drm: drm_auth: Convert mutex usage to guard(mutex)

Replace open-coded mutex handling with cleanup.h guard(mutex). This
simplifies the code and removes the "goto unlock" pattern.

Tested with igt tests core_auth and core_setmaster.

Signed-off-by: André Almeida <andrealmeid@igalia.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20250509142627.639419-1-andrealmeid@igalia.com

diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c
index 22aa015df387ca8a37f269b932bc5d35d4602f0d..d6bf605b4b903dcabf089a6573da3e9bf1a6422d 100644 (file)
--- a/drivers/gpu/drm/drm_auth.c
+++ b/drivers/gpu/drm/drm_auth.c
@@ -95,7 +95,7 @@ int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv)
        struct drm_auth *auth = data;
        int ret = 0;
 
-       mutex_lock(&dev->master_mutex);
+       guard(mutex)(&dev->master_mutex);
        if (!file_priv->magic) {
                ret = idr_alloc(&file_priv->master->magic_map, file_priv,
                                1, 0, GFP_KERNEL);
@@ -103,7 +103,6 @@ int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv)
                        file_priv->magic = ret;
        }
        auth->magic = file_priv->magic;
-       mutex_unlock(&dev->master_mutex);
 
        drm_dbg_core(dev, "%u\n", auth->magic);
 
@@ -118,13 +117,12 @@ int drm_authmagic(struct drm_device *dev, void *data,
 
        drm_dbg_core(dev, "%u\n", auth->magic);
 
-       mutex_lock(&dev->master_mutex);
+       guard(mutex)(&dev->master_mutex);
        file = idr_find(&file_priv->master->magic_map, auth->magic);
        if (file) {
                file->authenticated = 1;
                idr_replace(&file_priv->master->magic_map, NULL, auth->magic);
        }
-       mutex_unlock(&dev->master_mutex);
 
        return file ? 0 : -EINVAL;
 }
@@ -248,41 +246,33 @@ int drm_setmaster_ioctl(struct drm_device *dev, void *data,
 {
        int ret;
 
-       mutex_lock(&dev->master_mutex);
+       guard(mutex)(&dev->master_mutex);
 
        ret = drm_master_check_perm(dev, file_priv);
        if (ret)
-               goto out_unlock;
+               return ret;
 
        if (drm_is_current_master_locked(file_priv))
-               goto out_unlock;
+               return ret;
 
-       if (dev->master) {
-               ret = -EBUSY;
-               goto out_unlock;
-       }
+       if (dev->master)
+               return -EBUSY;
 
-       if (!file_priv->master) {
-               ret = -EINVAL;
-               goto out_unlock;
-       }
+       if (!file_priv->master)
+               return -EINVAL;
 
-       if (!file_priv->is_master) {
-               ret = drm_new_set_master(dev, file_priv);
-               goto out_unlock;
-       }
+       if (!file_priv->is_master)
+               return drm_new_set_master(dev, file_priv);
 
        if (file_priv->master->lessor != NULL) {
                drm_dbg_lease(dev,
                              "Attempt to set lessee %d as master\n",
                              file_priv->master->lessee_id);
-               ret = -EINVAL;
-               goto out_unlock;
+               return -EINVAL;
        }
 
        drm_set_master(dev, file_priv, false);
-out_unlock:
-       mutex_unlock(&dev->master_mutex);
+
        return ret;
 }
 
@@ -299,33 +289,27 @@ int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
 {
        int ret;
 
-       mutex_lock(&dev->master_mutex);
+       guard(mutex)(&dev->master_mutex);
 
        ret = drm_master_check_perm(dev, file_priv);
        if (ret)
-               goto out_unlock;
+               return ret;
 
-       if (!drm_is_current_master_locked(file_priv)) {
-               ret = -EINVAL;
-               goto out_unlock;
-       }
+       if (!drm_is_current_master_locked(file_priv))
+               return -EINVAL;
 
-       if (!dev->master) {
-               ret = -EINVAL;
-               goto out_unlock;
-       }
+       if (!dev->master)
+               return -EINVAL;
 
        if (file_priv->master->lessor != NULL) {
                drm_dbg_lease(dev,
                              "Attempt to drop lessee %d as master\n",
                              file_priv->master->lessee_id);
-               ret = -EINVAL;
-               goto out_unlock;
+               return -EINVAL;
        }
 
        drm_drop_master(dev, file_priv);
-out_unlock:
-       mutex_unlock(&dev->master_mutex);
+
        return ret;
 }
 
@@ -337,7 +321,7 @@ int drm_master_open(struct drm_file *file_priv)
        /* if there is no current master make this fd it, but do not create
         * any master object for render clients
         */
-       mutex_lock(&dev->master_mutex);
+       guard(mutex)(&dev->master_mutex);
        if (!dev->master) {
                ret = drm_new_set_master(dev, file_priv);
        } else {
@@ -345,7 +329,6 @@ int drm_master_open(struct drm_file *file_priv)
                file_priv->master = drm_master_get(dev->master);
                spin_unlock(&file_priv->master_lookup_lock);
        }
-       mutex_unlock(&dev->master_mutex);
 
        return ret;
 }
@@ -355,7 +338,7 @@ void drm_master_release(struct drm_file *file_priv)
        struct drm_device *dev = file_priv->minor->dev;
        struct drm_master *master;
 
-       mutex_lock(&dev->master_mutex);
+       guard(mutex)(&dev->master_mutex);
        master = file_priv->master;
        if (file_priv->magic)
                idr_remove(&file_priv->master->magic_map, file_priv->magic);
@@ -376,7 +359,6 @@ out:
        /* drop the master reference held by the file priv */
        if (file_priv->master)
                drm_master_put(&file_priv->master);
-       mutex_unlock(&dev->master_mutex);
 }
 
 /**