Prev: [PATCH 09/12] mtd: autoconvert trivial BKL users to private mutex
Next: [PATCH 00/12] autoconvert trivial BKL users to private mutex
From: Arnd Bergmann on 11 Jul 2010 17:30
All these files use the big kernel lock in a trivial
way to serialize their private file operations,
typically resulting from an earlier semi-automatic
pushdown from VFS.

None of these drivers appears to want to lock against
other code, and they all use the BKL as the top-level
lock in their file operations, meaning that there
is no lock-order inversion problem.

Consequently, we can remove the BKL completely,
replacing it with a per-file mutex in every case.
Using a scripted approach means we can avoid
typos.

file=$1
name=$2
if grep -q lock_kernel ${file} ; then
if grep -q 'include.*linux.mutex.h' ${file} ; then
sed -i '/include.*<linux\/smp_lock.h>/d' ${file}
else
sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file}
fi
sed -i ${file} \
-e "/^#include.*linux.mutex.h/,$ {
1,/^\(static\|int\|long\)/ {
/^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);

} }" \
-e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
-e '/[ ]*cycle_kernel_lock();/d'
else
sed -i -e '/include.*\<smp_lock.h\>/d' ${file} \
-e '/cycle_kernel_lock()/d'
fi

Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
Cc: Greg Kroah-Hartman <gregkh(a)suse.de>
Cc: linux-usb(a)vger.kernel.org
---
drivers/usb/gadget/printer.c | 7 ++++---
drivers/usb/misc/iowarrior.c | 15 ++++++++-------
drivers/usb/misc/rio500.c | 15 ++++++++-------
drivers/usb/misc/usblcd.c | 16 ++++++++--------
4 files changed, 28 insertions(+), 25 deletions(-)

diff --git a/drivers/usb/gadget/printer.c b/drivers/usb/gadget/printer.c
index 4c3ac5c..04c7bbf 100644
--- a/drivers/usb/gadget/printer.c
+++ b/drivers/usb/gadget/printer.c
@@ -25,7 +25,7 @@
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/timer.h>
@@ -70,6 +70,7 @@
#define DRIVER_DESC "Printer Gadget"
#define DRIVER_VERSION "2007 OCT 06"

+static DEFINE_MUTEX(printer_mutex);
static const char shortname [] = "printer";
static const char driver_desc [] = DRIVER_DESC;

@@ -476,7 +477,7 @@ printer_open(struct inode *inode, struct file *fd)
unsigned long flags;
int ret = -EBUSY;

- lock_kernel();
+ mutex_lock(&printer_mutex);
dev = container_of(inode->i_cdev, struct printer_dev, printer_cdev);

spin_lock_irqsave(&dev->lock, flags);
@@ -492,7 +493,7 @@ printer_open(struct inode *inode, struct file *fd)
spin_unlock_irqrestore(&dev->lock, flags);

DBG(dev, "printer_open returned %x\n", ret);
- unlock_kernel();
+ mutex_unlock(&printer_mutex);
return ret;
}

diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c
index 7dc9d3c..8296645 100644
--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -18,7 +18,7 @@
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/sched.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/poll.h>
#include <linux/usb/iowarrior.h>

@@ -61,6 +61,7 @@ MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

/* Module parameters */
+static DEFINE_MUTEX(iowarrior_mutex);
static int debug = 0;
module_param(debug, bool, 0644);
MODULE_PARM_DESC(debug, "debug=1 enables debugging messages");
@@ -493,7 +494,7 @@ static long iowarrior_ioctl(struct file *file, unsigned int cmd,
return -ENOMEM;

/* lock this object */
- lock_kernel();
+ mutex_lock(&iowarrior_mutex);
mutex_lock(&dev->mutex);

/* verify that the device wasn't unplugged */
@@ -585,7 +586,7 @@ static long iowarrior_ioctl(struct file *file, unsigned int cmd,
error_out:
/* unlock the device */
mutex_unlock(&dev->mutex);
- unlock_kernel();
+ mutex_unlock(&iowarrior_mutex);
kfree(buffer);
return retval;
}
@@ -602,12 +603,12 @@ static int iowarrior_open(struct inode *inode, struct file *file)

dbg("%s", __func__);

- lock_kernel();
+ mutex_lock(&iowarrior_mutex);
subminor = iminor(inode);

interface = usb_find_interface(&iowarrior_driver, subminor);
if (!interface) {
- unlock_kernel();
+ mutex_unlock(&iowarrior_mutex);
err("%s - error, can't find device for minor %d", __func__,
subminor);
return -ENODEV;
@@ -617,7 +618,7 @@ static int iowarrior_open(struct inode *inode, struct file *file)
dev = usb_get_intfdata(interface);
if (!dev) {
mutex_unlock(&iowarrior_open_disc_lock);
- unlock_kernel();
+ mutex_unlock(&iowarrior_mutex);
return -ENODEV;
}

@@ -644,7 +645,7 @@ static int iowarrior_open(struct inode *inode, struct file *file)

out:
mutex_unlock(&dev->mutex);
- unlock_kernel();
+ mutex_unlock(&iowarrior_mutex);
return retval;
}

diff --git a/drivers/usb/misc/rio500.c b/drivers/usb/misc/rio500.c
index a85771b..cc13ae6 100644
--- a/drivers/usb/misc/rio500.c
+++ b/drivers/usb/misc/rio500.c
@@ -32,7 +32,7 @@
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/errno.h>
#include <linux/random.h>
#include <linux/poll.h>
@@ -72,6 +72,7 @@ struct rio_usb_data {
struct mutex lock; /* general race avoidance */
};

+static DEFINE_MUTEX(rio500_mutex);
static struct rio_usb_data rio_instance;

static int open_rio(struct inode *inode, struct file *file)
@@ -79,12 +80,12 @@ static int open_rio(struct inode *inode, struct file *file)
struct rio_usb_data *rio = &rio_instance;

/* against disconnect() */
- lock_kernel();
+ mutex_lock(&rio500_mutex);
mutex_lock(&(rio->lock));

if (rio->isopen || !rio->present) {
mutex_unlock(&(rio->lock));
- unlock_kernel();
+ mutex_unlock(&rio500_mutex);
return -EBUSY;
}
rio->isopen = 1;
@@ -94,7 +95,7 @@ static int open_rio(struct inode *inode, struct file *file)
mutex_unlock(&(rio->lock));

dev_info(&rio->rio_dev->dev, "Rio opened.\n");
- unlock_kernel();
+ mutex_unlock(&rio500_mutex);

return 0;
}
@@ -491,7 +492,7 @@ static void disconnect_rio(struct usb_interface *intf)
struct rio_usb_data *rio = usb_get_intfdata (intf);

usb_set_intfdata (intf, NULL);
- lock_kernel();
+ mutex_lock(&rio500_mutex);
if (rio) {
usb_deregister_dev(intf, &usb_rio_class);

@@ -501,7 +502,7 @@ static void disconnect_rio(struct usb_interface *intf)
/* better let it finish - the release will do whats needed */
rio->rio_dev = NULL;
mutex_unlock(&(rio->lock));
- unlock_kernel();
+ mutex_unlock(&rio500_mutex);
return;
}
kfree(rio->ibuf);
@@ -512,7 +513,7 @@ static void disconnect_rio(struct usb_interface *intf)
rio->present = 0;
mutex_unlock(&(rio->lock));
}
- unlock_kernel();
+ mutex_unlock(&rio500_mutex);
}

static const struct usb_device_id rio_table[] = {
diff --git a/drivers/usb/misc/usblcd.c b/drivers/usb/misc/usblcd.c
index 7828c76..6ae39e3 100644
--- a/drivers/usb/misc/usblcd.c
+++ b/drivers/usb/misc/usblcd.c
@@ -16,7 +16,6 @@
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <asm/uaccess.h>
@@ -30,6 +29,7 @@
#define IOCTL_GET_DRV_VERSION 2


+static DEFINE_MUTEX(lcd_mutex);
static const struct usb_device_id id_table[] = {
{ .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
{ },
@@ -74,12 +74,12 @@ static int lcd_open(struct inode *inode, struct file *file)
struct usb_interface *interface;
int subminor, r;

- lock_kernel();
+ mutex_lock(&lcd_mutex);
subminor = iminor(inode);

interface = usb_find_interface(&lcd_driver, subminor);
if (!interface) {
- unlock_kernel();
+ mutex_unlock(&lcd_mutex);
err ("USBLCD: %s - error, can't find device for minor %d",
__func__, subminor);
return -ENODEV;
@@ -89,7 +89,7 @@ static int lcd_open(struct inode *inode, struct file *file)
dev = usb_get_intfdata(interface);
if (!dev) {
mutex_unlock(&open_disc_mutex);
- unlock_kernel();
+ mutex_unlock(&lcd_mutex);
return -ENODEV;
}

@@ -101,13 +101,13 @@ static int lcd_open(struct inode *inode, struct file *file)
r = usb_autopm_get_interface(interface);
if (r < 0) {
kref_put(&dev->kref, lcd_delete);
- unlock_kernel();
+ mutex_unlock(&lcd_mutex);
return r;
}

/* save our object in the file's private structure */
file->private_data = dev;
- unlock_kernel();
+ mutex_unlock(&lcd_mutex);

return 0;
}
@@ -164,14 +164,14 @@ static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

switch (cmd) {
case IOCTL_GET_HARD_VERSION:
- lock_kernel();
+ mutex_lock(&lcd_mutex);
bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice);
sprintf(buf,"%1d%1d.%1d%1d",
(bcdDevice & 0xF000)>>12,
(bcdDevice & 0xF00)>>8,
(bcdDevice & 0xF0)>>4,
(bcdDevice & 0xF));
- unlock_kernel();
+ mutex_unlock(&lcd_mutex);
if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
return -EFAULT;
break;
--
1.7.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
 | 
Pages: 1
Prev: [PATCH 09/12] mtd: autoconvert trivial BKL users to private mutex
Next: [PATCH 00/12] autoconvert trivial BKL users to private mutex