USB: autoconvert trivial BKL users to private mutex

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@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 8 insertions, 7 deletions

diff --git a/drivers/usb/misc/rio500.c b/drivers/usb/misc/rio500.c
index a85771b1563d..cc13ae61712a 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[] = {