GFS2: Fix cache coherency between truncate and O_DIRECT read

If a page was partially zeroed as the result of a truncate, then it was
not being correctly marked dirty. This resulted in the deleted data
reappearing if the file was read back via direct I/O.

Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 1153a078920c..329763530dc0 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -1012,7 +1012,7 @@ static int gfs2_block_truncate_page(struct address_space *mapping)
                 gfs2_trans_add_bh(ip->i_gl, bh, 0);
 
         zero_user(page, offset, length);
-
+        mark_buffer_dirty(bh);
 unlock:
         unlock_page(page);
         page_cache_release(page);