ocfs2: Support nested transactions

OCFS2 can easily support nested transactions. We just have to
take care and not spoil statistics acquire semaphore unnecessarily.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 7 insertions, 7 deletions

diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index 12b62a3cbf69..11a1178d5ee8 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -256,11 +256,9 @@ handle_t *ocfs2_start_trans(struct ocfs2_super *osb, int max_buffs)
         BUG_ON(osb->journal->j_state == OCFS2_JOURNAL_FREE);
         BUG_ON(max_buffs <= 0);
 
-        /* JBD might support this, but our journalling code doesn't yet. */
-        if (journal_current_handle()) {
-                mlog(ML_ERROR, "Recursive transaction attempted!\n");
-                BUG();
-        }
+        /* Nested transaction? Just return the handle... */
+        if (journal_current_handle())
+                return jbd2_journal_start(journal, max_buffs);
 
         down_read(&osb->journal->j_trans_barrier);
 
@@ -285,16 +283,18 @@ handle_t *ocfs2_start_trans(struct ocfs2_super *osb, int max_buffs)
 int ocfs2_commit_trans(struct ocfs2_super *osb,
                        handle_t *handle)
 {
-        int ret;
+        int ret, nested;
         struct ocfs2_journal *journal = osb->journal;
 
         BUG_ON(!handle);
 
+        nested = handle->h_ref > 1;
         ret = jbd2_journal_stop(handle);
         if (ret < 0)
                 mlog_errno(ret);
 
-        up_read(&journal->j_trans_barrier);
+        if (!nested)
+                up_read(&journal->j_trans_barrier);
 
         return ret;
 }