+static struct ctl_table *is_branch_in(struct ctl_table *branch,
+ struct ctl_table *table)
+{
+ struct ctl_table *p;
+ const char *s = branch->procname;
+
+ /* branch should have named subdirectory as its first element */
+ if (!s || !branch->child)
+ return NULL;
+
+ /* ... and nothing else */
+ if (branch[1].procname || branch[1].ctl_name)
+ return NULL;
+
+ /* table should contain subdirectory with the same name */
+ for (p = table; p->procname || p->ctl_name; p++) {
+ if (!p->child)
+ continue;
+ if (p->procname && strcmp(p->procname, s) == 0)
+ return p;
+ }
+ return NULL;
+}
+
+/* see if attaching q to p would be an improvement */
+static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
+{
+ struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
+ struct ctl_table *next;
+ int is_better = 0;
+ int not_in_parent = !p->attached_by;
+
+ while ((next = is_branch_in(by, to)) != NULL) {
+ if (by == q->attached_by)
+ is_better = 1;
+ if (to == p->attached_by)
+ not_in_parent = 1;
+ by = by->child;
+ to = next->child;
+ }
+
+ if (is_better && not_in_parent) {
+ q->attached_by = by;
+ q->attached_to = to;
+ q->parent = p;
+ }
+}
+