/*
* 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;
}
