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

[ALSA] Handle file operations during snd_card disconnects using static file->f_op

Browse Source 
Alsa used to kmalloc one file->f_op per file per disconnecting snd_card.
This led to oopses sometimes when file->f_op was freed before __fput()
finished.
Patch adds a virtual device for disconnect: VDD.
VDD consists of:
	LIST_HEAD(shutdown_files)
	    protected by DEFINE_SPINLOCK(shutdown_mutex)
	static struct file_operations snd_shutdown_f_ops
	    and functions assigned to it
	Additions to struct snd_monitor_file
	    to specify if instance is hidden by VDD or not.
A VDD's instance is
	created in snd_card_disconnect() under the card->files_lock.
	cleaned up in snd_card_file_remove() under the card->files_lock.

Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
This commit is contained in:
Karsten Wiese
2006-10-06 16:08:27 +02:00
committed by Jaroslav Kysela
parent 4130d59b1a
commit a9edfc6022
2 changed files with 54 additions and 42 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
include/sound/core.h
View File

@@ -89,10 +89,10 @@ struct snd_device {
struct snd_monitor_file {
struct file *file;
struct snd_monitor_file *next;
const struct file_operations *disconnected_f_op;
struct list_head shutdown_list;
};
struct snd_shutdown_f_ops; /* define it later in init.c */
/* main structure for soundcard */
struct snd_card {