[folded-merged] mm-rmap-simplify-pageanonexclusive-sanity-checks-when-adding-anon-rmap-fix.patch removed from -mm tree

[folded-merged] mm-rmap-simplify-pageanonexclusive-sanity-checks-when-adding-anon-rmap-fix.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm-rmap-simplify-pageanonexclusive-sanity-checks-when-adding-anon-rmap-fix
has been removed from the -mm tree.  Its filename was
     mm-rmap-simplify-pageanonexclusive-sanity-checks-when-adding-anon-rmap-fix.patch

This patch was dropped because it was folded into mm-rmap-simplify-pageanonexclusive-sanity-checks-when-adding-anon-rmap.patch

------------------------------------------------------
From: David Hildenbrand <david@redhat.com>
Subject: mm-rmap-simplify-pageanonexclusive-sanity-checks-when-adding-anon-rmap-fix
Date: Mon, 18 Sep 2023 11:16:57 +0200

While PTE-mapping a THP, we temporarily have an exclusive page of a THP
mapped by both, a PMD and a PTE at the same time.  Update our check to
allow for that combination.

Link: https://lkml.kernel.org/r/d8e5a093-2e22-c14b-7e64-6da280398d9f@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: syzbot+6e4f59235036c3c2e296@syzkaller.appspotmail.com
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/rmap.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/mm/rmap.c~mm-rmap-simplify-pageanonexclusive-sanity-checks-when-adding-anon-rmap-fix
+++ a/mm/rmap.c
@@ -1249,8 +1249,10 @@ void page_add_anon_rmap(struct page *pag
 	}
 	if (flags & RMAP_EXCLUSIVE)
 		SetPageAnonExclusive(page);
-	VM_WARN_ON_FOLIO(page_mapcount(page) > 1 && PageAnonExclusive(page),
-			 folio);
+	/* While PTE-mapping a THP we have a PMD and a PTE mapping. */
+	VM_WARN_ON_FOLIO((atomic_read(&page->_mapcount) > 0 ||
+			  (folio_test_large(folio) && folio_entire_mapcount(folio) > 1)) &&
+			 PageAnonExclusive(page), folio);
 
 	mlock_vma_folio(folio, vma, compound);
 }
_

Patches currently in -mm which might be from david@redhat.com are

mm-rmap-drop-stale-comment-in-page_add_anon_rmap-and-hugepage_add_anon_rmap.patch
mm-rmap-move-setpageanonexclusive-out-of-__page_set_anon_rmap.patch
mm-rmap-move-folio_test_anon-check-out-of-__folio_set_anon.patch
mm-rmap-warn-on-new-pte-mapped-folios-in-page_add_anon_rmap.patch
mm-rmap-simplify-pageanonexclusive-sanity-checks-when-adding-anon-rmap.patch
mm-rmap-pass-folio-to-hugepage_add_anon_rmap.patch
mm-rmap-move-setpageanonexclusive-out-of-page_move_anon_rmap.patch
mm-rmap-convert-page_move_anon_rmap-to-folio_move_anon_rmap.patch
memory-move-exclusivity-detection-in-do_wp_page-into-wp_can_reuse_anon_folio.patch