Commit e6684d08 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: hwdep: Use guard() for locking 



We can simplify the code gracefully with new guard() macro and co for
automatic cleanup of locks.

There are still a few remaining explicit mutex_lock/unlock calls, and
those are for the places where we do temporary unlock/relock, which
doesn't fit well with the guard(), so far.

Only the code refactoring, and no functional changes.

Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240227085306.9764-6-tiwai@suse.de
parent b0489269

sound/core/hwdep.c

+40 −49
Original line number Diff line number Diff line
@@ -149,12 +149,12 @@ static int snd_hwdep_release(struct inode *inode, struct file * file) 
	struct snd_hwdep *hw = file->private_data;

	struct module *mod = hw->card->module;



	mutex_lock(&hw->open_mutex);

	scoped_guard(mutex, &hw->open_mutex) {

		if (hw->ops.release)

			err = hw->ops.release(hw, file);

		if (hw->used > 0)

			hw->used--;

	mutex_unlock(&hw->open_mutex);

	}

	wake_up(&hw->open_wait);



	snd_card_file_remove(hw->card, file);
@@ -272,8 +272,8 @@ static int snd_hwdep_control_ioctl(struct snd_card *card, 


			if (get_user(device, (int __user *)arg))

				return -EFAULT;

			mutex_lock(&register_mutex);



			scoped_guard(mutex, &register_mutex) {

				if (device < 0)

					device = 0;

				else if (device < SNDRV_MINOR_HWDEPS)
@@ -288,27 +288,27 @@ static int snd_hwdep_control_ioctl(struct snd_card *card, 
				}

				if (device >= SNDRV_MINOR_HWDEPS)

					device = -1;

			mutex_unlock(&register_mutex);

				if (put_user(device, (int __user *)arg))

					return -EFAULT;

				return 0;

			}

			break;

		}

	case SNDRV_CTL_IOCTL_HWDEP_INFO:

		{

			struct snd_hwdep_info __user *info = (struct snd_hwdep_info __user *)arg;

			int device, err;

			int device;

			struct snd_hwdep *hwdep;



			if (get_user(device, &info->device))

				return -EFAULT;

			mutex_lock(&register_mutex);

			scoped_guard(mutex, &register_mutex) {

				hwdep = snd_hwdep_search(card, device);

			if (hwdep)

				err = snd_hwdep_info(hwdep, info);

			else

				err = -ENXIO;

			mutex_unlock(&register_mutex);

			return err;

				if (!hwdep)

					return -ENXIO;

				return snd_hwdep_info(hwdep, info);

			}

			break;

		}

	}

	return -ENOIOCTLCMD;
@@ -422,11 +422,9 @@ static int snd_hwdep_dev_register(struct snd_device *device) 
	struct snd_card *card = hwdep->card;

	int err;



	mutex_lock(&register_mutex);

	if (snd_hwdep_search(card, hwdep->device)) {

		mutex_unlock(&register_mutex);

	guard(mutex)(&register_mutex);

	if (snd_hwdep_search(card, hwdep->device))

		return -EBUSY;

	}

	list_add_tail(&hwdep->list, &snd_hwdep_devices);

	err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,

				  hwdep->card, hwdep->device,
@@ -434,7 +432,6 @@ static int snd_hwdep_dev_register(struct snd_device *device) 
	if (err < 0) {

		dev_err(hwdep->dev, "unable to register\n");

		list_del(&hwdep->list);

		mutex_unlock(&register_mutex);

		return err;

	}
@@ -454,7 +451,6 @@ static int snd_hwdep_dev_register(struct snd_device *device) 
			hwdep->ossreg = 1;

	}

#endif

	mutex_unlock(&register_mutex);

	return 0;

}
@@ -464,12 +460,10 @@ static int snd_hwdep_dev_disconnect(struct snd_device *device) 


	if (snd_BUG_ON(!hwdep))

		return -ENXIO;

	mutex_lock(&register_mutex);

	if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) {

		mutex_unlock(&register_mutex);

	guard(mutex)(&register_mutex);

	if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep)

		return -EINVAL;

	}

	mutex_lock(&hwdep->open_mutex);

	guard(mutex)(&hwdep->open_mutex);

	wake_up(&hwdep->open_wait);

#ifdef CONFIG_SND_OSSEMUL

	if (hwdep->ossreg)
@@ -477,8 +471,6 @@ static int snd_hwdep_dev_disconnect(struct snd_device *device) 
#endif

	snd_unregister_device(hwdep->dev);

	list_del_init(&hwdep->list);

	mutex_unlock(&hwdep->open_mutex);

	mutex_unlock(&register_mutex);

	return 0;

}
@@ -492,11 +484,10 @@ static void snd_hwdep_proc_read(struct snd_info_entry *entry, 
{

	struct snd_hwdep *hwdep;



	mutex_lock(&register_mutex);

	guard(mutex)(&register_mutex);

	list_for_each_entry(hwdep, &snd_hwdep_devices, list)

		snd_iprintf(buffer, "%02i-%02i: %s\n",

			    hwdep->card->number, hwdep->device, hwdep->name);

	mutex_unlock(&register_mutex);

}



static struct snd_info_entry *snd_hwdep_proc_entry;