linux-kernel - [PATCH v2 6/8] irqbypass: Use guard(mutex) in lieu of manual lock+unlock

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Message-ID: <20250516230734.2564775-7-seanjc@google.com>
Date: Fri, 16 May 2025 16:07:32 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>, 
	"Michael S. Tsirkin" <mst@...hat.com>, Jason Wang <jasowang@...hat.com>, 
	Alex Williamson <alex.williamson@...hat.com>
Cc: kvm@...r.kernel.org, virtualization@...ts.linux.dev, 
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Kevin Tian <kevin.tian@...el.com>, Oliver Upton <oliver.upton@...ux.dev>, 
	David Matlack <dmatlack@...gle.com>, Like Xu <like.xu.linux@...il.com>, 
	Binbin Wu <binbin.wu@...ux.intel.com>, Yong He <alexyonghe@...cent.com>
Subject: [PATCH v2 6/8] irqbypass: Use guard(mutex) in lieu of manual lock+unlock

Use guard(mutex) to clean up irqbypass's error handling.

Reviewed-by: Kevin Tian <kevin.tian@...el.com>
Acked-by: Michael S. Tsirkin <mst@...hat.com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 virt/lib/irqbypass.c | 38 ++++++++++----------------------------
 1 file changed, 10 insertions(+), 28 deletions(-)

diff --git a/virt/lib/irqbypass.c b/virt/lib/irqbypass.c
index 6a183459dc44..828556c081f5 100644
--- a/virt/lib/irqbypass.c
+++ b/virt/lib/irqbypass.c
@@ -99,33 +99,25 @@ int irq_bypass_register_producer(struct irq_bypass_producer *producer,
 	if (WARN_ON_ONCE(producer->eventfd))
 		return -EINVAL;
 
-	mutex_lock(&lock);
+	guard(mutex)(&lock);
 
 	list_for_each_entry(tmp, &producers, node) {
-		if (tmp->eventfd == eventfd) {
-			ret = -EBUSY;
-			goto out_err;
-		}
+		if (tmp->eventfd == eventfd)
+			return -EBUSY;
 	}
 
 	list_for_each_entry(consumer, &consumers, node) {
 		if (consumer->eventfd == eventfd) {
 			ret = __connect(producer, consumer);
 			if (ret)
-				goto out_err;
+				return ret;
 			break;
 		}
 	}
 
 	producer->eventfd = eventfd;
 	list_add(&producer->node, &producers);
-
-	mutex_unlock(&lock);
-
 	return 0;
-out_err:
-	mutex_unlock(&lock);
-	return ret;
 }
 EXPORT_SYMBOL_GPL(irq_bypass_register_producer);
 
@@ -141,14 +133,13 @@ void irq_bypass_unregister_producer(struct irq_bypass_producer *producer)
 	if (!producer->eventfd)
 		return;
 
-	mutex_lock(&lock);
+	guard(mutex)(&lock);
 
 	if (producer->consumer)
 		__disconnect(producer, producer->consumer);
 
 	producer->eventfd = NULL;
 	list_del(&producer->node);
-	mutex_unlock(&lock);
 }
 EXPORT_SYMBOL_GPL(irq_bypass_unregister_producer);
 
@@ -173,33 +164,25 @@ int irq_bypass_register_consumer(struct irq_bypass_consumer *consumer,
 	if (!consumer->add_producer || !consumer->del_producer)
 		return -EINVAL;
 
-	mutex_lock(&lock);
+	guard(mutex)(&lock);
 
 	list_for_each_entry(tmp, &consumers, node) {
-		if (tmp->eventfd == eventfd) {
-			ret = -EBUSY;
-			goto out_err;
-		}
+		if (tmp->eventfd == eventfd)
+			return -EBUSY;
 	}
 
 	list_for_each_entry(producer, &producers, node) {
 		if (producer->eventfd == eventfd) {
 			ret = __connect(producer, consumer);
 			if (ret)
-				goto out_err;
+				return ret;
 			break;
 		}
 	}
 
 	consumer->eventfd = eventfd;
 	list_add(&consumer->node, &consumers);
-
-	mutex_unlock(&lock);
-
 	return 0;
-out_err:
-	mutex_unlock(&lock);
-	return ret;
 }
 EXPORT_SYMBOL_GPL(irq_bypass_register_consumer);
 
@@ -215,13 +198,12 @@ void irq_bypass_unregister_consumer(struct irq_bypass_consumer *consumer)
 	if (!consumer->eventfd)
 		return;
 
-	mutex_lock(&lock);
+	guard(mutex)(&lock);
 
 	if (consumer->producer)
 		__disconnect(consumer->producer, consumer);
 
 	consumer->eventfd = NULL;
 	list_del(&consumer->node);
-	mutex_unlock(&lock);
 }
 EXPORT_SYMBOL_GPL(irq_bypass_unregister_consumer);
-- 
2.49.0.1112.g889b7c5bd8-goog