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>
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 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 @@
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 @@
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 @@
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 @@
/* 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 @@
rio->present = 0;
mutex_unlock(&(rio->lock));
}
- unlock_kernel();
+ mutex_unlock(&rio500_mutex);
}
static const struct usb_device_id rio_table[] = {