Merge tag 'v6.6-vfs.tmpfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

[platform/kernel/linux-starfive.git] / mm / internal.h

diff --git a/mm/internal.h b/mm/internal.h
index a7d9e98..8ed127c 100644 (file)
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -924,6 +924,13 @@ int migrate_device_coherent_page(struct page *page);
 struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags);
 int __must_check try_grab_page(struct page *page, unsigned int flags);
 
+/*
+ * mm/huge_memory.c
+ */
+struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
+                                  unsigned long addr, pmd_t *pmd,
+                                  unsigned int flags);
+
 enum {
        /* mark page accessed */
        FOLL_TOUCH = 1 << 16,
@@ -998,6 +1005,16 @@ static inline bool gup_must_unshare(struct vm_area_struct *vma,
                smp_rmb();
 
        /*
+        * During GUP-fast we might not get called on the head page for a
+        * hugetlb page that is mapped using cont-PTE, because GUP-fast does
+        * not work with the abstracted hugetlb PTEs that always point at the
+        * head page. For hugetlb, PageAnonExclusive only applies on the head
+        * page (as it cannot be partially COW-shared), so lookup the head page.
+        */
+       if (unlikely(!PageHead(page) && PageHuge(page)))
+               page = compound_head(page);
+
+       /*
         * Note that PageKsm() pages cannot be exclusive, and consequently,
         * cannot get pinned.
         */