IB/sa: Require SA registration

Require users to register with SA module, to prevent the sa_query
module text from going away while an SA query callback is still
running.  Update all in-tree users for the new interface.

Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 57 insertions, 10 deletions

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 488fa1d642..1178bd434d 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -62,6 +62,7 @@ static struct ib_client cma_client = {
         .remove = cma_remove_one
 };
 
+static struct ib_sa_client sa_client;
 static LIST_HEAD(dev_list);
 static LIST_HEAD(listen_any_list);
 static DEFINE_MUTEX(lock);
@@ -1323,7 +1324,7 @@ static int cma_query_ib_route(struct rdma_id_private *id_priv, int timeout_ms,
         path_rec.pkey = cpu_to_be16(ib_addr_get_pkey(addr));
         path_rec.numb_path = 1;
 
-        id_priv->query_id = ib_sa_path_rec_get(id_priv->id.device,
+        id_priv->query_id = ib_sa_path_rec_get(&sa_client, id_priv->id.device,
                                 id_priv->id.port_num, &path_rec,
                                 IB_SA_PATH_REC_DGID | IB_SA_PATH_REC_SGID |
                                 IB_SA_PATH_REC_PKEY | IB_SA_PATH_REC_NUMB_PATH,
@@ -2199,12 +2200,15 @@ static int cma_init(void)
         if (!cma_wq)
                 return -ENOMEM;
 
+        ib_sa_register_client(&sa_client);
+
         ret = ib_register_client(&cma_client);
         if (ret)
                 goto err;
         return 0;
 
 err:
+        ib_sa_unregister_client(&sa_client);
         destroy_workqueue(cma_wq);
         return ret;
 }
@@ -2212,6 +2216,7 @@ err:
 static void cma_cleanup(void)
 {
         ib_unregister_client(&cma_client);
+        ib_sa_unregister_client(&sa_client);
         destroy_workqueue(cma_wq);
         idr_destroy(&sdp_ps);
         idr_destroy(&tcp_ps);
diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
index ca8760a7d8..1706d3c7e9 100644
--- a/drivers/infiniband/core/sa_query.c
+++ b/drivers/infiniband/core/sa_query.c
@@ -1,6 +1,7 @@
 /*
  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
  * Copyright (c) 2005 Voltaire, Inc.  All rights reserved.
+ * Copyright (c) 2006 Intel Corporation.  All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -75,6 +76,7 @@ struct ib_sa_device {
 struct ib_sa_query {
         void (*callback)(struct ib_sa_query *, int, struct ib_sa_mad *);
         void (*release)(struct ib_sa_query *);
+        struct ib_sa_client    *client;
         struct ib_sa_port      *port;
         struct ib_mad_send_buf *mad_buf;
         struct ib_sa_sm_ah     *sm_ah;
@@ -415,6 +417,31 @@ static void ib_sa_event(struct ib_event_handler *handler, struct ib_event *event
         }
 }
 
+void ib_sa_register_client(struct ib_sa_client *client)
+{
+        atomic_set(&client->users, 1);
+        init_completion(&client->comp);
+}
+EXPORT_SYMBOL(ib_sa_register_client);
+
+static inline void ib_sa_client_get(struct ib_sa_client *client)
+{
+        atomic_inc(&client->users);
+}
+
+static inline void ib_sa_client_put(struct ib_sa_client *client)
+{
+        if (atomic_dec_and_test(&client->users))
+                complete(&client->comp);
+}
+
+void ib_sa_unregister_client(struct ib_sa_client *client)
+{
+        ib_sa_client_put(client);
+        wait_for_completion(&client->comp);
+}
+EXPORT_SYMBOL(ib_sa_unregister_client);
+
 /**
  * ib_sa_cancel_query - try to cancel an SA query
  * @id:ID of query to cancel
@@ -557,6 +584,7 @@ static void ib_sa_path_rec_release(struct ib_sa_query *sa_query)
 
 /**
  * ib_sa_path_rec_get - Start a Path get query
+ * @client:SA client
  * @device:device to send query on
  * @port_num: port number to send query on
  * @rec:Path Record to send in query
@@ -579,7 +607,8 @@ static void ib_sa_path_rec_release(struct ib_sa_query *sa_query)
  * error code.  Otherwise it is a query ID that can be used to cancel
  * the query.
  */
-int ib_sa_path_rec_get(struct ib_device *device, u8 port_num,
+int ib_sa_path_rec_get(struct ib_sa_client *client,
+                       struct ib_device *device, u8 port_num,
                        struct ib_sa_path_rec *rec,
                        ib_sa_comp_mask comp_mask,
                        int timeout_ms, gfp_t gfp_mask,
@@ -614,8 +643,10 @@ int ib_sa_path_rec_get(struct ib_device *device, u8 port_num,
                 goto err1;
         }
 
-        query->callback = callback;
-        query->context  = context;
+        ib_sa_client_get(client);
+        query->sa_query.client = client;
+        query->callback        = callback;
+        query->context         = context;
 
         mad = query->sa_query.mad_buf->mad;
         init_mad(mad, agent);
@@ -639,6 +670,7 @@ int ib_sa_path_rec_get(struct ib_device *device, u8 port_num,
 
 err2:
         *sa_query = NULL;
+        ib_sa_client_put(query->sa_query.client);
         ib_free_send_mad(query->sa_query.mad_buf);
 
 err1:
@@ -671,6 +703,7 @@ static void ib_sa_service_rec_release(struct ib_sa_query *sa_query)
 
 /**
  * ib_sa_service_rec_query - Start Service Record operation
+ * @client:SA client
  * @device:device to send request on
  * @port_num: port number to send request on
  * @method:SA method - should be get, set, or delete
@@ -695,7 +728,8 @@ static void ib_sa_service_rec_release(struct ib_sa_query *sa_query)
  * error code.  Otherwise it is a request ID that can be used to cancel
  * the query.
  */
-int ib_sa_service_rec_query(struct ib_device *device, u8 port_num, u8 method,
+int ib_sa_service_rec_query(struct ib_sa_client *client,
+                            struct ib_device *device, u8 port_num, u8 method,
                             struct ib_sa_service_rec *rec,
                             ib_sa_comp_mask comp_mask,
                             int timeout_ms, gfp_t gfp_mask,
@@ -735,8 +769,10 @@ int ib_sa_service_rec_query(struct ib_device *device, u8 port_num, u8 method,
                 goto err1;
         }
 
-        query->callback = callback;
-        query->context  = context;
+        ib_sa_client_get(client);
+        query->sa_query.client = client;
+        query->callback        = callback;
+        query->context         = context;
 
         mad = query->sa_query.mad_buf->mad;
         init_mad(mad, agent);
@@ -761,6 +797,7 @@ int ib_sa_service_rec_query(struct ib_device *device, u8 port_num, u8 method,
 
 err2:
         *sa_query = NULL;
+        ib_sa_client_put(query->sa_query.client);
         ib_free_send_mad(query->sa_query.mad_buf);
 
 err1:
@@ -791,7 +828,8 @@ static void ib_sa_mcmember_rec_release(struct ib_sa_query *sa_query)
         kfree(container_of(sa_query, struct ib_sa_mcmember_query, sa_query));
 }
 
-int ib_sa_mcmember_rec_query(struct ib_device *device, u8 port_num,
+int ib_sa_mcmember_rec_query(struct ib_sa_client *client,
+                             struct ib_device *device, u8 port_num,
                              u8 method,
                              struct ib_sa_mcmember_rec *rec,
                              ib_sa_comp_mask comp_mask,
@@ -827,8 +865,10 @@ int ib_sa_mcmember_rec_query(struct ib_device *device, u8 port_num,
                 goto err1;
         }
 
-        query->callback = callback;
-        query->context  = context;
+        ib_sa_client_get(client);
+        query->sa_query.client = client;
+        query->callback        = callback;
+        query->context         = context;
 
         mad = query->sa_query.mad_buf->mad;
         init_mad(mad, agent);
@@ -853,6 +893,7 @@ int ib_sa_mcmember_rec_query(struct ib_device *device, u8 port_num,
 
 err2:
         *sa_query = NULL;
+        ib_sa_client_put(query->sa_query.client);
         ib_free_send_mad(query->sa_query.mad_buf);
 
 err1:
@@ -889,6 +930,7 @@ static void send_handler(struct ib_mad_agent *agent,
 
         ib_free_send_mad(mad_send_wc->send_buf);
         kref_put(&query->sm_ah->ref, free_sm_ah);
+        ib_sa_client_put(query->client);
         query->release(query);
 }