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linux/drivers/scsi/libiscsi.c
Tony Battersby 6ee6a2f025 [SCSI] iscsi: return data transfer residual for data-out commands 
Currently, the iSCSI driver returns the data transfer residual for
data-in commands (e.g. read) but not data-out commands (e.g. write).
This patch makes it return the data transfer residual for both types of
commands.

Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2007-11-14 14:52:16 -06:00

2141 lines
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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/kfifo.h>
#include <linux/delay.h>
#include <asm/unaligned.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);
/* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
#define SNA32_CHECK 2147483648UL
static int iscsi_sna_lt(u32 n1, u32 n2)
{
return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
(n1 > n2 && (n2 - n1 < SNA32_CHECK)));
}
/* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
static int iscsi_sna_lte(u32 n1, u32 n2)
{
return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
(n1 > n2 && (n2 - n1 < SNA32_CHECK)));
}
void
iscsi_update_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);
/*
* standard specifies this check for when to update expected and
* max sequence numbers
*/
if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
return;
if (exp_cmdsn != session->exp_cmdsn &&
!iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
session->exp_cmdsn = exp_cmdsn;
if (max_cmdsn != session->max_cmdsn &&
!iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
session->max_cmdsn = max_cmdsn;
/*
* if the window closed with IO queued, then kick the
* xmit thread
*/
if (!list_empty(&session->leadconn->xmitqueue) ||
__kfifo_len(session->leadconn->mgmtqueue))
scsi_queue_work(session->host,
&session->leadconn->xmitwork);
}
}
EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *ctask,
struct iscsi_data *hdr)
{
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->unsol_offset);
if (ctask->unsol_count > conn->max_xmit_dlength) {
hton24(hdr->dlength, conn->max_xmit_dlength);
ctask->data_count = conn->max_xmit_dlength;
ctask->unsol_offset += ctask->data_count;
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 = build_itt(ctask->itt, conn->id, session->age);
hdr->data_length = cpu_to_be32(scsi_bufflen(sc));
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);
if (sc->cmd_len < MAX_COMMAND_SIZE)
memset(&hdr->cdb[sc->cmd_len], 0,
MAX_COMMAND_SIZE - sc->cmd_len);
ctask->data_count = 0;
ctask->imm_count = 0;
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->unsol_count = 0;
ctask->unsol_offset = 0;
ctask->unsol_datasn = 0;
if (session->imm_data_en) {
if (scsi_bufflen(sc) >= session->first_burst)
ctask->imm_count = min(session->first_burst,
conn->max_xmit_dlength);
else
ctask->imm_count = min(scsi_bufflen(sc),
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),
(scsi_bufflen(sc))) - ctask->imm_count;
ctask->unsol_offset = ctask->imm_count;
}
if (!ctask->unsol_count)
/* No unsolicit Data-Out's */
ctask->hdr->flags |= ISCSI_FLAG_CMD_FINAL;
} else {
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++;
debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x len %d "
"cmdsn %d win %d]\n",
sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
conn->id, sc, sc->cmnd[0], ctask->itt, scsi_bufflen(sc),
session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
}
/**
* iscsi_complete_command - return command back to scsi-ml
* @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_cmd_task *ctask)
{
struct iscsi_session *session = ctask->conn->session;
struct scsi_cmnd *sc = ctask->sc;
ctask->state = ISCSI_TASK_COMPLETED;
ctask->sc = NULL;
/* SCSI eh reuses commands to verify us */
sc->SCp.ptr = NULL;
list_del_init(&ctask->running);
__kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
sc->scsi_done(sc);
}
static void __iscsi_get_ctask(struct iscsi_cmd_task *ctask)
{
atomic_inc(&ctask->refcount);
}
static void __iscsi_put_ctask(struct iscsi_cmd_task *ctask)
{
if (atomic_dec_and_test(&ctask->refcount))
iscsi_complete_command(ctask);
}
/**
* 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 void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
struct iscsi_cmd_task *ctask, char *data,
int datalen)
{
struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
struct iscsi_session *session = conn->session;
struct scsi_cmnd *sc = ctask->sc;
iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
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) {
uint16_t 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 = be16_to_cpu(get_unaligned((__be16 *) data));
if (datalen < senselen)
goto invalid_datalen;
memcpy(sc->sense_buffer, data + 2,
min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
debug_scsi("copied %d bytes of sense\n",
min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
}
if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
int res_count = be32_to_cpu(rhdr->residual_count);
if (res_count > 0 && res_count <= scsi_bufflen(sc))
scsi_set_resid(sc, 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)
scsi_set_resid(sc, 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_put_ctask(ctask);
}
static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
{
struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
conn->tmfrsp_pdus_cnt++;
if (conn->tmabort_state != TMABORT_INITIAL)
return;
if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
conn->tmabort_state = TMABORT_SUCCESS;
else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
conn->tmabort_state = TMABORT_NOT_FOUND;
else
conn->tmabort_state = TMABORT_FAILED;
wake_up(&conn->ehwait);
}
static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
char *data, int datalen)
{
struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
struct iscsi_hdr rejected_pdu;
uint32_t itt;
conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
if (ntoh24(reject->dlength) > datalen)
return ISCSI_ERR_PROTO;
if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
itt = get_itt(rejected_pdu.itt);
printk(KERN_ERR "itt 0x%x had pdu (op 0x%x) rejected "
"due to DataDigest error.\n", itt,
rejected_pdu.opcode);
}
}
return 0;
}
/**
* __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 != RESERVED_ITT)
itt = get_itt(hdr->itt);
else
itt = ~0U;
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);
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_put_ctask(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);
iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
switch(opcode) {
case ISCSI_OP_LOGOUT_RSP:
if (datalen) {
rc = ISCSI_ERR_PROTO;
break;
}
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
*/
if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
rc = ISCSI_ERR_CONN_FAILED;
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;
}
iscsi_tmf_rsp(conn, hdr);
break;
case ISCSI_OP_NOOP_IN:
if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
rc = ISCSI_ERR_PROTO;
break;
}
conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
rc = ISCSI_ERR_CONN_FAILED;
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 == ~0U) {
iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
switch(opcode) {
case ISCSI_OP_NOOP_IN:
if (datalen) {
rc = ISCSI_ERR_PROTO;
break;
}
if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
break;
if (iscsi_recv_pdu(conn->cls_conn, hdr, NULL, 0))
rc = ISCSI_ERR_CONN_FAILED;
break;
case ISCSI_OP_REJECT:
rc = iscsi_handle_reject(conn, hdr, data, datalen);
break;
case ISCSI_OP_ASYNC_EVENT:
conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
rc = ISCSI_ERR_CONN_FAILED;
break;
default:
rc = ISCSI_ERR_BAD_OPCODE;
break;
}
} else
rc = ISCSI_ERR_BAD_ITT;
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 != RESERVED_ITT) {
if (((__force u32)hdr->itt & ISCSI_AGE_MASK) !=
(session->age << ISCSI_AGE_SHIFT)) {
printk(KERN_ERR "iscsi: received itt %x expected "
"session age (%x)\n", (__force u32)hdr->itt,
session->age & ISCSI_AGE_MASK);
return ISCSI_ERR_BAD_ITT;
}
if (((__force u32)hdr->itt & ISCSI_CID_MASK) !=
(conn->id << ISCSI_CID_SHIFT)) {
printk(KERN_ERR "iscsi: received itt %x, expected "
"CID (%x)\n", (__force u32)hdr->itt, conn->id);
return ISCSI_ERR_BAD_ITT;
}
itt = get_itt(hdr->itt);
} else
itt = ~0U;
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);
static void iscsi_prep_mtask(struct iscsi_conn *conn,
struct iscsi_mgmt_task *mtask)
{
struct iscsi_session *session = conn->session;
struct iscsi_hdr *hdr = mtask->hdr;
struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
/*
* pre-format CmdSN for outgoing PDU.
*/
nop->cmdsn = cpu_to_be32(session->cmdsn);
if (hdr->itt != RESERVED_ITT) {
hdr->itt = build_itt(mtask->itt, conn->id, session->age);
/*
* TODO: We always use immediate, so we never hit this.
* If we start to send tmfs or nops as non-immediate then
* we should start checking the cmdsn numbers for mgmt tasks.
*/
if (conn->c_stage == ISCSI_CONN_STARTED &&
!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
session->queued_cmdsn++;
session->cmdsn++;
}
}
if (session->tt->init_mgmt_task)
session->tt->init_mgmt_task(conn, mtask);
debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
hdr->opcode, hdr->itt, mtask->data_count);
}
static int iscsi_xmit_mtask(struct iscsi_conn *conn)
{
struct iscsi_hdr *hdr = conn->mtask->hdr;
int rc, was_logout = 0;
spin_unlock_bh(&conn->session->lock);
if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT) {
conn->session->state = ISCSI_STATE_IN_RECOVERY;
iscsi_block_session(session_to_cls(conn->session));
was_logout = 1;
}
rc = conn->session->tt->xmit_mgmt_task(conn, conn->mtask);
spin_lock_bh(&conn->session->lock);
if (rc)
return rc;
/* done with this in-progress mtask */
conn->mtask = NULL;
if (was_logout) {
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
return -ENODATA;
}
return 0;
}
static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
{
struct iscsi_session *session = conn->session;
/*
* Check for iSCSI window and take care of CmdSN wrap-around
*/
if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
debug_scsi("iSCSI CmdSN closed. ExpCmdSn %u MaxCmdSN %u "
"CmdSN %u/%u\n", session->exp_cmdsn,
session->max_cmdsn, session->cmdsn,
session->queued_cmdsn);
return -ENOSPC;
}
return 0;
}
static int iscsi_xmit_ctask(struct iscsi_conn *conn)
{
struct iscsi_cmd_task *ctask = conn->ctask;
int rc = 0;
/*
* serialize with TMF AbortTask
*/
if (ctask->state == ISCSI_TASK_ABORTING)
goto done;
__iscsi_get_ctask(ctask);
spin_unlock_bh(&conn->session->lock);
rc = conn->session->tt->xmit_cmd_task(conn, ctask);
spin_lock_bh(&conn->session->lock);
__iscsi_put_ctask(ctask);
done:
if (!rc)
/* done with this ctask */
conn->ctask = NULL;
return rc;
}
/**
* 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)
{
int rc = 0;
spin_lock_bh(&conn->session->lock);
if (unlikely(conn->suspend_tx)) {
debug_scsi("conn %d Tx suspended!\n", conn->id);
spin_unlock_bh(&conn->session->lock);
return -ENODATA;
}
if (conn->ctask) {
rc = iscsi_xmit_ctask(conn);
if (rc)
goto again;
}
if (conn->mtask) {
rc = iscsi_xmit_mtask(conn);
if (rc)
goto again;
}
/*
* process mgmt pdus like nops before commands since we should
* only have one nop-out as a ping from us and targets should not
* overflow us with nop-ins
*/
check_mgmt:
while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
sizeof(void*))) {
iscsi_prep_mtask(conn, conn->mtask);
list_add_tail(&conn->mtask->running, &conn->mgmt_run_list);
rc = iscsi_xmit_mtask(conn);
if (rc)
goto again;
}
/* process command queue */
while (!list_empty(&conn->xmitqueue)) {
/*
* iscsi tcp may readd the task to the xmitqueue to send
* write data
*/
conn->ctask = list_entry(conn->xmitqueue.next,
struct iscsi_cmd_task, running);
switch (conn->ctask->state) {
case ISCSI_TASK_ABORTING:
break;
case ISCSI_TASK_PENDING:
iscsi_prep_scsi_cmd_pdu(conn->ctask);
conn->session->tt->init_cmd_task(conn->ctask);
/* fall through */
default:
conn->ctask->state = ISCSI_TASK_RUNNING;
break;
}
list_move_tail(conn->xmitqueue.next, &conn->run_list);
rc = iscsi_xmit_ctask(conn);
if (rc)
goto again;
/*
* we could continuously get new ctask requests so
* we need to check the mgmt queue for nops that need to
* be sent to aviod starvation
*/
if (__kfifo_len(conn->mgmtqueue))
goto check_mgmt;
}
spin_unlock_bh(&conn->session->lock);
return -ENODATA;
again:
if (unlikely(conn->suspend_tx))
rc = -ENODATA;
spin_unlock_bh(&conn->session->lock);
return rc;
}
static void iscsi_xmitworker(struct work_struct *work)
{
struct iscsi_conn *conn =
container_of(work, struct iscsi_conn, xmitwork);
int rc;
/*
* serialize Xmit worker on a per-connection basis.
*/
do {
rc = iscsi_data_xmit(conn);
} while (rc >= 0 || rc == -EAGAIN);
}
enum {
FAILURE_BAD_HOST = 1,
FAILURE_SESSION_FAILED,
FAILURE_SESSION_FREED,
FAILURE_WINDOW_CLOSED,
FAILURE_OOM,
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;
sc->SCp.ptr = NULL;
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;
}
conn = session->leadconn;
if (!conn) {
reason = FAILURE_SESSION_FREED;
goto fault;
}
if (iscsi_check_cmdsn_window_closed(conn)) {
reason = FAILURE_WINDOW_CLOSED;
goto reject;
}
if (!__kfifo_get(session->cmdpool.queue, (void*)&ctask,
sizeof(void*))) {
reason = FAILURE_OOM;
goto reject;
}
session->queued_cmdsn++;
sc->SCp.phase = session->age;
sc->SCp.ptr = (char *)ctask;
atomic_set(&ctask->refcount, 1);
ctask->state = ISCSI_TASK_PENDING;
ctask->mtask = NULL;
ctask->conn = conn;
ctask->sc = sc;
INIT_LIST_HEAD(&ctask->running);
list_add_tail(&ctask->running, &conn->xmitqueue);
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);
scsi_set_resid(sc, scsi_bufflen(sc));
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 struct iscsi_mgmt_task *
__iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
char *data, uint32_t data_size)
{
struct iscsi_session *session = conn->session;
struct iscsi_mgmt_task *mtask;
if (session->state == ISCSI_STATE_TERMINATE)
return NULL;
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);
if (!__kfifo_get(session->mgmtpool.queue,
(void*)&mtask, sizeof(void*)))
return NULL;
}
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));
__kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
return mtask;
}
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;
struct iscsi_session *session = conn->session;
int err = 0;
spin_lock_bh(&session->lock);
if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
err = -EPERM;
spin_unlock_bh(&session->lock);
scsi_queue_work(session->host, &conn->xmitwork);
return err;
}
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]\n", 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\n",
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);
}
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;
/*
* 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;
ctask->mtask = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
NULL, 0);
if (!ctask->mtask) {
spin_unlock_bh(&session->lock);
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
spin_lock_bh(&session->lock)
debug_scsi("abort sent failure [itt 0x%x]\n", ctask->itt);
return -EPERM;
}
ctask->state = ISCSI_TASK_ABORTING;
debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
if (conn->tmabort_state == TMABORT_INITIAL) {
conn->tmfcmd_pdus_cnt++;
conn->tmabort_timer.expires = 20*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]\n", ctask->itt);
}
spin_unlock_bh(&session->lock);
mutex_unlock(&session->eh_mutex);
scsi_queue_work(session->host, &conn->xmitwork);
/*
* 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(&session->eh_mutex);
spin_lock_bh(&session->lock);
return 0;
}
/*
* session lock must be held
*/
static struct iscsi_mgmt_task *
iscsi_remove_mgmt_task(struct kfifo *fifo, uint32_t itt)
{
int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*);
struct iscsi_mgmt_task *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;
}
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->mgmtqueue, 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 must be held
*/
static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
int err)
{
struct scsi_cmnd *sc;
sc = ctask->sc;
if (!sc)
return;
if (ctask->state == ISCSI_TASK_PENDING)
/*
* cmd never made it to the xmit thread, so we should not count
* the cmd in the sequencing
*/
conn->session->queued_cmdsn--;
else
conn->session->tt->cleanup_cmd_task(conn, ctask);
iscsi_ctask_mtask_cleanup(ctask);
sc->result = err;
scsi_set_resid(sc, scsi_bufflen(sc));
if (conn->ctask == ctask)
conn->ctask = NULL;
/* release ref from queuecommand */
__iscsi_put_ctask(ctask);
}
static void iscsi_suspend_tx(struct iscsi_conn *conn)
{
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
scsi_flush_work(conn->session->host);
}
static void iscsi_start_tx(struct iscsi_conn *conn)
{
clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
scsi_queue_work(conn->session->host, &conn->xmitwork);
}
int iscsi_eh_abort(struct scsi_cmnd *sc)
{
struct Scsi_Host *host = sc->device->host;
struct iscsi_session *session = iscsi_hostdata(host->hostdata);
struct iscsi_cmd_task *ctask;
struct iscsi_conn *conn;
int rc;
mutex_lock(&session->eh_mutex);
spin_lock_bh(&session->lock);
/*
* if session was ISCSI_STATE_IN_RECOVERY then we may not have
* got the command.
*/
if (!sc->SCp.ptr) {
debug_scsi("sc never reached iscsi layer or it completed.\n");
spin_unlock_bh(&session->lock);
mutex_unlock(&session->eh_mutex);
return SUCCESS;
}
ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
conn = ctask->conn;
conn->eh_abort_cnt++;
debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
/*
* 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) {
debug_scsi("sc completed while abort in progress\n");
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;
}
if (ctask->state == ISCSI_TASK_PENDING) {
fail_command(conn, ctask, DID_ABORT << 16);
goto success;
}
conn->tmabort_state = TMABORT_INITIAL;
rc = iscsi_exec_abort_task(sc, ctask);
if (rc || sc->SCp.phase != session->age ||
session->state != ISCSI_STATE_LOGGED_IN)
goto failed;
iscsi_ctask_mtask_cleanup(ctask);
switch (conn->tmabort_state) {
case TMABORT_SUCCESS:
spin_unlock_bh(&session->lock);
iscsi_suspend_tx(conn);
/*
* clean up task if aborted. 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);
iscsi_start_tx(conn);
goto success_unlocked;
case TMABORT_NOT_FOUND:
if (!ctask->sc) {
/* ctask completed before tmf abort response */
debug_scsi("sc completed while abort in progress\n");
goto success;
}
/* fall through */
default:
/* timedout or failed */
spin_unlock_bh(&session->lock);
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
goto failed_unlocked;
}
success:
spin_unlock_bh(&session->lock);
success_unlocked:
debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
mutex_unlock(&session->eh_mutex);
return SUCCESS;
failed:
spin_unlock_bh(&session->lock);
failed_unlocked:
debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
mutex_unlock(&session->eh_mutex);
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
* @cmds_max: scsi host can queue
* @qdepth: scsi host cmds per lun
* @cmd_task_size: LLD ctask private data size
* @mgmt_task_size: LLD mtask private data size
* @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,
uint16_t cmds_max, uint16_t qdepth,
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;
if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
if (qdepth != 0)
printk(KERN_ERR "iscsi: invalid queue depth of %d. "
"Queue depth must be between 1 and %d.\n",
qdepth, ISCSI_MAX_CMD_PER_LUN);
qdepth = ISCSI_DEF_CMD_PER_LUN;
}
if (cmds_max < 2 || (cmds_max & (cmds_max - 1)) ||
cmds_max >= ISCSI_MGMT_ITT_OFFSET) {
if (cmds_max != 0)
printk(KERN_ERR "iscsi: invalid can_queue of %d. "
"can_queue must be a power of 2 and between "
"2 and %d - setting to %d.\n", cmds_max,
ISCSI_MGMT_ITT_OFFSET, ISCSI_DEF_XMIT_CMDS_MAX);
cmds_max = ISCSI_DEF_XMIT_CMDS_MAX;
}
shost = scsi_host_alloc(iscsit->host_template,
hostdata_privsize(sizeof(*session)));
if (!shost)
return NULL;
/* the iscsi layer takes one task for reserve */
shost->can_queue = cmds_max - 1;
shost->cmd_per_lun = qdepth;
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 = cmds_max;
session->queued_cmdsn = session->cmdsn = initial_cmdsn;
session->exp_cmdsn = initial_cmdsn + 1;
session->max_cmdsn = initial_cmdsn + 1;
session->max_r2t = 1;
session->tt = iscsit;
mutex_init(&session->eh_mutex);
/* 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;
INIT_LIST_HEAD(&ctask->running);
}
spin_lock_init(&session->lock);
/* 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;
INIT_LIST_HEAD(&mtask->running);
}
if (scsi_add_host(shost, NULL))
goto add_host_fail;
if (!try_module_get(iscsit->owner))
goto cls_session_fail;
cls_session = iscsi_create_session(shost, iscsit, 0);
if (!cls_session)
goto module_put;
*(unsigned long*)shost->hostdata = (unsigned long)cls_session;
return cls_session;
module_put:
module_put(iscsit->owner);
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);
struct module *owner = cls_session->transport->owner;
iscsi_unblock_session(cls_session);
scsi_remove_host(shost);
iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
kfree(session->password);
kfree(session->password_in);
kfree(session->username);
kfree(session->username_in);
kfree(session->targetname);
kfree(session->netdev);
kfree(session->hwaddress);
kfree(session->initiatorname);
iscsi_destroy_session(cls_session);
scsi_host_put(shost);
module_put(owner);
}
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);
INIT_LIST_HEAD(&conn->xmitqueue);
/* initialize general immediate & non-immediate PDU commands queue */
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);
/* 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(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
if (!data)
goto login_mtask_data_alloc_fail;
conn->login_mtask->data = conn->data = data;
init_timer(&conn->tmabort_timer);
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:
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;
spin_lock_bh(&session->lock);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
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);
/*
* 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);
}
/* flush queued up work because we free the connection below */
scsi_flush_work(session->host);
spin_lock_bh(&session->lock);
kfree(conn->data);
kfree(conn->persistent_address);
__kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
sizeof(void*));
if (session->leadconn == conn)
session->leadconn = NULL;
spin_unlock_bh(&session->lock);
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) {
printk(KERN_ERR "iscsi: can't start unbound connection\n");
return -EPERM;
}
if ((session->imm_data_en || !session->initial_r2t_en) &&
session->first_burst > session->max_burst) {
printk("iscsi: invalid burst lengths: "
"first_burst %d max_burst %d\n",
session->first_burst, session->max_burst);
return -EINVAL;
}
spin_lock_bh(&session->lock);
conn->c_stage = ISCSI_CONN_STARTED;
session->state = ISCSI_STATE_LOGGED_IN;
session->queued_cmdsn = session->cmdsn;
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->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 */
list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
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;
mutex_lock(&session->eh_mutex);
spin_lock_bh(&session->lock);
if (conn->stop_stage == STOP_CONN_TERM) {
spin_unlock_bh(&session->lock);
mutex_unlock(&session->eh_mutex);
return;
}
/*
* The LLD either freed/unset the lock on us, or userspace called
* stop but did not create a proper connection (connection was never
* bound or it was unbound then stop was called).
*/
if (!conn->recv_lock) {
spin_unlock_bh(&session->lock);
mutex_unlock(&session->eh_mutex);
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;
spin_unlock_bh(&session->lock);
iscsi_suspend_tx(conn);
write_lock_bh(conn->recv_lock);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
write_unlock_bh(conn->recv_lock);
/*
* 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));
}
}
/*
* flush queues.
*/
spin_lock_bh(&session->lock);
fail_all_commands(conn);
flush_control_queues(session, conn);
spin_unlock_bh(&session->lock);
mutex_unlock(&session->eh_mutex);
}
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 *conn = cls_conn->dd_data;
spin_lock_bh(&session->lock);
if (is_leading)
session->leadconn = conn;
spin_unlock_bh(&session->lock);
/*
* 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);
int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
enum iscsi_param param, char *buf, int buflen)
{
struct iscsi_conn *conn = cls_conn->dd_data;
struct iscsi_session *session = conn->session;
uint32_t value;
switch(param) {
case ISCSI_PARAM_MAX_RECV_DLENGTH:
sscanf(buf, "%d", &conn->max_recv_dlength);
break;
case ISCSI_PARAM_MAX_XMIT_DLENGTH:
sscanf(buf, "%d", &conn->max_xmit_dlength);
break;
case ISCSI_PARAM_HDRDGST_EN:
sscanf(buf, "%d", &conn->hdrdgst_en);
break;
case ISCSI_PARAM_DATADGST_EN:
sscanf(buf, "%d", &conn->datadgst_en);
break;
case ISCSI_PARAM_INITIAL_R2T_EN:
sscanf(buf, "%d", &session->initial_r2t_en);
break;
case ISCSI_PARAM_MAX_R2T:
sscanf(buf, "%d", &session->max_r2t);
break;
case ISCSI_PARAM_IMM_DATA_EN:
sscanf(buf, "%d", &session->imm_data_en);
break;
case ISCSI_PARAM_FIRST_BURST:
sscanf(buf, "%d", &session->first_burst);
break;
case ISCSI_PARAM_MAX_BURST:
sscanf(buf, "%d", &session->max_burst);
break;
case ISCSI_PARAM_PDU_INORDER_EN:
sscanf(buf, "%d", &session->pdu_inorder_en);
break;
case ISCSI_PARAM_DATASEQ_INORDER_EN:
sscanf(buf, "%d", &session->dataseq_inorder_en);
break;
case ISCSI_PARAM_ERL:
sscanf(buf, "%d", &session->erl);
break;
case ISCSI_PARAM_IFMARKER_EN:
sscanf(buf, "%d", &value);
BUG_ON(value);
break;
case ISCSI_PARAM_OFMARKER_EN:
sscanf(buf, "%d", &value);
BUG_ON(value);
break;
case ISCSI_PARAM_EXP_STATSN:
sscanf(buf, "%u", &conn->exp_statsn);
break;
case ISCSI_PARAM_USERNAME:
kfree(session->username);
session->username = kstrdup(buf, GFP_KERNEL);
if (!session->username)
return -ENOMEM;
break;
case ISCSI_PARAM_USERNAME_IN:
kfree(session->username_in);
session->username_in = kstrdup(buf, GFP_KERNEL);
if (!session->username_in)
return -ENOMEM;
break;
case ISCSI_PARAM_PASSWORD:
kfree(session->password);
session->password = kstrdup(buf, GFP_KERNEL);
if (!session->password)
return -ENOMEM;
break;
case ISCSI_PARAM_PASSWORD_IN:
kfree(session->password_in);
session->password_in = kstrdup(buf, GFP_KERNEL);
if (!session->password_in)
return -ENOMEM;
break;
case ISCSI_PARAM_TARGET_NAME:
/* this should not change between logins */
if (session->targetname)
break;
session->targetname = kstrdup(buf, GFP_KERNEL);
if (!session->targetname)
return -ENOMEM;
break;
case ISCSI_PARAM_TPGT:
sscanf(buf, "%d", &session->tpgt);
break;
case ISCSI_PARAM_PERSISTENT_PORT:
sscanf(buf, "%d", &conn->persistent_port);
break;
case ISCSI_PARAM_PERSISTENT_ADDRESS:
/*
* this is the address returned in discovery so it should
* not change between logins.
*/
if (conn->persistent_address)
break;
conn->persistent_address = kstrdup(buf, GFP_KERNEL);
if (!conn->persistent_address)
return -ENOMEM;
break;
default:
return -ENOSYS;
}
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_set_param);
int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
enum iscsi_param param, char *buf)
{
struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
int len;
switch(param) {
case ISCSI_PARAM_INITIAL_R2T_EN:
len = sprintf(buf, "%d\n", session->initial_r2t_en);
break;
case ISCSI_PARAM_MAX_R2T:
len = sprintf(buf, "%hu\n", session->max_r2t);
break;
case ISCSI_PARAM_IMM_DATA_EN:
len = sprintf(buf, "%d\n", session->imm_data_en);
break;
case ISCSI_PARAM_FIRST_BURST:
len = sprintf(buf, "%u\n", session->first_burst);
break;
case ISCSI_PARAM_MAX_BURST:
len = sprintf(buf, "%u\n", session->max_burst);
break;
case ISCSI_PARAM_PDU_INORDER_EN:
len = sprintf(buf, "%d\n", session->pdu_inorder_en);
break;
case ISCSI_PARAM_DATASEQ_INORDER_EN:
len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
break;
case ISCSI_PARAM_ERL:
len = sprintf(buf, "%d\n", session->erl);
break;
case ISCSI_PARAM_TARGET_NAME:
len = sprintf(buf, "%s\n", session->targetname);
break;
case ISCSI_PARAM_TPGT:
len = sprintf(buf, "%d\n", session->tpgt);
break;
case ISCSI_PARAM_USERNAME:
len = sprintf(buf, "%s\n", session->username);
break;
case ISCSI_PARAM_USERNAME_IN:
len = sprintf(buf, "%s\n", session->username_in);
break;
case ISCSI_PARAM_PASSWORD:
len = sprintf(buf, "%s\n", session->password);
break;
case ISCSI_PARAM_PASSWORD_IN:
len = sprintf(buf, "%s\n", session->password_in);
break;
default:
return -ENOSYS;
}
return len;
}
EXPORT_SYMBOL_GPL(iscsi_session_get_param);
int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
enum iscsi_param param, char *buf)
{
struct iscsi_conn *conn = cls_conn->dd_data;
int len;
switch(param) {
case ISCSI_PARAM_MAX_RECV_DLENGTH:
len = sprintf(buf, "%u\n", conn->max_recv_dlength);
break;
case ISCSI_PARAM_MAX_XMIT_DLENGTH:
len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
break;
case ISCSI_PARAM_HDRDGST_EN:
len = sprintf(buf, "%d\n", conn->hdrdgst_en);
break;
case ISCSI_PARAM_DATADGST_EN:
len = sprintf(buf, "%d\n", conn->datadgst_en);
break;
case ISCSI_PARAM_IFMARKER_EN:
len = sprintf(buf, "%d\n", conn->ifmarker_en);
break;
case ISCSI_PARAM_OFMARKER_EN:
len = sprintf(buf, "%d\n", conn->ofmarker_en);
break;
case ISCSI_PARAM_EXP_STATSN:
len = sprintf(buf, "%u\n", conn->exp_statsn);
break;
case ISCSI_PARAM_PERSISTENT_PORT:
len = sprintf(buf, "%d\n", conn->persistent_port);
break;
case ISCSI_PARAM_PERSISTENT_ADDRESS:
len = sprintf(buf, "%s\n", conn->persistent_address);
break;
default:
return -ENOSYS;
}
return len;
}
EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
char *buf)
{
struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
int len;
switch (param) {
case ISCSI_HOST_PARAM_NETDEV_NAME:
if (!session->netdev)
len = sprintf(buf, "%s\n", "default");
else
len = sprintf(buf, "%s\n", session->netdev);
break;
case ISCSI_HOST_PARAM_HWADDRESS:
if (!session->hwaddress)
len = sprintf(buf, "%s\n", "default");
else
len = sprintf(buf, "%s\n", session->hwaddress);
break;
case ISCSI_HOST_PARAM_INITIATOR_NAME:
if (!session->initiatorname)
len = sprintf(buf, "%s\n", "unknown");
else
len = sprintf(buf, "%s\n", session->initiatorname);
break;
default:
return -ENOSYS;
}
return len;
}
EXPORT_SYMBOL_GPL(iscsi_host_get_param);
int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
char *buf, int buflen)
{
struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
switch (param) {
case ISCSI_HOST_PARAM_NETDEV_NAME:
if (!session->netdev)
session->netdev = kstrdup(buf, GFP_KERNEL);
break;
case ISCSI_HOST_PARAM_HWADDRESS:
if (!session->hwaddress)
session->hwaddress = kstrdup(buf, GFP_KERNEL);
break;
case ISCSI_HOST_PARAM_INITIATOR_NAME:
if (!session->initiatorname)
session->initiatorname = kstrdup(buf, GFP_KERNEL);
break;
default:
return -ENOSYS;
}
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_host_set_param);
MODULE_AUTHOR("Mike Christie");
MODULE_DESCRIPTION("iSCSI library functions");
MODULE_LICENSE("GPL");
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