RDMA/rdma_cm: Delete rdma_addr_client

The only thing it does is block module unload while work is posted from
rdma_resolve_ip().

However, this is not the right place to do this. The users of
rdma_resolve_ip() must ensure their own module does not unload until
rdma_resolve_ip() calls the callback, or until rdma_addr_cancel() is
called.

Similarly callers to rdma_addr_find_l2_eth_by_grh() must ensure their
module does not unload while they are calling code.

The only two users are already safe, so there is no need for this.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

3 files changed, 6 insertions, 58 deletions

diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
index 9756cfbdef0e..4f32c4062fb6 100644
--- a/drivers/infiniband/core/addr.c
+++ b/drivers/infiniband/core/addr.c
@@ -56,7 +56,6 @@ struct addr_req {
         struct sockaddr_storage src_addr;
         struct sockaddr_storage dst_addr;
         struct rdma_dev_addr *addr;
-        struct rdma_addr_client *client;
         void *context;
         void (*callback)(int status, struct sockaddr *src_addr,
                          struct rdma_dev_addr *addr, void *context);
@@ -220,28 +219,6 @@ int rdma_addr_size_kss(struct __kernel_sockaddr_storage *addr)
 }
 EXPORT_SYMBOL(rdma_addr_size_kss);
 
-static struct rdma_addr_client self;
-
-void rdma_addr_register_client(struct rdma_addr_client *client)
-{
-        atomic_set(&client->refcount, 1);
-        init_completion(&client->comp);
-}
-EXPORT_SYMBOL(rdma_addr_register_client);
-
-static inline void put_client(struct rdma_addr_client *client)
-{
-        if (atomic_dec_and_test(&client->refcount))
-                complete(&client->comp);
-}
-
-void rdma_addr_unregister_client(struct rdma_addr_client *client)
-{
-        put_client(client);
-        wait_for_completion(&client->comp);
-}
-EXPORT_SYMBOL(rdma_addr_unregister_client);
-
 void rdma_copy_addr(struct rdma_dev_addr *dev_addr,
                     const struct net_device *dev,
                     const unsigned char *dst_dev_addr)
@@ -605,14 +582,12 @@ static void process_one_req(struct work_struct *_work)
                  */
                 cancel_delayed_work(&req->work);
                 list_del_init(&req->list);
-                put_client(req->client);
                 kfree(req);
         }
         spin_unlock_bh(&lock);
 }
 
-int rdma_resolve_ip(struct rdma_addr_client *client,
-                    struct sockaddr *src_addr, struct sockaddr *dst_addr,
+int rdma_resolve_ip(struct sockaddr *src_addr, struct sockaddr *dst_addr,
                     struct rdma_dev_addr *addr, int timeout_ms,
                     void (*callback)(int status, struct sockaddr *src_addr,
                                      struct rdma_dev_addr *addr, void *context),
@@ -644,8 +619,6 @@ int rdma_resolve_ip(struct rdma_addr_client *client,
         req->addr = addr;
         req->callback = callback;
         req->context = context;
-        req->client = client;
-        atomic_inc(&client->refcount);
         INIT_DELAYED_WORK(&req->work, process_one_req);
         req->seq = (u32)atomic_inc_return(&ib_nl_addr_request_seq);
 
@@ -661,7 +634,6 @@ int rdma_resolve_ip(struct rdma_addr_client *client,
                 break;
         default:
                 ret = req->status;
-                atomic_dec(&client->refcount);
                 goto err;
         }
         return ret;
@@ -722,7 +694,6 @@ void rdma_addr_cancel(struct rdma_dev_addr *addr)
                 found->callback(-ECANCELED, (struct sockaddr *)&found->src_addr,
                               found->addr, found->context);
 
-        put_client(found->client);
         kfree(found);
 }
 EXPORT_SYMBOL(rdma_addr_cancel);
@@ -761,8 +732,8 @@ int rdma_addr_find_l2_eth_by_grh(const union ib_gid *sgid,
         dev_addr.net = &init_net;
 
         init_completion(&ctx.comp);
-        ret = rdma_resolve_ip(&self, &sgid_addr._sockaddr, &dgid_addr._sockaddr,
-                        &dev_addr, 1000, resolve_cb, &ctx);
+        ret = rdma_resolve_ip(&sgid_addr._sockaddr, &dgid_addr._sockaddr,
+                              &dev_addr, 1000, resolve_cb, &ctx);
         if (ret)
                 return ret;
 
@@ -806,14 +777,13 @@ int addr_init(void)
                 return -ENOMEM;
 
         register_netevent_notifier(&nb);
-        rdma_addr_register_client(&self);
 
         return 0;
 }
 
 void addr_cleanup(void)
 {
-        rdma_addr_unregister_client(&self);
         unregister_netevent_notifier(&nb);
         destroy_workqueue(addr_wq);
+        WARN_ON(!list_empty(&req_list));
 }
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 51a641002e10..48300838e354 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -156,7 +156,6 @@ static struct ib_client cma_client = {
 };
 
 static struct ib_sa_client sa_client;
-static struct rdma_addr_client addr_client;
 static LIST_HEAD(dev_list);
 static LIST_HEAD(listen_any_list);
 static DEFINE_MUTEX(lock);
@@ -2910,7 +2909,7 @@ int rdma_resolve_addr(struct rdma_cm_id *id, struct sockaddr *src_addr,
                 if (dst_addr->sa_family == AF_IB) {
                         ret = cma_resolve_ib_addr(id_priv);
                 } else {
-                        ret = rdma_resolve_ip(&addr_client, cma_src_addr(id_priv),
+                        ret = rdma_resolve_ip(cma_src_addr(id_priv),
                                               dst_addr, &id->route.addr.dev_addr,
                                               timeout_ms, addr_handler, id_priv);
                 }
@@ -4547,7 +4546,6 @@ static int __init cma_init(void)
                 goto err_wq;
 
         ib_sa_register_client(&sa_client);
-        rdma_addr_register_client(&addr_client);
         register_netdevice_notifier(&cma_nb);
 
         ret = ib_register_client(&cma_client);
@@ -4561,7 +4559,6 @@ static int __init cma_init(void)
 
 err:
         unregister_netdevice_notifier(&cma_nb);
-        rdma_addr_unregister_client(&addr_client);
         ib_sa_unregister_client(&sa_client);
 err_wq:
         destroy_workqueue(cma_wq);
@@ -4574,7 +4571,6 @@ static void __exit cma_cleanup(void)
         rdma_nl_unregister(RDMA_NL_RDMA_CM);
         ib_unregister_client(&cma_client);
         unregister_netdevice_notifier(&cma_nb);
-        rdma_addr_unregister_client(&addr_client);
         ib_sa_unregister_client(&sa_client);
         unregister_pernet_subsys(&cma_pernet_operations);
         destroy_workqueue(cma_wq);
diff --git a/include/rdma/ib_addr.h b/include/rdma/ib_addr.h
index a08cc7278980..c2c8b1fdeead 100644
--- a/include/rdma/ib_addr.h
+++ b/include/rdma/ib_addr.h
@@ -49,22 +49,6 @@
 #include <net/ipv6.h>
 #include <net/net_namespace.h>
 
-struct rdma_addr_client {
-        atomic_t refcount;
-        struct completion comp;
-};
-
-/**
- * rdma_addr_register_client - Register an address client.
- */
-void rdma_addr_register_client(struct rdma_addr_client *client);
-
-/**
- * rdma_addr_unregister_client - Deregister an address client.
- * @client: Client object to deregister.
- */
-void rdma_addr_unregister_client(struct rdma_addr_client *client);
-
 /**
  * struct rdma_dev_addr - Contains resolved RDMA hardware addresses
  * @src_dev_addr:       Source MAC address.
@@ -99,7 +83,6 @@ int rdma_translate_ip(const struct sockaddr *addr,
 /**
  * rdma_resolve_ip - Resolve source and destination IP addresses to
  *   RDMA hardware addresses.
- * @client: Address client associated with request.
  * @src_addr: An optional source address to use in the resolution.  If a
  *   source address is not provided, a usable address will be returned via
  *   the callback.
@@ -112,8 +95,7 @@ int rdma_translate_ip(const struct sockaddr *addr,
  *   or been canceled.  A status of 0 indicates success.
  * @context: User-specified context associated with the call.
  */
-int rdma_resolve_ip(struct rdma_addr_client *client,
-                    struct sockaddr *src_addr, struct sockaddr *dst_addr,
+int rdma_resolve_ip(struct sockaddr *src_addr, struct sockaddr *dst_addr,
                     struct rdma_dev_addr *addr, int timeout_ms,
                     void (*callback)(int status, struct sockaddr *src_addr,
                                      struct rdma_dev_addr *addr, void *context),