27 static void btrfs_assert_tree_read_locked(struct extent_buffer *eb);
34 void btrfs_set_lock_blocking_rw(struct extent_buffer *eb, int rw)  in btrfs_set_lock_blocking_rw()  argument
42 	if (eb->lock_nested && current->pid == eb->lock_owner)  in btrfs_set_lock_blocking_rw()
45 		if (atomic_read(&eb->blocking_writers) == 0) {  in btrfs_set_lock_blocking_rw()
46 			WARN_ON(atomic_read(&eb->spinning_writers) != 1);  in btrfs_set_lock_blocking_rw()
47 			atomic_dec(&eb->spinning_writers);  in btrfs_set_lock_blocking_rw()
48 			btrfs_assert_tree_locked(eb);  in btrfs_set_lock_blocking_rw()
49 			atomic_inc(&eb->blocking_writers);  in btrfs_set_lock_blocking_rw()
50 			write_unlock(&eb->lock);  in btrfs_set_lock_blocking_rw()
53 		btrfs_assert_tree_read_locked(eb);  in btrfs_set_lock_blocking_rw()
54 		atomic_inc(&eb->blocking_readers);  in btrfs_set_lock_blocking_rw()
55 		WARN_ON(atomic_read(&eb->spinning_readers) == 0);  in btrfs_set_lock_blocking_rw()
56 		atomic_dec(&eb->spinning_readers);  in btrfs_set_lock_blocking_rw()
57 		read_unlock(&eb->lock);  in btrfs_set_lock_blocking_rw()
66 void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw)  in btrfs_clear_lock_blocking_rw()  argument
74 	if (eb->lock_nested && current->pid == eb->lock_owner)  in btrfs_clear_lock_blocking_rw()
78 		BUG_ON(atomic_read(&eb->blocking_writers) != 1);  in btrfs_clear_lock_blocking_rw()
79 		write_lock(&eb->lock);  in btrfs_clear_lock_blocking_rw()
80 		WARN_ON(atomic_read(&eb->spinning_writers));  in btrfs_clear_lock_blocking_rw()
81 		atomic_inc(&eb->spinning_writers);  in btrfs_clear_lock_blocking_rw()
82 		if (atomic_dec_and_test(&eb->blocking_writers) &&  in btrfs_clear_lock_blocking_rw()
83 		    waitqueue_active(&eb->write_lock_wq))  in btrfs_clear_lock_blocking_rw()
84 			wake_up(&eb->write_lock_wq);  in btrfs_clear_lock_blocking_rw()
86 		BUG_ON(atomic_read(&eb->blocking_readers) == 0);  in btrfs_clear_lock_blocking_rw()
87 		read_lock(&eb->lock);  in btrfs_clear_lock_blocking_rw()
88 		atomic_inc(&eb->spinning_readers);  in btrfs_clear_lock_blocking_rw()
89 		if (atomic_dec_and_test(&eb->blocking_readers) &&  in btrfs_clear_lock_blocking_rw()
90 		    waitqueue_active(&eb->read_lock_wq))  in btrfs_clear_lock_blocking_rw()
91 			wake_up(&eb->read_lock_wq);  in btrfs_clear_lock_blocking_rw()
100 void btrfs_tree_read_lock(struct extent_buffer *eb)  in btrfs_tree_read_lock()  argument
103 	BUG_ON(!atomic_read(&eb->blocking_writers) &&  in btrfs_tree_read_lock()
104 	       current->pid == eb->lock_owner);  in btrfs_tree_read_lock()
106 	read_lock(&eb->lock);  in btrfs_tree_read_lock()
107 	if (atomic_read(&eb->blocking_writers) &&  in btrfs_tree_read_lock()
108 	    current->pid == eb->lock_owner) {  in btrfs_tree_read_lock()
115 		BUG_ON(eb->lock_nested);  in btrfs_tree_read_lock()
116 		eb->lock_nested = 1;  in btrfs_tree_read_lock()
117 		read_unlock(&eb->lock);  in btrfs_tree_read_lock()
120 	if (atomic_read(&eb->blocking_writers)) {  in btrfs_tree_read_lock()
121 		read_unlock(&eb->lock);  in btrfs_tree_read_lock()
122 		wait_event(eb->write_lock_wq,  in btrfs_tree_read_lock()
123 			   atomic_read(&eb->blocking_writers) == 0);  in btrfs_tree_read_lock()
126 	atomic_inc(&eb->read_locks);  in btrfs_tree_read_lock()
127 	atomic_inc(&eb->spinning_readers);  in btrfs_tree_read_lock()
135 int btrfs_tree_read_lock_atomic(struct extent_buffer *eb)  in btrfs_tree_read_lock_atomic()  argument
137 	if (atomic_read(&eb->blocking_writers))  in btrfs_tree_read_lock_atomic()
140 	read_lock(&eb->lock);  in btrfs_tree_read_lock_atomic()
141 	if (atomic_read(&eb->blocking_writers)) {  in btrfs_tree_read_lock_atomic()
142 		read_unlock(&eb->lock);  in btrfs_tree_read_lock_atomic()
145 	atomic_inc(&eb->read_locks);  in btrfs_tree_read_lock_atomic()
146 	atomic_inc(&eb->spinning_readers);  in btrfs_tree_read_lock_atomic()
154 int btrfs_try_tree_read_lock(struct extent_buffer *eb)  in btrfs_try_tree_read_lock()  argument
156 	if (atomic_read(&eb->blocking_writers))  in btrfs_try_tree_read_lock()
159 	if (!read_trylock(&eb->lock))  in btrfs_try_tree_read_lock()
162 	if (atomic_read(&eb->blocking_writers)) {  in btrfs_try_tree_read_lock()
163 		read_unlock(&eb->lock);  in btrfs_try_tree_read_lock()
166 	atomic_inc(&eb->read_locks);  in btrfs_try_tree_read_lock()
167 	atomic_inc(&eb->spinning_readers);  in btrfs_try_tree_read_lock()
175 int btrfs_try_tree_write_lock(struct extent_buffer *eb)  in btrfs_try_tree_write_lock()  argument
177 	if (atomic_read(&eb->blocking_writers) ||  in btrfs_try_tree_write_lock()
178 	    atomic_read(&eb->blocking_readers))  in btrfs_try_tree_write_lock()
181 	write_lock(&eb->lock);  in btrfs_try_tree_write_lock()
182 	if (atomic_read(&eb->blocking_writers) ||  in btrfs_try_tree_write_lock()
183 	    atomic_read(&eb->blocking_readers)) {  in btrfs_try_tree_write_lock()
184 		write_unlock(&eb->lock);  in btrfs_try_tree_write_lock()
187 	atomic_inc(&eb->write_locks);  in btrfs_try_tree_write_lock()
188 	atomic_inc(&eb->spinning_writers);  in btrfs_try_tree_write_lock()
189 	eb->lock_owner = current->pid;  in btrfs_try_tree_write_lock()
196 void btrfs_tree_read_unlock(struct extent_buffer *eb)  in btrfs_tree_read_unlock()  argument
204 	if (eb->lock_nested && current->pid == eb->lock_owner) {  in btrfs_tree_read_unlock()
205 		eb->lock_nested = 0;  in btrfs_tree_read_unlock()
208 	btrfs_assert_tree_read_locked(eb);  in btrfs_tree_read_unlock()
209 	WARN_ON(atomic_read(&eb->spinning_readers) == 0);  in btrfs_tree_read_unlock()
210 	atomic_dec(&eb->spinning_readers);  in btrfs_tree_read_unlock()
211 	atomic_dec(&eb->read_locks);  in btrfs_tree_read_unlock()
212 	read_unlock(&eb->lock);  in btrfs_tree_read_unlock()
218 void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb)  in btrfs_tree_read_unlock_blocking()  argument
226 	if (eb->lock_nested && current->pid == eb->lock_owner) {  in btrfs_tree_read_unlock_blocking()
227 		eb->lock_nested = 0;  in btrfs_tree_read_unlock_blocking()
230 	btrfs_assert_tree_read_locked(eb);  in btrfs_tree_read_unlock_blocking()
231 	WARN_ON(atomic_read(&eb->blocking_readers) == 0);  in btrfs_tree_read_unlock_blocking()
232 	if (atomic_dec_and_test(&eb->blocking_readers) &&  in btrfs_tree_read_unlock_blocking()
233 	    waitqueue_active(&eb->read_lock_wq))  in btrfs_tree_read_unlock_blocking()
234 		wake_up(&eb->read_lock_wq);  in btrfs_tree_read_unlock_blocking()
235 	atomic_dec(&eb->read_locks);  in btrfs_tree_read_unlock_blocking()
242 void btrfs_tree_lock(struct extent_buffer *eb)  in btrfs_tree_lock()  argument
245 	wait_event(eb->read_lock_wq, atomic_read(&eb->blocking_readers) == 0);  in btrfs_tree_lock()
246 	wait_event(eb->write_lock_wq, atomic_read(&eb->blocking_writers) == 0);  in btrfs_tree_lock()
247 	write_lock(&eb->lock);  in btrfs_tree_lock()
248 	if (atomic_read(&eb->blocking_readers)) {  in btrfs_tree_lock()
249 		write_unlock(&eb->lock);  in btrfs_tree_lock()
250 		wait_event(eb->read_lock_wq,  in btrfs_tree_lock()
251 			   atomic_read(&eb->blocking_readers) == 0);  in btrfs_tree_lock()
254 	if (atomic_read(&eb->blocking_writers)) {  in btrfs_tree_lock()
255 		write_unlock(&eb->lock);  in btrfs_tree_lock()
256 		wait_event(eb->write_lock_wq,  in btrfs_tree_lock()
257 			   atomic_read(&eb->blocking_writers) == 0);  in btrfs_tree_lock()
260 	WARN_ON(atomic_read(&eb->spinning_writers));  in btrfs_tree_lock()
261 	atomic_inc(&eb->spinning_writers);  in btrfs_tree_lock()
262 	atomic_inc(&eb->write_locks);  in btrfs_tree_lock()
263 	eb->lock_owner = current->pid;  in btrfs_tree_lock()
269 void btrfs_tree_unlock(struct extent_buffer *eb)  in btrfs_tree_unlock()  argument
271 	int blockers = atomic_read(&eb->blocking_writers);  in btrfs_tree_unlock()
275 	btrfs_assert_tree_locked(eb);  in btrfs_tree_unlock()
276 	eb->lock_owner = 0;  in btrfs_tree_unlock()
277 	atomic_dec(&eb->write_locks);  in btrfs_tree_unlock()
280 		WARN_ON(atomic_read(&eb->spinning_writers));  in btrfs_tree_unlock()
281 		atomic_dec(&eb->blocking_writers);  in btrfs_tree_unlock()
283 		if (waitqueue_active(&eb->write_lock_wq))  in btrfs_tree_unlock()
284 			wake_up(&eb->write_lock_wq);  in btrfs_tree_unlock()
286 		WARN_ON(atomic_read(&eb->spinning_writers) != 1);  in btrfs_tree_unlock()
287 		atomic_dec(&eb->spinning_writers);  in btrfs_tree_unlock()
288 		write_unlock(&eb->lock);  in btrfs_tree_unlock()
292 void btrfs_assert_tree_locked(struct extent_buffer *eb)  in btrfs_assert_tree_locked()  argument
294 	BUG_ON(!atomic_read(&eb->write_locks));  in btrfs_assert_tree_locked()
297 static void btrfs_assert_tree_read_locked(struct extent_buffer *eb)  in btrfs_assert_tree_read_locked()  argument
299 	BUG_ON(!atomic_read(&eb->read_locks));  in btrfs_assert_tree_read_locked()