sbus: 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.
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/sbus/char/flash.c b/drivers/sbus/char/flash.c
index 368d662..ed9494e 100644
--- a/drivers/sbus/char/flash.c
+++ b/drivers/sbus/char/flash.c
@@ -10,7 +10,7 @@
#include <linux/fcntl.h>
#include <linux/poll.h>
#include <linux/init.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/of.h>
@@ -22,6 +22,7 @@
#include <asm/io.h>
#include <asm/upa.h>
+static DEFINE_MUTEX(flash_mutex);
static DEFINE_SPINLOCK(flash_lock);
static struct {
unsigned long read_base; /* Physical read address */
@@ -80,7 +81,7 @@
static long long
flash_llseek(struct file *file, long long offset, int origin)
{
- lock_kernel();
+ mutex_lock(&flash_mutex);
switch (origin) {
case 0:
file->f_pos = offset;
@@ -94,10 +95,10 @@
file->f_pos = flash.read_size;
break;
default:
- unlock_kernel();
+ mutex_unlock(&flash_mutex);
return -EINVAL;
}
- unlock_kernel();
+ mutex_unlock(&flash_mutex);
return file->f_pos;
}
@@ -125,13 +126,13 @@
static int
flash_open(struct inode *inode, struct file *file)
{
- lock_kernel();
+ mutex_lock(&flash_mutex);
if (test_and_set_bit(0, (void *)&flash.busy) != 0) {
- unlock_kernel();
+ mutex_unlock(&flash_mutex);
return -EBUSY;
}
- unlock_kernel();
+ mutex_unlock(&flash_mutex);
return 0;
}