Find a device given the host
struct scsi_device * scsi_device_lookup(struct Scsi_Host * shost, uint channel, uint id, uint lun);
shost
SCSI host pointer
channel
SCSI channel (zero if only one channel)
id
SCSI target number (physical unit number)
lun
SCSI Logical Unit Number
Looks up the scsi_device with the specified channel, id, lun for a given host. The returned scsi_device has an additional reference that needs to be released with scsi_device_put once you're done with it.