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libiscsi.c
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libiscsi.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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
*/
#include <linux/types.h>
#include <linux/kfifo.h>
#include <linux/delay.h>
#include <linux/log2.h>
#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <linux/module.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>
#include <trace/events/iscsi.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); \
iscsi_dbg_trace(trace_iscsi_dbg_conn, \
&(_conn)->cls_conn->dev, \
"%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); \
iscsi_dbg_trace(trace_iscsi_dbg_session, \
&(_session)->cls_session->dev, \
"%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); \
iscsi_dbg_trace(trace_iscsi_dbg_eh, \
&(_session)->cls_session->dev, \
"%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;
}
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;
}
/**
* 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;
u64 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;
fallthrough;
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 itt "
"0x%x/0x%x] "
"rejected.\n",
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 itt "
"0x%x/0x%x] fast abort.\n",
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, transfer_length;
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_get_prot_op(sc) != SCSI_PROT_NORMAL)
task->protected = true;
transfer_length = scsi_transfer_length(sc);
hdr->data_length = cpu_to_be32(transfer_length);
if (sc->sc_data_direction == DMA_TO_DEVICE) {
struct iscsi_r2t_info *r2t = &task->unsol_r2t;
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 (transfer_length >= session->first_burst)
task->imm_count = min(session->first_burst,
conn->max_xmit_dlength);
else
task->imm_count = min(transfer_length,
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,
transfer_length) -
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);
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 cmdsn %d win %d]\n",
sc->sc_data_direction == DMA_TO_DEVICE ?
"write" : "read", conn->id, sc, sc->cmnd[0],
task->itt, transfer_length,
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 back_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) {
/* 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)
{
refcount_inc(&task->refcount);
}
EXPORT_SYMBOL_GPL(__iscsi_get_task);
void __iscsi_put_task(struct iscsi_task *task)
{
if (refcount_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;
/* regular RX path uses back_lock */
spin_lock_bh(&session->back_lock);
__iscsi_put_task(task);
spin_unlock_bh(&session->back_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 back_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;
spin_lock_bh(&conn->taskqueuelock);
if (!list_empty(&task->running)) {
pr_debug_once("%s while task on list", __func__);
list_del_init(&task->running);
}
spin_unlock_bh(&conn->taskqueuelock);
if (conn->task == task)
conn->task = NULL;
if (READ_ONCE(conn->ping_task) == task)
WRITE_ONCE(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 back_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 back_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;
scsi_set_resid(sc, scsi_bufflen(sc));
/* regular RX path uses back_lock */
spin_lock_bh(&conn->session->back_lock);
iscsi_complete_task(task, state);
spin_unlock_bh(&conn->session->back_lock);
}
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;
}
if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
iscsi_conn_printk(KERN_ERR, conn, "Invalid buffer len of %u for login task. Max len is %u\n", data_size, ISCSI_DEF_MAX_RECV_SEG_LEN);
return NULL;
}
task = conn->login_task;
} else {
if (session->state != ISCSI_STATE_LOGGED_IN)
return NULL;
if (data_size != 0) {
iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
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.
*/
refcount_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 (unlikely(READ_ONCE(conn->ping_task) == INVALID_SCSI_TASK))
WRITE_ONCE(conn->ping_task, task);
if (!ihost->workq) {
if (iscsi_prep_mgmt_task(conn, task))
goto free_task;
if (session->tt->xmit_task(task))
goto free_task;
} else {
spin_lock_bh(&conn->taskqueuelock);
list_add_tail(&task->running, &conn->mgmtqueue);
spin_unlock_bh(&conn->taskqueuelock);
iscsi_conn_queue_work(conn);
}
return task;
free_task:
/* regular RX path uses back_lock */
spin_lock(&session->back_lock);
__iscsi_put_task(task);
spin_unlock(&session->back_lock);
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->frwd_lock);
if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
err = -EPERM;
spin_unlock_bh(&session->frwd_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. called under back_lock
**/
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 (task->protected) {
sector_t sector;
u8 ascq;
/**
* Transports that didn't implement check_protection
* callback but still published T10-PI support to scsi-mid
* deserve this BUG_ON.
**/
BUG_ON(!session->tt->check_protection);
ascq = session->tt->check_protection(task, §or);
if (ascq) {
sc->result = DRIVER_SENSE << 24 |
SAM_STAT_CHECK_CONDITION;
scsi_build_sense_buffer(1, sc->sense_buffer,
ILLEGAL_REQUEST, 0x10, ascq);
scsi_set_sense_information(sc->sense_buffer,
SCSI_SENSE_BUFFERSIZE,
sector);
goto out;
}
}
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)) {
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
*
* iscsi_data_in_rsp sets up the scsi_cmnd fields based on the data received
* then completes the command and task. called under back_lock
**/
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 <= sc->sdb.length))
scsi_set_resid(sc, 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 int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
{
struct iscsi_nopout hdr;
struct iscsi_task *task;
if (!rhdr) {
if (READ_ONCE(conn->ping_task))
return -EINVAL;
WRITE_ONCE(conn->ping_task, INVALID_SCSI_TASK);
}
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) {
if (!rhdr)
WRITE_ONCE(conn->ping_task, NULL);
iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
return -EIO;
} else if (!rhdr) {
/* only track our nops */
conn->last_ping = jiffies;
}
return 0;
}
/**
* iscsi_nop_out_rsp - SCSI NOP Response processing
* @task: scsi command task
* @nop: the nop structure
* @data: where to put the data
* @datalen: length of data
*
* iscsi_nop_out_rsp handles nop response from use or
* from user space. called under back_lock
**/
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 (READ_ONCE(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))