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