127 void init_ro_spine(struct ro_spine *s, struct dm_btree_info *info)  in init_ro_spine()  argument
129 	s->info = info;  in init_ro_spine()
130 	s->count = 0;  in init_ro_spine()
131 	s->nodes[0] = NULL;  in init_ro_spine()
132 	s->nodes[1] = NULL;  in init_ro_spine()
135 int exit_ro_spine(struct ro_spine *s)  in exit_ro_spine()  argument
139 	for (i = 0; i < s->count; i++) {  in exit_ro_spine()
140 		unlock_block(s->info, s->nodes[i]);  in exit_ro_spine()
146 int ro_step(struct ro_spine *s, dm_block_t new_child)  in ro_step()  argument
150 	if (s->count == 2) {  in ro_step()
151 		unlock_block(s->info, s->nodes[0]);  in ro_step()
152 		s->nodes[0] = s->nodes[1];  in ro_step()
153 		s->count--;  in ro_step()
156 	r = bn_read_lock(s->info, new_child, s->nodes + s->count);  in ro_step()
158 		s->count++;  in ro_step()
163 void ro_pop(struct ro_spine *s)  in ro_pop()  argument
165 	BUG_ON(!s->count);  in ro_pop()
166 	--s->count;  in ro_pop()
167 	unlock_block(s->info, s->nodes[s->count]);  in ro_pop()
170 struct btree_node *ro_node(struct ro_spine *s)  in ro_node()  argument
174 	BUG_ON(!s->count);  in ro_node()
175 	block = s->nodes[s->count - 1];  in ro_node()
182 void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info)  in init_shadow_spine()  argument
184 	s->info = info;  in init_shadow_spine()
185 	s->count = 0;  in init_shadow_spine()
188 int exit_shadow_spine(struct shadow_spine *s)  in exit_shadow_spine()  argument
192 	for (i = 0; i < s->count; i++) {  in exit_shadow_spine()
193 		unlock_block(s->info, s->nodes[i]);  in exit_shadow_spine()
199 int shadow_step(struct shadow_spine *s, dm_block_t b,  in shadow_step()  argument
204 	if (s->count == 2) {  in shadow_step()
205 		unlock_block(s->info, s->nodes[0]);  in shadow_step()
206 		s->nodes[0] = s->nodes[1];  in shadow_step()
207 		s->count--;  in shadow_step()
210 	r = bn_shadow(s->info, b, vt, s->nodes + s->count);  in shadow_step()
212 		if (!s->count)  in shadow_step()
213 			s->root = dm_block_location(s->nodes[0]);  in shadow_step()
215 		s->count++;  in shadow_step()
221 struct dm_block *shadow_current(struct shadow_spine *s)  in shadow_current()  argument
223 	BUG_ON(!s->count);  in shadow_current()
225 	return s->nodes[s->count - 1];  in shadow_current()
228 struct dm_block *shadow_parent(struct shadow_spine *s)  in shadow_parent()  argument
230 	BUG_ON(s->count != 2);  in shadow_parent()
232 	return s->count == 2 ? s->nodes[0] : NULL;  in shadow_parent()
235 int shadow_has_parent(struct shadow_spine *s)  in shadow_has_parent()  argument
237 	return s->count >= 2;  in shadow_has_parent()
240 int shadow_root(struct shadow_spine *s)  in shadow_root()  argument
242 	return s->root;  in shadow_root()