diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c
index ee2b74d1d1b5e..3490dcd99ad1f 100644
--- a/drivers/mtd/ubi/cdev.c
+++ b/drivers/mtd/ubi/cdev.c
@@ -416,7 +416,7 @@ static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
 		}
 
 		rsvd_bytes = (long long)vol->reserved_pebs *
-					ubi->leb_size-vol->data_pad;
+					vol->usable_leb_size;
 		if (bytes < 0 || bytes > rsvd_bytes) {
 			err = -EINVAL;
 			break;