[3.19-stable only] Revert "perf symbols: Fix dso lookup by long name and missing buildids"

This reverts commit fe4cb8a3.

Not suitable for 3.19-stable: no __dso__findlink_by_longname().

Cc: Luis Henriques <luis.henriques@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

tools/perf/util/dso.c

@@ -773,7 +773,6 @@ static struct dso *dso__findlink_by_longname(struct rb_root *root,
 		/* Add new node and rebalance tree */
 		rb_link_node(&dso->rb_node, parent, p);
 		rb_insert_color(&dso->rb_node, root);
-		dso->root = root;
 	}
 	return NULL;
 }
@@ -786,30 +785,15 @@ dso__find_by_longname(const struct rb_root *root, const char *name)
 
 void dso__set_long_name(struct dso *dso, const char *name, bool name_allocated)
 {
-	struct rb_root *root = dso->root;
-
 	if (name == NULL)
 		return;
 
 	if (dso->long_name_allocated)
 		free((char *)dso->long_name);
 
-	if (root) {
-		rb_erase(&dso->rb_node, root);
-		/*
-		 * __dso__findlink_by_longname() isn't guaranteed to add it
-		 * back, so a clean removal is required here.
-		 */
-		RB_CLEAR_NODE(&dso->rb_node);
-		dso->root = NULL;
-	}
-
 	dso->long_name		 = name;
 	dso->long_name_len	 = strlen(name);
 	dso->long_name_allocated = name_allocated;
-
-	if (root)
-		__dso__findlink_by_longname(root, dso, NULL);
 }
 
 void dso__set_short_name(struct dso *dso, const char *name, bool name_allocated)
@@ -902,7 +886,6 @@ struct dso *dso__new(const char *name)
 		dso->kernel = DSO_TYPE_USER;
 		dso->needs_swap = DSO_SWAP__UNSET;
 		RB_CLEAR_NODE(&dso->rb_node);
-		dso->root = NULL;
 		INIT_LIST_HEAD(&dso->node);
 		INIT_LIST_HEAD(&dso->data.open_entry);
 	}

tools/perf/util/dso.h

@@ -104,7 +104,6 @@ struct dsos {
 struct dso {
 	struct list_head node;
 	struct rb_node	 rb_node;	/* rbtree node sorted by long name */
-	struct rb_root	 *root;		/* root of rbtree that rb_node is in */
 	struct rb_root	 symbols[MAP__NR_TYPES];
 	struct rb_root	 symbol_names[MAP__NR_TYPES];
 	void		 *a2l;

tools/perf/util/machine.c

@@ -84,7 +84,6 @@ static void dsos__delete(struct dsos *dsos)
 
 	list_for_each_entry_safe(pos, n, &dsos->head, node) {
 		RB_CLEAR_NODE(&pos->rb_node);
-		pos->root = NULL;
 		list_del(&pos->node);
 		dso__delete(pos);
 	}