Remove the use of the compound_mapcount_ptr() wrapper, and add an
assertion that we're not passing a tail page if we're duplicating a PMD.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
include/linux/rmap.h | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index aa682a2a93ce..a6bd1f0a183d 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -208,7 +208,14 @@ void hugepage_add_new_anon_rmap(struct page *, struct vm_area_struct *,
static inline void __page_dup_rmap(struct page *page, bool compound)
{
- atomic_inc(compound ? compound_mapcount_ptr(page) : &page->_mapcount);
+ if (compound) {
+ struct folio *folio = (struct folio *)page;
+
+ VM_BUG_ON_PAGE(compound && !PageHead(page), page);
+ atomic_inc(&folio->_entire_mapcount);
+ } else {
+ atomic_inc(&page->_mapcount);
+ }
}
static inline void page_dup_file_rmap(struct page *page, bool compound)
--
2.35.1
