lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ALSA: Remove BKL from open multiplexer

Browse Source 
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: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai
2010-04-07 18:52:08 +02:00
parent 5b5cd553e3
commit 4cf19b848f
1 changed files with 38 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

67
sound/core/sound.c
View File

@@ -120,19 +120,12 @@ void *snd_lookup_minor_data(unsigned int minor, int type)
EXPORT_SYMBOL(snd_lookup_minor_data); 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 #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) { if (dev == SNDRV_MINOR_CONTROL) {
/* /dev/aloadC? */ /* /dev/aloadC? */
int card = SNDRV_MINOR_CARD(minor); int card = SNDRV_MINOR_CARD(minor);
@@ -142,42 +135,52 @@ static int __snd_open(struct inode *inode, struct file *file)
/* /dev/aloadSEQ */ /* /dev/aloadSEQ */
snd_request_other(minor); snd_request_other(minor);
} }
#ifndef CONFIG_SND_DYNAMIC_MINORS mutex_lock(&sound_mutex); /* reacuire lock */
/* /dev/snd/{controlC?,seq} */ return snd_minors[minor];
mptr = snd_minors[minor]; }
if (mptr == NULL) #else /* !CONFIG_MODULES */
#endif #define autoload_device(minor) NULL
#endif #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; return -ENODEV;
mutex_lock(&sound_mutex);
mptr = snd_minors[minor];
if (mptr == NULL) {
mptr = autoload_device(minor);
if (!mptr) {
mutex_unlock(&sound_mutex);
return -ENODEV;
}
} }
old_fops = file->f_op; old_fops = file->f_op;
file->f_op = fops_get(mptr->f_ops); file->f_op = fops_get(mptr->f_ops);
if (file->f_op == NULL) { if (file->f_op == NULL) {
file->f_op = old_fops; 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); err = file->f_op->open(inode, file);
if (err) { if (err) {
fops_put(file->f_op); fops_put(file->f_op);
file->f_op = fops_get(old_fops); file->f_op = fops_get(old_fops);
} }
}
fops_put(old_fops); fops_put(old_fops);
return err; 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 = static const struct file_operations snd_fops =
{ {
.owner = THIS_MODULE, .owner = THIS_MODULE,