Input: psmouse-smbus - use guard notation when acquiring mutex

This makes the code more compact and error handling more robust
by ensuring that mutexes are released in all code paths when control
leaves critical section.

Link: https://lore.kernel.org/r/ZsrAa9XcDvHeIs9T@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/mouse/psmouse-smbus.c b/drivers/input/mouse/psmouse-smbus.c
index 2a2459b..93420f0 100644 (file)
--- a/drivers/input/mouse/psmouse-smbus.c
+++ b/drivers/input/mouse/psmouse-smbus.c
@@ -35,7 +35,7 @@ static void psmouse_smbus_check_adapter(struct i2c_adapter *adapter)
        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HOST_NOTIFY))
                return;
 
-       mutex_lock(&psmouse_smbus_mutex);
+       guard(mutex)(&psmouse_smbus_mutex);
 
        list_for_each_entry(smbdev, &psmouse_smbus_list, node) {
                if (smbdev->dead)
@@ -55,15 +55,13 @@ static void psmouse_smbus_check_adapter(struct i2c_adapter *adapter)
                            "SMBus candidate adapter appeared, triggering rescan\n");
                serio_rescan(smbdev->psmouse->ps2dev.serio);
        }
-
-       mutex_unlock(&psmouse_smbus_mutex);
 }
 
 static void psmouse_smbus_detach_i2c_client(struct i2c_client *client)
 {
        struct psmouse_smbus_dev *smbdev, *tmp;
 
-       mutex_lock(&psmouse_smbus_mutex);
+       guard(mutex)(&psmouse_smbus_mutex);
 
        list_for_each_entry_safe(smbdev, tmp, &psmouse_smbus_list, node) {
                if (smbdev->client != client)
@@ -85,8 +83,6 @@ static void psmouse_smbus_detach_i2c_client(struct i2c_client *client)
                        kfree(smbdev);
                }
        }
-
-       mutex_unlock(&psmouse_smbus_mutex);
 }
 
 static int psmouse_smbus_notifier_call(struct notifier_block *nb,
@@ -171,7 +167,7 @@ static void psmouse_smbus_disconnect(struct psmouse *psmouse)
 {
        struct psmouse_smbus_dev *smbdev = psmouse->private;
 
-       mutex_lock(&psmouse_smbus_mutex);
+       guard(mutex)(&psmouse_smbus_mutex);
 
        if (smbdev->dead) {
                list_del(&smbdev->node);
@@ -186,8 +182,6 @@ static void psmouse_smbus_disconnect(struct psmouse *psmouse)
                psmouse_smbus_schedule_remove(smbdev->client);
        }
 
-       mutex_unlock(&psmouse_smbus_mutex);
-
        psmouse->private = NULL;
 }
 
@@ -219,7 +213,7 @@ void psmouse_smbus_cleanup(struct psmouse *psmouse)
 {
        struct psmouse_smbus_dev *smbdev, *tmp;
 
-       mutex_lock(&psmouse_smbus_mutex);
+       guard(mutex)(&psmouse_smbus_mutex);
 
        list_for_each_entry_safe(smbdev, tmp, &psmouse_smbus_list, node) {
                if (psmouse == smbdev->psmouse) {
@@ -227,8 +221,6 @@ void psmouse_smbus_cleanup(struct psmouse *psmouse)
                        kfree(smbdev);
                }
        }
-
-       mutex_unlock(&psmouse_smbus_mutex);
 }
 
 int psmouse_smbus_init(struct psmouse *psmouse,
@@ -267,9 +259,9 @@ int psmouse_smbus_init(struct psmouse *psmouse,
        psmouse->disconnect = psmouse_smbus_disconnect;
        psmouse->resync_time = 0;
 
-       mutex_lock(&psmouse_smbus_mutex);
-       list_add_tail(&smbdev->node, &psmouse_smbus_list);
-       mutex_unlock(&psmouse_smbus_mutex);
+       scoped_guard(mutex, &psmouse_smbus_mutex) {
+               list_add_tail(&smbdev->node, &psmouse_smbus_list);
+       }
 
        /* Bind to already existing adapters right away */
        error = i2c_for_each_dev(smbdev, psmouse_smbus_create_companion);
@@ -293,9 +285,9 @@ int psmouse_smbus_init(struct psmouse *psmouse,
        smbdev->board.platform_data = NULL;
 
        if (error < 0 || !leave_breadcrumbs) {
-               mutex_lock(&psmouse_smbus_mutex);
-               list_del(&smbdev->node);
-               mutex_unlock(&psmouse_smbus_mutex);
+               scoped_guard(mutex, &psmouse_smbus_mutex) {
+                       list_del(&smbdev->node);
+               }
 
                kfree(smbdev);
        }