1 files changed, 9 insertions, 6 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 2a3624adc0cf..17c508a941eb 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1988,9 +1988,12 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
         u64 nr_delalloc;
         u64 delalloc_end;
 
+
         WARN_ON(!PageLocked(page));
-        if (page->index > end_index) {
-                clear_extent_dirty(tree, start, page_end, GFP_NOFS);
+        page_offset = i_size & (PAGE_CACHE_SIZE - 1);
+        if (page->index > end_index ||
+           (page->index == end_index && !page_offset)) {
+                page->mapping->a_ops->invalidatepage(page, 0);
                 unlock_page(page);
                 return 0;
         }
@@ -1998,13 +2001,13 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
         if (page->index == end_index) {
                 char *userpage;
 
-                size_t offset = i_size & (PAGE_CACHE_SIZE - 1);
-
                 userpage = kmap_atomic(page, KM_USER0);
-                memset(userpage + offset, 0, PAGE_CACHE_SIZE - offset);
-                flush_dcache_page(page);
+                memset(userpage + page_offset, 0,
+                       PAGE_CACHE_SIZE - page_offset);
                 kunmap_atomic(userpage, KM_USER0);
+                flush_dcache_page(page);
         }
+        page_offset = 0;
 
         set_page_extent_mapped(page);