rem: mount->fs->ops->sync(mount->cookie);
add: if (FS_MOUNT_CALL(mount, sync)) FS_MOUNT_CALL(mount, sync)(mount->cookie);
context: fs_sync(void){	struct hash_iterator iter;	struct fs_mount *mount;	FUNCTION(("vfs_sync: entry.\n"));	/* cycle through and call sync on each mounted fs */	mutex_lock(&gMountOpMutex);	mutex_lock(&gMountMutex);	hash_open(gMountsTable, &iter);	while ((mount = hash_next(gMountsTable, &iter))) {		mount->fs->ops->sync(mount->cookie);	}	hash_close(gMountsTable, &iter, false);	mutex_unlock(&gMountMutex);	mutex_unlock(&gMountOpMutex);	return 0;}