mm/hwpoison: introduce put_hwpoison_page to put refcount for memory error handling

Introduce put_hwpoison_page to put refcount for memory error handling.

Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Suggested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/mm.h b/include/linux/mm.h
index bab8ff8..11df1a8 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2169,6 +2169,7 @@ extern int memory_failure(unsigned long pfn, int trapno, int flags);
 extern void memory_failure_queue(unsigned long pfn, int trapno, int flags);
 extern int unpoison_memory(unsigned long pfn);
 extern int get_hwpoison_page(struct page *page);
+extern void put_hwpoison_page(struct page *page);
 extern int sysctl_memory_failure_early_kill;
 extern int sysctl_memory_failure_recovery;
 extern void shake_page(struct page *p, int access);

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 863544d..5ceb825 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -934,6 +934,27 @@ int get_hwpoison_page(struct page *page)
 }
 EXPORT_SYMBOL_GPL(get_hwpoison_page);
 
+/**
+ * put_hwpoison_page() - Put refcount for memory error handling:
+ * @page:      raw error page (hit by memory error)
+ */
+void put_hwpoison_page(struct page *page)
+{
+       struct page *head = compound_head(page);
+
+       if (PageHuge(head)) {
+               put_page(head);
+               return;
+       }
+
+       if (PageTransHuge(head))
+               if (page != head)
+                       put_page(head);
+
+       put_page(page);
+}
+EXPORT_SYMBOL_GPL(put_hwpoison_page);
+
 /*
  * Do all that is necessary to remove user space mappings. Unmap
  * the pages and send SIGBUS to the processes if the data was dirty.