1 files changed, 20 insertions, 13 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 517860f2d75b..d1f1b54d3108 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -35,6 +35,7 @@
 #include <linux/hash.h>
 #include <linux/suspend.h>
 #include <linux/buffer_head.h>
+#include <linux/task_io_accounting_ops.h>
 #include <linux/bio.h>
 #include <linux/notifier.h>
 #include <linux/cpu.h>
@@ -724,20 +725,21 @@ int __set_page_dirty_buffers(struct page *page)
         }
         spin_unlock(&mapping->private_lock);
 
-        if (!TestSetPageDirty(page)) {
-                write_lock_irq(&mapping->tree_lock);
-                if (page->mapping) {    /* Race with truncate? */
-                        if (mapping_cap_account_dirty(mapping))
-                                __inc_zone_page_state(page, NR_FILE_DIRTY);
-                        radix_tree_tag_set(&mapping->page_tree,
-                                                page_index(page),
-                                                PAGECACHE_TAG_DIRTY);
+        if (TestSetPageDirty(page))
+                return 0;
+
+        write_lock_irq(&mapping->tree_lock);
+        if (page->mapping) {    /* Race with truncate? */
+                if (mapping_cap_account_dirty(mapping)) {
+                        __inc_zone_page_state(page, NR_FILE_DIRTY);
+                        task_io_account_write(PAGE_CACHE_SIZE);
                 }
-                write_unlock_irq(&mapping->tree_lock);
-                __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
-                return 1;
+                radix_tree_tag_set(&mapping->page_tree,
+                                page_index(page), PAGECACHE_TAG_DIRTY);
         }
-        return 0;
+        write_unlock_irq(&mapping->tree_lock);
+        __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
+        return 1;
 }
 EXPORT_SYMBOL(__set_page_dirty_buffers);
 
@@ -2851,8 +2853,13 @@ int try_to_free_buffers(struct page *page)
                  * could encounter a non-uptodate page, which is unresolvable.
                  * This only applies in the rare case where try_to_free_buffers
                  * succeeds but the page is not freed.
+                 *
+                 * Also, during truncate, discard_buffer will have marked all
+                 * the page's buffers clean.  We discover that here and clean
+                 * the page also.
                  */
-                clear_page_dirty(page);
+                if (test_clear_page_dirty(page))
+                        task_io_account_cancelled_write(PAGE_CACHE_SIZE);
         }
 out:
         if (buffers_to_free) {