V4L/DVB: 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: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/dvb/dvb-core/dmxdev.c b/drivers/media/dvb/dvb-core/dmxdev.c
index 0042306ea11b8539eeba3a8f41f73fd970e6e5f7..2de13b04b09d342ca2f1e701ba1c92f51bb89882 100644 (file)
--- a/drivers/media/dvb/dvb-core/dmxdev.c
+++ b/drivers/media/dvb/dvb-core/dmxdev.c
@@ -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)

diff --git a/drivers/media/dvb/dvb-core/dvb_ca_en50221.c b/drivers/media/dvb/dvb-core/dvb_ca_en50221.c
index cb97e6b8543295971d30f8b21c233791a725f26e..1723a984a522c9993e6b96f38af311fa46d3bae7 100644 (file)
--- a/drivers/media/dvb/dvb-core/dvb_ca_en50221.c
+++ b/drivers/media/dvb/dvb-core/dvb_ca_en50221.c
@@ -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);
 }
 
 

diff --git a/drivers/media/dvb/dvb-core/dvb_net.c b/drivers/media/dvb/dvb-core/dvb_net.c
index 6c3a8a06ccab03ed30fcf4481958a1d532f7fbcf..a08032284cbf62e4b4818ca8fd3c4a5da28c8eac 100644 (file)
--- a/drivers/media/dvb/dvb-core/dvb_net.c
+++ b/drivers/media/dvb/dvb-core/dvb_net.c
@@ -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)

diff --git a/drivers/media/dvb/dvb-core/dvbdev.c b/drivers/media/dvb/dvb-core/dvbdev.c
index b915c39d782f1edc994472d8788aaedc0b722b8c..28f486edcaf0a31be99c78adcdbcbc37e8c824cd 100644 (file)
--- a/drivers/media/dvb/dvb-core/dvbdev.c
+++ b/drivers/media/dvb/dvb-core/dvbdev.c
@@ -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;