19  * eb, the lockdep key is determined by the btrfs_root it belongs to and
20  * the level the eb occupies in the tree.
50 	DEFINE_LEVEL(stem, 1)						\
83 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb, int level)  in btrfs_set_buffer_lockdep_class()  argument
94 	lockdep_set_class_and_name(&eb->lock, &ks->keys[level], ks->names[level]);  in btrfs_set_buffer_lockdep_class()
97 void btrfs_maybe_reset_lockdep_class(struct btrfs_root *root, struct extent_buffer *eb)  in btrfs_maybe_reset_lockdep_class()  argument
101 					       eb, btrfs_header_level(eb));  in btrfs_maybe_reset_lockdep_class()
107 static void btrfs_set_eb_lock_owner(struct extent_buffer *eb, pid_t owner)  in btrfs_set_eb_lock_owner()  argument
109 	eb->lock_owner = owner;  in btrfs_set_eb_lock_owner()
112 static void btrfs_set_eb_lock_owner(struct extent_buffer *eb, pid_t owner) { }  in btrfs_set_eb_lock_owner()  argument
133  * @eb:		the eb to be locked
139 void btrfs_tree_read_lock_nested(struct extent_buffer *eb, enum btrfs_lock_nesting nest)  in btrfs_tree_read_lock_nested()  argument
146 	down_read_nested(&eb->lock, nest);  in btrfs_tree_read_lock_nested()
147 	trace_btrfs_tree_read_lock(eb, start_ns);  in btrfs_tree_read_lock_nested()
153  * Return 1 if the rwlock has been taken, 0 otherwise
155 int btrfs_try_tree_read_lock(struct extent_buffer *eb)  in btrfs_try_tree_read_lock()  argument
157 	if (down_read_trylock(&eb->lock)) {  in btrfs_try_tree_read_lock()
158 		trace_btrfs_try_tree_read_lock(eb);  in btrfs_try_tree_read_lock()
159 		return 1;  in btrfs_try_tree_read_lock()
167 void btrfs_tree_read_unlock(struct extent_buffer *eb)  in btrfs_tree_read_unlock()  argument
169 	trace_btrfs_tree_read_unlock(eb);  in btrfs_tree_read_unlock()
170 	up_read(&eb->lock);  in btrfs_tree_read_unlock()
174  * Lock eb for write.
176  * @eb:		the eb to lock
179  * Returns with the eb->lock write locked.
181 void btrfs_tree_lock_nested(struct extent_buffer *eb, enum btrfs_lock_nesting nest)  in btrfs_tree_lock_nested()  argument
182 	__acquires(&eb->lock)  in btrfs_tree_lock_nested()
189 	down_write_nested(&eb->lock, nest);  in btrfs_tree_lock_nested()
190 	btrfs_set_eb_lock_owner(eb, current->pid);  in btrfs_tree_lock_nested()
191 	trace_btrfs_tree_lock(eb, start_ns);  in btrfs_tree_lock_nested()
197 void btrfs_tree_unlock(struct extent_buffer *eb)  in btrfs_tree_unlock()  argument
199 	trace_btrfs_tree_unlock(eb);  in btrfs_tree_unlock()
200 	btrfs_set_eb_lock_owner(eb, 0);  in btrfs_tree_unlock()
201 	up_write(&eb->lock);  in btrfs_tree_unlock()
238 	struct extent_buffer *eb;  in btrfs_lock_root_node()  local
240 	while (1) {  in btrfs_lock_root_node()
241 		eb = btrfs_root_node(root);  in btrfs_lock_root_node()
243 		btrfs_maybe_reset_lockdep_class(root, eb);  in btrfs_lock_root_node()
244 		btrfs_tree_lock(eb);  in btrfs_lock_root_node()
245 		if (eb == root->node)  in btrfs_lock_root_node()
247 		btrfs_tree_unlock(eb);  in btrfs_lock_root_node()
248 		free_extent_buffer(eb);  in btrfs_lock_root_node()
250 	return eb;  in btrfs_lock_root_node()
261 	struct extent_buffer *eb;  in btrfs_read_lock_root_node()  local
263 	while (1) {  in btrfs_read_lock_root_node()
264 		eb = btrfs_root_node(root);  in btrfs_read_lock_root_node()
266 		btrfs_maybe_reset_lockdep_class(root, eb);  in btrfs_read_lock_root_node()
267 		btrfs_tree_read_lock(eb);  in btrfs_read_lock_root_node()
268 		if (eb == root->node)  in btrfs_read_lock_root_node()
270 		btrfs_tree_read_unlock(eb);  in btrfs_read_lock_root_node()
271 		free_extent_buffer(eb);  in btrfs_read_lock_root_node()
273 	return eb;  in btrfs_read_lock_root_node()
285 	struct extent_buffer *eb;  in btrfs_try_read_lock_root_node()  local
287 	while (1) {  in btrfs_try_read_lock_root_node()
288 		eb = btrfs_root_node(root);  in btrfs_try_read_lock_root_node()
289 		if (!btrfs_try_tree_read_lock(eb)) {  in btrfs_try_read_lock_root_node()
290 			free_extent_buffer(eb);  in btrfs_try_read_lock_root_node()
293 		if (eb == root->node)  in btrfs_try_read_lock_root_node()
295 		btrfs_tree_read_unlock(eb);  in btrfs_try_read_lock_root_node()
296 		free_extent_buffer(eb);  in btrfs_try_read_lock_root_node()
298 	return eb;  in btrfs_try_read_lock_root_node()