diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index b121d7d..fa24b40 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -501,7 +501,6 @@
 	}
 	spin_unlock(&commit_transaction->t_handle_lock);
 	commit_transaction->t_state = T_SWITCH;
-	write_unlock(&journal->j_state_lock);
 
 	J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <=
 			journal->j_max_transaction_buffers);
@@ -521,6 +520,8 @@
 	 * has reserved.  This is consistent with the existing behaviour
 	 * that multiple jbd2_journal_get_write_access() calls to the same
 	 * buffer are perfectly permissible.
+	 * We use journal->j_state_lock here to serialize processing of
+	 * t_reserved_list with eviction of buffers from journal_unmap_buffer().
 	 */
 	while (commit_transaction->t_reserved_list) {
 		jh = commit_transaction->t_reserved_list;
@@ -540,6 +541,7 @@
 		jbd2_journal_refile_buffer(journal, jh);
 	}
 
+	write_unlock(&journal->j_state_lock);
 	/*
 	 * Now try to drop any written-back buffers from the journal's
 	 * checkpoint lists.  We do this *before* commit because it potentially
@@ -562,13 +564,13 @@
 	 */
 	jbd2_journal_switch_revoke_table(journal);
 
+	write_lock(&journal->j_state_lock);
 	/*
 	 * Reserved credits cannot be claimed anymore, free them
 	 */
 	atomic_sub(atomic_read(&journal->j_reserved_credits),
 		   &commit_transaction->t_outstanding_credits);
 
-	write_lock(&journal->j_state_lock);
 	trace_jbd2_commit_flushing(journal, commit_transaction);
 	stats.run.rs_flushing = jiffies;
 	stats.run.rs_locked = jbd2_time_diff(stats.run.rs_locked,
@@ -579,7 +581,7 @@
 	journal->j_running_transaction = NULL;
 	start_time = ktime_get();
 	commit_transaction->t_log_start = journal->j_head;
-	wake_up(&journal->j_wait_transaction_locked);
+	wake_up_all(&journal->j_wait_transaction_locked);
 	write_unlock(&journal->j_state_lock);
 
 	jbd_debug(3, "JBD2: commit phase 2a\n");