From 613655fa39ff6957754fa8ceb8559980920eb8ee Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 2 Jun 2010 14:28:52 +0200 Subject: 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.*/d' ${file} else sed -i 's/include.*.*$/include /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.*\/d' ${file} \ -e '/cycle_kernel_lock()/d' fi Signed-off-by: Arnd Bergmann --- drivers/char/generic_nvram.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers/char/generic_nvram.c') diff --git a/drivers/char/generic_nvram.c b/drivers/char/generic_nvram.c index 82b5a88a82d..0e941b57482 100644 --- a/drivers/char/generic_nvram.c +++ b/drivers/char/generic_nvram.c @@ -19,7 +19,7 @@ #include #include #include -#include +#include #include #include #ifdef CONFIG_PPC_PMAC @@ -28,6 +28,7 @@ #define NVRAM_SIZE 8192 +static DEFINE_MUTEX(nvram_mutex); static ssize_t nvram_len; static loff_t nvram_llseek(struct file *file, loff_t offset, int origin) @@ -120,9 +121,9 @@ static long nvram_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned l { int ret; - lock_kernel(); + mutex_lock(&nvram_mutex); ret = nvram_ioctl(file, cmd, arg); - unlock_kernel(); + mutex_unlock(&nvram_mutex); return ret; } -- cgit v1.2.3-70-g09d2