From: Arnd Bergmann <arnd@relay.de.ibm.com>

The dm control device does not implement read/write, so it has no use for
seeking.  Using no_llseek prevents falling back to default_llseek, which
requires the BKL.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

---
 drivers/md/dm-ioctl.c |    1 +
 1 file changed, 1 insertion(+)

Index: linux-2.6.35/drivers/md/dm-ioctl.c
===================================================================
--- linux-2.6.35.orig/drivers/md/dm-ioctl.c
+++ linux-2.6.35/drivers/md/dm-ioctl.c
@@ -1602,6 +1602,7 @@ static long dm_compat_ctl_ioctl(struct f
 #endif
 
 static const struct file_operations _ctl_fops = {
+	.open = nonseekable_open,
 	.unlocked_ioctl	 = dm_ctl_ioctl,
 	.compat_ioctl = dm_compat_ctl_ioctl,
 	.owner	 = THIS_MODULE,