[CentOS] How to map ata#.# numbers to /dev/sd numbers?

On my C5 machine (a Dell XPS420) I have a 500Gb disk on the internal SATA
controller.

I also have a SiI3132 dual-port multi-device eSATA card.  This is connected
to an external SATA array of disks.

Now occasionally I see something like this in my logs

ata7.01: exception Emask 0x0 SAct 0x0 SErr 0x0 a ction 0x0
ata7.01: irq_stat 0x00060002, device error via D 2H FIS
ata7.01: cmd 25/00:08:47:1c:92/00:00:6c:00:00/e0 tag 0 dma 4096 in
         res 51/40:00:4e:1c:92/00:00:6c:00:00/00 Emask 0x9 (media error)
ata7.01: status: { DRDY ERR }
ata7.01: error: { UNC }
ata7.01: configured for UDMA/100
ata7: EH complete

How do I tell what disk this is complaining about?  Is there a way
to determine what ata7.01 maps to in terms of /dev/sd# values?

/proc/scsi/scsi doesn't obviously match scsi# numbers to ata# numbers :-(

-- 

rgds
Stephen