iscsi_target_erl0.c 26.8 KB
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/******************************************************************************
 * This file contains error recovery level zero functions used by
 * the iSCSI Target driver.
 *
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 * (c) Copyright 2007-2013 Datera, Inc.
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 *
 * 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.
 ******************************************************************************/

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#include <linux/sched/signal.h>

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#include <scsi/iscsi_proto.h>
#include <target/target_core_base.h>
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#include <target/target_core_fabric.h>
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#include <target/iscsi/iscsi_target_core.h>
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#include "iscsi_target_seq_pdu_list.h"
#include "iscsi_target_erl0.h"
#include "iscsi_target_erl1.h"
#include "iscsi_target_erl2.h"
#include "iscsi_target_util.h"
#include "iscsi_target.h"

/*
 *	Used to set values in struct iscsi_cmd that iscsit_dataout_check_sequence()
 *	checks against to determine a PDU's Offset+Length is within the current
 *	DataOUT Sequence.  Used for DataSequenceInOrder=Yes only.
 */
void iscsit_set_dataout_sequence_values(
	struct iscsi_cmd *cmd)
{
	struct iscsi_conn *conn = cmd->conn;
	/*
	 * Still set seq_start_offset and seq_end_offset for Unsolicited
	 * DataOUT, even if DataSequenceInOrder=No.
	 */
	if (cmd->unsolicited_data) {
		cmd->seq_start_offset = cmd->write_data_done;
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		cmd->seq_end_offset = min(cmd->se_cmd.data_length,
					conn->sess->sess_ops->FirstBurstLength);
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		return;
	}

	if (!conn->sess->sess_ops->DataSequenceInOrder)
		return;

	if (!cmd->seq_start_offset && !cmd->seq_end_offset) {
		cmd->seq_start_offset = cmd->write_data_done;
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		cmd->seq_end_offset = (cmd->se_cmd.data_length >
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			conn->sess->sess_ops->MaxBurstLength) ?
			(cmd->write_data_done +
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			conn->sess->sess_ops->MaxBurstLength) : cmd->se_cmd.data_length;
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	} else {
		cmd->seq_start_offset = cmd->seq_end_offset;
		cmd->seq_end_offset = ((cmd->seq_end_offset +
			conn->sess->sess_ops->MaxBurstLength) >=
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			cmd->se_cmd.data_length) ? cmd->se_cmd.data_length :
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			(cmd->seq_end_offset +
			 conn->sess->sess_ops->MaxBurstLength);
	}
}

static int iscsit_dataout_within_command_recovery_check(
	struct iscsi_cmd *cmd,
	unsigned char *buf)
{
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_data *hdr = (struct iscsi_data *) buf;
	u32 payload_length = ntoh24(hdr->dlength);

	/*
	 * We do the within-command recovery checks here as it is
	 * the first function called in iscsi_check_pre_dataout().
	 * Basically, if we are in within-command recovery and
	 * the PDU does not contain the offset the sequence needs,
	 * dump the payload.
	 *
	 * This only applies to DataPDUInOrder=Yes, for
	 * DataPDUInOrder=No we only re-request the failed PDU
	 * and check that all PDUs in a sequence are received
	 * upon end of sequence.
	 */
	if (conn->sess->sess_ops->DataSequenceInOrder) {
		if ((cmd->cmd_flags & ICF_WITHIN_COMMAND_RECOVERY) &&
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		    cmd->write_data_done != be32_to_cpu(hdr->offset))
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			goto dump;

		cmd->cmd_flags &= ~ICF_WITHIN_COMMAND_RECOVERY;
	} else {
		struct iscsi_seq *seq;

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		seq = iscsit_get_seq_holder(cmd, be32_to_cpu(hdr->offset),
					    payload_length);
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		if (!seq)
			return DATAOUT_CANNOT_RECOVER;
		/*
		 * Set the struct iscsi_seq pointer to reuse later.
		 */
		cmd->seq_ptr = seq;

		if (conn->sess->sess_ops->DataPDUInOrder) {
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			if (seq->status ==
			    DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY &&
			   (seq->offset != be32_to_cpu(hdr->offset) ||
			    seq->data_sn != be32_to_cpu(hdr->datasn)))
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				goto dump;
		} else {
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			if (seq->status ==
			     DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY &&
			    seq->data_sn != be32_to_cpu(hdr->datasn))
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				goto dump;
		}

		if (seq->status == DATAOUT_SEQUENCE_COMPLETE)
			goto dump;

		if (seq->status != DATAOUT_SEQUENCE_COMPLETE)
			seq->status = 0;
	}

	return DATAOUT_NORMAL;

dump:
	pr_err("Dumping DataOUT PDU Offset: %u Length: %d DataSN:"
		" 0x%08x\n", hdr->offset, payload_length, hdr->datasn);
	return iscsit_dump_data_payload(conn, payload_length, 1);
}

static int iscsit_dataout_check_unsolicited_sequence(
	struct iscsi_cmd *cmd,
	unsigned char *buf)
{
	u32 first_burst_len;
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_data *hdr = (struct iscsi_data *) buf;
	u32 payload_length = ntoh24(hdr->dlength);


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	if ((be32_to_cpu(hdr->offset) < cmd->seq_start_offset) ||
	   ((be32_to_cpu(hdr->offset) + payload_length) > cmd->seq_end_offset)) {
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		pr_err("Command ITT: 0x%08x with Offset: %u,"
		" Length: %u outside of Unsolicited Sequence %u:%u while"
		" DataSequenceInOrder=Yes.\n", cmd->init_task_tag,
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		be32_to_cpu(hdr->offset), payload_length, cmd->seq_start_offset,
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			cmd->seq_end_offset);
		return DATAOUT_CANNOT_RECOVER;
	}

	first_burst_len = (cmd->first_burst_len + payload_length);

	if (first_burst_len > conn->sess->sess_ops->FirstBurstLength) {
		pr_err("Total %u bytes exceeds FirstBurstLength: %u"
			" for this Unsolicited DataOut Burst.\n",
			first_burst_len, conn->sess->sess_ops->FirstBurstLength);
		transport_send_check_condition_and_sense(&cmd->se_cmd,
				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
		return DATAOUT_CANNOT_RECOVER;
	}

	/*
	 * Perform various MaxBurstLength and ISCSI_FLAG_CMD_FINAL sanity
	 * checks for the current Unsolicited DataOUT Sequence.
	 */
	if (hdr->flags & ISCSI_FLAG_CMD_FINAL) {
		/*
		 * Ignore ISCSI_FLAG_CMD_FINAL checks while DataPDUInOrder=No, end of
		 * sequence checks are handled in
		 * iscsit_dataout_datapduinorder_no_fbit().
		 */
		if (!conn->sess->sess_ops->DataPDUInOrder)
			goto out;

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		if ((first_burst_len != cmd->se_cmd.data_length) &&
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		    (first_burst_len != conn->sess->sess_ops->FirstBurstLength)) {
			pr_err("Unsolicited non-immediate data"
			" received %u does not equal FirstBurstLength: %u, and"
			" does not equal ExpXferLen %u.\n", first_burst_len,
				conn->sess->sess_ops->FirstBurstLength,
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				cmd->se_cmd.data_length);
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			transport_send_check_condition_and_sense(&cmd->se_cmd,
					TCM_INCORRECT_AMOUNT_OF_DATA, 0);
			return DATAOUT_CANNOT_RECOVER;
		}
	} else {
		if (first_burst_len == conn->sess->sess_ops->FirstBurstLength) {
			pr_err("Command ITT: 0x%08x reached"
			" FirstBurstLength: %u, but ISCSI_FLAG_CMD_FINAL is not set. protocol"
				" error.\n", cmd->init_task_tag,
				conn->sess->sess_ops->FirstBurstLength);
			return DATAOUT_CANNOT_RECOVER;
		}
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		if (first_burst_len == cmd->se_cmd.data_length) {
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			pr_err("Command ITT: 0x%08x reached"
			" ExpXferLen: %u, but ISCSI_FLAG_CMD_FINAL is not set. protocol"
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			" error.\n", cmd->init_task_tag, cmd->se_cmd.data_length);
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			return DATAOUT_CANNOT_RECOVER;
		}
	}

out:
	return DATAOUT_NORMAL;
}

static int iscsit_dataout_check_sequence(
	struct iscsi_cmd *cmd,
	unsigned char *buf)
{
	u32 next_burst_len;
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_seq *seq = NULL;
	struct iscsi_data *hdr = (struct iscsi_data *) buf;
	u32 payload_length = ntoh24(hdr->dlength);

	/*
	 * For DataSequenceInOrder=Yes: Check that the offset and offset+length
	 * is within range as defined by iscsi_set_dataout_sequence_values().
	 *
	 * For DataSequenceInOrder=No: Check that an struct iscsi_seq exists for
	 * offset+length tuple.
	 */
	if (conn->sess->sess_ops->DataSequenceInOrder) {
		/*
		 * Due to possibility of recovery DataOUT sent by the initiator
		 * fullfilling an Recovery R2T, it's best to just dump the
		 * payload here, instead of erroring out.
		 */
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		if ((be32_to_cpu(hdr->offset) < cmd->seq_start_offset) ||
		   ((be32_to_cpu(hdr->offset) + payload_length) > cmd->seq_end_offset)) {
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			pr_err("Command ITT: 0x%08x with Offset: %u,"
			" Length: %u outside of Sequence %u:%u while"
			" DataSequenceInOrder=Yes.\n", cmd->init_task_tag,
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			be32_to_cpu(hdr->offset), payload_length, cmd->seq_start_offset,
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				cmd->seq_end_offset);

			if (iscsit_dump_data_payload(conn, payload_length, 1) < 0)
				return DATAOUT_CANNOT_RECOVER;
			return DATAOUT_WITHIN_COMMAND_RECOVERY;
		}

		next_burst_len = (cmd->next_burst_len + payload_length);
	} else {
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		seq = iscsit_get_seq_holder(cmd, be32_to_cpu(hdr->offset),
					    payload_length);
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		if (!seq)
			return DATAOUT_CANNOT_RECOVER;
		/*
		 * Set the struct iscsi_seq pointer to reuse later.
		 */
		cmd->seq_ptr = seq;

		if (seq->status == DATAOUT_SEQUENCE_COMPLETE) {
			if (iscsit_dump_data_payload(conn, payload_length, 1) < 0)
				return DATAOUT_CANNOT_RECOVER;
			return DATAOUT_WITHIN_COMMAND_RECOVERY;
		}

		next_burst_len = (seq->next_burst_len + payload_length);
	}

	if (next_burst_len > conn->sess->sess_ops->MaxBurstLength) {
		pr_err("Command ITT: 0x%08x, NextBurstLength: %u and"
			" Length: %u exceeds MaxBurstLength: %u. protocol"
			" error.\n", cmd->init_task_tag,
			(next_burst_len - payload_length),
			payload_length, conn->sess->sess_ops->MaxBurstLength);
		return DATAOUT_CANNOT_RECOVER;
	}

	/*
	 * Perform various MaxBurstLength and ISCSI_FLAG_CMD_FINAL sanity
	 * checks for the current DataOUT Sequence.
	 */
	if (hdr->flags & ISCSI_FLAG_CMD_FINAL) {
		/*
		 * Ignore ISCSI_FLAG_CMD_FINAL checks while DataPDUInOrder=No, end of
		 * sequence checks are handled in
		 * iscsit_dataout_datapduinorder_no_fbit().
		 */
		if (!conn->sess->sess_ops->DataPDUInOrder)
			goto out;

		if (conn->sess->sess_ops->DataSequenceInOrder) {
			if ((next_burst_len <
			     conn->sess->sess_ops->MaxBurstLength) &&
			   ((cmd->write_data_done + payload_length) <
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			     cmd->se_cmd.data_length)) {
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				pr_err("Command ITT: 0x%08x set ISCSI_FLAG_CMD_FINAL"
				" before end of DataOUT sequence, protocol"
				" error.\n", cmd->init_task_tag);
				return DATAOUT_CANNOT_RECOVER;
			}
		} else {
			if (next_burst_len < seq->xfer_len) {
				pr_err("Command ITT: 0x%08x set ISCSI_FLAG_CMD_FINAL"
				" before end of DataOUT sequence, protocol"
				" error.\n", cmd->init_task_tag);
				return DATAOUT_CANNOT_RECOVER;
			}
		}
	} else {
		if (conn->sess->sess_ops->DataSequenceInOrder) {
			if (next_burst_len ==
					conn->sess->sess_ops->MaxBurstLength) {
				pr_err("Command ITT: 0x%08x reached"
				" MaxBurstLength: %u, but ISCSI_FLAG_CMD_FINAL is"
				" not set, protocol error.", cmd->init_task_tag,
					conn->sess->sess_ops->MaxBurstLength);
				return DATAOUT_CANNOT_RECOVER;
			}
			if ((cmd->write_data_done + payload_length) ==
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					cmd->se_cmd.data_length) {
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				pr_err("Command ITT: 0x%08x reached"
				" last DataOUT PDU in sequence but ISCSI_FLAG_"
				"CMD_FINAL is not set, protocol error.\n",
					cmd->init_task_tag);
				return DATAOUT_CANNOT_RECOVER;
			}
		} else {
			if (next_burst_len == seq->xfer_len) {
				pr_err("Command ITT: 0x%08x reached"
				" last DataOUT PDU in sequence but ISCSI_FLAG_"
				"CMD_FINAL is not set, protocol error.\n",
					cmd->init_task_tag);
				return DATAOUT_CANNOT_RECOVER;
			}
		}
	}

out:
	return DATAOUT_NORMAL;
}

static int iscsit_dataout_check_datasn(
	struct iscsi_cmd *cmd,
	unsigned char *buf)
{
	u32 data_sn = 0;
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_data *hdr = (struct iscsi_data *) buf;
	u32 payload_length = ntoh24(hdr->dlength);

	/*
	 * Considering the target has no method of re-requesting DataOUT
	 * by DataSN, if we receieve a greater DataSN than expected we
	 * assume the functions for DataPDUInOrder=[Yes,No] below will
	 * handle it.
	 *
	 * If the DataSN is less than expected, dump the payload.
	 */
	if (conn->sess->sess_ops->DataSequenceInOrder)
		data_sn = cmd->data_sn;
	else {
		struct iscsi_seq *seq = cmd->seq_ptr;
		data_sn = seq->data_sn;
	}

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	if (be32_to_cpu(hdr->datasn) > data_sn) {
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		pr_err("Command ITT: 0x%08x, received DataSN: 0x%08x"
			" higher than expected 0x%08x.\n", cmd->init_task_tag,
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				be32_to_cpu(hdr->datasn), data_sn);
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		goto recover;
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	} else if (be32_to_cpu(hdr->datasn) < data_sn) {
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		pr_err("Command ITT: 0x%08x, received DataSN: 0x%08x"
			" lower than expected 0x%08x, discarding payload.\n",
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			cmd->init_task_tag, be32_to_cpu(hdr->datasn), data_sn);
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		goto dump;
	}

	return DATAOUT_NORMAL;

recover:
	if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
		pr_err("Unable to perform within-command recovery"
				" while ERL=0.\n");
		return DATAOUT_CANNOT_RECOVER;
	}
dump:
	if (iscsit_dump_data_payload(conn, payload_length, 1) < 0)
		return DATAOUT_CANNOT_RECOVER;

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	return DATAOUT_WITHIN_COMMAND_RECOVERY;
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}

static int iscsit_dataout_pre_datapduinorder_yes(
	struct iscsi_cmd *cmd,
	unsigned char *buf)
{
	int dump = 0, recovery = 0;
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_data *hdr = (struct iscsi_data *) buf;
	u32 payload_length = ntoh24(hdr->dlength);

	/*
	 * For DataSequenceInOrder=Yes: If the offset is greater than the global
	 * DataPDUInOrder=Yes offset counter in struct iscsi_cmd a protcol error has
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	 * occurred and fail the connection.
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	 *
	 * For DataSequenceInOrder=No: If the offset is greater than the per
	 * sequence DataPDUInOrder=Yes offset counter in struct iscsi_seq a protocol
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	 * error has occurred and fail the connection.
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	 */
	if (conn->sess->sess_ops->DataSequenceInOrder) {
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		if (be32_to_cpu(hdr->offset) != cmd->write_data_done) {
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			pr_err("Command ITT: 0x%08x, received offset"
			" %u different than expected %u.\n", cmd->init_task_tag,
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				be32_to_cpu(hdr->offset), cmd->write_data_done);
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			recovery = 1;
			goto recover;
		}
	} else {
		struct iscsi_seq *seq = cmd->seq_ptr;

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		if (be32_to_cpu(hdr->offset) > seq->offset) {
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			pr_err("Command ITT: 0x%08x, received offset"
			" %u greater than expected %u.\n", cmd->init_task_tag,
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				be32_to_cpu(hdr->offset), seq->offset);
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			recovery = 1;
			goto recover;
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		} else if (be32_to_cpu(hdr->offset) < seq->offset) {
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			pr_err("Command ITT: 0x%08x, received offset"
			" %u less than expected %u, discarding payload.\n",
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				cmd->init_task_tag, be32_to_cpu(hdr->offset),
				seq->offset);
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			dump = 1;
			goto dump;
		}
	}

	return DATAOUT_NORMAL;

recover:
	if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
		pr_err("Unable to perform within-command recovery"
				" while ERL=0.\n");
		return DATAOUT_CANNOT_RECOVER;
	}
dump:
	if (iscsit_dump_data_payload(conn, payload_length, 1) < 0)
		return DATAOUT_CANNOT_RECOVER;

	return (recovery) ? iscsit_recover_dataout_sequence(cmd,
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		be32_to_cpu(hdr->offset), payload_length) :
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	       (dump) ? DATAOUT_WITHIN_COMMAND_RECOVERY : DATAOUT_NORMAL;
}

static int iscsit_dataout_pre_datapduinorder_no(
	struct iscsi_cmd *cmd,
	unsigned char *buf)
{
	struct iscsi_pdu *pdu;
	struct iscsi_data *hdr = (struct iscsi_data *) buf;
	u32 payload_length = ntoh24(hdr->dlength);

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	pdu = iscsit_get_pdu_holder(cmd, be32_to_cpu(hdr->offset),
				    payload_length);
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	if (!pdu)
		return DATAOUT_CANNOT_RECOVER;

	cmd->pdu_ptr = pdu;

	switch (pdu->status) {
	case ISCSI_PDU_NOT_RECEIVED:
	case ISCSI_PDU_CRC_FAILED:
	case ISCSI_PDU_TIMED_OUT:
		break;
	case ISCSI_PDU_RECEIVED_OK:
		pr_err("Command ITT: 0x%08x received already gotten"
			" Offset: %u, Length: %u\n", cmd->init_task_tag,
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				be32_to_cpu(hdr->offset), payload_length);
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		return iscsit_dump_data_payload(cmd->conn, payload_length, 1);
	default:
		return DATAOUT_CANNOT_RECOVER;
	}

	return DATAOUT_NORMAL;
}

static int iscsit_dataout_update_r2t(struct iscsi_cmd *cmd, u32 offset, u32 length)
{
	struct iscsi_r2t *r2t;

	if (cmd->unsolicited_data)
		return 0;

	r2t = iscsit_get_r2t_for_eos(cmd, offset, length);
	if (!r2t)
		return -1;

	spin_lock_bh(&cmd->r2t_lock);
	r2t->seq_complete = 1;
	cmd->outstanding_r2ts--;
	spin_unlock_bh(&cmd->r2t_lock);

	return 0;
}

static int iscsit_dataout_update_datapduinorder_no(
	struct iscsi_cmd *cmd,
	u32 data_sn,
	int f_bit)
{
	int ret = 0;
	struct iscsi_pdu *pdu = cmd->pdu_ptr;

	pdu->data_sn = data_sn;

	switch (pdu->status) {
	case ISCSI_PDU_NOT_RECEIVED:
		pdu->status = ISCSI_PDU_RECEIVED_OK;
		break;
	case ISCSI_PDU_CRC_FAILED:
		pdu->status = ISCSI_PDU_RECEIVED_OK;
		break;
	case ISCSI_PDU_TIMED_OUT:
		pdu->status = ISCSI_PDU_RECEIVED_OK;
		break;
	default:
		return DATAOUT_CANNOT_RECOVER;
	}

	if (f_bit) {
		ret = iscsit_dataout_datapduinorder_no_fbit(cmd, pdu);
		if (ret == DATAOUT_CANNOT_RECOVER)
			return ret;
	}

	return DATAOUT_NORMAL;
}

static int iscsit_dataout_post_crc_passed(
	struct iscsi_cmd *cmd,
	unsigned char *buf)
{
	int ret, send_r2t = 0;
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_seq *seq = NULL;
	struct iscsi_data *hdr = (struct iscsi_data *) buf;
	u32 payload_length = ntoh24(hdr->dlength);

	if (cmd->unsolicited_data) {
		if ((cmd->first_burst_len + payload_length) ==
		     conn->sess->sess_ops->FirstBurstLength) {
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			if (iscsit_dataout_update_r2t(cmd, be32_to_cpu(hdr->offset),
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					payload_length) < 0)
				return DATAOUT_CANNOT_RECOVER;
			send_r2t = 1;
		}

		if (!conn->sess->sess_ops->DataPDUInOrder) {
			ret = iscsit_dataout_update_datapduinorder_no(cmd,
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				be32_to_cpu(hdr->datasn),
				(hdr->flags & ISCSI_FLAG_CMD_FINAL));
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			if (ret == DATAOUT_CANNOT_RECOVER)
				return ret;
		}

		cmd->first_burst_len += payload_length;

		if (conn->sess->sess_ops->DataSequenceInOrder)
			cmd->data_sn++;
		else {
			seq = cmd->seq_ptr;
			seq->data_sn++;
			seq->offset += payload_length;
		}

		if (send_r2t) {
			if (seq)
				seq->status = DATAOUT_SEQUENCE_COMPLETE;
			cmd->first_burst_len = 0;
			cmd->unsolicited_data = 0;
		}
	} else {
		if (conn->sess->sess_ops->DataSequenceInOrder) {
			if ((cmd->next_burst_len + payload_length) ==
			     conn->sess->sess_ops->MaxBurstLength) {
587 588
				if (iscsit_dataout_update_r2t(cmd,
						be32_to_cpu(hdr->offset),
589 590 591 592 593 594 595
						payload_length) < 0)
					return DATAOUT_CANNOT_RECOVER;
				send_r2t = 1;
			}

			if (!conn->sess->sess_ops->DataPDUInOrder) {
				ret = iscsit_dataout_update_datapduinorder_no(
596
						cmd, be32_to_cpu(hdr->datasn),
597 598 599 600 601 602 603 604 605 606 607 608 609 610 611
						(hdr->flags & ISCSI_FLAG_CMD_FINAL));
				if (ret == DATAOUT_CANNOT_RECOVER)
					return ret;
			}

			cmd->next_burst_len += payload_length;
			cmd->data_sn++;

			if (send_r2t)
				cmd->next_burst_len = 0;
		} else {
			seq = cmd->seq_ptr;

			if ((seq->next_burst_len + payload_length) ==
			     seq->xfer_len) {
612 613
				if (iscsit_dataout_update_r2t(cmd,
						be32_to_cpu(hdr->offset),
614 615 616 617 618 619 620
						payload_length) < 0)
					return DATAOUT_CANNOT_RECOVER;
				send_r2t = 1;
			}

			if (!conn->sess->sess_ops->DataPDUInOrder) {
				ret = iscsit_dataout_update_datapduinorder_no(
621
						cmd, be32_to_cpu(hdr->datasn),
622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642
						(hdr->flags & ISCSI_FLAG_CMD_FINAL));
				if (ret == DATAOUT_CANNOT_RECOVER)
					return ret;
			}

			seq->data_sn++;
			seq->offset += payload_length;
			seq->next_burst_len += payload_length;

			if (send_r2t) {
				seq->next_burst_len = 0;
				seq->status = DATAOUT_SEQUENCE_COMPLETE;
			}
		}
	}

	if (send_r2t && conn->sess->sess_ops->DataSequenceInOrder)
		cmd->data_sn = 0;

	cmd->write_data_done += payload_length;

643
	if (cmd->write_data_done == cmd->se_cmd.data_length)
644 645 646 647 648
		return DATAOUT_SEND_TO_TRANSPORT;
	else if (send_r2t)
		return DATAOUT_SEND_R2T;
	else
		return DATAOUT_NORMAL;
649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680
}

static int iscsit_dataout_post_crc_failed(
	struct iscsi_cmd *cmd,
	unsigned char *buf)
{
	struct iscsi_conn *conn = cmd->conn;
	struct iscsi_pdu *pdu;
	struct iscsi_data *hdr = (struct iscsi_data *) buf;
	u32 payload_length = ntoh24(hdr->dlength);

	if (conn->sess->sess_ops->DataPDUInOrder)
		goto recover;
	/*
	 * The rest of this function is only called when DataPDUInOrder=No.
	 */
	pdu = cmd->pdu_ptr;

	switch (pdu->status) {
	case ISCSI_PDU_NOT_RECEIVED:
		pdu->status = ISCSI_PDU_CRC_FAILED;
		break;
	case ISCSI_PDU_CRC_FAILED:
		break;
	case ISCSI_PDU_TIMED_OUT:
		pdu->status = ISCSI_PDU_CRC_FAILED;
		break;
	default:
		return DATAOUT_CANNOT_RECOVER;
	}

recover:
681 682
	return iscsit_recover_dataout_sequence(cmd, be32_to_cpu(hdr->offset),
						payload_length);
683 684 685 686 687 688
}

/*
 *	Called from iscsit_handle_data_out() before DataOUT Payload is received
 *	and CRC computed.
 */
689
int iscsit_check_pre_dataout(
690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741
	struct iscsi_cmd *cmd,
	unsigned char *buf)
{
	int ret;
	struct iscsi_conn *conn = cmd->conn;

	ret = iscsit_dataout_within_command_recovery_check(cmd, buf);
	if ((ret == DATAOUT_WITHIN_COMMAND_RECOVERY) ||
	    (ret == DATAOUT_CANNOT_RECOVER))
		return ret;

	ret = iscsit_dataout_check_datasn(cmd, buf);
	if ((ret == DATAOUT_WITHIN_COMMAND_RECOVERY) ||
	    (ret == DATAOUT_CANNOT_RECOVER))
		return ret;

	if (cmd->unsolicited_data) {
		ret = iscsit_dataout_check_unsolicited_sequence(cmd, buf);
		if ((ret == DATAOUT_WITHIN_COMMAND_RECOVERY) ||
		    (ret == DATAOUT_CANNOT_RECOVER))
			return ret;
	} else {
		ret = iscsit_dataout_check_sequence(cmd, buf);
		if ((ret == DATAOUT_WITHIN_COMMAND_RECOVERY) ||
		    (ret == DATAOUT_CANNOT_RECOVER))
			return ret;
	}

	return (conn->sess->sess_ops->DataPDUInOrder) ?
		iscsit_dataout_pre_datapduinorder_yes(cmd, buf) :
		iscsit_dataout_pre_datapduinorder_no(cmd, buf);
}

/*
 *	Called from iscsit_handle_data_out() after DataOUT Payload is received
 *	and CRC computed.
 */
int iscsit_check_post_dataout(
	struct iscsi_cmd *cmd,
	unsigned char *buf,
	u8 data_crc_failed)
{
	struct iscsi_conn *conn = cmd->conn;

	cmd->dataout_timeout_retries = 0;

	if (!data_crc_failed)
		return iscsit_dataout_post_crc_passed(cmd, buf);
	else {
		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
			pr_err("Unable to recover from DataOUT CRC"
				" failure while ERL=0, closing session.\n");
742 743
			iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR,
					  buf);
744 745 746
			return DATAOUT_CANNOT_RECOVER;
		}

747
		iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR, buf);
748 749 750 751
		return iscsit_dataout_post_crc_failed(cmd, buf);
	}
}

752
void iscsit_handle_time2retain_timeout(struct timer_list *t)
753
{
754
	struct iscsi_session *sess = from_timer(sess, t, time2retain_timer);
755
	struct iscsi_portal_group *tpg = sess->tpg;
756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782
	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;

	spin_lock_bh(&se_tpg->session_lock);
	if (sess->time2retain_timer_flags & ISCSI_TF_STOP) {
		spin_unlock_bh(&se_tpg->session_lock);
		return;
	}
	if (atomic_read(&sess->session_reinstatement)) {
		pr_err("Exiting Time2Retain handler because"
				" session_reinstatement=1\n");
		spin_unlock_bh(&se_tpg->session_lock);
		return;
	}
	sess->time2retain_timer_flags |= ISCSI_TF_EXPIRED;

	pr_err("Time2Retain timer expired for SID: %u, cleaning up"
			" iSCSI session.\n", sess->sid);
	{
	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;

	if (tiqn) {
		spin_lock(&tiqn->sess_err_stats.lock);
		strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
			(void *)sess->sess_ops->InitiatorName);
		tiqn->sess_err_stats.last_sess_failure_type =
				ISCSI_SESS_ERR_CXN_TIMEOUT;
		tiqn->sess_err_stats.cxn_timeout_errors++;
783
		atomic_long_inc(&sess->conn_timeout_errors);
784 785 786 787 788
		spin_unlock(&tiqn->sess_err_stats.lock);
	}
	}

	spin_unlock_bh(&se_tpg->session_lock);
789
	iscsit_close_session(sess);
790 791
}

792
void iscsit_start_time2retain_handler(struct iscsi_session *sess)
793 794 795
{
	int tpg_active;
	/*
796
	 * Only start Time2Retain timer when the associated TPG is still in
797 798
	 * an ACTIVE (eg: not disabled or shutdown) state.
	 */
799 800 801
	spin_lock(&sess->tpg->tpg_state_lock);
	tpg_active = (sess->tpg->tpg_state == TPG_STATE_ACTIVE);
	spin_unlock(&sess->tpg->tpg_state_lock);
802 803 804 805 806 807 808 809 810 811 812 813

	if (!tpg_active)
		return;

	if (sess->time2retain_timer_flags & ISCSI_TF_RUNNING)
		return;

	pr_debug("Starting Time2Retain timer for %u seconds on"
		" SID: %u\n", sess->sess_ops->DefaultTime2Retain, sess->sid);

	sess->time2retain_timer_flags &= ~ISCSI_TF_STOP;
	sess->time2retain_timer_flags |= ISCSI_TF_RUNNING;
814 815
	mod_timer(&sess->time2retain_timer,
		  jiffies + sess->sess_ops->DefaultTime2Retain * HZ);
816 817 818 819 820
}

/*
 *	Called with spin_lock_bh(&struct se_portal_group->session_lock) held
 */
821
int iscsit_stop_time2retain_timer(struct iscsi_session *sess)
822
{
823
	struct iscsi_portal_group *tpg = sess->tpg;
824 825 826 827 828 829 830 831 832
	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;

	if (sess->time2retain_timer_flags & ISCSI_TF_EXPIRED)
		return -1;

	if (!(sess->time2retain_timer_flags & ISCSI_TF_RUNNING))
		return 0;

	sess->time2retain_timer_flags |= ISCSI_TF_STOP;
833
	spin_unlock(&se_tpg->session_lock);
834 835 836

	del_timer_sync(&sess->time2retain_timer);

837
	spin_lock(&se_tpg->session_lock);
838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857
	sess->time2retain_timer_flags &= ~ISCSI_TF_RUNNING;
	pr_debug("Stopped Time2Retain Timer for SID: %u\n",
			sess->sid);
	return 0;
}

void iscsit_connection_reinstatement_rcfr(struct iscsi_conn *conn)
{
	spin_lock_bh(&conn->state_lock);
	if (atomic_read(&conn->connection_exit)) {
		spin_unlock_bh(&conn->state_lock);
		goto sleep;
	}

	if (atomic_read(&conn->transport_failed)) {
		spin_unlock_bh(&conn->state_lock);
		goto sleep;
	}
	spin_unlock_bh(&conn->state_lock);

858 859 860 861
	if (conn->tx_thread && conn->tx_thread_active)
		send_sig(SIGINT, conn->tx_thread, 1);
	if (conn->rx_thread && conn->rx_thread_active)
		send_sig(SIGINT, conn->rx_thread, 1);
862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885

sleep:
	wait_for_completion(&conn->conn_wait_rcfr_comp);
	complete(&conn->conn_post_wait_comp);
}

void iscsit_cause_connection_reinstatement(struct iscsi_conn *conn, int sleep)
{
	spin_lock_bh(&conn->state_lock);
	if (atomic_read(&conn->connection_exit)) {
		spin_unlock_bh(&conn->state_lock);
		return;
	}

	if (atomic_read(&conn->transport_failed)) {
		spin_unlock_bh(&conn->state_lock);
		return;
	}

	if (atomic_read(&conn->connection_reinstatement)) {
		spin_unlock_bh(&conn->state_lock);
		return;
	}

886 887 888 889
	if (conn->tx_thread && conn->tx_thread_active)
		send_sig(SIGINT, conn->tx_thread, 1);
	if (conn->rx_thread && conn->rx_thread_active)
		send_sig(SIGINT, conn->rx_thread, 1);
890 891 892 893 894 895 896 897 898 899 900 901 902

	atomic_set(&conn->connection_reinstatement, 1);
	if (!sleep) {
		spin_unlock_bh(&conn->state_lock);
		return;
	}

	atomic_set(&conn->sleep_on_conn_wait_comp, 1);
	spin_unlock_bh(&conn->state_lock);

	wait_for_completion(&conn->conn_wait_comp);
	complete(&conn->conn_post_wait_comp);
}
903
EXPORT_SYMBOL(iscsit_cause_connection_reinstatement);
904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928

void iscsit_fall_back_to_erl0(struct iscsi_session *sess)
{
	pr_debug("Falling back to ErrorRecoveryLevel=0 for SID:"
			" %u\n", sess->sid);

	atomic_set(&sess->session_fall_back_to_erl0, 1);
}

static void iscsit_handle_connection_cleanup(struct iscsi_conn *conn)
{
	struct iscsi_session *sess = conn->sess;

	if ((sess->sess_ops->ErrorRecoveryLevel == 2) &&
	    !atomic_read(&sess->session_reinstatement) &&
	    !atomic_read(&sess->session_fall_back_to_erl0))
		iscsit_connection_recovery_transport_reset(conn);
	else {
		pr_debug("Performing cleanup for failed iSCSI"
			" Connection ID: %hu from %s\n", conn->cid,
			sess->sess_ops->InitiatorName);
		iscsit_close_connection(conn);
	}
}

929
void iscsit_take_action_for_connection_exit(struct iscsi_conn *conn, bool *conn_freed)
930
{
931 932
	*conn_freed = false;

933 934 935 936 937 938 939 940 941
	spin_lock_bh(&conn->state_lock);
	if (atomic_read(&conn->connection_exit)) {
		spin_unlock_bh(&conn->state_lock);
		return;
	}
	atomic_set(&conn->connection_exit, 1);

	if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT) {
		spin_unlock_bh(&conn->state_lock);
942
		iscsit_close_connection(conn);
943
		*conn_freed = true;
944 945 946 947 948 949 950 951 952 953 954 955 956
		return;
	}

	if (conn->conn_state == TARG_CONN_STATE_CLEANUP_WAIT) {
		spin_unlock_bh(&conn->state_lock);
		return;
	}

	pr_debug("Moving to TARG_CONN_STATE_CLEANUP_WAIT.\n");
	conn->conn_state = TARG_CONN_STATE_CLEANUP_WAIT;
	spin_unlock_bh(&conn->state_lock);

	iscsit_handle_connection_cleanup(conn);
957
	*conn_freed = true;
958
}