/* * Called with mm->page_table_lock held to protect against other * threads/the swapper from ripping pte's out from under us. */ static int filemap_sync_pte(pte_t *ptep, struct vm_area_struct *vma, unsigned long address, unsigned int flags) { pte_t pte = *ptep; unsigned long pfn = pte_pfn(pte); struct page *page; if (pte_present(pte) && pfn_valid(pfn)) { page = pfn_to_page(pfn); if (!PageReserved(page) && (ptep_clear_flush_dirty(vma, address, ptep) || page_test_and_clear_dirty(page))) set_page_dirty(page); } return 0; }
static unsigned long msync_pte_range(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end) { pte_t *pte; spinlock_t *ptl; int progress = 0; unsigned long ret = 0; again: pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); do { struct page *page; if (progress >= 64) { progress = 0; if (need_resched() || need_lockbreak(ptl)) break; } progress++; if (!pte_present(*pte)) continue; if (!pte_maybe_dirty(*pte)) continue; page = vm_normal_page(vma, addr, *pte); if (!page) continue; if (ptep_clear_flush_dirty(vma, addr, pte) || page_test_and_clear_dirty(page)) ret += set_page_dirty(page); progress += 3; } while (pte++, addr += PAGE_SIZE, addr != end); pte_unmap_unlock(pte - 1, ptl); cond_resched(); if (addr != end) goto again; return ret; }