1 files changed, 24 insertions, 2 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index f6c7ff316daf..30e7709a5121 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3992,6 +3992,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 			    unsigned long src_addr,
 			    struct page **pagep)
 {
+	int vm_shared = dst_vma->vm_flags & VM_SHARED;
 	struct hstate *h = hstate_vma(dst_vma);
 	pte_t _dst_pte;
 	spinlock_t *ptl;
@@ -4028,6 +4029,18 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 	__SetPageUptodate(page);
 	set_page_huge_active(page);
 
+	/*
+	 * If shared, add to page cache
+	 */
+	if (vm_shared) {
+		struct address_space *mapping = dst_vma->vm_file->f_mapping;
+		pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr);
+
+		ret = huge_add_to_page_cache(page, mapping, idx);
+		if (ret)
+			goto out_release_nounlock;
+	}
+
 	ptl = huge_pte_lockptr(h, dst_mm, dst_pte);
 	spin_lock(ptl);
 
@@ -4035,8 +4048,12 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 	if (!huge_pte_none(huge_ptep_get(dst_pte)))
 		goto out_release_unlock;
 
-	ClearPagePrivate(page);
-	hugepage_add_new_anon_rmap(page, dst_vma, dst_addr);
+	if (vm_shared) {
+		page_dup_rmap(page, true);
+	} else {
+		ClearPagePrivate(page);
+		hugepage_add_new_anon_rmap(page, dst_vma, dst_addr);
+	}
 
 	_dst_pte = make_huge_pte(dst_vma, page, dst_vma->vm_flags & VM_WRITE);
 	if (dst_vma->vm_flags & VM_WRITE)
@@ -4053,11 +4070,16 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 	update_mmu_cache(dst_vma, dst_addr, dst_pte);
 
 	spin_unlock(ptl);
+	if (vm_shared)
+		unlock_page(page);
 	ret = 0;
 out:
 	return ret;
 out_release_unlock:
 	spin_unlock(ptl);
+out_release_nounlock:
+	if (vm_shared)
+		unlock_page(page);
 	put_page(page);
 	goto out;
 }