Btrfs: remove the time check in btrfs_commit_transaction()

We checked the commit time to avoid committing the transaction
frequently, but it is unnecessary because:
- It made the transaction commit spend more time, and delayed the
  operation of the external writers(TRANS_START/TRANS_USERSPACE).
- Except the space that we have to commit transaction, such as
  snapshot creation, btrfs doesn't commit the transaction on its
  own initiative.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

1 files changed, 6 insertions, 23 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 75e7b150eb54..5e75ff486daf 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1566,10 +1566,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 {
         struct btrfs_transaction *cur_trans = trans->transaction;
         struct btrfs_transaction *prev_trans = NULL;
-        DEFINE_WAIT(wait);
         int ret;
-        int should_grow = 0;
-        unsigned long now = get_seconds();
 
         ret = btrfs_run_ordered_operations(trans, root, 0);
         if (ret) {
@@ -1660,28 +1657,14 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         if (ret)
                 goto cleanup_transaction;
 
-        if (!btrfs_test_opt(root, SSD) &&
-            (now < cur_trans->start_time || now - cur_trans->start_time < 1))
-                should_grow = 1;
-
-        do {
-                WARN_ON(cur_trans != trans->transaction);
-
-                ret = btrfs_flush_all_pending_stuffs(trans, root);
-                if (ret)
-                        goto cleanup_transaction;
-
-                prepare_to_wait(&cur_trans->writer_wait, &wait,
-                                TASK_UNINTERRUPTIBLE);
-
-                if (extwriter_counter_read(cur_trans) > 0)
-                        schedule();
-                else if (should_grow)
-                        schedule_timeout(1);
+        ret = btrfs_flush_all_pending_stuffs(trans, root);
+        if (ret)
+                goto cleanup_transaction;
 
-                finish_wait(&cur_trans->writer_wait, &wait);
-        } while (extwriter_counter_read(cur_trans) > 0);
+        wait_event(cur_trans->writer_wait,
+                   extwriter_counter_read(cur_trans) == 0);
 
+        /* some pending stuffs might be added after the previous flush. */
         ret = btrfs_flush_all_pending_stuffs(trans, root);
         if (ret)
                 goto cleanup_transaction;