block: autoconvert trivial BKL users to private mutex

The block device drivers have all gained new lock_kernel
calls from a recent pushdown, and some of the drivers
were already using the BKL before.

This turns the BKL into a set of per-driver mutexes.
Still need to check whether this is safe to do.

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>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/block/xd.c b/drivers/block/xd.c
index d5a3cd7..4abd2bc 100644
--- a/drivers/block/xd.c
+++ b/drivers/block/xd.c
@@ -46,7 +46,7 @@
 #include <linux/init.h>
 #include <linux/wait.h>
 #include <linux/blkdev.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/blkpg.h>
 #include <linux/delay.h>
 #include <linux/io.h>
@@ -58,6 +58,7 @@
 
 #include "xd.h"
 
+static DEFINE_MUTEX(xd_mutex);
 static void __init do_xd_setup (int *integers);
 #ifdef MODULE
 static int xd[5] = { -1,-1,-1,-1, };
@@ -381,9 +382,9 @@ static int xd_ioctl(struct block_device *bdev, fmode_t mode,
 {
 	int ret;
 
-	lock_kernel();
+	mutex_lock(&xd_mutex);
 	ret = xd_locked_ioctl(bdev, mode, cmd, param);
-	unlock_kernel();
+	mutex_unlock(&xd_mutex);
 
 	return ret;
 }