Use refcounting for sysfs devices
Use refcounting for sysfs devices

As we're caching sysfs devices we need to introduce some sort
of refcounting here. Otherwise the device might be removed from
other threads while we're still accessing it.

References: bnc#642846

Signed-off-by: Hannes Reinecke <b0d1e9e4a4e27620745ff49be9000da3174a4cc6@suse.de>

vijaychauhan/multipath-tools,unakatsuo/multipath-tools,unakatsuo/multipath-tools,unakatsuo/multipath-tools,vijaychauhan/multipath-tools