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v3.1
   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 <asm/unaligned.h>
  30#include <net/tcp.h>
  31#include <scsi/scsi_cmnd.h>
  32#include <scsi/scsi_device.h>
  33#include <scsi/scsi_eh.h>
  34#include <scsi/scsi_tcq.h>
  35#include <scsi/scsi_host.h>
  36#include <scsi/scsi.h>
  37#include <scsi/iscsi_proto.h>
  38#include <scsi/scsi_transport.h>
  39#include <scsi/scsi_transport_iscsi.h>
  40#include <scsi/libiscsi.h>
  41
  42static int iscsi_dbg_lib_conn;
  43module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  44		   S_IRUGO | S_IWUSR);
  45MODULE_PARM_DESC(debug_libiscsi_conn,
  46		 "Turn on debugging for connections in libiscsi module. "
  47		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  48
  49static int iscsi_dbg_lib_session;
  50module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  51		   S_IRUGO | S_IWUSR);
  52MODULE_PARM_DESC(debug_libiscsi_session,
  53		 "Turn on debugging for sessions in libiscsi module. "
  54		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  55
  56static int iscsi_dbg_lib_eh;
  57module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  58		   S_IRUGO | S_IWUSR);
  59MODULE_PARM_DESC(debug_libiscsi_eh,
  60		 "Turn on debugging for error handling in libiscsi module. "
  61		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  62
  63#define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)			\
  64	do {							\
  65		if (iscsi_dbg_lib_conn)				\
  66			iscsi_conn_printk(KERN_INFO, _conn,	\
  67					     "%s " dbg_fmt,	\
  68					     __func__, ##arg);	\
  69	} while (0);
  70
  71#define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)			\
  72	do {								\
  73		if (iscsi_dbg_lib_session)				\
  74			iscsi_session_printk(KERN_INFO, _session,	\
  75					     "%s " dbg_fmt,		\
  76					     __func__, ##arg);		\
  77	} while (0);
  78
  79#define ISCSI_DBG_EH(_session, dbg_fmt, arg...)				\
  80	do {								\
  81		if (iscsi_dbg_lib_eh)					\
  82			iscsi_session_printk(KERN_INFO, _session,	\
  83					     "%s " dbg_fmt,		\
  84					     __func__, ##arg);		\
  85	} while (0);
  86
  87inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
  88{
  89	struct Scsi_Host *shost = conn->session->host;
  90	struct iscsi_host *ihost = shost_priv(shost);
  91
  92	if (ihost->workq)
  93		queue_work(ihost->workq, &conn->xmitwork);
  94}
  95EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
  96
  97static void __iscsi_update_cmdsn(struct iscsi_session *session,
  98				 uint32_t exp_cmdsn, uint32_t max_cmdsn)
  99{
 100	/*
 101	 * standard specifies this check for when to update expected and
 102	 * max sequence numbers
 103	 */
 104	if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 105		return;
 106
 107	if (exp_cmdsn != session->exp_cmdsn &&
 108	    !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 109		session->exp_cmdsn = exp_cmdsn;
 110
 111	if (max_cmdsn != session->max_cmdsn &&
 112	    !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
 113		session->max_cmdsn = max_cmdsn;
 114		/*
 115		 * if the window closed with IO queued, then kick the
 116		 * xmit thread
 117		 */
 118		if (!list_empty(&session->leadconn->cmdqueue) ||
 119		    !list_empty(&session->leadconn->mgmtqueue))
 120			iscsi_conn_queue_work(session->leadconn);
 121	}
 122}
 123
 124void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 125{
 126	__iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 127			     be32_to_cpu(hdr->max_cmdsn));
 128}
 129EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 130
 131/**
 132 * iscsi_prep_data_out_pdu - initialize Data-Out
 133 * @task: scsi command task
 134 * @r2t: R2T info
 135 * @hdr: iscsi data in pdu
 136 *
 137 * Notes:
 138 *	Initialize Data-Out within this R2T sequence and finds
 139 *	proper data_offset within this SCSI command.
 140 *
 141 *	This function is called with connection lock taken.
 142 **/
 143void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 144			   struct iscsi_data *hdr)
 145{
 146	struct iscsi_conn *conn = task->conn;
 147	unsigned int left = r2t->data_length - r2t->sent;
 148
 149	task->hdr_len = sizeof(struct iscsi_data);
 150
 151	memset(hdr, 0, sizeof(struct iscsi_data));
 152	hdr->ttt = r2t->ttt;
 153	hdr->datasn = cpu_to_be32(r2t->datasn);
 154	r2t->datasn++;
 155	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 156	hdr->lun = task->lun;
 157	hdr->itt = task->hdr_itt;
 158	hdr->exp_statsn = r2t->exp_statsn;
 159	hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 160	if (left > conn->max_xmit_dlength) {
 161		hton24(hdr->dlength, conn->max_xmit_dlength);
 162		r2t->data_count = conn->max_xmit_dlength;
 163		hdr->flags = 0;
 164	} else {
 165		hton24(hdr->dlength, left);
 166		r2t->data_count = left;
 167		hdr->flags = ISCSI_FLAG_CMD_FINAL;
 168	}
 169	conn->dataout_pdus_cnt++;
 170}
 171EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 172
 173static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 174{
 175	unsigned exp_len = task->hdr_len + len;
 176
 177	if (exp_len > task->hdr_max) {
 178		WARN_ON(1);
 179		return -EINVAL;
 180	}
 181
 182	WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 183	task->hdr_len = exp_len;
 184	return 0;
 185}
 186
 187/*
 188 * make an extended cdb AHS
 189 */
 190static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 191{
 192	struct scsi_cmnd *cmd = task->sc;
 193	unsigned rlen, pad_len;
 194	unsigned short ahslength;
 195	struct iscsi_ecdb_ahdr *ecdb_ahdr;
 196	int rc;
 197
 198	ecdb_ahdr = iscsi_next_hdr(task);
 199	rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 200
 201	BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 202	ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 203
 204	pad_len = iscsi_padding(rlen);
 205
 206	rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 207	                   sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 208	if (rc)
 209		return rc;
 210
 211	if (pad_len)
 212		memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 213
 214	ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 215	ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 216	ecdb_ahdr->reserved = 0;
 217	memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 218
 219	ISCSI_DBG_SESSION(task->conn->session,
 220			  "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 221		          "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 222		          "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 223		          task->hdr_len);
 224	return 0;
 225}
 226
 227static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 228{
 229	struct scsi_cmnd *sc = task->sc;
 230	struct iscsi_rlength_ahdr *rlen_ahdr;
 231	int rc;
 232
 233	rlen_ahdr = iscsi_next_hdr(task);
 234	rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 235	if (rc)
 236		return rc;
 237
 238	rlen_ahdr->ahslength =
 239		cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 240						  sizeof(rlen_ahdr->reserved));
 241	rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 242	rlen_ahdr->reserved = 0;
 243	rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 244
 245	ISCSI_DBG_SESSION(task->conn->session,
 246			  "bidi-in rlen_ahdr->read_length(%d) "
 247		          "rlen_ahdr->ahslength(%d)\n",
 248		          be32_to_cpu(rlen_ahdr->read_length),
 249		          be16_to_cpu(rlen_ahdr->ahslength));
 250	return 0;
 251}
 252
 253/**
 254 * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 255 * @task: iscsi task
 256 * @opcode: opcode to check for
 257 *
 258 * During TMF a task has to be checked if it's affected.
 259 * All unrelated I/O can be passed through, but I/O to the
 260 * affected LUN should be restricted.
 261 * If 'fast_abort' is set we won't be sending any I/O to the
 262 * affected LUN.
 263 * Otherwise the target is waiting for all TTTs to be completed,
 264 * so we have to send all outstanding Data-Out PDUs to the target.
 265 */
 266static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 267{
 268	struct iscsi_conn *conn = task->conn;
 269	struct iscsi_tm *tmf = &conn->tmhdr;
 270	unsigned int hdr_lun;
 271
 272	if (conn->tmf_state == TMF_INITIAL)
 273		return 0;
 274
 275	if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 276		return 0;
 277
 278	switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 279	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 280		/*
 281		 * Allow PDUs for unrelated LUNs
 282		 */
 283		hdr_lun = scsilun_to_int(&tmf->lun);
 284		if (hdr_lun != task->sc->device->lun)
 285			return 0;
 286		/* fall through */
 287	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 288		/*
 289		 * Fail all SCSI cmd PDUs
 290		 */
 291		if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 292			iscsi_conn_printk(KERN_INFO, conn,
 293					  "task [op %x/%x itt "
 294					  "0x%x/0x%x] "
 295					  "rejected.\n",
 296					  task->hdr->opcode, opcode,
 297					  task->itt, task->hdr_itt);
 298			return -EACCES;
 299		}
 300		/*
 301		 * And also all data-out PDUs in response to R2T
 302		 * if fast_abort is set.
 303		 */
 304		if (conn->session->fast_abort) {
 305			iscsi_conn_printk(KERN_INFO, conn,
 306					  "task [op %x/%x itt "
 307					  "0x%x/0x%x] fast abort.\n",
 308					  task->hdr->opcode, opcode,
 309					  task->itt, task->hdr_itt);
 310			return -EACCES;
 311		}
 312		break;
 313	case ISCSI_TM_FUNC_ABORT_TASK:
 314		/*
 315		 * the caller has already checked if the task
 316		 * they want to abort was in the pending queue so if
 317		 * we are here the cmd pdu has gone out already, and
 318		 * we will only hit this for data-outs
 319		 */
 320		if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 321		    task->hdr_itt == tmf->rtt) {
 322			ISCSI_DBG_SESSION(conn->session,
 323					  "Preventing task %x/%x from sending "
 324					  "data-out due to abort task in "
 325					  "progress\n", task->itt,
 326					  task->hdr_itt);
 327			return -EACCES;
 328		}
 329		break;
 330	}
 331
 332	return 0;
 333}
 334
 335/**
 336 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 337 * @task: iscsi task
 338 *
 339 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 340 * fields like dlength or final based on how much data it sends
 341 */
 342static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 343{
 344	struct iscsi_conn *conn = task->conn;
 345	struct iscsi_session *session = conn->session;
 346	struct scsi_cmnd *sc = task->sc;
 347	struct iscsi_scsi_req *hdr;
 348	unsigned hdrlength, cmd_len;
 349	itt_t itt;
 350	int rc;
 351
 352	rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 353	if (rc)
 354		return rc;
 355
 356	if (conn->session->tt->alloc_pdu) {
 357		rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 358		if (rc)
 359			return rc;
 360	}
 361	hdr = (struct iscsi_scsi_req *)task->hdr;
 362	itt = hdr->itt;
 363	memset(hdr, 0, sizeof(*hdr));
 364
 365	if (session->tt->parse_pdu_itt)
 366		hdr->itt = task->hdr_itt = itt;
 367	else
 368		hdr->itt = task->hdr_itt = build_itt(task->itt,
 369						     task->conn->session->age);
 370	task->hdr_len = 0;
 371	rc = iscsi_add_hdr(task, sizeof(*hdr));
 372	if (rc)
 373		return rc;
 374	hdr->opcode = ISCSI_OP_SCSI_CMD;
 375	hdr->flags = ISCSI_ATTR_SIMPLE;
 376	int_to_scsilun(sc->device->lun, &hdr->lun);
 377	task->lun = hdr->lun;
 378	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 379	cmd_len = sc->cmd_len;
 380	if (cmd_len < ISCSI_CDB_SIZE)
 381		memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 382	else if (cmd_len > ISCSI_CDB_SIZE) {
 383		rc = iscsi_prep_ecdb_ahs(task);
 384		if (rc)
 385			return rc;
 386		cmd_len = ISCSI_CDB_SIZE;
 387	}
 388	memcpy(hdr->cdb, sc->cmnd, cmd_len);
 389
 390	task->imm_count = 0;
 391	if (scsi_bidi_cmnd(sc)) {
 392		hdr->flags |= ISCSI_FLAG_CMD_READ;
 393		rc = iscsi_prep_bidi_ahs(task);
 394		if (rc)
 395			return rc;
 396	}
 
 
 
 
 
 
 397	if (sc->sc_data_direction == DMA_TO_DEVICE) {
 398		unsigned out_len = scsi_out(sc)->length;
 399		struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 400
 401		hdr->data_length = cpu_to_be32(out_len);
 402		hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 403		/*
 404		 * Write counters:
 405		 *
 406		 *	imm_count	bytes to be sent right after
 407		 *			SCSI PDU Header
 408		 *
 409		 *	unsol_count	bytes(as Data-Out) to be sent
 410		 *			without	R2T ack right after
 411		 *			immediate data
 412		 *
 413		 *	r2t data_length bytes to be sent via R2T ack's
 414		 *
 415		 *      pad_count       bytes to be sent as zero-padding
 416		 */
 417		memset(r2t, 0, sizeof(*r2t));
 418
 419		if (session->imm_data_en) {
 420			if (out_len >= session->first_burst)
 421				task->imm_count = min(session->first_burst,
 422							conn->max_xmit_dlength);
 423			else
 424				task->imm_count = min(out_len,
 425							conn->max_xmit_dlength);
 426			hton24(hdr->dlength, task->imm_count);
 427		} else
 428			zero_data(hdr->dlength);
 429
 430		if (!session->initial_r2t_en) {
 431			r2t->data_length = min(session->first_burst, out_len) -
 
 432					       task->imm_count;
 433			r2t->data_offset = task->imm_count;
 434			r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 435			r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 436		}
 437
 438		if (!task->unsol_r2t.data_length)
 439			/* No unsolicit Data-Out's */
 440			hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 441	} else {
 442		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 443		zero_data(hdr->dlength);
 444		hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
 445
 446		if (sc->sc_data_direction == DMA_FROM_DEVICE)
 447			hdr->flags |= ISCSI_FLAG_CMD_READ;
 448	}
 449
 450	/* calculate size of additional header segments (AHSs) */
 451	hdrlength = task->hdr_len - sizeof(*hdr);
 452
 453	WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 454	hdrlength /= ISCSI_PAD_LEN;
 455
 456	WARN_ON(hdrlength >= 256);
 457	hdr->hlength = hdrlength & 0xFF;
 458	hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 459
 460	if (session->tt->init_task && session->tt->init_task(task))
 461		return -EIO;
 462
 463	task->state = ISCSI_TASK_RUNNING;
 464	session->cmdsn++;
 465
 466	conn->scsicmd_pdus_cnt++;
 467	ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 468			  "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
 469			  scsi_bidi_cmnd(sc) ? "bidirectional" :
 470			  sc->sc_data_direction == DMA_TO_DEVICE ?
 471			  "write" : "read", conn->id, sc, sc->cmnd[0],
 472			  task->itt, scsi_bufflen(sc),
 473			  scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 474			  session->cmdsn,
 475			  session->max_cmdsn - session->exp_cmdsn + 1);
 476	return 0;
 477}
 478
 479/**
 480 * iscsi_free_task - free a task
 481 * @task: iscsi cmd task
 482 *
 483 * Must be called with session lock.
 484 * This function returns the scsi command to scsi-ml or cleans
 485 * up mgmt tasks then returns the task to the pool.
 486 */
 487static void iscsi_free_task(struct iscsi_task *task)
 488{
 489	struct iscsi_conn *conn = task->conn;
 490	struct iscsi_session *session = conn->session;
 491	struct scsi_cmnd *sc = task->sc;
 492	int oldstate = task->state;
 493
 494	ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 495			  task->itt, task->state, task->sc);
 496
 497	session->tt->cleanup_task(task);
 498	task->state = ISCSI_TASK_FREE;
 499	task->sc = NULL;
 500	/*
 501	 * login task is preallocated so do not free
 502	 */
 503	if (conn->login_task == task)
 504		return;
 505
 506	kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 507
 508	if (sc) {
 509		task->sc = NULL;
 510		/* SCSI eh reuses commands to verify us */
 511		sc->SCp.ptr = NULL;
 512		/*
 513		 * queue command may call this to free the task, so
 514		 * it will decide how to return sc to scsi-ml.
 515		 */
 516		if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 517			sc->scsi_done(sc);
 518	}
 519}
 520
 521void __iscsi_get_task(struct iscsi_task *task)
 522{
 523	atomic_inc(&task->refcount);
 524}
 525EXPORT_SYMBOL_GPL(__iscsi_get_task);
 526
 527void __iscsi_put_task(struct iscsi_task *task)
 528{
 529	if (atomic_dec_and_test(&task->refcount))
 530		iscsi_free_task(task);
 531}
 532EXPORT_SYMBOL_GPL(__iscsi_put_task);
 533
 534void iscsi_put_task(struct iscsi_task *task)
 535{
 536	struct iscsi_session *session = task->conn->session;
 537
 538	spin_lock_bh(&session->lock);
 
 539	__iscsi_put_task(task);
 540	spin_unlock_bh(&session->lock);
 541}
 542EXPORT_SYMBOL_GPL(iscsi_put_task);
 543
 544/**
 545 * iscsi_complete_task - finish a task
 546 * @task: iscsi cmd task
 547 * @state: state to complete task with
 548 *
 549 * Must be called with session lock.
 550 */
 551static void iscsi_complete_task(struct iscsi_task *task, int state)
 552{
 553	struct iscsi_conn *conn = task->conn;
 554
 555	ISCSI_DBG_SESSION(conn->session,
 556			  "complete task itt 0x%x state %d sc %p\n",
 557			  task->itt, task->state, task->sc);
 558	if (task->state == ISCSI_TASK_COMPLETED ||
 559	    task->state == ISCSI_TASK_ABRT_TMF ||
 560	    task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 561	    task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 562		return;
 563	WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 564	task->state = state;
 565
 566	if (!list_empty(&task->running))
 567		list_del_init(&task->running);
 568
 569	if (conn->task == task)
 570		conn->task = NULL;
 571
 572	if (conn->ping_task == task)
 573		conn->ping_task = NULL;
 574
 575	/* release get from queueing */
 576	__iscsi_put_task(task);
 577}
 578
 579/**
 580 * iscsi_complete_scsi_task - finish scsi task normally
 581 * @task: iscsi task for scsi cmd
 582 * @exp_cmdsn: expected cmd sn in cpu format
 583 * @max_cmdsn: max cmd sn in cpu format
 584 *
 585 * This is used when drivers do not need or cannot perform
 586 * lower level pdu processing.
 587 *
 588 * Called with session lock
 589 */
 590void iscsi_complete_scsi_task(struct iscsi_task *task,
 591			      uint32_t exp_cmdsn, uint32_t max_cmdsn)
 592{
 593	struct iscsi_conn *conn = task->conn;
 594
 595	ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 596
 597	conn->last_recv = jiffies;
 598	__iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 599	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 600}
 601EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 602
 603
 604/*
 605 * session lock must be held and if not called for a task that is
 606 * still pending or from the xmit thread, then xmit thread must
 607 * be suspended.
 608 */
 609static void fail_scsi_task(struct iscsi_task *task, int err)
 610{
 611	struct iscsi_conn *conn = task->conn;
 612	struct scsi_cmnd *sc;
 613	int state;
 614
 615	/*
 616	 * if a command completes and we get a successful tmf response
 617	 * we will hit this because the scsi eh abort code does not take
 618	 * a ref to the task.
 619	 */
 620	sc = task->sc;
 621	if (!sc)
 622		return;
 623
 624	if (task->state == ISCSI_TASK_PENDING) {
 625		/*
 626		 * cmd never made it to the xmit thread, so we should not count
 627		 * the cmd in the sequencing
 628		 */
 629		conn->session->queued_cmdsn--;
 630		/* it was never sent so just complete like normal */
 631		state = ISCSI_TASK_COMPLETED;
 632	} else if (err == DID_TRANSPORT_DISRUPTED)
 633		state = ISCSI_TASK_ABRT_SESS_RECOV;
 634	else
 635		state = ISCSI_TASK_ABRT_TMF;
 636
 637	sc->result = err << 16;
 638	if (!scsi_bidi_cmnd(sc))
 639		scsi_set_resid(sc, scsi_bufflen(sc));
 640	else {
 641		scsi_out(sc)->resid = scsi_out(sc)->length;
 642		scsi_in(sc)->resid = scsi_in(sc)->length;
 643	}
 644
 
 
 645	iscsi_complete_task(task, state);
 
 646}
 647
 648static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 649				struct iscsi_task *task)
 650{
 651	struct iscsi_session *session = conn->session;
 652	struct iscsi_hdr *hdr = task->hdr;
 653	struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 654	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 655
 656	if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 657		return -ENOTCONN;
 658
 659	if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 660		nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 661	/*
 662	 * pre-format CmdSN for outgoing PDU.
 663	 */
 664	nop->cmdsn = cpu_to_be32(session->cmdsn);
 665	if (hdr->itt != RESERVED_ITT) {
 666		/*
 667		 * TODO: We always use immediate for normal session pdus.
 668		 * If we start to send tmfs or nops as non-immediate then
 669		 * we should start checking the cmdsn numbers for mgmt tasks.
 670		 *
 671		 * During discovery sessions iscsid sends TEXT as non immediate,
 672		 * but we always only send one PDU at a time.
 673		 */
 674		if (conn->c_stage == ISCSI_CONN_STARTED &&
 675		    !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 676			session->queued_cmdsn++;
 677			session->cmdsn++;
 678		}
 679	}
 680
 681	if (session->tt->init_task && session->tt->init_task(task))
 682		return -EIO;
 683
 684	if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 685		session->state = ISCSI_STATE_LOGGING_OUT;
 686
 687	task->state = ISCSI_TASK_RUNNING;
 688	ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 689			  "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 690			  hdr->itt, task->data_count);
 691	return 0;
 692}
 693
 694static struct iscsi_task *
 695__iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 696		      char *data, uint32_t data_size)
 697{
 698	struct iscsi_session *session = conn->session;
 699	struct iscsi_host *ihost = shost_priv(session->host);
 700	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 701	struct iscsi_task *task;
 702	itt_t itt;
 703
 704	if (session->state == ISCSI_STATE_TERMINATE)
 705		return NULL;
 706
 707	if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 708		/*
 709		 * Login and Text are sent serially, in
 710		 * request-followed-by-response sequence.
 711		 * Same task can be used. Same ITT must be used.
 712		 * Note that login_task is preallocated at conn_create().
 713		 */
 714		if (conn->login_task->state != ISCSI_TASK_FREE) {
 715			iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 716					  "progress. Cannot start new task.\n");
 717			return NULL;
 718		}
 719
 
 
 
 
 
 720		task = conn->login_task;
 721	} else {
 722		if (session->state != ISCSI_STATE_LOGGED_IN)
 723			return NULL;
 724
 
 
 
 
 
 725		BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 726		BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 727
 728		if (!kfifo_out(&session->cmdpool.queue,
 729				 (void*)&task, sizeof(void*)))
 730			return NULL;
 731	}
 732	/*
 733	 * released in complete pdu for task we expect a response for, and
 734	 * released by the lld when it has transmitted the task for
 735	 * pdus we do not expect a response for.
 736	 */
 737	atomic_set(&task->refcount, 1);
 738	task->conn = conn;
 739	task->sc = NULL;
 740	INIT_LIST_HEAD(&task->running);
 741	task->state = ISCSI_TASK_PENDING;
 742
 743	if (data_size) {
 744		memcpy(task->data, data, data_size);
 745		task->data_count = data_size;
 746	} else
 747		task->data_count = 0;
 748
 749	if (conn->session->tt->alloc_pdu) {
 750		if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 751			iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 752					 "pdu for mgmt task.\n");
 753			goto free_task;
 754		}
 755	}
 756
 757	itt = task->hdr->itt;
 758	task->hdr_len = sizeof(struct iscsi_hdr);
 759	memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 760
 761	if (hdr->itt != RESERVED_ITT) {
 762		if (session->tt->parse_pdu_itt)
 763			task->hdr->itt = itt;
 764		else
 765			task->hdr->itt = build_itt(task->itt,
 766						   task->conn->session->age);
 767	}
 768
 769	if (!ihost->workq) {
 770		if (iscsi_prep_mgmt_task(conn, task))
 771			goto free_task;
 772
 773		if (session->tt->xmit_task(task))
 774			goto free_task;
 775	} else {
 776		list_add_tail(&task->running, &conn->mgmtqueue);
 777		iscsi_conn_queue_work(conn);
 778	}
 779
 780	return task;
 781
 782free_task:
 
 
 783	__iscsi_put_task(task);
 
 784	return NULL;
 785}
 786
 787int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 788			char *data, uint32_t data_size)
 789{
 790	struct iscsi_conn *conn = cls_conn->dd_data;
 791	struct iscsi_session *session = conn->session;
 792	int err = 0;
 793
 794	spin_lock_bh(&session->lock);
 795	if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 796		err = -EPERM;
 797	spin_unlock_bh(&session->lock);
 798	return err;
 799}
 800EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 801
 802/**
 803 * iscsi_cmd_rsp - SCSI Command Response processing
 804 * @conn: iscsi connection
 805 * @hdr: iscsi header
 806 * @task: scsi command task
 807 * @data: cmd data buffer
 808 * @datalen: len of buffer
 809 *
 810 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 811 * then completes the command and task.
 812 **/
 813static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 814			       struct iscsi_task *task, char *data,
 815			       int datalen)
 816{
 817	struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 818	struct iscsi_session *session = conn->session;
 819	struct scsi_cmnd *sc = task->sc;
 820
 821	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 822	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 823
 824	sc->result = (DID_OK << 16) | rhdr->cmd_status;
 825
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 826	if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 827		sc->result = DID_ERROR << 16;
 828		goto out;
 829	}
 830
 831	if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 832		uint16_t senselen;
 833
 834		if (datalen < 2) {
 835invalid_datalen:
 836			iscsi_conn_printk(KERN_ERR,  conn,
 837					 "Got CHECK_CONDITION but invalid data "
 838					 "buffer size of %d\n", datalen);
 839			sc->result = DID_BAD_TARGET << 16;
 840			goto out;
 841		}
 842
 843		senselen = get_unaligned_be16(data);
 844		if (datalen < senselen)
 845			goto invalid_datalen;
 846
 847		memcpy(sc->sense_buffer, data + 2,
 848		       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 849		ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 850				  min_t(uint16_t, senselen,
 851				  SCSI_SENSE_BUFFERSIZE));
 852	}
 853
 854	if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 855			   ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 856		int res_count = be32_to_cpu(rhdr->bi_residual_count);
 857
 858		if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 859				(rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 860				 res_count <= scsi_in(sc)->length))
 861			scsi_in(sc)->resid = res_count;
 862		else
 863			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 864	}
 865
 866	if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 867	                   ISCSI_FLAG_CMD_OVERFLOW)) {
 868		int res_count = be32_to_cpu(rhdr->residual_count);
 869
 870		if (res_count > 0 &&
 871		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 872		     res_count <= scsi_bufflen(sc)))
 873			/* write side for bidi or uni-io set_resid */
 874			scsi_set_resid(sc, res_count);
 875		else
 876			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 877	}
 878out:
 879	ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 880			  sc, sc->result, task->itt);
 881	conn->scsirsp_pdus_cnt++;
 882	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 883}
 884
 885/**
 886 * iscsi_data_in_rsp - SCSI Data-In Response processing
 887 * @conn: iscsi connection
 888 * @hdr:  iscsi pdu
 889 * @task: scsi command task
 890 **/
 891static void
 892iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 893		  struct iscsi_task *task)
 894{
 895	struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 896	struct scsi_cmnd *sc = task->sc;
 897
 898	if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 899		return;
 900
 901	iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 902	sc->result = (DID_OK << 16) | rhdr->cmd_status;
 903	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 904	if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 905	                   ISCSI_FLAG_DATA_OVERFLOW)) {
 906		int res_count = be32_to_cpu(rhdr->residual_count);
 907
 908		if (res_count > 0 &&
 909		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 910		     res_count <= scsi_in(sc)->length))
 911			scsi_in(sc)->resid = res_count;
 912		else
 913			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 914	}
 915
 916	ISCSI_DBG_SESSION(conn->session, "data in with status done "
 917			  "[sc %p res %d itt 0x%x]\n",
 918			  sc, sc->result, task->itt);
 919	conn->scsirsp_pdus_cnt++;
 920	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 921}
 922
 923static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 924{
 925	struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 926
 927	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 928	conn->tmfrsp_pdus_cnt++;
 929
 930	if (conn->tmf_state != TMF_QUEUED)
 931		return;
 932
 933	if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 934		conn->tmf_state = TMF_SUCCESS;
 935	else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 936		conn->tmf_state = TMF_NOT_FOUND;
 937	else
 938		conn->tmf_state = TMF_FAILED;
 939	wake_up(&conn->ehwait);
 940}
 941
 942static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 943{
 944        struct iscsi_nopout hdr;
 945	struct iscsi_task *task;
 946
 947	if (!rhdr && conn->ping_task)
 948		return;
 949
 950	memset(&hdr, 0, sizeof(struct iscsi_nopout));
 951	hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 952	hdr.flags = ISCSI_FLAG_CMD_FINAL;
 953
 954	if (rhdr) {
 955		hdr.lun = rhdr->lun;
 956		hdr.ttt = rhdr->ttt;
 957		hdr.itt = RESERVED_ITT;
 958	} else
 959		hdr.ttt = RESERVED_ITT;
 960
 961	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 962	if (!task)
 963		iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 964	else if (!rhdr) {
 
 965		/* only track our nops */
 966		conn->ping_task = task;
 967		conn->last_ping = jiffies;
 968	}
 
 
 969}
 970
 971static int iscsi_nop_out_rsp(struct iscsi_task *task,
 972			     struct iscsi_nopin *nop, char *data, int datalen)
 973{
 974	struct iscsi_conn *conn = task->conn;
 975	int rc = 0;
 976
 977	if (conn->ping_task != task) {
 978		/*
 979		 * If this is not in response to one of our
 980		 * nops then it must be from userspace.
 981		 */
 982		if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
 983				   data, datalen))
 984			rc = ISCSI_ERR_CONN_FAILED;
 985	} else
 986		mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
 987	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 988	return rc;
 989}
 990
 991static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 992			       char *data, int datalen)
 993{
 994	struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 995	struct iscsi_hdr rejected_pdu;
 996	int opcode, rc = 0;
 997
 998	conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 999
1000	if (ntoh24(reject->dlength) > datalen ||
1001	    ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1002		iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1003				  "pdu. Invalid data length (pdu dlength "
1004				  "%u, datalen %d\n", ntoh24(reject->dlength),
1005				  datalen);
1006		return ISCSI_ERR_PROTO;
1007	}
1008	memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1009	opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1010
1011	switch (reject->reason) {
1012	case ISCSI_REASON_DATA_DIGEST_ERROR:
1013		iscsi_conn_printk(KERN_ERR, conn,
1014				  "pdu (op 0x%x itt 0x%x) rejected "
1015				  "due to DataDigest error.\n",
1016				  rejected_pdu.itt, opcode);
1017		break;
1018	case ISCSI_REASON_IMM_CMD_REJECT:
1019		iscsi_conn_printk(KERN_ERR, conn,
1020				  "pdu (op 0x%x itt 0x%x) rejected. Too many "
1021				  "immediate commands.\n",
1022				  rejected_pdu.itt, opcode);
1023		/*
1024		 * We only send one TMF at a time so if the target could not
1025		 * handle it, then it should get fixed (RFC mandates that
1026		 * a target can handle one immediate TMF per conn).
1027		 *
1028		 * For nops-outs, we could have sent more than one if
1029		 * the target is sending us lots of nop-ins
1030		 */
1031		if (opcode != ISCSI_OP_NOOP_OUT)
1032			return 0;
1033
1034		 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG))
1035			/*
1036			 * nop-out in response to target's nop-out rejected.
1037			 * Just resend.
1038			 */
 
 
 
1039			iscsi_send_nopout(conn,
1040					  (struct iscsi_nopin*)&rejected_pdu);
1041		else {
 
 
1042			struct iscsi_task *task;
1043			/*
1044			 * Our nop as ping got dropped. We know the target
1045			 * and transport are ok so just clean up
1046			 */
1047			task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1048			if (!task) {
1049				iscsi_conn_printk(KERN_ERR, conn,
1050						 "Invalid pdu reject. Could "
1051						 "not lookup rejected task.\n");
1052				rc = ISCSI_ERR_BAD_ITT;
1053			} else
1054				rc = iscsi_nop_out_rsp(task,
1055					(struct iscsi_nopin*)&rejected_pdu,
1056					NULL, 0);
1057		}
1058		break;
1059	default:
1060		iscsi_conn_printk(KERN_ERR, conn,
1061				  "pdu (op 0x%x itt 0x%x) rejected. Reason "
1062				  "code 0x%x\n", rejected_pdu.itt,
1063				  rejected_pdu.opcode, reject->reason);
1064		break;
1065	}
1066	return rc;
1067}
1068
1069/**
1070 * iscsi_itt_to_task - look up task by itt
1071 * @conn: iscsi connection
1072 * @itt: itt
1073 *
1074 * This should be used for mgmt tasks like login and nops, or if
1075 * the LDD's itt space does not include the session age.
1076 *
1077 * The session lock must be held.
1078 */
1079struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1080{
1081	struct iscsi_session *session = conn->session;
1082	int i;
1083
1084	if (itt == RESERVED_ITT)
1085		return NULL;
1086
1087	if (session->tt->parse_pdu_itt)
1088		session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1089	else
1090		i = get_itt(itt);
1091	if (i >= session->cmds_max)
1092		return NULL;
1093
1094	return session->cmds[i];
1095}
1096EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1097
1098/**
1099 * __iscsi_complete_pdu - complete pdu
1100 * @conn: iscsi conn
1101 * @hdr: iscsi header
1102 * @data: data buffer
1103 * @datalen: len of data buffer
1104 *
1105 * Completes pdu processing by freeing any resources allocated at
1106 * queuecommand or send generic. session lock must be held and verify
1107 * itt must have been called.
1108 */
1109int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1110			 char *data, int datalen)
1111{
1112	struct iscsi_session *session = conn->session;
1113	int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1114	struct iscsi_task *task;
1115	uint32_t itt;
1116
1117	conn->last_recv = jiffies;
1118	rc = iscsi_verify_itt(conn, hdr->itt);
1119	if (rc)
1120		return rc;
1121
1122	if (hdr->itt != RESERVED_ITT)
1123		itt = get_itt(hdr->itt);
1124	else
1125		itt = ~0U;
1126
1127	ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1128			  opcode, conn->id, itt, datalen);
1129
1130	if (itt == ~0U) {
1131		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1132
1133		switch(opcode) {
1134		case ISCSI_OP_NOOP_IN:
1135			if (datalen) {
1136				rc = ISCSI_ERR_PROTO;
1137				break;
1138			}
1139
1140			if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1141				break;
1142
 
 
 
1143			iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
 
 
1144			break;
1145		case ISCSI_OP_REJECT:
1146			rc = iscsi_handle_reject(conn, hdr, data, datalen);
1147			break;
1148		case ISCSI_OP_ASYNC_EVENT:
1149			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1150			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1151				rc = ISCSI_ERR_CONN_FAILED;
1152			break;
1153		default:
1154			rc = ISCSI_ERR_BAD_OPCODE;
1155			break;
1156		}
1157		goto out;
1158	}
1159
1160	switch(opcode) {
1161	case ISCSI_OP_SCSI_CMD_RSP:
1162	case ISCSI_OP_SCSI_DATA_IN:
1163		task = iscsi_itt_to_ctask(conn, hdr->itt);
1164		if (!task)
1165			return ISCSI_ERR_BAD_ITT;
1166		task->last_xfer = jiffies;
1167		break;
1168	case ISCSI_OP_R2T:
1169		/*
1170		 * LLD handles R2Ts if they need to.
1171		 */
1172		return 0;
1173	case ISCSI_OP_LOGOUT_RSP:
1174	case ISCSI_OP_LOGIN_RSP:
1175	case ISCSI_OP_TEXT_RSP:
1176	case ISCSI_OP_SCSI_TMFUNC_RSP:
1177	case ISCSI_OP_NOOP_IN:
1178		task = iscsi_itt_to_task(conn, hdr->itt);
1179		if (!task)
1180			return ISCSI_ERR_BAD_ITT;
1181		break;
1182	default:
1183		return ISCSI_ERR_BAD_OPCODE;
1184	}
1185
1186	switch(opcode) {
1187	case ISCSI_OP_SCSI_CMD_RSP:
1188		iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1189		break;
1190	case ISCSI_OP_SCSI_DATA_IN:
1191		iscsi_data_in_rsp(conn, hdr, task);
1192		break;
1193	case ISCSI_OP_LOGOUT_RSP:
1194		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1195		if (datalen) {
1196			rc = ISCSI_ERR_PROTO;
1197			break;
1198		}
1199		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1200		goto recv_pdu;
1201	case ISCSI_OP_LOGIN_RSP:
1202	case ISCSI_OP_TEXT_RSP:
1203		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1204		/*
1205		 * login related PDU's exp_statsn is handled in
1206		 * userspace
1207		 */
1208		goto recv_pdu;
1209	case ISCSI_OP_SCSI_TMFUNC_RSP:
1210		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1211		if (datalen) {
1212			rc = ISCSI_ERR_PROTO;
1213			break;
1214		}
1215
1216		iscsi_tmf_rsp(conn, hdr);
1217		iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1218		break;
1219	case ISCSI_OP_NOOP_IN:
1220		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1221		if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1222			rc = ISCSI_ERR_PROTO;
1223			break;
1224		}
1225		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1226
1227		rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1228				       data, datalen);
1229		break;
1230	default:
1231		rc = ISCSI_ERR_BAD_OPCODE;
1232		break;
1233	}
1234
1235out:
1236	return rc;
1237recv_pdu:
1238	if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1239		rc = ISCSI_ERR_CONN_FAILED;
1240	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1241	return rc;
1242}
1243EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1244
1245int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1246		       char *data, int datalen)
1247{
1248	int rc;
1249
1250	spin_lock(&conn->session->lock);
1251	rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1252	spin_unlock(&conn->session->lock);
1253	return rc;
1254}
1255EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1256
1257int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1258{
1259	struct iscsi_session *session = conn->session;
1260	int age = 0, i = 0;
1261
1262	if (itt == RESERVED_ITT)
1263		return 0;
1264
1265	if (session->tt->parse_pdu_itt)
1266		session->tt->parse_pdu_itt(conn, itt, &i, &age);
1267	else {
1268		i = get_itt(itt);
1269		age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1270	}
1271
1272	if (age != session->age) {
1273		iscsi_conn_printk(KERN_ERR, conn,
1274				  "received itt %x expected session age (%x)\n",
1275				  (__force u32)itt, session->age);
1276		return ISCSI_ERR_BAD_ITT;
1277	}
1278
1279	if (i >= session->cmds_max) {
1280		iscsi_conn_printk(KERN_ERR, conn,
1281				  "received invalid itt index %u (max cmds "
1282				   "%u.\n", i, session->cmds_max);
1283		return ISCSI_ERR_BAD_ITT;
1284	}
1285	return 0;
1286}
1287EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1288
1289/**
1290 * iscsi_itt_to_ctask - look up ctask by itt
1291 * @conn: iscsi connection
1292 * @itt: itt
1293 *
1294 * This should be used for cmd tasks.
1295 *
1296 * The session lock must be held.
1297 */
1298struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1299{
1300	struct iscsi_task *task;
1301
1302	if (iscsi_verify_itt(conn, itt))
1303		return NULL;
1304
1305	task = iscsi_itt_to_task(conn, itt);
1306	if (!task || !task->sc)
1307		return NULL;
1308
1309	if (task->sc->SCp.phase != conn->session->age) {
1310		iscsi_session_printk(KERN_ERR, conn->session,
1311				  "task's session age %d, expected %d\n",
1312				  task->sc->SCp.phase, conn->session->age);
1313		return NULL;
1314	}
1315
1316	return task;
1317}
1318EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1319
1320void iscsi_session_failure(struct iscsi_session *session,
1321			   enum iscsi_err err)
1322{
1323	struct iscsi_conn *conn;
1324	struct device *dev;
1325
1326	spin_lock_bh(&session->lock);
1327	conn = session->leadconn;
1328	if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1329		spin_unlock_bh(&session->lock);
1330		return;
1331	}
1332
1333	dev = get_device(&conn->cls_conn->dev);
1334	spin_unlock_bh(&session->lock);
1335	if (!dev)
1336	        return;
1337	/*
1338	 * if the host is being removed bypass the connection
1339	 * recovery initialization because we are going to kill
1340	 * the session.
1341	 */
1342	if (err == ISCSI_ERR_INVALID_HOST)
1343		iscsi_conn_error_event(conn->cls_conn, err);
1344	else
1345		iscsi_conn_failure(conn, err);
1346	put_device(dev);
1347}
1348EXPORT_SYMBOL_GPL(iscsi_session_failure);
1349
1350void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1351{
1352	struct iscsi_session *session = conn->session;
1353
1354	spin_lock_bh(&session->lock);
1355	if (session->state == ISCSI_STATE_FAILED) {
1356		spin_unlock_bh(&session->lock);
1357		return;
1358	}
1359
1360	if (conn->stop_stage == 0)
1361		session->state = ISCSI_STATE_FAILED;
1362	spin_unlock_bh(&session->lock);
1363
1364	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1365	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1366	iscsi_conn_error_event(conn->cls_conn, err);
1367}
1368EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1369
1370static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1371{
1372	struct iscsi_session *session = conn->session;
1373
1374	/*
1375	 * Check for iSCSI window and take care of CmdSN wrap-around
1376	 */
1377	if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1378		ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1379				  "%u MaxCmdSN %u CmdSN %u/%u\n",
1380				  session->exp_cmdsn, session->max_cmdsn,
1381				  session->cmdsn, session->queued_cmdsn);
1382		return -ENOSPC;
1383	}
1384	return 0;
1385}
1386
1387static int iscsi_xmit_task(struct iscsi_conn *conn)
1388{
1389	struct iscsi_task *task = conn->task;
1390	int rc;
1391
1392	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1393		return -ENODATA;
1394
1395	__iscsi_get_task(task);
1396	spin_unlock_bh(&conn->session->lock);
1397	rc = conn->session->tt->xmit_task(task);
1398	spin_lock_bh(&conn->session->lock);
1399	if (!rc) {
1400		/* done with this task */
1401		task->last_xfer = jiffies;
1402		conn->task = NULL;
1403	}
 
 
1404	__iscsi_put_task(task);
 
1405	return rc;
1406}
1407
1408/**
1409 * iscsi_requeue_task - requeue task to run from session workqueue
1410 * @task: task to requeue
1411 *
1412 * LLDs that need to run a task from the session workqueue should call
1413 * this. The session lock must be held. This should only be called
1414 * by software drivers.
1415 */
1416void iscsi_requeue_task(struct iscsi_task *task)
1417{
1418	struct iscsi_conn *conn = task->conn;
1419
1420	/*
1421	 * this may be on the requeue list already if the xmit_task callout
1422	 * is handling the r2ts while we are adding new ones
1423	 */
1424	if (list_empty(&task->running))
1425		list_add_tail(&task->running, &conn->requeue);
1426	iscsi_conn_queue_work(conn);
1427}
1428EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1429
1430/**
1431 * iscsi_data_xmit - xmit any command into the scheduled connection
1432 * @conn: iscsi connection
1433 *
1434 * Notes:
1435 *	The function can return -EAGAIN in which case the caller must
1436 *	re-schedule it again later or recover. '0' return code means
1437 *	successful xmit.
1438 **/
1439static int iscsi_data_xmit(struct iscsi_conn *conn)
1440{
1441	struct iscsi_task *task;
1442	int rc = 0;
1443
1444	spin_lock_bh(&conn->session->lock);
1445	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1446		ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1447		spin_unlock_bh(&conn->session->lock);
1448		return -ENODATA;
1449	}
1450
1451	if (conn->task) {
1452		rc = iscsi_xmit_task(conn);
1453	        if (rc)
1454		        goto done;
1455	}
1456
1457	/*
1458	 * process mgmt pdus like nops before commands since we should
1459	 * only have one nop-out as a ping from us and targets should not
1460	 * overflow us with nop-ins
1461	 */
1462check_mgmt:
1463	while (!list_empty(&conn->mgmtqueue)) {
1464		conn->task = list_entry(conn->mgmtqueue.next,
1465					 struct iscsi_task, running);
1466		list_del_init(&conn->task->running);
1467		if (iscsi_prep_mgmt_task(conn, conn->task)) {
 
 
1468			__iscsi_put_task(conn->task);
 
1469			conn->task = NULL;
1470			continue;
1471		}
1472		rc = iscsi_xmit_task(conn);
1473		if (rc)
1474			goto done;
1475	}
1476
1477	/* process pending command queue */
1478	while (!list_empty(&conn->cmdqueue)) {
1479		conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1480					running);
1481		list_del_init(&conn->task->running);
1482		if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1483			fail_scsi_task(conn->task, DID_IMM_RETRY);
1484			continue;
1485		}
1486		rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1487		if (rc) {
1488			if (rc == -ENOMEM || rc == -EACCES) {
1489				list_add_tail(&conn->task->running,
1490					      &conn->cmdqueue);
1491				conn->task = NULL;
1492				goto done;
1493			} else
1494				fail_scsi_task(conn->task, DID_ABORT);
1495			continue;
1496		}
1497		rc = iscsi_xmit_task(conn);
1498		if (rc)
1499			goto done;
1500		/*
1501		 * we could continuously get new task requests so
1502		 * we need to check the mgmt queue for nops that need to
1503		 * be sent to aviod starvation
1504		 */
1505		if (!list_empty(&conn->mgmtqueue))
1506			goto check_mgmt;
1507	}
1508
1509	while (!list_empty(&conn->requeue)) {
1510		/*
1511		 * we always do fastlogout - conn stop code will clean up.
1512		 */
1513		if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1514			break;
1515
1516		task = list_entry(conn->requeue.next, struct iscsi_task,
1517				  running);
1518		if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1519			break;
1520
1521		conn->task = task;
1522		list_del_init(&conn->task->running);
1523		conn->task->state = ISCSI_TASK_RUNNING;
1524		rc = iscsi_xmit_task(conn);
1525		if (rc)
1526			goto done;
1527		if (!list_empty(&conn->mgmtqueue))
1528			goto check_mgmt;
1529	}
1530	spin_unlock_bh(&conn->session->lock);
1531	return -ENODATA;
1532
1533done:
1534	spin_unlock_bh(&conn->session->lock);
1535	return rc;
1536}
1537
1538static void iscsi_xmitworker(struct work_struct *work)
1539{
1540	struct iscsi_conn *conn =
1541		container_of(work, struct iscsi_conn, xmitwork);
1542	int rc;
1543	/*
1544	 * serialize Xmit worker on a per-connection basis.
1545	 */
1546	do {
1547		rc = iscsi_data_xmit(conn);
1548	} while (rc >= 0 || rc == -EAGAIN);
1549}
1550
1551static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1552						  struct scsi_cmnd *sc)
1553{
1554	struct iscsi_task *task;
1555
1556	if (!kfifo_out(&conn->session->cmdpool.queue,
1557			 (void *) &task, sizeof(void *)))
1558		return NULL;
1559
1560	sc->SCp.phase = conn->session->age;
1561	sc->SCp.ptr = (char *) task;
1562
1563	atomic_set(&task->refcount, 1);
1564	task->state = ISCSI_TASK_PENDING;
1565	task->conn = conn;
1566	task->sc = sc;
1567	task->have_checked_conn = false;
1568	task->last_timeout = jiffies;
1569	task->last_xfer = jiffies;
 
1570	INIT_LIST_HEAD(&task->running);
1571	return task;
1572}
1573
1574enum {
1575	FAILURE_BAD_HOST = 1,
1576	FAILURE_SESSION_FAILED,
1577	FAILURE_SESSION_FREED,
1578	FAILURE_WINDOW_CLOSED,
1579	FAILURE_OOM,
1580	FAILURE_SESSION_TERMINATE,
1581	FAILURE_SESSION_IN_RECOVERY,
1582	FAILURE_SESSION_RECOVERY_TIMEOUT,
1583	FAILURE_SESSION_LOGGING_OUT,
1584	FAILURE_SESSION_NOT_READY,
1585};
1586
1587int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1588{
1589	struct iscsi_cls_session *cls_session;
1590	struct iscsi_host *ihost;
1591	int reason = 0;
1592	struct iscsi_session *session;
1593	struct iscsi_conn *conn;
1594	struct iscsi_task *task = NULL;
1595
1596	sc->result = 0;
1597	sc->SCp.ptr = NULL;
1598
1599	ihost = shost_priv(host);
1600
1601	cls_session = starget_to_session(scsi_target(sc->device));
1602	session = cls_session->dd_data;
1603	spin_lock_bh(&session->lock);
1604
1605	reason = iscsi_session_chkready(cls_session);
1606	if (reason) {
1607		sc->result = reason;
1608		goto fault;
1609	}
1610
1611	if (session->state != ISCSI_STATE_LOGGED_IN) {
1612		/*
1613		 * to handle the race between when we set the recovery state
1614		 * and block the session we requeue here (commands could
1615		 * be entering our queuecommand while a block is starting
1616		 * up because the block code is not locked)
1617		 */
1618		switch (session->state) {
1619		case ISCSI_STATE_FAILED:
1620		case ISCSI_STATE_IN_RECOVERY:
1621			reason = FAILURE_SESSION_IN_RECOVERY;
1622			sc->result = DID_IMM_RETRY << 16;
1623			break;
1624		case ISCSI_STATE_LOGGING_OUT:
1625			reason = FAILURE_SESSION_LOGGING_OUT;
1626			sc->result = DID_IMM_RETRY << 16;
1627			break;
1628		case ISCSI_STATE_RECOVERY_FAILED:
1629			reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1630			sc->result = DID_TRANSPORT_FAILFAST << 16;
1631			break;
1632		case ISCSI_STATE_TERMINATE:
1633			reason = FAILURE_SESSION_TERMINATE;
1634			sc->result = DID_NO_CONNECT << 16;
1635			break;
1636		default:
1637			reason = FAILURE_SESSION_FREED;
1638			sc->result = DID_NO_CONNECT << 16;
1639		}
1640		goto fault;
1641	}
1642
1643	conn = session->leadconn;
1644	if (!conn) {
1645		reason = FAILURE_SESSION_FREED;
1646		sc->result = DID_NO_CONNECT << 16;
1647		goto fault;
1648	}
1649
1650	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1651		reason = FAILURE_SESSION_IN_RECOVERY;
1652		sc->result = DID_REQUEUE;
1653		goto fault;
1654	}
1655
1656	if (iscsi_check_cmdsn_window_closed(conn)) {
1657		reason = FAILURE_WINDOW_CLOSED;
1658		goto reject;
1659	}
1660
1661	task = iscsi_alloc_task(conn, sc);
1662	if (!task) {
1663		reason = FAILURE_OOM;
1664		goto reject;
1665	}
1666
1667	if (!ihost->workq) {
1668		reason = iscsi_prep_scsi_cmd_pdu(task);
1669		if (reason) {
1670			if (reason == -ENOMEM ||  reason == -EACCES) {
1671				reason = FAILURE_OOM;
1672				goto prepd_reject;
1673			} else {
1674				sc->result = DID_ABORT << 16;
1675				goto prepd_fault;
1676			}
1677		}
1678		if (session->tt->xmit_task(task)) {
1679			session->cmdsn--;
1680			reason = FAILURE_SESSION_NOT_READY;
1681			goto prepd_reject;
1682		}
1683	} else {
1684		list_add_tail(&task->running, &conn->cmdqueue);
1685		iscsi_conn_queue_work(conn);
1686	}
1687
1688	session->queued_cmdsn++;
1689	spin_unlock_bh(&session->lock);
1690	return 0;
1691
1692prepd_reject:
1693	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1694reject:
1695	spin_unlock_bh(&session->lock);
1696	ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1697			  sc->cmnd[0], reason);
1698	return SCSI_MLQUEUE_TARGET_BUSY;
1699
1700prepd_fault:
1701	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1702fault:
1703	spin_unlock_bh(&session->lock);
1704	ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1705			  sc->cmnd[0], reason);
1706	if (!scsi_bidi_cmnd(sc))
1707		scsi_set_resid(sc, scsi_bufflen(sc));
1708	else {
1709		scsi_out(sc)->resid = scsi_out(sc)->length;
1710		scsi_in(sc)->resid = scsi_in(sc)->length;
1711	}
1712	sc->scsi_done(sc);
1713	return 0;
1714}
1715EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1716
1717int iscsi_change_queue_depth(struct scsi_device *sdev, int depth, int reason)
1718{
1719	switch (reason) {
1720	case SCSI_QDEPTH_DEFAULT:
1721		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1722		break;
1723	case SCSI_QDEPTH_QFULL:
1724		scsi_track_queue_full(sdev, depth);
1725		break;
1726	case SCSI_QDEPTH_RAMP_UP:
1727		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1728		break;
1729	default:
1730		return -EOPNOTSUPP;
1731	}
1732	return sdev->queue_depth;
1733}
1734EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1735
1736int iscsi_target_alloc(struct scsi_target *starget)
1737{
1738	struct iscsi_cls_session *cls_session = starget_to_session(starget);
1739	struct iscsi_session *session = cls_session->dd_data;
1740
1741	starget->can_queue = session->scsi_cmds_max;
1742	return 0;
1743}
1744EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1745
1746static void iscsi_tmf_timedout(unsigned long data)
1747{
1748	struct iscsi_conn *conn = (struct iscsi_conn *)data;
1749	struct iscsi_session *session = conn->session;
1750
1751	spin_lock(&session->lock);
1752	if (conn->tmf_state == TMF_QUEUED) {
1753		conn->tmf_state = TMF_TIMEDOUT;
1754		ISCSI_DBG_EH(session, "tmf timedout\n");
1755		/* unblock eh_abort() */
1756		wake_up(&conn->ehwait);
1757	}
1758	spin_unlock(&session->lock);
1759}
1760
1761static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1762				   struct iscsi_tm *hdr, int age,
1763				   int timeout)
1764{
1765	struct iscsi_session *session = conn->session;
1766	struct iscsi_task *task;
1767
1768	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1769				      NULL, 0);
1770	if (!task) {
1771		spin_unlock_bh(&session->lock);
1772		iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1773		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1774		spin_lock_bh(&session->lock);
1775		return -EPERM;
1776	}
1777	conn->tmfcmd_pdus_cnt++;
1778	conn->tmf_timer.expires = timeout * HZ + jiffies;
1779	conn->tmf_timer.function = iscsi_tmf_timedout;
1780	conn->tmf_timer.data = (unsigned long)conn;
1781	add_timer(&conn->tmf_timer);
1782	ISCSI_DBG_EH(session, "tmf set timeout\n");
1783
1784	spin_unlock_bh(&session->lock);
1785	mutex_unlock(&session->eh_mutex);
1786
1787	/*
1788	 * block eh thread until:
1789	 *
1790	 * 1) tmf response
1791	 * 2) tmf timeout
1792	 * 3) session is terminated or restarted or userspace has
1793	 * given up on recovery
1794	 */
1795	wait_event_interruptible(conn->ehwait, age != session->age ||
1796				 session->state != ISCSI_STATE_LOGGED_IN ||
1797				 conn->tmf_state != TMF_QUEUED);
1798	if (signal_pending(current))
1799		flush_signals(current);
1800	del_timer_sync(&conn->tmf_timer);
1801
1802	mutex_lock(&session->eh_mutex);
1803	spin_lock_bh(&session->lock);
1804	/* if the session drops it will clean up the task */
1805	if (age != session->age ||
1806	    session->state != ISCSI_STATE_LOGGED_IN)
1807		return -ENOTCONN;
1808	return 0;
1809}
1810
1811/*
1812 * Fail commands. session lock held and recv side suspended and xmit
1813 * thread flushed
1814 */
1815static void fail_scsi_tasks(struct iscsi_conn *conn, unsigned lun,
1816			    int error)
1817{
1818	struct iscsi_task *task;
1819	int i;
1820
1821	for (i = 0; i < conn->session->cmds_max; i++) {
1822		task = conn->session->cmds[i];
1823		if (!task->sc || task->state == ISCSI_TASK_FREE)
1824			continue;
1825
1826		if (lun != -1 && lun != task->sc->device->lun)
1827			continue;
1828
1829		ISCSI_DBG_SESSION(conn->session,
1830				  "failing sc %p itt 0x%x state %d\n",
1831				  task->sc, task->itt, task->state);
1832		fail_scsi_task(task, error);
1833	}
1834}
1835
1836/**
1837 * iscsi_suspend_queue - suspend iscsi_queuecommand
1838 * @conn: iscsi conn to stop queueing IO on
1839 *
1840 * This grabs the session lock to make sure no one is in
1841 * xmit_task/queuecommand, and then sets suspend to prevent
1842 * new commands from being queued. This only needs to be called
1843 * by offload drivers that need to sync a path like ep disconnect
1844 * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1845 * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1846 */
1847void iscsi_suspend_queue(struct iscsi_conn *conn)
1848{
1849	spin_lock_bh(&conn->session->lock);
1850	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1851	spin_unlock_bh(&conn->session->lock);
1852}
1853EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1854
1855/**
1856 * iscsi_suspend_tx - suspend iscsi_data_xmit
1857 * @conn: iscsi conn tp stop processing IO on.
1858 *
1859 * This function sets the suspend bit to prevent iscsi_data_xmit
1860 * from sending new IO, and if work is queued on the xmit thread
1861 * it will wait for it to be completed.
1862 */
1863void iscsi_suspend_tx(struct iscsi_conn *conn)
1864{
1865	struct Scsi_Host *shost = conn->session->host;
1866	struct iscsi_host *ihost = shost_priv(shost);
1867
1868	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1869	if (ihost->workq)
1870		flush_workqueue(ihost->workq);
1871}
1872EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1873
1874static void iscsi_start_tx(struct iscsi_conn *conn)
1875{
1876	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1877	iscsi_conn_queue_work(conn);
1878}
1879
1880/*
1881 * We want to make sure a ping is in flight. It has timed out.
1882 * And we are not busy processing a pdu that is making
1883 * progress but got started before the ping and is taking a while
1884 * to complete so the ping is just stuck behind it in a queue.
1885 */
1886static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1887{
1888	if (conn->ping_task &&
1889	    time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1890			   (conn->ping_timeout * HZ), jiffies))
1891		return 1;
1892	else
1893		return 0;
1894}
1895
1896static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1897{
1898	enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1899	struct iscsi_task *task = NULL, *running_task;
1900	struct iscsi_cls_session *cls_session;
1901	struct iscsi_session *session;
1902	struct iscsi_conn *conn;
1903	int i;
1904
1905	cls_session = starget_to_session(scsi_target(sc->device));
1906	session = cls_session->dd_data;
1907
1908	ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1909
1910	spin_lock(&session->lock);
 
 
 
 
 
 
 
 
 
 
1911	if (session->state != ISCSI_STATE_LOGGED_IN) {
1912		/*
1913		 * We are probably in the middle of iscsi recovery so let
1914		 * that complete and handle the error.
1915		 */
1916		rc = BLK_EH_RESET_TIMER;
1917		goto done;
1918	}
1919
1920	conn = session->leadconn;
1921	if (!conn) {
1922		/* In the middle of shuting down */
1923		rc = BLK_EH_RESET_TIMER;
1924		goto done;
1925	}
1926
1927	task = (struct iscsi_task *)sc->SCp.ptr;
1928	if (!task) {
1929		/*
1930		 * Raced with completion. Just reset timer, and let it
1931		 * complete normally
1932		 */
1933		rc = BLK_EH_RESET_TIMER;
1934		goto done;
1935	}
1936
1937	/*
1938	 * If we have sent (at least queued to the network layer) a pdu or
1939	 * recvd one for the task since the last timeout ask for
1940	 * more time. If on the next timeout we have not made progress
1941	 * we can check if it is the task or connection when we send the
1942	 * nop as a ping.
1943	 */
1944	if (time_after(task->last_xfer, task->last_timeout)) {
1945		ISCSI_DBG_EH(session, "Command making progress. Asking "
1946			     "scsi-ml for more time to complete. "
1947			     "Last data xfer at %lu. Last timeout was at "
1948			     "%lu\n.", task->last_xfer, task->last_timeout);
1949		task->have_checked_conn = false;
1950		rc = BLK_EH_RESET_TIMER;
1951		goto done;
1952	}
1953
1954	if (!conn->recv_timeout && !conn->ping_timeout)
1955		goto done;
1956	/*
1957	 * if the ping timedout then we are in the middle of cleaning up
1958	 * and can let the iscsi eh handle it
1959	 */
1960	if (iscsi_has_ping_timed_out(conn)) {
1961		rc = BLK_EH_RESET_TIMER;
1962		goto done;
1963	}
1964
1965	for (i = 0; i < conn->session->cmds_max; i++) {
1966		running_task = conn->session->cmds[i];
1967		if (!running_task->sc || running_task == task ||
1968		     running_task->state != ISCSI_TASK_RUNNING)
1969			continue;
1970
1971		/*
1972		 * Only check if cmds started before this one have made
1973		 * progress, or this could never fail
1974		 */
1975		if (time_after(running_task->sc->jiffies_at_alloc,
1976			       task->sc->jiffies_at_alloc))
1977			continue;
1978
1979		if (time_after(running_task->last_xfer, task->last_timeout)) {
1980			/*
1981			 * This task has not made progress, but a task
1982			 * started before us has transferred data since
1983			 * we started/last-checked. We could be queueing
1984			 * too many tasks or the LU is bad.
1985			 *
1986			 * If the device is bad the cmds ahead of us on
1987			 * other devs will complete, and this loop will
1988			 * eventually fail starting the scsi eh.
1989			 */
1990			ISCSI_DBG_EH(session, "Command has not made progress "
1991				     "but commands ahead of it have. "
1992				     "Asking scsi-ml for more time to "
1993				     "complete. Our last xfer vs running task "
1994				     "last xfer %lu/%lu. Last check %lu.\n",
1995				     task->last_xfer, running_task->last_xfer,
1996				     task->last_timeout);
1997			rc = BLK_EH_RESET_TIMER;
1998			goto done;
1999		}
2000	}
2001
2002	/* Assumes nop timeout is shorter than scsi cmd timeout */
2003	if (task->have_checked_conn)
2004		goto done;
2005
2006	/*
2007	 * Checking the transport already or nop from a cmd timeout still
2008	 * running
2009	 */
2010	if (conn->ping_task) {
2011		task->have_checked_conn = true;
2012		rc = BLK_EH_RESET_TIMER;
2013		goto done;
2014	}
2015
2016	/* Make sure there is a transport check done */
2017	iscsi_send_nopout(conn, NULL);
2018	task->have_checked_conn = true;
2019	rc = BLK_EH_RESET_TIMER;
2020
2021done:
2022	if (task)
2023		task->last_timeout = jiffies;
2024	spin_unlock(&session->lock);
2025	ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2026		     "timer reset" : "nh");
2027	return rc;
2028}
2029
2030static void iscsi_check_transport_timeouts(unsigned long data)
2031{
2032	struct iscsi_conn *conn = (struct iscsi_conn *)data;
2033	struct iscsi_session *session = conn->session;
2034	unsigned long recv_timeout, next_timeout = 0, last_recv;
2035
2036	spin_lock(&session->lock);
2037	if (session->state != ISCSI_STATE_LOGGED_IN)
2038		goto done;
2039
2040	recv_timeout = conn->recv_timeout;
2041	if (!recv_timeout)
2042		goto done;
2043
2044	recv_timeout *= HZ;
2045	last_recv = conn->last_recv;
2046
2047	if (iscsi_has_ping_timed_out(conn)) {
2048		iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2049				  "expired, recv timeout %d, last rx %lu, "
2050				  "last ping %lu, now %lu\n",
2051				  conn->ping_timeout, conn->recv_timeout,
2052				  last_recv, conn->last_ping, jiffies);
2053		spin_unlock(&session->lock);
2054		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2055		return;
2056	}
2057
2058	if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2059		/* send a ping to try to provoke some traffic */
2060		ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2061		iscsi_send_nopout(conn, NULL);
2062		next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
 
 
2063	} else
2064		next_timeout = last_recv + recv_timeout;
2065
2066	ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2067	mod_timer(&conn->transport_timer, next_timeout);
2068done:
2069	spin_unlock(&session->lock);
2070}
2071
2072static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2073				      struct iscsi_tm *hdr)
2074{
2075	memset(hdr, 0, sizeof(*hdr));
2076	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2077	hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2078	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2079	hdr->lun = task->lun;
2080	hdr->rtt = task->hdr_itt;
2081	hdr->refcmdsn = task->cmdsn;
2082}
2083
2084int iscsi_eh_abort(struct scsi_cmnd *sc)
2085{
2086	struct iscsi_cls_session *cls_session;
2087	struct iscsi_session *session;
2088	struct iscsi_conn *conn;
2089	struct iscsi_task *task;
2090	struct iscsi_tm *hdr;
2091	int rc, age;
2092
2093	cls_session = starget_to_session(scsi_target(sc->device));
2094	session = cls_session->dd_data;
2095
2096	ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2097
2098	mutex_lock(&session->eh_mutex);
2099	spin_lock_bh(&session->lock);
2100	/*
2101	 * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2102	 * got the command.
2103	 */
2104	if (!sc->SCp.ptr) {
2105		ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2106				      "it completed.\n");
2107		spin_unlock_bh(&session->lock);
2108		mutex_unlock(&session->eh_mutex);
2109		return SUCCESS;
2110	}
2111
2112	/*
2113	 * If we are not logged in or we have started a new session
2114	 * then let the host reset code handle this
2115	 */
2116	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2117	    sc->SCp.phase != session->age) {
2118		spin_unlock_bh(&session->lock);
2119		mutex_unlock(&session->eh_mutex);
2120		ISCSI_DBG_EH(session, "failing abort due to dropped "
2121				  "session.\n");
2122		return FAILED;
2123	}
2124
2125	conn = session->leadconn;
2126	conn->eh_abort_cnt++;
2127	age = session->age;
2128
2129	task = (struct iscsi_task *)sc->SCp.ptr;
2130	ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2131		     sc, task->itt);
2132
2133	/* task completed before time out */
2134	if (!task->sc) {
2135		ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2136		goto success;
2137	}
2138
2139	if (task->state == ISCSI_TASK_PENDING) {
2140		fail_scsi_task(task, DID_ABORT);
2141		goto success;
2142	}
2143
2144	/* only have one tmf outstanding at a time */
2145	if (conn->tmf_state != TMF_INITIAL)
2146		goto failed;
2147	conn->tmf_state = TMF_QUEUED;
2148
2149	hdr = &conn->tmhdr;
2150	iscsi_prep_abort_task_pdu(task, hdr);
2151
2152	if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
2153		rc = FAILED;
2154		goto failed;
2155	}
2156
2157	switch (conn->tmf_state) {
2158	case TMF_SUCCESS:
2159		spin_unlock_bh(&session->lock);
2160		/*
2161		 * stop tx side incase the target had sent a abort rsp but
2162		 * the initiator was still writing out data.
2163		 */
2164		iscsi_suspend_tx(conn);
2165		/*
2166		 * we do not stop the recv side because targets have been
2167		 * good and have never sent us a successful tmf response
2168		 * then sent more data for the cmd.
2169		 */
2170		spin_lock_bh(&session->lock);
2171		fail_scsi_task(task, DID_ABORT);
2172		conn->tmf_state = TMF_INITIAL;
2173		memset(hdr, 0, sizeof(*hdr));
2174		spin_unlock_bh(&session->lock);
2175		iscsi_start_tx(conn);
2176		goto success_unlocked;
2177	case TMF_TIMEDOUT:
2178		spin_unlock_bh(&session->lock);
2179		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2180		goto failed_unlocked;
2181	case TMF_NOT_FOUND:
2182		if (!sc->SCp.ptr) {
2183			conn->tmf_state = TMF_INITIAL;
2184			memset(hdr, 0, sizeof(*hdr));
2185			/* task completed before tmf abort response */
2186			ISCSI_DBG_EH(session, "sc completed while abort	in "
2187					      "progress\n");
2188			goto success;
2189		}
2190		/* fall through */
2191	default:
2192		conn->tmf_state = TMF_INITIAL;
2193		goto failed;
2194	}
2195
2196success:
2197	spin_unlock_bh(&session->lock);
2198success_unlocked:
2199	ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2200		     sc, task->itt);
2201	mutex_unlock(&session->eh_mutex);
2202	return SUCCESS;
2203
2204failed:
2205	spin_unlock_bh(&session->lock);
2206failed_unlocked:
2207	ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2208		     task ? task->itt : 0);
2209	mutex_unlock(&session->eh_mutex);
2210	return FAILED;
2211}
2212EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2213
2214static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2215{
2216	memset(hdr, 0, sizeof(*hdr));
2217	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2218	hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2219	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2220	int_to_scsilun(sc->device->lun, &hdr->lun);
2221	hdr->rtt = RESERVED_ITT;
2222}
2223
2224int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2225{
2226	struct iscsi_cls_session *cls_session;
2227	struct iscsi_session *session;
2228	struct iscsi_conn *conn;
2229	struct iscsi_tm *hdr;
2230	int rc = FAILED;
2231
2232	cls_session = starget_to_session(scsi_target(sc->device));
2233	session = cls_session->dd_data;
2234
2235	ISCSI_DBG_EH(session, "LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
 
2236
2237	mutex_lock(&session->eh_mutex);
2238	spin_lock_bh(&session->lock);
2239	/*
2240	 * Just check if we are not logged in. We cannot check for
2241	 * the phase because the reset could come from a ioctl.
2242	 */
2243	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2244		goto unlock;
2245	conn = session->leadconn;
2246
2247	/* only have one tmf outstanding at a time */
2248	if (conn->tmf_state != TMF_INITIAL)
2249		goto unlock;
2250	conn->tmf_state = TMF_QUEUED;
2251
2252	hdr = &conn->tmhdr;
2253	iscsi_prep_lun_reset_pdu(sc, hdr);
2254
2255	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2256				    session->lu_reset_timeout)) {
2257		rc = FAILED;
2258		goto unlock;
2259	}
2260
2261	switch (conn->tmf_state) {
2262	case TMF_SUCCESS:
2263		break;
2264	case TMF_TIMEDOUT:
2265		spin_unlock_bh(&session->lock);
2266		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2267		goto done;
2268	default:
2269		conn->tmf_state = TMF_INITIAL;
2270		goto unlock;
2271	}
2272
2273	rc = SUCCESS;
2274	spin_unlock_bh(&session->lock);
2275
2276	iscsi_suspend_tx(conn);
2277
2278	spin_lock_bh(&session->lock);
2279	memset(hdr, 0, sizeof(*hdr));
2280	fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2281	conn->tmf_state = TMF_INITIAL;
2282	spin_unlock_bh(&session->lock);
2283
2284	iscsi_start_tx(conn);
2285	goto done;
2286
2287unlock:
2288	spin_unlock_bh(&session->lock);
2289done:
2290	ISCSI_DBG_EH(session, "dev reset result = %s\n",
2291		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2292	mutex_unlock(&session->eh_mutex);
2293	return rc;
2294}
2295EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2296
2297void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2298{
2299	struct iscsi_session *session = cls_session->dd_data;
2300
2301	spin_lock_bh(&session->lock);
2302	if (session->state != ISCSI_STATE_LOGGED_IN) {
2303		session->state = ISCSI_STATE_RECOVERY_FAILED;
2304		if (session->leadconn)
2305			wake_up(&session->leadconn->ehwait);
2306	}
2307	spin_unlock_bh(&session->lock);
2308}
2309EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2310
2311/**
2312 * iscsi_eh_session_reset - drop session and attempt relogin
2313 * @sc: scsi command
2314 *
2315 * This function will wait for a relogin, session termination from
2316 * userspace, or a recovery/replacement timeout.
2317 */
2318int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2319{
2320	struct iscsi_cls_session *cls_session;
2321	struct iscsi_session *session;
2322	struct iscsi_conn *conn;
2323
2324	cls_session = starget_to_session(scsi_target(sc->device));
2325	session = cls_session->dd_data;
2326	conn = session->leadconn;
2327
2328	mutex_lock(&session->eh_mutex);
2329	spin_lock_bh(&session->lock);
2330	if (session->state == ISCSI_STATE_TERMINATE) {
2331failed:
2332		ISCSI_DBG_EH(session,
2333			     "failing session reset: Could not log back into "
2334			     "%s, %s [age %d]\n", session->targetname,
2335			     conn->persistent_address, session->age);
2336		spin_unlock_bh(&session->lock);
2337		mutex_unlock(&session->eh_mutex);
2338		return FAILED;
2339	}
2340
2341	spin_unlock_bh(&session->lock);
2342	mutex_unlock(&session->eh_mutex);
2343	/*
2344	 * we drop the lock here but the leadconn cannot be destoyed while
2345	 * we are in the scsi eh
2346	 */
2347	iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2348
2349	ISCSI_DBG_EH(session, "wait for relogin\n");
2350	wait_event_interruptible(conn->ehwait,
2351				 session->state == ISCSI_STATE_TERMINATE ||
2352				 session->state == ISCSI_STATE_LOGGED_IN ||
2353				 session->state == ISCSI_STATE_RECOVERY_FAILED);
2354	if (signal_pending(current))
2355		flush_signals(current);
2356
2357	mutex_lock(&session->eh_mutex);
2358	spin_lock_bh(&session->lock);
2359	if (session->state == ISCSI_STATE_LOGGED_IN) {
2360		ISCSI_DBG_EH(session,
2361			     "session reset succeeded for %s,%s\n",
2362			     session->targetname, conn->persistent_address);
2363	} else
2364		goto failed;
2365	spin_unlock_bh(&session->lock);
2366	mutex_unlock(&session->eh_mutex);
2367	return SUCCESS;
2368}
2369EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2370
2371static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2372{
2373	memset(hdr, 0, sizeof(*hdr));
2374	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2375	hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2376	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2377	hdr->rtt = RESERVED_ITT;
2378}
2379
2380/**
2381 * iscsi_eh_target_reset - reset target
2382 * @sc: scsi command
2383 *
2384 * This will attempt to send a warm target reset.
2385 */
2386int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2387{
2388	struct iscsi_cls_session *cls_session;
2389	struct iscsi_session *session;
2390	struct iscsi_conn *conn;
2391	struct iscsi_tm *hdr;
2392	int rc = FAILED;
2393
2394	cls_session = starget_to_session(scsi_target(sc->device));
2395	session = cls_session->dd_data;
2396
2397	ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2398		     session->targetname);
2399
2400	mutex_lock(&session->eh_mutex);
2401	spin_lock_bh(&session->lock);
2402	/*
2403	 * Just check if we are not logged in. We cannot check for
2404	 * the phase because the reset could come from a ioctl.
2405	 */
2406	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2407		goto unlock;
2408	conn = session->leadconn;
2409
2410	/* only have one tmf outstanding at a time */
2411	if (conn->tmf_state != TMF_INITIAL)
2412		goto unlock;
2413	conn->tmf_state = TMF_QUEUED;
2414
2415	hdr = &conn->tmhdr;
2416	iscsi_prep_tgt_reset_pdu(sc, hdr);
2417
2418	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2419				    session->tgt_reset_timeout)) {
2420		rc = FAILED;
2421		goto unlock;
2422	}
2423
2424	switch (conn->tmf_state) {
2425	case TMF_SUCCESS:
2426		break;
2427	case TMF_TIMEDOUT:
2428		spin_unlock_bh(&session->lock);
2429		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2430		goto done;
2431	default:
2432		conn->tmf_state = TMF_INITIAL;
2433		goto unlock;
2434	}
2435
2436	rc = SUCCESS;
2437	spin_unlock_bh(&session->lock);
2438
2439	iscsi_suspend_tx(conn);
2440
2441	spin_lock_bh(&session->lock);
2442	memset(hdr, 0, sizeof(*hdr));
2443	fail_scsi_tasks(conn, -1, DID_ERROR);
2444	conn->tmf_state = TMF_INITIAL;
2445	spin_unlock_bh(&session->lock);
2446
2447	iscsi_start_tx(conn);
2448	goto done;
2449
2450unlock:
2451	spin_unlock_bh(&session->lock);
2452done:
2453	ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2454		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2455	mutex_unlock(&session->eh_mutex);
2456	return rc;
2457}
2458EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
2459
2460/**
2461 * iscsi_eh_recover_target - reset target and possibly the session
2462 * @sc: scsi command
2463 *
2464 * This will attempt to send a warm target reset. If that fails,
2465 * we will escalate to ERL0 session recovery.
2466 */
2467int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2468{
2469	int rc;
2470
2471	rc = iscsi_eh_target_reset(sc);
2472	if (rc == FAILED)
2473		rc = iscsi_eh_session_reset(sc);
2474	return rc;
2475}
2476EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2477
2478/*
2479 * Pre-allocate a pool of @max items of @item_size. By default, the pool
2480 * should be accessed via kfifo_{get,put} on q->queue.
2481 * Optionally, the caller can obtain the array of object pointers
2482 * by passing in a non-NULL @items pointer
2483 */
2484int
2485iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2486{
2487	int i, num_arrays = 1;
2488
2489	memset(q, 0, sizeof(*q));
2490
2491	q->max = max;
2492
2493	/* If the user passed an items pointer, he wants a copy of
2494	 * the array. */
2495	if (items)
2496		num_arrays++;
2497	q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2498	if (q->pool == NULL)
2499		return -ENOMEM;
2500
2501	kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2502
2503	for (i = 0; i < max; i++) {
2504		q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2505		if (q->pool[i] == NULL) {
2506			q->max = i;
2507			goto enomem;
2508		}
2509		kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2510	}
2511
2512	if (items) {
2513		*items = q->pool + max;
2514		memcpy(*items, q->pool, max * sizeof(void *));
2515	}
2516
2517	return 0;
2518
2519enomem:
2520	iscsi_pool_free(q);
2521	return -ENOMEM;
2522}
2523EXPORT_SYMBOL_GPL(iscsi_pool_init);
2524
2525void iscsi_pool_free(struct iscsi_pool *q)
2526{
2527	int i;
2528
2529	for (i = 0; i < q->max; i++)
2530		kfree(q->pool[i]);
2531	kfree(q->pool);
2532}
2533EXPORT_SYMBOL_GPL(iscsi_pool_free);
2534
2535/**
2536 * iscsi_host_add - add host to system
2537 * @shost: scsi host
2538 * @pdev: parent device
2539 *
2540 * This should be called by partial offload and software iscsi drivers
2541 * to add a host to the system.
2542 */
2543int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2544{
2545	if (!shost->can_queue)
2546		shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2547
2548	if (!shost->cmd_per_lun)
2549		shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2550
2551	if (!shost->transportt->eh_timed_out)
2552		shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2553	return scsi_add_host(shost, pdev);
2554}
2555EXPORT_SYMBOL_GPL(iscsi_host_add);
2556
2557/**
2558 * iscsi_host_alloc - allocate a host and driver data
2559 * @sht: scsi host template
2560 * @dd_data_size: driver host data size
2561 * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2562 *
2563 * This should be called by partial offload and software iscsi drivers.
2564 * To access the driver specific memory use the iscsi_host_priv() macro.
2565 */
2566struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2567				   int dd_data_size, bool xmit_can_sleep)
2568{
2569	struct Scsi_Host *shost;
2570	struct iscsi_host *ihost;
2571
2572	shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2573	if (!shost)
2574		return NULL;
2575	ihost = shost_priv(shost);
2576
2577	if (xmit_can_sleep) {
2578		snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2579			"iscsi_q_%d", shost->host_no);
2580		ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2581		if (!ihost->workq)
2582			goto free_host;
2583	}
2584
2585	spin_lock_init(&ihost->lock);
2586	ihost->state = ISCSI_HOST_SETUP;
2587	ihost->num_sessions = 0;
2588	init_waitqueue_head(&ihost->session_removal_wq);
2589	return shost;
2590
2591free_host:
2592	scsi_host_put(shost);
2593	return NULL;
2594}
2595EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2596
2597static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2598{
2599	iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2600}
2601
2602/**
2603 * iscsi_host_remove - remove host and sessions
2604 * @shost: scsi host
2605 *
2606 * If there are any sessions left, this will initiate the removal and wait
2607 * for the completion.
2608 */
2609void iscsi_host_remove(struct Scsi_Host *shost)
2610{
2611	struct iscsi_host *ihost = shost_priv(shost);
2612	unsigned long flags;
2613
2614	spin_lock_irqsave(&ihost->lock, flags);
2615	ihost->state = ISCSI_HOST_REMOVED;
2616	spin_unlock_irqrestore(&ihost->lock, flags);
2617
2618	iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2619	wait_event_interruptible(ihost->session_removal_wq,
2620				 ihost->num_sessions == 0);
2621	if (signal_pending(current))
2622		flush_signals(current);
2623
2624	scsi_remove_host(shost);
2625	if (ihost->workq)
2626		destroy_workqueue(ihost->workq);
2627}
2628EXPORT_SYMBOL_GPL(iscsi_host_remove);
2629
2630void iscsi_host_free(struct Scsi_Host *shost)
2631{
2632	struct iscsi_host *ihost = shost_priv(shost);
2633
2634	kfree(ihost->netdev);
2635	kfree(ihost->hwaddress);
2636	kfree(ihost->initiatorname);
2637	scsi_host_put(shost);
2638}
2639EXPORT_SYMBOL_GPL(iscsi_host_free);
2640
2641static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2642{
2643	struct iscsi_host *ihost = shost_priv(shost);
2644	unsigned long flags;
2645
2646	shost = scsi_host_get(shost);
2647	if (!shost) {
2648		printk(KERN_ERR "Invalid state. Cannot notify host removal "
2649		      "of session teardown event because host already "
2650		      "removed.\n");
2651		return;
2652	}
2653
2654	spin_lock_irqsave(&ihost->lock, flags);
2655	ihost->num_sessions--;
2656	if (ihost->num_sessions == 0)
2657		wake_up(&ihost->session_removal_wq);
2658	spin_unlock_irqrestore(&ihost->lock, flags);
2659	scsi_host_put(shost);
2660}
2661
2662/**
2663 * iscsi_session_setup - create iscsi cls session and host and session
2664 * @iscsit: iscsi transport template
2665 * @shost: scsi host
2666 * @cmds_max: session can queue
2667 * @cmd_task_size: LLD task private data size
2668 * @initial_cmdsn: initial CmdSN
2669 *
2670 * This can be used by software iscsi_transports that allocate
2671 * a session per scsi host.
2672 *
2673 * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2674 * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2675 * for nop handling and login/logout requests.
2676 */
2677struct iscsi_cls_session *
2678iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2679		    uint16_t cmds_max, int dd_size, int cmd_task_size,
2680		    uint32_t initial_cmdsn, unsigned int id)
2681{
2682	struct iscsi_host *ihost = shost_priv(shost);
2683	struct iscsi_session *session;
2684	struct iscsi_cls_session *cls_session;
2685	int cmd_i, scsi_cmds, total_cmds = cmds_max;
2686	unsigned long flags;
2687
2688	spin_lock_irqsave(&ihost->lock, flags);
2689	if (ihost->state == ISCSI_HOST_REMOVED) {
2690		spin_unlock_irqrestore(&ihost->lock, flags);
2691		return NULL;
2692	}
2693	ihost->num_sessions++;
2694	spin_unlock_irqrestore(&ihost->lock, flags);
2695
2696	if (!total_cmds)
2697		total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2698	/*
2699	 * The iscsi layer needs some tasks for nop handling and tmfs,
2700	 * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2701	 * + 1 command for scsi IO.
2702	 */
2703	if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2704		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2705		       "must be a power of two that is at least %d.\n",
2706		       total_cmds, ISCSI_TOTAL_CMDS_MIN);
2707		goto dec_session_count;
2708	}
2709
2710	if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2711		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2712		       "must be a power of 2 less than or equal to %d.\n",
2713		       cmds_max, ISCSI_TOTAL_CMDS_MAX);
2714		total_cmds = ISCSI_TOTAL_CMDS_MAX;
2715	}
2716
2717	if (!is_power_of_2(total_cmds)) {
2718		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2719		       "must be a power of 2.\n", total_cmds);
2720		total_cmds = rounddown_pow_of_two(total_cmds);
2721		if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2722			return NULL;
2723		printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2724		       total_cmds);
2725	}
2726	scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2727
2728	cls_session = iscsi_alloc_session(shost, iscsit,
2729					  sizeof(struct iscsi_session) +
2730					  dd_size);
2731	if (!cls_session)
2732		goto dec_session_count;
2733	session = cls_session->dd_data;
2734	session->cls_session = cls_session;
2735	session->host = shost;
2736	session->state = ISCSI_STATE_FREE;
2737	session->fast_abort = 1;
2738	session->tgt_reset_timeout = 30;
2739	session->lu_reset_timeout = 15;
2740	session->abort_timeout = 10;
2741	session->scsi_cmds_max = scsi_cmds;
2742	session->cmds_max = total_cmds;
2743	session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2744	session->exp_cmdsn = initial_cmdsn + 1;
2745	session->max_cmdsn = initial_cmdsn + 1;
2746	session->max_r2t = 1;
2747	session->tt = iscsit;
2748	session->dd_data = cls_session->dd_data + sizeof(*session);
 
2749	mutex_init(&session->eh_mutex);
2750	spin_lock_init(&session->lock);
 
2751
2752	/* initialize SCSI PDU commands pool */
2753	if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2754			    (void***)&session->cmds,
2755			    cmd_task_size + sizeof(struct iscsi_task)))
2756		goto cmdpool_alloc_fail;
2757
2758	/* pre-format cmds pool with ITT */
2759	for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2760		struct iscsi_task *task = session->cmds[cmd_i];
2761
2762		if (cmd_task_size)
2763			task->dd_data = &task[1];
2764		task->itt = cmd_i;
2765		task->state = ISCSI_TASK_FREE;
2766		INIT_LIST_HEAD(&task->running);
2767	}
2768
2769	if (!try_module_get(iscsit->owner))
2770		goto module_get_fail;
2771
2772	if (iscsi_add_session(cls_session, id))
2773		goto cls_session_fail;
2774
2775	return cls_session;
2776
2777cls_session_fail:
2778	module_put(iscsit->owner);
2779module_get_fail:
2780	iscsi_pool_free(&session->cmdpool);
2781cmdpool_alloc_fail:
2782	iscsi_free_session(cls_session);
2783dec_session_count:
2784	iscsi_host_dec_session_cnt(shost);
2785	return NULL;
2786}
2787EXPORT_SYMBOL_GPL(iscsi_session_setup);
2788
2789/**
2790 * iscsi_session_teardown - destroy session, host, and cls_session
2791 * @cls_session: iscsi session
2792 *
2793 * The driver must have called iscsi_remove_session before
2794 * calling this.
2795 */
2796void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2797{
2798	struct iscsi_session *session = cls_session->dd_data;
2799	struct module *owner = cls_session->transport->owner;
2800	struct Scsi_Host *shost = session->host;
2801
2802	iscsi_pool_free(&session->cmdpool);
2803
2804	kfree(session->password);
2805	kfree(session->password_in);
2806	kfree(session->username);
2807	kfree(session->username_in);
2808	kfree(session->targetname);
 
2809	kfree(session->initiatorname);
 
 
 
2810	kfree(session->ifacename);
 
 
2811
2812	iscsi_destroy_session(cls_session);
2813	iscsi_host_dec_session_cnt(shost);
2814	module_put(owner);
2815}
2816EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2817
2818/**
2819 * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2820 * @cls_session: iscsi_cls_session
2821 * @dd_size: private driver data size
2822 * @conn_idx: cid
2823 */
2824struct iscsi_cls_conn *
2825iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2826		 uint32_t conn_idx)
2827{
2828	struct iscsi_session *session = cls_session->dd_data;
2829	struct iscsi_conn *conn;
2830	struct iscsi_cls_conn *cls_conn;
2831	char *data;
2832
2833	cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2834				     conn_idx);
2835	if (!cls_conn)
2836		return NULL;
2837	conn = cls_conn->dd_data;
2838	memset(conn, 0, sizeof(*conn) + dd_size);
2839
2840	conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2841	conn->session = session;
2842	conn->cls_conn = cls_conn;
2843	conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2844	conn->id = conn_idx;
2845	conn->exp_statsn = 0;
2846	conn->tmf_state = TMF_INITIAL;
2847
2848	init_timer(&conn->transport_timer);
2849	conn->transport_timer.data = (unsigned long)conn;
2850	conn->transport_timer.function = iscsi_check_transport_timeouts;
2851
2852	INIT_LIST_HEAD(&conn->mgmtqueue);
2853	INIT_LIST_HEAD(&conn->cmdqueue);
2854	INIT_LIST_HEAD(&conn->requeue);
2855	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2856
2857	/* allocate login_task used for the login/text sequences */
2858	spin_lock_bh(&session->lock);
2859	if (!kfifo_out(&session->cmdpool.queue,
2860                         (void*)&conn->login_task,
2861			 sizeof(void*))) {
2862		spin_unlock_bh(&session->lock);
2863		goto login_task_alloc_fail;
2864	}
2865	spin_unlock_bh(&session->lock);
2866
2867	data = (char *) __get_free_pages(GFP_KERNEL,
2868					 get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2869	if (!data)
2870		goto login_task_data_alloc_fail;
2871	conn->login_task->data = conn->data = data;
2872
2873	init_timer(&conn->tmf_timer);
2874	init_waitqueue_head(&conn->ehwait);
2875
2876	return cls_conn;
2877
2878login_task_data_alloc_fail:
2879	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2880		    sizeof(void*));
2881login_task_alloc_fail:
2882	iscsi_destroy_conn(cls_conn);
2883	return NULL;
2884}
2885EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2886
2887/**
2888 * iscsi_conn_teardown - teardown iscsi connection
2889 * cls_conn: iscsi class connection
2890 *
2891 * TODO: we may need to make this into a two step process
2892 * like scsi-mls remove + put host
2893 */
2894void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2895{
2896	struct iscsi_conn *conn = cls_conn->dd_data;
2897	struct iscsi_session *session = conn->session;
2898	unsigned long flags;
2899
2900	del_timer_sync(&conn->transport_timer);
2901
2902	spin_lock_bh(&session->lock);
 
2903	conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2904	if (session->leadconn == conn) {
2905		/*
2906		 * leading connection? then give up on recovery.
2907		 */
2908		session->state = ISCSI_STATE_TERMINATE;
2909		wake_up(&conn->ehwait);
2910	}
2911	spin_unlock_bh(&session->lock);
2912
2913	/*
2914	 * Block until all in-progress commands for this connection
2915	 * time out or fail.
2916	 */
2917	for (;;) {
2918		spin_lock_irqsave(session->host->host_lock, flags);
2919		if (!session->host->host_busy) { /* OK for ERL == 0 */
2920			spin_unlock_irqrestore(session->host->host_lock, flags);
2921			break;
2922		}
2923		spin_unlock_irqrestore(session->host->host_lock, flags);
2924		msleep_interruptible(500);
2925		iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2926				  "host_busy %d host_failed %d\n",
2927				  session->host->host_busy,
2928				  session->host->host_failed);
2929		/*
2930		 * force eh_abort() to unblock
2931		 */
2932		wake_up(&conn->ehwait);
2933	}
2934
2935	/* flush queued up work because we free the connection below */
2936	iscsi_suspend_tx(conn);
2937
2938	spin_lock_bh(&session->lock);
2939	free_pages((unsigned long) conn->data,
2940		   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2941	kfree(conn->persistent_address);
 
 
 
2942	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2943		    sizeof(void*));
 
2944	if (session->leadconn == conn)
2945		session->leadconn = NULL;
2946	spin_unlock_bh(&session->lock);
 
2947
2948	iscsi_destroy_conn(cls_conn);
2949}
2950EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2951
2952int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2953{
2954	struct iscsi_conn *conn = cls_conn->dd_data;
2955	struct iscsi_session *session = conn->session;
2956
2957	if (!session) {
2958		iscsi_conn_printk(KERN_ERR, conn,
2959				  "can't start unbound connection\n");
2960		return -EPERM;
2961	}
2962
2963	if ((session->imm_data_en || !session->initial_r2t_en) &&
2964	     session->first_burst > session->max_burst) {
2965		iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2966				  "first_burst %d max_burst %d\n",
2967				  session->first_burst, session->max_burst);
2968		return -EINVAL;
2969	}
2970
2971	if (conn->ping_timeout && !conn->recv_timeout) {
2972		iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2973				  "zero. Using 5 seconds\n.");
2974		conn->recv_timeout = 5;
2975	}
2976
2977	if (conn->recv_timeout && !conn->ping_timeout) {
2978		iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2979				  "zero. Using 5 seconds.\n");
2980		conn->ping_timeout = 5;
2981	}
2982
2983	spin_lock_bh(&session->lock);
2984	conn->c_stage = ISCSI_CONN_STARTED;
2985	session->state = ISCSI_STATE_LOGGED_IN;
2986	session->queued_cmdsn = session->cmdsn;
2987
2988	conn->last_recv = jiffies;
2989	conn->last_ping = jiffies;
2990	if (conn->recv_timeout && conn->ping_timeout)
2991		mod_timer(&conn->transport_timer,
2992			  jiffies + (conn->recv_timeout * HZ));
2993
2994	switch(conn->stop_stage) {
2995	case STOP_CONN_RECOVER:
2996		/*
2997		 * unblock eh_abort() if it is blocked. re-try all
2998		 * commands after successful recovery
2999		 */
3000		conn->stop_stage = 0;
3001		conn->tmf_state = TMF_INITIAL;
3002		session->age++;
3003		if (session->age == 16)
3004			session->age = 0;
3005		break;
3006	case STOP_CONN_TERM:
3007		conn->stop_stage = 0;
3008		break;
3009	default:
3010		break;
3011	}
3012	spin_unlock_bh(&session->lock);
3013
3014	iscsi_unblock_session(session->cls_session);
3015	wake_up(&conn->ehwait);
3016	return 0;
3017}
3018EXPORT_SYMBOL_GPL(iscsi_conn_start);
3019
3020static void
3021fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3022{
3023	struct iscsi_task *task;
3024	int i, state;
3025
3026	for (i = 0; i < conn->session->cmds_max; i++) {
3027		task = conn->session->cmds[i];
3028		if (task->sc)
3029			continue;
3030
3031		if (task->state == ISCSI_TASK_FREE)
3032			continue;
3033
3034		ISCSI_DBG_SESSION(conn->session,
3035				  "failing mgmt itt 0x%x state %d\n",
3036				  task->itt, task->state);
3037		state = ISCSI_TASK_ABRT_SESS_RECOV;
3038		if (task->state == ISCSI_TASK_PENDING)
3039			state = ISCSI_TASK_COMPLETED;
3040		iscsi_complete_task(task, state);
3041
3042	}
3043}
3044
3045static void iscsi_start_session_recovery(struct iscsi_session *session,
3046					 struct iscsi_conn *conn, int flag)
3047{
3048	int old_stop_stage;
3049
3050	mutex_lock(&session->eh_mutex);
3051	spin_lock_bh(&session->lock);
3052	if (conn->stop_stage == STOP_CONN_TERM) {
3053		spin_unlock_bh(&session->lock);
3054		mutex_unlock(&session->eh_mutex);
3055		return;
3056	}
3057
3058	/*
3059	 * When this is called for the in_login state, we only want to clean
3060	 * up the login task and connection. We do not need to block and set
3061	 * the recovery state again
3062	 */
3063	if (flag == STOP_CONN_TERM)
3064		session->state = ISCSI_STATE_TERMINATE;
3065	else if (conn->stop_stage != STOP_CONN_RECOVER)
3066		session->state = ISCSI_STATE_IN_RECOVERY;
3067
3068	old_stop_stage = conn->stop_stage;
3069	conn->stop_stage = flag;
3070	spin_unlock_bh(&session->lock);
3071
3072	del_timer_sync(&conn->transport_timer);
3073	iscsi_suspend_tx(conn);
3074
3075	spin_lock_bh(&session->lock);
3076	conn->c_stage = ISCSI_CONN_STOPPED;
3077	spin_unlock_bh(&session->lock);
3078
3079	/*
3080	 * for connection level recovery we should not calculate
3081	 * header digest. conn->hdr_size used for optimization
3082	 * in hdr_extract() and will be re-negotiated at
3083	 * set_param() time.
3084	 */
3085	if (flag == STOP_CONN_RECOVER) {
3086		conn->hdrdgst_en = 0;
3087		conn->datadgst_en = 0;
3088		if (session->state == ISCSI_STATE_IN_RECOVERY &&
3089		    old_stop_stage != STOP_CONN_RECOVER) {
3090			ISCSI_DBG_SESSION(session, "blocking session\n");
3091			iscsi_block_session(session->cls_session);
3092		}
3093	}
3094
3095	/*
3096	 * flush queues.
3097	 */
3098	spin_lock_bh(&session->lock);
3099	fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3100	fail_mgmt_tasks(session, conn);
3101	memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3102	spin_unlock_bh(&session->lock);
3103	mutex_unlock(&session->eh_mutex);
3104}
3105
3106void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3107{
3108	struct iscsi_conn *conn = cls_conn->dd_data;
3109	struct iscsi_session *session = conn->session;
3110
3111	switch (flag) {
3112	case STOP_CONN_RECOVER:
3113	case STOP_CONN_TERM:
3114		iscsi_start_session_recovery(session, conn, flag);
3115		break;
3116	default:
3117		iscsi_conn_printk(KERN_ERR, conn,
3118				  "invalid stop flag %d\n", flag);
3119	}
3120}
3121EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3122
3123int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3124		    struct iscsi_cls_conn *cls_conn, int is_leading)
3125{
3126	struct iscsi_session *session = cls_session->dd_data;
3127	struct iscsi_conn *conn = cls_conn->dd_data;
3128
3129	spin_lock_bh(&session->lock);
3130	if (is_leading)
3131		session->leadconn = conn;
3132	spin_unlock_bh(&session->lock);
3133
3134	/*
3135	 * Unblock xmitworker(), Login Phase will pass through.
3136	 */
3137	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3138	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3139	return 0;
3140}
3141EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3142
3143static int iscsi_switch_str_param(char **param, char *new_val_buf)
3144{
3145	char *new_val;
3146
3147	if (*param) {
3148		if (!strcmp(*param, new_val_buf))
3149			return 0;
3150	}
3151
3152	new_val = kstrdup(new_val_buf, GFP_NOIO);
3153	if (!new_val)
3154		return -ENOMEM;
3155
3156	kfree(*param);
3157	*param = new_val;
3158	return 0;
3159}
 
3160
3161int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3162		    enum iscsi_param param, char *buf, int buflen)
3163{
3164	struct iscsi_conn *conn = cls_conn->dd_data;
3165	struct iscsi_session *session = conn->session;
3166	uint32_t value;
3167
3168	switch(param) {
3169	case ISCSI_PARAM_FAST_ABORT:
3170		sscanf(buf, "%d", &session->fast_abort);
3171		break;
3172	case ISCSI_PARAM_ABORT_TMO:
3173		sscanf(buf, "%d", &session->abort_timeout);
3174		break;
3175	case ISCSI_PARAM_LU_RESET_TMO:
3176		sscanf(buf, "%d", &session->lu_reset_timeout);
3177		break;
3178	case ISCSI_PARAM_TGT_RESET_TMO:
3179		sscanf(buf, "%d", &session->tgt_reset_timeout);
3180		break;
3181	case ISCSI_PARAM_PING_TMO:
3182		sscanf(buf, "%d", &conn->ping_timeout);
3183		break;
3184	case ISCSI_PARAM_RECV_TMO:
3185		sscanf(buf, "%d", &conn->recv_timeout);
3186		break;
3187	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3188		sscanf(buf, "%d", &conn->max_recv_dlength);
3189		break;
3190	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3191		sscanf(buf, "%d", &conn->max_xmit_dlength);
3192		break;
3193	case ISCSI_PARAM_HDRDGST_EN:
3194		sscanf(buf, "%d", &conn->hdrdgst_en);
3195		break;
3196	case ISCSI_PARAM_DATADGST_EN:
3197		sscanf(buf, "%d", &conn->datadgst_en);
3198		break;
3199	case ISCSI_PARAM_INITIAL_R2T_EN:
3200		sscanf(buf, "%d", &session->initial_r2t_en);
3201		break;
3202	case ISCSI_PARAM_MAX_R2T:
3203		sscanf(buf, "%d", &session->max_r2t);
3204		break;
3205	case ISCSI_PARAM_IMM_DATA_EN:
3206		sscanf(buf, "%d", &session->imm_data_en);
3207		break;
3208	case ISCSI_PARAM_FIRST_BURST:
3209		sscanf(buf, "%d", &session->first_burst);
3210		break;
3211	case ISCSI_PARAM_MAX_BURST:
3212		sscanf(buf, "%d", &session->max_burst);
3213		break;
3214	case ISCSI_PARAM_PDU_INORDER_EN:
3215		sscanf(buf, "%d", &session->pdu_inorder_en);
3216		break;
3217	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3218		sscanf(buf, "%d", &session->dataseq_inorder_en);
3219		break;
3220	case ISCSI_PARAM_ERL:
3221		sscanf(buf, "%d", &session->erl);
3222		break;
3223	case ISCSI_PARAM_IFMARKER_EN:
3224		sscanf(buf, "%d", &value);
3225		BUG_ON(value);
3226		break;
3227	case ISCSI_PARAM_OFMARKER_EN:
3228		sscanf(buf, "%d", &value);
3229		BUG_ON(value);
3230		break;
3231	case ISCSI_PARAM_EXP_STATSN:
3232		sscanf(buf, "%u", &conn->exp_statsn);
3233		break;
3234	case ISCSI_PARAM_USERNAME:
3235		return iscsi_switch_str_param(&session->username, buf);
3236	case ISCSI_PARAM_USERNAME_IN:
3237		return iscsi_switch_str_param(&session->username_in, buf);
3238	case ISCSI_PARAM_PASSWORD:
3239		return iscsi_switch_str_param(&session->password, buf);
3240	case ISCSI_PARAM_PASSWORD_IN:
3241		return iscsi_switch_str_param(&session->password_in, buf);
3242	case ISCSI_PARAM_TARGET_NAME:
3243		return iscsi_switch_str_param(&session->targetname, buf);
 
 
3244	case ISCSI_PARAM_TPGT:
3245		sscanf(buf, "%d", &session->tpgt);
3246		break;
3247	case ISCSI_PARAM_PERSISTENT_PORT:
3248		sscanf(buf, "%d", &conn->persistent_port);
3249		break;
3250	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3251		return iscsi_switch_str_param(&conn->persistent_address, buf);
3252	case ISCSI_PARAM_IFACE_NAME:
3253		return iscsi_switch_str_param(&session->ifacename, buf);
3254	case ISCSI_PARAM_INITIATOR_NAME:
3255		return iscsi_switch_str_param(&session->initiatorname, buf);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3256	default:
3257		return -ENOSYS;
3258	}
3259
3260	return 0;
3261}
3262EXPORT_SYMBOL_GPL(iscsi_set_param);
3263
3264int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3265			    enum iscsi_param param, char *buf)
3266{
3267	struct iscsi_session *session = cls_session->dd_data;
3268	int len;
3269
3270	switch(param) {
3271	case ISCSI_PARAM_FAST_ABORT:
3272		len = sprintf(buf, "%d\n", session->fast_abort);
3273		break;
3274	case ISCSI_PARAM_ABORT_TMO:
3275		len = sprintf(buf, "%d\n", session->abort_timeout);
3276		break;
3277	case ISCSI_PARAM_LU_RESET_TMO:
3278		len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3279		break;
3280	case ISCSI_PARAM_TGT_RESET_TMO:
3281		len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3282		break;
3283	case ISCSI_PARAM_INITIAL_R2T_EN:
3284		len = sprintf(buf, "%d\n", session->initial_r2t_en);
3285		break;
3286	case ISCSI_PARAM_MAX_R2T:
3287		len = sprintf(buf, "%hu\n", session->max_r2t);
3288		break;
3289	case ISCSI_PARAM_IMM_DATA_EN:
3290		len = sprintf(buf, "%d\n", session->imm_data_en);
3291		break;
3292	case ISCSI_PARAM_FIRST_BURST:
3293		len = sprintf(buf, "%u\n", session->first_burst);
3294		break;
3295	case ISCSI_PARAM_MAX_BURST:
3296		len = sprintf(buf, "%u\n", session->max_burst);
3297		break;
3298	case ISCSI_PARAM_PDU_INORDER_EN:
3299		len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3300		break;
3301	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3302		len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3303		break;
 
 
 
3304	case ISCSI_PARAM_ERL:
3305		len = sprintf(buf, "%d\n", session->erl);
3306		break;
3307	case ISCSI_PARAM_TARGET_NAME:
3308		len = sprintf(buf, "%s\n", session->targetname);
3309		break;
 
 
 
3310	case ISCSI_PARAM_TPGT:
3311		len = sprintf(buf, "%d\n", session->tpgt);
3312		break;
3313	case ISCSI_PARAM_USERNAME:
3314		len = sprintf(buf, "%s\n", session->username);
3315		break;
3316	case ISCSI_PARAM_USERNAME_IN:
3317		len = sprintf(buf, "%s\n", session->username_in);
3318		break;
3319	case ISCSI_PARAM_PASSWORD:
3320		len = sprintf(buf, "%s\n", session->password);
3321		break;
3322	case ISCSI_PARAM_PASSWORD_IN:
3323		len = sprintf(buf, "%s\n", session->password_in);
3324		break;
3325	case ISCSI_PARAM_IFACE_NAME:
3326		len = sprintf(buf, "%s\n", session->ifacename);
3327		break;
3328	case ISCSI_PARAM_INITIATOR_NAME:
3329		len = sprintf(buf, "%s\n", session->initiatorname);
3330		break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3331	default:
3332		return -ENOSYS;
3333	}
3334
3335	return len;
3336}
3337EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3338
3339int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3340			      enum iscsi_param param, char *buf)
3341{
3342	struct sockaddr_in6 *sin6 = NULL;
3343	struct sockaddr_in *sin = NULL;
3344	int len;
3345
3346	switch (addr->ss_family) {
3347	case AF_INET:
3348		sin = (struct sockaddr_in *)addr;
3349		break;
3350	case AF_INET6:
3351		sin6 = (struct sockaddr_in6 *)addr;
3352		break;
3353	default:
3354		return -EINVAL;
3355	}
3356
3357	switch (param) {
3358	case ISCSI_PARAM_CONN_ADDRESS:
3359	case ISCSI_HOST_PARAM_IPADDRESS:
3360		if (sin)
3361			len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3362		else
3363			len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3364		break;
3365	case ISCSI_PARAM_CONN_PORT:
 
3366		if (sin)
3367			len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3368		else
3369			len = sprintf(buf, "%hu\n",
3370				      be16_to_cpu(sin6->sin6_port));
3371		break;
3372	default:
3373		return -EINVAL;
3374	}
3375
3376	return len;
3377}
3378EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3379
3380int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3381			 enum iscsi_param param, char *buf)
3382{
3383	struct iscsi_conn *conn = cls_conn->dd_data;
3384	int len;
3385
3386	switch(param) {
3387	case ISCSI_PARAM_PING_TMO:
3388		len = sprintf(buf, "%u\n", conn->ping_timeout);
3389		break;
3390	case ISCSI_PARAM_RECV_TMO:
3391		len = sprintf(buf, "%u\n", conn->recv_timeout);
3392		break;
3393	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3394		len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3395		break;
3396	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3397		len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3398		break;
3399	case ISCSI_PARAM_HDRDGST_EN:
3400		len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3401		break;
3402	case ISCSI_PARAM_DATADGST_EN:
3403		len = sprintf(buf, "%d\n", conn->datadgst_en);
3404		break;
3405	case ISCSI_PARAM_IFMARKER_EN:
3406		len = sprintf(buf, "%d\n", conn->ifmarker_en);
3407		break;
3408	case ISCSI_PARAM_OFMARKER_EN:
3409		len = sprintf(buf, "%d\n", conn->ofmarker_en);
3410		break;
3411	case ISCSI_PARAM_EXP_STATSN:
3412		len = sprintf(buf, "%u\n", conn->exp_statsn);
3413		break;
3414	case ISCSI_PARAM_PERSISTENT_PORT:
3415		len = sprintf(buf, "%d\n", conn->persistent_port);
3416		break;
3417	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3418		len = sprintf(buf, "%s\n", conn->persistent_address);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3419		break;
3420	default:
3421		return -ENOSYS;
3422	}
3423
3424	return len;
3425}
3426EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3427
3428int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3429			 char *buf)
3430{
3431	struct iscsi_host *ihost = shost_priv(shost);
3432	int len;
3433
3434	switch (param) {
3435	case ISCSI_HOST_PARAM_NETDEV_NAME:
3436		len = sprintf(buf, "%s\n", ihost->netdev);
3437		break;
3438	case ISCSI_HOST_PARAM_HWADDRESS:
3439		len = sprintf(buf, "%s\n", ihost->hwaddress);
3440		break;
3441	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3442		len = sprintf(buf, "%s\n", ihost->initiatorname);
3443		break;
3444	default:
3445		return -ENOSYS;
3446	}
3447
3448	return len;
3449}
3450EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3451
3452int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3453			 char *buf, int buflen)
3454{
3455	struct iscsi_host *ihost = shost_priv(shost);
3456
3457	switch (param) {
3458	case ISCSI_HOST_PARAM_NETDEV_NAME:
3459		return iscsi_switch_str_param(&ihost->netdev, buf);
3460	case ISCSI_HOST_PARAM_HWADDRESS:
3461		return iscsi_switch_str_param(&ihost->hwaddress, buf);
3462	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3463		return iscsi_switch_str_param(&ihost->initiatorname, buf);
3464	default:
3465		return -ENOSYS;
3466	}
3467
3468	return 0;
3469}
3470EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3471
3472MODULE_AUTHOR("Mike Christie");
3473MODULE_DESCRIPTION("iSCSI library functions");
3474MODULE_LICENSE("GPL");
v4.6
   1/*
   2 * iSCSI lib functions
   3 *
   4 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5 * Copyright (C) 2004 - 2006 Mike Christie
   6 * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7 * Copyright (C) 2004 - 2005 Alex Aizman
   8 * maintained by open-iscsi@googlegroups.com
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License as published by
  12 * the Free Software Foundation; either version 2 of the License, or
  13 * (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful,
  16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 * GNU General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program; if not, write to the Free Software
  22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23 */
  24#include <linux/types.h>
  25#include <linux/kfifo.h>
  26#include <linux/delay.h>
  27#include <linux/log2.h>
  28#include <linux/slab.h>
  29#include <linux/module.h>
  30#include <asm/unaligned.h>
  31#include <net/tcp.h>
  32#include <scsi/scsi_cmnd.h>
  33#include <scsi/scsi_device.h>
  34#include <scsi/scsi_eh.h>
  35#include <scsi/scsi_tcq.h>
  36#include <scsi/scsi_host.h>
  37#include <scsi/scsi.h>
  38#include <scsi/iscsi_proto.h>
  39#include <scsi/scsi_transport.h>
  40#include <scsi/scsi_transport_iscsi.h>
  41#include <scsi/libiscsi.h>
  42
  43static int iscsi_dbg_lib_conn;
  44module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  45		   S_IRUGO | S_IWUSR);
  46MODULE_PARM_DESC(debug_libiscsi_conn,
  47		 "Turn on debugging for connections in libiscsi module. "
  48		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  49
  50static int iscsi_dbg_lib_session;
  51module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  52		   S_IRUGO | S_IWUSR);
  53MODULE_PARM_DESC(debug_libiscsi_session,
  54		 "Turn on debugging for sessions in libiscsi module. "
  55		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  56
  57static int iscsi_dbg_lib_eh;
  58module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  59		   S_IRUGO | S_IWUSR);
  60MODULE_PARM_DESC(debug_libiscsi_eh,
  61		 "Turn on debugging for error handling in libiscsi module. "
  62		 "Set to 1 to turn on, and zero to turn off. Default is off.");
  63
  64#define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)			\
  65	do {							\
  66		if (iscsi_dbg_lib_conn)				\
  67			iscsi_conn_printk(KERN_INFO, _conn,	\
  68					     "%s " dbg_fmt,	\
  69					     __func__, ##arg);	\
  70	} while (0);
  71
  72#define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)			\
  73	do {								\
  74		if (iscsi_dbg_lib_session)				\
  75			iscsi_session_printk(KERN_INFO, _session,	\
  76					     "%s " dbg_fmt,		\
  77					     __func__, ##arg);		\
  78	} while (0);
  79
  80#define ISCSI_DBG_EH(_session, dbg_fmt, arg...)				\
  81	do {								\
  82		if (iscsi_dbg_lib_eh)					\
  83			iscsi_session_printk(KERN_INFO, _session,	\
  84					     "%s " dbg_fmt,		\
  85					     __func__, ##arg);		\
  86	} while (0);
  87
  88inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
  89{
  90	struct Scsi_Host *shost = conn->session->host;
  91	struct iscsi_host *ihost = shost_priv(shost);
  92
  93	if (ihost->workq)
  94		queue_work(ihost->workq, &conn->xmitwork);
  95}
  96EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
  97
  98static void __iscsi_update_cmdsn(struct iscsi_session *session,
  99				 uint32_t exp_cmdsn, uint32_t max_cmdsn)
 100{
 101	/*
 102	 * standard specifies this check for when to update expected and
 103	 * max sequence numbers
 104	 */
 105	if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 106		return;
 107
 108	if (exp_cmdsn != session->exp_cmdsn &&
 109	    !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 110		session->exp_cmdsn = exp_cmdsn;
 111
 112	if (max_cmdsn != session->max_cmdsn &&
 113	    !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
 114		session->max_cmdsn = max_cmdsn;
 
 
 
 
 
 
 
 
 115}
 116
 117void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 118{
 119	__iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 120			     be32_to_cpu(hdr->max_cmdsn));
 121}
 122EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 123
 124/**
 125 * iscsi_prep_data_out_pdu - initialize Data-Out
 126 * @task: scsi command task
 127 * @r2t: R2T info
 128 * @hdr: iscsi data in pdu
 129 *
 130 * Notes:
 131 *	Initialize Data-Out within this R2T sequence and finds
 132 *	proper data_offset within this SCSI command.
 133 *
 134 *	This function is called with connection lock taken.
 135 **/
 136void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 137			   struct iscsi_data *hdr)
 138{
 139	struct iscsi_conn *conn = task->conn;
 140	unsigned int left = r2t->data_length - r2t->sent;
 141
 142	task->hdr_len = sizeof(struct iscsi_data);
 143
 144	memset(hdr, 0, sizeof(struct iscsi_data));
 145	hdr->ttt = r2t->ttt;
 146	hdr->datasn = cpu_to_be32(r2t->datasn);
 147	r2t->datasn++;
 148	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 149	hdr->lun = task->lun;
 150	hdr->itt = task->hdr_itt;
 151	hdr->exp_statsn = r2t->exp_statsn;
 152	hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 153	if (left > conn->max_xmit_dlength) {
 154		hton24(hdr->dlength, conn->max_xmit_dlength);
 155		r2t->data_count = conn->max_xmit_dlength;
 156		hdr->flags = 0;
 157	} else {
 158		hton24(hdr->dlength, left);
 159		r2t->data_count = left;
 160		hdr->flags = ISCSI_FLAG_CMD_FINAL;
 161	}
 162	conn->dataout_pdus_cnt++;
 163}
 164EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 165
 166static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 167{
 168	unsigned exp_len = task->hdr_len + len;
 169
 170	if (exp_len > task->hdr_max) {
 171		WARN_ON(1);
 172		return -EINVAL;
 173	}
 174
 175	WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 176	task->hdr_len = exp_len;
 177	return 0;
 178}
 179
 180/*
 181 * make an extended cdb AHS
 182 */
 183static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 184{
 185	struct scsi_cmnd *cmd = task->sc;
 186	unsigned rlen, pad_len;
 187	unsigned short ahslength;
 188	struct iscsi_ecdb_ahdr *ecdb_ahdr;
 189	int rc;
 190
 191	ecdb_ahdr = iscsi_next_hdr(task);
 192	rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 193
 194	BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 195	ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 196
 197	pad_len = iscsi_padding(rlen);
 198
 199	rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 200	                   sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 201	if (rc)
 202		return rc;
 203
 204	if (pad_len)
 205		memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 206
 207	ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 208	ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 209	ecdb_ahdr->reserved = 0;
 210	memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 211
 212	ISCSI_DBG_SESSION(task->conn->session,
 213			  "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 214		          "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 215		          "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 216		          task->hdr_len);
 217	return 0;
 218}
 219
 220static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 221{
 222	struct scsi_cmnd *sc = task->sc;
 223	struct iscsi_rlength_ahdr *rlen_ahdr;
 224	int rc;
 225
 226	rlen_ahdr = iscsi_next_hdr(task);
 227	rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 228	if (rc)
 229		return rc;
 230
 231	rlen_ahdr->ahslength =
 232		cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 233						  sizeof(rlen_ahdr->reserved));
 234	rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 235	rlen_ahdr->reserved = 0;
 236	rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 237
 238	ISCSI_DBG_SESSION(task->conn->session,
 239			  "bidi-in rlen_ahdr->read_length(%d) "
 240		          "rlen_ahdr->ahslength(%d)\n",
 241		          be32_to_cpu(rlen_ahdr->read_length),
 242		          be16_to_cpu(rlen_ahdr->ahslength));
 243	return 0;
 244}
 245
 246/**
 247 * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 248 * @task: iscsi task
 249 * @opcode: opcode to check for
 250 *
 251 * During TMF a task has to be checked if it's affected.
 252 * All unrelated I/O can be passed through, but I/O to the
 253 * affected LUN should be restricted.
 254 * If 'fast_abort' is set we won't be sending any I/O to the
 255 * affected LUN.
 256 * Otherwise the target is waiting for all TTTs to be completed,
 257 * so we have to send all outstanding Data-Out PDUs to the target.
 258 */
 259static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 260{
 261	struct iscsi_conn *conn = task->conn;
 262	struct iscsi_tm *tmf = &conn->tmhdr;
 263	u64 hdr_lun;
 264
 265	if (conn->tmf_state == TMF_INITIAL)
 266		return 0;
 267
 268	if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 269		return 0;
 270
 271	switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 272	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 273		/*
 274		 * Allow PDUs for unrelated LUNs
 275		 */
 276		hdr_lun = scsilun_to_int(&tmf->lun);
 277		if (hdr_lun != task->sc->device->lun)
 278			return 0;
 279		/* fall through */
 280	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 281		/*
 282		 * Fail all SCSI cmd PDUs
 283		 */
 284		if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 285			iscsi_conn_printk(KERN_INFO, conn,
 286					  "task [op %x/%x itt "
 287					  "0x%x/0x%x] "
 288					  "rejected.\n",
 289					  task->hdr->opcode, opcode,
 290					  task->itt, task->hdr_itt);
 291			return -EACCES;
 292		}
 293		/*
 294		 * And also all data-out PDUs in response to R2T
 295		 * if fast_abort is set.
 296		 */
 297		if (conn->session->fast_abort) {
 298			iscsi_conn_printk(KERN_INFO, conn,
 299					  "task [op %x/%x itt "
 300					  "0x%x/0x%x] fast abort.\n",
 301					  task->hdr->opcode, opcode,
 302					  task->itt, task->hdr_itt);
 303			return -EACCES;
 304		}
 305		break;
 306	case ISCSI_TM_FUNC_ABORT_TASK:
 307		/*
 308		 * the caller has already checked if the task
 309		 * they want to abort was in the pending queue so if
 310		 * we are here the cmd pdu has gone out already, and
 311		 * we will only hit this for data-outs
 312		 */
 313		if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 314		    task->hdr_itt == tmf->rtt) {
 315			ISCSI_DBG_SESSION(conn->session,
 316					  "Preventing task %x/%x from sending "
 317					  "data-out due to abort task in "
 318					  "progress\n", task->itt,
 319					  task->hdr_itt);
 320			return -EACCES;
 321		}
 322		break;
 323	}
 324
 325	return 0;
 326}
 327
 328/**
 329 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 330 * @task: iscsi task
 331 *
 332 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 333 * fields like dlength or final based on how much data it sends
 334 */
 335static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 336{
 337	struct iscsi_conn *conn = task->conn;
 338	struct iscsi_session *session = conn->session;
 339	struct scsi_cmnd *sc = task->sc;
 340	struct iscsi_scsi_req *hdr;
 341	unsigned hdrlength, cmd_len, transfer_length;
 342	itt_t itt;
 343	int rc;
 344
 345	rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 346	if (rc)
 347		return rc;
 348
 349	if (conn->session->tt->alloc_pdu) {
 350		rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 351		if (rc)
 352			return rc;
 353	}
 354	hdr = (struct iscsi_scsi_req *)task->hdr;
 355	itt = hdr->itt;
 356	memset(hdr, 0, sizeof(*hdr));
 357
 358	if (session->tt->parse_pdu_itt)
 359		hdr->itt = task->hdr_itt = itt;
 360	else
 361		hdr->itt = task->hdr_itt = build_itt(task->itt,
 362						     task->conn->session->age);
 363	task->hdr_len = 0;
 364	rc = iscsi_add_hdr(task, sizeof(*hdr));
 365	if (rc)
 366		return rc;
 367	hdr->opcode = ISCSI_OP_SCSI_CMD;
 368	hdr->flags = ISCSI_ATTR_SIMPLE;
 369	int_to_scsilun(sc->device->lun, &hdr->lun);
 370	task->lun = hdr->lun;
 371	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 372	cmd_len = sc->cmd_len;
 373	if (cmd_len < ISCSI_CDB_SIZE)
 374		memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 375	else if (cmd_len > ISCSI_CDB_SIZE) {
 376		rc = iscsi_prep_ecdb_ahs(task);
 377		if (rc)
 378			return rc;
 379		cmd_len = ISCSI_CDB_SIZE;
 380	}
 381	memcpy(hdr->cdb, sc->cmnd, cmd_len);
 382
 383	task->imm_count = 0;
 384	if (scsi_bidi_cmnd(sc)) {
 385		hdr->flags |= ISCSI_FLAG_CMD_READ;
 386		rc = iscsi_prep_bidi_ahs(task);
 387		if (rc)
 388			return rc;
 389	}
 390
 391	if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 392		task->protected = true;
 393
 394	transfer_length = scsi_transfer_length(sc);
 395	hdr->data_length = cpu_to_be32(transfer_length);
 396	if (sc->sc_data_direction == DMA_TO_DEVICE) {
 
 397		struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 398
 
 399		hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 400		/*
 401		 * Write counters:
 402		 *
 403		 *	imm_count	bytes to be sent right after
 404		 *			SCSI PDU Header
 405		 *
 406		 *	unsol_count	bytes(as Data-Out) to be sent
 407		 *			without	R2T ack right after
 408		 *			immediate data
 409		 *
 410		 *	r2t data_length bytes to be sent via R2T ack's
 411		 *
 412		 *      pad_count       bytes to be sent as zero-padding
 413		 */
 414		memset(r2t, 0, sizeof(*r2t));
 415
 416		if (session->imm_data_en) {
 417			if (transfer_length >= session->first_burst)
 418				task->imm_count = min(session->first_burst,
 419							conn->max_xmit_dlength);
 420			else
 421				task->imm_count = min(transfer_length,
 422						      conn->max_xmit_dlength);
 423			hton24(hdr->dlength, task->imm_count);
 424		} else
 425			zero_data(hdr->dlength);
 426
 427		if (!session->initial_r2t_en) {
 428			r2t->data_length = min(session->first_burst,
 429					       transfer_length) -
 430					       task->imm_count;
 431			r2t->data_offset = task->imm_count;
 432			r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 433			r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 434		}
 435
 436		if (!task->unsol_r2t.data_length)
 437			/* No unsolicit Data-Out's */
 438			hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 439	} else {
 440		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 441		zero_data(hdr->dlength);
 
 442
 443		if (sc->sc_data_direction == DMA_FROM_DEVICE)
 444			hdr->flags |= ISCSI_FLAG_CMD_READ;
 445	}
 446
 447	/* calculate size of additional header segments (AHSs) */
 448	hdrlength = task->hdr_len - sizeof(*hdr);
 449
 450	WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 451	hdrlength /= ISCSI_PAD_LEN;
 452
 453	WARN_ON(hdrlength >= 256);
 454	hdr->hlength = hdrlength & 0xFF;
 455	hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 456
 457	if (session->tt->init_task && session->tt->init_task(task))
 458		return -EIO;
 459
 460	task->state = ISCSI_TASK_RUNNING;
 461	session->cmdsn++;
 462
 463	conn->scsicmd_pdus_cnt++;
 464	ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 465			  "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
 466			  scsi_bidi_cmnd(sc) ? "bidirectional" :
 467			  sc->sc_data_direction == DMA_TO_DEVICE ?
 468			  "write" : "read", conn->id, sc, sc->cmnd[0],
 469			  task->itt, transfer_length,
 470			  scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 471			  session->cmdsn,
 472			  session->max_cmdsn - session->exp_cmdsn + 1);
 473	return 0;
 474}
 475
 476/**
 477 * iscsi_free_task - free a task
 478 * @task: iscsi cmd task
 479 *
 480 * Must be called with session back_lock.
 481 * This function returns the scsi command to scsi-ml or cleans
 482 * up mgmt tasks then returns the task to the pool.
 483 */
 484static void iscsi_free_task(struct iscsi_task *task)
 485{
 486	struct iscsi_conn *conn = task->conn;
 487	struct iscsi_session *session = conn->session;
 488	struct scsi_cmnd *sc = task->sc;
 489	int oldstate = task->state;
 490
 491	ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 492			  task->itt, task->state, task->sc);
 493
 494	session->tt->cleanup_task(task);
 495	task->state = ISCSI_TASK_FREE;
 496	task->sc = NULL;
 497	/*
 498	 * login task is preallocated so do not free
 499	 */
 500	if (conn->login_task == task)
 501		return;
 502
 503	kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 504
 505	if (sc) {
 
 506		/* SCSI eh reuses commands to verify us */
 507		sc->SCp.ptr = NULL;
 508		/*
 509		 * queue command may call this to free the task, so
 510		 * it will decide how to return sc to scsi-ml.
 511		 */
 512		if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 513			sc->scsi_done(sc);
 514	}
 515}
 516
 517void __iscsi_get_task(struct iscsi_task *task)
 518{
 519	atomic_inc(&task->refcount);
 520}
 521EXPORT_SYMBOL_GPL(__iscsi_get_task);
 522
 523void __iscsi_put_task(struct iscsi_task *task)
 524{
 525	if (atomic_dec_and_test(&task->refcount))
 526		iscsi_free_task(task);
 527}
 528EXPORT_SYMBOL_GPL(__iscsi_put_task);
 529
 530void iscsi_put_task(struct iscsi_task *task)
 531{
 532	struct iscsi_session *session = task->conn->session;
 533
 534	/* regular RX path uses back_lock */
 535	spin_lock_bh(&session->back_lock);
 536	__iscsi_put_task(task);
 537	spin_unlock_bh(&session->back_lock);
 538}
 539EXPORT_SYMBOL_GPL(iscsi_put_task);
 540
 541/**
 542 * iscsi_complete_task - finish a task
 543 * @task: iscsi cmd task
 544 * @state: state to complete task with
 545 *
 546 * Must be called with session back_lock.
 547 */
 548static void iscsi_complete_task(struct iscsi_task *task, int state)
 549{
 550	struct iscsi_conn *conn = task->conn;
 551
 552	ISCSI_DBG_SESSION(conn->session,
 553			  "complete task itt 0x%x state %d sc %p\n",
 554			  task->itt, task->state, task->sc);
 555	if (task->state == ISCSI_TASK_COMPLETED ||
 556	    task->state == ISCSI_TASK_ABRT_TMF ||
 557	    task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 558	    task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 559		return;
 560	WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 561	task->state = state;
 562
 563	if (!list_empty(&task->running))
 564		list_del_init(&task->running);
 565
 566	if (conn->task == task)
 567		conn->task = NULL;
 568
 569	if (conn->ping_task == task)
 570		conn->ping_task = NULL;
 571
 572	/* release get from queueing */
 573	__iscsi_put_task(task);
 574}
 575
 576/**
 577 * iscsi_complete_scsi_task - finish scsi task normally
 578 * @task: iscsi task for scsi cmd
 579 * @exp_cmdsn: expected cmd sn in cpu format
 580 * @max_cmdsn: max cmd sn in cpu format
 581 *
 582 * This is used when drivers do not need or cannot perform
 583 * lower level pdu processing.
 584 *
 585 * Called with session back_lock
 586 */
 587void iscsi_complete_scsi_task(struct iscsi_task *task,
 588			      uint32_t exp_cmdsn, uint32_t max_cmdsn)
 589{
 590	struct iscsi_conn *conn = task->conn;
 591
 592	ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 593
 594	conn->last_recv = jiffies;
 595	__iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 596	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 597}
 598EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 599
 600
 601/*
 602 * session back_lock must be held and if not called for a task that is
 603 * still pending or from the xmit thread, then xmit thread must
 604 * be suspended.
 605 */
 606static void fail_scsi_task(struct iscsi_task *task, int err)
 607{
 608	struct iscsi_conn *conn = task->conn;
 609	struct scsi_cmnd *sc;
 610	int state;
 611
 612	/*
 613	 * if a command completes and we get a successful tmf response
 614	 * we will hit this because the scsi eh abort code does not take
 615	 * a ref to the task.
 616	 */
 617	sc = task->sc;
 618	if (!sc)
 619		return;
 620
 621	if (task->state == ISCSI_TASK_PENDING) {
 622		/*
 623		 * cmd never made it to the xmit thread, so we should not count
 624		 * the cmd in the sequencing
 625		 */
 626		conn->session->queued_cmdsn--;
 627		/* it was never sent so just complete like normal */
 628		state = ISCSI_TASK_COMPLETED;
 629	} else if (err == DID_TRANSPORT_DISRUPTED)
 630		state = ISCSI_TASK_ABRT_SESS_RECOV;
 631	else
 632		state = ISCSI_TASK_ABRT_TMF;
 633
 634	sc->result = err << 16;
 635	if (!scsi_bidi_cmnd(sc))
 636		scsi_set_resid(sc, scsi_bufflen(sc));
 637	else {
 638		scsi_out(sc)->resid = scsi_out(sc)->length;
 639		scsi_in(sc)->resid = scsi_in(sc)->length;
 640	}
 641
 642	/* regular RX path uses back_lock */
 643	spin_lock_bh(&conn->session->back_lock);
 644	iscsi_complete_task(task, state);
 645	spin_unlock_bh(&conn->session->back_lock);
 646}
 647
 648static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 649				struct iscsi_task *task)
 650{
 651	struct iscsi_session *session = conn->session;
 652	struct iscsi_hdr *hdr = task->hdr;
 653	struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 654	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 655
 656	if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 657		return -ENOTCONN;
 658
 659	if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 660		nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 661	/*
 662	 * pre-format CmdSN for outgoing PDU.
 663	 */
 664	nop->cmdsn = cpu_to_be32(session->cmdsn);
 665	if (hdr->itt != RESERVED_ITT) {
 666		/*
 667		 * TODO: We always use immediate for normal session pdus.
 668		 * If we start to send tmfs or nops as non-immediate then
 669		 * we should start checking the cmdsn numbers for mgmt tasks.
 670		 *
 671		 * During discovery sessions iscsid sends TEXT as non immediate,
 672		 * but we always only send one PDU at a time.
 673		 */
 674		if (conn->c_stage == ISCSI_CONN_STARTED &&
 675		    !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 676			session->queued_cmdsn++;
 677			session->cmdsn++;
 678		}
 679	}
 680
 681	if (session->tt->init_task && session->tt->init_task(task))
 682		return -EIO;
 683
 684	if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 685		session->state = ISCSI_STATE_LOGGING_OUT;
 686
 687	task->state = ISCSI_TASK_RUNNING;
 688	ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 689			  "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 690			  hdr->itt, task->data_count);
 691	return 0;
 692}
 693
 694static struct iscsi_task *
 695__iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 696		      char *data, uint32_t data_size)
 697{
 698	struct iscsi_session *session = conn->session;
 699	struct iscsi_host *ihost = shost_priv(session->host);
 700	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 701	struct iscsi_task *task;
 702	itt_t itt;
 703
 704	if (session->state == ISCSI_STATE_TERMINATE)
 705		return NULL;
 706
 707	if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 708		/*
 709		 * Login and Text are sent serially, in
 710		 * request-followed-by-response sequence.
 711		 * Same task can be used. Same ITT must be used.
 712		 * Note that login_task is preallocated at conn_create().
 713		 */
 714		if (conn->login_task->state != ISCSI_TASK_FREE) {
 715			iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 716					  "progress. Cannot start new task.\n");
 717			return NULL;
 718		}
 719
 720		if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 721			iscsi_conn_printk(KERN_ERR, conn, "Invalid buffer len of %u for login task. Max len is %u\n", data_size, ISCSI_DEF_MAX_RECV_SEG_LEN);
 722			return NULL;
 723		}
 724
 725		task = conn->login_task;
 726	} else {
 727		if (session->state != ISCSI_STATE_LOGGED_IN)
 728			return NULL;
 729
 730		if (data_size != 0) {
 731			iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 732			return NULL;
 733		}
 734
 735		BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 736		BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 737
 738		if (!kfifo_out(&session->cmdpool.queue,
 739				 (void*)&task, sizeof(void*)))
 740			return NULL;
 741	}
 742	/*
 743	 * released in complete pdu for task we expect a response for, and
 744	 * released by the lld when it has transmitted the task for
 745	 * pdus we do not expect a response for.
 746	 */
 747	atomic_set(&task->refcount, 1);
 748	task->conn = conn;
 749	task->sc = NULL;
 750	INIT_LIST_HEAD(&task->running);
 751	task->state = ISCSI_TASK_PENDING;
 752
 753	if (data_size) {
 754		memcpy(task->data, data, data_size);
 755		task->data_count = data_size;
 756	} else
 757		task->data_count = 0;
 758
 759	if (conn->session->tt->alloc_pdu) {
 760		if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 761			iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 762					 "pdu for mgmt task.\n");
 763			goto free_task;
 764		}
 765	}
 766
 767	itt = task->hdr->itt;
 768	task->hdr_len = sizeof(struct iscsi_hdr);
 769	memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 770
 771	if (hdr->itt != RESERVED_ITT) {
 772		if (session->tt->parse_pdu_itt)
 773			task->hdr->itt = itt;
 774		else
 775			task->hdr->itt = build_itt(task->itt,
 776						   task->conn->session->age);
 777	}
 778
 779	if (!ihost->workq) {
 780		if (iscsi_prep_mgmt_task(conn, task))
 781			goto free_task;
 782
 783		if (session->tt->xmit_task(task))
 784			goto free_task;
 785	} else {
 786		list_add_tail(&task->running, &conn->mgmtqueue);
 787		iscsi_conn_queue_work(conn);
 788	}
 789
 790	return task;
 791
 792free_task:
 793	/* regular RX path uses back_lock */
 794	spin_lock_bh(&session->back_lock);
 795	__iscsi_put_task(task);
 796	spin_unlock_bh(&session->back_lock);
 797	return NULL;
 798}
 799
 800int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 801			char *data, uint32_t data_size)
 802{
 803	struct iscsi_conn *conn = cls_conn->dd_data;
 804	struct iscsi_session *session = conn->session;
 805	int err = 0;
 806
 807	spin_lock_bh(&session->frwd_lock);
 808	if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 809		err = -EPERM;
 810	spin_unlock_bh(&session->frwd_lock);
 811	return err;
 812}
 813EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 814
 815/**
 816 * iscsi_cmd_rsp - SCSI Command Response processing
 817 * @conn: iscsi connection
 818 * @hdr: iscsi header
 819 * @task: scsi command task
 820 * @data: cmd data buffer
 821 * @datalen: len of buffer
 822 *
 823 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 824 * then completes the command and task.
 825 **/
 826static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 827			       struct iscsi_task *task, char *data,
 828			       int datalen)
 829{
 830	struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 831	struct iscsi_session *session = conn->session;
 832	struct scsi_cmnd *sc = task->sc;
 833
 834	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 835	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 836
 837	sc->result = (DID_OK << 16) | rhdr->cmd_status;
 838
 839	if (task->protected) {
 840		sector_t sector;
 841		u8 ascq;
 842
 843		/**
 844		 * Transports that didn't implement check_protection
 845		 * callback but still published T10-PI support to scsi-mid
 846		 * deserve this BUG_ON.
 847		 **/
 848		BUG_ON(!session->tt->check_protection);
 849
 850		ascq = session->tt->check_protection(task, &sector);
 851		if (ascq) {
 852			sc->result = DRIVER_SENSE << 24 |
 853				     SAM_STAT_CHECK_CONDITION;
 854			scsi_build_sense_buffer(1, sc->sense_buffer,
 855						ILLEGAL_REQUEST, 0x10, ascq);
 856			scsi_set_sense_information(sc->sense_buffer,
 857						   SCSI_SENSE_BUFFERSIZE,
 858						   sector);
 859			goto out;
 860		}
 861	}
 862
 863	if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 864		sc->result = DID_ERROR << 16;
 865		goto out;
 866	}
 867
 868	if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 869		uint16_t senselen;
 870
 871		if (datalen < 2) {
 872invalid_datalen:
 873			iscsi_conn_printk(KERN_ERR,  conn,
 874					 "Got CHECK_CONDITION but invalid data "
 875					 "buffer size of %d\n", datalen);
 876			sc->result = DID_BAD_TARGET << 16;
 877			goto out;
 878		}
 879
 880		senselen = get_unaligned_be16(data);
 881		if (datalen < senselen)
 882			goto invalid_datalen;
 883
 884		memcpy(sc->sense_buffer, data + 2,
 885		       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 886		ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 887				  min_t(uint16_t, senselen,
 888				  SCSI_SENSE_BUFFERSIZE));
 889	}
 890
 891	if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 892			   ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 893		int res_count = be32_to_cpu(rhdr->bi_residual_count);
 894
 895		if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 896				(rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 897				 res_count <= scsi_in(sc)->length))
 898			scsi_in(sc)->resid = res_count;
 899		else
 900			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 901	}
 902
 903	if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 904	                   ISCSI_FLAG_CMD_OVERFLOW)) {
 905		int res_count = be32_to_cpu(rhdr->residual_count);
 906
 907		if (res_count > 0 &&
 908		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 909		     res_count <= scsi_bufflen(sc)))
 910			/* write side for bidi or uni-io set_resid */
 911			scsi_set_resid(sc, res_count);
 912		else
 913			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 914	}
 915out:
 916	ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 917			  sc, sc->result, task->itt);
 918	conn->scsirsp_pdus_cnt++;
 919	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 920}
 921
 922/**
 923 * iscsi_data_in_rsp - SCSI Data-In Response processing
 924 * @conn: iscsi connection
 925 * @hdr:  iscsi pdu
 926 * @task: scsi command task
 927 **/
 928static void
 929iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 930		  struct iscsi_task *task)
 931{
 932	struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 933	struct scsi_cmnd *sc = task->sc;
 934
 935	if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 936		return;
 937
 938	iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 939	sc->result = (DID_OK << 16) | rhdr->cmd_status;
 940	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 941	if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 942	                   ISCSI_FLAG_DATA_OVERFLOW)) {
 943		int res_count = be32_to_cpu(rhdr->residual_count);
 944
 945		if (res_count > 0 &&
 946		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 947		     res_count <= scsi_in(sc)->length))
 948			scsi_in(sc)->resid = res_count;
 949		else
 950			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 951	}
 952
 953	ISCSI_DBG_SESSION(conn->session, "data in with status done "
 954			  "[sc %p res %d itt 0x%x]\n",
 955			  sc, sc->result, task->itt);
 956	conn->scsirsp_pdus_cnt++;
 957	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 958}
 959
 960static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 961{
 962	struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 963
 964	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 965	conn->tmfrsp_pdus_cnt++;
 966
 967	if (conn->tmf_state != TMF_QUEUED)
 968		return;
 969
 970	if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 971		conn->tmf_state = TMF_SUCCESS;
 972	else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 973		conn->tmf_state = TMF_NOT_FOUND;
 974	else
 975		conn->tmf_state = TMF_FAILED;
 976	wake_up(&conn->ehwait);
 977}
 978
 979static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 980{
 981        struct iscsi_nopout hdr;
 982	struct iscsi_task *task;
 983
 984	if (!rhdr && conn->ping_task)
 985		return -EINVAL;
 986
 987	memset(&hdr, 0, sizeof(struct iscsi_nopout));
 988	hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 989	hdr.flags = ISCSI_FLAG_CMD_FINAL;
 990
 991	if (rhdr) {
 992		hdr.lun = rhdr->lun;
 993		hdr.ttt = rhdr->ttt;
 994		hdr.itt = RESERVED_ITT;
 995	} else
 996		hdr.ttt = RESERVED_ITT;
 997
 998	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 999	if (!task) {
1000		iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
1001		return -EIO;
1002	} else if (!rhdr) {
1003		/* only track our nops */
1004		conn->ping_task = task;
1005		conn->last_ping = jiffies;
1006	}
1007
1008	return 0;
1009}
1010
1011static int iscsi_nop_out_rsp(struct iscsi_task *task,
1012			     struct iscsi_nopin *nop, char *data, int datalen)
1013{
1014	struct iscsi_conn *conn = task->conn;
1015	int rc = 0;
1016
1017	if (conn->ping_task != task) {
1018		/*
1019		 * If this is not in response to one of our
1020		 * nops then it must be from userspace.
1021		 */
1022		if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1023				   data, datalen))
1024			rc = ISCSI_ERR_CONN_FAILED;
1025	} else
1026		mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1027	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1028	return rc;
1029}
1030
1031static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1032			       char *data, int datalen)
1033{
1034	struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1035	struct iscsi_hdr rejected_pdu;
1036	int opcode, rc = 0;
1037
1038	conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1039
1040	if (ntoh24(reject->dlength) > datalen ||
1041	    ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1042		iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1043				  "pdu. Invalid data length (pdu dlength "
1044				  "%u, datalen %d\n", ntoh24(reject->dlength),
1045				  datalen);
1046		return ISCSI_ERR_PROTO;
1047	}
1048	memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1049	opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1050
1051	switch (reject->reason) {
1052	case ISCSI_REASON_DATA_DIGEST_ERROR:
1053		iscsi_conn_printk(KERN_ERR, conn,
1054				  "pdu (op 0x%x itt 0x%x) rejected "
1055				  "due to DataDigest error.\n",
1056				  opcode, rejected_pdu.itt);
1057		break;
1058	case ISCSI_REASON_IMM_CMD_REJECT:
1059		iscsi_conn_printk(KERN_ERR, conn,
1060				  "pdu (op 0x%x itt 0x%x) rejected. Too many "
1061				  "immediate commands.\n",
1062				  opcode, rejected_pdu.itt);
1063		/*
1064		 * We only send one TMF at a time so if the target could not
1065		 * handle it, then it should get fixed (RFC mandates that
1066		 * a target can handle one immediate TMF per conn).
1067		 *
1068		 * For nops-outs, we could have sent more than one if
1069		 * the target is sending us lots of nop-ins
1070		 */
1071		if (opcode != ISCSI_OP_NOOP_OUT)
1072			return 0;
1073
1074		 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1075			/*
1076			 * nop-out in response to target's nop-out rejected.
1077			 * Just resend.
1078			 */
1079			/* In RX path we are under back lock */
1080			spin_unlock(&conn->session->back_lock);
1081			spin_lock(&conn->session->frwd_lock);
1082			iscsi_send_nopout(conn,
1083					  (struct iscsi_nopin*)&rejected_pdu);
1084			spin_unlock(&conn->session->frwd_lock);
1085			spin_lock(&conn->session->back_lock);
1086		} else {
1087			struct iscsi_task *task;
1088			/*
1089			 * Our nop as ping got dropped. We know the target
1090			 * and transport are ok so just clean up
1091			 */
1092			task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1093			if (!task) {
1094				iscsi_conn_printk(KERN_ERR, conn,
1095						 "Invalid pdu reject. Could "
1096						 "not lookup rejected task.\n");
1097				rc = ISCSI_ERR_BAD_ITT;
1098			} else
1099				rc = iscsi_nop_out_rsp(task,
1100					(struct iscsi_nopin*)&rejected_pdu,
1101					NULL, 0);
1102		}
1103		break;
1104	default:
1105		iscsi_conn_printk(KERN_ERR, conn,
1106				  "pdu (op 0x%x itt 0x%x) rejected. Reason "
1107				  "code 0x%x\n", rejected_pdu.opcode,
1108				  rejected_pdu.itt, reject->reason);
1109		break;
1110	}
1111	return rc;
1112}
1113
1114/**
1115 * iscsi_itt_to_task - look up task by itt
1116 * @conn: iscsi connection
1117 * @itt: itt
1118 *
1119 * This should be used for mgmt tasks like login and nops, or if
1120 * the LDD's itt space does not include the session age.
1121 *
1122 * The session back_lock must be held.
1123 */
1124struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1125{
1126	struct iscsi_session *session = conn->session;
1127	int i;
1128
1129	if (itt == RESERVED_ITT)
1130		return NULL;
1131
1132	if (session->tt->parse_pdu_itt)
1133		session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1134	else
1135		i = get_itt(itt);
1136	if (i >= session->cmds_max)
1137		return NULL;
1138
1139	return session->cmds[i];
1140}
1141EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1142
1143/**
1144 * __iscsi_complete_pdu - complete pdu
1145 * @conn: iscsi conn
1146 * @hdr: iscsi header
1147 * @data: data buffer
1148 * @datalen: len of data buffer
1149 *
1150 * Completes pdu processing by freeing any resources allocated at
1151 * queuecommand or send generic. session back_lock must be held and verify
1152 * itt must have been called.
1153 */
1154int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1155			 char *data, int datalen)
1156{
1157	struct iscsi_session *session = conn->session;
1158	int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1159	struct iscsi_task *task;
1160	uint32_t itt;
1161
1162	conn->last_recv = jiffies;
1163	rc = iscsi_verify_itt(conn, hdr->itt);
1164	if (rc)
1165		return rc;
1166
1167	if (hdr->itt != RESERVED_ITT)
1168		itt = get_itt(hdr->itt);
1169	else
1170		itt = ~0U;
1171
1172	ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1173			  opcode, conn->id, itt, datalen);
1174
1175	if (itt == ~0U) {
1176		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1177
1178		switch(opcode) {
1179		case ISCSI_OP_NOOP_IN:
1180			if (datalen) {
1181				rc = ISCSI_ERR_PROTO;
1182				break;
1183			}
1184
1185			if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1186				break;
1187
1188			/* In RX path we are under back lock */
1189			spin_unlock(&session->back_lock);
1190			spin_lock(&session->frwd_lock);
1191			iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1192			spin_unlock(&session->frwd_lock);
1193			spin_lock(&session->back_lock);
1194			break;
1195		case ISCSI_OP_REJECT:
1196			rc = iscsi_handle_reject(conn, hdr, data, datalen);
1197			break;
1198		case ISCSI_OP_ASYNC_EVENT:
1199			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1200			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1201				rc = ISCSI_ERR_CONN_FAILED;
1202			break;
1203		default:
1204			rc = ISCSI_ERR_BAD_OPCODE;
1205			break;
1206		}
1207		goto out;
1208	}
1209
1210	switch(opcode) {
1211	case ISCSI_OP_SCSI_CMD_RSP:
1212	case ISCSI_OP_SCSI_DATA_IN:
1213		task = iscsi_itt_to_ctask(conn, hdr->itt);
1214		if (!task)
1215			return ISCSI_ERR_BAD_ITT;
1216		task->last_xfer = jiffies;
1217		break;
1218	case ISCSI_OP_R2T:
1219		/*
1220		 * LLD handles R2Ts if they need to.
1221		 */
1222		return 0;
1223	case ISCSI_OP_LOGOUT_RSP:
1224	case ISCSI_OP_LOGIN_RSP:
1225	case ISCSI_OP_TEXT_RSP:
1226	case ISCSI_OP_SCSI_TMFUNC_RSP:
1227	case ISCSI_OP_NOOP_IN:
1228		task = iscsi_itt_to_task(conn, hdr->itt);
1229		if (!task)
1230			return ISCSI_ERR_BAD_ITT;
1231		break;
1232	default:
1233		return ISCSI_ERR_BAD_OPCODE;
1234	}
1235
1236	switch(opcode) {
1237	case ISCSI_OP_SCSI_CMD_RSP:
1238		iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1239		break;
1240	case ISCSI_OP_SCSI_DATA_IN:
1241		iscsi_data_in_rsp(conn, hdr, task);
1242		break;
1243	case ISCSI_OP_LOGOUT_RSP:
1244		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1245		if (datalen) {
1246			rc = ISCSI_ERR_PROTO;
1247			break;
1248		}
1249		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1250		goto recv_pdu;
1251	case ISCSI_OP_LOGIN_RSP:
1252	case ISCSI_OP_TEXT_RSP:
1253		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1254		/*
1255		 * login related PDU's exp_statsn is handled in
1256		 * userspace
1257		 */
1258		goto recv_pdu;
1259	case ISCSI_OP_SCSI_TMFUNC_RSP:
1260		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1261		if (datalen) {
1262			rc = ISCSI_ERR_PROTO;
1263			break;
1264		}
1265
1266		iscsi_tmf_rsp(conn, hdr);
1267		iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1268		break;
1269	case ISCSI_OP_NOOP_IN:
1270		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1271		if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1272			rc = ISCSI_ERR_PROTO;
1273			break;
1274		}
1275		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1276
1277		rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1278				       data, datalen);
1279		break;
1280	default:
1281		rc = ISCSI_ERR_BAD_OPCODE;
1282		break;
1283	}
1284
1285out:
1286	return rc;
1287recv_pdu:
1288	if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1289		rc = ISCSI_ERR_CONN_FAILED;
1290	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1291	return rc;
1292}
1293EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1294
1295int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1296		       char *data, int datalen)
1297{
1298	int rc;
1299
1300	spin_lock(&conn->session->back_lock);
1301	rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1302	spin_unlock(&conn->session->back_lock);
1303	return rc;
1304}
1305EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1306
1307int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1308{
1309	struct iscsi_session *session = conn->session;
1310	int age = 0, i = 0;
1311
1312	if (itt == RESERVED_ITT)
1313		return 0;
1314
1315	if (session->tt->parse_pdu_itt)
1316		session->tt->parse_pdu_itt(conn, itt, &i, &age);
1317	else {
1318		i = get_itt(itt);
1319		age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1320	}
1321
1322	if (age != session->age) {
1323		iscsi_conn_printk(KERN_ERR, conn,
1324				  "received itt %x expected session age (%x)\n",
1325				  (__force u32)itt, session->age);
1326		return ISCSI_ERR_BAD_ITT;
1327	}
1328
1329	if (i >= session->cmds_max) {
1330		iscsi_conn_printk(KERN_ERR, conn,
1331				  "received invalid itt index %u (max cmds "
1332				   "%u.\n", i, session->cmds_max);
1333		return ISCSI_ERR_BAD_ITT;
1334	}
1335	return 0;
1336}
1337EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1338
1339/**
1340 * iscsi_itt_to_ctask - look up ctask by itt
1341 * @conn: iscsi connection
1342 * @itt: itt
1343 *
1344 * This should be used for cmd tasks.
1345 *
1346 * The session back_lock must be held.
1347 */
1348struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1349{
1350	struct iscsi_task *task;
1351
1352	if (iscsi_verify_itt(conn, itt))
1353		return NULL;
1354
1355	task = iscsi_itt_to_task(conn, itt);
1356	if (!task || !task->sc)
1357		return NULL;
1358
1359	if (task->sc->SCp.phase != conn->session->age) {
1360		iscsi_session_printk(KERN_ERR, conn->session,
1361				  "task's session age %d, expected %d\n",
1362				  task->sc->SCp.phase, conn->session->age);
1363		return NULL;
1364	}
1365
1366	return task;
1367}
1368EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1369
1370void iscsi_session_failure(struct iscsi_session *session,
1371			   enum iscsi_err err)
1372{
1373	struct iscsi_conn *conn;
1374	struct device *dev;
1375
1376	spin_lock_bh(&session->frwd_lock);
1377	conn = session->leadconn;
1378	if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1379		spin_unlock_bh(&session->frwd_lock);
1380		return;
1381	}
1382
1383	dev = get_device(&conn->cls_conn->dev);
1384	spin_unlock_bh(&session->frwd_lock);
1385	if (!dev)
1386	        return;
1387	/*
1388	 * if the host is being removed bypass the connection
1389	 * recovery initialization because we are going to kill
1390	 * the session.
1391	 */
1392	if (err == ISCSI_ERR_INVALID_HOST)
1393		iscsi_conn_error_event(conn->cls_conn, err);
1394	else
1395		iscsi_conn_failure(conn, err);
1396	put_device(dev);
1397}
1398EXPORT_SYMBOL_GPL(iscsi_session_failure);
1399
1400void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1401{
1402	struct iscsi_session *session = conn->session;
1403
1404	spin_lock_bh(&session->frwd_lock);
1405	if (session->state == ISCSI_STATE_FAILED) {
1406		spin_unlock_bh(&session->frwd_lock);
1407		return;
1408	}
1409
1410	if (conn->stop_stage == 0)
1411		session->state = ISCSI_STATE_FAILED;
1412	spin_unlock_bh(&session->frwd_lock);
1413
1414	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1415	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1416	iscsi_conn_error_event(conn->cls_conn, err);
1417}
1418EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1419
1420static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1421{
1422	struct iscsi_session *session = conn->session;
1423
1424	/*
1425	 * Check for iSCSI window and take care of CmdSN wrap-around
1426	 */
1427	if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1428		ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1429				  "%u MaxCmdSN %u CmdSN %u/%u\n",
1430				  session->exp_cmdsn, session->max_cmdsn,
1431				  session->cmdsn, session->queued_cmdsn);
1432		return -ENOSPC;
1433	}
1434	return 0;
1435}
1436
1437static int iscsi_xmit_task(struct iscsi_conn *conn)
1438{
1439	struct iscsi_task *task = conn->task;
1440	int rc;
1441
1442	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1443		return -ENODATA;
1444
1445	__iscsi_get_task(task);
1446	spin_unlock_bh(&conn->session->frwd_lock);
1447	rc = conn->session->tt->xmit_task(task);
1448	spin_lock_bh(&conn->session->frwd_lock);
1449	if (!rc) {
1450		/* done with this task */
1451		task->last_xfer = jiffies;
1452		conn->task = NULL;
1453	}
1454	/* regular RX path uses back_lock */
1455	spin_lock(&conn->session->back_lock);
1456	__iscsi_put_task(task);
1457	spin_unlock(&conn->session->back_lock);
1458	return rc;
1459}
1460
1461/**
1462 * iscsi_requeue_task - requeue task to run from session workqueue
1463 * @task: task to requeue
1464 *
1465 * LLDs that need to run a task from the session workqueue should call
1466 * this. The session frwd_lock must be held. This should only be called
1467 * by software drivers.
1468 */
1469void iscsi_requeue_task(struct iscsi_task *task)
1470{
1471	struct iscsi_conn *conn = task->conn;
1472
1473	/*
1474	 * this may be on the requeue list already if the xmit_task callout
1475	 * is handling the r2ts while we are adding new ones
1476	 */
1477	if (list_empty(&task->running))
1478		list_add_tail(&task->running, &conn->requeue);
1479	iscsi_conn_queue_work(conn);
1480}
1481EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1482
1483/**
1484 * iscsi_data_xmit - xmit any command into the scheduled connection
1485 * @conn: iscsi connection
1486 *
1487 * Notes:
1488 *	The function can return -EAGAIN in which case the caller must
1489 *	re-schedule it again later or recover. '0' return code means
1490 *	successful xmit.
1491 **/
1492static int iscsi_data_xmit(struct iscsi_conn *conn)
1493{
1494	struct iscsi_task *task;
1495	int rc = 0;
1496
1497	spin_lock_bh(&conn->session->frwd_lock);
1498	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1499		ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1500		spin_unlock_bh(&conn->session->frwd_lock);
1501		return -ENODATA;
1502	}
1503
1504	if (conn->task) {
1505		rc = iscsi_xmit_task(conn);
1506	        if (rc)
1507		        goto done;
1508	}
1509
1510	/*
1511	 * process mgmt pdus like nops before commands since we should
1512	 * only have one nop-out as a ping from us and targets should not
1513	 * overflow us with nop-ins
1514	 */
1515check_mgmt:
1516	while (!list_empty(&conn->mgmtqueue)) {
1517		conn->task = list_entry(conn->mgmtqueue.next,
1518					 struct iscsi_task, running);
1519		list_del_init(&conn->task->running);
1520		if (iscsi_prep_mgmt_task(conn, conn->task)) {
1521			/* regular RX path uses back_lock */
1522			spin_lock_bh(&conn->session->back_lock);
1523			__iscsi_put_task(conn->task);
1524			spin_unlock_bh(&conn->session->back_lock);
1525			conn->task = NULL;
1526			continue;
1527		}
1528		rc = iscsi_xmit_task(conn);
1529		if (rc)
1530			goto done;
1531	}
1532
1533	/* process pending command queue */
1534	while (!list_empty(&conn->cmdqueue)) {
1535		conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1536					running);
1537		list_del_init(&conn->task->running);
1538		if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1539			fail_scsi_task(conn->task, DID_IMM_RETRY);
1540			continue;
1541		}
1542		rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1543		if (rc) {
1544			if (rc == -ENOMEM || rc == -EACCES) {
1545				list_add_tail(&conn->task->running,
1546					      &conn->cmdqueue);
1547				conn->task = NULL;
1548				goto done;
1549			} else
1550				fail_scsi_task(conn->task, DID_ABORT);
1551			continue;
1552		}
1553		rc = iscsi_xmit_task(conn);
1554		if (rc)
1555			goto done;
1556		/*
1557		 * we could continuously get new task requests so
1558		 * we need to check the mgmt queue for nops that need to
1559		 * be sent to aviod starvation
1560		 */
1561		if (!list_empty(&conn->mgmtqueue))
1562			goto check_mgmt;
1563	}
1564
1565	while (!list_empty(&conn->requeue)) {
1566		/*
1567		 * we always do fastlogout - conn stop code will clean up.
1568		 */
1569		if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1570			break;
1571
1572		task = list_entry(conn->requeue.next, struct iscsi_task,
1573				  running);
1574		if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1575			break;
1576
1577		conn->task = task;
1578		list_del_init(&conn->task->running);
1579		conn->task->state = ISCSI_TASK_RUNNING;
1580		rc = iscsi_xmit_task(conn);
1581		if (rc)
1582			goto done;
1583		if (!list_empty(&conn->mgmtqueue))
1584			goto check_mgmt;
1585	}
1586	spin_unlock_bh(&conn->session->frwd_lock);
1587	return -ENODATA;
1588
1589done:
1590	spin_unlock_bh(&conn->session->frwd_lock);
1591	return rc;
1592}
1593
1594static void iscsi_xmitworker(struct work_struct *work)
1595{
1596	struct iscsi_conn *conn =
1597		container_of(work, struct iscsi_conn, xmitwork);
1598	int rc;
1599	/*
1600	 * serialize Xmit worker on a per-connection basis.
1601	 */
1602	do {
1603		rc = iscsi_data_xmit(conn);
1604	} while (rc >= 0 || rc == -EAGAIN);
1605}
1606
1607static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1608						  struct scsi_cmnd *sc)
1609{
1610	struct iscsi_task *task;
1611
1612	if (!kfifo_out(&conn->session->cmdpool.queue,
1613			 (void *) &task, sizeof(void *)))
1614		return NULL;
1615
1616	sc->SCp.phase = conn->session->age;
1617	sc->SCp.ptr = (char *) task;
1618
1619	atomic_set(&task->refcount, 1);
1620	task->state = ISCSI_TASK_PENDING;
1621	task->conn = conn;
1622	task->sc = sc;
1623	task->have_checked_conn = false;
1624	task->last_timeout = jiffies;
1625	task->last_xfer = jiffies;
1626	task->protected = false;
1627	INIT_LIST_HEAD(&task->running);
1628	return task;
1629}
1630
1631enum {
1632	FAILURE_BAD_HOST = 1,
1633	FAILURE_SESSION_FAILED,
1634	FAILURE_SESSION_FREED,
1635	FAILURE_WINDOW_CLOSED,
1636	FAILURE_OOM,
1637	FAILURE_SESSION_TERMINATE,
1638	FAILURE_SESSION_IN_RECOVERY,
1639	FAILURE_SESSION_RECOVERY_TIMEOUT,
1640	FAILURE_SESSION_LOGGING_OUT,
1641	FAILURE_SESSION_NOT_READY,
1642};
1643
1644int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1645{
1646	struct iscsi_cls_session *cls_session;
1647	struct iscsi_host *ihost;
1648	int reason = 0;
1649	struct iscsi_session *session;
1650	struct iscsi_conn *conn;
1651	struct iscsi_task *task = NULL;
1652
1653	sc->result = 0;
1654	sc->SCp.ptr = NULL;
1655
1656	ihost = shost_priv(host);
1657
1658	cls_session = starget_to_session(scsi_target(sc->device));
1659	session = cls_session->dd_data;
1660	spin_lock_bh(&session->frwd_lock);
1661
1662	reason = iscsi_session_chkready(cls_session);
1663	if (reason) {
1664		sc->result = reason;
1665		goto fault;
1666	}
1667
1668	if (session->state != ISCSI_STATE_LOGGED_IN) {
1669		/*
1670		 * to handle the race between when we set the recovery state
1671		 * and block the session we requeue here (commands could
1672		 * be entering our queuecommand while a block is starting
1673		 * up because the block code is not locked)
1674		 */
1675		switch (session->state) {
1676		case ISCSI_STATE_FAILED:
1677		case ISCSI_STATE_IN_RECOVERY:
1678			reason = FAILURE_SESSION_IN_RECOVERY;
1679			sc->result = DID_IMM_RETRY << 16;
1680			break;
1681		case ISCSI_STATE_LOGGING_OUT:
1682			reason = FAILURE_SESSION_LOGGING_OUT;
1683			sc->result = DID_IMM_RETRY << 16;
1684			break;
1685		case ISCSI_STATE_RECOVERY_FAILED:
1686			reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1687			sc->result = DID_TRANSPORT_FAILFAST << 16;
1688			break;
1689		case ISCSI_STATE_TERMINATE:
1690			reason = FAILURE_SESSION_TERMINATE;
1691			sc->result = DID_NO_CONNECT << 16;
1692			break;
1693		default:
1694			reason = FAILURE_SESSION_FREED;
1695			sc->result = DID_NO_CONNECT << 16;
1696		}
1697		goto fault;
1698	}
1699
1700	conn = session->leadconn;
1701	if (!conn) {
1702		reason = FAILURE_SESSION_FREED;
1703		sc->result = DID_NO_CONNECT << 16;
1704		goto fault;
1705	}
1706
1707	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1708		reason = FAILURE_SESSION_IN_RECOVERY;
1709		sc->result = DID_REQUEUE;
1710		goto fault;
1711	}
1712
1713	if (iscsi_check_cmdsn_window_closed(conn)) {
1714		reason = FAILURE_WINDOW_CLOSED;
1715		goto reject;
1716	}
1717
1718	task = iscsi_alloc_task(conn, sc);
1719	if (!task) {
1720		reason = FAILURE_OOM;
1721		goto reject;
1722	}
1723
1724	if (!ihost->workq) {
1725		reason = iscsi_prep_scsi_cmd_pdu(task);
1726		if (reason) {
1727			if (reason == -ENOMEM ||  reason == -EACCES) {
1728				reason = FAILURE_OOM;
1729				goto prepd_reject;
1730			} else {
1731				sc->result = DID_ABORT << 16;
1732				goto prepd_fault;
1733			}
1734		}
1735		if (session->tt->xmit_task(task)) {
1736			session->cmdsn--;
1737			reason = FAILURE_SESSION_NOT_READY;
1738			goto prepd_reject;
1739		}
1740	} else {
1741		list_add_tail(&task->running, &conn->cmdqueue);
1742		iscsi_conn_queue_work(conn);
1743	}
1744
1745	session->queued_cmdsn++;
1746	spin_unlock_bh(&session->frwd_lock);
1747	return 0;
1748
1749prepd_reject:
1750	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1751reject:
1752	spin_unlock_bh(&session->frwd_lock);
1753	ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1754			  sc->cmnd[0], reason);
1755	return SCSI_MLQUEUE_TARGET_BUSY;
1756
1757prepd_fault:
1758	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1759fault:
1760	spin_unlock_bh(&session->frwd_lock);
1761	ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1762			  sc->cmnd[0], reason);
1763	if (!scsi_bidi_cmnd(sc))
1764		scsi_set_resid(sc, scsi_bufflen(sc));
1765	else {
1766		scsi_out(sc)->resid = scsi_out(sc)->length;
1767		scsi_in(sc)->resid = scsi_in(sc)->length;
1768	}
1769	sc->scsi_done(sc);
1770	return 0;
1771}
1772EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1773
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1774int iscsi_target_alloc(struct scsi_target *starget)
1775{
1776	struct iscsi_cls_session *cls_session = starget_to_session(starget);
1777	struct iscsi_session *session = cls_session->dd_data;
1778
1779	starget->can_queue = session->scsi_cmds_max;
1780	return 0;
1781}
1782EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1783
1784static void iscsi_tmf_timedout(unsigned long data)
1785{
1786	struct iscsi_conn *conn = (struct iscsi_conn *)data;
1787	struct iscsi_session *session = conn->session;
1788
1789	spin_lock(&session->frwd_lock);
1790	if (conn->tmf_state == TMF_QUEUED) {
1791		conn->tmf_state = TMF_TIMEDOUT;
1792		ISCSI_DBG_EH(session, "tmf timedout\n");
1793		/* unblock eh_abort() */
1794		wake_up(&conn->ehwait);
1795	}
1796	spin_unlock(&session->frwd_lock);
1797}
1798
1799static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1800				   struct iscsi_tm *hdr, int age,
1801				   int timeout)
1802{
1803	struct iscsi_session *session = conn->session;
1804	struct iscsi_task *task;
1805
1806	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1807				      NULL, 0);
1808	if (!task) {
1809		spin_unlock_bh(&session->frwd_lock);
1810		iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1811		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1812		spin_lock_bh(&session->frwd_lock);
1813		return -EPERM;
1814	}
1815	conn->tmfcmd_pdus_cnt++;
1816	conn->tmf_timer.expires = timeout * HZ + jiffies;
1817	conn->tmf_timer.function = iscsi_tmf_timedout;
1818	conn->tmf_timer.data = (unsigned long)conn;
1819	add_timer(&conn->tmf_timer);
1820	ISCSI_DBG_EH(session, "tmf set timeout\n");
1821
1822	spin_unlock_bh(&session->frwd_lock);
1823	mutex_unlock(&session->eh_mutex);
1824
1825	/*
1826	 * block eh thread until:
1827	 *
1828	 * 1) tmf response
1829	 * 2) tmf timeout
1830	 * 3) session is terminated or restarted or userspace has
1831	 * given up on recovery
1832	 */
1833	wait_event_interruptible(conn->ehwait, age != session->age ||
1834				 session->state != ISCSI_STATE_LOGGED_IN ||
1835				 conn->tmf_state != TMF_QUEUED);
1836	if (signal_pending(current))
1837		flush_signals(current);
1838	del_timer_sync(&conn->tmf_timer);
1839
1840	mutex_lock(&session->eh_mutex);
1841	spin_lock_bh(&session->frwd_lock);
1842	/* if the session drops it will clean up the task */
1843	if (age != session->age ||
1844	    session->state != ISCSI_STATE_LOGGED_IN)
1845		return -ENOTCONN;
1846	return 0;
1847}
1848
1849/*
1850 * Fail commands. session lock held and recv side suspended and xmit
1851 * thread flushed
1852 */
1853static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
 
1854{
1855	struct iscsi_task *task;
1856	int i;
1857
1858	for (i = 0; i < conn->session->cmds_max; i++) {
1859		task = conn->session->cmds[i];
1860		if (!task->sc || task->state == ISCSI_TASK_FREE)
1861			continue;
1862
1863		if (lun != -1 && lun != task->sc->device->lun)
1864			continue;
1865
1866		ISCSI_DBG_SESSION(conn->session,
1867				  "failing sc %p itt 0x%x state %d\n",
1868				  task->sc, task->itt, task->state);
1869		fail_scsi_task(task, error);
1870	}
1871}
1872
1873/**
1874 * iscsi_suspend_queue - suspend iscsi_queuecommand
1875 * @conn: iscsi conn to stop queueing IO on
1876 *
1877 * This grabs the session frwd_lock to make sure no one is in
1878 * xmit_task/queuecommand, and then sets suspend to prevent
1879 * new commands from being queued. This only needs to be called
1880 * by offload drivers that need to sync a path like ep disconnect
1881 * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1882 * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1883 */
1884void iscsi_suspend_queue(struct iscsi_conn *conn)
1885{
1886	spin_lock_bh(&conn->session->frwd_lock);
1887	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1888	spin_unlock_bh(&conn->session->frwd_lock);
1889}
1890EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1891
1892/**
1893 * iscsi_suspend_tx - suspend iscsi_data_xmit
1894 * @conn: iscsi conn tp stop processing IO on.
1895 *
1896 * This function sets the suspend bit to prevent iscsi_data_xmit
1897 * from sending new IO, and if work is queued on the xmit thread
1898 * it will wait for it to be completed.
1899 */
1900void iscsi_suspend_tx(struct iscsi_conn *conn)
1901{
1902	struct Scsi_Host *shost = conn->session->host;
1903	struct iscsi_host *ihost = shost_priv(shost);
1904
1905	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1906	if (ihost->workq)
1907		flush_workqueue(ihost->workq);
1908}
1909EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1910
1911static void iscsi_start_tx(struct iscsi_conn *conn)
1912{
1913	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1914	iscsi_conn_queue_work(conn);
1915}
1916
1917/*
1918 * We want to make sure a ping is in flight. It has timed out.
1919 * And we are not busy processing a pdu that is making
1920 * progress but got started before the ping and is taking a while
1921 * to complete so the ping is just stuck behind it in a queue.
1922 */
1923static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1924{
1925	if (conn->ping_task &&
1926	    time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1927			   (conn->ping_timeout * HZ), jiffies))
1928		return 1;
1929	else
1930		return 0;
1931}
1932
1933static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1934{
1935	enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1936	struct iscsi_task *task = NULL, *running_task;
1937	struct iscsi_cls_session *cls_session;
1938	struct iscsi_session *session;
1939	struct iscsi_conn *conn;
1940	int i;
1941
1942	cls_session = starget_to_session(scsi_target(sc->device));
1943	session = cls_session->dd_data;
1944
1945	ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1946
1947	spin_lock(&session->frwd_lock);
1948	task = (struct iscsi_task *)sc->SCp.ptr;
1949	if (!task) {
1950		/*
1951		 * Raced with completion. Blk layer has taken ownership
1952		 * so let timeout code complete it now.
1953		 */
1954		rc = BLK_EH_HANDLED;
1955		goto done;
1956	}
1957
1958	if (session->state != ISCSI_STATE_LOGGED_IN) {
1959		/*
1960		 * We are probably in the middle of iscsi recovery so let
1961		 * that complete and handle the error.
1962		 */
1963		rc = BLK_EH_RESET_TIMER;
1964		goto done;
1965	}
1966
1967	conn = session->leadconn;
1968	if (!conn) {
1969		/* In the middle of shuting down */
1970		rc = BLK_EH_RESET_TIMER;
1971		goto done;
1972	}
1973
 
 
 
 
 
 
 
 
 
 
1974	/*
1975	 * If we have sent (at least queued to the network layer) a pdu or
1976	 * recvd one for the task since the last timeout ask for
1977	 * more time. If on the next timeout we have not made progress
1978	 * we can check if it is the task or connection when we send the
1979	 * nop as a ping.
1980	 */
1981	if (time_after(task->last_xfer, task->last_timeout)) {
1982		ISCSI_DBG_EH(session, "Command making progress. Asking "
1983			     "scsi-ml for more time to complete. "
1984			     "Last data xfer at %lu. Last timeout was at "
1985			     "%lu\n.", task->last_xfer, task->last_timeout);
1986		task->have_checked_conn = false;
1987		rc = BLK_EH_RESET_TIMER;
1988		goto done;
1989	}
1990
1991	if (!conn->recv_timeout && !conn->ping_timeout)
1992		goto done;
1993	/*
1994	 * if the ping timedout then we are in the middle of cleaning up
1995	 * and can let the iscsi eh handle it
1996	 */
1997	if (iscsi_has_ping_timed_out(conn)) {
1998		rc = BLK_EH_RESET_TIMER;
1999		goto done;
2000	}
2001
2002	for (i = 0; i < conn->session->cmds_max; i++) {
2003		running_task = conn->session->cmds[i];
2004		if (!running_task->sc || running_task == task ||
2005		     running_task->state != ISCSI_TASK_RUNNING)
2006			continue;
2007
2008		/*
2009		 * Only check if cmds started before this one have made
2010		 * progress, or this could never fail
2011		 */
2012		if (time_after(running_task->sc->jiffies_at_alloc,
2013			       task->sc->jiffies_at_alloc))
2014			continue;
2015
2016		if (time_after(running_task->last_xfer, task->last_timeout)) {
2017			/*
2018			 * This task has not made progress, but a task
2019			 * started before us has transferred data since
2020			 * we started/last-checked. We could be queueing
2021			 * too many tasks or the LU is bad.
2022			 *
2023			 * If the device is bad the cmds ahead of us on
2024			 * other devs will complete, and this loop will
2025			 * eventually fail starting the scsi eh.
2026			 */
2027			ISCSI_DBG_EH(session, "Command has not made progress "
2028				     "but commands ahead of it have. "
2029				     "Asking scsi-ml for more time to "
2030				     "complete. Our last xfer vs running task "
2031				     "last xfer %lu/%lu. Last check %lu.\n",
2032				     task->last_xfer, running_task->last_xfer,
2033				     task->last_timeout);
2034			rc = BLK_EH_RESET_TIMER;
2035			goto done;
2036		}
2037	}
2038
2039	/* Assumes nop timeout is shorter than scsi cmd timeout */
2040	if (task->have_checked_conn)
2041		goto done;
2042
2043	/*
2044	 * Checking the transport already or nop from a cmd timeout still
2045	 * running
2046	 */
2047	if (conn->ping_task) {
2048		task->have_checked_conn = true;
2049		rc = BLK_EH_RESET_TIMER;
2050		goto done;
2051	}
2052
2053	/* Make sure there is a transport check done */
2054	iscsi_send_nopout(conn, NULL);
2055	task->have_checked_conn = true;
2056	rc = BLK_EH_RESET_TIMER;
2057
2058done:
2059	if (task)
2060		task->last_timeout = jiffies;
2061	spin_unlock(&session->frwd_lock);
2062	ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2063		     "timer reset" : "nh");
2064	return rc;
2065}
2066
2067static void iscsi_check_transport_timeouts(unsigned long data)
2068{
2069	struct iscsi_conn *conn = (struct iscsi_conn *)data;
2070	struct iscsi_session *session = conn->session;
2071	unsigned long recv_timeout, next_timeout = 0, last_recv;
2072
2073	spin_lock(&session->frwd_lock);
2074	if (session->state != ISCSI_STATE_LOGGED_IN)
2075		goto done;
2076
2077	recv_timeout = conn->recv_timeout;
2078	if (!recv_timeout)
2079		goto done;
2080
2081	recv_timeout *= HZ;
2082	last_recv = conn->last_recv;
2083
2084	if (iscsi_has_ping_timed_out(conn)) {
2085		iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2086				  "expired, recv timeout %d, last rx %lu, "
2087				  "last ping %lu, now %lu\n",
2088				  conn->ping_timeout, conn->recv_timeout,
2089				  last_recv, conn->last_ping, jiffies);
2090		spin_unlock(&session->frwd_lock);
2091		iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2092		return;
2093	}
2094
2095	if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2096		/* send a ping to try to provoke some traffic */
2097		ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2098		if (iscsi_send_nopout(conn, NULL))
2099			next_timeout = jiffies + (1 * HZ);
2100		else
2101			next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2102	} else
2103		next_timeout = last_recv + recv_timeout;
2104
2105	ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2106	mod_timer(&conn->transport_timer, next_timeout);
2107done:
2108	spin_unlock(&session->frwd_lock);
2109}
2110
2111static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2112				      struct iscsi_tm *hdr)
2113{
2114	memset(hdr, 0, sizeof(*hdr));
2115	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2116	hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2117	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2118	hdr->lun = task->lun;
2119	hdr->rtt = task->hdr_itt;
2120	hdr->refcmdsn = task->cmdsn;
2121}
2122
2123int iscsi_eh_abort(struct scsi_cmnd *sc)
2124{
2125	struct iscsi_cls_session *cls_session;
2126	struct iscsi_session *session;
2127	struct iscsi_conn *conn;
2128	struct iscsi_task *task;
2129	struct iscsi_tm *hdr;
2130	int rc, age;
2131
2132	cls_session = starget_to_session(scsi_target(sc->device));
2133	session = cls_session->dd_data;
2134
2135	ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2136
2137	mutex_lock(&session->eh_mutex);
2138	spin_lock_bh(&session->frwd_lock);
2139	/*
2140	 * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2141	 * got the command.
2142	 */
2143	if (!sc->SCp.ptr) {
2144		ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2145				      "it completed.\n");
2146		spin_unlock_bh(&session->frwd_lock);
2147		mutex_unlock(&session->eh_mutex);
2148		return SUCCESS;
2149	}
2150
2151	/*
2152	 * If we are not logged in or we have started a new session
2153	 * then let the host reset code handle this
2154	 */
2155	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2156	    sc->SCp.phase != session->age) {
2157		spin_unlock_bh(&session->frwd_lock);
2158		mutex_unlock(&session->eh_mutex);
2159		ISCSI_DBG_EH(session, "failing abort due to dropped "
2160				  "session.\n");
2161		return FAILED;
2162	}
2163
2164	conn = session->leadconn;
2165	conn->eh_abort_cnt++;
2166	age = session->age;
2167
2168	task = (struct iscsi_task *)sc->SCp.ptr;
2169	ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2170		     sc, task->itt);
2171
2172	/* task completed before time out */
2173	if (!task->sc) {
2174		ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2175		goto success;
2176	}
2177
2178	if (task->state == ISCSI_TASK_PENDING) {
2179		fail_scsi_task(task, DID_ABORT);
2180		goto success;
2181	}
2182
2183	/* only have one tmf outstanding at a time */
2184	if (conn->tmf_state != TMF_INITIAL)
2185		goto failed;
2186	conn->tmf_state = TMF_QUEUED;
2187
2188	hdr = &conn->tmhdr;
2189	iscsi_prep_abort_task_pdu(task, hdr);
2190
2191	if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
2192		rc = FAILED;
2193		goto failed;
2194	}
2195
2196	switch (conn->tmf_state) {
2197	case TMF_SUCCESS:
2198		spin_unlock_bh(&session->frwd_lock);
2199		/*
2200		 * stop tx side incase the target had sent a abort rsp but
2201		 * the initiator was still writing out data.
2202		 */
2203		iscsi_suspend_tx(conn);
2204		/*
2205		 * we do not stop the recv side because targets have been
2206		 * good and have never sent us a successful tmf response
2207		 * then sent more data for the cmd.
2208		 */
2209		spin_lock_bh(&session->frwd_lock);
2210		fail_scsi_task(task, DID_ABORT);
2211		conn->tmf_state = TMF_INITIAL;
2212		memset(hdr, 0, sizeof(*hdr));
2213		spin_unlock_bh(&session->frwd_lock);
2214		iscsi_start_tx(conn);
2215		goto success_unlocked;
2216	case TMF_TIMEDOUT:
2217		spin_unlock_bh(&session->frwd_lock);
2218		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2219		goto failed_unlocked;
2220	case TMF_NOT_FOUND:
2221		if (!sc->SCp.ptr) {
2222			conn->tmf_state = TMF_INITIAL;
2223			memset(hdr, 0, sizeof(*hdr));
2224			/* task completed before tmf abort response */
2225			ISCSI_DBG_EH(session, "sc completed while abort	in "
2226					      "progress\n");
2227			goto success;
2228		}
2229		/* fall through */
2230	default:
2231		conn->tmf_state = TMF_INITIAL;
2232		goto failed;
2233	}
2234
2235success:
2236	spin_unlock_bh(&session->frwd_lock);
2237success_unlocked:
2238	ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2239		     sc, task->itt);
2240	mutex_unlock(&session->eh_mutex);
2241	return SUCCESS;
2242
2243failed:
2244	spin_unlock_bh(&session->frwd_lock);
2245failed_unlocked:
2246	ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2247		     task ? task->itt : 0);
2248	mutex_unlock(&session->eh_mutex);
2249	return FAILED;
2250}
2251EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2252
2253static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2254{
2255	memset(hdr, 0, sizeof(*hdr));
2256	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2257	hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2258	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2259	int_to_scsilun(sc->device->lun, &hdr->lun);
2260	hdr->rtt = RESERVED_ITT;
2261}
2262
2263int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2264{
2265	struct iscsi_cls_session *cls_session;
2266	struct iscsi_session *session;
2267	struct iscsi_conn *conn;
2268	struct iscsi_tm *hdr;
2269	int rc = FAILED;
2270
2271	cls_session = starget_to_session(scsi_target(sc->device));
2272	session = cls_session->dd_data;
2273
2274	ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2275		     sc->device->lun);
2276
2277	mutex_lock(&session->eh_mutex);
2278	spin_lock_bh(&session->frwd_lock);
2279	/*
2280	 * Just check if we are not logged in. We cannot check for
2281	 * the phase because the reset could come from a ioctl.
2282	 */
2283	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2284		goto unlock;
2285	conn = session->leadconn;
2286
2287	/* only have one tmf outstanding at a time */
2288	if (conn->tmf_state != TMF_INITIAL)
2289		goto unlock;
2290	conn->tmf_state = TMF_QUEUED;
2291
2292	hdr = &conn->tmhdr;
2293	iscsi_prep_lun_reset_pdu(sc, hdr);
2294
2295	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2296				    session->lu_reset_timeout)) {
2297		rc = FAILED;
2298		goto unlock;
2299	}
2300
2301	switch (conn->tmf_state) {
2302	case TMF_SUCCESS:
2303		break;
2304	case TMF_TIMEDOUT:
2305		spin_unlock_bh(&session->frwd_lock);
2306		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2307		goto done;
2308	default:
2309		conn->tmf_state = TMF_INITIAL;
2310		goto unlock;
2311	}
2312
2313	rc = SUCCESS;
2314	spin_unlock_bh(&session->frwd_lock);
2315
2316	iscsi_suspend_tx(conn);
2317
2318	spin_lock_bh(&session->frwd_lock);
2319	memset(hdr, 0, sizeof(*hdr));
2320	fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2321	conn->tmf_state = TMF_INITIAL;
2322	spin_unlock_bh(&session->frwd_lock);
2323
2324	iscsi_start_tx(conn);
2325	goto done;
2326
2327unlock:
2328	spin_unlock_bh(&session->frwd_lock);
2329done:
2330	ISCSI_DBG_EH(session, "dev reset result = %s\n",
2331		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2332	mutex_unlock(&session->eh_mutex);
2333	return rc;
2334}
2335EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2336
2337void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2338{
2339	struct iscsi_session *session = cls_session->dd_data;
2340
2341	spin_lock_bh(&session->frwd_lock);
2342	if (session->state != ISCSI_STATE_LOGGED_IN) {
2343		session->state = ISCSI_STATE_RECOVERY_FAILED;
2344		if (session->leadconn)
2345			wake_up(&session->leadconn->ehwait);
2346	}
2347	spin_unlock_bh(&session->frwd_lock);
2348}
2349EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2350
2351/**
2352 * iscsi_eh_session_reset - drop session and attempt relogin
2353 * @sc: scsi command
2354 *
2355 * This function will wait for a relogin, session termination from
2356 * userspace, or a recovery/replacement timeout.
2357 */
2358int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2359{
2360	struct iscsi_cls_session *cls_session;
2361	struct iscsi_session *session;
2362	struct iscsi_conn *conn;
2363
2364	cls_session = starget_to_session(scsi_target(sc->device));
2365	session = cls_session->dd_data;
2366	conn = session->leadconn;
2367
2368	mutex_lock(&session->eh_mutex);
2369	spin_lock_bh(&session->frwd_lock);
2370	if (session->state == ISCSI_STATE_TERMINATE) {
2371failed:
2372		ISCSI_DBG_EH(session,
2373			     "failing session reset: Could not log back into "
2374			     "%s, %s [age %d]\n", session->targetname,
2375			     conn->persistent_address, session->age);
2376		spin_unlock_bh(&session->frwd_lock);
2377		mutex_unlock(&session->eh_mutex);
2378		return FAILED;
2379	}
2380
2381	spin_unlock_bh(&session->frwd_lock);
2382	mutex_unlock(&session->eh_mutex);
2383	/*
2384	 * we drop the lock here but the leadconn cannot be destoyed while
2385	 * we are in the scsi eh
2386	 */
2387	iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2388
2389	ISCSI_DBG_EH(session, "wait for relogin\n");
2390	wait_event_interruptible(conn->ehwait,
2391				 session->state == ISCSI_STATE_TERMINATE ||
2392				 session->state == ISCSI_STATE_LOGGED_IN ||
2393				 session->state == ISCSI_STATE_RECOVERY_FAILED);
2394	if (signal_pending(current))
2395		flush_signals(current);
2396
2397	mutex_lock(&session->eh_mutex);
2398	spin_lock_bh(&session->frwd_lock);
2399	if (session->state == ISCSI_STATE_LOGGED_IN) {
2400		ISCSI_DBG_EH(session,
2401			     "session reset succeeded for %s,%s\n",
2402			     session->targetname, conn->persistent_address);
2403	} else
2404		goto failed;
2405	spin_unlock_bh(&session->frwd_lock);
2406	mutex_unlock(&session->eh_mutex);
2407	return SUCCESS;
2408}
2409EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2410
2411static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2412{
2413	memset(hdr, 0, sizeof(*hdr));
2414	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2415	hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2416	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2417	hdr->rtt = RESERVED_ITT;
2418}
2419
2420/**
2421 * iscsi_eh_target_reset - reset target
2422 * @sc: scsi command
2423 *
2424 * This will attempt to send a warm target reset.
2425 */
2426int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2427{
2428	struct iscsi_cls_session *cls_session;
2429	struct iscsi_session *session;
2430	struct iscsi_conn *conn;
2431	struct iscsi_tm *hdr;
2432	int rc = FAILED;
2433
2434	cls_session = starget_to_session(scsi_target(sc->device));
2435	session = cls_session->dd_data;
2436
2437	ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2438		     session->targetname);
2439
2440	mutex_lock(&session->eh_mutex);
2441	spin_lock_bh(&session->frwd_lock);
2442	/*
2443	 * Just check if we are not logged in. We cannot check for
2444	 * the phase because the reset could come from a ioctl.
2445	 */
2446	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2447		goto unlock;
2448	conn = session->leadconn;
2449
2450	/* only have one tmf outstanding at a time */
2451	if (conn->tmf_state != TMF_INITIAL)
2452		goto unlock;
2453	conn->tmf_state = TMF_QUEUED;
2454
2455	hdr = &conn->tmhdr;
2456	iscsi_prep_tgt_reset_pdu(sc, hdr);
2457
2458	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2459				    session->tgt_reset_timeout)) {
2460		rc = FAILED;
2461		goto unlock;
2462	}
2463
2464	switch (conn->tmf_state) {
2465	case TMF_SUCCESS:
2466		break;
2467	case TMF_TIMEDOUT:
2468		spin_unlock_bh(&session->frwd_lock);
2469		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2470		goto done;
2471	default:
2472		conn->tmf_state = TMF_INITIAL;
2473		goto unlock;
2474	}
2475
2476	rc = SUCCESS;
2477	spin_unlock_bh(&session->frwd_lock);
2478
2479	iscsi_suspend_tx(conn);
2480
2481	spin_lock_bh(&session->frwd_lock);
2482	memset(hdr, 0, sizeof(*hdr));
2483	fail_scsi_tasks(conn, -1, DID_ERROR);
2484	conn->tmf_state = TMF_INITIAL;
2485	spin_unlock_bh(&session->frwd_lock);
2486
2487	iscsi_start_tx(conn);
2488	goto done;
2489
2490unlock:
2491	spin_unlock_bh(&session->frwd_lock);
2492done:
2493	ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2494		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2495	mutex_unlock(&session->eh_mutex);
2496	return rc;
2497}
2498EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
2499
2500/**
2501 * iscsi_eh_recover_target - reset target and possibly the session
2502 * @sc: scsi command
2503 *
2504 * This will attempt to send a warm target reset. If that fails,
2505 * we will escalate to ERL0 session recovery.
2506 */
2507int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2508{
2509	int rc;
2510
2511	rc = iscsi_eh_target_reset(sc);
2512	if (rc == FAILED)
2513		rc = iscsi_eh_session_reset(sc);
2514	return rc;
2515}
2516EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2517
2518/*
2519 * Pre-allocate a pool of @max items of @item_size. By default, the pool
2520 * should be accessed via kfifo_{get,put} on q->queue.
2521 * Optionally, the caller can obtain the array of object pointers
2522 * by passing in a non-NULL @items pointer
2523 */
2524int
2525iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2526{
2527	int i, num_arrays = 1;
2528
2529	memset(q, 0, sizeof(*q));
2530
2531	q->max = max;
2532
2533	/* If the user passed an items pointer, he wants a copy of
2534	 * the array. */
2535	if (items)
2536		num_arrays++;
2537	q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2538	if (q->pool == NULL)
2539		return -ENOMEM;
2540
2541	kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2542
2543	for (i = 0; i < max; i++) {
2544		q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2545		if (q->pool[i] == NULL) {
2546			q->max = i;
2547			goto enomem;
2548		}
2549		kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2550	}
2551
2552	if (items) {
2553		*items = q->pool + max;
2554		memcpy(*items, q->pool, max * sizeof(void *));
2555	}
2556
2557	return 0;
2558
2559enomem:
2560	iscsi_pool_free(q);
2561	return -ENOMEM;
2562}
2563EXPORT_SYMBOL_GPL(iscsi_pool_init);
2564
2565void iscsi_pool_free(struct iscsi_pool *q)
2566{
2567	int i;
2568
2569	for (i = 0; i < q->max; i++)
2570		kfree(q->pool[i]);
2571	kfree(q->pool);
2572}
2573EXPORT_SYMBOL_GPL(iscsi_pool_free);
2574
2575/**
2576 * iscsi_host_add - add host to system
2577 * @shost: scsi host
2578 * @pdev: parent device
2579 *
2580 * This should be called by partial offload and software iscsi drivers
2581 * to add a host to the system.
2582 */
2583int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2584{
2585	if (!shost->can_queue)
2586		shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2587
2588	if (!shost->cmd_per_lun)
2589		shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2590
2591	if (!shost->transportt->eh_timed_out)
2592		shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2593	return scsi_add_host(shost, pdev);
2594}
2595EXPORT_SYMBOL_GPL(iscsi_host_add);
2596
2597/**
2598 * iscsi_host_alloc - allocate a host and driver data
2599 * @sht: scsi host template
2600 * @dd_data_size: driver host data size
2601 * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2602 *
2603 * This should be called by partial offload and software iscsi drivers.
2604 * To access the driver specific memory use the iscsi_host_priv() macro.
2605 */
2606struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2607				   int dd_data_size, bool xmit_can_sleep)
2608{
2609	struct Scsi_Host *shost;
2610	struct iscsi_host *ihost;
2611
2612	shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2613	if (!shost)
2614		return NULL;
2615	ihost = shost_priv(shost);
2616
2617	if (xmit_can_sleep) {
2618		snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2619			"iscsi_q_%d", shost->host_no);
2620		ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2621		if (!ihost->workq)
2622			goto free_host;
2623	}
2624
2625	spin_lock_init(&ihost->lock);
2626	ihost->state = ISCSI_HOST_SETUP;
2627	ihost->num_sessions = 0;
2628	init_waitqueue_head(&ihost->session_removal_wq);
2629	return shost;
2630
2631free_host:
2632	scsi_host_put(shost);
2633	return NULL;
2634}
2635EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2636
2637static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2638{
2639	iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2640}
2641
2642/**
2643 * iscsi_host_remove - remove host and sessions
2644 * @shost: scsi host
2645 *
2646 * If there are any sessions left, this will initiate the removal and wait
2647 * for the completion.
2648 */
2649void iscsi_host_remove(struct Scsi_Host *shost)
2650{
2651	struct iscsi_host *ihost = shost_priv(shost);
2652	unsigned long flags;
2653
2654	spin_lock_irqsave(&ihost->lock, flags);
2655	ihost->state = ISCSI_HOST_REMOVED;
2656	spin_unlock_irqrestore(&ihost->lock, flags);
2657
2658	iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2659	wait_event_interruptible(ihost->session_removal_wq,
2660				 ihost->num_sessions == 0);
2661	if (signal_pending(current))
2662		flush_signals(current);
2663
2664	scsi_remove_host(shost);
2665	if (ihost->workq)
2666		destroy_workqueue(ihost->workq);
2667}
2668EXPORT_SYMBOL_GPL(iscsi_host_remove);
2669
2670void iscsi_host_free(struct Scsi_Host *shost)
2671{
2672	struct iscsi_host *ihost = shost_priv(shost);
2673
2674	kfree(ihost->netdev);
2675	kfree(ihost->hwaddress);
2676	kfree(ihost->initiatorname);
2677	scsi_host_put(shost);
2678}
2679EXPORT_SYMBOL_GPL(iscsi_host_free);
2680
2681static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2682{
2683	struct iscsi_host *ihost = shost_priv(shost);
2684	unsigned long flags;
2685
2686	shost = scsi_host_get(shost);
2687	if (!shost) {
2688		printk(KERN_ERR "Invalid state. Cannot notify host removal "
2689		      "of session teardown event because host already "
2690		      "removed.\n");
2691		return;
2692	}
2693
2694	spin_lock_irqsave(&ihost->lock, flags);
2695	ihost->num_sessions--;
2696	if (ihost->num_sessions == 0)
2697		wake_up(&ihost->session_removal_wq);
2698	spin_unlock_irqrestore(&ihost->lock, flags);
2699	scsi_host_put(shost);
2700}
2701
2702/**
2703 * iscsi_session_setup - create iscsi cls session and host and session
2704 * @iscsit: iscsi transport template
2705 * @shost: scsi host
2706 * @cmds_max: session can queue
2707 * @cmd_task_size: LLD task private data size
2708 * @initial_cmdsn: initial CmdSN
2709 *
2710 * This can be used by software iscsi_transports that allocate
2711 * a session per scsi host.
2712 *
2713 * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2714 * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2715 * for nop handling and login/logout requests.
2716 */
2717struct iscsi_cls_session *
2718iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2719		    uint16_t cmds_max, int dd_size, int cmd_task_size,
2720		    uint32_t initial_cmdsn, unsigned int id)
2721{
2722	struct iscsi_host *ihost = shost_priv(shost);
2723	struct iscsi_session *session;
2724	struct iscsi_cls_session *cls_session;
2725	int cmd_i, scsi_cmds, total_cmds = cmds_max;
2726	unsigned long flags;
2727
2728	spin_lock_irqsave(&ihost->lock, flags);
2729	if (ihost->state == ISCSI_HOST_REMOVED) {
2730		spin_unlock_irqrestore(&ihost->lock, flags);
2731		return NULL;
2732	}
2733	ihost->num_sessions++;
2734	spin_unlock_irqrestore(&ihost->lock, flags);
2735
2736	if (!total_cmds)
2737		total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2738	/*
2739	 * The iscsi layer needs some tasks for nop handling and tmfs,
2740	 * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2741	 * + 1 command for scsi IO.
2742	 */
2743	if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2744		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2745		       "must be a power of two that is at least %d.\n",
2746		       total_cmds, ISCSI_TOTAL_CMDS_MIN);
2747		goto dec_session_count;
2748	}
2749
2750	if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2751		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2752		       "must be a power of 2 less than or equal to %d.\n",
2753		       cmds_max, ISCSI_TOTAL_CMDS_MAX);
2754		total_cmds = ISCSI_TOTAL_CMDS_MAX;
2755	}
2756
2757	if (!is_power_of_2(total_cmds)) {
2758		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2759		       "must be a power of 2.\n", total_cmds);
2760		total_cmds = rounddown_pow_of_two(total_cmds);
2761		if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2762			return NULL;
2763		printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2764		       total_cmds);
2765	}
2766	scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2767
2768	cls_session = iscsi_alloc_session(shost, iscsit,
2769					  sizeof(struct iscsi_session) +
2770					  dd_size);
2771	if (!cls_session)
2772		goto dec_session_count;
2773	session = cls_session->dd_data;
2774	session->cls_session = cls_session;
2775	session->host = shost;
2776	session->state = ISCSI_STATE_FREE;
2777	session->fast_abort = 1;
2778	session->tgt_reset_timeout = 30;
2779	session->lu_reset_timeout = 15;
2780	session->abort_timeout = 10;
2781	session->scsi_cmds_max = scsi_cmds;
2782	session->cmds_max = total_cmds;
2783	session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2784	session->exp_cmdsn = initial_cmdsn + 1;
2785	session->max_cmdsn = initial_cmdsn + 1;
2786	session->max_r2t = 1;
2787	session->tt = iscsit;
2788	session->dd_data = cls_session->dd_data + sizeof(*session);
2789
2790	mutex_init(&session->eh_mutex);
2791	spin_lock_init(&session->frwd_lock);
2792	spin_lock_init(&session->back_lock);
2793
2794	/* initialize SCSI PDU commands pool */
2795	if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2796			    (void***)&session->cmds,
2797			    cmd_task_size + sizeof(struct iscsi_task)))
2798		goto cmdpool_alloc_fail;
2799
2800	/* pre-format cmds pool with ITT */
2801	for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2802		struct iscsi_task *task = session->cmds[cmd_i];
2803
2804		if (cmd_task_size)
2805			task->dd_data = &task[1];
2806		task->itt = cmd_i;
2807		task->state = ISCSI_TASK_FREE;
2808		INIT_LIST_HEAD(&task->running);
2809	}
2810
2811	if (!try_module_get(iscsit->owner))
2812		goto module_get_fail;
2813
2814	if (iscsi_add_session(cls_session, id))
2815		goto cls_session_fail;
2816
2817	return cls_session;
2818
2819cls_session_fail:
2820	module_put(iscsit->owner);
2821module_get_fail:
2822	iscsi_pool_free(&session->cmdpool);
2823cmdpool_alloc_fail:
2824	iscsi_free_session(cls_session);
2825dec_session_count:
2826	iscsi_host_dec_session_cnt(shost);
2827	return NULL;
2828}
2829EXPORT_SYMBOL_GPL(iscsi_session_setup);
2830
2831/**
2832 * iscsi_session_teardown - destroy session, host, and cls_session
2833 * @cls_session: iscsi session
2834 *
2835 * The driver must have called iscsi_remove_session before
2836 * calling this.
2837 */
2838void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2839{
2840	struct iscsi_session *session = cls_session->dd_data;
2841	struct module *owner = cls_session->transport->owner;
2842	struct Scsi_Host *shost = session->host;
2843
2844	iscsi_pool_free(&session->cmdpool);
2845
2846	kfree(session->password);
2847	kfree(session->password_in);
2848	kfree(session->username);
2849	kfree(session->username_in);
2850	kfree(session->targetname);
2851	kfree(session->targetalias);
2852	kfree(session->initiatorname);
2853	kfree(session->boot_root);
2854	kfree(session->boot_nic);
2855	kfree(session->boot_target);
2856	kfree(session->ifacename);
2857	kfree(session->portal_type);
2858	kfree(session->discovery_parent_type);
2859
2860	iscsi_destroy_session(cls_session);
2861	iscsi_host_dec_session_cnt(shost);
2862	module_put(owner);
2863}
2864EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2865
2866/**
2867 * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2868 * @cls_session: iscsi_cls_session
2869 * @dd_size: private driver data size
2870 * @conn_idx: cid
2871 */
2872struct iscsi_cls_conn *
2873iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2874		 uint32_t conn_idx)
2875{
2876	struct iscsi_session *session = cls_session->dd_data;
2877	struct iscsi_conn *conn;
2878	struct iscsi_cls_conn *cls_conn;
2879	char *data;
2880
2881	cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2882				     conn_idx);
2883	if (!cls_conn)
2884		return NULL;
2885	conn = cls_conn->dd_data;
2886	memset(conn, 0, sizeof(*conn) + dd_size);
2887
2888	conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2889	conn->session = session;
2890	conn->cls_conn = cls_conn;
2891	conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2892	conn->id = conn_idx;
2893	conn->exp_statsn = 0;
2894	conn->tmf_state = TMF_INITIAL;
2895
2896	init_timer(&conn->transport_timer);
2897	conn->transport_timer.data = (unsigned long)conn;
2898	conn->transport_timer.function = iscsi_check_transport_timeouts;
2899
2900	INIT_LIST_HEAD(&conn->mgmtqueue);
2901	INIT_LIST_HEAD(&conn->cmdqueue);
2902	INIT_LIST_HEAD(&conn->requeue);
2903	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2904
2905	/* allocate login_task used for the login/text sequences */
2906	spin_lock_bh(&session->frwd_lock);
2907	if (!kfifo_out(&session->cmdpool.queue,
2908                         (void*)&conn->login_task,
2909			 sizeof(void*))) {
2910		spin_unlock_bh(&session->frwd_lock);
2911		goto login_task_alloc_fail;
2912	}
2913	spin_unlock_bh(&session->frwd_lock);
2914
2915	data = (char *) __get_free_pages(GFP_KERNEL,
2916					 get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2917	if (!data)
2918		goto login_task_data_alloc_fail;
2919	conn->login_task->data = conn->data = data;
2920
2921	init_timer(&conn->tmf_timer);
2922	init_waitqueue_head(&conn->ehwait);
2923
2924	return cls_conn;
2925
2926login_task_data_alloc_fail:
2927	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2928		    sizeof(void*));
2929login_task_alloc_fail:
2930	iscsi_destroy_conn(cls_conn);
2931	return NULL;
2932}
2933EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2934
2935/**
2936 * iscsi_conn_teardown - teardown iscsi connection
2937 * cls_conn: iscsi class connection
2938 *
2939 * TODO: we may need to make this into a two step process
2940 * like scsi-mls remove + put host
2941 */
2942void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2943{
2944	struct iscsi_conn *conn = cls_conn->dd_data;
2945	struct iscsi_session *session = conn->session;
 
2946
2947	del_timer_sync(&conn->transport_timer);
2948
2949	mutex_lock(&session->eh_mutex);
2950	spin_lock_bh(&session->frwd_lock);
2951	conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2952	if (session->leadconn == conn) {
2953		/*
2954		 * leading connection? then give up on recovery.
2955		 */
2956		session->state = ISCSI_STATE_TERMINATE;
2957		wake_up(&conn->ehwait);
2958	}
2959	spin_unlock_bh(&session->frwd_lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2960
2961	/* flush queued up work because we free the connection below */
2962	iscsi_suspend_tx(conn);
2963
2964	spin_lock_bh(&session->frwd_lock);
2965	free_pages((unsigned long) conn->data,
2966		   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2967	kfree(conn->persistent_address);
2968	kfree(conn->local_ipaddr);
2969	/* regular RX path uses back_lock */
2970	spin_lock_bh(&session->back_lock);
2971	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2972		    sizeof(void*));
2973	spin_unlock_bh(&session->back_lock);
2974	if (session->leadconn == conn)
2975		session->leadconn = NULL;
2976	spin_unlock_bh(&session->frwd_lock);
2977	mutex_unlock(&session->eh_mutex);
2978
2979	iscsi_destroy_conn(cls_conn);
2980}
2981EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2982
2983int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2984{
2985	struct iscsi_conn *conn = cls_conn->dd_data;
2986	struct iscsi_session *session = conn->session;
2987
2988	if (!session) {
2989		iscsi_conn_printk(KERN_ERR, conn,
2990				  "can't start unbound connection\n");
2991		return -EPERM;
2992	}
2993
2994	if ((session->imm_data_en || !session->initial_r2t_en) &&
2995	     session->first_burst > session->max_burst) {
2996		iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2997				  "first_burst %d max_burst %d\n",
2998				  session->first_burst, session->max_burst);
2999		return -EINVAL;
3000	}
3001
3002	if (conn->ping_timeout && !conn->recv_timeout) {
3003		iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3004				  "zero. Using 5 seconds\n.");
3005		conn->recv_timeout = 5;
3006	}
3007
3008	if (conn->recv_timeout && !conn->ping_timeout) {
3009		iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3010				  "zero. Using 5 seconds.\n");
3011		conn->ping_timeout = 5;
3012	}
3013
3014	spin_lock_bh(&session->frwd_lock);
3015	conn->c_stage = ISCSI_CONN_STARTED;
3016	session->state = ISCSI_STATE_LOGGED_IN;
3017	session->queued_cmdsn = session->cmdsn;
3018
3019	conn->last_recv = jiffies;
3020	conn->last_ping = jiffies;
3021	if (conn->recv_timeout && conn->ping_timeout)
3022		mod_timer(&conn->transport_timer,
3023			  jiffies + (conn->recv_timeout * HZ));
3024
3025	switch(conn->stop_stage) {
3026	case STOP_CONN_RECOVER:
3027		/*
3028		 * unblock eh_abort() if it is blocked. re-try all
3029		 * commands after successful recovery
3030		 */
3031		conn->stop_stage = 0;
3032		conn->tmf_state = TMF_INITIAL;
3033		session->age++;
3034		if (session->age == 16)
3035			session->age = 0;
3036		break;
3037	case STOP_CONN_TERM:
3038		conn->stop_stage = 0;
3039		break;
3040	default:
3041		break;
3042	}
3043	spin_unlock_bh(&session->frwd_lock);
3044
3045	iscsi_unblock_session(session->cls_session);
3046	wake_up(&conn->ehwait);
3047	return 0;
3048}
3049EXPORT_SYMBOL_GPL(iscsi_conn_start);
3050
3051static void
3052fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3053{
3054	struct iscsi_task *task;
3055	int i, state;
3056
3057	for (i = 0; i < conn->session->cmds_max; i++) {
3058		task = conn->session->cmds[i];
3059		if (task->sc)
3060			continue;
3061
3062		if (task->state == ISCSI_TASK_FREE)
3063			continue;
3064
3065		ISCSI_DBG_SESSION(conn->session,
3066				  "failing mgmt itt 0x%x state %d\n",
3067				  task->itt, task->state);
3068		state = ISCSI_TASK_ABRT_SESS_RECOV;
3069		if (task->state == ISCSI_TASK_PENDING)
3070			state = ISCSI_TASK_COMPLETED;
3071		iscsi_complete_task(task, state);
3072
3073	}
3074}
3075
3076static void iscsi_start_session_recovery(struct iscsi_session *session,
3077					 struct iscsi_conn *conn, int flag)
3078{
3079	int old_stop_stage;
3080
3081	mutex_lock(&session->eh_mutex);
3082	spin_lock_bh(&session->frwd_lock);
3083	if (conn->stop_stage == STOP_CONN_TERM) {
3084		spin_unlock_bh(&session->frwd_lock);
3085		mutex_unlock(&session->eh_mutex);
3086		return;
3087	}
3088
3089	/*
3090	 * When this is called for the in_login state, we only want to clean
3091	 * up the login task and connection. We do not need to block and set
3092	 * the recovery state again
3093	 */
3094	if (flag == STOP_CONN_TERM)
3095		session->state = ISCSI_STATE_TERMINATE;
3096	else if (conn->stop_stage != STOP_CONN_RECOVER)
3097		session->state = ISCSI_STATE_IN_RECOVERY;
3098
3099	old_stop_stage = conn->stop_stage;
3100	conn->stop_stage = flag;
3101	spin_unlock_bh(&session->frwd_lock);
3102
3103	del_timer_sync(&conn->transport_timer);
3104	iscsi_suspend_tx(conn);
3105
3106	spin_lock_bh(&session->frwd_lock);
3107	conn->c_stage = ISCSI_CONN_STOPPED;
3108	spin_unlock_bh(&session->frwd_lock);
3109
3110	/*
3111	 * for connection level recovery we should not calculate
3112	 * header digest. conn->hdr_size used for optimization
3113	 * in hdr_extract() and will be re-negotiated at
3114	 * set_param() time.
3115	 */
3116	if (flag == STOP_CONN_RECOVER) {
3117		conn->hdrdgst_en = 0;
3118		conn->datadgst_en = 0;
3119		if (session->state == ISCSI_STATE_IN_RECOVERY &&
3120		    old_stop_stage != STOP_CONN_RECOVER) {
3121			ISCSI_DBG_SESSION(session, "blocking session\n");
3122			iscsi_block_session(session->cls_session);
3123		}
3124	}
3125
3126	/*
3127	 * flush queues.
3128	 */
3129	spin_lock_bh(&session->frwd_lock);
3130	fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3131	fail_mgmt_tasks(session, conn);
3132	memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3133	spin_unlock_bh(&session->frwd_lock);
3134	mutex_unlock(&session->eh_mutex);
3135}
3136
3137void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3138{
3139	struct iscsi_conn *conn = cls_conn->dd_data;
3140	struct iscsi_session *session = conn->session;
3141
3142	switch (flag) {
3143	case STOP_CONN_RECOVER:
3144	case STOP_CONN_TERM:
3145		iscsi_start_session_recovery(session, conn, flag);
3146		break;
3147	default:
3148		iscsi_conn_printk(KERN_ERR, conn,
3149				  "invalid stop flag %d\n", flag);
3150	}
3151}
3152EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3153
3154int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3155		    struct iscsi_cls_conn *cls_conn, int is_leading)
3156{
3157	struct iscsi_session *session = cls_session->dd_data;
3158	struct iscsi_conn *conn = cls_conn->dd_data;
3159
3160	spin_lock_bh(&session->frwd_lock);
3161	if (is_leading)
3162		session->leadconn = conn;
3163	spin_unlock_bh(&session->frwd_lock);
3164
3165	/*
3166	 * Unblock xmitworker(), Login Phase will pass through.
3167	 */
3168	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3169	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3170	return 0;
3171}
3172EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3173
3174int iscsi_switch_str_param(char **param, char *new_val_buf)
3175{
3176	char *new_val;
3177
3178	if (*param) {
3179		if (!strcmp(*param, new_val_buf))
3180			return 0;
3181	}
3182
3183	new_val = kstrdup(new_val_buf, GFP_NOIO);
3184	if (!new_val)
3185		return -ENOMEM;
3186
3187	kfree(*param);
3188	*param = new_val;
3189	return 0;
3190}
3191EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3192
3193int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3194		    enum iscsi_param param, char *buf, int buflen)
3195{
3196	struct iscsi_conn *conn = cls_conn->dd_data;
3197	struct iscsi_session *session = conn->session;
3198	int val;
3199
3200	switch(param) {
3201	case ISCSI_PARAM_FAST_ABORT:
3202		sscanf(buf, "%d", &session->fast_abort);
3203		break;
3204	case ISCSI_PARAM_ABORT_TMO:
3205		sscanf(buf, "%d", &session->abort_timeout);
3206		break;
3207	case ISCSI_PARAM_LU_RESET_TMO:
3208		sscanf(buf, "%d", &session->lu_reset_timeout);
3209		break;
3210	case ISCSI_PARAM_TGT_RESET_TMO:
3211		sscanf(buf, "%d", &session->tgt_reset_timeout);
3212		break;
3213	case ISCSI_PARAM_PING_TMO:
3214		sscanf(buf, "%d", &conn->ping_timeout);
3215		break;
3216	case ISCSI_PARAM_RECV_TMO:
3217		sscanf(buf, "%d", &conn->recv_timeout);
3218		break;
3219	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3220		sscanf(buf, "%d", &conn->max_recv_dlength);
3221		break;
3222	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3223		sscanf(buf, "%d", &conn->max_xmit_dlength);
3224		break;
3225	case ISCSI_PARAM_HDRDGST_EN:
3226		sscanf(buf, "%d", &conn->hdrdgst_en);
3227		break;
3228	case ISCSI_PARAM_DATADGST_EN:
3229		sscanf(buf, "%d", &conn->datadgst_en);
3230		break;
3231	case ISCSI_PARAM_INITIAL_R2T_EN:
3232		sscanf(buf, "%d", &session->initial_r2t_en);
3233		break;
3234	case ISCSI_PARAM_MAX_R2T:
3235		sscanf(buf, "%hu", &session->max_r2t);
3236		break;
3237	case ISCSI_PARAM_IMM_DATA_EN:
3238		sscanf(buf, "%d", &session->imm_data_en);
3239		break;
3240	case ISCSI_PARAM_FIRST_BURST:
3241		sscanf(buf, "%d", &session->first_burst);
3242		break;
3243	case ISCSI_PARAM_MAX_BURST:
3244		sscanf(buf, "%d", &session->max_burst);
3245		break;
3246	case ISCSI_PARAM_PDU_INORDER_EN:
3247		sscanf(buf, "%d", &session->pdu_inorder_en);
3248		break;
3249	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3250		sscanf(buf, "%d", &session->dataseq_inorder_en);
3251		break;
3252	case ISCSI_PARAM_ERL:
3253		sscanf(buf, "%d", &session->erl);
3254		break;
 
 
 
 
 
 
 
 
3255	case ISCSI_PARAM_EXP_STATSN:
3256		sscanf(buf, "%u", &conn->exp_statsn);
3257		break;
3258	case ISCSI_PARAM_USERNAME:
3259		return iscsi_switch_str_param(&session->username, buf);
3260	case ISCSI_PARAM_USERNAME_IN:
3261		return iscsi_switch_str_param(&session->username_in, buf);
3262	case ISCSI_PARAM_PASSWORD:
3263		return iscsi_switch_str_param(&session->password, buf);
3264	case ISCSI_PARAM_PASSWORD_IN:
3265		return iscsi_switch_str_param(&session->password_in, buf);
3266	case ISCSI_PARAM_TARGET_NAME:
3267		return iscsi_switch_str_param(&session->targetname, buf);
3268	case ISCSI_PARAM_TARGET_ALIAS:
3269		return iscsi_switch_str_param(&session->targetalias, buf);
3270	case ISCSI_PARAM_TPGT:
3271		sscanf(buf, "%d", &session->tpgt);
3272		break;
3273	case ISCSI_PARAM_PERSISTENT_PORT:
3274		sscanf(buf, "%d", &conn->persistent_port);
3275		break;
3276	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3277		return iscsi_switch_str_param(&conn->persistent_address, buf);
3278	case ISCSI_PARAM_IFACE_NAME:
3279		return iscsi_switch_str_param(&session->ifacename, buf);
3280	case ISCSI_PARAM_INITIATOR_NAME:
3281		return iscsi_switch_str_param(&session->initiatorname, buf);
3282	case ISCSI_PARAM_BOOT_ROOT:
3283		return iscsi_switch_str_param(&session->boot_root, buf);
3284	case ISCSI_PARAM_BOOT_NIC:
3285		return iscsi_switch_str_param(&session->boot_nic, buf);
3286	case ISCSI_PARAM_BOOT_TARGET:
3287		return iscsi_switch_str_param(&session->boot_target, buf);
3288	case ISCSI_PARAM_PORTAL_TYPE:
3289		return iscsi_switch_str_param(&session->portal_type, buf);
3290	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3291		return iscsi_switch_str_param(&session->discovery_parent_type,
3292					      buf);
3293	case ISCSI_PARAM_DISCOVERY_SESS:
3294		sscanf(buf, "%d", &val);
3295		session->discovery_sess = !!val;
3296		break;
3297	case ISCSI_PARAM_LOCAL_IPADDR:
3298		return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3299	default:
3300		return -ENOSYS;
3301	}
3302
3303	return 0;
3304}
3305EXPORT_SYMBOL_GPL(iscsi_set_param);
3306
3307int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3308			    enum iscsi_param param, char *buf)
3309{
3310	struct iscsi_session *session = cls_session->dd_data;
3311	int len;
3312
3313	switch(param) {
3314	case ISCSI_PARAM_FAST_ABORT:
3315		len = sprintf(buf, "%d\n", session->fast_abort);
3316		break;
3317	case ISCSI_PARAM_ABORT_TMO:
3318		len = sprintf(buf, "%d\n", session->abort_timeout);
3319		break;
3320	case ISCSI_PARAM_LU_RESET_TMO:
3321		len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3322		break;
3323	case ISCSI_PARAM_TGT_RESET_TMO:
3324		len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3325		break;
3326	case ISCSI_PARAM_INITIAL_R2T_EN:
3327		len = sprintf(buf, "%d\n", session->initial_r2t_en);
3328		break;
3329	case ISCSI_PARAM_MAX_R2T:
3330		len = sprintf(buf, "%hu\n", session->max_r2t);
3331		break;
3332	case ISCSI_PARAM_IMM_DATA_EN:
3333		len = sprintf(buf, "%d\n", session->imm_data_en);
3334		break;
3335	case ISCSI_PARAM_FIRST_BURST:
3336		len = sprintf(buf, "%u\n", session->first_burst);
3337		break;
3338	case ISCSI_PARAM_MAX_BURST:
3339		len = sprintf(buf, "%u\n", session->max_burst);
3340		break;
3341	case ISCSI_PARAM_PDU_INORDER_EN:
3342		len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3343		break;
3344	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3345		len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3346		break;
3347	case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3348		len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3349		break;
3350	case ISCSI_PARAM_ERL:
3351		len = sprintf(buf, "%d\n", session->erl);
3352		break;
3353	case ISCSI_PARAM_TARGET_NAME:
3354		len = sprintf(buf, "%s\n", session->targetname);
3355		break;
3356	case ISCSI_PARAM_TARGET_ALIAS:
3357		len = sprintf(buf, "%s\n", session->targetalias);
3358		break;
3359	case ISCSI_PARAM_TPGT:
3360		len = sprintf(buf, "%d\n", session->tpgt);
3361		break;
3362	case ISCSI_PARAM_USERNAME:
3363		len = sprintf(buf, "%s\n", session->username);
3364		break;
3365	case ISCSI_PARAM_USERNAME_IN:
3366		len = sprintf(buf, "%s\n", session->username_in);
3367		break;
3368	case ISCSI_PARAM_PASSWORD:
3369		len = sprintf(buf, "%s\n", session->password);
3370		break;
3371	case ISCSI_PARAM_PASSWORD_IN:
3372		len = sprintf(buf, "%s\n", session->password_in);
3373		break;
3374	case ISCSI_PARAM_IFACE_NAME:
3375		len = sprintf(buf, "%s\n", session->ifacename);
3376		break;
3377	case ISCSI_PARAM_INITIATOR_NAME:
3378		len = sprintf(buf, "%s\n", session->initiatorname);
3379		break;
3380	case ISCSI_PARAM_BOOT_ROOT:
3381		len = sprintf(buf, "%s\n", session->boot_root);
3382		break;
3383	case ISCSI_PARAM_BOOT_NIC:
3384		len = sprintf(buf, "%s\n", session->boot_nic);
3385		break;
3386	case ISCSI_PARAM_BOOT_TARGET:
3387		len = sprintf(buf, "%s\n", session->boot_target);
3388		break;
3389	case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3390		len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3391		break;
3392	case ISCSI_PARAM_DISCOVERY_SESS:
3393		len = sprintf(buf, "%u\n", session->discovery_sess);
3394		break;
3395	case ISCSI_PARAM_PORTAL_TYPE:
3396		len = sprintf(buf, "%s\n", session->portal_type);
3397		break;
3398	case ISCSI_PARAM_CHAP_AUTH_EN:
3399		len = sprintf(buf, "%u\n", session->chap_auth_en);
3400		break;
3401	case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3402		len = sprintf(buf, "%u\n", session->discovery_logout_en);
3403		break;
3404	case ISCSI_PARAM_BIDI_CHAP_EN:
3405		len = sprintf(buf, "%u\n", session->bidi_chap_en);
3406		break;
3407	case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3408		len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3409		break;
3410	case ISCSI_PARAM_DEF_TIME2WAIT:
3411		len = sprintf(buf, "%d\n", session->time2wait);
3412		break;
3413	case ISCSI_PARAM_DEF_TIME2RETAIN:
3414		len = sprintf(buf, "%d\n", session->time2retain);
3415		break;
3416	case ISCSI_PARAM_TSID:
3417		len = sprintf(buf, "%u\n", session->tsid);
3418		break;
3419	case ISCSI_PARAM_ISID:
3420		len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3421			      session->isid[0], session->isid[1],
3422			      session->isid[2], session->isid[3],
3423			      session->isid[4], session->isid[5]);
3424		break;
3425	case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3426		len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3427		break;
3428	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3429		if (session->discovery_parent_type)
3430			len = sprintf(buf, "%s\n",
3431				      session->discovery_parent_type);
3432		else
3433			len = sprintf(buf, "\n");
3434		break;
3435	default:
3436		return -ENOSYS;
3437	}
3438
3439	return len;
3440}
3441EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3442
3443int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3444			      enum iscsi_param param, char *buf)
3445{
3446	struct sockaddr_in6 *sin6 = NULL;
3447	struct sockaddr_in *sin = NULL;
3448	int len;
3449
3450	switch (addr->ss_family) {
3451	case AF_INET:
3452		sin = (struct sockaddr_in *)addr;
3453		break;
3454	case AF_INET6:
3455		sin6 = (struct sockaddr_in6 *)addr;
3456		break;
3457	default:
3458		return -EINVAL;
3459	}
3460
3461	switch (param) {
3462	case ISCSI_PARAM_CONN_ADDRESS:
3463	case ISCSI_HOST_PARAM_IPADDRESS:
3464		if (sin)
3465			len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3466		else
3467			len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3468		break;
3469	case ISCSI_PARAM_CONN_PORT:
3470	case ISCSI_PARAM_LOCAL_PORT:
3471		if (sin)
3472			len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3473		else
3474			len = sprintf(buf, "%hu\n",
3475				      be16_to_cpu(sin6->sin6_port));
3476		break;
3477	default:
3478		return -EINVAL;
3479	}
3480
3481	return len;
3482}
3483EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3484
3485int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3486			 enum iscsi_param param, char *buf)
3487{
3488	struct iscsi_conn *conn = cls_conn->dd_data;
3489	int len;
3490
3491	switch(param) {
3492	case ISCSI_PARAM_PING_TMO:
3493		len = sprintf(buf, "%u\n", conn->ping_timeout);
3494		break;
3495	case ISCSI_PARAM_RECV_TMO:
3496		len = sprintf(buf, "%u\n", conn->recv_timeout);
3497		break;
3498	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3499		len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3500		break;
3501	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3502		len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3503		break;
3504	case ISCSI_PARAM_HDRDGST_EN:
3505		len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3506		break;
3507	case ISCSI_PARAM_DATADGST_EN:
3508		len = sprintf(buf, "%d\n", conn->datadgst_en);
3509		break;
3510	case ISCSI_PARAM_IFMARKER_EN:
3511		len = sprintf(buf, "%d\n", conn->ifmarker_en);
3512		break;
3513	case ISCSI_PARAM_OFMARKER_EN:
3514		len = sprintf(buf, "%d\n", conn->ofmarker_en);
3515		break;
3516	case ISCSI_PARAM_EXP_STATSN:
3517		len = sprintf(buf, "%u\n", conn->exp_statsn);
3518		break;
3519	case ISCSI_PARAM_PERSISTENT_PORT:
3520		len = sprintf(buf, "%d\n", conn->persistent_port);
3521		break;
3522	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3523		len = sprintf(buf, "%s\n", conn->persistent_address);
3524		break;
3525	case ISCSI_PARAM_STATSN:
3526		len = sprintf(buf, "%u\n", conn->statsn);
3527		break;
3528	case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3529		len = sprintf(buf, "%u\n", conn->max_segment_size);
3530		break;
3531	case ISCSI_PARAM_KEEPALIVE_TMO:
3532		len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3533		break;
3534	case ISCSI_PARAM_LOCAL_PORT:
3535		len = sprintf(buf, "%u\n", conn->local_port);
3536		break;
3537	case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3538		len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3539		break;
3540	case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3541		len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3542		break;
3543	case ISCSI_PARAM_TCP_WSF_DISABLE:
3544		len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3545		break;
3546	case ISCSI_PARAM_TCP_TIMER_SCALE:
3547		len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3548		break;
3549	case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3550		len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3551		break;
3552	case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3553		len = sprintf(buf, "%u\n", conn->fragment_disable);
3554		break;
3555	case ISCSI_PARAM_IPV4_TOS:
3556		len = sprintf(buf, "%u\n", conn->ipv4_tos);
3557		break;
3558	case ISCSI_PARAM_IPV6_TC:
3559		len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3560		break;
3561	case ISCSI_PARAM_IPV6_FLOW_LABEL:
3562		len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3563		break;
3564	case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3565		len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3566		break;
3567	case ISCSI_PARAM_TCP_XMIT_WSF:
3568		len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3569		break;
3570	case ISCSI_PARAM_TCP_RECV_WSF:
3571		len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3572		break;
3573	case ISCSI_PARAM_LOCAL_IPADDR:
3574		len = sprintf(buf, "%s\n", conn->local_ipaddr);
3575		break;
3576	default:
3577		return -ENOSYS;
3578	}
3579
3580	return len;
3581}
3582EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3583
3584int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3585			 char *buf)
3586{
3587	struct iscsi_host *ihost = shost_priv(shost);
3588	int len;
3589
3590	switch (param) {
3591	case ISCSI_HOST_PARAM_NETDEV_NAME:
3592		len = sprintf(buf, "%s\n", ihost->netdev);
3593		break;
3594	case ISCSI_HOST_PARAM_HWADDRESS:
3595		len = sprintf(buf, "%s\n", ihost->hwaddress);
3596		break;
3597	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3598		len = sprintf(buf, "%s\n", ihost->initiatorname);
3599		break;
3600	default:
3601		return -ENOSYS;
3602	}
3603
3604	return len;
3605}
3606EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3607
3608int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3609			 char *buf, int buflen)
3610{
3611	struct iscsi_host *ihost = shost_priv(shost);
3612
3613	switch (param) {
3614	case ISCSI_HOST_PARAM_NETDEV_NAME:
3615		return iscsi_switch_str_param(&ihost->netdev, buf);
3616	case ISCSI_HOST_PARAM_HWADDRESS:
3617		return iscsi_switch_str_param(&ihost->hwaddress, buf);
3618	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3619		return iscsi_switch_str_param(&ihost->initiatorname, buf);
3620	default:
3621		return -ENOSYS;
3622	}
3623
3624	return 0;
3625}
3626EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3627
3628MODULE_AUTHOR("Mike Christie");
3629MODULE_DESCRIPTION("iSCSI library functions");
3630MODULE_LICENSE("GPL");