rbd: rename some fields in struct rbd_dev

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
    obj_md_name --> header_name

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

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 */
+	char			*image_name;
-	size_t			obj_len;
+	size_t			image_name_len;
-	char			*obj_md_name; /* hdr nm. */
+	char			*header_name;
 	char			*pool_name;
 	int			pool_id;
 
@@ -1225,8 +1225,8 @@ 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,
+	dout("rbd_watch_cb %s notify_id=%lld opcode=%d\n",
-		notify_id, (int)opcode);
+		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);
@@ -1234,7 +1234,7 @@ 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);
 }
 
 /*
@@ -1322,7 +1322,7 @@ 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);
 }
 
@@ -1600,7 +1600,7 @@ 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)
@@ -1610,7 +1610,8 @@ 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;
 		}
 
@@ -1666,7 +1667,7 @@ 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);
 
@@ -1874,7 +1875,7 @@ 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,
@@ -2178,7 +2179,7 @@ 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);
@@ -2341,7 +2342,7 @@ static inline char *dup_token(const char **buf, size_t *lenp)
 }
 
 /*
- * This fills in the pool_name, obj, obj_len, snap_name, obj_len,
+ * This fills in the pool_name, image_name, image_name_len, snap_name,
  * rbd_dev, rbd_md_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.
@@ -2377,18 +2378,18 @@ static int rbd_add_parse_args(struct rbd_device *rbd_dev,
 	if (!rbd_dev->pool_name)
 		goto out_err;
 
-	rbd_dev->obj = dup_token(&buf, &rbd_dev->obj_len);
+	rbd_dev->image_name = dup_token(&buf, &rbd_dev->image_name_len);
-	if (!rbd_dev->obj)
+	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,
@@ -2412,8 +2413,8 @@ static int rbd_add_parse_args(struct rbd_device *rbd_dev,
 	return 0;
 
 out_err:
-	kfree(rbd_dev->obj_md_name);
+	kfree(rbd_dev->header_name);
-	kfree(rbd_dev->obj);
+	kfree(rbd_dev->image_name);
 	kfree(rbd_dev->pool_name);
 	rbd_dev->pool_name = NULL;
 
@@ -2517,8 +2518,8 @@ err_out_client:
 err_put_id:
 	if (rbd_dev->pool_name) {
 		kfree(rbd_dev->snap_name);
-		kfree(rbd_dev->obj_md_name);
+		kfree(rbd_dev->header_name);
-		kfree(rbd_dev->obj);
+		kfree(rbd_dev->image_name);
 		kfree(rbd_dev->pool_name);
 	}
 	rbd_id_put(rbd_dev);
@@ -2560,7 +2561,7 @@ 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);
 
@@ -2570,9 +2571,9 @@ 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->header_name);
 	kfree(rbd_dev->pool_name);
-	kfree(rbd_dev->obj);
+	kfree(rbd_dev->image_name);
 	rbd_id_put(rbd_dev);
 	kfree(rbd_dev);
 
@@ -2643,7 +2644,7 @@ 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);