archive/jbd2-dont-write-non-commit-blocks-synchronously

   1 jbd2: don't write non-commit blocks synchronously
   2
   3 We don't need to write the revoke blocks and descriptor blocks using
   4 WRITE_SYNC, since when we issue the commit block, thos blocks will get
   5 pushed out via REQ_FLUSH.  This will allow the journal blocks to be
   6 written in fewer i/o operations (otherwise we end up issuing a whole
   7 series of 4k writes unnecessarily).
   8
   9 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
  10 ---
  11  fs/jbd2/commit.c | 4 ++--
  12  1 file changed, 2 insertions(+), 2 deletions(-)
  13
  14 diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
  15 index cf2fc05..fb64629 100644
  16 --- a/fs/jbd2/commit.c
  17 +++ b/fs/jbd2/commit.c
  18 @@ -554,7 +554,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
  19
  20         blk_start_plug(&plug);
  21         jbd2_journal_write_revoke_records(journal, commit_transaction,
  22 -                                         &log_bufs, WRITE_SYNC);
  23 +                                         &log_bufs, WRITE);
  24         blk_finish_plug(&plug);
  25
  26         jbd_debug(3, "JBD2: commit phase 2b\n");
  27 @@ -739,7 +739,7 @@ start_journal_io:
  28                                 clear_buffer_dirty(bh);
  29                                 set_buffer_uptodate(bh);
  30                                 bh->b_end_io = journal_end_buffer_io_sync;
  31 -                               submit_bh(WRITE_SYNC, bh);
  32 +                               submit_bh(WRITE, bh);
  33                         }
  34                         cond_resched();
  35                         stats.run.rs_blocks_logged += bufs;