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