+static int page_mkclean_one(struct page *page, struct vm_area_struct *vma)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ unsigned long address;
+ pte_t *pte;
+ spinlock_t *ptl;
+ int ret = 0;
+
+ address = vma_address(page, vma);
+ if (address == -EFAULT)
+ goto out;
+
+ pte = page_check_address(page, mm, address, &ptl, 1);
+ if (!pte)
+ goto out;
+
+ if (pte_dirty(*pte) || pte_write(*pte)) {
+ pte_t entry;
+
+ flush_cache_page(vma, address, pte_pfn(*pte));
+ entry = ptep_clear_flush_notify(vma, address, pte);
+ entry = pte_wrprotect(entry);
+ entry = pte_mkclean(entry);
+ set_pte_at(mm, address, pte, entry);
+ ret = 1;
+ }
+
+ pte_unmap_unlock(pte, ptl);
+out:
+ return ret;
+}
+
+static int page_mkclean_file(struct address_space *mapping, struct page *page)
+{
+ pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+ struct vm_area_struct *vma;
+ struct prio_tree_iter iter;
+ int ret = 0;
+
+ BUG_ON(PageAnon(page));
+
+ spin_lock(&mapping->i_mmap_lock);
+ vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+ if (vma->vm_flags & VM_SHARED)
+ ret += page_mkclean_one(page, vma);
+ }
+ spin_unlock(&mapping->i_mmap_lock);
+ return ret;
+}
+
+int page_mkclean(struct page *page)
+{
+ int ret = 0;
+
+ BUG_ON(!PageLocked(page));
+
+ if (page_mapped(page)) {
+ struct address_space *mapping = page_mapping(page);
+ if (mapping) {
+ ret = page_mkclean_file(mapping, page);
+ if (page_test_dirty(page)) {
+ page_clear_dirty(page);
+ ret = 1;
+ }
+ }
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(page_mkclean);
+