SCSI error handle trace

Hi, all

Recently, fnic driver patches a feature that gathers various important stats for debugging issues. Sysadm can find problems via this trace utility, but just for fnic driver.
In Linux SCSI subsystem, only a few trace points are set and we can not trace deeply while middle layer handles error. AFAIK, scsi_dispatch_cmd_error is available for running command error in LLD, but how about Fibre Channel error or something like that?
A RAS tool named rasdaemon can use trace info to record errors. Now it supports cpu, memory and PCIe error recording. If SCSI subsystem exports more trace points, I think we can support SCSI error recording in rasdaemon.

Best regards,
Junliang Li