// SPDX-License-Identifier: GPL-2.0
/*
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 *  Swap reorganised 29.12.95, Stephen Tweedie.
 *  kswapd added: 7.1.96  sct
 *  Removed kswapd_ctl limits, and swap out as many pages as needed
 *  to bring the system back to freepages.high: 2.4.97, Rik van Riel.
 *  Zone aware kswapd started 02/00, Kanoj Sarcar (kanoj@sgi.com).
 *  Multiqueue VM started 5.8.00, Rik van Riel.
 */

/* Extracted unchanged from Linux v6.1, mm/vmscan.c:2296-2313.
 * Full function definition; surrounding kernel context is required.
 * Source: https://github.com/torvalds/linux/blob/v6.1/mm/vmscan.c#L2296
 * License text: GPL-2.0.txt (in this directory).
 */
int folio_isolate_lru(struct folio *folio)
{
	int ret = -EBUSY;

	VM_BUG_ON_FOLIO(!folio_ref_count(folio), folio);

	if (folio_test_clear_lru(folio)) {
		struct lruvec *lruvec;

		folio_get(folio);
		lruvec = folio_lruvec_lock_irq(folio);
		lruvec_del_folio(lruvec, folio);
		unlock_page_lruvec_irq(lruvec);
		ret = 0;
	}

	return ret;
}