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linux/drivers/scsi/libiscsi.c
Nicholas Bellinger 8304bbceee iscsi: Add Serial Number Arithmetic LT and GT into iscsi_proto.h 
This patch moves the iscsi_sna_lt() and iscsi_sna_lte(), along with
iscsi_sna_gt() and iscsi_sna_gte() from iscsi_target_mod into
static inlines inside of include/scsi/iscsi_proto.h

This patch also includes the ISCSI_HDR_LEN and ISCSI_CRC_LEN
definitions.

(Added JesperJ simpliciation for iscsi_sna_* usage)

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
2011-07-25 07:48:08 +00:00

3475 lines
91 KiB
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/kfifo.h>
#include <linux/delay.h>
#include <linux/log2.h>
#include <linux/slab.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>
static int iscsi_dbg_lib_conn;
module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug_libiscsi_conn,
"Turn on debugging for connections in libiscsi module. "
"Set to 1 to turn on, and zero to turn off. Default is off.");
static int iscsi_dbg_lib_session;
module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug_libiscsi_session,
"Turn on debugging for sessions in libiscsi module. "
"Set to 1 to turn on, and zero to turn off. Default is off.");
static int iscsi_dbg_lib_eh;
module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug_libiscsi_eh,
"Turn on debugging for error handling in libiscsi module. "
"Set to 1 to turn on, and zero to turn off. Default is off.");
#define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...) \
do { \
if (iscsi_dbg_lib_conn) \
iscsi_conn_printk(KERN_INFO, _conn, \
"%s " dbg_fmt, \
__func__, ##arg); \
} while (0);
#define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...) \
do { \
if (iscsi_dbg_lib_session) \
iscsi_session_printk(KERN_INFO, _session, \
"%s " dbg_fmt, \
__func__, ##arg); \
} while (0);
#define ISCSI_DBG_EH(_session, dbg_fmt, arg...) \
do { \
if (iscsi_dbg_lib_eh) \
iscsi_session_printk(KERN_INFO, _session, \
"%s " dbg_fmt, \
__func__, ##arg); \
} while (0);
inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
{
struct Scsi_Host *shost = conn->session->host;
struct iscsi_host *ihost = shost_priv(shost);
if (ihost->workq)
queue_work(ihost->workq, &conn->xmitwork);
}
EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
static void __iscsi_update_cmdsn(struct iscsi_session *session,
uint32_t exp_cmdsn, uint32_t max_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->cmdqueue) ||
!list_empty(&session->leadconn->mgmtqueue))
iscsi_conn_queue_work(session->leadconn);
}
}
void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
{
__iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
be32_to_cpu(hdr->max_cmdsn));
}
EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
/**
* iscsi_prep_data_out_pdu - initialize Data-Out
* @task: scsi command task
* @r2t: R2T info
* @hdr: iscsi data in pdu
*
* Notes:
* Initialize Data-Out within this R2T sequence and finds
* proper data_offset within this SCSI command.
*
* This function is called with connection lock taken.
**/
void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
struct iscsi_data *hdr)
{
struct iscsi_conn *conn = task->conn;
unsigned int left = r2t->data_length - r2t->sent;
task->hdr_len = sizeof(struct iscsi_data);
memset(hdr, 0, sizeof(struct iscsi_data));
hdr->ttt = r2t->ttt;
hdr->datasn = cpu_to_be32(r2t->datasn);
r2t->datasn++;
hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
hdr->lun = task->lun;
hdr->itt = task->hdr_itt;
hdr->exp_statsn = r2t->exp_statsn;
hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
if (left > conn->max_xmit_dlength) {
hton24(hdr->dlength, conn->max_xmit_dlength);
r2t->data_count = conn->max_xmit_dlength;
hdr->flags = 0;
} else {
hton24(hdr->dlength, left);
r2t->data_count = left;
hdr->flags = ISCSI_FLAG_CMD_FINAL;
}
conn->dataout_pdus_cnt++;
}
EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
{
unsigned exp_len = task->hdr_len + len;
if (exp_len > task->hdr_max) {
WARN_ON(1);
return -EINVAL;
}
WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
task->hdr_len = exp_len;
return 0;
}
/*
* make an extended cdb AHS
*/
static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
{
struct scsi_cmnd *cmd = task->sc;
unsigned rlen, pad_len;
unsigned short ahslength;
struct iscsi_ecdb_ahdr *ecdb_ahdr;
int rc;
ecdb_ahdr = iscsi_next_hdr(task);
rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
ahslength = rlen + sizeof(ecdb_ahdr->reserved);
pad_len = iscsi_padding(rlen);
rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
if (rc)
return rc;
if (pad_len)
memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
ecdb_ahdr->reserved = 0;
memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
ISCSI_DBG_SESSION(task->conn->session,
"iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
"rlen %d pad_len %d ahs_length %d iscsi_headers_size "
"%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
task->hdr_len);
return 0;
}
static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
{
struct scsi_cmnd *sc = task->sc;
struct iscsi_rlength_ahdr *rlen_ahdr;
int rc;
rlen_ahdr = iscsi_next_hdr(task);
rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
if (rc)
return rc;
rlen_ahdr->ahslength =
cpu_to_be16(sizeof(rlen_ahdr->read_length) +
sizeof(rlen_ahdr->reserved));
rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
rlen_ahdr->reserved = 0;
rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
ISCSI_DBG_SESSION(task->conn->session,
"bidi-in rlen_ahdr->read_length(%d) "
"rlen_ahdr->ahslength(%d)\n",
be32_to_cpu(rlen_ahdr->read_length),
be16_to_cpu(rlen_ahdr->ahslength));
return 0;
}
/**
* iscsi_check_tmf_restrictions - check if a task is affected by TMF
* @task: iscsi task
* @opcode: opcode to check for
*
* During TMF a task has to be checked if it's affected.
* All unrelated I/O can be passed through, but I/O to the
* affected LUN should be restricted.
* If 'fast_abort' is set we won't be sending any I/O to the
* affected LUN.
* Otherwise the target is waiting for all TTTs to be completed,
* so we have to send all outstanding Data-Out PDUs to the target.
*/
static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
{
struct iscsi_conn *conn = task->conn;
struct iscsi_tm *tmf = &conn->tmhdr;
unsigned int hdr_lun;
if (conn->tmf_state == TMF_INITIAL)
return 0;
if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
return 0;
switch (ISCSI_TM_FUNC_VALUE(tmf)) {
case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
/*
* Allow PDUs for unrelated LUNs
*/
hdr_lun = scsilun_to_int(&tmf->lun);
if (hdr_lun != task->sc->device->lun)
return 0;
/* fall through */
case ISCSI_TM_FUNC_TARGET_WARM_RESET:
/*
* Fail all SCSI cmd PDUs
*/
if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
iscsi_conn_printk(KERN_INFO, conn,
"task [op %x/%x itt "
"0x%x/0x%x] "
"rejected.\n",
task->hdr->opcode, opcode,
task->itt, task->hdr_itt);
return -EACCES;
}
/*
* And also all data-out PDUs in response to R2T
* if fast_abort is set.
*/
if (conn->session->fast_abort) {
iscsi_conn_printk(KERN_INFO, conn,
"task [op %x/%x itt "
"0x%x/0x%x] fast abort.\n",
task->hdr->opcode, opcode,
task->itt, task->hdr_itt);
return -EACCES;
}
break;
case ISCSI_TM_FUNC_ABORT_TASK:
/*
* the caller has already checked if the task
* they want to abort was in the pending queue so if
* we are here the cmd pdu has gone out already, and
* we will only hit this for data-outs
*/
if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
task->hdr_itt == tmf->rtt) {
ISCSI_DBG_SESSION(conn->session,
"Preventing task %x/%x from sending "
"data-out due to abort task in "
"progress\n", task->itt,
task->hdr_itt);
return -EACCES;
}
break;
}
return 0;
}
/**
* iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
* @task: iscsi 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 int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
{
struct iscsi_conn *conn = task->conn;
struct iscsi_session *session = conn->session;
struct scsi_cmnd *sc = task->sc;
struct iscsi_scsi_req *hdr;
unsigned hdrlength, cmd_len;
itt_t itt;
int rc;
rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
if (rc)
return rc;
if (conn->session->tt->alloc_pdu) {
rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
if (rc)
return rc;
}
hdr = (struct iscsi_scsi_req *)task->hdr;
itt = hdr->itt;
memset(hdr, 0, sizeof(*hdr));
if (session->tt->parse_pdu_itt)
hdr->itt = task->hdr_itt = itt;
else
hdr->itt = task->hdr_itt = build_itt(task->itt,
task->conn->session->age);
task->hdr_len = 0;
rc = iscsi_add_hdr(task, sizeof(*hdr));
if (rc)
return rc;
hdr->opcode = ISCSI_OP_SCSI_CMD;
hdr->flags = ISCSI_ATTR_SIMPLE;
int_to_scsilun(sc->device->lun, &hdr->lun);
task->lun = hdr->lun;
hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
cmd_len = sc->cmd_len;
if (cmd_len < ISCSI_CDB_SIZE)
memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
else if (cmd_len > ISCSI_CDB_SIZE) {
rc = iscsi_prep_ecdb_ahs(task);
if (rc)
return rc;
cmd_len = ISCSI_CDB_SIZE;
}
memcpy(hdr->cdb, sc->cmnd, cmd_len);
task->imm_count = 0;
if (scsi_bidi_cmnd(sc)) {
hdr->flags |= ISCSI_FLAG_CMD_READ;
rc = iscsi_prep_bidi_ahs(task);
if (rc)
return rc;
}
if (sc->sc_data_direction == DMA_TO_DEVICE) {
unsigned out_len = scsi_out(sc)->length;
struct iscsi_r2t_info *r2t = &task->unsol_r2t;
hdr->data_length = cpu_to_be32(out_len);
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_length bytes to be sent via R2T ack's
*
* pad_count bytes to be sent as zero-padding
*/
memset(r2t, 0, sizeof(*r2t));
if (session->imm_data_en) {
if (out_len >= session->first_burst)
task->imm_count = min(session->first_burst,
conn->max_xmit_dlength);
else
task->imm_count = min(out_len,
conn->max_xmit_dlength);
hton24(hdr->dlength, task->imm_count);
} else
zero_data(hdr->dlength);
if (!session->initial_r2t_en) {
r2t->data_length = min(session->first_burst, out_len) -
task->imm_count;
r2t->data_offset = task->imm_count;
r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
}
if (!task->unsol_r2t.data_length)
/* No unsolicit Data-Out's */
hdr->flags |= ISCSI_FLAG_CMD_FINAL;
} else {
hdr->flags |= ISCSI_FLAG_CMD_FINAL;
zero_data(hdr->dlength);
hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
if (sc->sc_data_direction == DMA_FROM_DEVICE)
hdr->flags |= ISCSI_FLAG_CMD_READ;
}
/* calculate size of additional header segments (AHSs) */
hdrlength = task->hdr_len - sizeof(*hdr);
WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
hdrlength /= ISCSI_PAD_LEN;
WARN_ON(hdrlength >= 256);
hdr->hlength = hdrlength & 0xFF;
hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
if (session->tt->init_task && session->tt->init_task(task))
return -EIO;
task->state = ISCSI_TASK_RUNNING;
session->cmdsn++;
conn->scsicmd_pdus_cnt++;
ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
"itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
scsi_bidi_cmnd(sc) ? "bidirectional" :
sc->sc_data_direction == DMA_TO_DEVICE ?
"write" : "read", conn->id, sc, sc->cmnd[0],
task->itt, scsi_bufflen(sc),
scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
session->cmdsn,
session->max_cmdsn - session->exp_cmdsn + 1);
return 0;
}
/**
* iscsi_free_task - free a task
* @task: iscsi cmd task
*
* Must be called with session lock.
* This function returns the scsi command to scsi-ml or cleans
* up mgmt tasks then returns the task to the pool.
*/
static void iscsi_free_task(struct iscsi_task *task)
{
struct iscsi_conn *conn = task->conn;
struct iscsi_session *session = conn->session;
struct scsi_cmnd *sc = task->sc;
int oldstate = task->state;
ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
task->itt, task->state, task->sc);
session->tt->cleanup_task(task);
task->state = ISCSI_TASK_FREE;
task->sc = NULL;
/*
* login task is preallocated so do not free
*/
if (conn->login_task == task)
return;
kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
if (sc) {
task->sc = NULL;
/* SCSI eh reuses commands to verify us */
sc->SCp.ptr = NULL;
/*
* queue command may call this to free the task, so
* it will decide how to return sc to scsi-ml.
*/
if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
sc->scsi_done(sc);
}
}
void __iscsi_get_task(struct iscsi_task *task)
{
atomic_inc(&task->refcount);
}
EXPORT_SYMBOL_GPL(__iscsi_get_task);
void __iscsi_put_task(struct iscsi_task *task)
{
if (atomic_dec_and_test(&task->refcount))
iscsi_free_task(task);
}
EXPORT_SYMBOL_GPL(__iscsi_put_task);
void iscsi_put_task(struct iscsi_task *task)
{
struct iscsi_session *session = task->conn->session;
spin_lock_bh(&session->lock);
__iscsi_put_task(task);
spin_unlock_bh(&session->lock);
}
EXPORT_SYMBOL_GPL(iscsi_put_task);
/**
* iscsi_complete_task - finish a task
* @task: iscsi cmd task
* @state: state to complete task with
*
* Must be called with session lock.
*/
static void iscsi_complete_task(struct iscsi_task *task, int state)
{
struct iscsi_conn *conn = task->conn;
ISCSI_DBG_SESSION(conn->session,
"complete task itt 0x%x state %d sc %p\n",
task->itt, task->state, task->sc);
if (task->state == ISCSI_TASK_COMPLETED ||
task->state == ISCSI_TASK_ABRT_TMF ||
task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
task->state == ISCSI_TASK_REQUEUE_SCSIQ)
return;
WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
task->state = state;
if (!list_empty(&task->running))
list_del_init(&task->running);
if (conn->task == task)
conn->task = NULL;
if (conn->ping_task == task)
conn->ping_task = NULL;
/* release get from queueing */
__iscsi_put_task(task);
}
/**
* iscsi_complete_scsi_task - finish scsi task normally
* @task: iscsi task for scsi cmd
* @exp_cmdsn: expected cmd sn in cpu format
* @max_cmdsn: max cmd sn in cpu format
*
* This is used when drivers do not need or cannot perform
* lower level pdu processing.
*
* Called with session lock
*/
void iscsi_complete_scsi_task(struct iscsi_task *task,
uint32_t exp_cmdsn, uint32_t max_cmdsn)
{
struct iscsi_conn *conn = task->conn;
ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
conn->last_recv = jiffies;
__iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
}
EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
/*
* session lock must be held and if not called for a task that is
* still pending or from the xmit thread, then xmit thread must
* be suspended.
*/
static void fail_scsi_task(struct iscsi_task *task, int err)
{
struct iscsi_conn *conn = task->conn;
struct scsi_cmnd *sc;
int state;
/*
* if a command completes and we get a successful tmf response
* we will hit this because the scsi eh abort code does not take
* a ref to the task.
*/
sc = task->sc;
if (!sc)
return;
if (task->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--;
/* it was never sent so just complete like normal */
state = ISCSI_TASK_COMPLETED;
} else if (err == DID_TRANSPORT_DISRUPTED)
state = ISCSI_TASK_ABRT_SESS_RECOV;
else
state = ISCSI_TASK_ABRT_TMF;
sc->result = err << 16;
if (!scsi_bidi_cmnd(sc))
scsi_set_resid(sc, scsi_bufflen(sc));
else {
scsi_out(sc)->resid = scsi_out(sc)->length;
scsi_in(sc)->resid = scsi_in(sc)->length;
}
iscsi_complete_task(task, state);
}
static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
struct iscsi_task *task)
{
struct iscsi_session *session = conn->session;
struct iscsi_hdr *hdr = task->hdr;
struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
return -ENOTCONN;
if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
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) {
/*
* TODO: We always use immediate for normal session pdus.
* If we start to send tmfs or nops as non-immediate then
* we should start checking the cmdsn numbers for mgmt tasks.
*
* During discovery sessions iscsid sends TEXT as non immediate,
* but we always only send one PDU at a time.
*/
if (conn->c_stage == ISCSI_CONN_STARTED &&
!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
session->queued_cmdsn++;
session->cmdsn++;
}
}
if (session->tt->init_task && session->tt->init_task(task))
return -EIO;
if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
session->state = ISCSI_STATE_LOGGING_OUT;
task->state = ISCSI_TASK_RUNNING;
ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
"datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
hdr->itt, task->data_count);
return 0;
}
static struct iscsi_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_host *ihost = shost_priv(session->host);
uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
struct iscsi_task *task;
itt_t itt;
if (session->state == ISCSI_STATE_TERMINATE)
return NULL;
if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
/*
* Login and Text are sent serially, in
* request-followed-by-response sequence.
* Same task can be used. Same ITT must be used.
* Note that login_task is preallocated at conn_create().
*/
if (conn->login_task->state != ISCSI_TASK_FREE) {
iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
"progress. Cannot start new task.\n");
return NULL;
}
task = conn->login_task;
} else {
if (session->state != ISCSI_STATE_LOGGED_IN)
return NULL;
BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
if (!kfifo_out(&session->cmdpool.queue,
(void*)&task, sizeof(void*)))
return NULL;
}
/*
* released in complete pdu for task we expect a response for, and
* released by the lld when it has transmitted the task for
* pdus we do not expect a response for.
*/
atomic_set(&task->refcount, 1);
task->conn = conn;
task->sc = NULL;
INIT_LIST_HEAD(&task->running);
task->state = ISCSI_TASK_PENDING;
if (data_size) {
memcpy(task->data, data, data_size);
task->data_count = data_size;
} else
task->data_count = 0;
if (conn->session->tt->alloc_pdu) {
if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
"pdu for mgmt task.\n");
goto free_task;
}
}
itt = task->hdr->itt;
task->hdr_len = sizeof(struct iscsi_hdr);
memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
if (hdr->itt != RESERVED_ITT) {
if (session->tt->parse_pdu_itt)
task->hdr->itt = itt;
else
task->hdr->itt = build_itt(task->itt,
task->conn->session->age);
}
if (!ihost->workq) {
if (iscsi_prep_mgmt_task(conn, task))
goto free_task;
if (session->tt->xmit_task(task))
goto free_task;
} else {
list_add_tail(&task->running, &conn->mgmtqueue);
iscsi_conn_queue_work(conn);
}
return task;
free_task:
__iscsi_put_task(task);
return NULL;
}
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);
return err;
}
EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
/**
* iscsi_cmd_rsp - SCSI Command Response processing
* @conn: iscsi connection
* @hdr: iscsi header
* @task: 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_task *task, char *data,
int datalen)
{
struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
struct iscsi_session *session = conn->session;
struct scsi_cmnd *sc = task->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:
iscsi_conn_printk(KERN_ERR, conn,
"Got CHECK_CONDITION but invalid data "
"buffer size of %d\n", datalen);
sc->result = DID_BAD_TARGET << 16;
goto out;
}
senselen = get_unaligned_be16(data);
if (datalen < senselen)
goto invalid_datalen;
memcpy(sc->sense_buffer, data + 2,
min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
min_t(uint16_t, senselen,
SCSI_SENSE_BUFFERSIZE));
}
if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
int res_count = be32_to_cpu(rhdr->bi_residual_count);
if (scsi_bidi_cmnd(sc) && res_count > 0 &&
(rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
res_count <= scsi_in(sc)->length))
scsi_in(sc)->resid = res_count;
else
sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
}
if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
ISCSI_FLAG_CMD_OVERFLOW)) {
int res_count = be32_to_cpu(rhdr->residual_count);
if (res_count > 0 &&
(rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
res_count <= scsi_bufflen(sc)))
/* write side for bidi or uni-io set_resid */
scsi_set_resid(sc, res_count);
else
sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
}
out:
ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
sc, sc->result, task->itt);
conn->scsirsp_pdus_cnt++;
iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
}
/**
* iscsi_data_in_rsp - SCSI Data-In Response processing
* @conn: iscsi connection
* @hdr: iscsi pdu
* @task: scsi command task
**/
static void
iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
struct iscsi_task *task)
{
struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
struct scsi_cmnd *sc = task->sc;
if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
return;
iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
sc->result = (DID_OK << 16) | rhdr->cmd_status;
conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
ISCSI_FLAG_DATA_OVERFLOW)) {
int res_count = be32_to_cpu(rhdr->residual_count);
if (res_count > 0 &&
(rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
res_count <= scsi_in(sc)->length))
scsi_in(sc)->resid = res_count;
else
sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
}
ISCSI_DBG_SESSION(conn->session, "data in with status done "
"[sc %p res %d itt 0x%x]\n",
sc, sc->result, task->itt);
conn->scsirsp_pdus_cnt++;
iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
}
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->tmf_state != TMF_QUEUED)
return;
if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
conn->tmf_state = TMF_SUCCESS;
else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
conn->tmf_state = TMF_NOT_FOUND;
else
conn->tmf_state = TMF_FAILED;
wake_up(&conn->ehwait);
}
static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
{
struct iscsi_nopout hdr;
struct iscsi_task *task;
if (!rhdr && conn->ping_task)
return;
memset(&hdr, 0, sizeof(struct iscsi_nopout));
hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
hdr.flags = ISCSI_FLAG_CMD_FINAL;
if (rhdr) {
hdr.lun = rhdr->lun;
hdr.ttt = rhdr->ttt;
hdr.itt = RESERVED_ITT;
} else
hdr.ttt = RESERVED_ITT;
task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
if (!task)
iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
else if (!rhdr) {
/* only track our nops */
conn->ping_task = task;
conn->last_ping = jiffies;
}
}
static int iscsi_nop_out_rsp(struct iscsi_task *task,
struct iscsi_nopin *nop, char *data, int datalen)
{
struct iscsi_conn *conn = task->conn;
int rc = 0;
if (conn->ping_task != task) {
/*
* If this is not in response to one of our
* nops then it must be from userspace.
*/
if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
data, datalen))
rc = ISCSI_ERR_CONN_FAILED;
} else
mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
return rc;
}
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;
int opcode, rc = 0;
conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
if (ntoh24(reject->dlength) > datalen ||
ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
"pdu. Invalid data length (pdu dlength "
"%u, datalen %d\n", ntoh24(reject->dlength),
datalen);
return ISCSI_ERR_PROTO;
}
memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
switch (reject->reason) {
case ISCSI_REASON_DATA_DIGEST_ERROR:
iscsi_conn_printk(KERN_ERR, conn,
"pdu (op 0x%x itt 0x%x) rejected "
"due to DataDigest error.\n",
rejected_pdu.itt, opcode);
break;
case ISCSI_REASON_IMM_CMD_REJECT:
iscsi_conn_printk(KERN_ERR, conn,
"pdu (op 0x%x itt 0x%x) rejected. Too many "
"immediate commands.\n",
rejected_pdu.itt, opcode);
/*
* We only send one TMF at a time so if the target could not
* handle it, then it should get fixed (RFC mandates that
* a target can handle one immediate TMF per conn).
*
* For nops-outs, we could have sent more than one if
* the target is sending us lots of nop-ins
*/
if (opcode != ISCSI_OP_NOOP_OUT)
return 0;
if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG))
/*
* nop-out in response to target's nop-out rejected.
* Just resend.
*/
iscsi_send_nopout(conn,
(struct iscsi_nopin*)&rejected_pdu);
else {
struct iscsi_task *task;
/*
* Our nop as ping got dropped. We know the target
* and transport are ok so just clean up
*/
task = iscsi_itt_to_task(conn, rejected_pdu.itt);
if (!task) {
iscsi_conn_printk(KERN_ERR, conn,
"Invalid pdu reject. Could "
"not lookup rejected task.\n");
rc = ISCSI_ERR_BAD_ITT;
} else
rc = iscsi_nop_out_rsp(task,
(struct iscsi_nopin*)&rejected_pdu,
NULL, 0);
}
break;
default:
iscsi_conn_printk(KERN_ERR, conn,
"pdu (op 0x%x itt 0x%x) rejected. Reason "
"code 0x%x\n", rejected_pdu.itt,
rejected_pdu.opcode, reject->reason);
break;
}
return rc;
}
/**
* iscsi_itt_to_task - look up task by itt
* @conn: iscsi connection
* @itt: itt
*
* This should be used for mgmt tasks like login and nops, or if
* the LDD's itt space does not include the session age.
*
* The session lock must be held.
*/
struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
{
struct iscsi_session *session = conn->session;
int i;
if (itt == RESERVED_ITT)
return NULL;
if (session->tt->parse_pdu_itt)
session->tt->parse_pdu_itt(conn, itt, &i, NULL);
else
i = get_itt(itt);
if (i >= session->cmds_max)
return NULL;
return session->cmds[i];
}
EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
/**
* __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_task *task;
uint32_t itt;
conn->last_recv = jiffies;
rc = iscsi_verify_itt(conn, hdr->itt);
if (rc)
return rc;
if (hdr->itt != RESERVED_ITT)
itt = get_itt(hdr->itt);
else
itt = ~0U;
ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
opcode, conn->id, itt, datalen);
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;
iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
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;
}
goto out;
}
switch(opcode) {
case ISCSI_OP_SCSI_CMD_RSP:
case ISCSI_OP_SCSI_DATA_IN:
task = iscsi_itt_to_ctask(conn, hdr->itt);
if (!task)
return ISCSI_ERR_BAD_ITT;
task->last_xfer = jiffies;
break;
case ISCSI_OP_R2T:
/*
* LLD handles R2Ts if they need to.
*/
return 0;
case ISCSI_OP_LOGOUT_RSP:
case ISCSI_OP_LOGIN_RSP:
case ISCSI_OP_TEXT_RSP:
case ISCSI_OP_SCSI_TMFUNC_RSP:
case ISCSI_OP_NOOP_IN:
task = iscsi_itt_to_task(conn, hdr->itt);
if (!task)
return ISCSI_ERR_BAD_ITT;
break;
default:
return ISCSI_ERR_BAD_OPCODE;
}
switch(opcode) {
case ISCSI_OP_SCSI_CMD_RSP:
iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
break;
case ISCSI_OP_SCSI_DATA_IN:
iscsi_data_in_rsp(conn, hdr, task);
break;
case ISCSI_OP_LOGOUT_RSP:
iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
if (datalen) {
rc = ISCSI_ERR_PROTO;
break;
}
conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
goto recv_pdu;
case ISCSI_OP_LOGIN_RSP:
case ISCSI_OP_TEXT_RSP:
iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
/*
* login related PDU's exp_statsn is handled in
* userspace
*/
goto recv_pdu;
case ISCSI_OP_SCSI_TMFUNC_RSP:
iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
if (datalen) {
rc = ISCSI_ERR_PROTO;
break;
}
iscsi_tmf_rsp(conn, hdr);
iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
break;
case ISCSI_OP_NOOP_IN:
iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
rc = ISCSI_ERR_PROTO;
break;
}
conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
data, datalen);
break;
default:
rc = ISCSI_ERR_BAD_OPCODE;
break;
}
out:
return rc;
recv_pdu:
if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
rc = ISCSI_ERR_CONN_FAILED;
iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
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);
int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
{
struct iscsi_session *session = conn->session;
int age = 0, i = 0;
if (itt == RESERVED_ITT)
return 0;
if (session->tt->parse_pdu_itt)
session->tt->parse_pdu_itt(conn, itt, &i, &age);
else {
i = get_itt(itt);
age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
}
if (age != session->age) {
iscsi_conn_printk(KERN_ERR, conn,
"received itt %x expected session age (%x)\n",
(__force u32)itt, session->age);
return ISCSI_ERR_BAD_ITT;
}
if (i >= session->cmds_max) {
iscsi_conn_printk(KERN_ERR, conn,
"received invalid itt index %u (max cmds "
"%u.\n", i, session->cmds_max);
return ISCSI_ERR_BAD_ITT;
}
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_verify_itt);
/**
* iscsi_itt_to_ctask - look up ctask by itt
* @conn: iscsi connection
* @itt: itt
*
* This should be used for cmd tasks.
*
* The session lock must be held.
*/
struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
{
struct iscsi_task *task;
if (iscsi_verify_itt(conn, itt))
return NULL;
task = iscsi_itt_to_task(conn, itt);
if (!task || !task->sc)
return NULL;
if (task->sc->SCp.phase != conn->session->age) {
iscsi_session_printk(KERN_ERR, conn->session,
"task's session age %d, expected %d\n",
task->sc->SCp.phase, conn->session->age);
return NULL;
}
return task;
}
EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
void iscsi_session_failure(struct iscsi_session *session,
enum iscsi_err err)
{
struct iscsi_conn *conn;
struct device *dev;
spin_lock_bh(&session->lock);
conn = session->leadconn;
if (session->state == ISCSI_STATE_TERMINATE || !conn) {
spin_unlock_bh(&session->lock);
return;
}
dev = get_device(&conn->cls_conn->dev);
spin_unlock_bh(&session->lock);
if (!dev)
return;
/*
* if the host is being removed bypass the connection
* recovery initialization because we are going to kill
* the session.
*/
if (err == ISCSI_ERR_INVALID_HOST)
iscsi_conn_error_event(conn->cls_conn, err);
else
iscsi_conn_failure(conn, err);
put_device(dev);
}
EXPORT_SYMBOL_GPL(iscsi_session_failure);
void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
{
struct iscsi_session *session = conn->session;
spin_lock_bh(&session->lock);
if (session->state == ISCSI_STATE_FAILED) {
spin_unlock_bh(&session->lock);
return;
}
if (conn->stop_stage == 0)
session->state = ISCSI_STATE_FAILED;
spin_unlock_bh(&session->lock);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
iscsi_conn_error_event(conn->cls_conn, err);
}
EXPORT_SYMBOL_GPL(iscsi_conn_failure);
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)) {
ISCSI_DBG_SESSION(session, "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_task(struct iscsi_conn *conn)
{
struct iscsi_task *task = conn->task;
int rc;
if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
return -ENODATA;
__iscsi_get_task(task);
spin_unlock_bh(&conn->session->lock);
rc = conn->session->tt->xmit_task(task);
spin_lock_bh(&conn->session->lock);
if (!rc) {
/* done with this task */
task->last_xfer = jiffies;
conn->task = NULL;
}
__iscsi_put_task(task);
return rc;
}
/**
* iscsi_requeue_task - requeue task to run from session workqueue
* @task: task to requeue
*
* LLDs that need to run a task from the session workqueue should call
* this. The session lock must be held. This should only be called
* by software drivers.
*/
void iscsi_requeue_task(struct iscsi_task *task)
{
struct iscsi_conn *conn = task->conn;
/*
* this may be on the requeue list already if the xmit_task callout
* is handling the r2ts while we are adding new ones
*/
if (list_empty(&task->running))
list_add_tail(&task->running, &conn->requeue);
iscsi_conn_queue_work(conn);
}
EXPORT_SYMBOL_GPL(iscsi_requeue_task);
/**
* 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_task *task;
int rc = 0;
spin_lock_bh(&conn->session->lock);
if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
spin_unlock_bh(&conn->session->lock);
return -ENODATA;
}
if (conn->task) {
rc = iscsi_xmit_task(conn);
if (rc)
goto done;
}
/*
* 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 (!list_empty(&conn->mgmtqueue)) {
conn->task = list_entry(conn->mgmtqueue.next,
struct iscsi_task, running);
list_del_init(&conn->task->running);
if (iscsi_prep_mgmt_task(conn, conn->task)) {
__iscsi_put_task(conn->task);
conn->task = NULL;
continue;
}
rc = iscsi_xmit_task(conn);
if (rc)
goto done;
}
/* process pending command queue */
while (!list_empty(&conn->cmdqueue)) {
conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
running);
list_del_init(&conn->task->running);
if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
fail_scsi_task(conn->task, DID_IMM_RETRY);
continue;
}
rc = iscsi_prep_scsi_cmd_pdu(conn->task);
if (rc) {
if (rc == -ENOMEM || rc == -EACCES) {
list_add_tail(&conn->task->running,
&conn->cmdqueue);
conn->task = NULL;
goto done;
} else
fail_scsi_task(conn->task, DID_ABORT);
continue;
}
rc = iscsi_xmit_task(conn);
if (rc)
goto done;
/*
* we could continuously get new task requests so
* we need to check the mgmt queue for nops that need to
* be sent to aviod starvation
*/
if (!list_empty(&conn->mgmtqueue))
goto check_mgmt;
}
while (!list_empty(&conn->requeue)) {
/*
* we always do fastlogout - conn stop code will clean up.
*/
if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
break;
task = list_entry(conn->requeue.next, struct iscsi_task,
running);
if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
break;
conn->task = task;
list_del_init(&conn->task->running);
conn->task->state = ISCSI_TASK_RUNNING;
rc = iscsi_xmit_task(conn);
if (rc)
goto done;
if (!list_empty(&conn->mgmtqueue))
goto check_mgmt;
}
spin_unlock_bh(&conn->session->lock);
return -ENODATA;
done:
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);
}
static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
struct scsi_cmnd *sc)
{
struct iscsi_task *task;
if (!kfifo_out(&conn->session->cmdpool.queue,
(void *) &task, sizeof(void *)))
return NULL;
sc->SCp.phase = conn->session->age;
sc->SCp.ptr = (char *) task;
atomic_set(&task->refcount, 1);
task->state = ISCSI_TASK_PENDING;
task->conn = conn;
task->sc = sc;
task->have_checked_conn = false;
task->last_timeout = jiffies;
task->last_xfer = jiffies;
INIT_LIST_HEAD(&task->running);
return task;
}
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,
FAILURE_SESSION_LOGGING_OUT,
FAILURE_SESSION_NOT_READY,
};
int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
{
struct iscsi_cls_session *cls_session;
struct iscsi_host *ihost;
int reason = 0;
struct iscsi_session *session;
struct iscsi_conn *conn;
struct iscsi_task *task = NULL;
sc->result = 0;
sc->SCp.ptr = NULL;
ihost = shost_priv(host);
cls_session = starget_to_session(scsi_target(sc->device));
session = cls_session->dd_data;
spin_lock_bh(&session->lock);
reason = iscsi_session_chkready(cls_session);
if (reason) {
sc->result = reason;
goto fault;
}
if (session->state != ISCSI_STATE_LOGGED_IN) {
/*
* 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)
*/
switch (session->state) {
case ISCSI_STATE_FAILED:
case ISCSI_STATE_IN_RECOVERY:
reason = FAILURE_SESSION_IN_RECOVERY;
sc->result = DID_IMM_RETRY << 16;
break;
case ISCSI_STATE_LOGGING_OUT:
reason = FAILURE_SESSION_LOGGING_OUT;
sc->result = DID_IMM_RETRY << 16;
break;
case ISCSI_STATE_RECOVERY_FAILED:
reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
sc->result = DID_TRANSPORT_FAILFAST << 16;
break;
case ISCSI_STATE_TERMINATE:
reason = FAILURE_SESSION_TERMINATE;
sc->result = DID_NO_CONNECT << 16;
break;
default:
reason = FAILURE_SESSION_FREED;
sc->result = DID_NO_CONNECT << 16;
}
goto fault;
}
conn = session->leadconn;
if (!conn) {
reason = FAILURE_SESSION_FREED;
sc->result = DID_NO_CONNECT << 16;
goto fault;
}
if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
reason = FAILURE_SESSION_IN_RECOVERY;
sc->result = DID_REQUEUE;
goto fault;
}
if (iscsi_check_cmdsn_window_closed(conn)) {
reason = FAILURE_WINDOW_CLOSED;
goto reject;
}
task = iscsi_alloc_task(conn, sc);
if (!task) {
reason = FAILURE_OOM;
goto reject;
}
if (!ihost->workq) {
reason = iscsi_prep_scsi_cmd_pdu(task);
if (reason) {
if (reason == -ENOMEM || reason == -EACCES) {
reason = FAILURE_OOM;
goto prepd_reject;
} else {
sc->result = DID_ABORT << 16;
goto prepd_fault;
}
}
if (session->tt->xmit_task(task)) {
session->cmdsn--;
reason = FAILURE_SESSION_NOT_READY;
goto prepd_reject;
}
} else {
list_add_tail(&task->running, &conn->cmdqueue);
iscsi_conn_queue_work(conn);
}
session->queued_cmdsn++;
spin_unlock_bh(&session->lock);
return 0;
prepd_reject:
iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
reject:
spin_unlock_bh(&session->lock);
ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
sc->cmnd[0], reason);
return SCSI_MLQUEUE_TARGET_BUSY;
prepd_fault:
iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
fault:
spin_unlock_bh(&session->lock);
ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
sc->cmnd[0], reason);
if (!scsi_bidi_cmnd(sc))
scsi_set_resid(sc, scsi_bufflen(sc));
else {
scsi_out(sc)->resid = scsi_out(sc)->length;
scsi_in(sc)->resid = scsi_in(sc)->length;
}
sc->scsi_done(sc);
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_queuecommand);
int iscsi_change_queue_depth(struct scsi_device *sdev, int depth, int reason)
{
switch (reason) {
case SCSI_QDEPTH_DEFAULT:
scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
break;
case SCSI_QDEPTH_QFULL:
scsi_track_queue_full(sdev, depth);
break;
case SCSI_QDEPTH_RAMP_UP:
scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
break;
default:
return -EOPNOTSUPP;
}
return sdev->queue_depth;
}
EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
int iscsi_target_alloc(struct scsi_target *starget)
{
struct iscsi_cls_session *cls_session = starget_to_session(starget);
struct iscsi_session *session = cls_session->dd_data;
starget->can_queue = session->scsi_cmds_max;
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_target_alloc);
static void iscsi_tmf_timedout(unsigned long data)
{
struct iscsi_conn *conn = (struct iscsi_conn *)data;
struct iscsi_session *session = conn->session;
spin_lock(&session->lock);
if (conn->tmf_state == TMF_QUEUED) {
conn->tmf_state = TMF_TIMEDOUT;
ISCSI_DBG_EH(session, "tmf timedout\n");
/* unblock eh_abort() */
wake_up(&conn->ehwait);
}
spin_unlock(&session->lock);
}
static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
struct iscsi_tm *hdr, int age,
int timeout)
{
struct iscsi_session *session = conn->session;
struct iscsi_task *task;
task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
NULL, 0);
if (!task) {
spin_unlock_bh(&session->lock);
iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
spin_lock_bh(&session->lock);
return -EPERM;
}
conn->tmfcmd_pdus_cnt++;
conn->tmf_timer.expires = timeout * HZ + jiffies;
conn->tmf_timer.function = iscsi_tmf_timedout;
conn->tmf_timer.data = (unsigned long)conn;
add_timer(&conn->tmf_timer);
ISCSI_DBG_EH(session, "tmf set timeout\n");
spin_unlock_bh(&session->lock);
mutex_unlock(&session->eh_mutex);
/*
* block eh thread until:
*
* 1) tmf response
* 2) tmf timeout
* 3) session is terminated or restarted or userspace has
* given up on recovery
*/
wait_event_interruptible(conn->ehwait, age != session->age ||
session->state != ISCSI_STATE_LOGGED_IN ||
conn->tmf_state != TMF_QUEUED);
if (signal_pending(current))
flush_signals(current);
del_timer_sync(&conn->tmf_timer);
mutex_lock(&session->eh_mutex);
spin_lock_bh(&session->lock);
/* if the session drops it will clean up the task */
if (age != session->age ||
session->state != ISCSI_STATE_LOGGED_IN)
return -ENOTCONN;
return 0;
}
/*
* Fail commands. session lock held and recv side suspended and xmit
* thread flushed
*/
static void fail_scsi_tasks(struct iscsi_conn *conn, unsigned lun,
int error)
{
struct iscsi_task *task;
int i;
for (i = 0; i < conn->session->cmds_max; i++) {
task = conn->session->cmds[i];
if (!task->sc || task->state == ISCSI_TASK_FREE)
continue;
if (lun != -1 && lun != task->sc->device->lun)
continue;
ISCSI_DBG_SESSION(conn->session,
"failing sc %p itt 0x%x state %d\n",
task->sc, task->itt, task->state);
fail_scsi_task(task, error);
}
}
/**
* iscsi_suspend_queue - suspend iscsi_queuecommand
* @conn: iscsi conn to stop queueing IO on
*
* This grabs the session lock to make sure no one is in
* xmit_task/queuecommand, and then sets suspend to prevent
* new commands from being queued. This only needs to be called
* by offload drivers that need to sync a path like ep disconnect
* with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
* will call iscsi_start_tx and iscsi_unblock_session when in FFP.
*/
void iscsi_suspend_queue(struct iscsi_conn *conn)
{
spin_lock_bh(&conn->session->lock);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
spin_unlock_bh(&conn->session->lock);
}
EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
/**
* iscsi_suspend_tx - suspend iscsi_data_xmit
* @conn: iscsi conn tp stop processing IO on.
*
* This function sets the suspend bit to prevent iscsi_data_xmit
* from sending new IO, and if work is queued on the xmit thread
* it will wait for it to be completed.
*/
void iscsi_suspend_tx(struct iscsi_conn *conn)
{
struct Scsi_Host *shost = conn->session->host;
struct iscsi_host *ihost = shost_priv(shost);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
if (ihost->workq)
flush_workqueue(ihost->workq);
}
EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
static void iscsi_start_tx(struct iscsi_conn *conn)
{
clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
iscsi_conn_queue_work(conn);
}
/*
* We want to make sure a ping is in flight. It has timed out.
* And we are not busy processing a pdu that is making
* progress but got started before the ping and is taking a while
* to complete so the ping is just stuck behind it in a queue.
*/
static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
{
if (conn->ping_task &&
time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
(conn->ping_timeout * HZ), jiffies))
return 1;
else
return 0;
}
static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
{
enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
struct iscsi_task *task = NULL, *running_task;
struct iscsi_cls_session *cls_session;
struct iscsi_session *session;
struct iscsi_conn *conn;
int i;
cls_session = starget_to_session(scsi_target(sc->device));
session = cls_session->dd_data;
ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
spin_lock(&session->lock);
if (session->state != ISCSI_STATE_LOGGED_IN) {
/*
* We are probably in the middle of iscsi recovery so let
* that complete and handle the error.
*/
rc = BLK_EH_RESET_TIMER;
goto done;
}
conn = session->leadconn;
if (!conn) {
/* In the middle of shuting down */
rc = BLK_EH_RESET_TIMER;
goto done;
}
task = (struct iscsi_task *)sc->SCp.ptr;
if (!task) {
/*
* Raced with completion. Just reset timer, and let it
* complete normally
*/
rc = BLK_EH_RESET_TIMER;
goto done;
}
/*
* If we have sent (at least queued to the network layer) a pdu or
* recvd one for the task since the last timeout ask for
* more time. If on the next timeout we have not made progress
* we can check if it is the task or connection when we send the
* nop as a ping.
*/
if (time_after(task->last_xfer, task->last_timeout)) {
ISCSI_DBG_EH(session, "Command making progress. Asking "
"scsi-ml for more time to complete. "
"Last data xfer at %lu. Last timeout was at "
"%lu\n.", task->last_xfer, task->last_timeout);
task->have_checked_conn = false;
rc = BLK_EH_RESET_TIMER;
goto done;
}
if (!conn->recv_timeout && !conn->ping_timeout)
goto done;
/*
* if the ping timedout then we are in the middle of cleaning up
* and can let the iscsi eh handle it
*/
if (iscsi_has_ping_timed_out(conn)) {
rc = BLK_EH_RESET_TIMER;
goto done;
}
for (i = 0; i < conn->session->cmds_max; i++) {
running_task = conn->session->cmds[i];
if (!running_task->sc || running_task == task ||
running_task->state != ISCSI_TASK_RUNNING)
continue;
/*
* Only check if cmds started before this one have made
* progress, or this could never fail
*/
if (time_after(running_task->sc->jiffies_at_alloc,
task->sc->jiffies_at_alloc))
continue;
if (time_after(running_task->last_xfer, task->last_timeout)) {
/*
* This task has not made progress, but a task
* started before us has transferred data since
* we started/last-checked. We could be queueing
* too many tasks or the LU is bad.
*
* If the device is bad the cmds ahead of us on
* other devs will complete, and this loop will
* eventually fail starting the scsi eh.
*/
ISCSI_DBG_EH(session, "Command has not made progress "
"but commands ahead of it have. "
"Asking scsi-ml for more time to "
"complete. Our last xfer vs running task "
"last xfer %lu/%lu. Last check %lu.\n",
task->last_xfer, running_task->last_xfer,
task->last_timeout);
rc = BLK_EH_RESET_TIMER;
goto done;
}
}
/* Assumes nop timeout is shorter than scsi cmd timeout */
if (task->have_checked_conn)
goto done;
/*
* Checking the transport already or nop from a cmd timeout still
* running
*/
if (conn->ping_task) {
task->have_checked_conn = true;
rc = BLK_EH_RESET_TIMER;
goto done;
}
/* Make sure there is a transport check done */
iscsi_send_nopout(conn, NULL);
task->have_checked_conn = true;
rc = BLK_EH_RESET_TIMER;
done:
if (task)
task->last_timeout = jiffies;
spin_unlock(&session->lock);
ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
"timer reset" : "nh");
return rc;
}
static void iscsi_check_transport_timeouts(unsigned long data)
{
struct iscsi_conn *conn = (struct iscsi_conn *)data;
struct iscsi_session *session = conn->session;
unsigned long recv_timeout, next_timeout = 0, last_recv;
spin_lock(&session->lock);
if (session->state != ISCSI_STATE_LOGGED_IN)
goto done;
recv_timeout = conn->recv_timeout;
if (!recv_timeout)
goto done;
recv_timeout *= HZ;
last_recv = conn->last_recv;
if (iscsi_has_ping_timed_out(conn)) {
iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
"expired, recv timeout %d, last rx %lu, "
"last ping %lu, now %lu\n",
conn->ping_timeout, conn->recv_timeout,
last_recv, conn->last_ping, jiffies);
spin_unlock(&session->lock);
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
return;
}
if (time_before_eq(last_recv + recv_timeout, jiffies)) {
/* send a ping to try to provoke some traffic */
ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
iscsi_send_nopout(conn, NULL);
next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
} else
next_timeout = last_recv + recv_timeout;
ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
mod_timer(&conn->transport_timer, next_timeout);
done:
spin_unlock(&session->lock);
}
static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
struct iscsi_tm *hdr)
{
memset(hdr, 0, sizeof(*hdr));
hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
hdr->flags |= ISCSI_FLAG_CMD_FINAL;
hdr->lun = task->lun;
hdr->rtt = task->hdr_itt;
hdr->refcmdsn = task->cmdsn;
}
int iscsi_eh_abort(struct scsi_cmnd *sc)
{
struct iscsi_cls_session *cls_session;
struct iscsi_session *session;
struct iscsi_conn *conn;
struct iscsi_task *task;
struct iscsi_tm *hdr;
int rc, age;
cls_session = starget_to_session(scsi_target(sc->device));
session = cls_session->dd_data;
ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
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) {
ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
"it completed.\n");
spin_unlock_bh(&session->lock);
mutex_unlock(&session->eh_mutex);
return SUCCESS;
}
/*
* If we are not logged in or we have started a new session
* then let the host reset code handle this
*/
if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
sc->SCp.phase != session->age) {
spin_unlock_bh(&session->lock);
mutex_unlock(&session->eh_mutex);
ISCSI_DBG_EH(session, "failing abort due to dropped "
"session.\n");
return FAILED;
}
conn = session->leadconn;
conn->eh_abort_cnt++;
age = session->age;
task = (struct iscsi_task *)sc->SCp.ptr;
ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
sc, task->itt);
/* task completed before time out */
if (!task->sc) {
ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
goto success;
}
if (task->state == ISCSI_TASK_PENDING) {
fail_scsi_task(task, DID_ABORT);
goto success;
}
/* only have one tmf outstanding at a time */
if (conn->tmf_state != TMF_INITIAL)
goto failed;
conn->tmf_state = TMF_QUEUED;
hdr = &conn->tmhdr;
iscsi_prep_abort_task_pdu(task, hdr);
if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
rc = FAILED;
goto failed;
}
switch (conn->tmf_state) {
case TMF_SUCCESS:
spin_unlock_bh(&session->lock);
/*
* stop tx side incase the target had sent a abort rsp but
* the initiator was still writing out data.
*/
iscsi_suspend_tx(conn);
/*
* we do not stop the recv side because targets have been
* good and have never sent us a successful tmf response
* then sent more data for the cmd.
*/
spin_lock_bh(&session->lock);
fail_scsi_task(task, DID_ABORT);
conn->tmf_state = TMF_INITIAL;
memset(hdr, 0, sizeof(*hdr));
spin_unlock_bh(&session->lock);
iscsi_start_tx(conn);
goto success_unlocked;
case TMF_TIMEDOUT:
spin_unlock_bh(&session->lock);
iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
goto failed_unlocked;
case TMF_NOT_FOUND:
if (!sc->SCp.ptr) {
conn->tmf_state = TMF_INITIAL;
memset(hdr, 0, sizeof(*hdr));
/* task completed before tmf abort response */
ISCSI_DBG_EH(session, "sc completed while abort in "
"progress\n");
goto success;
}
/* fall through */
default:
conn->tmf_state = TMF_INITIAL;
goto failed;
}
success:
spin_unlock_bh(&session->lock);
success_unlocked:
ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
sc, task->itt);
mutex_unlock(&session->eh_mutex);
return SUCCESS;
failed:
spin_unlock_bh(&session->lock);
failed_unlocked:
ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
task ? task->itt : 0);
mutex_unlock(&session->eh_mutex);
return FAILED;
}
EXPORT_SYMBOL_GPL(iscsi_eh_abort);
static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
{
memset(hdr, 0, sizeof(*hdr));
hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
hdr->flags |= ISCSI_FLAG_CMD_FINAL;
int_to_scsilun(sc->device->lun, &hdr->lun);
hdr->rtt = RESERVED_ITT;
}
int iscsi_eh_device_reset(struct scsi_cmnd *sc)
{
struct iscsi_cls_session *cls_session;
struct iscsi_session *session;
struct iscsi_conn *conn;
struct iscsi_tm *hdr;
int rc = FAILED;
cls_session = starget_to_session(scsi_target(sc->device));
session = cls_session->dd_data;
ISCSI_DBG_EH(session, "LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
mutex_lock(&session->eh_mutex);
spin_lock_bh(&session->lock);
/*
* Just check if we are not logged in. We cannot check for
* the phase because the reset could come from a ioctl.
*/
if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
goto unlock;
conn = session->leadconn;
/* only have one tmf outstanding at a time */
if (conn->tmf_state != TMF_INITIAL)
goto unlock;
conn->tmf_state = TMF_QUEUED;
hdr = &conn->tmhdr;
iscsi_prep_lun_reset_pdu(sc, hdr);
if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
session->lu_reset_timeout)) {
rc = FAILED;
goto unlock;
}
switch (conn->tmf_state) {
case TMF_SUCCESS:
break;
case TMF_TIMEDOUT:
spin_unlock_bh(&session->lock);
iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
goto done;
default:
conn->tmf_state = TMF_INITIAL;
goto unlock;
}
rc = SUCCESS;
spin_unlock_bh(&session->lock);
iscsi_suspend_tx(conn);
spin_lock_bh(&session->lock);
memset(hdr, 0, sizeof(*hdr));
fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
conn->tmf_state = TMF_INITIAL;
spin_unlock_bh(&session->lock);
iscsi_start_tx(conn);
goto done;
unlock:
spin_unlock_bh(&session->lock);
done:
ISCSI_DBG_EH(session, "dev reset result = %s\n",
rc == SUCCESS ? "SUCCESS" : "FAILED");
mutex_unlock(&session->eh_mutex);
return rc;
}
EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
{
struct iscsi_session *session = cls_session->dd_data;
spin_lock_bh(&session->lock);
if (session->state != ISCSI_STATE_LOGGED_IN) {
session->state = ISCSI_STATE_RECOVERY_FAILED;
if (session->leadconn)
wake_up(&session->leadconn->ehwait);
}
spin_unlock_bh(&session->lock);
}
EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
/**
* iscsi_eh_session_reset - drop session and attempt relogin
* @sc: scsi command
*
* This function will wait for a relogin, session termination from
* userspace, or a recovery/replacement timeout.
*/
int iscsi_eh_session_reset(struct scsi_cmnd *sc)
{
struct iscsi_cls_session *cls_session;
struct iscsi_session *session;
struct iscsi_conn *conn;
cls_session = starget_to_session(scsi_target(sc->device));
session = cls_session->dd_data;
conn = session->leadconn;
mutex_lock(&session->eh_mutex);
spin_lock_bh(&session->lock);
if (session->state == ISCSI_STATE_TERMINATE) {
failed:
ISCSI_DBG_EH(session,
"failing session reset: Could not log back into "
"%s, %s [age %d]\n", session->targetname,
conn->persistent_address, session->age);
spin_unlock_bh(&session->lock);
mutex_unlock(&session->eh_mutex);
return FAILED;
}
spin_unlock_bh(&session->lock);
mutex_unlock(&session->eh_mutex);
/*
* we drop the lock here but the leadconn cannot be destoyed while
* we are in the scsi eh
*/
iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
ISCSI_DBG_EH(session, "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);
mutex_lock(&session->eh_mutex);
spin_lock_bh(&session->lock);
if (session->state == ISCSI_STATE_LOGGED_IN) {
ISCSI_DBG_EH(session,
"session reset succeeded for %s,%s\n",
session->targetname, conn->persistent_address);
} else
goto failed;
spin_unlock_bh(&session->lock);
mutex_unlock(&session->eh_mutex);
return SUCCESS;
}
EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
{
memset(hdr, 0, sizeof(*hdr));
hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
hdr->flags |= ISCSI_FLAG_CMD_FINAL;
hdr->rtt = RESERVED_ITT;
}
/**
* iscsi_eh_target_reset - reset target
* @sc: scsi command
*
* This will attempt to send a warm target reset.
*/
int iscsi_eh_target_reset(struct scsi_cmnd *sc)
{
struct iscsi_cls_session *cls_session;
struct iscsi_session *session;
struct iscsi_conn *conn;
struct iscsi_tm *hdr;
int rc = FAILED;
cls_session = starget_to_session(scsi_target(sc->device));
session = cls_session->dd_data;
ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
session->targetname);
mutex_lock(&session->eh_mutex);
spin_lock_bh(&session->lock);
/*
* Just check if we are not logged in. We cannot check for
* the phase because the reset could come from a ioctl.
*/
if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
goto unlock;
conn = session->leadconn;
/* only have one tmf outstanding at a time */
if (conn->tmf_state != TMF_INITIAL)
goto unlock;
conn->tmf_state = TMF_QUEUED;
hdr = &conn->tmhdr;
iscsi_prep_tgt_reset_pdu(sc, hdr);
if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
session->tgt_reset_timeout)) {
rc = FAILED;
goto unlock;
}
switch (conn->tmf_state) {
case TMF_SUCCESS:
break;
case TMF_TIMEDOUT:
spin_unlock_bh(&session->lock);
iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
goto done;
default:
conn->tmf_state = TMF_INITIAL;
goto unlock;
}
rc = SUCCESS;
spin_unlock_bh(&session->lock);
iscsi_suspend_tx(conn);
spin_lock_bh(&session->lock);
memset(hdr, 0, sizeof(*hdr));
fail_scsi_tasks(conn, -1, DID_ERROR);
conn->tmf_state = TMF_INITIAL;
spin_unlock_bh(&session->lock);
iscsi_start_tx(conn);
goto done;
unlock:
spin_unlock_bh(&session->lock);
done:
ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
rc == SUCCESS ? "SUCCESS" : "FAILED");
mutex_unlock(&session->eh_mutex);
return rc;
}
EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
/**
* iscsi_eh_recover_target - reset target and possibly the session
* @sc: scsi command
*
* This will attempt to send a warm target reset. If that fails,
* we will escalate to ERL0 session recovery.
*/
int iscsi_eh_recover_target(struct scsi_cmnd *sc)
{
int rc;
rc = iscsi_eh_target_reset(sc);
if (rc == FAILED)
rc = iscsi_eh_session_reset(sc);
return rc;
}
EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
/*
* Pre-allocate a pool of @max items of @item_size. By default, the pool
* should be accessed via kfifo_{get,put} on q->queue.
* Optionally, the caller can obtain the array of object pointers
* by passing in a non-NULL @items pointer
*/
int
iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
{
int i, num_arrays = 1;
memset(q, 0, sizeof(*q));
q->max = max;
/* If the user passed an items pointer, he wants a copy of
* the array. */
if (items)
num_arrays++;
q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
if (q->pool == NULL)
return -ENOMEM;
kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
for (i = 0; i < max; i++) {
q->pool[i] = kzalloc(item_size, GFP_KERNEL);
if (q->pool[i] == NULL) {
q->max = i;
goto enomem;
}
kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
}
if (items) {
*items = q->pool + max;
memcpy(*items, q->pool, max * sizeof(void *));
}
return 0;
enomem:
iscsi_pool_free(q);
return -ENOMEM;
}
EXPORT_SYMBOL_GPL(iscsi_pool_init);
void iscsi_pool_free(struct iscsi_pool *q)
{
int i;
for (i = 0; i < q->max; i++)
kfree(q->pool[i]);
kfree(q->pool);
}
EXPORT_SYMBOL_GPL(iscsi_pool_free);
/**
* iscsi_host_add - add host to system
* @shost: scsi host
* @pdev: parent device
*
* This should be called by partial offload and software iscsi drivers
* to add a host to the system.
*/
int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
{
if (!shost->can_queue)
shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
if (!shost->cmd_per_lun)
shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
if (!shost->transportt->eh_timed_out)
shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
return scsi_add_host(shost, pdev);
}
EXPORT_SYMBOL_GPL(iscsi_host_add);
/**
* iscsi_host_alloc - allocate a host and driver data
* @sht: scsi host template
* @dd_data_size: driver host data size
* @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
*
* This should be called by partial offload and software iscsi drivers.
* To access the driver specific memory use the iscsi_host_priv() macro.
*/
struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
int dd_data_size, bool xmit_can_sleep)
{
struct Scsi_Host *shost;
struct iscsi_host *ihost;
shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
if (!shost)
return NULL;
ihost = shost_priv(shost);
if (xmit_can_sleep) {
snprintf(ihost->workq_name, sizeof(ihost->workq_name),
"iscsi_q_%d", shost->host_no);
ihost->workq = create_singlethread_workqueue(ihost->workq_name);
if (!ihost->workq)
goto free_host;
}
spin_lock_init(&ihost->lock);
ihost->state = ISCSI_HOST_SETUP;
ihost->num_sessions = 0;
init_waitqueue_head(&ihost->session_removal_wq);
return shost;
free_host:
scsi_host_put(shost);
return NULL;
}
EXPORT_SYMBOL_GPL(iscsi_host_alloc);
static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
{
iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
}
/**
* iscsi_host_remove - remove host and sessions
* @shost: scsi host
*
* If there are any sessions left, this will initiate the removal and wait
* for the completion.
*/
void iscsi_host_remove(struct Scsi_Host *shost)
{
struct iscsi_host *ihost = shost_priv(shost);
unsigned long flags;
spin_lock_irqsave(&ihost->lock, flags);
ihost->state = ISCSI_HOST_REMOVED;
spin_unlock_irqrestore(&ihost->lock, flags);
iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
wait_event_interruptible(ihost->session_removal_wq,
ihost->num_sessions == 0);
if (signal_pending(current))
flush_signals(current);
scsi_remove_host(shost);
if (ihost->workq)
destroy_workqueue(ihost->workq);
}
EXPORT_SYMBOL_GPL(iscsi_host_remove);
void iscsi_host_free(struct Scsi_Host *shost)
{
struct iscsi_host *ihost = shost_priv(shost);
kfree(ihost->netdev);
kfree(ihost->hwaddress);
kfree(ihost->initiatorname);
scsi_host_put(shost);
}
EXPORT_SYMBOL_GPL(iscsi_host_free);
static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
{
struct iscsi_host *ihost = shost_priv(shost);
unsigned long flags;
shost = scsi_host_get(shost);
if (!shost) {
printk(KERN_ERR "Invalid state. Cannot notify host removal "
"of session teardown event because host already "
"removed.\n");
return;
}
spin_lock_irqsave(&ihost->lock, flags);
ihost->num_sessions--;
if (ihost->num_sessions == 0)
wake_up(&ihost->session_removal_wq);
spin_unlock_irqrestore(&ihost->lock, flags);
scsi_host_put(shost);
}
/**
* iscsi_session_setup - create iscsi cls session and host and session
* @iscsit: iscsi transport template
* @shost: scsi host
* @cmds_max: session can queue
* @cmd_task_size: LLD task private data size
* @initial_cmdsn: initial CmdSN
*
* This can be used by software iscsi_transports that allocate
* a session per scsi host.
*
* Callers should set cmds_max to the largest total numer (mgmt + scsi) of
* tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
* for nop handling and login/logout requests.
*/
struct iscsi_cls_session *
iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
uint16_t cmds_max, int dd_size, int cmd_task_size,
uint32_t initial_cmdsn, unsigned int id)
{
struct iscsi_host *ihost = shost_priv(shost);
struct iscsi_session *session;
struct iscsi_cls_session *cls_session;
int cmd_i, scsi_cmds, total_cmds = cmds_max;
unsigned long flags;
spin_lock_irqsave(&ihost->lock, flags);
if (ihost->state == ISCSI_HOST_REMOVED) {
spin_unlock_irqrestore(&ihost->lock, flags);
return NULL;
}
ihost->num_sessions++;
spin_unlock_irqrestore(&ihost->lock, flags);
if (!total_cmds)
total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
/*
* The iscsi layer needs some tasks for nop handling and tmfs,
* so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
* + 1 command for scsi IO.
*/
if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
"must be a power of two that is at least %d.\n",
total_cmds, ISCSI_TOTAL_CMDS_MIN);
goto dec_session_count;
}
if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
"must be a power of 2 less than or equal to %d.\n",
cmds_max, ISCSI_TOTAL_CMDS_MAX);
total_cmds = ISCSI_TOTAL_CMDS_MAX;
}
if (!is_power_of_2(total_cmds)) {
printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
"must be a power of 2.\n", total_cmds);
total_cmds = rounddown_pow_of_two(total_cmds);
if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
return NULL;
printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
total_cmds);
}
scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
cls_session = iscsi_alloc_session(shost, iscsit,
sizeof(struct iscsi_session) +
dd_size);
if (!cls_session)
goto dec_session_count;
session = cls_session->dd_data;
session->cls_session = cls_session;
session->host = shost;
session->state = ISCSI_STATE_FREE;
session->fast_abort = 1;
session->tgt_reset_timeout = 30;
session->lu_reset_timeout = 15;
session->abort_timeout = 10;
session->scsi_cmds_max = scsi_cmds;
session->cmds_max = total_cmds;
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;
session->dd_data = cls_session->dd_data + sizeof(*session);
mutex_init(&session->eh_mutex);
spin_lock_init(&session->lock);
/* initialize SCSI PDU commands pool */
if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
(void***)&session->cmds,
cmd_task_size + sizeof(struct iscsi_task)))
goto cmdpool_alloc_fail;
/* pre-format cmds pool with ITT */
for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
struct iscsi_task *task = session->cmds[cmd_i];
if (cmd_task_size)
task->dd_data = &task[1];
task->itt = cmd_i;
task->state = ISCSI_TASK_FREE;
INIT_LIST_HEAD(&task->running);
}
if (!try_module_get(iscsit->owner))
goto module_get_fail;
if (iscsi_add_session(cls_session, id))
goto cls_session_fail;
return cls_session;
cls_session_fail:
module_put(iscsit->owner);
module_get_fail:
iscsi_pool_free(&session->cmdpool);
cmdpool_alloc_fail:
iscsi_free_session(cls_session);
dec_session_count:
iscsi_host_dec_session_cnt(shost);
return NULL;
}
EXPORT_SYMBOL_GPL(iscsi_session_setup);
/**
* iscsi_session_teardown - destroy session, host, and cls_session
* @cls_session: iscsi session
*
* The driver must have called iscsi_remove_session before
* calling this.
*/
void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
{
struct iscsi_session *session = cls_session->dd_data;
struct module *owner = cls_session->transport->owner;
struct Scsi_Host *shost = session->host;
iscsi_pool_free(&session->cmdpool);
kfree(session->password);
kfree(session->password_in);
kfree(session->username);
kfree(session->username_in);
kfree(session->targetname);
kfree(session->initiatorname);
kfree(session->ifacename);
iscsi_destroy_session(cls_session);
iscsi_host_dec_session_cnt(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
* @dd_size: private driver data size
* @conn_idx: cid
*/
struct iscsi_cls_conn *
iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
uint32_t conn_idx)
{
struct iscsi_session *session = cls_session->dd_data;
struct iscsi_conn *conn;
struct iscsi_cls_conn *cls_conn;
char *data;
cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
conn_idx);
if (!cls_conn)
return NULL;
conn = cls_conn->dd_data;
memset(conn, 0, sizeof(*conn) + dd_size);
conn->dd_data = cls_conn->dd_data + 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->tmf_state = TMF_INITIAL;
init_timer(&conn->transport_timer);
conn->transport_timer.data = (unsigned long)conn;
conn->transport_timer.function = iscsi_check_transport_timeouts;
INIT_LIST_HEAD(&conn->mgmtqueue);
INIT_LIST_HEAD(&conn->cmdqueue);
INIT_LIST_HEAD(&conn->requeue);
INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
/* allocate login_task used for the login/text sequences */
spin_lock_bh(&session->lock);
if (!kfifo_out(&session->cmdpool.queue,
(void*)&conn->login_task,
sizeof(void*))) {
spin_unlock_bh(&session->lock);
goto login_task_alloc_fail;
}
spin_unlock_bh(&session->lock);
data = (char *) __get_free_pages(GFP_KERNEL,
get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
if (!data)
goto login_task_data_alloc_fail;
conn->login_task->data = conn->data = data;
init_timer(&conn->tmf_timer);
init_waitqueue_head(&conn->ehwait);
return cls_conn;
login_task_data_alloc_fail:
kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
sizeof(void*));
login_task_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;
del_timer_sync(&conn->transport_timer);
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);
/*
* 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);
iscsi_conn_printk(KERN_INFO, conn, "iscsi 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 */
iscsi_suspend_tx(conn);
spin_lock_bh(&session->lock);
free_pages((unsigned long) conn->data,
get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
kfree(conn->persistent_address);
kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
sizeof(void*));
if (session->leadconn == conn)
session->leadconn = NULL;
spin_unlock_bh(&session->lock);
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) {
iscsi_conn_printk(KERN_ERR, conn,
"can't start unbound connection\n");
return -EPERM;
}
if ((session->imm_data_en || !session->initial_r2t_en) &&
session->first_burst > session->max_burst) {
iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
"first_burst %d max_burst %d\n",
session->first_burst, session->max_burst);
return -EINVAL;
}
if (conn->ping_timeout && !conn->recv_timeout) {
iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
"zero. Using 5 seconds\n.");
conn->recv_timeout = 5;
}
if (conn->recv_timeout && !conn->ping_timeout) {
iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
"zero. Using 5 seconds.\n");
conn->ping_timeout = 5;
}
spin_lock_bh(&session->lock);
conn->c_stage = ISCSI_CONN_STARTED;
session->state = ISCSI_STATE_LOGGED_IN;
session->queued_cmdsn = session->cmdsn;
conn->last_recv = jiffies;
conn->last_ping = jiffies;
if (conn->recv_timeout && conn->ping_timeout)
mod_timer(&conn->transport_timer,
jiffies + (conn->recv_timeout * HZ));
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->tmf_state = TMF_INITIAL;
session->age++;
if (session->age == 16)
session->age = 0;
break;
case STOP_CONN_TERM:
conn->stop_stage = 0;
break;
default:
break;
}
spin_unlock_bh(&session->lock);
iscsi_unblock_session(session->cls_session);
wake_up(&conn->ehwait);
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_conn_start);
static void
fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
{
struct iscsi_task *task;
int i, state;
for (i = 0; i < conn->session->cmds_max; i++) {
task = conn->session->cmds[i];
if (task->sc)
continue;
if (task->state == ISCSI_TASK_FREE)
continue;
ISCSI_DBG_SESSION(conn->session,
"failing mgmt itt 0x%x state %d\n",
task->itt, task->state);
state = ISCSI_TASK_ABRT_SESS_RECOV;
if (task->state == ISCSI_TASK_PENDING)
state = ISCSI_TASK_COMPLETED;
iscsi_complete_task(task, state);
}
}
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;
}
/*
* 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;
spin_unlock_bh(&session->lock);
del_timer_sync(&conn->transport_timer);
iscsi_suspend_tx(conn);
spin_lock_bh(&session->lock);
conn->c_stage = ISCSI_CONN_STOPPED;
spin_unlock_bh(&session->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) {
ISCSI_DBG_SESSION(session, "blocking session\n");
iscsi_block_session(session->cls_session);
}
}
/*
* flush queues.
*/
spin_lock_bh(&session->lock);
fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
fail_mgmt_tasks(session, conn);
memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
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:
iscsi_conn_printk(KERN_ERR, conn,
"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 = cls_session->dd_data;
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);
static int iscsi_switch_str_param(char **param, char *new_val_buf)
{
char *new_val;
if (*param) {
if (!strcmp(*param, new_val_buf))
return 0;
}
new_val = kstrdup(new_val_buf, GFP_NOIO);
if (!new_val)
return -ENOMEM;
kfree(*param);
*param = new_val;
return 0;
}
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_FAST_ABORT:
sscanf(buf, "%d", &session->fast_abort);
break;
case ISCSI_PARAM_ABORT_TMO:
sscanf(buf, "%d", &session->abort_timeout);
break;
case ISCSI_PARAM_LU_RESET_TMO:
sscanf(buf, "%d", &session->lu_reset_timeout);
break;
case ISCSI_PARAM_TGT_RESET_TMO:
sscanf(buf, "%d", &session->tgt_reset_timeout);
break;
case ISCSI_PARAM_PING_TMO:
sscanf(buf, "%d", &conn->ping_timeout);
break;
case ISCSI_PARAM_RECV_TMO:
sscanf(buf, "%d", &conn->recv_timeout);
break;
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:
return iscsi_switch_str_param(&session->username, buf);
case ISCSI_PARAM_USERNAME_IN:
return iscsi_switch_str_param(&session->username_in, buf);
case ISCSI_PARAM_PASSWORD:
return iscsi_switch_str_param(&session->password, buf);
case ISCSI_PARAM_PASSWORD_IN:
return iscsi_switch_str_param(&session->password_in, buf);
case ISCSI_PARAM_TARGET_NAME:
return iscsi_switch_str_param(&session->targetname, buf);
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:
return iscsi_switch_str_param(&conn->persistent_address, buf);
case ISCSI_PARAM_IFACE_NAME:
return iscsi_switch_str_param(&session->ifacename, buf);
case ISCSI_PARAM_INITIATOR_NAME:
return iscsi_switch_str_param(&session->initiatorname, buf);
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 iscsi_session *session = cls_session->dd_data;
int len;
switch(param) {
case ISCSI_PARAM_FAST_ABORT:
len = sprintf(buf, "%d\n", session->fast_abort);
break;
case ISCSI_PARAM_ABORT_TMO:
len = sprintf(buf, "%d\n", session->abort_timeout);
break;
case ISCSI_PARAM_LU_RESET_TMO:
len = sprintf(buf, "%d\n", session->lu_reset_timeout);
break;
case ISCSI_PARAM_TGT_RESET_TMO:
len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
break;
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;
case ISCSI_PARAM_IFACE_NAME:
len = sprintf(buf, "%s\n", session->ifacename);
break;
case ISCSI_PARAM_INITIATOR_NAME:
len = sprintf(buf, "%s\n", session->initiatorname);
break;
default:
return -ENOSYS;
}
return len;
}
EXPORT_SYMBOL_GPL(iscsi_session_get_param);
int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
enum iscsi_param param, char *buf)
{
struct sockaddr_in6 *sin6 = NULL;
struct sockaddr_in *sin = NULL;
int len;
switch (addr->ss_family) {
case AF_INET:
sin = (struct sockaddr_in *)addr;
break;
case AF_INET6:
sin6 = (struct sockaddr_in6 *)addr;
break;
default:
return -EINVAL;
}
switch (param) {
case ISCSI_PARAM_CONN_ADDRESS:
case ISCSI_HOST_PARAM_IPADDRESS:
if (sin)
len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
else
len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
break;
case ISCSI_PARAM_CONN_PORT:
if (sin)
len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
else
len = sprintf(buf, "%hu\n",
be16_to_cpu(sin6->sin6_port));
break;
default:
return -EINVAL;
}
return len;
}
EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_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_PING_TMO:
len = sprintf(buf, "%u\n", conn->ping_timeout);
break;
case ISCSI_PARAM_RECV_TMO:
len = sprintf(buf, "%u\n", conn->recv_timeout);
break;
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_host *ihost = shost_priv(shost);
int len;
switch (param) {
case ISCSI_HOST_PARAM_NETDEV_NAME:
len = sprintf(buf, "%s\n", ihost->netdev);
break;
case ISCSI_HOST_PARAM_HWADDRESS:
len = sprintf(buf, "%s\n", ihost->hwaddress);
break;
case ISCSI_HOST_PARAM_INITIATOR_NAME:
len = sprintf(buf, "%s\n", ihost->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_host *ihost = shost_priv(shost);
switch (param) {
case ISCSI_HOST_PARAM_NETDEV_NAME:
return iscsi_switch_str_param(&ihost->netdev, buf);
case ISCSI_HOST_PARAM_HWADDRESS:
return iscsi_switch_str_param(&ihost->hwaddress, buf);
case ISCSI_HOST_PARAM_INITIATOR_NAME:
return iscsi_switch_str_param(&ihost->initiatorname, buf);
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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