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