xref: /linux/drivers/target/iscsi/iscsi_target.c (revision 841b86f3289dbe858daeceec36423d4ea286fac2)
1 /*******************************************************************************
2  * This file contains main functions related to the iSCSI Target Core Driver.
3  *
4  * (c) Copyright 2007-2013 Datera, Inc.
5  *
6  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  ******************************************************************************/
18 
19 #include <crypto/hash.h>
20 #include <linux/string.h>
21 #include <linux/kthread.h>
22 #include <linux/completion.h>
23 #include <linux/module.h>
24 #include <linux/vmalloc.h>
25 #include <linux/idr.h>
26 #include <linux/delay.h>
27 #include <linux/sched/signal.h>
28 #include <asm/unaligned.h>
29 #include <net/ipv6.h>
30 #include <scsi/scsi_proto.h>
31 #include <scsi/iscsi_proto.h>
32 #include <scsi/scsi_tcq.h>
33 #include <target/target_core_base.h>
34 #include <target/target_core_fabric.h>
35 
36 #include <target/iscsi/iscsi_target_core.h>
37 #include "iscsi_target_parameters.h"
38 #include "iscsi_target_seq_pdu_list.h"
39 #include "iscsi_target_datain_values.h"
40 #include "iscsi_target_erl0.h"
41 #include "iscsi_target_erl1.h"
42 #include "iscsi_target_erl2.h"
43 #include "iscsi_target_login.h"
44 #include "iscsi_target_tmr.h"
45 #include "iscsi_target_tpg.h"
46 #include "iscsi_target_util.h"
47 #include "iscsi_target.h"
48 #include "iscsi_target_device.h"
49 #include <target/iscsi/iscsi_target_stat.h>
50 
51 #include <target/iscsi/iscsi_transport.h>
52 
53 static LIST_HEAD(g_tiqn_list);
54 static LIST_HEAD(g_np_list);
55 static DEFINE_SPINLOCK(tiqn_lock);
56 static DEFINE_MUTEX(np_lock);
57 
58 static struct idr tiqn_idr;
59 struct idr sess_idr;
60 struct mutex auth_id_lock;
61 spinlock_t sess_idr_lock;
62 
63 struct iscsit_global *iscsit_global;
64 
65 struct kmem_cache *lio_qr_cache;
66 struct kmem_cache *lio_dr_cache;
67 struct kmem_cache *lio_ooo_cache;
68 struct kmem_cache *lio_r2t_cache;
69 
70 static int iscsit_handle_immediate_data(struct iscsi_cmd *,
71 			struct iscsi_scsi_req *, u32);
72 
73 struct iscsi_tiqn *iscsit_get_tiqn_for_login(unsigned char *buf)
74 {
75 	struct iscsi_tiqn *tiqn = NULL;
76 
77 	spin_lock(&tiqn_lock);
78 	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
79 		if (!strcmp(tiqn->tiqn, buf)) {
80 
81 			spin_lock(&tiqn->tiqn_state_lock);
82 			if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
83 				tiqn->tiqn_access_count++;
84 				spin_unlock(&tiqn->tiqn_state_lock);
85 				spin_unlock(&tiqn_lock);
86 				return tiqn;
87 			}
88 			spin_unlock(&tiqn->tiqn_state_lock);
89 		}
90 	}
91 	spin_unlock(&tiqn_lock);
92 
93 	return NULL;
94 }
95 
96 static int iscsit_set_tiqn_shutdown(struct iscsi_tiqn *tiqn)
97 {
98 	spin_lock(&tiqn->tiqn_state_lock);
99 	if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
100 		tiqn->tiqn_state = TIQN_STATE_SHUTDOWN;
101 		spin_unlock(&tiqn->tiqn_state_lock);
102 		return 0;
103 	}
104 	spin_unlock(&tiqn->tiqn_state_lock);
105 
106 	return -1;
107 }
108 
109 void iscsit_put_tiqn_for_login(struct iscsi_tiqn *tiqn)
110 {
111 	spin_lock(&tiqn->tiqn_state_lock);
112 	tiqn->tiqn_access_count--;
113 	spin_unlock(&tiqn->tiqn_state_lock);
114 }
115 
116 /*
117  * Note that IQN formatting is expected to be done in userspace, and
118  * no explict IQN format checks are done here.
119  */
120 struct iscsi_tiqn *iscsit_add_tiqn(unsigned char *buf)
121 {
122 	struct iscsi_tiqn *tiqn = NULL;
123 	int ret;
124 
125 	if (strlen(buf) >= ISCSI_IQN_LEN) {
126 		pr_err("Target IQN exceeds %d bytes\n",
127 				ISCSI_IQN_LEN);
128 		return ERR_PTR(-EINVAL);
129 	}
130 
131 	tiqn = kzalloc(sizeof(*tiqn), GFP_KERNEL);
132 	if (!tiqn)
133 		return ERR_PTR(-ENOMEM);
134 
135 	sprintf(tiqn->tiqn, "%s", buf);
136 	INIT_LIST_HEAD(&tiqn->tiqn_list);
137 	INIT_LIST_HEAD(&tiqn->tiqn_tpg_list);
138 	spin_lock_init(&tiqn->tiqn_state_lock);
139 	spin_lock_init(&tiqn->tiqn_tpg_lock);
140 	spin_lock_init(&tiqn->sess_err_stats.lock);
141 	spin_lock_init(&tiqn->login_stats.lock);
142 	spin_lock_init(&tiqn->logout_stats.lock);
143 
144 	tiqn->tiqn_state = TIQN_STATE_ACTIVE;
145 
146 	idr_preload(GFP_KERNEL);
147 	spin_lock(&tiqn_lock);
148 
149 	ret = idr_alloc(&tiqn_idr, NULL, 0, 0, GFP_NOWAIT);
150 	if (ret < 0) {
151 		pr_err("idr_alloc() failed for tiqn->tiqn_index\n");
152 		spin_unlock(&tiqn_lock);
153 		idr_preload_end();
154 		kfree(tiqn);
155 		return ERR_PTR(ret);
156 	}
157 	tiqn->tiqn_index = ret;
158 	list_add_tail(&tiqn->tiqn_list, &g_tiqn_list);
159 
160 	spin_unlock(&tiqn_lock);
161 	idr_preload_end();
162 
163 	pr_debug("CORE[0] - Added iSCSI Target IQN: %s\n", tiqn->tiqn);
164 
165 	return tiqn;
166 
167 }
168 
169 static void iscsit_wait_for_tiqn(struct iscsi_tiqn *tiqn)
170 {
171 	/*
172 	 * Wait for accesses to said struct iscsi_tiqn to end.
173 	 */
174 	spin_lock(&tiqn->tiqn_state_lock);
175 	while (tiqn->tiqn_access_count != 0) {
176 		spin_unlock(&tiqn->tiqn_state_lock);
177 		msleep(10);
178 		spin_lock(&tiqn->tiqn_state_lock);
179 	}
180 	spin_unlock(&tiqn->tiqn_state_lock);
181 }
182 
183 void iscsit_del_tiqn(struct iscsi_tiqn *tiqn)
184 {
185 	/*
186 	 * iscsit_set_tiqn_shutdown sets tiqn->tiqn_state = TIQN_STATE_SHUTDOWN
187 	 * while holding tiqn->tiqn_state_lock.  This means that all subsequent
188 	 * attempts to access this struct iscsi_tiqn will fail from both transport
189 	 * fabric and control code paths.
190 	 */
191 	if (iscsit_set_tiqn_shutdown(tiqn) < 0) {
192 		pr_err("iscsit_set_tiqn_shutdown() failed\n");
193 		return;
194 	}
195 
196 	iscsit_wait_for_tiqn(tiqn);
197 
198 	spin_lock(&tiqn_lock);
199 	list_del(&tiqn->tiqn_list);
200 	idr_remove(&tiqn_idr, tiqn->tiqn_index);
201 	spin_unlock(&tiqn_lock);
202 
203 	pr_debug("CORE[0] - Deleted iSCSI Target IQN: %s\n",
204 			tiqn->tiqn);
205 	kfree(tiqn);
206 }
207 
208 int iscsit_access_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
209 {
210 	int ret;
211 	/*
212 	 * Determine if the network portal is accepting storage traffic.
213 	 */
214 	spin_lock_bh(&np->np_thread_lock);
215 	if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
216 		spin_unlock_bh(&np->np_thread_lock);
217 		return -1;
218 	}
219 	spin_unlock_bh(&np->np_thread_lock);
220 	/*
221 	 * Determine if the portal group is accepting storage traffic.
222 	 */
223 	spin_lock_bh(&tpg->tpg_state_lock);
224 	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
225 		spin_unlock_bh(&tpg->tpg_state_lock);
226 		return -1;
227 	}
228 	spin_unlock_bh(&tpg->tpg_state_lock);
229 
230 	/*
231 	 * Here we serialize access across the TIQN+TPG Tuple.
232 	 */
233 	ret = down_interruptible(&tpg->np_login_sem);
234 	if (ret != 0)
235 		return -1;
236 
237 	spin_lock_bh(&tpg->tpg_state_lock);
238 	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
239 		spin_unlock_bh(&tpg->tpg_state_lock);
240 		up(&tpg->np_login_sem);
241 		return -1;
242 	}
243 	spin_unlock_bh(&tpg->tpg_state_lock);
244 
245 	return 0;
246 }
247 
248 void iscsit_login_kref_put(struct kref *kref)
249 {
250 	struct iscsi_tpg_np *tpg_np = container_of(kref,
251 				struct iscsi_tpg_np, tpg_np_kref);
252 
253 	complete(&tpg_np->tpg_np_comp);
254 }
255 
256 int iscsit_deaccess_np(struct iscsi_np *np, struct iscsi_portal_group *tpg,
257 		       struct iscsi_tpg_np *tpg_np)
258 {
259 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
260 
261 	up(&tpg->np_login_sem);
262 
263 	if (tpg_np)
264 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
265 
266 	if (tiqn)
267 		iscsit_put_tiqn_for_login(tiqn);
268 
269 	return 0;
270 }
271 
272 bool iscsit_check_np_match(
273 	struct sockaddr_storage *sockaddr,
274 	struct iscsi_np *np,
275 	int network_transport)
276 {
277 	struct sockaddr_in *sock_in, *sock_in_e;
278 	struct sockaddr_in6 *sock_in6, *sock_in6_e;
279 	bool ip_match = false;
280 	u16 port, port_e;
281 
282 	if (sockaddr->ss_family == AF_INET6) {
283 		sock_in6 = (struct sockaddr_in6 *)sockaddr;
284 		sock_in6_e = (struct sockaddr_in6 *)&np->np_sockaddr;
285 
286 		if (!memcmp(&sock_in6->sin6_addr.in6_u,
287 			    &sock_in6_e->sin6_addr.in6_u,
288 			    sizeof(struct in6_addr)))
289 			ip_match = true;
290 
291 		port = ntohs(sock_in6->sin6_port);
292 		port_e = ntohs(sock_in6_e->sin6_port);
293 	} else {
294 		sock_in = (struct sockaddr_in *)sockaddr;
295 		sock_in_e = (struct sockaddr_in *)&np->np_sockaddr;
296 
297 		if (sock_in->sin_addr.s_addr == sock_in_e->sin_addr.s_addr)
298 			ip_match = true;
299 
300 		port = ntohs(sock_in->sin_port);
301 		port_e = ntohs(sock_in_e->sin_port);
302 	}
303 
304 	if (ip_match && (port_e == port) &&
305 	    (np->np_network_transport == network_transport))
306 		return true;
307 
308 	return false;
309 }
310 
311 /*
312  * Called with mutex np_lock held
313  */
314 static struct iscsi_np *iscsit_get_np(
315 	struct sockaddr_storage *sockaddr,
316 	int network_transport)
317 {
318 	struct iscsi_np *np;
319 	bool match;
320 
321 	list_for_each_entry(np, &g_np_list, np_list) {
322 		spin_lock_bh(&np->np_thread_lock);
323 		if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
324 			spin_unlock_bh(&np->np_thread_lock);
325 			continue;
326 		}
327 
328 		match = iscsit_check_np_match(sockaddr, np, network_transport);
329 		if (match) {
330 			/*
331 			 * Increment the np_exports reference count now to
332 			 * prevent iscsit_del_np() below from being called
333 			 * while iscsi_tpg_add_network_portal() is called.
334 			 */
335 			np->np_exports++;
336 			spin_unlock_bh(&np->np_thread_lock);
337 			return np;
338 		}
339 		spin_unlock_bh(&np->np_thread_lock);
340 	}
341 
342 	return NULL;
343 }
344 
345 struct iscsi_np *iscsit_add_np(
346 	struct sockaddr_storage *sockaddr,
347 	int network_transport)
348 {
349 	struct iscsi_np *np;
350 	int ret;
351 
352 	mutex_lock(&np_lock);
353 
354 	/*
355 	 * Locate the existing struct iscsi_np if already active..
356 	 */
357 	np = iscsit_get_np(sockaddr, network_transport);
358 	if (np) {
359 		mutex_unlock(&np_lock);
360 		return np;
361 	}
362 
363 	np = kzalloc(sizeof(*np), GFP_KERNEL);
364 	if (!np) {
365 		mutex_unlock(&np_lock);
366 		return ERR_PTR(-ENOMEM);
367 	}
368 
369 	np->np_flags |= NPF_IP_NETWORK;
370 	np->np_network_transport = network_transport;
371 	spin_lock_init(&np->np_thread_lock);
372 	init_completion(&np->np_restart_comp);
373 	INIT_LIST_HEAD(&np->np_list);
374 
375 	timer_setup(&np->np_login_timer, iscsi_handle_login_thread_timeout, 0);
376 
377 	ret = iscsi_target_setup_login_socket(np, sockaddr);
378 	if (ret != 0) {
379 		kfree(np);
380 		mutex_unlock(&np_lock);
381 		return ERR_PTR(ret);
382 	}
383 
384 	np->np_thread = kthread_run(iscsi_target_login_thread, np, "iscsi_np");
385 	if (IS_ERR(np->np_thread)) {
386 		pr_err("Unable to create kthread: iscsi_np\n");
387 		ret = PTR_ERR(np->np_thread);
388 		kfree(np);
389 		mutex_unlock(&np_lock);
390 		return ERR_PTR(ret);
391 	}
392 	/*
393 	 * Increment the np_exports reference count now to prevent
394 	 * iscsit_del_np() below from being run while a new call to
395 	 * iscsi_tpg_add_network_portal() for a matching iscsi_np is
396 	 * active.  We don't need to hold np->np_thread_lock at this
397 	 * point because iscsi_np has not been added to g_np_list yet.
398 	 */
399 	np->np_exports = 1;
400 	np->np_thread_state = ISCSI_NP_THREAD_ACTIVE;
401 
402 	list_add_tail(&np->np_list, &g_np_list);
403 	mutex_unlock(&np_lock);
404 
405 	pr_debug("CORE[0] - Added Network Portal: %pISpc on %s\n",
406 		&np->np_sockaddr, np->np_transport->name);
407 
408 	return np;
409 }
410 
411 int iscsit_reset_np_thread(
412 	struct iscsi_np *np,
413 	struct iscsi_tpg_np *tpg_np,
414 	struct iscsi_portal_group *tpg,
415 	bool shutdown)
416 {
417 	spin_lock_bh(&np->np_thread_lock);
418 	if (np->np_thread_state == ISCSI_NP_THREAD_INACTIVE) {
419 		spin_unlock_bh(&np->np_thread_lock);
420 		return 0;
421 	}
422 	np->np_thread_state = ISCSI_NP_THREAD_RESET;
423 	atomic_inc(&np->np_reset_count);
424 
425 	if (np->np_thread) {
426 		spin_unlock_bh(&np->np_thread_lock);
427 		send_sig(SIGINT, np->np_thread, 1);
428 		wait_for_completion(&np->np_restart_comp);
429 		spin_lock_bh(&np->np_thread_lock);
430 	}
431 	spin_unlock_bh(&np->np_thread_lock);
432 
433 	if (tpg_np && shutdown) {
434 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
435 
436 		wait_for_completion(&tpg_np->tpg_np_comp);
437 	}
438 
439 	return 0;
440 }
441 
442 static void iscsit_free_np(struct iscsi_np *np)
443 {
444 	if (np->np_socket)
445 		sock_release(np->np_socket);
446 }
447 
448 int iscsit_del_np(struct iscsi_np *np)
449 {
450 	spin_lock_bh(&np->np_thread_lock);
451 	np->np_exports--;
452 	if (np->np_exports) {
453 		np->enabled = true;
454 		spin_unlock_bh(&np->np_thread_lock);
455 		return 0;
456 	}
457 	np->np_thread_state = ISCSI_NP_THREAD_SHUTDOWN;
458 	spin_unlock_bh(&np->np_thread_lock);
459 
460 	if (np->np_thread) {
461 		/*
462 		 * We need to send the signal to wakeup Linux/Net
463 		 * which may be sleeping in sock_accept()..
464 		 */
465 		send_sig(SIGINT, np->np_thread, 1);
466 		kthread_stop(np->np_thread);
467 		np->np_thread = NULL;
468 	}
469 
470 	np->np_transport->iscsit_free_np(np);
471 
472 	mutex_lock(&np_lock);
473 	list_del(&np->np_list);
474 	mutex_unlock(&np_lock);
475 
476 	pr_debug("CORE[0] - Removed Network Portal: %pISpc on %s\n",
477 		&np->np_sockaddr, np->np_transport->name);
478 
479 	iscsit_put_transport(np->np_transport);
480 	kfree(np);
481 	return 0;
482 }
483 
484 static void iscsit_get_rx_pdu(struct iscsi_conn *);
485 
486 int iscsit_queue_rsp(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
487 {
488 	return iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
489 }
490 EXPORT_SYMBOL(iscsit_queue_rsp);
491 
492 void iscsit_aborted_task(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
493 {
494 	spin_lock_bh(&conn->cmd_lock);
495 	if (!list_empty(&cmd->i_conn_node) &&
496 	    !(cmd->se_cmd.transport_state & CMD_T_FABRIC_STOP))
497 		list_del_init(&cmd->i_conn_node);
498 	spin_unlock_bh(&conn->cmd_lock);
499 
500 	__iscsit_free_cmd(cmd, true);
501 }
502 EXPORT_SYMBOL(iscsit_aborted_task);
503 
504 static void iscsit_do_crypto_hash_buf(struct ahash_request *, const void *,
505 				      u32, u32, u8 *, u8 *);
506 static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *);
507 
508 static int
509 iscsit_xmit_nondatain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
510 			  const void *data_buf, u32 data_buf_len)
511 {
512 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)cmd->pdu;
513 	struct kvec *iov;
514 	u32 niov = 0, tx_size = ISCSI_HDR_LEN;
515 	int ret;
516 
517 	iov = &cmd->iov_misc[0];
518 	iov[niov].iov_base	= cmd->pdu;
519 	iov[niov++].iov_len	= ISCSI_HDR_LEN;
520 
521 	if (conn->conn_ops->HeaderDigest) {
522 		u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];
523 
524 		iscsit_do_crypto_hash_buf(conn->conn_tx_hash, hdr,
525 					  ISCSI_HDR_LEN, 0, NULL,
526 					  (u8 *)header_digest);
527 
528 		iov[0].iov_len += ISCSI_CRC_LEN;
529 		tx_size += ISCSI_CRC_LEN;
530 		pr_debug("Attaching CRC32C HeaderDigest"
531 			 " to opcode 0x%x 0x%08x\n",
532 			 hdr->opcode, *header_digest);
533 	}
534 
535 	if (data_buf_len) {
536 		u32 padding = ((-data_buf_len) & 3);
537 
538 		iov[niov].iov_base	= (void *)data_buf;
539 		iov[niov++].iov_len	= data_buf_len;
540 		tx_size += data_buf_len;
541 
542 		if (padding != 0) {
543 			iov[niov].iov_base = &cmd->pad_bytes;
544 			iov[niov++].iov_len = padding;
545 			tx_size += padding;
546 			pr_debug("Attaching %u additional"
547 				 " padding bytes.\n", padding);
548 		}
549 
550 		if (conn->conn_ops->DataDigest) {
551 			iscsit_do_crypto_hash_buf(conn->conn_tx_hash,
552 						  data_buf, data_buf_len,
553 						  padding,
554 						  (u8 *)&cmd->pad_bytes,
555 						  (u8 *)&cmd->data_crc);
556 
557 			iov[niov].iov_base = &cmd->data_crc;
558 			iov[niov++].iov_len = ISCSI_CRC_LEN;
559 			tx_size += ISCSI_CRC_LEN;
560 			pr_debug("Attached DataDigest for %u"
561 				 " bytes opcode 0x%x, CRC 0x%08x\n",
562 				 data_buf_len, hdr->opcode, cmd->data_crc);
563 		}
564 	}
565 
566 	cmd->iov_misc_count = niov;
567 	cmd->tx_size = tx_size;
568 
569 	ret = iscsit_send_tx_data(cmd, conn, 1);
570 	if (ret < 0) {
571 		iscsit_tx_thread_wait_for_tcp(conn);
572 		return ret;
573 	}
574 
575 	return 0;
576 }
577 
578 static int iscsit_map_iovec(struct iscsi_cmd *, struct kvec *, u32, u32);
579 static void iscsit_unmap_iovec(struct iscsi_cmd *);
580 static u32 iscsit_do_crypto_hash_sg(struct ahash_request *, struct iscsi_cmd *,
581 				    u32, u32, u32, u8 *);
582 static int
583 iscsit_xmit_datain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
584 		       const struct iscsi_datain *datain)
585 {
586 	struct kvec *iov;
587 	u32 iov_count = 0, tx_size = 0;
588 	int ret, iov_ret;
589 
590 	iov = &cmd->iov_data[0];
591 	iov[iov_count].iov_base	= cmd->pdu;
592 	iov[iov_count++].iov_len = ISCSI_HDR_LEN;
593 	tx_size += ISCSI_HDR_LEN;
594 
595 	if (conn->conn_ops->HeaderDigest) {
596 		u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];
597 
598 		iscsit_do_crypto_hash_buf(conn->conn_tx_hash, cmd->pdu,
599 					  ISCSI_HDR_LEN, 0, NULL,
600 					  (u8 *)header_digest);
601 
602 		iov[0].iov_len += ISCSI_CRC_LEN;
603 		tx_size += ISCSI_CRC_LEN;
604 
605 		pr_debug("Attaching CRC32 HeaderDigest for DataIN PDU 0x%08x\n",
606 			 *header_digest);
607 	}
608 
609 	iov_ret = iscsit_map_iovec(cmd, &cmd->iov_data[1],
610 				   datain->offset, datain->length);
611 	if (iov_ret < 0)
612 		return -1;
613 
614 	iov_count += iov_ret;
615 	tx_size += datain->length;
616 
617 	cmd->padding = ((-datain->length) & 3);
618 	if (cmd->padding) {
619 		iov[iov_count].iov_base		= cmd->pad_bytes;
620 		iov[iov_count++].iov_len	= cmd->padding;
621 		tx_size += cmd->padding;
622 
623 		pr_debug("Attaching %u padding bytes\n", cmd->padding);
624 	}
625 
626 	if (conn->conn_ops->DataDigest) {
627 		cmd->data_crc = iscsit_do_crypto_hash_sg(conn->conn_tx_hash,
628 							 cmd, datain->offset,
629 							 datain->length,
630 							 cmd->padding,
631 							 cmd->pad_bytes);
632 
633 		iov[iov_count].iov_base	= &cmd->data_crc;
634 		iov[iov_count++].iov_len = ISCSI_CRC_LEN;
635 		tx_size += ISCSI_CRC_LEN;
636 
637 		pr_debug("Attached CRC32C DataDigest %d bytes, crc 0x%08x\n",
638 			 datain->length + cmd->padding, cmd->data_crc);
639 	}
640 
641 	cmd->iov_data_count = iov_count;
642 	cmd->tx_size = tx_size;
643 
644 	ret = iscsit_fe_sendpage_sg(cmd, conn);
645 
646 	iscsit_unmap_iovec(cmd);
647 
648 	if (ret < 0) {
649 		iscsit_tx_thread_wait_for_tcp(conn);
650 		return ret;
651 	}
652 
653 	return 0;
654 }
655 
656 static int iscsit_xmit_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
657 			   struct iscsi_datain_req *dr, const void *buf,
658 			   u32 buf_len)
659 {
660 	if (dr)
661 		return iscsit_xmit_datain_pdu(conn, cmd, buf);
662 	else
663 		return iscsit_xmit_nondatain_pdu(conn, cmd, buf, buf_len);
664 }
665 
666 static enum target_prot_op iscsit_get_sup_prot_ops(struct iscsi_conn *conn)
667 {
668 	return TARGET_PROT_NORMAL;
669 }
670 
671 static struct iscsit_transport iscsi_target_transport = {
672 	.name			= "iSCSI/TCP",
673 	.transport_type		= ISCSI_TCP,
674 	.rdma_shutdown		= false,
675 	.owner			= NULL,
676 	.iscsit_setup_np	= iscsit_setup_np,
677 	.iscsit_accept_np	= iscsit_accept_np,
678 	.iscsit_free_np		= iscsit_free_np,
679 	.iscsit_get_login_rx	= iscsit_get_login_rx,
680 	.iscsit_put_login_tx	= iscsit_put_login_tx,
681 	.iscsit_get_dataout	= iscsit_build_r2ts_for_cmd,
682 	.iscsit_immediate_queue	= iscsit_immediate_queue,
683 	.iscsit_response_queue	= iscsit_response_queue,
684 	.iscsit_queue_data_in	= iscsit_queue_rsp,
685 	.iscsit_queue_status	= iscsit_queue_rsp,
686 	.iscsit_aborted_task	= iscsit_aborted_task,
687 	.iscsit_xmit_pdu	= iscsit_xmit_pdu,
688 	.iscsit_get_rx_pdu	= iscsit_get_rx_pdu,
689 	.iscsit_get_sup_prot_ops = iscsit_get_sup_prot_ops,
690 };
691 
692 static int __init iscsi_target_init_module(void)
693 {
694 	int ret = 0, size;
695 
696 	pr_debug("iSCSI-Target "ISCSIT_VERSION"\n");
697 	iscsit_global = kzalloc(sizeof(*iscsit_global), GFP_KERNEL);
698 	if (!iscsit_global)
699 		return -1;
700 
701 	spin_lock_init(&iscsit_global->ts_bitmap_lock);
702 	mutex_init(&auth_id_lock);
703 	spin_lock_init(&sess_idr_lock);
704 	idr_init(&tiqn_idr);
705 	idr_init(&sess_idr);
706 
707 	ret = target_register_template(&iscsi_ops);
708 	if (ret)
709 		goto out;
710 
711 	size = BITS_TO_LONGS(ISCSIT_BITMAP_BITS) * sizeof(long);
712 	iscsit_global->ts_bitmap = vzalloc(size);
713 	if (!iscsit_global->ts_bitmap)
714 		goto configfs_out;
715 
716 	lio_qr_cache = kmem_cache_create("lio_qr_cache",
717 			sizeof(struct iscsi_queue_req),
718 			__alignof__(struct iscsi_queue_req), 0, NULL);
719 	if (!lio_qr_cache) {
720 		pr_err("nable to kmem_cache_create() for"
721 				" lio_qr_cache\n");
722 		goto bitmap_out;
723 	}
724 
725 	lio_dr_cache = kmem_cache_create("lio_dr_cache",
726 			sizeof(struct iscsi_datain_req),
727 			__alignof__(struct iscsi_datain_req), 0, NULL);
728 	if (!lio_dr_cache) {
729 		pr_err("Unable to kmem_cache_create() for"
730 				" lio_dr_cache\n");
731 		goto qr_out;
732 	}
733 
734 	lio_ooo_cache = kmem_cache_create("lio_ooo_cache",
735 			sizeof(struct iscsi_ooo_cmdsn),
736 			__alignof__(struct iscsi_ooo_cmdsn), 0, NULL);
737 	if (!lio_ooo_cache) {
738 		pr_err("Unable to kmem_cache_create() for"
739 				" lio_ooo_cache\n");
740 		goto dr_out;
741 	}
742 
743 	lio_r2t_cache = kmem_cache_create("lio_r2t_cache",
744 			sizeof(struct iscsi_r2t), __alignof__(struct iscsi_r2t),
745 			0, NULL);
746 	if (!lio_r2t_cache) {
747 		pr_err("Unable to kmem_cache_create() for"
748 				" lio_r2t_cache\n");
749 		goto ooo_out;
750 	}
751 
752 	iscsit_register_transport(&iscsi_target_transport);
753 
754 	if (iscsit_load_discovery_tpg() < 0)
755 		goto r2t_out;
756 
757 	return ret;
758 r2t_out:
759 	iscsit_unregister_transport(&iscsi_target_transport);
760 	kmem_cache_destroy(lio_r2t_cache);
761 ooo_out:
762 	kmem_cache_destroy(lio_ooo_cache);
763 dr_out:
764 	kmem_cache_destroy(lio_dr_cache);
765 qr_out:
766 	kmem_cache_destroy(lio_qr_cache);
767 bitmap_out:
768 	vfree(iscsit_global->ts_bitmap);
769 configfs_out:
770 	/* XXX: this probably wants it to be it's own unwind step.. */
771 	if (iscsit_global->discovery_tpg)
772 		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
773 	target_unregister_template(&iscsi_ops);
774 out:
775 	kfree(iscsit_global);
776 	return -ENOMEM;
777 }
778 
779 static void __exit iscsi_target_cleanup_module(void)
780 {
781 	iscsit_release_discovery_tpg();
782 	iscsit_unregister_transport(&iscsi_target_transport);
783 	kmem_cache_destroy(lio_qr_cache);
784 	kmem_cache_destroy(lio_dr_cache);
785 	kmem_cache_destroy(lio_ooo_cache);
786 	kmem_cache_destroy(lio_r2t_cache);
787 
788 	/*
789 	 * Shutdown discovery sessions and disable discovery TPG
790 	 */
791 	if (iscsit_global->discovery_tpg)
792 		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
793 
794 	target_unregister_template(&iscsi_ops);
795 
796 	vfree(iscsit_global->ts_bitmap);
797 	kfree(iscsit_global);
798 }
799 
800 int iscsit_add_reject(
801 	struct iscsi_conn *conn,
802 	u8 reason,
803 	unsigned char *buf)
804 {
805 	struct iscsi_cmd *cmd;
806 
807 	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
808 	if (!cmd)
809 		return -1;
810 
811 	cmd->iscsi_opcode = ISCSI_OP_REJECT;
812 	cmd->reject_reason = reason;
813 
814 	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
815 	if (!cmd->buf_ptr) {
816 		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
817 		iscsit_free_cmd(cmd, false);
818 		return -1;
819 	}
820 
821 	spin_lock_bh(&conn->cmd_lock);
822 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
823 	spin_unlock_bh(&conn->cmd_lock);
824 
825 	cmd->i_state = ISTATE_SEND_REJECT;
826 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
827 
828 	return -1;
829 }
830 EXPORT_SYMBOL(iscsit_add_reject);
831 
832 static int iscsit_add_reject_from_cmd(
833 	struct iscsi_cmd *cmd,
834 	u8 reason,
835 	bool add_to_conn,
836 	unsigned char *buf)
837 {
838 	struct iscsi_conn *conn;
839 
840 	if (!cmd->conn) {
841 		pr_err("cmd->conn is NULL for ITT: 0x%08x\n",
842 				cmd->init_task_tag);
843 		return -1;
844 	}
845 	conn = cmd->conn;
846 
847 	cmd->iscsi_opcode = ISCSI_OP_REJECT;
848 	cmd->reject_reason = reason;
849 
850 	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
851 	if (!cmd->buf_ptr) {
852 		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
853 		iscsit_free_cmd(cmd, false);
854 		return -1;
855 	}
856 
857 	if (add_to_conn) {
858 		spin_lock_bh(&conn->cmd_lock);
859 		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
860 		spin_unlock_bh(&conn->cmd_lock);
861 	}
862 
863 	cmd->i_state = ISTATE_SEND_REJECT;
864 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
865 	/*
866 	 * Perform the kref_put now if se_cmd has already been setup by
867 	 * scsit_setup_scsi_cmd()
868 	 */
869 	if (cmd->se_cmd.se_tfo != NULL) {
870 		pr_debug("iscsi reject: calling target_put_sess_cmd >>>>>>\n");
871 		target_put_sess_cmd(&cmd->se_cmd);
872 	}
873 	return -1;
874 }
875 
876 static int iscsit_add_reject_cmd(struct iscsi_cmd *cmd, u8 reason,
877 				 unsigned char *buf)
878 {
879 	return iscsit_add_reject_from_cmd(cmd, reason, true, buf);
880 }
881 
882 int iscsit_reject_cmd(struct iscsi_cmd *cmd, u8 reason, unsigned char *buf)
883 {
884 	return iscsit_add_reject_from_cmd(cmd, reason, false, buf);
885 }
886 EXPORT_SYMBOL(iscsit_reject_cmd);
887 
888 /*
889  * Map some portion of the allocated scatterlist to an iovec, suitable for
890  * kernel sockets to copy data in/out.
891  */
892 static int iscsit_map_iovec(
893 	struct iscsi_cmd *cmd,
894 	struct kvec *iov,
895 	u32 data_offset,
896 	u32 data_length)
897 {
898 	u32 i = 0;
899 	struct scatterlist *sg;
900 	unsigned int page_off;
901 
902 	/*
903 	 * We know each entry in t_data_sg contains a page.
904 	 */
905 	u32 ent = data_offset / PAGE_SIZE;
906 
907 	if (ent >= cmd->se_cmd.t_data_nents) {
908 		pr_err("Initial page entry out-of-bounds\n");
909 		return -1;
910 	}
911 
912 	sg = &cmd->se_cmd.t_data_sg[ent];
913 	page_off = (data_offset % PAGE_SIZE);
914 
915 	cmd->first_data_sg = sg;
916 	cmd->first_data_sg_off = page_off;
917 
918 	while (data_length) {
919 		u32 cur_len = min_t(u32, data_length, sg->length - page_off);
920 
921 		iov[i].iov_base = kmap(sg_page(sg)) + sg->offset + page_off;
922 		iov[i].iov_len = cur_len;
923 
924 		data_length -= cur_len;
925 		page_off = 0;
926 		sg = sg_next(sg);
927 		i++;
928 	}
929 
930 	cmd->kmapped_nents = i;
931 
932 	return i;
933 }
934 
935 static void iscsit_unmap_iovec(struct iscsi_cmd *cmd)
936 {
937 	u32 i;
938 	struct scatterlist *sg;
939 
940 	sg = cmd->first_data_sg;
941 
942 	for (i = 0; i < cmd->kmapped_nents; i++)
943 		kunmap(sg_page(&sg[i]));
944 }
945 
946 static void iscsit_ack_from_expstatsn(struct iscsi_conn *conn, u32 exp_statsn)
947 {
948 	LIST_HEAD(ack_list);
949 	struct iscsi_cmd *cmd, *cmd_p;
950 
951 	conn->exp_statsn = exp_statsn;
952 
953 	if (conn->sess->sess_ops->RDMAExtensions)
954 		return;
955 
956 	spin_lock_bh(&conn->cmd_lock);
957 	list_for_each_entry_safe(cmd, cmd_p, &conn->conn_cmd_list, i_conn_node) {
958 		spin_lock(&cmd->istate_lock);
959 		if ((cmd->i_state == ISTATE_SENT_STATUS) &&
960 		    iscsi_sna_lt(cmd->stat_sn, exp_statsn)) {
961 			cmd->i_state = ISTATE_REMOVE;
962 			spin_unlock(&cmd->istate_lock);
963 			list_move_tail(&cmd->i_conn_node, &ack_list);
964 			continue;
965 		}
966 		spin_unlock(&cmd->istate_lock);
967 	}
968 	spin_unlock_bh(&conn->cmd_lock);
969 
970 	list_for_each_entry_safe(cmd, cmd_p, &ack_list, i_conn_node) {
971 		list_del_init(&cmd->i_conn_node);
972 		iscsit_free_cmd(cmd, false);
973 	}
974 }
975 
976 static int iscsit_allocate_iovecs(struct iscsi_cmd *cmd)
977 {
978 	u32 iov_count = max(1UL, DIV_ROUND_UP(cmd->se_cmd.data_length, PAGE_SIZE));
979 
980 	iov_count += ISCSI_IOV_DATA_BUFFER;
981 	cmd->iov_data = kcalloc(iov_count, sizeof(*cmd->iov_data), GFP_KERNEL);
982 	if (!cmd->iov_data)
983 		return -ENOMEM;
984 
985 	cmd->orig_iov_data_count = iov_count;
986 	return 0;
987 }
988 
989 int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
990 			  unsigned char *buf)
991 {
992 	int data_direction, payload_length;
993 	struct iscsi_scsi_req *hdr;
994 	int iscsi_task_attr;
995 	int sam_task_attr;
996 
997 	atomic_long_inc(&conn->sess->cmd_pdus);
998 
999 	hdr			= (struct iscsi_scsi_req *) buf;
1000 	payload_length		= ntoh24(hdr->dlength);
1001 
1002 	/* FIXME; Add checks for AdditionalHeaderSegment */
1003 
1004 	if (!(hdr->flags & ISCSI_FLAG_CMD_WRITE) &&
1005 	    !(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
1006 		pr_err("ISCSI_FLAG_CMD_WRITE & ISCSI_FLAG_CMD_FINAL"
1007 				" not set. Bad iSCSI Initiator.\n");
1008 		return iscsit_add_reject_cmd(cmd,
1009 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1010 	}
1011 
1012 	if (((hdr->flags & ISCSI_FLAG_CMD_READ) ||
1013 	     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) && !hdr->data_length) {
1014 		/*
1015 		 * From RFC-3720 Section 10.3.1:
1016 		 *
1017 		 * "Either or both of R and W MAY be 1 when either the
1018 		 *  Expected Data Transfer Length and/or Bidirectional Read
1019 		 *  Expected Data Transfer Length are 0"
1020 		 *
1021 		 * For this case, go ahead and clear the unnecssary bits
1022 		 * to avoid any confusion with ->data_direction.
1023 		 */
1024 		hdr->flags &= ~ISCSI_FLAG_CMD_READ;
1025 		hdr->flags &= ~ISCSI_FLAG_CMD_WRITE;
1026 
1027 		pr_warn("ISCSI_FLAG_CMD_READ or ISCSI_FLAG_CMD_WRITE"
1028 			" set when Expected Data Transfer Length is 0 for"
1029 			" CDB: 0x%02x, Fixing up flags\n", hdr->cdb[0]);
1030 	}
1031 
1032 	if (!(hdr->flags & ISCSI_FLAG_CMD_READ) &&
1033 	    !(hdr->flags & ISCSI_FLAG_CMD_WRITE) && (hdr->data_length != 0)) {
1034 		pr_err("ISCSI_FLAG_CMD_READ and/or ISCSI_FLAG_CMD_WRITE"
1035 			" MUST be set if Expected Data Transfer Length is not 0."
1036 			" Bad iSCSI Initiator\n");
1037 		return iscsit_add_reject_cmd(cmd,
1038 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1039 	}
1040 
1041 	if ((hdr->flags & ISCSI_FLAG_CMD_READ) &&
1042 	    (hdr->flags & ISCSI_FLAG_CMD_WRITE)) {
1043 		pr_err("Bidirectional operations not supported!\n");
1044 		return iscsit_add_reject_cmd(cmd,
1045 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1046 	}
1047 
1048 	if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
1049 		pr_err("Illegally set Immediate Bit in iSCSI Initiator"
1050 				" Scsi Command PDU.\n");
1051 		return iscsit_add_reject_cmd(cmd,
1052 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1053 	}
1054 
1055 	if (payload_length && !conn->sess->sess_ops->ImmediateData) {
1056 		pr_err("ImmediateData=No but DataSegmentLength=%u,"
1057 			" protocol error.\n", payload_length);
1058 		return iscsit_add_reject_cmd(cmd,
1059 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1060 	}
1061 
1062 	if ((be32_to_cpu(hdr->data_length) == payload_length) &&
1063 	    (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))) {
1064 		pr_err("Expected Data Transfer Length and Length of"
1065 			" Immediate Data are the same, but ISCSI_FLAG_CMD_FINAL"
1066 			" bit is not set protocol error\n");
1067 		return iscsit_add_reject_cmd(cmd,
1068 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1069 	}
1070 
1071 	if (payload_length > be32_to_cpu(hdr->data_length)) {
1072 		pr_err("DataSegmentLength: %u is greater than"
1073 			" EDTL: %u, protocol error.\n", payload_length,
1074 				hdr->data_length);
1075 		return iscsit_add_reject_cmd(cmd,
1076 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1077 	}
1078 
1079 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1080 		pr_err("DataSegmentLength: %u is greater than"
1081 			" MaxXmitDataSegmentLength: %u, protocol error.\n",
1082 			payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
1083 		return iscsit_add_reject_cmd(cmd,
1084 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1085 	}
1086 
1087 	if (payload_length > conn->sess->sess_ops->FirstBurstLength) {
1088 		pr_err("DataSegmentLength: %u is greater than"
1089 			" FirstBurstLength: %u, protocol error.\n",
1090 			payload_length, conn->sess->sess_ops->FirstBurstLength);
1091 		return iscsit_add_reject_cmd(cmd,
1092 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1093 	}
1094 
1095 	data_direction = (hdr->flags & ISCSI_FLAG_CMD_WRITE) ? DMA_TO_DEVICE :
1096 			 (hdr->flags & ISCSI_FLAG_CMD_READ) ? DMA_FROM_DEVICE :
1097 			  DMA_NONE;
1098 
1099 	cmd->data_direction = data_direction;
1100 	iscsi_task_attr = hdr->flags & ISCSI_FLAG_CMD_ATTR_MASK;
1101 	/*
1102 	 * Figure out the SAM Task Attribute for the incoming SCSI CDB
1103 	 */
1104 	if ((iscsi_task_attr == ISCSI_ATTR_UNTAGGED) ||
1105 	    (iscsi_task_attr == ISCSI_ATTR_SIMPLE))
1106 		sam_task_attr = TCM_SIMPLE_TAG;
1107 	else if (iscsi_task_attr == ISCSI_ATTR_ORDERED)
1108 		sam_task_attr = TCM_ORDERED_TAG;
1109 	else if (iscsi_task_attr == ISCSI_ATTR_HEAD_OF_QUEUE)
1110 		sam_task_attr = TCM_HEAD_TAG;
1111 	else if (iscsi_task_attr == ISCSI_ATTR_ACA)
1112 		sam_task_attr = TCM_ACA_TAG;
1113 	else {
1114 		pr_debug("Unknown iSCSI Task Attribute: 0x%02x, using"
1115 			" TCM_SIMPLE_TAG\n", iscsi_task_attr);
1116 		sam_task_attr = TCM_SIMPLE_TAG;
1117 	}
1118 
1119 	cmd->iscsi_opcode	= ISCSI_OP_SCSI_CMD;
1120 	cmd->i_state		= ISTATE_NEW_CMD;
1121 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
1122 	cmd->immediate_data	= (payload_length) ? 1 : 0;
1123 	cmd->unsolicited_data	= ((!(hdr->flags & ISCSI_FLAG_CMD_FINAL) &&
1124 				     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) ? 1 : 0);
1125 	if (cmd->unsolicited_data)
1126 		cmd->cmd_flags |= ICF_NON_IMMEDIATE_UNSOLICITED_DATA;
1127 
1128 	conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
1129 	if (hdr->flags & ISCSI_FLAG_CMD_READ)
1130 		cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
1131 	else
1132 		cmd->targ_xfer_tag = 0xFFFFFFFF;
1133 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
1134 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
1135 	cmd->first_burst_len	= payload_length;
1136 
1137 	if (!conn->sess->sess_ops->RDMAExtensions &&
1138 	     cmd->data_direction == DMA_FROM_DEVICE) {
1139 		struct iscsi_datain_req *dr;
1140 
1141 		dr = iscsit_allocate_datain_req();
1142 		if (!dr)
1143 			return iscsit_add_reject_cmd(cmd,
1144 					ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1145 
1146 		iscsit_attach_datain_req(cmd, dr);
1147 	}
1148 
1149 	/*
1150 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
1151 	 */
1152 	transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
1153 			conn->sess->se_sess, be32_to_cpu(hdr->data_length),
1154 			cmd->data_direction, sam_task_attr,
1155 			cmd->sense_buffer + 2);
1156 
1157 	pr_debug("Got SCSI Command, ITT: 0x%08x, CmdSN: 0x%08x,"
1158 		" ExpXferLen: %u, Length: %u, CID: %hu\n", hdr->itt,
1159 		hdr->cmdsn, be32_to_cpu(hdr->data_length), payload_length,
1160 		conn->cid);
1161 
1162 	target_get_sess_cmd(&cmd->se_cmd, true);
1163 
1164 	cmd->sense_reason = transport_lookup_cmd_lun(&cmd->se_cmd,
1165 						     scsilun_to_int(&hdr->lun));
1166 	if (cmd->sense_reason)
1167 		goto attach_cmd;
1168 
1169 	/* only used for printks or comparing with ->ref_task_tag */
1170 	cmd->se_cmd.tag = (__force u32)cmd->init_task_tag;
1171 	cmd->sense_reason = target_setup_cmd_from_cdb(&cmd->se_cmd, hdr->cdb);
1172 	if (cmd->sense_reason) {
1173 		if (cmd->sense_reason == TCM_OUT_OF_RESOURCES) {
1174 			return iscsit_add_reject_cmd(cmd,
1175 					ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1176 		}
1177 
1178 		goto attach_cmd;
1179 	}
1180 
1181 	if (iscsit_build_pdu_and_seq_lists(cmd, payload_length) < 0) {
1182 		return iscsit_add_reject_cmd(cmd,
1183 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1184 	}
1185 
1186 attach_cmd:
1187 	spin_lock_bh(&conn->cmd_lock);
1188 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
1189 	spin_unlock_bh(&conn->cmd_lock);
1190 	/*
1191 	 * Check if we need to delay processing because of ALUA
1192 	 * Active/NonOptimized primary access state..
1193 	 */
1194 	core_alua_check_nonop_delay(&cmd->se_cmd);
1195 
1196 	return 0;
1197 }
1198 EXPORT_SYMBOL(iscsit_setup_scsi_cmd);
1199 
1200 void iscsit_set_unsoliticed_dataout(struct iscsi_cmd *cmd)
1201 {
1202 	iscsit_set_dataout_sequence_values(cmd);
1203 
1204 	spin_lock_bh(&cmd->dataout_timeout_lock);
1205 	iscsit_start_dataout_timer(cmd, cmd->conn);
1206 	spin_unlock_bh(&cmd->dataout_timeout_lock);
1207 }
1208 EXPORT_SYMBOL(iscsit_set_unsoliticed_dataout);
1209 
1210 int iscsit_process_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1211 			    struct iscsi_scsi_req *hdr)
1212 {
1213 	int cmdsn_ret = 0;
1214 	/*
1215 	 * Check the CmdSN against ExpCmdSN/MaxCmdSN here if
1216 	 * the Immediate Bit is not set, and no Immediate
1217 	 * Data is attached.
1218 	 *
1219 	 * A PDU/CmdSN carrying Immediate Data can only
1220 	 * be processed after the DataCRC has passed.
1221 	 * If the DataCRC fails, the CmdSN MUST NOT
1222 	 * be acknowledged. (See below)
1223 	 */
1224 	if (!cmd->immediate_data) {
1225 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
1226 					(unsigned char *)hdr, hdr->cmdsn);
1227 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1228 			return -1;
1229 		else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
1230 			target_put_sess_cmd(&cmd->se_cmd);
1231 			return 0;
1232 		}
1233 	}
1234 
1235 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
1236 
1237 	/*
1238 	 * If no Immediate Data is attached, it's OK to return now.
1239 	 */
1240 	if (!cmd->immediate_data) {
1241 		if (!cmd->sense_reason && cmd->unsolicited_data)
1242 			iscsit_set_unsoliticed_dataout(cmd);
1243 		if (!cmd->sense_reason)
1244 			return 0;
1245 
1246 		target_put_sess_cmd(&cmd->se_cmd);
1247 		return 0;
1248 	}
1249 
1250 	/*
1251 	 * Early CHECK_CONDITIONs with ImmediateData never make it to command
1252 	 * execution.  These exceptions are processed in CmdSN order using
1253 	 * iscsit_check_received_cmdsn() in iscsit_get_immediate_data() below.
1254 	 */
1255 	if (cmd->sense_reason)
1256 		return 1;
1257 	/*
1258 	 * Call directly into transport_generic_new_cmd() to perform
1259 	 * the backend memory allocation.
1260 	 */
1261 	cmd->sense_reason = transport_generic_new_cmd(&cmd->se_cmd);
1262 	if (cmd->sense_reason)
1263 		return 1;
1264 
1265 	return 0;
1266 }
1267 EXPORT_SYMBOL(iscsit_process_scsi_cmd);
1268 
1269 static int
1270 iscsit_get_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
1271 			  bool dump_payload)
1272 {
1273 	int cmdsn_ret = 0, immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
1274 	/*
1275 	 * Special case for Unsupported SAM WRITE Opcodes and ImmediateData=Yes.
1276 	 */
1277 	if (dump_payload)
1278 		goto after_immediate_data;
1279 	/*
1280 	 * Check for underflow case where both EDTL and immediate data payload
1281 	 * exceeds what is presented by CDB's TRANSFER LENGTH, and what has
1282 	 * already been set in target_cmd_size_check() as se_cmd->data_length.
1283 	 *
1284 	 * For this special case, fail the command and dump the immediate data
1285 	 * payload.
1286 	 */
1287 	if (cmd->first_burst_len > cmd->se_cmd.data_length) {
1288 		cmd->sense_reason = TCM_INVALID_CDB_FIELD;
1289 		goto after_immediate_data;
1290 	}
1291 
1292 	immed_ret = iscsit_handle_immediate_data(cmd, hdr,
1293 					cmd->first_burst_len);
1294 after_immediate_data:
1295 	if (immed_ret == IMMEDIATE_DATA_NORMAL_OPERATION) {
1296 		/*
1297 		 * A PDU/CmdSN carrying Immediate Data passed
1298 		 * DataCRC, check against ExpCmdSN/MaxCmdSN if
1299 		 * Immediate Bit is not set.
1300 		 */
1301 		cmdsn_ret = iscsit_sequence_cmd(cmd->conn, cmd,
1302 					(unsigned char *)hdr, hdr->cmdsn);
1303 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1304 			return -1;
1305 
1306 		if (cmd->sense_reason || cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
1307 			int rc;
1308 
1309 			rc = iscsit_dump_data_payload(cmd->conn,
1310 						      cmd->first_burst_len, 1);
1311 			target_put_sess_cmd(&cmd->se_cmd);
1312 			return rc;
1313 		} else if (cmd->unsolicited_data)
1314 			iscsit_set_unsoliticed_dataout(cmd);
1315 
1316 	} else if (immed_ret == IMMEDIATE_DATA_ERL1_CRC_FAILURE) {
1317 		/*
1318 		 * Immediate Data failed DataCRC and ERL>=1,
1319 		 * silently drop this PDU and let the initiator
1320 		 * plug the CmdSN gap.
1321 		 *
1322 		 * FIXME: Send Unsolicited NOPIN with reserved
1323 		 * TTT here to help the initiator figure out
1324 		 * the missing CmdSN, although they should be
1325 		 * intelligent enough to determine the missing
1326 		 * CmdSN and issue a retry to plug the sequence.
1327 		 */
1328 		cmd->i_state = ISTATE_REMOVE;
1329 		iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, cmd->i_state);
1330 	} else /* immed_ret == IMMEDIATE_DATA_CANNOT_RECOVER */
1331 		return -1;
1332 
1333 	return 0;
1334 }
1335 
1336 static int
1337 iscsit_handle_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1338 			   unsigned char *buf)
1339 {
1340 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)buf;
1341 	int rc, immed_data;
1342 	bool dump_payload = false;
1343 
1344 	rc = iscsit_setup_scsi_cmd(conn, cmd, buf);
1345 	if (rc < 0)
1346 		return 0;
1347 	/*
1348 	 * Allocation iovecs needed for struct socket operations for
1349 	 * traditional iSCSI block I/O.
1350 	 */
1351 	if (iscsit_allocate_iovecs(cmd) < 0) {
1352 		return iscsit_reject_cmd(cmd,
1353 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1354 	}
1355 	immed_data = cmd->immediate_data;
1356 
1357 	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
1358 	if (rc < 0)
1359 		return rc;
1360 	else if (rc > 0)
1361 		dump_payload = true;
1362 
1363 	if (!immed_data)
1364 		return 0;
1365 
1366 	return iscsit_get_immediate_data(cmd, hdr, dump_payload);
1367 }
1368 
1369 static u32 iscsit_do_crypto_hash_sg(
1370 	struct ahash_request *hash,
1371 	struct iscsi_cmd *cmd,
1372 	u32 data_offset,
1373 	u32 data_length,
1374 	u32 padding,
1375 	u8 *pad_bytes)
1376 {
1377 	u32 data_crc;
1378 	struct scatterlist *sg;
1379 	unsigned int page_off;
1380 
1381 	crypto_ahash_init(hash);
1382 
1383 	sg = cmd->first_data_sg;
1384 	page_off = cmd->first_data_sg_off;
1385 
1386 	while (data_length) {
1387 		u32 cur_len = min_t(u32, data_length, (sg->length - page_off));
1388 
1389 		ahash_request_set_crypt(hash, sg, NULL, cur_len);
1390 		crypto_ahash_update(hash);
1391 
1392 		data_length -= cur_len;
1393 		page_off = 0;
1394 		/* iscsit_map_iovec has already checked for invalid sg pointers */
1395 		sg = sg_next(sg);
1396 	}
1397 
1398 	if (padding) {
1399 		struct scatterlist pad_sg;
1400 
1401 		sg_init_one(&pad_sg, pad_bytes, padding);
1402 		ahash_request_set_crypt(hash, &pad_sg, (u8 *)&data_crc,
1403 					padding);
1404 		crypto_ahash_finup(hash);
1405 	} else {
1406 		ahash_request_set_crypt(hash, NULL, (u8 *)&data_crc, 0);
1407 		crypto_ahash_final(hash);
1408 	}
1409 
1410 	return data_crc;
1411 }
1412 
1413 static void iscsit_do_crypto_hash_buf(
1414 	struct ahash_request *hash,
1415 	const void *buf,
1416 	u32 payload_length,
1417 	u32 padding,
1418 	u8 *pad_bytes,
1419 	u8 *data_crc)
1420 {
1421 	struct scatterlist sg[2];
1422 
1423 	sg_init_table(sg, ARRAY_SIZE(sg));
1424 	sg_set_buf(sg, buf, payload_length);
1425 	sg_set_buf(sg + 1, pad_bytes, padding);
1426 
1427 	ahash_request_set_crypt(hash, sg, data_crc, payload_length + padding);
1428 
1429 	crypto_ahash_digest(hash);
1430 }
1431 
1432 int
1433 __iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
1434 			   struct iscsi_cmd *cmd, u32 payload_length,
1435 			   bool *success)
1436 {
1437 	struct iscsi_data *hdr = buf;
1438 	struct se_cmd *se_cmd;
1439 	int rc;
1440 
1441 	/* iSCSI write */
1442 	atomic_long_add(payload_length, &conn->sess->rx_data_octets);
1443 
1444 	pr_debug("Got DataOut ITT: 0x%08x, TTT: 0x%08x,"
1445 		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
1446 		hdr->itt, hdr->ttt, hdr->datasn, ntohl(hdr->offset),
1447 		payload_length, conn->cid);
1448 
1449 	if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
1450 		pr_err("Command ITT: 0x%08x received DataOUT after"
1451 			" last DataOUT received, dumping payload\n",
1452 			cmd->init_task_tag);
1453 		return iscsit_dump_data_payload(conn, payload_length, 1);
1454 	}
1455 
1456 	if (cmd->data_direction != DMA_TO_DEVICE) {
1457 		pr_err("Command ITT: 0x%08x received DataOUT for a"
1458 			" NON-WRITE command.\n", cmd->init_task_tag);
1459 		return iscsit_dump_data_payload(conn, payload_length, 1);
1460 	}
1461 	se_cmd = &cmd->se_cmd;
1462 	iscsit_mod_dataout_timer(cmd);
1463 
1464 	if ((be32_to_cpu(hdr->offset) + payload_length) > cmd->se_cmd.data_length) {
1465 		pr_err("DataOut Offset: %u, Length %u greater than"
1466 			" iSCSI Command EDTL %u, protocol error.\n",
1467 			hdr->offset, payload_length, cmd->se_cmd.data_length);
1468 		return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_INVALID, buf);
1469 	}
1470 
1471 	if (cmd->unsolicited_data) {
1472 		int dump_unsolicited_data = 0;
1473 
1474 		if (conn->sess->sess_ops->InitialR2T) {
1475 			pr_err("Received unexpected unsolicited data"
1476 				" while InitialR2T=Yes, protocol error.\n");
1477 			transport_send_check_condition_and_sense(&cmd->se_cmd,
1478 					TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
1479 			return -1;
1480 		}
1481 		/*
1482 		 * Special case for dealing with Unsolicited DataOUT
1483 		 * and Unsupported SAM WRITE Opcodes and SE resource allocation
1484 		 * failures;
1485 		 */
1486 
1487 		/* Something's amiss if we're not in WRITE_PENDING state... */
1488 		WARN_ON(se_cmd->t_state != TRANSPORT_WRITE_PENDING);
1489 		if (!(se_cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE))
1490 			dump_unsolicited_data = 1;
1491 
1492 		if (dump_unsolicited_data) {
1493 			/*
1494 			 * Check if a delayed TASK_ABORTED status needs to
1495 			 * be sent now if the ISCSI_FLAG_CMD_FINAL has been
1496 			 * received with the unsolicited data out.
1497 			 */
1498 			if (hdr->flags & ISCSI_FLAG_CMD_FINAL)
1499 				iscsit_stop_dataout_timer(cmd);
1500 
1501 			transport_check_aborted_status(se_cmd,
1502 					(hdr->flags & ISCSI_FLAG_CMD_FINAL));
1503 			return iscsit_dump_data_payload(conn, payload_length, 1);
1504 		}
1505 	} else {
1506 		/*
1507 		 * For the normal solicited data path:
1508 		 *
1509 		 * Check for a delayed TASK_ABORTED status and dump any
1510 		 * incoming data out payload if one exists.  Also, when the
1511 		 * ISCSI_FLAG_CMD_FINAL is set to denote the end of the current
1512 		 * data out sequence, we decrement outstanding_r2ts.  Once
1513 		 * outstanding_r2ts reaches zero, go ahead and send the delayed
1514 		 * TASK_ABORTED status.
1515 		 */
1516 		if (se_cmd->transport_state & CMD_T_ABORTED) {
1517 			if (hdr->flags & ISCSI_FLAG_CMD_FINAL)
1518 				if (--cmd->outstanding_r2ts < 1) {
1519 					iscsit_stop_dataout_timer(cmd);
1520 					transport_check_aborted_status(
1521 							se_cmd, 1);
1522 				}
1523 
1524 			return iscsit_dump_data_payload(conn, payload_length, 1);
1525 		}
1526 	}
1527 	/*
1528 	 * Perform DataSN, DataSequenceInOrder, DataPDUInOrder, and
1529 	 * within-command recovery checks before receiving the payload.
1530 	 */
1531 	rc = iscsit_check_pre_dataout(cmd, buf);
1532 	if (rc == DATAOUT_WITHIN_COMMAND_RECOVERY)
1533 		return 0;
1534 	else if (rc == DATAOUT_CANNOT_RECOVER)
1535 		return -1;
1536 	*success = true;
1537 	return 0;
1538 }
1539 EXPORT_SYMBOL(__iscsit_check_dataout_hdr);
1540 
1541 int
1542 iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
1543 			 struct iscsi_cmd **out_cmd)
1544 {
1545 	struct iscsi_data *hdr = buf;
1546 	struct iscsi_cmd *cmd;
1547 	u32 payload_length = ntoh24(hdr->dlength);
1548 	int rc;
1549 	bool success = false;
1550 
1551 	if (!payload_length) {
1552 		pr_warn_ratelimited("DataOUT payload is ZERO, ignoring.\n");
1553 		return 0;
1554 	}
1555 
1556 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1557 		pr_err_ratelimited("DataSegmentLength: %u is greater than"
1558 			" MaxXmitDataSegmentLength: %u\n", payload_length,
1559 			conn->conn_ops->MaxXmitDataSegmentLength);
1560 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR, buf);
1561 	}
1562 
1563 	cmd = iscsit_find_cmd_from_itt_or_dump(conn, hdr->itt, payload_length);
1564 	if (!cmd)
1565 		return 0;
1566 
1567 	rc = __iscsit_check_dataout_hdr(conn, buf, cmd, payload_length, &success);
1568 
1569 	if (success)
1570 		*out_cmd = cmd;
1571 
1572 	return rc;
1573 }
1574 EXPORT_SYMBOL(iscsit_check_dataout_hdr);
1575 
1576 static int
1577 iscsit_get_dataout(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1578 		   struct iscsi_data *hdr)
1579 {
1580 	struct kvec *iov;
1581 	u32 checksum, iov_count = 0, padding = 0, rx_got = 0, rx_size = 0;
1582 	u32 payload_length = ntoh24(hdr->dlength);
1583 	int iov_ret, data_crc_failed = 0;
1584 
1585 	rx_size += payload_length;
1586 	iov = &cmd->iov_data[0];
1587 
1588 	iov_ret = iscsit_map_iovec(cmd, iov, be32_to_cpu(hdr->offset),
1589 				   payload_length);
1590 	if (iov_ret < 0)
1591 		return -1;
1592 
1593 	iov_count += iov_ret;
1594 
1595 	padding = ((-payload_length) & 3);
1596 	if (padding != 0) {
1597 		iov[iov_count].iov_base	= cmd->pad_bytes;
1598 		iov[iov_count++].iov_len = padding;
1599 		rx_size += padding;
1600 		pr_debug("Receiving %u padding bytes.\n", padding);
1601 	}
1602 
1603 	if (conn->conn_ops->DataDigest) {
1604 		iov[iov_count].iov_base = &checksum;
1605 		iov[iov_count++].iov_len = ISCSI_CRC_LEN;
1606 		rx_size += ISCSI_CRC_LEN;
1607 	}
1608 
1609 	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
1610 
1611 	iscsit_unmap_iovec(cmd);
1612 
1613 	if (rx_got != rx_size)
1614 		return -1;
1615 
1616 	if (conn->conn_ops->DataDigest) {
1617 		u32 data_crc;
1618 
1619 		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
1620 						    be32_to_cpu(hdr->offset),
1621 						    payload_length, padding,
1622 						    cmd->pad_bytes);
1623 
1624 		if (checksum != data_crc) {
1625 			pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
1626 				" DataSN: 0x%08x, CRC32C DataDigest 0x%08x"
1627 				" does not match computed 0x%08x\n",
1628 				hdr->itt, hdr->offset, payload_length,
1629 				hdr->datasn, checksum, data_crc);
1630 			data_crc_failed = 1;
1631 		} else {
1632 			pr_debug("Got CRC32C DataDigest 0x%08x for"
1633 				" %u bytes of Data Out\n", checksum,
1634 				payload_length);
1635 		}
1636 	}
1637 
1638 	return data_crc_failed;
1639 }
1640 
1641 int
1642 iscsit_check_dataout_payload(struct iscsi_cmd *cmd, struct iscsi_data *hdr,
1643 			     bool data_crc_failed)
1644 {
1645 	struct iscsi_conn *conn = cmd->conn;
1646 	int rc, ooo_cmdsn;
1647 	/*
1648 	 * Increment post receive data and CRC values or perform
1649 	 * within-command recovery.
1650 	 */
1651 	rc = iscsit_check_post_dataout(cmd, (unsigned char *)hdr, data_crc_failed);
1652 	if ((rc == DATAOUT_NORMAL) || (rc == DATAOUT_WITHIN_COMMAND_RECOVERY))
1653 		return 0;
1654 	else if (rc == DATAOUT_SEND_R2T) {
1655 		iscsit_set_dataout_sequence_values(cmd);
1656 		conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
1657 	} else if (rc == DATAOUT_SEND_TO_TRANSPORT) {
1658 		/*
1659 		 * Handle extra special case for out of order
1660 		 * Unsolicited Data Out.
1661 		 */
1662 		spin_lock_bh(&cmd->istate_lock);
1663 		ooo_cmdsn = (cmd->cmd_flags & ICF_OOO_CMDSN);
1664 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
1665 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
1666 		spin_unlock_bh(&cmd->istate_lock);
1667 
1668 		iscsit_stop_dataout_timer(cmd);
1669 		if (ooo_cmdsn)
1670 			return 0;
1671 		target_execute_cmd(&cmd->se_cmd);
1672 		return 0;
1673 	} else /* DATAOUT_CANNOT_RECOVER */
1674 		return -1;
1675 
1676 	return 0;
1677 }
1678 EXPORT_SYMBOL(iscsit_check_dataout_payload);
1679 
1680 static int iscsit_handle_data_out(struct iscsi_conn *conn, unsigned char *buf)
1681 {
1682 	struct iscsi_cmd *cmd = NULL;
1683 	struct iscsi_data *hdr = (struct iscsi_data *)buf;
1684 	int rc;
1685 	bool data_crc_failed = false;
1686 
1687 	rc = iscsit_check_dataout_hdr(conn, buf, &cmd);
1688 	if (rc < 0)
1689 		return 0;
1690 	else if (!cmd)
1691 		return 0;
1692 
1693 	rc = iscsit_get_dataout(conn, cmd, hdr);
1694 	if (rc < 0)
1695 		return rc;
1696 	else if (rc > 0)
1697 		data_crc_failed = true;
1698 
1699 	return iscsit_check_dataout_payload(cmd, hdr, data_crc_failed);
1700 }
1701 
1702 int iscsit_setup_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1703 			 struct iscsi_nopout *hdr)
1704 {
1705 	u32 payload_length = ntoh24(hdr->dlength);
1706 
1707 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
1708 		pr_err("NopOUT Flag's, Left Most Bit not set, protocol error.\n");
1709 		if (!cmd)
1710 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1711 						 (unsigned char *)hdr);
1712 
1713 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1714 					 (unsigned char *)hdr);
1715 	}
1716 
1717 	if (hdr->itt == RESERVED_ITT && !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
1718 		pr_err("NOPOUT ITT is reserved, but Immediate Bit is"
1719 			" not set, protocol error.\n");
1720 		if (!cmd)
1721 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1722 						 (unsigned char *)hdr);
1723 
1724 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1725 					 (unsigned char *)hdr);
1726 	}
1727 
1728 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1729 		pr_err("NOPOUT Ping Data DataSegmentLength: %u is"
1730 			" greater than MaxXmitDataSegmentLength: %u, protocol"
1731 			" error.\n", payload_length,
1732 			conn->conn_ops->MaxXmitDataSegmentLength);
1733 		if (!cmd)
1734 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1735 						 (unsigned char *)hdr);
1736 
1737 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1738 					 (unsigned char *)hdr);
1739 	}
1740 
1741 	pr_debug("Got NOPOUT Ping %s ITT: 0x%08x, TTT: 0x%08x,"
1742 		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, Length: %u\n",
1743 		hdr->itt == RESERVED_ITT ? "Response" : "Request",
1744 		hdr->itt, hdr->ttt, hdr->cmdsn, hdr->exp_statsn,
1745 		payload_length);
1746 	/*
1747 	 * This is not a response to a Unsolicited NopIN, which means
1748 	 * it can either be a NOPOUT ping request (with a valid ITT),
1749 	 * or a NOPOUT not requesting a NOPIN (with a reserved ITT).
1750 	 * Either way, make sure we allocate an struct iscsi_cmd, as both
1751 	 * can contain ping data.
1752 	 */
1753 	if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1754 		cmd->iscsi_opcode	= ISCSI_OP_NOOP_OUT;
1755 		cmd->i_state		= ISTATE_SEND_NOPIN;
1756 		cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ?
1757 						1 : 0);
1758 		conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
1759 		cmd->targ_xfer_tag	= 0xFFFFFFFF;
1760 		cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
1761 		cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
1762 		cmd->data_direction	= DMA_NONE;
1763 	}
1764 
1765 	return 0;
1766 }
1767 EXPORT_SYMBOL(iscsit_setup_nop_out);
1768 
1769 int iscsit_process_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1770 			   struct iscsi_nopout *hdr)
1771 {
1772 	struct iscsi_cmd *cmd_p = NULL;
1773 	int cmdsn_ret = 0;
1774 	/*
1775 	 * Initiator is expecting a NopIN ping reply..
1776 	 */
1777 	if (hdr->itt != RESERVED_ITT) {
1778 		if (!cmd)
1779 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1780 						(unsigned char *)hdr);
1781 
1782 		spin_lock_bh(&conn->cmd_lock);
1783 		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
1784 		spin_unlock_bh(&conn->cmd_lock);
1785 
1786 		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
1787 
1788 		if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
1789 			iscsit_add_cmd_to_response_queue(cmd, conn,
1790 							 cmd->i_state);
1791 			return 0;
1792 		}
1793 
1794 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
1795 				(unsigned char *)hdr, hdr->cmdsn);
1796                 if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
1797 			return 0;
1798 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1799 			return -1;
1800 
1801 		return 0;
1802 	}
1803 	/*
1804 	 * This was a response to a unsolicited NOPIN ping.
1805 	 */
1806 	if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
1807 		cmd_p = iscsit_find_cmd_from_ttt(conn, be32_to_cpu(hdr->ttt));
1808 		if (!cmd_p)
1809 			return -EINVAL;
1810 
1811 		iscsit_stop_nopin_response_timer(conn);
1812 
1813 		cmd_p->i_state = ISTATE_REMOVE;
1814 		iscsit_add_cmd_to_immediate_queue(cmd_p, conn, cmd_p->i_state);
1815 
1816 		iscsit_start_nopin_timer(conn);
1817 		return 0;
1818 	}
1819 	/*
1820 	 * Otherwise, initiator is not expecting a NOPIN is response.
1821 	 * Just ignore for now.
1822 	 */
1823 
1824 	if (cmd)
1825 		iscsit_free_cmd(cmd, false);
1826 
1827         return 0;
1828 }
1829 EXPORT_SYMBOL(iscsit_process_nop_out);
1830 
1831 static int iscsit_handle_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1832 				 unsigned char *buf)
1833 {
1834 	unsigned char *ping_data = NULL;
1835 	struct iscsi_nopout *hdr = (struct iscsi_nopout *)buf;
1836 	struct kvec *iov = NULL;
1837 	u32 payload_length = ntoh24(hdr->dlength);
1838 	int ret;
1839 
1840 	ret = iscsit_setup_nop_out(conn, cmd, hdr);
1841 	if (ret < 0)
1842 		return 0;
1843 	/*
1844 	 * Handle NOP-OUT payload for traditional iSCSI sockets
1845 	 */
1846 	if (payload_length && hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1847 		u32 checksum, data_crc, padding = 0;
1848 		int niov = 0, rx_got, rx_size = payload_length;
1849 
1850 		ping_data = kzalloc(payload_length + 1, GFP_KERNEL);
1851 		if (!ping_data) {
1852 			ret = -1;
1853 			goto out;
1854 		}
1855 
1856 		iov = &cmd->iov_misc[0];
1857 		iov[niov].iov_base	= ping_data;
1858 		iov[niov++].iov_len	= payload_length;
1859 
1860 		padding = ((-payload_length) & 3);
1861 		if (padding != 0) {
1862 			pr_debug("Receiving %u additional bytes"
1863 				" for padding.\n", padding);
1864 			iov[niov].iov_base	= &cmd->pad_bytes;
1865 			iov[niov++].iov_len	= padding;
1866 			rx_size += padding;
1867 		}
1868 		if (conn->conn_ops->DataDigest) {
1869 			iov[niov].iov_base	= &checksum;
1870 			iov[niov++].iov_len	= ISCSI_CRC_LEN;
1871 			rx_size += ISCSI_CRC_LEN;
1872 		}
1873 
1874 		rx_got = rx_data(conn, &cmd->iov_misc[0], niov, rx_size);
1875 		if (rx_got != rx_size) {
1876 			ret = -1;
1877 			goto out;
1878 		}
1879 
1880 		if (conn->conn_ops->DataDigest) {
1881 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash,
1882 					ping_data, payload_length,
1883 					padding, cmd->pad_bytes,
1884 					(u8 *)&data_crc);
1885 
1886 			if (checksum != data_crc) {
1887 				pr_err("Ping data CRC32C DataDigest"
1888 				" 0x%08x does not match computed 0x%08x\n",
1889 					checksum, data_crc);
1890 				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1891 					pr_err("Unable to recover from"
1892 					" NOPOUT Ping DataCRC failure while in"
1893 						" ERL=0.\n");
1894 					ret = -1;
1895 					goto out;
1896 				} else {
1897 					/*
1898 					 * Silently drop this PDU and let the
1899 					 * initiator plug the CmdSN gap.
1900 					 */
1901 					pr_debug("Dropping NOPOUT"
1902 					" Command CmdSN: 0x%08x due to"
1903 					" DataCRC error.\n", hdr->cmdsn);
1904 					ret = 0;
1905 					goto out;
1906 				}
1907 			} else {
1908 				pr_debug("Got CRC32C DataDigest"
1909 				" 0x%08x for %u bytes of ping data.\n",
1910 					checksum, payload_length);
1911 			}
1912 		}
1913 
1914 		ping_data[payload_length] = '\0';
1915 		/*
1916 		 * Attach ping data to struct iscsi_cmd->buf_ptr.
1917 		 */
1918 		cmd->buf_ptr = ping_data;
1919 		cmd->buf_ptr_size = payload_length;
1920 
1921 		pr_debug("Got %u bytes of NOPOUT ping"
1922 			" data.\n", payload_length);
1923 		pr_debug("Ping Data: \"%s\"\n", ping_data);
1924 	}
1925 
1926 	return iscsit_process_nop_out(conn, cmd, hdr);
1927 out:
1928 	if (cmd)
1929 		iscsit_free_cmd(cmd, false);
1930 
1931 	kfree(ping_data);
1932 	return ret;
1933 }
1934 
1935 static enum tcm_tmreq_table iscsit_convert_tmf(u8 iscsi_tmf)
1936 {
1937 	switch (iscsi_tmf) {
1938 	case ISCSI_TM_FUNC_ABORT_TASK:
1939 		return TMR_ABORT_TASK;
1940 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
1941 		return TMR_ABORT_TASK_SET;
1942 	case ISCSI_TM_FUNC_CLEAR_ACA:
1943 		return TMR_CLEAR_ACA;
1944 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
1945 		return TMR_CLEAR_TASK_SET;
1946 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
1947 		return TMR_LUN_RESET;
1948 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
1949 		return TMR_TARGET_WARM_RESET;
1950 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
1951 		return TMR_TARGET_COLD_RESET;
1952 	default:
1953 		return TMR_UNKNOWN;
1954 	}
1955 }
1956 
1957 int
1958 iscsit_handle_task_mgt_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1959 			   unsigned char *buf)
1960 {
1961 	struct se_tmr_req *se_tmr;
1962 	struct iscsi_tmr_req *tmr_req;
1963 	struct iscsi_tm *hdr;
1964 	int out_of_order_cmdsn = 0, ret;
1965 	bool sess_ref = false;
1966 	u8 function, tcm_function = TMR_UNKNOWN;
1967 
1968 	hdr			= (struct iscsi_tm *) buf;
1969 	hdr->flags &= ~ISCSI_FLAG_CMD_FINAL;
1970 	function = hdr->flags;
1971 
1972 	pr_debug("Got Task Management Request ITT: 0x%08x, CmdSN:"
1973 		" 0x%08x, Function: 0x%02x, RefTaskTag: 0x%08x, RefCmdSN:"
1974 		" 0x%08x, CID: %hu\n", hdr->itt, hdr->cmdsn, function,
1975 		hdr->rtt, hdr->refcmdsn, conn->cid);
1976 
1977 	if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
1978 	    ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
1979 	     hdr->rtt != RESERVED_ITT)) {
1980 		pr_err("RefTaskTag should be set to 0xFFFFFFFF.\n");
1981 		hdr->rtt = RESERVED_ITT;
1982 	}
1983 
1984 	if ((function == ISCSI_TM_FUNC_TASK_REASSIGN) &&
1985 			!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
1986 		pr_err("Task Management Request TASK_REASSIGN not"
1987 			" issued as immediate command, bad iSCSI Initiator"
1988 				"implementation\n");
1989 		return iscsit_add_reject_cmd(cmd,
1990 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1991 	}
1992 	if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
1993 	    be32_to_cpu(hdr->refcmdsn) != ISCSI_RESERVED_TAG)
1994 		hdr->refcmdsn = cpu_to_be32(ISCSI_RESERVED_TAG);
1995 
1996 	cmd->data_direction = DMA_NONE;
1997 	cmd->tmr_req = kzalloc(sizeof(*cmd->tmr_req), GFP_KERNEL);
1998 	if (!cmd->tmr_req)
1999 		return iscsit_add_reject_cmd(cmd,
2000 					     ISCSI_REASON_BOOKMARK_NO_RESOURCES,
2001 					     buf);
2002 
2003 	/*
2004 	 * TASK_REASSIGN for ERL=2 / connection stays inside of
2005 	 * LIO-Target $FABRIC_MOD
2006 	 */
2007 	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
2008 		transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
2009 				      conn->sess->se_sess, 0, DMA_NONE,
2010 				      TCM_SIMPLE_TAG, cmd->sense_buffer + 2);
2011 
2012 		target_get_sess_cmd(&cmd->se_cmd, true);
2013 		sess_ref = true;
2014 		tcm_function = iscsit_convert_tmf(function);
2015 		if (tcm_function == TMR_UNKNOWN) {
2016 			pr_err("Unknown iSCSI TMR Function:"
2017 			       " 0x%02x\n", function);
2018 			return iscsit_add_reject_cmd(cmd,
2019 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
2020 		}
2021 	}
2022 	ret = core_tmr_alloc_req(&cmd->se_cmd, cmd->tmr_req, tcm_function,
2023 				 GFP_KERNEL);
2024 	if (ret < 0)
2025 		return iscsit_add_reject_cmd(cmd,
2026 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
2027 
2028 	cmd->tmr_req->se_tmr_req = cmd->se_cmd.se_tmr_req;
2029 
2030 	cmd->iscsi_opcode	= ISCSI_OP_SCSI_TMFUNC;
2031 	cmd->i_state		= ISTATE_SEND_TASKMGTRSP;
2032 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2033 	cmd->init_task_tag	= hdr->itt;
2034 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2035 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
2036 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
2037 	se_tmr			= cmd->se_cmd.se_tmr_req;
2038 	tmr_req			= cmd->tmr_req;
2039 	/*
2040 	 * Locate the struct se_lun for all TMRs not related to ERL=2 TASK_REASSIGN
2041 	 */
2042 	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
2043 		ret = transport_lookup_tmr_lun(&cmd->se_cmd,
2044 					       scsilun_to_int(&hdr->lun));
2045 		if (ret < 0) {
2046 			se_tmr->response = ISCSI_TMF_RSP_NO_LUN;
2047 			goto attach;
2048 		}
2049 	}
2050 
2051 	switch (function) {
2052 	case ISCSI_TM_FUNC_ABORT_TASK:
2053 		se_tmr->response = iscsit_tmr_abort_task(cmd, buf);
2054 		if (se_tmr->response)
2055 			goto attach;
2056 		break;
2057 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
2058 	case ISCSI_TM_FUNC_CLEAR_ACA:
2059 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
2060 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
2061 		break;
2062 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
2063 		if (iscsit_tmr_task_warm_reset(conn, tmr_req, buf) < 0) {
2064 			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
2065 			goto attach;
2066 		}
2067 		break;
2068 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
2069 		if (iscsit_tmr_task_cold_reset(conn, tmr_req, buf) < 0) {
2070 			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
2071 			goto attach;
2072 		}
2073 		break;
2074 	case ISCSI_TM_FUNC_TASK_REASSIGN:
2075 		se_tmr->response = iscsit_tmr_task_reassign(cmd, buf);
2076 		/*
2077 		 * Perform sanity checks on the ExpDataSN only if the
2078 		 * TASK_REASSIGN was successful.
2079 		 */
2080 		if (se_tmr->response)
2081 			break;
2082 
2083 		if (iscsit_check_task_reassign_expdatasn(tmr_req, conn) < 0)
2084 			return iscsit_add_reject_cmd(cmd,
2085 					ISCSI_REASON_BOOKMARK_INVALID, buf);
2086 		break;
2087 	default:
2088 		pr_err("Unknown TMR function: 0x%02x, protocol"
2089 			" error.\n", function);
2090 		se_tmr->response = ISCSI_TMF_RSP_NOT_SUPPORTED;
2091 		goto attach;
2092 	}
2093 
2094 	if ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
2095 	    (se_tmr->response == ISCSI_TMF_RSP_COMPLETE))
2096 		se_tmr->call_transport = 1;
2097 attach:
2098 	spin_lock_bh(&conn->cmd_lock);
2099 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2100 	spin_unlock_bh(&conn->cmd_lock);
2101 
2102 	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
2103 		int cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
2104 		if (cmdsn_ret == CMDSN_HIGHER_THAN_EXP)
2105 			out_of_order_cmdsn = 1;
2106 		else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
2107 			return 0;
2108 		else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2109 			return -1;
2110 	}
2111 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2112 
2113 	if (out_of_order_cmdsn || !(hdr->opcode & ISCSI_OP_IMMEDIATE))
2114 		return 0;
2115 	/*
2116 	 * Found the referenced task, send to transport for processing.
2117 	 */
2118 	if (se_tmr->call_transport)
2119 		return transport_generic_handle_tmr(&cmd->se_cmd);
2120 
2121 	/*
2122 	 * Could not find the referenced LUN, task, or Task Management
2123 	 * command not authorized or supported.  Change state and
2124 	 * let the tx_thread send the response.
2125 	 *
2126 	 * For connection recovery, this is also the default action for
2127 	 * TMR TASK_REASSIGN.
2128 	 */
2129 	if (sess_ref) {
2130 		pr_debug("Handle TMR, using sess_ref=true check\n");
2131 		target_put_sess_cmd(&cmd->se_cmd);
2132 	}
2133 
2134 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2135 	return 0;
2136 }
2137 EXPORT_SYMBOL(iscsit_handle_task_mgt_cmd);
2138 
2139 /* #warning FIXME: Support Text Command parameters besides SendTargets */
2140 int
2141 iscsit_setup_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2142 		      struct iscsi_text *hdr)
2143 {
2144 	u32 payload_length = ntoh24(hdr->dlength);
2145 
2146 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
2147 		pr_err("Unable to accept text parameter length: %u"
2148 			"greater than MaxXmitDataSegmentLength %u.\n",
2149 		       payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
2150 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
2151 					 (unsigned char *)hdr);
2152 	}
2153 
2154 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL) ||
2155 	     (hdr->flags & ISCSI_FLAG_TEXT_CONTINUE)) {
2156 		pr_err("Multi sequence text commands currently not supported\n");
2157 		return iscsit_reject_cmd(cmd, ISCSI_REASON_CMD_NOT_SUPPORTED,
2158 					(unsigned char *)hdr);
2159 	}
2160 
2161 	pr_debug("Got Text Request: ITT: 0x%08x, CmdSN: 0x%08x,"
2162 		" ExpStatSN: 0x%08x, Length: %u\n", hdr->itt, hdr->cmdsn,
2163 		hdr->exp_statsn, payload_length);
2164 
2165 	cmd->iscsi_opcode	= ISCSI_OP_TEXT;
2166 	cmd->i_state		= ISTATE_SEND_TEXTRSP;
2167 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2168 	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
2169 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2170 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
2171 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
2172 	cmd->data_direction	= DMA_NONE;
2173 	kfree(cmd->text_in_ptr);
2174 	cmd->text_in_ptr	= NULL;
2175 
2176 	return 0;
2177 }
2178 EXPORT_SYMBOL(iscsit_setup_text_cmd);
2179 
2180 int
2181 iscsit_process_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2182 			struct iscsi_text *hdr)
2183 {
2184 	unsigned char *text_in = cmd->text_in_ptr, *text_ptr;
2185 	int cmdsn_ret;
2186 
2187 	if (!text_in) {
2188 		cmd->targ_xfer_tag = be32_to_cpu(hdr->ttt);
2189 		if (cmd->targ_xfer_tag == 0xFFFFFFFF) {
2190 			pr_err("Unable to locate text_in buffer for sendtargets"
2191 			       " discovery\n");
2192 			goto reject;
2193 		}
2194 		goto empty_sendtargets;
2195 	}
2196 	if (strncmp("SendTargets", text_in, 11) != 0) {
2197 		pr_err("Received Text Data that is not"
2198 			" SendTargets, cannot continue.\n");
2199 		goto reject;
2200 	}
2201 	text_ptr = strchr(text_in, '=');
2202 	if (!text_ptr) {
2203 		pr_err("No \"=\" separator found in Text Data,"
2204 			"  cannot continue.\n");
2205 		goto reject;
2206 	}
2207 	if (!strncmp("=All", text_ptr, 4)) {
2208 		cmd->cmd_flags |= ICF_SENDTARGETS_ALL;
2209 	} else if (!strncmp("=iqn.", text_ptr, 5) ||
2210 		   !strncmp("=eui.", text_ptr, 5)) {
2211 		cmd->cmd_flags |= ICF_SENDTARGETS_SINGLE;
2212 	} else {
2213 		pr_err("Unable to locate valid SendTargets=%s value\n", text_ptr);
2214 		goto reject;
2215 	}
2216 
2217 	spin_lock_bh(&conn->cmd_lock);
2218 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2219 	spin_unlock_bh(&conn->cmd_lock);
2220 
2221 empty_sendtargets:
2222 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2223 
2224 	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
2225 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
2226 				(unsigned char *)hdr, hdr->cmdsn);
2227 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2228 			return -1;
2229 
2230 		return 0;
2231 	}
2232 
2233 	return iscsit_execute_cmd(cmd, 0);
2234 
2235 reject:
2236 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
2237 				 (unsigned char *)hdr);
2238 }
2239 EXPORT_SYMBOL(iscsit_process_text_cmd);
2240 
2241 static int
2242 iscsit_handle_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2243 		       unsigned char *buf)
2244 {
2245 	struct iscsi_text *hdr = (struct iscsi_text *)buf;
2246 	char *text_in = NULL;
2247 	u32 payload_length = ntoh24(hdr->dlength);
2248 	int rx_size, rc;
2249 
2250 	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
2251 	if (rc < 0)
2252 		return 0;
2253 
2254 	rx_size = payload_length;
2255 	if (payload_length) {
2256 		u32 checksum = 0, data_crc = 0;
2257 		u32 padding = 0, pad_bytes = 0;
2258 		int niov = 0, rx_got;
2259 		struct kvec iov[3];
2260 
2261 		text_in = kzalloc(payload_length, GFP_KERNEL);
2262 		if (!text_in)
2263 			goto reject;
2264 
2265 		cmd->text_in_ptr = text_in;
2266 
2267 		memset(iov, 0, 3 * sizeof(struct kvec));
2268 		iov[niov].iov_base	= text_in;
2269 		iov[niov++].iov_len	= payload_length;
2270 
2271 		padding = ((-payload_length) & 3);
2272 		if (padding != 0) {
2273 			iov[niov].iov_base = &pad_bytes;
2274 			iov[niov++].iov_len  = padding;
2275 			rx_size += padding;
2276 			pr_debug("Receiving %u additional bytes"
2277 					" for padding.\n", padding);
2278 		}
2279 		if (conn->conn_ops->DataDigest) {
2280 			iov[niov].iov_base	= &checksum;
2281 			iov[niov++].iov_len	= ISCSI_CRC_LEN;
2282 			rx_size += ISCSI_CRC_LEN;
2283 		}
2284 
2285 		rx_got = rx_data(conn, &iov[0], niov, rx_size);
2286 		if (rx_got != rx_size)
2287 			goto reject;
2288 
2289 		if (conn->conn_ops->DataDigest) {
2290 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash,
2291 					text_in, payload_length,
2292 					padding, (u8 *)&pad_bytes,
2293 					(u8 *)&data_crc);
2294 
2295 			if (checksum != data_crc) {
2296 				pr_err("Text data CRC32C DataDigest"
2297 					" 0x%08x does not match computed"
2298 					" 0x%08x\n", checksum, data_crc);
2299 				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2300 					pr_err("Unable to recover from"
2301 					" Text Data digest failure while in"
2302 						" ERL=0.\n");
2303 					goto reject;
2304 				} else {
2305 					/*
2306 					 * Silently drop this PDU and let the
2307 					 * initiator plug the CmdSN gap.
2308 					 */
2309 					pr_debug("Dropping Text"
2310 					" Command CmdSN: 0x%08x due to"
2311 					" DataCRC error.\n", hdr->cmdsn);
2312 					kfree(text_in);
2313 					return 0;
2314 				}
2315 			} else {
2316 				pr_debug("Got CRC32C DataDigest"
2317 					" 0x%08x for %u bytes of text data.\n",
2318 						checksum, payload_length);
2319 			}
2320 		}
2321 		text_in[payload_length - 1] = '\0';
2322 		pr_debug("Successfully read %d bytes of text"
2323 				" data.\n", payload_length);
2324 	}
2325 
2326 	return iscsit_process_text_cmd(conn, cmd, hdr);
2327 
2328 reject:
2329 	kfree(cmd->text_in_ptr);
2330 	cmd->text_in_ptr = NULL;
2331 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
2332 }
2333 
2334 int iscsit_logout_closesession(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2335 {
2336 	struct iscsi_conn *conn_p;
2337 	struct iscsi_session *sess = conn->sess;
2338 
2339 	pr_debug("Received logout request CLOSESESSION on CID: %hu"
2340 		" for SID: %u.\n", conn->cid, conn->sess->sid);
2341 
2342 	atomic_set(&sess->session_logout, 1);
2343 	atomic_set(&conn->conn_logout_remove, 1);
2344 	conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_SESSION;
2345 
2346 	iscsit_inc_conn_usage_count(conn);
2347 	iscsit_inc_session_usage_count(sess);
2348 
2349 	spin_lock_bh(&sess->conn_lock);
2350 	list_for_each_entry(conn_p, &sess->sess_conn_list, conn_list) {
2351 		if (conn_p->conn_state != TARG_CONN_STATE_LOGGED_IN)
2352 			continue;
2353 
2354 		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
2355 		conn_p->conn_state = TARG_CONN_STATE_IN_LOGOUT;
2356 	}
2357 	spin_unlock_bh(&sess->conn_lock);
2358 
2359 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2360 
2361 	return 0;
2362 }
2363 
2364 int iscsit_logout_closeconnection(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2365 {
2366 	struct iscsi_conn *l_conn;
2367 	struct iscsi_session *sess = conn->sess;
2368 
2369 	pr_debug("Received logout request CLOSECONNECTION for CID:"
2370 		" %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
2371 
2372 	/*
2373 	 * A Logout Request with a CLOSECONNECTION reason code for a CID
2374 	 * can arrive on a connection with a differing CID.
2375 	 */
2376 	if (conn->cid == cmd->logout_cid) {
2377 		spin_lock_bh(&conn->state_lock);
2378 		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
2379 		conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
2380 
2381 		atomic_set(&conn->conn_logout_remove, 1);
2382 		conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_CONNECTION;
2383 		iscsit_inc_conn_usage_count(conn);
2384 
2385 		spin_unlock_bh(&conn->state_lock);
2386 	} else {
2387 		/*
2388 		 * Handle all different cid CLOSECONNECTION requests in
2389 		 * iscsit_logout_post_handler_diffcid() as to give enough
2390 		 * time for any non immediate command's CmdSN to be
2391 		 * acknowledged on the connection in question.
2392 		 *
2393 		 * Here we simply make sure the CID is still around.
2394 		 */
2395 		l_conn = iscsit_get_conn_from_cid(sess,
2396 				cmd->logout_cid);
2397 		if (!l_conn) {
2398 			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
2399 			iscsit_add_cmd_to_response_queue(cmd, conn,
2400 					cmd->i_state);
2401 			return 0;
2402 		}
2403 
2404 		iscsit_dec_conn_usage_count(l_conn);
2405 	}
2406 
2407 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2408 
2409 	return 0;
2410 }
2411 
2412 int iscsit_logout_removeconnforrecovery(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2413 {
2414 	struct iscsi_session *sess = conn->sess;
2415 
2416 	pr_debug("Received explicit REMOVECONNFORRECOVERY logout for"
2417 		" CID: %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
2418 
2419 	if (sess->sess_ops->ErrorRecoveryLevel != 2) {
2420 		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
2421 			" while ERL!=2.\n");
2422 		cmd->logout_response = ISCSI_LOGOUT_RECOVERY_UNSUPPORTED;
2423 		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2424 		return 0;
2425 	}
2426 
2427 	if (conn->cid == cmd->logout_cid) {
2428 		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
2429 			" with CID: %hu on CID: %hu, implementation error.\n",
2430 				cmd->logout_cid, conn->cid);
2431 		cmd->logout_response = ISCSI_LOGOUT_CLEANUP_FAILED;
2432 		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2433 		return 0;
2434 	}
2435 
2436 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2437 
2438 	return 0;
2439 }
2440 
2441 int
2442 iscsit_handle_logout_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2443 			unsigned char *buf)
2444 {
2445 	int cmdsn_ret, logout_remove = 0;
2446 	u8 reason_code = 0;
2447 	struct iscsi_logout *hdr;
2448 	struct iscsi_tiqn *tiqn = iscsit_snmp_get_tiqn(conn);
2449 
2450 	hdr			= (struct iscsi_logout *) buf;
2451 	reason_code		= (hdr->flags & 0x7f);
2452 
2453 	if (tiqn) {
2454 		spin_lock(&tiqn->logout_stats.lock);
2455 		if (reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION)
2456 			tiqn->logout_stats.normal_logouts++;
2457 		else
2458 			tiqn->logout_stats.abnormal_logouts++;
2459 		spin_unlock(&tiqn->logout_stats.lock);
2460 	}
2461 
2462 	pr_debug("Got Logout Request ITT: 0x%08x CmdSN: 0x%08x"
2463 		" ExpStatSN: 0x%08x Reason: 0x%02x CID: %hu on CID: %hu\n",
2464 		hdr->itt, hdr->cmdsn, hdr->exp_statsn, reason_code,
2465 		hdr->cid, conn->cid);
2466 
2467 	if (conn->conn_state != TARG_CONN_STATE_LOGGED_IN) {
2468 		pr_err("Received logout request on connection that"
2469 			" is not in logged in state, ignoring request.\n");
2470 		iscsit_free_cmd(cmd, false);
2471 		return 0;
2472 	}
2473 
2474 	cmd->iscsi_opcode       = ISCSI_OP_LOGOUT;
2475 	cmd->i_state            = ISTATE_SEND_LOGOUTRSP;
2476 	cmd->immediate_cmd      = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2477 	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
2478 	cmd->targ_xfer_tag      = 0xFFFFFFFF;
2479 	cmd->cmd_sn             = be32_to_cpu(hdr->cmdsn);
2480 	cmd->exp_stat_sn        = be32_to_cpu(hdr->exp_statsn);
2481 	cmd->logout_cid         = be16_to_cpu(hdr->cid);
2482 	cmd->logout_reason      = reason_code;
2483 	cmd->data_direction     = DMA_NONE;
2484 
2485 	/*
2486 	 * We need to sleep in these cases (by returning 1) until the Logout
2487 	 * Response gets sent in the tx thread.
2488 	 */
2489 	if ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION) ||
2490 	   ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION) &&
2491 	    be16_to_cpu(hdr->cid) == conn->cid))
2492 		logout_remove = 1;
2493 
2494 	spin_lock_bh(&conn->cmd_lock);
2495 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2496 	spin_unlock_bh(&conn->cmd_lock);
2497 
2498 	if (reason_code != ISCSI_LOGOUT_REASON_RECOVERY)
2499 		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2500 
2501 	/*
2502 	 * Immediate commands are executed, well, immediately.
2503 	 * Non-Immediate Logout Commands are executed in CmdSN order.
2504 	 */
2505 	if (cmd->immediate_cmd) {
2506 		int ret = iscsit_execute_cmd(cmd, 0);
2507 
2508 		if (ret < 0)
2509 			return ret;
2510 	} else {
2511 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
2512 		if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
2513 			logout_remove = 0;
2514 		else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2515 			return -1;
2516 	}
2517 
2518 	return logout_remove;
2519 }
2520 EXPORT_SYMBOL(iscsit_handle_logout_cmd);
2521 
2522 int iscsit_handle_snack(
2523 	struct iscsi_conn *conn,
2524 	unsigned char *buf)
2525 {
2526 	struct iscsi_snack *hdr;
2527 
2528 	hdr			= (struct iscsi_snack *) buf;
2529 	hdr->flags		&= ~ISCSI_FLAG_CMD_FINAL;
2530 
2531 	pr_debug("Got ISCSI_INIT_SNACK, ITT: 0x%08x, ExpStatSN:"
2532 		" 0x%08x, Type: 0x%02x, BegRun: 0x%08x, RunLength: 0x%08x,"
2533 		" CID: %hu\n", hdr->itt, hdr->exp_statsn, hdr->flags,
2534 			hdr->begrun, hdr->runlength, conn->cid);
2535 
2536 	if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2537 		pr_err("Initiator sent SNACK request while in"
2538 			" ErrorRecoveryLevel=0.\n");
2539 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2540 					 buf);
2541 	}
2542 	/*
2543 	 * SNACK_DATA and SNACK_R2T are both 0,  so check which function to
2544 	 * call from inside iscsi_send_recovery_datain_or_r2t().
2545 	 */
2546 	switch (hdr->flags & ISCSI_FLAG_SNACK_TYPE_MASK) {
2547 	case 0:
2548 		return iscsit_handle_recovery_datain_or_r2t(conn, buf,
2549 			hdr->itt,
2550 			be32_to_cpu(hdr->ttt),
2551 			be32_to_cpu(hdr->begrun),
2552 			be32_to_cpu(hdr->runlength));
2553 	case ISCSI_FLAG_SNACK_TYPE_STATUS:
2554 		return iscsit_handle_status_snack(conn, hdr->itt,
2555 			be32_to_cpu(hdr->ttt),
2556 			be32_to_cpu(hdr->begrun), be32_to_cpu(hdr->runlength));
2557 	case ISCSI_FLAG_SNACK_TYPE_DATA_ACK:
2558 		return iscsit_handle_data_ack(conn, be32_to_cpu(hdr->ttt),
2559 			be32_to_cpu(hdr->begrun),
2560 			be32_to_cpu(hdr->runlength));
2561 	case ISCSI_FLAG_SNACK_TYPE_RDATA:
2562 		/* FIXME: Support R-Data SNACK */
2563 		pr_err("R-Data SNACK Not Supported.\n");
2564 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2565 					 buf);
2566 	default:
2567 		pr_err("Unknown SNACK type 0x%02x, protocol"
2568 			" error.\n", hdr->flags & 0x0f);
2569 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2570 					 buf);
2571 	}
2572 
2573 	return 0;
2574 }
2575 EXPORT_SYMBOL(iscsit_handle_snack);
2576 
2577 static void iscsit_rx_thread_wait_for_tcp(struct iscsi_conn *conn)
2578 {
2579 	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
2580 	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
2581 		wait_for_completion_interruptible_timeout(
2582 					&conn->rx_half_close_comp,
2583 					ISCSI_RX_THREAD_TCP_TIMEOUT * HZ);
2584 	}
2585 }
2586 
2587 static int iscsit_handle_immediate_data(
2588 	struct iscsi_cmd *cmd,
2589 	struct iscsi_scsi_req *hdr,
2590 	u32 length)
2591 {
2592 	int iov_ret, rx_got = 0, rx_size = 0;
2593 	u32 checksum, iov_count = 0, padding = 0;
2594 	struct iscsi_conn *conn = cmd->conn;
2595 	struct kvec *iov;
2596 
2597 	iov_ret = iscsit_map_iovec(cmd, cmd->iov_data, cmd->write_data_done, length);
2598 	if (iov_ret < 0)
2599 		return IMMEDIATE_DATA_CANNOT_RECOVER;
2600 
2601 	rx_size = length;
2602 	iov_count = iov_ret;
2603 	iov = &cmd->iov_data[0];
2604 
2605 	padding = ((-length) & 3);
2606 	if (padding != 0) {
2607 		iov[iov_count].iov_base	= cmd->pad_bytes;
2608 		iov[iov_count++].iov_len = padding;
2609 		rx_size += padding;
2610 	}
2611 
2612 	if (conn->conn_ops->DataDigest) {
2613 		iov[iov_count].iov_base		= &checksum;
2614 		iov[iov_count++].iov_len	= ISCSI_CRC_LEN;
2615 		rx_size += ISCSI_CRC_LEN;
2616 	}
2617 
2618 	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
2619 
2620 	iscsit_unmap_iovec(cmd);
2621 
2622 	if (rx_got != rx_size) {
2623 		iscsit_rx_thread_wait_for_tcp(conn);
2624 		return IMMEDIATE_DATA_CANNOT_RECOVER;
2625 	}
2626 
2627 	if (conn->conn_ops->DataDigest) {
2628 		u32 data_crc;
2629 
2630 		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
2631 						    cmd->write_data_done, length, padding,
2632 						    cmd->pad_bytes);
2633 
2634 		if (checksum != data_crc) {
2635 			pr_err("ImmediateData CRC32C DataDigest 0x%08x"
2636 				" does not match computed 0x%08x\n", checksum,
2637 				data_crc);
2638 
2639 			if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2640 				pr_err("Unable to recover from"
2641 					" Immediate Data digest failure while"
2642 					" in ERL=0.\n");
2643 				iscsit_reject_cmd(cmd,
2644 						ISCSI_REASON_DATA_DIGEST_ERROR,
2645 						(unsigned char *)hdr);
2646 				return IMMEDIATE_DATA_CANNOT_RECOVER;
2647 			} else {
2648 				iscsit_reject_cmd(cmd,
2649 						ISCSI_REASON_DATA_DIGEST_ERROR,
2650 						(unsigned char *)hdr);
2651 				return IMMEDIATE_DATA_ERL1_CRC_FAILURE;
2652 			}
2653 		} else {
2654 			pr_debug("Got CRC32C DataDigest 0x%08x for"
2655 				" %u bytes of Immediate Data\n", checksum,
2656 				length);
2657 		}
2658 	}
2659 
2660 	cmd->write_data_done += length;
2661 
2662 	if (cmd->write_data_done == cmd->se_cmd.data_length) {
2663 		spin_lock_bh(&cmd->istate_lock);
2664 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
2665 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
2666 		spin_unlock_bh(&cmd->istate_lock);
2667 	}
2668 
2669 	return IMMEDIATE_DATA_NORMAL_OPERATION;
2670 }
2671 
2672 /*
2673  *	Called with sess->conn_lock held.
2674  */
2675 /* #warning iscsi_build_conn_drop_async_message() only sends out on connections
2676 	with active network interface */
2677 static void iscsit_build_conn_drop_async_message(struct iscsi_conn *conn)
2678 {
2679 	struct iscsi_cmd *cmd;
2680 	struct iscsi_conn *conn_p;
2681 	bool found = false;
2682 
2683 	/*
2684 	 * Only send a Asynchronous Message on connections whos network
2685 	 * interface is still functional.
2686 	 */
2687 	list_for_each_entry(conn_p, &conn->sess->sess_conn_list, conn_list) {
2688 		if (conn_p->conn_state == TARG_CONN_STATE_LOGGED_IN) {
2689 			iscsit_inc_conn_usage_count(conn_p);
2690 			found = true;
2691 			break;
2692 		}
2693 	}
2694 
2695 	if (!found)
2696 		return;
2697 
2698 	cmd = iscsit_allocate_cmd(conn_p, TASK_RUNNING);
2699 	if (!cmd) {
2700 		iscsit_dec_conn_usage_count(conn_p);
2701 		return;
2702 	}
2703 
2704 	cmd->logout_cid = conn->cid;
2705 	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
2706 	cmd->i_state = ISTATE_SEND_ASYNCMSG;
2707 
2708 	spin_lock_bh(&conn_p->cmd_lock);
2709 	list_add_tail(&cmd->i_conn_node, &conn_p->conn_cmd_list);
2710 	spin_unlock_bh(&conn_p->cmd_lock);
2711 
2712 	iscsit_add_cmd_to_response_queue(cmd, conn_p, cmd->i_state);
2713 	iscsit_dec_conn_usage_count(conn_p);
2714 }
2715 
2716 static int iscsit_send_conn_drop_async_message(
2717 	struct iscsi_cmd *cmd,
2718 	struct iscsi_conn *conn)
2719 {
2720 	struct iscsi_async *hdr;
2721 
2722 	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
2723 
2724 	hdr			= (struct iscsi_async *) cmd->pdu;
2725 	hdr->opcode		= ISCSI_OP_ASYNC_EVENT;
2726 	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
2727 	cmd->init_task_tag	= RESERVED_ITT;
2728 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2729 	put_unaligned_be64(0xFFFFFFFFFFFFFFFFULL, &hdr->rsvd4[0]);
2730 	cmd->stat_sn		= conn->stat_sn++;
2731 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2732 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2733 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2734 	hdr->async_event	= ISCSI_ASYNC_MSG_DROPPING_CONNECTION;
2735 	hdr->param1		= cpu_to_be16(cmd->logout_cid);
2736 	hdr->param2		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Wait);
2737 	hdr->param3		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Retain);
2738 
2739 	pr_debug("Sending Connection Dropped Async Message StatSN:"
2740 		" 0x%08x, for CID: %hu on CID: %hu\n", cmd->stat_sn,
2741 			cmd->logout_cid, conn->cid);
2742 
2743 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
2744 }
2745 
2746 static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *conn)
2747 {
2748 	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
2749 	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
2750 		wait_for_completion_interruptible_timeout(
2751 					&conn->tx_half_close_comp,
2752 					ISCSI_TX_THREAD_TCP_TIMEOUT * HZ);
2753 	}
2754 }
2755 
2756 void
2757 iscsit_build_datain_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2758 			struct iscsi_datain *datain, struct iscsi_data_rsp *hdr,
2759 			bool set_statsn)
2760 {
2761 	hdr->opcode		= ISCSI_OP_SCSI_DATA_IN;
2762 	hdr->flags		= datain->flags;
2763 	if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
2764 		if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
2765 			hdr->flags |= ISCSI_FLAG_DATA_OVERFLOW;
2766 			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
2767 		} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
2768 			hdr->flags |= ISCSI_FLAG_DATA_UNDERFLOW;
2769 			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
2770 		}
2771 	}
2772 	hton24(hdr->dlength, datain->length);
2773 	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
2774 		int_to_scsilun(cmd->se_cmd.orig_fe_lun,
2775 				(struct scsi_lun *)&hdr->lun);
2776 	else
2777 		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
2778 
2779 	hdr->itt		= cmd->init_task_tag;
2780 
2781 	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
2782 		hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
2783 	else
2784 		hdr->ttt		= cpu_to_be32(0xFFFFFFFF);
2785 	if (set_statsn)
2786 		hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2787 	else
2788 		hdr->statsn		= cpu_to_be32(0xFFFFFFFF);
2789 
2790 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2791 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2792 	hdr->datasn		= cpu_to_be32(datain->data_sn);
2793 	hdr->offset		= cpu_to_be32(datain->offset);
2794 
2795 	pr_debug("Built DataIN ITT: 0x%08x, StatSN: 0x%08x,"
2796 		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
2797 		cmd->init_task_tag, ntohl(hdr->statsn), ntohl(hdr->datasn),
2798 		ntohl(hdr->offset), datain->length, conn->cid);
2799 }
2800 EXPORT_SYMBOL(iscsit_build_datain_pdu);
2801 
2802 static int iscsit_send_datain(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2803 {
2804 	struct iscsi_data_rsp *hdr = (struct iscsi_data_rsp *)&cmd->pdu[0];
2805 	struct iscsi_datain datain;
2806 	struct iscsi_datain_req *dr;
2807 	int eodr = 0, ret;
2808 	bool set_statsn = false;
2809 
2810 	memset(&datain, 0, sizeof(struct iscsi_datain));
2811 	dr = iscsit_get_datain_values(cmd, &datain);
2812 	if (!dr) {
2813 		pr_err("iscsit_get_datain_values failed for ITT: 0x%08x\n",
2814 				cmd->init_task_tag);
2815 		return -1;
2816 	}
2817 	/*
2818 	 * Be paranoid and double check the logic for now.
2819 	 */
2820 	if ((datain.offset + datain.length) > cmd->se_cmd.data_length) {
2821 		pr_err("Command ITT: 0x%08x, datain.offset: %u and"
2822 			" datain.length: %u exceeds cmd->data_length: %u\n",
2823 			cmd->init_task_tag, datain.offset, datain.length,
2824 			cmd->se_cmd.data_length);
2825 		return -1;
2826 	}
2827 
2828 	atomic_long_add(datain.length, &conn->sess->tx_data_octets);
2829 	/*
2830 	 * Special case for successfully execution w/ both DATAIN
2831 	 * and Sense Data.
2832 	 */
2833 	if ((datain.flags & ISCSI_FLAG_DATA_STATUS) &&
2834 	    (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE))
2835 		datain.flags &= ~ISCSI_FLAG_DATA_STATUS;
2836 	else {
2837 		if ((dr->dr_complete == DATAIN_COMPLETE_NORMAL) ||
2838 		    (dr->dr_complete == DATAIN_COMPLETE_CONNECTION_RECOVERY)) {
2839 			iscsit_increment_maxcmdsn(cmd, conn->sess);
2840 			cmd->stat_sn = conn->stat_sn++;
2841 			set_statsn = true;
2842 		} else if (dr->dr_complete ==
2843 			   DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY)
2844 			set_statsn = true;
2845 	}
2846 
2847 	iscsit_build_datain_pdu(cmd, conn, &datain, hdr, set_statsn);
2848 
2849 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, dr, &datain, 0);
2850 	if (ret < 0)
2851 		return ret;
2852 
2853 	if (dr->dr_complete) {
2854 		eodr = (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ?
2855 				2 : 1;
2856 		iscsit_free_datain_req(cmd, dr);
2857 	}
2858 
2859 	return eodr;
2860 }
2861 
2862 int
2863 iscsit_build_logout_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2864 			struct iscsi_logout_rsp *hdr)
2865 {
2866 	struct iscsi_conn *logout_conn = NULL;
2867 	struct iscsi_conn_recovery *cr = NULL;
2868 	struct iscsi_session *sess = conn->sess;
2869 	/*
2870 	 * The actual shutting down of Sessions and/or Connections
2871 	 * for CLOSESESSION and CLOSECONNECTION Logout Requests
2872 	 * is done in scsi_logout_post_handler().
2873 	 */
2874 	switch (cmd->logout_reason) {
2875 	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
2876 		pr_debug("iSCSI session logout successful, setting"
2877 			" logout response to ISCSI_LOGOUT_SUCCESS.\n");
2878 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2879 		break;
2880 	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
2881 		if (cmd->logout_response == ISCSI_LOGOUT_CID_NOT_FOUND)
2882 			break;
2883 		/*
2884 		 * For CLOSECONNECTION logout requests carrying
2885 		 * a matching logout CID -> local CID, the reference
2886 		 * for the local CID will have been incremented in
2887 		 * iscsi_logout_closeconnection().
2888 		 *
2889 		 * For CLOSECONNECTION logout requests carrying
2890 		 * a different CID than the connection it arrived
2891 		 * on, the connection responding to cmd->logout_cid
2892 		 * is stopped in iscsit_logout_post_handler_diffcid().
2893 		 */
2894 
2895 		pr_debug("iSCSI CID: %hu logout on CID: %hu"
2896 			" successful.\n", cmd->logout_cid, conn->cid);
2897 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2898 		break;
2899 	case ISCSI_LOGOUT_REASON_RECOVERY:
2900 		if ((cmd->logout_response == ISCSI_LOGOUT_RECOVERY_UNSUPPORTED) ||
2901 		    (cmd->logout_response == ISCSI_LOGOUT_CLEANUP_FAILED))
2902 			break;
2903 		/*
2904 		 * If the connection is still active from our point of view
2905 		 * force connection recovery to occur.
2906 		 */
2907 		logout_conn = iscsit_get_conn_from_cid_rcfr(sess,
2908 				cmd->logout_cid);
2909 		if (logout_conn) {
2910 			iscsit_connection_reinstatement_rcfr(logout_conn);
2911 			iscsit_dec_conn_usage_count(logout_conn);
2912 		}
2913 
2914 		cr = iscsit_get_inactive_connection_recovery_entry(
2915 				conn->sess, cmd->logout_cid);
2916 		if (!cr) {
2917 			pr_err("Unable to locate CID: %hu for"
2918 			" REMOVECONNFORRECOVERY Logout Request.\n",
2919 				cmd->logout_cid);
2920 			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
2921 			break;
2922 		}
2923 
2924 		iscsit_discard_cr_cmds_by_expstatsn(cr, cmd->exp_stat_sn);
2925 
2926 		pr_debug("iSCSI REMOVECONNFORRECOVERY logout"
2927 			" for recovery for CID: %hu on CID: %hu successful.\n",
2928 				cmd->logout_cid, conn->cid);
2929 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2930 		break;
2931 	default:
2932 		pr_err("Unknown cmd->logout_reason: 0x%02x\n",
2933 				cmd->logout_reason);
2934 		return -1;
2935 	}
2936 
2937 	hdr->opcode		= ISCSI_OP_LOGOUT_RSP;
2938 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
2939 	hdr->response		= cmd->logout_response;
2940 	hdr->itt		= cmd->init_task_tag;
2941 	cmd->stat_sn		= conn->stat_sn++;
2942 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2943 
2944 	iscsit_increment_maxcmdsn(cmd, conn->sess);
2945 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2946 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2947 
2948 	pr_debug("Built Logout Response ITT: 0x%08x StatSN:"
2949 		" 0x%08x Response: 0x%02x CID: %hu on CID: %hu\n",
2950 		cmd->init_task_tag, cmd->stat_sn, hdr->response,
2951 		cmd->logout_cid, conn->cid);
2952 
2953 	return 0;
2954 }
2955 EXPORT_SYMBOL(iscsit_build_logout_rsp);
2956 
2957 static int
2958 iscsit_send_logout(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2959 {
2960 	int rc;
2961 
2962 	rc = iscsit_build_logout_rsp(cmd, conn,
2963 			(struct iscsi_logout_rsp *)&cmd->pdu[0]);
2964 	if (rc < 0)
2965 		return rc;
2966 
2967 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
2968 }
2969 
2970 void
2971 iscsit_build_nopin_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2972 		       struct iscsi_nopin *hdr, bool nopout_response)
2973 {
2974 	hdr->opcode		= ISCSI_OP_NOOP_IN;
2975 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
2976         hton24(hdr->dlength, cmd->buf_ptr_size);
2977 	if (nopout_response)
2978 		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
2979 	hdr->itt		= cmd->init_task_tag;
2980 	hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
2981 	cmd->stat_sn		= (nopout_response) ? conn->stat_sn++ :
2982 				  conn->stat_sn;
2983 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2984 
2985 	if (nopout_response)
2986 		iscsit_increment_maxcmdsn(cmd, conn->sess);
2987 
2988 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2989 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2990 
2991 	pr_debug("Built NOPIN %s Response ITT: 0x%08x, TTT: 0x%08x,"
2992 		" StatSN: 0x%08x, Length %u\n", (nopout_response) ?
2993 		"Solicited" : "Unsolicited", cmd->init_task_tag,
2994 		cmd->targ_xfer_tag, cmd->stat_sn, cmd->buf_ptr_size);
2995 }
2996 EXPORT_SYMBOL(iscsit_build_nopin_rsp);
2997 
2998 /*
2999  *	Unsolicited NOPIN, either requesting a response or not.
3000  */
3001 static int iscsit_send_unsolicited_nopin(
3002 	struct iscsi_cmd *cmd,
3003 	struct iscsi_conn *conn,
3004 	int want_response)
3005 {
3006 	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
3007 	int ret;
3008 
3009 	iscsit_build_nopin_rsp(cmd, conn, hdr, false);
3010 
3011 	pr_debug("Sending Unsolicited NOPIN TTT: 0x%08x StatSN:"
3012 		" 0x%08x CID: %hu\n", hdr->ttt, cmd->stat_sn, conn->cid);
3013 
3014 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3015 	if (ret < 0)
3016 		return ret;
3017 
3018 	spin_lock_bh(&cmd->istate_lock);
3019 	cmd->i_state = want_response ?
3020 		ISTATE_SENT_NOPIN_WANT_RESPONSE : ISTATE_SENT_STATUS;
3021 	spin_unlock_bh(&cmd->istate_lock);
3022 
3023 	return 0;
3024 }
3025 
3026 static int
3027 iscsit_send_nopin(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3028 {
3029 	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
3030 
3031 	iscsit_build_nopin_rsp(cmd, conn, hdr, true);
3032 
3033 	/*
3034 	 * NOPOUT Ping Data is attached to struct iscsi_cmd->buf_ptr.
3035 	 * NOPOUT DataSegmentLength is at struct iscsi_cmd->buf_ptr_size.
3036 	 */
3037 	pr_debug("Echoing back %u bytes of ping data.\n", cmd->buf_ptr_size);
3038 
3039 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3040 						     cmd->buf_ptr,
3041 						     cmd->buf_ptr_size);
3042 }
3043 
3044 static int iscsit_send_r2t(
3045 	struct iscsi_cmd *cmd,
3046 	struct iscsi_conn *conn)
3047 {
3048 	struct iscsi_r2t *r2t;
3049 	struct iscsi_r2t_rsp *hdr;
3050 	int ret;
3051 
3052 	r2t = iscsit_get_r2t_from_list(cmd);
3053 	if (!r2t)
3054 		return -1;
3055 
3056 	hdr			= (struct iscsi_r2t_rsp *) cmd->pdu;
3057 	memset(hdr, 0, ISCSI_HDR_LEN);
3058 	hdr->opcode		= ISCSI_OP_R2T;
3059 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3060 	int_to_scsilun(cmd->se_cmd.orig_fe_lun,
3061 			(struct scsi_lun *)&hdr->lun);
3062 	hdr->itt		= cmd->init_task_tag;
3063 	if (conn->conn_transport->iscsit_get_r2t_ttt)
3064 		conn->conn_transport->iscsit_get_r2t_ttt(conn, cmd, r2t);
3065 	else
3066 		r2t->targ_xfer_tag = session_get_next_ttt(conn->sess);
3067 	hdr->ttt		= cpu_to_be32(r2t->targ_xfer_tag);
3068 	hdr->statsn		= cpu_to_be32(conn->stat_sn);
3069 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3070 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3071 	hdr->r2tsn		= cpu_to_be32(r2t->r2t_sn);
3072 	hdr->data_offset	= cpu_to_be32(r2t->offset);
3073 	hdr->data_length	= cpu_to_be32(r2t->xfer_len);
3074 
3075 	pr_debug("Built %sR2T, ITT: 0x%08x, TTT: 0x%08x, StatSN:"
3076 		" 0x%08x, R2TSN: 0x%08x, Offset: %u, DDTL: %u, CID: %hu\n",
3077 		(!r2t->recovery_r2t) ? "" : "Recovery ", cmd->init_task_tag,
3078 		r2t->targ_xfer_tag, ntohl(hdr->statsn), r2t->r2t_sn,
3079 			r2t->offset, r2t->xfer_len, conn->cid);
3080 
3081 	spin_lock_bh(&cmd->r2t_lock);
3082 	r2t->sent_r2t = 1;
3083 	spin_unlock_bh(&cmd->r2t_lock);
3084 
3085 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3086 	if (ret < 0) {
3087 		return ret;
3088 	}
3089 
3090 	spin_lock_bh(&cmd->dataout_timeout_lock);
3091 	iscsit_start_dataout_timer(cmd, conn);
3092 	spin_unlock_bh(&cmd->dataout_timeout_lock);
3093 
3094 	return 0;
3095 }
3096 
3097 /*
3098  *	@recovery: If called from iscsi_task_reassign_complete_write() for
3099  *		connection recovery.
3100  */
3101 int iscsit_build_r2ts_for_cmd(
3102 	struct iscsi_conn *conn,
3103 	struct iscsi_cmd *cmd,
3104 	bool recovery)
3105 {
3106 	int first_r2t = 1;
3107 	u32 offset = 0, xfer_len = 0;
3108 
3109 	spin_lock_bh(&cmd->r2t_lock);
3110 	if (cmd->cmd_flags & ICF_SENT_LAST_R2T) {
3111 		spin_unlock_bh(&cmd->r2t_lock);
3112 		return 0;
3113 	}
3114 
3115 	if (conn->sess->sess_ops->DataSequenceInOrder &&
3116 	    !recovery)
3117 		cmd->r2t_offset = max(cmd->r2t_offset, cmd->write_data_done);
3118 
3119 	while (cmd->outstanding_r2ts < conn->sess->sess_ops->MaxOutstandingR2T) {
3120 		if (conn->sess->sess_ops->DataSequenceInOrder) {
3121 			offset = cmd->r2t_offset;
3122 
3123 			if (first_r2t && recovery) {
3124 				int new_data_end = offset +
3125 					conn->sess->sess_ops->MaxBurstLength -
3126 					cmd->next_burst_len;
3127 
3128 				if (new_data_end > cmd->se_cmd.data_length)
3129 					xfer_len = cmd->se_cmd.data_length - offset;
3130 				else
3131 					xfer_len =
3132 						conn->sess->sess_ops->MaxBurstLength -
3133 						cmd->next_burst_len;
3134 			} else {
3135 				int new_data_end = offset +
3136 					conn->sess->sess_ops->MaxBurstLength;
3137 
3138 				if (new_data_end > cmd->se_cmd.data_length)
3139 					xfer_len = cmd->se_cmd.data_length - offset;
3140 				else
3141 					xfer_len = conn->sess->sess_ops->MaxBurstLength;
3142 			}
3143 			cmd->r2t_offset += xfer_len;
3144 
3145 			if (cmd->r2t_offset == cmd->se_cmd.data_length)
3146 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3147 		} else {
3148 			struct iscsi_seq *seq;
3149 
3150 			seq = iscsit_get_seq_holder_for_r2t(cmd);
3151 			if (!seq) {
3152 				spin_unlock_bh(&cmd->r2t_lock);
3153 				return -1;
3154 			}
3155 
3156 			offset = seq->offset;
3157 			xfer_len = seq->xfer_len;
3158 
3159 			if (cmd->seq_send_order == cmd->seq_count)
3160 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3161 		}
3162 		cmd->outstanding_r2ts++;
3163 		first_r2t = 0;
3164 
3165 		if (iscsit_add_r2t_to_list(cmd, offset, xfer_len, 0, 0) < 0) {
3166 			spin_unlock_bh(&cmd->r2t_lock);
3167 			return -1;
3168 		}
3169 
3170 		if (cmd->cmd_flags & ICF_SENT_LAST_R2T)
3171 			break;
3172 	}
3173 	spin_unlock_bh(&cmd->r2t_lock);
3174 
3175 	return 0;
3176 }
3177 EXPORT_SYMBOL(iscsit_build_r2ts_for_cmd);
3178 
3179 void iscsit_build_rsp_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3180 			bool inc_stat_sn, struct iscsi_scsi_rsp *hdr)
3181 {
3182 	if (inc_stat_sn)
3183 		cmd->stat_sn = conn->stat_sn++;
3184 
3185 	atomic_long_inc(&conn->sess->rsp_pdus);
3186 
3187 	memset(hdr, 0, ISCSI_HDR_LEN);
3188 	hdr->opcode		= ISCSI_OP_SCSI_CMD_RSP;
3189 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3190 	if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
3191 		hdr->flags |= ISCSI_FLAG_CMD_OVERFLOW;
3192 		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
3193 	} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
3194 		hdr->flags |= ISCSI_FLAG_CMD_UNDERFLOW;
3195 		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
3196 	}
3197 	hdr->response		= cmd->iscsi_response;
3198 	hdr->cmd_status		= cmd->se_cmd.scsi_status;
3199 	hdr->itt		= cmd->init_task_tag;
3200 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3201 
3202 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3203 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3204 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3205 
3206 	pr_debug("Built SCSI Response, ITT: 0x%08x, StatSN: 0x%08x,"
3207 		" Response: 0x%02x, SAM Status: 0x%02x, CID: %hu\n",
3208 		cmd->init_task_tag, cmd->stat_sn, cmd->se_cmd.scsi_status,
3209 		cmd->se_cmd.scsi_status, conn->cid);
3210 }
3211 EXPORT_SYMBOL(iscsit_build_rsp_pdu);
3212 
3213 static int iscsit_send_response(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3214 {
3215 	struct iscsi_scsi_rsp *hdr = (struct iscsi_scsi_rsp *)&cmd->pdu[0];
3216 	bool inc_stat_sn = (cmd->i_state == ISTATE_SEND_STATUS);
3217 	void *data_buf = NULL;
3218 	u32 padding = 0, data_buf_len = 0;
3219 
3220 	iscsit_build_rsp_pdu(cmd, conn, inc_stat_sn, hdr);
3221 
3222 	/*
3223 	 * Attach SENSE DATA payload to iSCSI Response PDU
3224 	 */
3225 	if (cmd->se_cmd.sense_buffer &&
3226 	   ((cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
3227 	    (cmd->se_cmd.se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
3228 		put_unaligned_be16(cmd->se_cmd.scsi_sense_length, cmd->sense_buffer);
3229 		cmd->se_cmd.scsi_sense_length += sizeof (__be16);
3230 
3231 		padding		= -(cmd->se_cmd.scsi_sense_length) & 3;
3232 		hton24(hdr->dlength, (u32)cmd->se_cmd.scsi_sense_length);
3233 		data_buf = cmd->sense_buffer;
3234 		data_buf_len = cmd->se_cmd.scsi_sense_length + padding;
3235 
3236 		if (padding) {
3237 			memset(cmd->sense_buffer +
3238 				cmd->se_cmd.scsi_sense_length, 0, padding);
3239 			pr_debug("Adding %u bytes of padding to"
3240 				" SENSE.\n", padding);
3241 		}
3242 
3243 		pr_debug("Attaching SENSE DATA: %u bytes to iSCSI"
3244 				" Response PDU\n",
3245 				cmd->se_cmd.scsi_sense_length);
3246 	}
3247 
3248 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, data_buf,
3249 						     data_buf_len);
3250 }
3251 
3252 static u8 iscsit_convert_tcm_tmr_rsp(struct se_tmr_req *se_tmr)
3253 {
3254 	switch (se_tmr->response) {
3255 	case TMR_FUNCTION_COMPLETE:
3256 		return ISCSI_TMF_RSP_COMPLETE;
3257 	case TMR_TASK_DOES_NOT_EXIST:
3258 		return ISCSI_TMF_RSP_NO_TASK;
3259 	case TMR_LUN_DOES_NOT_EXIST:
3260 		return ISCSI_TMF_RSP_NO_LUN;
3261 	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
3262 		return ISCSI_TMF_RSP_NOT_SUPPORTED;
3263 	case TMR_FUNCTION_REJECTED:
3264 	default:
3265 		return ISCSI_TMF_RSP_REJECTED;
3266 	}
3267 }
3268 
3269 void
3270 iscsit_build_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3271 			  struct iscsi_tm_rsp *hdr)
3272 {
3273 	struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req;
3274 
3275 	hdr->opcode		= ISCSI_OP_SCSI_TMFUNC_RSP;
3276 	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
3277 	hdr->response		= iscsit_convert_tcm_tmr_rsp(se_tmr);
3278 	hdr->itt		= cmd->init_task_tag;
3279 	cmd->stat_sn		= conn->stat_sn++;
3280 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3281 
3282 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3283 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3284 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3285 
3286 	pr_debug("Built Task Management Response ITT: 0x%08x,"
3287 		" StatSN: 0x%08x, Response: 0x%02x, CID: %hu\n",
3288 		cmd->init_task_tag, cmd->stat_sn, hdr->response, conn->cid);
3289 }
3290 EXPORT_SYMBOL(iscsit_build_task_mgt_rsp);
3291 
3292 static int
3293 iscsit_send_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3294 {
3295 	struct iscsi_tm_rsp *hdr = (struct iscsi_tm_rsp *)&cmd->pdu[0];
3296 
3297 	iscsit_build_task_mgt_rsp(cmd, conn, hdr);
3298 
3299 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3300 }
3301 
3302 static bool iscsit_check_inaddr_any(struct iscsi_np *np)
3303 {
3304 	bool ret = false;
3305 
3306 	if (np->np_sockaddr.ss_family == AF_INET6) {
3307 		const struct sockaddr_in6 sin6 = {
3308 			.sin6_addr = IN6ADDR_ANY_INIT };
3309 		struct sockaddr_in6 *sock_in6 =
3310 			 (struct sockaddr_in6 *)&np->np_sockaddr;
3311 
3312 		if (!memcmp(sock_in6->sin6_addr.s6_addr,
3313 				sin6.sin6_addr.s6_addr, 16))
3314 			ret = true;
3315 	} else {
3316 		struct sockaddr_in * sock_in =
3317 			(struct sockaddr_in *)&np->np_sockaddr;
3318 
3319 		if (sock_in->sin_addr.s_addr == htonl(INADDR_ANY))
3320 			ret = true;
3321 	}
3322 
3323 	return ret;
3324 }
3325 
3326 #define SENDTARGETS_BUF_LIMIT 32768U
3327 
3328 static int
3329 iscsit_build_sendtargets_response(struct iscsi_cmd *cmd,
3330 				  enum iscsit_transport_type network_transport,
3331 				  int skip_bytes, bool *completed)
3332 {
3333 	char *payload = NULL;
3334 	struct iscsi_conn *conn = cmd->conn;
3335 	struct iscsi_portal_group *tpg;
3336 	struct iscsi_tiqn *tiqn;
3337 	struct iscsi_tpg_np *tpg_np;
3338 	int buffer_len, end_of_buf = 0, len = 0, payload_len = 0;
3339 	int target_name_printed;
3340 	unsigned char buf[ISCSI_IQN_LEN+12]; /* iqn + "TargetName=" + \0 */
3341 	unsigned char *text_in = cmd->text_in_ptr, *text_ptr = NULL;
3342 	bool active;
3343 
3344 	buffer_len = min(conn->conn_ops->MaxRecvDataSegmentLength,
3345 			 SENDTARGETS_BUF_LIMIT);
3346 
3347 	payload = kzalloc(buffer_len, GFP_KERNEL);
3348 	if (!payload)
3349 		return -ENOMEM;
3350 
3351 	/*
3352 	 * Locate pointer to iqn./eui. string for ICF_SENDTARGETS_SINGLE
3353 	 * explicit case..
3354 	 */
3355 	if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) {
3356 		text_ptr = strchr(text_in, '=');
3357 		if (!text_ptr) {
3358 			pr_err("Unable to locate '=' string in text_in:"
3359 			       " %s\n", text_in);
3360 			kfree(payload);
3361 			return -EINVAL;
3362 		}
3363 		/*
3364 		 * Skip over '=' character..
3365 		 */
3366 		text_ptr += 1;
3367 	}
3368 
3369 	spin_lock(&tiqn_lock);
3370 	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
3371 		if ((cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) &&
3372 		     strcmp(tiqn->tiqn, text_ptr)) {
3373 			continue;
3374 		}
3375 
3376 		target_name_printed = 0;
3377 
3378 		spin_lock(&tiqn->tiqn_tpg_lock);
3379 		list_for_each_entry(tpg, &tiqn->tiqn_tpg_list, tpg_list) {
3380 
3381 			/* If demo_mode_discovery=0 and generate_node_acls=0
3382 			 * (demo mode dislabed) do not return
3383 			 * TargetName+TargetAddress unless a NodeACL exists.
3384 			 */
3385 
3386 			if ((tpg->tpg_attrib.generate_node_acls == 0) &&
3387 			    (tpg->tpg_attrib.demo_mode_discovery == 0) &&
3388 			    (!target_tpg_has_node_acl(&tpg->tpg_se_tpg,
3389 				cmd->conn->sess->sess_ops->InitiatorName))) {
3390 				continue;
3391 			}
3392 
3393 			spin_lock(&tpg->tpg_state_lock);
3394 			active = (tpg->tpg_state == TPG_STATE_ACTIVE);
3395 			spin_unlock(&tpg->tpg_state_lock);
3396 
3397 			if (!active && tpg->tpg_attrib.tpg_enabled_sendtargets)
3398 				continue;
3399 
3400 			spin_lock(&tpg->tpg_np_lock);
3401 			list_for_each_entry(tpg_np, &tpg->tpg_gnp_list,
3402 						tpg_np_list) {
3403 				struct iscsi_np *np = tpg_np->tpg_np;
3404 				bool inaddr_any = iscsit_check_inaddr_any(np);
3405 				struct sockaddr_storage *sockaddr;
3406 
3407 				if (np->np_network_transport != network_transport)
3408 					continue;
3409 
3410 				if (!target_name_printed) {
3411 					len = sprintf(buf, "TargetName=%s",
3412 						      tiqn->tiqn);
3413 					len += 1;
3414 
3415 					if ((len + payload_len) > buffer_len) {
3416 						spin_unlock(&tpg->tpg_np_lock);
3417 						spin_unlock(&tiqn->tiqn_tpg_lock);
3418 						end_of_buf = 1;
3419 						goto eob;
3420 					}
3421 
3422 					if (skip_bytes && len <= skip_bytes) {
3423 						skip_bytes -= len;
3424 					} else {
3425 						memcpy(payload + payload_len, buf, len);
3426 						payload_len += len;
3427 						target_name_printed = 1;
3428 						if (len > skip_bytes)
3429 							skip_bytes = 0;
3430 					}
3431 				}
3432 
3433 				if (inaddr_any)
3434 					sockaddr = &conn->local_sockaddr;
3435 				else
3436 					sockaddr = &np->np_sockaddr;
3437 
3438 				len = sprintf(buf, "TargetAddress="
3439 					      "%pISpc,%hu",
3440 					      sockaddr,
3441 					      tpg->tpgt);
3442 				len += 1;
3443 
3444 				if ((len + payload_len) > buffer_len) {
3445 					spin_unlock(&tpg->tpg_np_lock);
3446 					spin_unlock(&tiqn->tiqn_tpg_lock);
3447 					end_of_buf = 1;
3448 					goto eob;
3449 				}
3450 
3451 				if (skip_bytes && len <= skip_bytes) {
3452 					skip_bytes -= len;
3453 				} else {
3454 					memcpy(payload + payload_len, buf, len);
3455 					payload_len += len;
3456 					if (len > skip_bytes)
3457 						skip_bytes = 0;
3458 				}
3459 			}
3460 			spin_unlock(&tpg->tpg_np_lock);
3461 		}
3462 		spin_unlock(&tiqn->tiqn_tpg_lock);
3463 eob:
3464 		if (end_of_buf) {
3465 			*completed = false;
3466 			break;
3467 		}
3468 
3469 		if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE)
3470 			break;
3471 	}
3472 	spin_unlock(&tiqn_lock);
3473 
3474 	cmd->buf_ptr = payload;
3475 
3476 	return payload_len;
3477 }
3478 
3479 int
3480 iscsit_build_text_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3481 		      struct iscsi_text_rsp *hdr,
3482 		      enum iscsit_transport_type network_transport)
3483 {
3484 	int text_length, padding;
3485 	bool completed = true;
3486 
3487 	text_length = iscsit_build_sendtargets_response(cmd, network_transport,
3488 							cmd->read_data_done,
3489 							&completed);
3490 	if (text_length < 0)
3491 		return text_length;
3492 
3493 	if (completed) {
3494 		hdr->flags = ISCSI_FLAG_CMD_FINAL;
3495 	} else {
3496 		hdr->flags = ISCSI_FLAG_TEXT_CONTINUE;
3497 		cmd->read_data_done += text_length;
3498 		if (cmd->targ_xfer_tag == 0xFFFFFFFF)
3499 			cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
3500 	}
3501 	hdr->opcode = ISCSI_OP_TEXT_RSP;
3502 	padding = ((-text_length) & 3);
3503 	hton24(hdr->dlength, text_length);
3504 	hdr->itt = cmd->init_task_tag;
3505 	hdr->ttt = cpu_to_be32(cmd->targ_xfer_tag);
3506 	cmd->stat_sn = conn->stat_sn++;
3507 	hdr->statsn = cpu_to_be32(cmd->stat_sn);
3508 
3509 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3510 	/*
3511 	 * Reset maxcmdsn_inc in multi-part text payload exchanges to
3512 	 * correctly increment MaxCmdSN for each response answering a
3513 	 * non immediate text request with a valid CmdSN.
3514 	 */
3515 	cmd->maxcmdsn_inc = 0;
3516 	hdr->exp_cmdsn = cpu_to_be32(conn->sess->exp_cmd_sn);
3517 	hdr->max_cmdsn = cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3518 
3519 	pr_debug("Built Text Response: ITT: 0x%08x, TTT: 0x%08x, StatSN: 0x%08x,"
3520 		" Length: %u, CID: %hu F: %d C: %d\n", cmd->init_task_tag,
3521 		cmd->targ_xfer_tag, cmd->stat_sn, text_length, conn->cid,
3522 		!!(hdr->flags & ISCSI_FLAG_CMD_FINAL),
3523 		!!(hdr->flags & ISCSI_FLAG_TEXT_CONTINUE));
3524 
3525 	return text_length + padding;
3526 }
3527 EXPORT_SYMBOL(iscsit_build_text_rsp);
3528 
3529 static int iscsit_send_text_rsp(
3530 	struct iscsi_cmd *cmd,
3531 	struct iscsi_conn *conn)
3532 {
3533 	struct iscsi_text_rsp *hdr = (struct iscsi_text_rsp *)cmd->pdu;
3534 	int text_length;
3535 
3536 	text_length = iscsit_build_text_rsp(cmd, conn, hdr,
3537 				conn->conn_transport->transport_type);
3538 	if (text_length < 0)
3539 		return text_length;
3540 
3541 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3542 						     cmd->buf_ptr,
3543 						     text_length);
3544 }
3545 
3546 void
3547 iscsit_build_reject(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3548 		    struct iscsi_reject *hdr)
3549 {
3550 	hdr->opcode		= ISCSI_OP_REJECT;
3551 	hdr->reason		= cmd->reject_reason;
3552 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3553 	hton24(hdr->dlength, ISCSI_HDR_LEN);
3554 	hdr->ffffffff		= cpu_to_be32(0xffffffff);
3555 	cmd->stat_sn		= conn->stat_sn++;
3556 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3557 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3558 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3559 
3560 }
3561 EXPORT_SYMBOL(iscsit_build_reject);
3562 
3563 static int iscsit_send_reject(
3564 	struct iscsi_cmd *cmd,
3565 	struct iscsi_conn *conn)
3566 {
3567 	struct iscsi_reject *hdr = (struct iscsi_reject *)&cmd->pdu[0];
3568 
3569 	iscsit_build_reject(cmd, conn, hdr);
3570 
3571 	pr_debug("Built Reject PDU StatSN: 0x%08x, Reason: 0x%02x,"
3572 		" CID: %hu\n", ntohl(hdr->statsn), hdr->reason, conn->cid);
3573 
3574 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3575 						     cmd->buf_ptr,
3576 						     ISCSI_HDR_LEN);
3577 }
3578 
3579 void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
3580 {
3581 	int ord, cpu;
3582 	/*
3583 	 * bitmap_id is assigned from iscsit_global->ts_bitmap from
3584 	 * within iscsit_start_kthreads()
3585 	 *
3586 	 * Here we use bitmap_id to determine which CPU that this
3587 	 * iSCSI connection's RX/TX threads will be scheduled to
3588 	 * execute upon.
3589 	 */
3590 	ord = conn->bitmap_id % cpumask_weight(cpu_online_mask);
3591 	for_each_online_cpu(cpu) {
3592 		if (ord-- == 0) {
3593 			cpumask_set_cpu(cpu, conn->conn_cpumask);
3594 			return;
3595 		}
3596 	}
3597 	/*
3598 	 * This should never be reached..
3599 	 */
3600 	dump_stack();
3601 	cpumask_setall(conn->conn_cpumask);
3602 }
3603 
3604 int
3605 iscsit_immediate_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
3606 {
3607 	int ret;
3608 
3609 	switch (state) {
3610 	case ISTATE_SEND_R2T:
3611 		ret = iscsit_send_r2t(cmd, conn);
3612 		if (ret < 0)
3613 			goto err;
3614 		break;
3615 	case ISTATE_REMOVE:
3616 		spin_lock_bh(&conn->cmd_lock);
3617 		list_del_init(&cmd->i_conn_node);
3618 		spin_unlock_bh(&conn->cmd_lock);
3619 
3620 		iscsit_free_cmd(cmd, false);
3621 		break;
3622 	case ISTATE_SEND_NOPIN_WANT_RESPONSE:
3623 		iscsit_mod_nopin_response_timer(conn);
3624 		ret = iscsit_send_unsolicited_nopin(cmd, conn, 1);
3625 		if (ret < 0)
3626 			goto err;
3627 		break;
3628 	case ISTATE_SEND_NOPIN_NO_RESPONSE:
3629 		ret = iscsit_send_unsolicited_nopin(cmd, conn, 0);
3630 		if (ret < 0)
3631 			goto err;
3632 		break;
3633 	default:
3634 		pr_err("Unknown Opcode: 0x%02x ITT:"
3635 		       " 0x%08x, i_state: %d on CID: %hu\n",
3636 		       cmd->iscsi_opcode, cmd->init_task_tag, state,
3637 		       conn->cid);
3638 		goto err;
3639 	}
3640 
3641 	return 0;
3642 
3643 err:
3644 	return -1;
3645 }
3646 EXPORT_SYMBOL(iscsit_immediate_queue);
3647 
3648 static int
3649 iscsit_handle_immediate_queue(struct iscsi_conn *conn)
3650 {
3651 	struct iscsit_transport *t = conn->conn_transport;
3652 	struct iscsi_queue_req *qr;
3653 	struct iscsi_cmd *cmd;
3654 	u8 state;
3655 	int ret;
3656 
3657 	while ((qr = iscsit_get_cmd_from_immediate_queue(conn))) {
3658 		atomic_set(&conn->check_immediate_queue, 0);
3659 		cmd = qr->cmd;
3660 		state = qr->state;
3661 		kmem_cache_free(lio_qr_cache, qr);
3662 
3663 		ret = t->iscsit_immediate_queue(conn, cmd, state);
3664 		if (ret < 0)
3665 			return ret;
3666 	}
3667 
3668 	return 0;
3669 }
3670 
3671 int
3672 iscsit_response_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
3673 {
3674 	int ret;
3675 
3676 check_rsp_state:
3677 	switch (state) {
3678 	case ISTATE_SEND_DATAIN:
3679 		ret = iscsit_send_datain(cmd, conn);
3680 		if (ret < 0)
3681 			goto err;
3682 		else if (!ret)
3683 			/* more drs */
3684 			goto check_rsp_state;
3685 		else if (ret == 1) {
3686 			/* all done */
3687 			spin_lock_bh(&cmd->istate_lock);
3688 			cmd->i_state = ISTATE_SENT_STATUS;
3689 			spin_unlock_bh(&cmd->istate_lock);
3690 
3691 			if (atomic_read(&conn->check_immediate_queue))
3692 				return 1;
3693 
3694 			return 0;
3695 		} else if (ret == 2) {
3696 			/* Still must send status,
3697 			   SCF_TRANSPORT_TASK_SENSE was set */
3698 			spin_lock_bh(&cmd->istate_lock);
3699 			cmd->i_state = ISTATE_SEND_STATUS;
3700 			spin_unlock_bh(&cmd->istate_lock);
3701 			state = ISTATE_SEND_STATUS;
3702 			goto check_rsp_state;
3703 		}
3704 
3705 		break;
3706 	case ISTATE_SEND_STATUS:
3707 	case ISTATE_SEND_STATUS_RECOVERY:
3708 		ret = iscsit_send_response(cmd, conn);
3709 		break;
3710 	case ISTATE_SEND_LOGOUTRSP:
3711 		ret = iscsit_send_logout(cmd, conn);
3712 		break;
3713 	case ISTATE_SEND_ASYNCMSG:
3714 		ret = iscsit_send_conn_drop_async_message(
3715 			cmd, conn);
3716 		break;
3717 	case ISTATE_SEND_NOPIN:
3718 		ret = iscsit_send_nopin(cmd, conn);
3719 		break;
3720 	case ISTATE_SEND_REJECT:
3721 		ret = iscsit_send_reject(cmd, conn);
3722 		break;
3723 	case ISTATE_SEND_TASKMGTRSP:
3724 		ret = iscsit_send_task_mgt_rsp(cmd, conn);
3725 		if (ret != 0)
3726 			break;
3727 		ret = iscsit_tmr_post_handler(cmd, conn);
3728 		if (ret != 0)
3729 			iscsit_fall_back_to_erl0(conn->sess);
3730 		break;
3731 	case ISTATE_SEND_TEXTRSP:
3732 		ret = iscsit_send_text_rsp(cmd, conn);
3733 		break;
3734 	default:
3735 		pr_err("Unknown Opcode: 0x%02x ITT:"
3736 		       " 0x%08x, i_state: %d on CID: %hu\n",
3737 		       cmd->iscsi_opcode, cmd->init_task_tag,
3738 		       state, conn->cid);
3739 		goto err;
3740 	}
3741 	if (ret < 0)
3742 		goto err;
3743 
3744 	switch (state) {
3745 	case ISTATE_SEND_LOGOUTRSP:
3746 		if (!iscsit_logout_post_handler(cmd, conn))
3747 			return -ECONNRESET;
3748 		/* fall through */
3749 	case ISTATE_SEND_STATUS:
3750 	case ISTATE_SEND_ASYNCMSG:
3751 	case ISTATE_SEND_NOPIN:
3752 	case ISTATE_SEND_STATUS_RECOVERY:
3753 	case ISTATE_SEND_TEXTRSP:
3754 	case ISTATE_SEND_TASKMGTRSP:
3755 	case ISTATE_SEND_REJECT:
3756 		spin_lock_bh(&cmd->istate_lock);
3757 		cmd->i_state = ISTATE_SENT_STATUS;
3758 		spin_unlock_bh(&cmd->istate_lock);
3759 		break;
3760 	default:
3761 		pr_err("Unknown Opcode: 0x%02x ITT:"
3762 		       " 0x%08x, i_state: %d on CID: %hu\n",
3763 		       cmd->iscsi_opcode, cmd->init_task_tag,
3764 		       cmd->i_state, conn->cid);
3765 		goto err;
3766 	}
3767 
3768 	if (atomic_read(&conn->check_immediate_queue))
3769 		return 1;
3770 
3771 	return 0;
3772 
3773 err:
3774 	return -1;
3775 }
3776 EXPORT_SYMBOL(iscsit_response_queue);
3777 
3778 static int iscsit_handle_response_queue(struct iscsi_conn *conn)
3779 {
3780 	struct iscsit_transport *t = conn->conn_transport;
3781 	struct iscsi_queue_req *qr;
3782 	struct iscsi_cmd *cmd;
3783 	u8 state;
3784 	int ret;
3785 
3786 	while ((qr = iscsit_get_cmd_from_response_queue(conn))) {
3787 		cmd = qr->cmd;
3788 		state = qr->state;
3789 		kmem_cache_free(lio_qr_cache, qr);
3790 
3791 		ret = t->iscsit_response_queue(conn, cmd, state);
3792 		if (ret == 1 || ret < 0)
3793 			return ret;
3794 	}
3795 
3796 	return 0;
3797 }
3798 
3799 int iscsi_target_tx_thread(void *arg)
3800 {
3801 	int ret = 0;
3802 	struct iscsi_conn *conn = arg;
3803 	bool conn_freed = false;
3804 
3805 	/*
3806 	 * Allow ourselves to be interrupted by SIGINT so that a
3807 	 * connection recovery / failure event can be triggered externally.
3808 	 */
3809 	allow_signal(SIGINT);
3810 
3811 	while (!kthread_should_stop()) {
3812 		/*
3813 		 * Ensure that both TX and RX per connection kthreads
3814 		 * are scheduled to run on the same CPU.
3815 		 */
3816 		iscsit_thread_check_cpumask(conn, current, 1);
3817 
3818 		wait_event_interruptible(conn->queues_wq,
3819 					 !iscsit_conn_all_queues_empty(conn));
3820 
3821 		if (signal_pending(current))
3822 			goto transport_err;
3823 
3824 get_immediate:
3825 		ret = iscsit_handle_immediate_queue(conn);
3826 		if (ret < 0)
3827 			goto transport_err;
3828 
3829 		ret = iscsit_handle_response_queue(conn);
3830 		if (ret == 1) {
3831 			goto get_immediate;
3832 		} else if (ret == -ECONNRESET) {
3833 			conn_freed = true;
3834 			goto out;
3835 		} else if (ret < 0) {
3836 			goto transport_err;
3837 		}
3838 	}
3839 
3840 transport_err:
3841 	/*
3842 	 * Avoid the normal connection failure code-path if this connection
3843 	 * is still within LOGIN mode, and iscsi_np process context is
3844 	 * responsible for cleaning up the early connection failure.
3845 	 */
3846 	if (conn->conn_state != TARG_CONN_STATE_IN_LOGIN)
3847 		iscsit_take_action_for_connection_exit(conn, &conn_freed);
3848 out:
3849 	if (!conn_freed) {
3850 		while (!kthread_should_stop()) {
3851 			msleep(100);
3852 		}
3853 	}
3854 	return 0;
3855 }
3856 
3857 static int iscsi_target_rx_opcode(struct iscsi_conn *conn, unsigned char *buf)
3858 {
3859 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)buf;
3860 	struct iscsi_cmd *cmd;
3861 	int ret = 0;
3862 
3863 	switch (hdr->opcode & ISCSI_OPCODE_MASK) {
3864 	case ISCSI_OP_SCSI_CMD:
3865 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3866 		if (!cmd)
3867 			goto reject;
3868 
3869 		ret = iscsit_handle_scsi_cmd(conn, cmd, buf);
3870 		break;
3871 	case ISCSI_OP_SCSI_DATA_OUT:
3872 		ret = iscsit_handle_data_out(conn, buf);
3873 		break;
3874 	case ISCSI_OP_NOOP_OUT:
3875 		cmd = NULL;
3876 		if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
3877 			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3878 			if (!cmd)
3879 				goto reject;
3880 		}
3881 		ret = iscsit_handle_nop_out(conn, cmd, buf);
3882 		break;
3883 	case ISCSI_OP_SCSI_TMFUNC:
3884 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3885 		if (!cmd)
3886 			goto reject;
3887 
3888 		ret = iscsit_handle_task_mgt_cmd(conn, cmd, buf);
3889 		break;
3890 	case ISCSI_OP_TEXT:
3891 		if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
3892 			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
3893 			if (!cmd)
3894 				goto reject;
3895 		} else {
3896 			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3897 			if (!cmd)
3898 				goto reject;
3899 		}
3900 
3901 		ret = iscsit_handle_text_cmd(conn, cmd, buf);
3902 		break;
3903 	case ISCSI_OP_LOGOUT:
3904 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3905 		if (!cmd)
3906 			goto reject;
3907 
3908 		ret = iscsit_handle_logout_cmd(conn, cmd, buf);
3909 		if (ret > 0)
3910 			wait_for_completion_timeout(&conn->conn_logout_comp,
3911 					SECONDS_FOR_LOGOUT_COMP * HZ);
3912 		break;
3913 	case ISCSI_OP_SNACK:
3914 		ret = iscsit_handle_snack(conn, buf);
3915 		break;
3916 	default:
3917 		pr_err("Got unknown iSCSI OpCode: 0x%02x\n", hdr->opcode);
3918 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
3919 			pr_err("Cannot recover from unknown"
3920 			" opcode while ERL=0, closing iSCSI connection.\n");
3921 			return -1;
3922 		}
3923 		pr_err("Unable to recover from unknown opcode while OFMarker=No,"
3924 		       " closing iSCSI connection.\n");
3925 		ret = -1;
3926 		break;
3927 	}
3928 
3929 	return ret;
3930 reject:
3931 	return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
3932 }
3933 
3934 static bool iscsi_target_check_conn_state(struct iscsi_conn *conn)
3935 {
3936 	bool ret;
3937 
3938 	spin_lock_bh(&conn->state_lock);
3939 	ret = (conn->conn_state != TARG_CONN_STATE_LOGGED_IN);
3940 	spin_unlock_bh(&conn->state_lock);
3941 
3942 	return ret;
3943 }
3944 
3945 static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
3946 {
3947 	int ret;
3948 	u8 buffer[ISCSI_HDR_LEN], opcode;
3949 	u32 checksum = 0, digest = 0;
3950 	struct kvec iov;
3951 
3952 	while (!kthread_should_stop()) {
3953 		/*
3954 		 * Ensure that both TX and RX per connection kthreads
3955 		 * are scheduled to run on the same CPU.
3956 		 */
3957 		iscsit_thread_check_cpumask(conn, current, 0);
3958 
3959 		memset(buffer, 0, ISCSI_HDR_LEN);
3960 		memset(&iov, 0, sizeof(struct kvec));
3961 
3962 		iov.iov_base	= buffer;
3963 		iov.iov_len	= ISCSI_HDR_LEN;
3964 
3965 		ret = rx_data(conn, &iov, 1, ISCSI_HDR_LEN);
3966 		if (ret != ISCSI_HDR_LEN) {
3967 			iscsit_rx_thread_wait_for_tcp(conn);
3968 			return;
3969 		}
3970 
3971 		if (conn->conn_ops->HeaderDigest) {
3972 			iov.iov_base	= &digest;
3973 			iov.iov_len	= ISCSI_CRC_LEN;
3974 
3975 			ret = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
3976 			if (ret != ISCSI_CRC_LEN) {
3977 				iscsit_rx_thread_wait_for_tcp(conn);
3978 				return;
3979 			}
3980 
3981 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash,
3982 					buffer, ISCSI_HDR_LEN,
3983 					0, NULL, (u8 *)&checksum);
3984 
3985 			if (digest != checksum) {
3986 				pr_err("HeaderDigest CRC32C failed,"
3987 					" received 0x%08x, computed 0x%08x\n",
3988 					digest, checksum);
3989 				/*
3990 				 * Set the PDU to 0xff so it will intentionally
3991 				 * hit default in the switch below.
3992 				 */
3993 				memset(buffer, 0xff, ISCSI_HDR_LEN);
3994 				atomic_long_inc(&conn->sess->conn_digest_errors);
3995 			} else {
3996 				pr_debug("Got HeaderDigest CRC32C"
3997 						" 0x%08x\n", checksum);
3998 			}
3999 		}
4000 
4001 		if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
4002 			return;
4003 
4004 		opcode = buffer[0] & ISCSI_OPCODE_MASK;
4005 
4006 		if (conn->sess->sess_ops->SessionType &&
4007 		   ((!(opcode & ISCSI_OP_TEXT)) ||
4008 		    (!(opcode & ISCSI_OP_LOGOUT)))) {
4009 			pr_err("Received illegal iSCSI Opcode: 0x%02x"
4010 			" while in Discovery Session, rejecting.\n", opcode);
4011 			iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
4012 					  buffer);
4013 			return;
4014 		}
4015 
4016 		ret = iscsi_target_rx_opcode(conn, buffer);
4017 		if (ret < 0)
4018 			return;
4019 	}
4020 }
4021 
4022 int iscsi_target_rx_thread(void *arg)
4023 {
4024 	int rc;
4025 	struct iscsi_conn *conn = arg;
4026 	bool conn_freed = false;
4027 
4028 	/*
4029 	 * Allow ourselves to be interrupted by SIGINT so that a
4030 	 * connection recovery / failure event can be triggered externally.
4031 	 */
4032 	allow_signal(SIGINT);
4033 	/*
4034 	 * Wait for iscsi_post_login_handler() to complete before allowing
4035 	 * incoming iscsi/tcp socket I/O, and/or failing the connection.
4036 	 */
4037 	rc = wait_for_completion_interruptible(&conn->rx_login_comp);
4038 	if (rc < 0 || iscsi_target_check_conn_state(conn))
4039 		goto out;
4040 
4041 	if (!conn->conn_transport->iscsit_get_rx_pdu)
4042 		return 0;
4043 
4044 	conn->conn_transport->iscsit_get_rx_pdu(conn);
4045 
4046 	if (!signal_pending(current))
4047 		atomic_set(&conn->transport_failed, 1);
4048 	iscsit_take_action_for_connection_exit(conn, &conn_freed);
4049 
4050 out:
4051 	if (!conn_freed) {
4052 		while (!kthread_should_stop()) {
4053 			msleep(100);
4054 		}
4055 	}
4056 
4057 	return 0;
4058 }
4059 
4060 static void iscsit_release_commands_from_conn(struct iscsi_conn *conn)
4061 {
4062 	LIST_HEAD(tmp_list);
4063 	struct iscsi_cmd *cmd = NULL, *cmd_tmp = NULL;
4064 	struct iscsi_session *sess = conn->sess;
4065 	/*
4066 	 * We expect this function to only ever be called from either RX or TX
4067 	 * thread context via iscsit_close_connection() once the other context
4068 	 * has been reset -> returned sleeping pre-handler state.
4069 	 */
4070 	spin_lock_bh(&conn->cmd_lock);
4071 	list_splice_init(&conn->conn_cmd_list, &tmp_list);
4072 
4073 	list_for_each_entry(cmd, &tmp_list, i_conn_node) {
4074 		struct se_cmd *se_cmd = &cmd->se_cmd;
4075 
4076 		if (se_cmd->se_tfo != NULL) {
4077 			spin_lock(&se_cmd->t_state_lock);
4078 			se_cmd->transport_state |= CMD_T_FABRIC_STOP;
4079 			spin_unlock(&se_cmd->t_state_lock);
4080 		}
4081 	}
4082 	spin_unlock_bh(&conn->cmd_lock);
4083 
4084 	list_for_each_entry_safe(cmd, cmd_tmp, &tmp_list, i_conn_node) {
4085 		list_del_init(&cmd->i_conn_node);
4086 
4087 		iscsit_increment_maxcmdsn(cmd, sess);
4088 		iscsit_free_cmd(cmd, true);
4089 
4090 	}
4091 }
4092 
4093 static void iscsit_stop_timers_for_cmds(
4094 	struct iscsi_conn *conn)
4095 {
4096 	struct iscsi_cmd *cmd;
4097 
4098 	spin_lock_bh(&conn->cmd_lock);
4099 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
4100 		if (cmd->data_direction == DMA_TO_DEVICE)
4101 			iscsit_stop_dataout_timer(cmd);
4102 	}
4103 	spin_unlock_bh(&conn->cmd_lock);
4104 }
4105 
4106 int iscsit_close_connection(
4107 	struct iscsi_conn *conn)
4108 {
4109 	int conn_logout = (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT);
4110 	struct iscsi_session	*sess = conn->sess;
4111 
4112 	pr_debug("Closing iSCSI connection CID %hu on SID:"
4113 		" %u\n", conn->cid, sess->sid);
4114 	/*
4115 	 * Always up conn_logout_comp for the traditional TCP and HW_OFFLOAD
4116 	 * case just in case the RX Thread in iscsi_target_rx_opcode() is
4117 	 * sleeping and the logout response never got sent because the
4118 	 * connection failed.
4119 	 *
4120 	 * However for iser-target, isert_wait4logout() is using conn_logout_comp
4121 	 * to signal logout response TX interrupt completion.  Go ahead and skip
4122 	 * this for iser since isert_rx_opcode() does not wait on logout failure,
4123 	 * and to avoid iscsi_conn pointer dereference in iser-target code.
4124 	 */
4125 	if (!conn->conn_transport->rdma_shutdown)
4126 		complete(&conn->conn_logout_comp);
4127 
4128 	if (!strcmp(current->comm, ISCSI_RX_THREAD_NAME)) {
4129 		if (conn->tx_thread &&
4130 		    cmpxchg(&conn->tx_thread_active, true, false)) {
4131 			send_sig(SIGINT, conn->tx_thread, 1);
4132 			kthread_stop(conn->tx_thread);
4133 		}
4134 	} else if (!strcmp(current->comm, ISCSI_TX_THREAD_NAME)) {
4135 		if (conn->rx_thread &&
4136 		    cmpxchg(&conn->rx_thread_active, true, false)) {
4137 			send_sig(SIGINT, conn->rx_thread, 1);
4138 			kthread_stop(conn->rx_thread);
4139 		}
4140 	}
4141 
4142 	spin_lock(&iscsit_global->ts_bitmap_lock);
4143 	bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
4144 			      get_order(1));
4145 	spin_unlock(&iscsit_global->ts_bitmap_lock);
4146 
4147 	iscsit_stop_timers_for_cmds(conn);
4148 	iscsit_stop_nopin_response_timer(conn);
4149 	iscsit_stop_nopin_timer(conn);
4150 
4151 	if (conn->conn_transport->iscsit_wait_conn)
4152 		conn->conn_transport->iscsit_wait_conn(conn);
4153 
4154 	/*
4155 	 * During Connection recovery drop unacknowledged out of order
4156 	 * commands for this connection, and prepare the other commands
4157 	 * for reallegiance.
4158 	 *
4159 	 * During normal operation clear the out of order commands (but
4160 	 * do not free the struct iscsi_ooo_cmdsn's) and release all
4161 	 * struct iscsi_cmds.
4162 	 */
4163 	if (atomic_read(&conn->connection_recovery)) {
4164 		iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(conn);
4165 		iscsit_prepare_cmds_for_reallegiance(conn);
4166 	} else {
4167 		iscsit_clear_ooo_cmdsns_for_conn(conn);
4168 		iscsit_release_commands_from_conn(conn);
4169 	}
4170 	iscsit_free_queue_reqs_for_conn(conn);
4171 
4172 	/*
4173 	 * Handle decrementing session or connection usage count if
4174 	 * a logout response was not able to be sent because the
4175 	 * connection failed.  Fall back to Session Recovery here.
4176 	 */
4177 	if (atomic_read(&conn->conn_logout_remove)) {
4178 		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_SESSION) {
4179 			iscsit_dec_conn_usage_count(conn);
4180 			iscsit_dec_session_usage_count(sess);
4181 		}
4182 		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION)
4183 			iscsit_dec_conn_usage_count(conn);
4184 
4185 		atomic_set(&conn->conn_logout_remove, 0);
4186 		atomic_set(&sess->session_reinstatement, 0);
4187 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4188 	}
4189 
4190 	spin_lock_bh(&sess->conn_lock);
4191 	list_del(&conn->conn_list);
4192 
4193 	/*
4194 	 * Attempt to let the Initiator know this connection failed by
4195 	 * sending an Connection Dropped Async Message on another
4196 	 * active connection.
4197 	 */
4198 	if (atomic_read(&conn->connection_recovery))
4199 		iscsit_build_conn_drop_async_message(conn);
4200 
4201 	spin_unlock_bh(&sess->conn_lock);
4202 
4203 	/*
4204 	 * If connection reinstatement is being performed on this connection,
4205 	 * up the connection reinstatement semaphore that is being blocked on
4206 	 * in iscsit_cause_connection_reinstatement().
4207 	 */
4208 	spin_lock_bh(&conn->state_lock);
4209 	if (atomic_read(&conn->sleep_on_conn_wait_comp)) {
4210 		spin_unlock_bh(&conn->state_lock);
4211 		complete(&conn->conn_wait_comp);
4212 		wait_for_completion(&conn->conn_post_wait_comp);
4213 		spin_lock_bh(&conn->state_lock);
4214 	}
4215 
4216 	/*
4217 	 * If connection reinstatement is being performed on this connection
4218 	 * by receiving a REMOVECONNFORRECOVERY logout request, up the
4219 	 * connection wait rcfr semaphore that is being blocked on
4220 	 * an iscsit_connection_reinstatement_rcfr().
4221 	 */
4222 	if (atomic_read(&conn->connection_wait_rcfr)) {
4223 		spin_unlock_bh(&conn->state_lock);
4224 		complete(&conn->conn_wait_rcfr_comp);
4225 		wait_for_completion(&conn->conn_post_wait_comp);
4226 		spin_lock_bh(&conn->state_lock);
4227 	}
4228 	atomic_set(&conn->connection_reinstatement, 1);
4229 	spin_unlock_bh(&conn->state_lock);
4230 
4231 	/*
4232 	 * If any other processes are accessing this connection pointer we
4233 	 * must wait until they have completed.
4234 	 */
4235 	iscsit_check_conn_usage_count(conn);
4236 
4237 	ahash_request_free(conn->conn_tx_hash);
4238 	if (conn->conn_rx_hash) {
4239 		struct crypto_ahash *tfm;
4240 
4241 		tfm = crypto_ahash_reqtfm(conn->conn_rx_hash);
4242 		ahash_request_free(conn->conn_rx_hash);
4243 		crypto_free_ahash(tfm);
4244 	}
4245 
4246 	free_cpumask_var(conn->conn_cpumask);
4247 
4248 	kfree(conn->conn_ops);
4249 	conn->conn_ops = NULL;
4250 
4251 	if (conn->sock)
4252 		sock_release(conn->sock);
4253 
4254 	if (conn->conn_transport->iscsit_free_conn)
4255 		conn->conn_transport->iscsit_free_conn(conn);
4256 
4257 	iscsit_put_transport(conn->conn_transport);
4258 
4259 	pr_debug("Moving to TARG_CONN_STATE_FREE.\n");
4260 	conn->conn_state = TARG_CONN_STATE_FREE;
4261 	kfree(conn);
4262 
4263 	spin_lock_bh(&sess->conn_lock);
4264 	atomic_dec(&sess->nconn);
4265 	pr_debug("Decremented iSCSI connection count to %hu from node:"
4266 		" %s\n", atomic_read(&sess->nconn),
4267 		sess->sess_ops->InitiatorName);
4268 	/*
4269 	 * Make sure that if one connection fails in an non ERL=2 iSCSI
4270 	 * Session that they all fail.
4271 	 */
4272 	if ((sess->sess_ops->ErrorRecoveryLevel != 2) && !conn_logout &&
4273 	     !atomic_read(&sess->session_logout))
4274 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4275 
4276 	/*
4277 	 * If this was not the last connection in the session, and we are
4278 	 * performing session reinstatement or falling back to ERL=0, call
4279 	 * iscsit_stop_session() without sleeping to shutdown the other
4280 	 * active connections.
4281 	 */
4282 	if (atomic_read(&sess->nconn)) {
4283 		if (!atomic_read(&sess->session_reinstatement) &&
4284 		    !atomic_read(&sess->session_fall_back_to_erl0)) {
4285 			spin_unlock_bh(&sess->conn_lock);
4286 			return 0;
4287 		}
4288 		if (!atomic_read(&sess->session_stop_active)) {
4289 			atomic_set(&sess->session_stop_active, 1);
4290 			spin_unlock_bh(&sess->conn_lock);
4291 			iscsit_stop_session(sess, 0, 0);
4292 			return 0;
4293 		}
4294 		spin_unlock_bh(&sess->conn_lock);
4295 		return 0;
4296 	}
4297 
4298 	/*
4299 	 * If this was the last connection in the session and one of the
4300 	 * following is occurring:
4301 	 *
4302 	 * Session Reinstatement is not being performed, and are falling back
4303 	 * to ERL=0 call iscsit_close_session().
4304 	 *
4305 	 * Session Logout was requested.  iscsit_close_session() will be called
4306 	 * elsewhere.
4307 	 *
4308 	 * Session Continuation is not being performed, start the Time2Retain
4309 	 * handler and check if sleep_on_sess_wait_sem is active.
4310 	 */
4311 	if (!atomic_read(&sess->session_reinstatement) &&
4312 	     atomic_read(&sess->session_fall_back_to_erl0)) {
4313 		spin_unlock_bh(&sess->conn_lock);
4314 		iscsit_close_session(sess);
4315 
4316 		return 0;
4317 	} else if (atomic_read(&sess->session_logout)) {
4318 		pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
4319 		sess->session_state = TARG_SESS_STATE_FREE;
4320 		spin_unlock_bh(&sess->conn_lock);
4321 
4322 		if (atomic_read(&sess->sleep_on_sess_wait_comp))
4323 			complete(&sess->session_wait_comp);
4324 
4325 		return 0;
4326 	} else {
4327 		pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
4328 		sess->session_state = TARG_SESS_STATE_FAILED;
4329 
4330 		if (!atomic_read(&sess->session_continuation)) {
4331 			spin_unlock_bh(&sess->conn_lock);
4332 			iscsit_start_time2retain_handler(sess);
4333 		} else
4334 			spin_unlock_bh(&sess->conn_lock);
4335 
4336 		if (atomic_read(&sess->sleep_on_sess_wait_comp))
4337 			complete(&sess->session_wait_comp);
4338 
4339 		return 0;
4340 	}
4341 }
4342 
4343 /*
4344  * If the iSCSI Session for the iSCSI Initiator Node exists,
4345  * forcefully shutdown the iSCSI NEXUS.
4346  */
4347 int iscsit_close_session(struct iscsi_session *sess)
4348 {
4349 	struct iscsi_portal_group *tpg = sess->tpg;
4350 	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
4351 
4352 	if (atomic_read(&sess->nconn)) {
4353 		pr_err("%d connection(s) still exist for iSCSI session"
4354 			" to %s\n", atomic_read(&sess->nconn),
4355 			sess->sess_ops->InitiatorName);
4356 		BUG();
4357 	}
4358 
4359 	spin_lock_bh(&se_tpg->session_lock);
4360 	atomic_set(&sess->session_logout, 1);
4361 	atomic_set(&sess->session_reinstatement, 1);
4362 	iscsit_stop_time2retain_timer(sess);
4363 	spin_unlock_bh(&se_tpg->session_lock);
4364 
4365 	/*
4366 	 * transport_deregister_session_configfs() will clear the
4367 	 * struct se_node_acl->nacl_sess pointer now as a iscsi_np process context
4368 	 * can be setting it again with __transport_register_session() in
4369 	 * iscsi_post_login_handler() again after the iscsit_stop_session()
4370 	 * completes in iscsi_np context.
4371 	 */
4372 	transport_deregister_session_configfs(sess->se_sess);
4373 
4374 	/*
4375 	 * If any other processes are accessing this session pointer we must
4376 	 * wait until they have completed.  If we are in an interrupt (the
4377 	 * time2retain handler) and contain and active session usage count we
4378 	 * restart the timer and exit.
4379 	 */
4380 	if (!in_interrupt()) {
4381 		if (iscsit_check_session_usage_count(sess) == 1)
4382 			iscsit_stop_session(sess, 1, 1);
4383 	} else {
4384 		if (iscsit_check_session_usage_count(sess) == 2) {
4385 			atomic_set(&sess->session_logout, 0);
4386 			iscsit_start_time2retain_handler(sess);
4387 			return 0;
4388 		}
4389 	}
4390 
4391 	transport_deregister_session(sess->se_sess);
4392 
4393 	if (sess->sess_ops->ErrorRecoveryLevel == 2)
4394 		iscsit_free_connection_recovery_entires(sess);
4395 
4396 	iscsit_free_all_ooo_cmdsns(sess);
4397 
4398 	spin_lock_bh(&se_tpg->session_lock);
4399 	pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
4400 	sess->session_state = TARG_SESS_STATE_FREE;
4401 	pr_debug("Released iSCSI session from node: %s\n",
4402 			sess->sess_ops->InitiatorName);
4403 	tpg->nsessions--;
4404 	if (tpg->tpg_tiqn)
4405 		tpg->tpg_tiqn->tiqn_nsessions--;
4406 
4407 	pr_debug("Decremented number of active iSCSI Sessions on"
4408 		" iSCSI TPG: %hu to %u\n", tpg->tpgt, tpg->nsessions);
4409 
4410 	spin_lock(&sess_idr_lock);
4411 	idr_remove(&sess_idr, sess->session_index);
4412 	spin_unlock(&sess_idr_lock);
4413 
4414 	kfree(sess->sess_ops);
4415 	sess->sess_ops = NULL;
4416 	spin_unlock_bh(&se_tpg->session_lock);
4417 
4418 	kfree(sess);
4419 	return 0;
4420 }
4421 
4422 static void iscsit_logout_post_handler_closesession(
4423 	struct iscsi_conn *conn)
4424 {
4425 	struct iscsi_session *sess = conn->sess;
4426 	int sleep = 1;
4427 	/*
4428 	 * Traditional iscsi/tcp will invoke this logic from TX thread
4429 	 * context during session logout, so clear tx_thread_active and
4430 	 * sleep if iscsit_close_connection() has not already occured.
4431 	 *
4432 	 * Since iser-target invokes this logic from it's own workqueue,
4433 	 * always sleep waiting for RX/TX thread shutdown to complete
4434 	 * within iscsit_close_connection().
4435 	 */
4436 	if (!conn->conn_transport->rdma_shutdown) {
4437 		sleep = cmpxchg(&conn->tx_thread_active, true, false);
4438 		if (!sleep)
4439 			return;
4440 	}
4441 
4442 	atomic_set(&conn->conn_logout_remove, 0);
4443 	complete(&conn->conn_logout_comp);
4444 
4445 	iscsit_dec_conn_usage_count(conn);
4446 	iscsit_stop_session(sess, sleep, sleep);
4447 	iscsit_dec_session_usage_count(sess);
4448 	iscsit_close_session(sess);
4449 }
4450 
4451 static void iscsit_logout_post_handler_samecid(
4452 	struct iscsi_conn *conn)
4453 {
4454 	int sleep = 1;
4455 
4456 	if (!conn->conn_transport->rdma_shutdown) {
4457 		sleep = cmpxchg(&conn->tx_thread_active, true, false);
4458 		if (!sleep)
4459 			return;
4460 	}
4461 
4462 	atomic_set(&conn->conn_logout_remove, 0);
4463 	complete(&conn->conn_logout_comp);
4464 
4465 	iscsit_cause_connection_reinstatement(conn, sleep);
4466 	iscsit_dec_conn_usage_count(conn);
4467 }
4468 
4469 static void iscsit_logout_post_handler_diffcid(
4470 	struct iscsi_conn *conn,
4471 	u16 cid)
4472 {
4473 	struct iscsi_conn *l_conn;
4474 	struct iscsi_session *sess = conn->sess;
4475 	bool conn_found = false;
4476 
4477 	if (!sess)
4478 		return;
4479 
4480 	spin_lock_bh(&sess->conn_lock);
4481 	list_for_each_entry(l_conn, &sess->sess_conn_list, conn_list) {
4482 		if (l_conn->cid == cid) {
4483 			iscsit_inc_conn_usage_count(l_conn);
4484 			conn_found = true;
4485 			break;
4486 		}
4487 	}
4488 	spin_unlock_bh(&sess->conn_lock);
4489 
4490 	if (!conn_found)
4491 		return;
4492 
4493 	if (l_conn->sock)
4494 		l_conn->sock->ops->shutdown(l_conn->sock, RCV_SHUTDOWN);
4495 
4496 	spin_lock_bh(&l_conn->state_lock);
4497 	pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
4498 	l_conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
4499 	spin_unlock_bh(&l_conn->state_lock);
4500 
4501 	iscsit_cause_connection_reinstatement(l_conn, 1);
4502 	iscsit_dec_conn_usage_count(l_conn);
4503 }
4504 
4505 /*
4506  *	Return of 0 causes the TX thread to restart.
4507  */
4508 int iscsit_logout_post_handler(
4509 	struct iscsi_cmd *cmd,
4510 	struct iscsi_conn *conn)
4511 {
4512 	int ret = 0;
4513 
4514 	switch (cmd->logout_reason) {
4515 	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
4516 		switch (cmd->logout_response) {
4517 		case ISCSI_LOGOUT_SUCCESS:
4518 		case ISCSI_LOGOUT_CLEANUP_FAILED:
4519 		default:
4520 			iscsit_logout_post_handler_closesession(conn);
4521 			break;
4522 		}
4523 		ret = 0;
4524 		break;
4525 	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
4526 		if (conn->cid == cmd->logout_cid) {
4527 			switch (cmd->logout_response) {
4528 			case ISCSI_LOGOUT_SUCCESS:
4529 			case ISCSI_LOGOUT_CLEANUP_FAILED:
4530 			default:
4531 				iscsit_logout_post_handler_samecid(conn);
4532 				break;
4533 			}
4534 			ret = 0;
4535 		} else {
4536 			switch (cmd->logout_response) {
4537 			case ISCSI_LOGOUT_SUCCESS:
4538 				iscsit_logout_post_handler_diffcid(conn,
4539 					cmd->logout_cid);
4540 				break;
4541 			case ISCSI_LOGOUT_CID_NOT_FOUND:
4542 			case ISCSI_LOGOUT_CLEANUP_FAILED:
4543 			default:
4544 				break;
4545 			}
4546 			ret = 1;
4547 		}
4548 		break;
4549 	case ISCSI_LOGOUT_REASON_RECOVERY:
4550 		switch (cmd->logout_response) {
4551 		case ISCSI_LOGOUT_SUCCESS:
4552 		case ISCSI_LOGOUT_CID_NOT_FOUND:
4553 		case ISCSI_LOGOUT_RECOVERY_UNSUPPORTED:
4554 		case ISCSI_LOGOUT_CLEANUP_FAILED:
4555 		default:
4556 			break;
4557 		}
4558 		ret = 1;
4559 		break;
4560 	default:
4561 		break;
4562 
4563 	}
4564 	return ret;
4565 }
4566 EXPORT_SYMBOL(iscsit_logout_post_handler);
4567 
4568 void iscsit_fail_session(struct iscsi_session *sess)
4569 {
4570 	struct iscsi_conn *conn;
4571 
4572 	spin_lock_bh(&sess->conn_lock);
4573 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
4574 		pr_debug("Moving to TARG_CONN_STATE_CLEANUP_WAIT.\n");
4575 		conn->conn_state = TARG_CONN_STATE_CLEANUP_WAIT;
4576 	}
4577 	spin_unlock_bh(&sess->conn_lock);
4578 
4579 	pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
4580 	sess->session_state = TARG_SESS_STATE_FAILED;
4581 }
4582 
4583 int iscsit_free_session(struct iscsi_session *sess)
4584 {
4585 	u16 conn_count = atomic_read(&sess->nconn);
4586 	struct iscsi_conn *conn, *conn_tmp = NULL;
4587 	int is_last;
4588 
4589 	spin_lock_bh(&sess->conn_lock);
4590 	atomic_set(&sess->sleep_on_sess_wait_comp, 1);
4591 
4592 	list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
4593 			conn_list) {
4594 		if (conn_count == 0)
4595 			break;
4596 
4597 		if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
4598 			is_last = 1;
4599 		} else {
4600 			iscsit_inc_conn_usage_count(conn_tmp);
4601 			is_last = 0;
4602 		}
4603 		iscsit_inc_conn_usage_count(conn);
4604 
4605 		spin_unlock_bh(&sess->conn_lock);
4606 		iscsit_cause_connection_reinstatement(conn, 1);
4607 		spin_lock_bh(&sess->conn_lock);
4608 
4609 		iscsit_dec_conn_usage_count(conn);
4610 		if (is_last == 0)
4611 			iscsit_dec_conn_usage_count(conn_tmp);
4612 
4613 		conn_count--;
4614 	}
4615 
4616 	if (atomic_read(&sess->nconn)) {
4617 		spin_unlock_bh(&sess->conn_lock);
4618 		wait_for_completion(&sess->session_wait_comp);
4619 	} else
4620 		spin_unlock_bh(&sess->conn_lock);
4621 
4622 	iscsit_close_session(sess);
4623 	return 0;
4624 }
4625 
4626 void iscsit_stop_session(
4627 	struct iscsi_session *sess,
4628 	int session_sleep,
4629 	int connection_sleep)
4630 {
4631 	u16 conn_count = atomic_read(&sess->nconn);
4632 	struct iscsi_conn *conn, *conn_tmp = NULL;
4633 	int is_last;
4634 
4635 	spin_lock_bh(&sess->conn_lock);
4636 	if (session_sleep)
4637 		atomic_set(&sess->sleep_on_sess_wait_comp, 1);
4638 
4639 	if (connection_sleep) {
4640 		list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
4641 				conn_list) {
4642 			if (conn_count == 0)
4643 				break;
4644 
4645 			if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
4646 				is_last = 1;
4647 			} else {
4648 				iscsit_inc_conn_usage_count(conn_tmp);
4649 				is_last = 0;
4650 			}
4651 			iscsit_inc_conn_usage_count(conn);
4652 
4653 			spin_unlock_bh(&sess->conn_lock);
4654 			iscsit_cause_connection_reinstatement(conn, 1);
4655 			spin_lock_bh(&sess->conn_lock);
4656 
4657 			iscsit_dec_conn_usage_count(conn);
4658 			if (is_last == 0)
4659 				iscsit_dec_conn_usage_count(conn_tmp);
4660 			conn_count--;
4661 		}
4662 	} else {
4663 		list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
4664 			iscsit_cause_connection_reinstatement(conn, 0);
4665 	}
4666 
4667 	if (session_sleep && atomic_read(&sess->nconn)) {
4668 		spin_unlock_bh(&sess->conn_lock);
4669 		wait_for_completion(&sess->session_wait_comp);
4670 	} else
4671 		spin_unlock_bh(&sess->conn_lock);
4672 }
4673 
4674 int iscsit_release_sessions_for_tpg(struct iscsi_portal_group *tpg, int force)
4675 {
4676 	struct iscsi_session *sess;
4677 	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
4678 	struct se_session *se_sess, *se_sess_tmp;
4679 	LIST_HEAD(free_list);
4680 	int session_count = 0;
4681 
4682 	spin_lock_bh(&se_tpg->session_lock);
4683 	if (tpg->nsessions && !force) {
4684 		spin_unlock_bh(&se_tpg->session_lock);
4685 		return -1;
4686 	}
4687 
4688 	list_for_each_entry_safe(se_sess, se_sess_tmp, &se_tpg->tpg_sess_list,
4689 			sess_list) {
4690 		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
4691 
4692 		spin_lock(&sess->conn_lock);
4693 		if (atomic_read(&sess->session_fall_back_to_erl0) ||
4694 		    atomic_read(&sess->session_logout) ||
4695 		    (sess->time2retain_timer_flags & ISCSI_TF_EXPIRED)) {
4696 			spin_unlock(&sess->conn_lock);
4697 			continue;
4698 		}
4699 		atomic_set(&sess->session_reinstatement, 1);
4700 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4701 		spin_unlock(&sess->conn_lock);
4702 
4703 		list_move_tail(&se_sess->sess_list, &free_list);
4704 	}
4705 	spin_unlock_bh(&se_tpg->session_lock);
4706 
4707 	list_for_each_entry_safe(se_sess, se_sess_tmp, &free_list, sess_list) {
4708 		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
4709 
4710 		iscsit_free_session(sess);
4711 		session_count++;
4712 	}
4713 
4714 	pr_debug("Released %d iSCSI Session(s) from Target Portal"
4715 			" Group: %hu\n", session_count, tpg->tpgt);
4716 	return 0;
4717 }
4718 
4719 MODULE_DESCRIPTION("iSCSI-Target Driver for mainline target infrastructure");
4720 MODULE_VERSION("4.1.x");
4721 MODULE_AUTHOR("nab@Linux-iSCSI.org");
4722 MODULE_LICENSE("GPL");
4723 
4724 module_init(iscsi_target_init_module);
4725 module_exit(iscsi_target_cleanup_module);
4726