diff options
author | Arnd Bergmann <arnd@arndb.de> | 2010-06-02 14:28:52 +0200 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2010-10-05 15:01:04 +0200 |
commit | 613655fa39ff6957754fa8ceb8559980920eb8ee (patch) | |
tree | ad19600cb81207b24188683d7fc4ae88013339d1 /drivers/char/nvram.c | |
parent | 609146fdb319cebce93be550938ab852f7bade90 (diff) | |
download | linux-613655fa39ff6957754fa8ceb8559980920eb8ee.tar.gz |
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>
Diffstat (limited to 'drivers/char/nvram.c')
-rw-r--r-- | drivers/char/nvram.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c index 66d2917b003f..166f1e7aaa7e 100644 --- a/drivers/char/nvram.c +++ b/drivers/char/nvram.c @@ -109,10 +109,11 @@ #include <linux/spinlock.h> #include <linux/io.h> #include <linux/uaccess.h> -#include <linux/smp_lock.h> +#include <linux/mutex.h> #include <asm/system.h> +static DEFINE_MUTEX(nvram_mutex); static DEFINE_SPINLOCK(nvram_state_lock); static int nvram_open_cnt; /* #times opened */ static int nvram_open_mode; /* special open modes */ @@ -308,7 +309,7 @@ static long nvram_ioctl(struct file *file, unsigned int cmd, if (!capable(CAP_SYS_ADMIN)) return -EACCES; - lock_kernel(); + mutex_lock(&nvram_mutex); spin_lock_irq(&rtc_lock); for (i = 0; i < NVRAM_BYTES; ++i) @@ -316,7 +317,7 @@ static long nvram_ioctl(struct file *file, unsigned int cmd, __nvram_set_checksum(); spin_unlock_irq(&rtc_lock); - unlock_kernel(); + mutex_unlock(&nvram_mutex); return 0; case NVRAM_SETCKS: @@ -325,11 +326,11 @@ static long nvram_ioctl(struct file *file, unsigned int cmd, if (!capable(CAP_SYS_ADMIN)) return -EACCES; - lock_kernel(); + mutex_lock(&nvram_mutex); spin_lock_irq(&rtc_lock); __nvram_set_checksum(); spin_unlock_irq(&rtc_lock); - unlock_kernel(); + mutex_unlock(&nvram_mutex); return 0; default: |