Mapping ata device number to logical device name

From http://www.phuket-data-wizards.com/blog/2011/07/16/matching-linux-ata-numbers-to-the-device-names/:
The command grep '[0-9]' /sys/class/scsi_host/host{0..9}/unique_id will provide output like
/sys/class/scsi_host/host0/unique_id:1
/sys/class/scsi_host/host1/unique_id:2
/sys/class/scsi_host/host2/unique_id:0
/sys/class/scsi_host/host3/unique_id:0
/sys/class/scsi_host/host4/unique_id:3
/sys/class/scsi_host/host5/unique_id:4
/sys/class/scsi_host/host6/unique_id:5
/sys/class/scsi_host/host7/unique_id:6
so we can match the unique id used in kernel error messages to the host number. Then the command ls -l /sys/block/sd* will show us which device name belongs to which host number:
/sys/block/sda -> ../devices/pci0000:00/0000:00:13.2/usb1/1-6/1-6:1.0/host2/target2:0:0/2:0:0:0/block/sda
/sys/block/sdb -> ../devices/pci0000:00/0000:00:13.2/usb1/1-8/1-8:1.0/host3/target3:0:0/3:0:0:0/block/sdb
/sys/block/sdc -> ../devices/pci0000:00/0000:00:12.0/host6/target6:0:0/6:0:0:0/block/sdc /sys/block/sdd -> ../devices/pci0000:00/0000:00:13.2/usb1/1-8/1-8:1.0/host3/target3:0:0/3:0:0:1/block/sdd
/sys/block/sde -> ../devices/pci0000:00/0000:00:13.2/usb1/1-8/1-8:1.0/host3/target3:0:0/3:0:0:2/block/sde /sys/block/sdf -> ../devices/pci0000:00/0000:00:13.2/usb1/1-8/1-8:1.0/host3/target3:0:0/3:0:0:3/block/sdf
/sys/block/sdg -> ../devices/pci0000:00/0000:00:12.0/host7/target7:0:0/7:0:0:0/block/sdg
From these two outputs we can see that the unique id 6 maps to host7, and host7 maps to /dev/sdg. And finally, with the command hdparm -i /dev/sdg:
/dev/sdg: Model=ST3500418AS, FwRev=CC34, SerialNo=6VM2KSFD
we can find the serial number of the drive.