drivers: autoconvert trivial BKL users to private mutex
authorArnd Bergmann <arnd@arndb.de>
Wed, 2 Jun 2010 12:28:52 +0000 (14:28 +0200)
committerArnd Bergmann <arnd@arndb.de>
Tue, 5 Oct 2010 13:01:04 +0000 (15:01 +0200)
commit613655fa39ff6957754fa8ceb8559980920eb8ee
treead19600cb81207b24188683d7fc4ae88013339d1
parent609146fdb319cebce93be550938ab852f7bade90
drivers: 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.

These drivers do not seem to be under active
maintainance from my brief investigation. Apologies
to those maintainers that I have missed.

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>
35 files changed:
drivers/block/paride/pg.c
drivers/block/paride/pt.c
drivers/char/apm-emulation.c
drivers/char/applicom.c
drivers/char/ds1302.c
drivers/char/ds1620.c
drivers/char/dsp56k.c
drivers/char/dtlk.c
drivers/char/generic_nvram.c
drivers/char/genrtc.c
drivers/char/i8k.c
drivers/char/ip2/ip2main.c
drivers/char/lp.c
drivers/char/mbcs.c
drivers/char/mmtimer.c
drivers/char/mwave/mwavedd.c
drivers/char/nvram.c
drivers/char/nwflash.c
drivers/char/pcmcia/cm4000_cs.c
drivers/char/pcmcia/cm4040_cs.c
drivers/char/ppdev.c
drivers/char/rio/rio_linux.c
drivers/char/snsc.c
drivers/char/toshiba.c
drivers/char/viotape.c
drivers/char/xilinx_hwicap/xilinx_hwicap.c
drivers/hwmon/fschmd.c
drivers/hwmon/w83793.c
drivers/input/misc/hp_sdc_rtc.c
drivers/misc/phantom.c
drivers/pci/hotplug/cpqphp_sysfs.c
drivers/rtc/rtc-m41t80.c
drivers/sbus/char/jsflash.c
drivers/telephony/ixj.c
drivers/watchdog/cpwd.c