HWPOISON, hugetlb: enable error handling path for hugepage

This patch just enables handling path. Real containing and
recovering operation will be implemented in following patches.

Dependency:
  "hugetlb, rmap: add reverse mapping for hugepage."

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

1 files changed, 22 insertions, 17 deletions

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 620b0b461593..1ec68c80788e 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -45,6 +45,7 @@
 #include <linux/page-isolation.h>
 #include <linux/suspend.h>
 #include <linux/slab.h>
+#include <linux/hugetlb.h>
 #include "internal.h"
 
 int sysctl_memory_failure_early_kill __read_mostly = 0;
@@ -837,6 +838,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
         int ret;
         int i;
         int kill = 1;
+        struct page *hpage = compound_head(p);
 
         if (PageReserved(p) || PageSlab(p))
                 return SWAP_SUCCESS;
@@ -845,10 +847,10 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
          * This check implies we don't kill processes if their pages
          * are in the swap cache early. Those are always late kills.
          */
-        if (!page_mapped(p))
+        if (!page_mapped(hpage))
                 return SWAP_SUCCESS;
 
-        if (PageCompound(p) || PageKsm(p))
+        if (PageKsm(p))
                 return SWAP_FAIL;
 
         if (PageSwapCache(p)) {
@@ -863,10 +865,11 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
          * XXX: the dirty test could be racy: set_page_dirty() may not always
          * be called inside page lock (it's recommended but not enforced).
          */
-        mapping = page_mapping(p);
-        if (!PageDirty(p) && mapping && mapping_cap_writeback_dirty(mapping)) {
-                if (page_mkclean(p)) {
-                        SetPageDirty(p);
+        mapping = page_mapping(hpage);
+        if (!PageDirty(hpage) && mapping &&
+            mapping_cap_writeback_dirty(mapping)) {
+                if (page_mkclean(hpage)) {
+                        SetPageDirty(hpage);
                 } else {
                         kill = 0;
                         ttu |= TTU_IGNORE_HWPOISON;
@@ -885,14 +888,14 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
          * there's nothing that can be done.
          */
         if (kill)
-                collect_procs(p, &tokill);
+                collect_procs(hpage, &tokill);
 
         /*
          * try_to_unmap can fail temporarily due to races.
          * Try a few times (RED-PEN better strategy?)
          */
         for (i = 0; i < N_UNMAP_TRIES; i++) {
-                ret = try_to_unmap(p, ttu);
+                ret = try_to_unmap(hpage, ttu);
                 if (ret == SWAP_SUCCESS)
                         break;
                 pr_debug("MCE %#lx: try_to_unmap retry needed %d\n", pfn,  ret);
@@ -900,7 +903,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
 
         if (ret != SWAP_SUCCESS)
                 printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n",
-                                pfn, page_mapcount(p));
+                                pfn, page_mapcount(hpage));
 
         /*
          * Now that the dirty bit has been propagated to the
@@ -911,7 +914,7 @@ 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(p), trapno,
+        kill_procs_ao(&tokill, !!PageDirty(hpage), trapno,
                       ret != SWAP_SUCCESS, pfn);
 
         return ret;
@@ -921,6 +924,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
 {
         struct page_state *ps;
         struct page *p;
+        struct page *hpage;
         int res;
 
         if (!sysctl_memory_failure_recovery)
@@ -934,6 +938,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
         }
 
         p = pfn_to_page(pfn);
+        hpage = compound_head(p);
         if (TestSetPageHWPoison(p)) {
                 printk(KERN_ERR "MCE %#lx: already hardware poisoned\n", pfn);
                 return 0;
@@ -953,7 +958,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
          * that may make page_freeze_refs()/page_unfreeze_refs() mismatch.
          */
         if (!(flags & MF_COUNT_INCREASED) &&
-                !get_page_unless_zero(compound_head(p))) {
+                !get_page_unless_zero(hpage)) {
                 if (is_free_buddy_page(p)) {
                         action_result(pfn, "free buddy", DELAYED);
                         return 0;
@@ -971,9 +976,9 @@ 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))
+        if (!PageLRU(p) && !PageHuge(p))
                 shake_page(p, 0);
-        if (!PageLRU(p)) {
+        if (!PageLRU(p) && !PageHuge(p)) {
                 /*
                  * shake_page could have turned it free.
                  */
@@ -991,7 +996,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
          * It's very difficult to mess with pages currently under IO
          * and in many cases impossible, so we just avoid it here.
          */
-        lock_page_nosync(p);
+        lock_page_nosync(hpage);
 
         /*
          * unpoison always clear PG_hwpoison inside page lock
@@ -1004,8 +1009,8 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
         if (hwpoison_filter(p)) {
                 if (TestClearPageHWPoison(p))
                         atomic_long_dec(&mce_bad_pages);
-                unlock_page(p);
-                put_page(p);
+                unlock_page(hpage);
+                put_page(hpage);
                 return 0;
         }
 
@@ -1038,7 +1043,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
                 }
         }
 out:
-        unlock_page(p);
+        unlock_page(hpage);
         return res;
 }
 EXPORT_SYMBOL_GPL(__memory_failure);