Commit 38b57f82 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

target: Add protected fabric + unprotected device support 



This patch adds a new target_core_fabric_ops callback for allowing fabric
drivers to expose a TPG attribute for signaling when a T10-PI protected
fabric wants to function with an un-protected device without T10-PI.

This specifically is to allow LIO to perform WRITE_STRIP + READ_INSERT
operations when functioning with non T10-PI enabled devices, seperate
from any available hw offloads the fabric supports.

This is done using a new se_sess->sess_prot_type that is set at fabric
session creation time based upon the TPG attribute.  It currently cannot
be changed for individual sessions after initial creation.

Also, update existing target_core_sbc.c code to honor sess_prot_type when
setting up cmd->prot_op + cmd->prot_type assignments.

(Add unlikely and !! boolean conversion in sbc_check_prot - Sagi)

Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Doug Gilbert <dgilbert@interlog.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 823ddd87

drivers/target/target_core_sbc.c

+33 −11
Original line number Diff line number Diff line
@@ -581,11 +581,12 @@ sbc_compare_and_write(struct se_cmd *cmd) 
}



static int

sbc_set_prot_op_checks(u8 protect, enum target_prot_type prot_type,

sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,

		       bool is_write, struct se_cmd *cmd)

{

	if (is_write) {

		cmd->prot_op = protect ? TARGET_PROT_DOUT_PASS :

		cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :

			       protect ? TARGET_PROT_DOUT_PASS :

			       TARGET_PROT_DOUT_INSERT;

		switch (protect) {

		case 0x0:
@@ -610,7 +611,8 @@ sbc_set_prot_op_checks(u8 protect, enum target_prot_type prot_type, 
			return -EINVAL;

		}

	} else {

		cmd->prot_op = protect ? TARGET_PROT_DIN_PASS :

		cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :

			       protect ? TARGET_PROT_DIN_PASS :

			       TARGET_PROT_DIN_STRIP;

		switch (protect) {

		case 0x0:
@@ -644,11 +646,15 @@ sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb, 
	       u32 sectors, bool is_write)

{

	u8 protect = cdb[1] >> 5;

	int sp_ops = cmd->se_sess->sup_prot_ops;

	int pi_prot_type = dev->dev_attrib.pi_prot_type;

	bool fabric_prot = false;



	if (!cmd->t_prot_sg || !cmd->t_prot_nents) {

		if (protect && !dev->dev_attrib.pi_prot_type) {

			pr_err("CDB contains protect bit, but device does not"

			       " advertise PROTECT=1 feature bit\n");

		if (unlikely(protect &&

		    !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {

			pr_err("CDB contains protect bit, but device + fabric does"

			       " not advertise PROTECT=1 feature bit\n");

			return TCM_INVALID_CDB_FIELD;

		}

		if (cmd->prot_pto)
@@ -669,15 +675,28 @@ sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb, 
		cmd->reftag_seed = cmd->t_task_lba;

		break;

	case TARGET_DIF_TYPE0_PROT:

		/*

		 * See if the fabric supports T10-PI, and the session has been

		 * configured to allow export PROTECT=1 feature bit with backend

		 * devices that don't support T10-PI.

		 */

		fabric_prot = is_write ?

			      !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :

			      !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));



		if (fabric_prot && cmd->se_sess->sess_prot_type) {

			pi_prot_type = cmd->se_sess->sess_prot_type;

			break;

		}

		/* Fallthrough */

	default:

		return TCM_NO_SENSE;

	}



	if (sbc_set_prot_op_checks(protect, dev->dev_attrib.pi_prot_type,

				   is_write, cmd))

	if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))

		return TCM_INVALID_CDB_FIELD;



	cmd->prot_type = dev->dev_attrib.pi_prot_type;

	cmd->prot_type = pi_prot_type;

	cmd->prot_length = dev->prot_length * sectors;



	/**
@@ -1231,6 +1250,9 @@ sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read, 
	unsigned int i, len, left;

	unsigned int offset = sg_off;



	if (!sg)

		return;



	left = sectors * dev->prot_length;



	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {

drivers/target/target_core_transport.c

+8 −0
Original line number Diff line number Diff line
@@ -322,10 +322,18 @@ void __transport_register_session( 
	struct se_session *se_sess,

	void *fabric_sess_ptr)

{

	struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;

	unsigned char buf[PR_REG_ISID_LEN];



	se_sess->se_tpg = se_tpg;

	se_sess->fabric_sess_ptr = fabric_sess_ptr;

	/*

	 * Determine if fabric allows for T10-PI feature bits to be exposed

	 * to initiators for device backends with !dev->dev_attrib.pi_prot_type

	 */

	if (tfo->tpg_check_prot_fabric_only)

		se_sess->sess_prot_type = tfo->tpg_check_prot_fabric_only(se_tpg);



	/*

	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t

	 *

include/target/target_core_base.h

+1 −0
Original line number Diff line number Diff line
@@ -616,6 +616,7 @@ struct se_session { 
	unsigned		sess_tearing_down:1;

	u64			sess_bin_isid;

	enum target_prot_op	sup_prot_ops;

	enum target_prot_type	sess_prot_type;

	struct se_node_acl	*se_node_acl;

	struct se_portal_group *se_tpg;

	void			*fabric_sess_ptr;

include/target/target_core_fabric.h

+8 −0
Original line number Diff line number Diff line
@@ -27,6 +27,14 @@ struct target_core_fabric_ops { 
	 * inquiry response

	 */

	int (*tpg_check_demo_mode_login_only)(struct se_portal_group *);

	/*

	 * Optionally used as a configfs tunable to determine when

	 * target-core should signal the PROTECT=1 feature bit for

	 * backends that don't support T10-PI, so that either fabric

	 * HW offload or target-core emulation performs the associated

	 * WRITE_STRIP and READ_INSERT operations.

	 */

	int (*tpg_check_prot_fabric_only)(struct se_portal_group *);

	struct se_node_acl *(*tpg_alloc_fabric_acl)(

					struct se_portal_group *);

	void (*tpg_release_fabric_acl)(struct se_portal_group *,

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