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/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_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 @@
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 @@
error_out:
/* unlock the device */
mutex_unlock(&dev->mutex);
- unlock_kernel();
+ mutex_unlock(&iowarrior_mutex);
kfree(buffer);
return retval;
}
@@ -602,12 +603,12 @@
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 @@
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 @@
out:
mutex_unlock(&dev->mutex);
- unlock_kernel();
+ mutex_unlock(&iowarrior_mutex);
return retval;
}