[PATCH V3 2/2] MCE: fix an error of mce_bad_pages statistics

[Xishi Qiu]

1) adjust the function structure, there are too many return points
   randomly intermingled with some "goto done" return points.
2) use atomic_long_inc instead of atomic_long_add.

Signed-off-by: Xishi Qiu <qiuxi...@huawei.com>
Signed-off-by: Jiang Liu <jiang....@huawei.com>
---
 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 9b74983..81f942d 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;

@@ -1437,7 +1438,7 @@ 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 */
@@ -1447,7 +1448,7 @@ done:
        unlock_page(hpage);

        dequeue_hwpoisoned_huge_page(hpage);
-
+out:
        return ret;
 }

@@ -1479,24 +1480,28 @@ 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;

@@ -1515,14 +1520,15 @@ 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;
        }

        /*
@@ -1577,14 +1583,14 @@ 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 */
        lock_page(page);
-       atomic_long_add(1, &mce_bad_pages);
+       atomic_long_inc(&mce_bad_pages);
        SetPageHWPoison(page);
        unlock_page(page);
-
+out:
        return ret;
 }
-- 
1.7.1


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