RDMA/iwpm: Rely on the rdma_nl_[un]register() to ensure that requests are valid

The core netlink code alread guarentees that no netlink callback can be
running outside the rdma_nl_register/unregister() region and this
registration happens during module init/exit. Thus it is already prevented
that iwpm_valid_client() can ever fail. Remove it.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Leon Romanovsky <[e-mail]>
Signed-off-by: Jason Gunthorpe <[e-mail]>

drivers/infiniband/core/iwpm_msg.c

···
 	const char *err_str = "";
 	int ret = -EINVAL;
 
-	if (!iwpm_valid_client(nl_client)) {
-		err_str = "Invalid port mapper client";
-		goto pid_query_error;
-	}
 	if (iwpm_check_registration(nl_client, IWPM_REG_VALID) ||
 			iwpm_user_pid == IWPM_PID_UNAVAILABLE)
 		return 0;
···
 	const char *err_str = "";
 	int ret = -EINVAL;
 
-	if (!iwpm_valid_client(nl_client)) {
-		err_str = "Invalid port mapper client";
-		goto add_mapping_error;
-	}
 	if (!iwpm_valid_pid())
 		return 0;
 	if (!iwpm_check_registration(nl_client, IWPM_REG_VALID)) {
···
 	const char *err_str = "";
 	int ret = -EINVAL;
 
-	if (!iwpm_valid_client(nl_client)) {
-		err_str = "Invalid port mapper client";
-		goto query_mapping_error;
-	}
 	if (!iwpm_valid_pid())
 		return 0;
 	if (!iwpm_check_registration(nl_client, IWPM_REG_VALID)) {
···
 	const char *err_str = "";
 	int ret = -EINVAL;
 
-	if (!iwpm_valid_client(nl_client)) {
-		err_str = "Invalid port mapper client";
-		goto remove_mapping_error;
-	}
 	if (!iwpm_valid_pid())
 		return 0;
 	if (iwpm_check_registration(nl_client, IWPM_REG_UNDEF)) {
···
 	atomic_set(&echo_nlmsg_seq, cb->nlh->nlmsg_seq);
 	pr_debug("%s: iWarp Port Mapper (pid = %d) is available!\n",
 			__func__, iwpm_user_pid);
-	if (iwpm_valid_client(nl_client))
-		iwpm_set_registration(nl_client, IWPM_REG_VALID);
+	iwpm_set_registration(nl_client, IWPM_REG_VALID);
 register_pid_response_exit:
 	nlmsg_request->request_done = 1;
 	/* always for found nlmsg_request */
···
 		return ret;
 
 	nl_client = RDMA_NL_GET_CLIENT(cb->nlh->nlmsg_type);
-	if (!iwpm_valid_client(nl_client)) {
-		pr_info("%s: Invalid port mapper client = %u\n",
-				__func__, nl_client);
-		return ret;
-	}
 	atomic_set(&echo_nlmsg_seq, cb->nlh->nlmsg_seq);
 
 	local_sockaddr = (struct sockaddr_storage *)
···
 		return ret;
 	}
 	nl_client = RDMA_NL_GET_CLIENT(cb->nlh->nlmsg_type);
-	if (!iwpm_valid_client(nl_client)) {
-		pr_info("%s: Invalid port mapper client = %u\n",
-				__func__, nl_client);
-		return ret;
-	}
 	iwpm_set_registration(nl_client, IWPM_REG_INCOMPL);
 	atomic_set(&echo_nlmsg_seq, cb->nlh->nlmsg_seq);
 	iwpm_user_pid = cb->nlh->nlmsg_pid;
···
 	}
 	abi_version = nla_get_u16(nltb[IWPM_NLA_HELLO_ABI_VERSION]);
 	nl_client = RDMA_NL_GET_CLIENT(cb->nlh->nlmsg_type);
-	if (!iwpm_valid_client(nl_client)) {
-		pr_info("%s: Invalid port mapper client = %u\n",
-				__func__, nl_client);
-		return ret;
-	}
 	iwpm_set_registration(nl_client, IWPM_REG_INCOMPL);
 	atomic_set(&echo_nlmsg_seq, cb->nlh->nlmsg_seq);
 	iwpm_ulib_version = min_t(u16, IWPM_UABI_VERSION, abi_version);

drivers/infiniband/core/iwpm_util.c

···
 		return -ENOMEM;
 	}
 
-	iwpm_set_valid(nl_client, 1);
 	iwpm_set_registration(nl_client, IWPM_REG_UNDEF);
 	pr_debug("%s: Mapinfo and reminfo tables are created\n", __func__);
 	return 0;
···
 	free_hash_bucket();
 	free_reminfo_bucket();
 	pr_debug("%s: Resources are destroyed\n", __func__);
-	iwpm_set_valid(nl_client, 0);
 	iwpm_set_registration(nl_client, IWPM_REG_UNDEF);
 	return 0;
 }
···
 	unsigned long flags;
 	int ret = -EINVAL;
 
-	if (!iwpm_valid_client(nl_client))
-		return ret;
 	map_info = kzalloc(sizeof(struct iwpm_mapping_info), GFP_KERNEL);
 	if (!map_info)
 		return -ENOMEM;
···
 	unsigned long flags;
 	int ret = -EINVAL;
 
-	if (!iwpm_valid_client(nl_client)) {
-		pr_info("%s: Invalid client = %u\n", __func__, nl_client);
-		return ret;
-	}
 	spin_lock_irqsave(&iwpm_reminfo_lock, flags);
 	if (iwpm_reminfo_bucket) {
 		hash_bucket_head = get_reminfo_hash_bucket(
···
 int iwpm_get_nlmsg_seq(void)
 {
 	return atomic_inc_return(&iwpm_admin.nlmsg_seq);
-}
-
-int iwpm_valid_client(u8 nl_client)
-{
-	return iwpm_admin.client_list[nl_client];
-}
-
-void iwpm_set_valid(u8 nl_client, int valid)
-{
-	iwpm_admin.client_list[nl_client] = valid;
 }
 
 /* valid client */

drivers/infiniband/core/iwpm_util.h

···
 
 struct iwpm_admin_data {
 	atomic_t nlmsg_seq;
-	int      client_list[RDMA_NL_NUM_CLIENTS];
 	u32      reg_list[RDMA_NL_NUM_CLIENTS];
 };
 
···
  * @reminfo: The remote info to be added
  */
 void iwpm_add_remote_info(struct iwpm_remote_info *reminfo);
-
-/**
- * iwpm_valid_client - Check if the port mapper client is valid
- * @nl_client: The index of the netlink client
- *
- * Valid clients need to call iwpm_init() before using
- * the port mapper
- */
-int iwpm_valid_client(u8 nl_client);
-
-/**
- * iwpm_set_valid - Set the port mapper client to valid or not
- * @nl_client: The index of the netlink client
- * @valid: 1 if valid or 0 if invalid
- */
-void iwpm_set_valid(u8 nl_client, int valid);
 
 /**
  * iwpm_check_registration - Check if the client registration