[SCSI] tgt: add I_T nexus support

tgt uses scsi_host as I_T nexus. This works for ibmvstgt because it
creates one scsi_host for one initiator. However, other target drivers
don't work like that.

This adds I_T nexus support, which enable one scsi_host to handle
multiple initiators. New scsi_tgt_it_nexus_create/destroy functions
are expected be called transport classes. For example, ibmvstgt
creates an initiator remote port, then the srp transport calls
tgt_it_nexus_create. tgt doesn't manages I_T nexus, instead it tells
tgtd, user-space daemon, to create a new I_T nexus.

On the receiving the response from tgtd, tgt calls
shost->transportt->it_nexus_response. transports should notify a
lld. The srp transport uses it_nexus_response callback in
srp_function_template to do that.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This commit is contained in:
FUJITA Tomonori
2007-07-11 15:08:17 +09:00
committed by James Bottomley
parent aebd5e476e
commit 2c47f9efbe
7 changed files with 161 additions and 37 deletions
+6
View File
@@ -65,6 +65,12 @@ struct scsi_transport_template {
* EH_NOT_HANDLED Begin normal error recovery
*/
enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
/*
* Used as callback for the completion of i_t_nexus request
* for target drivers.
*/
int (* it_nexus_response)(struct Scsi_Host *, u64, int);
};
#define transport_class_to_shost(tc) \