Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[cascardo/linux.git] / mm / memory-failure.c

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index c53543d..1f4446a 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -909,6 +909,18 @@ int get_hwpoison_page(struct page *page)
         * directly for tail pages.
         */
        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.
+                * This should be better than triggering BUG_ON when kernel
+                * tries to touch the "partially handled" page.
+                */
+               if (!PageAnon(head)) {
+                       pr_err("MCE: %#lx: non anonymous thp\n",
+                               page_to_pfn(page));
+                       return 0;
+               }
+
                if (get_page_unless_zero(head)) {
                        if (PageTail(page))
                                get_page(page);
@@ -1134,17 +1146,11 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
        }
 
        if (!PageHuge(p) && PageTransHuge(hpage)) {
-               if (!PageAnon(hpage)) {
-                       pr_err("MCE: %#lx: non anonymous thp\n", pfn);
-                       if (TestClearPageHWPoison(p))
-                               atomic_long_sub(nr_pages, &num_poisoned_pages);
-                       put_page(p);
-                       if (p != hpage)
-                               put_page(hpage);
-                       return -EBUSY;
-               }
-               if (unlikely(split_huge_page(hpage))) {
-                       pr_err("MCE: %#lx: thp split failed\n", pfn);
+               if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
+                       if (!PageAnon(hpage))
+                               pr_err("MCE: %#lx: non anonymous thp\n", pfn);
+                       else
+                               pr_err("MCE: %#lx: thp split failed\n", pfn);
                        if (TestClearPageHWPoison(p))
                                atomic_long_sub(nr_pages, &num_poisoned_pages);
                        put_page(p);
@@ -1209,9 +1215,9 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
        if (!PageHWPoison(p)) {
                printk(KERN_ERR "MCE %#lx: just unpoisoned\n", pfn);
                atomic_long_sub(nr_pages, &num_poisoned_pages);
+               unlock_page(hpage);
                put_page(hpage);
-               res = 0;
-               goto out;
+               return 0;
        }
        if (hwpoison_filter(p)) {
                if (TestClearPageHWPoison(p))
@@ -1535,6 +1541,8 @@ static int get_any_page(struct page *page, unsigned long pfn, int flags)
                 */
                ret = __get_any_page(page, pfn, 0);
                if (!PageLRU(page)) {
+                       /* Drop page reference which is from __get_any_page() */
+                       put_page(page);
                        pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n",
                                pfn, page->flags);
                        return -EIO;
@@ -1564,13 +1572,12 @@ static int soft_offline_huge_page(struct page *page, int flags)
        unlock_page(hpage);
 
        ret = isolate_huge_page(hpage, &pagelist);
-       if (ret) {
-               /*
-                * get_any_page() and isolate_huge_page() takes a refcount each,
-                * so need to drop one here.
-                */
-               put_page(hpage);
-       } else {
+       /*
+        * get_any_page() and isolate_huge_page() takes a refcount each,
+        * so need to drop one here.
+        */
+       put_page(hpage);
+       if (!ret) {
                pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);
                return -EBUSY;
        }
@@ -1656,6 +1663,8 @@ static int __soft_offline_page(struct page *page, int flags)
                inc_zone_page_state(page, NR_ISOLATED_ANON +
                                        page_is_file_cache(page));
                list_add(&page->lru, &pagelist);
+               if (!TestSetPageHWPoison(page))
+                       atomic_long_inc(&num_poisoned_pages);
                ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
                                        MIGRATE_SYNC, MR_MEMORY_FAILURE);
                if (ret) {
@@ -1670,9 +1679,8 @@ static int __soft_offline_page(struct page *page, int flags)
                                pfn, ret, page->flags);
                        if (ret > 0)
                                ret = -EIO;
-               } else {
-                       SetPageHWPoison(page);
-                       atomic_long_inc(&num_poisoned_pages);
+                       if (TestClearPageHWPoison(page))
+                               atomic_long_dec(&num_poisoned_pages);
                }
        } else {
                pr_info("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n",