Merge remote-tracking branch 'torvalds/master' into perf/core

To pick up fixes, since perf/urgent is already upstream.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 33 insertions, 3 deletions

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 85ad98c00fd9..0143d32bc666 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -949,6 +949,17 @@ static int page_action(struct page_state *ps, struct page *p,
 	return (result == MF_RECOVERED || result == MF_DELAYED) ? 0 : -EBUSY;
 }
 
+/*
+ * Return true if a page type of a given page is supported by hwpoison
+ * mechanism (while handling could fail), otherwise false.  This function
+ * does not return true for hugetlb or device memory pages, so it's assumed
+ * to be called only in the context where we never have such pages.
+ */
+static inline bool HWPoisonHandlable(struct page *page)
+{
+	return PageLRU(page) || __PageMovable(page);
+}
+
 /**
  * __get_hwpoison_page() - Get refcount for memory error handling:
  * @page:	raw error page (hit by memory error)
@@ -959,8 +970,22 @@ static int page_action(struct page_state *ps, struct page *p,
 static int __get_hwpoison_page(struct page *page)
 {
 	struct page *head = compound_head(page);
+	int ret = 0;
+	bool hugetlb = false;
+
+	ret = get_hwpoison_huge_page(head, &hugetlb);
+	if (hugetlb)
+		return ret;
 
-	if (!PageHuge(head) && PageTransHuge(head)) {
+	/*
+	 * This check prevents from calling get_hwpoison_unless_zero()
+	 * for any unsupported type of page in order to reduce the risk of
+	 * unexpected races caused by taking a page refcount.
+	 */
+	if (!HWPoisonHandlable(head))
+		return 0;
+
+	if (PageTransHuge(head)) {
 		/*
 		 * Non anonymous thp exists only in allocation/free time. We
 		 * can't handle such a case correctly, so let's give it up.
@@ -1017,7 +1042,7 @@ try_again:
 			ret = -EIO;
 		}
 	} else {
-		if (PageHuge(p) || PageLRU(p) || __PageMovable(p)) {
+		if (PageHuge(p) || HWPoisonHandlable(p)) {
 			ret = 1;
 		} else {
 			/*
@@ -1527,7 +1552,12 @@ try_again:
 		return 0;
 	}
 
-	if (!PageTransTail(p) && !PageLRU(p))
+	/*
+	 * __munlock_pagevec may clear a writeback page's LRU flag without
+	 * page_lock. We need wait writeback completion for this page or it
+	 * may trigger vfs BUG while evict inode.
+	 */
+	if (!PageTransTail(p) && !PageLRU(p) && !PageWriteback(p))
 		goto identify_page_state;
 
 	/*