1 files changed, 17 insertions, 42 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index be6dbf995c0c..01439953abf5 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -146,8 +146,11 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
 	pte = pte_mkold(mk_pte(new, vma->vm_page_prot));
 	if (pte_swp_soft_dirty(*ptep))
 		pte = pte_mksoft_dirty(pte);
+
+	/* Recheck VMA as permissions can change since migration started  */
 	if (is_write_migration_entry(entry))
-		pte = pte_mkwrite(pte);
+		pte = maybe_mkwrite(pte, vma);
+
 #ifdef CONFIG_HUGETLB_PAGE
 	if (PageHuge(new)) {
 		pte = pte_mkhuge(pte);
@@ -780,6 +783,7 @@ static int move_to_new_page(struct page *newpage, struct page *page,
 	if (rc != MIGRATEPAGE_SUCCESS) {
 		newpage->mapping = NULL;
 	} else {
+		mem_cgroup_migrate(page, newpage, false);
 		if (remap_swapcache)
 			remove_migration_ptes(page, newpage);
 		page->mapping = NULL;
@@ -795,7 +799,6 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
 {
 	int rc = -EAGAIN;
 	int remap_swapcache = 1;
-	struct mem_cgroup *mem;
 	struct anon_vma *anon_vma = NULL;
 
 	if (!trylock_page(page)) {
@@ -821,9 +824,6 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
 		lock_page(page);
 	}
 
-	/* charge against new page */
-	mem_cgroup_prepare_migration(page, newpage, &mem);
-
 	if (PageWriteback(page)) {
 		/*
 		 * Only in the case of a full synchronous migration is it
@@ -833,10 +833,10 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
 		 */
 		if (mode != MIGRATE_SYNC) {
 			rc = -EBUSY;
-			goto uncharge;
+			goto out_unlock;
 		}
 		if (!force)
-			goto uncharge;
+			goto out_unlock;
 		wait_on_page_writeback(page);
 	}
 	/*
@@ -872,11 +872,11 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
 			 */
 			remap_swapcache = 0;
 		} else {
-			goto uncharge;
+			goto out_unlock;
 		}
 	}
 
-	if (unlikely(balloon_page_movable(page))) {
+	if (unlikely(isolated_balloon_page(page))) {
 		/*
 		 * A ballooned page does not need any special attention from
 		 * physical to virtual reverse mapping procedures.
@@ -885,7 +885,7 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
 		 * the page migration right away (proteced by page lock).
 		 */
 		rc = balloon_page_migrate(newpage, page, mode);
-		goto uncharge;
+		goto out_unlock;
 	}
 
 	/*
@@ -904,7 +904,7 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
 		VM_BUG_ON_PAGE(PageAnon(page), page);
 		if (page_has_private(page)) {
 			try_to_free_buffers(page);
-			goto uncharge;
+			goto out_unlock;
 		}
 		goto skip_unmap;
 	}
@@ -923,10 +923,7 @@ skip_unmap:
 	if (anon_vma)
 		put_anon_vma(anon_vma);
 
-uncharge:
-	mem_cgroup_end_migration(mem, page, newpage,
-				 (rc == MIGRATEPAGE_SUCCESS ||
-				  rc == MIGRATEPAGE_BALLOON_SUCCESS));
+out_unlock:
 	unlock_page(page);
 out:
 	return rc;
@@ -958,17 +955,6 @@ static int unmap_and_move(new_page_t get_new_page, free_page_t put_new_page,
 
 	rc = __unmap_and_move(page, newpage, force, mode);
 
-	if (unlikely(rc == MIGRATEPAGE_BALLOON_SUCCESS)) {
-		/*
-		 * A ballooned page has been migrated already.
-		 * Now, it's the time to wrap-up counters,
-		 * handle the page back to Buddy and return.
-		 */
-		dec_zone_page_state(page, NR_ISOLATED_ANON +
-				    page_is_file_cache(page));
-		balloon_page_free(page);
-		return MIGRATEPAGE_SUCCESS;
-	}
 out:
 	if (rc != -EAGAIN) {
 		/*
@@ -991,6 +977,9 @@ out:
 	if (rc != MIGRATEPAGE_SUCCESS && put_new_page) {
 		ClearPageSwapBacked(newpage);
 		put_new_page(newpage, private);
+	} else if (unlikely(__is_movable_balloon_page(newpage))) {
+		/* drop our reference, page already in the balloon */
+		put_page(newpage);
 	} else
 		putback_lru_page(newpage);
 
@@ -1786,7 +1775,6 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 	pg_data_t *pgdat = NODE_DATA(node);
 	int isolated = 0;
 	struct page *new_page = NULL;
-	struct mem_cgroup *memcg = NULL;
 	int page_lru = page_is_file_cache(page);
 	unsigned long mmun_start = address & HPAGE_PMD_MASK;
 	unsigned long mmun_end = mmun_start + HPAGE_PMD_SIZE;
@@ -1852,15 +1840,6 @@ fail_putback:
 		goto out_unlock;
 	}
 
-	/*
-	 * Traditional migration needs to prepare the memcg charge
-	 * transaction early to prevent the old page from being
-	 * uncharged when installing migration entries.  Here we can
-	 * save the potential rollback and start the charge transfer
-	 * only when migration is already known to end successfully.
-	 */
-	mem_cgroup_prepare_migration(page, new_page, &memcg);
-
 	orig_entry = *pmd;
 	entry = mk_pmd(new_page, vma->vm_page_prot);
 	entry = pmd_mkhuge(entry);
@@ -1888,14 +1867,10 @@ fail_putback:
 		goto fail_putback;
 	}
 
+	mem_cgroup_migrate(page, new_page, false);
+
 	page_remove_rmap(page);
 
-	/*
-	 * Finish the charge transaction under the page table lock to
-	 * prevent split_huge_page() from dividing up the charge
-	 * before it's fully transferred to the new page.
-	 */
-	mem_cgroup_end_migration(memcg, page, new_page, true);
 	spin_unlock(ptl);
 	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);