# cd /sys/cdev/major/sg0
# ls
device
# tree
.
`-- device -> ../../../devices/pci0000:00/0000:00:0e.0/host0/0:0:1:0

1 directory, 0 files
# cd device/
# ls
block   detach_state    generic  online  queue_depth  rev         type
delete  device_blocked  model    power   rescan       scsi_level  vendor
# cd generic/
# getcwd
/sys/cdev/major/sg0