sound: snd_ctl_remove_unlocked_id: simplify user control counting
Move the decrementing of the user controls counter from snd_ctl_elem_remove to snd_ctl_remove_unlocked_id; this saves the separate locking of the controls semaphore, and therefore removes a harmless race. Since the purpose of the function is to operate on user controls (the control being unlocked is just a prerequisite), rename it to snd_ctl_remove_user_ctl. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
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@ -414,7 +414,7 @@ int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
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EXPORT_SYMBOL(snd_ctl_remove_id);
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/**
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* snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
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* snd_ctl_remove_user_ctl - remove and release the unlocked user control
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* @file: active control handle
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* @id: the control id to remove
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*
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@ -423,8 +423,8 @@ EXPORT_SYMBOL(snd_ctl_remove_id);
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*
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* Returns 0 if successful, or a negative error code on failure.
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*/
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static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
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struct snd_ctl_elem_id *id)
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static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
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struct snd_ctl_elem_id *id)
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{
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struct snd_card *card = file->card;
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struct snd_kcontrol *kctl;
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@ -442,6 +442,9 @@ static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
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goto error;
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}
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ret = snd_ctl_remove(card, kctl);
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if (ret < 0)
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goto error;
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card->user_ctl_count--;
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error:
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up_write(&card->controls_rwsem);
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return ret;
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@ -1053,18 +1056,10 @@ static int snd_ctl_elem_remove(struct snd_ctl_file *file,
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struct snd_ctl_elem_id __user *_id)
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{
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struct snd_ctl_elem_id id;
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int err;
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if (copy_from_user(&id, _id, sizeof(id)))
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return -EFAULT;
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err = snd_ctl_remove_unlocked_id(file, &id);
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if (! err) {
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struct snd_card *card = file->card;
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down_write(&card->controls_rwsem);
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card->user_ctl_count--;
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up_write(&card->controls_rwsem);
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}
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return err;
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return snd_ctl_remove_user_ctl(file, &id);
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}
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static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
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