---
 drivers/md/dm-flakey.c |    7 +++++++
 drivers/md/dm-linear.c |   10 +++++++++-
 drivers/md/dm-mpath.c  |    6 ++++++
 3 files changed, 22 insertions(+), 1 deletion(-)

Index: linux/drivers/md/dm-flakey.c
===================================================================
--- linux.orig/drivers/md/dm-flakey.c
+++ linux/drivers/md/dm-flakey.c
@@ -369,6 +369,13 @@ static int flakey_ioctl(struct dm_target
 {
 	struct flakey_c *fc = ti->private;
  
+	/*
+	 * Only pass ioctls through if the device sizes match exactly.
+	 */
+	if (fc->start ||
+	    ti->len != i_size_read(fc->dev->bdev->bd_inode) >> SECTOR_SHIFT)
+		return -ENOTTY;
+
 	return __blkdev_driver_ioctl(fc->dev->bdev, fc->dev->mode, cmd, arg);
 }
 
Index: linux/drivers/md/dm-linear.c
===================================================================
--- linux.orig/drivers/md/dm-linear.c
+++ linux/drivers/md/dm-linear.c
@@ -115,7 +115,15 @@ static int linear_status(struct dm_targe
 static int linear_ioctl(struct dm_target *ti, unsigned int cmd,
 			unsigned long arg)
 {
-	struct linear_c *lc = (struct linear_c *) ti->private;
+	struct linear_c *lc = ti->private;
+
+	/*
+	 * Only pass ioctls through if the device sizes match exactly.
+	 */
+	if (lc->start ||
+	    ti->len != i_size_read(lc->dev->bdev->bd_inode) >> SECTOR_SHIFT)
+		return -ENOTTY;
+
 	return __blkdev_driver_ioctl(lc->dev->bdev, lc->dev->mode, cmd, arg);
 }
 
Index: linux/drivers/md/dm-mpath.c
===================================================================
--- linux.orig/drivers/md/dm-mpath.c
+++ linux/drivers/md/dm-mpath.c
@@ -1520,6 +1520,12 @@ static int multipath_ioctl(struct dm_tar
 
 	spin_unlock_irqrestore(&m->lock, flags);
 
+	/*
+	 * Only pass ioctls through if the device sizes match exactly.
+	 */
+	if (ti->len != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT)
+		return -ENOTTY;
+
 	return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg);
 }