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>
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index ba9c3e0..e148341 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -44,7 +44,6 @@
 #include <linux/init.h>
 #include <linux/blkdev.h>
 #include <linux/mutex.h>
-#include <linux/smp_lock.h>
 #include <linux/slab.h>
 #include <asm/uaccess.h>
 
@@ -76,6 +75,7 @@
 	 CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
 	 CDC_MRW|CDC_MRW_W|CDC_RAM)
 
+static DEFINE_MUTEX(sr_mutex);
 static int sr_probe(struct device *);
 static int sr_remove(struct device *);
 static int sr_done(struct scsi_cmnd *);
@@ -470,24 +470,24 @@
 	struct scsi_cd *cd;
 	int ret = -ENXIO;
 
-	lock_kernel();
+	mutex_lock(&sr_mutex);
 	cd = scsi_cd_get(bdev->bd_disk);
 	if (cd) {
 		ret = cdrom_open(&cd->cdi, bdev, mode);
 		if (ret)
 			scsi_cd_put(cd);
 	}
-	unlock_kernel();
+	mutex_unlock(&sr_mutex);
 	return ret;
 }
 
 static int sr_block_release(struct gendisk *disk, fmode_t mode)
 {
 	struct scsi_cd *cd = scsi_cd(disk);
-	lock_kernel();
+	mutex_lock(&sr_mutex);
 	cdrom_release(&cd->cdi, mode);
 	scsi_cd_put(cd);
-	unlock_kernel();
+	mutex_unlock(&sr_mutex);
 	return 0;
 }
 
@@ -499,7 +499,7 @@
 	void __user *argp = (void __user *)arg;
 	int ret;
 
-	lock_kernel();
+	mutex_lock(&sr_mutex);
 
 	/*
 	 * Send SCSI addressing ioctls directly to mid level, send other
@@ -529,7 +529,7 @@
 	ret = scsi_ioctl(sdev, cmd, argp);
 
 out:
-	unlock_kernel();
+	mutex_unlock(&sr_mutex);
 	return ret;
 }