linux-kernel - [PATCH v4 3/8] driver core: Move true expression out of if condition in 3 device finding APIs

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Message-Id: <20241218-class_fix-v4-3-3c40f098356b@quicinc.com>
Date: Wed, 18 Dec 2024 08:01:33 +0800
From: Zijun Hu <zijun_hu@...oud.com>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
 "Rafael J. Wysocki" <rafael@...nel.org>, Tejun Heo <tj@...nel.org>, 
 Josef Bacik <josef@...icpanda.com>, Jens Axboe <axboe@...nel.dk>, 
 Boris Burkov <boris@....io>, Davidlohr Bueso <dave@...olabs.net>, 
 Jonathan Cameron <jonathan.cameron@...wei.com>, 
 Dave Jiang <dave.jiang@...el.com>, 
 Alison Schofield <alison.schofield@...el.com>, 
 Vishal Verma <vishal.l.verma@...el.com>, Ira Weiny <ira.weiny@...el.com>, 
 Dan Williams <dan.j.williams@...el.com>
Cc: Zijun Hu <zijun_hu@...oud.com>, linux-kernel@...r.kernel.org, 
 cgroups@...r.kernel.org, linux-block@...r.kernel.org, 
 linux-cxl@...r.kernel.org, Zijun Hu <quic_zijuhu@...cinc.com>, 
 Fan Ni <fan.ni@...sung.com>, Jonathan Cameron <Jonathan.Cameron@...wei.com>
Subject: [PATCH v4 3/8] driver core: Move true expression out of if
 condition in 3 device finding APIs

From: Zijun Hu <quic_zijuhu@...cinc.com>

For bus_find_device(), driver_find_device(), and device_find_child(), all
of their function body have pattern below:

{
	struct klist_iter i;
	struct device *dev;

	...
	while ((dev = next_device(&i)))
		if (match(dev, data) && get_device(dev))
			break;
	...
}

The expression 'get_device(dev)' in the if condition always returns true
since @dev != NULL.

Move the expression to if body to make logic of these APIs more clearer.

Reviewed-by: Fan Ni <fan.ni@...sung.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@...wei.com>
Signed-off-by: Zijun Hu <quic_zijuhu@...cinc.com>
---
 drivers/base/bus.c    | 7 +++++--
 drivers/base/core.c   | 7 +++++--
 drivers/base/driver.c | 7 +++++--
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 657c93c38b0dc2a2247e5f482fadd3a9376a58e8..73a56f376d3a05962ce0931a2fe8b4d8839157f2 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -402,9 +402,12 @@ struct device *bus_find_device(const struct bus_type *bus,

 	klist_iter_init_node(&sp->klist_devices, &i,
 			     (start ? &start->p->knode_bus : NULL));
-	while ((dev = next_device(&i)))
-		if (match(dev, data) && get_device(dev))
+	while ((dev = next_device(&i))) {
+		if (match(dev, data)) {
+			get_device(dev);
 			break;
+		}
+	}
 	klist_iter_exit(&i);
 	subsys_put(sp);
 	return dev;
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 8bdbc9e657e832a063542391426f570ccb5c18b9..69bb6bf4bd12395226ee3c99e2f63d15c7e342a5 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4089,9 +4089,12 @@ struct device *device_find_child(struct device *parent, const void *data,
 		return NULL;

 	klist_iter_init(&parent->p->klist_children, &i);
-	while ((child = next_device(&i)))
-		if (match(child, data) && get_device(child))
+	while ((child = next_device(&i))) {
+		if (match(child, data)) {
+			get_device(child);
 			break;
+		}
+	}
 	klist_iter_exit(&i);
 	return child;
 }
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index b4eb5b89c4ee7bc35458fc75730b16a6d1e804d3..6f033a741aa7ce6138d1c61e49e72b2a3eb85e06 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -160,9 +160,12 @@ struct device *driver_find_device(const struct device_driver *drv,

 	klist_iter_init_node(&drv->p->klist_devices, &i,
 			     (start ? &start->p->knode_driver : NULL));
-	while ((dev = next_device(&i)))
-		if (match(dev, data) && get_device(dev))
+	while ((dev = next_device(&i))) {
+		if (match(dev, data)) {
+			get_device(dev);
 			break;
+		}
+	}
 	klist_iter_exit(&i);
 	return dev;
 }

-- 
2.34.1