drbd: get rid of drbd_queue_work_front

The last user was al_write_transaction, if called with "delegate",
and the last user to call it with "delegate = true" was the receiver
thread, which has no need to delegate, but can call it himself.

Finally drop the delegate parameter, drop the extra
w_al_write_transaction callback, and drop drbd_queue_work_front.

Do not (yet) change dequeue_work_item to dequeue_work_batch, though.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

1 files changed, 6 insertions, 63 deletions

diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c
index 5add2016216c..5f82a36f799d 100644
--- a/drivers/block/drbd/drbd_actlog.c
+++ b/drivers/block/drbd/drbd_actlog.c
@@ -92,14 +92,6 @@ struct __packed al_transaction_on_disk {
 	__be32	context[AL_CONTEXT_PER_TRANSACTION];
 };
 
-struct update_al_work {
-	struct drbd_work w;
-	struct drbd_device *device;
-	struct completion event;
-	int err;
-};
-
-
 void *drbd_md_get_buffer(struct drbd_device *device)
 {
 	int r;
@@ -291,26 +283,12 @@ bool drbd_al_begin_io_prepare(struct drbd_device *device, struct drbd_interval *
 	return need_transaction;
 }
 
-static int al_write_transaction(struct drbd_device *device, bool delegate);
+static int al_write_transaction(struct drbd_device *device);
 
-/* When called through generic_make_request(), we must delegate
- * activity log I/O to the worker thread: a further request
- * submitted via generic_make_request() within the same task
- * would be queued on current->bio_list, and would only start
- * after this function returns (see generic_make_request()).
- *
- * However, if we *are* the worker, we must not delegate to ourselves.
- */
-
-/*
- * @delegate:   delegate activity log I/O to the worker thread
- */
-void drbd_al_begin_io_commit(struct drbd_device *device, bool delegate)
+void drbd_al_begin_io_commit(struct drbd_device *device)
 {
 	bool locked = false;
 
-	BUG_ON(delegate && current == first_peer_device(device)->connection->worker.task);
-
 	/* Serialize multiple transactions.
 	 * This uses test_and_set_bit, memory barrier is implicit.
 	 */
@@ -329,7 +307,7 @@ void drbd_al_begin_io_commit(struct drbd_device *device, bool delegate)
 			rcu_read_unlock();
 
 			if (write_al_updates)
-				al_write_transaction(device, delegate);
+				al_write_transaction(device);
 			spin_lock_irq(&device->al_lock);
 			/* FIXME
 			if (err)
@@ -346,12 +324,10 @@ void drbd_al_begin_io_commit(struct drbd_device *device, bool delegate)
 /*
  * @delegate:   delegate activity log I/O to the worker thread
  */
-void drbd_al_begin_io(struct drbd_device *device, struct drbd_interval *i, bool delegate)
+void drbd_al_begin_io(struct drbd_device *device, struct drbd_interval *i)
 {
-	BUG_ON(delegate && current == first_peer_device(device)->connection->worker.task);
-
 	if (drbd_al_begin_io_prepare(device, i))
-		drbd_al_begin_io_commit(device, delegate);
+		drbd_al_begin_io_commit(device);
 }
 
 int drbd_al_begin_io_nonblock(struct drbd_device *device, struct drbd_interval *i)
@@ -464,8 +440,7 @@ static sector_t al_tr_number_to_on_disk_sector(struct drbd_device *device)
 	return device->ldev->md.md_offset + device->ldev->md.al_offset + t;
 }
 
-static int
-_al_write_transaction(struct drbd_device *device)
+int al_write_transaction(struct drbd_device *device)
 {
 	struct al_transaction_on_disk *buffer;
 	struct lc_element *e;
@@ -575,38 +550,6 @@ _al_write_transaction(struct drbd_device *device)
 	return err;
 }
 
-
-static int w_al_write_transaction(struct drbd_work *w, int unused)
-{
-	struct update_al_work *aw = container_of(w, struct update_al_work, w);
-	struct drbd_device *device = aw->device;
-	int err;
-
-	err = _al_write_transaction(device);
-	aw->err = err;
-	complete(&aw->event);
-
-	return err != -EIO ? err : 0;
-}
-
-/* Calls from worker context (see w_restart_disk_io()) need to write the
-   transaction directly. Others came through generic_make_request(),
-   those need to delegate it to the worker. */
-static int al_write_transaction(struct drbd_device *device, bool delegate)
-{
-	if (delegate) {
-		struct update_al_work al_work;
-		init_completion(&al_work.event);
-		al_work.w.cb = w_al_write_transaction;
-		al_work.device = device;
-		drbd_queue_work_front(&first_peer_device(device)->connection->sender_work,
-				      &al_work.w);
-		wait_for_completion(&al_work.event);
-		return al_work.err;
-	} else
-		return _al_write_transaction(device);
-}
-
 static int _try_lc_del(struct drbd_device *device, struct lc_element *al_ext)
 {
 	int rv;