static void dentry_lru_add(struct dentry *dentry)
{
	if (unlikely(!(dentry->d_flags & DCACHE_LRU_LIST)))
		d_lru_add(dentry);
	else if (unlikely(!(dentry->d_flags & DCACHE_REFERENCED)))
		dentry->d_flags |= DCACHE_REFERENCED;
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.