From: Arnd Bergmann <[email-masked]>

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 <[email-masked]>
Signed-off-by: Frederic Weisbecker <[email-masked]>
Signed-off-by: Andrew Morton <[email-masked]>
Signed-off-by: Alasdair G Kergon <[email-masked]>

---
 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,