X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=mm%2Fmigrate.c;h=13f47fbe35504475cf82fd148037d717425067e2;hb=8e524793fdfb061fc31936d9adaa026d7bdc916c;hp=a8025befc32363ce37400a38710c8b87b7b38779;hpb=b73117c49364551ff789db7c424a115ac5b77850;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

diff --git a/mm/migrate.c b/mm/migrate.c
index a8025be..13f47fb 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -148,8 +148,11 @@ 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);
@@ -178,6 +181,37 @@ out:
 }
 
 /*
+ * Congratulations to trinity for discovering this bug.
+ * mm/fremap.c's remap_file_pages() accepts any range within a single vma to
+ * convert that vma to VM_NONLINEAR; and generic_file_remap_pages() will then
+ * replace the specified range by file ptes throughout (maybe populated after).
+ * If page migration finds a page within that range, while it's still located
+ * by vma_interval_tree rather than lost to i_mmap_nonlinear list, no problem:
+ * zap_pte() clears the temporary migration entry before mmap_sem is dropped.
+ * But if the migrating page is in a part of the vma outside the range to be
+ * remapped, then it will not be cleared, and remove_migration_ptes() needs to
+ * deal with it.  Fortunately, this part of the vma is of course still linear,
+ * so we just need to use linear location on the nonlinear list.
+ */
+static int remove_linear_migration_ptes_from_nonlinear(struct page *page,
+		struct address_space *mapping, void *arg)
+{
+	struct vm_area_struct *vma;
+	/* hugetlbfs does not support remap_pages, so no huge pgoff worries */
+	pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+	unsigned long addr;
+
+	list_for_each_entry(vma,
+		&mapping->i_mmap_nonlinear, shared.nonlinear) {
+
+		addr = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+		if (addr >= vma->vm_start && addr < vma->vm_end)
+			remove_migration_pte(page, vma, addr, arg);
+	}
+	return SWAP_AGAIN;
+}
+
+/*
  * Get rid of all migration entries and replace them by
  * references to the indicated page.
  */
@@ -186,6 +220,7 @@ static void remove_migration_ptes(struct page *old, struct page *new)
 	struct rmap_walk_control rwc = {
 		.rmap_one = remove_migration_pte,
 		.arg = old,
+		.file_nonlinear = remove_linear_migration_ptes_from_nonlinear,
 	};
 
 	rmap_walk(new, &rwc);
@@ -499,7 +534,7 @@ void migrate_page_copy(struct page *newpage, struct page *page)
 	if (PageUptodate(page))
 		SetPageUptodate(newpage);
 	if (TestClearPageActive(page)) {
-		VM_BUG_ON(PageUnevictable(page));
+		VM_BUG_ON_PAGE(PageUnevictable(page), page);
 		SetPageActive(newpage);
 	} else if (TestClearPageUnevictable(page))
 		SetPageUnevictable(newpage);
@@ -871,7 +906,7 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
 	 * free the metadata, so the page can be freed.
 	 */
 	if (!page->mapping) {
-		VM_BUG_ON(PageAnon(page));
+		VM_BUG_ON_PAGE(PageAnon(page), page);
 		if (page_has_private(page)) {
 			try_to_free_buffers(page);
 			goto uncharge;
@@ -1158,7 +1193,7 @@ static struct page *new_page_node(struct page *p, unsigned long private,
 					pm->node);
 	else
 		return alloc_pages_exact_node(pm->node,
-				GFP_HIGHUSER_MOVABLE | GFP_THISNODE, 0);
+				GFP_HIGHUSER_MOVABLE | __GFP_THISNODE, 0);
 }
 
 /*
@@ -1544,12 +1579,10 @@ static struct page *alloc_misplaced_dst_page(struct page *page,
 	struct page *newpage;
 
 	newpage = alloc_pages_exact_node(nid,
-					 (GFP_HIGHUSER_MOVABLE | GFP_THISNODE |
-					  __GFP_NOMEMALLOC | __GFP_NORETRY |
-					  __GFP_NOWARN) &
+					 (GFP_HIGHUSER_MOVABLE |
+					  __GFP_THISNODE | __GFP_NOMEMALLOC |
+					  __GFP_NORETRY | __GFP_NOWARN) &
 					 ~GFP_IOFS, 0);
-	if (newpage)
-		page_cpupid_xchg_last(newpage, page_cpupid_last(page));
 
 	return newpage;
 }
@@ -1618,7 +1651,7 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
 {
 	int page_lru;
 
-	VM_BUG_ON(compound_order(page) && !PageTransHuge(page));
+	VM_BUG_ON_PAGE(compound_order(page) && !PageTransHuge(page), page);
 
 	/* Avoid migrating to a node that is nearly full */
 	if (!migrate_balanced_pgdat(pgdat, 1UL << compound_order(page)))
@@ -1749,12 +1782,11 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 		goto out_dropref;
 
 	new_page = alloc_pages_node(node,
-		(GFP_TRANSHUGE | GFP_THISNODE) & ~__GFP_WAIT, HPAGE_PMD_ORDER);
+		(GFP_TRANSHUGE | __GFP_THISNODE) & ~__GFP_WAIT,
+		HPAGE_PMD_ORDER);
 	if (!new_page)
 		goto out_fail;
 
-	page_cpupid_xchg_last(new_page, page_cpupid_last(page));
-
 	isolated = numamigrate_isolate_page(pgdat, page);
 	if (!isolated) {
 		put_page(new_page);