Hi All,
I'm working on getting task management functions working with the Emulex OCS SDK FC/FCoE driver on LIO/TCM. I have a couple of questions about the handling of ABORT_TASK and LUN_RESET. First, here's what I see happening for ABORT_TASK:
ABORT_TASK
==========
1. target_submit_tmr() upcall from OCS fabric module to TCM
2. target_tmr_work(): core_tmr_abort_task: loop through sess_cmd_list
a. if (tmr->ref_task_tag == get_task_tag)
i. cmd->transport_state |= CMD_T_ABORTED
ii. transport_send_task_abort():
1. cmd->scsi_status = SAM_STAT_TASK_ABORTED
2. .queue_status() downcall
It's not obvious to me why the queue_status() downcall would be made with scsi_status = SAM_STAT_TASK_ABORTED. It would seem to imply that an FCP_RESPONSE with status=40h should be sent on the wire for the associated FCP_CMND. However, since an ABTS was received for the command, no response will be sent for the FCP_CMND itself. Am I reading this correctly?
The SAM_STAT_TASK_ABORTED status makes more sense to me in the context of LUN_RESET, where the TAS bit (Control mode page) would apply.
LUN_RESET
=========
1. target_submit_tmr() upcall from OCS fabric module to TCM
2. target_tmr_work(): core_tmr_lun_reset
a. core_tmr_drain_tmr_list()
b. core_tmr_drain_state_list(): for each command in dev->state_list
i. cmd->transport_state |= ABORTED
ii. core_tmr_handle_tas_abort()
1. transport_send_task_abort()
core_tmr_handle_tas_abort() has the following 'if' statement before calling transport_send_task_abort():
if ((tmr_nacl &&
(tmr_nacl == cmd->se_sess->se_node_acl)) || tas)
transport_send_task_abort(cmd);
It makes sense that if TAS=1, the .queue_status downcall would be made with scsi_status=SAM_STAT_TASK_ABORTED. However, I don't understand the "(tmr_nacl && tmr_nacl == cmd->se_sess->se_node_acl)" part of this statement. When I configure TAS=0 and send a LUN Reset, the tmr_nacl matches the se_node_acl so the call to transport_send_task_abort() is made regardless of "tas". I would think that if TAS=0, the transport_send_task_abort() call would be skipped. What am I missing?
Any help would be greatly appreciated.
Regards,
Alex
P.S. I'm using the memcopy ramdisk backstore on the 3.13.3 kernel.
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