Commit 4cf19b84 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: Remove BKL from open multiplexer 



Use a local mutex instead of BKL.  This should suffice since each device
type has also its open_mutex.
Also, a bit of clean-up of the legacy device auto-loading code.

Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 5b5cd553

sound/core/sound.c

+38 −35
Original line number Diff line number Diff line
@@ -120,19 +120,12 @@ void *snd_lookup_minor_data(unsigned int minor, int type) 


EXPORT_SYMBOL(snd_lookup_minor_data);



static int __snd_open(struct inode *inode, struct file *file)

{

	unsigned int minor = iminor(inode);

	struct snd_minor *mptr = NULL;

	const struct file_operations *old_fops;

	int err = 0;



	if (minor >= ARRAY_SIZE(snd_minors))

		return -ENODEV;

	mptr = snd_minors[minor];

	if (mptr == NULL) {

#ifdef CONFIG_MODULES

		int dev = SNDRV_MINOR_DEVICE(minor);

static struct snd_minor *autoload_device(unsigned int minor)

{

	int dev;

	mutex_unlock(&sound_mutex); /* release lock temporarily */

	dev = SNDRV_MINOR_DEVICE(minor);

	if (dev == SNDRV_MINOR_CONTROL) {

		/* /dev/aloadC? */

		int card = SNDRV_MINOR_CARD(minor);
@@ -142,42 +135,52 @@ static int __snd_open(struct inode *inode, struct file *file) 
		/* /dev/aloadSEQ */

		snd_request_other(minor);

	}

#ifndef CONFIG_SND_DYNAMIC_MINORS

		/* /dev/snd/{controlC?,seq} */

	mutex_lock(&sound_mutex); /* reacuire lock */

	return snd_minors[minor];

}

#else /* !CONFIG_MODULES */

#define autoload_device(minor)	NULL

#endif /* CONFIG_MODULES */



static int snd_open(struct inode *inode, struct file *file)

{

	unsigned int minor = iminor(inode);

	struct snd_minor *mptr = NULL;

	const struct file_operations *old_fops;

	int err = 0;



	if (minor >= ARRAY_SIZE(snd_minors))

		return -ENODEV;

	mutex_lock(&sound_mutex);

	mptr = snd_minors[minor];

		if (mptr == NULL)

#endif

#endif

	if (mptr == NULL) {

		mptr = autoload_device(minor);

		if (!mptr) {

			mutex_unlock(&sound_mutex);

			return -ENODEV;

		}

	}

	old_fops = file->f_op;

	file->f_op = fops_get(mptr->f_ops);

	if (file->f_op == NULL) {

		file->f_op = old_fops;

		return -ENODEV;

		err = -ENODEV;

	}

	if (file->f_op->open)

	mutex_unlock(&sound_mutex);

	if (err < 0)

		return err;



	if (file->f_op->open) {

		err = file->f_op->open(inode, file);

		if (err) {

			fops_put(file->f_op);

			file->f_op = fops_get(old_fops);

		}

	}

	fops_put(old_fops);

	return err;

}





/* BKL pushdown: nasty #ifdef avoidance wrapper */

static int snd_open(struct inode *inode, struct file *file)

{

	int ret;



	lock_kernel();

	ret = __snd_open(inode, file);

	unlock_kernel();

	return ret;

}



static const struct file_operations snd_fops =

{

	.owner =	THIS_MODULE,