1 files changed, 72 insertions, 22 deletions

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 548fbd70f026..0207c2f6f8bd 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -233,8 +233,8 @@ void shake_page(struct page *p, int access)
         }
 
         /*
-         * Only all shrink_slab here (which would also
-         * shrink other caches) if access is not potentially fatal.
+         * Only call shrink_slab here (which would also shrink other caches) if
+         * access is not potentially fatal.
          */
         if (access) {
                 int nr;
@@ -386,8 +386,6 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill,
         struct task_struct *tsk;
         struct anon_vma *av;
 
-        if (!PageHuge(page) && unlikely(split_huge_page(page)))
-                return;
         read_lock(&tasklist_lock);
         av = page_lock_anon_vma(page);
         if (av == NULL) /* Not actually mapped anymore */
@@ -856,6 +854,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
         int ret;
         int kill = 1;
         struct page *hpage = compound_head(p);
+        struct page *ppage;
 
         if (PageReserved(p) || PageSlab(p))
                 return SWAP_SUCCESS;
@@ -897,6 +896,44 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
         }
 
         /*
+         * ppage: poisoned page
+         *   if p is regular page(4k page)
+         *        ppage == real poisoned page;
+         *   else p is hugetlb or THP, ppage == head page.
+         */
+        ppage = hpage;
+
+        if (PageTransHuge(hpage)) {
+                /*
+                 * Verify that this isn't a hugetlbfs head page, the check for
+                 * PageAnon is just for avoid tripping a split_huge_page
+                 * internal debug check, as split_huge_page refuses to deal with
+                 * anything that isn't an anon page. PageAnon can't go away fro
+                 * under us because we hold a refcount on the hpage, without a
+                 * refcount on the hpage. split_huge_page can't be safely called
+                 * in the first place, having a refcount on the tail isn't
+                 * enough * to be safe.
+                 */
+                if (!PageHuge(hpage) && PageAnon(hpage)) {
+                        if (unlikely(split_huge_page(hpage))) {
+                                /*
+                                 * FIXME: if splitting THP is failed, it is
+                                 * better to stop the following operation rather
+                                 * than causing panic by unmapping. System might
+                                 * survive if the page is freed later.
+                                 */
+                                printk(KERN_INFO
+                                        "MCE %#lx: failed to split THP\n", pfn);
+
+                                BUG_ON(!PageHWPoison(p));
+                                return SWAP_FAIL;
+                        }
+                        /* THP is split, so ppage should be the real poisoned page. */
+                        ppage = p;
+                }
+        }
+
+        /*
          * First collect all the processes that have the page
          * mapped in dirty form.  This has to be done before try_to_unmap,
          * because ttu takes the rmap data structures down.
@@ -905,12 +942,18 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
          * there's nothing that can be done.
          */
         if (kill)
-                collect_procs(hpage, &tokill);
+                collect_procs(ppage, &tokill);
+
+        if (hpage != ppage)
+                lock_page_nosync(ppage);
 
-        ret = try_to_unmap(hpage, ttu);
+        ret = try_to_unmap(ppage, ttu);
         if (ret != SWAP_SUCCESS)
                 printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n",
-                                pfn, page_mapcount(hpage));
+                                pfn, page_mapcount(ppage));
+
+        if (hpage != ppage)
+                unlock_page(ppage);
 
         /*
          * Now that the dirty bit has been propagated to the
@@ -921,7 +964,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
          * use a more force-full uncatchable kill to prevent
          * any accesses to the poisoned memory.
          */
-        kill_procs_ao(&tokill, !!PageDirty(hpage), trapno,
+        kill_procs_ao(&tokill, !!PageDirty(ppage), trapno,
                       ret != SWAP_SUCCESS, p, pfn);
 
         return ret;
@@ -1022,19 +1065,22 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
          * The check (unnecessarily) ignores LRU pages being isolated and
          * walked by the page reclaim code, however that's not a big loss.
          */
-        if (!PageLRU(p) && !PageHuge(p))
-                shake_page(p, 0);
-        if (!PageLRU(p) && !PageHuge(p)) {
-                /*
-                 * shake_page could have turned it free.
-                 */
-                if (is_free_buddy_page(p)) {
-                        action_result(pfn, "free buddy, 2nd try", DELAYED);
-                        return 0;
+        if (!PageHuge(p) && !PageTransCompound(p)) {
+                if (!PageLRU(p))
+                        shake_page(p, 0);
+                if (!PageLRU(p)) {
+                        /*
+                         * shake_page could have turned it free.
+                         */
+                        if (is_free_buddy_page(p)) {
+                                action_result(pfn, "free buddy, 2nd try",
+                                                DELAYED);
+                                return 0;
+                        }
+                        action_result(pfn, "non LRU", IGNORED);
+                        put_page(p);
+                        return -EBUSY;
                 }
-                action_result(pfn, "non LRU", IGNORED);
-                put_page(p);
-                return -EBUSY;
         }
 
         /*
@@ -1064,7 +1110,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
          * For error on the tail page, we should set PG_hwpoison
          * on the head page to show that the hugepage is hwpoisoned
          */
-        if (PageTail(p) && TestSetPageHWPoison(hpage)) {
+        if (PageHuge(p) && PageTail(p) && TestSetPageHWPoison(hpage)) {
                 action_result(pfn, "hugepage already hardware poisoned",
                                 IGNORED);
                 unlock_page(hpage);
@@ -1295,7 +1341,10 @@ static int soft_offline_huge_page(struct page *page, int flags)
         ret = migrate_huge_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0,
                                 true);
         if (ret) {
-                putback_lru_pages(&pagelist);
+                struct page *page1, *page2;
+                list_for_each_entry_safe(page1, page2, &pagelist, lru)
+                        put_page(page1);
+
                 pr_debug("soft offline: %#lx: migration failed %d, type %lx\n",
                          pfn, ret, page->flags);
                 if (ret > 0)
@@ -1419,6 +1468,7 @@ int soft_offline_page(struct page *page, int flags)
                 ret = migrate_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL,
                                                                 0, true);
                 if (ret) {
+                        putback_lru_pages(&pagelist);
                         pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
                                 pfn, ret, page->flags);
                         if (ret > 0)