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dvb-core: kill the big kernel lock

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The dvb core only uses the big kernel lock in the open
and ioctl functions, which means it can be replaced with
a dvb specific mutex. Fortunately, all the ioctl functions
go through dvb_usercopy, so we can move the serialization
in there.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: linux-media@vger.kernel.org
This commit is contained in:
Arnd Bergmann
2010-09-11 19:56:45 +02:00
parent adfedd216d
commit 72024f1ec5
4 changed files with 11 additions and 40 deletions
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17
drivers/media/dvb/dvb-core/dmxdev.c
View File

@@ -25,7 +25,6 @@
#include <linux/slab.h> #include <linux/slab.h>
#include <linux/vmalloc.h> #include <linux/vmalloc.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/smp_lock.h>
#include <linux/poll.h> #include <linux/poll.h>
#include <linux/ioctl.h> #include <linux/ioctl.h>
#include <linux/wait.h> #include <linux/wait.h>
@@ -1088,13 +1087,7 @@ static int dvb_demux_do_ioctl(struct file *file,
static long dvb_demux_ioctl(struct file *file, unsigned int cmd, static long dvb_demux_ioctl(struct file *file, unsigned int cmd,
unsigned long arg) unsigned long arg)
{ {
int ret; return dvb_usercopy(file, cmd, arg, dvb_demux_do_ioctl);
lock_kernel();
ret = dvb_usercopy(file, cmd, arg, dvb_demux_do_ioctl);
unlock_kernel();
return ret;
} }
static unsigned int dvb_demux_poll(struct file *file, poll_table *wait) static unsigned int dvb_demux_poll(struct file *file, poll_table *wait)
@@ -1186,13 +1179,7 @@ static int dvb_dvr_do_ioctl(struct file *file,
static long dvb_dvr_ioctl(struct file *file, static long dvb_dvr_ioctl(struct file *file,
unsigned int cmd, unsigned long arg) unsigned int cmd, unsigned long arg)
{ {
int ret; return dvb_usercopy(file, cmd, arg, dvb_dvr_do_ioctl);
lock_kernel();
ret = dvb_usercopy(file, cmd, arg, dvb_dvr_do_ioctl);
unlock_kernel();
return ret;
} }
static unsigned int dvb_dvr_poll(struct file *file, poll_table *wait) static unsigned int dvb_dvr_poll(struct file *file, poll_table *wait)

8
drivers/media/dvb/dvb-core/dvb_ca_en50221.c
View File

@@ -1259,13 +1259,7 @@ static int dvb_ca_en50221_io_do_ioctl(struct file *file,
static long dvb_ca_en50221_io_ioctl(struct file *file, static long dvb_ca_en50221_io_ioctl(struct file *file,
unsigned int cmd, unsigned long arg) unsigned int cmd, unsigned long arg)
{ {
int ret; return dvb_usercopy(file, cmd, arg, dvb_ca_en50221_io_do_ioctl);
lock_kernel();
ret = dvb_usercopy(file, cmd, arg, dvb_ca_en50221_io_do_ioctl);
unlock_kernel();
return ret;
} }

9
drivers/media/dvb/dvb-core/dvb_net.c
View File

@@ -59,7 +59,6 @@
#include <linux/netdevice.h> #include <linux/netdevice.h>
#include <linux/etherdevice.h> #include <linux/etherdevice.h>
#include <linux/dvb/net.h> #include <linux/dvb/net.h>
#include <linux/smp_lock.h>
#include <linux/uio.h> #include <linux/uio.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
#include <linux/crc32.h> #include <linux/crc32.h>
@@ -1445,13 +1444,7 @@ static int dvb_net_do_ioctl(struct file *file,
static long dvb_net_ioctl(struct file *file, static long dvb_net_ioctl(struct file *file,
unsigned int cmd, unsigned long arg) unsigned int cmd, unsigned long arg)
{ {
int ret; return dvb_usercopy(file, cmd, arg, dvb_net_do_ioctl);
lock_kernel();
ret = dvb_usercopy(file, cmd, arg, dvb_net_do_ioctl);
unlock_kernel();
return ret;
} }
static int dvb_net_close(struct inode *inode, struct file *file) static int dvb_net_close(struct inode *inode, struct file *file)

17
drivers/media/dvb/dvb-core/dvbdev.c
View File

@@ -32,9 +32,9 @@
#include <linux/fs.h> #include <linux/fs.h>
#include <linux/cdev.h> #include <linux/cdev.h>
#include <linux/mutex.h> #include <linux/mutex.h>
#include <linux/smp_lock.h>
#include "dvbdev.h" #include "dvbdev.h"
static DEFINE_MUTEX(dvbdev_mutex);
static int dvbdev_debug; static int dvbdev_debug;
module_param(dvbdev_debug, int, 0644); module_param(dvbdev_debug, int, 0644);
@@ -68,7 +68,7 @@ static int dvb_device_open(struct inode *inode, struct file *file)
{ {
struct dvb_device *dvbdev; struct dvb_device *dvbdev;
lock_kernel(); mutex_lock(&dvbdev_mutex);
down_read(&minor_rwsem); down_read(&minor_rwsem);
dvbdev = dvb_minors[iminor(inode)]; dvbdev = dvb_minors[iminor(inode)];
@@ -91,12 +91,12 @@ static int dvb_device_open(struct inode *inode, struct file *file)
} }
fops_put(old_fops); fops_put(old_fops);
up_read(&minor_rwsem); up_read(&minor_rwsem);
unlock_kernel(); mutex_unlock(&dvbdev_mutex);
return err; return err;
} }
fail: fail:
up_read(&minor_rwsem); up_read(&minor_rwsem);
unlock_kernel(); mutex_unlock(&dvbdev_mutex);
return -ENODEV; return -ENODEV;
} }
@@ -158,7 +158,6 @@ long dvb_generic_ioctl(struct file *file,
unsigned int cmd, unsigned long arg) unsigned int cmd, unsigned long arg)
{ {
struct dvb_device *dvbdev = file->private_data; struct dvb_device *dvbdev = file->private_data;
int ret;
if (!dvbdev) if (!dvbdev)
return -ENODEV; return -ENODEV;
@@ -166,11 +165,7 @@ long dvb_generic_ioctl(struct file *file,
if (!dvbdev->kernel_ioctl) if (!dvbdev->kernel_ioctl)
return -EINVAL; return -EINVAL;
lock_kernel(); return dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
ret = dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
unlock_kernel();
return ret;
} }
EXPORT_SYMBOL(dvb_generic_ioctl); EXPORT_SYMBOL(dvb_generic_ioctl);
@@ -421,8 +416,10 @@ int dvb_usercopy(struct file *file,
} }
/* call driver */ /* call driver */
mutex_lock(&dvbdev_mutex);
if ((err = func(file, cmd, parg)) == -ENOIOCTLCMD) if ((err = func(file, cmd, parg)) == -ENOIOCTLCMD)
err = -EINVAL; err = -EINVAL;
mutex_unlock(&dvbdev_mutex);
if (err < 0) if (err < 0)
goto out; goto out;