From: Sagi Grimberg <sagi@grimberg.me>
Date: Sun, 2 Jul 2017 11:20:50 +0300
Subject: RDMA/core: make ib_device.add method optional
Patch-mainline: v4.14-rc1
Git-commit: b059e2108d7ac2d63001735f11d79ee670d9e3fe
References: bsc#1046306 FATE#322942

ib_clients can indeed fill .add to NULL, but then they will not see
any device removal notifications. The reason is that that
ib_register_client and ib_register_device checked existence of .add
before adding the creating a corresponding client_data and adding
it to the list. Simple condition reverse fixes the issue.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/core/device.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -523,7 +523,7 @@ int ib_register_device(struct ib_device
 	device->reg_state = IB_DEV_REGISTERED;
 
 	list_for_each_entry(client, &client_list, list)
-		if (client->add && !add_client_context(device, client))
+		if (!add_client_context(device, client) && client->add)
 			client->add(device);
 
 	device->index = __dev_new_index();
@@ -613,7 +613,7 @@ int ib_register_client(struct ib_client
 	mutex_lock(&device_mutex);
 
 	list_for_each_entry(device, &device_list, core_list)
-		if (client->add && !add_client_context(device, client))
+		if (!add_client_context(device, client) && client->add)
 			client->add(device);
 
 	down_write(&lists_rwsem);