swap_info: private to swapfile.c

[safe/jmp/linux-2.6] / mm / truncate.c

diff --git a/mm/truncate.c b/mm/truncate.c
index 5900afc..2c147a7 100644 (file)
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -93,11 +93,11 @@ EXPORT_SYMBOL(cancel_dirty_page);
  * its lock, b) when a concurrent invalidate_mapping_pages got there first and
  * c) when tmpfs swizzles a page between a tmpfs inode and swapper_space.
  */
-static void
+static int
 truncate_complete_page(struct address_space *mapping, struct page *page)
 {
        if (page->mapping != mapping)
-               return;
+               return -EIO;
 
        if (page_has_private(page))
                do_invalidatepage(page, 0);
@@ -108,6 +108,7 @@ truncate_complete_page(struct address_space *mapping, struct page *page)
        remove_from_page_cache(page);
        ClearPageMappedToDisk(page);
        page_cache_release(page);       /* pagecache ref */
+       return 0;
 }
 
 /*
@@ -135,6 +136,51 @@ invalidate_complete_page(struct address_space *mapping, struct page *page)
        return ret;
 }
 
+int truncate_inode_page(struct address_space *mapping, struct page *page)
+{
+       if (page_mapped(page)) {
+               unmap_mapping_range(mapping,
+                                  (loff_t)page->index << PAGE_CACHE_SHIFT,
+                                  PAGE_CACHE_SIZE, 0);
+       }
+       return truncate_complete_page(mapping, page);
+}
+
+/*
+ * Used to get rid of pages on hardware memory corruption.
+ */
+int generic_error_remove_page(struct address_space *mapping, struct page *page)
+{
+       if (!mapping)
+               return -EINVAL;
+       /*
+        * Only punch for normal data pages for now.
+        * Handling other types like directories would need more auditing.
+        */
+       if (!S_ISREG(mapping->host->i_mode))
+               return -EIO;
+       return truncate_inode_page(mapping, page);
+}
+EXPORT_SYMBOL(generic_error_remove_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
@@ -196,12 +242,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
                                unlock_page(page);
                                continue;
                        }
-                       if (page_mapped(page)) {
-                               unmap_mapping_range(mapping,
-                                 (loff_t)page_index<<PAGE_CACHE_SHIFT,
-                                 PAGE_CACHE_SIZE, 0);
-                       }
-                       truncate_complete_page(mapping, page);
+                       truncate_inode_page(mapping, page);
                        unlock_page(page);
                }
                pagevec_release(&pvec);
@@ -238,15 +279,10 @@ void truncate_inode_pages_range(struct address_space *mapping,
                                break;
                        lock_page(page);
                        wait_on_page_writeback(page);
-                       if (page_mapped(page)) {
-                               unmap_mapping_range(mapping,
-                                 (loff_t)page->index<<PAGE_CACHE_SHIFT,
-                                 PAGE_CACHE_SIZE, 0);
-                       }
+                       truncate_inode_page(mapping, page);
                        if (page->index > next)
                                next = page->index;
                        next++;
-                       truncate_complete_page(mapping, page);
                        unlock_page(page);
                }
                pagevec_release(&pvec);
@@ -311,12 +347,8 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping,
                        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;
@@ -458,7 +490,7 @@ EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);
  * Any pages which are found to be mapped into pagetables are unmapped prior to
  * invalidation.
  *
- * Returns -EIO if any pages could not be invalidated.
+ * Returns -EBUSY if any pages could not be invalidated.
  */
 int invalidate_inode_pages2(struct address_space *mapping)
 {