[PATCH V4 2/3] MCE: fix an error of mce_bad_pages statistics

[Xishi Qiu]

There are too many return points randomly intermingled with some
"goto done" return points. So adjust the function structure, one
for the success path, the other for the failure path.
Use atomic_long_inc instead of atomic_long_add.

Signed-off-by: Xishi Qiu <qiuxishi@xxxxxxxxxx>
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
---
 mm/memory-failure.c |   34 ++++++++++++++++++++--------------
 1 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 3a8b4b2..e513a7b 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1421,12 +1421,13 @@ static int soft_offline_huge_page(struct page *page, int flags)

 	if (PageHWPoison(hpage)) {
 		pr_info("soft offline: %#lx hugepage already poisoned\n", pfn);
-		return -EBUSY;
+		ret = -EBUSY;
+		goto out;
 	}

 	ret = get_any_page(page, pfn, flags);
 	if (ret < 0)
-		return ret;
+		goto out;
 	if (ret == 0)
 		goto done;

@@ -1437,14 +1438,14 @@ static int soft_offline_huge_page(struct page *page, int flags)
 	if (ret) {
 		pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
 			pfn, ret, page->flags);
-		return ret;
+		goto out;
 	}
 done:
 	/* keep elevated page count for bad page */
 	atomic_long_add(1 << compound_trans_order(hpage), &mce_bad_pages);
 	set_page_hwpoison_huge_page(hpage);
 	dequeue_hwpoisoned_huge_page(hpage);
-
+out:
 	return ret;
 }

@@ -1476,24 +1477,28 @@ int soft_offline_page(struct page *page, int flags)
 	unsigned long pfn = page_to_pfn(page);
 	struct page *hpage = compound_trans_head(page);

-	if (PageHuge(page))
-		return soft_offline_huge_page(page, flags);
+	if (PageHuge(page)) {
+		ret = soft_offline_huge_page(page, flags);
+		goto out;
+	}
 	if (PageTransHuge(hpage)) {
 		if (PageAnon(hpage) && unlikely(split_huge_page(hpage))) {
 			pr_info("soft offline: %#lx: failed to split THP\n",
 				pfn);
-			return -EBUSY;
+			ret = -EBUSY;
+			goto out;
 		}
 	}

 	if (PageHWPoison(page)) {
 		pr_info("soft offline: %#lx page already poisoned\n", pfn);
-		return -EBUSY;
+		ret = -EBUSY;
+		goto out;
 	}

 	ret = get_any_page(page, pfn, flags);
 	if (ret < 0)
-		return ret;
+		goto out;
 	if (ret == 0)
 		goto done;

@@ -1512,14 +1517,15 @@ int soft_offline_page(struct page *page, int flags)
 		 */
 		ret = get_any_page(page, pfn, 0);
 		if (ret < 0)
-			return ret;
+			goto out;
 		if (ret == 0)
 			goto done;
 	}
 	if (!PageLRU(page)) {
 		pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n",
 			pfn, page->flags);
-		return -EIO;
+		ret = -EIO;
+		goto out;
 	}

 	/*
@@ -1574,12 +1580,12 @@ int soft_offline_page(struct page *page, int flags)
 			pfn, ret, page_count(page), page->flags);
 	}
 	if (ret)
-		return ret;
+		goto out;

 done:
 	/* keep elevated page count for bad page */
-	atomic_long_add(1, &mce_bad_pages);
+	atomic_long_inc(&mce_bad_pages);
 	SetPageHWPoison(page);
-
+out:
 	return ret;
 }
-- 
1.7.1


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