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 		int r2 = unlock_block(s->info, s->nodes[i]);  in exit_ro_spine()
148 int ro_step(struct ro_spine *s, dm_block_t new_child)  in ro_step()  argument
152 	if (s->count == 2) {  in ro_step()
153 		r = unlock_block(s->info, s->nodes[0]);  in ro_step()
156 		s->nodes[0] = s->nodes[1];  in ro_step()
157 		s->count--;  in ro_step()
160 	r = bn_read_lock(s->info, new_child, s->nodes + s->count);  in ro_step()
162 		s->count++;  in ro_step()
167 void ro_pop(struct ro_spine *s)  in ro_pop()  argument
169 	BUG_ON(!s->count);  in ro_pop()
170 	--s->count;  in ro_pop()
171 	unlock_block(s->info, s->nodes[s->count]);  in ro_pop()
174 struct btree_node *ro_node(struct ro_spine *s)  in ro_node()  argument
178 	BUG_ON(!s->count);  in ro_node()
179 	block = s->nodes[s->count - 1];  in ro_node()
186 void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info)  in init_shadow_spine()  argument
188 	s->info = info;  in init_shadow_spine()
189 	s->count = 0;  in init_shadow_spine()
192 int exit_shadow_spine(struct shadow_spine *s)  in exit_shadow_spine()  argument
196 	for (i = 0; i < s->count; i++) {  in exit_shadow_spine()
197 		int r2 = unlock_block(s->info, s->nodes[i]);  in exit_shadow_spine()
205 int shadow_step(struct shadow_spine *s, dm_block_t b,  in shadow_step()  argument
210 	if (s->count == 2) {  in shadow_step()
211 		r = unlock_block(s->info, s->nodes[0]);  in shadow_step()
214 		s->nodes[0] = s->nodes[1];  in shadow_step()
215 		s->count--;  in shadow_step()
218 	r = bn_shadow(s->info, b, vt, s->nodes + s->count);  in shadow_step()
220 		if (!s->count)  in shadow_step()
221 			s->root = dm_block_location(s->nodes[0]);  in shadow_step()
223 		s->count++;  in shadow_step()
229 struct dm_block *shadow_current(struct shadow_spine *s)  in shadow_current()  argument
231 	BUG_ON(!s->count);  in shadow_current()
233 	return s->nodes[s->count - 1];  in shadow_current()
236 struct dm_block *shadow_parent(struct shadow_spine *s)  in shadow_parent()  argument
238 	BUG_ON(s->count != 2);  in shadow_parent()
240 	return s->count == 2 ? s->nodes[0] : NULL;  in shadow_parent()
243 int shadow_has_parent(struct shadow_spine *s)  in shadow_has_parent()  argument
245 	return s->count >= 2;  in shadow_has_parent()
248 int shadow_root(struct shadow_spine *s)  in shadow_root()  argument
250 	return s->root;  in shadow_root()