connection: introduce kdbus_conn_find_reply()

Introduce kdbus_conn_find_reply() and factor out the list walking
code from kdbus_cmd_msg_cancel() and kdbus_conn_check_access().
There will be one more user later.

Signed-off-by: Daniel Mack <daniel@zonque.org>

diff --git a/connection.c b/connection.c
index cca14a49d4cc457239a89ee1fef0c65c16732f90..2a1745b8d6a9ff97e4c74731272114355aee5088 100644 (file)
--- a/connection.c
+++ b/connection.c
@@ -360,6 +360,29 @@ exit:
        return ret;
 }
 
+static int kdbus_conn_find_reply(struct kdbus_conn *conn_replying,
+                                struct kdbus_conn *conn_reply_dst,
+                                uint64_t cookie,
+                                struct kdbus_conn_reply **reply)
+{
+       struct kdbus_conn_reply *r;
+       int ret = -ENOENT;
+
+       if (atomic_read(&conn_reply_dst->reply_count) == 0)
+               return -ENOENT;
+
+       list_for_each_entry(r, &conn_replying->reply_list, entry) {
+               if (r->reply_dst == conn_reply_dst &&
+                   r->cookie == cookie) {
+                       *reply = r;
+                       ret = 0;
+                       break;
+               }
+       }
+
+       return ret;
+}
+
 /**
  * kdbus_cmd_msg_cancel() - cancel all pending sync requests
  *                         with the given cookie
@@ -372,10 +395,10 @@ exit:
 int kdbus_cmd_msg_cancel(struct kdbus_conn *conn,
                         u64 cookie)
 {
-       struct kdbus_conn_reply *reply, *reply_tmp;
+       struct kdbus_conn_reply *reply;
        struct kdbus_conn *c;
        bool found = false;
-       int i;
+       int ret, i;
 
        if (atomic_read(&conn->reply_count) == 0)
                return -ENOENT;
@@ -387,14 +410,10 @@ int kdbus_cmd_msg_cancel(struct kdbus_conn *conn,
                        continue;
 
                mutex_lock(&c->lock);
-               list_for_each_entry_safe(reply, reply_tmp,
-                                        &c->reply_list, entry) {
-                       if (reply->sync &&
-                           reply->reply_dst == conn &&
-                           reply->cookie == cookie) {
-                               kdbus_conn_reply_sync(reply, -ECANCELED);
-                               found = true;
-                       }
+               ret = kdbus_conn_find_reply(c, conn, cookie, &reply);
+               if (ret == 0) {
+                       kdbus_conn_reply_sync(reply, -ECANCELED);
+                       found = true;
                }
                mutex_unlock(&c->lock);
        }
@@ -417,21 +436,19 @@ static int kdbus_conn_check_access(struct kdbus_ep *ep,
         * matching entry, allow the message to be sent, and remove it.
         */
        if (reply_wake && msg->cookie_reply > 0) {
-               struct kdbus_conn_reply *r, *tmp;
+               struct kdbus_conn_reply *r;
 
                mutex_lock(&conn_src->lock);
-               list_for_each_entry_safe(r, tmp, &conn_src->reply_list, entry) {
-                       if (r->reply_dst == conn_dst &&
-                           r->cookie == msg->cookie_reply) {
-                               list_del_init(&r->entry);
-                               if (r->sync)
-                                       *reply_wake = kdbus_conn_reply_ref(r);
-                               else
-                                       kdbus_conn_reply_unref(r);
-
-                               allowed = true;
-                               break;
-                       }
+               ret = kdbus_conn_find_reply(conn_src, conn_dst,
+                                           msg->cookie_reply, &r);
+               if (ret == 0) {
+                       list_del_init(&r->entry);
+                       if (r->sync)
+                               *reply_wake = kdbus_conn_reply_ref(r);
+                       else
+                               kdbus_conn_reply_unref(r);
+
+                       allowed = true;
                }
                mutex_unlock(&conn_src->lock);
        }