[PATCH] dm: export blkdev_driver_ioctl

Export blkdev_driver_ioctl for device-mapper.

If we get as far as the device-mapper ioctl handler, we know the ioctl is not
a standard block layer BLK* one, so we don't need to check for them a second
time and can call blkdev_driver_ioctl() directly.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

block/ioctl.c

@@ -199,7 +199,7 @@ static int blkdev_locked_ioctl(struct file *file, struct block_device *bdev,
 	return -ENOIOCTLCMD;
 }
 
-static int blkdev_driver_ioctl(struct inode *inode, struct file *file,
+int blkdev_driver_ioctl(struct inode *inode, struct file *file,
 			struct gendisk *disk, unsigned cmd, unsigned long arg)
 {
 	int ret;
@@ -215,6 +215,7 @@ static int blkdev_driver_ioctl(struct inode *inode, struct file *file,
 
 	return -ENOTTY;
 }
+EXPORT_SYMBOL_GPL(blkdev_driver_ioctl);
 
 int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd,
 			unsigned long arg)

drivers/md/dm-linear.c

@@ -105,7 +105,7 @@ static int linear_ioctl(struct dm_target *ti, struct inode *inode,
 	struct linear_c *lc = (struct linear_c *) ti->private;
 	struct block_device *bdev = lc->dev->bdev;
 
-	return blkdev_ioctl(bdev->bd_inode, filp, cmd, arg);
+	return blkdev_driver_ioctl(bdev->bd_inode, filp, bdev->bd_disk, cmd, arg);
 }
 
 static struct target_type linear_target = {

drivers/md/dm-mpath.c

@@ -1290,7 +1290,8 @@ static int multipath_ioctl(struct dm_target *ti, struct inode *inode,
 
 	spin_unlock_irqrestore(&m->lock, flags);
 
-	return r ? : blkdev_ioctl(bdev->bd_inode, filp, cmd, arg);
+	return r ? : blkdev_driver_ioctl(bdev->bd_inode, filp, bdev->bd_disk,
+		     cmd, arg);
 }
 
 /*-----------------------------------------------------------------

include/linux/fs.h

@@ -1523,6 +1523,9 @@ extern const struct file_operations def_fifo_fops;
 #ifdef CONFIG_BLOCK
 extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
 extern int blkdev_ioctl(struct inode *, struct file *, unsigned, unsigned long);
+extern int blkdev_driver_ioctl(struct inode *inode, struct file *file,
+			       struct gendisk *disk, unsigned cmd,
+			       unsigned long arg);
 extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
 extern int blkdev_get(struct block_device *, mode_t, unsigned);
 extern int blkdev_put(struct block_device *);