scsi_target with multiple luns

[Hidetoshi Shimokawa]

I have not fully analyzed the problem but I'll describe it just for a note.
I'd like to ask maintainers of scsi_target for further analysis.

I experiance a problem with small number(1) of simq and multiple
scsi_target(8) instances.

As far as I understand, the following situation could occur under a fairly
heavy load.

1. process A send a request -> cam send to sim
2. process B send a request -> blocked because the simq is full
3. the request of process A is finished (in the context of process A)
4. cam/scsi_target tries to send the request of process B.
   But the mapped memory is of process A, and scsi_target send wrong
   ccb to sim.

Maybe, we should rewrite scsi_target in kernel space with GEOM support..

/\ Hidetoshi Shimokawa
\/  simokawa at FreeBSD.ORG