From 194605d45dcb511983caca699d81855693b25fe0 Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Wed, 27 Sep 2023 21:09:01 -0500 Subject: [PATCH] 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: Mike Christie Link: https://lore.kernel.org/r/20230928020907.5730-2-michael.christie@oracle.com Signed-off-by: Martin K. Petersen --- drivers/infiniband/ulp/srpt/ib_srpt.c | 3 +++ drivers/scsi/elx/efct/efct_lio.c | 5 +++++ drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c | 3 +++ drivers/scsi/qla2xxx/tcm_qla2xxx.c | 6 ++++++ drivers/target/iscsi/iscsi_target_configfs.c | 3 +++ drivers/target/loopback/tcm_loop.c | 2 ++ drivers/target/sbp/sbp_target.c | 3 +++ drivers/target/tcm_fc/tfc_conf.c | 3 +++ drivers/usb/gadget/function/f_tcm.c | 3 +++ drivers/vhost/scsi.c | 3 +++ drivers/xen/xen-scsiback.c | 3 +++ include/target/target_core_base.h | 9 +++++++++ include/target/target_core_fabric.h | 9 +++++++++ 13 files changed, 55 insertions(+) diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c index c12005eab14c19..58f70cfec45a72 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.c +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c @@ -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, }; /** diff --git a/drivers/scsi/elx/efct/efct_lio.c b/drivers/scsi/elx/efct/efct_lio.c index a982b9cf987017..6a6ec32c46bdf3 100644 --- a/drivers/scsi/elx/efct/efct_lio.c +++ b/drivers/scsi/elx/efct/efct_lio.c @@ -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) diff --git a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c index 385f812b8793c2..4dc411a5810701 100644 --- a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c +++ b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c @@ -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) {}; diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c index 3b5ba4b47b3b27..796cea463cfdff 100644 --- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c +++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c @@ -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) diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configfs.c index bf190dcb9eee20..88db94f382bb92 100644 --- a/drivers/target/iscsi/iscsi_target_configfs.c +++ b/drivers/target/iscsi/iscsi_target_configfs.c @@ -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, }; diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c index 4ec99a55ac305a..fbacccdd2ff685 100644 --- a/drivers/target/loopback/tcm_loop.c +++ b/drivers/target/loopback/tcm_loop.c @@ -1102,6 +1102,8 @@ static const struct target_core_fabric_ops loop_ops = { .tfc_wwn_attrs = tcm_loop_wwn_attrs, .tfc_tpg_base_attrs = tcm_loop_tpg_attrs, .tfc_tpg_attrib_attrs = tcm_loop_tpg_attrib_attrs, + .default_submit_type = TARGET_QUEUE_SUBMIT, + .direct_submit_supp = 0, }; static int __init tcm_loop_fabric_init(void) diff --git a/drivers/target/sbp/sbp_target.c b/drivers/target/sbp/sbp_target.c index 2a761bc0919389..b604fcae21e112 100644 --- a/drivers/target/sbp/sbp_target.c +++ b/drivers/target/sbp/sbp_target.c @@ -2278,6 +2278,9 @@ static const struct target_core_fabric_ops sbp_ops = { .tfc_wwn_attrs = sbp_wwn_attrs, .tfc_tpg_base_attrs = sbp_tpg_base_attrs, .tfc_tpg_attrib_attrs = sbp_tpg_attrib_attrs, + + .default_submit_type = TARGET_DIRECT_SUBMIT, + .direct_submit_supp = 1, }; static int __init sbp_init(void) diff --git a/drivers/target/tcm_fc/tfc_conf.c b/drivers/target/tcm_fc/tfc_conf.c index 6ac3fc1a7d39bb..5ee03d1cba2bee 100644 --- a/drivers/target/tcm_fc/tfc_conf.c +++ b/drivers/target/tcm_fc/tfc_conf.c @@ -432,6 +432,9 @@ static const struct target_core_fabric_ops ft_fabric_ops = { .tfc_wwn_attrs = ft_wwn_attrs, .tfc_tpg_nacl_base_attrs = ft_nacl_base_attrs, + + .default_submit_type = TARGET_DIRECT_SUBMIT, + .direct_submit_supp = 1, }; static struct notifier_block ft_notifier = { diff --git a/drivers/usb/gadget/function/f_tcm.c b/drivers/usb/gadget/function/f_tcm.c index 79ed2e6e576aab..ff33f31bcdf645 100644 --- a/drivers/usb/gadget/function/f_tcm.c +++ b/drivers/usb/gadget/function/f_tcm.c @@ -1687,6 +1687,9 @@ static const struct target_core_fabric_ops usbg_ops = { .tfc_wwn_attrs = usbg_wwn_attrs, .tfc_tpg_base_attrs = usbg_base_attrs, + + .default_submit_type = TARGET_DIRECT_SUBMIT, + .direct_submit_supp = 1, }; /* Start gadget.c code */ diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index abef0619c7901a..dc274463bdf027 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -2598,6 +2598,9 @@ static const struct target_core_fabric_ops vhost_scsi_ops = { .tfc_wwn_attrs = vhost_scsi_wwn_attrs, .tfc_tpg_base_attrs = vhost_scsi_tpg_attrs, .tfc_tpg_attrib_attrs = vhost_scsi_tpg_attrib_attrs, + + .default_submit_type = TARGET_QUEUE_SUBMIT, + .direct_submit_supp = 1, }; static int __init vhost_scsi_init(void) diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c index 8b77e4c06e43f8..0c51edfd13dcdf 100644 --- a/drivers/xen/xen-scsiback.c +++ b/drivers/xen/xen-scsiback.c @@ -1832,6 +1832,9 @@ static const struct target_core_fabric_ops scsiback_ops = { .tfc_wwn_attrs = scsiback_wwn_attrs, .tfc_tpg_base_attrs = scsiback_tpg_attrs, .tfc_tpg_param_attrs = scsiback_param_attrs, + + .default_submit_type = TARGET_DIRECT_SUBMIT, + .direct_submit_supp = 1, }; static const struct xenbus_device_id scsiback_ids[] = { diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index 159567359bbb0f..401abdf8a9ef5b 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -108,6 +108,15 @@ #define SE_MODE_PAGE_BUF 512 #define SE_SENSE_BUF 96 +enum target_submit_type { + /* Use the fabric driver's default submission type */ + TARGET_FABRIC_DEFAULT_SUBMIT, + /* Submit from the calling context */ + TARGET_DIRECT_SUBMIT, + /* Defer submission to the LIO workqueue */ + TARGET_QUEUE_SUBMIT, +}; + /* struct se_hba->hba_flags */ enum hba_flags_table { HBA_FLAGS_INTERNAL_USE = 0x01, diff --git a/include/target/target_core_fabric.h b/include/target/target_core_fabric.h index 2a6c4c935666aa..dcd7d76d2f3010 100644 --- a/include/target/target_core_fabric.h +++ b/include/target/target_core_fabric.h @@ -118,6 +118,15 @@ struct target_core_fabric_ops { * its entirety before a command is aborted. */ unsigned int write_pending_must_be_called:1; + /* + * Set this if the driver supports submitting commands to the backend + * from target_submit/target_submit_cmd. + */ + unsigned int direct_submit_supp:1; + /* + * Set this to a target_submit_type value. + */ + u8 default_submit_type; }; int target_register_template(const struct target_core_fabric_ops *fo);