ocfs2: Don't duplicate pages past i_size during CoW.
During CoW, the pages after i_size don't contain valid data, so there's
no need to read and duplicate them.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index 32949df..3ac5aa7 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -2931,6 +2931,12 @@
offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits;
end = offset + (new_len << OCFS2_SB(sb)->s_clustersize_bits);
+ /*
+ * We only duplicate pages until we reach the page contains i_size - 1.
+ * So trim 'end' to i_size.
+ */
+ if (end > i_size_read(context->inode))
+ end = i_size_read(context->inode);
while (offset < end) {
page_index = offset >> PAGE_CACHE_SHIFT;