autofs: fix "fix dev ioctl number range check"

102a340f had a typo that made the count macro negative (-13).
The acutal check used by ioctl is ((cmd - cmd_first) > COUNT),
so it needs to be positive (13).

* 102a340f is a commit in linux-next which hasn't been merged
to mainline upstream.

Link: http://lkml.kernel.org/r/20160831033420.9910.16809.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index dd71bd4ff903bed270098daff620e4c47854d70d..477989d255bef9d5ae307de49f446b32e802271a 100644 (file)
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -21,7 +21,7 @@
 
 #define AUTOFS_DEV_IOCTL_IOC_FIRST     (AUTOFS_DEV_IOCTL_VERSION)
 #define AUTOFS_DEV_IOCTL_IOC_COUNT \
-       (AUTOFS_DEV_IOCTL_VERSION_CMD - AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD)
+       (AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD)
 
 #include <linux/kernel.h>
 #include <linux/slab.h>