Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:

 - large KASAN update to use arm's "software tag-based mode"

 - a few misc things

 - sh updates

 - ocfs2 updates

 - just about all of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (167 commits)
  kernel/fork.c: mark 'stack_vm_area' with __maybe_unused
  memcg, oom: notify on oom killer invocation from the charge path
  mm, swap: fix swapoff with KSM pages
  include/linux/gfp.h: fix typo
  mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm
  hugetlbfs: Use i_mmap_rwsem to fix page fault/truncate race
  hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization
  memory_hotplug: add missing newlines to debugging output
  mm: remove __hugepage_set_anon_rmap()
  include/linux/vmstat.h: remove unused page state adjustment macro
  mm/page_alloc.c: allow error injection
  mm: migrate: drop unused argument of migrate_page_move_mapping()
  blkdev: avoid migration stalls for blkdev pages
  mm: migrate: provide buffer_migrate_page_norefs()
  mm: migrate: move migrate_page_lock_buffers()
  mm: migrate: lock buffers before migrate_page_move_mapping()
  mm: migration: factor out code to compute expected number of page references
  mm, page_alloc: enable pcpu_drain with zone capability
  kmemleak: add config to select auto scan
  mm/page_alloc.c: don't call kasan_free_pages() at deferred mem init
  ...

1 files changed, 26 insertions, 33 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index 85b7f9423352..21a26cf51114 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -25,6 +25,7 @@
  *     page->flags PG_locked (lock_page)
  *       hugetlbfs_i_mmap_rwsem_key (in huge_pmd_share)
  *         mapping->i_mmap_rwsem
+ *           hugetlb_fault_mutex (hugetlbfs specific page fault mutex)
  *           anon_vma->rwsem
  *             mm->page_table_lock or pte_lock
  *               zone_lru_lock (in mark_page_accessed, isolate_lru_page)
@@ -889,15 +890,17 @@ static bool page_mkclean_one(struct page *page, struct vm_area_struct *vma,
 		.address = address,
 		.flags = PVMW_SYNC,
 	};
-	unsigned long start = address, end;
+	struct mmu_notifier_range range;
 	int *cleaned = arg;
 
 	/*
 	 * We have to assume the worse case ie pmd for invalidation. Note that
 	 * the page can not be free from this function.
 	 */
-	end = min(vma->vm_end, start + (PAGE_SIZE << compound_order(page)));
-	mmu_notifier_invalidate_range_start(vma->vm_mm, start, end);
+	mmu_notifier_range_init(&range, vma->vm_mm, address,
+				min(vma->vm_end, address +
+				    (PAGE_SIZE << compound_order(page))));
+	mmu_notifier_invalidate_range_start(&range);
 
 	while (page_vma_mapped_walk(&pvmw)) {
 		unsigned long cstart;
@@ -949,7 +952,7 @@ static bool page_mkclean_one(struct page *page, struct vm_area_struct *vma,
 			(*cleaned)++;
 	}
 
-	mmu_notifier_invalidate_range_end(vma->vm_mm, start, end);
+	mmu_notifier_invalidate_range_end(&range);
 
 	return true;
 }
@@ -1017,7 +1020,7 @@ void page_move_anon_rmap(struct page *page, struct vm_area_struct *vma)
 
 /**
  * __page_set_anon_rmap - set up new anonymous rmap
- * @page:	Page to add to rmap	
+ * @page:	Page or Hugepage to add to rmap
  * @vma:	VM area to add page to.
  * @address:	User virtual address of the mapping	
  * @exclusive:	the page is exclusively owned by the current process
@@ -1345,7 +1348,7 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 	pte_t pteval;
 	struct page *subpage;
 	bool ret = true;
-	unsigned long start = address, end;
+	struct mmu_notifier_range range;
 	enum ttu_flags flags = (enum ttu_flags)arg;
 
 	/* munlock has nothing to gain from examining un-locked vmas */
@@ -1369,15 +1372,21 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 	 * Note that the page can not be free in this function as call of
 	 * try_to_unmap() must hold a reference on the page.
 	 */
-	end = min(vma->vm_end, start + (PAGE_SIZE << compound_order(page)));
+	mmu_notifier_range_init(&range, vma->vm_mm, vma->vm_start,
+				min(vma->vm_end, vma->vm_start +
+				    (PAGE_SIZE << compound_order(page))));
 	if (PageHuge(page)) {
 		/*
 		 * If sharing is possible, start and end will be adjusted
 		 * accordingly.
+		 *
+		 * If called for a huge page, caller must hold i_mmap_rwsem
+		 * in write mode as it is possible to call huge_pmd_unshare.
 		 */
-		adjust_range_if_pmd_sharing_possible(vma, &start, &end);
+		adjust_range_if_pmd_sharing_possible(vma, &range.start,
+						     &range.end);
 	}
-	mmu_notifier_invalidate_range_start(vma->vm_mm, start, end);
+	mmu_notifier_invalidate_range_start(&range);
 
 	while (page_vma_mapped_walk(&pvmw)) {
 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
@@ -1428,9 +1437,10 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 				 * we must flush them all.  start/end were
 				 * already adjusted above to cover this range.
 				 */
-				flush_cache_range(vma, start, end);
-				flush_tlb_range(vma, start, end);
-				mmu_notifier_invalidate_range(mm, start, end);
+				flush_cache_range(vma, range.start, range.end);
+				flush_tlb_range(vma, range.start, range.end);
+				mmu_notifier_invalidate_range(mm, range.start,
+							      range.end);
 
 				/*
 				 * The ref count of the PMD page was dropped
@@ -1650,7 +1660,7 @@ discard:
 		put_page(page);
 	}
 
-	mmu_notifier_invalidate_range_end(vma->vm_mm, start, end);
+	mmu_notifier_invalidate_range_end(&range);
 
 	return ret;
 }
@@ -1910,27 +1920,10 @@ void rmap_walk_locked(struct page *page, struct rmap_walk_control *rwc)
 
 #ifdef CONFIG_HUGETLB_PAGE
 /*
- * The following three functions are for anonymous (private mapped) hugepages.
+ * The following two functions are for anonymous (private mapped) hugepages.
  * Unlike common anonymous pages, anonymous hugepages have no accounting code
  * and no lru code, because we handle hugepages differently from common pages.
  */
-static void __hugepage_set_anon_rmap(struct page *page,
-	struct vm_area_struct *vma, unsigned long address, int exclusive)
-{
-	struct anon_vma *anon_vma = vma->anon_vma;
-
-	BUG_ON(!anon_vma);
-
-	if (PageAnon(page))
-		return;
-	if (!exclusive)
-		anon_vma = anon_vma->root;
-
-	anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
-	page->mapping = (struct address_space *) anon_vma;
-	page->index = linear_page_index(vma, address);
-}
-
 void hugepage_add_anon_rmap(struct page *page,
 			    struct vm_area_struct *vma, unsigned long address)
 {
@@ -1942,7 +1935,7 @@ void hugepage_add_anon_rmap(struct page *page,
 	/* address might be in next vma when migration races vma_adjust */
 	first = atomic_inc_and_test(compound_mapcount_ptr(page));
 	if (first)
-		__hugepage_set_anon_rmap(page, vma, address, 0);
+		__page_set_anon_rmap(page, vma, address, 0);
 }
 
 void hugepage_add_new_anon_rmap(struct page *page,
@@ -1950,6 +1943,6 @@ void hugepage_add_new_anon_rmap(struct page *page,
 {
 	BUG_ON(address < vma->vm_start || address >= vma->vm_end);
 	atomic_set(compound_mapcount_ptr(page), 0);
-	__hugepage_set_anon_rmap(page, vma, address, 1);
+	__page_set_anon_rmap(page, vma, address, 1);
 }
 #endif /* CONFIG_HUGETLB_PAGE */