diff options
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 40158b59729e..e2155d791d99 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -434,6 +434,71 @@ int page_referenced(struct page *page, int is_locked) return referenced; } +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, entry; + spinlock_t *ptl; + int ret = 0; + + address = vma_address(page, vma); + if (address == -EFAULT) + goto out; + + pte = page_check_address(page, mm, address, &ptl); + if (!pte) + goto out; + + if (!pte_dirty(*pte) && !pte_write(*pte)) + goto unlock; + + entry = ptep_get_and_clear(mm, address, pte); + entry = pte_mkclean(entry); + entry = pte_wrprotect(entry); + ptep_establish(vma, address, pte, entry); + lazy_mmu_prot_update(entry); + ret = 1; + +unlock: + 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); + } + + return ret; +} + /** * page_set_anon_rmap - setup new anonymous rmap * @page: the page to add the mapping to |