloc(rbd_dev->obj_len
> +	rbd_dev->header_name = kmalloc(rbd_dev->image_name_len
>   						+ sizeof (RBD_SUFFIX),
>   					GFP_KERNEL);
> -	if (!rbd_dev->obj_md_name)
> +	if (!rbd_dev->header_name)
>   		goto out_err;
> -	sprintf(rbd_dev->obj_md_name, "%s%s", rbd_dev->obj, RBD_SUFFIX);
> +	sprintf(rbd_dev->header_name, "%s%s", rbd_dev->image_name, RBD_SUFFIX);
>
>   	/*
>   	 * The snapshot name is optional.  If none is is supplied,
> @@ -2403,8 +2404,8 @@ static char *rbd_add_parse_args(struct rbd_device
> *rbd_dev,
>   	return pool_name;
>
>   out_err:
> -	kfree(rbd_dev->obj_md_name);
> -	kfree(rbd_dev->obj);
> +	kfree(rbd_dev->header_name);
> +	kfree(rbd_dev->image_name);
>   	kfree(pool_name);
>
>   	return ERR_PTR(ret);
> @@ -2513,8 +2514,8 @@ err_out_client:
>   err_put_id:
>   	if (pool_name) {
>   		kfree(rbd_dev->snap_name);
> -		kfree(rbd_dev->obj_md_name);
> -		kfree(rbd_dev->obj);
> +		kfree(rbd_dev->header_name);
> +		kfree(rbd_dev->image_name);
>   		kfree(pool_name);
>   	}
>   	rbd_id_put(rbd_dev);
> @@ -2556,7 +2557,7 @@ static void rbd_dev_release(struct device *dev)
>   						    rbd_dev->watch_request);
>   	}
>   	if (rbd_dev->watch_event)
> -		rbd_req_sync_unwatch(rbd_dev, rbd_dev->obj_md_name);
> +		rbd_req_sync_unwatch(rbd_dev, rbd_dev->header_name);
>
>   	rbd_put_client(rbd_dev);
>
> @@ -2566,8 +2567,8 @@ static void rbd_dev_release(struct device *dev)
>
>   	/* done with the id, and with the rbd_dev */
>   	kfree(rbd_dev->snap_name);
> -	kfree(rbd_dev->obj_md_name);
> -	kfree(rbd_dev->obj);
> +	kfree(rbd_dev->header_name);
> +	kfree(rbd_dev->image_name);
>   	rbd_id_put(rbd_dev);
>   	kfree(rbd_dev);
>
> @@ -2638,7 +2639,7 @@ static ssize_t rbd_snap_add(struct device *dev,
>   	mutex_unlock(&ctl_mutex);
>
>   	/* make a best effort, don't error if failed */
> -	rbd_req_sync_notify(rbd_dev, rbd_dev->obj_md_name);
> +	rbd_req_sync_notify(rbd_dev, rbd_dev->header_name);
>
>   	ret = count;
>   	kfree(name);