jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging

'write_op' was still used, even though it was always WRITE_SYNC now.
Add plugging around the cases where it submits IO, and flush them
before we end up waiting for that IO.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 8 insertions, 10 deletions

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 3da1cc4346d5..fa36d7662b21 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -329,7 +329,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         int tag_bytes = journal_tag_bytes(journal);
         struct buffer_head *cbh = NULL; /* For transactional checksums */
         __u32 crc32_sum = ~0;
-        int write_op = WRITE_SYNC;
+        struct blk_plug plug;
 
         /*
          * First job: lock down the current transaction and wait for
@@ -363,13 +363,6 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         write_lock(&journal->j_state_lock);
         commit_transaction->t_state = T_LOCKED;
 
-        /*
-         * Use plugged writes here, since we want to submit several before
-         * we unplug the device. We don't do explicit unplugging in here,
-         * instead we rely on sync_buffer() doing the unplug for us.
-         */
-        if (commit_transaction->t_synchronous_commit)
-                write_op = WRITE_SYNC;
         trace_jbd2_commit_locking(journal, commit_transaction);
         stats.run.rs_wait = commit_transaction->t_max_wait;
         stats.run.rs_locked = jiffies;
@@ -469,8 +462,10 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         if (err)
                 jbd2_journal_abort(journal, err);
 
+        blk_start_plug(&plug);
         jbd2_journal_write_revoke_records(journal, commit_transaction,
-                                          write_op);
+                                          WRITE_SYNC);
+        blk_finish_plug(&plug);
 
         jbd_debug(3, "JBD: commit phase 2\n");
 
@@ -497,6 +492,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         err = 0;
         descriptor = NULL;
         bufs = 0;
+        blk_start_plug(&plug);
         while (commit_transaction->t_buffers) {
 
                 /* Find the next buffer to be journaled... */
@@ -658,7 +654,7 @@ start_journal_io:
                                 clear_buffer_dirty(bh);
                                 set_buffer_uptodate(bh);
                                 bh->b_end_io = journal_end_buffer_io_sync;
-                                submit_bh(write_op, bh);
+                                submit_bh(WRITE_SYNC, bh);
                         }
                         cond_resched();
                         stats.run.rs_blocks_logged += bufs;
@@ -699,6 +695,8 @@ start_journal_io:
                         __jbd2_journal_abort_hard(journal);
         }
 
+        blk_finish_plug(&plug);
+
         /* Lo and behold: we have just managed to send a transaction to
            the log.  Before we can commit it, wait for the IO so far to
            complete.  Control buffers being written are on the