Commit 194605d4 authored by Mike Christie's avatar Mike Christie Committed by Martin K. Petersen
Browse files

scsi: target: Have drivers report if they support direct submissions 



In some cases, like with multiple LUN targets or where the target has to
respond to transport level requests from the receiving context it can be
better to defer cmd submission to a helper thread. If the backend driver
blocks on something like request/tag allocation it can block the entire
target submission path and other LUs and transport IO on that session.

In other cases like single LUN targets with storage that can support all
the commands that the target can queue, then it's best to submit the cmd
to the backend from the target's cmd receiving context.

Subsequent commits will allow the user to config what they prefer, but
drivers like loop can't directly submit because they can be called from a
context that can't sleep. And, drivers like vhost-scsi can support direct
submission, but need to keep their default behavior of deferring execution
to avoid possible regressions where the backend can block.

Make the drivers tell LIO core if they support direct submissions and their
current default, so we can prevent users from misconfiguring the system and
initialize devices correctly.

Signed-off-by: default avatarMike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20230928020907.5730-2-michael.christie@oracle.com


Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 40ddd6df

drivers/infiniband/ulp/srpt/ib_srpt.c

+3 −0
Original line number Diff line number Diff line
@@ -3867,6 +3867,9 @@ static const struct target_core_fabric_ops srpt_template = { 
	.tfc_discovery_attrs		= srpt_da_attrs,

	.tfc_wwn_attrs			= srpt_wwn_attrs,

	.tfc_tpg_attrib_attrs		= srpt_tpg_attrib_attrs,



	.default_submit_type		= TARGET_DIRECT_SUBMIT,

	.direct_submit_supp		= 1,

};



/**

drivers/scsi/elx/efct/efct_lio.c

+5 −0
Original line number Diff line number Diff line
@@ -1611,6 +1611,8 @@ static const struct target_core_fabric_ops efct_lio_ops = { 
	.sess_get_initiator_sid		= NULL,

	.tfc_tpg_base_attrs		= efct_lio_tpg_attrs,

	.tfc_tpg_attrib_attrs           = efct_lio_tpg_attrib_attrs,

	.default_submit_type		= TARGET_DIRECT_SUBMIT,

	.direct_submit_supp		= 1,

};



static const struct target_core_fabric_ops efct_lio_npiv_ops = {
@@ -1646,6 +1648,9 @@ static const struct target_core_fabric_ops efct_lio_npiv_ops = { 
	.sess_get_initiator_sid		= NULL,

	.tfc_tpg_base_attrs		= efct_lio_npiv_tpg_attrs,

	.tfc_tpg_attrib_attrs		= efct_lio_npiv_tpg_attrib_attrs,



	.default_submit_type		= TARGET_DIRECT_SUBMIT,

	.direct_submit_supp		= 1,

};



int efct_scsi_tgt_driver_init(void)

drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c

+3 −0
Original line number Diff line number Diff line
@@ -3975,6 +3975,9 @@ static const struct target_core_fabric_ops ibmvscsis_ops = { 
	.fabric_drop_tpg		= ibmvscsis_drop_tpg,



	.tfc_wwn_attrs			= ibmvscsis_wwn_attrs,



	.default_submit_type		= TARGET_DIRECT_SUBMIT,

	.direct_submit_supp		= 1,

};



static void ibmvscsis_dev_release(struct device *dev) {};

drivers/scsi/qla2xxx/tcm_qla2xxx.c

+6 −0
Original line number Diff line number Diff line
@@ -1822,6 +1822,9 @@ static const struct target_core_fabric_ops tcm_qla2xxx_ops = { 
	.tfc_wwn_attrs			= tcm_qla2xxx_wwn_attrs,

	.tfc_tpg_base_attrs		= tcm_qla2xxx_tpg_attrs,

	.tfc_tpg_attrib_attrs		= tcm_qla2xxx_tpg_attrib_attrs,



	.default_submit_type		= TARGET_DIRECT_SUBMIT,

	.direct_submit_supp		= 1,

};



static const struct target_core_fabric_ops tcm_qla2xxx_npiv_ops = {
@@ -1859,6 +1862,9 @@ static const struct target_core_fabric_ops tcm_qla2xxx_npiv_ops = { 
	.fabric_init_nodeacl		= tcm_qla2xxx_init_nodeacl,



	.tfc_wwn_attrs			= tcm_qla2xxx_wwn_attrs,



	.default_submit_type		= TARGET_DIRECT_SUBMIT,

	.direct_submit_supp		= 1,

};



static int tcm_qla2xxx_register_configfs(void)

drivers/target/iscsi/iscsi_target_configfs.c

+3 −0
Original line number Diff line number Diff line
@@ -1590,4 +1590,7 @@ const struct target_core_fabric_ops iscsi_ops = { 
	.tfc_tpg_nacl_param_attrs	= lio_target_nacl_param_attrs,



	.write_pending_must_be_called	= 1,



	.default_submit_type		= TARGET_DIRECT_SUBMIT,

	.direct_submit_supp		= 1,

};