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Subject[RFC-v4 10/12] iscsi-target: Add support for task management operations
Date
From: Nicholas Bellinger <nab@linux-iscsi.org>

This patch adds support for iSCSI task management operations called
directly from iscsi_target.c TMR request/response PDU logic, and
interfaces struct se_lun -> struct se_device for assoication
of TMRs to TCM backend devices.

Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
---
drivers/target/iscsi/iscsi_target_tmr.c | 854 +++++++++++++++++++++++++++++++
drivers/target/iscsi/iscsi_target_tmr.h | 14 +
2 files changed, 868 insertions(+), 0 deletions(-)
create mode 100644 drivers/target/iscsi/iscsi_target_tmr.c
create mode 100644 drivers/target/iscsi/iscsi_target_tmr.h
diff --git a/drivers/target/iscsi/iscsi_target_tmr.c b/drivers/target/iscsi/iscsi_target_tmr.c
new file mode 100644
index 0000000..43121c0
--- /dev/null
+++ b/drivers/target/iscsi/iscsi_target_tmr.c
@@ -0,0 +1,854 @@
+/*******************************************************************************
+ * This file contains the iSCSI Target specific Task Management functions.
+ *
+ * © Copyright 2007-2011 RisingTide Systems LLC.
+ *
+ * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
+ *
+ * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ ******************************************************************************/
+
+#include <asm/unaligned.h>
+#include <scsi/iscsi_proto.h>
+#include <target/target_core_base.h>
+#include <target/target_core_transport.h>
+
+#include "iscsi_target_debug.h"
+#include "iscsi_target_core.h"
+#include "iscsi_target_seq_pdu_list.h"
+#include "iscsi_target_datain_values.h"
+#include "iscsi_target_device.h"
+#include "iscsi_target_erl0.h"
+#include "iscsi_target_erl1.h"
+#include "iscsi_target_erl2.h"
+#include "iscsi_target_tmr.h"
+#include "iscsi_target_tpg.h"
+#include "iscsi_target_util.h"
+#include "iscsi_target.h"
+
+u8 iscsit_tmr_abort_task(
+ struct iscsi_cmd *cmd,
+ unsigned char *buf)
+{
+ struct iscsi_cmd *ref_cmd;
+ struct iscsi_conn *conn = cmd->conn;
+ struct iscsi_tmr_req *tmr_req = cmd->tmr_req;
+ struct se_tmr_req *se_tmr = SE_CMD(cmd)->se_tmr_req;
+ struct iscsi_tm *hdr = (struct iscsi_tm *) buf;
+
+ ref_cmd = iscsit_find_cmd_from_itt(conn, hdr->rtt);
+ if (!ref_cmd) {
+ printk(KERN_ERR "Unable to locate RefTaskTag: 0x%08x on CID:"
+ " %hu.\n", hdr->rtt, conn->cid);
+ return ((hdr->refcmdsn >= conn->sess->exp_cmd_sn) &&
+ (hdr->refcmdsn <= conn->sess->max_cmd_sn)) ?
+ ISCSI_TMF_RSP_COMPLETE : ISCSI_TMF_RSP_NO_TASK;
+ }
+ if (ref_cmd->cmd_sn != hdr->refcmdsn) {
+ printk(KERN_ERR "RefCmdSN 0x%08x does not equal"
+ " task's CmdSN 0x%08x. Rejecting ABORT_TASK.\n",
+ hdr->refcmdsn, ref_cmd->cmd_sn);
+ return ISCSI_TMF_RSP_REJECTED;
+ }
+
+ se_tmr->ref_task_tag = hdr->rtt;
+ se_tmr->ref_cmd = &ref_cmd->se_cmd;
+ tmr_req->ref_cmd_sn = hdr->refcmdsn;
+ tmr_req->exp_data_sn = hdr->exp_datasn;
+
+ return ISCSI_TMF_RSP_COMPLETE;
+}
+
+/*
+ * Called from iscsit_handle_task_mgt_cmd().
+ */
+int iscsit_tmr_task_warm_reset(
+ struct iscsi_conn *conn,
+ struct iscsi_tmr_req *tmr_req,
+ unsigned char *buf)
+{
+ struct iscsi_session *sess = conn->sess;
+ struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
+#if 0
+ struct iscsi_init_task_mgt_cmnd *hdr =
+ (struct iscsi_init_task_mgt_cmnd *) buf;
+#endif
+ if (!na->tmr_warm_reset) {
+ printk(KERN_ERR "TMR Opcode TARGET_WARM_RESET authorization"
+ " failed for Initiator Node: %s\n",
+ sess->se_sess->se_node_acl->initiatorname);
+ return -1;
+ }
+ /*
+ * Do the real work in transport_generic_do_tmr().
+ */
+ return 0;
+}
+
+int iscsit_tmr_task_cold_reset(
+ struct iscsi_conn *conn,
+ struct iscsi_tmr_req *tmr_req,
+ unsigned char *buf)
+{
+ struct iscsi_session *sess = conn->sess;
+ struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
+
+ if (!na->tmr_cold_reset) {
+ printk(KERN_ERR "TMR Opcode TARGET_COLD_RESET authorization"
+ " failed for Initiator Node: %s\n",
+ sess->se_sess->se_node_acl->initiatorname);
+ return -1;
+ }
+ /*
+ * Do the real work in transport_generic_do_tmr().
+ */
+ return 0;
+}
+
+u8 iscsit_tmr_task_reassign(
+ struct iscsi_cmd *cmd,
+ unsigned char *buf)
+{
+ struct iscsi_cmd *ref_cmd = NULL;
+ struct iscsi_conn *conn = cmd->conn;
+ struct iscsi_conn_recovery *cr = NULL;
+ struct iscsi_tmr_req *tmr_req = cmd->tmr_req;
+ struct se_tmr_req *se_tmr = SE_CMD(cmd)->se_tmr_req;
+ struct iscsi_tm *hdr = (struct iscsi_tm *) buf;
+ int ret;
+
+ TRACE(TRACE_ERL2, "Got TASK_REASSIGN TMR ITT: 0x%08x,"
+ " RefTaskTag: 0x%08x, ExpDataSN: 0x%08x, CID: %hu\n",
+ hdr->itt, hdr->rtt, hdr->exp_datasn, conn->cid);
+
+ if (conn->sess->sess_ops->ErrorRecoveryLevel != 2) {
+ printk(KERN_ERR "TMR TASK_REASSIGN not supported in ERL<2,"
+ " ignoring request.\n");
+ return ISCSI_TMF_RSP_NOT_SUPPORTED;
+ }
+
+ ret = iscsit_find_cmd_for_recovery(conn->sess, &ref_cmd, &cr, hdr->rtt);
+ if (ret == -2) {
+ printk(KERN_ERR "Command ITT: 0x%08x is still alligent to CID:"
+ " %hu\n", ref_cmd->init_task_tag, cr->cid);
+ return ISCSI_TMF_RSP_TASK_ALLEGIANT;
+ } else if (ret == -1) {
+ printk(KERN_ERR "Unable to locate RefTaskTag: 0x%08x in"
+ " connection recovery command list.\n", hdr->rtt);
+ return ISCSI_TMF_RSP_NO_TASK;
+ }
+ /*
+ * Temporary check to prevent connection recovery for
+ * connections with a differing MaxRecvDataSegmentLength.
+ */
+ if (cr->maxrecvdatasegmentlength !=
+ conn->conn_ops->MaxRecvDataSegmentLength) {
+ printk(KERN_ERR "Unable to perform connection recovery for"
+ " differing MaxRecvDataSegmentLength, rejecting"
+ " TMR TASK_REASSIGN.\n");
+ return ISCSI_TMF_RSP_REJECTED;
+ }
+
+ se_tmr->ref_task_tag = hdr->rtt;
+ se_tmr->ref_cmd = &ref_cmd->se_cmd;
+ se_tmr->ref_task_lun = get_unaligned_le64(&hdr->lun[0]);
+ tmr_req->ref_cmd_sn = hdr->refcmdsn;
+ tmr_req->exp_data_sn = hdr->exp_datasn;
+ tmr_req->conn_recovery = cr;
+ tmr_req->task_reassign = 1;
+ /*
+ * Command can now be reassigned to a new connection.
+ * The task management response must be sent before the
+ * reassignment actually happens. See iscsi_tmr_post_handler().
+ */
+ return ISCSI_TMF_RSP_COMPLETE;
+}
+
+static void iscsit_task_reassign_remove_cmd(
+ struct iscsi_cmd *cmd,
+ struct iscsi_conn_recovery *cr,
+ struct iscsi_session *sess)
+{
+ int ret;
+
+ spin_lock(&cr->conn_recovery_cmd_lock);
+ ret = iscsit_remove_cmd_from_connection_recovery(cmd, sess);
+ spin_unlock(&cr->conn_recovery_cmd_lock);
+ if (!ret) {
+ printk(KERN_INFO "iSCSI connection recovery successful for CID:"
+ " %hu on SID: %u\n", cr->cid, sess->sid);
+ iscsit_remove_active_connection_recovery_entry(cr, sess);
+ }
+
+ return;
+}
+
+static int iscsit_task_reassign_complete_nop_out(
+ struct iscsi_tmr_req *tmr_req,
+ struct iscsi_conn *conn)
+{
+ struct se_tmr_req *se_tmr = tmr_req->se_tmr_req;
+ struct se_cmd *se_cmd = se_tmr->ref_cmd;
+ struct iscsi_cmd *cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd);
+ struct iscsi_conn_recovery *cr;
+
+ if (!cmd->cr) {
+ printk(KERN_ERR "struct iscsi_conn_recovery pointer for ITT: 0x%08x"
+ " is NULL!\n", cmd->init_task_tag);
+ return -1;
+ }
+ cr = cmd->cr;
+
+ /*
+ * Reset the StatSN so a new one for this commands new connection
+ * will be assigned.
+ * Reset the ExpStatSN as well so we may receive Status SNACKs.
+ */
+ cmd->stat_sn = cmd->exp_stat_sn = 0;
+
+ iscsit_task_reassign_remove_cmd(cmd, cr, conn->sess);
+
+ spin_lock_bh(&conn->cmd_lock);
+ list_add_tail(&cmd->i_list, &conn->conn_cmd_list);
+ spin_unlock_bh(&conn->cmd_lock);
+
+ cmd->i_state = ISTATE_SEND_NOPIN;
+ iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
+ return 0;
+}
+
+static int iscsit_task_reassign_complete_write(
+ struct iscsi_cmd *cmd,
+ struct iscsi_tmr_req *tmr_req)
+{
+ int no_build_r2ts = 0;
+ u32 length = 0, offset = 0;
+ struct iscsi_conn *conn = cmd->conn;
+ struct se_cmd *se_cmd = SE_CMD(cmd);
+ /*
+ * The Initiator must not send a R2T SNACK with a Begrun less than
+ * the TMR TASK_REASSIGN's ExpDataSN.
+ */
+ if (!tmr_req->exp_data_sn) {
+ cmd->cmd_flags &= ~ICF_GOT_DATACK_SNACK;
+ cmd->acked_data_sn = 0;
+ } else {
+ cmd->cmd_flags |= ICF_GOT_DATACK_SNACK;
+ cmd->acked_data_sn = (tmr_req->exp_data_sn - 1);
+ }
+
+ /*
+ * The TMR TASK_REASSIGN's ExpDataSN contains the next R2TSN the
+ * Initiator is expecting. The Target controls all WRITE operations
+ * so if we have received all DataOUT we can safety ignore Initiator.
+ */
+ if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
+ if (!atomic_read(&cmd->transport_sent)) {
+ TRACE(TRACE_ERL2, "WRITE ITT: 0x%08x: t_state: %d"
+ " never sent to transport\n",
+ cmd->init_task_tag, cmd->se_cmd.t_state);
+ return transport_generic_handle_data(se_cmd);
+ }
+
+ cmd->i_state = ISTATE_SEND_STATUS;
+ iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
+ return 0;
+ }
+
+ /*
+ * Special case to deal with DataSequenceInOrder=No and Non-Immeidate
+ * Unsolicited DataOut.
+ */
+ if (cmd->unsolicited_data) {
+ cmd->unsolicited_data = 0;
+
+ offset = cmd->next_burst_len = cmd->write_data_done;
+
+ if ((conn->sess->sess_ops->FirstBurstLength - offset) >=
+ cmd->data_length) {
+ no_build_r2ts = 1;
+ length = (cmd->data_length - offset);
+ } else
+ length = (conn->sess->sess_ops->FirstBurstLength - offset);
+
+ spin_lock_bh(&cmd->r2t_lock);
+ if (iscsit_add_r2t_to_list(cmd, offset, length, 0, 0) < 0) {
+ spin_unlock_bh(&cmd->r2t_lock);
+ return -1;
+ }
+ cmd->outstanding_r2ts++;
+ spin_unlock_bh(&cmd->r2t_lock);
+
+ if (no_build_r2ts)
+ return 0;
+ }
+ /*
+ * iscsit_build_r2ts_for_cmd() can handle the rest from here.
+ */
+ return iscsit_build_r2ts_for_cmd(cmd, conn, 2);
+}
+
+static int iscsit_task_reassign_complete_read(
+ struct iscsi_cmd *cmd,
+ struct iscsi_tmr_req *tmr_req)
+{
+ struct iscsi_conn *conn = cmd->conn;
+ struct iscsi_datain_req *dr;
+ struct se_cmd *se_cmd = SE_CMD(cmd);
+ /*
+ * The Initiator must not send a Data SNACK with a BegRun less than
+ * the TMR TASK_REASSIGN's ExpDataSN.
+ */
+ if (!tmr_req->exp_data_sn) {
+ cmd->cmd_flags &= ~ICF_GOT_DATACK_SNACK;
+ cmd->acked_data_sn = 0;
+ } else {
+ cmd->cmd_flags |= ICF_GOT_DATACK_SNACK;
+ cmd->acked_data_sn = (tmr_req->exp_data_sn - 1);
+ }
+
+ if (!atomic_read(&cmd->transport_sent)) {
+ printk(KERN_INFO "READ ITT: 0x%08x: t_state: %d never sent to"
+ " transport\n", cmd->init_task_tag,
+ SE_CMD(cmd)->t_state);
+ transport_generic_handle_cdb(se_cmd);
+ return 0;
+ }
+
+ if (!atomic_read(&T_TASK(se_cmd)->t_transport_complete)) {
+ printk(KERN_ERR "READ ITT: 0x%08x: t_state: %d, never returned"
+ " from transport\n", cmd->init_task_tag,
+ SE_CMD(cmd)->t_state);
+ return -1;
+ }
+
+ dr = iscsit_allocate_datain_req();
+ if (!dr)
+ return -1;
+ /*
+ * The TMR TASK_REASSIGN's ExpDataSN contains the next DataSN the
+ * Initiator is expecting.
+ */
+ dr->data_sn = dr->begrun = tmr_req->exp_data_sn;
+ dr->runlength = 0;
+ dr->generate_recovery_values = 1;
+ dr->recovery = DATAIN_CONNECTION_RECOVERY;
+
+ iscsit_attach_datain_req(cmd, dr);
+
+ cmd->i_state = ISTATE_SEND_DATAIN;
+ iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
+ return 0;
+}
+
+static int iscsit_task_reassign_complete_none(
+ struct iscsi_cmd *cmd,
+ struct iscsi_tmr_req *tmr_req)
+{
+ struct iscsi_conn *conn = cmd->conn;
+
+ cmd->i_state = ISTATE_SEND_STATUS;
+ iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
+ return 0;
+}
+
+static int iscsit_task_reassign_complete_scsi_cmnd(
+ struct iscsi_tmr_req *tmr_req,
+ struct iscsi_conn *conn)
+{
+ struct se_tmr_req *se_tmr = tmr_req->se_tmr_req;
+ struct se_cmd *se_cmd = se_tmr->ref_cmd;
+ struct iscsi_cmd *cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd);
+ struct iscsi_conn_recovery *cr;
+
+ if (!cmd->cr) {
+ printk(KERN_ERR "struct iscsi_conn_recovery pointer for ITT: 0x%08x"
+ " is NULL!\n", cmd->init_task_tag);
+ return -1;
+ }
+ cr = cmd->cr;
+
+ /*
+ * Reset the StatSN so a new one for this commands new connection
+ * will be assigned.
+ * Reset the ExpStatSN as well so we may receive Status SNACKs.
+ */
+ cmd->stat_sn = cmd->exp_stat_sn = 0;
+
+ iscsit_task_reassign_remove_cmd(cmd, cr, conn->sess);
+
+ spin_lock_bh(&conn->cmd_lock);
+ list_add_tail(&cmd->i_list, &conn->conn_cmd_list);
+ spin_unlock_bh(&conn->cmd_lock);
+
+ if (se_cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
+ cmd->i_state = ISTATE_SEND_STATUS;
+ iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
+ return 0;
+ }
+
+ switch (cmd->data_direction) {
+ case DMA_TO_DEVICE:
+ return iscsit_task_reassign_complete_write(cmd, tmr_req);
+ case DMA_FROM_DEVICE:
+ return iscsit_task_reassign_complete_read(cmd, tmr_req);
+ case DMA_NONE:
+ return iscsit_task_reassign_complete_none(cmd, tmr_req);
+ default:
+ printk(KERN_ERR "Unknown cmd->data_direction: 0x%02x\n",
+ cmd->data_direction);
+ return -1;
+ }
+
+ return 0;
+}
+
+static int iscsit_task_reassign_complete(
+ struct iscsi_tmr_req *tmr_req,
+ struct iscsi_conn *conn)
+{
+ struct se_tmr_req *se_tmr = tmr_req->se_tmr_req;
+ struct se_cmd *se_cmd;
+ struct iscsi_cmd *cmd;
+ int ret = 0;
+
+ if (!se_tmr->ref_cmd) {
+ printk(KERN_ERR "TMR Request is missing a RefCmd struct iscsi_cmd.\n");
+ return -1;
+ }
+ se_cmd = se_tmr->ref_cmd;
+ cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd);
+
+ cmd->conn = conn;
+
+ switch (cmd->iscsi_opcode) {
+ case ISCSI_OP_NOOP_OUT:
+ ret = iscsit_task_reassign_complete_nop_out(tmr_req, conn);
+ break;
+ case ISCSI_OP_SCSI_CMD:
+ ret = iscsit_task_reassign_complete_scsi_cmnd(tmr_req, conn);
+ break;
+ default:
+ printk(KERN_ERR "Illegal iSCSI Opcode 0x%02x during"
+ " command realligence\n", cmd->iscsi_opcode);
+ return -1;
+ }
+
+ if (ret != 0)
+ return ret;
+
+ TRACE(TRACE_ERL2, "Completed connection realligence for Opcode: 0x%02x,"
+ " ITT: 0x%08x to CID: %hu.\n", cmd->iscsi_opcode,
+ cmd->init_task_tag, conn->cid);
+
+ return 0;
+}
+
+/*
+ * Handles special after-the-fact actions related to TMRs.
+ * Right now the only one that its really needed for is
+ * connection recovery releated TASK_REASSIGN.
+ */
+extern int iscsit_tmr_post_handler(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
+{
+ struct iscsi_tmr_req *tmr_req = cmd->tmr_req;
+ struct se_tmr_req *se_tmr = SE_CMD(cmd)->se_tmr_req;
+
+ if (tmr_req->task_reassign &&
+ (se_tmr->response == ISCSI_TMF_RSP_COMPLETE))
+ return iscsit_task_reassign_complete(tmr_req, conn);
+
+ return 0;
+}
+
+/*
+ * Nothing to do here, but leave it for good measure. :-)
+ */
+int iscsit_task_reassign_prepare_read(
+ struct iscsi_tmr_req *tmr_req,
+ struct iscsi_conn *conn)
+{
+ return 0;
+}
+
+static void iscsit_task_reassign_prepare_unsolicited_dataout(
+ struct iscsi_cmd *cmd,
+ struct iscsi_conn *conn)
+{
+ int i, j;
+ struct iscsi_pdu *pdu = NULL;
+ struct iscsi_seq *seq = NULL;
+
+ if (conn->sess->sess_ops->DataSequenceInOrder) {
+ cmd->data_sn = 0;
+
+ if (cmd->immediate_data)
+ cmd->r2t_offset += (cmd->first_burst_len -
+ cmd->seq_start_offset);
+
+ if (conn->sess->sess_ops->DataPDUInOrder) {
+ cmd->write_data_done -= (cmd->immediate_data) ?
+ (cmd->first_burst_len -
+ cmd->seq_start_offset) :
+ cmd->first_burst_len;
+ cmd->first_burst_len = 0;
+ return;
+ }
+
+ for (i = 0; i < cmd->pdu_count; i++) {
+ pdu = &cmd->pdu_list[i];
+
+ if (pdu->status != ISCSI_PDU_RECEIVED_OK)
+ continue;
+
+ if ((pdu->offset >= cmd->seq_start_offset) &&
+ ((pdu->offset + pdu->length) <=
+ cmd->seq_end_offset)) {
+ cmd->first_burst_len -= pdu->length;
+ cmd->write_data_done -= pdu->length;
+ pdu->status = ISCSI_PDU_NOT_RECEIVED;
+ }
+ }
+ } else {
+ for (i = 0; i < cmd->seq_count; i++) {
+ seq = &cmd->seq_list[i];
+
+ if (seq->type != SEQTYPE_UNSOLICITED)
+ continue;
+
+ cmd->write_data_done -=
+ (seq->offset - seq->orig_offset);
+ cmd->first_burst_len = 0;
+ seq->data_sn = 0;
+ seq->offset = seq->orig_offset;
+ seq->next_burst_len = 0;
+ seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY;
+
+ if (conn->sess->sess_ops->DataPDUInOrder)
+ continue;
+
+ for (j = 0; j < seq->pdu_count; j++) {
+ pdu = &cmd->pdu_list[j+seq->pdu_start];
+
+ if (pdu->status != ISCSI_PDU_RECEIVED_OK)
+ continue;
+
+ pdu->status = ISCSI_PDU_NOT_RECEIVED;
+ }
+ }
+ }
+
+ return;
+}
+
+int iscsit_task_reassign_prepare_write(
+ struct iscsi_tmr_req *tmr_req,
+ struct iscsi_conn *conn)
+{
+ struct se_tmr_req *se_tmr = tmr_req->se_tmr_req;
+ struct se_cmd *se_cmd = se_tmr->ref_cmd;
+ struct iscsi_cmd *cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd);
+ struct iscsi_pdu *pdu = NULL;
+ struct iscsi_r2t *r2t = NULL, *r2t_tmp;
+ int first_incomplete_r2t = 1, i = 0;
+
+ /*
+ * The command was in the process of receiving Unsolicited DataOUT when
+ * the connection failed.
+ */
+ if (cmd->unsolicited_data)
+ iscsit_task_reassign_prepare_unsolicited_dataout(cmd, conn);
+
+ /*
+ * The Initiator is requesting R2Ts starting from zero, skip
+ * checking acknowledged R2Ts and start checking struct iscsi_r2ts
+ * greater than zero.
+ */
+ if (!tmr_req->exp_data_sn)
+ goto drop_unacknowledged_r2ts;
+
+ /*
+ * We now check that the PDUs in DataOUT sequences below
+ * the TMR TASK_REASSIGN ExpDataSN (R2TSN the Initiator is
+ * expecting next) have all the DataOUT they require to complete
+ * the DataOUT sequence. First scan from R2TSN 0 to TMR
+ * TASK_REASSIGN ExpDataSN-1.
+ *
+ * If we have not received all DataOUT in question, we must
+ * make sure to make the appropriate changes to values in
+ * struct iscsi_cmd (and elsewhere depending on session parameters)
+ * so iscsit_build_r2ts_for_cmd() in iscsit_task_reassign_complete_write()
+ * will resend a new R2T for the DataOUT sequences in question.
+ */
+ spin_lock_bh(&cmd->r2t_lock);
+ if (list_empty(&cmd->cmd_r2t_list)) {
+ spin_unlock_bh(&cmd->r2t_lock);
+ return -1;
+ }
+
+ list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
+
+ if (r2t->r2t_sn >= tmr_req->exp_data_sn)
+ continue;
+ /*
+ * Safely ignore Recovery R2Ts and R2Ts that have completed
+ * DataOUT sequences.
+ */
+ if (r2t->seq_complete)
+ continue;
+
+ if (r2t->recovery_r2t)
+ continue;
+
+ /*
+ * DataSequenceInOrder=Yes:
+ *
+ * Taking into account the iSCSI implementation requirement of
+ * MaxOutstandingR2T=1 while ErrorRecoveryLevel>0 and
+ * DataSequenceInOrder=Yes, we must take into consideration
+ * the following:
+ *
+ * DataSequenceInOrder=No:
+ *
+ * Taking into account that the Initiator controls the (possibly
+ * random) PDU Order in (possibly random) Sequence Order of
+ * DataOUT the target requests with R2Ts, we must take into
+ * consideration the following:
+ *
+ * DataPDUInOrder=Yes for DataSequenceInOrder=[Yes,No]:
+ *
+ * While processing non-complete R2T DataOUT sequence requests
+ * the Target will re-request only the total sequence length
+ * minus current received offset. This is because we must
+ * assume the initiator will continue sending DataOUT from the
+ * last PDU before the connection failed.
+ *
+ * DataPDUInOrder=No for DataSequenceInOrder=[Yes,No]:
+ *
+ * While processing non-complete R2T DataOUT sequence requests
+ * the Target will re-request the entire DataOUT sequence if
+ * any single PDU is missing from the sequence. This is because
+ * we have no logical method to determine the next PDU offset,
+ * and we must assume the Initiator will be sending any random
+ * PDU offset in the current sequence after TASK_REASSIGN
+ * has completed.
+ */
+ if (conn->sess->sess_ops->DataSequenceInOrder) {
+ if (!first_incomplete_r2t) {
+ cmd->r2t_offset -= r2t->xfer_len;
+ goto next;
+ }
+
+ if (conn->sess->sess_ops->DataPDUInOrder) {
+ cmd->data_sn = 0;
+ cmd->r2t_offset -= (r2t->xfer_len -
+ cmd->next_burst_len);
+ first_incomplete_r2t = 0;
+ goto next;
+ }
+
+ cmd->data_sn = 0;
+ cmd->r2t_offset -= r2t->xfer_len;
+
+ for (i = 0; i < cmd->pdu_count; i++) {
+ pdu = &cmd->pdu_list[i];
+
+ if (pdu->status != ISCSI_PDU_RECEIVED_OK)
+ continue;
+
+ if ((pdu->offset >= r2t->offset) &&
+ (pdu->offset < (r2t->offset +
+ r2t->xfer_len))) {
+ cmd->next_burst_len -= pdu->length;
+ cmd->write_data_done -= pdu->length;
+ pdu->status = ISCSI_PDU_NOT_RECEIVED;
+ }
+ }
+
+ first_incomplete_r2t = 0;
+ } else {
+ struct iscsi_seq *seq;
+
+ seq = iscsit_get_seq_holder(cmd, r2t->offset,
+ r2t->xfer_len);
+ if (!seq) {
+ spin_unlock_bh(&cmd->r2t_lock);
+ return -1;
+ }
+
+ cmd->write_data_done -=
+ (seq->offset - seq->orig_offset);
+ seq->data_sn = 0;
+ seq->offset = seq->orig_offset;
+ seq->next_burst_len = 0;
+ seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY;
+
+ cmd->seq_send_order--;
+
+ if (conn->sess->sess_ops->DataPDUInOrder)
+ goto next;
+
+ for (i = 0; i < seq->pdu_count; i++) {
+ pdu = &cmd->pdu_list[i+seq->pdu_start];
+
+ if (pdu->status != ISCSI_PDU_RECEIVED_OK)
+ continue;
+
+ pdu->status = ISCSI_PDU_NOT_RECEIVED;
+ }
+ }
+
+next:
+ cmd->outstanding_r2ts--;
+ }
+ spin_unlock_bh(&cmd->r2t_lock);
+
+ /*
+ * We now drop all unacknowledged R2Ts, ie: ExpDataSN from TMR
+ * TASK_REASSIGN to the last R2T in the list.. We are also careful
+ * to check that the Initiator is not requesting R2Ts for DataOUT
+ * sequences it has already completed.
+ *
+ * Free each R2T in question and adjust values in struct iscsi_cmd
+ * accordingly so iscsit_build_r2ts_for_cmd() do the rest of
+ * the work after the TMR TASK_REASSIGN Response is sent.
+ */
+drop_unacknowledged_r2ts:
+
+ cmd->cmd_flags &= ~ICF_SENT_LAST_R2T;
+ cmd->r2t_sn = tmr_req->exp_data_sn;
+
+ spin_lock_bh(&cmd->r2t_lock);
+ list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list) {
+ /*
+ * Skip up to the R2T Sequence number provided by the
+ * iSCSI TASK_REASSIGN TMR
+ */
+ if (r2t->r2t_sn < tmr_req->exp_data_sn)
+ continue;
+
+ if (r2t->seq_complete) {
+ printk(KERN_ERR "Initiator is requesting R2Ts from"
+ " R2TSN: 0x%08x, but R2TSN: 0x%08x, Offset: %u,"
+ " Length: %u is already complete."
+ " BAD INITIATOR ERL=2 IMPLEMENTATION!\n",
+ tmr_req->exp_data_sn, r2t->r2t_sn,
+ r2t->offset, r2t->xfer_len);
+ spin_unlock_bh(&cmd->r2t_lock);
+ return -1;
+ }
+
+ if (r2t->recovery_r2t) {
+ iscsit_free_r2t(r2t, cmd);
+ continue;
+ }
+
+ /* DataSequenceInOrder=Yes:
+ *
+ * Taking into account the iSCSI implementation requirement of
+ * MaxOutstandingR2T=1 while ErrorRecoveryLevel>0 and
+ * DataSequenceInOrder=Yes, it's safe to subtract the R2Ts
+ * entire transfer length from the commands R2T offset marker.
+ *
+ * DataSequenceInOrder=No:
+ *
+ * We subtract the difference from struct iscsi_seq between the
+ * current offset and original offset from cmd->write_data_done
+ * for account for DataOUT PDUs already received. Then reset
+ * the current offset to the original and zero out the current
+ * burst length, to make sure we re-request the entire DataOUT
+ * sequence.
+ */
+ if (conn->sess->sess_ops->DataSequenceInOrder)
+ cmd->r2t_offset -= r2t->xfer_len;
+ else
+ cmd->seq_send_order--;
+
+ cmd->outstanding_r2ts--;
+ iscsit_free_r2t(r2t, cmd);
+ }
+ spin_unlock_bh(&cmd->r2t_lock);
+
+ return 0;
+}
+
+/*
+ * Performs sanity checks TMR TASK_REASSIGN's ExpDataSN for
+ * a given struct iscsi_cmd.
+ */
+int iscsit_check_task_reassign_expdatasn(
+ struct iscsi_tmr_req *tmr_req,
+ struct iscsi_conn *conn)
+{
+ struct se_tmr_req *se_tmr = tmr_req->se_tmr_req;
+ struct se_cmd *se_cmd = se_tmr->ref_cmd;
+ struct iscsi_cmd *ref_cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd);
+
+ if (ref_cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD)
+ return 0;
+
+ if (se_cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
+ return 0;
+
+ if (ref_cmd->data_direction == DMA_NONE)
+ return 0;
+
+ /*
+ * For READs the TMR TASK_REASSIGNs ExpDataSN contains the next DataSN
+ * of DataIN the Initiator is expecting.
+ *
+ * Also check that the Initiator is not re-requesting DataIN that has
+ * already been acknowledged with a DataAck SNACK.
+ */
+ if (ref_cmd->data_direction == DMA_FROM_DEVICE) {
+ if (tmr_req->exp_data_sn > ref_cmd->data_sn) {
+ printk(KERN_ERR "Received ExpDataSN: 0x%08x for READ"
+ " in TMR TASK_REASSIGN greater than command's"
+ " DataSN: 0x%08x.\n", tmr_req->exp_data_sn,
+ ref_cmd->data_sn);
+ return -1;
+ }
+ if ((ref_cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
+ (tmr_req->exp_data_sn <= ref_cmd->acked_data_sn)) {
+ printk(KERN_ERR "Received ExpDataSN: 0x%08x for READ"
+ " in TMR TASK_REASSIGN for previously"
+ " acknowledged DataIN: 0x%08x,"
+ " protocol error\n", tmr_req->exp_data_sn,
+ ref_cmd->acked_data_sn);
+ return -1;
+ }
+ return iscsit_task_reassign_prepare_read(tmr_req, conn);
+ }
+
+ /*
+ * For WRITEs the TMR TASK_REASSIGNs ExpDataSN contains the next R2TSN
+ * for R2Ts the Initiator is expecting.
+ *
+ * Do the magic in iscsit_task_reassign_prepare_write().
+ */
+ if (ref_cmd->data_direction == DMA_TO_DEVICE) {
+ if (tmr_req->exp_data_sn > ref_cmd->r2t_sn) {
+ printk(KERN_ERR "Received ExpDataSN: 0x%08x for WRITE"
+ " in TMR TASK_REASSIGN greater than command's"
+ " R2TSN: 0x%08x.\n", tmr_req->exp_data_sn,
+ ref_cmd->r2t_sn);
+ return -1;
+ }
+ return iscsit_task_reassign_prepare_write(tmr_req, conn);
+ }
+
+ printk(KERN_ERR "Unknown iSCSI data_direction: 0x%02x\n",
+ ref_cmd->data_direction);
+
+ return -1;
+}
diff --git a/drivers/target/iscsi/iscsi_target_tmr.h b/drivers/target/iscsi/iscsi_target_tmr.h
new file mode 100644
index 0000000..142e992
--- /dev/null
+++ b/drivers/target/iscsi/iscsi_target_tmr.h
@@ -0,0 +1,14 @@
+#ifndef ISCSI_TARGET_TMR_H
+#define ISCSI_TARGET_TMR_H
+
+extern u8 iscsit_tmr_abort_task(struct iscsi_cmd *, unsigned char *);
+extern int iscsit_tmr_task_warm_reset(struct iscsi_conn *, struct iscsi_tmr_req *,
+ unsigned char *);
+extern int iscsit_tmr_task_cold_reset(struct iscsi_conn *, struct iscsi_tmr_req *,
+ unsigned char *);
+extern u8 iscsit_tmr_task_reassign(struct iscsi_cmd *, unsigned char *);
+extern int iscsit_tmr_post_handler(struct iscsi_cmd *, struct iscsi_conn *);
+extern int iscsit_check_task_reassign_expdatasn(struct iscsi_tmr_req *,
+ struct iscsi_conn *);
+
+#endif /* ISCSI_TARGET_TMR_H */
--
1.7.4.1
--
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