Description of problem:

lsblk was meant as debugging utility which is usable even in situation when e.g. device-mapper devices are suspended, multipath devices are blocked etc.

It should (in default mode) read only information from /sys and /pro (IOW read only virtual filesystems).

Unfortunately in RHEL6 version it uses check_mount_point() function (formerly from ext utils) which tries to open device (to check if it can be opened exclusively.)

This is wrong and should be avoided (it will perhaps produce even some selinux alerts - lsblk can be run from use account.)

In upstream this problem is already solved by using libmount.

Moreover, there is bug in scanning "ro" sysfs attribute which causes another device open
(one line fix).

Version-Release number of selected component (if applicable):
util-linux-ng-2.17.2-12.7.el6.i686

How reproducible:
# strace lsblk /dev/sda1 2>&1 |grep open\( |grep sda1
open("/sys/block/sda/sda1", O_RDONLY|O_LARGEFILE) = 4

open("/dev/sda1", O_RDONLY|O_LARGEFILE) = 5          
open("/dev/sda1", O_RDONLY|O_EXCL|O_LARGEFILE) = -1 EBUSY (Device or resource busy)
(these are wrong)

Expected results:

Do not open device at all.