1 files changed, 9 insertions, 4 deletions

diff --git a/fs/dax.c b/fs/dax.c
index f3a44a7c14b3..3652b26a0048 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -565,7 +565,7 @@ static void *dax_insert_mapping_entry(struct address_space *mapping,
                 ret = __radix_tree_lookup(page_tree, index, &node, &slot);
                 WARN_ON_ONCE(ret != entry);
                 __radix_tree_replace(page_tree, node, slot,
-                                     new_entry, NULL, NULL);
+                                     new_entry, NULL);
                 entry = new_entry;
         }
 
@@ -614,6 +614,13 @@ static void dax_mapping_entry_mkclean(struct address_space *mapping,
                 if (follow_pte_pmd(vma->vm_mm, address, &start, &end, &ptep, &pmdp, &ptl))
                         continue;
 
+                /*
+                 * No need to call mmu_notifier_invalidate_range() as we are
+                 * downgrading page table protection not changing it to point
+                 * to a new page.
+                 *
+                 * See Documentation/vm/mmu_notifier.txt
+                 */
                 if (pmdp) {
 #ifdef CONFIG_FS_DAX_PMD
                         pmd_t pmd;
@@ -628,7 +635,6 @@ static void dax_mapping_entry_mkclean(struct address_space *mapping,
                         pmd = pmd_wrprotect(pmd);
                         pmd = pmd_mkclean(pmd);
                         set_pmd_at(vma->vm_mm, address, pmdp, pmd);
-                        mmu_notifier_invalidate_range(vma->vm_mm, start, end);
 unlock_pmd:
                         spin_unlock(ptl);
 #endif
@@ -643,7 +649,6 @@ unlock_pmd:
                         pte = pte_wrprotect(pte);
                         pte = pte_mkclean(pte);
                         set_pte_at(vma->vm_mm, address, ptep, pte);
-                        mmu_notifier_invalidate_range(vma->vm_mm, start, end);
 unlock_pte:
                         pte_unmap_unlock(ptep, ptl);
                 }
@@ -789,7 +794,7 @@ int dax_writeback_mapping_range(struct address_space *mapping,
 
         tag_pages_for_writeback(mapping, start_index, end_index);
 
-        pagevec_init(&pvec, 0);
+        pagevec_init(&pvec);
         while (!done) {
                 pvec.nr = find_get_entries_tag(mapping, start_index,
                                 PAGECACHE_TAG_TOWRITE, PAGEVEC_SIZE,