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/watchdog/cpwd.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) (limited to 'drivers/watchdog') diff --git a/drivers/watchdog/cpwd.c b/drivers/watchdog/cpwd.c index 566343b3c131..b7d96e6236a1 100644 --- a/drivers/watchdog/cpwd.c +++ b/drivers/watchdog/cpwd.c @@ -25,7 +25,7 @@ #include #include #include -#include +#include #include #include #include @@ -89,6 +89,7 @@ struct cpwd { } devs[WD_NUMDEVS]; }; +static DEFINE_MUTEX(cpwd_mutex); static struct cpwd *cpwd_device; /* Sun uses Altera PLD EPF8820ATC144-4 @@ -368,7 +369,7 @@ static int cpwd_open(struct inode *inode, struct file *f) { struct cpwd *p = cpwd_device; - lock_kernel(); + mutex_lock(&cpwd_mutex); switch (iminor(inode)) { case WD0_MINOR: case WD1_MINOR: @@ -376,7 +377,7 @@ static int cpwd_open(struct inode *inode, struct file *f) break; default: - unlock_kernel(); + mutex_unlock(&cpwd_mutex); return -ENODEV; } @@ -386,13 +387,13 @@ static int cpwd_open(struct inode *inode, struct file *f) IRQF_SHARED, DRIVER_NAME, p)) { printk(KERN_ERR PFX "Cannot register IRQ %d\n", p->irq); - unlock_kernel(); + mutex_unlock(&cpwd_mutex); return -EBUSY; } p->initialized = true; } - unlock_kernel(); + mutex_unlock(&cpwd_mutex); return nonseekable_open(inode, f); } @@ -482,9 +483,9 @@ static long cpwd_compat_ioctl(struct file *file, unsigned int cmd, case WIOCSTART: case WIOCSTOP: case WIOCGSTAT: - lock_kernel(); + mutex_lock(&cpwd_mutex); rval = cpwd_ioctl(file, cmd, arg); - unlock_kernel(); + mutex_unlock(&cpwd_mutex); break; /* everything else is handled by the generic compat layer */ -- cgit v1.2.3