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OpenCloudOS-Kernel/drivers/scsi/libiscsi.c

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/*
* iSCSI lib functions
*
* Copyright (C) 2006 Red Hat, Inc. All rights reserved.
* Copyright (C) 2004 - 2006 Mike Christie
* Copyright (C) 2004 - 2005 Dmitry Yusupov
* Copyright (C) 2004 - 2005 Alex Aizman
* maintained by open-iscsi@googlegroups.com
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/kfifo.h>
#include <linux/delay.h>
#include <net/tcp.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi.h>
#include <scsi/iscsi_proto.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_iscsi.h>
#include <scsi/libiscsi.h>
struct iscsi_session *
class_to_transport_session(struct iscsi_cls_session *cls_session)
{
struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
return iscsi_hostdata(shost->hostdata);
}
EXPORT_SYMBOL_GPL(class_to_transport_session);
#define INVALID_SN_DELTA 0xffff
int
iscsi_check_assign_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
{
uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
if (max_cmdsn < exp_cmdsn -1 &&
max_cmdsn > exp_cmdsn - INVALID_SN_DELTA)
return ISCSI_ERR_MAX_CMDSN;
if (max_cmdsn > session->max_cmdsn ||
max_cmdsn < session->max_cmdsn - INVALID_SN_DELTA)
session->max_cmdsn = max_cmdsn;
if (exp_cmdsn > session->exp_cmdsn ||
exp_cmdsn < session->exp_cmdsn - INVALID_SN_DELTA)
session->exp_cmdsn = exp_cmdsn;
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_check_assign_cmdsn);
void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *ctask,
struct iscsi_data *hdr,
int transport_data_cnt)
{
struct iscsi_conn *conn = ctask->conn;
memset(hdr, 0, sizeof(struct iscsi_data));
hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
ctask->unsol_datasn++;
hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
hdr->itt = ctask->hdr->itt;
hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
hdr->offset = cpu_to_be32(ctask->total_length -
transport_data_cnt -
ctask->unsol_count);
if (ctask->unsol_count > conn->max_xmit_dlength) {
hton24(hdr->dlength, conn->max_xmit_dlength);
ctask->data_count = conn->max_xmit_dlength;
hdr->flags = 0;
} else {
hton24(hdr->dlength, ctask->unsol_count);
ctask->data_count = ctask->unsol_count;
hdr->flags = ISCSI_FLAG_CMD_FINAL;
}
}
EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);
/**
* iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
* @ctask: iscsi cmd task
*
* Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
* fields like dlength or final based on how much data it sends
*/
static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
{
struct iscsi_conn *conn = ctask->conn;
struct iscsi_session *session = conn->session;
struct iscsi_cmd *hdr = ctask->hdr;
struct scsi_cmnd *sc = ctask->sc;
hdr->opcode = ISCSI_OP_SCSI_CMD;
hdr->flags = ISCSI_ATTR_SIMPLE;
int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
hdr->itt = ctask->itt | (conn->id << ISCSI_CID_SHIFT) |
(session->age << ISCSI_AGE_SHIFT);
hdr->data_length = cpu_to_be32(sc->request_bufflen);
hdr->cmdsn = cpu_to_be32(session->cmdsn);
session->cmdsn++;
hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
memcpy(hdr->cdb, sc->cmnd, sc->cmd_len);
memset(&hdr->cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);
if (sc->sc_data_direction == DMA_TO_DEVICE) {
hdr->flags |= ISCSI_FLAG_CMD_WRITE;
/*
* Write counters:
*
* imm_count bytes to be sent right after
* SCSI PDU Header
*
* unsol_count bytes(as Data-Out) to be sent
* without R2T ack right after
* immediate data
*
* r2t_data_count bytes to be sent via R2T ack's
*
* pad_count bytes to be sent as zero-padding
*/
ctask->imm_count = 0;
ctask->unsol_count = 0;
ctask->unsol_datasn = 0;
if (session->imm_data_en) {
if (ctask->total_length >= session->first_burst)
ctask->imm_count = min(session->first_burst,
conn->max_xmit_dlength);
else
ctask->imm_count = min(ctask->total_length,
conn->max_xmit_dlength);
hton24(ctask->hdr->dlength, ctask->imm_count);
} else
zero_data(ctask->hdr->dlength);
if (!session->initial_r2t_en)
ctask->unsol_count = min(session->first_burst,
ctask->total_length) - ctask->imm_count;
if (!ctask->unsol_count)
/* No unsolicit Data-Out's */
ctask->hdr->flags |= ISCSI_FLAG_CMD_FINAL;
} else {
ctask->datasn = 0;
hdr->flags |= ISCSI_FLAG_CMD_FINAL;
zero_data(hdr->dlength);
if (sc->sc_data_direction == DMA_FROM_DEVICE)
hdr->flags |= ISCSI_FLAG_CMD_READ;
}
conn->scsicmd_pdus_cnt++;
}
EXPORT_SYMBOL_GPL(iscsi_prep_scsi_cmd_pdu);
/**
* iscsi_complete_command - return command back to scsi-ml
* @session: iscsi session
* @ctask: iscsi cmd task
*
* Must be called with session lock.
* This function returns the scsi command to scsi-ml and returns
* the cmd task to the pool of available cmd tasks.
*/
static void iscsi_complete_command(struct iscsi_session *session,
struct iscsi_cmd_task *ctask)
{
struct scsi_cmnd *sc = ctask->sc;
ctask->sc = NULL;
list_del_init(&ctask->running);
__kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
sc->scsi_done(sc);
}
/**
* iscsi_cmd_rsp - SCSI Command Response processing
* @conn: iscsi connection
* @hdr: iscsi header
* @ctask: scsi command task
* @data: cmd data buffer
* @datalen: len of buffer
*
* iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
* then completes the command and task.
**/
static int iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
struct iscsi_cmd_task *ctask, char *data,
int datalen)
{
int rc;
struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
struct iscsi_session *session = conn->session;
struct scsi_cmnd *sc = ctask->sc;
rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
if (rc) {
sc->result = DID_ERROR << 16;
goto out;
}
conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
sc->result = (DID_OK << 16) | rhdr->cmd_status;
if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
sc->result = DID_ERROR << 16;
goto out;
}
if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
int senselen;
if (datalen < 2) {
invalid_datalen:
printk(KERN_ERR "iscsi: Got CHECK_CONDITION but "
"invalid data buffer size of %d\n", datalen);
sc->result = DID_BAD_TARGET << 16;
goto out;
}
senselen = (data[0] << 8) | data[1];
if (datalen < senselen)
goto invalid_datalen;
memcpy(sc->sense_buffer, data + 2,
min(senselen, SCSI_SENSE_BUFFERSIZE));
debug_scsi("copied %d bytes of sense\n",
min(senselen, SCSI_SENSE_BUFFERSIZE));
}
if (sc->sc_data_direction == DMA_TO_DEVICE)
goto out;
if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
int res_count = be32_to_cpu(rhdr->residual_count);
if (res_count > 0 && res_count <= sc->request_bufflen)
sc->resid = res_count;
else
sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
} else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
sc->resid = be32_to_cpu(rhdr->residual_count);
out:
debug_scsi("done [sc %lx res %d itt 0x%x]\n",
(long)sc, sc->result, ctask->itt);
conn->scsirsp_pdus_cnt++;
iscsi_complete_command(conn->session, ctask);
return rc;
}
/**
* __iscsi_complete_pdu - complete pdu
* @conn: iscsi conn
* @hdr: iscsi header
* @data: data buffer
* @datalen: len of data buffer
*
* Completes pdu processing by freeing any resources allocated at
* queuecommand or send generic. session lock must be held and verify
* itt must have been called.
*/
int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
char *data, int datalen)
{
struct iscsi_session *session = conn->session;
int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
struct iscsi_cmd_task *ctask;
struct iscsi_mgmt_task *mtask;
uint32_t itt;
if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG))
itt = hdr->itt & ISCSI_ITT_MASK;
else
itt = hdr->itt;
if (itt < session->cmds_max) {
ctask = session->cmds[itt];
debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n",
opcode, conn->id, ctask->itt, datalen);
switch(opcode) {
case ISCSI_OP_SCSI_CMD_RSP:
BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
rc = iscsi_scsi_cmd_rsp(conn, hdr, ctask, data,
datalen);
break;
case ISCSI_OP_SCSI_DATA_IN:
BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
conn->scsirsp_pdus_cnt++;
iscsi_complete_command(session, ctask);
}
break;
case ISCSI_OP_R2T:
/* LLD handles this for now */
break;
default:
rc = ISCSI_ERR_BAD_OPCODE;
break;
}
} else if (itt >= ISCSI_MGMT_ITT_OFFSET &&
itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) {
mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET];
debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
opcode, conn->id, mtask->itt, datalen);
rc = iscsi_check_assign_cmdsn(session,
(struct iscsi_nopin*)hdr);
if (rc)
goto done;
switch(opcode) {
case ISCSI_OP_LOGOUT_RSP:
conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
/* fall through */
case ISCSI_OP_LOGIN_RSP:
case ISCSI_OP_TEXT_RSP:
/*
* login related PDU's exp_statsn is handled in
* userspace
*/
rc = iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen);
list_del(&mtask->running);
if (conn->login_mtask != mtask)
__kfifo_put(session->mgmtpool.queue,
(void*)&mtask, sizeof(void*));
break;
case ISCSI_OP_SCSI_TMFUNC_RSP:
if (datalen) {
rc = ISCSI_ERR_PROTO;
break;
}
conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
conn->tmfrsp_pdus_cnt++;
if (conn->tmabort_state == TMABORT_INITIAL) {
conn->tmabort_state =
((struct iscsi_tm_rsp *)hdr)->
response == ISCSI_TMF_RSP_COMPLETE ?
TMABORT_SUCCESS:TMABORT_FAILED;
/* unblock eh_abort() */
wake_up(&conn->ehwait);
}
break;
case ISCSI_OP_NOOP_IN:
if (hdr->ttt != ISCSI_RESERVED_TAG) {
rc = ISCSI_ERR_PROTO;
break;
}
conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
rc = iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen);
list_del(&mtask->running);
if (conn->login_mtask != mtask)
__kfifo_put(session->mgmtpool.queue,
(void*)&mtask, sizeof(void*));
break;
default:
rc = ISCSI_ERR_BAD_OPCODE;
break;
}
} else if (itt == ISCSI_RESERVED_TAG) {
switch(opcode) {
case ISCSI_OP_NOOP_IN:
if (!datalen) {
rc = iscsi_check_assign_cmdsn(session,
(struct iscsi_nopin*)hdr);
if (!rc && hdr->ttt != ISCSI_RESERVED_TAG)
rc = iscsi_recv_pdu(conn->cls_conn,
hdr, NULL, 0);
} else
rc = ISCSI_ERR_PROTO;
break;
case ISCSI_OP_REJECT:
/* we need sth like iscsi_reject_rsp()*/
case ISCSI_OP_ASYNC_EVENT:
conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
/* we need sth like iscsi_async_event_rsp() */
rc = ISCSI_ERR_BAD_OPCODE;
break;
default:
rc = ISCSI_ERR_BAD_OPCODE;
break;
}
} else
rc = ISCSI_ERR_BAD_ITT;
done:
return rc;
}
EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
char *data, int datalen)
{
int rc;
spin_lock(&conn->session->lock);
rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
spin_unlock(&conn->session->lock);
return rc;
}
EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
/* verify itt (itt encoding: age+cid+itt) */
int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
uint32_t *ret_itt)
{
struct iscsi_session *session = conn->session;
struct iscsi_cmd_task *ctask;
uint32_t itt;
if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
if ((hdr->itt & ISCSI_AGE_MASK) !=
(session->age << ISCSI_AGE_SHIFT)) {
printk(KERN_ERR "iscsi: received itt %x expected "
"session age (%x)\n", hdr->itt,
session->age & ISCSI_AGE_MASK);
return ISCSI_ERR_BAD_ITT;
}
if ((hdr->itt & ISCSI_CID_MASK) !=
(conn->id << ISCSI_CID_SHIFT)) {
printk(KERN_ERR "iscsi: received itt %x, expected "
"CID (%x)\n", hdr->itt, conn->id);
return ISCSI_ERR_BAD_ITT;
}
itt = hdr->itt & ISCSI_ITT_MASK;
} else
itt = hdr->itt;
if (itt < session->cmds_max) {
ctask = session->cmds[itt];
if (!ctask->sc) {
printk(KERN_INFO "iscsi: dropping ctask with "
"itt 0x%x\n", ctask->itt);
/* force drop */
return ISCSI_ERR_NO_SCSI_CMD;
}
if (ctask->sc->SCp.phase != session->age) {
printk(KERN_ERR "iscsi: ctask's session age %d, "
"expected %d\n", ctask->sc->SCp.phase,
session->age);
return ISCSI_ERR_SESSION_FAILED;
}
}
*ret_itt = itt;
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_verify_itt);
void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
{
struct iscsi_session *session = conn->session;
unsigned long flags;
spin_lock_irqsave(&session->lock, flags);
if (session->state == ISCSI_STATE_FAILED) {
spin_unlock_irqrestore(&session->lock, flags);
return;
}
if (conn->stop_stage == 0)
session->state = ISCSI_STATE_FAILED;
spin_unlock_irqrestore(&session->lock, flags);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
iscsi_conn_error(conn->cls_conn, err);
}
EXPORT_SYMBOL_GPL(iscsi_conn_failure);
/**
* iscsi_data_xmit - xmit any command into the scheduled connection
* @conn: iscsi connection
*
* Notes:
* The function can return -EAGAIN in which case the caller must
* re-schedule it again later or recover. '0' return code means
* successful xmit.
**/
static int iscsi_data_xmit(struct iscsi_conn *conn)
{
struct iscsi_transport *tt;
int rc = 0;
if (unlikely(conn->suspend_tx)) {
debug_scsi("conn %d Tx suspended!\n", conn->id);
return -ENODATA;
}
tt = conn->session->tt;
/*
* Transmit in the following order:
*
* 1) un-finished xmit (ctask or mtask)
* 2) immediate control PDUs
* 3) write data
* 4) SCSI commands
* 5) non-immediate control PDUs
*
* No need to lock around __kfifo_get as long as
* there's one producer and one consumer.
*/
BUG_ON(conn->ctask && conn->mtask);
if (conn->ctask) {
rc = tt->xmit_cmd_task(conn, conn->ctask);
if (rc)
goto again;
/* done with this in-progress ctask */
conn->ctask = NULL;
}
if (conn->mtask) {
rc = tt->xmit_mgmt_task(conn, conn->mtask);
if (rc)
goto again;
/* done with this in-progress mtask */
conn->mtask = NULL;
}
/* process immediate first */
if (unlikely(__kfifo_len(conn->immqueue))) {
while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
sizeof(void*))) {
spin_lock_bh(&conn->session->lock);
list_add_tail(&conn->mtask->running,
&conn->mgmt_run_list);
spin_unlock_bh(&conn->session->lock);
rc = tt->xmit_mgmt_task(conn, conn->mtask);
if (rc)
goto again;
}
/* done with this mtask */
conn->mtask = NULL;
}
/* process command queue */
while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask,
sizeof(void*))) {
/*
* iscsi tcp may readd the task to the xmitqueue to send
* write data
*/
spin_lock_bh(&conn->session->lock);
if (list_empty(&conn->ctask->running))
list_add_tail(&conn->ctask->running, &conn->run_list);
spin_unlock_bh(&conn->session->lock);
rc = tt->xmit_cmd_task(conn, conn->ctask);
if (rc)
goto again;
}
/* done with this ctask */
conn->ctask = NULL;
/* process the rest control plane PDUs, if any */
if (unlikely(__kfifo_len(conn->mgmtqueue))) {
while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
sizeof(void*))) {
spin_lock_bh(&conn->session->lock);
list_add_tail(&conn->mtask->running,
&conn->mgmt_run_list);
spin_unlock_bh(&conn->session->lock);
rc = tt->xmit_mgmt_task(conn, conn->mtask);
if (rc)
goto again;
}
/* done with this mtask */
conn->mtask = NULL;
}
return -ENODATA;
again:
if (unlikely(conn->suspend_tx))
return -ENODATA;
return rc;
}
static void iscsi_xmitworker(void *data)
{
struct iscsi_conn *conn = data;
int rc;
/*
* serialize Xmit worker on a per-connection basis.
*/
mutex_lock(&conn->xmitmutex);
do {
rc = iscsi_data_xmit(conn);
} while (rc >= 0 || rc == -EAGAIN);
mutex_unlock(&conn->xmitmutex);
}
enum {
FAILURE_BAD_HOST = 1,
FAILURE_SESSION_FAILED,
FAILURE_SESSION_FREED,
FAILURE_WINDOW_CLOSED,
FAILURE_SESSION_TERMINATE,
FAILURE_SESSION_IN_RECOVERY,
FAILURE_SESSION_RECOVERY_TIMEOUT,
};
int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
{
struct Scsi_Host *host;
int reason = 0;
struct iscsi_session *session;
struct iscsi_conn *conn;
struct iscsi_cmd_task *ctask = NULL;
sc->scsi_done = done;
sc->result = 0;
host = sc->device->host;
session = iscsi_hostdata(host->hostdata);
spin_lock(&session->lock);
/*
* ISCSI_STATE_FAILED is a temp. state. The recovery
* code will decide what is best to do with command queued
* during this time
*/
if (session->state != ISCSI_STATE_LOGGED_IN &&
session->state != ISCSI_STATE_FAILED) {
/*
* to handle the race between when we set the recovery state
* and block the session we requeue here (commands could
* be entering our queuecommand while a block is starting
* up because the block code is not locked)
*/
if (session->state == ISCSI_STATE_IN_RECOVERY) {
reason = FAILURE_SESSION_IN_RECOVERY;
goto reject;
}
if (session->state == ISCSI_STATE_RECOVERY_FAILED)
reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
else if (session->state == ISCSI_STATE_TERMINATE)
reason = FAILURE_SESSION_TERMINATE;
else
reason = FAILURE_SESSION_FREED;
goto fault;
}
/*
* Check for iSCSI window and take care of CmdSN wrap-around
*/
if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
reason = FAILURE_WINDOW_CLOSED;
goto reject;
}
conn = session->leadconn;
__kfifo_get(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
sc->SCp.phase = session->age;
sc->SCp.ptr = (char *)ctask;
ctask->mtask = NULL;
ctask->conn = conn;
ctask->sc = sc;
INIT_LIST_HEAD(&ctask->running);
ctask->total_length = sc->request_bufflen;
iscsi_prep_scsi_cmd_pdu(ctask);
session->tt->init_cmd_task(ctask);
__kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
debug_scsi(
"ctask enq [%s cid %d sc %lx itt 0x%x len %d cmdsn %d win %d]\n",
sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
conn->id, (long)sc, ctask->itt, sc->request_bufflen,
session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
spin_unlock(&session->lock);
scsi_queue_work(host, &conn->xmitwork);
return 0;
reject:
spin_unlock(&session->lock);
debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
return SCSI_MLQUEUE_HOST_BUSY;
fault:
spin_unlock(&session->lock);
printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
sc->cmnd[0], reason);
sc->result = (DID_NO_CONNECT << 16);
sc->resid = sc->request_bufflen;
sc->scsi_done(sc);
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_queuecommand);
int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
{
if (depth > ISCSI_MAX_CMD_PER_LUN)
depth = ISCSI_MAX_CMD_PER_LUN;
scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
return sdev->queue_depth;
}
EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
static int
iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
char *data, uint32_t data_size)
{
struct iscsi_session *session = conn->session;
struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
struct iscsi_mgmt_task *mtask;
spin_lock_bh(&session->lock);
if (session->state == ISCSI_STATE_TERMINATE) {
spin_unlock_bh(&session->lock);
return -EPERM;
}
if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
/*
* Login and Text are sent serially, in
* request-followed-by-response sequence.
* Same mtask can be used. Same ITT must be used.
* Note that login_mtask is preallocated at conn_create().
*/
mtask = conn->login_mtask;
else {
BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
if (!__kfifo_get(session->mgmtpool.queue,
(void*)&mtask, sizeof(void*))) {
spin_unlock_bh(&session->lock);
return -ENOSPC;
}
}
/*
* pre-format CmdSN for outgoing PDU.
*/
if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
hdr->itt = mtask->itt | (conn->id << ISCSI_CID_SHIFT) |
(session->age << ISCSI_AGE_SHIFT);
nop->cmdsn = cpu_to_be32(session->cmdsn);
if (conn->c_stage == ISCSI_CONN_STARTED &&
!(hdr->opcode & ISCSI_OP_IMMEDIATE))
session->cmdsn++;
} else
/* do not advance CmdSN */
nop->cmdsn = cpu_to_be32(session->cmdsn);
if (data_size) {
memcpy(mtask->data, data, data_size);
mtask->data_count = data_size;
} else
mtask->data_count = 0;
INIT_LIST_HEAD(&mtask->running);
memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
if (session->tt->init_mgmt_task)
session->tt->init_mgmt_task(conn, mtask, data, data_size);
spin_unlock_bh(&session->lock);
debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
hdr->opcode, hdr->itt, data_size);
/*
* since send_pdu() could be called at least from two contexts,
* we need to serialize __kfifo_put, so we don't have to take
* additional lock on fast data-path
*/
if (hdr->opcode & ISCSI_OP_IMMEDIATE)
__kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
else
__kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
scsi_queue_work(session->host, &conn->xmitwork);
return 0;
}
int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
char *data, uint32_t data_size)
{
struct iscsi_conn *conn = cls_conn->dd_data;
int rc;
mutex_lock(&conn->xmitmutex);
rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
mutex_unlock(&conn->xmitmutex);
return rc;
}
EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
{
struct iscsi_session *session = class_to_transport_session(cls_session);
struct iscsi_conn *conn = session->leadconn;
spin_lock_bh(&session->lock);
if (session->state != ISCSI_STATE_LOGGED_IN) {
session->state = ISCSI_STATE_RECOVERY_FAILED;
if (conn)
wake_up(&conn->ehwait);
}
spin_unlock_bh(&session->lock);
}
EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
int iscsi_eh_host_reset(struct scsi_cmnd *sc)
{
struct Scsi_Host *host = sc->device->host;
struct iscsi_session *session = iscsi_hostdata(host->hostdata);
struct iscsi_conn *conn = session->leadconn;
int fail_session = 0;
spin_lock_bh(&session->lock);
if (session->state == ISCSI_STATE_TERMINATE) {
failed:
debug_scsi("failing host reset: session terminated "
"[CID %d age %d]", conn->id, session->age);
spin_unlock_bh(&session->lock);
return FAILED;
}
if (sc->SCp.phase == session->age) {
debug_scsi("failing connection CID %d due to SCSI host reset",
conn->id);
fail_session = 1;
}
spin_unlock_bh(&session->lock);
/*
* we drop the lock here but the leadconn cannot be destoyed while
* we are in the scsi eh
*/
if (fail_session)
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
debug_scsi("iscsi_eh_host_reset wait for relogin\n");
wait_event_interruptible(conn->ehwait,
session->state == ISCSI_STATE_TERMINATE ||
session->state == ISCSI_STATE_LOGGED_IN ||
session->state == ISCSI_STATE_RECOVERY_FAILED);
if (signal_pending(current))
flush_signals(current);
spin_lock_bh(&session->lock);
if (session->state == ISCSI_STATE_LOGGED_IN)
printk(KERN_INFO "iscsi: host reset succeeded\n");
else
goto failed;
spin_unlock_bh(&session->lock);
return SUCCESS;
}
EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
static void iscsi_tmabort_timedout(unsigned long data)
{
struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
struct iscsi_conn *conn = ctask->conn;
struct iscsi_session *session = conn->session;
spin_lock(&session->lock);
if (conn->tmabort_state == TMABORT_INITIAL) {
conn->tmabort_state = TMABORT_TIMEDOUT;
debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
ctask->sc, ctask->itt);
/* unblock eh_abort() */
wake_up(&conn->ehwait);
}
spin_unlock(&session->lock);
}
/* must be called with the mutex lock */
static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
struct iscsi_cmd_task *ctask)
{
struct iscsi_conn *conn = ctask->conn;
struct iscsi_session *session = conn->session;
struct iscsi_tm *hdr = &conn->tmhdr;
int rc;
/*
* ctask timed out but session is OK requests must be serialized.
*/
memset(hdr, 0, sizeof(struct iscsi_tm));
hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
hdr->flags |= ISCSI_FLAG_CMD_FINAL;
memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
hdr->rtt = ctask->hdr->itt;
hdr->refcmdsn = ctask->hdr->cmdsn;
rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
NULL, 0);
if (rc) {
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
debug_scsi("abort sent failure [itt 0x%x] %d", ctask->itt, rc);
return rc;
}
debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
spin_lock_bh(&session->lock);
ctask->mtask = (struct iscsi_mgmt_task *)
session->mgmt_cmds[(hdr->itt & ISCSI_ITT_MASK) -
ISCSI_MGMT_ITT_OFFSET];
if (conn->tmabort_state == TMABORT_INITIAL) {
conn->tmfcmd_pdus_cnt++;
conn->tmabort_timer.expires = 10*HZ + jiffies;
conn->tmabort_timer.function = iscsi_tmabort_timedout;
conn->tmabort_timer.data = (unsigned long)ctask;
add_timer(&conn->tmabort_timer);
debug_scsi("abort set timeout [itt 0x%x]", ctask->itt);
}
spin_unlock_bh(&session->lock);
mutex_unlock(&conn->xmitmutex);
/*
* block eh thread until:
*
* 1) abort response
* 2) abort timeout
* 3) session is terminated or restarted or userspace has
* given up on recovery
*/
wait_event_interruptible(conn->ehwait,
sc->SCp.phase != session->age ||
session->state != ISCSI_STATE_LOGGED_IN ||
conn->tmabort_state != TMABORT_INITIAL);
if (signal_pending(current))
flush_signals(current);
del_timer_sync(&conn->tmabort_timer);
mutex_lock(&conn->xmitmutex);
return 0;
}
/*
* xmit mutex and session lock must be held
*/
#define iscsi_remove_task(tasktype) \
static struct iscsi_##tasktype * \
iscsi_remove_##tasktype(struct kfifo *fifo, uint32_t itt) \
{ \
int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*); \
struct iscsi_##tasktype *task; \
\
debug_scsi("searching %d tasks\n", nr_tasks); \
\
for (i = 0; i < nr_tasks; i++) { \
__kfifo_get(fifo, (void*)&task, sizeof(void*)); \
debug_scsi("check task %u\n", task->itt); \
\
if (task->itt == itt) { \
debug_scsi("matched task\n"); \
return task; \
} \
\
__kfifo_put(fifo, (void*)&task, sizeof(void*)); \
} \
return NULL; \
}
iscsi_remove_task(mgmt_task);
iscsi_remove_task(cmd_task);
static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
{
struct iscsi_conn *conn = ctask->conn;
struct iscsi_session *session = conn->session;
if (!ctask->mtask)
return -EINVAL;
if (!iscsi_remove_mgmt_task(conn->immqueue, ctask->mtask->itt))
list_del(&ctask->mtask->running);
__kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
sizeof(void*));
ctask->mtask = NULL;
return 0;
}
/*
* session lock and xmitmutex must be held
*/
static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
int err)
{
struct scsi_cmnd *sc;
conn->session->tt->cleanup_cmd_task(conn, ctask);
iscsi_ctask_mtask_cleanup(ctask);
sc = ctask->sc;
if (!sc)
return;
sc->result = err;
sc->resid = sc->request_bufflen;
iscsi_complete_command(conn->session, ctask);
}
int iscsi_eh_abort(struct scsi_cmnd *sc)
{
struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
struct iscsi_conn *conn = ctask->conn;
struct iscsi_session *session = conn->session;
struct iscsi_cmd_task *pending_ctask;
int rc;
conn->eh_abort_cnt++;
debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
mutex_lock(&conn->xmitmutex);
spin_lock_bh(&session->lock);
/*
* If we are not logged in or we have started a new session
* then let the host reset code handle this
*/
if (session->state != ISCSI_STATE_LOGGED_IN ||
sc->SCp.phase != session->age)
goto failed;
/* ctask completed before time out */
if (!ctask->sc)
goto success;
/* what should we do here ? */
if (conn->ctask == ctask) {
printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. "
"Failing abort\n", sc, ctask->itt);
goto failed;
}
/* check for the easy pending cmd abort */
pending_ctask = iscsi_remove_cmd_task(conn->xmitqueue, ctask->itt);
if (pending_ctask) {
/* iscsi_tcp queues write transfers on the xmitqueue */
if (list_empty(&pending_ctask->running)) {
debug_scsi("found pending task\n");
goto success;
} else
__kfifo_put(conn->xmitqueue, (void*)&pending_ctask,
sizeof(void*));
}
conn->tmabort_state = TMABORT_INITIAL;
spin_unlock_bh(&session->lock);
rc = iscsi_exec_abort_task(sc, ctask);
spin_lock_bh(&session->lock);
iscsi_ctask_mtask_cleanup(ctask);
if (rc || sc->SCp.phase != session->age ||
session->state != ISCSI_STATE_LOGGED_IN)
goto failed;
/* ctask completed before tmf abort response */
if (!ctask->sc) {
debug_scsi("sc completed while abort in progress\n");
goto success;
}
if (conn->tmabort_state != TMABORT_SUCCESS) {
spin_unlock_bh(&session->lock);
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
spin_lock_bh(&session->lock);
goto failed;
}
success:
debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
spin_unlock_bh(&session->lock);
/*
* clean up task if aborted. we have the xmitmutex so grab
* the recv lock as a writer
*/
write_lock_bh(conn->recv_lock);
spin_lock(&session->lock);
fail_command(conn, ctask, DID_ABORT << 16);
spin_unlock(&session->lock);
write_unlock_bh(conn->recv_lock);
mutex_unlock(&conn->xmitmutex);
return SUCCESS;
failed:
spin_unlock_bh(&session->lock);
mutex_unlock(&conn->xmitmutex);
debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
return FAILED;
}
EXPORT_SYMBOL_GPL(iscsi_eh_abort);
int
iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
{
int i;
*items = kmalloc(max * sizeof(void*), GFP_KERNEL);
if (*items == NULL)
return -ENOMEM;
q->max = max;
q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
if (q->pool == NULL) {
kfree(*items);
return -ENOMEM;
}
q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
GFP_KERNEL, NULL);
if (q->queue == ERR_PTR(-ENOMEM)) {
kfree(q->pool);
kfree(*items);
return -ENOMEM;
}
for (i = 0; i < max; i++) {
q->pool[i] = kmalloc(item_size, GFP_KERNEL);
if (q->pool[i] == NULL) {
int j;
for (j = 0; j < i; j++)
kfree(q->pool[j]);
kfifo_free(q->queue);
kfree(q->pool);
kfree(*items);
return -ENOMEM;
}
memset(q->pool[i], 0, item_size);
(*items)[i] = q->pool[i];
__kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
}
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_pool_init);
void iscsi_pool_free(struct iscsi_queue *q, void **items)
{
int i;
for (i = 0; i < q->max; i++)
kfree(items[i]);
kfree(q->pool);
kfree(items);
}
EXPORT_SYMBOL_GPL(iscsi_pool_free);
/*
* iSCSI Session's hostdata organization:
*
* *------------------* <== hostdata_session(host->hostdata)
* | ptr to class sess|
* |------------------| <== iscsi_hostdata(host->hostdata)
* | iscsi_session |
* *------------------*
*/
#define hostdata_privsize(_sz) (sizeof(unsigned long) + _sz + \
_sz % sizeof(unsigned long))
#define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
/**
* iscsi_session_setup - create iscsi cls session and host and session
* @scsit: scsi transport template
* @iscsit: iscsi transport template
* @initial_cmdsn: initial CmdSN
* @hostno: host no allocated
*
* This can be used by software iscsi_transports that allocate
* a session per scsi host.
**/
struct iscsi_cls_session *
iscsi_session_setup(struct iscsi_transport *iscsit,
struct scsi_transport_template *scsit,
int cmd_task_size, int mgmt_task_size,
uint32_t initial_cmdsn, uint32_t *hostno)
{
struct Scsi_Host *shost;
struct iscsi_session *session;
struct iscsi_cls_session *cls_session;
int cmd_i;
shost = scsi_host_alloc(iscsit->host_template,
hostdata_privsize(sizeof(*session)));
if (!shost)
return NULL;
shost->max_id = 1;
shost->max_channel = 0;
shost->max_lun = iscsit->max_lun;
shost->max_cmd_len = iscsit->max_cmd_len;
shost->transportt = scsit;
shost->transportt->create_work_queue = 1;
*hostno = shost->host_no;
session = iscsi_hostdata(shost->hostdata);
memset(session, 0, sizeof(struct iscsi_session));
session->host = shost;
session->state = ISCSI_STATE_FREE;
session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
session->cmds_max = ISCSI_XMIT_CMDS_MAX;
session->cmdsn = initial_cmdsn;
session->exp_cmdsn = initial_cmdsn + 1;
session->max_cmdsn = initial_cmdsn + 1;
session->max_r2t = 1;
session->tt = iscsit;
/* initialize SCSI PDU commands pool */
if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
(void***)&session->cmds,
cmd_task_size + sizeof(struct iscsi_cmd_task)))
goto cmdpool_alloc_fail;
/* pre-format cmds pool with ITT */
for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
if (cmd_task_size)
ctask->dd_data = &ctask[1];
ctask->itt = cmd_i;
}
spin_lock_init(&session->lock);
INIT_LIST_HEAD(&session->connections);
/* initialize immediate command pool */
if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
(void***)&session->mgmt_cmds,
mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
goto mgmtpool_alloc_fail;
/* pre-format immediate cmds pool with ITT */
for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
if (mgmt_task_size)
mtask->dd_data = &mtask[1];
mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
}
if (scsi_add_host(shost, NULL))
goto add_host_fail;
cls_session = iscsi_create_session(shost, iscsit, 0);
if (!cls_session)
goto cls_session_fail;
*(unsigned long*)shost->hostdata = (unsigned long)cls_session;
return cls_session;
cls_session_fail:
scsi_remove_host(shost);
add_host_fail:
iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
mgmtpool_alloc_fail:
iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
cmdpool_alloc_fail:
scsi_host_put(shost);
return NULL;
}
EXPORT_SYMBOL_GPL(iscsi_session_setup);
/**
* iscsi_session_teardown - destroy session, host, and cls_session
* shost: scsi host
*
* This can be used by software iscsi_transports that allocate
* a session per scsi host.
**/
void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
{
struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
scsi_remove_host(shost);
iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
iscsi_destroy_session(cls_session);
scsi_host_put(shost);
}
EXPORT_SYMBOL_GPL(iscsi_session_teardown);
/**
* iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
* @cls_session: iscsi_cls_session
* @conn_idx: cid
**/
struct iscsi_cls_conn *
iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
{
struct iscsi_session *session = class_to_transport_session(cls_session);
struct iscsi_conn *conn;
struct iscsi_cls_conn *cls_conn;
char *data;
cls_conn = iscsi_create_conn(cls_session, conn_idx);
if (!cls_conn)
return NULL;
conn = cls_conn->dd_data;
memset(conn, 0, sizeof(*conn));
conn->session = session;
conn->cls_conn = cls_conn;
conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
conn->id = conn_idx;
conn->exp_statsn = 0;
conn->tmabort_state = TMABORT_INITIAL;
INIT_LIST_HEAD(&conn->run_list);
INIT_LIST_HEAD(&conn->mgmt_run_list);
/* initialize general xmit PDU commands queue */
conn->xmitqueue = kfifo_alloc(session->cmds_max * sizeof(void*),
GFP_KERNEL, NULL);
if (conn->xmitqueue == ERR_PTR(-ENOMEM))
goto xmitqueue_alloc_fail;
/* initialize general immediate & non-immediate PDU commands queue */
conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
GFP_KERNEL, NULL);
if (conn->immqueue == ERR_PTR(-ENOMEM))
goto immqueue_alloc_fail;
conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
GFP_KERNEL, NULL);
if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
goto mgmtqueue_alloc_fail;
INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
/* allocate login_mtask used for the login/text sequences */
spin_lock_bh(&session->lock);
if (!__kfifo_get(session->mgmtpool.queue,
(void*)&conn->login_mtask,
sizeof(void*))) {
spin_unlock_bh(&session->lock);
goto login_mtask_alloc_fail;
}
spin_unlock_bh(&session->lock);
data = kmalloc(DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL);
if (!data)
goto login_mtask_data_alloc_fail;
conn->login_mtask->data = data;
init_timer(&conn->tmabort_timer);
mutex_init(&conn->xmitmutex);
init_waitqueue_head(&conn->ehwait);
return cls_conn;
login_mtask_data_alloc_fail:
__kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
sizeof(void*));
login_mtask_alloc_fail:
kfifo_free(conn->mgmtqueue);
mgmtqueue_alloc_fail:
kfifo_free(conn->immqueue);
immqueue_alloc_fail:
kfifo_free(conn->xmitqueue);
xmitqueue_alloc_fail:
iscsi_destroy_conn(cls_conn);
return NULL;
}
EXPORT_SYMBOL_GPL(iscsi_conn_setup);
/**
* iscsi_conn_teardown - teardown iscsi connection
* cls_conn: iscsi class connection
*
* TODO: we may need to make this into a two step process
* like scsi-mls remove + put host
*/
void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
{
struct iscsi_conn *conn = cls_conn->dd_data;
struct iscsi_session *session = conn->session;
unsigned long flags;
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
mutex_lock(&conn->xmitmutex);
if (conn->c_stage == ISCSI_CONN_INITIAL_STAGE) {
if (session->tt->suspend_conn_recv)
session->tt->suspend_conn_recv(conn);
session->tt->terminate_conn(conn);
}
spin_lock_bh(&session->lock);
conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
if (session->leadconn == conn) {
/*
* leading connection? then give up on recovery.
*/
session->state = ISCSI_STATE_TERMINATE;
wake_up(&conn->ehwait);
}
spin_unlock_bh(&session->lock);
mutex_unlock(&conn->xmitmutex);
/*
* Block until all in-progress commands for this connection
* time out or fail.
*/
for (;;) {
spin_lock_irqsave(session->host->host_lock, flags);
if (!session->host->host_busy) { /* OK for ERL == 0 */
spin_unlock_irqrestore(session->host->host_lock, flags);
break;
}
spin_unlock_irqrestore(session->host->host_lock, flags);
msleep_interruptible(500);
printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
"host_failed %d\n", session->host->host_busy,
session->host->host_failed);
/*
* force eh_abort() to unblock
*/
wake_up(&conn->ehwait);
}
spin_lock_bh(&session->lock);
kfree(conn->login_mtask->data);
__kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
sizeof(void*));
list_del(&conn->item);
if (list_empty(&session->connections))
session->leadconn = NULL;
if (session->leadconn && session->leadconn == conn)
session->leadconn = container_of(session->connections.next,
struct iscsi_conn, item);
if (session->leadconn == NULL)
/* no connections exits.. reset sequencing */
session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
spin_unlock_bh(&session->lock);
kfifo_free(conn->xmitqueue);
kfifo_free(conn->immqueue);
kfifo_free(conn->mgmtqueue);
iscsi_destroy_conn(cls_conn);
}
EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
{
struct iscsi_conn *conn = cls_conn->dd_data;
struct iscsi_session *session = conn->session;
if (session == NULL) {
printk(KERN_ERR "iscsi: can't start unbound connection\n");
return -EPERM;
}
spin_lock_bh(&session->lock);
conn->c_stage = ISCSI_CONN_STARTED;
session->state = ISCSI_STATE_LOGGED_IN;
switch(conn->stop_stage) {
case STOP_CONN_RECOVER:
/*
* unblock eh_abort() if it is blocked. re-try all
* commands after successful recovery
*/
conn->stop_stage = 0;
conn->tmabort_state = TMABORT_INITIAL;
session->age++;
spin_unlock_bh(&session->lock);
iscsi_unblock_session(session_to_cls(session));
wake_up(&conn->ehwait);
return 0;
case STOP_CONN_TERM:
conn->stop_stage = 0;
break;
default:
break;
}
spin_unlock_bh(&session->lock);
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_conn_start);
static void
flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
{
struct iscsi_mgmt_task *mtask, *tmp;
/* handle pending */
while (__kfifo_get(conn->immqueue, (void*)&mtask, sizeof(void*)) ||
__kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
if (mtask == conn->login_mtask)
continue;
debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
sizeof(void*));
}
/* handle running */
list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
list_del(&mtask->running);
if (mtask == conn->login_mtask)
continue;
__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
sizeof(void*));
}
conn->mtask = NULL;
}
/* Fail commands. Mutex and session lock held and recv side suspended */
static void fail_all_commands(struct iscsi_conn *conn)
{
struct iscsi_cmd_task *ctask, *tmp;
/* flush pending */
while (__kfifo_get(conn->xmitqueue, (void*)&ctask, sizeof(void*))) {
debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
ctask->itt);
fail_command(conn, ctask, DID_BUS_BUSY << 16);
}
/* fail all other running */
list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
debug_scsi("failing in progress sc %p itt 0x%x\n",
ctask->sc, ctask->itt);
fail_command(conn, ctask, DID_BUS_BUSY << 16);
}
conn->ctask = NULL;
}
static void iscsi_start_session_recovery(struct iscsi_session *session,
struct iscsi_conn *conn, int flag)
{
int old_stop_stage;
spin_lock_bh(&session->lock);
if (conn->stop_stage == STOP_CONN_TERM) {
spin_unlock_bh(&session->lock);
return;
}
/*
* When this is called for the in_login state, we only want to clean
* up the login task and connection. We do not need to block and set
* the recovery state again
*/
if (flag == STOP_CONN_TERM)
session->state = ISCSI_STATE_TERMINATE;
else if (conn->stop_stage != STOP_CONN_RECOVER)
session->state = ISCSI_STATE_IN_RECOVERY;
old_stop_stage = conn->stop_stage;
conn->stop_stage = flag;
conn->c_stage = ISCSI_CONN_STOPPED;
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
spin_unlock_bh(&session->lock);
if (session->tt->suspend_conn_recv)
session->tt->suspend_conn_recv(conn);
mutex_lock(&conn->xmitmutex);
/*
* for connection level recovery we should not calculate
* header digest. conn->hdr_size used for optimization
* in hdr_extract() and will be re-negotiated at
* set_param() time.
*/
if (flag == STOP_CONN_RECOVER) {
conn->hdrdgst_en = 0;
conn->datadgst_en = 0;
if (session->state == ISCSI_STATE_IN_RECOVERY &&
old_stop_stage != STOP_CONN_RECOVER) {
debug_scsi("blocking session\n");
iscsi_block_session(session_to_cls(session));
}
}
session->tt->terminate_conn(conn);
/*
* flush queues.
*/
spin_lock_bh(&session->lock);
fail_all_commands(conn);
flush_control_queues(session, conn);
spin_unlock_bh(&session->lock);
mutex_unlock(&conn->xmitmutex);
}
void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
{
struct iscsi_conn *conn = cls_conn->dd_data;
struct iscsi_session *session = conn->session;
switch (flag) {
case STOP_CONN_RECOVER:
case STOP_CONN_TERM:
iscsi_start_session_recovery(session, conn, flag);
break;
default:
printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
}
}
EXPORT_SYMBOL_GPL(iscsi_conn_stop);
int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
struct iscsi_cls_conn *cls_conn, int is_leading)
{
struct iscsi_session *session = class_to_transport_session(cls_session);
struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = cls_conn->dd_data;
/* lookup for existing connection */
spin_lock_bh(&session->lock);
list_for_each_entry(tmp, &session->connections, item) {
if (tmp == conn) {
if (conn->c_stage != ISCSI_CONN_STOPPED ||
conn->stop_stage == STOP_CONN_TERM) {
printk(KERN_ERR "iscsi: can't bind "
"non-stopped connection (%d:%d)\n",
conn->c_stage, conn->stop_stage);
spin_unlock_bh(&session->lock);
return -EIO;
}
break;
}
}
if (tmp != conn) {
/* bind new iSCSI connection to session */
conn->session = session;
list_add(&conn->item, &session->connections);
}
spin_unlock_bh(&session->lock);
if (is_leading)
session->leadconn = conn;
/*
* Unblock xmitworker(), Login Phase will pass through.
*/
clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_conn_bind);
MODULE_AUTHOR("Mike Christie");
MODULE_DESCRIPTION("iSCSI library functions");
MODULE_LICENSE("GPL");
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