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v4.10.11
   1/*
   2 * iSCSI lib functions
   3 *
   4 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5 * Copyright (C) 2004 - 2006 Mike Christie
   6 * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7 * Copyright (C) 2004 - 2005 Alex Aizman
   8 * maintained by open-iscsi@googlegroups.com
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License as published by
  12 * the Free Software Foundation; either version 2 of the License, or
  13 * (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful,
  16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 * GNU General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program; if not, write to the Free Software
  22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23 */
  24#include <linux/types.h>
  25#include <linux/kfifo.h>
  26#include <linux/delay.h>
  27#include <linux/log2.h>
  28#include <linux/slab.h>
  29#include <linux/module.h>
  30#include <asm/unaligned.h>
  31#include <net/tcp.h>
  32#include <scsi/scsi_cmnd.h>
  33#include <scsi/scsi_device.h>
  34#include <scsi/scsi_eh.h>
  35#include <scsi/scsi_tcq.h>
  36#include <scsi/scsi_host.h>
  37#include <scsi/scsi.h>
  38#include <scsi/iscsi_proto.h>
  39#include <scsi/scsi_transport.h>
  40#include <scsi/scsi_transport_iscsi.h>
  41#include <scsi/libiscsi.h>
  42
  43static int iscsi_dbg_lib_conn;
  44module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  45		   S_IRUGO | S_IWUSR);
  46MODULE_PARM_DESC(debug_libiscsi_conn,
  47		 "Turn on debugging for connections in libiscsi module. "
  48		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  49
  50static int iscsi_dbg_lib_session;
  51module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  52		   S_IRUGO | S_IWUSR);
  53MODULE_PARM_DESC(debug_libiscsi_session,
  54		 "Turn on debugging for sessions in libiscsi module. "
  55		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  56
  57static int iscsi_dbg_lib_eh;
  58module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  59		   S_IRUGO | S_IWUSR);
  60MODULE_PARM_DESC(debug_libiscsi_eh,
  61		 "Turn on debugging for error handling in libiscsi module. "
  62		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  63
  64#define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)			\
  65	do {							\
  66		if (iscsi_dbg_lib_conn)				\
  67			iscsi_conn_printk(KERN_INFO, _conn,	\
  68					     "%s " dbg_fmt,	\
  69					     __func__, ##arg);	\
  70	} while (0);
  71
  72#define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)			\
  73	do {								\
  74		if (iscsi_dbg_lib_session)				\
  75			iscsi_session_printk(KERN_INFO, _session,	\
  76					     "%s " dbg_fmt,		\
  77					     __func__, ##arg);		\
  78	} while (0);
  79
  80#define ISCSI_DBG_EH(_session, dbg_fmt, arg...)				\
  81	do {								\
  82		if (iscsi_dbg_lib_eh)					\
  83			iscsi_session_printk(KERN_INFO, _session,	\
  84					     "%s " dbg_fmt,		\
  85					     __func__, ##arg);		\
  86	} while (0);
  87
  88inline void iscsi_conn_queue_work(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_work);
  97
  98static void __iscsi_update_cmdsn(struct iscsi_session *session,
  99				 uint32_t exp_cmdsn, uint32_t max_cmdsn)
 100{
 101	/*
 102	 * standard specifies this check for when to update expected and
 103	 * max sequence numbers
 104	 */
 105	if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 106		return;
 107
 108	if (exp_cmdsn != session->exp_cmdsn &&
 109	    !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 110		session->exp_cmdsn = exp_cmdsn;
 111
 112	if (max_cmdsn != session->max_cmdsn &&
 113	    !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
 114		session->max_cmdsn = max_cmdsn;
 115}
 116
 117void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 118{
 119	__iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 120			     be32_to_cpu(hdr->max_cmdsn));
 121}
 122EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 123
 124/**
 125 * iscsi_prep_data_out_pdu - initialize Data-Out
 126 * @task: scsi command task
 127 * @r2t: R2T info
 128 * @hdr: iscsi data in pdu
 129 *
 130 * Notes:
 131 *	Initialize Data-Out within this R2T sequence and finds
 132 *	proper data_offset within this SCSI command.
 133 *
 134 *	This function is called with connection lock taken.
 135 **/
 136void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 137			   struct iscsi_data *hdr)
 138{
 139	struct iscsi_conn *conn = task->conn;
 140	unsigned int left = r2t->data_length - r2t->sent;
 141
 142	task->hdr_len = sizeof(struct iscsi_data);
 143
 144	memset(hdr, 0, sizeof(struct iscsi_data));
 145	hdr->ttt = r2t->ttt;
 146	hdr->datasn = cpu_to_be32(r2t->datasn);
 147	r2t->datasn++;
 148	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 149	hdr->lun = task->lun;
 150	hdr->itt = task->hdr_itt;
 151	hdr->exp_statsn = r2t->exp_statsn;
 152	hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 153	if (left > conn->max_xmit_dlength) {
 154		hton24(hdr->dlength, conn->max_xmit_dlength);
 155		r2t->data_count = conn->max_xmit_dlength;
 156		hdr->flags = 0;
 157	} else {
 158		hton24(hdr->dlength, left);
 159		r2t->data_count = left;
 160		hdr->flags = ISCSI_FLAG_CMD_FINAL;
 161	}
 162	conn->dataout_pdus_cnt++;
 163}
 164EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 165
 166static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 167{
 168	unsigned exp_len = task->hdr_len + len;
 169
 170	if (exp_len > task->hdr_max) {
 171		WARN_ON(1);
 172		return -EINVAL;
 173	}
 174
 175	WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 176	task->hdr_len = exp_len;
 177	return 0;
 178}
 179
 180/*
 181 * make an extended cdb AHS
 182 */
 183static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 184{
 185	struct scsi_cmnd *cmd = task->sc;
 186	unsigned rlen, pad_len;
 187	unsigned short ahslength;
 188	struct iscsi_ecdb_ahdr *ecdb_ahdr;
 189	int rc;
 190
 191	ecdb_ahdr = iscsi_next_hdr(task);
 192	rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 193
 194	BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 195	ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 196
 197	pad_len = iscsi_padding(rlen);
 198
 199	rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 200	                   sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 201	if (rc)
 202		return rc;
 203
 204	if (pad_len)
 205		memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 206
 207	ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 208	ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 209	ecdb_ahdr->reserved = 0;
 210	memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 211
 212	ISCSI_DBG_SESSION(task->conn->session,
 213			  "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 214		          "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 215		          "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 216		          task->hdr_len);
 217	return 0;
 218}
 219
 220static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 221{
 222	struct scsi_cmnd *sc = task->sc;
 223	struct iscsi_rlength_ahdr *rlen_ahdr;
 224	int rc;
 225
 226	rlen_ahdr = iscsi_next_hdr(task);
 227	rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 228	if (rc)
 229		return rc;
 230
 231	rlen_ahdr->ahslength =
 232		cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 233						  sizeof(rlen_ahdr->reserved));
 234	rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 235	rlen_ahdr->reserved = 0;
 236	rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 237
 238	ISCSI_DBG_SESSION(task->conn->session,
 239			  "bidi-in rlen_ahdr->read_length(%d) "
 240		          "rlen_ahdr->ahslength(%d)\n",
 241		          be32_to_cpu(rlen_ahdr->read_length),
 242		          be16_to_cpu(rlen_ahdr->ahslength));
 243	return 0;
 244}
 245
 246/**
 247 * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 248 * @task: iscsi task
 249 * @opcode: opcode to check for
 250 *
 251 * During TMF a task has to be checked if it's affected.
 252 * All unrelated I/O can be passed through, but I/O to the
 253 * affected LUN should be restricted.
 254 * If 'fast_abort' is set we won't be sending any I/O to the
 255 * affected LUN.
 256 * Otherwise the target is waiting for all TTTs to be completed,
 257 * so we have to send all outstanding Data-Out PDUs to the target.
 258 */
 259static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 260{
 261	struct iscsi_conn *conn = task->conn;
 262	struct iscsi_tm *tmf = &conn->tmhdr;
 263	u64 hdr_lun;
 264
 265	if (conn->tmf_state == TMF_INITIAL)
 266		return 0;
 267
 268	if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 269		return 0;
 270
 271	switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 272	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 273		/*
 274		 * Allow PDUs for unrelated LUNs
 275		 */
 276		hdr_lun = scsilun_to_int(&tmf->lun);
 277		if (hdr_lun != task->sc->device->lun)
 278			return 0;
 279		/* fall through */
 280	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 281		/*
 282		 * Fail all SCSI cmd PDUs
 283		 */
 284		if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 285			iscsi_conn_printk(KERN_INFO, conn,
 286					  "task [op %x/%x itt "
 287					  "0x%x/0x%x] "
 288					  "rejected.\n",
 289					  task->hdr->opcode, opcode,
 290					  task->itt, task->hdr_itt);
 291			return -EACCES;
 292		}
 293		/*
 294		 * And also all data-out PDUs in response to R2T
 295		 * if fast_abort is set.
 296		 */
 297		if (conn->session->fast_abort) {
 298			iscsi_conn_printk(KERN_INFO, conn,
 299					  "task [op %x/%x itt "
 300					  "0x%x/0x%x] fast abort.\n",
 301					  task->hdr->opcode, opcode,
 302					  task->itt, task->hdr_itt);
 303			return -EACCES;
 304		}
 305		break;
 306	case ISCSI_TM_FUNC_ABORT_TASK:
 307		/*
 308		 * the caller has already checked if the task
 309		 * they want to abort was in the pending queue so if
 310		 * we are here the cmd pdu has gone out already, and
 311		 * we will only hit this for data-outs
 312		 */
 313		if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 314		    task->hdr_itt == tmf->rtt) {
 315			ISCSI_DBG_SESSION(conn->session,
 316					  "Preventing task %x/%x from sending "
 317					  "data-out due to abort task in "
 318					  "progress\n", task->itt,
 319					  task->hdr_itt);
 320			return -EACCES;
 321		}
 322		break;
 323	}
 324
 325	return 0;
 326}
 327
 328/**
 329 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 330 * @task: iscsi task
 331 *
 332 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 333 * fields like dlength or final based on how much data it sends
 334 */
 335static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 336{
 337	struct iscsi_conn *conn = task->conn;
 338	struct iscsi_session *session = conn->session;
 339	struct scsi_cmnd *sc = task->sc;
 340	struct iscsi_scsi_req *hdr;
 341	unsigned hdrlength, cmd_len, transfer_length;
 342	itt_t itt;
 343	int rc;
 344
 345	rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 346	if (rc)
 347		return rc;
 348
 349	if (conn->session->tt->alloc_pdu) {
 350		rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 351		if (rc)
 352			return rc;
 353	}
 354	hdr = (struct iscsi_scsi_req *)task->hdr;
 355	itt = hdr->itt;
 356	memset(hdr, 0, sizeof(*hdr));
 357
 358	if (session->tt->parse_pdu_itt)
 359		hdr->itt = task->hdr_itt = itt;
 360	else
 361		hdr->itt = task->hdr_itt = build_itt(task->itt,
 362						     task->conn->session->age);
 363	task->hdr_len = 0;
 364	rc = iscsi_add_hdr(task, sizeof(*hdr));
 365	if (rc)
 366		return rc;
 367	hdr->opcode = ISCSI_OP_SCSI_CMD;
 368	hdr->flags = ISCSI_ATTR_SIMPLE;
 369	int_to_scsilun(sc->device->lun, &hdr->lun);
 370	task->lun = hdr->lun;
 371	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 372	cmd_len = sc->cmd_len;
 373	if (cmd_len < ISCSI_CDB_SIZE)
 374		memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 375	else if (cmd_len > ISCSI_CDB_SIZE) {
 376		rc = iscsi_prep_ecdb_ahs(task);
 377		if (rc)
 378			return rc;
 379		cmd_len = ISCSI_CDB_SIZE;
 380	}
 381	memcpy(hdr->cdb, sc->cmnd, cmd_len);
 382
 383	task->imm_count = 0;
 384	if (scsi_bidi_cmnd(sc)) {
 385		hdr->flags |= ISCSI_FLAG_CMD_READ;
 386		rc = iscsi_prep_bidi_ahs(task);
 387		if (rc)
 388			return rc;
 389	}
 390
 391	if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 392		task->protected = true;
 393
 394	transfer_length = scsi_transfer_length(sc);
 395	hdr->data_length = cpu_to_be32(transfer_length);
 396	if (sc->sc_data_direction == DMA_TO_DEVICE) {
 
 397		struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 398
 
 399		hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 400		/*
 401		 * Write counters:
 402		 *
 403		 *	imm_count	bytes to be sent right after
 404		 *			SCSI PDU Header
 405		 *
 406		 *	unsol_count	bytes(as Data-Out) to be sent
 407		 *			without	R2T ack right after
 408		 *			immediate data
 409		 *
 410		 *	r2t data_length bytes to be sent via R2T ack's
 411		 *
 412		 *      pad_count       bytes to be sent as zero-padding
 413		 */
 414		memset(r2t, 0, sizeof(*r2t));
 415
 416		if (session->imm_data_en) {
 417			if (transfer_length >= session->first_burst)
 418				task->imm_count = min(session->first_burst,
 419							conn->max_xmit_dlength);
 420			else
 421				task->imm_count = min(transfer_length,
 422						      conn->max_xmit_dlength);
 423			hton24(hdr->dlength, task->imm_count);
 424		} else
 425			zero_data(hdr->dlength);
 426
 427		if (!session->initial_r2t_en) {
 428			r2t->data_length = min(session->first_burst,
 429					       transfer_length) -
 430					       task->imm_count;
 431			r2t->data_offset = task->imm_count;
 432			r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 433			r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 434		}
 435
 436		if (!task->unsol_r2t.data_length)
 437			/* No unsolicit Data-Out's */
 438			hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 439	} else {
 440		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 441		zero_data(hdr->dlength);
 
 442
 443		if (sc->sc_data_direction == DMA_FROM_DEVICE)
 444			hdr->flags |= ISCSI_FLAG_CMD_READ;
 445	}
 446
 447	/* calculate size of additional header segments (AHSs) */
 448	hdrlength = task->hdr_len - sizeof(*hdr);
 449
 450	WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 451	hdrlength /= ISCSI_PAD_LEN;
 452
 453	WARN_ON(hdrlength >= 256);
 454	hdr->hlength = hdrlength & 0xFF;
 455	hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 456
 457	if (session->tt->init_task && session->tt->init_task(task))
 458		return -EIO;
 459
 460	task->state = ISCSI_TASK_RUNNING;
 461	session->cmdsn++;
 462
 463	conn->scsicmd_pdus_cnt++;
 464	ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 465			  "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
 466			  scsi_bidi_cmnd(sc) ? "bidirectional" :
 467			  sc->sc_data_direction == DMA_TO_DEVICE ?
 468			  "write" : "read", conn->id, sc, sc->cmnd[0],
 469			  task->itt, transfer_length,
 470			  scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 471			  session->cmdsn,
 472			  session->max_cmdsn - session->exp_cmdsn + 1);
 473	return 0;
 474}
 475
 476/**
 477 * iscsi_free_task - free a task
 478 * @task: iscsi cmd task
 479 *
 480 * Must be called with session back_lock.
 481 * This function returns the scsi command to scsi-ml or cleans
 482 * up mgmt tasks then returns the task to the pool.
 483 */
 484static void iscsi_free_task(struct iscsi_task *task)
 485{
 486	struct iscsi_conn *conn = task->conn;
 487	struct iscsi_session *session = conn->session;
 488	struct scsi_cmnd *sc = task->sc;
 489	int oldstate = task->state;
 490
 491	ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 492			  task->itt, task->state, task->sc);
 493
 494	session->tt->cleanup_task(task);
 495	task->state = ISCSI_TASK_FREE;
 496	task->sc = NULL;
 497	/*
 498	 * login task is preallocated so do not free
 499	 */
 500	if (conn->login_task == task)
 501		return;
 502
 503	kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 504
 505	if (sc) {
 506		/* SCSI eh reuses commands to verify us */
 507		sc->SCp.ptr = NULL;
 508		/*
 509		 * queue command may call this to free the task, so
 510		 * it will decide how to return sc to scsi-ml.
 511		 */
 512		if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 513			sc->scsi_done(sc);
 514	}
 515}
 516
 517void __iscsi_get_task(struct iscsi_task *task)
 518{
 519	atomic_inc(&task->refcount);
 520}
 521EXPORT_SYMBOL_GPL(__iscsi_get_task);
 522
 523void __iscsi_put_task(struct iscsi_task *task)
 524{
 525	if (atomic_dec_and_test(&task->refcount))
 526		iscsi_free_task(task);
 527}
 528EXPORT_SYMBOL_GPL(__iscsi_put_task);
 529
 530void iscsi_put_task(struct iscsi_task *task)
 531{
 532	struct iscsi_session *session = task->conn->session;
 533
 534	/* regular RX path uses back_lock */
 535	spin_lock_bh(&session->back_lock);
 536	__iscsi_put_task(task);
 537	spin_unlock_bh(&session->back_lock);
 538}
 539EXPORT_SYMBOL_GPL(iscsi_put_task);
 540
 541/**
 542 * iscsi_complete_task - finish a task
 543 * @task: iscsi cmd task
 544 * @state: state to complete task with
 545 *
 546 * Must be called with session back_lock.
 547 */
 548static void iscsi_complete_task(struct iscsi_task *task, int state)
 549{
 550	struct iscsi_conn *conn = task->conn;
 551
 552	ISCSI_DBG_SESSION(conn->session,
 553			  "complete task itt 0x%x state %d sc %p\n",
 554			  task->itt, task->state, task->sc);
 555	if (task->state == ISCSI_TASK_COMPLETED ||
 556	    task->state == ISCSI_TASK_ABRT_TMF ||
 557	    task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 558	    task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 559		return;
 560	WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 561	task->state = state;
 562
 563	spin_lock_bh(&conn->taskqueuelock);
 564	if (!list_empty(&task->running)) {
 565		pr_debug_once("%s while task on list", __func__);
 566		list_del_init(&task->running);
 567	}
 568	spin_unlock_bh(&conn->taskqueuelock);
 569
 570	if (conn->task == task)
 571		conn->task = NULL;
 572
 573	if (conn->ping_task == task)
 574		conn->ping_task = NULL;
 575
 576	/* release get from queueing */
 577	__iscsi_put_task(task);
 578}
 579
 580/**
 581 * iscsi_complete_scsi_task - finish scsi task normally
 582 * @task: iscsi task for scsi cmd
 583 * @exp_cmdsn: expected cmd sn in cpu format
 584 * @max_cmdsn: max cmd sn in cpu format
 585 *
 586 * This is used when drivers do not need or cannot perform
 587 * lower level pdu processing.
 588 *
 589 * Called with session back_lock
 590 */
 591void iscsi_complete_scsi_task(struct iscsi_task *task,
 592			      uint32_t exp_cmdsn, uint32_t max_cmdsn)
 593{
 594	struct iscsi_conn *conn = task->conn;
 595
 596	ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 597
 598	conn->last_recv = jiffies;
 599	__iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 600	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 601}
 602EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 603
 604
 605/*
 606 * session back_lock must be held and if not called for a task that is
 607 * still pending or from the xmit thread, then xmit thread must
 608 * be suspended.
 609 */
 610static void fail_scsi_task(struct iscsi_task *task, int err)
 611{
 612	struct iscsi_conn *conn = task->conn;
 613	struct scsi_cmnd *sc;
 614	int state;
 615
 616	/*
 617	 * if a command completes and we get a successful tmf response
 618	 * we will hit this because the scsi eh abort code does not take
 619	 * a ref to the task.
 620	 */
 621	sc = task->sc;
 622	if (!sc)
 623		return;
 624
 625	if (task->state == ISCSI_TASK_PENDING) {
 626		/*
 627		 * cmd never made it to the xmit thread, so we should not count
 628		 * the cmd in the sequencing
 629		 */
 630		conn->session->queued_cmdsn--;
 631		/* it was never sent so just complete like normal */
 632		state = ISCSI_TASK_COMPLETED;
 633	} else if (err == DID_TRANSPORT_DISRUPTED)
 634		state = ISCSI_TASK_ABRT_SESS_RECOV;
 635	else
 636		state = ISCSI_TASK_ABRT_TMF;
 637
 638	sc->result = err << 16;
 639	if (!scsi_bidi_cmnd(sc))
 640		scsi_set_resid(sc, scsi_bufflen(sc));
 641	else {
 642		scsi_out(sc)->resid = scsi_out(sc)->length;
 643		scsi_in(sc)->resid = scsi_in(sc)->length;
 644	}
 645
 646	/* regular RX path uses back_lock */
 647	spin_lock_bh(&conn->session->back_lock);
 648	iscsi_complete_task(task, state);
 649	spin_unlock_bh(&conn->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
 698static struct iscsi_task *
 699__iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 700		      char *data, uint32_t data_size)
 701{
 702	struct iscsi_session *session = conn->session;
 703	struct iscsi_host *ihost = shost_priv(session->host);
 704	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 705	struct iscsi_task *task;
 706	itt_t itt;
 707
 708	if (session->state == ISCSI_STATE_TERMINATE)
 709		return NULL;
 710
 711	if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 712		/*
 713		 * Login and Text are sent serially, in
 714		 * request-followed-by-response sequence.
 715		 * Same task can be used. Same ITT must be used.
 716		 * Note that login_task is preallocated at conn_create().
 717		 */
 718		if (conn->login_task->state != ISCSI_TASK_FREE) {
 719			iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 720					  "progress. Cannot start new task.\n");
 721			return NULL;
 722		}
 723
 724		if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 725			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);
 726			return NULL;
 727		}
 728
 729		task = conn->login_task;
 730	} else {
 731		if (session->state != ISCSI_STATE_LOGGED_IN)
 732			return NULL;
 733
 734		if (data_size != 0) {
 735			iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 736			return NULL;
 737		}
 738
 739		BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 740		BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 741
 742		if (!kfifo_out(&session->cmdpool.queue,
 743				 (void*)&task, sizeof(void*)))
 744			return NULL;
 745	}
 746	/*
 747	 * released in complete pdu for task we expect a response for, and
 748	 * released by the lld when it has transmitted the task for
 749	 * pdus we do not expect a response for.
 750	 */
 751	atomic_set(&task->refcount, 1);
 752	task->conn = conn;
 753	task->sc = NULL;
 754	INIT_LIST_HEAD(&task->running);
 755	task->state = ISCSI_TASK_PENDING;
 756
 757	if (data_size) {
 758		memcpy(task->data, data, data_size);
 759		task->data_count = data_size;
 760	} else
 761		task->data_count = 0;
 762
 763	if (conn->session->tt->alloc_pdu) {
 764		if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 765			iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 766					 "pdu for mgmt task.\n");
 767			goto free_task;
 768		}
 769	}
 770
 771	itt = task->hdr->itt;
 772	task->hdr_len = sizeof(struct iscsi_hdr);
 773	memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 774
 775	if (hdr->itt != RESERVED_ITT) {
 776		if (session->tt->parse_pdu_itt)
 777			task->hdr->itt = itt;
 778		else
 779			task->hdr->itt = build_itt(task->itt,
 780						   task->conn->session->age);
 781	}
 782
 783	if (!ihost->workq) {
 784		if (iscsi_prep_mgmt_task(conn, task))
 785			goto free_task;
 786
 787		if (session->tt->xmit_task(task))
 788			goto free_task;
 789	} else {
 790		spin_lock_bh(&conn->taskqueuelock);
 791		list_add_tail(&task->running, &conn->mgmtqueue);
 792		spin_unlock_bh(&conn->taskqueuelock);
 793		iscsi_conn_queue_work(conn);
 794	}
 795
 796	return task;
 797
 798free_task:
 799	/* regular RX path uses back_lock */
 800	spin_lock(&session->back_lock);
 801	__iscsi_put_task(task);
 802	spin_unlock(&session->back_lock);
 803	return NULL;
 804}
 805
 806int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 807			char *data, uint32_t data_size)
 808{
 809	struct iscsi_conn *conn = cls_conn->dd_data;
 810	struct iscsi_session *session = conn->session;
 811	int err = 0;
 812
 813	spin_lock_bh(&session->frwd_lock);
 814	if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 815		err = -EPERM;
 816	spin_unlock_bh(&session->frwd_lock);
 817	return err;
 818}
 819EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 820
 821/**
 822 * iscsi_cmd_rsp - SCSI Command Response processing
 823 * @conn: iscsi connection
 824 * @hdr: iscsi header
 825 * @task: scsi command task
 826 * @data: cmd data buffer
 827 * @datalen: len of buffer
 828 *
 829 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 830 * then completes the command and task.
 831 **/
 832static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 833			       struct iscsi_task *task, char *data,
 834			       int datalen)
 835{
 836	struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 837	struct iscsi_session *session = conn->session;
 838	struct scsi_cmnd *sc = task->sc;
 839
 840	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 841	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 842
 843	sc->result = (DID_OK << 16) | rhdr->cmd_status;
 844
 845	if (task->protected) {
 846		sector_t sector;
 847		u8 ascq;
 848
 849		/**
 850		 * Transports that didn't implement check_protection
 851		 * callback but still published T10-PI support to scsi-mid
 852		 * deserve this BUG_ON.
 853		 **/
 854		BUG_ON(!session->tt->check_protection);
 855
 856		ascq = session->tt->check_protection(task, &sector);
 857		if (ascq) {
 858			sc->result = DRIVER_SENSE << 24 |
 859				     SAM_STAT_CHECK_CONDITION;
 860			scsi_build_sense_buffer(1, sc->sense_buffer,
 861						ILLEGAL_REQUEST, 0x10, ascq);
 862			scsi_set_sense_information(sc->sense_buffer,
 863						   SCSI_SENSE_BUFFERSIZE,
 864						   sector);
 
 
 
 865			goto out;
 866		}
 867	}
 868
 869	if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 870		sc->result = DID_ERROR << 16;
 871		goto out;
 872	}
 873
 874	if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 875		uint16_t senselen;
 876
 877		if (datalen < 2) {
 878invalid_datalen:
 879			iscsi_conn_printk(KERN_ERR,  conn,
 880					 "Got CHECK_CONDITION but invalid data "
 881					 "buffer size of %d\n", datalen);
 882			sc->result = DID_BAD_TARGET << 16;
 883			goto out;
 884		}
 885
 886		senselen = get_unaligned_be16(data);
 887		if (datalen < senselen)
 888			goto invalid_datalen;
 889
 890		memcpy(sc->sense_buffer, data + 2,
 891		       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 892		ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 893				  min_t(uint16_t, senselen,
 894				  SCSI_SENSE_BUFFERSIZE));
 895	}
 896
 897	if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 898			   ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 899		int res_count = be32_to_cpu(rhdr->bi_residual_count);
 900
 901		if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 902				(rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 903				 res_count <= scsi_in(sc)->length))
 904			scsi_in(sc)->resid = res_count;
 905		else
 906			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 907	}
 908
 909	if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 910	                   ISCSI_FLAG_CMD_OVERFLOW)) {
 911		int res_count = be32_to_cpu(rhdr->residual_count);
 912
 913		if (res_count > 0 &&
 914		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 915		     res_count <= scsi_bufflen(sc)))
 916			/* write side for bidi or uni-io set_resid */
 917			scsi_set_resid(sc, res_count);
 918		else
 919			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 920	}
 921out:
 922	ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 923			  sc, sc->result, task->itt);
 924	conn->scsirsp_pdus_cnt++;
 925	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 926}
 927
 928/**
 929 * iscsi_data_in_rsp - SCSI Data-In Response processing
 930 * @conn: iscsi connection
 931 * @hdr:  iscsi pdu
 932 * @task: scsi command task
 933 **/
 934static void
 935iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 936		  struct iscsi_task *task)
 937{
 938	struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 939	struct scsi_cmnd *sc = task->sc;
 940
 941	if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 942		return;
 943
 944	iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 945	sc->result = (DID_OK << 16) | rhdr->cmd_status;
 946	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 947	if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 948	                   ISCSI_FLAG_DATA_OVERFLOW)) {
 949		int res_count = be32_to_cpu(rhdr->residual_count);
 950
 951		if (res_count > 0 &&
 952		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 953		     res_count <= scsi_in(sc)->length))
 954			scsi_in(sc)->resid = res_count;
 955		else
 956			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 957	}
 958
 959	ISCSI_DBG_SESSION(conn->session, "data in with status done "
 960			  "[sc %p res %d itt 0x%x]\n",
 961			  sc, sc->result, task->itt);
 962	conn->scsirsp_pdus_cnt++;
 963	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 964}
 965
 966static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 967{
 968	struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 969
 970	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 971	conn->tmfrsp_pdus_cnt++;
 972
 973	if (conn->tmf_state != TMF_QUEUED)
 974		return;
 975
 976	if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 977		conn->tmf_state = TMF_SUCCESS;
 978	else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 979		conn->tmf_state = TMF_NOT_FOUND;
 980	else
 981		conn->tmf_state = TMF_FAILED;
 982	wake_up(&conn->ehwait);
 983}
 984
 985static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 986{
 987        struct iscsi_nopout hdr;
 988	struct iscsi_task *task;
 989
 990	if (!rhdr && conn->ping_task)
 991		return -EINVAL;
 992
 993	memset(&hdr, 0, sizeof(struct iscsi_nopout));
 994	hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 995	hdr.flags = ISCSI_FLAG_CMD_FINAL;
 996
 997	if (rhdr) {
 998		hdr.lun = rhdr->lun;
 999		hdr.ttt = rhdr->ttt;
1000		hdr.itt = RESERVED_ITT;
1001	} else
1002		hdr.ttt = RESERVED_ITT;
1003
1004	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
1005	if (!task) {
1006		iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
1007		return -EIO;
1008	} else if (!rhdr) {
1009		/* only track our nops */
1010		conn->ping_task = task;
1011		conn->last_ping = jiffies;
1012	}
1013
1014	return 0;
1015}
1016
1017static int iscsi_nop_out_rsp(struct iscsi_task *task,
1018			     struct iscsi_nopin *nop, char *data, int datalen)
1019{
1020	struct iscsi_conn *conn = task->conn;
1021	int rc = 0;
1022
1023	if (conn->ping_task != task) {
1024		/*
1025		 * If this is not in response to one of our
1026		 * nops then it must be from userspace.
1027		 */
1028		if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1029				   data, datalen))
1030			rc = ISCSI_ERR_CONN_FAILED;
1031	} else
1032		mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1033	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1034	return rc;
1035}
1036
1037static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1038			       char *data, int datalen)
1039{
1040	struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1041	struct iscsi_hdr rejected_pdu;
1042	int opcode, rc = 0;
1043
1044	conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1045
1046	if (ntoh24(reject->dlength) > datalen ||
1047	    ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1048		iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1049				  "pdu. Invalid data length (pdu dlength "
1050				  "%u, datalen %d\n", ntoh24(reject->dlength),
1051				  datalen);
1052		return ISCSI_ERR_PROTO;
1053	}
1054	memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1055	opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1056
1057	switch (reject->reason) {
1058	case ISCSI_REASON_DATA_DIGEST_ERROR:
1059		iscsi_conn_printk(KERN_ERR, conn,
1060				  "pdu (op 0x%x itt 0x%x) rejected "
1061				  "due to DataDigest error.\n",
1062				  opcode, rejected_pdu.itt);
1063		break;
1064	case ISCSI_REASON_IMM_CMD_REJECT:
1065		iscsi_conn_printk(KERN_ERR, conn,
1066				  "pdu (op 0x%x itt 0x%x) rejected. Too many "
1067				  "immediate commands.\n",
1068				  opcode, rejected_pdu.itt);
1069		/*
1070		 * We only send one TMF at a time so if the target could not
1071		 * handle it, then it should get fixed (RFC mandates that
1072		 * a target can handle one immediate TMF per conn).
1073		 *
1074		 * For nops-outs, we could have sent more than one if
1075		 * the target is sending us lots of nop-ins
1076		 */
1077		if (opcode != ISCSI_OP_NOOP_OUT)
1078			return 0;
1079
1080		 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1081			/*
1082			 * nop-out in response to target's nop-out rejected.
1083			 * Just resend.
1084			 */
1085			/* In RX path we are under back lock */
1086			spin_unlock(&conn->session->back_lock);
1087			spin_lock(&conn->session->frwd_lock);
1088			iscsi_send_nopout(conn,
1089					  (struct iscsi_nopin*)&rejected_pdu);
1090			spin_unlock(&conn->session->frwd_lock);
1091			spin_lock(&conn->session->back_lock);
1092		} else {
1093			struct iscsi_task *task;
1094			/*
1095			 * Our nop as ping got dropped. We know the target
1096			 * and transport are ok so just clean up
1097			 */
1098			task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1099			if (!task) {
1100				iscsi_conn_printk(KERN_ERR, conn,
1101						 "Invalid pdu reject. Could "
1102						 "not lookup rejected task.\n");
1103				rc = ISCSI_ERR_BAD_ITT;
1104			} else
1105				rc = iscsi_nop_out_rsp(task,
1106					(struct iscsi_nopin*)&rejected_pdu,
1107					NULL, 0);
1108		}
1109		break;
1110	default:
1111		iscsi_conn_printk(KERN_ERR, conn,
1112				  "pdu (op 0x%x itt 0x%x) rejected. Reason "
1113				  "code 0x%x\n", rejected_pdu.opcode,
1114				  rejected_pdu.itt, reject->reason);
1115		break;
1116	}
1117	return rc;
1118}
1119
1120/**
1121 * iscsi_itt_to_task - look up task by itt
1122 * @conn: iscsi connection
1123 * @itt: itt
1124 *
1125 * This should be used for mgmt tasks like login and nops, or if
1126 * the LDD's itt space does not include the session age.
1127 *
1128 * The session back_lock must be held.
1129 */
1130struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1131{
1132	struct iscsi_session *session = conn->session;
1133	int i;
1134
1135	if (itt == RESERVED_ITT)
1136		return NULL;
1137
1138	if (session->tt->parse_pdu_itt)
1139		session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1140	else
1141		i = get_itt(itt);
1142	if (i >= session->cmds_max)
1143		return NULL;
1144
1145	return session->cmds[i];
1146}
1147EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1148
1149/**
1150 * __iscsi_complete_pdu - complete pdu
1151 * @conn: iscsi conn
1152 * @hdr: iscsi header
1153 * @data: data buffer
1154 * @datalen: len of data buffer
1155 *
1156 * Completes pdu processing by freeing any resources allocated at
1157 * queuecommand or send generic. session back_lock must be held and verify
1158 * itt must have been called.
1159 */
1160int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1161			 char *data, int datalen)
1162{
1163	struct iscsi_session *session = conn->session;
1164	int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1165	struct iscsi_task *task;
1166	uint32_t itt;
1167
1168	conn->last_recv = jiffies;
1169	rc = iscsi_verify_itt(conn, hdr->itt);
1170	if (rc)
1171		return rc;
1172
1173	if (hdr->itt != RESERVED_ITT)
1174		itt = get_itt(hdr->itt);
1175	else
1176		itt = ~0U;
1177
1178	ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1179			  opcode, conn->id, itt, datalen);
1180
1181	if (itt == ~0U) {
1182		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1183
1184		switch(opcode) {
1185		case ISCSI_OP_NOOP_IN:
1186			if (datalen) {
1187				rc = ISCSI_ERR_PROTO;
1188				break;
1189			}
1190
1191			if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1192				break;
1193
1194			/* In RX path we are under back lock */
1195			spin_unlock(&session->back_lock);
1196			spin_lock(&session->frwd_lock);
1197			iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1198			spin_unlock(&session->frwd_lock);
1199			spin_lock(&session->back_lock);
1200			break;
1201		case ISCSI_OP_REJECT:
1202			rc = iscsi_handle_reject(conn, hdr, data, datalen);
1203			break;
1204		case ISCSI_OP_ASYNC_EVENT:
1205			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1206			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1207				rc = ISCSI_ERR_CONN_FAILED;
1208			break;
1209		default:
1210			rc = ISCSI_ERR_BAD_OPCODE;
1211			break;
1212		}
1213		goto out;
1214	}
1215
1216	switch(opcode) {
1217	case ISCSI_OP_SCSI_CMD_RSP:
1218	case ISCSI_OP_SCSI_DATA_IN:
1219		task = iscsi_itt_to_ctask(conn, hdr->itt);
1220		if (!task)
1221			return ISCSI_ERR_BAD_ITT;
1222		task->last_xfer = jiffies;
1223		break;
1224	case ISCSI_OP_R2T:
1225		/*
1226		 * LLD handles R2Ts if they need to.
1227		 */
1228		return 0;
1229	case ISCSI_OP_LOGOUT_RSP:
1230	case ISCSI_OP_LOGIN_RSP:
1231	case ISCSI_OP_TEXT_RSP:
1232	case ISCSI_OP_SCSI_TMFUNC_RSP:
1233	case ISCSI_OP_NOOP_IN:
1234		task = iscsi_itt_to_task(conn, hdr->itt);
1235		if (!task)
1236			return ISCSI_ERR_BAD_ITT;
1237		break;
1238	default:
1239		return ISCSI_ERR_BAD_OPCODE;
1240	}
1241
1242	switch(opcode) {
1243	case ISCSI_OP_SCSI_CMD_RSP:
1244		iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1245		break;
1246	case ISCSI_OP_SCSI_DATA_IN:
1247		iscsi_data_in_rsp(conn, hdr, task);
1248		break;
1249	case ISCSI_OP_LOGOUT_RSP:
1250		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1251		if (datalen) {
1252			rc = ISCSI_ERR_PROTO;
1253			break;
1254		}
1255		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1256		goto recv_pdu;
1257	case ISCSI_OP_LOGIN_RSP:
1258	case ISCSI_OP_TEXT_RSP:
1259		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1260		/*
1261		 * login related PDU's exp_statsn is handled in
1262		 * userspace
1263		 */
1264		goto recv_pdu;
1265	case ISCSI_OP_SCSI_TMFUNC_RSP:
1266		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1267		if (datalen) {
1268			rc = ISCSI_ERR_PROTO;
1269			break;
1270		}
1271
1272		iscsi_tmf_rsp(conn, hdr);
1273		iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1274		break;
1275	case ISCSI_OP_NOOP_IN:
1276		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1277		if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1278			rc = ISCSI_ERR_PROTO;
1279			break;
1280		}
1281		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1282
1283		rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1284				       data, datalen);
1285		break;
1286	default:
1287		rc = ISCSI_ERR_BAD_OPCODE;
1288		break;
1289	}
1290
1291out:
1292	return rc;
1293recv_pdu:
1294	if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1295		rc = ISCSI_ERR_CONN_FAILED;
1296	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1297	return rc;
1298}
1299EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1300
1301int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1302		       char *data, int datalen)
1303{
1304	int rc;
1305
1306	spin_lock(&conn->session->back_lock);
1307	rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1308	spin_unlock(&conn->session->back_lock);
1309	return rc;
1310}
1311EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1312
1313int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1314{
1315	struct iscsi_session *session = conn->session;
1316	int age = 0, i = 0;
1317
1318	if (itt == RESERVED_ITT)
1319		return 0;
1320
1321	if (session->tt->parse_pdu_itt)
1322		session->tt->parse_pdu_itt(conn, itt, &i, &age);
1323	else {
1324		i = get_itt(itt);
1325		age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1326	}
1327
1328	if (age != session->age) {
1329		iscsi_conn_printk(KERN_ERR, conn,
1330				  "received itt %x expected session age (%x)\n",
1331				  (__force u32)itt, session->age);
1332		return ISCSI_ERR_BAD_ITT;
1333	}
1334
1335	if (i >= session->cmds_max) {
1336		iscsi_conn_printk(KERN_ERR, conn,
1337				  "received invalid itt index %u (max cmds "
1338				   "%u.\n", i, session->cmds_max);
1339		return ISCSI_ERR_BAD_ITT;
1340	}
1341	return 0;
1342}
1343EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1344
1345/**
1346 * iscsi_itt_to_ctask - look up ctask by itt
1347 * @conn: iscsi connection
1348 * @itt: itt
1349 *
1350 * This should be used for cmd tasks.
1351 *
1352 * The session back_lock must be held.
1353 */
1354struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1355{
1356	struct iscsi_task *task;
1357
1358	if (iscsi_verify_itt(conn, itt))
1359		return NULL;
1360
1361	task = iscsi_itt_to_task(conn, itt);
1362	if (!task || !task->sc)
1363		return NULL;
1364
1365	if (task->sc->SCp.phase != conn->session->age) {
1366		iscsi_session_printk(KERN_ERR, conn->session,
1367				  "task's session age %d, expected %d\n",
1368				  task->sc->SCp.phase, conn->session->age);
1369		return NULL;
1370	}
1371
1372	return task;
1373}
1374EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1375
1376void iscsi_session_failure(struct iscsi_session *session,
1377			   enum iscsi_err err)
1378{
1379	struct iscsi_conn *conn;
1380	struct device *dev;
1381
1382	spin_lock_bh(&session->frwd_lock);
1383	conn = session->leadconn;
1384	if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1385		spin_unlock_bh(&session->frwd_lock);
1386		return;
1387	}
1388
1389	dev = get_device(&conn->cls_conn->dev);
1390	spin_unlock_bh(&session->frwd_lock);
1391	if (!dev)
1392	        return;
1393	/*
1394	 * if the host is being removed bypass the connection
1395	 * recovery initialization because we are going to kill
1396	 * the session.
1397	 */
1398	if (err == ISCSI_ERR_INVALID_HOST)
1399		iscsi_conn_error_event(conn->cls_conn, err);
1400	else
1401		iscsi_conn_failure(conn, err);
1402	put_device(dev);
1403}
1404EXPORT_SYMBOL_GPL(iscsi_session_failure);
1405
1406void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1407{
1408	struct iscsi_session *session = conn->session;
1409
1410	spin_lock_bh(&session->frwd_lock);
1411	if (session->state == ISCSI_STATE_FAILED) {
1412		spin_unlock_bh(&session->frwd_lock);
1413		return;
1414	}
1415
1416	if (conn->stop_stage == 0)
1417		session->state = ISCSI_STATE_FAILED;
1418	spin_unlock_bh(&session->frwd_lock);
1419
1420	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1421	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1422	iscsi_conn_error_event(conn->cls_conn, err);
1423}
1424EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1425
1426static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1427{
1428	struct iscsi_session *session = conn->session;
1429
1430	/*
1431	 * Check for iSCSI window and take care of CmdSN wrap-around
1432	 */
1433	if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1434		ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1435				  "%u MaxCmdSN %u CmdSN %u/%u\n",
1436				  session->exp_cmdsn, session->max_cmdsn,
1437				  session->cmdsn, session->queued_cmdsn);
1438		return -ENOSPC;
1439	}
1440	return 0;
1441}
1442
1443static int iscsi_xmit_task(struct iscsi_conn *conn)
1444{
1445	struct iscsi_task *task = conn->task;
1446	int rc;
1447
1448	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1449		return -ENODATA;
1450
1451	__iscsi_get_task(task);
1452	spin_unlock_bh(&conn->session->frwd_lock);
1453	rc = conn->session->tt->xmit_task(task);
1454	spin_lock_bh(&conn->session->frwd_lock);
1455	if (!rc) {
1456		/* done with this task */
1457		task->last_xfer = jiffies;
1458		conn->task = NULL;
1459	}
1460	/* regular RX path uses back_lock */
1461	spin_lock(&conn->session->back_lock);
1462	__iscsi_put_task(task);
1463	spin_unlock(&conn->session->back_lock);
1464	return rc;
1465}
1466
1467/**
1468 * iscsi_requeue_task - requeue task to run from session workqueue
1469 * @task: task to requeue
1470 *
1471 * LLDs that need to run a task from the session workqueue should call
1472 * this. The session frwd_lock must be held. This should only be called
1473 * by software drivers.
1474 */
1475void iscsi_requeue_task(struct iscsi_task *task)
1476{
1477	struct iscsi_conn *conn = task->conn;
1478
1479	/*
1480	 * this may be on the requeue list already if the xmit_task callout
1481	 * is handling the r2ts while we are adding new ones
1482	 */
1483	spin_lock_bh(&conn->taskqueuelock);
1484	if (list_empty(&task->running))
1485		list_add_tail(&task->running, &conn->requeue);
1486	spin_unlock_bh(&conn->taskqueuelock);
1487	iscsi_conn_queue_work(conn);
1488}
1489EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1490
1491/**
1492 * iscsi_data_xmit - xmit any command into the scheduled connection
1493 * @conn: iscsi connection
1494 *
1495 * Notes:
1496 *	The function can return -EAGAIN in which case the caller must
1497 *	re-schedule it again later or recover. '0' return code means
1498 *	successful xmit.
1499 **/
1500static int iscsi_data_xmit(struct iscsi_conn *conn)
1501{
1502	struct iscsi_task *task;
1503	int rc = 0;
1504
1505	spin_lock_bh(&conn->session->frwd_lock);
1506	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1507		ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1508		spin_unlock_bh(&conn->session->frwd_lock);
1509		return -ENODATA;
1510	}
1511
1512	if (conn->task) {
1513		rc = iscsi_xmit_task(conn);
1514	        if (rc)
1515		        goto done;
1516	}
1517
1518	/*
1519	 * process mgmt pdus like nops before commands since we should
1520	 * only have one nop-out as a ping from us and targets should not
1521	 * overflow us with nop-ins
1522	 */
1523	spin_lock_bh(&conn->taskqueuelock);
1524check_mgmt:
1525	while (!list_empty(&conn->mgmtqueue)) {
1526		conn->task = list_entry(conn->mgmtqueue.next,
1527					 struct iscsi_task, running);
1528		list_del_init(&conn->task->running);
1529		spin_unlock_bh(&conn->taskqueuelock);
1530		if (iscsi_prep_mgmt_task(conn, conn->task)) {
1531			/* regular RX path uses back_lock */
1532			spin_lock_bh(&conn->session->back_lock);
1533			__iscsi_put_task(conn->task);
1534			spin_unlock_bh(&conn->session->back_lock);
1535			conn->task = NULL;
1536			spin_lock_bh(&conn->taskqueuelock);
1537			continue;
1538		}
1539		rc = iscsi_xmit_task(conn);
1540		if (rc)
1541			goto done;
1542		spin_lock_bh(&conn->taskqueuelock);
1543	}
1544
1545	/* process pending command queue */
1546	while (!list_empty(&conn->cmdqueue)) {
1547		conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1548					running);
1549		list_del_init(&conn->task->running);
1550		spin_unlock_bh(&conn->taskqueuelock);
1551		if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1552			fail_scsi_task(conn->task, DID_IMM_RETRY);
1553			spin_lock_bh(&conn->taskqueuelock);
1554			continue;
1555		}
1556		rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1557		if (rc) {
1558			if (rc == -ENOMEM || rc == -EACCES) {
1559				spin_lock_bh(&conn->taskqueuelock);
1560				list_add_tail(&conn->task->running,
1561					      &conn->cmdqueue);
1562				conn->task = NULL;
1563				spin_unlock_bh(&conn->taskqueuelock);
1564				goto done;
1565			} else
1566				fail_scsi_task(conn->task, DID_ABORT);
1567			spin_lock_bh(&conn->taskqueuelock);
1568			continue;
1569		}
1570		rc = iscsi_xmit_task(conn);
1571		if (rc)
1572			goto done;
1573		/*
1574		 * we could continuously get new task requests so
1575		 * we need to check the mgmt queue for nops that need to
1576		 * be sent to aviod starvation
1577		 */
1578		spin_lock_bh(&conn->taskqueuelock);
1579		if (!list_empty(&conn->mgmtqueue))
1580			goto check_mgmt;
1581	}
1582
1583	while (!list_empty(&conn->requeue)) {
1584		/*
1585		 * we always do fastlogout - conn stop code will clean up.
1586		 */
1587		if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1588			break;
1589
1590		task = list_entry(conn->requeue.next, struct iscsi_task,
1591				  running);
1592		if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1593			break;
1594
1595		conn->task = task;
1596		list_del_init(&conn->task->running);
1597		conn->task->state = ISCSI_TASK_RUNNING;
1598		spin_unlock_bh(&conn->taskqueuelock);
1599		rc = iscsi_xmit_task(conn);
1600		if (rc)
1601			goto done;
1602		spin_lock_bh(&conn->taskqueuelock);
1603		if (!list_empty(&conn->mgmtqueue))
1604			goto check_mgmt;
1605	}
1606	spin_unlock_bh(&conn->taskqueuelock);
1607	spin_unlock_bh(&conn->session->frwd_lock);
1608	return -ENODATA;
1609
1610done:
1611	spin_unlock_bh(&conn->session->frwd_lock);
1612	return rc;
1613}
1614
1615static void iscsi_xmitworker(struct work_struct *work)
1616{
1617	struct iscsi_conn *conn =
1618		container_of(work, struct iscsi_conn, xmitwork);
1619	int rc;
1620	/*
1621	 * serialize Xmit worker on a per-connection basis.
1622	 */
1623	do {
1624		rc = iscsi_data_xmit(conn);
1625	} while (rc >= 0 || rc == -EAGAIN);
1626}
1627
1628static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1629						  struct scsi_cmnd *sc)
1630{
1631	struct iscsi_task *task;
1632
1633	if (!kfifo_out(&conn->session->cmdpool.queue,
1634			 (void *) &task, sizeof(void *)))
1635		return NULL;
1636
1637	sc->SCp.phase = conn->session->age;
1638	sc->SCp.ptr = (char *) task;
1639
1640	atomic_set(&task->refcount, 1);
1641	task->state = ISCSI_TASK_PENDING;
1642	task->conn = conn;
1643	task->sc = sc;
1644	task->have_checked_conn = false;
1645	task->last_timeout = jiffies;
1646	task->last_xfer = jiffies;
1647	task->protected = false;
1648	INIT_LIST_HEAD(&task->running);
1649	return task;
1650}
1651
1652enum {
1653	FAILURE_BAD_HOST = 1,
1654	FAILURE_SESSION_FAILED,
1655	FAILURE_SESSION_FREED,
1656	FAILURE_WINDOW_CLOSED,
1657	FAILURE_OOM,
1658	FAILURE_SESSION_TERMINATE,
1659	FAILURE_SESSION_IN_RECOVERY,
1660	FAILURE_SESSION_RECOVERY_TIMEOUT,
1661	FAILURE_SESSION_LOGGING_OUT,
1662	FAILURE_SESSION_NOT_READY,
1663};
1664
1665int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1666{
1667	struct iscsi_cls_session *cls_session;
1668	struct iscsi_host *ihost;
1669	int reason = 0;
1670	struct iscsi_session *session;
1671	struct iscsi_conn *conn;
1672	struct iscsi_task *task = NULL;
1673
1674	sc->result = 0;
1675	sc->SCp.ptr = NULL;
1676
1677	ihost = shost_priv(host);
1678
1679	cls_session = starget_to_session(scsi_target(sc->device));
1680	session = cls_session->dd_data;
1681	spin_lock_bh(&session->frwd_lock);
1682
1683	reason = iscsi_session_chkready(cls_session);
1684	if (reason) {
1685		sc->result = reason;
1686		goto fault;
1687	}
1688
1689	if (session->state != ISCSI_STATE_LOGGED_IN) {
1690		/*
1691		 * to handle the race between when we set the recovery state
1692		 * and block the session we requeue here (commands could
1693		 * be entering our queuecommand while a block is starting
1694		 * up because the block code is not locked)
1695		 */
1696		switch (session->state) {
1697		case ISCSI_STATE_FAILED:
1698		case ISCSI_STATE_IN_RECOVERY:
1699			reason = FAILURE_SESSION_IN_RECOVERY;
1700			sc->result = DID_IMM_RETRY << 16;
1701			break;
1702		case ISCSI_STATE_LOGGING_OUT:
1703			reason = FAILURE_SESSION_LOGGING_OUT;
1704			sc->result = DID_IMM_RETRY << 16;
1705			break;
1706		case ISCSI_STATE_RECOVERY_FAILED:
1707			reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1708			sc->result = DID_TRANSPORT_FAILFAST << 16;
1709			break;
1710		case ISCSI_STATE_TERMINATE:
1711			reason = FAILURE_SESSION_TERMINATE;
1712			sc->result = DID_NO_CONNECT << 16;
1713			break;
1714		default:
1715			reason = FAILURE_SESSION_FREED;
1716			sc->result = DID_NO_CONNECT << 16;
1717		}
1718		goto fault;
1719	}
1720
1721	conn = session->leadconn;
1722	if (!conn) {
1723		reason = FAILURE_SESSION_FREED;
1724		sc->result = DID_NO_CONNECT << 16;
1725		goto fault;
1726	}
1727
1728	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1729		reason = FAILURE_SESSION_IN_RECOVERY;
1730		sc->result = DID_REQUEUE;
1731		goto fault;
1732	}
1733
1734	if (iscsi_check_cmdsn_window_closed(conn)) {
1735		reason = FAILURE_WINDOW_CLOSED;
1736		goto reject;
1737	}
1738
1739	task = iscsi_alloc_task(conn, sc);
1740	if (!task) {
1741		reason = FAILURE_OOM;
1742		goto reject;
1743	}
1744
1745	if (!ihost->workq) {
1746		reason = iscsi_prep_scsi_cmd_pdu(task);
1747		if (reason) {
1748			if (reason == -ENOMEM ||  reason == -EACCES) {
1749				reason = FAILURE_OOM;
1750				goto prepd_reject;
1751			} else {
1752				sc->result = DID_ABORT << 16;
1753				goto prepd_fault;
1754			}
1755		}
1756		if (session->tt->xmit_task(task)) {
1757			session->cmdsn--;
1758			reason = FAILURE_SESSION_NOT_READY;
1759			goto prepd_reject;
1760		}
1761	} else {
1762		spin_lock_bh(&conn->taskqueuelock);
1763		list_add_tail(&task->running, &conn->cmdqueue);
1764		spin_unlock_bh(&conn->taskqueuelock);
1765		iscsi_conn_queue_work(conn);
1766	}
1767
1768	session->queued_cmdsn++;
1769	spin_unlock_bh(&session->frwd_lock);
1770	return 0;
1771
1772prepd_reject:
1773	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1774reject:
1775	spin_unlock_bh(&session->frwd_lock);
1776	ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1777			  sc->cmnd[0], reason);
1778	return SCSI_MLQUEUE_TARGET_BUSY;
1779
1780prepd_fault:
1781	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1782fault:
1783	spin_unlock_bh(&session->frwd_lock);
1784	ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1785			  sc->cmnd[0], reason);
1786	if (!scsi_bidi_cmnd(sc))
1787		scsi_set_resid(sc, scsi_bufflen(sc));
1788	else {
1789		scsi_out(sc)->resid = scsi_out(sc)->length;
1790		scsi_in(sc)->resid = scsi_in(sc)->length;
1791	}
1792	sc->scsi_done(sc);
1793	return 0;
1794}
1795EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1796
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1797int iscsi_target_alloc(struct scsi_target *starget)
1798{
1799	struct iscsi_cls_session *cls_session = starget_to_session(starget);
1800	struct iscsi_session *session = cls_session->dd_data;
1801
1802	starget->can_queue = session->scsi_cmds_max;
1803	return 0;
1804}
1805EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1806
1807static void iscsi_tmf_timedout(unsigned long data)
1808{
1809	struct iscsi_conn *conn = (struct iscsi_conn *)data;
1810	struct iscsi_session *session = conn->session;
1811
1812	spin_lock(&session->frwd_lock);
1813	if (conn->tmf_state == TMF_QUEUED) {
1814		conn->tmf_state = TMF_TIMEDOUT;
1815		ISCSI_DBG_EH(session, "tmf timedout\n");
1816		/* unblock eh_abort() */
1817		wake_up(&conn->ehwait);
1818	}
1819	spin_unlock(&session->frwd_lock);
1820}
1821
1822static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1823				   struct iscsi_tm *hdr, int age,
1824				   int timeout)
1825{
1826	struct iscsi_session *session = conn->session;
1827	struct iscsi_task *task;
1828
1829	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1830				      NULL, 0);
1831	if (!task) {
1832		spin_unlock_bh(&session->frwd_lock);
1833		iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1834		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1835		spin_lock_bh(&session->frwd_lock);
1836		return -EPERM;
1837	}
1838	conn->tmfcmd_pdus_cnt++;
1839	conn->tmf_timer.expires = timeout * HZ + jiffies;
1840	conn->tmf_timer.function = iscsi_tmf_timedout;
1841	conn->tmf_timer.data = (unsigned long)conn;
1842	add_timer(&conn->tmf_timer);
1843	ISCSI_DBG_EH(session, "tmf set timeout\n");
1844
1845	spin_unlock_bh(&session->frwd_lock);
1846	mutex_unlock(&session->eh_mutex);
1847
1848	/*
1849	 * block eh thread until:
1850	 *
1851	 * 1) tmf response
1852	 * 2) tmf timeout
1853	 * 3) session is terminated or restarted or userspace has
1854	 * given up on recovery
1855	 */
1856	wait_event_interruptible(conn->ehwait, age != session->age ||
1857				 session->state != ISCSI_STATE_LOGGED_IN ||
1858				 conn->tmf_state != TMF_QUEUED);
1859	if (signal_pending(current))
1860		flush_signals(current);
1861	del_timer_sync(&conn->tmf_timer);
1862
1863	mutex_lock(&session->eh_mutex);
1864	spin_lock_bh(&session->frwd_lock);
1865	/* if the session drops it will clean up the task */
1866	if (age != session->age ||
1867	    session->state != ISCSI_STATE_LOGGED_IN)
1868		return -ENOTCONN;
1869	return 0;
1870}
1871
1872/*
1873 * Fail commands. session lock held and recv side suspended and xmit
1874 * thread flushed
1875 */
1876static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
 
1877{
1878	struct iscsi_task *task;
1879	int i;
1880
1881	for (i = 0; i < conn->session->cmds_max; i++) {
1882		task = conn->session->cmds[i];
1883		if (!task->sc || task->state == ISCSI_TASK_FREE)
1884			continue;
1885
1886		if (lun != -1 && lun != task->sc->device->lun)
1887			continue;
1888
1889		ISCSI_DBG_SESSION(conn->session,
1890				  "failing sc %p itt 0x%x state %d\n",
1891				  task->sc, task->itt, task->state);
1892		fail_scsi_task(task, error);
1893	}
1894}
1895
1896/**
1897 * iscsi_suspend_queue - suspend iscsi_queuecommand
1898 * @conn: iscsi conn to stop queueing IO on
1899 *
1900 * This grabs the session frwd_lock to make sure no one is in
1901 * xmit_task/queuecommand, and then sets suspend to prevent
1902 * new commands from being queued. This only needs to be called
1903 * by offload drivers that need to sync a path like ep disconnect
1904 * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1905 * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1906 */
1907void iscsi_suspend_queue(struct iscsi_conn *conn)
1908{
1909	spin_lock_bh(&conn->session->frwd_lock);
1910	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1911	spin_unlock_bh(&conn->session->frwd_lock);
1912}
1913EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1914
1915/**
1916 * iscsi_suspend_tx - suspend iscsi_data_xmit
1917 * @conn: iscsi conn tp stop processing IO on.
1918 *
1919 * This function sets the suspend bit to prevent iscsi_data_xmit
1920 * from sending new IO, and if work is queued on the xmit thread
1921 * it will wait for it to be completed.
1922 */
1923void iscsi_suspend_tx(struct iscsi_conn *conn)
1924{
1925	struct Scsi_Host *shost = conn->session->host;
1926	struct iscsi_host *ihost = shost_priv(shost);
1927
1928	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1929	if (ihost->workq)
1930		flush_workqueue(ihost->workq);
1931}
1932EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1933
1934static void iscsi_start_tx(struct iscsi_conn *conn)
1935{
1936	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1937	iscsi_conn_queue_work(conn);
1938}
1939
1940/*
1941 * We want to make sure a ping is in flight. It has timed out.
1942 * And we are not busy processing a pdu that is making
1943 * progress but got started before the ping and is taking a while
1944 * to complete so the ping is just stuck behind it in a queue.
1945 */
1946static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1947{
1948	if (conn->ping_task &&
1949	    time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1950			   (conn->ping_timeout * HZ), jiffies))
1951		return 1;
1952	else
1953		return 0;
1954}
1955
1956static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1957{
1958	enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1959	struct iscsi_task *task = NULL, *running_task;
1960	struct iscsi_cls_session *cls_session;
1961	struct iscsi_session *session;
1962	struct iscsi_conn *conn;
1963	int i;
1964
1965	cls_session = starget_to_session(scsi_target(sc->device));
1966	session = cls_session->dd_data;
1967
1968	ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1969
1970	spin_lock(&session->frwd_lock);
1971	task = (struct iscsi_task *)sc->SCp.ptr;
1972	if (!task) {
1973		/*
1974		 * Raced with completion. Blk layer has taken ownership
1975		 * so let timeout code complete it now.
1976		 */
1977		rc = BLK_EH_HANDLED;
1978		goto done;
1979	}
1980
1981	if (session->state != ISCSI_STATE_LOGGED_IN) {
1982		/*
1983		 * We are probably in the middle of iscsi recovery so let
1984		 * that complete and handle the error.
1985		 */
1986		rc = BLK_EH_RESET_TIMER;
1987		goto done;
1988	}
1989
1990	conn = session->leadconn;
1991	if (!conn) {
1992		/* In the middle of shuting down */
1993		rc = BLK_EH_RESET_TIMER;
1994		goto done;
1995	}
1996
1997	/*
1998	 * If we have sent (at least queued to the network layer) a pdu or
1999	 * recvd one for the task since the last timeout ask for
2000	 * more time. If on the next timeout we have not made progress
2001	 * we can check if it is the task or connection when we send the
2002	 * nop as a ping.
2003	 */
2004	if (time_after(task->last_xfer, task->last_timeout)) {
2005		ISCSI_DBG_EH(session, "Command making progress. Asking "
2006			     "scsi-ml for more time to complete. "
2007			     "Last data xfer at %lu. Last timeout was at "
2008			     "%lu\n.", task->last_xfer, task->last_timeout);
2009		task->have_checked_conn = false;
2010		rc = BLK_EH_RESET_TIMER;
2011		goto done;
2012	}
2013
2014	if (!conn->recv_timeout && !conn->ping_timeout)
2015		goto done;
2016	/*
2017	 * if the ping timedout then we are in the middle of cleaning up
2018	 * and can let the iscsi eh handle it
2019	 */
2020	if (iscsi_has_ping_timed_out(conn)) {
2021		rc = BLK_EH_RESET_TIMER;
2022		goto done;
2023	}
2024
2025	for (i = 0; i < conn->session->cmds_max; i++) {
2026		running_task = conn->session->cmds[i];
2027		if (!running_task->sc || running_task == task ||
2028		     running_task->state != ISCSI_TASK_RUNNING)
2029			continue;
2030
2031		/*
2032		 * Only check if cmds started before this one have made
2033		 * progress, or this could never fail
2034		 */
2035		if (time_after(running_task->sc->jiffies_at_alloc,
2036			       task->sc->jiffies_at_alloc))
2037			continue;
2038
2039		if (time_after(running_task->last_xfer, task->last_timeout)) {
2040			/*
2041			 * This task has not made progress, but a task
2042			 * started before us has transferred data since
2043			 * we started/last-checked. We could be queueing
2044			 * too many tasks or the LU is bad.
2045			 *
2046			 * If the device is bad the cmds ahead of us on
2047			 * other devs will complete, and this loop will
2048			 * eventually fail starting the scsi eh.
2049			 */
2050			ISCSI_DBG_EH(session, "Command has not made progress "
2051				     "but commands ahead of it have. "
2052				     "Asking scsi-ml for more time to "
2053				     "complete. Our last xfer vs running task "
2054				     "last xfer %lu/%lu. Last check %lu.\n",
2055				     task->last_xfer, running_task->last_xfer,
2056				     task->last_timeout);
2057			rc = BLK_EH_RESET_TIMER;
2058			goto done;
2059		}
2060	}
2061
2062	/* Assumes nop timeout is shorter than scsi cmd timeout */
2063	if (task->have_checked_conn)
2064		goto done;
2065
2066	/*
2067	 * Checking the transport already or nop from a cmd timeout still
2068	 * running
2069	 */
2070	if (conn->ping_task) {
2071		task->have_checked_conn = true;
2072		rc = BLK_EH_RESET_TIMER;
2073		goto done;
2074	}
2075
2076	/* Make sure there is a transport check done */
2077	iscsi_send_nopout(conn, NULL);
2078	task->have_checked_conn = true;
2079	rc = BLK_EH_RESET_TIMER;
2080
2081done:
2082	if (task)
2083		task->last_timeout = jiffies;
2084	spin_unlock(&session->frwd_lock);
2085	ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2086		     "timer reset" : "nh");
2087	return rc;
2088}
2089
2090static void iscsi_check_transport_timeouts(unsigned long data)
2091{
2092	struct iscsi_conn *conn = (struct iscsi_conn *)data;
2093	struct iscsi_session *session = conn->session;
2094	unsigned long recv_timeout, next_timeout = 0, last_recv;
2095
2096	spin_lock(&session->frwd_lock);
2097	if (session->state != ISCSI_STATE_LOGGED_IN)
2098		goto done;
2099
2100	recv_timeout = conn->recv_timeout;
2101	if (!recv_timeout)
2102		goto done;
2103
2104	recv_timeout *= HZ;
2105	last_recv = conn->last_recv;
2106
2107	if (iscsi_has_ping_timed_out(conn)) {
2108		iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2109				  "expired, recv timeout %d, last rx %lu, "
2110				  "last ping %lu, now %lu\n",
2111				  conn->ping_timeout, conn->recv_timeout,
2112				  last_recv, conn->last_ping, jiffies);
2113		spin_unlock(&session->frwd_lock);
2114		iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2115		return;
2116	}
2117
2118	if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2119		/* send a ping to try to provoke some traffic */
2120		ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2121		if (iscsi_send_nopout(conn, NULL))
2122			next_timeout = jiffies + (1 * HZ);
2123		else
2124			next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2125	} else
2126		next_timeout = last_recv + recv_timeout;
2127
2128	ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2129	mod_timer(&conn->transport_timer, next_timeout);
2130done:
2131	spin_unlock(&session->frwd_lock);
2132}
2133
2134static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2135				      struct iscsi_tm *hdr)
2136{
2137	memset(hdr, 0, sizeof(*hdr));
2138	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2139	hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2140	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2141	hdr->lun = task->lun;
2142	hdr->rtt = task->hdr_itt;
2143	hdr->refcmdsn = task->cmdsn;
2144}
2145
2146int iscsi_eh_abort(struct scsi_cmnd *sc)
2147{
2148	struct iscsi_cls_session *cls_session;
2149	struct iscsi_session *session;
2150	struct iscsi_conn *conn;
2151	struct iscsi_task *task;
2152	struct iscsi_tm *hdr;
2153	int age;
2154
2155	cls_session = starget_to_session(scsi_target(sc->device));
2156	session = cls_session->dd_data;
2157
2158	ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2159
2160	mutex_lock(&session->eh_mutex);
2161	spin_lock_bh(&session->frwd_lock);
2162	/*
2163	 * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2164	 * got the command.
2165	 */
2166	if (!sc->SCp.ptr) {
2167		ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2168				      "it completed.\n");
2169		spin_unlock_bh(&session->frwd_lock);
2170		mutex_unlock(&session->eh_mutex);
2171		return SUCCESS;
2172	}
2173
2174	/*
2175	 * If we are not logged in or we have started a new session
2176	 * then let the host reset code handle this
2177	 */
2178	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2179	    sc->SCp.phase != session->age) {
2180		spin_unlock_bh(&session->frwd_lock);
2181		mutex_unlock(&session->eh_mutex);
2182		ISCSI_DBG_EH(session, "failing abort due to dropped "
2183				  "session.\n");
2184		return FAILED;
2185	}
2186
2187	conn = session->leadconn;
2188	conn->eh_abort_cnt++;
2189	age = session->age;
2190
2191	task = (struct iscsi_task *)sc->SCp.ptr;
2192	ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2193		     sc, task->itt);
2194
2195	/* task completed before time out */
2196	if (!task->sc) {
2197		ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2198		goto success;
2199	}
2200
2201	if (task->state == ISCSI_TASK_PENDING) {
2202		fail_scsi_task(task, DID_ABORT);
2203		goto success;
2204	}
2205
2206	/* only have one tmf outstanding at a time */
2207	if (conn->tmf_state != TMF_INITIAL)
2208		goto failed;
2209	conn->tmf_state = TMF_QUEUED;
2210
2211	hdr = &conn->tmhdr;
2212	iscsi_prep_abort_task_pdu(task, hdr);
2213
2214	if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
 
2215		goto failed;
 
2216
2217	switch (conn->tmf_state) {
2218	case TMF_SUCCESS:
2219		spin_unlock_bh(&session->frwd_lock);
2220		/*
2221		 * stop tx side incase the target had sent a abort rsp but
2222		 * the initiator was still writing out data.
2223		 */
2224		iscsi_suspend_tx(conn);
2225		/*
2226		 * we do not stop the recv side because targets have been
2227		 * good and have never sent us a successful tmf response
2228		 * then sent more data for the cmd.
2229		 */
2230		spin_lock_bh(&session->frwd_lock);
2231		fail_scsi_task(task, DID_ABORT);
2232		conn->tmf_state = TMF_INITIAL;
2233		memset(hdr, 0, sizeof(*hdr));
2234		spin_unlock_bh(&session->frwd_lock);
2235		iscsi_start_tx(conn);
2236		goto success_unlocked;
2237	case TMF_TIMEDOUT:
2238		spin_unlock_bh(&session->frwd_lock);
2239		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2240		goto failed_unlocked;
2241	case TMF_NOT_FOUND:
2242		if (!sc->SCp.ptr) {
2243			conn->tmf_state = TMF_INITIAL;
2244			memset(hdr, 0, sizeof(*hdr));
2245			/* task completed before tmf abort response */
2246			ISCSI_DBG_EH(session, "sc completed while abort	in "
2247					      "progress\n");
2248			goto success;
2249		}
2250		/* fall through */
2251	default:
2252		conn->tmf_state = TMF_INITIAL;
2253		goto failed;
2254	}
2255
2256success:
2257	spin_unlock_bh(&session->frwd_lock);
2258success_unlocked:
2259	ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2260		     sc, task->itt);
2261	mutex_unlock(&session->eh_mutex);
2262	return SUCCESS;
2263
2264failed:
2265	spin_unlock_bh(&session->frwd_lock);
2266failed_unlocked:
2267	ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2268		     task ? task->itt : 0);
2269	mutex_unlock(&session->eh_mutex);
2270	return FAILED;
2271}
2272EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2273
2274static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2275{
2276	memset(hdr, 0, sizeof(*hdr));
2277	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2278	hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2279	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2280	int_to_scsilun(sc->device->lun, &hdr->lun);
2281	hdr->rtt = RESERVED_ITT;
2282}
2283
2284int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2285{
2286	struct iscsi_cls_session *cls_session;
2287	struct iscsi_session *session;
2288	struct iscsi_conn *conn;
2289	struct iscsi_tm *hdr;
2290	int rc = FAILED;
2291
2292	cls_session = starget_to_session(scsi_target(sc->device));
2293	session = cls_session->dd_data;
2294
2295	ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2296		     sc->device->lun);
2297
2298	mutex_lock(&session->eh_mutex);
2299	spin_lock_bh(&session->frwd_lock);
2300	/*
2301	 * Just check if we are not logged in. We cannot check for
2302	 * the phase because the reset could come from a ioctl.
2303	 */
2304	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2305		goto unlock;
2306	conn = session->leadconn;
2307
2308	/* only have one tmf outstanding at a time */
2309	if (conn->tmf_state != TMF_INITIAL)
2310		goto unlock;
2311	conn->tmf_state = TMF_QUEUED;
2312
2313	hdr = &conn->tmhdr;
2314	iscsi_prep_lun_reset_pdu(sc, hdr);
2315
2316	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2317				    session->lu_reset_timeout)) {
2318		rc = FAILED;
2319		goto unlock;
2320	}
2321
2322	switch (conn->tmf_state) {
2323	case TMF_SUCCESS:
2324		break;
2325	case TMF_TIMEDOUT:
2326		spin_unlock_bh(&session->frwd_lock);
2327		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2328		goto done;
2329	default:
2330		conn->tmf_state = TMF_INITIAL;
2331		goto unlock;
2332	}
2333
2334	rc = SUCCESS;
2335	spin_unlock_bh(&session->frwd_lock);
2336
2337	iscsi_suspend_tx(conn);
2338
2339	spin_lock_bh(&session->frwd_lock);
2340	memset(hdr, 0, sizeof(*hdr));
2341	fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2342	conn->tmf_state = TMF_INITIAL;
2343	spin_unlock_bh(&session->frwd_lock);
2344
2345	iscsi_start_tx(conn);
2346	goto done;
2347
2348unlock:
2349	spin_unlock_bh(&session->frwd_lock);
2350done:
2351	ISCSI_DBG_EH(session, "dev reset result = %s\n",
2352		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2353	mutex_unlock(&session->eh_mutex);
2354	return rc;
2355}
2356EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2357
2358void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2359{
2360	struct iscsi_session *session = cls_session->dd_data;
2361
2362	spin_lock_bh(&session->frwd_lock);
2363	if (session->state != ISCSI_STATE_LOGGED_IN) {
2364		session->state = ISCSI_STATE_RECOVERY_FAILED;
2365		if (session->leadconn)
2366			wake_up(&session->leadconn->ehwait);
2367	}
2368	spin_unlock_bh(&session->frwd_lock);
2369}
2370EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2371
2372/**
2373 * iscsi_eh_session_reset - drop session and attempt relogin
2374 * @sc: scsi command
2375 *
2376 * This function will wait for a relogin, session termination from
2377 * userspace, or a recovery/replacement timeout.
2378 */
2379int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2380{
2381	struct iscsi_cls_session *cls_session;
2382	struct iscsi_session *session;
2383	struct iscsi_conn *conn;
2384
2385	cls_session = starget_to_session(scsi_target(sc->device));
2386	session = cls_session->dd_data;
2387	conn = session->leadconn;
2388
2389	mutex_lock(&session->eh_mutex);
2390	spin_lock_bh(&session->frwd_lock);
2391	if (session->state == ISCSI_STATE_TERMINATE) {
2392failed:
2393		ISCSI_DBG_EH(session,
2394			     "failing session reset: Could not log back into "
2395			     "%s, %s [age %d]\n", session->targetname,
2396			     conn->persistent_address, session->age);
2397		spin_unlock_bh(&session->frwd_lock);
2398		mutex_unlock(&session->eh_mutex);
2399		return FAILED;
2400	}
2401
2402	spin_unlock_bh(&session->frwd_lock);
2403	mutex_unlock(&session->eh_mutex);
2404	/*
2405	 * we drop the lock here but the leadconn cannot be destoyed while
2406	 * we are in the scsi eh
2407	 */
2408	iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2409
2410	ISCSI_DBG_EH(session, "wait for relogin\n");
2411	wait_event_interruptible(conn->ehwait,
2412				 session->state == ISCSI_STATE_TERMINATE ||
2413				 session->state == ISCSI_STATE_LOGGED_IN ||
2414				 session->state == ISCSI_STATE_RECOVERY_FAILED);
2415	if (signal_pending(current))
2416		flush_signals(current);
2417
2418	mutex_lock(&session->eh_mutex);
2419	spin_lock_bh(&session->frwd_lock);
2420	if (session->state == ISCSI_STATE_LOGGED_IN) {
2421		ISCSI_DBG_EH(session,
2422			     "session reset succeeded for %s,%s\n",
2423			     session->targetname, conn->persistent_address);
2424	} else
2425		goto failed;
2426	spin_unlock_bh(&session->frwd_lock);
2427	mutex_unlock(&session->eh_mutex);
2428	return SUCCESS;
2429}
2430EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2431
2432static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2433{
2434	memset(hdr, 0, sizeof(*hdr));
2435	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2436	hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2437	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2438	hdr->rtt = RESERVED_ITT;
2439}
2440
2441/**
2442 * iscsi_eh_target_reset - reset target
2443 * @sc: scsi command
2444 *
2445 * This will attempt to send a warm target reset.
2446 */
2447static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2448{
2449	struct iscsi_cls_session *cls_session;
2450	struct iscsi_session *session;
2451	struct iscsi_conn *conn;
2452	struct iscsi_tm *hdr;
2453	int rc = FAILED;
2454
2455	cls_session = starget_to_session(scsi_target(sc->device));
2456	session = cls_session->dd_data;
2457
2458	ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2459		     session->targetname);
2460
2461	mutex_lock(&session->eh_mutex);
2462	spin_lock_bh(&session->frwd_lock);
2463	/*
2464	 * Just check if we are not logged in. We cannot check for
2465	 * the phase because the reset could come from a ioctl.
2466	 */
2467	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2468		goto unlock;
2469	conn = session->leadconn;
2470
2471	/* only have one tmf outstanding at a time */
2472	if (conn->tmf_state != TMF_INITIAL)
2473		goto unlock;
2474	conn->tmf_state = TMF_QUEUED;
2475
2476	hdr = &conn->tmhdr;
2477	iscsi_prep_tgt_reset_pdu(sc, hdr);
2478
2479	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2480				    session->tgt_reset_timeout)) {
2481		rc = FAILED;
2482		goto unlock;
2483	}
2484
2485	switch (conn->tmf_state) {
2486	case TMF_SUCCESS:
2487		break;
2488	case TMF_TIMEDOUT:
2489		spin_unlock_bh(&session->frwd_lock);
2490		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2491		goto done;
2492	default:
2493		conn->tmf_state = TMF_INITIAL;
2494		goto unlock;
2495	}
2496
2497	rc = SUCCESS;
2498	spin_unlock_bh(&session->frwd_lock);
2499
2500	iscsi_suspend_tx(conn);
2501
2502	spin_lock_bh(&session->frwd_lock);
2503	memset(hdr, 0, sizeof(*hdr));
2504	fail_scsi_tasks(conn, -1, DID_ERROR);
2505	conn->tmf_state = TMF_INITIAL;
2506	spin_unlock_bh(&session->frwd_lock);
2507
2508	iscsi_start_tx(conn);
2509	goto done;
2510
2511unlock:
2512	spin_unlock_bh(&session->frwd_lock);
2513done:
2514	ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2515		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2516	mutex_unlock(&session->eh_mutex);
2517	return rc;
2518}
 
2519
2520/**
2521 * iscsi_eh_recover_target - reset target and possibly the session
2522 * @sc: scsi command
2523 *
2524 * This will attempt to send a warm target reset. If that fails,
2525 * we will escalate to ERL0 session recovery.
2526 */
2527int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2528{
2529	int rc;
2530
2531	rc = iscsi_eh_target_reset(sc);
2532	if (rc == FAILED)
2533		rc = iscsi_eh_session_reset(sc);
2534	return rc;
2535}
2536EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2537
2538/*
2539 * Pre-allocate a pool of @max items of @item_size. By default, the pool
2540 * should be accessed via kfifo_{get,put} on q->queue.
2541 * Optionally, the caller can obtain the array of object pointers
2542 * by passing in a non-NULL @items pointer
2543 */
2544int
2545iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2546{
2547	int i, num_arrays = 1;
2548
2549	memset(q, 0, sizeof(*q));
2550
2551	q->max = max;
2552
2553	/* If the user passed an items pointer, he wants a copy of
2554	 * the array. */
2555	if (items)
2556		num_arrays++;
2557	q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2558	if (q->pool == NULL)
2559		return -ENOMEM;
2560
2561	kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2562
2563	for (i = 0; i < max; i++) {
2564		q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2565		if (q->pool[i] == NULL) {
2566			q->max = i;
2567			goto enomem;
2568		}
2569		kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2570	}
2571
2572	if (items) {
2573		*items = q->pool + max;
2574		memcpy(*items, q->pool, max * sizeof(void *));
2575	}
2576
2577	return 0;
2578
2579enomem:
2580	iscsi_pool_free(q);
2581	return -ENOMEM;
2582}
2583EXPORT_SYMBOL_GPL(iscsi_pool_init);
2584
2585void iscsi_pool_free(struct iscsi_pool *q)
2586{
2587	int i;
2588
2589	for (i = 0; i < q->max; i++)
2590		kfree(q->pool[i]);
2591	kfree(q->pool);
2592}
2593EXPORT_SYMBOL_GPL(iscsi_pool_free);
2594
2595/**
2596 * iscsi_host_add - add host to system
2597 * @shost: scsi host
2598 * @pdev: parent device
2599 *
2600 * This should be called by partial offload and software iscsi drivers
2601 * to add a host to the system.
2602 */
2603int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2604{
2605	if (!shost->can_queue)
2606		shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2607
2608	if (!shost->cmd_per_lun)
2609		shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2610
2611	if (!shost->transportt->eh_timed_out)
2612		shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2613	return scsi_add_host(shost, pdev);
2614}
2615EXPORT_SYMBOL_GPL(iscsi_host_add);
2616
2617/**
2618 * iscsi_host_alloc - allocate a host and driver data
2619 * @sht: scsi host template
2620 * @dd_data_size: driver host data size
2621 * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2622 *
2623 * This should be called by partial offload and software iscsi drivers.
2624 * To access the driver specific memory use the iscsi_host_priv() macro.
2625 */
2626struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2627				   int dd_data_size, bool xmit_can_sleep)
2628{
2629	struct Scsi_Host *shost;
2630	struct iscsi_host *ihost;
2631
2632	shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2633	if (!shost)
2634		return NULL;
2635	ihost = shost_priv(shost);
2636
2637	if (xmit_can_sleep) {
2638		snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2639			"iscsi_q_%d", shost->host_no);
2640		ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2641		if (!ihost->workq)
2642			goto free_host;
2643	}
2644
2645	spin_lock_init(&ihost->lock);
2646	ihost->state = ISCSI_HOST_SETUP;
2647	ihost->num_sessions = 0;
2648	init_waitqueue_head(&ihost->session_removal_wq);
2649	return shost;
2650
2651free_host:
2652	scsi_host_put(shost);
2653	return NULL;
2654}
2655EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2656
2657static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2658{
2659	iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2660}
2661
2662/**
2663 * iscsi_host_remove - remove host and sessions
2664 * @shost: scsi host
2665 *
2666 * If there are any sessions left, this will initiate the removal and wait
2667 * for the completion.
2668 */
2669void iscsi_host_remove(struct Scsi_Host *shost)
2670{
2671	struct iscsi_host *ihost = shost_priv(shost);
2672	unsigned long flags;
2673
2674	spin_lock_irqsave(&ihost->lock, flags);
2675	ihost->state = ISCSI_HOST_REMOVED;
2676	spin_unlock_irqrestore(&ihost->lock, flags);
2677
2678	iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2679	wait_event_interruptible(ihost->session_removal_wq,
2680				 ihost->num_sessions == 0);
2681	if (signal_pending(current))
2682		flush_signals(current);
2683
2684	scsi_remove_host(shost);
2685	if (ihost->workq)
2686		destroy_workqueue(ihost->workq);
2687}
2688EXPORT_SYMBOL_GPL(iscsi_host_remove);
2689
2690void iscsi_host_free(struct Scsi_Host *shost)
2691{
2692	struct iscsi_host *ihost = shost_priv(shost);
2693
2694	kfree(ihost->netdev);
2695	kfree(ihost->hwaddress);
2696	kfree(ihost->initiatorname);
2697	scsi_host_put(shost);
2698}
2699EXPORT_SYMBOL_GPL(iscsi_host_free);
2700
2701static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2702{
2703	struct iscsi_host *ihost = shost_priv(shost);
2704	unsigned long flags;
2705
2706	shost = scsi_host_get(shost);
2707	if (!shost) {
2708		printk(KERN_ERR "Invalid state. Cannot notify host removal "
2709		      "of session teardown event because host already "
2710		      "removed.\n");
2711		return;
2712	}
2713
2714	spin_lock_irqsave(&ihost->lock, flags);
2715	ihost->num_sessions--;
2716	if (ihost->num_sessions == 0)
2717		wake_up(&ihost->session_removal_wq);
2718	spin_unlock_irqrestore(&ihost->lock, flags);
2719	scsi_host_put(shost);
2720}
2721
2722/**
2723 * iscsi_session_setup - create iscsi cls session and host and session
2724 * @iscsit: iscsi transport template
2725 * @shost: scsi host
2726 * @cmds_max: session can queue
2727 * @cmd_task_size: LLD task private data size
2728 * @initial_cmdsn: initial CmdSN
2729 *
2730 * This can be used by software iscsi_transports that allocate
2731 * a session per scsi host.
2732 *
2733 * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2734 * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2735 * for nop handling and login/logout requests.
2736 */
2737struct iscsi_cls_session *
2738iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2739		    uint16_t cmds_max, int dd_size, int cmd_task_size,
2740		    uint32_t initial_cmdsn, unsigned int id)
2741{
2742	struct iscsi_host *ihost = shost_priv(shost);
2743	struct iscsi_session *session;
2744	struct iscsi_cls_session *cls_session;
2745	int cmd_i, scsi_cmds, total_cmds = cmds_max;
2746	unsigned long flags;
2747
2748	spin_lock_irqsave(&ihost->lock, flags);
2749	if (ihost->state == ISCSI_HOST_REMOVED) {
2750		spin_unlock_irqrestore(&ihost->lock, flags);
2751		return NULL;
2752	}
2753	ihost->num_sessions++;
2754	spin_unlock_irqrestore(&ihost->lock, flags);
2755
2756	if (!total_cmds)
2757		total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2758	/*
2759	 * The iscsi layer needs some tasks for nop handling and tmfs,
2760	 * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2761	 * + 1 command for scsi IO.
2762	 */
2763	if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2764		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2765		       "must be a power of two that is at least %d.\n",
2766		       total_cmds, ISCSI_TOTAL_CMDS_MIN);
2767		goto dec_session_count;
2768	}
2769
2770	if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2771		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2772		       "must be a power of 2 less than or equal to %d.\n",
2773		       cmds_max, ISCSI_TOTAL_CMDS_MAX);
2774		total_cmds = ISCSI_TOTAL_CMDS_MAX;
2775	}
2776
2777	if (!is_power_of_2(total_cmds)) {
2778		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2779		       "must be a power of 2.\n", total_cmds);
2780		total_cmds = rounddown_pow_of_two(total_cmds);
2781		if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2782			return NULL;
2783		printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2784		       total_cmds);
2785	}
2786	scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2787
2788	cls_session = iscsi_alloc_session(shost, iscsit,
2789					  sizeof(struct iscsi_session) +
2790					  dd_size);
2791	if (!cls_session)
2792		goto dec_session_count;
2793	session = cls_session->dd_data;
2794	session->cls_session = cls_session;
2795	session->host = shost;
2796	session->state = ISCSI_STATE_FREE;
2797	session->fast_abort = 1;
2798	session->tgt_reset_timeout = 30;
2799	session->lu_reset_timeout = 15;
2800	session->abort_timeout = 10;
2801	session->scsi_cmds_max = scsi_cmds;
2802	session->cmds_max = total_cmds;
2803	session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2804	session->exp_cmdsn = initial_cmdsn + 1;
2805	session->max_cmdsn = initial_cmdsn + 1;
2806	session->max_r2t = 1;
2807	session->tt = iscsit;
2808	session->dd_data = cls_session->dd_data + sizeof(*session);
2809
2810	mutex_init(&session->eh_mutex);
2811	spin_lock_init(&session->frwd_lock);
2812	spin_lock_init(&session->back_lock);
2813
2814	/* initialize SCSI PDU commands pool */
2815	if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2816			    (void***)&session->cmds,
2817			    cmd_task_size + sizeof(struct iscsi_task)))
2818		goto cmdpool_alloc_fail;
2819
2820	/* pre-format cmds pool with ITT */
2821	for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2822		struct iscsi_task *task = session->cmds[cmd_i];
2823
2824		if (cmd_task_size)
2825			task->dd_data = &task[1];
2826		task->itt = cmd_i;
2827		task->state = ISCSI_TASK_FREE;
2828		INIT_LIST_HEAD(&task->running);
2829	}
2830
2831	if (!try_module_get(iscsit->owner))
2832		goto module_get_fail;
2833
2834	if (iscsi_add_session(cls_session, id))
2835		goto cls_session_fail;
2836
2837	return cls_session;
2838
2839cls_session_fail:
2840	module_put(iscsit->owner);
2841module_get_fail:
2842	iscsi_pool_free(&session->cmdpool);
2843cmdpool_alloc_fail:
2844	iscsi_free_session(cls_session);
2845dec_session_count:
2846	iscsi_host_dec_session_cnt(shost);
2847	return NULL;
2848}
2849EXPORT_SYMBOL_GPL(iscsi_session_setup);
2850
2851/**
2852 * iscsi_session_teardown - destroy session, host, and cls_session
2853 * @cls_session: iscsi session
2854 *
2855 * The driver must have called iscsi_remove_session before
2856 * calling this.
2857 */
2858void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2859{
2860	struct iscsi_session *session = cls_session->dd_data;
2861	struct module *owner = cls_session->transport->owner;
2862	struct Scsi_Host *shost = session->host;
2863
2864	iscsi_pool_free(&session->cmdpool);
2865
2866	kfree(session->password);
2867	kfree(session->password_in);
2868	kfree(session->username);
2869	kfree(session->username_in);
2870	kfree(session->targetname);
2871	kfree(session->targetalias);
2872	kfree(session->initiatorname);
2873	kfree(session->boot_root);
2874	kfree(session->boot_nic);
2875	kfree(session->boot_target);
2876	kfree(session->ifacename);
2877	kfree(session->portal_type);
2878	kfree(session->discovery_parent_type);
2879
2880	iscsi_destroy_session(cls_session);
2881	iscsi_host_dec_session_cnt(shost);
2882	module_put(owner);
2883}
2884EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2885
2886/**
2887 * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2888 * @cls_session: iscsi_cls_session
2889 * @dd_size: private driver data size
2890 * @conn_idx: cid
2891 */
2892struct iscsi_cls_conn *
2893iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2894		 uint32_t conn_idx)
2895{
2896	struct iscsi_session *session = cls_session->dd_data;
2897	struct iscsi_conn *conn;
2898	struct iscsi_cls_conn *cls_conn;
2899	char *data;
2900
2901	cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2902				     conn_idx);
2903	if (!cls_conn)
2904		return NULL;
2905	conn = cls_conn->dd_data;
2906	memset(conn, 0, sizeof(*conn) + dd_size);
2907
2908	conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2909	conn->session = session;
2910	conn->cls_conn = cls_conn;
2911	conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2912	conn->id = conn_idx;
2913	conn->exp_statsn = 0;
2914	conn->tmf_state = TMF_INITIAL;
2915
2916	init_timer(&conn->transport_timer);
2917	conn->transport_timer.data = (unsigned long)conn;
2918	conn->transport_timer.function = iscsi_check_transport_timeouts;
2919
2920	INIT_LIST_HEAD(&conn->mgmtqueue);
2921	INIT_LIST_HEAD(&conn->cmdqueue);
2922	INIT_LIST_HEAD(&conn->requeue);
2923	spin_lock_init(&conn->taskqueuelock);
2924	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2925
2926	/* allocate login_task used for the login/text sequences */
2927	spin_lock_bh(&session->frwd_lock);
2928	if (!kfifo_out(&session->cmdpool.queue,
2929                         (void*)&conn->login_task,
2930			 sizeof(void*))) {
2931		spin_unlock_bh(&session->frwd_lock);
2932		goto login_task_alloc_fail;
2933	}
2934	spin_unlock_bh(&session->frwd_lock);
2935
2936	data = (char *) __get_free_pages(GFP_KERNEL,
2937					 get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2938	if (!data)
2939		goto login_task_data_alloc_fail;
2940	conn->login_task->data = conn->data = data;
2941
2942	init_timer(&conn->tmf_timer);
2943	init_waitqueue_head(&conn->ehwait);
2944
2945	return cls_conn;
2946
2947login_task_data_alloc_fail:
2948	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2949		    sizeof(void*));
2950login_task_alloc_fail:
2951	iscsi_destroy_conn(cls_conn);
2952	return NULL;
2953}
2954EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2955
2956/**
2957 * iscsi_conn_teardown - teardown iscsi connection
2958 * cls_conn: iscsi class connection
2959 *
2960 * TODO: we may need to make this into a two step process
2961 * like scsi-mls remove + put host
2962 */
2963void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2964{
2965	struct iscsi_conn *conn = cls_conn->dd_data;
2966	struct iscsi_session *session = conn->session;
 
2967
2968	del_timer_sync(&conn->transport_timer);
2969
2970	mutex_lock(&session->eh_mutex);
2971	spin_lock_bh(&session->frwd_lock);
2972	conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2973	if (session->leadconn == conn) {
2974		/*
2975		 * leading connection? then give up on recovery.
2976		 */
2977		session->state = ISCSI_STATE_TERMINATE;
2978		wake_up(&conn->ehwait);
2979	}
2980	spin_unlock_bh(&session->frwd_lock);
2981
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2982	/* flush queued up work because we free the connection below */
2983	iscsi_suspend_tx(conn);
2984
2985	spin_lock_bh(&session->frwd_lock);
2986	free_pages((unsigned long) conn->data,
2987		   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2988	kfree(conn->persistent_address);
2989	kfree(conn->local_ipaddr);
2990	/* regular RX path uses back_lock */
2991	spin_lock_bh(&session->back_lock);
2992	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2993		    sizeof(void*));
2994	spin_unlock_bh(&session->back_lock);
2995	if (session->leadconn == conn)
2996		session->leadconn = NULL;
2997	spin_unlock_bh(&session->frwd_lock);
2998	mutex_unlock(&session->eh_mutex);
2999
3000	iscsi_destroy_conn(cls_conn);
3001}
3002EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3003
3004int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3005{
3006	struct iscsi_conn *conn = cls_conn->dd_data;
3007	struct iscsi_session *session = conn->session;
3008
3009	if (!session) {
3010		iscsi_conn_printk(KERN_ERR, conn,
3011				  "can't start unbound connection\n");
3012		return -EPERM;
3013	}
3014
3015	if ((session->imm_data_en || !session->initial_r2t_en) &&
3016	     session->first_burst > session->max_burst) {
3017		iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3018				  "first_burst %d max_burst %d\n",
3019				  session->first_burst, session->max_burst);
3020		return -EINVAL;
3021	}
3022
3023	if (conn->ping_timeout && !conn->recv_timeout) {
3024		iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3025				  "zero. Using 5 seconds\n.");
3026		conn->recv_timeout = 5;
3027	}
3028
3029	if (conn->recv_timeout && !conn->ping_timeout) {
3030		iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3031				  "zero. Using 5 seconds.\n");
3032		conn->ping_timeout = 5;
3033	}
3034
3035	spin_lock_bh(&session->frwd_lock);
3036	conn->c_stage = ISCSI_CONN_STARTED;
3037	session->state = ISCSI_STATE_LOGGED_IN;
3038	session->queued_cmdsn = session->cmdsn;
3039
3040	conn->last_recv = jiffies;
3041	conn->last_ping = jiffies;
3042	if (conn->recv_timeout && conn->ping_timeout)
3043		mod_timer(&conn->transport_timer,
3044			  jiffies + (conn->recv_timeout * HZ));
3045
3046	switch(conn->stop_stage) {
3047	case STOP_CONN_RECOVER:
3048		/*
3049		 * unblock eh_abort() if it is blocked. re-try all
3050		 * commands after successful recovery
3051		 */
3052		conn->stop_stage = 0;
3053		conn->tmf_state = TMF_INITIAL;
3054		session->age++;
3055		if (session->age == 16)
3056			session->age = 0;
3057		break;
3058	case STOP_CONN_TERM:
3059		conn->stop_stage = 0;
3060		break;
3061	default:
3062		break;
3063	}
3064	spin_unlock_bh(&session->frwd_lock);
3065
3066	iscsi_unblock_session(session->cls_session);
3067	wake_up(&conn->ehwait);
3068	return 0;
3069}
3070EXPORT_SYMBOL_GPL(iscsi_conn_start);
3071
3072static void
3073fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3074{
3075	struct iscsi_task *task;
3076	int i, state;
3077
3078	for (i = 0; i < conn->session->cmds_max; i++) {
3079		task = conn->session->cmds[i];
3080		if (task->sc)
3081			continue;
3082
3083		if (task->state == ISCSI_TASK_FREE)
3084			continue;
3085
3086		ISCSI_DBG_SESSION(conn->session,
3087				  "failing mgmt itt 0x%x state %d\n",
3088				  task->itt, task->state);
3089		state = ISCSI_TASK_ABRT_SESS_RECOV;
3090		if (task->state == ISCSI_TASK_PENDING)
3091			state = ISCSI_TASK_COMPLETED;
3092		iscsi_complete_task(task, state);
3093
3094	}
3095}
3096
3097static void iscsi_start_session_recovery(struct iscsi_session *session,
3098					 struct iscsi_conn *conn, int flag)
3099{
3100	int old_stop_stage;
3101
3102	mutex_lock(&session->eh_mutex);
3103	spin_lock_bh(&session->frwd_lock);
3104	if (conn->stop_stage == STOP_CONN_TERM) {
3105		spin_unlock_bh(&session->frwd_lock);
3106		mutex_unlock(&session->eh_mutex);
3107		return;
3108	}
3109
3110	/*
3111	 * When this is called for the in_login state, we only want to clean
3112	 * up the login task and connection. We do not need to block and set
3113	 * the recovery state again
3114	 */
3115	if (flag == STOP_CONN_TERM)
3116		session->state = ISCSI_STATE_TERMINATE;
3117	else if (conn->stop_stage != STOP_CONN_RECOVER)
3118		session->state = ISCSI_STATE_IN_RECOVERY;
3119
3120	old_stop_stage = conn->stop_stage;
3121	conn->stop_stage = flag;
3122	spin_unlock_bh(&session->frwd_lock);
3123
3124	del_timer_sync(&conn->transport_timer);
3125	iscsi_suspend_tx(conn);
3126
3127	spin_lock_bh(&session->frwd_lock);
3128	conn->c_stage = ISCSI_CONN_STOPPED;
3129	spin_unlock_bh(&session->frwd_lock);
3130
3131	/*
3132	 * for connection level recovery we should not calculate
3133	 * header digest. conn->hdr_size used for optimization
3134	 * in hdr_extract() and will be re-negotiated at
3135	 * set_param() time.
3136	 */
3137	if (flag == STOP_CONN_RECOVER) {
3138		conn->hdrdgst_en = 0;
3139		conn->datadgst_en = 0;
3140		if (session->state == ISCSI_STATE_IN_RECOVERY &&
3141		    old_stop_stage != STOP_CONN_RECOVER) {
3142			ISCSI_DBG_SESSION(session, "blocking session\n");
3143			iscsi_block_session(session->cls_session);
3144		}
3145	}
3146
3147	/*
3148	 * flush queues.
3149	 */
3150	spin_lock_bh(&session->frwd_lock);
3151	fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3152	fail_mgmt_tasks(session, conn);
3153	memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3154	spin_unlock_bh(&session->frwd_lock);
3155	mutex_unlock(&session->eh_mutex);
3156}
3157
3158void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3159{
3160	struct iscsi_conn *conn = cls_conn->dd_data;
3161	struct iscsi_session *session = conn->session;
3162
3163	switch (flag) {
3164	case STOP_CONN_RECOVER:
3165	case STOP_CONN_TERM:
3166		iscsi_start_session_recovery(session, conn, flag);
3167		break;
3168	default:
3169		iscsi_conn_printk(KERN_ERR, conn,
3170				  "invalid stop flag %d\n", flag);
3171	}
3172}
3173EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3174
3175int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3176		    struct iscsi_cls_conn *cls_conn, int is_leading)
3177{
3178	struct iscsi_session *session = cls_session->dd_data;
3179	struct iscsi_conn *conn = cls_conn->dd_data;
3180
3181	spin_lock_bh(&session->frwd_lock);
3182	if (is_leading)
3183		session->leadconn = conn;
3184	spin_unlock_bh(&session->frwd_lock);
3185
3186	/*
3187	 * Unblock xmitworker(), Login Phase will pass through.
3188	 */
3189	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3190	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3191	return 0;
3192}
3193EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3194
3195int iscsi_switch_str_param(char **param, char *new_val_buf)
3196{
3197	char *new_val;
3198
3199	if (*param) {
3200		if (!strcmp(*param, new_val_buf))
3201			return 0;
3202	}
3203
3204	new_val = kstrdup(new_val_buf, GFP_NOIO);
3205	if (!new_val)
3206		return -ENOMEM;
3207
3208	kfree(*param);
3209	*param = new_val;
3210	return 0;
3211}
3212EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3213
3214int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3215		    enum iscsi_param param, char *buf, int buflen)
3216{
3217	struct iscsi_conn *conn = cls_conn->dd_data;
3218	struct iscsi_session *session = conn->session;
3219	int val;
3220
3221	switch(param) {
3222	case ISCSI_PARAM_FAST_ABORT:
3223		sscanf(buf, "%d", &session->fast_abort);
3224		break;
3225	case ISCSI_PARAM_ABORT_TMO:
3226		sscanf(buf, "%d", &session->abort_timeout);
3227		break;
3228	case ISCSI_PARAM_LU_RESET_TMO:
3229		sscanf(buf, "%d", &session->lu_reset_timeout);
3230		break;
3231	case ISCSI_PARAM_TGT_RESET_TMO:
3232		sscanf(buf, "%d", &session->tgt_reset_timeout);
3233		break;
3234	case ISCSI_PARAM_PING_TMO:
3235		sscanf(buf, "%d", &conn->ping_timeout);
3236		break;
3237	case ISCSI_PARAM_RECV_TMO:
3238		sscanf(buf, "%d", &conn->recv_timeout);
3239		break;
3240	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3241		sscanf(buf, "%d", &conn->max_recv_dlength);
3242		break;
3243	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3244		sscanf(buf, "%d", &conn->max_xmit_dlength);
3245		break;
3246	case ISCSI_PARAM_HDRDGST_EN:
3247		sscanf(buf, "%d", &conn->hdrdgst_en);
3248		break;
3249	case ISCSI_PARAM_DATADGST_EN:
3250		sscanf(buf, "%d", &conn->datadgst_en);
3251		break;
3252	case ISCSI_PARAM_INITIAL_R2T_EN:
3253		sscanf(buf, "%d", &session->initial_r2t_en);
3254		break;
3255	case ISCSI_PARAM_MAX_R2T:
3256		sscanf(buf, "%hu", &session->max_r2t);
3257		break;
3258	case ISCSI_PARAM_IMM_DATA_EN:
3259		sscanf(buf, "%d", &session->imm_data_en);
3260		break;
3261	case ISCSI_PARAM_FIRST_BURST:
3262		sscanf(buf, "%d", &session->first_burst);
3263		break;
3264	case ISCSI_PARAM_MAX_BURST:
3265		sscanf(buf, "%d", &session->max_burst);
3266		break;
3267	case ISCSI_PARAM_PDU_INORDER_EN:
3268		sscanf(buf, "%d", &session->pdu_inorder_en);
3269		break;
3270	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3271		sscanf(buf, "%d", &session->dataseq_inorder_en);
3272		break;
3273	case ISCSI_PARAM_ERL:
3274		sscanf(buf, "%d", &session->erl);
3275		break;
3276	case ISCSI_PARAM_EXP_STATSN:
3277		sscanf(buf, "%u", &conn->exp_statsn);
3278		break;
3279	case ISCSI_PARAM_USERNAME:
3280		return iscsi_switch_str_param(&session->username, buf);
3281	case ISCSI_PARAM_USERNAME_IN:
3282		return iscsi_switch_str_param(&session->username_in, buf);
3283	case ISCSI_PARAM_PASSWORD:
3284		return iscsi_switch_str_param(&session->password, buf);
3285	case ISCSI_PARAM_PASSWORD_IN:
3286		return iscsi_switch_str_param(&session->password_in, buf);
3287	case ISCSI_PARAM_TARGET_NAME:
3288		return iscsi_switch_str_param(&session->targetname, buf);
3289	case ISCSI_PARAM_TARGET_ALIAS:
3290		return iscsi_switch_str_param(&session->targetalias, buf);
3291	case ISCSI_PARAM_TPGT:
3292		sscanf(buf, "%d", &session->tpgt);
3293		break;
3294	case ISCSI_PARAM_PERSISTENT_PORT:
3295		sscanf(buf, "%d", &conn->persistent_port);
3296		break;
3297	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3298		return iscsi_switch_str_param(&conn->persistent_address, buf);
3299	case ISCSI_PARAM_IFACE_NAME:
3300		return iscsi_switch_str_param(&session->ifacename, buf);
3301	case ISCSI_PARAM_INITIATOR_NAME:
3302		return iscsi_switch_str_param(&session->initiatorname, buf);
3303	case ISCSI_PARAM_BOOT_ROOT:
3304		return iscsi_switch_str_param(&session->boot_root, buf);
3305	case ISCSI_PARAM_BOOT_NIC:
3306		return iscsi_switch_str_param(&session->boot_nic, buf);
3307	case ISCSI_PARAM_BOOT_TARGET:
3308		return iscsi_switch_str_param(&session->boot_target, buf);
3309	case ISCSI_PARAM_PORTAL_TYPE:
3310		return iscsi_switch_str_param(&session->portal_type, buf);
3311	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3312		return iscsi_switch_str_param(&session->discovery_parent_type,
3313					      buf);
3314	case ISCSI_PARAM_DISCOVERY_SESS:
3315		sscanf(buf, "%d", &val);
3316		session->discovery_sess = !!val;
3317		break;
3318	case ISCSI_PARAM_LOCAL_IPADDR:
3319		return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3320	default:
3321		return -ENOSYS;
3322	}
3323
3324	return 0;
3325}
3326EXPORT_SYMBOL_GPL(iscsi_set_param);
3327
3328int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3329			    enum iscsi_param param, char *buf)
3330{
3331	struct iscsi_session *session = cls_session->dd_data;
3332	int len;
3333
3334	switch(param) {
3335	case ISCSI_PARAM_FAST_ABORT:
3336		len = sprintf(buf, "%d\n", session->fast_abort);
3337		break;
3338	case ISCSI_PARAM_ABORT_TMO:
3339		len = sprintf(buf, "%d\n", session->abort_timeout);
3340		break;
3341	case ISCSI_PARAM_LU_RESET_TMO:
3342		len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3343		break;
3344	case ISCSI_PARAM_TGT_RESET_TMO:
3345		len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3346		break;
3347	case ISCSI_PARAM_INITIAL_R2T_EN:
3348		len = sprintf(buf, "%d\n", session->initial_r2t_en);
3349		break;
3350	case ISCSI_PARAM_MAX_R2T:
3351		len = sprintf(buf, "%hu\n", session->max_r2t);
3352		break;
3353	case ISCSI_PARAM_IMM_DATA_EN:
3354		len = sprintf(buf, "%d\n", session->imm_data_en);
3355		break;
3356	case ISCSI_PARAM_FIRST_BURST:
3357		len = sprintf(buf, "%u\n", session->first_burst);
3358		break;
3359	case ISCSI_PARAM_MAX_BURST:
3360		len = sprintf(buf, "%u\n", session->max_burst);
3361		break;
3362	case ISCSI_PARAM_PDU_INORDER_EN:
3363		len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3364		break;
3365	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3366		len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3367		break;
3368	case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3369		len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3370		break;
3371	case ISCSI_PARAM_ERL:
3372		len = sprintf(buf, "%d\n", session->erl);
3373		break;
3374	case ISCSI_PARAM_TARGET_NAME:
3375		len = sprintf(buf, "%s\n", session->targetname);
3376		break;
3377	case ISCSI_PARAM_TARGET_ALIAS:
3378		len = sprintf(buf, "%s\n", session->targetalias);
3379		break;
3380	case ISCSI_PARAM_TPGT:
3381		len = sprintf(buf, "%d\n", session->tpgt);
3382		break;
3383	case ISCSI_PARAM_USERNAME:
3384		len = sprintf(buf, "%s\n", session->username);
3385		break;
3386	case ISCSI_PARAM_USERNAME_IN:
3387		len = sprintf(buf, "%s\n", session->username_in);
3388		break;
3389	case ISCSI_PARAM_PASSWORD:
3390		len = sprintf(buf, "%s\n", session->password);
3391		break;
3392	case ISCSI_PARAM_PASSWORD_IN:
3393		len = sprintf(buf, "%s\n", session->password_in);
3394		break;
3395	case ISCSI_PARAM_IFACE_NAME:
3396		len = sprintf(buf, "%s\n", session->ifacename);
3397		break;
3398	case ISCSI_PARAM_INITIATOR_NAME:
3399		len = sprintf(buf, "%s\n", session->initiatorname);
3400		break;
3401	case ISCSI_PARAM_BOOT_ROOT:
3402		len = sprintf(buf, "%s\n", session->boot_root);
3403		break;
3404	case ISCSI_PARAM_BOOT_NIC:
3405		len = sprintf(buf, "%s\n", session->boot_nic);
3406		break;
3407	case ISCSI_PARAM_BOOT_TARGET:
3408		len = sprintf(buf, "%s\n", session->boot_target);
3409		break;
3410	case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3411		len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3412		break;
3413	case ISCSI_PARAM_DISCOVERY_SESS:
3414		len = sprintf(buf, "%u\n", session->discovery_sess);
3415		break;
3416	case ISCSI_PARAM_PORTAL_TYPE:
3417		len = sprintf(buf, "%s\n", session->portal_type);
3418		break;
3419	case ISCSI_PARAM_CHAP_AUTH_EN:
3420		len = sprintf(buf, "%u\n", session->chap_auth_en);
3421		break;
3422	case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3423		len = sprintf(buf, "%u\n", session->discovery_logout_en);
3424		break;
3425	case ISCSI_PARAM_BIDI_CHAP_EN:
3426		len = sprintf(buf, "%u\n", session->bidi_chap_en);
3427		break;
3428	case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3429		len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3430		break;
3431	case ISCSI_PARAM_DEF_TIME2WAIT:
3432		len = sprintf(buf, "%d\n", session->time2wait);
3433		break;
3434	case ISCSI_PARAM_DEF_TIME2RETAIN:
3435		len = sprintf(buf, "%d\n", session->time2retain);
3436		break;
3437	case ISCSI_PARAM_TSID:
3438		len = sprintf(buf, "%u\n", session->tsid);
3439		break;
3440	case ISCSI_PARAM_ISID:
3441		len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3442			      session->isid[0], session->isid[1],
3443			      session->isid[2], session->isid[3],
3444			      session->isid[4], session->isid[5]);
3445		break;
3446	case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3447		len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3448		break;
3449	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3450		if (session->discovery_parent_type)
3451			len = sprintf(buf, "%s\n",
3452				      session->discovery_parent_type);
3453		else
3454			len = sprintf(buf, "\n");
3455		break;
3456	default:
3457		return -ENOSYS;
3458	}
3459
3460	return len;
3461}
3462EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3463
3464int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3465			      enum iscsi_param param, char *buf)
3466{
3467	struct sockaddr_in6 *sin6 = NULL;
3468	struct sockaddr_in *sin = NULL;
3469	int len;
3470
3471	switch (addr->ss_family) {
3472	case AF_INET:
3473		sin = (struct sockaddr_in *)addr;
3474		break;
3475	case AF_INET6:
3476		sin6 = (struct sockaddr_in6 *)addr;
3477		break;
3478	default:
3479		return -EINVAL;
3480	}
3481
3482	switch (param) {
3483	case ISCSI_PARAM_CONN_ADDRESS:
3484	case ISCSI_HOST_PARAM_IPADDRESS:
3485		if (sin)
3486			len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3487		else
3488			len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3489		break;
3490	case ISCSI_PARAM_CONN_PORT:
3491	case ISCSI_PARAM_LOCAL_PORT:
3492		if (sin)
3493			len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3494		else
3495			len = sprintf(buf, "%hu\n",
3496				      be16_to_cpu(sin6->sin6_port));
3497		break;
3498	default:
3499		return -EINVAL;
3500	}
3501
3502	return len;
3503}
3504EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3505
3506int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3507			 enum iscsi_param param, char *buf)
3508{
3509	struct iscsi_conn *conn = cls_conn->dd_data;
3510	int len;
3511
3512	switch(param) {
3513	case ISCSI_PARAM_PING_TMO:
3514		len = sprintf(buf, "%u\n", conn->ping_timeout);
3515		break;
3516	case ISCSI_PARAM_RECV_TMO:
3517		len = sprintf(buf, "%u\n", conn->recv_timeout);
3518		break;
3519	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3520		len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3521		break;
3522	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3523		len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3524		break;
3525	case ISCSI_PARAM_HDRDGST_EN:
3526		len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3527		break;
3528	case ISCSI_PARAM_DATADGST_EN:
3529		len = sprintf(buf, "%d\n", conn->datadgst_en);
3530		break;
3531	case ISCSI_PARAM_IFMARKER_EN:
3532		len = sprintf(buf, "%d\n", conn->ifmarker_en);
3533		break;
3534	case ISCSI_PARAM_OFMARKER_EN:
3535		len = sprintf(buf, "%d\n", conn->ofmarker_en);
3536		break;
3537	case ISCSI_PARAM_EXP_STATSN:
3538		len = sprintf(buf, "%u\n", conn->exp_statsn);
3539		break;
3540	case ISCSI_PARAM_PERSISTENT_PORT:
3541		len = sprintf(buf, "%d\n", conn->persistent_port);
3542		break;
3543	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3544		len = sprintf(buf, "%s\n", conn->persistent_address);
3545		break;
3546	case ISCSI_PARAM_STATSN:
3547		len = sprintf(buf, "%u\n", conn->statsn);
3548		break;
3549	case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3550		len = sprintf(buf, "%u\n", conn->max_segment_size);
3551		break;
3552	case ISCSI_PARAM_KEEPALIVE_TMO:
3553		len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3554		break;
3555	case ISCSI_PARAM_LOCAL_PORT:
3556		len = sprintf(buf, "%u\n", conn->local_port);
3557		break;
3558	case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3559		len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3560		break;
3561	case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3562		len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3563		break;
3564	case ISCSI_PARAM_TCP_WSF_DISABLE:
3565		len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3566		break;
3567	case ISCSI_PARAM_TCP_TIMER_SCALE:
3568		len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3569		break;
3570	case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3571		len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3572		break;
3573	case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3574		len = sprintf(buf, "%u\n", conn->fragment_disable);
3575		break;
3576	case ISCSI_PARAM_IPV4_TOS:
3577		len = sprintf(buf, "%u\n", conn->ipv4_tos);
3578		break;
3579	case ISCSI_PARAM_IPV6_TC:
3580		len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3581		break;
3582	case ISCSI_PARAM_IPV6_FLOW_LABEL:
3583		len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3584		break;
3585	case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3586		len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3587		break;
3588	case ISCSI_PARAM_TCP_XMIT_WSF:
3589		len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3590		break;
3591	case ISCSI_PARAM_TCP_RECV_WSF:
3592		len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3593		break;
3594	case ISCSI_PARAM_LOCAL_IPADDR:
3595		len = sprintf(buf, "%s\n", conn->local_ipaddr);
3596		break;
3597	default:
3598		return -ENOSYS;
3599	}
3600
3601	return len;
3602}
3603EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3604
3605int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3606			 char *buf)
3607{
3608	struct iscsi_host *ihost = shost_priv(shost);
3609	int len;
3610
3611	switch (param) {
3612	case ISCSI_HOST_PARAM_NETDEV_NAME:
3613		len = sprintf(buf, "%s\n", ihost->netdev);
3614		break;
3615	case ISCSI_HOST_PARAM_HWADDRESS:
3616		len = sprintf(buf, "%s\n", ihost->hwaddress);
3617		break;
3618	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3619		len = sprintf(buf, "%s\n", ihost->initiatorname);
3620		break;
3621	default:
3622		return -ENOSYS;
3623	}
3624
3625	return len;
3626}
3627EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3628
3629int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3630			 char *buf, int buflen)
3631{
3632	struct iscsi_host *ihost = shost_priv(shost);
3633
3634	switch (param) {
3635	case ISCSI_HOST_PARAM_NETDEV_NAME:
3636		return iscsi_switch_str_param(&ihost->netdev, buf);
3637	case ISCSI_HOST_PARAM_HWADDRESS:
3638		return iscsi_switch_str_param(&ihost->hwaddress, buf);
3639	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3640		return iscsi_switch_str_param(&ihost->initiatorname, buf);
3641	default:
3642		return -ENOSYS;
3643	}
3644
3645	return 0;
3646}
3647EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3648
3649MODULE_AUTHOR("Mike Christie");
3650MODULE_DESCRIPTION("iSCSI library functions");
3651MODULE_LICENSE("GPL");
v3.15
   1/*
   2 * iSCSI lib functions
   3 *
   4 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5 * Copyright (C) 2004 - 2006 Mike Christie
   6 * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7 * Copyright (C) 2004 - 2005 Alex Aizman
   8 * maintained by open-iscsi@googlegroups.com
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License as published by
  12 * the Free Software Foundation; either version 2 of the License, or
  13 * (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful,
  16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 * GNU General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program; if not, write to the Free Software
  22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23 */
  24#include <linux/types.h>
  25#include <linux/kfifo.h>
  26#include <linux/delay.h>
  27#include <linux/log2.h>
  28#include <linux/slab.h>
  29#include <linux/module.h>
  30#include <asm/unaligned.h>
  31#include <net/tcp.h>
  32#include <scsi/scsi_cmnd.h>
  33#include <scsi/scsi_device.h>
  34#include <scsi/scsi_eh.h>
  35#include <scsi/scsi_tcq.h>
  36#include <scsi/scsi_host.h>
  37#include <scsi/scsi.h>
  38#include <scsi/iscsi_proto.h>
  39#include <scsi/scsi_transport.h>
  40#include <scsi/scsi_transport_iscsi.h>
  41#include <scsi/libiscsi.h>
  42
  43static int iscsi_dbg_lib_conn;
  44module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  45		   S_IRUGO | S_IWUSR);
  46MODULE_PARM_DESC(debug_libiscsi_conn,
  47		 "Turn on debugging for connections in libiscsi module. "
  48		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  49
  50static int iscsi_dbg_lib_session;
  51module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  52		   S_IRUGO | S_IWUSR);
  53MODULE_PARM_DESC(debug_libiscsi_session,
  54		 "Turn on debugging for sessions in libiscsi module. "
  55		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  56
  57static int iscsi_dbg_lib_eh;
  58module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  59		   S_IRUGO | S_IWUSR);
  60MODULE_PARM_DESC(debug_libiscsi_eh,
  61		 "Turn on debugging for error handling in libiscsi module. "
  62		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  63
  64#define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)			\
  65	do {							\
  66		if (iscsi_dbg_lib_conn)				\
  67			iscsi_conn_printk(KERN_INFO, _conn,	\
  68					     "%s " dbg_fmt,	\
  69					     __func__, ##arg);	\
  70	} while (0);
  71
  72#define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)			\
  73	do {								\
  74		if (iscsi_dbg_lib_session)				\
  75			iscsi_session_printk(KERN_INFO, _session,	\
  76					     "%s " dbg_fmt,		\
  77					     __func__, ##arg);		\
  78	} while (0);
  79
  80#define ISCSI_DBG_EH(_session, dbg_fmt, arg...)				\
  81	do {								\
  82		if (iscsi_dbg_lib_eh)					\
  83			iscsi_session_printk(KERN_INFO, _session,	\
  84					     "%s " dbg_fmt,		\
  85					     __func__, ##arg);		\
  86	} while (0);
  87
  88inline void iscsi_conn_queue_work(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_work);
  97
  98static void __iscsi_update_cmdsn(struct iscsi_session *session,
  99				 uint32_t exp_cmdsn, uint32_t max_cmdsn)
 100{
 101	/*
 102	 * standard specifies this check for when to update expected and
 103	 * max sequence numbers
 104	 */
 105	if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 106		return;
 107
 108	if (exp_cmdsn != session->exp_cmdsn &&
 109	    !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 110		session->exp_cmdsn = exp_cmdsn;
 111
 112	if (max_cmdsn != session->max_cmdsn &&
 113	    !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
 114		session->max_cmdsn = max_cmdsn;
 115}
 116
 117void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 118{
 119	__iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 120			     be32_to_cpu(hdr->max_cmdsn));
 121}
 122EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 123
 124/**
 125 * iscsi_prep_data_out_pdu - initialize Data-Out
 126 * @task: scsi command task
 127 * @r2t: R2T info
 128 * @hdr: iscsi data in pdu
 129 *
 130 * Notes:
 131 *	Initialize Data-Out within this R2T sequence and finds
 132 *	proper data_offset within this SCSI command.
 133 *
 134 *	This function is called with connection lock taken.
 135 **/
 136void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 137			   struct iscsi_data *hdr)
 138{
 139	struct iscsi_conn *conn = task->conn;
 140	unsigned int left = r2t->data_length - r2t->sent;
 141
 142	task->hdr_len = sizeof(struct iscsi_data);
 143
 144	memset(hdr, 0, sizeof(struct iscsi_data));
 145	hdr->ttt = r2t->ttt;
 146	hdr->datasn = cpu_to_be32(r2t->datasn);
 147	r2t->datasn++;
 148	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 149	hdr->lun = task->lun;
 150	hdr->itt = task->hdr_itt;
 151	hdr->exp_statsn = r2t->exp_statsn;
 152	hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 153	if (left > conn->max_xmit_dlength) {
 154		hton24(hdr->dlength, conn->max_xmit_dlength);
 155		r2t->data_count = conn->max_xmit_dlength;
 156		hdr->flags = 0;
 157	} else {
 158		hton24(hdr->dlength, left);
 159		r2t->data_count = left;
 160		hdr->flags = ISCSI_FLAG_CMD_FINAL;
 161	}
 162	conn->dataout_pdus_cnt++;
 163}
 164EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 165
 166static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 167{
 168	unsigned exp_len = task->hdr_len + len;
 169
 170	if (exp_len > task->hdr_max) {
 171		WARN_ON(1);
 172		return -EINVAL;
 173	}
 174
 175	WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 176	task->hdr_len = exp_len;
 177	return 0;
 178}
 179
 180/*
 181 * make an extended cdb AHS
 182 */
 183static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 184{
 185	struct scsi_cmnd *cmd = task->sc;
 186	unsigned rlen, pad_len;
 187	unsigned short ahslength;
 188	struct iscsi_ecdb_ahdr *ecdb_ahdr;
 189	int rc;
 190
 191	ecdb_ahdr = iscsi_next_hdr(task);
 192	rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 193
 194	BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 195	ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 196
 197	pad_len = iscsi_padding(rlen);
 198
 199	rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 200	                   sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 201	if (rc)
 202		return rc;
 203
 204	if (pad_len)
 205		memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 206
 207	ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 208	ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 209	ecdb_ahdr->reserved = 0;
 210	memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 211
 212	ISCSI_DBG_SESSION(task->conn->session,
 213			  "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 214		          "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 215		          "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 216		          task->hdr_len);
 217	return 0;
 218}
 219
 220static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 221{
 222	struct scsi_cmnd *sc = task->sc;
 223	struct iscsi_rlength_ahdr *rlen_ahdr;
 224	int rc;
 225
 226	rlen_ahdr = iscsi_next_hdr(task);
 227	rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 228	if (rc)
 229		return rc;
 230
 231	rlen_ahdr->ahslength =
 232		cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 233						  sizeof(rlen_ahdr->reserved));
 234	rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 235	rlen_ahdr->reserved = 0;
 236	rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 237
 238	ISCSI_DBG_SESSION(task->conn->session,
 239			  "bidi-in rlen_ahdr->read_length(%d) "
 240		          "rlen_ahdr->ahslength(%d)\n",
 241		          be32_to_cpu(rlen_ahdr->read_length),
 242		          be16_to_cpu(rlen_ahdr->ahslength));
 243	return 0;
 244}
 245
 246/**
 247 * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 248 * @task: iscsi task
 249 * @opcode: opcode to check for
 250 *
 251 * During TMF a task has to be checked if it's affected.
 252 * All unrelated I/O can be passed through, but I/O to the
 253 * affected LUN should be restricted.
 254 * If 'fast_abort' is set we won't be sending any I/O to the
 255 * affected LUN.
 256 * Otherwise the target is waiting for all TTTs to be completed,
 257 * so we have to send all outstanding Data-Out PDUs to the target.
 258 */
 259static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 260{
 261	struct iscsi_conn *conn = task->conn;
 262	struct iscsi_tm *tmf = &conn->tmhdr;
 263	unsigned int hdr_lun;
 264
 265	if (conn->tmf_state == TMF_INITIAL)
 266		return 0;
 267
 268	if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 269		return 0;
 270
 271	switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 272	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 273		/*
 274		 * Allow PDUs for unrelated LUNs
 275		 */
 276		hdr_lun = scsilun_to_int(&tmf->lun);
 277		if (hdr_lun != task->sc->device->lun)
 278			return 0;
 279		/* fall through */
 280	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 281		/*
 282		 * Fail all SCSI cmd PDUs
 283		 */
 284		if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 285			iscsi_conn_printk(KERN_INFO, conn,
 286					  "task [op %x/%x itt "
 287					  "0x%x/0x%x] "
 288					  "rejected.\n",
 289					  task->hdr->opcode, opcode,
 290					  task->itt, task->hdr_itt);
 291			return -EACCES;
 292		}
 293		/*
 294		 * And also all data-out PDUs in response to R2T
 295		 * if fast_abort is set.
 296		 */
 297		if (conn->session->fast_abort) {
 298			iscsi_conn_printk(KERN_INFO, conn,
 299					  "task [op %x/%x itt "
 300					  "0x%x/0x%x] fast abort.\n",
 301					  task->hdr->opcode, opcode,
 302					  task->itt, task->hdr_itt);
 303			return -EACCES;
 304		}
 305		break;
 306	case ISCSI_TM_FUNC_ABORT_TASK:
 307		/*
 308		 * the caller has already checked if the task
 309		 * they want to abort was in the pending queue so if
 310		 * we are here the cmd pdu has gone out already, and
 311		 * we will only hit this for data-outs
 312		 */
 313		if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 314		    task->hdr_itt == tmf->rtt) {
 315			ISCSI_DBG_SESSION(conn->session,
 316					  "Preventing task %x/%x from sending "
 317					  "data-out due to abort task in "
 318					  "progress\n", task->itt,
 319					  task->hdr_itt);
 320			return -EACCES;
 321		}
 322		break;
 323	}
 324
 325	return 0;
 326}
 327
 328/**
 329 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 330 * @task: iscsi task
 331 *
 332 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 333 * fields like dlength or final based on how much data it sends
 334 */
 335static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 336{
 337	struct iscsi_conn *conn = task->conn;
 338	struct iscsi_session *session = conn->session;
 339	struct scsi_cmnd *sc = task->sc;
 340	struct iscsi_scsi_req *hdr;
 341	unsigned hdrlength, cmd_len;
 342	itt_t itt;
 343	int rc;
 344
 345	rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 346	if (rc)
 347		return rc;
 348
 349	if (conn->session->tt->alloc_pdu) {
 350		rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 351		if (rc)
 352			return rc;
 353	}
 354	hdr = (struct iscsi_scsi_req *)task->hdr;
 355	itt = hdr->itt;
 356	memset(hdr, 0, sizeof(*hdr));
 357
 358	if (session->tt->parse_pdu_itt)
 359		hdr->itt = task->hdr_itt = itt;
 360	else
 361		hdr->itt = task->hdr_itt = build_itt(task->itt,
 362						     task->conn->session->age);
 363	task->hdr_len = 0;
 364	rc = iscsi_add_hdr(task, sizeof(*hdr));
 365	if (rc)
 366		return rc;
 367	hdr->opcode = ISCSI_OP_SCSI_CMD;
 368	hdr->flags = ISCSI_ATTR_SIMPLE;
 369	int_to_scsilun(sc->device->lun, &hdr->lun);
 370	task->lun = hdr->lun;
 371	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 372	cmd_len = sc->cmd_len;
 373	if (cmd_len < ISCSI_CDB_SIZE)
 374		memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 375	else if (cmd_len > ISCSI_CDB_SIZE) {
 376		rc = iscsi_prep_ecdb_ahs(task);
 377		if (rc)
 378			return rc;
 379		cmd_len = ISCSI_CDB_SIZE;
 380	}
 381	memcpy(hdr->cdb, sc->cmnd, cmd_len);
 382
 383	task->imm_count = 0;
 384	if (scsi_bidi_cmnd(sc)) {
 385		hdr->flags |= ISCSI_FLAG_CMD_READ;
 386		rc = iscsi_prep_bidi_ahs(task);
 387		if (rc)
 388			return rc;
 389	}
 390
 391	if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 392		task->protected = true;
 393
 
 
 394	if (sc->sc_data_direction == DMA_TO_DEVICE) {
 395		unsigned out_len = scsi_out(sc)->length;
 396		struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 397
 398		hdr->data_length = cpu_to_be32(out_len);
 399		hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 400		/*
 401		 * Write counters:
 402		 *
 403		 *	imm_count	bytes to be sent right after
 404		 *			SCSI PDU Header
 405		 *
 406		 *	unsol_count	bytes(as Data-Out) to be sent
 407		 *			without	R2T ack right after
 408		 *			immediate data
 409		 *
 410		 *	r2t data_length bytes to be sent via R2T ack's
 411		 *
 412		 *      pad_count       bytes to be sent as zero-padding
 413		 */
 414		memset(r2t, 0, sizeof(*r2t));
 415
 416		if (session->imm_data_en) {
 417			if (out_len >= session->first_burst)
 418				task->imm_count = min(session->first_burst,
 419							conn->max_xmit_dlength);
 420			else
 421				task->imm_count = min(out_len,
 422							conn->max_xmit_dlength);
 423			hton24(hdr->dlength, task->imm_count);
 424		} else
 425			zero_data(hdr->dlength);
 426
 427		if (!session->initial_r2t_en) {
 428			r2t->data_length = min(session->first_burst, out_len) -
 
 429					       task->imm_count;
 430			r2t->data_offset = task->imm_count;
 431			r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 432			r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 433		}
 434
 435		if (!task->unsol_r2t.data_length)
 436			/* No unsolicit Data-Out's */
 437			hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 438	} else {
 439		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 440		zero_data(hdr->dlength);
 441		hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
 442
 443		if (sc->sc_data_direction == DMA_FROM_DEVICE)
 444			hdr->flags |= ISCSI_FLAG_CMD_READ;
 445	}
 446
 447	/* calculate size of additional header segments (AHSs) */
 448	hdrlength = task->hdr_len - sizeof(*hdr);
 449
 450	WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 451	hdrlength /= ISCSI_PAD_LEN;
 452
 453	WARN_ON(hdrlength >= 256);
 454	hdr->hlength = hdrlength & 0xFF;
 455	hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 456
 457	if (session->tt->init_task && session->tt->init_task(task))
 458		return -EIO;
 459
 460	task->state = ISCSI_TASK_RUNNING;
 461	session->cmdsn++;
 462
 463	conn->scsicmd_pdus_cnt++;
 464	ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 465			  "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
 466			  scsi_bidi_cmnd(sc) ? "bidirectional" :
 467			  sc->sc_data_direction == DMA_TO_DEVICE ?
 468			  "write" : "read", conn->id, sc, sc->cmnd[0],
 469			  task->itt, scsi_bufflen(sc),
 470			  scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 471			  session->cmdsn,
 472			  session->max_cmdsn - session->exp_cmdsn + 1);
 473	return 0;
 474}
 475
 476/**
 477 * iscsi_free_task - free a task
 478 * @task: iscsi cmd task
 479 *
 480 * Must be called with session back_lock.
 481 * This function returns the scsi command to scsi-ml or cleans
 482 * up mgmt tasks then returns the task to the pool.
 483 */
 484static void iscsi_free_task(struct iscsi_task *task)
 485{
 486	struct iscsi_conn *conn = task->conn;
 487	struct iscsi_session *session = conn->session;
 488	struct scsi_cmnd *sc = task->sc;
 489	int oldstate = task->state;
 490
 491	ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 492			  task->itt, task->state, task->sc);
 493
 494	session->tt->cleanup_task(task);
 495	task->state = ISCSI_TASK_FREE;
 496	task->sc = NULL;
 497	/*
 498	 * login task is preallocated so do not free
 499	 */
 500	if (conn->login_task == task)
 501		return;
 502
 503	kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 504
 505	if (sc) {
 506		/* SCSI eh reuses commands to verify us */
 507		sc->SCp.ptr = NULL;
 508		/*
 509		 * queue command may call this to free the task, so
 510		 * it will decide how to return sc to scsi-ml.
 511		 */
 512		if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 513			sc->scsi_done(sc);
 514	}
 515}
 516
 517void __iscsi_get_task(struct iscsi_task *task)
 518{
 519	atomic_inc(&task->refcount);
 520}
 521EXPORT_SYMBOL_GPL(__iscsi_get_task);
 522
 523void __iscsi_put_task(struct iscsi_task *task)
 524{
 525	if (atomic_dec_and_test(&task->refcount))
 526		iscsi_free_task(task);
 527}
 528EXPORT_SYMBOL_GPL(__iscsi_put_task);
 529
 530void iscsi_put_task(struct iscsi_task *task)
 531{
 532	struct iscsi_session *session = task->conn->session;
 533
 534	/* regular RX path uses back_lock */
 535	spin_lock_bh(&session->back_lock);
 536	__iscsi_put_task(task);
 537	spin_unlock_bh(&session->back_lock);
 538}
 539EXPORT_SYMBOL_GPL(iscsi_put_task);
 540
 541/**
 542 * iscsi_complete_task - finish a task
 543 * @task: iscsi cmd task
 544 * @state: state to complete task with
 545 *
 546 * Must be called with session back_lock.
 547 */
 548static void iscsi_complete_task(struct iscsi_task *task, int state)
 549{
 550	struct iscsi_conn *conn = task->conn;
 551
 552	ISCSI_DBG_SESSION(conn->session,
 553			  "complete task itt 0x%x state %d sc %p\n",
 554			  task->itt, task->state, task->sc);
 555	if (task->state == ISCSI_TASK_COMPLETED ||
 556	    task->state == ISCSI_TASK_ABRT_TMF ||
 557	    task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 558	    task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 559		return;
 560	WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 561	task->state = state;
 562
 563	if (!list_empty(&task->running))
 
 
 564		list_del_init(&task->running);
 
 
 565
 566	if (conn->task == task)
 567		conn->task = NULL;
 568
 569	if (conn->ping_task == task)
 570		conn->ping_task = NULL;
 571
 572	/* release get from queueing */
 573	__iscsi_put_task(task);
 574}
 575
 576/**
 577 * iscsi_complete_scsi_task - finish scsi task normally
 578 * @task: iscsi task for scsi cmd
 579 * @exp_cmdsn: expected cmd sn in cpu format
 580 * @max_cmdsn: max cmd sn in cpu format
 581 *
 582 * This is used when drivers do not need or cannot perform
 583 * lower level pdu processing.
 584 *
 585 * Called with session back_lock
 586 */
 587void iscsi_complete_scsi_task(struct iscsi_task *task,
 588			      uint32_t exp_cmdsn, uint32_t max_cmdsn)
 589{
 590	struct iscsi_conn *conn = task->conn;
 591
 592	ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 593
 594	conn->last_recv = jiffies;
 595	__iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 596	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 597}
 598EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 599
 600
 601/*
 602 * session back_lock must be held and if not called for a task that is
 603 * still pending or from the xmit thread, then xmit thread must
 604 * be suspended.
 605 */
 606static void fail_scsi_task(struct iscsi_task *task, int err)
 607{
 608	struct iscsi_conn *conn = task->conn;
 609	struct scsi_cmnd *sc;
 610	int state;
 611
 612	/*
 613	 * if a command completes and we get a successful tmf response
 614	 * we will hit this because the scsi eh abort code does not take
 615	 * a ref to the task.
 616	 */
 617	sc = task->sc;
 618	if (!sc)
 619		return;
 620
 621	if (task->state == ISCSI_TASK_PENDING) {
 622		/*
 623		 * cmd never made it to the xmit thread, so we should not count
 624		 * the cmd in the sequencing
 625		 */
 626		conn->session->queued_cmdsn--;
 627		/* it was never sent so just complete like normal */
 628		state = ISCSI_TASK_COMPLETED;
 629	} else if (err == DID_TRANSPORT_DISRUPTED)
 630		state = ISCSI_TASK_ABRT_SESS_RECOV;
 631	else
 632		state = ISCSI_TASK_ABRT_TMF;
 633
 634	sc->result = err << 16;
 635	if (!scsi_bidi_cmnd(sc))
 636		scsi_set_resid(sc, scsi_bufflen(sc));
 637	else {
 638		scsi_out(sc)->resid = scsi_out(sc)->length;
 639		scsi_in(sc)->resid = scsi_in(sc)->length;
 640	}
 641
 642	/* regular RX path uses back_lock */
 643	spin_lock_bh(&conn->session->back_lock);
 644	iscsi_complete_task(task, state);
 645	spin_unlock_bh(&conn->session->back_lock);
 646}
 647
 648static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 649				struct iscsi_task *task)
 650{
 651	struct iscsi_session *session = conn->session;
 652	struct iscsi_hdr *hdr = task->hdr;
 653	struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 654	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 655
 656	if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 657		return -ENOTCONN;
 658
 659	if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 660		nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 661	/*
 662	 * pre-format CmdSN for outgoing PDU.
 663	 */
 664	nop->cmdsn = cpu_to_be32(session->cmdsn);
 665	if (hdr->itt != RESERVED_ITT) {
 666		/*
 667		 * TODO: We always use immediate for normal session pdus.
 668		 * If we start to send tmfs or nops as non-immediate then
 669		 * we should start checking the cmdsn numbers for mgmt tasks.
 670		 *
 671		 * During discovery sessions iscsid sends TEXT as non immediate,
 672		 * but we always only send one PDU at a time.
 673		 */
 674		if (conn->c_stage == ISCSI_CONN_STARTED &&
 675		    !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 676			session->queued_cmdsn++;
 677			session->cmdsn++;
 678		}
 679	}
 680
 681	if (session->tt->init_task && session->tt->init_task(task))
 682		return -EIO;
 683
 684	if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 685		session->state = ISCSI_STATE_LOGGING_OUT;
 686
 687	task->state = ISCSI_TASK_RUNNING;
 688	ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 689			  "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 690			  hdr->itt, task->data_count);
 691	return 0;
 692}
 693
 694static struct iscsi_task *
 695__iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 696		      char *data, uint32_t data_size)
 697{
 698	struct iscsi_session *session = conn->session;
 699	struct iscsi_host *ihost = shost_priv(session->host);
 700	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 701	struct iscsi_task *task;
 702	itt_t itt;
 703
 704	if (session->state == ISCSI_STATE_TERMINATE)
 705		return NULL;
 706
 707	if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 708		/*
 709		 * Login and Text are sent serially, in
 710		 * request-followed-by-response sequence.
 711		 * Same task can be used. Same ITT must be used.
 712		 * Note that login_task is preallocated at conn_create().
 713		 */
 714		if (conn->login_task->state != ISCSI_TASK_FREE) {
 715			iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 716					  "progress. Cannot start new task.\n");
 717			return NULL;
 718		}
 719
 
 
 
 
 
 720		task = conn->login_task;
 721	} else {
 722		if (session->state != ISCSI_STATE_LOGGED_IN)
 723			return NULL;
 724
 
 
 
 
 
 725		BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 726		BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 727
 728		if (!kfifo_out(&session->cmdpool.queue,
 729				 (void*)&task, sizeof(void*)))
 730			return NULL;
 731	}
 732	/*
 733	 * released in complete pdu for task we expect a response for, and
 734	 * released by the lld when it has transmitted the task for
 735	 * pdus we do not expect a response for.
 736	 */
 737	atomic_set(&task->refcount, 1);
 738	task->conn = conn;
 739	task->sc = NULL;
 740	INIT_LIST_HEAD(&task->running);
 741	task->state = ISCSI_TASK_PENDING;
 742
 743	if (data_size) {
 744		memcpy(task->data, data, data_size);
 745		task->data_count = data_size;
 746	} else
 747		task->data_count = 0;
 748
 749	if (conn->session->tt->alloc_pdu) {
 750		if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 751			iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 752					 "pdu for mgmt task.\n");
 753			goto free_task;
 754		}
 755	}
 756
 757	itt = task->hdr->itt;
 758	task->hdr_len = sizeof(struct iscsi_hdr);
 759	memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 760
 761	if (hdr->itt != RESERVED_ITT) {
 762		if (session->tt->parse_pdu_itt)
 763			task->hdr->itt = itt;
 764		else
 765			task->hdr->itt = build_itt(task->itt,
 766						   task->conn->session->age);
 767	}
 768
 769	if (!ihost->workq) {
 770		if (iscsi_prep_mgmt_task(conn, task))
 771			goto free_task;
 772
 773		if (session->tt->xmit_task(task))
 774			goto free_task;
 775	} else {
 
 776		list_add_tail(&task->running, &conn->mgmtqueue);
 
 777		iscsi_conn_queue_work(conn);
 778	}
 779
 780	return task;
 781
 782free_task:
 783	/* regular RX path uses back_lock */
 784	spin_lock_bh(&session->back_lock);
 785	__iscsi_put_task(task);
 786	spin_unlock_bh(&session->back_lock);
 787	return NULL;
 788}
 789
 790int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 791			char *data, uint32_t data_size)
 792{
 793	struct iscsi_conn *conn = cls_conn->dd_data;
 794	struct iscsi_session *session = conn->session;
 795	int err = 0;
 796
 797	spin_lock_bh(&session->frwd_lock);
 798	if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 799		err = -EPERM;
 800	spin_unlock_bh(&session->frwd_lock);
 801	return err;
 802}
 803EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 804
 805/**
 806 * iscsi_cmd_rsp - SCSI Command Response processing
 807 * @conn: iscsi connection
 808 * @hdr: iscsi header
 809 * @task: scsi command task
 810 * @data: cmd data buffer
 811 * @datalen: len of buffer
 812 *
 813 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 814 * then completes the command and task.
 815 **/
 816static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 817			       struct iscsi_task *task, char *data,
 818			       int datalen)
 819{
 820	struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 821	struct iscsi_session *session = conn->session;
 822	struct scsi_cmnd *sc = task->sc;
 823
 824	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 825	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 826
 827	sc->result = (DID_OK << 16) | rhdr->cmd_status;
 828
 829	if (task->protected) {
 830		sector_t sector;
 831		u8 ascq;
 832
 833		/**
 834		 * Transports that didn't implement check_protection
 835		 * callback but still published T10-PI support to scsi-mid
 836		 * deserve this BUG_ON.
 837		 **/
 838		BUG_ON(!session->tt->check_protection);
 839
 840		ascq = session->tt->check_protection(task, &sector);
 841		if (ascq) {
 842			sc->result = DRIVER_SENSE << 24 |
 843				     SAM_STAT_CHECK_CONDITION;
 844			scsi_build_sense_buffer(1, sc->sense_buffer,
 845						ILLEGAL_REQUEST, 0x10, ascq);
 846			sc->sense_buffer[7] = 0xc; /* Additional sense length */
 847			sc->sense_buffer[8] = 0;   /* Information desc type */
 848			sc->sense_buffer[9] = 0xa; /* Additional desc length */
 849			sc->sense_buffer[10] = 0x80; /* Validity bit */
 850
 851			put_unaligned_be64(sector, &sc->sense_buffer[12]);
 852			goto out;
 853		}
 854	}
 855
 856	if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 857		sc->result = DID_ERROR << 16;
 858		goto out;
 859	}
 860
 861	if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 862		uint16_t senselen;
 863
 864		if (datalen < 2) {
 865invalid_datalen:
 866			iscsi_conn_printk(KERN_ERR,  conn,
 867					 "Got CHECK_CONDITION but invalid data "
 868					 "buffer size of %d\n", datalen);
 869			sc->result = DID_BAD_TARGET << 16;
 870			goto out;
 871		}
 872
 873		senselen = get_unaligned_be16(data);
 874		if (datalen < senselen)
 875			goto invalid_datalen;
 876
 877		memcpy(sc->sense_buffer, data + 2,
 878		       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 879		ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 880				  min_t(uint16_t, senselen,
 881				  SCSI_SENSE_BUFFERSIZE));
 882	}
 883
 884	if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 885			   ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 886		int res_count = be32_to_cpu(rhdr->bi_residual_count);
 887
 888		if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 889				(rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 890				 res_count <= scsi_in(sc)->length))
 891			scsi_in(sc)->resid = res_count;
 892		else
 893			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 894	}
 895
 896	if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 897	                   ISCSI_FLAG_CMD_OVERFLOW)) {
 898		int res_count = be32_to_cpu(rhdr->residual_count);
 899
 900		if (res_count > 0 &&
 901		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 902		     res_count <= scsi_bufflen(sc)))
 903			/* write side for bidi or uni-io set_resid */
 904			scsi_set_resid(sc, res_count);
 905		else
 906			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 907	}
 908out:
 909	ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 910			  sc, sc->result, task->itt);
 911	conn->scsirsp_pdus_cnt++;
 912	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 913}
 914
 915/**
 916 * iscsi_data_in_rsp - SCSI Data-In Response processing
 917 * @conn: iscsi connection
 918 * @hdr:  iscsi pdu
 919 * @task: scsi command task
 920 **/
 921static void
 922iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 923		  struct iscsi_task *task)
 924{
 925	struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 926	struct scsi_cmnd *sc = task->sc;
 927
 928	if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 929		return;
 930
 931	iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 932	sc->result = (DID_OK << 16) | rhdr->cmd_status;
 933	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 934	if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 935	                   ISCSI_FLAG_DATA_OVERFLOW)) {
 936		int res_count = be32_to_cpu(rhdr->residual_count);
 937
 938		if (res_count > 0 &&
 939		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 940		     res_count <= scsi_in(sc)->length))
 941			scsi_in(sc)->resid = res_count;
 942		else
 943			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 944	}
 945
 946	ISCSI_DBG_SESSION(conn->session, "data in with status done "
 947			  "[sc %p res %d itt 0x%x]\n",
 948			  sc, sc->result, task->itt);
 949	conn->scsirsp_pdus_cnt++;
 950	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 951}
 952
 953static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 954{
 955	struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 956
 957	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 958	conn->tmfrsp_pdus_cnt++;
 959
 960	if (conn->tmf_state != TMF_QUEUED)
 961		return;
 962
 963	if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 964		conn->tmf_state = TMF_SUCCESS;
 965	else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 966		conn->tmf_state = TMF_NOT_FOUND;
 967	else
 968		conn->tmf_state = TMF_FAILED;
 969	wake_up(&conn->ehwait);
 970}
 971
 972static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 973{
 974        struct iscsi_nopout hdr;
 975	struct iscsi_task *task;
 976
 977	if (!rhdr && conn->ping_task)
 978		return;
 979
 980	memset(&hdr, 0, sizeof(struct iscsi_nopout));
 981	hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 982	hdr.flags = ISCSI_FLAG_CMD_FINAL;
 983
 984	if (rhdr) {
 985		hdr.lun = rhdr->lun;
 986		hdr.ttt = rhdr->ttt;
 987		hdr.itt = RESERVED_ITT;
 988	} else
 989		hdr.ttt = RESERVED_ITT;
 990
 991	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 992	if (!task)
 993		iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 994	else if (!rhdr) {
 
 995		/* only track our nops */
 996		conn->ping_task = task;
 997		conn->last_ping = jiffies;
 998	}
 
 
 999}
1000
1001static int iscsi_nop_out_rsp(struct iscsi_task *task,
1002			     struct iscsi_nopin *nop, char *data, int datalen)
1003{
1004	struct iscsi_conn *conn = task->conn;
1005	int rc = 0;
1006
1007	if (conn->ping_task != task) {
1008		/*
1009		 * If this is not in response to one of our
1010		 * nops then it must be from userspace.
1011		 */
1012		if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1013				   data, datalen))
1014			rc = ISCSI_ERR_CONN_FAILED;
1015	} else
1016		mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1017	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1018	return rc;
1019}
1020
1021static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1022			       char *data, int datalen)
1023{
1024	struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1025	struct iscsi_hdr rejected_pdu;
1026	int opcode, rc = 0;
1027
1028	conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1029
1030	if (ntoh24(reject->dlength) > datalen ||
1031	    ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1032		iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1033				  "pdu. Invalid data length (pdu dlength "
1034				  "%u, datalen %d\n", ntoh24(reject->dlength),
1035				  datalen);
1036		return ISCSI_ERR_PROTO;
1037	}
1038	memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1039	opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1040
1041	switch (reject->reason) {
1042	case ISCSI_REASON_DATA_DIGEST_ERROR:
1043		iscsi_conn_printk(KERN_ERR, conn,
1044				  "pdu (op 0x%x itt 0x%x) rejected "
1045				  "due to DataDigest error.\n",
1046				  opcode, rejected_pdu.itt);
1047		break;
1048	case ISCSI_REASON_IMM_CMD_REJECT:
1049		iscsi_conn_printk(KERN_ERR, conn,
1050				  "pdu (op 0x%x itt 0x%x) rejected. Too many "
1051				  "immediate commands.\n",
1052				  opcode, rejected_pdu.itt);
1053		/*
1054		 * We only send one TMF at a time so if the target could not
1055		 * handle it, then it should get fixed (RFC mandates that
1056		 * a target can handle one immediate TMF per conn).
1057		 *
1058		 * For nops-outs, we could have sent more than one if
1059		 * the target is sending us lots of nop-ins
1060		 */
1061		if (opcode != ISCSI_OP_NOOP_OUT)
1062			return 0;
1063
1064		 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1065			/*
1066			 * nop-out in response to target's nop-out rejected.
1067			 * Just resend.
1068			 */
1069			/* In RX path we are under back lock */
1070			spin_unlock(&conn->session->back_lock);
1071			spin_lock(&conn->session->frwd_lock);
1072			iscsi_send_nopout(conn,
1073					  (struct iscsi_nopin*)&rejected_pdu);
1074			spin_unlock(&conn->session->frwd_lock);
1075			spin_lock(&conn->session->back_lock);
1076		} else {
1077			struct iscsi_task *task;
1078			/*
1079			 * Our nop as ping got dropped. We know the target
1080			 * and transport are ok so just clean up
1081			 */
1082			task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1083			if (!task) {
1084				iscsi_conn_printk(KERN_ERR, conn,
1085						 "Invalid pdu reject. Could "
1086						 "not lookup rejected task.\n");
1087				rc = ISCSI_ERR_BAD_ITT;
1088			} else
1089				rc = iscsi_nop_out_rsp(task,
1090					(struct iscsi_nopin*)&rejected_pdu,
1091					NULL, 0);
1092		}
1093		break;
1094	default:
1095		iscsi_conn_printk(KERN_ERR, conn,
1096				  "pdu (op 0x%x itt 0x%x) rejected. Reason "
1097				  "code 0x%x\n", rejected_pdu.opcode,
1098				  rejected_pdu.itt, reject->reason);
1099		break;
1100	}
1101	return rc;
1102}
1103
1104/**
1105 * iscsi_itt_to_task - look up task by itt
1106 * @conn: iscsi connection
1107 * @itt: itt
1108 *
1109 * This should be used for mgmt tasks like login and nops, or if
1110 * the LDD's itt space does not include the session age.
1111 *
1112 * The session back_lock must be held.
1113 */
1114struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1115{
1116	struct iscsi_session *session = conn->session;
1117	int i;
1118
1119	if (itt == RESERVED_ITT)
1120		return NULL;
1121
1122	if (session->tt->parse_pdu_itt)
1123		session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1124	else
1125		i = get_itt(itt);
1126	if (i >= session->cmds_max)
1127		return NULL;
1128
1129	return session->cmds[i];
1130}
1131EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1132
1133/**
1134 * __iscsi_complete_pdu - complete pdu
1135 * @conn: iscsi conn
1136 * @hdr: iscsi header
1137 * @data: data buffer
1138 * @datalen: len of data buffer
1139 *
1140 * Completes pdu processing by freeing any resources allocated at
1141 * queuecommand or send generic. session back_lock must be held and verify
1142 * itt must have been called.
1143 */
1144int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1145			 char *data, int datalen)
1146{
1147	struct iscsi_session *session = conn->session;
1148	int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1149	struct iscsi_task *task;
1150	uint32_t itt;
1151
1152	conn->last_recv = jiffies;
1153	rc = iscsi_verify_itt(conn, hdr->itt);
1154	if (rc)
1155		return rc;
1156
1157	if (hdr->itt != RESERVED_ITT)
1158		itt = get_itt(hdr->itt);
1159	else
1160		itt = ~0U;
1161
1162	ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1163			  opcode, conn->id, itt, datalen);
1164
1165	if (itt == ~0U) {
1166		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1167
1168		switch(opcode) {
1169		case ISCSI_OP_NOOP_IN:
1170			if (datalen) {
1171				rc = ISCSI_ERR_PROTO;
1172				break;
1173			}
1174
1175			if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1176				break;
1177
1178			/* In RX path we are under back lock */
1179			spin_unlock(&session->back_lock);
1180			spin_lock(&session->frwd_lock);
1181			iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1182			spin_unlock(&session->frwd_lock);
1183			spin_lock(&session->back_lock);
1184			break;
1185		case ISCSI_OP_REJECT:
1186			rc = iscsi_handle_reject(conn, hdr, data, datalen);
1187			break;
1188		case ISCSI_OP_ASYNC_EVENT:
1189			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1190			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1191				rc = ISCSI_ERR_CONN_FAILED;
1192			break;
1193		default:
1194			rc = ISCSI_ERR_BAD_OPCODE;
1195			break;
1196		}
1197		goto out;
1198	}
1199
1200	switch(opcode) {
1201	case ISCSI_OP_SCSI_CMD_RSP:
1202	case ISCSI_OP_SCSI_DATA_IN:
1203		task = iscsi_itt_to_ctask(conn, hdr->itt);
1204		if (!task)
1205			return ISCSI_ERR_BAD_ITT;
1206		task->last_xfer = jiffies;
1207		break;
1208	case ISCSI_OP_R2T:
1209		/*
1210		 * LLD handles R2Ts if they need to.
1211		 */
1212		return 0;
1213	case ISCSI_OP_LOGOUT_RSP:
1214	case ISCSI_OP_LOGIN_RSP:
1215	case ISCSI_OP_TEXT_RSP:
1216	case ISCSI_OP_SCSI_TMFUNC_RSP:
1217	case ISCSI_OP_NOOP_IN:
1218		task = iscsi_itt_to_task(conn, hdr->itt);
1219		if (!task)
1220			return ISCSI_ERR_BAD_ITT;
1221		break;
1222	default:
1223		return ISCSI_ERR_BAD_OPCODE;
1224	}
1225
1226	switch(opcode) {
1227	case ISCSI_OP_SCSI_CMD_RSP:
1228		iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1229		break;
1230	case ISCSI_OP_SCSI_DATA_IN:
1231		iscsi_data_in_rsp(conn, hdr, task);
1232		break;
1233	case ISCSI_OP_LOGOUT_RSP:
1234		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1235		if (datalen) {
1236			rc = ISCSI_ERR_PROTO;
1237			break;
1238		}
1239		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1240		goto recv_pdu;
1241	case ISCSI_OP_LOGIN_RSP:
1242	case ISCSI_OP_TEXT_RSP:
1243		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1244		/*
1245		 * login related PDU's exp_statsn is handled in
1246		 * userspace
1247		 */
1248		goto recv_pdu;
1249	case ISCSI_OP_SCSI_TMFUNC_RSP:
1250		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1251		if (datalen) {
1252			rc = ISCSI_ERR_PROTO;
1253			break;
1254		}
1255
1256		iscsi_tmf_rsp(conn, hdr);
1257		iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1258		break;
1259	case ISCSI_OP_NOOP_IN:
1260		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1261		if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1262			rc = ISCSI_ERR_PROTO;
1263			break;
1264		}
1265		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1266
1267		rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1268				       data, datalen);
1269		break;
1270	default:
1271		rc = ISCSI_ERR_BAD_OPCODE;
1272		break;
1273	}
1274
1275out:
1276	return rc;
1277recv_pdu:
1278	if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1279		rc = ISCSI_ERR_CONN_FAILED;
1280	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1281	return rc;
1282}
1283EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1284
1285int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1286		       char *data, int datalen)
1287{
1288	int rc;
1289
1290	spin_lock(&conn->session->back_lock);
1291	rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1292	spin_unlock(&conn->session->back_lock);
1293	return rc;
1294}
1295EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1296
1297int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1298{
1299	struct iscsi_session *session = conn->session;
1300	int age = 0, i = 0;
1301
1302	if (itt == RESERVED_ITT)
1303		return 0;
1304
1305	if (session->tt->parse_pdu_itt)
1306		session->tt->parse_pdu_itt(conn, itt, &i, &age);
1307	else {
1308		i = get_itt(itt);
1309		age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1310	}
1311
1312	if (age != session->age) {
1313		iscsi_conn_printk(KERN_ERR, conn,
1314				  "received itt %x expected session age (%x)\n",
1315				  (__force u32)itt, session->age);
1316		return ISCSI_ERR_BAD_ITT;
1317	}
1318
1319	if (i >= session->cmds_max) {
1320		iscsi_conn_printk(KERN_ERR, conn,
1321				  "received invalid itt index %u (max cmds "
1322				   "%u.\n", i, session->cmds_max);
1323		return ISCSI_ERR_BAD_ITT;
1324	}
1325	return 0;
1326}
1327EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1328
1329/**
1330 * iscsi_itt_to_ctask - look up ctask by itt
1331 * @conn: iscsi connection
1332 * @itt: itt
1333 *
1334 * This should be used for cmd tasks.
1335 *
1336 * The session back_lock must be held.
1337 */
1338struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1339{
1340	struct iscsi_task *task;
1341
1342	if (iscsi_verify_itt(conn, itt))
1343		return NULL;
1344
1345	task = iscsi_itt_to_task(conn, itt);
1346	if (!task || !task->sc)
1347		return NULL;
1348
1349	if (task->sc->SCp.phase != conn->session->age) {
1350		iscsi_session_printk(KERN_ERR, conn->session,
1351				  "task's session age %d, expected %d\n",
1352				  task->sc->SCp.phase, conn->session->age);
1353		return NULL;
1354	}
1355
1356	return task;
1357}
1358EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1359
1360void iscsi_session_failure(struct iscsi_session *session,
1361			   enum iscsi_err err)
1362{
1363	struct iscsi_conn *conn;
1364	struct device *dev;
1365
1366	spin_lock_bh(&session->frwd_lock);
1367	conn = session->leadconn;
1368	if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1369		spin_unlock_bh(&session->frwd_lock);
1370		return;
1371	}
1372
1373	dev = get_device(&conn->cls_conn->dev);
1374	spin_unlock_bh(&session->frwd_lock);
1375	if (!dev)
1376	        return;
1377	/*
1378	 * if the host is being removed bypass the connection
1379	 * recovery initialization because we are going to kill
1380	 * the session.
1381	 */
1382	if (err == ISCSI_ERR_INVALID_HOST)
1383		iscsi_conn_error_event(conn->cls_conn, err);
1384	else
1385		iscsi_conn_failure(conn, err);
1386	put_device(dev);
1387}
1388EXPORT_SYMBOL_GPL(iscsi_session_failure);
1389
1390void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1391{
1392	struct iscsi_session *session = conn->session;
1393
1394	spin_lock_bh(&session->frwd_lock);
1395	if (session->state == ISCSI_STATE_FAILED) {
1396		spin_unlock_bh(&session->frwd_lock);
1397		return;
1398	}
1399
1400	if (conn->stop_stage == 0)
1401		session->state = ISCSI_STATE_FAILED;
1402	spin_unlock_bh(&session->frwd_lock);
1403
1404	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1405	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1406	iscsi_conn_error_event(conn->cls_conn, err);
1407}
1408EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1409
1410static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1411{
1412	struct iscsi_session *session = conn->session;
1413
1414	/*
1415	 * Check for iSCSI window and take care of CmdSN wrap-around
1416	 */
1417	if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1418		ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1419				  "%u MaxCmdSN %u CmdSN %u/%u\n",
1420				  session->exp_cmdsn, session->max_cmdsn,
1421				  session->cmdsn, session->queued_cmdsn);
1422		return -ENOSPC;
1423	}
1424	return 0;
1425}
1426
1427static int iscsi_xmit_task(struct iscsi_conn *conn)
1428{
1429	struct iscsi_task *task = conn->task;
1430	int rc;
1431
1432	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1433		return -ENODATA;
1434
1435	__iscsi_get_task(task);
1436	spin_unlock_bh(&conn->session->frwd_lock);
1437	rc = conn->session->tt->xmit_task(task);
1438	spin_lock_bh(&conn->session->frwd_lock);
1439	if (!rc) {
1440		/* done with this task */
1441		task->last_xfer = jiffies;
1442		conn->task = NULL;
1443	}
1444	/* regular RX path uses back_lock */
1445	spin_lock_bh(&conn->session->back_lock);
1446	__iscsi_put_task(task);
1447	spin_unlock_bh(&conn->session->back_lock);
1448	return rc;
1449}
1450
1451/**
1452 * iscsi_requeue_task - requeue task to run from session workqueue
1453 * @task: task to requeue
1454 *
1455 * LLDs that need to run a task from the session workqueue should call
1456 * this. The session frwd_lock must be held. This should only be called
1457 * by software drivers.
1458 */
1459void iscsi_requeue_task(struct iscsi_task *task)
1460{
1461	struct iscsi_conn *conn = task->conn;
1462
1463	/*
1464	 * this may be on the requeue list already if the xmit_task callout
1465	 * is handling the r2ts while we are adding new ones
1466	 */
 
1467	if (list_empty(&task->running))
1468		list_add_tail(&task->running, &conn->requeue);
 
1469	iscsi_conn_queue_work(conn);
1470}
1471EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1472
1473/**
1474 * iscsi_data_xmit - xmit any command into the scheduled connection
1475 * @conn: iscsi connection
1476 *
1477 * Notes:
1478 *	The function can return -EAGAIN in which case the caller must
1479 *	re-schedule it again later or recover. '0' return code means
1480 *	successful xmit.
1481 **/
1482static int iscsi_data_xmit(struct iscsi_conn *conn)
1483{
1484	struct iscsi_task *task;
1485	int rc = 0;
1486
1487	spin_lock_bh(&conn->session->frwd_lock);
1488	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1489		ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1490		spin_unlock_bh(&conn->session->frwd_lock);
1491		return -ENODATA;
1492	}
1493
1494	if (conn->task) {
1495		rc = iscsi_xmit_task(conn);
1496	        if (rc)
1497		        goto done;
1498	}
1499
1500	/*
1501	 * process mgmt pdus like nops before commands since we should
1502	 * only have one nop-out as a ping from us and targets should not
1503	 * overflow us with nop-ins
1504	 */
 
1505check_mgmt:
1506	while (!list_empty(&conn->mgmtqueue)) {
1507		conn->task = list_entry(conn->mgmtqueue.next,
1508					 struct iscsi_task, running);
1509		list_del_init(&conn->task->running);
 
1510		if (iscsi_prep_mgmt_task(conn, conn->task)) {
1511			/* regular RX path uses back_lock */
1512			spin_lock_bh(&conn->session->back_lock);
1513			__iscsi_put_task(conn->task);
1514			spin_unlock_bh(&conn->session->back_lock);
1515			conn->task = NULL;
 
1516			continue;
1517		}
1518		rc = iscsi_xmit_task(conn);
1519		if (rc)
1520			goto done;
 
1521	}
1522
1523	/* process pending command queue */
1524	while (!list_empty(&conn->cmdqueue)) {
1525		conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1526					running);
1527		list_del_init(&conn->task->running);
 
1528		if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1529			fail_scsi_task(conn->task, DID_IMM_RETRY);
 
1530			continue;
1531		}
1532		rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1533		if (rc) {
1534			if (rc == -ENOMEM || rc == -EACCES) {
 
1535				list_add_tail(&conn->task->running,
1536					      &conn->cmdqueue);
1537				conn->task = NULL;
 
1538				goto done;
1539			} else
1540				fail_scsi_task(conn->task, DID_ABORT);
 
1541			continue;
1542		}
1543		rc = iscsi_xmit_task(conn);
1544		if (rc)
1545			goto done;
1546		/*
1547		 * we could continuously get new task requests so
1548		 * we need to check the mgmt queue for nops that need to
1549		 * be sent to aviod starvation
1550		 */
 
1551		if (!list_empty(&conn->mgmtqueue))
1552			goto check_mgmt;
1553	}
1554
1555	while (!list_empty(&conn->requeue)) {
1556		/*
1557		 * we always do fastlogout - conn stop code will clean up.
1558		 */
1559		if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1560			break;
1561
1562		task = list_entry(conn->requeue.next, struct iscsi_task,
1563				  running);
1564		if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1565			break;
1566
1567		conn->task = task;
1568		list_del_init(&conn->task->running);
1569		conn->task->state = ISCSI_TASK_RUNNING;
 
1570		rc = iscsi_xmit_task(conn);
1571		if (rc)
1572			goto done;
 
1573		if (!list_empty(&conn->mgmtqueue))
1574			goto check_mgmt;
1575	}
 
1576	spin_unlock_bh(&conn->session->frwd_lock);
1577	return -ENODATA;
1578
1579done:
1580	spin_unlock_bh(&conn->session->frwd_lock);
1581	return rc;
1582}
1583
1584static void iscsi_xmitworker(struct work_struct *work)
1585{
1586	struct iscsi_conn *conn =
1587		container_of(work, struct iscsi_conn, xmitwork);
1588	int rc;
1589	/*
1590	 * serialize Xmit worker on a per-connection basis.
1591	 */
1592	do {
1593		rc = iscsi_data_xmit(conn);
1594	} while (rc >= 0 || rc == -EAGAIN);
1595}
1596
1597static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1598						  struct scsi_cmnd *sc)
1599{
1600	struct iscsi_task *task;
1601
1602	if (!kfifo_out(&conn->session->cmdpool.queue,
1603			 (void *) &task, sizeof(void *)))
1604		return NULL;
1605
1606	sc->SCp.phase = conn->session->age;
1607	sc->SCp.ptr = (char *) task;
1608
1609	atomic_set(&task->refcount, 1);
1610	task->state = ISCSI_TASK_PENDING;
1611	task->conn = conn;
1612	task->sc = sc;
1613	task->have_checked_conn = false;
1614	task->last_timeout = jiffies;
1615	task->last_xfer = jiffies;
1616	task->protected = false;
1617	INIT_LIST_HEAD(&task->running);
1618	return task;
1619}
1620
1621enum {
1622	FAILURE_BAD_HOST = 1,
1623	FAILURE_SESSION_FAILED,
1624	FAILURE_SESSION_FREED,
1625	FAILURE_WINDOW_CLOSED,
1626	FAILURE_OOM,
1627	FAILURE_SESSION_TERMINATE,
1628	FAILURE_SESSION_IN_RECOVERY,
1629	FAILURE_SESSION_RECOVERY_TIMEOUT,
1630	FAILURE_SESSION_LOGGING_OUT,
1631	FAILURE_SESSION_NOT_READY,
1632};
1633
1634int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1635{
1636	struct iscsi_cls_session *cls_session;
1637	struct iscsi_host *ihost;
1638	int reason = 0;
1639	struct iscsi_session *session;
1640	struct iscsi_conn *conn;
1641	struct iscsi_task *task = NULL;
1642
1643	sc->result = 0;
1644	sc->SCp.ptr = NULL;
1645
1646	ihost = shost_priv(host);
1647
1648	cls_session = starget_to_session(scsi_target(sc->device));
1649	session = cls_session->dd_data;
1650	spin_lock_bh(&session->frwd_lock);
1651
1652	reason = iscsi_session_chkready(cls_session);
1653	if (reason) {
1654		sc->result = reason;
1655		goto fault;
1656	}
1657
1658	if (session->state != ISCSI_STATE_LOGGED_IN) {
1659		/*
1660		 * to handle the race between when we set the recovery state
1661		 * and block the session we requeue here (commands could
1662		 * be entering our queuecommand while a block is starting
1663		 * up because the block code is not locked)
1664		 */
1665		switch (session->state) {
1666		case ISCSI_STATE_FAILED:
1667		case ISCSI_STATE_IN_RECOVERY:
1668			reason = FAILURE_SESSION_IN_RECOVERY;
1669			sc->result = DID_IMM_RETRY << 16;
1670			break;
1671		case ISCSI_STATE_LOGGING_OUT:
1672			reason = FAILURE_SESSION_LOGGING_OUT;
1673			sc->result = DID_IMM_RETRY << 16;
1674			break;
1675		case ISCSI_STATE_RECOVERY_FAILED:
1676			reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1677			sc->result = DID_TRANSPORT_FAILFAST << 16;
1678			break;
1679		case ISCSI_STATE_TERMINATE:
1680			reason = FAILURE_SESSION_TERMINATE;
1681			sc->result = DID_NO_CONNECT << 16;
1682			break;
1683		default:
1684			reason = FAILURE_SESSION_FREED;
1685			sc->result = DID_NO_CONNECT << 16;
1686		}
1687		goto fault;
1688	}
1689
1690	conn = session->leadconn;
1691	if (!conn) {
1692		reason = FAILURE_SESSION_FREED;
1693		sc->result = DID_NO_CONNECT << 16;
1694		goto fault;
1695	}
1696
1697	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1698		reason = FAILURE_SESSION_IN_RECOVERY;
1699		sc->result = DID_REQUEUE;
1700		goto fault;
1701	}
1702
1703	if (iscsi_check_cmdsn_window_closed(conn)) {
1704		reason = FAILURE_WINDOW_CLOSED;
1705		goto reject;
1706	}
1707
1708	task = iscsi_alloc_task(conn, sc);
1709	if (!task) {
1710		reason = FAILURE_OOM;
1711		goto reject;
1712	}
1713
1714	if (!ihost->workq) {
1715		reason = iscsi_prep_scsi_cmd_pdu(task);
1716		if (reason) {
1717			if (reason == -ENOMEM ||  reason == -EACCES) {
1718				reason = FAILURE_OOM;
1719				goto prepd_reject;
1720			} else {
1721				sc->result = DID_ABORT << 16;
1722				goto prepd_fault;
1723			}
1724		}
1725		if (session->tt->xmit_task(task)) {
1726			session->cmdsn--;
1727			reason = FAILURE_SESSION_NOT_READY;
1728			goto prepd_reject;
1729		}
1730	} else {
 
1731		list_add_tail(&task->running, &conn->cmdqueue);
 
1732		iscsi_conn_queue_work(conn);
1733	}
1734
1735	session->queued_cmdsn++;
1736	spin_unlock_bh(&session->frwd_lock);
1737	return 0;
1738
1739prepd_reject:
1740	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1741reject:
1742	spin_unlock_bh(&session->frwd_lock);
1743	ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1744			  sc->cmnd[0], reason);
1745	return SCSI_MLQUEUE_TARGET_BUSY;
1746
1747prepd_fault:
1748	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1749fault:
1750	spin_unlock_bh(&session->frwd_lock);
1751	ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1752			  sc->cmnd[0], reason);
1753	if (!scsi_bidi_cmnd(sc))
1754		scsi_set_resid(sc, scsi_bufflen(sc));
1755	else {
1756		scsi_out(sc)->resid = scsi_out(sc)->length;
1757		scsi_in(sc)->resid = scsi_in(sc)->length;
1758	}
1759	sc->scsi_done(sc);
1760	return 0;
1761}
1762EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1763
1764int iscsi_change_queue_depth(struct scsi_device *sdev, int depth, int reason)
1765{
1766	switch (reason) {
1767	case SCSI_QDEPTH_DEFAULT:
1768		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1769		break;
1770	case SCSI_QDEPTH_QFULL:
1771		scsi_track_queue_full(sdev, depth);
1772		break;
1773	case SCSI_QDEPTH_RAMP_UP:
1774		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1775		break;
1776	default:
1777		return -EOPNOTSUPP;
1778	}
1779	return sdev->queue_depth;
1780}
1781EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1782
1783int iscsi_target_alloc(struct scsi_target *starget)
1784{
1785	struct iscsi_cls_session *cls_session = starget_to_session(starget);
1786	struct iscsi_session *session = cls_session->dd_data;
1787
1788	starget->can_queue = session->scsi_cmds_max;
1789	return 0;
1790}
1791EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1792
1793static void iscsi_tmf_timedout(unsigned long data)
1794{
1795	struct iscsi_conn *conn = (struct iscsi_conn *)data;
1796	struct iscsi_session *session = conn->session;
1797
1798	spin_lock(&session->frwd_lock);
1799	if (conn->tmf_state == TMF_QUEUED) {
1800		conn->tmf_state = TMF_TIMEDOUT;
1801		ISCSI_DBG_EH(session, "tmf timedout\n");
1802		/* unblock eh_abort() */
1803		wake_up(&conn->ehwait);
1804	}
1805	spin_unlock(&session->frwd_lock);
1806}
1807
1808static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1809				   struct iscsi_tm *hdr, int age,
1810				   int timeout)
1811{
1812	struct iscsi_session *session = conn->session;
1813	struct iscsi_task *task;
1814
1815	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1816				      NULL, 0);
1817	if (!task) {
1818		spin_unlock_bh(&session->frwd_lock);
1819		iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1820		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1821		spin_lock_bh(&session->frwd_lock);
1822		return -EPERM;
1823	}
1824	conn->tmfcmd_pdus_cnt++;
1825	conn->tmf_timer.expires = timeout * HZ + jiffies;
1826	conn->tmf_timer.function = iscsi_tmf_timedout;
1827	conn->tmf_timer.data = (unsigned long)conn;
1828	add_timer(&conn->tmf_timer);
1829	ISCSI_DBG_EH(session, "tmf set timeout\n");
1830
1831	spin_unlock_bh(&session->frwd_lock);
1832	mutex_unlock(&session->eh_mutex);
1833
1834	/*
1835	 * block eh thread until:
1836	 *
1837	 * 1) tmf response
1838	 * 2) tmf timeout
1839	 * 3) session is terminated or restarted or userspace has
1840	 * given up on recovery
1841	 */
1842	wait_event_interruptible(conn->ehwait, age != session->age ||
1843				 session->state != ISCSI_STATE_LOGGED_IN ||
1844				 conn->tmf_state != TMF_QUEUED);
1845	if (signal_pending(current))
1846		flush_signals(current);
1847	del_timer_sync(&conn->tmf_timer);
1848
1849	mutex_lock(&session->eh_mutex);
1850	spin_lock_bh(&session->frwd_lock);
1851	/* if the session drops it will clean up the task */
1852	if (age != session->age ||
1853	    session->state != ISCSI_STATE_LOGGED_IN)
1854		return -ENOTCONN;
1855	return 0;
1856}
1857
1858/*
1859 * Fail commands. session lock held and recv side suspended and xmit
1860 * thread flushed
1861 */
1862static void fail_scsi_tasks(struct iscsi_conn *conn, unsigned lun,
1863			    int error)
1864{
1865	struct iscsi_task *task;
1866	int i;
1867
1868	for (i = 0; i < conn->session->cmds_max; i++) {
1869		task = conn->session->cmds[i];
1870		if (!task->sc || task->state == ISCSI_TASK_FREE)
1871			continue;
1872
1873		if (lun != -1 && lun != task->sc->device->lun)
1874			continue;
1875
1876		ISCSI_DBG_SESSION(conn->session,
1877				  "failing sc %p itt 0x%x state %d\n",
1878				  task->sc, task->itt, task->state);
1879		fail_scsi_task(task, error);
1880	}
1881}
1882
1883/**
1884 * iscsi_suspend_queue - suspend iscsi_queuecommand
1885 * @conn: iscsi conn to stop queueing IO on
1886 *
1887 * This grabs the session frwd_lock to make sure no one is in
1888 * xmit_task/queuecommand, and then sets suspend to prevent
1889 * new commands from being queued. This only needs to be called
1890 * by offload drivers that need to sync a path like ep disconnect
1891 * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1892 * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1893 */
1894void iscsi_suspend_queue(struct iscsi_conn *conn)
1895{
1896	spin_lock_bh(&conn->session->frwd_lock);
1897	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1898	spin_unlock_bh(&conn->session->frwd_lock);
1899}
1900EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1901
1902/**
1903 * iscsi_suspend_tx - suspend iscsi_data_xmit
1904 * @conn: iscsi conn tp stop processing IO on.
1905 *
1906 * This function sets the suspend bit to prevent iscsi_data_xmit
1907 * from sending new IO, and if work is queued on the xmit thread
1908 * it will wait for it to be completed.
1909 */
1910void iscsi_suspend_tx(struct iscsi_conn *conn)
1911{
1912	struct Scsi_Host *shost = conn->session->host;
1913	struct iscsi_host *ihost = shost_priv(shost);
1914
1915	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1916	if (ihost->workq)
1917		flush_workqueue(ihost->workq);
1918}
1919EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1920
1921static void iscsi_start_tx(struct iscsi_conn *conn)
1922{
1923	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1924	iscsi_conn_queue_work(conn);
1925}
1926
1927/*
1928 * We want to make sure a ping is in flight. It has timed out.
1929 * And we are not busy processing a pdu that is making
1930 * progress but got started before the ping and is taking a while
1931 * to complete so the ping is just stuck behind it in a queue.
1932 */
1933static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1934{
1935	if (conn->ping_task &&
1936	    time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1937			   (conn->ping_timeout * HZ), jiffies))
1938		return 1;
1939	else
1940		return 0;
1941}
1942
1943static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1944{
1945	enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1946	struct iscsi_task *task = NULL, *running_task;
1947	struct iscsi_cls_session *cls_session;
1948	struct iscsi_session *session;
1949	struct iscsi_conn *conn;
1950	int i;
1951
1952	cls_session = starget_to_session(scsi_target(sc->device));
1953	session = cls_session->dd_data;
1954
1955	ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1956
1957	spin_lock(&session->frwd_lock);
1958	task = (struct iscsi_task *)sc->SCp.ptr;
1959	if (!task) {
1960		/*
1961		 * Raced with completion. Blk layer has taken ownership
1962		 * so let timeout code complete it now.
1963		 */
1964		rc = BLK_EH_HANDLED;
1965		goto done;
1966	}
1967
1968	if (session->state != ISCSI_STATE_LOGGED_IN) {
1969		/*
1970		 * We are probably in the middle of iscsi recovery so let
1971		 * that complete and handle the error.
1972		 */
1973		rc = BLK_EH_RESET_TIMER;
1974		goto done;
1975	}
1976
1977	conn = session->leadconn;
1978	if (!conn) {
1979		/* In the middle of shuting down */
1980		rc = BLK_EH_RESET_TIMER;
1981		goto done;
1982	}
1983
1984	/*
1985	 * If we have sent (at least queued to the network layer) a pdu or
1986	 * recvd one for the task since the last timeout ask for
1987	 * more time. If on the next timeout we have not made progress
1988	 * we can check if it is the task or connection when we send the
1989	 * nop as a ping.
1990	 */
1991	if (time_after(task->last_xfer, task->last_timeout)) {
1992		ISCSI_DBG_EH(session, "Command making progress. Asking "
1993			     "scsi-ml for more time to complete. "
1994			     "Last data xfer at %lu. Last timeout was at "
1995			     "%lu\n.", task->last_xfer, task->last_timeout);
1996		task->have_checked_conn = false;
1997		rc = BLK_EH_RESET_TIMER;
1998		goto done;
1999	}
2000
2001	if (!conn->recv_timeout && !conn->ping_timeout)
2002		goto done;
2003	/*
2004	 * if the ping timedout then we are in the middle of cleaning up
2005	 * and can let the iscsi eh handle it
2006	 */
2007	if (iscsi_has_ping_timed_out(conn)) {
2008		rc = BLK_EH_RESET_TIMER;
2009		goto done;
2010	}
2011
2012	for (i = 0; i < conn->session->cmds_max; i++) {
2013		running_task = conn->session->cmds[i];
2014		if (!running_task->sc || running_task == task ||
2015		     running_task->state != ISCSI_TASK_RUNNING)
2016			continue;
2017
2018		/*
2019		 * Only check if cmds started before this one have made
2020		 * progress, or this could never fail
2021		 */
2022		if (time_after(running_task->sc->jiffies_at_alloc,
2023			       task->sc->jiffies_at_alloc))
2024			continue;
2025
2026		if (time_after(running_task->last_xfer, task->last_timeout)) {
2027			/*
2028			 * This task has not made progress, but a task
2029			 * started before us has transferred data since
2030			 * we started/last-checked. We could be queueing
2031			 * too many tasks or the LU is bad.
2032			 *
2033			 * If the device is bad the cmds ahead of us on
2034			 * other devs will complete, and this loop will
2035			 * eventually fail starting the scsi eh.
2036			 */
2037			ISCSI_DBG_EH(session, "Command has not made progress "
2038				     "but commands ahead of it have. "
2039				     "Asking scsi-ml for more time to "
2040				     "complete. Our last xfer vs running task "
2041				     "last xfer %lu/%lu. Last check %lu.\n",
2042				     task->last_xfer, running_task->last_xfer,
2043				     task->last_timeout);
2044			rc = BLK_EH_RESET_TIMER;
2045			goto done;
2046		}
2047	}
2048
2049	/* Assumes nop timeout is shorter than scsi cmd timeout */
2050	if (task->have_checked_conn)
2051		goto done;
2052
2053	/*
2054	 * Checking the transport already or nop from a cmd timeout still
2055	 * running
2056	 */
2057	if (conn->ping_task) {
2058		task->have_checked_conn = true;
2059		rc = BLK_EH_RESET_TIMER;
2060		goto done;
2061	}
2062
2063	/* Make sure there is a transport check done */
2064	iscsi_send_nopout(conn, NULL);
2065	task->have_checked_conn = true;
2066	rc = BLK_EH_RESET_TIMER;
2067
2068done:
2069	if (task)
2070		task->last_timeout = jiffies;
2071	spin_unlock(&session->frwd_lock);
2072	ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2073		     "timer reset" : "nh");
2074	return rc;
2075}
2076
2077static void iscsi_check_transport_timeouts(unsigned long data)
2078{
2079	struct iscsi_conn *conn = (struct iscsi_conn *)data;
2080	struct iscsi_session *session = conn->session;
2081	unsigned long recv_timeout, next_timeout = 0, last_recv;
2082
2083	spin_lock(&session->frwd_lock);
2084	if (session->state != ISCSI_STATE_LOGGED_IN)
2085		goto done;
2086
2087	recv_timeout = conn->recv_timeout;
2088	if (!recv_timeout)
2089		goto done;
2090
2091	recv_timeout *= HZ;
2092	last_recv = conn->last_recv;
2093
2094	if (iscsi_has_ping_timed_out(conn)) {
2095		iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2096				  "expired, recv timeout %d, last rx %lu, "
2097				  "last ping %lu, now %lu\n",
2098				  conn->ping_timeout, conn->recv_timeout,
2099				  last_recv, conn->last_ping, jiffies);
2100		spin_unlock(&session->frwd_lock);
2101		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2102		return;
2103	}
2104
2105	if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2106		/* send a ping to try to provoke some traffic */
2107		ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2108		iscsi_send_nopout(conn, NULL);
2109		next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
 
 
2110	} else
2111		next_timeout = last_recv + recv_timeout;
2112
2113	ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2114	mod_timer(&conn->transport_timer, next_timeout);
2115done:
2116	spin_unlock(&session->frwd_lock);
2117}
2118
2119static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2120				      struct iscsi_tm *hdr)
2121{
2122	memset(hdr, 0, sizeof(*hdr));
2123	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2124	hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2125	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2126	hdr->lun = task->lun;
2127	hdr->rtt = task->hdr_itt;
2128	hdr->refcmdsn = task->cmdsn;
2129}
2130
2131int iscsi_eh_abort(struct scsi_cmnd *sc)
2132{
2133	struct iscsi_cls_session *cls_session;
2134	struct iscsi_session *session;
2135	struct iscsi_conn *conn;
2136	struct iscsi_task *task;
2137	struct iscsi_tm *hdr;
2138	int rc, age;
2139
2140	cls_session = starget_to_session(scsi_target(sc->device));
2141	session = cls_session->dd_data;
2142
2143	ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2144
2145	mutex_lock(&session->eh_mutex);
2146	spin_lock_bh(&session->frwd_lock);
2147	/*
2148	 * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2149	 * got the command.
2150	 */
2151	if (!sc->SCp.ptr) {
2152		ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2153				      "it completed.\n");
2154		spin_unlock_bh(&session->frwd_lock);
2155		mutex_unlock(&session->eh_mutex);
2156		return SUCCESS;
2157	}
2158
2159	/*
2160	 * If we are not logged in or we have started a new session
2161	 * then let the host reset code handle this
2162	 */
2163	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2164	    sc->SCp.phase != session->age) {
2165		spin_unlock_bh(&session->frwd_lock);
2166		mutex_unlock(&session->eh_mutex);
2167		ISCSI_DBG_EH(session, "failing abort due to dropped "
2168				  "session.\n");
2169		return FAILED;
2170	}
2171
2172	conn = session->leadconn;
2173	conn->eh_abort_cnt++;
2174	age = session->age;
2175
2176	task = (struct iscsi_task *)sc->SCp.ptr;
2177	ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2178		     sc, task->itt);
2179
2180	/* task completed before time out */
2181	if (!task->sc) {
2182		ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2183		goto success;
2184	}
2185
2186	if (task->state == ISCSI_TASK_PENDING) {
2187		fail_scsi_task(task, DID_ABORT);
2188		goto success;
2189	}
2190
2191	/* only have one tmf outstanding at a time */
2192	if (conn->tmf_state != TMF_INITIAL)
2193		goto failed;
2194	conn->tmf_state = TMF_QUEUED;
2195
2196	hdr = &conn->tmhdr;
2197	iscsi_prep_abort_task_pdu(task, hdr);
2198
2199	if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
2200		rc = FAILED;
2201		goto failed;
2202	}
2203
2204	switch (conn->tmf_state) {
2205	case TMF_SUCCESS:
2206		spin_unlock_bh(&session->frwd_lock);
2207		/*
2208		 * stop tx side incase the target had sent a abort rsp but
2209		 * the initiator was still writing out data.
2210		 */
2211		iscsi_suspend_tx(conn);
2212		/*
2213		 * we do not stop the recv side because targets have been
2214		 * good and have never sent us a successful tmf response
2215		 * then sent more data for the cmd.
2216		 */
2217		spin_lock_bh(&session->frwd_lock);
2218		fail_scsi_task(task, DID_ABORT);
2219		conn->tmf_state = TMF_INITIAL;
2220		memset(hdr, 0, sizeof(*hdr));
2221		spin_unlock_bh(&session->frwd_lock);
2222		iscsi_start_tx(conn);
2223		goto success_unlocked;
2224	case TMF_TIMEDOUT:
2225		spin_unlock_bh(&session->frwd_lock);
2226		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2227		goto failed_unlocked;
2228	case TMF_NOT_FOUND:
2229		if (!sc->SCp.ptr) {
2230			conn->tmf_state = TMF_INITIAL;
2231			memset(hdr, 0, sizeof(*hdr));
2232			/* task completed before tmf abort response */
2233			ISCSI_DBG_EH(session, "sc completed while abort	in "
2234					      "progress\n");
2235			goto success;
2236		}
2237		/* fall through */
2238	default:
2239		conn->tmf_state = TMF_INITIAL;
2240		goto failed;
2241	}
2242
2243success:
2244	spin_unlock_bh(&session->frwd_lock);
2245success_unlocked:
2246	ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2247		     sc, task->itt);
2248	mutex_unlock(&session->eh_mutex);
2249	return SUCCESS;
2250
2251failed:
2252	spin_unlock_bh(&session->frwd_lock);
2253failed_unlocked:
2254	ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2255		     task ? task->itt : 0);
2256	mutex_unlock(&session->eh_mutex);
2257	return FAILED;
2258}
2259EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2260
2261static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2262{
2263	memset(hdr, 0, sizeof(*hdr));
2264	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2265	hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2266	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2267	int_to_scsilun(sc->device->lun, &hdr->lun);
2268	hdr->rtt = RESERVED_ITT;
2269}
2270
2271int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2272{
2273	struct iscsi_cls_session *cls_session;
2274	struct iscsi_session *session;
2275	struct iscsi_conn *conn;
2276	struct iscsi_tm *hdr;
2277	int rc = FAILED;
2278
2279	cls_session = starget_to_session(scsi_target(sc->device));
2280	session = cls_session->dd_data;
2281
2282	ISCSI_DBG_EH(session, "LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
 
2283
2284	mutex_lock(&session->eh_mutex);
2285	spin_lock_bh(&session->frwd_lock);
2286	/*
2287	 * Just check if we are not logged in. We cannot check for
2288	 * the phase because the reset could come from a ioctl.
2289	 */
2290	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2291		goto unlock;
2292	conn = session->leadconn;
2293
2294	/* only have one tmf outstanding at a time */
2295	if (conn->tmf_state != TMF_INITIAL)
2296		goto unlock;
2297	conn->tmf_state = TMF_QUEUED;
2298
2299	hdr = &conn->tmhdr;
2300	iscsi_prep_lun_reset_pdu(sc, hdr);
2301
2302	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2303				    session->lu_reset_timeout)) {
2304		rc = FAILED;
2305		goto unlock;
2306	}
2307
2308	switch (conn->tmf_state) {
2309	case TMF_SUCCESS:
2310		break;
2311	case TMF_TIMEDOUT:
2312		spin_unlock_bh(&session->frwd_lock);
2313		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2314		goto done;
2315	default:
2316		conn->tmf_state = TMF_INITIAL;
2317		goto unlock;
2318	}
2319
2320	rc = SUCCESS;
2321	spin_unlock_bh(&session->frwd_lock);
2322
2323	iscsi_suspend_tx(conn);
2324
2325	spin_lock_bh(&session->frwd_lock);
2326	memset(hdr, 0, sizeof(*hdr));
2327	fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2328	conn->tmf_state = TMF_INITIAL;
2329	spin_unlock_bh(&session->frwd_lock);
2330
2331	iscsi_start_tx(conn);
2332	goto done;
2333
2334unlock:
2335	spin_unlock_bh(&session->frwd_lock);
2336done:
2337	ISCSI_DBG_EH(session, "dev reset result = %s\n",
2338		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2339	mutex_unlock(&session->eh_mutex);
2340	return rc;
2341}
2342EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2343
2344void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2345{
2346	struct iscsi_session *session = cls_session->dd_data;
2347
2348	spin_lock_bh(&session->frwd_lock);
2349	if (session->state != ISCSI_STATE_LOGGED_IN) {
2350		session->state = ISCSI_STATE_RECOVERY_FAILED;
2351		if (session->leadconn)
2352			wake_up(&session->leadconn->ehwait);
2353	}
2354	spin_unlock_bh(&session->frwd_lock);
2355}
2356EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2357
2358/**
2359 * iscsi_eh_session_reset - drop session and attempt relogin
2360 * @sc: scsi command
2361 *
2362 * This function will wait for a relogin, session termination from
2363 * userspace, or a recovery/replacement timeout.
2364 */
2365int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2366{
2367	struct iscsi_cls_session *cls_session;
2368	struct iscsi_session *session;
2369	struct iscsi_conn *conn;
2370
2371	cls_session = starget_to_session(scsi_target(sc->device));
2372	session = cls_session->dd_data;
2373	conn = session->leadconn;
2374
2375	mutex_lock(&session->eh_mutex);
2376	spin_lock_bh(&session->frwd_lock);
2377	if (session->state == ISCSI_STATE_TERMINATE) {
2378failed:
2379		ISCSI_DBG_EH(session,
2380			     "failing session reset: Could not log back into "
2381			     "%s, %s [age %d]\n", session->targetname,
2382			     conn->persistent_address, session->age);
2383		spin_unlock_bh(&session->frwd_lock);
2384		mutex_unlock(&session->eh_mutex);
2385		return FAILED;
2386	}
2387
2388	spin_unlock_bh(&session->frwd_lock);
2389	mutex_unlock(&session->eh_mutex);
2390	/*
2391	 * we drop the lock here but the leadconn cannot be destoyed while
2392	 * we are in the scsi eh
2393	 */
2394	iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2395
2396	ISCSI_DBG_EH(session, "wait for relogin\n");
2397	wait_event_interruptible(conn->ehwait,
2398				 session->state == ISCSI_STATE_TERMINATE ||
2399				 session->state == ISCSI_STATE_LOGGED_IN ||
2400				 session->state == ISCSI_STATE_RECOVERY_FAILED);
2401	if (signal_pending(current))
2402		flush_signals(current);
2403
2404	mutex_lock(&session->eh_mutex);
2405	spin_lock_bh(&session->frwd_lock);
2406	if (session->state == ISCSI_STATE_LOGGED_IN) {
2407		ISCSI_DBG_EH(session,
2408			     "session reset succeeded for %s,%s\n",
2409			     session->targetname, conn->persistent_address);
2410	} else
2411		goto failed;
2412	spin_unlock_bh(&session->frwd_lock);
2413	mutex_unlock(&session->eh_mutex);
2414	return SUCCESS;
2415}
2416EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2417
2418static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2419{
2420	memset(hdr, 0, sizeof(*hdr));
2421	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2422	hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2423	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2424	hdr->rtt = RESERVED_ITT;
2425}
2426
2427/**
2428 * iscsi_eh_target_reset - reset target
2429 * @sc: scsi command
2430 *
2431 * This will attempt to send a warm target reset.
2432 */
2433int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2434{
2435	struct iscsi_cls_session *cls_session;
2436	struct iscsi_session *session;
2437	struct iscsi_conn *conn;
2438	struct iscsi_tm *hdr;
2439	int rc = FAILED;
2440
2441	cls_session = starget_to_session(scsi_target(sc->device));
2442	session = cls_session->dd_data;
2443
2444	ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2445		     session->targetname);
2446
2447	mutex_lock(&session->eh_mutex);
2448	spin_lock_bh(&session->frwd_lock);
2449	/*
2450	 * Just check if we are not logged in. We cannot check for
2451	 * the phase because the reset could come from a ioctl.
2452	 */
2453	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2454		goto unlock;
2455	conn = session->leadconn;
2456
2457	/* only have one tmf outstanding at a time */
2458	if (conn->tmf_state != TMF_INITIAL)
2459		goto unlock;
2460	conn->tmf_state = TMF_QUEUED;
2461
2462	hdr = &conn->tmhdr;
2463	iscsi_prep_tgt_reset_pdu(sc, hdr);
2464
2465	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2466				    session->tgt_reset_timeout)) {
2467		rc = FAILED;
2468		goto unlock;
2469	}
2470
2471	switch (conn->tmf_state) {
2472	case TMF_SUCCESS:
2473		break;
2474	case TMF_TIMEDOUT:
2475		spin_unlock_bh(&session->frwd_lock);
2476		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2477		goto done;
2478	default:
2479		conn->tmf_state = TMF_INITIAL;
2480		goto unlock;
2481	}
2482
2483	rc = SUCCESS;
2484	spin_unlock_bh(&session->frwd_lock);
2485
2486	iscsi_suspend_tx(conn);
2487
2488	spin_lock_bh(&session->frwd_lock);
2489	memset(hdr, 0, sizeof(*hdr));
2490	fail_scsi_tasks(conn, -1, DID_ERROR);
2491	conn->tmf_state = TMF_INITIAL;
2492	spin_unlock_bh(&session->frwd_lock);
2493
2494	iscsi_start_tx(conn);
2495	goto done;
2496
2497unlock:
2498	spin_unlock_bh(&session->frwd_lock);
2499done:
2500	ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2501		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2502	mutex_unlock(&session->eh_mutex);
2503	return rc;
2504}
2505EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
2506
2507/**
2508 * iscsi_eh_recover_target - reset target and possibly the session
2509 * @sc: scsi command
2510 *
2511 * This will attempt to send a warm target reset. If that fails,
2512 * we will escalate to ERL0 session recovery.
2513 */
2514int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2515{
2516	int rc;
2517
2518	rc = iscsi_eh_target_reset(sc);
2519	if (rc == FAILED)
2520		rc = iscsi_eh_session_reset(sc);
2521	return rc;
2522}
2523EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2524
2525/*
2526 * Pre-allocate a pool of @max items of @item_size. By default, the pool
2527 * should be accessed via kfifo_{get,put} on q->queue.
2528 * Optionally, the caller can obtain the array of object pointers
2529 * by passing in a non-NULL @items pointer
2530 */
2531int
2532iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2533{
2534	int i, num_arrays = 1;
2535
2536	memset(q, 0, sizeof(*q));
2537
2538	q->max = max;
2539
2540	/* If the user passed an items pointer, he wants a copy of
2541	 * the array. */
2542	if (items)
2543		num_arrays++;
2544	q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2545	if (q->pool == NULL)
2546		return -ENOMEM;
2547
2548	kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2549
2550	for (i = 0; i < max; i++) {
2551		q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2552		if (q->pool[i] == NULL) {
2553			q->max = i;
2554			goto enomem;
2555		}
2556		kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2557	}
2558
2559	if (items) {
2560		*items = q->pool + max;
2561		memcpy(*items, q->pool, max * sizeof(void *));
2562	}
2563
2564	return 0;
2565
2566enomem:
2567	iscsi_pool_free(q);
2568	return -ENOMEM;
2569}
2570EXPORT_SYMBOL_GPL(iscsi_pool_init);
2571
2572void iscsi_pool_free(struct iscsi_pool *q)
2573{
2574	int i;
2575
2576	for (i = 0; i < q->max; i++)
2577		kfree(q->pool[i]);
2578	kfree(q->pool);
2579}
2580EXPORT_SYMBOL_GPL(iscsi_pool_free);
2581
2582/**
2583 * iscsi_host_add - add host to system
2584 * @shost: scsi host
2585 * @pdev: parent device
2586 *
2587 * This should be called by partial offload and software iscsi drivers
2588 * to add a host to the system.
2589 */
2590int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2591{
2592	if (!shost->can_queue)
2593		shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2594
2595	if (!shost->cmd_per_lun)
2596		shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2597
2598	if (!shost->transportt->eh_timed_out)
2599		shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2600	return scsi_add_host(shost, pdev);
2601}
2602EXPORT_SYMBOL_GPL(iscsi_host_add);
2603
2604/**
2605 * iscsi_host_alloc - allocate a host and driver data
2606 * @sht: scsi host template
2607 * @dd_data_size: driver host data size
2608 * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2609 *
2610 * This should be called by partial offload and software iscsi drivers.
2611 * To access the driver specific memory use the iscsi_host_priv() macro.
2612 */
2613struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2614				   int dd_data_size, bool xmit_can_sleep)
2615{
2616	struct Scsi_Host *shost;
2617	struct iscsi_host *ihost;
2618
2619	shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2620	if (!shost)
2621		return NULL;
2622	ihost = shost_priv(shost);
2623
2624	if (xmit_can_sleep) {
2625		snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2626			"iscsi_q_%d", shost->host_no);
2627		ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2628		if (!ihost->workq)
2629			goto free_host;
2630	}
2631
2632	spin_lock_init(&ihost->lock);
2633	ihost->state = ISCSI_HOST_SETUP;
2634	ihost->num_sessions = 0;
2635	init_waitqueue_head(&ihost->session_removal_wq);
2636	return shost;
2637
2638free_host:
2639	scsi_host_put(shost);
2640	return NULL;
2641}
2642EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2643
2644static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2645{
2646	iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2647}
2648
2649/**
2650 * iscsi_host_remove - remove host and sessions
2651 * @shost: scsi host
2652 *
2653 * If there are any sessions left, this will initiate the removal and wait
2654 * for the completion.
2655 */
2656void iscsi_host_remove(struct Scsi_Host *shost)
2657{
2658	struct iscsi_host *ihost = shost_priv(shost);
2659	unsigned long flags;
2660
2661	spin_lock_irqsave(&ihost->lock, flags);
2662	ihost->state = ISCSI_HOST_REMOVED;
2663	spin_unlock_irqrestore(&ihost->lock, flags);
2664
2665	iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2666	wait_event_interruptible(ihost->session_removal_wq,
2667				 ihost->num_sessions == 0);
2668	if (signal_pending(current))
2669		flush_signals(current);
2670
2671	scsi_remove_host(shost);
2672	if (ihost->workq)
2673		destroy_workqueue(ihost->workq);
2674}
2675EXPORT_SYMBOL_GPL(iscsi_host_remove);
2676
2677void iscsi_host_free(struct Scsi_Host *shost)
2678{
2679	struct iscsi_host *ihost = shost_priv(shost);
2680
2681	kfree(ihost->netdev);
2682	kfree(ihost->hwaddress);
2683	kfree(ihost->initiatorname);
2684	scsi_host_put(shost);
2685}
2686EXPORT_SYMBOL_GPL(iscsi_host_free);
2687
2688static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2689{
2690	struct iscsi_host *ihost = shost_priv(shost);
2691	unsigned long flags;
2692
2693	shost = scsi_host_get(shost);
2694	if (!shost) {
2695		printk(KERN_ERR "Invalid state. Cannot notify host removal "
2696		      "of session teardown event because host already "
2697		      "removed.\n");
2698		return;
2699	}
2700
2701	spin_lock_irqsave(&ihost->lock, flags);
2702	ihost->num_sessions--;
2703	if (ihost->num_sessions == 0)
2704		wake_up(&ihost->session_removal_wq);
2705	spin_unlock_irqrestore(&ihost->lock, flags);
2706	scsi_host_put(shost);
2707}
2708
2709/**
2710 * iscsi_session_setup - create iscsi cls session and host and session
2711 * @iscsit: iscsi transport template
2712 * @shost: scsi host
2713 * @cmds_max: session can queue
2714 * @cmd_task_size: LLD task private data size
2715 * @initial_cmdsn: initial CmdSN
2716 *
2717 * This can be used by software iscsi_transports that allocate
2718 * a session per scsi host.
2719 *
2720 * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2721 * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2722 * for nop handling and login/logout requests.
2723 */
2724struct iscsi_cls_session *
2725iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2726		    uint16_t cmds_max, int dd_size, int cmd_task_size,
2727		    uint32_t initial_cmdsn, unsigned int id)
2728{
2729	struct iscsi_host *ihost = shost_priv(shost);
2730	struct iscsi_session *session;
2731	struct iscsi_cls_session *cls_session;
2732	int cmd_i, scsi_cmds, total_cmds = cmds_max;
2733	unsigned long flags;
2734
2735	spin_lock_irqsave(&ihost->lock, flags);
2736	if (ihost->state == ISCSI_HOST_REMOVED) {
2737		spin_unlock_irqrestore(&ihost->lock, flags);
2738		return NULL;
2739	}
2740	ihost->num_sessions++;
2741	spin_unlock_irqrestore(&ihost->lock, flags);
2742
2743	if (!total_cmds)
2744		total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2745	/*
2746	 * The iscsi layer needs some tasks for nop handling and tmfs,
2747	 * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2748	 * + 1 command for scsi IO.
2749	 */
2750	if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2751		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2752		       "must be a power of two that is at least %d.\n",
2753		       total_cmds, ISCSI_TOTAL_CMDS_MIN);
2754		goto dec_session_count;
2755	}
2756
2757	if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2758		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2759		       "must be a power of 2 less than or equal to %d.\n",
2760		       cmds_max, ISCSI_TOTAL_CMDS_MAX);
2761		total_cmds = ISCSI_TOTAL_CMDS_MAX;
2762	}
2763
2764	if (!is_power_of_2(total_cmds)) {
2765		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2766		       "must be a power of 2.\n", total_cmds);
2767		total_cmds = rounddown_pow_of_two(total_cmds);
2768		if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2769			return NULL;
2770		printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2771		       total_cmds);
2772	}
2773	scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2774
2775	cls_session = iscsi_alloc_session(shost, iscsit,
2776					  sizeof(struct iscsi_session) +
2777					  dd_size);
2778	if (!cls_session)
2779		goto dec_session_count;
2780	session = cls_session->dd_data;
2781	session->cls_session = cls_session;
2782	session->host = shost;
2783	session->state = ISCSI_STATE_FREE;
2784	session->fast_abort = 1;
2785	session->tgt_reset_timeout = 30;
2786	session->lu_reset_timeout = 15;
2787	session->abort_timeout = 10;
2788	session->scsi_cmds_max = scsi_cmds;
2789	session->cmds_max = total_cmds;
2790	session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2791	session->exp_cmdsn = initial_cmdsn + 1;
2792	session->max_cmdsn = initial_cmdsn + 1;
2793	session->max_r2t = 1;
2794	session->tt = iscsit;
2795	session->dd_data = cls_session->dd_data + sizeof(*session);
2796
2797	mutex_init(&session->eh_mutex);
2798	spin_lock_init(&session->frwd_lock);
2799	spin_lock_init(&session->back_lock);
2800
2801	/* initialize SCSI PDU commands pool */
2802	if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2803			    (void***)&session->cmds,
2804			    cmd_task_size + sizeof(struct iscsi_task)))
2805		goto cmdpool_alloc_fail;
2806
2807	/* pre-format cmds pool with ITT */
2808	for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2809		struct iscsi_task *task = session->cmds[cmd_i];
2810
2811		if (cmd_task_size)
2812			task->dd_data = &task[1];
2813		task->itt = cmd_i;
2814		task->state = ISCSI_TASK_FREE;
2815		INIT_LIST_HEAD(&task->running);
2816	}
2817
2818	if (!try_module_get(iscsit->owner))
2819		goto module_get_fail;
2820
2821	if (iscsi_add_session(cls_session, id))
2822		goto cls_session_fail;
2823
2824	return cls_session;
2825
2826cls_session_fail:
2827	module_put(iscsit->owner);
2828module_get_fail:
2829	iscsi_pool_free(&session->cmdpool);
2830cmdpool_alloc_fail:
2831	iscsi_free_session(cls_session);
2832dec_session_count:
2833	iscsi_host_dec_session_cnt(shost);
2834	return NULL;
2835}
2836EXPORT_SYMBOL_GPL(iscsi_session_setup);
2837
2838/**
2839 * iscsi_session_teardown - destroy session, host, and cls_session
2840 * @cls_session: iscsi session
2841 *
2842 * The driver must have called iscsi_remove_session before
2843 * calling this.
2844 */
2845void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2846{
2847	struct iscsi_session *session = cls_session->dd_data;
2848	struct module *owner = cls_session->transport->owner;
2849	struct Scsi_Host *shost = session->host;
2850
2851	iscsi_pool_free(&session->cmdpool);
2852
2853	kfree(session->password);
2854	kfree(session->password_in);
2855	kfree(session->username);
2856	kfree(session->username_in);
2857	kfree(session->targetname);
2858	kfree(session->targetalias);
2859	kfree(session->initiatorname);
2860	kfree(session->boot_root);
2861	kfree(session->boot_nic);
2862	kfree(session->boot_target);
2863	kfree(session->ifacename);
2864	kfree(session->portal_type);
2865	kfree(session->discovery_parent_type);
2866
2867	iscsi_destroy_session(cls_session);
2868	iscsi_host_dec_session_cnt(shost);
2869	module_put(owner);
2870}
2871EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2872
2873/**
2874 * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2875 * @cls_session: iscsi_cls_session
2876 * @dd_size: private driver data size
2877 * @conn_idx: cid
2878 */
2879struct iscsi_cls_conn *
2880iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2881		 uint32_t conn_idx)
2882{
2883	struct iscsi_session *session = cls_session->dd_data;
2884	struct iscsi_conn *conn;
2885	struct iscsi_cls_conn *cls_conn;
2886	char *data;
2887
2888	cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2889				     conn_idx);
2890	if (!cls_conn)
2891		return NULL;
2892	conn = cls_conn->dd_data;
2893	memset(conn, 0, sizeof(*conn) + dd_size);
2894
2895	conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2896	conn->session = session;
2897	conn->cls_conn = cls_conn;
2898	conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2899	conn->id = conn_idx;
2900	conn->exp_statsn = 0;
2901	conn->tmf_state = TMF_INITIAL;
2902
2903	init_timer(&conn->transport_timer);
2904	conn->transport_timer.data = (unsigned long)conn;
2905	conn->transport_timer.function = iscsi_check_transport_timeouts;
2906
2907	INIT_LIST_HEAD(&conn->mgmtqueue);
2908	INIT_LIST_HEAD(&conn->cmdqueue);
2909	INIT_LIST_HEAD(&conn->requeue);
 
2910	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2911
2912	/* allocate login_task used for the login/text sequences */
2913	spin_lock_bh(&session->frwd_lock);
2914	if (!kfifo_out(&session->cmdpool.queue,
2915                         (void*)&conn->login_task,
2916			 sizeof(void*))) {
2917		spin_unlock_bh(&session->frwd_lock);
2918		goto login_task_alloc_fail;
2919	}
2920	spin_unlock_bh(&session->frwd_lock);
2921
2922	data = (char *) __get_free_pages(GFP_KERNEL,
2923					 get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2924	if (!data)
2925		goto login_task_data_alloc_fail;
2926	conn->login_task->data = conn->data = data;
2927
2928	init_timer(&conn->tmf_timer);
2929	init_waitqueue_head(&conn->ehwait);
2930
2931	return cls_conn;
2932
2933login_task_data_alloc_fail:
2934	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2935		    sizeof(void*));
2936login_task_alloc_fail:
2937	iscsi_destroy_conn(cls_conn);
2938	return NULL;
2939}
2940EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2941
2942/**
2943 * iscsi_conn_teardown - teardown iscsi connection
2944 * cls_conn: iscsi class connection
2945 *
2946 * TODO: we may need to make this into a two step process
2947 * like scsi-mls remove + put host
2948 */
2949void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2950{
2951	struct iscsi_conn *conn = cls_conn->dd_data;
2952	struct iscsi_session *session = conn->session;
2953	unsigned long flags;
2954
2955	del_timer_sync(&conn->transport_timer);
2956
 
2957	spin_lock_bh(&session->frwd_lock);
2958	conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2959	if (session->leadconn == conn) {
2960		/*
2961		 * leading connection? then give up on recovery.
2962		 */
2963		session->state = ISCSI_STATE_TERMINATE;
2964		wake_up(&conn->ehwait);
2965	}
2966	spin_unlock_bh(&session->frwd_lock);
2967
2968	/*
2969	 * Block until all in-progress commands for this connection
2970	 * time out or fail.
2971	 */
2972	for (;;) {
2973		spin_lock_irqsave(session->host->host_lock, flags);
2974		if (!session->host->host_busy) { /* OK for ERL == 0 */
2975			spin_unlock_irqrestore(session->host->host_lock, flags);
2976			break;
2977		}
2978		spin_unlock_irqrestore(session->host->host_lock, flags);
2979		msleep_interruptible(500);
2980		iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2981				  "host_busy %d host_failed %d\n",
2982				  session->host->host_busy,
2983				  session->host->host_failed);
2984		/*
2985		 * force eh_abort() to unblock
2986		 */
2987		wake_up(&conn->ehwait);
2988	}
2989
2990	/* flush queued up work because we free the connection below */
2991	iscsi_suspend_tx(conn);
2992
2993	spin_lock_bh(&session->frwd_lock);
2994	free_pages((unsigned long) conn->data,
2995		   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2996	kfree(conn->persistent_address);
2997	kfree(conn->local_ipaddr);
2998	/* regular RX path uses back_lock */
2999	spin_lock_bh(&session->back_lock);
3000	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3001		    sizeof(void*));
3002	spin_unlock_bh(&session->back_lock);
3003	if (session->leadconn == conn)
3004		session->leadconn = NULL;
3005	spin_unlock_bh(&session->frwd_lock);
 
3006
3007	iscsi_destroy_conn(cls_conn);
3008}
3009EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3010
3011int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3012{
3013	struct iscsi_conn *conn = cls_conn->dd_data;
3014	struct iscsi_session *session = conn->session;
3015
3016	if (!session) {
3017		iscsi_conn_printk(KERN_ERR, conn,
3018				  "can't start unbound connection\n");
3019		return -EPERM;
3020	}
3021
3022	if ((session->imm_data_en || !session->initial_r2t_en) &&
3023	     session->first_burst > session->max_burst) {
3024		iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3025				  "first_burst %d max_burst %d\n",
3026				  session->first_burst, session->max_burst);
3027		return -EINVAL;
3028	}
3029
3030	if (conn->ping_timeout && !conn->recv_timeout) {
3031		iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3032				  "zero. Using 5 seconds\n.");
3033		conn->recv_timeout = 5;
3034	}
3035
3036	if (conn->recv_timeout && !conn->ping_timeout) {
3037		iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3038				  "zero. Using 5 seconds.\n");
3039		conn->ping_timeout = 5;
3040	}
3041
3042	spin_lock_bh(&session->frwd_lock);
3043	conn->c_stage = ISCSI_CONN_STARTED;
3044	session->state = ISCSI_STATE_LOGGED_IN;
3045	session->queued_cmdsn = session->cmdsn;
3046
3047	conn->last_recv = jiffies;
3048	conn->last_ping = jiffies;
3049	if (conn->recv_timeout && conn->ping_timeout)
3050		mod_timer(&conn->transport_timer,
3051			  jiffies + (conn->recv_timeout * HZ));
3052
3053	switch(conn->stop_stage) {
3054	case STOP_CONN_RECOVER:
3055		/*
3056		 * unblock eh_abort() if it is blocked. re-try all
3057		 * commands after successful recovery
3058		 */
3059		conn->stop_stage = 0;
3060		conn->tmf_state = TMF_INITIAL;
3061		session->age++;
3062		if (session->age == 16)
3063			session->age = 0;
3064		break;
3065	case STOP_CONN_TERM:
3066		conn->stop_stage = 0;
3067		break;
3068	default:
3069		break;
3070	}
3071	spin_unlock_bh(&session->frwd_lock);
3072
3073	iscsi_unblock_session(session->cls_session);
3074	wake_up(&conn->ehwait);
3075	return 0;
3076}
3077EXPORT_SYMBOL_GPL(iscsi_conn_start);
3078
3079static void
3080fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3081{
3082	struct iscsi_task *task;
3083	int i, state;
3084
3085	for (i = 0; i < conn->session->cmds_max; i++) {
3086		task = conn->session->cmds[i];
3087		if (task->sc)
3088			continue;
3089
3090		if (task->state == ISCSI_TASK_FREE)
3091			continue;
3092
3093		ISCSI_DBG_SESSION(conn->session,
3094				  "failing mgmt itt 0x%x state %d\n",
3095				  task->itt, task->state);
3096		state = ISCSI_TASK_ABRT_SESS_RECOV;
3097		if (task->state == ISCSI_TASK_PENDING)
3098			state = ISCSI_TASK_COMPLETED;
3099		iscsi_complete_task(task, state);
3100
3101	}
3102}
3103
3104static void iscsi_start_session_recovery(struct iscsi_session *session,
3105					 struct iscsi_conn *conn, int flag)
3106{
3107	int old_stop_stage;
3108
3109	mutex_lock(&session->eh_mutex);
3110	spin_lock_bh(&session->frwd_lock);
3111	if (conn->stop_stage == STOP_CONN_TERM) {
3112		spin_unlock_bh(&session->frwd_lock);
3113		mutex_unlock(&session->eh_mutex);
3114		return;
3115	}
3116
3117	/*
3118	 * When this is called for the in_login state, we only want to clean
3119	 * up the login task and connection. We do not need to block and set
3120	 * the recovery state again
3121	 */
3122	if (flag == STOP_CONN_TERM)
3123		session->state = ISCSI_STATE_TERMINATE;
3124	else if (conn->stop_stage != STOP_CONN_RECOVER)
3125		session->state = ISCSI_STATE_IN_RECOVERY;
3126
3127	old_stop_stage = conn->stop_stage;
3128	conn->stop_stage = flag;
3129	spin_unlock_bh(&session->frwd_lock);
3130
3131	del_timer_sync(&conn->transport_timer);
3132	iscsi_suspend_tx(conn);
3133
3134	spin_lock_bh(&session->frwd_lock);
3135	conn->c_stage = ISCSI_CONN_STOPPED;
3136	spin_unlock_bh(&session->frwd_lock);
3137
3138	/*
3139	 * for connection level recovery we should not calculate
3140	 * header digest. conn->hdr_size used for optimization
3141	 * in hdr_extract() and will be re-negotiated at
3142	 * set_param() time.
3143	 */
3144	if (flag == STOP_CONN_RECOVER) {
3145		conn->hdrdgst_en = 0;
3146		conn->datadgst_en = 0;
3147		if (session->state == ISCSI_STATE_IN_RECOVERY &&
3148		    old_stop_stage != STOP_CONN_RECOVER) {
3149			ISCSI_DBG_SESSION(session, "blocking session\n");
3150			iscsi_block_session(session->cls_session);
3151		}
3152	}
3153
3154	/*
3155	 * flush queues.
3156	 */
3157	spin_lock_bh(&session->frwd_lock);
3158	fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3159	fail_mgmt_tasks(session, conn);
3160	memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3161	spin_unlock_bh(&session->frwd_lock);
3162	mutex_unlock(&session->eh_mutex);
3163}
3164
3165void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3166{
3167	struct iscsi_conn *conn = cls_conn->dd_data;
3168	struct iscsi_session *session = conn->session;
3169
3170	switch (flag) {
3171	case STOP_CONN_RECOVER:
3172	case STOP_CONN_TERM:
3173		iscsi_start_session_recovery(session, conn, flag);
3174		break;
3175	default:
3176		iscsi_conn_printk(KERN_ERR, conn,
3177				  "invalid stop flag %d\n", flag);
3178	}
3179}
3180EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3181
3182int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3183		    struct iscsi_cls_conn *cls_conn, int is_leading)
3184{
3185	struct iscsi_session *session = cls_session->dd_data;
3186	struct iscsi_conn *conn = cls_conn->dd_data;
3187
3188	spin_lock_bh(&session->frwd_lock);
3189	if (is_leading)
3190		session->leadconn = conn;
3191	spin_unlock_bh(&session->frwd_lock);
3192
3193	/*
3194	 * Unblock xmitworker(), Login Phase will pass through.
3195	 */
3196	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3197	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3198	return 0;
3199}
3200EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3201
3202int iscsi_switch_str_param(char **param, char *new_val_buf)
3203{
3204	char *new_val;
3205
3206	if (*param) {
3207		if (!strcmp(*param, new_val_buf))
3208			return 0;
3209	}
3210
3211	new_val = kstrdup(new_val_buf, GFP_NOIO);
3212	if (!new_val)
3213		return -ENOMEM;
3214
3215	kfree(*param);
3216	*param = new_val;
3217	return 0;
3218}
3219EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3220
3221int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3222		    enum iscsi_param param, char *buf, int buflen)
3223{
3224	struct iscsi_conn *conn = cls_conn->dd_data;
3225	struct iscsi_session *session = conn->session;
3226	int val;
3227
3228	switch(param) {
3229	case ISCSI_PARAM_FAST_ABORT:
3230		sscanf(buf, "%d", &session->fast_abort);
3231		break;
3232	case ISCSI_PARAM_ABORT_TMO:
3233		sscanf(buf, "%d", &session->abort_timeout);
3234		break;
3235	case ISCSI_PARAM_LU_RESET_TMO:
3236		sscanf(buf, "%d", &session->lu_reset_timeout);
3237		break;
3238	case ISCSI_PARAM_TGT_RESET_TMO:
3239		sscanf(buf, "%d", &session->tgt_reset_timeout);
3240		break;
3241	case ISCSI_PARAM_PING_TMO:
3242		sscanf(buf, "%d", &conn->ping_timeout);
3243		break;
3244	case ISCSI_PARAM_RECV_TMO:
3245		sscanf(buf, "%d", &conn->recv_timeout);
3246		break;
3247	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3248		sscanf(buf, "%d", &conn->max_recv_dlength);
3249		break;
3250	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3251		sscanf(buf, "%d", &conn->max_xmit_dlength);
3252		break;
3253	case ISCSI_PARAM_HDRDGST_EN:
3254		sscanf(buf, "%d", &conn->hdrdgst_en);
3255		break;
3256	case ISCSI_PARAM_DATADGST_EN:
3257		sscanf(buf, "%d", &conn->datadgst_en);
3258		break;
3259	case ISCSI_PARAM_INITIAL_R2T_EN:
3260		sscanf(buf, "%d", &session->initial_r2t_en);
3261		break;
3262	case ISCSI_PARAM_MAX_R2T:
3263		sscanf(buf, "%hu", &session->max_r2t);
3264		break;
3265	case ISCSI_PARAM_IMM_DATA_EN:
3266		sscanf(buf, "%d", &session->imm_data_en);
3267		break;
3268	case ISCSI_PARAM_FIRST_BURST:
3269		sscanf(buf, "%d", &session->first_burst);
3270		break;
3271	case ISCSI_PARAM_MAX_BURST:
3272		sscanf(buf, "%d", &session->max_burst);
3273		break;
3274	case ISCSI_PARAM_PDU_INORDER_EN:
3275		sscanf(buf, "%d", &session->pdu_inorder_en);
3276		break;
3277	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3278		sscanf(buf, "%d", &session->dataseq_inorder_en);
3279		break;
3280	case ISCSI_PARAM_ERL:
3281		sscanf(buf, "%d", &session->erl);
3282		break;
3283	case ISCSI_PARAM_EXP_STATSN:
3284		sscanf(buf, "%u", &conn->exp_statsn);
3285		break;
3286	case ISCSI_PARAM_USERNAME:
3287		return iscsi_switch_str_param(&session->username, buf);
3288	case ISCSI_PARAM_USERNAME_IN:
3289		return iscsi_switch_str_param(&session->username_in, buf);
3290	case ISCSI_PARAM_PASSWORD:
3291		return iscsi_switch_str_param(&session->password, buf);
3292	case ISCSI_PARAM_PASSWORD_IN:
3293		return iscsi_switch_str_param(&session->password_in, buf);
3294	case ISCSI_PARAM_TARGET_NAME:
3295		return iscsi_switch_str_param(&session->targetname, buf);
3296	case ISCSI_PARAM_TARGET_ALIAS:
3297		return iscsi_switch_str_param(&session->targetalias, buf);
3298	case ISCSI_PARAM_TPGT:
3299		sscanf(buf, "%d", &session->tpgt);
3300		break;
3301	case ISCSI_PARAM_PERSISTENT_PORT:
3302		sscanf(buf, "%d", &conn->persistent_port);
3303		break;
3304	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3305		return iscsi_switch_str_param(&conn->persistent_address, buf);
3306	case ISCSI_PARAM_IFACE_NAME:
3307		return iscsi_switch_str_param(&session->ifacename, buf);
3308	case ISCSI_PARAM_INITIATOR_NAME:
3309		return iscsi_switch_str_param(&session->initiatorname, buf);
3310	case ISCSI_PARAM_BOOT_ROOT:
3311		return iscsi_switch_str_param(&session->boot_root, buf);
3312	case ISCSI_PARAM_BOOT_NIC:
3313		return iscsi_switch_str_param(&session->boot_nic, buf);
3314	case ISCSI_PARAM_BOOT_TARGET:
3315		return iscsi_switch_str_param(&session->boot_target, buf);
3316	case ISCSI_PARAM_PORTAL_TYPE:
3317		return iscsi_switch_str_param(&session->portal_type, buf);
3318	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3319		return iscsi_switch_str_param(&session->discovery_parent_type,
3320					      buf);
3321	case ISCSI_PARAM_DISCOVERY_SESS:
3322		sscanf(buf, "%d", &val);
3323		session->discovery_sess = !!val;
3324		break;
3325	case ISCSI_PARAM_LOCAL_IPADDR:
3326		return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3327	default:
3328		return -ENOSYS;
3329	}
3330
3331	return 0;
3332}
3333EXPORT_SYMBOL_GPL(iscsi_set_param);
3334
3335int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3336			    enum iscsi_param param, char *buf)
3337{
3338	struct iscsi_session *session = cls_session->dd_data;
3339	int len;
3340
3341	switch(param) {
3342	case ISCSI_PARAM_FAST_ABORT:
3343		len = sprintf(buf, "%d\n", session->fast_abort);
3344		break;
3345	case ISCSI_PARAM_ABORT_TMO:
3346		len = sprintf(buf, "%d\n", session->abort_timeout);
3347		break;
3348	case ISCSI_PARAM_LU_RESET_TMO:
3349		len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3350		break;
3351	case ISCSI_PARAM_TGT_RESET_TMO:
3352		len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3353		break;
3354	case ISCSI_PARAM_INITIAL_R2T_EN:
3355		len = sprintf(buf, "%d\n", session->initial_r2t_en);
3356		break;
3357	case ISCSI_PARAM_MAX_R2T:
3358		len = sprintf(buf, "%hu\n", session->max_r2t);
3359		break;
3360	case ISCSI_PARAM_IMM_DATA_EN:
3361		len = sprintf(buf, "%d\n", session->imm_data_en);
3362		break;
3363	case ISCSI_PARAM_FIRST_BURST:
3364		len = sprintf(buf, "%u\n", session->first_burst);
3365		break;
3366	case ISCSI_PARAM_MAX_BURST:
3367		len = sprintf(buf, "%u\n", session->max_burst);
3368		break;
3369	case ISCSI_PARAM_PDU_INORDER_EN:
3370		len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3371		break;
3372	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3373		len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3374		break;
3375	case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3376		len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3377		break;
3378	case ISCSI_PARAM_ERL:
3379		len = sprintf(buf, "%d\n", session->erl);
3380		break;
3381	case ISCSI_PARAM_TARGET_NAME:
3382		len = sprintf(buf, "%s\n", session->targetname);
3383		break;
3384	case ISCSI_PARAM_TARGET_ALIAS:
3385		len = sprintf(buf, "%s\n", session->targetalias);
3386		break;
3387	case ISCSI_PARAM_TPGT:
3388		len = sprintf(buf, "%d\n", session->tpgt);
3389		break;
3390	case ISCSI_PARAM_USERNAME:
3391		len = sprintf(buf, "%s\n", session->username);
3392		break;
3393	case ISCSI_PARAM_USERNAME_IN:
3394		len = sprintf(buf, "%s\n", session->username_in);
3395		break;
3396	case ISCSI_PARAM_PASSWORD:
3397		len = sprintf(buf, "%s\n", session->password);
3398		break;
3399	case ISCSI_PARAM_PASSWORD_IN:
3400		len = sprintf(buf, "%s\n", session->password_in);
3401		break;
3402	case ISCSI_PARAM_IFACE_NAME:
3403		len = sprintf(buf, "%s\n", session->ifacename);
3404		break;
3405	case ISCSI_PARAM_INITIATOR_NAME:
3406		len = sprintf(buf, "%s\n", session->initiatorname);
3407		break;
3408	case ISCSI_PARAM_BOOT_ROOT:
3409		len = sprintf(buf, "%s\n", session->boot_root);
3410		break;
3411	case ISCSI_PARAM_BOOT_NIC:
3412		len = sprintf(buf, "%s\n", session->boot_nic);
3413		break;
3414	case ISCSI_PARAM_BOOT_TARGET:
3415		len = sprintf(buf, "%s\n", session->boot_target);
3416		break;
3417	case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3418		len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3419		break;
3420	case ISCSI_PARAM_DISCOVERY_SESS:
3421		len = sprintf(buf, "%u\n", session->discovery_sess);
3422		break;
3423	case ISCSI_PARAM_PORTAL_TYPE:
3424		len = sprintf(buf, "%s\n", session->portal_type);
3425		break;
3426	case ISCSI_PARAM_CHAP_AUTH_EN:
3427		len = sprintf(buf, "%u\n", session->chap_auth_en);
3428		break;
3429	case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3430		len = sprintf(buf, "%u\n", session->discovery_logout_en);
3431		break;
3432	case ISCSI_PARAM_BIDI_CHAP_EN:
3433		len = sprintf(buf, "%u\n", session->bidi_chap_en);
3434		break;
3435	case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3436		len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3437		break;
3438	case ISCSI_PARAM_DEF_TIME2WAIT:
3439		len = sprintf(buf, "%d\n", session->time2wait);
3440		break;
3441	case ISCSI_PARAM_DEF_TIME2RETAIN:
3442		len = sprintf(buf, "%d\n", session->time2retain);
3443		break;
3444	case ISCSI_PARAM_TSID:
3445		len = sprintf(buf, "%u\n", session->tsid);
3446		break;
3447	case ISCSI_PARAM_ISID:
3448		len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3449			      session->isid[0], session->isid[1],
3450			      session->isid[2], session->isid[3],
3451			      session->isid[4], session->isid[5]);
3452		break;
3453	case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3454		len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3455		break;
3456	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3457		if (session->discovery_parent_type)
3458			len = sprintf(buf, "%s\n",
3459				      session->discovery_parent_type);
3460		else
3461			len = sprintf(buf, "\n");
3462		break;
3463	default:
3464		return -ENOSYS;
3465	}
3466
3467	return len;
3468}
3469EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3470
3471int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3472			      enum iscsi_param param, char *buf)
3473{
3474	struct sockaddr_in6 *sin6 = NULL;
3475	struct sockaddr_in *sin = NULL;
3476	int len;
3477
3478	switch (addr->ss_family) {
3479	case AF_INET:
3480		sin = (struct sockaddr_in *)addr;
3481		break;
3482	case AF_INET6:
3483		sin6 = (struct sockaddr_in6 *)addr;
3484		break;
3485	default:
3486		return -EINVAL;
3487	}
3488
3489	switch (param) {
3490	case ISCSI_PARAM_CONN_ADDRESS:
3491	case ISCSI_HOST_PARAM_IPADDRESS:
3492		if (sin)
3493			len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3494		else
3495			len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3496		break;
3497	case ISCSI_PARAM_CONN_PORT:
 
3498		if (sin)
3499			len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3500		else
3501			len = sprintf(buf, "%hu\n",
3502				      be16_to_cpu(sin6->sin6_port));
3503		break;
3504	default:
3505		return -EINVAL;
3506	}
3507
3508	return len;
3509}
3510EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3511
3512int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3513			 enum iscsi_param param, char *buf)
3514{
3515	struct iscsi_conn *conn = cls_conn->dd_data;
3516	int len;
3517
3518	switch(param) {
3519	case ISCSI_PARAM_PING_TMO:
3520		len = sprintf(buf, "%u\n", conn->ping_timeout);
3521		break;
3522	case ISCSI_PARAM_RECV_TMO:
3523		len = sprintf(buf, "%u\n", conn->recv_timeout);
3524		break;
3525	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3526		len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3527		break;
3528	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3529		len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3530		break;
3531	case ISCSI_PARAM_HDRDGST_EN:
3532		len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3533		break;
3534	case ISCSI_PARAM_DATADGST_EN:
3535		len = sprintf(buf, "%d\n", conn->datadgst_en);
3536		break;
3537	case ISCSI_PARAM_IFMARKER_EN:
3538		len = sprintf(buf, "%d\n", conn->ifmarker_en);
3539		break;
3540	case ISCSI_PARAM_OFMARKER_EN:
3541		len = sprintf(buf, "%d\n", conn->ofmarker_en);
3542		break;
3543	case ISCSI_PARAM_EXP_STATSN:
3544		len = sprintf(buf, "%u\n", conn->exp_statsn);
3545		break;
3546	case ISCSI_PARAM_PERSISTENT_PORT:
3547		len = sprintf(buf, "%d\n", conn->persistent_port);
3548		break;
3549	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3550		len = sprintf(buf, "%s\n", conn->persistent_address);
3551		break;
3552	case ISCSI_PARAM_STATSN:
3553		len = sprintf(buf, "%u\n", conn->statsn);
3554		break;
3555	case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3556		len = sprintf(buf, "%u\n", conn->max_segment_size);
3557		break;
3558	case ISCSI_PARAM_KEEPALIVE_TMO:
3559		len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3560		break;
3561	case ISCSI_PARAM_LOCAL_PORT:
3562		len = sprintf(buf, "%u\n", conn->local_port);
3563		break;
3564	case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3565		len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3566		break;
3567	case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3568		len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3569		break;
3570	case ISCSI_PARAM_TCP_WSF_DISABLE:
3571		len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3572		break;
3573	case ISCSI_PARAM_TCP_TIMER_SCALE:
3574		len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3575		break;
3576	case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3577		len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3578		break;
3579	case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3580		len = sprintf(buf, "%u\n", conn->fragment_disable);
3581		break;
3582	case ISCSI_PARAM_IPV4_TOS:
3583		len = sprintf(buf, "%u\n", conn->ipv4_tos);
3584		break;
3585	case ISCSI_PARAM_IPV6_TC:
3586		len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3587		break;
3588	case ISCSI_PARAM_IPV6_FLOW_LABEL:
3589		len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3590		break;
3591	case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3592		len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3593		break;
3594	case ISCSI_PARAM_TCP_XMIT_WSF:
3595		len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3596		break;
3597	case ISCSI_PARAM_TCP_RECV_WSF:
3598		len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3599		break;
3600	case ISCSI_PARAM_LOCAL_IPADDR:
3601		len = sprintf(buf, "%s\n", conn->local_ipaddr);
3602		break;
3603	default:
3604		return -ENOSYS;
3605	}
3606
3607	return len;
3608}
3609EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3610
3611int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3612			 char *buf)
3613{
3614	struct iscsi_host *ihost = shost_priv(shost);
3615	int len;
3616
3617	switch (param) {
3618	case ISCSI_HOST_PARAM_NETDEV_NAME:
3619		len = sprintf(buf, "%s\n", ihost->netdev);
3620		break;
3621	case ISCSI_HOST_PARAM_HWADDRESS:
3622		len = sprintf(buf, "%s\n", ihost->hwaddress);
3623		break;
3624	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3625		len = sprintf(buf, "%s\n", ihost->initiatorname);
3626		break;
3627	default:
3628		return -ENOSYS;
3629	}
3630
3631	return len;
3632}
3633EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3634
3635int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3636			 char *buf, int buflen)
3637{
3638	struct iscsi_host *ihost = shost_priv(shost);
3639
3640	switch (param) {
3641	case ISCSI_HOST_PARAM_NETDEV_NAME:
3642		return iscsi_switch_str_param(&ihost->netdev, buf);
3643	case ISCSI_HOST_PARAM_HWADDRESS:
3644		return iscsi_switch_str_param(&ihost->hwaddress, buf);
3645	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3646		return iscsi_switch_str_param(&ihost->initiatorname, buf);
3647	default:
3648		return -ENOSYS;
3649	}
3650
3651	return 0;
3652}
3653EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3654
3655MODULE_AUTHOR("Mike Christie");
3656MODULE_DESCRIPTION("iSCSI library functions");
3657MODULE_LICENSE("GPL");