diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c95f018d4a1e9f2e6c752e9e961f6ed309e86d65..b3c30719bf5d02f24e1fccf14691f1458e397635 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2702,7 +2702,7 @@ int btrfs_grow_device(struct btrfs_trans_handle *trans,
 
 	mutex_lock(&fs_info->chunk_mutex);
 	old_total = btrfs_super_total_bytes(super_copy);
-	diff = new_size - device->total_bytes;
+	diff = round_down(new_size - device->total_bytes, fs_info->sectorsize);
 
 	if (new_size <= device->total_bytes ||
 	    device->is_tgtdev_for_dev_replace) {
@@ -4406,7 +4406,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 	u64 diff;
 
 	new_size = round_down(new_size, fs_info->sectorsize);
-	diff = old_size - new_size;
+	diff = round_down(old_size - new_size, fs_info->sectorsize);
 
 	if (device->is_tgtdev_for_dev_replace)
 		return -EINVAL;