1 files changed, 10 insertions, 3 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 01c9620bb001..9c8f158dd2db 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -972,6 +972,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         struct extent_io_tree *pinned_copy;
         DEFINE_WAIT(wait);
         int ret;
+        int should_grow = 0;
+        unsigned long now = get_seconds();
 
         /* make a pass through all the delayed refs we have so far
          * any runnings procs may add more while we are here
@@ -1029,6 +1031,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
                 }
         }
 
+        if (now < cur_trans->start_time || now - cur_trans->start_time < 1)
+                should_grow = 1;
+
         do {
                 int snap_pending = 0;
                 joined = cur_trans->num_joined;
@@ -1041,7 +1046,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 
                 if (cur_trans->num_writers > 1)
                         timeout = MAX_SCHEDULE_TIMEOUT;
-                else
+                else if (should_grow)
                         timeout = 1;
 
                 mutex_unlock(&root->fs_info->trans_mutex);
@@ -1051,12 +1056,14 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
                         BUG_ON(ret);
                 }
 
-                schedule_timeout(timeout);
+                smp_mb();
+                if (cur_trans->num_writers > 1 || should_grow)
+                        schedule_timeout(timeout);
 
                 mutex_lock(&root->fs_info->trans_mutex);
                 finish_wait(&cur_trans->writer_wait, &wait);
         } while (cur_trans->num_writers > 1 ||
-                 (cur_trans->num_joined != joined));
+                 (should_grow && cur_trans->num_joined != joined));
 
         ret = create_pending_snapshots(trans, root->fs_info);
         BUG_ON(ret);