jbd2: relocate assert after state lock in journal_commit_transaction()

The state lock is taken after we are doing an assert on the state
value, not before.  So we might in fact be doing an assert on a
transient value.  Ensure the state check is within the scope of
the state lock being taken.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/jbd2/commit.c

@@ -427,13 +427,13 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	J_ASSERT(journal->j_committing_transaction == NULL);
 
 	commit_transaction = journal->j_running_transaction;
-	J_ASSERT(commit_transaction->t_state == T_RUNNING);
 
 	trace_jbd2_start_commit(journal, commit_transaction);
 	jbd_debug(1, "JBD2: starting commit of transaction %d\n",
 			commit_transaction->t_tid);
 
 	write_lock(&journal->j_state_lock);
+	J_ASSERT(commit_transaction->t_state == T_RUNNING);
 	commit_transaction->t_state = T_LOCKED;
 
 	trace_jbd2_commit_locking(journal, commit_transaction);