/*******************************************************************************
* This file contains error recovery level one used by the iSCSI Target driver.
*
* \u00a9 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 <linux/list.h>
#include <scsi/iscsi_proto.h>
#include <target/target_core_base.h>
#include <target/target_core_transport.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_tpg.h"
#include "iscsi_target_util.h"
#include "iscsi_target_erl0.h"
#include "iscsi_target_erl1.h"
#include "iscsi_target_erl2.h"
#include "iscsi_target.h"
#define OFFLOAD_BUF_SIZE 32768
/*
* Used to dump excess datain payload for certain error recovery
* situations. Receive in OFFLOAD_BUF_SIZE max of datain per rx_data().
*
* dump_padding_digest denotes if padding and data digests need
* to be dumped.
*/
int iscsit_dump_data_payload(
struct iscsi_conn *conn,
u32 buf_len,
int dump_padding_digest)
{
char *buf, pad_bytes[4];
int ret = DATAOUT_WITHIN_COMMAND_RECOVERY, rx_got;
u32 length, padding, offset = 0, size;
struct kvec iov;
length = (buf_len > OFFLOAD_BUF_SIZE) ? OFFLOAD_BUF_SIZE : buf_len;
buf = kzalloc(length, GFP_ATOMIC);
if (!buf) {
pr_err("Unable to allocate %u bytes for offload"
" buffer.\n", length);
return -1;
}
memset(&iov, 0, sizeof(struct kvec));
while (offset < buf_len) {
size = ((offset + length) > buf_len) ?
(buf_len - offset) : length;
iov.iov_len = size;
iov.iov_base = buf;
rx_got = rx_data(conn, &iov, 1, size);
if (rx_got != size) {
ret = DATAOUT_CANNOT_RECOVER;
goto out;
}
offset += size;
}
if (!dump_padding_digest)
goto out;
padding = ((-buf_len) & 3);
if (padding != 0) {
iov.iov_len = padding;
iov.iov_base = pad_bytes;
rx_got = rx_data(conn, &iov, 1, padding);
if (rx_got != padding) {
ret = DATAOUT_CANNOT_RECOVER;
goto out;
}
}
if (conn->conn_ops->DataDigest) {
u32 data_crc;
iov.iov_len = ISCSI_CRC_LEN;
iov.iov_base = &data_crc;
rx_got = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
if (rx_got != ISCSI_CRC_LEN) {
ret = DATAOUT_CANNOT_RECOVER;
goto out;
}
}
out:
kfree(buf);
return ret;
}
/*
* Used for retransmitting R2Ts from a R2T SNACK request.
*/
static int iscsit_send_recovery_r2t_for_snack(
struct iscsi_cmd *cmd,
struct iscsi_r2t *r2t)
{
/*
* If the struct iscsi_r2t has not been sent yet, we can safely
* ignore retransmission
* of the R2TSN in question.
*/
spin_lock_bh(&cmd->r2t_lock);
if (!r2t->sent_r2t) {
spin_unlock_bh(&cmd->r2t_lock);
return 0;
}
r2t->sent_r2t = 0;
spin_unlock_bh(&cmd->r2t_lock);
iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
return 0;
}
static int iscsit_handle_r2t_snack(
struct iscsi_cmd *cmd,
unsigned char *buf,
u32 begrun,
u32 runlength)
{
u32 last_r2tsn;
struct iscsi_r2t *r2t;
/*
* Make sure the initiator is not requesting retransmission
* of R2TSNs already acknowledged by a TMR TASK_REASSIGN.
*/
if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
(begrun <= cmd->acked_data_sn)) {
pr_err("ITT: 0x%08x, R2T SNACK requesting"
" retransmission of R2TSN: 0x%08x to 0x%08x but already"
" acked to R2TSN: 0x%08x by TMR TASK_REASSIGN,"
" protocol error.\n", cmd->init_task_tag, begrun,
(begrun + runlength), cmd->acked_data_sn);
return iscsit_add_reject_from_cmd(
ISCSI_REASON_PROTOCOL_ERROR,
1, 0, buf, cmd);
}
if (runlength) {
if ((begrun + runlength) > cmd->r2t_sn) {
pr_err("Command ITT: 0x%08x received R2T SNACK"
" with BegRun: 0x%08x, RunLength: 0x%08x, exceeds"
" current R2TSN: 0x%08x, protocol error.\n",
cmd->init_task_tag, begrun, runlength, cmd->r2t_sn);
return iscsit_add_reject_from_cmd(
ISCSI_REASON_BOOKMARK_INVALID, 1, 0, buf, cmd);
}
last_r2tsn = (begrun + runlength);
} else
last_r2tsn = cmd->r2t_sn;
while (begrun < last_r2tsn) {
r2t = iscsit_get_holder_for_r2tsn(cmd, begrun);
if (!r2t)
return -1;
if (iscsit_send_recovery_r2t_for_snack(cmd, r2t) < 0)
return -1;
begrun++;
}
return 0;
}
/*
* Generates Offsets and NextBurstLength based on Begrun and Runlength
* carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
*
* For DataSequenceInOrder=Yes and DataPDUInOrder=[Yes,No] only.
*
* FIXME: How is this handled for a RData SNACK?
*/
int iscsit_create_recovery_datain_values_datasequenceinorder_yes(
struct iscsi_cmd *cmd,
struct iscsi_datain_req *dr)
{
u32 data_sn = 0, data_sn_count = 0;
u32 pdu_start = 0, seq_no = 0;
u32 begrun = dr->begrun;
struct iscsi_conn *conn = cmd->conn;
while (begrun > data_sn++) {
data_sn_count++;
if ((dr->next_burst_len +
conn->conn_ops->MaxRecvDataSegmentLength) <
conn->sess->sess_ops->MaxBurstLength) {
dr->read_data_done +=
conn->conn_ops->MaxRecvDataSegmentLength;
dr->next_burst_len +=
conn->conn_ops->MaxRecvDataSegmentLength;
} else {
dr->read_data_done +=
(conn->sess->sess_ops->MaxBurstLength -
dr->next_burst_len);
dr->next_burst_len = 0;
pdu_start += data_sn_count;
data_sn_count = 0;
seq_no++;
}
}
if (!conn->sess->sess_ops->DataPDUInOrder) {
cmd->seq_no = seq_no;
cmd->pdu_start = pdu_start;
cmd->pdu_send_order = data_sn_count;
}
return 0;
}
/*
* Generates Offsets and NextBurstLength based on Begrun and Runlength
* carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
*
* For DataSequenceInOrder=No and DataPDUInOrder=[Yes,No] only.
*
* FIXME: How is this handled for a RData SNACK?
*/
int iscsit_create_recovery_datain_values_datasequenceinorder_no(
struct iscsi_cmd *cmd,
struct iscsi_datain_req *dr)
{
int found_seq = 0, i;
u32 data_sn, read_data_done = 0, seq_send_order = 0;
u32 begrun = dr->begrun;
u32 runlength = dr->runlength;
struct iscsi_conn *conn = cmd->conn;
struct iscsi_seq *first_seq = NULL, *seq = NULL;
if (!cmd->seq_list) {
pr_err("struct iscsi_cmd->seq_list is NULL!\n");
return -1;
}
/*
* Calculate read_data_done for all sequences containing a
* first_datasn and last_datasn less than the BegRun.
*
* Locate the struct iscsi_seq the BegRun lies within and calculate
* NextBurstLenghth up to the DataSN based on MaxRecvDataSegmentLength.
*
* Also use struct iscsi_seq->seq_send_order to determine where to start.
*/
for (i = 0; i < cmd->seq_count; i++) {
seq = &cmd->seq_list[i];
if (!seq->seq_send_order)
first_seq = seq;
/*
* No data has been transferred for this DataIN sequence, so the
* seq->first_datasn and seq->last_datasn have not been set.
*/
if (!seq->sent) {
#if 0
pr_err("Ignoring non-sent sequence 0x%08x ->"
" 0x%08x\n\n", seq->first_datasn,
seq->last_datasn);
#endif
continue;
}
/*
* This DataIN sequence is precedes the received BegRun, add the
* total xfer_len of the sequence to read_data_done and reset
* seq->pdu_send_order.
*/
if ((seq->first_datasn < begrun) &&
(seq->last_datasn < begrun)) {
#if 0
pr_err("Pre BegRun sequence 0x%08x ->"
" 0x%08x\n", seq->first_datasn,
seq->last_datasn);
#endif
read_data_done += cmd->seq_list[i].xfer_len;
seq->next_burst_len = seq->pdu_send_order = 0;
continue;
}
/*
* The BegRun lies within this DataIN sequence.
*/
if ((seq->first_datasn <= begrun) &&
(seq->last_datasn >= begrun)) {
#if 0
pr_err("Found sequence begrun: 0x%08x in"
" 0x%08x -> 0x%08x\n", begrun,
seq->first_datasn, seq->last_datasn);
#endif
seq_send_order = seq->seq_send_order;
data_sn = seq->first_datasn;
seq->next_burst_len = seq->pdu_send_order = 0;
found_seq = 1;
/*
* For DataPDUInOrder=Yes, while the first DataSN of
* the sequence is less than the received BegRun, add
* the MaxRecvDataSegmentLength to read_data_done and
* to the sequence's next_burst_len;
*
* For DataPDUInOrder=No, while the first DataSN of the
* sequence is less than the received BegRun, find the
* struct iscsi_pdu of the DataSN in question and add the
* MaxRecvDataSegmentLength to read_data_done and to the
* sequence's next_burst_len;
*/
if (conn->sess->sess_ops->DataPDUInOrder) {
while (data_sn < begrun) {
seq->pdu_send_order++;
read_data_done +=
conn->conn_ops->MaxRecvDataSegmentLength;
seq->next_burst_len +=
conn->conn_ops->MaxRecvDataSegmentLength;
data_sn++;
}
} else {
int j;
struct iscsi_pdu *pdu;
while (data_sn < begrun) {
seq->pdu_send_order++;
for (j = 0; j < seq->pdu_count; j++) {
pdu = &cmd->pdu_list[
seq->pdu_start + j];
if (pdu->data_sn == data_sn) {
read_data_done +=
pdu->length;
seq->next_burst_len +=
pdu->length;
}
}
data_sn++;
}
}
continue;
}
/*
* This DataIN sequence is larger than the received BegRun,
* reset seq->pdu_send_order and continue.
*/
if ((seq->first_datasn > begrun) ||
(seq->last_datasn > begrun)) {
#if 0
pr_err("Post BegRun sequence 0x%08x -> 0x%08x\n",
seq->first_datasn, seq->last_datasn);
#endif
seq->next_burst_len = seq->pdu_send_order = 0;
continue;
}
}
if (!found_seq) {
if (!begrun) {
if (!first_seq) {
pr_err("ITT: 0x%08x, Begrun: 0x%08x"
" but first_seq is NULL\n",
cmd->init_task_tag, begrun);
return -1;
}
seq_send_order = first_seq->seq_send_order;
seq->next_burst_len = seq->pdu_send_order = 0;
goto done;
}
pr_err("Unable to locate struct iscsi_seq for ITT: 0x%08x,"
" BegRun: 0x%08x, RunLength: 0x%08x while"
" DataSequenceInOrder=No and DataPDUInOrder=%s.\n",
cmd->init_task_tag, begrun, runlength,
(conn->sess->sess_ops->DataPDUInOrder) ? "Yes" : "No");
return -1;
}
done:
dr->read_data_done = read_data_done;
dr->seq_send_order = seq_send_order;
return 0;
}
static int iscsit_handle_recovery_datain(
struct iscsi_cmd *cmd,
unsigned char *buf,
u32 begrun,
u32 runlength)
{
struct iscsi_conn *conn = cmd->conn;
struct iscsi_datain_req *dr;
struct se_cmd *se_cmd = &cmd->se_cmd;
if (!atomic_read(&se_cmd->t_transport_complete)) {
pr_err("Ignoring ITT: 0x%08x Data SNACK\n",
cmd->init_task_tag);
return 0;
}
/*
* Make sure the initiator is not requesting retransmission
* of DataSNs already acknowledged by a Data ACK SNACK.
*/
if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
(begrun <= cmd->acked_data_sn)) {
pr_err("ITT: 0x%08x, Data SNACK requesting"
" retransmission of DataSN: 0x%08x to 0x%08x but"
" already acked to DataSN: 0x%08x by Data ACK SNACK,"
" protocol error.\n", cmd->init_task_tag, begrun,
(begrun + runlength), cmd->acked_data_sn);
return iscsit_add_reject_from_cmd(ISCSI_REASON_PROTOCOL_ERROR,
1, 0, buf, cmd);
}
/*
* Make sure BegRun and RunLength in the Data SNACK are sane.
* Note: (cmd->data_sn - 1) will carry the maximum DataSN sent.
*/
if ((begrun + runlength) > (cmd->data_sn - 1)) {
pr_err("Initiator requesting BegRun: 0x%08x, RunLength"
": 0x%08x greater than maximum DataSN: 0x%08x.\n",
begrun, runlength, (cmd->data_sn - 1));
return iscsit_add_reject_from_cmd(ISCSI_REASON_BOOKMARK_INVALID,
1, 0, buf, cmd);
}
dr = iscsit_allocate_datain_req();
if (!dr)
return iscsit_add_reject_from_cmd(ISCSI_REASON_BOOKMARK_NO_RESOURCES,
1, 0, buf, cmd);
dr->data_sn = dr->begrun = begrun;
dr->runlength = runlength;
dr->generate_recovery_values = 1;
dr->recovery = DATAIN_WITHIN_COMMAND_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;
}
int iscsit_handle_recovery_datain_or_r2t(
struct iscsi_conn *conn,
unsigned char *buf,
u32 init_task_tag,
u32 targ_xfer_tag,
u32 begrun,
u32 runlength)
{
struct iscsi_cmd *cmd;
cmd = iscsit_find_cmd_from_itt(conn, init_task_tag);
if (!cmd)
return 0;
/*
* FIXME: This will not work for bidi commands.
*/
switch (cmd->data_direction) {
case DMA_TO_DEVICE:
return iscsit_handle_r2t_snack(cmd, buf, begrun, runlength);
case DMA_FROM_DEVICE:
return iscsit_handle_recovery_datain(cmd, buf, begrun,
runlength);
default:
pr_err("Unknown cmd->data_direction: 0x%02x\n",
cmd->data_direction);
return -1;
}
return 0;
}
/* #warning FIXME: Status SNACK needs to be dependent on OPCODE!!! */
int iscsit_handle_status_snack(
struct iscsi_conn *conn,
u32 init_task_tag,
u32 targ_xfer_tag,
u32 begrun,
u32 runlength)
{
struct iscsi_cmd *cmd = NULL;
u32 last_statsn;
int found_cmd;
if (conn->exp_statsn > begrun) {
pr_err("Got Status SNACK Begrun: 0x%08x, RunLength:"
" 0x%08x but already got ExpStatSN: 0x%08x on CID:"
" %hu.\n", begrun, runlength, conn->exp_statsn,
conn->cid);
return 0;
}
last_statsn = (!runlength) ? conn->stat_sn : (begrun + runlength);
while (begrun < last_statsn) {
found_cmd = 0;
spin_lock_bh(&conn->cmd_lock);
list_for_each_entry(cmd, &conn->conn_cmd_list, i_list) {
if (cmd->stat_sn == begrun) {
found_cmd = 1;
break;
}
}
spin_unlock_bh(&conn->cmd_lock);
if (!found_cmd) {
pr_err("Unable to find StatSN: 0x%08x for"
" a Status SNACK, assuming this was a"
" protactic SNACK for an untransmitted"
" StatSN, ignoring.\n", begrun);
begrun++;
continue;
}
spin_lock_bh(&cmd->istate_lock);
if (cmd->i_state == ISTATE_SEND_DATAIN) {
spin_unlock_bh(&cmd->istate_lock);
pr_err("Ignoring Status SNACK for BegRun:"
" 0x%08x, RunLength: 0x%08x, assuming this was"
" a protactic SNACK for an untransmitted"
" StatSN\n", begrun, runlength);
begrun++;
continue;
}
spin_unlock_bh(&cmd->istate_lock);
cmd->i_state = ISTATE_SEND_STATUS_RECOVERY;
iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
begrun++;
}
return 0;
}
int iscsit_handle_data_ack(
struct iscsi_conn *conn,
u32 targ_xfer_tag,
u32 begrun,
u32 runlength)
{
struct iscsi_cmd *cmd = NULL;
cmd = iscsit_find_cmd_from_ttt(conn, targ_xfer_tag);
if (!cmd) {
pr_err("Data ACK SNACK for TTT: 0x%08x is"
" invalid.\n", targ_xfer_tag);
return -1;
}
if (begrun <= cmd->acked_data_sn) {
pr_err("ITT: 0x%08x Data ACK SNACK BegRUN: 0x%08x is"
" less than the already acked DataSN: 0x%08x.\n",
cmd->init_task_tag, begrun, cmd->acked_data_sn);
return -1;
}
/*
* For Data ACK SNACK, BegRun is the next expected DataSN.
* (see iSCSI v19: 10.16.6)
*/
cmd->cmd_flags |= ICF_GOT_DATACK_SNACK;
cmd->acked_data_sn = (begrun - 1);
pr_debug("Received Data ACK SNACK for ITT: 0x%08x,"
" updated acked DataSN to 0x%08x.\n",
cmd->init_task_tag, cmd->acked_data_sn);
return 0;
}
static int iscsit_send_recovery_r2t(
struct iscsi_cmd *cmd,
u32 offset,
u32 xfer_len)
{
int ret;
spin_lock_bh(&cmd->r2t_lock);
ret = iscsit_add_r2t_to_list(cmd, offset, xfer_len, 1, 0);
spin_unlock_bh(&cmd->r2t_lock);
return ret;
}
int iscsit_dataout_datapduinorder_no_fbit(
struct iscsi_cmd *cmd,
struct iscsi_pdu *pdu)
{
int i, send_recovery_r2t = 0, recovery = 0;
u32 length = 0, offset = 0, pdu_count = 0, xfer_len = 0;
struct iscsi_conn *conn = cmd->conn;
struct iscsi_pdu *first_pdu = NULL;
/*
* Get an struct iscsi_pdu pointer to the first PDU, and total PDU count
* of the DataOUT sequence.
*/
if (conn->sess->sess_ops->DataSequenceInOrder) {
for (i = 0; i < cmd->pdu_count; i++) {
if (cmd->pdu_list[i].seq_no == pdu->seq_no) {
if (!first_pdu)
first_pdu = &cmd->pdu_list[i];
xfer_len += cmd->pdu_list[i].length;
pdu_count++;
} else if (pdu_count)
break;
}
} else {
struct iscsi_seq *seq = cmd->seq_ptr;
first_pdu = &cmd->pdu_list[seq->pdu_start];
pdu_count = seq->pdu_count;
}
if (!first_pdu || !pdu_count)
return DATAOUT_CANNOT_RECOVER;
/*
* Loop through the ending DataOUT Sequence checking each struct iscsi_pdu.
* The following ugly logic does batching of not received PDUs.
*/
for (i = 0; i < pdu_count; i++) {
if (first_pdu[i].status == ISCSI_PDU_RECEIVED_OK) {
if (!send_recovery_r2t)
continue;
if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
return DATAOUT_CANNOT_RECOVER;
send_recovery_r2t = length = offset = 0;
continue;
}
/*
* Set recovery = 1 for any missing, CRC failed, or timed
* out PDUs to let the DataOUT logic know that this sequence
* has not been completed yet.
*
* Also, only send a Recovery R2T for ISCSI_PDU_NOT_RECEIVED.
* We assume if the PDU either failed CRC or timed out
* that a Recovery R2T has already been sent.
*/
recovery = 1;
if (first_pdu[i].status != ISCSI_PDU_NOT_RECEIVED)
continue;
if (!offset)
offset = first_pdu[i].offset;
length += first_pdu[i].length;
send_recovery_r2t = 1;
}
if (send_recovery_r2t)
if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
return DATAOUT_CANNOT_RECOVER;
return (!recovery) ? DATAOUT_NORMAL : DATAOUT_WITHIN_COMMAND_RECOVERY;
}
static int iscsit_recalculate_dataout_values(
struct iscsi_cmd *cmd,
u32 pdu_offset,
u32 pdu_length,
u32 *r2t_offset,
u32 *r2t_length)
{
int i;
struct iscsi_conn *conn = cmd->conn;
struct iscsi_pdu *pdu = NULL;
if (conn->sess->sess_ops->DataSequenceInOrder) {
cmd->data_sn = 0;
if (conn->sess->sess_ops->DataPDUInOrder) {
*r2t_offset = cmd->write_data_done;
*r2t_length = (cmd->seq_end_offset -
cmd->write_data_done);
return 0;
}
*r2t_offset = cmd->seq_start_offset;
*r2t_length = (cmd->seq_end_offset - cmd->seq_start_offset);
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)) {
if (!cmd->unsolicited_data)
cmd->next_burst_len -= pdu->length;
else
cmd->first_burst_len -= pdu->length;
cmd->write_data_done -= pdu->length;
pdu->status = ISCSI_PDU_NOT_RECEIVED;
}
}
} else {
struct iscsi_seq *seq = NULL;
seq = iscsit_get_seq_holder(cmd, pdu_offset, pdu_length);
if (!seq)
return -1;
*r2t_offset = seq->orig_offset;
*r2t_length = seq->xfer_len;
cmd->write_data_done -= (seq->offset - seq->orig_offset);
if (cmd->immediate_data)
cmd->first_burst_len = cmd->write_data_done;
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)
return 0;
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;
}
}
return 0;
}
int iscsit_recover_dataout_sequence(
struct iscsi_cmd *cmd,
u32 pdu_offset,
u32 pdu_length)
{
u32 r2t_length = 0, r2t_offset = 0;
spin_lock_bh(&cmd->istate_lock);
cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
spin_unlock_bh(&cmd->istate_lock);
if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
&r2t_offset, &r2t_length) < 0)
return DATAOUT_CANNOT_RECOVER;
iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length);
return DATAOUT_WITHIN_COMMAND_RECOVERY;
}
static struct iscsi_ooo_cmdsn *iscsit_allocate_ooo_cmdsn(void)
{
struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL;
ooo_cmdsn = kmem_cache_zalloc(lio_ooo_cache, GFP_ATOMIC);
if (!ooo_cmdsn) {
pr_err("Unable to allocate memory for"
" struct iscsi_ooo_cmdsn.\n");
return NULL;
}
INIT_LIST_HEAD(&ooo_cmdsn->ooo_list);
return ooo_cmdsn;
}
/*
* Called with sess->cmdsn_mutex held.
*/
static int iscsit_attach_ooo_cmdsn(
struct iscsi_session *sess,
struct iscsi_ooo_cmdsn *ooo_cmdsn)
{
struct iscsi_ooo_cmdsn *ooo_tail, *ooo_tmp;
/*
* We attach the struct iscsi_ooo_cmdsn entry to the out of order
* list in increasing CmdSN order.
* This allows iscsi_execute_ooo_cmdsns() to detect any
* additional CmdSN holes while performing delayed execution.
*/
if (list_empty(&sess->sess_ooo_cmdsn_list))
list_add_tail(&ooo_cmdsn->ooo_list,
&sess->sess_ooo_cmdsn_list);
else {
ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
typeof(*ooo_tail), ooo_list);
/*
* CmdSN is greater than the tail of the list.
*/
if (ooo_tail->cmdsn < ooo_cmdsn->cmdsn)
list_add_tail(&ooo_cmdsn->ooo_list,
&sess->sess_ooo_cmdsn_list);
else {
/*
* CmdSN is either lower than the head, or somewhere
* in the middle.
*/
list_for_each_entry(ooo_tmp, &sess->sess_ooo_cmdsn_list,
ooo_list) {
if (ooo_tmp->cmdsn < ooo_cmdsn->cmdsn)
continue;
list_add(&ooo_cmdsn->ooo_list,
&ooo_tmp->ooo_list);
break;
}
}
}
return 0;
}
/*
* Removes an struct iscsi_ooo_cmdsn from a session's list,
* called with struct iscsi_session->cmdsn_mutex held.
*/
void iscsit_remove_ooo_cmdsn(
struct iscsi_session *sess,
struct iscsi_ooo_cmdsn *ooo_cmdsn)
{
list_del(&ooo_cmdsn->ooo_list);
kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
}
void iscsit_clear_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
{
struct iscsi_ooo_cmdsn *ooo_cmdsn;
struct iscsi_session *sess = conn->sess;
mutex_lock(&sess->cmdsn_mutex);
list_for_each_entry(ooo_cmdsn, &sess->sess_ooo_cmdsn_list, ooo_list) {
if (ooo_cmdsn->cid != conn->cid)
continue;
ooo_cmdsn->cmd = NULL;
}
mutex_unlock(&sess->cmdsn_mutex);
}
/*
* Called with sess->cmdsn_mutex held.
*/
int iscsit_execute_ooo_cmdsns(struct iscsi_session *sess)
{
int ooo_count = 0;
struct iscsi_cmd *cmd = NULL;
struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
&sess->sess_ooo_cmdsn_list, ooo_list) {
if (ooo_cmdsn->cmdsn != sess->exp_cmd_sn)
continue;
if (!ooo_cmdsn->cmd) {
sess->exp_cmd_sn++;
iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
continue;
}
cmd = ooo_cmdsn->cmd;
cmd->i_state = cmd->deferred_i_state;
ooo_count++;
sess->exp_cmd_sn++;
pr_debug("Executing out of order CmdSN: 0x%08x,"
" incremented ExpCmdSN to 0x%08x.\n",
cmd->cmd_sn, sess->exp_cmd_sn);
iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
if (iscsit_execute_cmd(cmd, 1) < 0)
return -1;
continue;
}
return ooo_count;
}
/*
* Called either:
*
* 1. With sess->cmdsn_mutex held from iscsi_execute_ooo_cmdsns()
* or iscsi_check_received_cmdsn().
* 2. With no locks held directly from iscsi_handle_XXX_pdu() functions
* for immediate commands.
*/
int iscsit_execute_cmd(struct iscsi_cmd *cmd, int ooo)
{
struct se_cmd *se_cmd = &cmd->se_cmd;
int lr = 0;
spin_lock_bh(&cmd->istate_lock);
if (ooo)
cmd->cmd_flags &= ~ICF_OOO_CMDSN;
switch (cmd->iscsi_opcode) {
case ISCSI_OP_SCSI_CMD:
/*
* Go ahead and send the CHECK_CONDITION status for
* any SCSI CDB exceptions that may have occurred, also
* handle the SCF_SCSI_RESERVATION_CONFLICT case here as well.
*/
if (se_cmd->se_cmd_flags & SCF_SCSI_CDB_EXCEPTION) {
if (se_cmd->se_cmd_flags &
SCF_SCSI_RESERVATION_CONFLICT) {
cmd->i_state = ISTATE_SEND_STATUS;
spin_unlock_bh(&cmd->istate_lock);
iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
cmd->i_state);
return 0;
}
spin_unlock_bh(&cmd->istate_lock);
/*
* Determine if delayed TASK_ABORTED status for WRITEs
* should be sent now if no unsolicited data out
* payloads are expected, or if the delayed status
* should be sent after unsolicited data out with
* ISCSI_FLAG_CMD_FINAL set in iscsi_handle_data_out()
*/
if (transport_check_aborted_status(se_cmd,
(cmd->unsolicited_data == 0)) != 0)
return 0;
/*
* Otherwise send CHECK_CONDITION and sense for
* exception
*/
return transport_send_check_condition_and_sense(se_cmd,
se_cmd->scsi_sense_reason, 0);
}
/*
* Special case for delayed CmdSN with Immediate
* Data and/or Unsolicited Data Out attached.
*/
if (cmd->immediate_data) {
if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
spin_unlock_bh(&cmd->istate_lock);
return transport_generic_handle_data(
&cmd->se_cmd);
}
spin_unlock_bh(&cmd->istate_lock);
if (!(cmd->cmd_flags &
ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
/*
* Send the delayed TASK_ABORTED status for
* WRITEs if no more unsolicitied data is
* expected.
*/
if (transport_check_aborted_status(se_cmd, 1)
!= 0)
return 0;
iscsit_set_dataout_sequence_values(cmd);
iscsit_build_r2ts_for_cmd(cmd, cmd->conn, 0);
}
return 0;
}
/*
* The default handler.
*/
spin_unlock_bh(&cmd->istate_lock);
if ((cmd->data_direction == DMA_TO_DEVICE) &&
!(cmd->cmd_flags & ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
/*
* Send the delayed TASK_ABORTED status for WRITEs if
* no more nsolicitied data is expected.
*/
if (transport_check_aborted_status(se_cmd, 1) != 0)
return 0;
iscsit_set_dataout_sequence_values(cmd);
spin_lock_bh(&cmd->dataout_timeout_lock);
iscsit_start_dataout_timer(cmd, cmd->conn);
spin_unlock_bh(&cmd->dataout_timeout_lock);
}
return transport_handle_cdb_direct(&cmd->se_cmd);
case ISCSI_OP_NOOP_OUT:
case ISCSI_OP_TEXT:
spin_unlock_bh(&cmd->istate_lock);
iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
break;
case ISCSI_OP_SCSI_TMFUNC:
if (se_cmd->se_cmd_flags & SCF_SCSI_CDB_EXCEPTION) {
spin_unlock_bh(&cmd->istate_lock);
iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
cmd->i_state);
return 0;
}
spin_unlock_bh(&cmd->istate_lock);
return transport_generic_handle_tmr(&cmd->se_cmd);
case ISCSI_OP_LOGOUT:
spin_unlock_bh(&cmd->istate_lock);
switch (cmd->logout_reason) {
case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
lr = iscsit_logout_closesession(cmd, cmd->conn);
break;
case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
lr = iscsit_logout_closeconnection(cmd, cmd->conn);
break;
case ISCSI_LOGOUT_REASON_RECOVERY:
lr = iscsit_logout_removeconnforrecovery(cmd, cmd->conn);
break;
default:
pr_err("Unknown iSCSI Logout Request Code:"
" 0x%02x\n", cmd->logout_reason);
return -1;
}
return lr;
default:
spin_unlock_bh(&cmd->istate_lock);
pr_err("Cannot perform out of order execution for"
" unknown iSCSI Opcode: 0x%02x\n", cmd->iscsi_opcode);
return -1;
}
return 0;
}
void iscsit_free_all_ooo_cmdsns(struct iscsi_session *sess)
{
struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
mutex_lock(&sess->cmdsn_mutex);
list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
&sess->sess_ooo_cmdsn_list, ooo_list) {
list_del(&ooo_cmdsn->ooo_list);
kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
}
mutex_unlock(&sess->cmdsn_mutex);
}
int iscsit_handle_ooo_cmdsn(
struct iscsi_session *sess,
struct iscsi_cmd *cmd,
u32 cmdsn)
{
int batch = 0;
struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL, *ooo_tail = NULL;
cmd->deferred_i_state = cmd->i_state;
cmd->i_state = ISTATE_DEFERRED_CMD;
cmd->cmd_flags |= ICF_OOO_CMDSN;
if (list_empty(&sess->sess_ooo_cmdsn_list))
batch = 1;
else {
ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
typeof(*ooo_tail), ooo_list);
if (ooo_tail->cmdsn != (cmdsn - 1))
batch = 1;
}
ooo_cmdsn = iscsit_allocate_ooo_cmdsn();
if (!ooo_cmdsn)
return CMDSN_ERROR_CANNOT_RECOVER;
ooo_cmdsn->cmd = cmd;
ooo_cmdsn->batch_count = (batch) ?
(cmdsn - sess->exp_cmd_sn) : 1;
ooo_cmdsn->cid = cmd->conn->cid;
ooo_cmdsn->exp_cmdsn = sess->exp_cmd_sn;
ooo_cmdsn->cmdsn = cmdsn;
if (iscsit_attach_ooo_cmdsn(sess, ooo_cmdsn) < 0) {
kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
return CMDSN_ERROR_CANNOT_RECOVER;
}
return CMDSN_HIGHER_THAN_EXP;
}
static int iscsit_set_dataout_timeout_values(
struct iscsi_cmd *cmd,
u32 *offset,
u32 *length)
{
struct iscsi_conn *conn = cmd->conn;
struct iscsi_r2t *r2t;
if (cmd->unsolicited_data) {
*offset = 0;
*length = (conn->sess->sess_ops->FirstBurstLength >
cmd->data_length) ?
cmd->data_length :
conn->sess->sess_ops->FirstBurstLength;
return 0;
}
spin_lock_bh(&cmd->r2t_lock);
if (list_empty(&cmd->cmd_r2t_list)) {
pr_err("cmd->cmd_r2t_list is empty!\n");
spin_unlock_bh(&cmd->r2t_lock);
return -1;
}
list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
if (r2t->sent_r2t && !r2t->recovery_r2t && !r2t->seq_complete) {
*offset = r2t->offset;
*length = r2t->xfer_len;
spin_unlock_bh(&cmd->r2t_lock);
return 0;
}
}
spin_unlock_bh(&cmd->r2t_lock);
pr_err("Unable to locate any incomplete DataOUT"
" sequences for ITT: 0x%08x.\n", cmd->init_task_tag);
return -1;
}
/*
* NOTE: Called from interrupt (timer) context.
*/
static void iscsit_handle_dataout_timeout(unsigned long data)
{
u32 pdu_length = 0, pdu_offset = 0;
u32 r2t_length = 0, r2t_offset = 0;
struct iscsi_cmd *cmd = (struct iscsi_cmd *) data;
struct iscsi_conn *conn = cmd->conn;
struct iscsi_session *sess = NULL;
struct iscsi_node_attrib *na;
iscsit_inc_conn_usage_count(conn);
spin_lock_bh(&cmd->dataout_timeout_lock);
if (cmd->dataout_timer_flags & ISCSI_TF_STOP) {
spin_unlock_bh(&cmd->dataout_timeout_lock);
iscsit_dec_conn_usage_count(conn);
return;
}
cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
sess = conn->sess;
na = iscsit_tpg_get_node_attrib(sess);
if (!sess->sess_ops->ErrorRecoveryLevel) {
pr_debug("Unable to recover from DataOut timeout while"
" in ERL=0.\n");
goto failure;
}
if (++cmd->dataout_timeout_retries == na->dataout_timeout_retries) {
pr_debug("Command ITT: 0x%08x exceeded max retries"
" for DataOUT timeout %u, closing iSCSI connection.\n",
cmd->init_task_tag, na->dataout_timeout_retries);
goto failure;
}
cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
if (conn->sess->sess_ops->DataSequenceInOrder) {
if (conn->sess->sess_ops->DataPDUInOrder) {
pdu_offset = cmd->write_data_done;
if ((pdu_offset + (conn->sess->sess_ops->MaxBurstLength -
cmd->next_burst_len)) > cmd->data_length)
pdu_length = (cmd->data_length -
cmd->write_data_done);
else
pdu_length = (conn->sess->sess_ops->MaxBurstLength -
cmd->next_burst_len);
} else {
pdu_offset = cmd->seq_start_offset;
pdu_length = (cmd->seq_end_offset -
cmd->seq_start_offset);
}
} else {
if (iscsit_set_dataout_timeout_values(cmd, &pdu_offset,
&pdu_length) < 0)
goto failure;
}
if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
&r2t_offset, &r2t_length) < 0)
goto failure;
pr_debug("Command ITT: 0x%08x timed out waiting for"
" completion of %sDataOUT Sequence Offset: %u, Length: %u\n",
cmd->init_task_tag, (cmd->unsolicited_data) ? "Unsolicited " :
"", r2t_offset, r2t_length);
if (iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length) < 0)
goto failure;
iscsit_start_dataout_timer(cmd, conn);
spin_unlock_bh(&cmd->dataout_timeout_lock);
iscsit_dec_conn_usage_count(conn);
return;
failure:
spin_unlock_bh(&cmd->dataout_timeout_lock);
iscsit_cause_connection_reinstatement(conn, 0);
iscsit_dec_conn_usage_count(conn);
}
void iscsit_mod_dataout_timer(struct iscsi_cmd *cmd)
{
struct iscsi_conn *conn = cmd->conn;
struct iscsi_session *sess = conn->sess;
struct iscsi_node_attrib *na = na = iscsit_tpg_get_node_attrib(sess);
spin_lock_bh(&cmd->dataout_timeout_lock);
if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
spin_unlock_bh(&cmd->dataout_timeout_lock);
return;
}
mod_timer(&cmd->dataout_timer,
(get_jiffies_64() + na->dataout_timeout * HZ));
pr_debug("Updated DataOUT timer for ITT: 0x%08x",
cmd->init_task_tag);
spin_unlock_bh(&cmd->dataout_timeout_lock);
}
/*
* Called with cmd->dataout_timeout_lock held.
*/
void iscsit_start_dataout_timer(
struct iscsi_cmd *cmd,
struct iscsi_conn *conn)
{
struct iscsi_session *sess = conn->sess;
struct iscsi_node_attrib *na = na = iscsit_tpg_get_node_attrib(sess);
if (cmd->dataout_timer_flags & ISCSI_TF_RUNNING)
return;
pr_debug("Starting DataOUT timer for ITT: 0x%08x on"
" CID: %hu.\n", cmd->init_task_tag, conn->cid);
init_timer(&cmd->dataout_timer);
cmd->dataout_timer.expires = (get_jiffies_64() + na->dataout_timeout * HZ);
cmd->dataout_timer.data = (unsigned long)cmd;
cmd->dataout_timer.function = iscsit_handle_dataout_timeout;
cmd->dataout_timer_flags &= ~ISCSI_TF_STOP;
cmd->dataout_timer_flags |= ISCSI_TF_RUNNING;
add_timer(&cmd->dataout_timer);
}
void iscsit_stop_dataout_timer(struct iscsi_cmd *cmd)
{
spin_lock_bh(&cmd->dataout_timeout_lock);
if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
spin_unlock_bh(&cmd->dataout_timeout_lock);
return;
}
cmd->dataout_timer_flags |= ISCSI_TF_STOP;
spin_unlock_bh(&cmd->dataout_timeout_lock);
del_timer_sync(&cmd->dataout_timer);
spin_lock_bh(&cmd->dataout_timeout_lock);
cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
pr_debug("Stopped DataOUT Timer for ITT: 0x%08x\n",
cmd->init_task_tag);
spin_unlock_bh(&cmd->dataout_timeout_lock);
}
