jbd2: fix a potential race while discarding reserved buffers after an abort

[linux-2.6-microblaze.git] / fs / jbd2 / commit.c

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 5b9408e..ac7f067 100644 (file)
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -488,7 +488,6 @@ void jbd2_journal_commit_transaction(journal_t *journal)
        jbd2_journal_wait_updates(journal);
 
        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);
@@ -508,6 +507,8 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         * 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;
@@ -527,6 +528,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
                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