1 files changed, 17 insertions, 1 deletions

diff --git a/fs/btrfs/async-thread.h b/fs/btrfs/async-thread.h
index 4ec9a2ee0f9d..31be4ed8b63e 100644
--- a/fs/btrfs/async-thread.h
+++ b/fs/btrfs/async-thread.h
@@ -37,10 +37,16 @@ struct btrfs_worker_thread;
  */
 struct btrfs_work {
         /*
-         * only func should be set to the function you want called
+         * func should be set to the function you want called
          * your work struct is passed as the only arg
+         *
+         * ordered_func must be set for work sent to an ordered work queue,
+         * and it is called to complete a given work item in the same
+         * order they were sent to the queue.
          */
         void (*func)(struct btrfs_work *work);
+        void (*ordered_func)(struct btrfs_work *work);
+        void (*ordered_free)(struct btrfs_work *work);
 
         /*
          * flags should be set to zero.  It is used to make sure the
@@ -51,6 +57,7 @@ struct btrfs_work {
         /* don't touch these */
         struct btrfs_worker_thread *worker;
         struct list_head list;
+        struct list_head order_list;
 };
 
 struct btrfs_workers {
@@ -63,6 +70,9 @@ struct btrfs_workers {
         /* once a worker has this many requests or fewer, it is idle */
         int idle_thresh;
 
+        /* force completions in the order they were queued */
+        int ordered;
+
         /* list with all the work threads.  The workers on the idle thread
          * may be actively servicing jobs, but they haven't yet hit the
          * idle thresh limit above.
@@ -70,6 +80,12 @@ struct btrfs_workers {
         struct list_head worker_list;
         struct list_head idle_list;
 
+        /*
+         * when operating in ordered mode, this maintains the list
+         * of work items waiting for completion
+         */
+        struct list_head order_list;
+
         /* lock for finding the next worker thread to queue on */
         spinlock_t lock;