git/linux-cryptodev-2.6
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git synced 2026-04-23 05:56:14 -04:00
Code Issues Packages Projects Releases Wiki Activity

isdn: autoconvert trivial BKL users to private mutex

Browse Source 
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>
This commit is contained in:
Arnd Bergmann
2010-07-11 11:18:53 +00:00
committed by David S. Miller
parent d361fd599a
commit 76a64921da
9 changed files with 48 additions and 46 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
drivers/isdn/mISDN/timerdev.c
View File

@@ -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 @@ mISDN_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
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 @@ mISDN_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
default:
ret = -EINVAL;
}
unlock_kernel();
mutex_unlock(&mISDN_mutex);
return ret;
}