Commit 8f2a8536 authored by Changpeng Liu's avatar Changpeng Liu Committed by Jim Harris
Browse files

scsi: add persistent reservation out command with preempt service action support 



A PERSISTENT RESERVE OUT command with PREEMPT service action action is used to:
a) preempt (i.e., replace) the persistent reservation and remove registrations; or
b) remove registrations.

Change-Id: I906b09057e5ddef0ea2fe180bb5fff6e9e0a04f6
Signed-off-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/436092


Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
parent 8d79b410

lib/scsi/scsi_pr.c

+123 −0
Original line number Diff line number Diff line
@@ -378,6 +378,123 @@ error_exit: 
	return -EINVAL;

}



static void

spdk_scsi_pr_remove_all_regs_by_key(struct spdk_scsi_lun *lun, uint64_t sa_rkey)

{

	struct spdk_scsi_pr_registrant *reg, *tmp;



	TAILQ_FOREACH_SAFE(reg, &lun->reg_head, link, tmp) {

		if (reg->rkey == sa_rkey) {

			spdk_scsi_pr_unregister_registrant(lun, reg);

		}

	}

}



static void

spdk_scsi_pr_remove_all_other_regs(struct spdk_scsi_lun *lun, struct spdk_scsi_pr_registrant *reg)

{

	struct spdk_scsi_pr_registrant *reg_tmp, *reg_tmp2;



	TAILQ_FOREACH_SAFE(reg_tmp, &lun->reg_head, link, reg_tmp2) {

		if (reg_tmp != reg) {

			spdk_scsi_pr_unregister_registrant(lun, reg_tmp);

		}

	}

}



static int

spdk_scsi_pr_out_preempt(struct spdk_scsi_task *task,

			 enum spdk_scsi_pr_out_service_action_code action,

			 enum spdk_scsi_pr_type_code rtype,

			 uint64_t rkey, uint64_t sa_rkey)

{

	struct spdk_scsi_lun *lun = task->lun;

	struct spdk_scsi_pr_registrant *reg;

	bool all_regs = false;



	SPDK_DEBUGLOG(SPDK_LOG_SCSI, "PR OUT PREEMPT: rkey 0x%"PRIx64", sa_rkey 0x%"PRIx64" "

		      "action %u, type %u, reservation type %u\n",

		      rkey, sa_rkey, action, rtype, lun->reservation.rtype);



	/* I_T nexus is not registered */

	reg = spdk_scsi_pr_get_registrant(lun, task->initiator_port, task->target_port);

	if (!reg) {

		SPDK_ERRLOG("No registration\n");

		goto conflict;

	}

	if (rkey != reg->rkey) {

		SPDK_ERRLOG("Reservation key 0x%"PRIx64" doesn't match "

			    "registrant's key 0x%"PRIx64"\n", rkey, reg->rkey);

		goto conflict;

	}



	/* no persistent reservation */

	if (lun->reservation.holder == NULL) {

		spdk_scsi_pr_remove_all_regs_by_key(lun, sa_rkey);

		SPDK_DEBUGLOG(SPDK_LOG_SCSI, "PREEMPT: no persistent reservation\n");

		goto exit;

	}



	all_regs = spdk_scsi_pr_is_all_registrants_type(lun);



	if (all_regs) {

		if (sa_rkey != 0) {

			spdk_scsi_pr_remove_all_regs_by_key(lun, sa_rkey);

			SPDK_DEBUGLOG(SPDK_LOG_SCSI, "PREEMPT: All registrants type with sa_rkey\n");

		} else {

			/* remove all other registrants and release persistent reservation if any */

			spdk_scsi_pr_remove_all_other_regs(lun, reg);

			/* create persistent reservation using new type and scope */

			spdk_scsi_pr_reserve_reservation(lun, rtype, 0, reg);

			SPDK_DEBUGLOG(SPDK_LOG_SCSI, "PREEMPT: All registrants type with sa_rkey zeroed\n");

		}

		goto exit;

	}



	assert(lun->reservation.crkey != 0);



	if (sa_rkey != lun->reservation.crkey) {

		if (!sa_rkey) {

			SPDK_ERRLOG("Zeroed sa_rkey\n");

			spdk_scsi_task_set_status(task, SPDK_SCSI_STATUS_CHECK_CONDITION,

						  SPDK_SCSI_SENSE_ILLEGAL_REQUEST,

						  SPDK_SCSI_ASC_INVALID_FIELD_IN_CDB,

						  SPDK_SCSI_ASCQ_CAUSE_NOT_REPORTABLE);

			return -EINVAL;

		}

		spdk_scsi_pr_remove_all_regs_by_key(lun, sa_rkey);

		goto exit;

	}



	if (spdk_scsi_pr_registrant_is_holder(lun, reg)) {

		spdk_scsi_pr_reserve_reservation(lun, rtype, rkey, reg);

		SPDK_DEBUGLOG(SPDK_LOG_SCSI, "PREEMPT: preempt itself with type %u\n", rtype);

		goto exit;

	}



	/* unregister registrants if any */

	spdk_scsi_pr_remove_all_regs_by_key(lun, sa_rkey);

	reg = spdk_scsi_pr_get_registrant(lun, task->initiator_port, task->target_port);

	if (!reg) {

		SPDK_ERRLOG("Current I_T nexus registrant was removed\n");

		goto conflict;

	}



	/* preempt the holder */

	spdk_scsi_pr_reserve_reservation(lun, rtype, rkey, reg);



exit:

	lun->pr_generation++;

	return 0;



conflict:

	spdk_scsi_task_set_status(task, SPDK_SCSI_STATUS_RESERVATION_CONFLICT,

				  SPDK_SCSI_SENSE_NO_SENSE,

				  SPDK_SCSI_ASC_NO_ADDITIONAL_SENSE,

				  SPDK_SCSI_ASCQ_CAUSE_NOT_REPORTABLE);

	return -EINVAL;

}



int

spdk_scsi_pr_out(struct spdk_scsi_task *task,

		 uint8_t *cdb, uint8_t *data,
@@ -423,6 +540,12 @@ spdk_scsi_pr_out(struct spdk_scsi_task *task, 
	case SPDK_SCSI_PR_OUT_CLEAR:

		rc = spdk_scsi_pr_out_clear(task, rkey);

		break;

	case SPDK_SCSI_PR_OUT_PREEMPT:

		if (scope != SPDK_SCSI_PR_LU_SCOPE) {

			goto invalid;

		}

		rc = spdk_scsi_pr_out_preempt(task, action, rtype, rkey, sa_rkey);

		break;

	default:

		SPDK_ERRLOG("Invalid service action code %u\n", action);

		goto invalid;