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, 7 insertions, 6 deletions

diff --git a/drivers/s390/char/tape_block.c b/drivers/s390/char/tape_block.c
index 85cf607..f0fa9ca 100644
--- a/drivers/s390/char/tape_block.c
+++ b/drivers/s390/char/tape_block.c
@@ -16,7 +16,7 @@
 #include <linux/fs.h>
 #include <linux/module.h>
 #include <linux/blkdev.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/interrupt.h>
 #include <linux/buffer_head.h>
 #include <linux/kernel.h>
@@ -45,6 +45,7 @@
 /*
  * file operation structure for tape block frontend
  */
+static DEFINE_MUTEX(tape_block_mutex);
 static int tapeblock_open(struct block_device *, fmode_t);
 static int tapeblock_release(struct gendisk *, fmode_t);
 static int tapeblock_medium_changed(struct gendisk *);
@@ -361,7 +362,7 @@ tapeblock_open(struct block_device *bdev, fmode_t mode)
 	struct tape_device *	device;
 	int			rc;
 
-	lock_kernel();
+	mutex_lock(&tape_block_mutex);
 	device = tape_get_device(disk->private_data);
 
 	if (device->required_tapemarks) {
@@ -385,14 +386,14 @@ tapeblock_open(struct block_device *bdev, fmode_t mode)
 	 *       is called.
 	 */
 	tape_state_set(device, TS_BLKUSE);
-	unlock_kernel();
+	mutex_unlock(&tape_block_mutex);
 	return 0;
 
 release:
 	tape_release(device);
  put_device:
 	tape_put_device(device);
-	unlock_kernel();
+	mutex_unlock(&tape_block_mutex);
 	return rc;
 }
 
@@ -407,11 +408,11 @@ tapeblock_release(struct gendisk *disk, fmode_t mode)
 {
 	struct tape_device *device = disk->private_data;
  
-	lock_kernel();
+	mutex_lock(&tape_block_mutex);
 	tape_state_set(device, TS_IN_USE);
 	tape_release(device);
 	tape_put_device(device);
-	unlock_kernel();
+	mutex_unlock(&tape_block_mutex);
 
 	return 0;
 }