[PATCH] JBD: add some locking assertions

Drop in a few assertions to ensure that the locking rules are being adhered
to.

fs/jbd/transaction.c

@@ -1498,6 +1498,7 @@ void __journal_unfile_buffer(struct journal_head *jh)
 	transaction_t *transaction;
 	struct buffer_head *bh = jh2bh(jh);
 
+	J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
 	transaction = jh->b_transaction;
 	if (transaction)
 		assert_spin_locked(&transaction->t_journal->j_list_lock);
@@ -1924,6 +1925,7 @@ void __journal_file_buffer(struct journal_head *jh,
 	int was_dirty = 0;
 	struct buffer_head *bh = jh2bh(jh);
 
+	J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
 	assert_spin_locked(&transaction->t_journal->j_list_lock);
 
 #ifdef __SMP__
@@ -2013,6 +2015,7 @@ void __journal_refile_buffer(struct journal_head *jh)
 	int was_dirty;
 	struct buffer_head *bh = jh2bh(jh);
 
+	J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
 	if (jh->b_transaction)
 		assert_spin_locked(&jh->b_transaction->t_journal->j_list_lock);
 

include/linux/jbd.h

@@ -322,6 +322,11 @@ static inline int jbd_trylock_bh_state(struct buffer_head *bh)
 	return bit_spin_trylock(BH_State, &bh->b_state);
 }
 
+static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
+{
+	return bit_spin_is_locked(BH_State, &bh->b_state);
+}
+
 static inline void jbd_unlock_bh_state(struct buffer_head *bh)
 {
 	bit_spin_unlock(BH_State, &bh->b_state);