mm: convert page_mkclean_one() to use page_vma_mapped_walk()

For consistency, it worth converting all page_check_address() to
page_vma_mapped_walk(), so we could drop the former.

PMD handling here is future-proofing, we don't have users yet.  ext4
with huge pages will be the first.

Link: http://lkml.kernel.org/r/20170129173858.45174-7-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/rmap.c b/mm/rmap.c
index c4bad599cc7bdf08a22b8869b522c64c0383f662..58597de049fd80548949fee531c5a8a60d07dc1b 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1017,34 +1017,56 @@ int page_referenced(struct page *page,
 static int page_mkclean_one(struct page *page, struct vm_area_struct *vma,
                            unsigned long address, void *arg)
 {
-       struct mm_struct *mm = vma->vm_mm;
-       pte_t *pte;
-       spinlock_t *ptl;
-       int ret = 0;
+       struct page_vma_mapped_walk pvmw = {
+               .page = page,
+               .vma = vma,
+               .address = address,
+               .flags = PVMW_SYNC,
+       };
        int *cleaned = arg;
 
-       pte = page_check_address(page, mm, address, &ptl, 1);
-       if (!pte)
-               goto out;
-
-       if (pte_dirty(*pte) || pte_write(*pte)) {
-               pte_t entry;
+       while (page_vma_mapped_walk(&pvmw)) {
+               int ret = 0;
+               address = pvmw.address;
+               if (pvmw.pte) {
+                       pte_t entry;
+                       pte_t *pte = pvmw.pte;
+
+                       if (!pte_dirty(*pte) && !pte_write(*pte))
+                               continue;
+
+                       flush_cache_page(vma, address, pte_pfn(*pte));
+                       entry = ptep_clear_flush(vma, address, pte);
+                       entry = pte_wrprotect(entry);
+                       entry = pte_mkclean(entry);
+                       set_pte_at(vma->vm_mm, address, pte, entry);
+                       ret = 1;
+               } else {
+#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
+                       pmd_t *pmd = pvmw.pmd;
+                       pmd_t entry;
+
+                       if (!pmd_dirty(*pmd) && !pmd_write(*pmd))
+                               continue;
+
+                       flush_cache_page(vma, address, page_to_pfn(page));
+                       entry = pmdp_huge_clear_flush(vma, address, pmd);
+                       entry = pmd_wrprotect(entry);
+                       entry = pmd_mkclean(entry);
+                       set_pmd_at(vma->vm_mm, address, pmd, entry);
+                       ret = 1;
+#else
+                       /* unexpected pmd-mapped page? */
+                       WARN_ON_ONCE(1);
+#endif
+               }
 
-               flush_cache_page(vma, address, pte_pfn(*pte));
-               entry = ptep_clear_flush(vma, address, pte);
-               entry = pte_wrprotect(entry);
-               entry = pte_mkclean(entry);
-               set_pte_at(mm, address, pte, entry);
-               ret = 1;
+               if (ret) {
+                       mmu_notifier_invalidate_page(vma->vm_mm, address);
+                       (*cleaned)++;
+               }
        }
 
-       pte_unmap_unlock(pte, ptl);
-
-       if (ret) {
-               mmu_notifier_invalidate_page(mm, address);
-               (*cleaned)++;
-       }
-out:
        return SWAP_AGAIN;
 }