sched: make early bootup sched_clock() use safer

[sfrench/cifs-2.6.git] / mm / truncate.c

diff --git a/mm/truncate.c b/mm/truncate.c
index 7c994f2d614519df007e16eb93f1a8a393589a2e..c35c49e54fb6527eae91cb02177fc2b05a00abad 100644 (file)
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -8,6 +8,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/backing-dev.h>
 #include <linux/mm.h>
 #include <linux/swap.h>
 #include <linux/module.h>
@@ -20,7 +21,7 @@
 
 
 /**
- * do_invalidatepage - invalidate part of all of a page
+ * do_invalidatepage - invalidate part or all of a page
  * @page: the page which is affected
  * @offset: the index of the truncation point
  *
@@ -47,7 +48,7 @@ void do_invalidatepage(struct page *page, unsigned long offset)
 
 static inline void truncate_partial_page(struct page *page, unsigned partial)
 {
-       zero_user_page(page, partial, PAGE_CACHE_SIZE - partial, KM_USER0);
+       zero_user_segment(page, partial, PAGE_CACHE_SIZE);
        if (PagePrivate(page))
                do_invalidatepage(page, partial);
 }
@@ -72,6 +73,8 @@ void cancel_dirty_page(struct page *page, unsigned int account_size)
                struct address_space *mapping = page->mapping;
                if (mapping && mapping_cap_account_dirty(mapping)) {
                        dec_zone_page_state(page, NR_FILE_DIRTY);
+                       dec_bdi_stat(mapping->backing_dev_info,
+                                       BDI_RECLAIMABLE);
                        if (account_size)
                                task_io_account_cancelled_write(account_size);
                }
@@ -81,8 +84,8 @@ EXPORT_SYMBOL(cancel_dirty_page);
 
 /*
  * If truncate cannot remove the fs-private metadata from the page, the page
- * becomes anonymous.  It will be left on the LRU and may even be mapped into
- * user pagetables if we're racing with filemap_nopage().
+ * becomes orphaned.  It will be left on the LRU and may even be mapped into
+ * user pagetables if we're racing with filemap_fault().
  *
  * We need to bale out if page->mapping is no longer equal to the original
  * mapping.  This happens a) when the VM reclaimed the page while we waited on
@@ -95,14 +98,14 @@ truncate_complete_page(struct address_space *mapping, struct page *page)
        if (page->mapping != mapping)
                return;
 
-       cancel_dirty_page(page, PAGE_CACHE_SIZE);
-
        if (PagePrivate(page))
                do_invalidatepage(page, 0);
 
+       cancel_dirty_page(page, PAGE_CACHE_SIZE);
+
+       remove_from_page_cache(page);
        ClearPageUptodate(page);
        ClearPageMappedToDisk(page);
-       remove_from_page_cache(page);
        page_cache_release(page);       /* pagecache ref */
 }
 
@@ -192,6 +195,11 @@ 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);
                        unlock_page(page);
                }
@@ -229,6 +237,11 @@ 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);
+                       }
                        if (page->index > next)
                                next = page->index;
                        next++;
@@ -405,7 +418,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
                                break;
                        }
                        wait_on_page_writeback(page);
-                       while (page_mapped(page)) {
+                       if (page_mapped(page)) {
                                if (!did_range_unmap) {
                                        /*
                                         * Zap the rest of the file in one hit.
@@ -425,6 +438,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
                                          PAGE_CACHE_SIZE, 0);
                                }
                        }
+                       BUG_ON(page_mapped(page));
                        ret = do_launder_page(mapping, page);
                        if (ret == 0 && !invalidate_complete_page2(mapping, page))
                                ret = -EIO;