Commit 262ef636 authored by Mike Christie's avatar Mike Christie Committed by James Bottomley
Browse files

[SCSI] libiscsi: allow drivers to modify the itt sent to the target 



bnx2i and cxgb3i need to encode LLD info in the itt so that
the firmware/hardware can process the pdu. This patch allows
the LLDs to encode info in the task->hdr->itt that they
setup in the alloc_pdu callout (any resources that are allocated
can be freed with the pdu in the cleanup_task callout). If
the LLD encodes info in the itt they should implement a
parse_pdu_itt callout. If parse_pdu_itt is not implemented
libiscsi will do the right thing for the LLD.

Signed-off-by: default avatarMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 38e1a8f5

drivers/scsi/libiscsi.c

+34 −13
Original line number Diff line number Diff line
@@ -222,12 +222,14 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task) 
	struct scsi_cmnd *sc = task->sc;

	struct iscsi_cmd *hdr;

	unsigned hdrlength, cmd_len;

	itt_t itt;

	int rc;



	rc = conn->session->tt->alloc_pdu(task);

	if (rc)

		return rc;

	hdr = (struct iscsi_cmd *) task->hdr;

	itt = hdr->itt;

	memset(hdr, 0, sizeof(*hdr));



	task->hdr_len = 0;
@@ -238,7 +240,11 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task) 
	hdr->flags = ISCSI_ATTR_SIMPLE;

	int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);

	memcpy(task->lun, hdr->lun, sizeof(task->lun));

	hdr->itt = task->hdr_itt = build_itt(task->itt, session->age);

	if (session->tt->parse_pdu_itt)

		hdr->itt = task->hdr_itt = itt;

	else

		hdr->itt = task->hdr_itt = build_itt(task->itt,

						     task->conn->session->age);

	hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);

	session->cmdsn++;

	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
@@ -457,7 +463,6 @@ static int iscsi_prep_mgmt_task(struct iscsi_conn *conn, 
	 */

	nop->cmdsn = cpu_to_be32(session->cmdsn);

	if (hdr->itt != RESERVED_ITT) {

		hdr->itt = build_itt(task->itt, session->age);

		/*

		 * TODO: We always use immediate, so we never hit this.

		 * If we start to send tmfs or nops as non-immediate then
@@ -490,6 +495,7 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr, 
{

	struct iscsi_session *session = conn->session;

	struct iscsi_task *task;

	itt_t itt;



	if (session->state == ISCSI_STATE_TERMINATE)

		return NULL;
@@ -531,9 +537,18 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr, 
				 "pdu for mgmt task.\n");

		goto requeue_task;

	}

	itt = task->hdr->itt;

	task->hdr_len = sizeof(struct iscsi_hdr);



	memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));



	if (hdr->itt != RESERVED_ITT) {

		if (session->tt->parse_pdu_itt)

			task->hdr->itt = itt;

		else

			task->hdr->itt = build_itt(task->itt,

						   task->conn->session->age);

	}



	INIT_LIST_HEAD(&task->running);

	list_add_tail(&task->running, &conn->mgmtqueue);
@@ -745,7 +760,6 @@ static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr, 
{

	struct iscsi_reject *reject = (struct iscsi_reject *)hdr;

	struct iscsi_hdr rejected_pdu;

	uint32_t itt;



	conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
@@ -755,10 +769,9 @@ static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr, 


		if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {

			memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));

			itt = get_itt(rejected_pdu.itt);

			iscsi_conn_printk(KERN_ERR, conn,

					  "itt 0x%x had pdu (op 0x%x) rejected "

					  "due to DataDigest error.\n", itt,

					  "pdu (op 0x%x) rejected "

					  "due to DataDigest error.\n",

					  rejected_pdu.opcode);

		}

	}
@@ -778,11 +791,14 @@ static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr, 
static struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)

{

	struct iscsi_session *session = conn->session;

	uint32_t i;

	int i;



	if (itt == RESERVED_ITT)

		return NULL;



	if (session->tt->parse_pdu_itt)

		session->tt->parse_pdu_itt(conn, itt, &i, NULL);

	else

		i = get_itt(itt);

	if (i >= session->cmds_max)

		return NULL;
@@ -958,20 +974,25 @@ EXPORT_SYMBOL_GPL(iscsi_complete_pdu); 
int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)

{

	struct iscsi_session *session = conn->session;

	uint32_t i;

	int age = 0, i = 0;



	if (itt == RESERVED_ITT)

		return 0;



	if (((__force u32)itt & ISCSI_AGE_MASK) !=

	    (session->age << ISCSI_AGE_SHIFT)) {

	if (session->tt->parse_pdu_itt)

		session->tt->parse_pdu_itt(conn, itt, &i, &age);

	else {

		i = get_itt(itt);

		age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;

	}



	if (age != session->age) {

		iscsi_conn_printk(KERN_ERR, conn,

				  "received itt %x expected session age (%x)\n",

				  (__force u32)itt, session->age);

		return ISCSI_ERR_BAD_ITT;

	}



	i = get_itt(itt);

	if (i >= session->cmds_max) {

		iscsi_conn_printk(KERN_ERR, conn,

				  "received invalid itt index %u (max cmds "

include/scsi/libiscsi.h

+3 −2
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <linux/workqueue.h>

#include <scsi/iscsi_proto.h>

#include <scsi/iscsi_if.h>

#include <scsi/scsi_transport_iscsi.h>



struct scsi_transport_template;

struct scsi_host_template;
@@ -70,12 +71,12 @@ enum { 
/* Connection suspend "bit" */

#define ISCSI_SUSPEND_BIT		1



#define ISCSI_ITT_MASK			(0x1fff)

#define ISCSI_ITT_MASK			0x1fff

#define ISCSI_TOTAL_CMDS_MAX		4096

/* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */

#define ISCSI_TOTAL_CMDS_MIN		16

#define ISCSI_AGE_SHIFT			28

#define ISCSI_AGE_MASK			(0xf << ISCSI_AGE_SHIFT)

#define ISCSI_AGE_MASK			0xf



#define ISCSI_ADDRESS_BUF_LEN		64

include/scsi/scsi_transport_iscsi.h

+3 −0
Original line number Diff line number Diff line
@@ -122,6 +122,9 @@ struct iscsi_transport { 
	int (*xmit_pdu) (struct iscsi_task *task);

	int (*init_pdu) (struct iscsi_task *task, unsigned int offset,

			 unsigned int count);

	void (*parse_pdu_itt) (struct iscsi_conn *conn, itt_t itt,

			       int *index, int *age);



	void (*session_recovery_timedout) (struct iscsi_cls_session *session);

	struct iscsi_endpoint *(*ep_connect) (struct sockaddr *dst_addr,

					      int non_blocking);

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