Comment # 2 on bug 1162435 from John Wolfe

(In reply to Flex Liu from comment #1)
> This issue would be introduced by:
> 
> https://github.com/vmware/open-vm-tools/commit/
> 83dbe8ed5bf6f9e770e22c670c5617bc93e48e55
> 
> We need fix it to handle the btrfs subvolumns properly.

Looking into this issue now.

Original testing of this change was with BTRFS on SLES-15 SP0.   Checking to
determine what may be different with the BTRFS on SLES-12 SP4 and why the
diskInfo is unable to walk the /sys/class/block links.

In the meantime, the quickest fix for the warning message spew is to replace
the g_warning() with g_debug() at line #683 in
open-vm-tools/services/plugins/guestInfo/diskInfo.c        

g_warning("%s: Missing disk device name; VMDK mapping unavailable "