xref: /openbmc/linux/drivers/scsi/libiscsi.c (revision c21b37f6)
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 <asm/unaligned.h>
28 #include <net/tcp.h>
29 #include <scsi/scsi_cmnd.h>
30 #include <scsi/scsi_device.h>
31 #include <scsi/scsi_eh.h>
32 #include <scsi/scsi_tcq.h>
33 #include <scsi/scsi_host.h>
34 #include <scsi/scsi.h>
35 #include <scsi/iscsi_proto.h>
36 #include <scsi/scsi_transport.h>
37 #include <scsi/scsi_transport_iscsi.h>
38 #include <scsi/libiscsi.h>
39 
40 struct iscsi_session *
41 class_to_transport_session(struct iscsi_cls_session *cls_session)
42 {
43 	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
44 	return iscsi_hostdata(shost->hostdata);
45 }
46 EXPORT_SYMBOL_GPL(class_to_transport_session);
47 
48 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
49 #define SNA32_CHECK 2147483648UL
50 
51 static int iscsi_sna_lt(u32 n1, u32 n2)
52 {
53 	return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
54 			    (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
55 }
56 
57 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
58 static int iscsi_sna_lte(u32 n1, u32 n2)
59 {
60 	return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
61 			    (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
62 }
63 
64 void
65 iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
66 {
67 	uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
68 	uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
69 
70 	/*
71 	 * standard specifies this check for when to update expected and
72 	 * max sequence numbers
73 	 */
74 	if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
75 		return;
76 
77 	if (exp_cmdsn != session->exp_cmdsn &&
78 	    !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
79 		session->exp_cmdsn = exp_cmdsn;
80 
81 	if (max_cmdsn != session->max_cmdsn &&
82 	    !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
83 		session->max_cmdsn = max_cmdsn;
84 		/*
85 		 * if the window closed with IO queued, then kick the
86 		 * xmit thread
87 		 */
88 		if (!list_empty(&session->leadconn->xmitqueue) ||
89 		    __kfifo_len(session->leadconn->mgmtqueue))
90 			scsi_queue_work(session->host,
91 					&session->leadconn->xmitwork);
92 	}
93 }
94 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
95 
96 void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *ctask,
97 				   struct iscsi_data *hdr)
98 {
99 	struct iscsi_conn *conn = ctask->conn;
100 
101 	memset(hdr, 0, sizeof(struct iscsi_data));
102 	hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
103 	hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
104 	ctask->unsol_datasn++;
105 	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
106 	memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
107 
108 	hdr->itt = ctask->hdr->itt;
109 	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
110 	hdr->offset = cpu_to_be32(ctask->unsol_offset);
111 
112 	if (ctask->unsol_count > conn->max_xmit_dlength) {
113 		hton24(hdr->dlength, conn->max_xmit_dlength);
114 		ctask->data_count = conn->max_xmit_dlength;
115 		ctask->unsol_offset += ctask->data_count;
116 		hdr->flags = 0;
117 	} else {
118 		hton24(hdr->dlength, ctask->unsol_count);
119 		ctask->data_count = ctask->unsol_count;
120 		hdr->flags = ISCSI_FLAG_CMD_FINAL;
121 	}
122 }
123 EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);
124 
125 /**
126  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
127  * @ctask: iscsi cmd task
128  *
129  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
130  * fields like dlength or final based on how much data it sends
131  */
132 static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
133 {
134 	struct iscsi_conn *conn = ctask->conn;
135 	struct iscsi_session *session = conn->session;
136 	struct iscsi_cmd *hdr = ctask->hdr;
137 	struct scsi_cmnd *sc = ctask->sc;
138 
139         hdr->opcode = ISCSI_OP_SCSI_CMD;
140         hdr->flags = ISCSI_ATTR_SIMPLE;
141         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
142         hdr->itt = build_itt(ctask->itt, conn->id, session->age);
143         hdr->data_length = cpu_to_be32(scsi_bufflen(sc));
144         hdr->cmdsn = cpu_to_be32(session->cmdsn);
145         session->cmdsn++;
146         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
147         memcpy(hdr->cdb, sc->cmnd, sc->cmd_len);
148 	if (sc->cmd_len < MAX_COMMAND_SIZE)
149 		memset(&hdr->cdb[sc->cmd_len], 0,
150 			MAX_COMMAND_SIZE - sc->cmd_len);
151 
152 	ctask->data_count = 0;
153 	ctask->imm_count = 0;
154 	if (sc->sc_data_direction == DMA_TO_DEVICE) {
155 		hdr->flags |= ISCSI_FLAG_CMD_WRITE;
156 		/*
157 		 * Write counters:
158 		 *
159 		 *	imm_count	bytes to be sent right after
160 		 *			SCSI PDU Header
161 		 *
162 		 *	unsol_count	bytes(as Data-Out) to be sent
163 		 *			without	R2T ack right after
164 		 *			immediate data
165 		 *
166 		 *	r2t_data_count	bytes to be sent via R2T ack's
167 		 *
168 		 *      pad_count       bytes to be sent as zero-padding
169 		 */
170 		ctask->unsol_count = 0;
171 		ctask->unsol_offset = 0;
172 		ctask->unsol_datasn = 0;
173 
174 		if (session->imm_data_en) {
175 			if (scsi_bufflen(sc) >= session->first_burst)
176 				ctask->imm_count = min(session->first_burst,
177 							conn->max_xmit_dlength);
178 			else
179 				ctask->imm_count = min(scsi_bufflen(sc),
180 							conn->max_xmit_dlength);
181 			hton24(ctask->hdr->dlength, ctask->imm_count);
182 		} else
183 			zero_data(ctask->hdr->dlength);
184 
185 		if (!session->initial_r2t_en) {
186 			ctask->unsol_count = min((session->first_burst),
187 				(scsi_bufflen(sc))) - ctask->imm_count;
188 			ctask->unsol_offset = ctask->imm_count;
189 		}
190 
191 		if (!ctask->unsol_count)
192 			/* No unsolicit Data-Out's */
193 			ctask->hdr->flags |= ISCSI_FLAG_CMD_FINAL;
194 	} else {
195 		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
196 		zero_data(hdr->dlength);
197 
198 		if (sc->sc_data_direction == DMA_FROM_DEVICE)
199 			hdr->flags |= ISCSI_FLAG_CMD_READ;
200 	}
201 
202 	conn->scsicmd_pdus_cnt++;
203 
204         debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x len %d "
205 		"cmdsn %d win %d]\n",
206                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
207 		conn->id, sc, sc->cmnd[0], ctask->itt, scsi_bufflen(sc),
208                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
209 }
210 
211 /**
212  * iscsi_complete_command - return command back to scsi-ml
213  * @ctask: iscsi cmd task
214  *
215  * Must be called with session lock.
216  * This function returns the scsi command to scsi-ml and returns
217  * the cmd task to the pool of available cmd tasks.
218  */
219 static void iscsi_complete_command(struct iscsi_cmd_task *ctask)
220 {
221 	struct iscsi_session *session = ctask->conn->session;
222 	struct scsi_cmnd *sc = ctask->sc;
223 
224 	ctask->state = ISCSI_TASK_COMPLETED;
225 	ctask->sc = NULL;
226 	/* SCSI eh reuses commands to verify us */
227 	sc->SCp.ptr = NULL;
228 	list_del_init(&ctask->running);
229 	__kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
230 	sc->scsi_done(sc);
231 }
232 
233 static void __iscsi_get_ctask(struct iscsi_cmd_task *ctask)
234 {
235 	atomic_inc(&ctask->refcount);
236 }
237 
238 static void __iscsi_put_ctask(struct iscsi_cmd_task *ctask)
239 {
240 	if (atomic_dec_and_test(&ctask->refcount))
241 		iscsi_complete_command(ctask);
242 }
243 
244 /**
245  * iscsi_cmd_rsp - SCSI Command Response processing
246  * @conn: iscsi connection
247  * @hdr: iscsi header
248  * @ctask: scsi command task
249  * @data: cmd data buffer
250  * @datalen: len of buffer
251  *
252  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
253  * then completes the command and task.
254  **/
255 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
256 			       struct iscsi_cmd_task *ctask, char *data,
257 			       int datalen)
258 {
259 	struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
260 	struct iscsi_session *session = conn->session;
261 	struct scsi_cmnd *sc = ctask->sc;
262 
263 	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
264 	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
265 
266 	sc->result = (DID_OK << 16) | rhdr->cmd_status;
267 
268 	if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
269 		sc->result = DID_ERROR << 16;
270 		goto out;
271 	}
272 
273 	if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
274 		uint16_t senselen;
275 
276 		if (datalen < 2) {
277 invalid_datalen:
278 			printk(KERN_ERR "iscsi: Got CHECK_CONDITION but "
279 			       "invalid data buffer size of %d\n", datalen);
280 			sc->result = DID_BAD_TARGET << 16;
281 			goto out;
282 		}
283 
284 		senselen = be16_to_cpu(get_unaligned((__be16 *) data));
285 		if (datalen < senselen)
286 			goto invalid_datalen;
287 
288 		memcpy(sc->sense_buffer, data + 2,
289 		       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
290 		debug_scsi("copied %d bytes of sense\n",
291 			   min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
292 	}
293 
294 	if (sc->sc_data_direction == DMA_TO_DEVICE)
295 		goto out;
296 
297 	if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
298 		int res_count = be32_to_cpu(rhdr->residual_count);
299 
300 		if (res_count > 0 && res_count <= scsi_bufflen(sc))
301 			scsi_set_resid(sc, res_count);
302 		else
303 			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
304 	} else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
305 		sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
306 	else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
307 		scsi_set_resid(sc, be32_to_cpu(rhdr->residual_count));
308 
309 out:
310 	debug_scsi("done [sc %lx res %d itt 0x%x]\n",
311 		   (long)sc, sc->result, ctask->itt);
312 	conn->scsirsp_pdus_cnt++;
313 
314 	__iscsi_put_ctask(ctask);
315 }
316 
317 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
318 {
319 	struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
320 
321 	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
322 	conn->tmfrsp_pdus_cnt++;
323 
324 	if (conn->tmabort_state != TMABORT_INITIAL)
325 		return;
326 
327 	if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
328 		conn->tmabort_state = TMABORT_SUCCESS;
329 	else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
330 		conn->tmabort_state = TMABORT_NOT_FOUND;
331 	else
332 		conn->tmabort_state = TMABORT_FAILED;
333 	wake_up(&conn->ehwait);
334 }
335 
336 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
337 			       char *data, int datalen)
338 {
339 	struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
340 	struct iscsi_hdr rejected_pdu;
341 	uint32_t itt;
342 
343 	conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
344 
345 	if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
346 		if (ntoh24(reject->dlength) > datalen)
347 			return ISCSI_ERR_PROTO;
348 
349 		if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
350 			memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
351 			itt = get_itt(rejected_pdu.itt);
352 			printk(KERN_ERR "itt 0x%x had pdu (op 0x%x) rejected "
353 				"due to DataDigest error.\n", itt,
354 				rejected_pdu.opcode);
355 		}
356 	}
357 	return 0;
358 }
359 
360 /**
361  * __iscsi_complete_pdu - complete pdu
362  * @conn: iscsi conn
363  * @hdr: iscsi header
364  * @data: data buffer
365  * @datalen: len of data buffer
366  *
367  * Completes pdu processing by freeing any resources allocated at
368  * queuecommand or send generic. session lock must be held and verify
369  * itt must have been called.
370  */
371 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
372 			 char *data, int datalen)
373 {
374 	struct iscsi_session *session = conn->session;
375 	int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
376 	struct iscsi_cmd_task *ctask;
377 	struct iscsi_mgmt_task *mtask;
378 	uint32_t itt;
379 
380 	if (hdr->itt != RESERVED_ITT)
381 		itt = get_itt(hdr->itt);
382 	else
383 		itt = ~0U;
384 
385 	if (itt < session->cmds_max) {
386 		ctask = session->cmds[itt];
387 
388 		debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n",
389 			   opcode, conn->id, ctask->itt, datalen);
390 
391 		switch(opcode) {
392 		case ISCSI_OP_SCSI_CMD_RSP:
393 			BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
394 			iscsi_scsi_cmd_rsp(conn, hdr, ctask, data,
395 					   datalen);
396 			break;
397 		case ISCSI_OP_SCSI_DATA_IN:
398 			BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
399 			if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
400 				conn->scsirsp_pdus_cnt++;
401 				__iscsi_put_ctask(ctask);
402 			}
403 			break;
404 		case ISCSI_OP_R2T:
405 			/* LLD handles this for now */
406 			break;
407 		default:
408 			rc = ISCSI_ERR_BAD_OPCODE;
409 			break;
410 		}
411 	} else if (itt >= ISCSI_MGMT_ITT_OFFSET &&
412 		   itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) {
413 		mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET];
414 
415 		debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
416 			   opcode, conn->id, mtask->itt, datalen);
417 
418 		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
419 		switch(opcode) {
420 		case ISCSI_OP_LOGOUT_RSP:
421 			if (datalen) {
422 				rc = ISCSI_ERR_PROTO;
423 				break;
424 			}
425 			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
426 			/* fall through */
427 		case ISCSI_OP_LOGIN_RSP:
428 		case ISCSI_OP_TEXT_RSP:
429 			/*
430 			 * login related PDU's exp_statsn is handled in
431 			 * userspace
432 			 */
433 			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
434 				rc = ISCSI_ERR_CONN_FAILED;
435 			list_del(&mtask->running);
436 			if (conn->login_mtask != mtask)
437 				__kfifo_put(session->mgmtpool.queue,
438 					    (void*)&mtask, sizeof(void*));
439 			break;
440 		case ISCSI_OP_SCSI_TMFUNC_RSP:
441 			if (datalen) {
442 				rc = ISCSI_ERR_PROTO;
443 				break;
444 			}
445 
446 			iscsi_tmf_rsp(conn, hdr);
447 			break;
448 		case ISCSI_OP_NOOP_IN:
449 			if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
450 				rc = ISCSI_ERR_PROTO;
451 				break;
452 			}
453 			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
454 
455 			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
456 				rc = ISCSI_ERR_CONN_FAILED;
457 			list_del(&mtask->running);
458 			if (conn->login_mtask != mtask)
459 				__kfifo_put(session->mgmtpool.queue,
460 					    (void*)&mtask, sizeof(void*));
461 			break;
462 		default:
463 			rc = ISCSI_ERR_BAD_OPCODE;
464 			break;
465 		}
466 	} else if (itt == ~0U) {
467 		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
468 
469 		switch(opcode) {
470 		case ISCSI_OP_NOOP_IN:
471 			if (datalen) {
472 				rc = ISCSI_ERR_PROTO;
473 				break;
474 			}
475 
476 			if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
477 				break;
478 
479 			if (iscsi_recv_pdu(conn->cls_conn, hdr, NULL, 0))
480 				rc = ISCSI_ERR_CONN_FAILED;
481 			break;
482 		case ISCSI_OP_REJECT:
483 			rc = iscsi_handle_reject(conn, hdr, data, datalen);
484 			break;
485 		case ISCSI_OP_ASYNC_EVENT:
486 			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
487 			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
488 				rc = ISCSI_ERR_CONN_FAILED;
489 			break;
490 		default:
491 			rc = ISCSI_ERR_BAD_OPCODE;
492 			break;
493 		}
494 	} else
495 		rc = ISCSI_ERR_BAD_ITT;
496 
497 	return rc;
498 }
499 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
500 
501 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
502 		       char *data, int datalen)
503 {
504 	int rc;
505 
506 	spin_lock(&conn->session->lock);
507 	rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
508 	spin_unlock(&conn->session->lock);
509 	return rc;
510 }
511 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
512 
513 /* verify itt (itt encoding: age+cid+itt) */
514 int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
515 		     uint32_t *ret_itt)
516 {
517 	struct iscsi_session *session = conn->session;
518 	struct iscsi_cmd_task *ctask;
519 	uint32_t itt;
520 
521 	if (hdr->itt != RESERVED_ITT) {
522 		if (((__force u32)hdr->itt & ISCSI_AGE_MASK) !=
523 		    (session->age << ISCSI_AGE_SHIFT)) {
524 			printk(KERN_ERR "iscsi: received itt %x expected "
525 				"session age (%x)\n", (__force u32)hdr->itt,
526 				session->age & ISCSI_AGE_MASK);
527 			return ISCSI_ERR_BAD_ITT;
528 		}
529 
530 		if (((__force u32)hdr->itt & ISCSI_CID_MASK) !=
531 		    (conn->id << ISCSI_CID_SHIFT)) {
532 			printk(KERN_ERR "iscsi: received itt %x, expected "
533 				"CID (%x)\n", (__force u32)hdr->itt, conn->id);
534 			return ISCSI_ERR_BAD_ITT;
535 		}
536 		itt = get_itt(hdr->itt);
537 	} else
538 		itt = ~0U;
539 
540 	if (itt < session->cmds_max) {
541 		ctask = session->cmds[itt];
542 
543 		if (!ctask->sc) {
544 			printk(KERN_INFO "iscsi: dropping ctask with "
545 			       "itt 0x%x\n", ctask->itt);
546 			/* force drop */
547 			return ISCSI_ERR_NO_SCSI_CMD;
548 		}
549 
550 		if (ctask->sc->SCp.phase != session->age) {
551 			printk(KERN_ERR "iscsi: ctask's session age %d, "
552 				"expected %d\n", ctask->sc->SCp.phase,
553 				session->age);
554 			return ISCSI_ERR_SESSION_FAILED;
555 		}
556 	}
557 
558 	*ret_itt = itt;
559 	return 0;
560 }
561 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
562 
563 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
564 {
565 	struct iscsi_session *session = conn->session;
566 	unsigned long flags;
567 
568 	spin_lock_irqsave(&session->lock, flags);
569 	if (session->state == ISCSI_STATE_FAILED) {
570 		spin_unlock_irqrestore(&session->lock, flags);
571 		return;
572 	}
573 
574 	if (conn->stop_stage == 0)
575 		session->state = ISCSI_STATE_FAILED;
576 	spin_unlock_irqrestore(&session->lock, flags);
577 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
578 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
579 	iscsi_conn_error(conn->cls_conn, err);
580 }
581 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
582 
583 static void iscsi_prep_mtask(struct iscsi_conn *conn,
584 			     struct iscsi_mgmt_task *mtask)
585 {
586 	struct iscsi_session *session = conn->session;
587 	struct iscsi_hdr *hdr = mtask->hdr;
588 	struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
589 
590 	if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
591 	    hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
592 		nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
593 	/*
594 	 * pre-format CmdSN for outgoing PDU.
595 	 */
596 	nop->cmdsn = cpu_to_be32(session->cmdsn);
597 	if (hdr->itt != RESERVED_ITT) {
598 		hdr->itt = build_itt(mtask->itt, conn->id, session->age);
599 		/*
600 		 * TODO: We always use immediate, so we never hit this.
601 		 * If we start to send tmfs or nops as non-immediate then
602 		 * we should start checking the cmdsn numbers for mgmt tasks.
603 		 */
604 		if (conn->c_stage == ISCSI_CONN_STARTED &&
605 		    !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
606 			session->queued_cmdsn++;
607 			session->cmdsn++;
608 		}
609 	}
610 
611 	if (session->tt->init_mgmt_task)
612 		session->tt->init_mgmt_task(conn, mtask);
613 
614 	debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
615 		   hdr->opcode, hdr->itt, mtask->data_count);
616 }
617 
618 static int iscsi_xmit_mtask(struct iscsi_conn *conn)
619 {
620 	struct iscsi_hdr *hdr = conn->mtask->hdr;
621 	int rc, was_logout = 0;
622 
623 	spin_unlock_bh(&conn->session->lock);
624 	if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT) {
625 		conn->session->state = ISCSI_STATE_IN_RECOVERY;
626 		iscsi_block_session(session_to_cls(conn->session));
627 		was_logout = 1;
628 	}
629 	rc = conn->session->tt->xmit_mgmt_task(conn, conn->mtask);
630 	spin_lock_bh(&conn->session->lock);
631 	if (rc)
632 		return rc;
633 
634 	/* done with this in-progress mtask */
635 	conn->mtask = NULL;
636 
637 	if (was_logout) {
638 		set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
639 		return -ENODATA;
640 	}
641 	return 0;
642 }
643 
644 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
645 {
646 	struct iscsi_session *session = conn->session;
647 
648 	/*
649 	 * Check for iSCSI window and take care of CmdSN wrap-around
650 	 */
651 	if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
652 		debug_scsi("iSCSI CmdSN closed. ExpCmdSn %u MaxCmdSN %u "
653 			   "CmdSN %u/%u\n", session->exp_cmdsn,
654 			   session->max_cmdsn, session->cmdsn,
655 			   session->queued_cmdsn);
656 		return -ENOSPC;
657 	}
658 	return 0;
659 }
660 
661 static int iscsi_xmit_ctask(struct iscsi_conn *conn)
662 {
663 	struct iscsi_cmd_task *ctask = conn->ctask;
664 	int rc = 0;
665 
666 	/*
667 	 * serialize with TMF AbortTask
668 	 */
669 	if (ctask->state == ISCSI_TASK_ABORTING)
670 		goto done;
671 
672 	__iscsi_get_ctask(ctask);
673 	spin_unlock_bh(&conn->session->lock);
674 	rc = conn->session->tt->xmit_cmd_task(conn, ctask);
675 	spin_lock_bh(&conn->session->lock);
676 	__iscsi_put_ctask(ctask);
677 
678 done:
679 	if (!rc)
680 		/* done with this ctask */
681 		conn->ctask = NULL;
682 	return rc;
683 }
684 
685 /**
686  * iscsi_data_xmit - xmit any command into the scheduled connection
687  * @conn: iscsi connection
688  *
689  * Notes:
690  *	The function can return -EAGAIN in which case the caller must
691  *	re-schedule it again later or recover. '0' return code means
692  *	successful xmit.
693  **/
694 static int iscsi_data_xmit(struct iscsi_conn *conn)
695 {
696 	int rc = 0;
697 
698 	spin_lock_bh(&conn->session->lock);
699 	if (unlikely(conn->suspend_tx)) {
700 		debug_scsi("conn %d Tx suspended!\n", conn->id);
701 		spin_unlock_bh(&conn->session->lock);
702 		return -ENODATA;
703 	}
704 
705 	if (conn->ctask) {
706 		rc = iscsi_xmit_ctask(conn);
707 		if (rc)
708 			goto again;
709 	}
710 
711 	if (conn->mtask) {
712 		rc = iscsi_xmit_mtask(conn);
713 	        if (rc)
714 		        goto again;
715 	}
716 
717 	/*
718 	 * process mgmt pdus like nops before commands since we should
719 	 * only have one nop-out as a ping from us and targets should not
720 	 * overflow us with nop-ins
721 	 */
722 check_mgmt:
723 	while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
724 			   sizeof(void*))) {
725 		iscsi_prep_mtask(conn, conn->mtask);
726 		list_add_tail(&conn->mtask->running, &conn->mgmt_run_list);
727 		rc = iscsi_xmit_mtask(conn);
728 		if (rc)
729 			goto again;
730 	}
731 
732 	/* process command queue */
733 	while (!list_empty(&conn->xmitqueue)) {
734 		/*
735 		 * iscsi tcp may readd the task to the xmitqueue to send
736 		 * write data
737 		 */
738 		conn->ctask = list_entry(conn->xmitqueue.next,
739 					 struct iscsi_cmd_task, running);
740 		if (conn->ctask->state == ISCSI_TASK_PENDING) {
741 			iscsi_prep_scsi_cmd_pdu(conn->ctask);
742 			conn->session->tt->init_cmd_task(conn->ctask);
743 		}
744 		conn->ctask->state = ISCSI_TASK_RUNNING;
745 		list_move_tail(conn->xmitqueue.next, &conn->run_list);
746 		rc = iscsi_xmit_ctask(conn);
747 		if (rc)
748 			goto again;
749 		/*
750 		 * we could continuously get new ctask requests so
751 		 * we need to check the mgmt queue for nops that need to
752 		 * be sent to aviod starvation
753 		 */
754 		if (__kfifo_len(conn->mgmtqueue))
755 			goto check_mgmt;
756 	}
757 	spin_unlock_bh(&conn->session->lock);
758 	return -ENODATA;
759 
760 again:
761 	if (unlikely(conn->suspend_tx))
762 		rc = -ENODATA;
763 	spin_unlock_bh(&conn->session->lock);
764 	return rc;
765 }
766 
767 static void iscsi_xmitworker(struct work_struct *work)
768 {
769 	struct iscsi_conn *conn =
770 		container_of(work, struct iscsi_conn, xmitwork);
771 	int rc;
772 	/*
773 	 * serialize Xmit worker on a per-connection basis.
774 	 */
775 	do {
776 		rc = iscsi_data_xmit(conn);
777 	} while (rc >= 0 || rc == -EAGAIN);
778 }
779 
780 enum {
781 	FAILURE_BAD_HOST = 1,
782 	FAILURE_SESSION_FAILED,
783 	FAILURE_SESSION_FREED,
784 	FAILURE_WINDOW_CLOSED,
785 	FAILURE_OOM,
786 	FAILURE_SESSION_TERMINATE,
787 	FAILURE_SESSION_IN_RECOVERY,
788 	FAILURE_SESSION_RECOVERY_TIMEOUT,
789 };
790 
791 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
792 {
793 	struct Scsi_Host *host;
794 	int reason = 0;
795 	struct iscsi_session *session;
796 	struct iscsi_conn *conn;
797 	struct iscsi_cmd_task *ctask = NULL;
798 
799 	sc->scsi_done = done;
800 	sc->result = 0;
801 	sc->SCp.ptr = NULL;
802 
803 	host = sc->device->host;
804 	session = iscsi_hostdata(host->hostdata);
805 
806 	spin_lock(&session->lock);
807 
808 	/*
809 	 * ISCSI_STATE_FAILED is a temp. state. The recovery
810 	 * code will decide what is best to do with command queued
811 	 * during this time
812 	 */
813 	if (session->state != ISCSI_STATE_LOGGED_IN &&
814 	    session->state != ISCSI_STATE_FAILED) {
815 		/*
816 		 * to handle the race between when we set the recovery state
817 		 * and block the session we requeue here (commands could
818 		 * be entering our queuecommand while a block is starting
819 		 * up because the block code is not locked)
820 		 */
821 		if (session->state == ISCSI_STATE_IN_RECOVERY) {
822 			reason = FAILURE_SESSION_IN_RECOVERY;
823 			goto reject;
824 		}
825 
826 		if (session->state == ISCSI_STATE_RECOVERY_FAILED)
827 			reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
828 		else if (session->state == ISCSI_STATE_TERMINATE)
829 			reason = FAILURE_SESSION_TERMINATE;
830 		else
831 			reason = FAILURE_SESSION_FREED;
832 		goto fault;
833 	}
834 
835 	conn = session->leadconn;
836 	if (!conn) {
837 		reason = FAILURE_SESSION_FREED;
838 		goto fault;
839 	}
840 
841 	if (iscsi_check_cmdsn_window_closed(conn)) {
842 		reason = FAILURE_WINDOW_CLOSED;
843 		goto reject;
844 	}
845 
846 	if (!__kfifo_get(session->cmdpool.queue, (void*)&ctask,
847 			 sizeof(void*))) {
848 		reason = FAILURE_OOM;
849 		goto reject;
850 	}
851 	session->queued_cmdsn++;
852 
853 	sc->SCp.phase = session->age;
854 	sc->SCp.ptr = (char *)ctask;
855 
856 	atomic_set(&ctask->refcount, 1);
857 	ctask->state = ISCSI_TASK_PENDING;
858 	ctask->mtask = NULL;
859 	ctask->conn = conn;
860 	ctask->sc = sc;
861 	INIT_LIST_HEAD(&ctask->running);
862 
863 	list_add_tail(&ctask->running, &conn->xmitqueue);
864 	spin_unlock(&session->lock);
865 
866 	scsi_queue_work(host, &conn->xmitwork);
867 	return 0;
868 
869 reject:
870 	spin_unlock(&session->lock);
871 	debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
872 	return SCSI_MLQUEUE_HOST_BUSY;
873 
874 fault:
875 	spin_unlock(&session->lock);
876 	printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
877 	       sc->cmnd[0], reason);
878 	sc->result = (DID_NO_CONNECT << 16);
879 	scsi_set_resid(sc, scsi_bufflen(sc));
880 	sc->scsi_done(sc);
881 	return 0;
882 }
883 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
884 
885 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
886 {
887 	if (depth > ISCSI_MAX_CMD_PER_LUN)
888 		depth = ISCSI_MAX_CMD_PER_LUN;
889 	scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
890 	return sdev->queue_depth;
891 }
892 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
893 
894 static struct iscsi_mgmt_task *
895 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
896 		      char *data, uint32_t data_size)
897 {
898 	struct iscsi_session *session = conn->session;
899 	struct iscsi_mgmt_task *mtask;
900 
901 	if (session->state == ISCSI_STATE_TERMINATE)
902 		return NULL;
903 
904 	if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
905 	    hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
906 		/*
907 		 * Login and Text are sent serially, in
908 		 * request-followed-by-response sequence.
909 		 * Same mtask can be used. Same ITT must be used.
910 		 * Note that login_mtask is preallocated at conn_create().
911 		 */
912 		mtask = conn->login_mtask;
913 	else {
914 		BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
915 		BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
916 
917 		if (!__kfifo_get(session->mgmtpool.queue,
918 				 (void*)&mtask, sizeof(void*)))
919 			return NULL;
920 	}
921 
922 	if (data_size) {
923 		memcpy(mtask->data, data, data_size);
924 		mtask->data_count = data_size;
925 	} else
926 		mtask->data_count = 0;
927 
928 	INIT_LIST_HEAD(&mtask->running);
929 	memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
930 	__kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
931 	return mtask;
932 }
933 
934 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
935 			char *data, uint32_t data_size)
936 {
937 	struct iscsi_conn *conn = cls_conn->dd_data;
938 	struct iscsi_session *session = conn->session;
939 	int err = 0;
940 
941 	spin_lock_bh(&session->lock);
942 	if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
943 		err = -EPERM;
944 	spin_unlock_bh(&session->lock);
945 	scsi_queue_work(session->host, &conn->xmitwork);
946 	return err;
947 }
948 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
949 
950 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
951 {
952 	struct iscsi_session *session = class_to_transport_session(cls_session);
953 	struct iscsi_conn *conn = session->leadconn;
954 
955 	spin_lock_bh(&session->lock);
956 	if (session->state != ISCSI_STATE_LOGGED_IN) {
957 		session->state = ISCSI_STATE_RECOVERY_FAILED;
958 		if (conn)
959 			wake_up(&conn->ehwait);
960 	}
961 	spin_unlock_bh(&session->lock);
962 }
963 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
964 
965 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
966 {
967 	struct Scsi_Host *host = sc->device->host;
968 	struct iscsi_session *session = iscsi_hostdata(host->hostdata);
969 	struct iscsi_conn *conn = session->leadconn;
970 	int fail_session = 0;
971 
972 	spin_lock_bh(&session->lock);
973 	if (session->state == ISCSI_STATE_TERMINATE) {
974 failed:
975 		debug_scsi("failing host reset: session terminated "
976 			   "[CID %d age %d]\n", conn->id, session->age);
977 		spin_unlock_bh(&session->lock);
978 		return FAILED;
979 	}
980 
981 	if (sc->SCp.phase == session->age) {
982 		debug_scsi("failing connection CID %d due to SCSI host reset\n",
983 			   conn->id);
984 		fail_session = 1;
985 	}
986 	spin_unlock_bh(&session->lock);
987 
988 	/*
989 	 * we drop the lock here but the leadconn cannot be destoyed while
990 	 * we are in the scsi eh
991 	 */
992 	if (fail_session)
993 		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
994 
995 	debug_scsi("iscsi_eh_host_reset wait for relogin\n");
996 	wait_event_interruptible(conn->ehwait,
997 				 session->state == ISCSI_STATE_TERMINATE ||
998 				 session->state == ISCSI_STATE_LOGGED_IN ||
999 				 session->state == ISCSI_STATE_RECOVERY_FAILED);
1000 	if (signal_pending(current))
1001 		flush_signals(current);
1002 
1003 	spin_lock_bh(&session->lock);
1004 	if (session->state == ISCSI_STATE_LOGGED_IN)
1005 		printk(KERN_INFO "iscsi: host reset succeeded\n");
1006 	else
1007 		goto failed;
1008 	spin_unlock_bh(&session->lock);
1009 
1010 	return SUCCESS;
1011 }
1012 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
1013 
1014 static void iscsi_tmabort_timedout(unsigned long data)
1015 {
1016 	struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
1017 	struct iscsi_conn *conn = ctask->conn;
1018 	struct iscsi_session *session = conn->session;
1019 
1020 	spin_lock(&session->lock);
1021 	if (conn->tmabort_state == TMABORT_INITIAL) {
1022 		conn->tmabort_state = TMABORT_TIMEDOUT;
1023 		debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
1024 			ctask->sc, ctask->itt);
1025 		/* unblock eh_abort() */
1026 		wake_up(&conn->ehwait);
1027 	}
1028 	spin_unlock(&session->lock);
1029 }
1030 
1031 static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
1032 				 struct iscsi_cmd_task *ctask)
1033 {
1034 	struct iscsi_conn *conn = ctask->conn;
1035 	struct iscsi_session *session = conn->session;
1036 	struct iscsi_tm *hdr = &conn->tmhdr;
1037 
1038 	/*
1039 	 * ctask timed out but session is OK requests must be serialized.
1040 	 */
1041 	memset(hdr, 0, sizeof(struct iscsi_tm));
1042 	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1043 	hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
1044 	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1045 	memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1046 	hdr->rtt = ctask->hdr->itt;
1047 	hdr->refcmdsn = ctask->hdr->cmdsn;
1048 
1049 	ctask->mtask = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1050 					    NULL, 0);
1051 	if (!ctask->mtask) {
1052 		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1053 		debug_scsi("abort sent failure [itt 0x%x]\n", ctask->itt);
1054 		return -EPERM;
1055 	}
1056 	ctask->state = ISCSI_TASK_ABORTING;
1057 
1058 	debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
1059 
1060 	if (conn->tmabort_state == TMABORT_INITIAL) {
1061 		conn->tmfcmd_pdus_cnt++;
1062 		conn->tmabort_timer.expires = 20*HZ + jiffies;
1063 		conn->tmabort_timer.function = iscsi_tmabort_timedout;
1064 		conn->tmabort_timer.data = (unsigned long)ctask;
1065 		add_timer(&conn->tmabort_timer);
1066 		debug_scsi("abort set timeout [itt 0x%x]\n", ctask->itt);
1067 	}
1068 	spin_unlock_bh(&session->lock);
1069 	scsi_queue_work(session->host, &conn->xmitwork);
1070 
1071 	/*
1072 	 * block eh thread until:
1073 	 *
1074 	 * 1) abort response
1075 	 * 2) abort timeout
1076 	 * 3) session is terminated or restarted or userspace has
1077 	 * given up on recovery
1078 	 */
1079 	wait_event_interruptible(conn->ehwait,
1080 				 sc->SCp.phase != session->age ||
1081 				 session->state != ISCSI_STATE_LOGGED_IN ||
1082 				 conn->tmabort_state != TMABORT_INITIAL);
1083 	if (signal_pending(current))
1084 		flush_signals(current);
1085 	del_timer_sync(&conn->tmabort_timer);
1086 	spin_lock_bh(&session->lock);
1087 	return 0;
1088 }
1089 
1090 /*
1091  * session lock must be held
1092  */
1093 static struct iscsi_mgmt_task *
1094 iscsi_remove_mgmt_task(struct kfifo *fifo, uint32_t itt)
1095 {
1096 	int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*);
1097 	struct iscsi_mgmt_task *task;
1098 
1099 	debug_scsi("searching %d tasks\n", nr_tasks);
1100 
1101 	for (i = 0; i < nr_tasks; i++) {
1102 		__kfifo_get(fifo, (void*)&task, sizeof(void*));
1103 		debug_scsi("check task %u\n", task->itt);
1104 
1105 		if (task->itt == itt) {
1106 			debug_scsi("matched task\n");
1107 			return task;
1108 		}
1109 
1110 		__kfifo_put(fifo, (void*)&task, sizeof(void*));
1111 	}
1112 	return NULL;
1113 }
1114 
1115 static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
1116 {
1117 	struct iscsi_conn *conn = ctask->conn;
1118 	struct iscsi_session *session = conn->session;
1119 
1120 	if (!ctask->mtask)
1121 		return -EINVAL;
1122 
1123 	if (!iscsi_remove_mgmt_task(conn->mgmtqueue, ctask->mtask->itt))
1124 		list_del(&ctask->mtask->running);
1125 	__kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
1126 		    sizeof(void*));
1127 	ctask->mtask = NULL;
1128 	return 0;
1129 }
1130 
1131 /*
1132  * session lock must be held
1133  */
1134 static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1135 			 int err)
1136 {
1137 	struct scsi_cmnd *sc;
1138 
1139 	sc = ctask->sc;
1140 	if (!sc)
1141 		return;
1142 
1143 	if (ctask->state == ISCSI_TASK_PENDING)
1144 		/*
1145 		 * cmd never made it to the xmit thread, so we should not count
1146 		 * the cmd in the sequencing
1147 		 */
1148 		conn->session->queued_cmdsn--;
1149 	else
1150 		conn->session->tt->cleanup_cmd_task(conn, ctask);
1151 	iscsi_ctask_mtask_cleanup(ctask);
1152 
1153 	sc->result = err;
1154 	scsi_set_resid(sc, scsi_bufflen(sc));
1155 	if (conn->ctask == ctask)
1156 		conn->ctask = NULL;
1157 	/* release ref from queuecommand */
1158 	__iscsi_put_ctask(ctask);
1159 }
1160 
1161 int iscsi_eh_abort(struct scsi_cmnd *sc)
1162 {
1163 	struct iscsi_cmd_task *ctask;
1164 	struct iscsi_conn *conn;
1165 	struct iscsi_session *session;
1166 	int rc;
1167 
1168 	/*
1169 	 * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1170 	 * got the command.
1171 	 */
1172 	if (!sc->SCp.ptr) {
1173 		debug_scsi("sc never reached iscsi layer or it completed.\n");
1174 		return SUCCESS;
1175 	}
1176 
1177 	ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1178 	conn = ctask->conn;
1179 	session = conn->session;
1180 
1181 	conn->eh_abort_cnt++;
1182 	debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1183 
1184 	spin_lock_bh(&session->lock);
1185 
1186 	/*
1187 	 * If we are not logged in or we have started a new session
1188 	 * then let the host reset code handle this
1189 	 */
1190 	if (session->state != ISCSI_STATE_LOGGED_IN ||
1191 	    sc->SCp.phase != session->age)
1192 		goto failed;
1193 
1194 	/* ctask completed before time out */
1195 	if (!ctask->sc) {
1196 		debug_scsi("sc completed while abort in progress\n");
1197 		goto success;
1198 	}
1199 
1200 	/* what should we do here ? */
1201 	if (conn->ctask == ctask) {
1202 		printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. "
1203 		       "Failing abort\n", sc, ctask->itt);
1204 		goto failed;
1205 	}
1206 
1207 	if (ctask->state == ISCSI_TASK_PENDING) {
1208 		fail_command(conn, ctask, DID_ABORT << 16);
1209 		goto success;
1210 	}
1211 
1212 	conn->tmabort_state = TMABORT_INITIAL;
1213 	rc = iscsi_exec_abort_task(sc, ctask);
1214 	if (rc || sc->SCp.phase != session->age ||
1215 	    session->state != ISCSI_STATE_LOGGED_IN)
1216 		goto failed;
1217 	iscsi_ctask_mtask_cleanup(ctask);
1218 
1219 	switch (conn->tmabort_state) {
1220 	case TMABORT_SUCCESS:
1221 		spin_unlock_bh(&session->lock);
1222 		/*
1223 		 * clean up task if aborted. grab the recv lock as a writer
1224 		 */
1225 		write_lock_bh(conn->recv_lock);
1226 		spin_lock(&session->lock);
1227 		fail_command(conn, ctask, DID_ABORT << 16);
1228 		spin_unlock(&session->lock);
1229 		write_unlock_bh(conn->recv_lock);
1230 		/*
1231 		 * make sure xmit thread is not still touching the
1232 		 * ctask/scsi_cmnd
1233 		 */
1234 		scsi_flush_work(session->host);
1235 		goto success_unlocked;
1236 	case TMABORT_NOT_FOUND:
1237 		if (!ctask->sc) {
1238 			/* ctask completed before tmf abort response */
1239 			debug_scsi("sc completed while abort in progress\n");
1240 			goto success;
1241 		}
1242 		/* fall through */
1243 	default:
1244 		/* timedout or failed */
1245 		spin_unlock_bh(&session->lock);
1246 		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1247 		goto failed_unlocked;
1248 	}
1249 
1250 success:
1251 	spin_unlock_bh(&session->lock);
1252 success_unlocked:
1253 	debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1254 	return SUCCESS;
1255 
1256 failed:
1257 	spin_unlock_bh(&session->lock);
1258 failed_unlocked:
1259 	debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1260 	return FAILED;
1261 }
1262 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1263 
1264 int
1265 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
1266 {
1267 	int i;
1268 
1269 	*items = kmalloc(max * sizeof(void*), GFP_KERNEL);
1270 	if (*items == NULL)
1271 		return -ENOMEM;
1272 
1273 	q->max = max;
1274 	q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
1275 	if (q->pool == NULL) {
1276 		kfree(*items);
1277 		return -ENOMEM;
1278 	}
1279 
1280 	q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1281 			      GFP_KERNEL, NULL);
1282 	if (q->queue == ERR_PTR(-ENOMEM)) {
1283 		kfree(q->pool);
1284 		kfree(*items);
1285 		return -ENOMEM;
1286 	}
1287 
1288 	for (i = 0; i < max; i++) {
1289 		q->pool[i] = kmalloc(item_size, GFP_KERNEL);
1290 		if (q->pool[i] == NULL) {
1291 			int j;
1292 
1293 			for (j = 0; j < i; j++)
1294 				kfree(q->pool[j]);
1295 
1296 			kfifo_free(q->queue);
1297 			kfree(q->pool);
1298 			kfree(*items);
1299 			return -ENOMEM;
1300 		}
1301 		memset(q->pool[i], 0, item_size);
1302 		(*items)[i] = q->pool[i];
1303 		__kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1304 	}
1305 	return 0;
1306 }
1307 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1308 
1309 void iscsi_pool_free(struct iscsi_queue *q, void **items)
1310 {
1311 	int i;
1312 
1313 	for (i = 0; i < q->max; i++)
1314 		kfree(items[i]);
1315 	kfree(q->pool);
1316 	kfree(items);
1317 }
1318 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1319 
1320 /*
1321  * iSCSI Session's hostdata organization:
1322  *
1323  *    *------------------* <== hostdata_session(host->hostdata)
1324  *    | ptr to class sess|
1325  *    |------------------| <== iscsi_hostdata(host->hostdata)
1326  *    | iscsi_session    |
1327  *    *------------------*
1328  */
1329 
1330 #define hostdata_privsize(_sz)	(sizeof(unsigned long) + _sz + \
1331 				 _sz % sizeof(unsigned long))
1332 
1333 #define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1334 
1335 /**
1336  * iscsi_session_setup - create iscsi cls session and host and session
1337  * @scsit: scsi transport template
1338  * @iscsit: iscsi transport template
1339  * @cmds_max: scsi host can queue
1340  * @qdepth: scsi host cmds per lun
1341  * @cmd_task_size: LLD ctask private data size
1342  * @mgmt_task_size: LLD mtask private data size
1343  * @initial_cmdsn: initial CmdSN
1344  * @hostno: host no allocated
1345  *
1346  * This can be used by software iscsi_transports that allocate
1347  * a session per scsi host.
1348  **/
1349 struct iscsi_cls_session *
1350 iscsi_session_setup(struct iscsi_transport *iscsit,
1351 		    struct scsi_transport_template *scsit,
1352 		    uint16_t cmds_max, uint16_t qdepth,
1353 		    int cmd_task_size, int mgmt_task_size,
1354 		    uint32_t initial_cmdsn, uint32_t *hostno)
1355 {
1356 	struct Scsi_Host *shost;
1357 	struct iscsi_session *session;
1358 	struct iscsi_cls_session *cls_session;
1359 	int cmd_i;
1360 
1361 	if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
1362 		if (qdepth != 0)
1363 			printk(KERN_ERR "iscsi: invalid queue depth of %d. "
1364 			      "Queue depth must be between 1 and %d.\n",
1365 			      qdepth, ISCSI_MAX_CMD_PER_LUN);
1366 		qdepth = ISCSI_DEF_CMD_PER_LUN;
1367 	}
1368 
1369 	if (cmds_max < 2 || (cmds_max & (cmds_max - 1)) ||
1370 	    cmds_max >= ISCSI_MGMT_ITT_OFFSET) {
1371 		if (cmds_max != 0)
1372 			printk(KERN_ERR "iscsi: invalid can_queue of %d. "
1373 			       "can_queue must be a power of 2 and between "
1374 			       "2 and %d - setting to %d.\n", cmds_max,
1375 			       ISCSI_MGMT_ITT_OFFSET, ISCSI_DEF_XMIT_CMDS_MAX);
1376 		cmds_max = ISCSI_DEF_XMIT_CMDS_MAX;
1377 	}
1378 
1379 	shost = scsi_host_alloc(iscsit->host_template,
1380 				hostdata_privsize(sizeof(*session)));
1381 	if (!shost)
1382 		return NULL;
1383 
1384 	/* the iscsi layer takes one task for reserve */
1385 	shost->can_queue = cmds_max - 1;
1386 	shost->cmd_per_lun = qdepth;
1387 	shost->max_id = 1;
1388 	shost->max_channel = 0;
1389 	shost->max_lun = iscsit->max_lun;
1390 	shost->max_cmd_len = iscsit->max_cmd_len;
1391 	shost->transportt = scsit;
1392 	shost->transportt->create_work_queue = 1;
1393 	*hostno = shost->host_no;
1394 
1395 	session = iscsi_hostdata(shost->hostdata);
1396 	memset(session, 0, sizeof(struct iscsi_session));
1397 	session->host = shost;
1398 	session->state = ISCSI_STATE_FREE;
1399 	session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1400 	session->cmds_max = cmds_max;
1401 	session->queued_cmdsn = session->cmdsn = initial_cmdsn;
1402 	session->exp_cmdsn = initial_cmdsn + 1;
1403 	session->max_cmdsn = initial_cmdsn + 1;
1404 	session->max_r2t = 1;
1405 	session->tt = iscsit;
1406 
1407 	/* initialize SCSI PDU commands pool */
1408 	if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1409 			    (void***)&session->cmds,
1410 			    cmd_task_size + sizeof(struct iscsi_cmd_task)))
1411 		goto cmdpool_alloc_fail;
1412 
1413 	/* pre-format cmds pool with ITT */
1414 	for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1415 		struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1416 
1417 		if (cmd_task_size)
1418 			ctask->dd_data = &ctask[1];
1419 		ctask->itt = cmd_i;
1420 		INIT_LIST_HEAD(&ctask->running);
1421 	}
1422 
1423 	spin_lock_init(&session->lock);
1424 
1425 	/* initialize immediate command pool */
1426 	if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1427 			   (void***)&session->mgmt_cmds,
1428 			   mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1429 		goto mgmtpool_alloc_fail;
1430 
1431 
1432 	/* pre-format immediate cmds pool with ITT */
1433 	for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1434 		struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1435 
1436 		if (mgmt_task_size)
1437 			mtask->dd_data = &mtask[1];
1438 		mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1439 		INIT_LIST_HEAD(&mtask->running);
1440 	}
1441 
1442 	if (scsi_add_host(shost, NULL))
1443 		goto add_host_fail;
1444 
1445 	if (!try_module_get(iscsit->owner))
1446 		goto cls_session_fail;
1447 
1448 	cls_session = iscsi_create_session(shost, iscsit, 0);
1449 	if (!cls_session)
1450 		goto module_put;
1451 	*(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1452 
1453 	return cls_session;
1454 
1455 module_put:
1456 	module_put(iscsit->owner);
1457 cls_session_fail:
1458 	scsi_remove_host(shost);
1459 add_host_fail:
1460 	iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1461 mgmtpool_alloc_fail:
1462 	iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1463 cmdpool_alloc_fail:
1464 	scsi_host_put(shost);
1465 	return NULL;
1466 }
1467 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1468 
1469 /**
1470  * iscsi_session_teardown - destroy session, host, and cls_session
1471  * shost: scsi host
1472  *
1473  * This can be used by software iscsi_transports that allocate
1474  * a session per scsi host.
1475  **/
1476 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1477 {
1478 	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1479 	struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1480 	struct module *owner = cls_session->transport->owner;
1481 
1482 	iscsi_unblock_session(cls_session);
1483 	scsi_remove_host(shost);
1484 
1485 	iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1486 	iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1487 
1488 	kfree(session->password);
1489 	kfree(session->password_in);
1490 	kfree(session->username);
1491 	kfree(session->username_in);
1492 	kfree(session->targetname);
1493 	kfree(session->netdev);
1494 	kfree(session->hwaddress);
1495 	kfree(session->initiatorname);
1496 
1497 	iscsi_destroy_session(cls_session);
1498 	scsi_host_put(shost);
1499 	module_put(owner);
1500 }
1501 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1502 
1503 /**
1504  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1505  * @cls_session: iscsi_cls_session
1506  * @conn_idx: cid
1507  **/
1508 struct iscsi_cls_conn *
1509 iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1510 {
1511 	struct iscsi_session *session = class_to_transport_session(cls_session);
1512 	struct iscsi_conn *conn;
1513 	struct iscsi_cls_conn *cls_conn;
1514 	char *data;
1515 
1516 	cls_conn = iscsi_create_conn(cls_session, conn_idx);
1517 	if (!cls_conn)
1518 		return NULL;
1519 	conn = cls_conn->dd_data;
1520 	memset(conn, 0, sizeof(*conn));
1521 
1522 	conn->session = session;
1523 	conn->cls_conn = cls_conn;
1524 	conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1525 	conn->id = conn_idx;
1526 	conn->exp_statsn = 0;
1527 	conn->tmabort_state = TMABORT_INITIAL;
1528 	INIT_LIST_HEAD(&conn->run_list);
1529 	INIT_LIST_HEAD(&conn->mgmt_run_list);
1530 	INIT_LIST_HEAD(&conn->xmitqueue);
1531 
1532 	/* initialize general immediate & non-immediate PDU commands queue */
1533 	conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1534 			                GFP_KERNEL, NULL);
1535 	if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
1536 		goto mgmtqueue_alloc_fail;
1537 
1538 	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
1539 
1540 	/* allocate login_mtask used for the login/text sequences */
1541 	spin_lock_bh(&session->lock);
1542 	if (!__kfifo_get(session->mgmtpool.queue,
1543                          (void*)&conn->login_mtask,
1544 			 sizeof(void*))) {
1545 		spin_unlock_bh(&session->lock);
1546 		goto login_mtask_alloc_fail;
1547 	}
1548 	spin_unlock_bh(&session->lock);
1549 
1550 	data = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
1551 	if (!data)
1552 		goto login_mtask_data_alloc_fail;
1553 	conn->login_mtask->data = conn->data = data;
1554 
1555 	init_timer(&conn->tmabort_timer);
1556 	init_waitqueue_head(&conn->ehwait);
1557 
1558 	return cls_conn;
1559 
1560 login_mtask_data_alloc_fail:
1561 	__kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1562 		    sizeof(void*));
1563 login_mtask_alloc_fail:
1564 	kfifo_free(conn->mgmtqueue);
1565 mgmtqueue_alloc_fail:
1566 	iscsi_destroy_conn(cls_conn);
1567 	return NULL;
1568 }
1569 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1570 
1571 /**
1572  * iscsi_conn_teardown - teardown iscsi connection
1573  * cls_conn: iscsi class connection
1574  *
1575  * TODO: we may need to make this into a two step process
1576  * like scsi-mls remove + put host
1577  */
1578 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1579 {
1580 	struct iscsi_conn *conn = cls_conn->dd_data;
1581 	struct iscsi_session *session = conn->session;
1582 	unsigned long flags;
1583 
1584 	spin_lock_bh(&session->lock);
1585 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1586 	conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1587 	if (session->leadconn == conn) {
1588 		/*
1589 		 * leading connection? then give up on recovery.
1590 		 */
1591 		session->state = ISCSI_STATE_TERMINATE;
1592 		wake_up(&conn->ehwait);
1593 	}
1594 	spin_unlock_bh(&session->lock);
1595 
1596 	/*
1597 	 * Block until all in-progress commands for this connection
1598 	 * time out or fail.
1599 	 */
1600 	for (;;) {
1601 		spin_lock_irqsave(session->host->host_lock, flags);
1602 		if (!session->host->host_busy) { /* OK for ERL == 0 */
1603 			spin_unlock_irqrestore(session->host->host_lock, flags);
1604 			break;
1605 		}
1606 		spin_unlock_irqrestore(session->host->host_lock, flags);
1607 		msleep_interruptible(500);
1608 		printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
1609 		       "host_failed %d\n", session->host->host_busy,
1610 		       session->host->host_failed);
1611 		/*
1612 		 * force eh_abort() to unblock
1613 		 */
1614 		wake_up(&conn->ehwait);
1615 	}
1616 
1617 	/* flush queued up work because we free the connection below */
1618 	scsi_flush_work(session->host);
1619 
1620 	spin_lock_bh(&session->lock);
1621 	kfree(conn->data);
1622 	kfree(conn->persistent_address);
1623 	__kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1624 		    sizeof(void*));
1625 	if (session->leadconn == conn)
1626 		session->leadconn = NULL;
1627 	spin_unlock_bh(&session->lock);
1628 
1629 	kfifo_free(conn->mgmtqueue);
1630 
1631 	iscsi_destroy_conn(cls_conn);
1632 }
1633 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1634 
1635 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1636 {
1637 	struct iscsi_conn *conn = cls_conn->dd_data;
1638 	struct iscsi_session *session = conn->session;
1639 
1640 	if (!session) {
1641 		printk(KERN_ERR "iscsi: can't start unbound connection\n");
1642 		return -EPERM;
1643 	}
1644 
1645 	if ((session->imm_data_en || !session->initial_r2t_en) &&
1646 	     session->first_burst > session->max_burst) {
1647 		printk("iscsi: invalid burst lengths: "
1648 		       "first_burst %d max_burst %d\n",
1649 		       session->first_burst, session->max_burst);
1650 		return -EINVAL;
1651 	}
1652 
1653 	spin_lock_bh(&session->lock);
1654 	conn->c_stage = ISCSI_CONN_STARTED;
1655 	session->state = ISCSI_STATE_LOGGED_IN;
1656 	session->queued_cmdsn = session->cmdsn;
1657 
1658 	switch(conn->stop_stage) {
1659 	case STOP_CONN_RECOVER:
1660 		/*
1661 		 * unblock eh_abort() if it is blocked. re-try all
1662 		 * commands after successful recovery
1663 		 */
1664 		conn->stop_stage = 0;
1665 		conn->tmabort_state = TMABORT_INITIAL;
1666 		session->age++;
1667 		spin_unlock_bh(&session->lock);
1668 
1669 		iscsi_unblock_session(session_to_cls(session));
1670 		wake_up(&conn->ehwait);
1671 		return 0;
1672 	case STOP_CONN_TERM:
1673 		conn->stop_stage = 0;
1674 		break;
1675 	default:
1676 		break;
1677 	}
1678 	spin_unlock_bh(&session->lock);
1679 
1680 	return 0;
1681 }
1682 EXPORT_SYMBOL_GPL(iscsi_conn_start);
1683 
1684 static void
1685 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1686 {
1687 	struct iscsi_mgmt_task *mtask, *tmp;
1688 
1689 	/* handle pending */
1690 	while (__kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
1691 		if (mtask == conn->login_mtask)
1692 			continue;
1693 		debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1694 		__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1695 			    sizeof(void*));
1696 	}
1697 
1698 	/* handle running */
1699 	list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1700 		debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
1701 		list_del(&mtask->running);
1702 
1703 		if (mtask == conn->login_mtask)
1704 			continue;
1705 		__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1706 			   sizeof(void*));
1707 	}
1708 
1709 	conn->mtask = NULL;
1710 }
1711 
1712 /* Fail commands. Mutex and session lock held and recv side suspended */
1713 static void fail_all_commands(struct iscsi_conn *conn)
1714 {
1715 	struct iscsi_cmd_task *ctask, *tmp;
1716 
1717 	/* flush pending */
1718 	list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
1719 		debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
1720 			   ctask->itt);
1721 		fail_command(conn, ctask, DID_BUS_BUSY << 16);
1722 	}
1723 
1724 	/* fail all other running */
1725 	list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1726 		debug_scsi("failing in progress sc %p itt 0x%x\n",
1727 			   ctask->sc, ctask->itt);
1728 		fail_command(conn, ctask, DID_BUS_BUSY << 16);
1729 	}
1730 
1731 	conn->ctask = NULL;
1732 }
1733 
1734 static void iscsi_start_session_recovery(struct iscsi_session *session,
1735 					 struct iscsi_conn *conn, int flag)
1736 {
1737 	int old_stop_stage;
1738 
1739 	spin_lock_bh(&session->lock);
1740 	if (conn->stop_stage == STOP_CONN_TERM) {
1741 		spin_unlock_bh(&session->lock);
1742 		return;
1743 	}
1744 
1745 	/*
1746 	 * When this is called for the in_login state, we only want to clean
1747 	 * up the login task and connection. We do not need to block and set
1748 	 * the recovery state again
1749 	 */
1750 	if (flag == STOP_CONN_TERM)
1751 		session->state = ISCSI_STATE_TERMINATE;
1752 	else if (conn->stop_stage != STOP_CONN_RECOVER)
1753 		session->state = ISCSI_STATE_IN_RECOVERY;
1754 
1755 	old_stop_stage = conn->stop_stage;
1756 	conn->stop_stage = flag;
1757 	conn->c_stage = ISCSI_CONN_STOPPED;
1758 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1759 	spin_unlock_bh(&session->lock);
1760 	scsi_flush_work(session->host);
1761 
1762 	write_lock_bh(conn->recv_lock);
1763 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1764 	write_unlock_bh(conn->recv_lock);
1765 
1766 	/*
1767 	 * for connection level recovery we should not calculate
1768 	 * header digest. conn->hdr_size used for optimization
1769 	 * in hdr_extract() and will be re-negotiated at
1770 	 * set_param() time.
1771 	 */
1772 	if (flag == STOP_CONN_RECOVER) {
1773 		conn->hdrdgst_en = 0;
1774 		conn->datadgst_en = 0;
1775 		if (session->state == ISCSI_STATE_IN_RECOVERY &&
1776 		    old_stop_stage != STOP_CONN_RECOVER) {
1777 			debug_scsi("blocking session\n");
1778 			iscsi_block_session(session_to_cls(session));
1779 		}
1780 	}
1781 
1782 	/*
1783 	 * flush queues.
1784 	 */
1785 	spin_lock_bh(&session->lock);
1786 	fail_all_commands(conn);
1787 	flush_control_queues(session, conn);
1788 	spin_unlock_bh(&session->lock);
1789 }
1790 
1791 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1792 {
1793 	struct iscsi_conn *conn = cls_conn->dd_data;
1794 	struct iscsi_session *session = conn->session;
1795 
1796 	switch (flag) {
1797 	case STOP_CONN_RECOVER:
1798 	case STOP_CONN_TERM:
1799 		iscsi_start_session_recovery(session, conn, flag);
1800 		break;
1801 	default:
1802 		printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
1803 	}
1804 }
1805 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1806 
1807 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1808 		    struct iscsi_cls_conn *cls_conn, int is_leading)
1809 {
1810 	struct iscsi_session *session = class_to_transport_session(cls_session);
1811 	struct iscsi_conn *conn = cls_conn->dd_data;
1812 
1813 	spin_lock_bh(&session->lock);
1814 	if (is_leading)
1815 		session->leadconn = conn;
1816 	spin_unlock_bh(&session->lock);
1817 
1818 	/*
1819 	 * Unblock xmitworker(), Login Phase will pass through.
1820 	 */
1821 	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1822 	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1823 	return 0;
1824 }
1825 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1826 
1827 
1828 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
1829 		    enum iscsi_param param, char *buf, int buflen)
1830 {
1831 	struct iscsi_conn *conn = cls_conn->dd_data;
1832 	struct iscsi_session *session = conn->session;
1833 	uint32_t value;
1834 
1835 	switch(param) {
1836 	case ISCSI_PARAM_MAX_RECV_DLENGTH:
1837 		sscanf(buf, "%d", &conn->max_recv_dlength);
1838 		break;
1839 	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1840 		sscanf(buf, "%d", &conn->max_xmit_dlength);
1841 		break;
1842 	case ISCSI_PARAM_HDRDGST_EN:
1843 		sscanf(buf, "%d", &conn->hdrdgst_en);
1844 		break;
1845 	case ISCSI_PARAM_DATADGST_EN:
1846 		sscanf(buf, "%d", &conn->datadgst_en);
1847 		break;
1848 	case ISCSI_PARAM_INITIAL_R2T_EN:
1849 		sscanf(buf, "%d", &session->initial_r2t_en);
1850 		break;
1851 	case ISCSI_PARAM_MAX_R2T:
1852 		sscanf(buf, "%d", &session->max_r2t);
1853 		break;
1854 	case ISCSI_PARAM_IMM_DATA_EN:
1855 		sscanf(buf, "%d", &session->imm_data_en);
1856 		break;
1857 	case ISCSI_PARAM_FIRST_BURST:
1858 		sscanf(buf, "%d", &session->first_burst);
1859 		break;
1860 	case ISCSI_PARAM_MAX_BURST:
1861 		sscanf(buf, "%d", &session->max_burst);
1862 		break;
1863 	case ISCSI_PARAM_PDU_INORDER_EN:
1864 		sscanf(buf, "%d", &session->pdu_inorder_en);
1865 		break;
1866 	case ISCSI_PARAM_DATASEQ_INORDER_EN:
1867 		sscanf(buf, "%d", &session->dataseq_inorder_en);
1868 		break;
1869 	case ISCSI_PARAM_ERL:
1870 		sscanf(buf, "%d", &session->erl);
1871 		break;
1872 	case ISCSI_PARAM_IFMARKER_EN:
1873 		sscanf(buf, "%d", &value);
1874 		BUG_ON(value);
1875 		break;
1876 	case ISCSI_PARAM_OFMARKER_EN:
1877 		sscanf(buf, "%d", &value);
1878 		BUG_ON(value);
1879 		break;
1880 	case ISCSI_PARAM_EXP_STATSN:
1881 		sscanf(buf, "%u", &conn->exp_statsn);
1882 		break;
1883 	case ISCSI_PARAM_USERNAME:
1884 		kfree(session->username);
1885 		session->username = kstrdup(buf, GFP_KERNEL);
1886 		if (!session->username)
1887 			return -ENOMEM;
1888 		break;
1889 	case ISCSI_PARAM_USERNAME_IN:
1890 		kfree(session->username_in);
1891 		session->username_in = kstrdup(buf, GFP_KERNEL);
1892 		if (!session->username_in)
1893 			return -ENOMEM;
1894 		break;
1895 	case ISCSI_PARAM_PASSWORD:
1896 		kfree(session->password);
1897 		session->password = kstrdup(buf, GFP_KERNEL);
1898 		if (!session->password)
1899 			return -ENOMEM;
1900 		break;
1901 	case ISCSI_PARAM_PASSWORD_IN:
1902 		kfree(session->password_in);
1903 		session->password_in = kstrdup(buf, GFP_KERNEL);
1904 		if (!session->password_in)
1905 			return -ENOMEM;
1906 		break;
1907 	case ISCSI_PARAM_TARGET_NAME:
1908 		/* this should not change between logins */
1909 		if (session->targetname)
1910 			break;
1911 
1912 		session->targetname = kstrdup(buf, GFP_KERNEL);
1913 		if (!session->targetname)
1914 			return -ENOMEM;
1915 		break;
1916 	case ISCSI_PARAM_TPGT:
1917 		sscanf(buf, "%d", &session->tpgt);
1918 		break;
1919 	case ISCSI_PARAM_PERSISTENT_PORT:
1920 		sscanf(buf, "%d", &conn->persistent_port);
1921 		break;
1922 	case ISCSI_PARAM_PERSISTENT_ADDRESS:
1923 		/*
1924 		 * this is the address returned in discovery so it should
1925 		 * not change between logins.
1926 		 */
1927 		if (conn->persistent_address)
1928 			break;
1929 
1930 		conn->persistent_address = kstrdup(buf, GFP_KERNEL);
1931 		if (!conn->persistent_address)
1932 			return -ENOMEM;
1933 		break;
1934 	default:
1935 		return -ENOSYS;
1936 	}
1937 
1938 	return 0;
1939 }
1940 EXPORT_SYMBOL_GPL(iscsi_set_param);
1941 
1942 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
1943 			    enum iscsi_param param, char *buf)
1944 {
1945 	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1946 	struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1947 	int len;
1948 
1949 	switch(param) {
1950 	case ISCSI_PARAM_INITIAL_R2T_EN:
1951 		len = sprintf(buf, "%d\n", session->initial_r2t_en);
1952 		break;
1953 	case ISCSI_PARAM_MAX_R2T:
1954 		len = sprintf(buf, "%hu\n", session->max_r2t);
1955 		break;
1956 	case ISCSI_PARAM_IMM_DATA_EN:
1957 		len = sprintf(buf, "%d\n", session->imm_data_en);
1958 		break;
1959 	case ISCSI_PARAM_FIRST_BURST:
1960 		len = sprintf(buf, "%u\n", session->first_burst);
1961 		break;
1962 	case ISCSI_PARAM_MAX_BURST:
1963 		len = sprintf(buf, "%u\n", session->max_burst);
1964 		break;
1965 	case ISCSI_PARAM_PDU_INORDER_EN:
1966 		len = sprintf(buf, "%d\n", session->pdu_inorder_en);
1967 		break;
1968 	case ISCSI_PARAM_DATASEQ_INORDER_EN:
1969 		len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
1970 		break;
1971 	case ISCSI_PARAM_ERL:
1972 		len = sprintf(buf, "%d\n", session->erl);
1973 		break;
1974 	case ISCSI_PARAM_TARGET_NAME:
1975 		len = sprintf(buf, "%s\n", session->targetname);
1976 		break;
1977 	case ISCSI_PARAM_TPGT:
1978 		len = sprintf(buf, "%d\n", session->tpgt);
1979 		break;
1980 	case ISCSI_PARAM_USERNAME:
1981 		len = sprintf(buf, "%s\n", session->username);
1982 		break;
1983 	case ISCSI_PARAM_USERNAME_IN:
1984 		len = sprintf(buf, "%s\n", session->username_in);
1985 		break;
1986 	case ISCSI_PARAM_PASSWORD:
1987 		len = sprintf(buf, "%s\n", session->password);
1988 		break;
1989 	case ISCSI_PARAM_PASSWORD_IN:
1990 		len = sprintf(buf, "%s\n", session->password_in);
1991 		break;
1992 	default:
1993 		return -ENOSYS;
1994 	}
1995 
1996 	return len;
1997 }
1998 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
1999 
2000 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2001 			 enum iscsi_param param, char *buf)
2002 {
2003 	struct iscsi_conn *conn = cls_conn->dd_data;
2004 	int len;
2005 
2006 	switch(param) {
2007 	case ISCSI_PARAM_MAX_RECV_DLENGTH:
2008 		len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2009 		break;
2010 	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2011 		len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2012 		break;
2013 	case ISCSI_PARAM_HDRDGST_EN:
2014 		len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2015 		break;
2016 	case ISCSI_PARAM_DATADGST_EN:
2017 		len = sprintf(buf, "%d\n", conn->datadgst_en);
2018 		break;
2019 	case ISCSI_PARAM_IFMARKER_EN:
2020 		len = sprintf(buf, "%d\n", conn->ifmarker_en);
2021 		break;
2022 	case ISCSI_PARAM_OFMARKER_EN:
2023 		len = sprintf(buf, "%d\n", conn->ofmarker_en);
2024 		break;
2025 	case ISCSI_PARAM_EXP_STATSN:
2026 		len = sprintf(buf, "%u\n", conn->exp_statsn);
2027 		break;
2028 	case ISCSI_PARAM_PERSISTENT_PORT:
2029 		len = sprintf(buf, "%d\n", conn->persistent_port);
2030 		break;
2031 	case ISCSI_PARAM_PERSISTENT_ADDRESS:
2032 		len = sprintf(buf, "%s\n", conn->persistent_address);
2033 		break;
2034 	default:
2035 		return -ENOSYS;
2036 	}
2037 
2038 	return len;
2039 }
2040 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2041 
2042 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2043 			 char *buf)
2044 {
2045 	struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2046 	int len;
2047 
2048 	switch (param) {
2049 	case ISCSI_HOST_PARAM_NETDEV_NAME:
2050 		if (!session->netdev)
2051 			len = sprintf(buf, "%s\n", "default");
2052 		else
2053 			len = sprintf(buf, "%s\n", session->netdev);
2054 		break;
2055 	case ISCSI_HOST_PARAM_HWADDRESS:
2056 		if (!session->hwaddress)
2057 			len = sprintf(buf, "%s\n", "default");
2058 		else
2059 			len = sprintf(buf, "%s\n", session->hwaddress);
2060 		break;
2061 	case ISCSI_HOST_PARAM_INITIATOR_NAME:
2062 		if (!session->initiatorname)
2063 			len = sprintf(buf, "%s\n", "unknown");
2064 		else
2065 			len = sprintf(buf, "%s\n", session->initiatorname);
2066 		break;
2067 
2068 	default:
2069 		return -ENOSYS;
2070 	}
2071 
2072 	return len;
2073 }
2074 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2075 
2076 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2077 			 char *buf, int buflen)
2078 {
2079 	struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2080 
2081 	switch (param) {
2082 	case ISCSI_HOST_PARAM_NETDEV_NAME:
2083 		if (!session->netdev)
2084 			session->netdev = kstrdup(buf, GFP_KERNEL);
2085 		break;
2086 	case ISCSI_HOST_PARAM_HWADDRESS:
2087 		if (!session->hwaddress)
2088 			session->hwaddress = kstrdup(buf, GFP_KERNEL);
2089 		break;
2090 	case ISCSI_HOST_PARAM_INITIATOR_NAME:
2091 		if (!session->initiatorname)
2092 			session->initiatorname = kstrdup(buf, GFP_KERNEL);
2093 		break;
2094 	default:
2095 		return -ENOSYS;
2096 	}
2097 
2098 	return 0;
2099 }
2100 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2101 
2102 MODULE_AUTHOR("Mike Christie");
2103 MODULE_DESCRIPTION("iSCSI library functions");
2104 MODULE_LICENSE("GPL");
2105