HWPOISON: Add invalidate_inode_page
Add a simple way to invalidate a single page
This is just a refactoring of the truncate.c code.
Originally from Fengguang, modified by Andi Kleen.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 8cbc0aa..b05bbde 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -796,6 +796,8 @@
int truncate_inode_page(struct address_space *mapping, struct page *page);
+int invalidate_inode_page(struct page *page);
+
#ifdef CONFIG_MMU
extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, unsigned int flags);
diff --git a/mm/truncate.c b/mm/truncate.c
index 2519a7c..ea132f7 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -146,6 +146,24 @@
return truncate_complete_page(mapping, page);
}
+/*
+ * Safely invalidate one page from its pagecache mapping.
+ * It only drops clean, unused pages. The page must be locked.
+ *
+ * Returns 1 if the page is successfully invalidated, otherwise 0.
+ */
+int invalidate_inode_page(struct page *page)
+{
+ struct address_space *mapping = page_mapping(page);
+ if (!mapping)
+ return 0;
+ if (PageDirty(page) || PageWriteback(page))
+ return 0;
+ if (page_mapped(page))
+ return 0;
+ return invalidate_complete_page(mapping, page);
+}
+
/**
* truncate_inode_pages - truncate range of pages specified by start & end byte offsets
* @mapping: mapping to truncate
@@ -312,12 +330,8 @@
if (lock_failed)
continue;
- if (PageDirty(page) || PageWriteback(page))
- goto unlock;
- if (page_mapped(page))
- goto unlock;
- ret += invalidate_complete_page(mapping, page);
-unlock:
+ ret += invalidate_inode_page(page);
+
unlock_page(page);
if (next > end)
break;
