[PATCH] dm: Use nonseekable_open

[Frederic Weisbecker <fweisbec@gmail.com>]

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>
Cc: Alasdair G Kergon <agk@redhat.com>
[drop useless llseek = no_llseek]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
---
 drivers/md/dm-ioctl.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index d7500e1..78b28eb 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1593,6 +1593,7 @@ static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
 #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,
-- 
1.6.2.3