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Commit 72024f1e authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

dvb-core: kill the big kernel lock 



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: default avatarArnd Bergmann <arnd@arndb.de>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: linux-media@vger.kernel.org
parent adfedd21

drivers/media/dvb/dvb-core/dmxdev.c

+2 −15
Original line number Diff line number Diff line
@@ -25,7 +25,6 @@ 
#include <linux/slab.h>

#include <linux/vmalloc.h>

#include <linux/module.h>

#include <linux/smp_lock.h>

#include <linux/poll.h>

#include <linux/ioctl.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,

			    unsigned long arg)

{

	int ret;



	lock_kernel();

	ret = dvb_usercopy(file, cmd, arg, dvb_demux_do_ioctl);

	unlock_kernel();



	return ret;

	return dvb_usercopy(file, cmd, arg, dvb_demux_do_ioctl);

}



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,

			 unsigned int cmd, unsigned long arg)

{

	int ret;



	lock_kernel();

	ret = dvb_usercopy(file, cmd, arg, dvb_dvr_do_ioctl);

	unlock_kernel();



	return ret;

	return dvb_usercopy(file, cmd, arg, dvb_dvr_do_ioctl);

}



static unsigned int dvb_dvr_poll(struct file *file, poll_table *wait)

drivers/media/dvb/dvb-core/dvb_ca_en50221.c

+1 −7
Original line number Diff line number Diff line
@@ -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,

				    unsigned int cmd, unsigned long arg)

{

	int ret;



	lock_kernel();

	ret = dvb_usercopy(file, cmd, arg, dvb_ca_en50221_io_do_ioctl);

	unlock_kernel();



	return ret;

	return dvb_usercopy(file, cmd, arg, dvb_ca_en50221_io_do_ioctl);

}

drivers/media/dvb/dvb-core/dvb_net.c

+1 −8
Original line number Diff line number Diff line
@@ -59,7 +59,6 @@ 
#include <linux/netdevice.h>

#include <linux/etherdevice.h>

#include <linux/dvb/net.h>

#include <linux/smp_lock.h>

#include <linux/uio.h>

#include <asm/uaccess.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,

	      unsigned int cmd, unsigned long arg)

{

	int ret;



	lock_kernel();

	ret = dvb_usercopy(file, cmd, arg, dvb_net_do_ioctl);

	unlock_kernel();



	return ret;

	return dvb_usercopy(file, cmd, arg, dvb_net_do_ioctl);

}



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

drivers/media/dvb/dvb-core/dvbdev.c

+7 −10
Original line number Diff line number Diff line
@@ -32,9 +32,9 @@ 
#include <linux/fs.h>

#include <linux/cdev.h>

#include <linux/mutex.h>

#include <linux/smp_lock.h>

#include "dvbdev.h"



static DEFINE_MUTEX(dvbdev_mutex);

static int dvbdev_debug;



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;



	lock_kernel();

	mutex_lock(&dvbdev_mutex);

	down_read(&minor_rwsem);

	dvbdev = dvb_minors[iminor(inode)];
@@ -91,12 +91,12 @@ static int dvb_device_open(struct inode *inode, struct file *file) 
		}

		fops_put(old_fops);

		up_read(&minor_rwsem);

		unlock_kernel();

		mutex_unlock(&dvbdev_mutex);

		return err;

	}

fail:

	up_read(&minor_rwsem);

	unlock_kernel();

	mutex_unlock(&dvbdev_mutex);

	return -ENODEV;

}
@@ -158,7 +158,6 @@ long dvb_generic_ioctl(struct file *file, 
		       unsigned int cmd, unsigned long arg)

{

	struct dvb_device *dvbdev = file->private_data;

	int ret;



	if (!dvbdev)

		return -ENODEV;
@@ -166,11 +165,7 @@ long dvb_generic_ioctl(struct file *file, 
	if (!dvbdev->kernel_ioctl)

		return -EINVAL;



	lock_kernel();

	ret = dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);

	unlock_kernel();



	return ret;

	return dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);

}

EXPORT_SYMBOL(dvb_generic_ioctl);
@@ -421,8 +416,10 @@ int dvb_usercopy(struct file *file, 
	}



	/* call driver */

	mutex_lock(&dvbdev_mutex);

	if ((err = func(file, cmd, parg)) == -ENOIOCTLCMD)

		err = -EINVAL;

	mutex_unlock(&dvbdev_mutex);



	if (err < 0)

		goto out;