6efb5ece_t2_____Unix__Linux_System_Call__Error_Code
[Description] A component of a path was not searchable. (See also path_resolution(2).) Or, mounting a read-only filesystem was attempted without giving the MS_RDONLY flag. Or, the block device source is located on a filesystem mounted with the MS_NODEV option. [Error Code] 
EACCES
umount2() - Unix, Linux System Call