+static int ocfs2_check_if_ancestor(struct ocfs2_super *osb,
+ u64 src_inode_no, u64 dest_inode_no)
+{
+ int ret = 0, i = 0;
+ u64 parent_inode_no = 0;
+ u64 child_inode_no = src_inode_no;
+ struct inode *child_inode;
+
+#define MAX_LOOKUP_TIMES 32
+ while (1) {
+ child_inode = ocfs2_iget(osb, child_inode_no, 0, 0);
+ if (IS_ERR(child_inode)) {
+ ret = PTR_ERR(child_inode);
+ break;
+ }
+
+ ret = ocfs2_inode_lock(child_inode, NULL, 0);
+ if (ret < 0) {
+ iput(child_inode);
+ if (ret != -ENOENT)
+ mlog_errno(ret);
+ break;
+ }
+
+ ret = ocfs2_lookup_ino_from_name(child_inode, "..", 2,
+ &parent_inode_no);
+ ocfs2_inode_unlock(child_inode, 0);
+ iput(child_inode);
+ if (ret < 0) {
+ ret = -ENOENT;
+ break;
+ }
+
+ if (parent_inode_no == dest_inode_no) {
+ ret = 1;
+ break;
+ }
+
+ if (parent_inode_no == osb->root_inode->i_ino) {
+ ret = 0;
+ break;
+ }
+
+ child_inode_no = parent_inode_no;
+
+ if (++i >= MAX_LOOKUP_TIMES) {
+ mlog(ML_NOTICE, "max lookup times reached, filesystem "
+ "may have nested directories, "
+ "src inode: %llu, dest inode: %llu.\n",
+ (unsigned long long)src_inode_no,
+ (unsigned long long)dest_inode_no);
+ ret = 0;
+ break;
+ }
+ }
+
+ return ret;
+}
+