diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 335e252a99f500f847387e7bf4b3eae49a24d241..3e744dd17ac5e3d65ad504f2fd3a8c081f5e65ea 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1569,8 +1569,7 @@ static noinline int btrfs_ioctl_resize(struct file *file,
 		goto out_free;
 	}
 
-	new_size = div_u64(new_size, fs_info->sectorsize);
-	new_size *= fs_info->sectorsize;
+	new_size = round_down(new_size, fs_info->sectorsize);
 
 	btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
 			  rcu_str_deref(device->name), new_size);