src/patches/suse-2.6.27.25/patches.suse/ocfs2-Support-nested-transactions.patch

   1 From: Jan Kara <jack@suse.cz>
   2 References: fate#302681
   3 Subject: [PATCH 19/28] ocfs2: Support nested transactions
   4 Patch-mainline: 2.6.29?
   5
   6 OCFS2 can easily support nested transactions. We just have to
   7 take care and not spoil statistics acquire semaphore unnecessarily.
   8
   9 Signed-off-by: Jan Kara <jack@suse.cz>
  10 ---
  11  fs/ocfs2/journal.c |   14 +++++++-------
  12  1 files changed, 7 insertions(+), 7 deletions(-)
  13
  14 Index: linux-2.6.27/fs/ocfs2/journal.c
  15 ===================================================================
  16 --- linux-2.6.27.orig/fs/ocfs2/journal.c        2008-10-24 11:40:35.000000000 +0200
  17 +++ linux-2.6.27/fs/ocfs2/journal.c     2008-10-24 14:19:31.000000000 +0200
  18 @@ -256,11 +256,9 @@
  19         BUG_ON(osb->journal->j_state == OCFS2_JOURNAL_FREE);
  20         BUG_ON(max_buffs <= 0);
  21
  22 -       /* JBD might support this, but our journalling code doesn't yet. */
  23 -       if (journal_current_handle()) {
  24 -               mlog(ML_ERROR, "Recursive transaction attempted!\n");
  25 -               BUG();
  26 -       }
  27 +       /* Nested transaction? Just return the handle... */
  28 +       if (journal_current_handle())
  29 +               return jbd2_journal_start(journal, max_buffs);
  30
  31         down_read(&osb->journal->j_trans_barrier);
  32
  33 @@ -285,16 +283,18 @@
  34  int ocfs2_commit_trans(struct ocfs2_super *osb,
  35                        handle_t *handle)
  36  {
  37 -       int ret;
  38 +       int ret, nested;
  39         struct ocfs2_journal *journal = osb->journal;
  40
  41         BUG_ON(!handle);
  42
  43 +       nested = handle->h_ref > 1;
  44         ret = jbd2_journal_stop(handle);
  45         if (ret < 0)
  46                 mlog_errno(ret);
  47
  48 -       up_read(&journal->j_trans_barrier);
  49 +       if (!nested)
  50 +               up_read(&journal->j_trans_barrier);
  51
  52         return ret;
  53  }