hwpoison: fix the handling path of the victimized page frame that belong to non-LRU

Until now, the kernel has the same policy to handle victimized page frames
that belong to kernel-space(reserved/slab-subsystem) or non-LRU(unknown
page state).  In other word, the result of handling either of these
victimized page frames is (IGNORED | FAILED), and the return value of
memory_failure() is -EBUSY.

This patch is to avoid that memory_failure() returns very soon due to the
"true" value of (!PageLRU(p)), and it also ensures that action_result()
can report more precise information("reserved kernel", "kernel slab", and
"unknown page state") instead of "non LRU", especially for memory errors
which are detected by memory-scrubbing.

Signed-off-by: Chen Yucong <slaoub@gmail.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index cd8989c1027ea6e2446af6ff148b5a947c8cbc0f..c6399e32893178b835457388371e8e4f85512361 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -895,7 +895,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
        struct page *hpage = *hpagep;
        struct page *ppage;
 
-       if (PageReserved(p) || PageSlab(p))
+       if (PageReserved(p) || PageSlab(p) || !PageLRU(p))
                return SWAP_SUCCESS;
 
        /*
@@ -1159,9 +1159,6 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
                                        action_result(pfn, "free buddy, 2nd try", DELAYED);
                                return 0;
                        }
-                       action_result(pfn, "non LRU", IGNORED);
-                       put_page(p);
-                       return -EBUSY;
                }
        }
 
@@ -1194,6 +1191,9 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
                return 0;
        }
 
+       if (!PageHuge(p) && !PageTransTail(p) && !PageLRU(p))
+               goto identify_page_state;
+
        /*
         * For error on the tail page, we should set PG_hwpoison
         * on the head page to show that the hugepage is hwpoisoned
@@ -1243,6 +1243,7 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
                goto out;
        }
 
+identify_page_state:
        res = -EBUSY;
        /*
         * The first check uses the current page flags which may not have any