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Date: Tue, 30 Apr 2024 23:47:45 +0100
From: Jules Irenge <jbi.octave@gmail.com>
To: leon@kernel.org
Cc: jgg@ziepe.ca, wenglianfa@huawei.com, linux-rdma@vger.kernel.org,
	linux-kernel@vger.kernel.org, lishifeng@sangfor.com.cn,
	gustavoars@kernel.org
Subject: [PATCH v2] RDMA/core: Remove NULL check before dev_{put, hold}
Message-ID: <ZjF1Eedxwhn4JSkz@octinomon.home>
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Coccinelle reports a warning

WARNING: NULL check before dev_{put, hold} functions is not needed

The reason is the call netdev_{put, hold} of dev_{put,hold} will check NULL
There is no need to check before using dev_{put, hold}

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
---
Changes in v2:
  - Merge two previous patches into one as directed 

 drivers/infiniband/core/device.c        | 10 +++-------
 drivers/infiniband/core/lag.c           |  3 +--
 drivers/infiniband/core/roce_gid_mgmt.c |  3 +--
 3 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 07cb6c5ffda0..55aa7aa32d4a 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -2174,8 +2174,7 @@ int ib_device_set_netdev(struct ib_device *ib_dev, struct net_device *ndev,
 	spin_unlock_irqrestore(&pdata->netdev_lock, flags);
 
 	add_ndev_hash(pdata);
-	if (old_ndev)
-		__dev_put(old_ndev);
+	__dev_put(old_ndev);
 
 	return 0;
 }
@@ -2235,8 +2234,7 @@ struct net_device *ib_device_get_netdev(struct ib_device *ib_dev,
 		spin_lock(&pdata->netdev_lock);
 		res = rcu_dereference_protected(
 			pdata->netdev, lockdep_is_held(&pdata->netdev_lock));
-		if (res)
-			dev_hold(res);
+		dev_hold(res);
 		spin_unlock(&pdata->netdev_lock);
 	}
 
@@ -2311,9 +2309,7 @@ void ib_enum_roce_netdev(struct ib_device *ib_dev,
 
 			if (filter(ib_dev, port, idev, filter_cookie))
 				cb(ib_dev, port, idev, cookie);
-
-			if (idev)
-				dev_put(idev);
+			dev_put(idev);
 		}
 }
 
diff --git a/drivers/infiniband/core/lag.c b/drivers/infiniband/core/lag.c
index eca6e37c72ba..8fd80adfe833 100644
--- a/drivers/infiniband/core/lag.c
+++ b/drivers/infiniband/core/lag.c
@@ -93,8 +93,7 @@ static struct net_device *rdma_get_xmit_slave_udp(struct ib_device *device,
 	slave = netdev_get_xmit_slave(master, skb,
 				      !!(device->lag_flags &
 					 RDMA_LAG_FLAGS_HASH_ALL_SLAVES));
-	if (slave)
-		dev_hold(slave);
+	dev_hold(slave);
 	rcu_read_unlock();
 	kfree_skb(skb);
 	return slave;
diff --git a/drivers/infiniband/core/roce_gid_mgmt.c b/drivers/infiniband/core/roce_gid_mgmt.c
index e958c43dd28f..d5131b3ba8ab 100644
--- a/drivers/infiniband/core/roce_gid_mgmt.c
+++ b/drivers/infiniband/core/roce_gid_mgmt.c
@@ -601,8 +601,7 @@ static void del_netdev_default_ips_join(struct ib_device *ib_dev, u32 port,
 
 	rcu_read_lock();
 	master_ndev = netdev_master_upper_dev_get_rcu(rdma_ndev);
-	if (master_ndev)
-		dev_hold(master_ndev);
+	dev_hold(master_ndev);
 	rcu_read_unlock();
 
 	if (master_ndev) {
-- 
2.43.2