isdn: 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>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/isdn/mISDN/timerdev.c b/drivers/isdn/mISDN/timerdev.c
index 81048b8..de43c8c 100644
--- a/drivers/isdn/mISDN/timerdev.c
+++ b/drivers/isdn/mISDN/timerdev.c
@@ -24,9 +24,10 @@
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mISDNif.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include "core.h"
+static DEFINE_MUTEX(mISDN_mutex);
static u_int *debug;
@@ -224,7 +225,7 @@
if (*debug & DEBUG_TIMER)
printk(KERN_DEBUG "%s(%p, %x, %lx)\n", __func__,
filep, cmd, arg);
- lock_kernel();
+ mutex_lock(&mISDN_mutex);
switch (cmd) {
case IMADDTIMER:
if (get_user(tout, (int __user *)arg)) {
@@ -256,7 +257,7 @@
default:
ret = -EINVAL;
}
- unlock_kernel();
+ mutex_unlock(&mISDN_mutex);
return ret;
}