block: push down BKL into .locked_ioctl

As a preparation for the removal of the big kernel
lock in the block layer, this removes the BKL
from the common ioctl handling code, moving it
into every single driver still using it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 2e74e7d..6751789 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -24,6 +24,7 @@
 #include <linux/errno.h>
 #include <linux/file.h>
 #include <linux/ioctl.h>
+#include <linux/smp_lock.h>
 #include <linux/compiler.h>
 #include <linux/err.h>
 #include <linux/kernel.h>
@@ -716,9 +717,11 @@
 	dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n",
 			lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg);
 
+	lock_kernel();
 	mutex_lock(&lo->tx_lock);
 	error = __nbd_ioctl(bdev, lo, cmd, arg);
 	mutex_unlock(&lo->tx_lock);
+	unlock_kernel();
 
 	return error;
 }
@@ -726,7 +729,7 @@
 static const struct block_device_operations nbd_fops =
 {
 	.owner =	THIS_MODULE,
-	.locked_ioctl =	nbd_ioctl,
+	.ioctl =	nbd_ioctl,
 };
 
 /*