From 17ff9389bd562b66e2292ac676bdcbc98ddea73b Mon Sep 17 00:00:00 2001
From: Daniel Mack <zonque@gmail.com>
Date: Mon, 17 Mar 2014 17:05:43 +0100
Subject: move waitqueue from endpoint to connection

This way, we don't unnecessarily wake up all connection on an endpoint.

Suggested by scampa.giovanni:

  http://code.google.com/p/d-bus/issues/detail?id=1
---
 connection.c | 8 ++++++--
 connection.h | 2 ++
 endpoint.c   | 7 -------
 endpoint.h   | 2 --
 handle.c     | 9 ++-------
 5 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/connection.c b/connection.c
index 55e567cfb9d..99f7ee6df7f 100644
--- a/connection.c
+++ b/connection.c
@@ -705,7 +705,7 @@ static int kdbus_conn_queue_insert(struct kdbus_conn *conn,
 	mutex_unlock(&conn->lock);
 
 	/* wake up poll() */
-	wake_up_interruptible(&conn->ep->wait);
+	wake_up_interruptible(&conn->wait);
 
 	return 0;
 }
@@ -1532,6 +1532,9 @@ int kdbus_conn_disconnect(struct kdbus_conn *conn, bool ensure_queue_empty)
 	/* remove all names associated with this connection */
 	kdbus_name_remove_by_conn(conn->bus->name_registry, conn);
 
+	/* wake up the queue so that users can get a POLLERR */
+	wake_up_interruptible(&conn->wait);
+
 	kdbus_notify_id_change(KDBUS_ITEM_ID_REMOVE, conn->id, conn->flags,
 			       &notify_list);
 
@@ -1657,7 +1660,7 @@ int kdbus_conn_move_messages(struct kdbus_conn *conn_dst,
 	mutex_unlock(&conn_dst->lock);
 
 	/* wake up poll() */
-	wake_up_interruptible(&conn_dst->ep->wait);
+	wake_up_interruptible(&conn_dst->wait);
 
 	return ret;
 }
@@ -1987,6 +1990,7 @@ int kdbus_conn_new(struct kdbus_ep *ep,
 	atomic_set(&conn->reply_count, 0);
 	INIT_DELAYED_WORK(&conn->work, kdbus_conn_work);
 	conn->cred = current_cred();
+	init_waitqueue_head(&conn->wait);
 
 	/* init entry, so we can unconditionally remove it */
 	INIT_LIST_HEAD(&conn->monitor_entry);
diff --git a/connection.h b/connection.h
index 04f23c19e47..a7780d8efc9 100644
--- a/connection.h
+++ b/connection.h
@@ -56,6 +56,7 @@
  * @msg_count:		Number of queued messages
  * @reply_count:	Number of requests this connection has issued, and
  *			waits for replies from the peer
+ * @wait:		Wake up this endpoint
  */
 struct kdbus_conn {
 	struct kref kref;
@@ -88,6 +89,7 @@ struct kdbus_conn {
 	size_t name_count;
 	size_t msg_count;
 	atomic_t reply_count;
+	wait_queue_head_t wait;
 };
 
 struct kdbus_kmsg;
diff --git a/endpoint.c b/endpoint.c
index 3dc9b49ea7f..69718989b5d 100644
--- a/endpoint.c
+++ b/endpoint.c
@@ -85,12 +85,6 @@ void kdbus_ep_disconnect(struct kdbus_ep *ep)
 		idr_remove(&ep->bus->domain->idr, ep->minor);
 		ep->minor = 0;
 	}
-
-	/*
-	 * wake up the queue so the connections can report
-	 * POLLERR to their users.
-	 */
-	wake_up_interruptible(&ep->wait);
 }
 
 static void __kdbus_ep_free(struct kref *kref)
@@ -167,7 +161,6 @@ int kdbus_ep_new(struct kdbus_bus *bus, const char *name,
 	e->uid = uid;
 	e->gid = gid;
 	e->mode = mode;
-	init_waitqueue_head(&e->wait);
 
 	e->name = kstrdup(name, GFP_KERNEL);
 	if (!e->name) {
diff --git a/endpoint.h b/endpoint.h
index 7a5b41bbbbe..7385a095253 100644
--- a/endpoint.h
+++ b/endpoint.h
@@ -29,7 +29,6 @@
  * @uid:		UID owning this endpoint
  * @gid:		GID owning this endpoint
  * @bus_entry:		bus' endpoints
- * @wait:		Wake up this endpoint
  * @lock:		Endpoint data lock
  * @user:		Custom enpoints account against an anonymous user
  * @policy_db:		Uploaded policy
@@ -50,7 +49,6 @@ struct kdbus_ep {
 	kuid_t uid;
 	kgid_t gid;
 	struct list_head bus_entry;
-	wait_queue_head_t wait;
 	struct mutex lock;
 	struct kdbus_domain_user *user;
 	struct kdbus_policy_db *policy_db;
diff --git a/handle.c b/handle.c
index e0eb60943a9..b0b95aaea38 100644
--- a/handle.c
+++ b/handle.c
@@ -815,7 +815,6 @@ static unsigned int kdbus_handle_poll(struct file *file,
 	struct kdbus_handle *handle = file->private_data;
 	struct kdbus_conn *conn;
 	unsigned int mask = 0;
-	bool disconnected;
 
 	/* Only a connected endpoint can read/write data */
 	if (handle->type != KDBUS_HANDLE_EP_CONNECTED)
@@ -823,15 +822,11 @@ static unsigned int kdbus_handle_poll(struct file *file,
 
 	conn = handle->conn;
 
-	poll_wait(file, &conn->ep->wait, wait);
+	poll_wait(file, &conn->wait, wait);
 
 	mutex_lock(&conn->lock);
 
-	mutex_lock(&conn->ep->lock);
-	disconnected = conn->ep->disconnected;
-	mutex_unlock(&conn->ep->lock);
-
-	if (unlikely(disconnected))
+	if (unlikely(conn->disconnected))
 		mask |= POLLERR | POLLHUP;
 	else if (!list_empty(&conn->msg_list))
 		mask |= POLLIN | POLLRDNORM;
-- 
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