libiscsi.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * iSCSI lib functions
   4 *
   5 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   6 * Copyright (C) 2004 - 2006 Mike Christie
   7 * Copyright (C) 2004 - 2005 Dmitry Yusupov
   8 * Copyright (C) 2004 - 2005 Alex Aizman
   9 * maintained by open-iscsi@googlegroups.com
  10 */
  11#include <linux/types.h>
  12#include <linux/kfifo.h>
  13#include <linux/delay.h>
  14#include <linux/log2.h>
  15#include <linux/slab.h>
  16#include <linux/sched/signal.h>
  17#include <linux/module.h>
  18#include <linux/unaligned.h>
  19#include <net/tcp.h>
  20#include <scsi/scsi_cmnd.h>
  21#include <scsi/scsi_device.h>
  22#include <scsi/scsi_eh.h>
  23#include <scsi/scsi_tcq.h>
  24#include <scsi/scsi_host.h>
  25#include <scsi/scsi.h>
  26#include <scsi/iscsi_proto.h>
  27#include <scsi/scsi_transport.h>
  28#include <scsi/scsi_transport_iscsi.h>
  29#include <scsi/libiscsi.h>
  30#include <trace/events/iscsi.h>
  31
  32static int iscsi_dbg_lib_conn;
  33module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  34		   S_IRUGO | S_IWUSR);
  35MODULE_PARM_DESC(debug_libiscsi_conn,
  36		 "Turn on debugging for connections in libiscsi module. "
  37		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  38
  39static int iscsi_dbg_lib_session;
  40module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  41		   S_IRUGO | S_IWUSR);
  42MODULE_PARM_DESC(debug_libiscsi_session,
  43		 "Turn on debugging for sessions in libiscsi module. "
  44		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  45
  46static int iscsi_dbg_lib_eh;
  47module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  48		   S_IRUGO | S_IWUSR);
  49MODULE_PARM_DESC(debug_libiscsi_eh,
  50		 "Turn on debugging for error handling in libiscsi module. "
  51		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  52
  53#define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)			\
  54	do {							\
  55		if (iscsi_dbg_lib_conn)				\
  56			iscsi_conn_printk(KERN_INFO, _conn,	\
  57					     "%s " dbg_fmt,	\
  58					     __func__, ##arg);	\
  59		iscsi_dbg_trace(trace_iscsi_dbg_conn,		\
  60				&(_conn)->cls_conn->dev,	\
  61				"%s " dbg_fmt, __func__, ##arg);\
  62	} while (0);
  63
  64#define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)			\
  65	do {								\
  66		if (iscsi_dbg_lib_session)				\
  67			iscsi_session_printk(KERN_INFO, _session,	\
  68					     "%s " dbg_fmt,		\
  69					     __func__, ##arg);		\
  70		iscsi_dbg_trace(trace_iscsi_dbg_session, 		\
  71				&(_session)->cls_session->dev,		\
  72				"%s " dbg_fmt, __func__, ##arg);	\
  73	} while (0);
  74
  75#define ISCSI_DBG_EH(_session, dbg_fmt, arg...)				\
  76	do {								\
  77		if (iscsi_dbg_lib_eh)					\
  78			iscsi_session_printk(KERN_INFO, _session,	\
  79					     "%s " dbg_fmt,		\
  80					     __func__, ##arg);		\
  81		iscsi_dbg_trace(trace_iscsi_dbg_eh,			\
  82				&(_session)->cls_session->dev,		\
  83				"%s " dbg_fmt, __func__, ##arg);	\
  84	} while (0);
  85
  86#define ISCSI_CMD_COMPL_WAIT 5
  87
  88inline void iscsi_conn_queue_xmit(struct iscsi_conn *conn)
  89{
  90	struct Scsi_Host *shost = conn->session->host;
  91	struct iscsi_host *ihost = shost_priv(shost);
  92
  93	if (ihost->workq)
  94		queue_work(ihost->workq, &conn->xmitwork);
  95}
  96EXPORT_SYMBOL_GPL(iscsi_conn_queue_xmit);
  97
  98inline void iscsi_conn_queue_recv(struct iscsi_conn *conn)
  99{
 100	struct Scsi_Host *shost = conn->session->host;
 101	struct iscsi_host *ihost = shost_priv(shost);
 102
 103	if (ihost->workq && !test_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags))
 104		queue_work(ihost->workq, &conn->recvwork);
 105}
 106EXPORT_SYMBOL_GPL(iscsi_conn_queue_recv);
 107
 108static void __iscsi_update_cmdsn(struct iscsi_session *session,
 109				 uint32_t exp_cmdsn, uint32_t max_cmdsn)
 110{
 111	/*
 112	 * standard specifies this check for when to update expected and
 113	 * max sequence numbers
 114	 */
 115	if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 116		return;
 117
 118	if (exp_cmdsn != session->exp_cmdsn &&
 119	    !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 120		session->exp_cmdsn = exp_cmdsn;
 121
 122	if (max_cmdsn != session->max_cmdsn &&
 123	    !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
 124		session->max_cmdsn = max_cmdsn;
 125}
 126
 127void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 128{
 129	__iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 130			     be32_to_cpu(hdr->max_cmdsn));
 131}
 132EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 133
 134/**
 135 * iscsi_prep_data_out_pdu - initialize Data-Out
 136 * @task: scsi command task
 137 * @r2t: R2T info
 138 * @hdr: iscsi data in pdu
 139 *
 140 * Notes:
 141 *	Initialize Data-Out within this R2T sequence and finds
 142 *	proper data_offset within this SCSI command.
 143 *
 144 *	This function is called with connection lock taken.
 145 **/
 146void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 147			   struct iscsi_data *hdr)
 148{
 149	struct iscsi_conn *conn = task->conn;
 150	unsigned int left = r2t->data_length - r2t->sent;
 151
 152	task->hdr_len = sizeof(struct iscsi_data);
 153
 154	memset(hdr, 0, sizeof(struct iscsi_data));
 155	hdr->ttt = r2t->ttt;
 156	hdr->datasn = cpu_to_be32(r2t->datasn);
 157	r2t->datasn++;
 158	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 159	hdr->lun = task->lun;
 160	hdr->itt = task->hdr_itt;
 161	hdr->exp_statsn = r2t->exp_statsn;
 162	hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 163	if (left > conn->max_xmit_dlength) {
 164		hton24(hdr->dlength, conn->max_xmit_dlength);
 165		r2t->data_count = conn->max_xmit_dlength;
 166		hdr->flags = 0;
 167	} else {
 168		hton24(hdr->dlength, left);
 169		r2t->data_count = left;
 170		hdr->flags = ISCSI_FLAG_CMD_FINAL;
 171	}
 172	conn->dataout_pdus_cnt++;
 173}
 174EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 175
 176static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 177{
 178	unsigned exp_len = task->hdr_len + len;
 179
 180	if (exp_len > task->hdr_max) {
 181		WARN_ON(1);
 182		return -EINVAL;
 183	}
 184
 185	WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 186	task->hdr_len = exp_len;
 187	return 0;
 188}
 189
 190/*
 191 * make an extended cdb AHS
 192 */
 193static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 194{
 195	struct scsi_cmnd *cmd = task->sc;
 196	unsigned rlen, pad_len;
 197	unsigned short ahslength;
 198	struct iscsi_ecdb_ahdr *ecdb_ahdr;
 199	int rc;
 200
 201	ecdb_ahdr = iscsi_next_hdr(task);
 202	rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 203
 204	BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 205	ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 206
 207	pad_len = iscsi_padding(rlen);
 208
 209	rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 210	                   sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 211	if (rc)
 212		return rc;
 213
 214	if (pad_len)
 215		memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 216
 217	ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 218	ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 219	ecdb_ahdr->reserved = 0;
 220	memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 221
 222	ISCSI_DBG_SESSION(task->conn->session,
 223			  "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 224		          "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 225		          "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 226		          task->hdr_len);
 227	return 0;
 228}
 229
 230/**
 231 * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 232 * @task: iscsi task
 233 * @opcode: opcode to check for
 234 *
 235 * During TMF a task has to be checked if it's affected.
 236 * All unrelated I/O can be passed through, but I/O to the
 237 * affected LUN should be restricted.
 238 * If 'fast_abort' is set we won't be sending any I/O to the
 239 * affected LUN.
 240 * Otherwise the target is waiting for all TTTs to be completed,
 241 * so we have to send all outstanding Data-Out PDUs to the target.
 242 */
 243static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 244{
 245	struct iscsi_session *session = task->conn->session;
 246	struct iscsi_tm *tmf = &session->tmhdr;
 247	u64 hdr_lun;
 248
 249	if (session->tmf_state == TMF_INITIAL)
 250		return 0;
 251
 252	if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 253		return 0;
 254
 255	switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 256	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 257		/*
 258		 * Allow PDUs for unrelated LUNs
 259		 */
 260		hdr_lun = scsilun_to_int(&tmf->lun);
 261		if (hdr_lun != task->sc->device->lun)
 262			return 0;
 263		fallthrough;
 264	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 265		/*
 266		 * Fail all SCSI cmd PDUs
 267		 */
 268		if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 269			iscsi_session_printk(KERN_INFO, session,
 270					     "task [op %x itt 0x%x/0x%x] rejected.\n",
 271					     opcode, task->itt, task->hdr_itt);
 272			return -EACCES;
 273		}
 274		/*
 275		 * And also all data-out PDUs in response to R2T
 276		 * if fast_abort is set.
 277		 */
 278		if (session->fast_abort) {
 279			iscsi_session_printk(KERN_INFO, session,
 280					     "task [op %x itt 0x%x/0x%x] fast abort.\n",
 281					     opcode, task->itt, task->hdr_itt);
 282			return -EACCES;
 283		}
 284		break;
 285	case ISCSI_TM_FUNC_ABORT_TASK:
 286		/*
 287		 * the caller has already checked if the task
 288		 * they want to abort was in the pending queue so if
 289		 * we are here the cmd pdu has gone out already, and
 290		 * we will only hit this for data-outs
 291		 */
 292		if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 293		    task->hdr_itt == tmf->rtt) {
 294			ISCSI_DBG_SESSION(session,
 295					  "Preventing task %x/%x from sending "
 296					  "data-out due to abort task in "
 297					  "progress\n", task->itt,
 298					  task->hdr_itt);
 299			return -EACCES;
 300		}
 301		break;
 302	}
 303
 304	return 0;
 305}
 306
 307/**
 308 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 309 * @task: iscsi task
 310 *
 311 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 312 * fields like dlength or final based on how much data it sends
 313 */
 314static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 315{
 316	struct iscsi_conn *conn = task->conn;
 317	struct iscsi_session *session = conn->session;
 318	struct scsi_cmnd *sc = task->sc;
 319	struct iscsi_scsi_req *hdr;
 320	unsigned hdrlength, cmd_len, transfer_length;
 321	itt_t itt;
 322	int rc;
 323
 324	rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 325	if (rc)
 326		return rc;
 327
 328	if (conn->session->tt->alloc_pdu) {
 329		rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 330		if (rc)
 331			return rc;
 332	}
 333	hdr = (struct iscsi_scsi_req *)task->hdr;
 334	itt = hdr->itt;
 335	memset(hdr, 0, sizeof(*hdr));
 336
 337	if (session->tt->parse_pdu_itt)
 338		hdr->itt = task->hdr_itt = itt;
 339	else
 340		hdr->itt = task->hdr_itt = build_itt(task->itt,
 341						     task->conn->session->age);
 342	task->hdr_len = 0;
 343	rc = iscsi_add_hdr(task, sizeof(*hdr));
 344	if (rc)
 345		return rc;
 346	hdr->opcode = ISCSI_OP_SCSI_CMD;
 347	hdr->flags = ISCSI_ATTR_SIMPLE;
 348	int_to_scsilun(sc->device->lun, &hdr->lun);
 349	task->lun = hdr->lun;
 350	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 351	cmd_len = sc->cmd_len;
 352	if (cmd_len < ISCSI_CDB_SIZE)
 353		memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 354	else if (cmd_len > ISCSI_CDB_SIZE) {
 355		rc = iscsi_prep_ecdb_ahs(task);
 356		if (rc)
 357			return rc;
 358		cmd_len = ISCSI_CDB_SIZE;
 359	}
 360	memcpy(hdr->cdb, sc->cmnd, cmd_len);
 361
 362	task->imm_count = 0;
 363	if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 364		task->protected = true;
 365
 366	transfer_length = scsi_transfer_length(sc);
 367	hdr->data_length = cpu_to_be32(transfer_length);
 368	if (sc->sc_data_direction == DMA_TO_DEVICE) {
 369		struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 370
 371		hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 372		/*
 373		 * Write counters:
 374		 *
 375		 *	imm_count	bytes to be sent right after
 376		 *			SCSI PDU Header
 377		 *
 378		 *	unsol_count	bytes(as Data-Out) to be sent
 379		 *			without	R2T ack right after
 380		 *			immediate data
 381		 *
 382		 *	r2t data_length bytes to be sent via R2T ack's
 383		 *
 384		 *      pad_count       bytes to be sent as zero-padding
 385		 */
 386		memset(r2t, 0, sizeof(*r2t));
 387
 388		if (session->imm_data_en) {
 389			if (transfer_length >= session->first_burst)
 390				task->imm_count = min(session->first_burst,
 391							conn->max_xmit_dlength);
 392			else
 393				task->imm_count = min(transfer_length,
 394						      conn->max_xmit_dlength);
 395			hton24(hdr->dlength, task->imm_count);
 396		} else
 397			zero_data(hdr->dlength);
 398
 399		if (!session->initial_r2t_en) {
 400			r2t->data_length = min(session->first_burst,
 401					       transfer_length) -
 402					       task->imm_count;
 403			r2t->data_offset = task->imm_count;
 404			r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 405			r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 406		}
 407
 408		if (!task->unsol_r2t.data_length)
 409			/* No unsolicit Data-Out's */
 410			hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 411	} else {
 412		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 413		zero_data(hdr->dlength);
 414
 415		if (sc->sc_data_direction == DMA_FROM_DEVICE)
 416			hdr->flags |= ISCSI_FLAG_CMD_READ;
 417	}
 418
 419	/* calculate size of additional header segments (AHSs) */
 420	hdrlength = task->hdr_len - sizeof(*hdr);
 421
 422	WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 423	hdrlength /= ISCSI_PAD_LEN;
 424
 425	WARN_ON(hdrlength >= 256);
 426	hdr->hlength = hdrlength & 0xFF;
 427	hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 428
 429	if (session->tt->init_task && session->tt->init_task(task))
 430		return -EIO;
 431
 432	task->state = ISCSI_TASK_RUNNING;
 433	session->cmdsn++;
 434
 435	conn->scsicmd_pdus_cnt++;
 436	ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 437			  "itt 0x%x len %d cmdsn %d win %d]\n",
 438			  sc->sc_data_direction == DMA_TO_DEVICE ?
 439			  "write" : "read", conn->id, sc, sc->cmnd[0],
 440			  task->itt, transfer_length,
 441			  session->cmdsn,
 442			  session->max_cmdsn - session->exp_cmdsn + 1);
 443	return 0;
 444}
 445
 446/**
 447 * iscsi_free_task - free a task
 448 * @task: iscsi cmd task
 449 *
 450 * Must be called with session back_lock.
 451 * This function returns the scsi command to scsi-ml or cleans
 452 * up mgmt tasks then returns the task to the pool.
 453 */
 454static void iscsi_free_task(struct iscsi_task *task)
 455{
 456	struct iscsi_conn *conn = task->conn;
 457	struct iscsi_session *session = conn->session;
 458	struct scsi_cmnd *sc = task->sc;
 459	int oldstate = task->state;
 460
 461	ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 462			  task->itt, task->state, task->sc);
 463
 464	session->tt->cleanup_task(task);
 465	task->state = ISCSI_TASK_FREE;
 466	task->sc = NULL;
 467	/*
 468	 * login task is preallocated so do not free
 469	 */
 470	if (conn->login_task == task)
 471		return;
 472
 473	kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 474
 475	if (sc) {
 476		/* SCSI eh reuses commands to verify us */
 477		iscsi_cmd(sc)->task = NULL;
 478		/*
 479		 * queue command may call this to free the task, so
 480		 * it will decide how to return sc to scsi-ml.
 481		 */
 482		if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 483			scsi_done(sc);
 484	}
 485}
 486
 487bool iscsi_get_task(struct iscsi_task *task)
 488{
 489	return refcount_inc_not_zero(&task->refcount);
 490}
 491EXPORT_SYMBOL_GPL(iscsi_get_task);
 492
 493/**
 494 * __iscsi_put_task - drop the refcount on a task
 495 * @task: iscsi_task to drop the refcount on
 496 *
 497 * The back_lock must be held when calling in case it frees the task.
 498 */
 499void __iscsi_put_task(struct iscsi_task *task)
 500{
 501	if (refcount_dec_and_test(&task->refcount))
 502		iscsi_free_task(task);
 503}
 504EXPORT_SYMBOL_GPL(__iscsi_put_task);
 505
 506void iscsi_put_task(struct iscsi_task *task)
 507{
 508	struct iscsi_session *session = task->conn->session;
 509
 510	if (refcount_dec_and_test(&task->refcount)) {
 511		spin_lock_bh(&session->back_lock);
 512		iscsi_free_task(task);
 513		spin_unlock_bh(&session->back_lock);
 514	}
 515}
 516EXPORT_SYMBOL_GPL(iscsi_put_task);
 517
 518/**
 519 * iscsi_complete_task - finish a task
 520 * @task: iscsi cmd task
 521 * @state: state to complete task with
 522 *
 523 * Must be called with session back_lock.
 524 */
 525static void iscsi_complete_task(struct iscsi_task *task, int state)
 526{
 527	struct iscsi_conn *conn = task->conn;
 528
 529	ISCSI_DBG_SESSION(conn->session,
 530			  "complete task itt 0x%x state %d sc %p\n",
 531			  task->itt, task->state, task->sc);
 532	if (task->state == ISCSI_TASK_COMPLETED ||
 533	    task->state == ISCSI_TASK_ABRT_TMF ||
 534	    task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 535	    task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 536		return;
 537	WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 538	task->state = state;
 539
 540	if (READ_ONCE(conn->ping_task) == task)
 541		WRITE_ONCE(conn->ping_task, NULL);
 542
 543	/* release get from queueing */
 544	__iscsi_put_task(task);
 545}
 546
 547/**
 548 * iscsi_complete_scsi_task - finish scsi task normally
 549 * @task: iscsi task for scsi cmd
 550 * @exp_cmdsn: expected cmd sn in cpu format
 551 * @max_cmdsn: max cmd sn in cpu format
 552 *
 553 * This is used when drivers do not need or cannot perform
 554 * lower level pdu processing.
 555 *
 556 * Called with session back_lock
 557 */
 558void iscsi_complete_scsi_task(struct iscsi_task *task,
 559			      uint32_t exp_cmdsn, uint32_t max_cmdsn)
 560{
 561	struct iscsi_conn *conn = task->conn;
 562
 563	ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 564
 565	conn->last_recv = jiffies;
 566	__iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 567	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 568}
 569EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 570
 571/*
 572 * Must be called with back and frwd lock
 573 */
 574static bool cleanup_queued_task(struct iscsi_task *task)
 575{
 576	struct iscsi_conn *conn = task->conn;
 577	bool early_complete = false;
 578
 579	/*
 580	 * We might have raced where we handled a R2T early and got a response
 581	 * but have not yet taken the task off the requeue list, then a TMF or
 582	 * recovery happened and so we can still see it here.
 583	 */
 584	if (task->state == ISCSI_TASK_COMPLETED)
 585		early_complete = true;
 586
 587	if (!list_empty(&task->running)) {
 588		list_del_init(&task->running);
 589		/*
 590		 * If it's on a list but still running this could be cleanup
 591		 * from a TMF or session recovery.
 592		 */
 593		if (task->state == ISCSI_TASK_RUNNING ||
 594		    task->state == ISCSI_TASK_COMPLETED)
 595			__iscsi_put_task(task);
 596	}
 597
 598	if (conn->session->running_aborted_task == task) {
 599		conn->session->running_aborted_task = NULL;
 600		__iscsi_put_task(task);
 601	}
 602
 603	if (conn->task == task) {
 604		conn->task = NULL;
 605		__iscsi_put_task(task);
 606	}
 607
 608	return early_complete;
 609}
 610
 611/*
 612 * session back and frwd lock must be held and if not called for a task that
 613 * is still pending or from the xmit thread, then xmit thread must be suspended
 614 */
 615static void __fail_scsi_task(struct iscsi_task *task, int err)
 616{
 617	struct iscsi_conn *conn = task->conn;
 618	struct scsi_cmnd *sc;
 619	int state;
 620
 621	if (cleanup_queued_task(task))
 622		return;
 623
 624	if (task->state == ISCSI_TASK_PENDING) {
 625		/*
 626		 * cmd never made it to the xmit thread, so we should not count
 627		 * the cmd in the sequencing
 628		 */
 629		conn->session->queued_cmdsn--;
 630		/* it was never sent so just complete like normal */
 631		state = ISCSI_TASK_COMPLETED;
 632	} else if (err == DID_TRANSPORT_DISRUPTED)
 633		state = ISCSI_TASK_ABRT_SESS_RECOV;
 634	else
 635		state = ISCSI_TASK_ABRT_TMF;
 636
 637	sc = task->sc;
 638	sc->result = err << 16;
 639	scsi_set_resid(sc, scsi_bufflen(sc));
 640	iscsi_complete_task(task, state);
 641}
 642
 643static void fail_scsi_task(struct iscsi_task *task, int err)
 644{
 645	struct iscsi_session *session = task->conn->session;
 646
 647	spin_lock_bh(&session->back_lock);
 648	__fail_scsi_task(task, err);
 649	spin_unlock_bh(&session->back_lock);
 650}
 651
 652static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 653				struct iscsi_task *task)
 654{
 655	struct iscsi_session *session = conn->session;
 656	struct iscsi_hdr *hdr = task->hdr;
 657	struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 658	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 659
 660	if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 661		return -ENOTCONN;
 662
 663	if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 664		nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 665	/*
 666	 * pre-format CmdSN for outgoing PDU.
 667	 */
 668	nop->cmdsn = cpu_to_be32(session->cmdsn);
 669	if (hdr->itt != RESERVED_ITT) {
 670		/*
 671		 * TODO: We always use immediate for normal session pdus.
 672		 * If we start to send tmfs or nops as non-immediate then
 673		 * we should start checking the cmdsn numbers for mgmt tasks.
 674		 *
 675		 * During discovery sessions iscsid sends TEXT as non immediate,
 676		 * but we always only send one PDU at a time.
 677		 */
 678		if (conn->c_stage == ISCSI_CONN_STARTED &&
 679		    !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 680			session->queued_cmdsn++;
 681			session->cmdsn++;
 682		}
 683	}
 684
 685	if (session->tt->init_task && session->tt->init_task(task))
 686		return -EIO;
 687
 688	if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 689		session->state = ISCSI_STATE_LOGGING_OUT;
 690
 691	task->state = ISCSI_TASK_RUNNING;
 692	ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 693			  "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 694			  hdr->itt, task->data_count);
 695	return 0;
 696}
 697
 698/**
 699 * iscsi_alloc_mgmt_task - allocate and setup a mgmt task.
 700 * @conn: iscsi conn that the task will be sent on.
 701 * @hdr: iscsi pdu that will be sent.
 702 * @data: buffer for data segment if needed.
 703 * @data_size: length of data in bytes.
 704 */
 705static struct iscsi_task *
 706iscsi_alloc_mgmt_task(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 707		      char *data, uint32_t data_size)
 708{
 709	struct iscsi_session *session = conn->session;
 710	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 711	struct iscsi_task *task;
 712	itt_t itt;
 713
 714	if (session->state == ISCSI_STATE_TERMINATE ||
 715	    !test_bit(ISCSI_CONN_FLAG_BOUND, &conn->flags))
 716		return NULL;
 717
 718	if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 719		/*
 720		 * Login and Text are sent serially, in
 721		 * request-followed-by-response sequence.
 722		 * Same task can be used. Same ITT must be used.
 723		 * Note that login_task is preallocated at conn_create().
 724		 */
 725		if (conn->login_task->state != ISCSI_TASK_FREE) {
 726			iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 727					  "progress. Cannot start new task.\n");
 728			return NULL;
 729		}
 730
 731		if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 732			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);
 733			return NULL;
 734		}
 735
 736		task = conn->login_task;
 737	} else {
 738		if (session->state != ISCSI_STATE_LOGGED_IN)
 739			return NULL;
 740
 741		if (data_size != 0) {
 742			iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 743			return NULL;
 744		}
 745
 746		BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 747		BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 748
 749		if (!kfifo_out(&session->cmdpool.queue,
 750				 (void*)&task, sizeof(void*)))
 751			return NULL;
 752	}
 753	/*
 754	 * released in complete pdu for task we expect a response for, and
 755	 * released by the lld when it has transmitted the task for
 756	 * pdus we do not expect a response for.
 757	 */
 758	refcount_set(&task->refcount, 1);
 759	task->conn = conn;
 760	task->sc = NULL;
 761	INIT_LIST_HEAD(&task->running);
 762	task->state = ISCSI_TASK_PENDING;
 763
 764	if (data_size) {
 765		memcpy(task->data, data, data_size);
 766		task->data_count = data_size;
 767	} else
 768		task->data_count = 0;
 769
 770	if (conn->session->tt->alloc_pdu) {
 771		if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 772			iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 773					 "pdu for mgmt task.\n");
 774			goto free_task;
 775		}
 776	}
 777
 778	itt = task->hdr->itt;
 779	task->hdr_len = sizeof(struct iscsi_hdr);
 780	memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 781
 782	if (hdr->itt != RESERVED_ITT) {
 783		if (session->tt->parse_pdu_itt)
 784			task->hdr->itt = itt;
 785		else
 786			task->hdr->itt = build_itt(task->itt,
 787						   task->conn->session->age);
 788	}
 789
 790	return task;
 791
 792free_task:
 793	iscsi_put_task(task);
 794	return NULL;
 795}
 796
 797/**
 798 * iscsi_send_mgmt_task - Send task created with iscsi_alloc_mgmt_task.
 799 * @task: iscsi task to send.
 800 *
 801 * On failure this returns a non-zero error code, and the driver must free
 802 * the task with iscsi_put_task;
 803 */
 804static int iscsi_send_mgmt_task(struct iscsi_task *task)
 805{
 806	struct iscsi_conn *conn = task->conn;
 807	struct iscsi_session *session = conn->session;
 808	struct iscsi_host *ihost = shost_priv(conn->session->host);
 809	int rc = 0;
 810
 811	if (!ihost->workq) {
 812		rc = iscsi_prep_mgmt_task(conn, task);
 813		if (rc)
 814			return rc;
 815
 816		rc = session->tt->xmit_task(task);
 817		if (rc)
 818			return rc;
 819	} else {
 820		list_add_tail(&task->running, &conn->mgmtqueue);
 821		iscsi_conn_queue_xmit(conn);
 822	}
 823
 824	return 0;
 825}
 826
 827static int __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 828				 char *data, uint32_t data_size)
 829{
 830	struct iscsi_task *task;
 831	int rc;
 832
 833	task = iscsi_alloc_mgmt_task(conn, hdr, data, data_size);
 834	if (!task)
 835		return -ENOMEM;
 836
 837	rc = iscsi_send_mgmt_task(task);
 838	if (rc)
 839		iscsi_put_task(task);
 840	return rc;
 841}
 842
 843int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 844			char *data, uint32_t data_size)
 845{
 846	struct iscsi_conn *conn = cls_conn->dd_data;
 847	struct iscsi_session *session = conn->session;
 848	int err = 0;
 849
 850	spin_lock_bh(&session->frwd_lock);
 851	if (__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 852		err = -EPERM;
 853	spin_unlock_bh(&session->frwd_lock);
 854	return err;
 855}
 856EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 857
 858/**
 859 * iscsi_scsi_cmd_rsp - SCSI Command Response processing
 860 * @conn: iscsi connection
 861 * @hdr: iscsi header
 862 * @task: scsi command task
 863 * @data: cmd data buffer
 864 * @datalen: len of buffer
 865 *
 866 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 867 * then completes the command and task. called under back_lock
 868 **/
 869static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 870			       struct iscsi_task *task, char *data,
 871			       int datalen)
 872{
 873	struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 874	struct iscsi_session *session = conn->session;
 875	struct scsi_cmnd *sc = task->sc;
 876
 877	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 878	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 879
 880	sc->result = (DID_OK << 16) | rhdr->cmd_status;
 881
 882	if (task->protected) {
 883		sector_t sector;
 884		u8 ascq;
 885
 886		/**
 887		 * Transports that didn't implement check_protection
 888		 * callback but still published T10-PI support to scsi-mid
 889		 * deserve this BUG_ON.
 890		 **/
 891		BUG_ON(!session->tt->check_protection);
 892
 893		ascq = session->tt->check_protection(task, &sector);
 894		if (ascq) {
 895			scsi_build_sense(sc, 1, ILLEGAL_REQUEST, 0x10, ascq);
 896			scsi_set_sense_information(sc->sense_buffer,
 897						   SCSI_SENSE_BUFFERSIZE,
 898						   sector);
 899			goto out;
 900		}
 901	}
 902
 903	if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 904		sc->result = DID_ERROR << 16;
 905		goto out;
 906	}
 907
 908	if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 909		uint16_t senselen;
 910
 911		if (datalen < 2) {
 912invalid_datalen:
 913			iscsi_conn_printk(KERN_ERR,  conn,
 914					 "Got CHECK_CONDITION but invalid data "
 915					 "buffer size of %d\n", datalen);
 916			sc->result = DID_BAD_TARGET << 16;
 917			goto out;
 918		}
 919
 920		senselen = get_unaligned_be16(data);
 921		if (datalen < senselen)
 922			goto invalid_datalen;
 923
 924		memcpy(sc->sense_buffer, data + 2,
 925		       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 926		ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 927				  min_t(uint16_t, senselen,
 928				  SCSI_SENSE_BUFFERSIZE));
 929	}
 930
 931	if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 932			   ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 933		sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 934	}
 935
 936	if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 937	                   ISCSI_FLAG_CMD_OVERFLOW)) {
 938		int res_count = be32_to_cpu(rhdr->residual_count);
 939
 940		if (res_count > 0 &&
 941		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 942		     res_count <= scsi_bufflen(sc)))
 943			/* write side for bidi or uni-io set_resid */
 944			scsi_set_resid(sc, res_count);
 945		else
 946			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 947	}
 948out:
 949	ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 950			  sc, sc->result, task->itt);
 951	conn->scsirsp_pdus_cnt++;
 952	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 953}
 954
 955/**
 956 * iscsi_data_in_rsp - SCSI Data-In Response processing
 957 * @conn: iscsi connection
 958 * @hdr:  iscsi pdu
 959 * @task: scsi command task
 960 *
 961 * iscsi_data_in_rsp sets up the scsi_cmnd fields based on the data received
 962 * then completes the command and task. called under back_lock
 963 **/
 964static void
 965iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 966		  struct iscsi_task *task)
 967{
 968	struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 969	struct scsi_cmnd *sc = task->sc;
 970
 971	if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 972		return;
 973
 974	iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 975	sc->result = (DID_OK << 16) | rhdr->cmd_status;
 976	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 977	if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 978	                   ISCSI_FLAG_DATA_OVERFLOW)) {
 979		int res_count = be32_to_cpu(rhdr->residual_count);
 980
 981		if (res_count > 0 &&
 982		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 983		     res_count <= sc->sdb.length))
 984			scsi_set_resid(sc, res_count);
 985		else
 986			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 987	}
 988
 989	ISCSI_DBG_SESSION(conn->session, "data in with status done "
 990			  "[sc %p res %d itt 0x%x]\n",
 991			  sc, sc->result, task->itt);
 992	conn->scsirsp_pdus_cnt++;
 993	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 994}
 995
 996static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 997{
 998	struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 999	struct iscsi_session *session = conn->session;
1000
1001	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1002	conn->tmfrsp_pdus_cnt++;
1003
1004	if (session->tmf_state != TMF_QUEUED)
1005		return;
1006
1007	if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
1008		session->tmf_state = TMF_SUCCESS;
1009	else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
1010		session->tmf_state = TMF_NOT_FOUND;
1011	else
1012		session->tmf_state = TMF_FAILED;
1013	wake_up(&session->ehwait);
1014}
1015
1016static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
1017{
1018        struct iscsi_nopout hdr;
1019	struct iscsi_task *task;
1020
1021	if (!rhdr) {
1022		if (READ_ONCE(conn->ping_task))
1023			return -EINVAL;
1024	}
1025
1026	memset(&hdr, 0, sizeof(struct iscsi_nopout));
1027	hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
1028	hdr.flags = ISCSI_FLAG_CMD_FINAL;
1029
1030	if (rhdr) {
1031		hdr.lun = rhdr->lun;
1032		hdr.ttt = rhdr->ttt;
1033		hdr.itt = RESERVED_ITT;
1034	} else
1035		hdr.ttt = RESERVED_ITT;
1036
1037	task = iscsi_alloc_mgmt_task(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
1038	if (!task)
1039		return -ENOMEM;
1040
1041	if (!rhdr)
1042		WRITE_ONCE(conn->ping_task, task);
1043
1044	if (iscsi_send_mgmt_task(task)) {
1045		if (!rhdr)
1046			WRITE_ONCE(conn->ping_task, NULL);
1047		iscsi_put_task(task);
1048
1049		iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
1050		return -EIO;
1051	} else if (!rhdr) {
1052		/* only track our nops */
1053		conn->last_ping = jiffies;
1054	}
1055
1056	return 0;
1057}
1058
1059/**
1060 * iscsi_nop_out_rsp - SCSI NOP Response processing
1061 * @task: scsi command task
1062 * @nop: the nop structure
1063 * @data: where to put the data
1064 * @datalen: length of data
1065 *
1066 * iscsi_nop_out_rsp handles nop response from use or
1067 * from user space. called under back_lock
1068 **/
1069static int iscsi_nop_out_rsp(struct iscsi_task *task,
1070			     struct iscsi_nopin *nop, char *data, int datalen)
1071{
1072	struct iscsi_conn *conn = task->conn;
1073	int rc = 0;
1074
1075	if (READ_ONCE(conn->ping_task) != task) {
1076		/*
1077		 * If this is not in response to one of our
1078		 * nops then it must be from userspace.
1079		 */
1080		if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1081				   data, datalen))
1082			rc = ISCSI_ERR_CONN_FAILED;
1083	} else
1084		mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1085	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1086	return rc;
1087}
1088
1089static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1090			       char *data, int datalen)
1091{
1092	struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1093	struct iscsi_hdr rejected_pdu;
1094	int opcode, rc = 0;
1095
1096	conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1097
1098	if (ntoh24(reject->dlength) > datalen ||
1099	    ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1100		iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1101				  "pdu. Invalid data length (pdu dlength "
1102				  "%u, datalen %d\n", ntoh24(reject->dlength),
1103				  datalen);
1104		return ISCSI_ERR_PROTO;
1105	}
1106	memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1107	opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1108
1109	switch (reject->reason) {
1110	case ISCSI_REASON_DATA_DIGEST_ERROR:
1111		iscsi_conn_printk(KERN_ERR, conn,
1112				  "pdu (op 0x%x itt 0x%x) rejected "
1113				  "due to DataDigest error.\n",
1114				  opcode, rejected_pdu.itt);
1115		break;
1116	case ISCSI_REASON_IMM_CMD_REJECT:
1117		iscsi_conn_printk(KERN_ERR, conn,
1118				  "pdu (op 0x%x itt 0x%x) rejected. Too many "
1119				  "immediate commands.\n",
1120				  opcode, rejected_pdu.itt);
1121		/*
1122		 * We only send one TMF at a time so if the target could not
1123		 * handle it, then it should get fixed (RFC mandates that
1124		 * a target can handle one immediate TMF per conn).
1125		 *
1126		 * For nops-outs, we could have sent more than one if
1127		 * the target is sending us lots of nop-ins
1128		 */
1129		if (opcode != ISCSI_OP_NOOP_OUT)
1130			return 0;
1131
1132		if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1133			/*
1134			 * nop-out in response to target's nop-out rejected.
1135			 * Just resend.
1136			 */
1137			/* In RX path we are under back lock */
1138			spin_unlock(&conn->session->back_lock);
1139			spin_lock(&conn->session->frwd_lock);
1140			iscsi_send_nopout(conn,
1141					  (struct iscsi_nopin*)&rejected_pdu);
1142			spin_unlock(&conn->session->frwd_lock);
1143			spin_lock(&conn->session->back_lock);
1144		} else {
1145			struct iscsi_task *task;
1146			/*
1147			 * Our nop as ping got dropped. We know the target
1148			 * and transport are ok so just clean up
1149			 */
1150			task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1151			if (!task) {
1152				iscsi_conn_printk(KERN_ERR, conn,
1153						 "Invalid pdu reject. Could "
1154						 "not lookup rejected task.\n");
1155				rc = ISCSI_ERR_BAD_ITT;
1156			} else
1157				rc = iscsi_nop_out_rsp(task,
1158					(struct iscsi_nopin*)&rejected_pdu,
1159					NULL, 0);
1160		}
1161		break;
1162	default:
1163		iscsi_conn_printk(KERN_ERR, conn,
1164				  "pdu (op 0x%x itt 0x%x) rejected. Reason "
1165				  "code 0x%x\n", rejected_pdu.opcode,
1166				  rejected_pdu.itt, reject->reason);
1167		break;
1168	}
1169	return rc;
1170}
1171
1172/**
1173 * iscsi_itt_to_task - look up task by itt
1174 * @conn: iscsi connection
1175 * @itt: itt
1176 *
1177 * This should be used for mgmt tasks like login and nops, or if
1178 * the LDD's itt space does not include the session age.
1179 *
1180 * The session back_lock must be held.
1181 */
1182struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1183{
1184	struct iscsi_session *session = conn->session;
1185	int i;
1186
1187	if (itt == RESERVED_ITT)
1188		return NULL;
1189
1190	if (session->tt->parse_pdu_itt)
1191		session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1192	else
1193		i = get_itt(itt);
1194	if (i >= session->cmds_max)
1195		return NULL;
1196
1197	return session->cmds[i];
1198}
1199EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1200
1201/**
1202 * __iscsi_complete_pdu - complete pdu
1203 * @conn: iscsi conn
1204 * @hdr: iscsi header
1205 * @data: data buffer
1206 * @datalen: len of data buffer
1207 *
1208 * Completes pdu processing by freeing any resources allocated at
1209 * queuecommand or send generic. session back_lock must be held and verify
1210 * itt must have been called.
1211 */
1212int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1213			 char *data, int datalen)
1214{
1215	struct iscsi_session *session = conn->session;
1216	int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1217	struct iscsi_task *task;
1218	uint32_t itt;
1219
1220	conn->last_recv = jiffies;
1221	rc = iscsi_verify_itt(conn, hdr->itt);
1222	if (rc)
1223		return rc;
1224
1225	if (hdr->itt != RESERVED_ITT)
1226		itt = get_itt(hdr->itt);
1227	else
1228		itt = ~0U;
1229
1230	ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1231			  opcode, conn->id, itt, datalen);
1232
1233	if (itt == ~0U) {
1234		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1235
1236		switch(opcode) {
1237		case ISCSI_OP_NOOP_IN:
1238			if (datalen) {
1239				rc = ISCSI_ERR_PROTO;
1240				break;
1241			}
1242
1243			if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1244				break;
1245
1246			/* In RX path we are under back lock */
1247			spin_unlock(&session->back_lock);
1248			spin_lock(&session->frwd_lock);
1249			iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1250			spin_unlock(&session->frwd_lock);
1251			spin_lock(&session->back_lock);
1252			break;
1253		case ISCSI_OP_REJECT:
1254			rc = iscsi_handle_reject(conn, hdr, data, datalen);
1255			break;
1256		case ISCSI_OP_ASYNC_EVENT:
1257			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1258			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1259				rc = ISCSI_ERR_CONN_FAILED;
1260			break;
1261		default:
1262			rc = ISCSI_ERR_BAD_OPCODE;
1263			break;
1264		}
1265		goto out;
1266	}
1267
1268	switch(opcode) {
1269	case ISCSI_OP_SCSI_CMD_RSP:
1270	case ISCSI_OP_SCSI_DATA_IN:
1271		task = iscsi_itt_to_ctask(conn, hdr->itt);
1272		if (!task)
1273			return ISCSI_ERR_BAD_ITT;
1274		task->last_xfer = jiffies;
1275		break;
1276	case ISCSI_OP_R2T:
1277		/*
1278		 * LLD handles R2Ts if they need to.
1279		 */
1280		return 0;
1281	case ISCSI_OP_LOGOUT_RSP:
1282	case ISCSI_OP_LOGIN_RSP:
1283	case ISCSI_OP_TEXT_RSP:
1284	case ISCSI_OP_SCSI_TMFUNC_RSP:
1285	case ISCSI_OP_NOOP_IN:
1286		task = iscsi_itt_to_task(conn, hdr->itt);
1287		if (!task)
1288			return ISCSI_ERR_BAD_ITT;
1289		break;
1290	default:
1291		return ISCSI_ERR_BAD_OPCODE;
1292	}
1293
1294	switch(opcode) {
1295	case ISCSI_OP_SCSI_CMD_RSP:
1296		iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1297		break;
1298	case ISCSI_OP_SCSI_DATA_IN:
1299		iscsi_data_in_rsp(conn, hdr, task);
1300		break;
1301	case ISCSI_OP_LOGOUT_RSP:
1302		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1303		if (datalen) {
1304			rc = ISCSI_ERR_PROTO;
1305			break;
1306		}
1307		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1308		goto recv_pdu;
1309	case ISCSI_OP_LOGIN_RSP:
1310	case ISCSI_OP_TEXT_RSP:
1311		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1312		/*
1313		 * login related PDU's exp_statsn is handled in
1314		 * userspace
1315		 */
1316		goto recv_pdu;
1317	case ISCSI_OP_SCSI_TMFUNC_RSP:
1318		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1319		if (datalen) {
1320			rc = ISCSI_ERR_PROTO;
1321			break;
1322		}
1323
1324		iscsi_tmf_rsp(conn, hdr);
1325		iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1326		break;
1327	case ISCSI_OP_NOOP_IN:
1328		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1329		if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1330			rc = ISCSI_ERR_PROTO;
1331			break;
1332		}
1333		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1334
1335		rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1336				       data, datalen);
1337		break;
1338	default:
1339		rc = ISCSI_ERR_BAD_OPCODE;
1340		break;
1341	}
1342
1343out:
1344	return rc;
1345recv_pdu:
1346	if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1347		rc = ISCSI_ERR_CONN_FAILED;
1348	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1349	return rc;
1350}
1351EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1352
1353int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1354		       char *data, int datalen)
1355{
1356	int rc;
1357
1358	spin_lock(&conn->session->back_lock);
1359	rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1360	spin_unlock(&conn->session->back_lock);
1361	return rc;
1362}
1363EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1364
1365int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1366{
1367	struct iscsi_session *session = conn->session;
1368	int age = 0, i = 0;
1369
1370	if (itt == RESERVED_ITT)
1371		return 0;
1372
1373	if (session->tt->parse_pdu_itt)
1374		session->tt->parse_pdu_itt(conn, itt, &i, &age);
1375	else {
1376		i = get_itt(itt);
1377		age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1378	}
1379
1380	if (age != session->age) {
1381		iscsi_conn_printk(KERN_ERR, conn,
1382				  "received itt %x expected session age (%x)\n",
1383				  (__force u32)itt, session->age);
1384		return ISCSI_ERR_BAD_ITT;
1385	}
1386
1387	if (i >= session->cmds_max) {
1388		iscsi_conn_printk(KERN_ERR, conn,
1389				  "received invalid itt index %u (max cmds "
1390				   "%u.\n", i, session->cmds_max);
1391		return ISCSI_ERR_BAD_ITT;
1392	}
1393	return 0;
1394}
1395EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1396
1397/**
1398 * iscsi_itt_to_ctask - look up ctask by itt
1399 * @conn: iscsi connection
1400 * @itt: itt
1401 *
1402 * This should be used for cmd tasks.
1403 *
1404 * The session back_lock must be held.
1405 */
1406struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1407{
1408	struct iscsi_task *task;
1409
1410	if (iscsi_verify_itt(conn, itt))
1411		return NULL;
1412
1413	task = iscsi_itt_to_task(conn, itt);
1414	if (!task || !task->sc)
1415		return NULL;
1416
1417	if (iscsi_cmd(task->sc)->age != conn->session->age) {
1418		iscsi_session_printk(KERN_ERR, conn->session,
1419				  "task's session age %d, expected %d\n",
1420				  iscsi_cmd(task->sc)->age, conn->session->age);
1421		return NULL;
1422	}
1423
1424	return task;
1425}
1426EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1427
1428void iscsi_session_failure(struct iscsi_session *session,
1429			   enum iscsi_err err)
1430{
1431	struct iscsi_conn *conn;
1432
1433	spin_lock_bh(&session->frwd_lock);
1434	conn = session->leadconn;
1435	if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1436		spin_unlock_bh(&session->frwd_lock);
1437		return;
1438	}
1439
1440	iscsi_get_conn(conn->cls_conn);
1441	spin_unlock_bh(&session->frwd_lock);
1442	/*
1443	 * if the host is being removed bypass the connection
1444	 * recovery initialization because we are going to kill
1445	 * the session.
1446	 */
1447	if (err == ISCSI_ERR_INVALID_HOST)
1448		iscsi_conn_error_event(conn->cls_conn, err);
1449	else
1450		iscsi_conn_failure(conn, err);
1451	iscsi_put_conn(conn->cls_conn);
1452}
1453EXPORT_SYMBOL_GPL(iscsi_session_failure);
1454
1455static bool iscsi_set_conn_failed(struct iscsi_conn *conn)
1456{
1457	struct iscsi_session *session = conn->session;
1458
1459	if (session->state == ISCSI_STATE_FAILED)
1460		return false;
1461
1462	if (conn->stop_stage == 0)
1463		session->state = ISCSI_STATE_FAILED;
1464
1465	set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
1466	set_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags);
1467	return true;
1468}
1469
1470void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1471{
1472	struct iscsi_session *session = conn->session;
1473	bool needs_evt;
1474
1475	spin_lock_bh(&session->frwd_lock);
1476	needs_evt = iscsi_set_conn_failed(conn);
1477	spin_unlock_bh(&session->frwd_lock);
1478
1479	if (needs_evt)
1480		iscsi_conn_error_event(conn->cls_conn, err);
1481}
1482EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1483
1484static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1485{
1486	struct iscsi_session *session = conn->session;
1487
1488	/*
1489	 * Check for iSCSI window and take care of CmdSN wrap-around
1490	 */
1491	if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1492		ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1493				  "%u MaxCmdSN %u CmdSN %u/%u\n",
1494				  session->exp_cmdsn, session->max_cmdsn,
1495				  session->cmdsn, session->queued_cmdsn);
1496		return -ENOSPC;
1497	}
1498	return 0;
1499}
1500
1501static int iscsi_xmit_task(struct iscsi_conn *conn, struct iscsi_task *task,
1502			   bool was_requeue)
1503{
1504	int rc;
1505
1506	if (!conn->task) {
1507		/*
1508		 * Take a ref so we can access it after xmit_task().
1509		 *
1510		 * This should never fail because the failure paths will have
1511		 * stopped the xmit thread.
1512		 */
1513		if (!iscsi_get_task(task)) {
1514			WARN_ON_ONCE(1);
1515			return 0;
1516		}
1517	} else {
1518		/* Already have a ref from when we failed to send it last call */
1519		conn->task = NULL;
1520	}
1521
1522	/*
1523	 * If this was a requeue for a R2T we have an extra ref on the task in
1524	 * case a bad target sends a cmd rsp before we have handled the task.
1525	 */
1526	if (was_requeue)
1527		iscsi_put_task(task);
1528
1529	/*
1530	 * Do this after dropping the extra ref because if this was a requeue
1531	 * it's removed from that list and cleanup_queued_task would miss it.
1532	 */
1533	if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1534		/*
1535		 * Save the task and ref in case we weren't cleaning up this
1536		 * task and get woken up again.
1537		 */
1538		conn->task = task;
1539		return -ENODATA;
1540	}
1541
1542	spin_unlock_bh(&conn->session->frwd_lock);
1543	rc = conn->session->tt->xmit_task(task);
1544	spin_lock_bh(&conn->session->frwd_lock);
1545	if (!rc) {
1546		/* done with this task */
1547		task->last_xfer = jiffies;
1548	} else {
1549		/*
1550		 * get an extra ref that is released next time we access it
1551		 * as conn->task above.
1552		 */
1553		iscsi_get_task(task);
1554		conn->task = task;
1555	}
1556
1557	iscsi_put_task(task);
1558	return rc;
1559}
1560
1561/**
1562 * iscsi_requeue_task - requeue task to run from session workqueue
1563 * @task: task to requeue
1564 *
1565 * Callers must have taken a ref to the task that is going to be requeued.
1566 */
1567void iscsi_requeue_task(struct iscsi_task *task)
1568{
1569	struct iscsi_conn *conn = task->conn;
1570
1571	/*
1572	 * this may be on the requeue list already if the xmit_task callout
1573	 * is handling the r2ts while we are adding new ones
1574	 */
1575	spin_lock_bh(&conn->session->frwd_lock);
1576	if (list_empty(&task->running)) {
1577		list_add_tail(&task->running, &conn->requeue);
1578	} else {
1579		/*
1580		 * Don't need the extra ref since it's already requeued and
1581		 * has a ref.
1582		 */
1583		iscsi_put_task(task);
1584	}
1585	iscsi_conn_queue_xmit(conn);
1586	spin_unlock_bh(&conn->session->frwd_lock);
1587}
1588EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1589
1590/**
1591 * iscsi_data_xmit - xmit any command into the scheduled connection
1592 * @conn: iscsi connection
1593 *
1594 * Notes:
1595 *	The function can return -EAGAIN in which case the caller must
1596 *	re-schedule it again later or recover. '0' return code means
1597 *	successful xmit.
1598 **/
1599static int iscsi_data_xmit(struct iscsi_conn *conn)
1600{
1601	struct iscsi_task *task;
1602	int rc = 0;
1603
1604	spin_lock_bh(&conn->session->frwd_lock);
1605	if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1606		ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1607		spin_unlock_bh(&conn->session->frwd_lock);
1608		return -ENODATA;
1609	}
1610
1611	if (conn->task) {
1612		rc = iscsi_xmit_task(conn, conn->task, false);
1613	        if (rc)
1614		        goto done;
1615	}
1616
1617	/*
1618	 * process mgmt pdus like nops before commands since we should
1619	 * only have one nop-out as a ping from us and targets should not
1620	 * overflow us with nop-ins
1621	 */
1622check_mgmt:
1623	while (!list_empty(&conn->mgmtqueue)) {
1624		task = list_entry(conn->mgmtqueue.next, struct iscsi_task,
1625				  running);
1626		list_del_init(&task->running);
1627		if (iscsi_prep_mgmt_task(conn, task)) {
1628			/* regular RX path uses back_lock */
1629			spin_lock_bh(&conn->session->back_lock);
1630			__iscsi_put_task(task);
1631			spin_unlock_bh(&conn->session->back_lock);
1632			continue;
1633		}
1634		rc = iscsi_xmit_task(conn, task, false);
1635		if (rc)
1636			goto done;
1637	}
1638
1639check_requeue:
1640	while (!list_empty(&conn->requeue)) {
1641		/*
1642		 * we always do fastlogout - conn stop code will clean up.
1643		 */
1644		if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1645			break;
1646
1647		task = list_entry(conn->requeue.next, struct iscsi_task,
1648				  running);
1649
1650		if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1651			break;
1652
1653		list_del_init(&task->running);
1654		rc = iscsi_xmit_task(conn, task, true);
1655		if (rc)
1656			goto done;
1657		if (!list_empty(&conn->mgmtqueue))
1658			goto check_mgmt;
1659	}
1660
1661	/* process pending command queue */
1662	while (!list_empty(&conn->cmdqueue)) {
1663		task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1664				  running);
1665		list_del_init(&task->running);
1666		if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1667			fail_scsi_task(task, DID_IMM_RETRY);
1668			continue;
1669		}
1670		rc = iscsi_prep_scsi_cmd_pdu(task);
1671		if (rc) {
1672			if (rc == -ENOMEM || rc == -EACCES)
1673				fail_scsi_task(task, DID_IMM_RETRY);
1674			else
1675				fail_scsi_task(task, DID_ABORT);
1676			continue;
1677		}
1678		rc = iscsi_xmit_task(conn, task, false);
1679		if (rc)
1680			goto done;
1681		/*
1682		 * we could continuously get new task requests so
1683		 * we need to check the mgmt queue for nops that need to
1684		 * be sent to aviod starvation
1685		 */
1686		if (!list_empty(&conn->mgmtqueue))
1687			goto check_mgmt;
1688		if (!list_empty(&conn->requeue))
1689			goto check_requeue;
1690	}
1691
1692	spin_unlock_bh(&conn->session->frwd_lock);
1693	return -ENODATA;
1694
1695done:
1696	spin_unlock_bh(&conn->session->frwd_lock);
1697	return rc;
1698}
1699
1700static void iscsi_xmitworker(struct work_struct *work)
1701{
1702	struct iscsi_conn *conn =
1703		container_of(work, struct iscsi_conn, xmitwork);
1704	int rc;
1705	/*
1706	 * serialize Xmit worker on a per-connection basis.
1707	 */
1708	do {
1709		rc = iscsi_data_xmit(conn);
1710	} while (rc >= 0 || rc == -EAGAIN);
1711}
1712
1713static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1714						  struct scsi_cmnd *sc)
1715{
1716	struct iscsi_task *task;
1717
1718	if (!kfifo_out(&conn->session->cmdpool.queue,
1719			 (void *) &task, sizeof(void *)))
1720		return NULL;
1721
1722	iscsi_cmd(sc)->age = conn->session->age;
1723	iscsi_cmd(sc)->task = task;
1724
1725	refcount_set(&task->refcount, 1);
1726	task->state = ISCSI_TASK_PENDING;
1727	task->conn = conn;
1728	task->sc = sc;
1729	task->have_checked_conn = false;
1730	task->last_timeout = jiffies;
1731	task->last_xfer = jiffies;
1732	task->protected = false;
1733	INIT_LIST_HEAD(&task->running);
1734	return task;
1735}
1736
1737enum {
1738	FAILURE_BAD_HOST = 1,
1739	FAILURE_SESSION_FAILED,
1740	FAILURE_SESSION_FREED,
1741	FAILURE_WINDOW_CLOSED,
1742	FAILURE_OOM,
1743	FAILURE_SESSION_TERMINATE,
1744	FAILURE_SESSION_IN_RECOVERY,
1745	FAILURE_SESSION_RECOVERY_TIMEOUT,
1746	FAILURE_SESSION_LOGGING_OUT,
1747	FAILURE_SESSION_NOT_READY,
1748};
1749
1750int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1751{
1752	struct iscsi_cls_session *cls_session;
1753	struct iscsi_host *ihost;
1754	int reason = 0;
1755	struct iscsi_session *session;
1756	struct iscsi_conn *conn;
1757	struct iscsi_task *task = NULL;
1758
1759	sc->result = 0;
1760	iscsi_cmd(sc)->task = NULL;
1761
1762	ihost = shost_priv(host);
1763
1764	cls_session = starget_to_session(scsi_target(sc->device));
1765	session = cls_session->dd_data;
1766	spin_lock_bh(&session->frwd_lock);
1767
1768	reason = iscsi_session_chkready(cls_session);
1769	if (reason) {
1770		sc->result = reason;
1771		goto fault;
1772	}
1773
1774	if (session->state != ISCSI_STATE_LOGGED_IN) {
1775		/*
1776		 * to handle the race between when we set the recovery state
1777		 * and block the session we requeue here (commands could
1778		 * be entering our queuecommand while a block is starting
1779		 * up because the block code is not locked)
1780		 */
1781		switch (session->state) {
1782		case ISCSI_STATE_FAILED:
1783			/*
1784			 * cmds should fail during shutdown, if the session
1785			 * state is bad, allowing completion to happen
1786			 */
1787			if (unlikely(system_state != SYSTEM_RUNNING)) {
1788				reason = FAILURE_SESSION_FAILED;
1789				sc->result = DID_NO_CONNECT << 16;
1790				break;
1791			}
1792			fallthrough;
1793		case ISCSI_STATE_IN_RECOVERY:
1794			reason = FAILURE_SESSION_IN_RECOVERY;
1795			sc->result = DID_IMM_RETRY << 16;
1796			break;
1797		case ISCSI_STATE_LOGGING_OUT:
1798			reason = FAILURE_SESSION_LOGGING_OUT;
1799			sc->result = DID_IMM_RETRY << 16;
1800			break;
1801		case ISCSI_STATE_RECOVERY_FAILED:
1802			reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1803			sc->result = DID_TRANSPORT_FAILFAST << 16;
1804			break;
1805		case ISCSI_STATE_TERMINATE:
1806			reason = FAILURE_SESSION_TERMINATE;
1807			sc->result = DID_NO_CONNECT << 16;
1808			break;
1809		default:
1810			reason = FAILURE_SESSION_FREED;
1811			sc->result = DID_NO_CONNECT << 16;
1812		}
1813		goto fault;
1814	}
1815
1816	conn = session->leadconn;
1817	if (!conn) {
1818		reason = FAILURE_SESSION_FREED;
1819		sc->result = DID_NO_CONNECT << 16;
1820		goto fault;
1821	}
1822
1823	if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1824		reason = FAILURE_SESSION_IN_RECOVERY;
1825		sc->result = DID_REQUEUE << 16;
1826		goto fault;
1827	}
1828
1829	if (iscsi_check_cmdsn_window_closed(conn)) {
1830		reason = FAILURE_WINDOW_CLOSED;
1831		goto reject;
1832	}
1833
1834	task = iscsi_alloc_task(conn, sc);
1835	if (!task) {
1836		reason = FAILURE_OOM;
1837		goto reject;
1838	}
1839
1840	if (!ihost->workq) {
1841		reason = iscsi_prep_scsi_cmd_pdu(task);
1842		if (reason) {
1843			if (reason == -ENOMEM ||  reason == -EACCES) {
1844				reason = FAILURE_OOM;
1845				goto prepd_reject;
1846			} else {
1847				sc->result = DID_ABORT << 16;
1848				goto prepd_fault;
1849			}
1850		}
1851		if (session->tt->xmit_task(task)) {
1852			session->cmdsn--;
1853			reason = FAILURE_SESSION_NOT_READY;
1854			goto prepd_reject;
1855		}
1856	} else {
1857		list_add_tail(&task->running, &conn->cmdqueue);
1858		iscsi_conn_queue_xmit(conn);
1859	}
1860
1861	session->queued_cmdsn++;
1862	spin_unlock_bh(&session->frwd_lock);
1863	return 0;
1864
1865prepd_reject:
1866	spin_lock_bh(&session->back_lock);
1867	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1868	spin_unlock_bh(&session->back_lock);
1869reject:
1870	spin_unlock_bh(&session->frwd_lock);
1871	ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1872			  sc->cmnd[0], reason);
1873	return SCSI_MLQUEUE_TARGET_BUSY;
1874
1875prepd_fault:
1876	spin_lock_bh(&session->back_lock);
1877	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1878	spin_unlock_bh(&session->back_lock);
1879fault:
1880	spin_unlock_bh(&session->frwd_lock);
1881	ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1882			  sc->cmnd[0], reason);
1883	scsi_set_resid(sc, scsi_bufflen(sc));
1884	scsi_done(sc);
1885	return 0;
1886}
1887EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1888
1889int iscsi_target_alloc(struct scsi_target *starget)
1890{
1891	struct iscsi_cls_session *cls_session = starget_to_session(starget);
1892	struct iscsi_session *session = cls_session->dd_data;
1893
1894	starget->can_queue = session->scsi_cmds_max;
1895	return 0;
1896}
1897EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1898
1899static void iscsi_tmf_timedout(struct timer_list *t)
1900{
1901	struct iscsi_session *session = timer_container_of(session, t,
1902							   tmf_timer);
1903
1904	spin_lock(&session->frwd_lock);
1905	if (session->tmf_state == TMF_QUEUED) {
1906		session->tmf_state = TMF_TIMEDOUT;
1907		ISCSI_DBG_EH(session, "tmf timedout\n");
1908		/* unblock eh_abort() */
1909		wake_up(&session->ehwait);
1910	}
1911	spin_unlock(&session->frwd_lock);
1912}
1913
1914static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1915				   struct iscsi_tm *hdr, int age,
1916				   int timeout)
1917	__must_hold(&session->frwd_lock)
1918{
1919	struct iscsi_session *session = conn->session;
1920
1921	if (__iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr, NULL, 0)) {
1922		spin_unlock_bh(&session->frwd_lock);
1923		iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1924		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1925		spin_lock_bh(&session->frwd_lock);
1926		return -EPERM;
1927	}
1928	conn->tmfcmd_pdus_cnt++;
1929	session->tmf_timer.expires = timeout * HZ + jiffies;
1930	add_timer(&session->tmf_timer);
1931	ISCSI_DBG_EH(session, "tmf set timeout\n");
1932
1933	spin_unlock_bh(&session->frwd_lock);
1934	mutex_unlock(&session->eh_mutex);
1935
1936	/*
1937	 * block eh thread until:
1938	 *
1939	 * 1) tmf response
1940	 * 2) tmf timeout
1941	 * 3) session is terminated or restarted or userspace has
1942	 * given up on recovery
1943	 */
1944	wait_event_interruptible(session->ehwait, age != session->age ||
1945				 session->state != ISCSI_STATE_LOGGED_IN ||
1946				 session->tmf_state != TMF_QUEUED);
1947	if (signal_pending(current))
1948		flush_signals(current);
1949	timer_delete_sync(&session->tmf_timer);
1950
1951	mutex_lock(&session->eh_mutex);
1952	spin_lock_bh(&session->frwd_lock);
1953	/* if the session drops it will clean up the task */
1954	if (age != session->age ||
1955	    session->state != ISCSI_STATE_LOGGED_IN)
1956		return -ENOTCONN;
1957	return 0;
1958}
1959
1960/*
1961 * Fail commands. session frwd lock held and xmit thread flushed.
1962 */
1963static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1964{
1965	struct iscsi_session *session = conn->session;
1966	struct iscsi_task *task;
1967	int i;
1968
1969restart_cmd_loop:
1970	spin_lock_bh(&session->back_lock);
1971	for (i = 0; i < session->cmds_max; i++) {
1972		task = session->cmds[i];
1973		if (!task->sc || task->state == ISCSI_TASK_FREE)
1974			continue;
1975
1976		if (lun != -1 && lun != task->sc->device->lun)
1977			continue;
1978		/*
1979		 * The cmd is completing but if this is called from an eh
1980		 * callout path then when we return scsi-ml owns the cmd. Wait
1981		 * for the completion path to finish freeing the cmd.
1982		 */
1983		if (!iscsi_get_task(task)) {
1984			spin_unlock_bh(&session->back_lock);
1985			spin_unlock_bh(&session->frwd_lock);
1986			udelay(ISCSI_CMD_COMPL_WAIT);
1987			spin_lock_bh(&session->frwd_lock);
1988			goto restart_cmd_loop;
1989		}
1990
1991		ISCSI_DBG_SESSION(session,
1992				  "failing sc %p itt 0x%x state %d\n",
1993				  task->sc, task->itt, task->state);
1994		__fail_scsi_task(task, error);
1995		__iscsi_put_task(task);
1996	}
1997	spin_unlock_bh(&session->back_lock);
1998}
1999
2000/**
2001 * iscsi_suspend_queue - suspend iscsi_queuecommand
2002 * @conn: iscsi conn to stop queueing IO on
2003 *
2004 * This grabs the session frwd_lock to make sure no one is in
2005 * xmit_task/queuecommand, and then sets suspend to prevent
2006 * new commands from being queued. This only needs to be called
2007 * by offload drivers that need to sync a path like ep disconnect
2008 * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
2009 * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
2010 */
2011void iscsi_suspend_queue(struct iscsi_conn *conn)
2012{
2013	spin_lock_bh(&conn->session->frwd_lock);
2014	set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
2015	spin_unlock_bh(&conn->session->frwd_lock);
2016}
2017EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
2018
2019/**
2020 * iscsi_suspend_tx - suspend iscsi_data_xmit
2021 * @conn: iscsi conn to stop processing IO on.
2022 *
2023 * This function sets the suspend bit to prevent iscsi_data_xmit
2024 * from sending new IO, and if work is queued on the xmit thread
2025 * it will wait for it to be completed.
2026 */
2027void iscsi_suspend_tx(struct iscsi_conn *conn)
2028{
2029	struct Scsi_Host *shost = conn->session->host;
2030	struct iscsi_host *ihost = shost_priv(shost);
2031
2032	set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
2033	if (ihost->workq)
2034		flush_work(&conn->xmitwork);
2035}
2036EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
2037
2038static void iscsi_start_tx(struct iscsi_conn *conn)
2039{
2040	clear_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
2041	iscsi_conn_queue_xmit(conn);
2042}
2043
2044/**
2045 * iscsi_suspend_rx - Prevent recvwork from running again.
2046 * @conn: iscsi conn to stop.
2047 */
2048void iscsi_suspend_rx(struct iscsi_conn *conn)
2049{
2050	struct Scsi_Host *shost = conn->session->host;
2051	struct iscsi_host *ihost = shost_priv(shost);
2052
2053	set_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags);
2054	if (ihost->workq)
2055		flush_work(&conn->recvwork);
2056}
2057EXPORT_SYMBOL_GPL(iscsi_suspend_rx);
2058
2059/*
2060 * We want to make sure a ping is in flight. It has timed out.
2061 * And we are not busy processing a pdu that is making
2062 * progress but got started before the ping and is taking a while
2063 * to complete so the ping is just stuck behind it in a queue.
2064 */
2065static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
2066{
2067	if (READ_ONCE(conn->ping_task) &&
2068	    time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
2069			   (conn->ping_timeout * HZ), jiffies))
2070		return 1;
2071	else
2072		return 0;
2073}
2074
2075enum scsi_timeout_action iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
2076{
2077	enum scsi_timeout_action rc = SCSI_EH_NOT_HANDLED;
2078	struct iscsi_task *task = NULL, *running_task;
2079	struct iscsi_cls_session *cls_session;
2080	struct iscsi_session *session;
2081	struct iscsi_conn *conn;
2082	int i;
2083
2084	cls_session = starget_to_session(scsi_target(sc->device));
2085	session = cls_session->dd_data;
2086
2087	ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
2088
2089	spin_lock_bh(&session->frwd_lock);
2090	spin_lock(&session->back_lock);
2091	task = iscsi_cmd(sc)->task;
2092	if (!task) {
2093		/*
2094		 * Raced with completion. Blk layer has taken ownership
2095		 * so let timeout code complete it now.
2096		 */
2097		rc = SCSI_EH_NOT_HANDLED;
2098		spin_unlock(&session->back_lock);
2099		goto done;
2100	}
2101	if (!iscsi_get_task(task)) {
2102		/*
2103		 * Racing with the completion path right now, so give it more
2104		 * time so that path can complete it like normal.
2105		 */
2106		rc = SCSI_EH_RESET_TIMER;
2107		task = NULL;
2108		spin_unlock(&session->back_lock);
2109		goto done;
2110	}
2111	spin_unlock(&session->back_lock);
2112
2113	if (session->state != ISCSI_STATE_LOGGED_IN) {
2114		/*
2115		 * During shutdown, if session is prematurely disconnected,
2116		 * recovery won't happen and there will be hung cmds. Not
2117		 * handling cmds would trigger EH, also bad in this case.
2118		 * Instead, handle cmd, allow completion to happen and let
2119		 * upper layer to deal with the result.
2120		 */
2121		if (unlikely(system_state != SYSTEM_RUNNING)) {
2122			sc->result = DID_NO_CONNECT << 16;
2123			ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
2124			rc = SCSI_EH_NOT_HANDLED;
2125			goto done;
2126		}
2127		/*
2128		 * We are probably in the middle of iscsi recovery so let
2129		 * that complete and handle the error.
2130		 */
2131		rc = SCSI_EH_RESET_TIMER;
2132		goto done;
2133	}
2134
2135	conn = session->leadconn;
2136	if (!conn) {
2137		/* In the middle of shuting down */
2138		rc = SCSI_EH_RESET_TIMER;
2139		goto done;
2140	}
2141
2142	/*
2143	 * If we have sent (at least queued to the network layer) a pdu or
2144	 * recvd one for the task since the last timeout ask for
2145	 * more time. If on the next timeout we have not made progress
2146	 * we can check if it is the task or connection when we send the
2147	 * nop as a ping.
2148	 */
2149	if (time_after(task->last_xfer, task->last_timeout)) {
2150		ISCSI_DBG_EH(session, "Command making progress. Asking "
2151			     "scsi-ml for more time to complete. "
2152			     "Last data xfer at %lu. Last timeout was at "
2153			     "%lu\n.", task->last_xfer, task->last_timeout);
2154		task->have_checked_conn = false;
2155		rc = SCSI_EH_RESET_TIMER;
2156		goto done;
2157	}
2158
2159	if (!conn->recv_timeout && !conn->ping_timeout)
2160		goto done;
2161	/*
2162	 * if the ping timedout then we are in the middle of cleaning up
2163	 * and can let the iscsi eh handle it
2164	 */
2165	if (iscsi_has_ping_timed_out(conn)) {
2166		rc = SCSI_EH_RESET_TIMER;
2167		goto done;
2168	}
2169
2170	spin_lock(&session->back_lock);
2171	for (i = 0; i < conn->session->cmds_max; i++) {
2172		running_task = conn->session->cmds[i];
2173		if (!running_task->sc || running_task == task ||
2174		     running_task->state != ISCSI_TASK_RUNNING)
2175			continue;
2176
2177		/*
2178		 * Only check if cmds started before this one have made
2179		 * progress, or this could never fail
2180		 */
2181		if (time_after(running_task->sc->jiffies_at_alloc,
2182			       task->sc->jiffies_at_alloc))
2183			continue;
2184
2185		if (time_after(running_task->last_xfer, task->last_timeout)) {
2186			/*
2187			 * This task has not made progress, but a task
2188			 * started before us has transferred data since
2189			 * we started/last-checked. We could be queueing
2190			 * too many tasks or the LU is bad.
2191			 *
2192			 * If the device is bad the cmds ahead of us on
2193			 * other devs will complete, and this loop will
2194			 * eventually fail starting the scsi eh.
2195			 */
2196			ISCSI_DBG_EH(session, "Command has not made progress "
2197				     "but commands ahead of it have. "
2198				     "Asking scsi-ml for more time to "
2199				     "complete. Our last xfer vs running task "
2200				     "last xfer %lu/%lu. Last check %lu.\n",
2201				     task->last_xfer, running_task->last_xfer,
2202				     task->last_timeout);
2203			spin_unlock(&session->back_lock);
2204			rc = SCSI_EH_RESET_TIMER;
2205			goto done;
2206		}
2207	}
2208	spin_unlock(&session->back_lock);
2209
2210	/* Assumes nop timeout is shorter than scsi cmd timeout */
2211	if (task->have_checked_conn)
2212		goto done;
2213
2214	/*
2215	 * Checking the transport already or nop from a cmd timeout still
2216	 * running
2217	 */
2218	if (READ_ONCE(conn->ping_task)) {
2219		task->have_checked_conn = true;
2220		rc = SCSI_EH_RESET_TIMER;
2221		goto done;
2222	}
2223
2224	/* Make sure there is a transport check done */
2225	iscsi_send_nopout(conn, NULL);
2226	task->have_checked_conn = true;
2227	rc = SCSI_EH_RESET_TIMER;
2228
2229done:
2230	spin_unlock_bh(&session->frwd_lock);
2231
2232	if (task) {
2233		task->last_timeout = jiffies;
2234		iscsi_put_task(task);
2235	}
2236	ISCSI_DBG_EH(session, "return %s\n", rc == SCSI_EH_RESET_TIMER ?
2237		     "timer reset" : "shutdown or nh");
2238	return rc;
2239}
2240EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2241
2242static void iscsi_check_transport_timeouts(struct timer_list *t)
2243{
2244	struct iscsi_conn *conn = timer_container_of(conn, t, transport_timer);
2245	struct iscsi_session *session = conn->session;
2246	unsigned long recv_timeout, next_timeout = 0, last_recv;
2247
2248	spin_lock(&session->frwd_lock);
2249	if (session->state != ISCSI_STATE_LOGGED_IN)
2250		goto done;
2251
2252	recv_timeout = conn->recv_timeout;
2253	if (!recv_timeout)
2254		goto done;
2255
2256	recv_timeout *= HZ;
2257	last_recv = conn->last_recv;
2258
2259	if (iscsi_has_ping_timed_out(conn)) {
2260		iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2261				  "expired, recv timeout %d, last rx %lu, "
2262				  "last ping %lu, now %lu\n",
2263				  conn->ping_timeout, conn->recv_timeout,
2264				  last_recv, conn->last_ping, jiffies);
2265		spin_unlock(&session->frwd_lock);
2266		iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2267		return;
2268	}
2269
2270	if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2271		/* send a ping to try to provoke some traffic */
2272		ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2273		if (iscsi_send_nopout(conn, NULL))
2274			next_timeout = jiffies + (1 * HZ);
2275		else
2276			next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2277	} else
2278		next_timeout = last_recv + recv_timeout;
2279
2280	ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2281	mod_timer(&conn->transport_timer, next_timeout);
2282done:
2283	spin_unlock(&session->frwd_lock);
2284}
2285
2286/**
2287 * iscsi_conn_unbind - prevent queueing to conn.
2288 * @cls_conn: iscsi conn ep is bound to.
2289 * @is_active: is the conn in use for boot or is this for EH/termination
2290 *
2291 * This must be called by drivers implementing the ep_disconnect callout.
2292 * It disables queueing to the connection from libiscsi in preparation for
2293 * an ep_disconnect call.
2294 */
2295void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active)
2296{
2297	struct iscsi_session *session;
2298	struct iscsi_conn *conn;
2299
2300	if (!cls_conn)
2301		return;
2302
2303	conn = cls_conn->dd_data;
2304	session = conn->session;
2305	/*
2306	 * Wait for iscsi_eh calls to exit. We don't wait for the tmf to
2307	 * complete or timeout. The caller just wants to know what's running
2308	 * is everything that needs to be cleaned up, and no cmds will be
2309	 * queued.
2310	 */
2311	mutex_lock(&session->eh_mutex);
2312
2313	iscsi_suspend_queue(conn);
2314	iscsi_suspend_tx(conn);
2315
2316	spin_lock_bh(&session->frwd_lock);
2317	clear_bit(ISCSI_CONN_FLAG_BOUND, &conn->flags);
2318
2319	if (!is_active) {
2320		/*
2321		 * if logout timed out before userspace could even send a PDU
2322		 * the state might still be in ISCSI_STATE_LOGGED_IN and
2323		 * allowing new cmds and TMFs.
2324		 */
2325		if (session->state == ISCSI_STATE_LOGGED_IN)
2326			iscsi_set_conn_failed(conn);
2327	}
2328	spin_unlock_bh(&session->frwd_lock);
2329	mutex_unlock(&session->eh_mutex);
2330}
2331EXPORT_SYMBOL_GPL(iscsi_conn_unbind);
2332
2333static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2334				      struct iscsi_tm *hdr)
2335{
2336	memset(hdr, 0, sizeof(*hdr));
2337	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2338	hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2339	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2340	hdr->lun = task->lun;
2341	hdr->rtt = task->hdr_itt;
2342	hdr->refcmdsn = task->cmdsn;
2343}
2344
2345int iscsi_eh_abort(struct scsi_cmnd *sc)
2346{
2347	struct iscsi_cls_session *cls_session;
2348	struct iscsi_session *session;
2349	struct iscsi_conn *conn;
2350	struct iscsi_task *task;
2351	struct iscsi_tm *hdr;
2352	int age;
2353
2354	cls_session = starget_to_session(scsi_target(sc->device));
2355	session = cls_session->dd_data;
2356
2357	ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2358
2359completion_check:
2360	mutex_lock(&session->eh_mutex);
2361	spin_lock_bh(&session->frwd_lock);
2362	/*
2363	 * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2364	 * got the command.
2365	 */
2366	if (!iscsi_cmd(sc)->task) {
2367		ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2368				      "it completed.\n");
2369		spin_unlock_bh(&session->frwd_lock);
2370		mutex_unlock(&session->eh_mutex);
2371		return SUCCESS;
2372	}
2373
2374	/*
2375	 * If we are not logged in or we have started a new session
2376	 * then let the host reset code handle this
2377	 */
2378	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2379	    iscsi_cmd(sc)->age != session->age) {
2380		spin_unlock_bh(&session->frwd_lock);
2381		mutex_unlock(&session->eh_mutex);
2382		ISCSI_DBG_EH(session, "failing abort due to dropped "
2383				  "session.\n");
2384		return FAILED;
2385	}
2386
2387	spin_lock(&session->back_lock);
2388	task = iscsi_cmd(sc)->task;
2389	if (!task || !task->sc) {
2390		/* task completed before time out */
2391		ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2392
2393		spin_unlock(&session->back_lock);
2394		spin_unlock_bh(&session->frwd_lock);
2395		mutex_unlock(&session->eh_mutex);
2396		return SUCCESS;
2397	}
2398
2399	if (!iscsi_get_task(task)) {
2400		spin_unlock(&session->back_lock);
2401		spin_unlock_bh(&session->frwd_lock);
2402		mutex_unlock(&session->eh_mutex);
2403		/* We are just about to call iscsi_free_task so wait for it. */
2404		udelay(ISCSI_CMD_COMPL_WAIT);
2405		goto completion_check;
2406	}
2407
2408	ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n", sc, task->itt);
2409	conn = session->leadconn;
2410	iscsi_get_conn(conn->cls_conn);
2411	conn->eh_abort_cnt++;
2412	age = session->age;
2413	spin_unlock(&session->back_lock);
2414
2415	if (task->state == ISCSI_TASK_PENDING) {
2416		fail_scsi_task(task, DID_ABORT);
2417		goto success;
2418	}
2419
2420	/* only have one tmf outstanding at a time */
2421	if (session->tmf_state != TMF_INITIAL)
2422		goto failed;
2423	session->tmf_state = TMF_QUEUED;
2424
2425	hdr = &session->tmhdr;
2426	iscsi_prep_abort_task_pdu(task, hdr);
2427
2428	if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2429		goto failed;
2430
2431	switch (session->tmf_state) {
2432	case TMF_SUCCESS:
2433		spin_unlock_bh(&session->frwd_lock);
2434		/*
2435		 * stop tx side incase the target had sent a abort rsp but
2436		 * the initiator was still writing out data.
2437		 */
2438		iscsi_suspend_tx(conn);
2439		/*
2440		 * we do not stop the recv side because targets have been
2441		 * good and have never sent us a successful tmf response
2442		 * then sent more data for the cmd.
2443		 */
2444		spin_lock_bh(&session->frwd_lock);
2445		fail_scsi_task(task, DID_ABORT);
2446		session->tmf_state = TMF_INITIAL;
2447		memset(hdr, 0, sizeof(*hdr));
2448		spin_unlock_bh(&session->frwd_lock);
2449		iscsi_start_tx(conn);
2450		goto success_unlocked;
2451	case TMF_TIMEDOUT:
2452		session->running_aborted_task = task;
2453		spin_unlock_bh(&session->frwd_lock);
2454		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2455		goto failed_unlocked;
2456	case TMF_NOT_FOUND:
2457		if (iscsi_task_is_completed(task)) {
2458			session->tmf_state = TMF_INITIAL;
2459			memset(hdr, 0, sizeof(*hdr));
2460			/* task completed before tmf abort response */
2461			ISCSI_DBG_EH(session, "sc completed while abort	in "
2462					      "progress\n");
2463			goto success;
2464		}
2465		fallthrough;
2466	default:
2467		session->tmf_state = TMF_INITIAL;
2468		goto failed;
2469	}
2470
2471success:
2472	spin_unlock_bh(&session->frwd_lock);
2473success_unlocked:
2474	ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2475		     sc, task->itt);
2476	iscsi_put_task(task);
2477	iscsi_put_conn(conn->cls_conn);
2478	mutex_unlock(&session->eh_mutex);
2479	return SUCCESS;
2480
2481failed:
2482	spin_unlock_bh(&session->frwd_lock);
2483failed_unlocked:
2484	ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2485		     task ? task->itt : 0);
2486	/*
2487	 * The driver might be accessing the task so hold the ref. The conn
2488	 * stop cleanup will drop the ref after ep_disconnect so we know the
2489	 * driver's no longer touching the task.
2490	 */
2491	if (!session->running_aborted_task)
2492		iscsi_put_task(task);
2493
2494	iscsi_put_conn(conn->cls_conn);
2495	mutex_unlock(&session->eh_mutex);
2496	return FAILED;
2497}
2498EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2499
2500static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2501{
2502	memset(hdr, 0, sizeof(*hdr));
2503	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2504	hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2505	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2506	int_to_scsilun(sc->device->lun, &hdr->lun);
2507	hdr->rtt = RESERVED_ITT;
2508}
2509
2510int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2511{
2512	struct iscsi_cls_session *cls_session;
2513	struct iscsi_session *session;
2514	struct iscsi_conn *conn;
2515	struct iscsi_tm *hdr;
2516	int rc = FAILED;
2517
2518	cls_session = starget_to_session(scsi_target(sc->device));
2519	session = cls_session->dd_data;
2520
2521	ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2522		     sc->device->lun);
2523
2524	mutex_lock(&session->eh_mutex);
2525	spin_lock_bh(&session->frwd_lock);
2526	/*
2527	 * Just check if we are not logged in. We cannot check for
2528	 * the phase because the reset could come from a ioctl.
2529	 */
2530	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2531		goto unlock;
2532	conn = session->leadconn;
2533
2534	/* only have one tmf outstanding at a time */
2535	if (session->tmf_state != TMF_INITIAL)
2536		goto unlock;
2537	session->tmf_state = TMF_QUEUED;
2538
2539	hdr = &session->tmhdr;
2540	iscsi_prep_lun_reset_pdu(sc, hdr);
2541
2542	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2543				    session->lu_reset_timeout)) {
2544		rc = FAILED;
2545		goto unlock;
2546	}
2547
2548	switch (session->tmf_state) {
2549	case TMF_SUCCESS:
2550		break;
2551	case TMF_TIMEDOUT:
2552		spin_unlock_bh(&session->frwd_lock);
2553		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2554		goto done;
2555	default:
2556		session->tmf_state = TMF_INITIAL;
2557		goto unlock;
2558	}
2559
2560	rc = SUCCESS;
2561	spin_unlock_bh(&session->frwd_lock);
2562
2563	iscsi_suspend_tx(conn);
2564
2565	spin_lock_bh(&session->frwd_lock);
2566	memset(hdr, 0, sizeof(*hdr));
2567	fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2568	session->tmf_state = TMF_INITIAL;
2569	spin_unlock_bh(&session->frwd_lock);
2570
2571	iscsi_start_tx(conn);
2572	goto done;
2573
2574unlock:
2575	spin_unlock_bh(&session->frwd_lock);
2576done:
2577	ISCSI_DBG_EH(session, "dev reset result = %s\n",
2578		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2579	mutex_unlock(&session->eh_mutex);
2580	return rc;
2581}
2582EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2583
2584void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2585{
2586	struct iscsi_session *session = cls_session->dd_data;
2587
2588	spin_lock_bh(&session->frwd_lock);
2589	if (session->state != ISCSI_STATE_LOGGED_IN) {
2590		session->state = ISCSI_STATE_RECOVERY_FAILED;
2591		wake_up(&session->ehwait);
2592	}
2593	spin_unlock_bh(&session->frwd_lock);
2594}
2595EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2596
2597/**
2598 * iscsi_eh_session_reset - drop session and attempt relogin
2599 * @sc: scsi command
2600 *
2601 * This function will wait for a relogin, session termination from
2602 * userspace, or a recovery/replacement timeout.
2603 */
2604int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2605{
2606	struct iscsi_cls_session *cls_session;
2607	struct iscsi_session *session;
2608	struct iscsi_conn *conn;
2609
2610	cls_session = starget_to_session(scsi_target(sc->device));
2611	session = cls_session->dd_data;
2612
2613	mutex_lock(&session->eh_mutex);
2614	spin_lock_bh(&session->frwd_lock);
2615	if (session->state == ISCSI_STATE_TERMINATE) {
2616failed:
2617		ISCSI_DBG_EH(session,
2618			     "failing session reset: Could not log back into "
2619			     "%s [age %d]\n", session->targetname,
2620			     session->age);
2621		spin_unlock_bh(&session->frwd_lock);
2622		mutex_unlock(&session->eh_mutex);
2623		return FAILED;
2624	}
2625
2626	conn = session->leadconn;
2627	iscsi_get_conn(conn->cls_conn);
2628
2629	spin_unlock_bh(&session->frwd_lock);
2630	mutex_unlock(&session->eh_mutex);
2631
2632	iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2633	iscsi_put_conn(conn->cls_conn);
2634
2635	ISCSI_DBG_EH(session, "wait for relogin\n");
2636	wait_event_interruptible(session->ehwait,
2637				 session->state == ISCSI_STATE_TERMINATE ||
2638				 session->state == ISCSI_STATE_LOGGED_IN ||
2639				 session->state == ISCSI_STATE_RECOVERY_FAILED);
2640	if (signal_pending(current))
2641		flush_signals(current);
2642
2643	mutex_lock(&session->eh_mutex);
2644	spin_lock_bh(&session->frwd_lock);
2645	if (session->state == ISCSI_STATE_LOGGED_IN) {
2646		ISCSI_DBG_EH(session,
2647			     "session reset succeeded for %s,%s\n",
2648			     session->targetname, conn->persistent_address);
2649	} else
2650		goto failed;
2651	spin_unlock_bh(&session->frwd_lock);
2652	mutex_unlock(&session->eh_mutex);
2653	return SUCCESS;
2654}
2655EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2656
2657static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2658{
2659	memset(hdr, 0, sizeof(*hdr));
2660	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2661	hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2662	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2663	hdr->rtt = RESERVED_ITT;
2664}
2665
2666/**
2667 * iscsi_eh_target_reset - reset target
2668 * @sc: scsi command
2669 *
2670 * This will attempt to send a warm target reset.
2671 */
2672static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2673{
2674	struct iscsi_cls_session *cls_session;
2675	struct iscsi_session *session;
2676	struct iscsi_conn *conn;
2677	struct iscsi_tm *hdr;
2678	int rc = FAILED;
2679
2680	cls_session = starget_to_session(scsi_target(sc->device));
2681	session = cls_session->dd_data;
2682
2683	ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2684		     session->targetname);
2685
2686	mutex_lock(&session->eh_mutex);
2687	spin_lock_bh(&session->frwd_lock);
2688	/*
2689	 * Just check if we are not logged in. We cannot check for
2690	 * the phase because the reset could come from a ioctl.
2691	 */
2692	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2693		goto unlock;
2694	conn = session->leadconn;
2695
2696	/* only have one tmf outstanding at a time */
2697	if (session->tmf_state != TMF_INITIAL)
2698		goto unlock;
2699	session->tmf_state = TMF_QUEUED;
2700
2701	hdr = &session->tmhdr;
2702	iscsi_prep_tgt_reset_pdu(sc, hdr);
2703
2704	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2705				    session->tgt_reset_timeout)) {
2706		rc = FAILED;
2707		goto unlock;
2708	}
2709
2710	switch (session->tmf_state) {
2711	case TMF_SUCCESS:
2712		break;
2713	case TMF_TIMEDOUT:
2714		spin_unlock_bh(&session->frwd_lock);
2715		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2716		goto done;
2717	default:
2718		session->tmf_state = TMF_INITIAL;
2719		goto unlock;
2720	}
2721
2722	rc = SUCCESS;
2723	spin_unlock_bh(&session->frwd_lock);
2724
2725	iscsi_suspend_tx(conn);
2726
2727	spin_lock_bh(&session->frwd_lock);
2728	memset(hdr, 0, sizeof(*hdr));
2729	fail_scsi_tasks(conn, -1, DID_ERROR);
2730	session->tmf_state = TMF_INITIAL;
2731	spin_unlock_bh(&session->frwd_lock);
2732
2733	iscsi_start_tx(conn);
2734	goto done;
2735
2736unlock:
2737	spin_unlock_bh(&session->frwd_lock);
2738done:
2739	ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2740		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2741	mutex_unlock(&session->eh_mutex);
2742	return rc;
2743}
2744
2745/**
2746 * iscsi_eh_recover_target - reset target and possibly the session
2747 * @sc: scsi command
2748 *
2749 * This will attempt to send a warm target reset. If that fails,
2750 * we will escalate to ERL0 session recovery.
2751 */
2752int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2753{
2754	int rc;
2755
2756	rc = iscsi_eh_target_reset(sc);
2757	if (rc == FAILED)
2758		rc = iscsi_eh_session_reset(sc);
2759	return rc;
2760}
2761EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2762
2763/*
2764 * Pre-allocate a pool of @max items of @item_size. By default, the pool
2765 * should be accessed via kfifo_{get,put} on q->queue.
2766 * Optionally, the caller can obtain the array of object pointers
2767 * by passing in a non-NULL @items pointer
2768 */
2769int
2770iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2771{
2772	int i, num_arrays = 1;
2773
2774	memset(q, 0, sizeof(*q));
2775
2776	q->max = max;
2777
2778	/* If the user passed an items pointer, he wants a copy of
2779	 * the array. */
2780	if (items)
2781		num_arrays++;
2782	q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2783	if (q->pool == NULL)
2784		return -ENOMEM;
2785
2786	kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2787
2788	for (i = 0; i < max; i++) {
2789		q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2790		if (q->pool[i] == NULL) {
2791			q->max = i;
2792			goto enomem;
2793		}
2794		kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2795	}
2796
2797	if (items) {
2798		*items = q->pool + max;
2799		memcpy(*items, q->pool, max * sizeof(void *));
2800	}
2801
2802	return 0;
2803
2804enomem:
2805	iscsi_pool_free(q);
2806	return -ENOMEM;
2807}
2808EXPORT_SYMBOL_GPL(iscsi_pool_init);
2809
2810void iscsi_pool_free(struct iscsi_pool *q)
2811{
2812	int i;
2813
2814	for (i = 0; i < q->max; i++)
2815		kfree(q->pool[i]);
2816	kvfree(q->pool);
2817}
2818EXPORT_SYMBOL_GPL(iscsi_pool_free);
2819
2820int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
2821				 uint16_t requested_cmds_max)
2822{
2823	int scsi_cmds, total_cmds = requested_cmds_max;
2824
2825check:
2826	if (!total_cmds)
2827		total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2828	/*
2829	 * The iscsi layer needs some tasks for nop handling and tmfs,
2830	 * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2831	 * + 1 command for scsi IO.
2832	 */
2833	if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2834		printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of two that is at least %d.\n",
2835		       total_cmds, ISCSI_TOTAL_CMDS_MIN);
2836		return -EINVAL;
2837	}
2838
2839	if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2840		printk(KERN_INFO "iscsi: invalid max cmds of %d. Must be a power of 2 less than or equal to %d. Using %d.\n",
2841		       requested_cmds_max, ISCSI_TOTAL_CMDS_MAX,
2842		       ISCSI_TOTAL_CMDS_MAX);
2843		total_cmds = ISCSI_TOTAL_CMDS_MAX;
2844	}
2845
2846	if (!is_power_of_2(total_cmds)) {
2847		total_cmds = rounddown_pow_of_two(total_cmds);
2848		if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2849			printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of 2 greater than %d.\n", requested_cmds_max, ISCSI_TOTAL_CMDS_MIN);
2850			return -EINVAL;
2851		}
2852
2853		printk(KERN_INFO "iscsi: invalid max cmds %d. Must be a power of 2. Rounding max cmds down to %d.\n",
2854		       requested_cmds_max, total_cmds);
2855	}
2856
2857	scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2858	if (shost->can_queue && scsi_cmds > shost->can_queue) {
2859		total_cmds = shost->can_queue;
2860
2861		printk(KERN_INFO "iscsi: requested max cmds %u is higher than driver limit. Using driver limit %u\n",
2862		       requested_cmds_max, shost->can_queue);
2863		goto check;
2864	}
2865
2866	return scsi_cmds;
2867}
2868EXPORT_SYMBOL_GPL(iscsi_host_get_max_scsi_cmds);
2869
2870/**
2871 * iscsi_host_add - add host to system
2872 * @shost: scsi host
2873 * @pdev: parent device
2874 *
2875 * This should be called by partial offload and software iscsi drivers
2876 * to add a host to the system.
2877 */
2878int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2879{
2880	if (!shost->can_queue)
2881		shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2882
2883	if (!shost->cmd_per_lun)
2884		shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2885
2886	return scsi_add_host(shost, pdev);
2887}
2888EXPORT_SYMBOL_GPL(iscsi_host_add);
2889
2890/**
2891 * iscsi_host_alloc - allocate a host and driver data
2892 * @sht: scsi host template
2893 * @dd_data_size: driver host data size
2894 * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2895 *
2896 * This should be called by partial offload and software iscsi drivers.
2897 * To access the driver specific memory use the iscsi_host_priv() macro.
2898 */
2899struct Scsi_Host *iscsi_host_alloc(const struct scsi_host_template *sht,
2900				   int dd_data_size, bool xmit_can_sleep)
2901{
2902	struct Scsi_Host *shost;
2903	struct iscsi_host *ihost;
2904
2905	shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2906	if (!shost)
2907		return NULL;
2908	ihost = shost_priv(shost);
2909
2910	if (xmit_can_sleep) {
2911		ihost->workq = alloc_workqueue("iscsi_q_%d",
2912			WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
2913			1, shost->host_no);
2914		if (!ihost->workq)
2915			goto free_host;
2916	}
2917
2918	spin_lock_init(&ihost->lock);
2919	ihost->state = ISCSI_HOST_SETUP;
2920	ihost->num_sessions = 0;
2921	init_waitqueue_head(&ihost->session_removal_wq);
2922	return shost;
2923
2924free_host:
2925	scsi_host_put(shost);
2926	return NULL;
2927}
2928EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2929
2930static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2931{
2932	iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2933}
2934
2935/**
2936 * iscsi_host_remove - remove host and sessions
2937 * @shost: scsi host
2938 * @is_shutdown: true if called from a driver shutdown callout
2939 *
2940 * If there are any sessions left, this will initiate the removal and wait
2941 * for the completion.
2942 */
2943void iscsi_host_remove(struct Scsi_Host *shost, bool is_shutdown)
2944{
2945	struct iscsi_host *ihost = shost_priv(shost);
2946	unsigned long flags;
2947
2948	spin_lock_irqsave(&ihost->lock, flags);
2949	ihost->state = ISCSI_HOST_REMOVED;
2950	spin_unlock_irqrestore(&ihost->lock, flags);
2951
2952	if (!is_shutdown)
2953		iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2954	else
2955		iscsi_host_for_each_session(shost, iscsi_force_destroy_session);
2956
2957	wait_event_interruptible(ihost->session_removal_wq,
2958				 ihost->num_sessions == 0);
2959	if (signal_pending(current))
2960		flush_signals(current);
2961
2962	scsi_remove_host(shost);
2963}
2964EXPORT_SYMBOL_GPL(iscsi_host_remove);
2965
2966void iscsi_host_free(struct Scsi_Host *shost)
2967{
2968	struct iscsi_host *ihost = shost_priv(shost);
2969
2970	if (ihost->workq)
2971		destroy_workqueue(ihost->workq);
2972
2973	kfree(ihost->netdev);
2974	kfree(ihost->hwaddress);
2975	kfree(ihost->initiatorname);
2976	scsi_host_put(shost);
2977}
2978EXPORT_SYMBOL_GPL(iscsi_host_free);
2979
2980static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2981{
2982	struct iscsi_host *ihost = shost_priv(shost);
2983	unsigned long flags;
2984
2985	shost = scsi_host_get(shost);
2986	if (!shost) {
2987		printk(KERN_ERR "Invalid state. Cannot notify host removal "
2988		      "of session teardown event because host already "
2989		      "removed.\n");
2990		return;
2991	}
2992
2993	spin_lock_irqsave(&ihost->lock, flags);
2994	ihost->num_sessions--;
2995	if (ihost->num_sessions == 0)
2996		wake_up(&ihost->session_removal_wq);
2997	spin_unlock_irqrestore(&ihost->lock, flags);
2998	scsi_host_put(shost);
2999}
3000
3001/**
3002 * iscsi_session_setup - create iscsi cls session and host and session
3003 * @iscsit: iscsi transport template
3004 * @shost: scsi host
3005 * @cmds_max: session can queue
3006 * @dd_size: private driver data size, added to session allocation size
3007 * @cmd_task_size: LLD task private data size
3008 * @initial_cmdsn: initial CmdSN
3009 * @id: target ID to add to this session
3010 *
3011 * This can be used by software iscsi_transports that allocate
3012 * a session per scsi host.
3013 *
3014 * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
3015 * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
3016 * for nop handling and login/logout requests.
3017 */
3018struct iscsi_cls_session *
3019iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
3020		    uint16_t cmds_max, int dd_size, int cmd_task_size,
3021		    uint32_t initial_cmdsn, unsigned int id)
3022{
3023	struct iscsi_host *ihost = shost_priv(shost);
3024	struct iscsi_session *session;
3025	struct iscsi_cls_session *cls_session;
3026	int cmd_i, scsi_cmds;
3027	unsigned long flags;
3028
3029	spin_lock_irqsave(&ihost->lock, flags);
3030	if (ihost->state == ISCSI_HOST_REMOVED) {
3031		spin_unlock_irqrestore(&ihost->lock, flags);
3032		return NULL;
3033	}
3034	ihost->num_sessions++;
3035	spin_unlock_irqrestore(&ihost->lock, flags);
3036
3037	scsi_cmds = iscsi_host_get_max_scsi_cmds(shost, cmds_max);
3038	if (scsi_cmds < 0)
3039		goto dec_session_count;
3040
3041	cls_session = iscsi_alloc_session(shost, iscsit,
3042					  sizeof(struct iscsi_session) +
3043					  dd_size);
3044	if (!cls_session)
3045		goto dec_session_count;
3046	session = cls_session->dd_data;
3047	session->cls_session = cls_session;
3048	session->host = shost;
3049	session->state = ISCSI_STATE_FREE;
3050	session->fast_abort = 1;
3051	session->tgt_reset_timeout = 30;
3052	session->lu_reset_timeout = 15;
3053	session->abort_timeout = 10;
3054	session->scsi_cmds_max = scsi_cmds;
3055	session->cmds_max = scsi_cmds + ISCSI_MGMT_CMDS_MAX;
3056	session->queued_cmdsn = session->cmdsn = initial_cmdsn;
3057	session->exp_cmdsn = initial_cmdsn + 1;
3058	session->max_cmdsn = initial_cmdsn + 1;
3059	session->max_r2t = 1;
3060	session->tt = iscsit;
3061	session->dd_data = cls_session->dd_data + sizeof(*session);
3062
3063	session->tmf_state = TMF_INITIAL;
3064	timer_setup(&session->tmf_timer, iscsi_tmf_timedout, 0);
3065	mutex_init(&session->eh_mutex);
3066	init_waitqueue_head(&session->ehwait);
3067
3068	spin_lock_init(&session->frwd_lock);
3069	spin_lock_init(&session->back_lock);
3070
3071	/* initialize SCSI PDU commands pool */
3072	if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
3073			    (void***)&session->cmds,
3074			    cmd_task_size + sizeof(struct iscsi_task)))
3075		goto cmdpool_alloc_fail;
3076
3077	/* pre-format cmds pool with ITT */
3078	for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
3079		struct iscsi_task *task = session->cmds[cmd_i];
3080
3081		if (cmd_task_size)
3082			task->dd_data = &task[1];
3083		task->itt = cmd_i;
3084		task->state = ISCSI_TASK_FREE;
3085		INIT_LIST_HEAD(&task->running);
3086	}
3087
3088	if (!try_module_get(iscsit->owner))
3089		goto module_get_fail;
3090
3091	if (iscsi_add_session(cls_session, id))
3092		goto cls_session_fail;
3093
3094	return cls_session;
3095
3096cls_session_fail:
3097	module_put(iscsit->owner);
3098module_get_fail:
3099	iscsi_pool_free(&session->cmdpool);
3100cmdpool_alloc_fail:
3101	iscsi_free_session(cls_session);
3102dec_session_count:
3103	iscsi_host_dec_session_cnt(shost);
3104	return NULL;
3105}
3106EXPORT_SYMBOL_GPL(iscsi_session_setup);
3107
3108/*
3109 * issi_session_remove - Remove session from iSCSI class.
3110 */
3111void iscsi_session_remove(struct iscsi_cls_session *cls_session)
3112{
3113	struct iscsi_session *session = cls_session->dd_data;
3114	struct Scsi_Host *shost = session->host;
3115
3116	iscsi_remove_session(cls_session);
3117	/*
3118	 * host removal only has to wait for its children to be removed from
3119	 * sysfs, and iscsi_tcp needs to do iscsi_host_remove before freeing
3120	 * the session, so drop the session count here.
3121	 */
3122	iscsi_host_dec_session_cnt(shost);
3123}
3124EXPORT_SYMBOL_GPL(iscsi_session_remove);
3125
3126/**
3127 * iscsi_session_free - Free iscsi session and it's resources
3128 * @cls_session: iscsi session
3129 */
3130void iscsi_session_free(struct iscsi_cls_session *cls_session)
3131{
3132	struct iscsi_session *session = cls_session->dd_data;
3133	struct module *owner = cls_session->transport->owner;
3134
3135	iscsi_pool_free(&session->cmdpool);
3136	kfree(session->password);
3137	kfree(session->password_in);
3138	kfree(session->username);
3139	kfree(session->username_in);
3140	kfree(session->targetname);
3141	kfree(session->targetalias);
3142	kfree(session->initiatorname);
3143	kfree(session->boot_root);
3144	kfree(session->boot_nic);
3145	kfree(session->boot_target);
3146	kfree(session->ifacename);
3147	kfree(session->portal_type);
3148	kfree(session->discovery_parent_type);
3149
3150	iscsi_free_session(cls_session);
3151	module_put(owner);
3152}
3153EXPORT_SYMBOL_GPL(iscsi_session_free);
3154
3155/**
3156 * iscsi_session_teardown - destroy session and cls_session
3157 * @cls_session: iscsi session
3158 */
3159void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
3160{
3161	iscsi_session_remove(cls_session);
3162	iscsi_session_free(cls_session);
3163}
3164EXPORT_SYMBOL_GPL(iscsi_session_teardown);
3165
3166/**
3167 * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
3168 * @cls_session: iscsi_cls_session
3169 * @dd_size: private driver data size
3170 * @conn_idx: cid
3171 */
3172struct iscsi_cls_conn *
3173iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
3174		 uint32_t conn_idx)
3175{
3176	struct iscsi_session *session = cls_session->dd_data;
3177	struct iscsi_conn *conn;
3178	struct iscsi_cls_conn *cls_conn;
3179	char *data;
3180	int err;
3181
3182	cls_conn = iscsi_alloc_conn(cls_session, sizeof(*conn) + dd_size,
3183				     conn_idx);
3184	if (!cls_conn)
3185		return NULL;
3186	conn = cls_conn->dd_data;
3187
3188	if (dd_size)
3189		conn->dd_data = cls_conn->dd_data + sizeof(*conn);
3190	conn->session = session;
3191	conn->cls_conn = cls_conn;
3192	conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
3193	conn->id = conn_idx;
3194	conn->exp_statsn = 0;
3195
3196	timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
3197
3198	INIT_LIST_HEAD(&conn->mgmtqueue);
3199	INIT_LIST_HEAD(&conn->cmdqueue);
3200	INIT_LIST_HEAD(&conn->requeue);
3201	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
3202
3203	/* allocate login_task used for the login/text sequences */
3204	spin_lock_bh(&session->frwd_lock);
3205	if (!kfifo_out(&session->cmdpool.queue,
3206                         (void*)&conn->login_task,
3207			 sizeof(void*))) {
3208		spin_unlock_bh(&session->frwd_lock);
3209		goto login_task_alloc_fail;
3210	}
3211	spin_unlock_bh(&session->frwd_lock);
3212
3213	data = (char *) __get_free_pages(GFP_KERNEL,
3214					 get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3215	if (!data)
3216		goto login_task_data_alloc_fail;
3217	conn->login_task->data = conn->data = data;
3218
3219	err = iscsi_add_conn(cls_conn);
3220	if (err)
3221		goto login_task_add_dev_fail;
3222
3223	return cls_conn;
3224
3225login_task_add_dev_fail:
3226	free_pages((unsigned long) conn->data,
3227		   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3228
3229login_task_data_alloc_fail:
3230	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3231		    sizeof(void*));
3232login_task_alloc_fail:
3233	iscsi_put_conn(cls_conn);
3234	return NULL;
3235}
3236EXPORT_SYMBOL_GPL(iscsi_conn_setup);
3237
3238/**
3239 * iscsi_conn_teardown - teardown iscsi connection
3240 * @cls_conn: iscsi class connection
3241 *
3242 * TODO: we may need to make this into a two step process
3243 * like scsi-mls remove + put host
3244 */
3245void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
3246{
3247	struct iscsi_conn *conn = cls_conn->dd_data;
3248	struct iscsi_session *session = conn->session;
3249
3250	iscsi_remove_conn(cls_conn);
3251
3252	timer_delete_sync(&conn->transport_timer);
3253
3254	mutex_lock(&session->eh_mutex);
3255	spin_lock_bh(&session->frwd_lock);
3256	conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
3257	if (session->leadconn == conn) {
3258		/*
3259		 * leading connection? then give up on recovery.
3260		 */
3261		session->state = ISCSI_STATE_TERMINATE;
3262		wake_up(&session->ehwait);
3263	}
3264	spin_unlock_bh(&session->frwd_lock);
3265
3266	/* flush queued up work because we free the connection below */
3267	iscsi_suspend_tx(conn);
3268
3269	spin_lock_bh(&session->frwd_lock);
3270	free_pages((unsigned long) conn->data,
3271		   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3272	kfree(conn->persistent_address);
3273	kfree(conn->local_ipaddr);
3274	/* regular RX path uses back_lock */
3275	spin_lock_bh(&session->back_lock);
3276	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3277		    sizeof(void*));
3278	spin_unlock_bh(&session->back_lock);
3279	if (session->leadconn == conn)
3280		session->leadconn = NULL;
3281	spin_unlock_bh(&session->frwd_lock);
3282	mutex_unlock(&session->eh_mutex);
3283
3284	iscsi_put_conn(cls_conn);
3285}
3286EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3287
3288int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3289{
3290	struct iscsi_conn *conn = cls_conn->dd_data;
3291	struct iscsi_session *session = conn->session;
3292
3293	if (!session) {
3294		iscsi_conn_printk(KERN_ERR, conn,
3295				  "can't start unbound connection\n");
3296		return -EPERM;
3297	}
3298
3299	if ((session->imm_data_en || !session->initial_r2t_en) &&
3300	     session->first_burst > session->max_burst) {
3301		iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3302				  "first_burst %d max_burst %d\n",
3303				  session->first_burst, session->max_burst);
3304		return -EINVAL;
3305	}
3306
3307	if (conn->ping_timeout && !conn->recv_timeout) {
3308		iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3309				  "zero. Using 5 seconds\n.");
3310		conn->recv_timeout = 5;
3311	}
3312
3313	if (conn->recv_timeout && !conn->ping_timeout) {
3314		iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3315				  "zero. Using 5 seconds.\n");
3316		conn->ping_timeout = 5;
3317	}
3318
3319	spin_lock_bh(&session->frwd_lock);
3320	conn->c_stage = ISCSI_CONN_STARTED;
3321	session->state = ISCSI_STATE_LOGGED_IN;
3322	session->queued_cmdsn = session->cmdsn;
3323
3324	conn->last_recv = jiffies;
3325	conn->last_ping = jiffies;
3326	if (conn->recv_timeout && conn->ping_timeout)
3327		mod_timer(&conn->transport_timer,
3328			  jiffies + (conn->recv_timeout * HZ));
3329
3330	switch(conn->stop_stage) {
3331	case STOP_CONN_RECOVER:
3332		/*
3333		 * unblock eh_abort() if it is blocked. re-try all
3334		 * commands after successful recovery
3335		 */
3336		conn->stop_stage = 0;
3337		session->tmf_state = TMF_INITIAL;
3338		session->age++;
3339		if (session->age == 16)
3340			session->age = 0;
3341		break;
3342	case STOP_CONN_TERM:
3343		conn->stop_stage = 0;
3344		break;
3345	default:
3346		break;
3347	}
3348	spin_unlock_bh(&session->frwd_lock);
3349
3350	iscsi_unblock_session(session->cls_session);
3351	wake_up(&session->ehwait);
3352	return 0;
3353}
3354EXPORT_SYMBOL_GPL(iscsi_conn_start);
3355
3356static void
3357fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3358{
3359	struct iscsi_task *task;
3360	int i, state;
3361
3362	for (i = 0; i < conn->session->cmds_max; i++) {
3363		task = conn->session->cmds[i];
3364		if (task->sc)
3365			continue;
3366
3367		if (task->state == ISCSI_TASK_FREE)
3368			continue;
3369
3370		ISCSI_DBG_SESSION(conn->session,
3371				  "failing mgmt itt 0x%x state %d\n",
3372				  task->itt, task->state);
3373
3374		spin_lock_bh(&session->back_lock);
3375		if (cleanup_queued_task(task)) {
3376			spin_unlock_bh(&session->back_lock);
3377			continue;
3378		}
3379
3380		state = ISCSI_TASK_ABRT_SESS_RECOV;
3381		if (task->state == ISCSI_TASK_PENDING)
3382			state = ISCSI_TASK_COMPLETED;
3383		iscsi_complete_task(task, state);
3384		spin_unlock_bh(&session->back_lock);
3385	}
3386}
3387
3388void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3389{
3390	struct iscsi_conn *conn = cls_conn->dd_data;
3391	struct iscsi_session *session = conn->session;
3392	int old_stop_stage;
3393
3394	mutex_lock(&session->eh_mutex);
3395	spin_lock_bh(&session->frwd_lock);
3396	if (conn->stop_stage == STOP_CONN_TERM) {
3397		spin_unlock_bh(&session->frwd_lock);
3398		mutex_unlock(&session->eh_mutex);
3399		return;
3400	}
3401
3402	/*
3403	 * When this is called for the in_login state, we only want to clean
3404	 * up the login task and connection. We do not need to block and set
3405	 * the recovery state again
3406	 */
3407	if (flag == STOP_CONN_TERM)
3408		session->state = ISCSI_STATE_TERMINATE;
3409	else if (conn->stop_stage != STOP_CONN_RECOVER)
3410		session->state = ISCSI_STATE_IN_RECOVERY;
3411
3412	old_stop_stage = conn->stop_stage;
3413	conn->stop_stage = flag;
3414	spin_unlock_bh(&session->frwd_lock);
3415
3416	timer_delete_sync(&conn->transport_timer);
3417	iscsi_suspend_tx(conn);
3418
3419	spin_lock_bh(&session->frwd_lock);
3420	conn->c_stage = ISCSI_CONN_STOPPED;
3421	spin_unlock_bh(&session->frwd_lock);
3422
3423	/*
3424	 * for connection level recovery we should not calculate
3425	 * header digest. conn->hdr_size used for optimization
3426	 * in hdr_extract() and will be re-negotiated at
3427	 * set_param() time.
3428	 */
3429	if (flag == STOP_CONN_RECOVER) {
3430		conn->hdrdgst_en = 0;
3431		conn->datadgst_en = 0;
3432		if (session->state == ISCSI_STATE_IN_RECOVERY &&
3433		    old_stop_stage != STOP_CONN_RECOVER) {
3434			ISCSI_DBG_SESSION(session, "blocking session\n");
3435			iscsi_block_session(session->cls_session);
3436		}
3437	}
3438
3439	/*
3440	 * flush queues.
3441	 */
3442	spin_lock_bh(&session->frwd_lock);
3443	fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3444	fail_mgmt_tasks(session, conn);
3445	memset(&session->tmhdr, 0, sizeof(session->tmhdr));
3446	spin_unlock_bh(&session->frwd_lock);
3447	mutex_unlock(&session->eh_mutex);
3448}
3449EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3450
3451int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3452		    struct iscsi_cls_conn *cls_conn, int is_leading)
3453{
3454	struct iscsi_session *session = cls_session->dd_data;
3455	struct iscsi_conn *conn = cls_conn->dd_data;
3456
3457	spin_lock_bh(&session->frwd_lock);
3458	if (is_leading)
3459		session->leadconn = conn;
3460
3461	set_bit(ISCSI_CONN_FLAG_BOUND, &conn->flags);
3462	spin_unlock_bh(&session->frwd_lock);
3463
3464	/*
3465	 * The target could have reduced it's window size between logins, so
3466	 * we have to reset max/exp cmdsn so we can see the new values.
3467	 */
3468	spin_lock_bh(&session->back_lock);
3469	session->max_cmdsn = session->exp_cmdsn = session->cmdsn + 1;
3470	spin_unlock_bh(&session->back_lock);
3471	/*
3472	 * Unblock xmitworker(), Login Phase will pass through.
3473	 */
3474	clear_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags);
3475	clear_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
3476	return 0;
3477}
3478EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3479
3480int iscsi_switch_str_param(char **param, char *new_val_buf)
3481{
3482	char *new_val;
3483
3484	if (*param) {
3485		if (!strcmp(*param, new_val_buf))
3486			return 0;
3487	}
3488
3489	new_val = kstrdup(new_val_buf, GFP_NOIO);
3490	if (!new_val)
3491		return -ENOMEM;
3492
3493	kfree(*param);
3494	*param = new_val;
3495	return 0;
3496}
3497EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3498
3499int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3500		    enum iscsi_param param, char *buf, int buflen)
3501{
3502	struct iscsi_conn *conn = cls_conn->dd_data;
3503	struct iscsi_session *session = conn->session;
3504	int val;
3505
3506	switch(param) {
3507	case ISCSI_PARAM_FAST_ABORT:
3508		sscanf(buf, "%d", &session->fast_abort);
3509		break;
3510	case ISCSI_PARAM_ABORT_TMO:
3511		sscanf(buf, "%d", &session->abort_timeout);
3512		break;
3513	case ISCSI_PARAM_LU_RESET_TMO:
3514		sscanf(buf, "%d", &session->lu_reset_timeout);
3515		break;
3516	case ISCSI_PARAM_TGT_RESET_TMO:
3517		sscanf(buf, "%d", &session->tgt_reset_timeout);
3518		break;
3519	case ISCSI_PARAM_PING_TMO:
3520		sscanf(buf, "%d", &conn->ping_timeout);
3521		break;
3522	case ISCSI_PARAM_RECV_TMO:
3523		sscanf(buf, "%d", &conn->recv_timeout);
3524		break;
3525	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3526		sscanf(buf, "%d", &conn->max_recv_dlength);
3527		break;
3528	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3529		sscanf(buf, "%d", &conn->max_xmit_dlength);
3530		break;
3531	case ISCSI_PARAM_HDRDGST_EN:
3532		sscanf(buf, "%d", &conn->hdrdgst_en);
3533		break;
3534	case ISCSI_PARAM_DATADGST_EN:
3535		sscanf(buf, "%d", &conn->datadgst_en);
3536		break;
3537	case ISCSI_PARAM_INITIAL_R2T_EN:
3538		sscanf(buf, "%d", &session->initial_r2t_en);
3539		break;
3540	case ISCSI_PARAM_MAX_R2T:
3541		sscanf(buf, "%hu", &session->max_r2t);
3542		break;
3543	case ISCSI_PARAM_IMM_DATA_EN:
3544		sscanf(buf, "%d", &session->imm_data_en);
3545		break;
3546	case ISCSI_PARAM_FIRST_BURST:
3547		sscanf(buf, "%d", &session->first_burst);
3548		break;
3549	case ISCSI_PARAM_MAX_BURST:
3550		sscanf(buf, "%d", &session->max_burst);
3551		break;
3552	case ISCSI_PARAM_PDU_INORDER_EN:
3553		sscanf(buf, "%d", &session->pdu_inorder_en);
3554		break;
3555	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3556		sscanf(buf, "%d", &session->dataseq_inorder_en);
3557		break;
3558	case ISCSI_PARAM_ERL:
3559		sscanf(buf, "%d", &session->erl);
3560		break;
3561	case ISCSI_PARAM_EXP_STATSN:
3562		sscanf(buf, "%u", &conn->exp_statsn);
3563		break;
3564	case ISCSI_PARAM_USERNAME:
3565		return iscsi_switch_str_param(&session->username, buf);
3566	case ISCSI_PARAM_USERNAME_IN:
3567		return iscsi_switch_str_param(&session->username_in, buf);
3568	case ISCSI_PARAM_PASSWORD:
3569		return iscsi_switch_str_param(&session->password, buf);
3570	case ISCSI_PARAM_PASSWORD_IN:
3571		return iscsi_switch_str_param(&session->password_in, buf);
3572	case ISCSI_PARAM_TARGET_NAME:
3573		return iscsi_switch_str_param(&session->targetname, buf);
3574	case ISCSI_PARAM_TARGET_ALIAS:
3575		return iscsi_switch_str_param(&session->targetalias, buf);
3576	case ISCSI_PARAM_TPGT:
3577		sscanf(buf, "%d", &session->tpgt);
3578		break;
3579	case ISCSI_PARAM_PERSISTENT_PORT:
3580		sscanf(buf, "%d", &conn->persistent_port);
3581		break;
3582	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3583		return iscsi_switch_str_param(&conn->persistent_address, buf);
3584	case ISCSI_PARAM_IFACE_NAME:
3585		return iscsi_switch_str_param(&session->ifacename, buf);
3586	case ISCSI_PARAM_INITIATOR_NAME:
3587		return iscsi_switch_str_param(&session->initiatorname, buf);
3588	case ISCSI_PARAM_BOOT_ROOT:
3589		return iscsi_switch_str_param(&session->boot_root, buf);
3590	case ISCSI_PARAM_BOOT_NIC:
3591		return iscsi_switch_str_param(&session->boot_nic, buf);
3592	case ISCSI_PARAM_BOOT_TARGET:
3593		return iscsi_switch_str_param(&session->boot_target, buf);
3594	case ISCSI_PARAM_PORTAL_TYPE:
3595		return iscsi_switch_str_param(&session->portal_type, buf);
3596	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3597		return iscsi_switch_str_param(&session->discovery_parent_type,
3598					      buf);
3599	case ISCSI_PARAM_DISCOVERY_SESS:
3600		sscanf(buf, "%d", &val);
3601		session->discovery_sess = !!val;
3602		break;
3603	case ISCSI_PARAM_LOCAL_IPADDR:
3604		return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3605	default:
3606		return -ENOSYS;
3607	}
3608
3609	return 0;
3610}
3611EXPORT_SYMBOL_GPL(iscsi_set_param);
3612
3613int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3614			    enum iscsi_param param, char *buf)
3615{
3616	struct iscsi_session *session = cls_session->dd_data;
3617	int len;
3618
3619	switch(param) {
3620	case ISCSI_PARAM_FAST_ABORT:
3621		len = sysfs_emit(buf, "%d\n", session->fast_abort);
3622		break;
3623	case ISCSI_PARAM_ABORT_TMO:
3624		len = sysfs_emit(buf, "%d\n", session->abort_timeout);
3625		break;
3626	case ISCSI_PARAM_LU_RESET_TMO:
3627		len = sysfs_emit(buf, "%d\n", session->lu_reset_timeout);
3628		break;
3629	case ISCSI_PARAM_TGT_RESET_TMO:
3630		len = sysfs_emit(buf, "%d\n", session->tgt_reset_timeout);
3631		break;
3632	case ISCSI_PARAM_INITIAL_R2T_EN:
3633		len = sysfs_emit(buf, "%d\n", session->initial_r2t_en);
3634		break;
3635	case ISCSI_PARAM_MAX_R2T:
3636		len = sysfs_emit(buf, "%hu\n", session->max_r2t);
3637		break;
3638	case ISCSI_PARAM_IMM_DATA_EN:
3639		len = sysfs_emit(buf, "%d\n", session->imm_data_en);
3640		break;
3641	case ISCSI_PARAM_FIRST_BURST:
3642		len = sysfs_emit(buf, "%u\n", session->first_burst);
3643		break;
3644	case ISCSI_PARAM_MAX_BURST:
3645		len = sysfs_emit(buf, "%u\n", session->max_burst);
3646		break;
3647	case ISCSI_PARAM_PDU_INORDER_EN:
3648		len = sysfs_emit(buf, "%d\n", session->pdu_inorder_en);
3649		break;
3650	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3651		len = sysfs_emit(buf, "%d\n", session->dataseq_inorder_en);
3652		break;
3653	case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3654		len = sysfs_emit(buf, "%d\n", session->def_taskmgmt_tmo);
3655		break;
3656	case ISCSI_PARAM_ERL:
3657		len = sysfs_emit(buf, "%d\n", session->erl);
3658		break;
3659	case ISCSI_PARAM_TARGET_NAME:
3660		len = sysfs_emit(buf, "%s\n", session->targetname);
3661		break;
3662	case ISCSI_PARAM_TARGET_ALIAS:
3663		len = sysfs_emit(buf, "%s\n", session->targetalias);
3664		break;
3665	case ISCSI_PARAM_TPGT:
3666		len = sysfs_emit(buf, "%d\n", session->tpgt);
3667		break;
3668	case ISCSI_PARAM_USERNAME:
3669		len = sysfs_emit(buf, "%s\n", session->username);
3670		break;
3671	case ISCSI_PARAM_USERNAME_IN:
3672		len = sysfs_emit(buf, "%s\n", session->username_in);
3673		break;
3674	case ISCSI_PARAM_PASSWORD:
3675		len = sysfs_emit(buf, "%s\n", session->password);
3676		break;
3677	case ISCSI_PARAM_PASSWORD_IN:
3678		len = sysfs_emit(buf, "%s\n", session->password_in);
3679		break;
3680	case ISCSI_PARAM_IFACE_NAME:
3681		len = sysfs_emit(buf, "%s\n", session->ifacename);
3682		break;
3683	case ISCSI_PARAM_INITIATOR_NAME:
3684		len = sysfs_emit(buf, "%s\n", session->initiatorname);
3685		break;
3686	case ISCSI_PARAM_BOOT_ROOT:
3687		len = sysfs_emit(buf, "%s\n", session->boot_root);
3688		break;
3689	case ISCSI_PARAM_BOOT_NIC:
3690		len = sysfs_emit(buf, "%s\n", session->boot_nic);
3691		break;
3692	case ISCSI_PARAM_BOOT_TARGET:
3693		len = sysfs_emit(buf, "%s\n", session->boot_target);
3694		break;
3695	case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3696		len = sysfs_emit(buf, "%u\n", session->auto_snd_tgt_disable);
3697		break;
3698	case ISCSI_PARAM_DISCOVERY_SESS:
3699		len = sysfs_emit(buf, "%u\n", session->discovery_sess);
3700		break;
3701	case ISCSI_PARAM_PORTAL_TYPE:
3702		len = sysfs_emit(buf, "%s\n", session->portal_type);
3703		break;
3704	case ISCSI_PARAM_CHAP_AUTH_EN:
3705		len = sysfs_emit(buf, "%u\n", session->chap_auth_en);
3706		break;
3707	case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3708		len = sysfs_emit(buf, "%u\n", session->discovery_logout_en);
3709		break;
3710	case ISCSI_PARAM_BIDI_CHAP_EN:
3711		len = sysfs_emit(buf, "%u\n", session->bidi_chap_en);
3712		break;
3713	case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3714		len = sysfs_emit(buf, "%u\n", session->discovery_auth_optional);
3715		break;
3716	case ISCSI_PARAM_DEF_TIME2WAIT:
3717		len = sysfs_emit(buf, "%d\n", session->time2wait);
3718		break;
3719	case ISCSI_PARAM_DEF_TIME2RETAIN:
3720		len = sysfs_emit(buf, "%d\n", session->time2retain);
3721		break;
3722	case ISCSI_PARAM_TSID:
3723		len = sysfs_emit(buf, "%u\n", session->tsid);
3724		break;
3725	case ISCSI_PARAM_ISID:
3726		len = sysfs_emit(buf, "%02x%02x%02x%02x%02x%02x\n",
3727			      session->isid[0], session->isid[1],
3728			      session->isid[2], session->isid[3],
3729			      session->isid[4], session->isid[5]);
3730		break;
3731	case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3732		len = sysfs_emit(buf, "%u\n", session->discovery_parent_idx);
3733		break;
3734	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3735		if (session->discovery_parent_type)
3736			len = sysfs_emit(buf, "%s\n",
3737				      session->discovery_parent_type);
3738		else
3739			len = sysfs_emit(buf, "\n");
3740		break;
3741	default:
3742		return -ENOSYS;
3743	}
3744
3745	return len;
3746}
3747EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3748
3749int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3750			      enum iscsi_param param, char *buf)
3751{
3752	struct sockaddr_in6 *sin6 = NULL;
3753	struct sockaddr_in *sin = NULL;
3754	int len;
3755
3756	switch (addr->ss_family) {
3757	case AF_INET:
3758		sin = (struct sockaddr_in *)addr;
3759		break;
3760	case AF_INET6:
3761		sin6 = (struct sockaddr_in6 *)addr;
3762		break;
3763	default:
3764		return -EINVAL;
3765	}
3766
3767	switch (param) {
3768	case ISCSI_PARAM_CONN_ADDRESS:
3769	case ISCSI_HOST_PARAM_IPADDRESS:
3770		if (sin)
3771			len = sysfs_emit(buf, "%pI4\n", &sin->sin_addr.s_addr);
3772		else
3773			len = sysfs_emit(buf, "%pI6\n", &sin6->sin6_addr);
3774		break;
3775	case ISCSI_PARAM_CONN_PORT:
3776	case ISCSI_PARAM_LOCAL_PORT:
3777		if (sin)
3778			len = sysfs_emit(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3779		else
3780			len = sysfs_emit(buf, "%hu\n",
3781				      be16_to_cpu(sin6->sin6_port));
3782		break;
3783	default:
3784		return -EINVAL;
3785	}
3786
3787	return len;
3788}
3789EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3790
3791int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3792			 enum iscsi_param param, char *buf)
3793{
3794	struct iscsi_conn *conn = cls_conn->dd_data;
3795	int len;
3796
3797	switch(param) {
3798	case ISCSI_PARAM_PING_TMO:
3799		len = sysfs_emit(buf, "%u\n", conn->ping_timeout);
3800		break;
3801	case ISCSI_PARAM_RECV_TMO:
3802		len = sysfs_emit(buf, "%u\n", conn->recv_timeout);
3803		break;
3804	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3805		len = sysfs_emit(buf, "%u\n", conn->max_recv_dlength);
3806		break;
3807	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3808		len = sysfs_emit(buf, "%u\n", conn->max_xmit_dlength);
3809		break;
3810	case ISCSI_PARAM_HDRDGST_EN:
3811		len = sysfs_emit(buf, "%d\n", conn->hdrdgst_en);
3812		break;
3813	case ISCSI_PARAM_DATADGST_EN:
3814		len = sysfs_emit(buf, "%d\n", conn->datadgst_en);
3815		break;
3816	case ISCSI_PARAM_IFMARKER_EN:
3817		len = sysfs_emit(buf, "%d\n", conn->ifmarker_en);
3818		break;
3819	case ISCSI_PARAM_OFMARKER_EN:
3820		len = sysfs_emit(buf, "%d\n", conn->ofmarker_en);
3821		break;
3822	case ISCSI_PARAM_EXP_STATSN:
3823		len = sysfs_emit(buf, "%u\n", conn->exp_statsn);
3824		break;
3825	case ISCSI_PARAM_PERSISTENT_PORT:
3826		len = sysfs_emit(buf, "%d\n", conn->persistent_port);
3827		break;
3828	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3829		len = sysfs_emit(buf, "%s\n", conn->persistent_address);
3830		break;
3831	case ISCSI_PARAM_STATSN:
3832		len = sysfs_emit(buf, "%u\n", conn->statsn);
3833		break;
3834	case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3835		len = sysfs_emit(buf, "%u\n", conn->max_segment_size);
3836		break;
3837	case ISCSI_PARAM_KEEPALIVE_TMO:
3838		len = sysfs_emit(buf, "%u\n", conn->keepalive_tmo);
3839		break;
3840	case ISCSI_PARAM_LOCAL_PORT:
3841		len = sysfs_emit(buf, "%u\n", conn->local_port);
3842		break;
3843	case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3844		len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_stat);
3845		break;
3846	case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3847		len = sysfs_emit(buf, "%u\n", conn->tcp_nagle_disable);
3848		break;
3849	case ISCSI_PARAM_TCP_WSF_DISABLE:
3850		len = sysfs_emit(buf, "%u\n", conn->tcp_wsf_disable);
3851		break;
3852	case ISCSI_PARAM_TCP_TIMER_SCALE:
3853		len = sysfs_emit(buf, "%u\n", conn->tcp_timer_scale);
3854		break;
3855	case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3856		len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_en);
3857		break;
3858	case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3859		len = sysfs_emit(buf, "%u\n", conn->fragment_disable);
3860		break;
3861	case ISCSI_PARAM_IPV4_TOS:
3862		len = sysfs_emit(buf, "%u\n", conn->ipv4_tos);
3863		break;
3864	case ISCSI_PARAM_IPV6_TC:
3865		len = sysfs_emit(buf, "%u\n", conn->ipv6_traffic_class);
3866		break;
3867	case ISCSI_PARAM_IPV6_FLOW_LABEL:
3868		len = sysfs_emit(buf, "%u\n", conn->ipv6_flow_label);
3869		break;
3870	case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3871		len = sysfs_emit(buf, "%u\n", conn->is_fw_assigned_ipv6);
3872		break;
3873	case ISCSI_PARAM_TCP_XMIT_WSF:
3874		len = sysfs_emit(buf, "%u\n", conn->tcp_xmit_wsf);
3875		break;
3876	case ISCSI_PARAM_TCP_RECV_WSF:
3877		len = sysfs_emit(buf, "%u\n", conn->tcp_recv_wsf);
3878		break;
3879	case ISCSI_PARAM_LOCAL_IPADDR:
3880		len = sysfs_emit(buf, "%s\n", conn->local_ipaddr);
3881		break;
3882	default:
3883		return -ENOSYS;
3884	}
3885
3886	return len;
3887}
3888EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3889
3890int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3891			 char *buf)
3892{
3893	struct iscsi_host *ihost = shost_priv(shost);
3894	int len;
3895
3896	switch (param) {
3897	case ISCSI_HOST_PARAM_NETDEV_NAME:
3898		len = sysfs_emit(buf, "%s\n", ihost->netdev);
3899		break;
3900	case ISCSI_HOST_PARAM_HWADDRESS:
3901		len = sysfs_emit(buf, "%s\n", ihost->hwaddress);
3902		break;
3903	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3904		len = sysfs_emit(buf, "%s\n", ihost->initiatorname);
3905		break;
3906	default:
3907		return -ENOSYS;
3908	}
3909
3910	return len;
3911}
3912EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3913
3914int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3915			 char *buf, int buflen)
3916{
3917	struct iscsi_host *ihost = shost_priv(shost);
3918
3919	switch (param) {
3920	case ISCSI_HOST_PARAM_NETDEV_NAME:
3921		return iscsi_switch_str_param(&ihost->netdev, buf);
3922	case ISCSI_HOST_PARAM_HWADDRESS:
3923		return iscsi_switch_str_param(&ihost->hwaddress, buf);
3924	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3925		return iscsi_switch_str_param(&ihost->initiatorname, buf);
3926	default:
3927		return -ENOSYS;
3928	}
3929
3930	return 0;
3931}
3932EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3933
3934MODULE_AUTHOR("Mike Christie");
3935MODULE_DESCRIPTION("iSCSI library functions");
3936MODULE_LICENSE("GPL");