1 files changed, 24 insertions, 59 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index bb4a96c7b682..900c74b6aa62 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -477,17 +477,6 @@ static int reclaimer_offset(struct scan_control *sc)
 	return PGSTEAL_DIRECT - PGSTEAL_KSWAPD;
 }
 
-static inline int is_page_cache_freeable(struct folio *folio)
-{
-	/*
-	 * A freeable page cache folio is referenced only by the caller
-	 * that isolated the folio, the page cache and optional filesystem
-	 * private data at folio->private.
-	 */
-	return folio_ref_count(folio) - folio_test_private(folio) ==
-		1 + folio_nr_pages(folio);
-}
-
 /*
  * We detected a synchronous write error writing a folio out.  Probably
  * -ENOSPC.  We need to propagate that into the address_space for a subsequent
@@ -696,24 +685,12 @@ static pageout_t pageout(struct folio *folio, struct address_space *mapping,
 	 * block, for some throttling. This happens by accident, because
 	 * swap_backing_dev_info is bust: it doesn't reflect the
 	 * congestion state of the swapdevs.  Easy to fix, if needed.
+	 *
+	 * A freeable shmem or swapcache folio is referenced only by the
+	 * caller that isolated the folio and the page cache.
 	 */
-	if (!is_page_cache_freeable(folio))
-		return PAGE_KEEP;
-	if (!mapping) {
-		/*
-		 * Some data journaling orphaned folios can have
-		 * folio->mapping == NULL while being dirty with clean buffers.
-		 */
-		if (folio_test_private(folio)) {
-			if (try_to_free_buffers(folio)) {
-				folio_clear_dirty(folio);
-				pr_info("%s: orphaned folio\n", __func__);
-				return PAGE_CLEAN;
-			}
-		}
+	if (folio_ref_count(folio) != 1 + folio_nr_pages(folio) || !mapping)
 		return PAGE_KEEP;
-	}
-
 	if (!shmem_mapping(mapping) && !folio_test_anon(folio))
 		return PAGE_ACTIVATE;
 	if (!folio_clear_dirty_for_io(folio))
@@ -1054,7 +1031,7 @@ static unsigned int demote_folio_list(struct list_head *demote_folios,
 		 * When this happens, 'page' will likely just be discarded
 		 * instead of migrated.
 		 */
-		.gfp_mask = (GFP_HIGHUSER_MOVABLE & ~__GFP_RECLAIM) | __GFP_NOWARN |
+		.gfp_mask = (GFP_HIGHUSER_MOVABLE & ~__GFP_RECLAIM) |
 			__GFP_NOMEMALLOC | GFP_NOWAIT,
 		.nid = target_nid,
 		.nmask = &allowed_mask,
@@ -1318,7 +1295,7 @@ retry:
 					    split_folio_to_list(folio, folio_list))
 						goto activate_locked;
 				}
-				if (folio_alloc_swap(folio, __GFP_HIGH | __GFP_NOWARN)) {
+				if (folio_alloc_swap(folio)) {
 					int __maybe_unused order = folio_order(folio);
 
 					if (!folio_test_large(folio))
@@ -1334,7 +1311,7 @@ retry:
 					}
 #endif
 					count_mthp_stat(order, MTHP_STAT_SWPOUT_FALLBACK);
-					if (folio_alloc_swap(folio, __GFP_HIGH | __GFP_NOWARN))
+					if (folio_alloc_swap(folio))
 						goto activate_locked_split;
 				}
 				/*
@@ -1409,21 +1386,7 @@ retry:
 
 		mapping = folio_mapping(folio);
 		if (folio_test_dirty(folio)) {
-			/*
-			 * Only kswapd can writeback filesystem folios
-			 * to avoid risk of stack overflow. But avoid
-			 * injecting inefficient single-folio I/O into
-			 * flusher writeback as much as possible: only
-			 * write folios when we've encountered many
-			 * dirty folios, and when we've already scanned
-			 * the rest of the LRU for clean folios and see
-			 * the same dirty folios again (with the reclaim
-			 * flag set).
-			 */
-			if (folio_is_file_lru(folio) &&
-			    (!current_is_kswapd() ||
-			     !folio_test_reclaim(folio) ||
-			     !test_bit(PGDAT_DIRTY, &pgdat->flags))) {
+			if (folio_is_file_lru(folio)) {
 				/*
 				 * Immediately reclaim when written back.
 				 * Similar in principle to folio_deactivate()
@@ -1432,7 +1395,8 @@ retry:
 				 */
 				node_stat_mod_folio(folio, NR_VMSCAN_IMMEDIATE,
 						nr_pages);
-				folio_set_reclaim(folio);
+				if (!folio_test_reclaim(folio))
+					folio_set_reclaim(folio);
 
 				goto activate_locked;
 			}
@@ -2054,7 +2018,7 @@ static unsigned long shrink_inactive_list(unsigned long nr_to_scan,
 	spin_lock_irq(&lruvec->lru_lock);
 	move_folios_to_lru(lruvec, &folio_list);
 
-	__mod_lruvec_state(lruvec, PGDEMOTE_KSWAPD + reclaimer_offset(sc),
+	mod_lruvec_state(lruvec, PGDEMOTE_KSWAPD + reclaimer_offset(sc),
 					stat.nr_demoted);
 	__mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken);
 	item = PGSTEAL_KSWAPD + reclaimer_offset(sc);
@@ -3773,7 +3737,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long start, unsigned long end,
 	pud = pud_offset(p4d, start & P4D_MASK);
 restart:
 	for (i = pud_index(start), addr = start; addr != end; i++, addr = next) {
-		pud_t val = READ_ONCE(pud[i]);
+		pud_t val = pudp_get(pud + i);
 
 		next = pud_addr_end(addr, end);
 
@@ -4780,7 +4744,7 @@ retry:
 		reset_batch_size(walk);
 	}
 
-	__mod_lruvec_state(lruvec, PGDEMOTE_KSWAPD + reclaimer_offset(sc),
+	mod_lruvec_state(lruvec, PGDEMOTE_KSWAPD + reclaimer_offset(sc),
 					stat.nr_demoted);
 
 	item = PGSTEAL_KSWAPD + reclaimer_offset(sc);
@@ -6127,11 +6091,6 @@ again:
 		if (sc->nr.writeback && sc->nr.writeback == sc->nr.taken)
 			set_bit(PGDAT_WRITEBACK, &pgdat->flags);
 
-		/* Allow kswapd to start writing pages during reclaim.*/
-		if (sc->nr.unqueued_dirty &&
-			sc->nr.unqueued_dirty == sc->nr.file_taken)
-			set_bit(PGDAT_DIRTY, &pgdat->flags);
-
 		/*
 		 * If kswapd scans pages marked for immediate
 		 * reclaim and under writeback (nr_immediate), it
@@ -6872,7 +6831,6 @@ static void clear_pgdat_congested(pg_data_t *pgdat)
 
 	clear_bit(LRUVEC_NODE_CONGESTED, &lruvec->flags);
 	clear_bit(LRUVEC_CGROUP_CONGESTED, &lruvec->flags);
-	clear_bit(PGDAT_DIRTY, &pgdat->flags);
 	clear_bit(PGDAT_WRITEBACK, &pgdat->flags);
 }
 
@@ -7169,7 +7127,12 @@ restart:
 		goto restart;
 	}
 
-	if (!sc.nr_reclaimed)
+	/*
+	 * If the reclaim was boosted, we might still be far from the
+	 * watermark_high at this point. We need to avoid increasing the
+	 * failure count to prevent the kswapd thread from stopping.
+	 */
+	if (!sc.nr_reclaimed && !boosted)
 		atomic_inc(&pgdat->kswapd_failures);
 
 out:
@@ -7623,9 +7586,11 @@ static unsigned long node_pagecache_reclaimable(struct pglist_data *pgdat)
 	else
 		nr_pagecache_reclaimable = node_unmapped_file_pages(pgdat);
 
-	/* If we can't clean pages, remove dirty pages from consideration */
-	if (!(node_reclaim_mode & RECLAIM_WRITE))
-		delta += node_page_state(pgdat, NR_FILE_DIRTY);
+	/*
+	 * Since we can't clean folios through reclaim, remove dirty file
+	 * folios from consideration.
+	 */
+	delta += node_page_state(pgdat, NR_FILE_DIRTY);
 
 	/* Watch for any possible underflows due to delta */
 	if (unlikely(delta > nr_pagecache_reclaimable))