mm: soft-offline: exit with failure for non anonymous thp

Currently memory_failure() doesn't handle non anonymous thp case, because we can hardly expect the error handling to be successful, and it can just hit some corner case which results in BUG_ON or something severe like that. This is also the case for soft offline code, so let's make it in the same way. Orignal code has a MF_COUNT_INCREASED check before put_hwpoison_page(), but it's unnecessary because get_any_page() is already called when running on this code, which takes a refcount of the target page regardress of the flag. So this patch also removes it. [[email protected]: fix build] Signed-off-by: Naoya Horiguchi <[email protected]> Cc: Andi Kleen <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
tadfisher · Jan 16, 2016 · 98fd1ef · 98fd1ef
1 parent acc14dc
commit 98fd1ef
Showing 1 changed file with 8 additions and 8 deletions.
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
@@ -1691,16 +1691,16 @@ static int soft_offline_in_use_page(struct page *page, int flags)
 
 	if (!PageHuge(page) && PageTransHuge(hpage)) {
 		lock_page(hpage);
-		ret = split_huge_page(hpage);
-		unlock_page(hpage);
-		if (unlikely(ret || PageTransCompound(page) ||
-			     !PageAnon(page))) {
-			pr_info("soft offline: %#lx: failed to split THP\n",
-				page_to_pfn(page));
-			if (flags & MF_COUNT_INCREASED)
-				put_hwpoison_page(hpage);
+		if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
+			unlock_page(hpage);
+			if (!PageAnon(hpage))
+				pr_info("soft offline: %#lx: non anonymous thp\n", page_to_pfn(page));
+			else
+				pr_info("soft offline: %#lx: thp split failed\n", page_to_pfn(page));
+			put_hwpoison_page(hpage);
 			return -EBUSY;
 		}
+		unlock_page(hpage);
 		get_hwpoison_page(page);
 		put_hwpoison_page(hpage);
 	}