125 void init_ro_spine(struct ro_spine *s, struct dm_btree_info *info)  in init_ro_spine()  argument
127 	s->info = info;  in init_ro_spine()
128 	s->count = 0;  in init_ro_spine()
129 	s->nodes[0] = NULL;  in init_ro_spine()
130 	s->nodes[1] = NULL;  in init_ro_spine()
133 void exit_ro_spine(struct ro_spine *s)  in exit_ro_spine()  argument
137 	for (i = 0; i < s->count; i++) {  in exit_ro_spine()
138 		unlock_block(s->info, s->nodes[i]);  in exit_ro_spine()
142 int ro_step(struct ro_spine *s, dm_block_t new_child)  in ro_step()  argument
146 	if (s->count == 2) {  in ro_step()
147 		unlock_block(s->info, s->nodes[0]);  in ro_step()
148 		s->nodes[0] = s->nodes[1];  in ro_step()
149 		s->count--;  in ro_step()
152 	r = bn_read_lock(s->info, new_child, s->nodes + s->count);  in ro_step()
154 		s->count++;  in ro_step()
159 void ro_pop(struct ro_spine *s)  in ro_pop()  argument
161 	BUG_ON(!s->count);  in ro_pop()
162 	--s->count;  in ro_pop()
163 	unlock_block(s->info, s->nodes[s->count]);  in ro_pop()
166 struct btree_node *ro_node(struct ro_spine *s)  in ro_node()  argument
170 	BUG_ON(!s->count);  in ro_node()
171 	block = s->nodes[s->count - 1];  in ro_node()
178 void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info)  in init_shadow_spine()  argument
180 	s->info = info;  in init_shadow_spine()
181 	s->count = 0;  in init_shadow_spine()
184 void exit_shadow_spine(struct shadow_spine *s)  in exit_shadow_spine()  argument
188 	for (i = 0; i < s->count; i++) {  in exit_shadow_spine()
189 		unlock_block(s->info, s->nodes[i]);  in exit_shadow_spine()
193 int shadow_step(struct shadow_spine *s, dm_block_t b,  in shadow_step()  argument
198 	if (s->count == 2) {  in shadow_step()
199 		unlock_block(s->info, s->nodes[0]);  in shadow_step()
200 		s->nodes[0] = s->nodes[1];  in shadow_step()
201 		s->count--;  in shadow_step()
204 	r = bn_shadow(s->info, b, vt, s->nodes + s->count);  in shadow_step()
206 		if (!s->count)  in shadow_step()
207 			s->root = dm_block_location(s->nodes[0]);  in shadow_step()
209 		s->count++;  in shadow_step()
215 struct dm_block *shadow_current(struct shadow_spine *s)  in shadow_current()  argument
217 	BUG_ON(!s->count);  in shadow_current()
219 	return s->nodes[s->count - 1];  in shadow_current()
222 struct dm_block *shadow_parent(struct shadow_spine *s)  in shadow_parent()  argument
224 	BUG_ON(s->count != 2);  in shadow_parent()
226 	return s->count == 2 ? s->nodes[0] : NULL;  in shadow_parent()
229 int shadow_has_parent(struct shadow_spine *s)  in shadow_has_parent()  argument
231 	return s->count >= 2;  in shadow_has_parent()
234 dm_block_t shadow_root(struct shadow_spine *s)  in shadow_root()  argument
236 	return s->root;  in shadow_root()