HWPOISON, hugetlb: isolate corrupted hugepage

If error hugepage is not in-use, we can fully recovery from error
by dequeuing it from freelist, so return RECOVERY.
Otherwise whether or not we can recovery depends on user processes,
so return DELAYED.

Dependency:
  "HWPOISON, hugetlb: enable error handling path for hugepage"

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
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, 16 insertions, 0 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index aa3c517..8c163f6 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2825,3 +2825,19 @@ void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
 	hugetlb_put_quota(inode->i_mapping, (chg - freed));
 	hugetlb_acct_memory(h, -(chg - freed));
 }
+
+/*
+ * This function is called from memory failure code.
+ * Assume the caller holds page lock of the head page.
+ */
+void __isolate_hwpoisoned_huge_page(struct page *hpage)
+{
+	struct hstate *h = page_hstate(hpage);
+	int nid = page_to_nid(hpage);
+
+	spin_lock(&hugetlb_lock);
+	list_del(&hpage->lru);
+	h->free_huge_pages--;
+	h->free_huge_pages_node[nid]--;
+	spin_unlock(&hugetlb_lock);
+}