xref: /linux/drivers/target/iscsi/iscsi_target.c (revision bd628c1bed7902ec1f24ba0fe70758949146abbe)
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 <linux/inet.h>
30 #include <net/ipv6.h>
31 #include <scsi/scsi_proto.h>
32 #include <scsi/iscsi_proto.h>
33 #include <scsi/scsi_tcq.h>
34 #include <target/target_core_base.h>
35 #include <target/target_core_fabric.h>
36 
37 #include <target/iscsi/iscsi_target_core.h>
38 #include "iscsi_target_parameters.h"
39 #include "iscsi_target_seq_pdu_list.h"
40 #include "iscsi_target_datain_values.h"
41 #include "iscsi_target_erl0.h"
42 #include "iscsi_target_erl1.h"
43 #include "iscsi_target_erl2.h"
44 #include "iscsi_target_login.h"
45 #include "iscsi_target_tmr.h"
46 #include "iscsi_target_tpg.h"
47 #include "iscsi_target_util.h"
48 #include "iscsi_target.h"
49 #include "iscsi_target_device.h"
50 #include <target/iscsi/iscsi_target_stat.h>
51 
52 #include <target/iscsi/iscsi_transport.h>
53 
54 static LIST_HEAD(g_tiqn_list);
55 static LIST_HEAD(g_np_list);
56 static DEFINE_SPINLOCK(tiqn_lock);
57 static DEFINE_MUTEX(np_lock);
58 
59 static struct idr tiqn_idr;
60 DEFINE_IDA(sess_ida);
61 struct mutex auth_id_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, const void *, void *);
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 					  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, &cmd->pad_bytes,
554 						  &cmd->data_crc);
555 
556 			iov[niov].iov_base = &cmd->data_crc;
557 			iov[niov++].iov_len = ISCSI_CRC_LEN;
558 			tx_size += ISCSI_CRC_LEN;
559 			pr_debug("Attached DataDigest for %u"
560 				 " bytes opcode 0x%x, CRC 0x%08x\n",
561 				 data_buf_len, hdr->opcode, cmd->data_crc);
562 		}
563 	}
564 
565 	cmd->iov_misc_count = niov;
566 	cmd->tx_size = tx_size;
567 
568 	ret = iscsit_send_tx_data(cmd, conn, 1);
569 	if (ret < 0) {
570 		iscsit_tx_thread_wait_for_tcp(conn);
571 		return ret;
572 	}
573 
574 	return 0;
575 }
576 
577 static int iscsit_map_iovec(struct iscsi_cmd *, struct kvec *, u32, u32);
578 static void iscsit_unmap_iovec(struct iscsi_cmd *);
579 static u32 iscsit_do_crypto_hash_sg(struct ahash_request *, struct iscsi_cmd *,
580 				    u32, u32, u32, u8 *);
581 static int
582 iscsit_xmit_datain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
583 		       const struct iscsi_datain *datain)
584 {
585 	struct kvec *iov;
586 	u32 iov_count = 0, tx_size = 0;
587 	int ret, iov_ret;
588 
589 	iov = &cmd->iov_data[0];
590 	iov[iov_count].iov_base	= cmd->pdu;
591 	iov[iov_count++].iov_len = ISCSI_HDR_LEN;
592 	tx_size += ISCSI_HDR_LEN;
593 
594 	if (conn->conn_ops->HeaderDigest) {
595 		u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];
596 
597 		iscsit_do_crypto_hash_buf(conn->conn_tx_hash, cmd->pdu,
598 					  ISCSI_HDR_LEN, 0, NULL,
599 					  header_digest);
600 
601 		iov[0].iov_len += ISCSI_CRC_LEN;
602 		tx_size += ISCSI_CRC_LEN;
603 
604 		pr_debug("Attaching CRC32 HeaderDigest for DataIN PDU 0x%08x\n",
605 			 *header_digest);
606 	}
607 
608 	iov_ret = iscsit_map_iovec(cmd, &cmd->iov_data[1],
609 				   datain->offset, datain->length);
610 	if (iov_ret < 0)
611 		return -1;
612 
613 	iov_count += iov_ret;
614 	tx_size += datain->length;
615 
616 	cmd->padding = ((-datain->length) & 3);
617 	if (cmd->padding) {
618 		iov[iov_count].iov_base		= cmd->pad_bytes;
619 		iov[iov_count++].iov_len	= cmd->padding;
620 		tx_size += cmd->padding;
621 
622 		pr_debug("Attaching %u padding bytes\n", cmd->padding);
623 	}
624 
625 	if (conn->conn_ops->DataDigest) {
626 		cmd->data_crc = iscsit_do_crypto_hash_sg(conn->conn_tx_hash,
627 							 cmd, datain->offset,
628 							 datain->length,
629 							 cmd->padding,
630 							 cmd->pad_bytes);
631 
632 		iov[iov_count].iov_base	= &cmd->data_crc;
633 		iov[iov_count++].iov_len = ISCSI_CRC_LEN;
634 		tx_size += ISCSI_CRC_LEN;
635 
636 		pr_debug("Attached CRC32C DataDigest %d bytes, crc 0x%08x\n",
637 			 datain->length + cmd->padding, cmd->data_crc);
638 	}
639 
640 	cmd->iov_data_count = iov_count;
641 	cmd->tx_size = tx_size;
642 
643 	ret = iscsit_fe_sendpage_sg(cmd, conn);
644 
645 	iscsit_unmap_iovec(cmd);
646 
647 	if (ret < 0) {
648 		iscsit_tx_thread_wait_for_tcp(conn);
649 		return ret;
650 	}
651 
652 	return 0;
653 }
654 
655 static int iscsit_xmit_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
656 			   struct iscsi_datain_req *dr, const void *buf,
657 			   u32 buf_len)
658 {
659 	if (dr)
660 		return iscsit_xmit_datain_pdu(conn, cmd, buf);
661 	else
662 		return iscsit_xmit_nondatain_pdu(conn, cmd, buf, buf_len);
663 }
664 
665 static enum target_prot_op iscsit_get_sup_prot_ops(struct iscsi_conn *conn)
666 {
667 	return TARGET_PROT_NORMAL;
668 }
669 
670 static struct iscsit_transport iscsi_target_transport = {
671 	.name			= "iSCSI/TCP",
672 	.transport_type		= ISCSI_TCP,
673 	.rdma_shutdown		= false,
674 	.owner			= NULL,
675 	.iscsit_setup_np	= iscsit_setup_np,
676 	.iscsit_accept_np	= iscsit_accept_np,
677 	.iscsit_free_np		= iscsit_free_np,
678 	.iscsit_get_login_rx	= iscsit_get_login_rx,
679 	.iscsit_put_login_tx	= iscsit_put_login_tx,
680 	.iscsit_get_dataout	= iscsit_build_r2ts_for_cmd,
681 	.iscsit_immediate_queue	= iscsit_immediate_queue,
682 	.iscsit_response_queue	= iscsit_response_queue,
683 	.iscsit_queue_data_in	= iscsit_queue_rsp,
684 	.iscsit_queue_status	= iscsit_queue_rsp,
685 	.iscsit_aborted_task	= iscsit_aborted_task,
686 	.iscsit_xmit_pdu	= iscsit_xmit_pdu,
687 	.iscsit_get_rx_pdu	= iscsit_get_rx_pdu,
688 	.iscsit_get_sup_prot_ops = iscsit_get_sup_prot_ops,
689 };
690 
691 static int __init iscsi_target_init_module(void)
692 {
693 	int ret = 0, size;
694 
695 	pr_debug("iSCSI-Target "ISCSIT_VERSION"\n");
696 	iscsit_global = kzalloc(sizeof(*iscsit_global), GFP_KERNEL);
697 	if (!iscsit_global)
698 		return -1;
699 
700 	spin_lock_init(&iscsit_global->ts_bitmap_lock);
701 	mutex_init(&auth_id_lock);
702 	idr_init(&tiqn_idr);
703 
704 	ret = target_register_template(&iscsi_ops);
705 	if (ret)
706 		goto out;
707 
708 	size = BITS_TO_LONGS(ISCSIT_BITMAP_BITS) * sizeof(long);
709 	iscsit_global->ts_bitmap = vzalloc(size);
710 	if (!iscsit_global->ts_bitmap)
711 		goto configfs_out;
712 
713 	lio_qr_cache = kmem_cache_create("lio_qr_cache",
714 			sizeof(struct iscsi_queue_req),
715 			__alignof__(struct iscsi_queue_req), 0, NULL);
716 	if (!lio_qr_cache) {
717 		pr_err("nable to kmem_cache_create() for"
718 				" lio_qr_cache\n");
719 		goto bitmap_out;
720 	}
721 
722 	lio_dr_cache = kmem_cache_create("lio_dr_cache",
723 			sizeof(struct iscsi_datain_req),
724 			__alignof__(struct iscsi_datain_req), 0, NULL);
725 	if (!lio_dr_cache) {
726 		pr_err("Unable to kmem_cache_create() for"
727 				" lio_dr_cache\n");
728 		goto qr_out;
729 	}
730 
731 	lio_ooo_cache = kmem_cache_create("lio_ooo_cache",
732 			sizeof(struct iscsi_ooo_cmdsn),
733 			__alignof__(struct iscsi_ooo_cmdsn), 0, NULL);
734 	if (!lio_ooo_cache) {
735 		pr_err("Unable to kmem_cache_create() for"
736 				" lio_ooo_cache\n");
737 		goto dr_out;
738 	}
739 
740 	lio_r2t_cache = kmem_cache_create("lio_r2t_cache",
741 			sizeof(struct iscsi_r2t), __alignof__(struct iscsi_r2t),
742 			0, NULL);
743 	if (!lio_r2t_cache) {
744 		pr_err("Unable to kmem_cache_create() for"
745 				" lio_r2t_cache\n");
746 		goto ooo_out;
747 	}
748 
749 	iscsit_register_transport(&iscsi_target_transport);
750 
751 	if (iscsit_load_discovery_tpg() < 0)
752 		goto r2t_out;
753 
754 	return ret;
755 r2t_out:
756 	iscsit_unregister_transport(&iscsi_target_transport);
757 	kmem_cache_destroy(lio_r2t_cache);
758 ooo_out:
759 	kmem_cache_destroy(lio_ooo_cache);
760 dr_out:
761 	kmem_cache_destroy(lio_dr_cache);
762 qr_out:
763 	kmem_cache_destroy(lio_qr_cache);
764 bitmap_out:
765 	vfree(iscsit_global->ts_bitmap);
766 configfs_out:
767 	/* XXX: this probably wants it to be it's own unwind step.. */
768 	if (iscsit_global->discovery_tpg)
769 		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
770 	target_unregister_template(&iscsi_ops);
771 out:
772 	kfree(iscsit_global);
773 	return -ENOMEM;
774 }
775 
776 static void __exit iscsi_target_cleanup_module(void)
777 {
778 	iscsit_release_discovery_tpg();
779 	iscsit_unregister_transport(&iscsi_target_transport);
780 	kmem_cache_destroy(lio_qr_cache);
781 	kmem_cache_destroy(lio_dr_cache);
782 	kmem_cache_destroy(lio_ooo_cache);
783 	kmem_cache_destroy(lio_r2t_cache);
784 
785 	/*
786 	 * Shutdown discovery sessions and disable discovery TPG
787 	 */
788 	if (iscsit_global->discovery_tpg)
789 		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
790 
791 	target_unregister_template(&iscsi_ops);
792 
793 	vfree(iscsit_global->ts_bitmap);
794 	kfree(iscsit_global);
795 }
796 
797 int iscsit_add_reject(
798 	struct iscsi_conn *conn,
799 	u8 reason,
800 	unsigned char *buf)
801 {
802 	struct iscsi_cmd *cmd;
803 
804 	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
805 	if (!cmd)
806 		return -1;
807 
808 	cmd->iscsi_opcode = ISCSI_OP_REJECT;
809 	cmd->reject_reason = reason;
810 
811 	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
812 	if (!cmd->buf_ptr) {
813 		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
814 		iscsit_free_cmd(cmd, false);
815 		return -1;
816 	}
817 
818 	spin_lock_bh(&conn->cmd_lock);
819 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
820 	spin_unlock_bh(&conn->cmd_lock);
821 
822 	cmd->i_state = ISTATE_SEND_REJECT;
823 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
824 
825 	return -1;
826 }
827 EXPORT_SYMBOL(iscsit_add_reject);
828 
829 static int iscsit_add_reject_from_cmd(
830 	struct iscsi_cmd *cmd,
831 	u8 reason,
832 	bool add_to_conn,
833 	unsigned char *buf)
834 {
835 	struct iscsi_conn *conn;
836 	const bool do_put = cmd->se_cmd.se_tfo != NULL;
837 
838 	if (!cmd->conn) {
839 		pr_err("cmd->conn is NULL for ITT: 0x%08x\n",
840 				cmd->init_task_tag);
841 		return -1;
842 	}
843 	conn = cmd->conn;
844 
845 	cmd->iscsi_opcode = ISCSI_OP_REJECT;
846 	cmd->reject_reason = reason;
847 
848 	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
849 	if (!cmd->buf_ptr) {
850 		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
851 		iscsit_free_cmd(cmd, false);
852 		return -1;
853 	}
854 
855 	if (add_to_conn) {
856 		spin_lock_bh(&conn->cmd_lock);
857 		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
858 		spin_unlock_bh(&conn->cmd_lock);
859 	}
860 
861 	cmd->i_state = ISTATE_SEND_REJECT;
862 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
863 	/*
864 	 * Perform the kref_put now if se_cmd has already been setup by
865 	 * scsit_setup_scsi_cmd()
866 	 */
867 	if (do_put) {
868 		pr_debug("iscsi reject: calling target_put_sess_cmd >>>>>>\n");
869 		target_put_sess_cmd(&cmd->se_cmd);
870 	}
871 	return -1;
872 }
873 
874 static int iscsit_add_reject_cmd(struct iscsi_cmd *cmd, u8 reason,
875 				 unsigned char *buf)
876 {
877 	return iscsit_add_reject_from_cmd(cmd, reason, true, buf);
878 }
879 
880 int iscsit_reject_cmd(struct iscsi_cmd *cmd, u8 reason, unsigned char *buf)
881 {
882 	return iscsit_add_reject_from_cmd(cmd, reason, false, buf);
883 }
884 EXPORT_SYMBOL(iscsit_reject_cmd);
885 
886 /*
887  * Map some portion of the allocated scatterlist to an iovec, suitable for
888  * kernel sockets to copy data in/out.
889  */
890 static int iscsit_map_iovec(
891 	struct iscsi_cmd *cmd,
892 	struct kvec *iov,
893 	u32 data_offset,
894 	u32 data_length)
895 {
896 	u32 i = 0;
897 	struct scatterlist *sg;
898 	unsigned int page_off;
899 
900 	/*
901 	 * We know each entry in t_data_sg contains a page.
902 	 */
903 	u32 ent = data_offset / PAGE_SIZE;
904 
905 	if (ent >= cmd->se_cmd.t_data_nents) {
906 		pr_err("Initial page entry out-of-bounds\n");
907 		return -1;
908 	}
909 
910 	sg = &cmd->se_cmd.t_data_sg[ent];
911 	page_off = (data_offset % PAGE_SIZE);
912 
913 	cmd->first_data_sg = sg;
914 	cmd->first_data_sg_off = page_off;
915 
916 	while (data_length) {
917 		u32 cur_len = min_t(u32, data_length, sg->length - page_off);
918 
919 		iov[i].iov_base = kmap(sg_page(sg)) + sg->offset + page_off;
920 		iov[i].iov_len = cur_len;
921 
922 		data_length -= cur_len;
923 		page_off = 0;
924 		sg = sg_next(sg);
925 		i++;
926 	}
927 
928 	cmd->kmapped_nents = i;
929 
930 	return i;
931 }
932 
933 static void iscsit_unmap_iovec(struct iscsi_cmd *cmd)
934 {
935 	u32 i;
936 	struct scatterlist *sg;
937 
938 	sg = cmd->first_data_sg;
939 
940 	for (i = 0; i < cmd->kmapped_nents; i++)
941 		kunmap(sg_page(&sg[i]));
942 }
943 
944 static void iscsit_ack_from_expstatsn(struct iscsi_conn *conn, u32 exp_statsn)
945 {
946 	LIST_HEAD(ack_list);
947 	struct iscsi_cmd *cmd, *cmd_p;
948 
949 	conn->exp_statsn = exp_statsn;
950 
951 	if (conn->sess->sess_ops->RDMAExtensions)
952 		return;
953 
954 	spin_lock_bh(&conn->cmd_lock);
955 	list_for_each_entry_safe(cmd, cmd_p, &conn->conn_cmd_list, i_conn_node) {
956 		spin_lock(&cmd->istate_lock);
957 		if ((cmd->i_state == ISTATE_SENT_STATUS) &&
958 		    iscsi_sna_lt(cmd->stat_sn, exp_statsn)) {
959 			cmd->i_state = ISTATE_REMOVE;
960 			spin_unlock(&cmd->istate_lock);
961 			list_move_tail(&cmd->i_conn_node, &ack_list);
962 			continue;
963 		}
964 		spin_unlock(&cmd->istate_lock);
965 	}
966 	spin_unlock_bh(&conn->cmd_lock);
967 
968 	list_for_each_entry_safe(cmd, cmd_p, &ack_list, i_conn_node) {
969 		list_del_init(&cmd->i_conn_node);
970 		iscsit_free_cmd(cmd, false);
971 	}
972 }
973 
974 static int iscsit_allocate_iovecs(struct iscsi_cmd *cmd)
975 {
976 	u32 iov_count = max(1UL, DIV_ROUND_UP(cmd->se_cmd.data_length, PAGE_SIZE));
977 
978 	iov_count += ISCSI_IOV_DATA_BUFFER;
979 	cmd->iov_data = kcalloc(iov_count, sizeof(*cmd->iov_data), GFP_KERNEL);
980 	if (!cmd->iov_data)
981 		return -ENOMEM;
982 
983 	cmd->orig_iov_data_count = iov_count;
984 	return 0;
985 }
986 
987 int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
988 			  unsigned char *buf)
989 {
990 	int data_direction, payload_length;
991 	struct iscsi_scsi_req *hdr;
992 	int iscsi_task_attr;
993 	int sam_task_attr;
994 
995 	atomic_long_inc(&conn->sess->cmd_pdus);
996 
997 	hdr			= (struct iscsi_scsi_req *) buf;
998 	payload_length		= ntoh24(hdr->dlength);
999 
1000 	/* FIXME; Add checks for AdditionalHeaderSegment */
1001 
1002 	if (!(hdr->flags & ISCSI_FLAG_CMD_WRITE) &&
1003 	    !(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
1004 		pr_err("ISCSI_FLAG_CMD_WRITE & ISCSI_FLAG_CMD_FINAL"
1005 				" not set. Bad iSCSI Initiator.\n");
1006 		return iscsit_add_reject_cmd(cmd,
1007 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1008 	}
1009 
1010 	if (((hdr->flags & ISCSI_FLAG_CMD_READ) ||
1011 	     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) && !hdr->data_length) {
1012 		/*
1013 		 * From RFC-3720 Section 10.3.1:
1014 		 *
1015 		 * "Either or both of R and W MAY be 1 when either the
1016 		 *  Expected Data Transfer Length and/or Bidirectional Read
1017 		 *  Expected Data Transfer Length are 0"
1018 		 *
1019 		 * For this case, go ahead and clear the unnecssary bits
1020 		 * to avoid any confusion with ->data_direction.
1021 		 */
1022 		hdr->flags &= ~ISCSI_FLAG_CMD_READ;
1023 		hdr->flags &= ~ISCSI_FLAG_CMD_WRITE;
1024 
1025 		pr_warn("ISCSI_FLAG_CMD_READ or ISCSI_FLAG_CMD_WRITE"
1026 			" set when Expected Data Transfer Length is 0 for"
1027 			" CDB: 0x%02x, Fixing up flags\n", hdr->cdb[0]);
1028 	}
1029 
1030 	if (!(hdr->flags & ISCSI_FLAG_CMD_READ) &&
1031 	    !(hdr->flags & ISCSI_FLAG_CMD_WRITE) && (hdr->data_length != 0)) {
1032 		pr_err("ISCSI_FLAG_CMD_READ and/or ISCSI_FLAG_CMD_WRITE"
1033 			" MUST be set if Expected Data Transfer Length is not 0."
1034 			" Bad iSCSI Initiator\n");
1035 		return iscsit_add_reject_cmd(cmd,
1036 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1037 	}
1038 
1039 	if ((hdr->flags & ISCSI_FLAG_CMD_READ) &&
1040 	    (hdr->flags & ISCSI_FLAG_CMD_WRITE)) {
1041 		pr_err("Bidirectional operations not supported!\n");
1042 		return iscsit_add_reject_cmd(cmd,
1043 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1044 	}
1045 
1046 	if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
1047 		pr_err("Illegally set Immediate Bit in iSCSI Initiator"
1048 				" Scsi Command PDU.\n");
1049 		return iscsit_add_reject_cmd(cmd,
1050 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1051 	}
1052 
1053 	if (payload_length && !conn->sess->sess_ops->ImmediateData) {
1054 		pr_err("ImmediateData=No but DataSegmentLength=%u,"
1055 			" protocol error.\n", payload_length);
1056 		return iscsit_add_reject_cmd(cmd,
1057 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1058 	}
1059 
1060 	if ((be32_to_cpu(hdr->data_length) == payload_length) &&
1061 	    (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))) {
1062 		pr_err("Expected Data Transfer Length and Length of"
1063 			" Immediate Data are the same, but ISCSI_FLAG_CMD_FINAL"
1064 			" bit is not set protocol error\n");
1065 		return iscsit_add_reject_cmd(cmd,
1066 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1067 	}
1068 
1069 	if (payload_length > be32_to_cpu(hdr->data_length)) {
1070 		pr_err("DataSegmentLength: %u is greater than"
1071 			" EDTL: %u, protocol error.\n", payload_length,
1072 				hdr->data_length);
1073 		return iscsit_add_reject_cmd(cmd,
1074 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1075 	}
1076 
1077 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1078 		pr_err("DataSegmentLength: %u is greater than"
1079 			" MaxXmitDataSegmentLength: %u, protocol error.\n",
1080 			payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
1081 		return iscsit_add_reject_cmd(cmd,
1082 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1083 	}
1084 
1085 	if (payload_length > conn->sess->sess_ops->FirstBurstLength) {
1086 		pr_err("DataSegmentLength: %u is greater than"
1087 			" FirstBurstLength: %u, protocol error.\n",
1088 			payload_length, conn->sess->sess_ops->FirstBurstLength);
1089 		return iscsit_add_reject_cmd(cmd,
1090 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1091 	}
1092 
1093 	data_direction = (hdr->flags & ISCSI_FLAG_CMD_WRITE) ? DMA_TO_DEVICE :
1094 			 (hdr->flags & ISCSI_FLAG_CMD_READ) ? DMA_FROM_DEVICE :
1095 			  DMA_NONE;
1096 
1097 	cmd->data_direction = data_direction;
1098 	iscsi_task_attr = hdr->flags & ISCSI_FLAG_CMD_ATTR_MASK;
1099 	/*
1100 	 * Figure out the SAM Task Attribute for the incoming SCSI CDB
1101 	 */
1102 	if ((iscsi_task_attr == ISCSI_ATTR_UNTAGGED) ||
1103 	    (iscsi_task_attr == ISCSI_ATTR_SIMPLE))
1104 		sam_task_attr = TCM_SIMPLE_TAG;
1105 	else if (iscsi_task_attr == ISCSI_ATTR_ORDERED)
1106 		sam_task_attr = TCM_ORDERED_TAG;
1107 	else if (iscsi_task_attr == ISCSI_ATTR_HEAD_OF_QUEUE)
1108 		sam_task_attr = TCM_HEAD_TAG;
1109 	else if (iscsi_task_attr == ISCSI_ATTR_ACA)
1110 		sam_task_attr = TCM_ACA_TAG;
1111 	else {
1112 		pr_debug("Unknown iSCSI Task Attribute: 0x%02x, using"
1113 			" TCM_SIMPLE_TAG\n", iscsi_task_attr);
1114 		sam_task_attr = TCM_SIMPLE_TAG;
1115 	}
1116 
1117 	cmd->iscsi_opcode	= ISCSI_OP_SCSI_CMD;
1118 	cmd->i_state		= ISTATE_NEW_CMD;
1119 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
1120 	cmd->immediate_data	= (payload_length) ? 1 : 0;
1121 	cmd->unsolicited_data	= ((!(hdr->flags & ISCSI_FLAG_CMD_FINAL) &&
1122 				     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) ? 1 : 0);
1123 	if (cmd->unsolicited_data)
1124 		cmd->cmd_flags |= ICF_NON_IMMEDIATE_UNSOLICITED_DATA;
1125 
1126 	conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
1127 	if (hdr->flags & ISCSI_FLAG_CMD_READ)
1128 		cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
1129 	else
1130 		cmd->targ_xfer_tag = 0xFFFFFFFF;
1131 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
1132 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
1133 	cmd->first_burst_len	= payload_length;
1134 
1135 	if (!conn->sess->sess_ops->RDMAExtensions &&
1136 	     cmd->data_direction == DMA_FROM_DEVICE) {
1137 		struct iscsi_datain_req *dr;
1138 
1139 		dr = iscsit_allocate_datain_req();
1140 		if (!dr)
1141 			return iscsit_add_reject_cmd(cmd,
1142 					ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1143 
1144 		iscsit_attach_datain_req(cmd, dr);
1145 	}
1146 
1147 	/*
1148 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
1149 	 */
1150 	transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
1151 			conn->sess->se_sess, be32_to_cpu(hdr->data_length),
1152 			cmd->data_direction, sam_task_attr,
1153 			cmd->sense_buffer + 2);
1154 
1155 	pr_debug("Got SCSI Command, ITT: 0x%08x, CmdSN: 0x%08x,"
1156 		" ExpXferLen: %u, Length: %u, CID: %hu\n", hdr->itt,
1157 		hdr->cmdsn, be32_to_cpu(hdr->data_length), payload_length,
1158 		conn->cid);
1159 
1160 	target_get_sess_cmd(&cmd->se_cmd, true);
1161 
1162 	cmd->sense_reason = transport_lookup_cmd_lun(&cmd->se_cmd,
1163 						     scsilun_to_int(&hdr->lun));
1164 	if (cmd->sense_reason)
1165 		goto attach_cmd;
1166 
1167 	/* only used for printks or comparing with ->ref_task_tag */
1168 	cmd->se_cmd.tag = (__force u32)cmd->init_task_tag;
1169 	cmd->sense_reason = target_setup_cmd_from_cdb(&cmd->se_cmd, hdr->cdb);
1170 	if (cmd->sense_reason) {
1171 		if (cmd->sense_reason == TCM_OUT_OF_RESOURCES) {
1172 			return iscsit_add_reject_cmd(cmd,
1173 					ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1174 		}
1175 
1176 		goto attach_cmd;
1177 	}
1178 
1179 	if (iscsit_build_pdu_and_seq_lists(cmd, payload_length) < 0) {
1180 		return iscsit_add_reject_cmd(cmd,
1181 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1182 	}
1183 
1184 attach_cmd:
1185 	spin_lock_bh(&conn->cmd_lock);
1186 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
1187 	spin_unlock_bh(&conn->cmd_lock);
1188 	/*
1189 	 * Check if we need to delay processing because of ALUA
1190 	 * Active/NonOptimized primary access state..
1191 	 */
1192 	core_alua_check_nonop_delay(&cmd->se_cmd);
1193 
1194 	return 0;
1195 }
1196 EXPORT_SYMBOL(iscsit_setup_scsi_cmd);
1197 
1198 void iscsit_set_unsoliticed_dataout(struct iscsi_cmd *cmd)
1199 {
1200 	iscsit_set_dataout_sequence_values(cmd);
1201 
1202 	spin_lock_bh(&cmd->dataout_timeout_lock);
1203 	iscsit_start_dataout_timer(cmd, cmd->conn);
1204 	spin_unlock_bh(&cmd->dataout_timeout_lock);
1205 }
1206 EXPORT_SYMBOL(iscsit_set_unsoliticed_dataout);
1207 
1208 int iscsit_process_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1209 			    struct iscsi_scsi_req *hdr)
1210 {
1211 	int cmdsn_ret = 0;
1212 	/*
1213 	 * Check the CmdSN against ExpCmdSN/MaxCmdSN here if
1214 	 * the Immediate Bit is not set, and no Immediate
1215 	 * Data is attached.
1216 	 *
1217 	 * A PDU/CmdSN carrying Immediate Data can only
1218 	 * be processed after the DataCRC has passed.
1219 	 * If the DataCRC fails, the CmdSN MUST NOT
1220 	 * be acknowledged. (See below)
1221 	 */
1222 	if (!cmd->immediate_data) {
1223 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
1224 					(unsigned char *)hdr, hdr->cmdsn);
1225 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1226 			return -1;
1227 		else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
1228 			target_put_sess_cmd(&cmd->se_cmd);
1229 			return 0;
1230 		}
1231 	}
1232 
1233 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
1234 
1235 	/*
1236 	 * If no Immediate Data is attached, it's OK to return now.
1237 	 */
1238 	if (!cmd->immediate_data) {
1239 		if (!cmd->sense_reason && cmd->unsolicited_data)
1240 			iscsit_set_unsoliticed_dataout(cmd);
1241 		if (!cmd->sense_reason)
1242 			return 0;
1243 
1244 		target_put_sess_cmd(&cmd->se_cmd);
1245 		return 0;
1246 	}
1247 
1248 	/*
1249 	 * Early CHECK_CONDITIONs with ImmediateData never make it to command
1250 	 * execution.  These exceptions are processed in CmdSN order using
1251 	 * iscsit_check_received_cmdsn() in iscsit_get_immediate_data() below.
1252 	 */
1253 	if (cmd->sense_reason)
1254 		return 1;
1255 	/*
1256 	 * Call directly into transport_generic_new_cmd() to perform
1257 	 * the backend memory allocation.
1258 	 */
1259 	cmd->sense_reason = transport_generic_new_cmd(&cmd->se_cmd);
1260 	if (cmd->sense_reason)
1261 		return 1;
1262 
1263 	return 0;
1264 }
1265 EXPORT_SYMBOL(iscsit_process_scsi_cmd);
1266 
1267 static int
1268 iscsit_get_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
1269 			  bool dump_payload)
1270 {
1271 	int cmdsn_ret = 0, immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
1272 	/*
1273 	 * Special case for Unsupported SAM WRITE Opcodes and ImmediateData=Yes.
1274 	 */
1275 	if (dump_payload)
1276 		goto after_immediate_data;
1277 	/*
1278 	 * Check for underflow case where both EDTL and immediate data payload
1279 	 * exceeds what is presented by CDB's TRANSFER LENGTH, and what has
1280 	 * already been set in target_cmd_size_check() as se_cmd->data_length.
1281 	 *
1282 	 * For this special case, fail the command and dump the immediate data
1283 	 * payload.
1284 	 */
1285 	if (cmd->first_burst_len > cmd->se_cmd.data_length) {
1286 		cmd->sense_reason = TCM_INVALID_CDB_FIELD;
1287 		goto after_immediate_data;
1288 	}
1289 
1290 	immed_ret = iscsit_handle_immediate_data(cmd, hdr,
1291 					cmd->first_burst_len);
1292 after_immediate_data:
1293 	if (immed_ret == IMMEDIATE_DATA_NORMAL_OPERATION) {
1294 		/*
1295 		 * A PDU/CmdSN carrying Immediate Data passed
1296 		 * DataCRC, check against ExpCmdSN/MaxCmdSN if
1297 		 * Immediate Bit is not set.
1298 		 */
1299 		cmdsn_ret = iscsit_sequence_cmd(cmd->conn, cmd,
1300 					(unsigned char *)hdr, hdr->cmdsn);
1301 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1302 			return -1;
1303 
1304 		if (cmd->sense_reason || cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
1305 			int rc;
1306 
1307 			rc = iscsit_dump_data_payload(cmd->conn,
1308 						      cmd->first_burst_len, 1);
1309 			target_put_sess_cmd(&cmd->se_cmd);
1310 			return rc;
1311 		} else if (cmd->unsolicited_data)
1312 			iscsit_set_unsoliticed_dataout(cmd);
1313 
1314 	} else if (immed_ret == IMMEDIATE_DATA_ERL1_CRC_FAILURE) {
1315 		/*
1316 		 * Immediate Data failed DataCRC and ERL>=1,
1317 		 * silently drop this PDU and let the initiator
1318 		 * plug the CmdSN gap.
1319 		 *
1320 		 * FIXME: Send Unsolicited NOPIN with reserved
1321 		 * TTT here to help the initiator figure out
1322 		 * the missing CmdSN, although they should be
1323 		 * intelligent enough to determine the missing
1324 		 * CmdSN and issue a retry to plug the sequence.
1325 		 */
1326 		cmd->i_state = ISTATE_REMOVE;
1327 		iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, cmd->i_state);
1328 	} else /* immed_ret == IMMEDIATE_DATA_CANNOT_RECOVER */
1329 		return -1;
1330 
1331 	return 0;
1332 }
1333 
1334 static int
1335 iscsit_handle_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1336 			   unsigned char *buf)
1337 {
1338 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)buf;
1339 	int rc, immed_data;
1340 	bool dump_payload = false;
1341 
1342 	rc = iscsit_setup_scsi_cmd(conn, cmd, buf);
1343 	if (rc < 0)
1344 		return 0;
1345 	/*
1346 	 * Allocation iovecs needed for struct socket operations for
1347 	 * traditional iSCSI block I/O.
1348 	 */
1349 	if (iscsit_allocate_iovecs(cmd) < 0) {
1350 		return iscsit_reject_cmd(cmd,
1351 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1352 	}
1353 	immed_data = cmd->immediate_data;
1354 
1355 	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
1356 	if (rc < 0)
1357 		return rc;
1358 	else if (rc > 0)
1359 		dump_payload = true;
1360 
1361 	if (!immed_data)
1362 		return 0;
1363 
1364 	return iscsit_get_immediate_data(cmd, hdr, dump_payload);
1365 }
1366 
1367 static u32 iscsit_do_crypto_hash_sg(
1368 	struct ahash_request *hash,
1369 	struct iscsi_cmd *cmd,
1370 	u32 data_offset,
1371 	u32 data_length,
1372 	u32 padding,
1373 	u8 *pad_bytes)
1374 {
1375 	u32 data_crc;
1376 	struct scatterlist *sg;
1377 	unsigned int page_off;
1378 
1379 	crypto_ahash_init(hash);
1380 
1381 	sg = cmd->first_data_sg;
1382 	page_off = cmd->first_data_sg_off;
1383 
1384 	while (data_length) {
1385 		u32 cur_len = min_t(u32, data_length, (sg->length - page_off));
1386 
1387 		ahash_request_set_crypt(hash, sg, NULL, cur_len);
1388 		crypto_ahash_update(hash);
1389 
1390 		data_length -= cur_len;
1391 		page_off = 0;
1392 		/* iscsit_map_iovec has already checked for invalid sg pointers */
1393 		sg = sg_next(sg);
1394 	}
1395 
1396 	if (padding) {
1397 		struct scatterlist pad_sg;
1398 
1399 		sg_init_one(&pad_sg, pad_bytes, padding);
1400 		ahash_request_set_crypt(hash, &pad_sg, (u8 *)&data_crc,
1401 					padding);
1402 		crypto_ahash_finup(hash);
1403 	} else {
1404 		ahash_request_set_crypt(hash, NULL, (u8 *)&data_crc, 0);
1405 		crypto_ahash_final(hash);
1406 	}
1407 
1408 	return data_crc;
1409 }
1410 
1411 static void iscsit_do_crypto_hash_buf(struct ahash_request *hash,
1412 	const void *buf, u32 payload_length, u32 padding,
1413 	const void *pad_bytes, void *data_crc)
1414 {
1415 	struct scatterlist sg[2];
1416 
1417 	sg_init_table(sg, ARRAY_SIZE(sg));
1418 	sg_set_buf(sg, buf, payload_length);
1419 	if (padding)
1420 		sg_set_buf(sg + 1, pad_bytes, padding);
1421 
1422 	ahash_request_set_crypt(hash, sg, data_crc, payload_length + padding);
1423 
1424 	crypto_ahash_digest(hash);
1425 }
1426 
1427 int
1428 __iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
1429 			   struct iscsi_cmd *cmd, u32 payload_length,
1430 			   bool *success)
1431 {
1432 	struct iscsi_data *hdr = buf;
1433 	struct se_cmd *se_cmd;
1434 	int rc;
1435 
1436 	/* iSCSI write */
1437 	atomic_long_add(payload_length, &conn->sess->rx_data_octets);
1438 
1439 	pr_debug("Got DataOut ITT: 0x%08x, TTT: 0x%08x,"
1440 		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
1441 		hdr->itt, hdr->ttt, hdr->datasn, ntohl(hdr->offset),
1442 		payload_length, conn->cid);
1443 
1444 	if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
1445 		pr_err("Command ITT: 0x%08x received DataOUT after"
1446 			" last DataOUT received, dumping payload\n",
1447 			cmd->init_task_tag);
1448 		return iscsit_dump_data_payload(conn, payload_length, 1);
1449 	}
1450 
1451 	if (cmd->data_direction != DMA_TO_DEVICE) {
1452 		pr_err("Command ITT: 0x%08x received DataOUT for a"
1453 			" NON-WRITE command.\n", cmd->init_task_tag);
1454 		return iscsit_dump_data_payload(conn, payload_length, 1);
1455 	}
1456 	se_cmd = &cmd->se_cmd;
1457 	iscsit_mod_dataout_timer(cmd);
1458 
1459 	if ((be32_to_cpu(hdr->offset) + payload_length) > cmd->se_cmd.data_length) {
1460 		pr_err("DataOut Offset: %u, Length %u greater than iSCSI Command EDTL %u, protocol error.\n",
1461 		       be32_to_cpu(hdr->offset), payload_length,
1462 		       cmd->se_cmd.data_length);
1463 		return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_INVALID, buf);
1464 	}
1465 
1466 	if (cmd->unsolicited_data) {
1467 		int dump_unsolicited_data = 0;
1468 
1469 		if (conn->sess->sess_ops->InitialR2T) {
1470 			pr_err("Received unexpected unsolicited data"
1471 				" while InitialR2T=Yes, protocol error.\n");
1472 			transport_send_check_condition_and_sense(&cmd->se_cmd,
1473 					TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
1474 			return -1;
1475 		}
1476 		/*
1477 		 * Special case for dealing with Unsolicited DataOUT
1478 		 * and Unsupported SAM WRITE Opcodes and SE resource allocation
1479 		 * failures;
1480 		 */
1481 
1482 		/* Something's amiss if we're not in WRITE_PENDING state... */
1483 		WARN_ON(se_cmd->t_state != TRANSPORT_WRITE_PENDING);
1484 		if (!(se_cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE))
1485 			dump_unsolicited_data = 1;
1486 
1487 		if (dump_unsolicited_data) {
1488 			/*
1489 			 * Check if a delayed TASK_ABORTED status needs to
1490 			 * be sent now if the ISCSI_FLAG_CMD_FINAL has been
1491 			 * received with the unsolicited data out.
1492 			 */
1493 			if (hdr->flags & ISCSI_FLAG_CMD_FINAL)
1494 				iscsit_stop_dataout_timer(cmd);
1495 
1496 			return iscsit_dump_data_payload(conn, payload_length, 1);
1497 		}
1498 	} else {
1499 		/*
1500 		 * For the normal solicited data path:
1501 		 *
1502 		 * Check for a delayed TASK_ABORTED status and dump any
1503 		 * incoming data out payload if one exists.  Also, when the
1504 		 * ISCSI_FLAG_CMD_FINAL is set to denote the end of the current
1505 		 * data out sequence, we decrement outstanding_r2ts.  Once
1506 		 * outstanding_r2ts reaches zero, go ahead and send the delayed
1507 		 * TASK_ABORTED status.
1508 		 */
1509 		if (se_cmd->transport_state & CMD_T_ABORTED) {
1510 			if (hdr->flags & ISCSI_FLAG_CMD_FINAL &&
1511 			    --cmd->outstanding_r2ts < 1)
1512 				iscsit_stop_dataout_timer(cmd);
1513 
1514 			return iscsit_dump_data_payload(conn, payload_length, 1);
1515 		}
1516 	}
1517 	/*
1518 	 * Perform DataSN, DataSequenceInOrder, DataPDUInOrder, and
1519 	 * within-command recovery checks before receiving the payload.
1520 	 */
1521 	rc = iscsit_check_pre_dataout(cmd, buf);
1522 	if (rc == DATAOUT_WITHIN_COMMAND_RECOVERY)
1523 		return 0;
1524 	else if (rc == DATAOUT_CANNOT_RECOVER)
1525 		return -1;
1526 	*success = true;
1527 	return 0;
1528 }
1529 EXPORT_SYMBOL(__iscsit_check_dataout_hdr);
1530 
1531 int
1532 iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
1533 			 struct iscsi_cmd **out_cmd)
1534 {
1535 	struct iscsi_data *hdr = buf;
1536 	struct iscsi_cmd *cmd;
1537 	u32 payload_length = ntoh24(hdr->dlength);
1538 	int rc;
1539 	bool success = false;
1540 
1541 	if (!payload_length) {
1542 		pr_warn_ratelimited("DataOUT payload is ZERO, ignoring.\n");
1543 		return 0;
1544 	}
1545 
1546 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1547 		pr_err_ratelimited("DataSegmentLength: %u is greater than"
1548 			" MaxXmitDataSegmentLength: %u\n", payload_length,
1549 			conn->conn_ops->MaxXmitDataSegmentLength);
1550 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR, buf);
1551 	}
1552 
1553 	cmd = iscsit_find_cmd_from_itt_or_dump(conn, hdr->itt, payload_length);
1554 	if (!cmd)
1555 		return 0;
1556 
1557 	rc = __iscsit_check_dataout_hdr(conn, buf, cmd, payload_length, &success);
1558 
1559 	if (success)
1560 		*out_cmd = cmd;
1561 
1562 	return rc;
1563 }
1564 EXPORT_SYMBOL(iscsit_check_dataout_hdr);
1565 
1566 static int
1567 iscsit_get_dataout(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1568 		   struct iscsi_data *hdr)
1569 {
1570 	struct kvec *iov;
1571 	u32 checksum, iov_count = 0, padding = 0, rx_got = 0, rx_size = 0;
1572 	u32 payload_length = ntoh24(hdr->dlength);
1573 	int iov_ret, data_crc_failed = 0;
1574 
1575 	rx_size += payload_length;
1576 	iov = &cmd->iov_data[0];
1577 
1578 	iov_ret = iscsit_map_iovec(cmd, iov, be32_to_cpu(hdr->offset),
1579 				   payload_length);
1580 	if (iov_ret < 0)
1581 		return -1;
1582 
1583 	iov_count += iov_ret;
1584 
1585 	padding = ((-payload_length) & 3);
1586 	if (padding != 0) {
1587 		iov[iov_count].iov_base	= cmd->pad_bytes;
1588 		iov[iov_count++].iov_len = padding;
1589 		rx_size += padding;
1590 		pr_debug("Receiving %u padding bytes.\n", padding);
1591 	}
1592 
1593 	if (conn->conn_ops->DataDigest) {
1594 		iov[iov_count].iov_base = &checksum;
1595 		iov[iov_count++].iov_len = ISCSI_CRC_LEN;
1596 		rx_size += ISCSI_CRC_LEN;
1597 	}
1598 
1599 	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
1600 
1601 	iscsit_unmap_iovec(cmd);
1602 
1603 	if (rx_got != rx_size)
1604 		return -1;
1605 
1606 	if (conn->conn_ops->DataDigest) {
1607 		u32 data_crc;
1608 
1609 		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
1610 						    be32_to_cpu(hdr->offset),
1611 						    payload_length, padding,
1612 						    cmd->pad_bytes);
1613 
1614 		if (checksum != data_crc) {
1615 			pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
1616 				" DataSN: 0x%08x, CRC32C DataDigest 0x%08x"
1617 				" does not match computed 0x%08x\n",
1618 				hdr->itt, hdr->offset, payload_length,
1619 				hdr->datasn, checksum, data_crc);
1620 			data_crc_failed = 1;
1621 		} else {
1622 			pr_debug("Got CRC32C DataDigest 0x%08x for"
1623 				" %u bytes of Data Out\n", checksum,
1624 				payload_length);
1625 		}
1626 	}
1627 
1628 	return data_crc_failed;
1629 }
1630 
1631 int
1632 iscsit_check_dataout_payload(struct iscsi_cmd *cmd, struct iscsi_data *hdr,
1633 			     bool data_crc_failed)
1634 {
1635 	struct iscsi_conn *conn = cmd->conn;
1636 	int rc, ooo_cmdsn;
1637 	/*
1638 	 * Increment post receive data and CRC values or perform
1639 	 * within-command recovery.
1640 	 */
1641 	rc = iscsit_check_post_dataout(cmd, (unsigned char *)hdr, data_crc_failed);
1642 	if ((rc == DATAOUT_NORMAL) || (rc == DATAOUT_WITHIN_COMMAND_RECOVERY))
1643 		return 0;
1644 	else if (rc == DATAOUT_SEND_R2T) {
1645 		iscsit_set_dataout_sequence_values(cmd);
1646 		conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
1647 	} else if (rc == DATAOUT_SEND_TO_TRANSPORT) {
1648 		/*
1649 		 * Handle extra special case for out of order
1650 		 * Unsolicited Data Out.
1651 		 */
1652 		spin_lock_bh(&cmd->istate_lock);
1653 		ooo_cmdsn = (cmd->cmd_flags & ICF_OOO_CMDSN);
1654 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
1655 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
1656 		spin_unlock_bh(&cmd->istate_lock);
1657 
1658 		iscsit_stop_dataout_timer(cmd);
1659 		if (ooo_cmdsn)
1660 			return 0;
1661 		target_execute_cmd(&cmd->se_cmd);
1662 		return 0;
1663 	} else /* DATAOUT_CANNOT_RECOVER */
1664 		return -1;
1665 
1666 	return 0;
1667 }
1668 EXPORT_SYMBOL(iscsit_check_dataout_payload);
1669 
1670 static int iscsit_handle_data_out(struct iscsi_conn *conn, unsigned char *buf)
1671 {
1672 	struct iscsi_cmd *cmd = NULL;
1673 	struct iscsi_data *hdr = (struct iscsi_data *)buf;
1674 	int rc;
1675 	bool data_crc_failed = false;
1676 
1677 	rc = iscsit_check_dataout_hdr(conn, buf, &cmd);
1678 	if (rc < 0)
1679 		return 0;
1680 	else if (!cmd)
1681 		return 0;
1682 
1683 	rc = iscsit_get_dataout(conn, cmd, hdr);
1684 	if (rc < 0)
1685 		return rc;
1686 	else if (rc > 0)
1687 		data_crc_failed = true;
1688 
1689 	return iscsit_check_dataout_payload(cmd, hdr, data_crc_failed);
1690 }
1691 
1692 int iscsit_setup_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1693 			 struct iscsi_nopout *hdr)
1694 {
1695 	u32 payload_length = ntoh24(hdr->dlength);
1696 
1697 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
1698 		pr_err("NopOUT Flag's, Left Most Bit not set, protocol error.\n");
1699 		if (!cmd)
1700 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1701 						 (unsigned char *)hdr);
1702 
1703 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1704 					 (unsigned char *)hdr);
1705 	}
1706 
1707 	if (hdr->itt == RESERVED_ITT && !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
1708 		pr_err("NOPOUT ITT is reserved, but Immediate Bit is"
1709 			" not set, protocol error.\n");
1710 		if (!cmd)
1711 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1712 						 (unsigned char *)hdr);
1713 
1714 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1715 					 (unsigned char *)hdr);
1716 	}
1717 
1718 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1719 		pr_err("NOPOUT Ping Data DataSegmentLength: %u is"
1720 			" greater than MaxXmitDataSegmentLength: %u, protocol"
1721 			" error.\n", payload_length,
1722 			conn->conn_ops->MaxXmitDataSegmentLength);
1723 		if (!cmd)
1724 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1725 						 (unsigned char *)hdr);
1726 
1727 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1728 					 (unsigned char *)hdr);
1729 	}
1730 
1731 	pr_debug("Got NOPOUT Ping %s ITT: 0x%08x, TTT: 0x%08x,"
1732 		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, Length: %u\n",
1733 		hdr->itt == RESERVED_ITT ? "Response" : "Request",
1734 		hdr->itt, hdr->ttt, hdr->cmdsn, hdr->exp_statsn,
1735 		payload_length);
1736 	/*
1737 	 * This is not a response to a Unsolicited NopIN, which means
1738 	 * it can either be a NOPOUT ping request (with a valid ITT),
1739 	 * or a NOPOUT not requesting a NOPIN (with a reserved ITT).
1740 	 * Either way, make sure we allocate an struct iscsi_cmd, as both
1741 	 * can contain ping data.
1742 	 */
1743 	if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1744 		cmd->iscsi_opcode	= ISCSI_OP_NOOP_OUT;
1745 		cmd->i_state		= ISTATE_SEND_NOPIN;
1746 		cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ?
1747 						1 : 0);
1748 		conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
1749 		cmd->targ_xfer_tag	= 0xFFFFFFFF;
1750 		cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
1751 		cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
1752 		cmd->data_direction	= DMA_NONE;
1753 	}
1754 
1755 	return 0;
1756 }
1757 EXPORT_SYMBOL(iscsit_setup_nop_out);
1758 
1759 int iscsit_process_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1760 			   struct iscsi_nopout *hdr)
1761 {
1762 	struct iscsi_cmd *cmd_p = NULL;
1763 	int cmdsn_ret = 0;
1764 	/*
1765 	 * Initiator is expecting a NopIN ping reply..
1766 	 */
1767 	if (hdr->itt != RESERVED_ITT) {
1768 		if (!cmd)
1769 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1770 						(unsigned char *)hdr);
1771 
1772 		spin_lock_bh(&conn->cmd_lock);
1773 		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
1774 		spin_unlock_bh(&conn->cmd_lock);
1775 
1776 		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
1777 
1778 		if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
1779 			iscsit_add_cmd_to_response_queue(cmd, conn,
1780 							 cmd->i_state);
1781 			return 0;
1782 		}
1783 
1784 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
1785 				(unsigned char *)hdr, hdr->cmdsn);
1786                 if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
1787 			return 0;
1788 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1789 			return -1;
1790 
1791 		return 0;
1792 	}
1793 	/*
1794 	 * This was a response to a unsolicited NOPIN ping.
1795 	 */
1796 	if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
1797 		cmd_p = iscsit_find_cmd_from_ttt(conn, be32_to_cpu(hdr->ttt));
1798 		if (!cmd_p)
1799 			return -EINVAL;
1800 
1801 		iscsit_stop_nopin_response_timer(conn);
1802 
1803 		cmd_p->i_state = ISTATE_REMOVE;
1804 		iscsit_add_cmd_to_immediate_queue(cmd_p, conn, cmd_p->i_state);
1805 
1806 		iscsit_start_nopin_timer(conn);
1807 		return 0;
1808 	}
1809 	/*
1810 	 * Otherwise, initiator is not expecting a NOPIN is response.
1811 	 * Just ignore for now.
1812 	 */
1813 
1814 	if (cmd)
1815 		iscsit_free_cmd(cmd, false);
1816 
1817         return 0;
1818 }
1819 EXPORT_SYMBOL(iscsit_process_nop_out);
1820 
1821 static int iscsit_handle_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1822 				 unsigned char *buf)
1823 {
1824 	unsigned char *ping_data = NULL;
1825 	struct iscsi_nopout *hdr = (struct iscsi_nopout *)buf;
1826 	struct kvec *iov = NULL;
1827 	u32 payload_length = ntoh24(hdr->dlength);
1828 	int ret;
1829 
1830 	ret = iscsit_setup_nop_out(conn, cmd, hdr);
1831 	if (ret < 0)
1832 		return 0;
1833 	/*
1834 	 * Handle NOP-OUT payload for traditional iSCSI sockets
1835 	 */
1836 	if (payload_length && hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1837 		u32 checksum, data_crc, padding = 0;
1838 		int niov = 0, rx_got, rx_size = payload_length;
1839 
1840 		ping_data = kzalloc(payload_length + 1, GFP_KERNEL);
1841 		if (!ping_data) {
1842 			ret = -1;
1843 			goto out;
1844 		}
1845 
1846 		iov = &cmd->iov_misc[0];
1847 		iov[niov].iov_base	= ping_data;
1848 		iov[niov++].iov_len	= payload_length;
1849 
1850 		padding = ((-payload_length) & 3);
1851 		if (padding != 0) {
1852 			pr_debug("Receiving %u additional bytes"
1853 				" for padding.\n", padding);
1854 			iov[niov].iov_base	= &cmd->pad_bytes;
1855 			iov[niov++].iov_len	= padding;
1856 			rx_size += padding;
1857 		}
1858 		if (conn->conn_ops->DataDigest) {
1859 			iov[niov].iov_base	= &checksum;
1860 			iov[niov++].iov_len	= ISCSI_CRC_LEN;
1861 			rx_size += ISCSI_CRC_LEN;
1862 		}
1863 
1864 		rx_got = rx_data(conn, &cmd->iov_misc[0], niov, rx_size);
1865 		if (rx_got != rx_size) {
1866 			ret = -1;
1867 			goto out;
1868 		}
1869 
1870 		if (conn->conn_ops->DataDigest) {
1871 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash, ping_data,
1872 						  payload_length, padding,
1873 						  cmd->pad_bytes, &data_crc);
1874 
1875 			if (checksum != data_crc) {
1876 				pr_err("Ping data CRC32C DataDigest"
1877 				" 0x%08x does not match computed 0x%08x\n",
1878 					checksum, data_crc);
1879 				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1880 					pr_err("Unable to recover from"
1881 					" NOPOUT Ping DataCRC failure while in"
1882 						" ERL=0.\n");
1883 					ret = -1;
1884 					goto out;
1885 				} else {
1886 					/*
1887 					 * Silently drop this PDU and let the
1888 					 * initiator plug the CmdSN gap.
1889 					 */
1890 					pr_debug("Dropping NOPOUT"
1891 					" Command CmdSN: 0x%08x due to"
1892 					" DataCRC error.\n", hdr->cmdsn);
1893 					ret = 0;
1894 					goto out;
1895 				}
1896 			} else {
1897 				pr_debug("Got CRC32C DataDigest"
1898 				" 0x%08x for %u bytes of ping data.\n",
1899 					checksum, payload_length);
1900 			}
1901 		}
1902 
1903 		ping_data[payload_length] = '\0';
1904 		/*
1905 		 * Attach ping data to struct iscsi_cmd->buf_ptr.
1906 		 */
1907 		cmd->buf_ptr = ping_data;
1908 		cmd->buf_ptr_size = payload_length;
1909 
1910 		pr_debug("Got %u bytes of NOPOUT ping"
1911 			" data.\n", payload_length);
1912 		pr_debug("Ping Data: \"%s\"\n", ping_data);
1913 	}
1914 
1915 	return iscsit_process_nop_out(conn, cmd, hdr);
1916 out:
1917 	if (cmd)
1918 		iscsit_free_cmd(cmd, false);
1919 
1920 	kfree(ping_data);
1921 	return ret;
1922 }
1923 
1924 static enum tcm_tmreq_table iscsit_convert_tmf(u8 iscsi_tmf)
1925 {
1926 	switch (iscsi_tmf) {
1927 	case ISCSI_TM_FUNC_ABORT_TASK:
1928 		return TMR_ABORT_TASK;
1929 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
1930 		return TMR_ABORT_TASK_SET;
1931 	case ISCSI_TM_FUNC_CLEAR_ACA:
1932 		return TMR_CLEAR_ACA;
1933 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
1934 		return TMR_CLEAR_TASK_SET;
1935 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
1936 		return TMR_LUN_RESET;
1937 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
1938 		return TMR_TARGET_WARM_RESET;
1939 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
1940 		return TMR_TARGET_COLD_RESET;
1941 	default:
1942 		return TMR_UNKNOWN;
1943 	}
1944 }
1945 
1946 int
1947 iscsit_handle_task_mgt_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1948 			   unsigned char *buf)
1949 {
1950 	struct se_tmr_req *se_tmr;
1951 	struct iscsi_tmr_req *tmr_req;
1952 	struct iscsi_tm *hdr;
1953 	int out_of_order_cmdsn = 0, ret;
1954 	u8 function, tcm_function = TMR_UNKNOWN;
1955 
1956 	hdr			= (struct iscsi_tm *) buf;
1957 	hdr->flags &= ~ISCSI_FLAG_CMD_FINAL;
1958 	function = hdr->flags;
1959 
1960 	pr_debug("Got Task Management Request ITT: 0x%08x, CmdSN:"
1961 		" 0x%08x, Function: 0x%02x, RefTaskTag: 0x%08x, RefCmdSN:"
1962 		" 0x%08x, CID: %hu\n", hdr->itt, hdr->cmdsn, function,
1963 		hdr->rtt, hdr->refcmdsn, conn->cid);
1964 
1965 	if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
1966 	    ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
1967 	     hdr->rtt != RESERVED_ITT)) {
1968 		pr_err("RefTaskTag should be set to 0xFFFFFFFF.\n");
1969 		hdr->rtt = RESERVED_ITT;
1970 	}
1971 
1972 	if ((function == ISCSI_TM_FUNC_TASK_REASSIGN) &&
1973 			!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
1974 		pr_err("Task Management Request TASK_REASSIGN not"
1975 			" issued as immediate command, bad iSCSI Initiator"
1976 				"implementation\n");
1977 		return iscsit_add_reject_cmd(cmd,
1978 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1979 	}
1980 	if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
1981 	    be32_to_cpu(hdr->refcmdsn) != ISCSI_RESERVED_TAG)
1982 		hdr->refcmdsn = cpu_to_be32(ISCSI_RESERVED_TAG);
1983 
1984 	cmd->data_direction = DMA_NONE;
1985 	cmd->tmr_req = kzalloc(sizeof(*cmd->tmr_req), GFP_KERNEL);
1986 	if (!cmd->tmr_req) {
1987 		return iscsit_add_reject_cmd(cmd,
1988 					     ISCSI_REASON_BOOKMARK_NO_RESOURCES,
1989 					     buf);
1990 	}
1991 
1992 	transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
1993 			      conn->sess->se_sess, 0, DMA_NONE,
1994 			      TCM_SIMPLE_TAG, cmd->sense_buffer + 2);
1995 
1996 	target_get_sess_cmd(&cmd->se_cmd, true);
1997 
1998 	/*
1999 	 * TASK_REASSIGN for ERL=2 / connection stays inside of
2000 	 * LIO-Target $FABRIC_MOD
2001 	 */
2002 	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
2003 		tcm_function = iscsit_convert_tmf(function);
2004 		if (tcm_function == TMR_UNKNOWN) {
2005 			pr_err("Unknown iSCSI TMR Function:"
2006 			       " 0x%02x\n", function);
2007 			return iscsit_add_reject_cmd(cmd,
2008 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
2009 		}
2010 	}
2011 	ret = core_tmr_alloc_req(&cmd->se_cmd, cmd->tmr_req, tcm_function,
2012 				 GFP_KERNEL);
2013 	if (ret < 0)
2014 		return iscsit_add_reject_cmd(cmd,
2015 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
2016 
2017 	cmd->tmr_req->se_tmr_req = cmd->se_cmd.se_tmr_req;
2018 
2019 	cmd->iscsi_opcode	= ISCSI_OP_SCSI_TMFUNC;
2020 	cmd->i_state		= ISTATE_SEND_TASKMGTRSP;
2021 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2022 	cmd->init_task_tag	= hdr->itt;
2023 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2024 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
2025 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
2026 	se_tmr			= cmd->se_cmd.se_tmr_req;
2027 	tmr_req			= cmd->tmr_req;
2028 	/*
2029 	 * Locate the struct se_lun for all TMRs not related to ERL=2 TASK_REASSIGN
2030 	 */
2031 	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
2032 		ret = transport_lookup_tmr_lun(&cmd->se_cmd,
2033 					       scsilun_to_int(&hdr->lun));
2034 		if (ret < 0) {
2035 			se_tmr->response = ISCSI_TMF_RSP_NO_LUN;
2036 			goto attach;
2037 		}
2038 	}
2039 
2040 	switch (function) {
2041 	case ISCSI_TM_FUNC_ABORT_TASK:
2042 		se_tmr->response = iscsit_tmr_abort_task(cmd, buf);
2043 		if (se_tmr->response)
2044 			goto attach;
2045 		break;
2046 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
2047 	case ISCSI_TM_FUNC_CLEAR_ACA:
2048 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
2049 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
2050 		break;
2051 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
2052 		if (iscsit_tmr_task_warm_reset(conn, tmr_req, buf) < 0) {
2053 			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
2054 			goto attach;
2055 		}
2056 		break;
2057 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
2058 		if (iscsit_tmr_task_cold_reset(conn, tmr_req, buf) < 0) {
2059 			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
2060 			goto attach;
2061 		}
2062 		break;
2063 	case ISCSI_TM_FUNC_TASK_REASSIGN:
2064 		se_tmr->response = iscsit_tmr_task_reassign(cmd, buf);
2065 		/*
2066 		 * Perform sanity checks on the ExpDataSN only if the
2067 		 * TASK_REASSIGN was successful.
2068 		 */
2069 		if (se_tmr->response)
2070 			break;
2071 
2072 		if (iscsit_check_task_reassign_expdatasn(tmr_req, conn) < 0)
2073 			return iscsit_add_reject_cmd(cmd,
2074 					ISCSI_REASON_BOOKMARK_INVALID, buf);
2075 		break;
2076 	default:
2077 		pr_err("Unknown TMR function: 0x%02x, protocol"
2078 			" error.\n", function);
2079 		se_tmr->response = ISCSI_TMF_RSP_NOT_SUPPORTED;
2080 		goto attach;
2081 	}
2082 
2083 	if ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
2084 	    (se_tmr->response == ISCSI_TMF_RSP_COMPLETE))
2085 		se_tmr->call_transport = 1;
2086 attach:
2087 	spin_lock_bh(&conn->cmd_lock);
2088 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2089 	spin_unlock_bh(&conn->cmd_lock);
2090 
2091 	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
2092 		int cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
2093 		if (cmdsn_ret == CMDSN_HIGHER_THAN_EXP) {
2094 			out_of_order_cmdsn = 1;
2095 		} else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
2096 			target_put_sess_cmd(&cmd->se_cmd);
2097 			return 0;
2098 		} else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER) {
2099 			return -1;
2100 		}
2101 	}
2102 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2103 
2104 	if (out_of_order_cmdsn || !(hdr->opcode & ISCSI_OP_IMMEDIATE))
2105 		return 0;
2106 	/*
2107 	 * Found the referenced task, send to transport for processing.
2108 	 */
2109 	if (se_tmr->call_transport)
2110 		return transport_generic_handle_tmr(&cmd->se_cmd);
2111 
2112 	/*
2113 	 * Could not find the referenced LUN, task, or Task Management
2114 	 * command not authorized or supported.  Change state and
2115 	 * let the tx_thread send the response.
2116 	 *
2117 	 * For connection recovery, this is also the default action for
2118 	 * TMR TASK_REASSIGN.
2119 	 */
2120 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2121 	target_put_sess_cmd(&cmd->se_cmd);
2122 	return 0;
2123 }
2124 EXPORT_SYMBOL(iscsit_handle_task_mgt_cmd);
2125 
2126 /* #warning FIXME: Support Text Command parameters besides SendTargets */
2127 int
2128 iscsit_setup_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2129 		      struct iscsi_text *hdr)
2130 {
2131 	u32 payload_length = ntoh24(hdr->dlength);
2132 
2133 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
2134 		pr_err("Unable to accept text parameter length: %u"
2135 			"greater than MaxXmitDataSegmentLength %u.\n",
2136 		       payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
2137 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
2138 					 (unsigned char *)hdr);
2139 	}
2140 
2141 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL) ||
2142 	     (hdr->flags & ISCSI_FLAG_TEXT_CONTINUE)) {
2143 		pr_err("Multi sequence text commands currently not supported\n");
2144 		return iscsit_reject_cmd(cmd, ISCSI_REASON_CMD_NOT_SUPPORTED,
2145 					(unsigned char *)hdr);
2146 	}
2147 
2148 	pr_debug("Got Text Request: ITT: 0x%08x, CmdSN: 0x%08x,"
2149 		" ExpStatSN: 0x%08x, Length: %u\n", hdr->itt, hdr->cmdsn,
2150 		hdr->exp_statsn, payload_length);
2151 
2152 	cmd->iscsi_opcode	= ISCSI_OP_TEXT;
2153 	cmd->i_state		= ISTATE_SEND_TEXTRSP;
2154 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2155 	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
2156 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2157 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
2158 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
2159 	cmd->data_direction	= DMA_NONE;
2160 	kfree(cmd->text_in_ptr);
2161 	cmd->text_in_ptr	= NULL;
2162 
2163 	return 0;
2164 }
2165 EXPORT_SYMBOL(iscsit_setup_text_cmd);
2166 
2167 int
2168 iscsit_process_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2169 			struct iscsi_text *hdr)
2170 {
2171 	unsigned char *text_in = cmd->text_in_ptr, *text_ptr;
2172 	int cmdsn_ret;
2173 
2174 	if (!text_in) {
2175 		cmd->targ_xfer_tag = be32_to_cpu(hdr->ttt);
2176 		if (cmd->targ_xfer_tag == 0xFFFFFFFF) {
2177 			pr_err("Unable to locate text_in buffer for sendtargets"
2178 			       " discovery\n");
2179 			goto reject;
2180 		}
2181 		goto empty_sendtargets;
2182 	}
2183 	if (strncmp("SendTargets", text_in, 11) != 0) {
2184 		pr_err("Received Text Data that is not"
2185 			" SendTargets, cannot continue.\n");
2186 		goto reject;
2187 	}
2188 	text_ptr = strchr(text_in, '=');
2189 	if (!text_ptr) {
2190 		pr_err("No \"=\" separator found in Text Data,"
2191 			"  cannot continue.\n");
2192 		goto reject;
2193 	}
2194 	if (!strncmp("=All", text_ptr, 4)) {
2195 		cmd->cmd_flags |= ICF_SENDTARGETS_ALL;
2196 	} else if (!strncmp("=iqn.", text_ptr, 5) ||
2197 		   !strncmp("=eui.", text_ptr, 5)) {
2198 		cmd->cmd_flags |= ICF_SENDTARGETS_SINGLE;
2199 	} else {
2200 		pr_err("Unable to locate valid SendTargets=%s value\n", text_ptr);
2201 		goto reject;
2202 	}
2203 
2204 	spin_lock_bh(&conn->cmd_lock);
2205 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2206 	spin_unlock_bh(&conn->cmd_lock);
2207 
2208 empty_sendtargets:
2209 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2210 
2211 	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
2212 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
2213 				(unsigned char *)hdr, hdr->cmdsn);
2214 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2215 			return -1;
2216 
2217 		return 0;
2218 	}
2219 
2220 	return iscsit_execute_cmd(cmd, 0);
2221 
2222 reject:
2223 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
2224 				 (unsigned char *)hdr);
2225 }
2226 EXPORT_SYMBOL(iscsit_process_text_cmd);
2227 
2228 static int
2229 iscsit_handle_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2230 		       unsigned char *buf)
2231 {
2232 	struct iscsi_text *hdr = (struct iscsi_text *)buf;
2233 	char *text_in = NULL;
2234 	u32 payload_length = ntoh24(hdr->dlength);
2235 	int rx_size, rc;
2236 
2237 	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
2238 	if (rc < 0)
2239 		return 0;
2240 
2241 	rx_size = payload_length;
2242 	if (payload_length) {
2243 		u32 checksum = 0, data_crc = 0;
2244 		u32 padding = 0, pad_bytes = 0;
2245 		int niov = 0, rx_got;
2246 		struct kvec iov[3];
2247 
2248 		text_in = kzalloc(payload_length, GFP_KERNEL);
2249 		if (!text_in)
2250 			goto reject;
2251 
2252 		cmd->text_in_ptr = text_in;
2253 
2254 		memset(iov, 0, 3 * sizeof(struct kvec));
2255 		iov[niov].iov_base	= text_in;
2256 		iov[niov++].iov_len	= payload_length;
2257 
2258 		padding = ((-payload_length) & 3);
2259 		if (padding != 0) {
2260 			iov[niov].iov_base = &pad_bytes;
2261 			iov[niov++].iov_len  = padding;
2262 			rx_size += padding;
2263 			pr_debug("Receiving %u additional bytes"
2264 					" for padding.\n", padding);
2265 		}
2266 		if (conn->conn_ops->DataDigest) {
2267 			iov[niov].iov_base	= &checksum;
2268 			iov[niov++].iov_len	= ISCSI_CRC_LEN;
2269 			rx_size += ISCSI_CRC_LEN;
2270 		}
2271 
2272 		rx_got = rx_data(conn, &iov[0], niov, rx_size);
2273 		if (rx_got != rx_size)
2274 			goto reject;
2275 
2276 		if (conn->conn_ops->DataDigest) {
2277 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash, text_in,
2278 						  payload_length, padding,
2279 						  &pad_bytes, &data_crc);
2280 
2281 			if (checksum != data_crc) {
2282 				pr_err("Text data CRC32C DataDigest"
2283 					" 0x%08x does not match computed"
2284 					" 0x%08x\n", checksum, data_crc);
2285 				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2286 					pr_err("Unable to recover from"
2287 					" Text Data digest failure while in"
2288 						" ERL=0.\n");
2289 					goto reject;
2290 				} else {
2291 					/*
2292 					 * Silently drop this PDU and let the
2293 					 * initiator plug the CmdSN gap.
2294 					 */
2295 					pr_debug("Dropping Text"
2296 					" Command CmdSN: 0x%08x due to"
2297 					" DataCRC error.\n", hdr->cmdsn);
2298 					kfree(text_in);
2299 					return 0;
2300 				}
2301 			} else {
2302 				pr_debug("Got CRC32C DataDigest"
2303 					" 0x%08x for %u bytes of text data.\n",
2304 						checksum, payload_length);
2305 			}
2306 		}
2307 		text_in[payload_length - 1] = '\0';
2308 		pr_debug("Successfully read %d bytes of text"
2309 				" data.\n", payload_length);
2310 	}
2311 
2312 	return iscsit_process_text_cmd(conn, cmd, hdr);
2313 
2314 reject:
2315 	kfree(cmd->text_in_ptr);
2316 	cmd->text_in_ptr = NULL;
2317 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
2318 }
2319 
2320 int iscsit_logout_closesession(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2321 {
2322 	struct iscsi_conn *conn_p;
2323 	struct iscsi_session *sess = conn->sess;
2324 
2325 	pr_debug("Received logout request CLOSESESSION on CID: %hu"
2326 		" for SID: %u.\n", conn->cid, conn->sess->sid);
2327 
2328 	atomic_set(&sess->session_logout, 1);
2329 	atomic_set(&conn->conn_logout_remove, 1);
2330 	conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_SESSION;
2331 
2332 	iscsit_inc_conn_usage_count(conn);
2333 	iscsit_inc_session_usage_count(sess);
2334 
2335 	spin_lock_bh(&sess->conn_lock);
2336 	list_for_each_entry(conn_p, &sess->sess_conn_list, conn_list) {
2337 		if (conn_p->conn_state != TARG_CONN_STATE_LOGGED_IN)
2338 			continue;
2339 
2340 		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
2341 		conn_p->conn_state = TARG_CONN_STATE_IN_LOGOUT;
2342 	}
2343 	spin_unlock_bh(&sess->conn_lock);
2344 
2345 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2346 
2347 	return 0;
2348 }
2349 
2350 int iscsit_logout_closeconnection(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2351 {
2352 	struct iscsi_conn *l_conn;
2353 	struct iscsi_session *sess = conn->sess;
2354 
2355 	pr_debug("Received logout request CLOSECONNECTION for CID:"
2356 		" %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
2357 
2358 	/*
2359 	 * A Logout Request with a CLOSECONNECTION reason code for a CID
2360 	 * can arrive on a connection with a differing CID.
2361 	 */
2362 	if (conn->cid == cmd->logout_cid) {
2363 		spin_lock_bh(&conn->state_lock);
2364 		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
2365 		conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
2366 
2367 		atomic_set(&conn->conn_logout_remove, 1);
2368 		conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_CONNECTION;
2369 		iscsit_inc_conn_usage_count(conn);
2370 
2371 		spin_unlock_bh(&conn->state_lock);
2372 	} else {
2373 		/*
2374 		 * Handle all different cid CLOSECONNECTION requests in
2375 		 * iscsit_logout_post_handler_diffcid() as to give enough
2376 		 * time for any non immediate command's CmdSN to be
2377 		 * acknowledged on the connection in question.
2378 		 *
2379 		 * Here we simply make sure the CID is still around.
2380 		 */
2381 		l_conn = iscsit_get_conn_from_cid(sess,
2382 				cmd->logout_cid);
2383 		if (!l_conn) {
2384 			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
2385 			iscsit_add_cmd_to_response_queue(cmd, conn,
2386 					cmd->i_state);
2387 			return 0;
2388 		}
2389 
2390 		iscsit_dec_conn_usage_count(l_conn);
2391 	}
2392 
2393 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2394 
2395 	return 0;
2396 }
2397 
2398 int iscsit_logout_removeconnforrecovery(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2399 {
2400 	struct iscsi_session *sess = conn->sess;
2401 
2402 	pr_debug("Received explicit REMOVECONNFORRECOVERY logout for"
2403 		" CID: %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
2404 
2405 	if (sess->sess_ops->ErrorRecoveryLevel != 2) {
2406 		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
2407 			" while ERL!=2.\n");
2408 		cmd->logout_response = ISCSI_LOGOUT_RECOVERY_UNSUPPORTED;
2409 		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2410 		return 0;
2411 	}
2412 
2413 	if (conn->cid == cmd->logout_cid) {
2414 		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
2415 			" with CID: %hu on CID: %hu, implementation error.\n",
2416 				cmd->logout_cid, conn->cid);
2417 		cmd->logout_response = ISCSI_LOGOUT_CLEANUP_FAILED;
2418 		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2419 		return 0;
2420 	}
2421 
2422 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2423 
2424 	return 0;
2425 }
2426 
2427 int
2428 iscsit_handle_logout_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2429 			unsigned char *buf)
2430 {
2431 	int cmdsn_ret, logout_remove = 0;
2432 	u8 reason_code = 0;
2433 	struct iscsi_logout *hdr;
2434 	struct iscsi_tiqn *tiqn = iscsit_snmp_get_tiqn(conn);
2435 
2436 	hdr			= (struct iscsi_logout *) buf;
2437 	reason_code		= (hdr->flags & 0x7f);
2438 
2439 	if (tiqn) {
2440 		spin_lock(&tiqn->logout_stats.lock);
2441 		if (reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION)
2442 			tiqn->logout_stats.normal_logouts++;
2443 		else
2444 			tiqn->logout_stats.abnormal_logouts++;
2445 		spin_unlock(&tiqn->logout_stats.lock);
2446 	}
2447 
2448 	pr_debug("Got Logout Request ITT: 0x%08x CmdSN: 0x%08x"
2449 		" ExpStatSN: 0x%08x Reason: 0x%02x CID: %hu on CID: %hu\n",
2450 		hdr->itt, hdr->cmdsn, hdr->exp_statsn, reason_code,
2451 		hdr->cid, conn->cid);
2452 
2453 	if (conn->conn_state != TARG_CONN_STATE_LOGGED_IN) {
2454 		pr_err("Received logout request on connection that"
2455 			" is not in logged in state, ignoring request.\n");
2456 		iscsit_free_cmd(cmd, false);
2457 		return 0;
2458 	}
2459 
2460 	cmd->iscsi_opcode       = ISCSI_OP_LOGOUT;
2461 	cmd->i_state            = ISTATE_SEND_LOGOUTRSP;
2462 	cmd->immediate_cmd      = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2463 	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
2464 	cmd->targ_xfer_tag      = 0xFFFFFFFF;
2465 	cmd->cmd_sn             = be32_to_cpu(hdr->cmdsn);
2466 	cmd->exp_stat_sn        = be32_to_cpu(hdr->exp_statsn);
2467 	cmd->logout_cid         = be16_to_cpu(hdr->cid);
2468 	cmd->logout_reason      = reason_code;
2469 	cmd->data_direction     = DMA_NONE;
2470 
2471 	/*
2472 	 * We need to sleep in these cases (by returning 1) until the Logout
2473 	 * Response gets sent in the tx thread.
2474 	 */
2475 	if ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION) ||
2476 	   ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION) &&
2477 	    be16_to_cpu(hdr->cid) == conn->cid))
2478 		logout_remove = 1;
2479 
2480 	spin_lock_bh(&conn->cmd_lock);
2481 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2482 	spin_unlock_bh(&conn->cmd_lock);
2483 
2484 	if (reason_code != ISCSI_LOGOUT_REASON_RECOVERY)
2485 		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2486 
2487 	/*
2488 	 * Immediate commands are executed, well, immediately.
2489 	 * Non-Immediate Logout Commands are executed in CmdSN order.
2490 	 */
2491 	if (cmd->immediate_cmd) {
2492 		int ret = iscsit_execute_cmd(cmd, 0);
2493 
2494 		if (ret < 0)
2495 			return ret;
2496 	} else {
2497 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
2498 		if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
2499 			logout_remove = 0;
2500 		else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2501 			return -1;
2502 	}
2503 
2504 	return logout_remove;
2505 }
2506 EXPORT_SYMBOL(iscsit_handle_logout_cmd);
2507 
2508 int iscsit_handle_snack(
2509 	struct iscsi_conn *conn,
2510 	unsigned char *buf)
2511 {
2512 	struct iscsi_snack *hdr;
2513 
2514 	hdr			= (struct iscsi_snack *) buf;
2515 	hdr->flags		&= ~ISCSI_FLAG_CMD_FINAL;
2516 
2517 	pr_debug("Got ISCSI_INIT_SNACK, ITT: 0x%08x, ExpStatSN:"
2518 		" 0x%08x, Type: 0x%02x, BegRun: 0x%08x, RunLength: 0x%08x,"
2519 		" CID: %hu\n", hdr->itt, hdr->exp_statsn, hdr->flags,
2520 			hdr->begrun, hdr->runlength, conn->cid);
2521 
2522 	if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2523 		pr_err("Initiator sent SNACK request while in"
2524 			" ErrorRecoveryLevel=0.\n");
2525 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2526 					 buf);
2527 	}
2528 	/*
2529 	 * SNACK_DATA and SNACK_R2T are both 0,  so check which function to
2530 	 * call from inside iscsi_send_recovery_datain_or_r2t().
2531 	 */
2532 	switch (hdr->flags & ISCSI_FLAG_SNACK_TYPE_MASK) {
2533 	case 0:
2534 		return iscsit_handle_recovery_datain_or_r2t(conn, buf,
2535 			hdr->itt,
2536 			be32_to_cpu(hdr->ttt),
2537 			be32_to_cpu(hdr->begrun),
2538 			be32_to_cpu(hdr->runlength));
2539 	case ISCSI_FLAG_SNACK_TYPE_STATUS:
2540 		return iscsit_handle_status_snack(conn, hdr->itt,
2541 			be32_to_cpu(hdr->ttt),
2542 			be32_to_cpu(hdr->begrun), be32_to_cpu(hdr->runlength));
2543 	case ISCSI_FLAG_SNACK_TYPE_DATA_ACK:
2544 		return iscsit_handle_data_ack(conn, be32_to_cpu(hdr->ttt),
2545 			be32_to_cpu(hdr->begrun),
2546 			be32_to_cpu(hdr->runlength));
2547 	case ISCSI_FLAG_SNACK_TYPE_RDATA:
2548 		/* FIXME: Support R-Data SNACK */
2549 		pr_err("R-Data SNACK Not Supported.\n");
2550 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2551 					 buf);
2552 	default:
2553 		pr_err("Unknown SNACK type 0x%02x, protocol"
2554 			" error.\n", hdr->flags & 0x0f);
2555 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2556 					 buf);
2557 	}
2558 
2559 	return 0;
2560 }
2561 EXPORT_SYMBOL(iscsit_handle_snack);
2562 
2563 static void iscsit_rx_thread_wait_for_tcp(struct iscsi_conn *conn)
2564 {
2565 	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
2566 	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
2567 		wait_for_completion_interruptible_timeout(
2568 					&conn->rx_half_close_comp,
2569 					ISCSI_RX_THREAD_TCP_TIMEOUT * HZ);
2570 	}
2571 }
2572 
2573 static int iscsit_handle_immediate_data(
2574 	struct iscsi_cmd *cmd,
2575 	struct iscsi_scsi_req *hdr,
2576 	u32 length)
2577 {
2578 	int iov_ret, rx_got = 0, rx_size = 0;
2579 	u32 checksum, iov_count = 0, padding = 0;
2580 	struct iscsi_conn *conn = cmd->conn;
2581 	struct kvec *iov;
2582 
2583 	iov_ret = iscsit_map_iovec(cmd, cmd->iov_data, cmd->write_data_done, length);
2584 	if (iov_ret < 0)
2585 		return IMMEDIATE_DATA_CANNOT_RECOVER;
2586 
2587 	rx_size = length;
2588 	iov_count = iov_ret;
2589 	iov = &cmd->iov_data[0];
2590 
2591 	padding = ((-length) & 3);
2592 	if (padding != 0) {
2593 		iov[iov_count].iov_base	= cmd->pad_bytes;
2594 		iov[iov_count++].iov_len = padding;
2595 		rx_size += padding;
2596 	}
2597 
2598 	if (conn->conn_ops->DataDigest) {
2599 		iov[iov_count].iov_base		= &checksum;
2600 		iov[iov_count++].iov_len	= ISCSI_CRC_LEN;
2601 		rx_size += ISCSI_CRC_LEN;
2602 	}
2603 
2604 	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
2605 
2606 	iscsit_unmap_iovec(cmd);
2607 
2608 	if (rx_got != rx_size) {
2609 		iscsit_rx_thread_wait_for_tcp(conn);
2610 		return IMMEDIATE_DATA_CANNOT_RECOVER;
2611 	}
2612 
2613 	if (conn->conn_ops->DataDigest) {
2614 		u32 data_crc;
2615 
2616 		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
2617 						    cmd->write_data_done, length, padding,
2618 						    cmd->pad_bytes);
2619 
2620 		if (checksum != data_crc) {
2621 			pr_err("ImmediateData CRC32C DataDigest 0x%08x"
2622 				" does not match computed 0x%08x\n", checksum,
2623 				data_crc);
2624 
2625 			if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2626 				pr_err("Unable to recover from"
2627 					" Immediate Data digest failure while"
2628 					" in ERL=0.\n");
2629 				iscsit_reject_cmd(cmd,
2630 						ISCSI_REASON_DATA_DIGEST_ERROR,
2631 						(unsigned char *)hdr);
2632 				return IMMEDIATE_DATA_CANNOT_RECOVER;
2633 			} else {
2634 				iscsit_reject_cmd(cmd,
2635 						ISCSI_REASON_DATA_DIGEST_ERROR,
2636 						(unsigned char *)hdr);
2637 				return IMMEDIATE_DATA_ERL1_CRC_FAILURE;
2638 			}
2639 		} else {
2640 			pr_debug("Got CRC32C DataDigest 0x%08x for"
2641 				" %u bytes of Immediate Data\n", checksum,
2642 				length);
2643 		}
2644 	}
2645 
2646 	cmd->write_data_done += length;
2647 
2648 	if (cmd->write_data_done == cmd->se_cmd.data_length) {
2649 		spin_lock_bh(&cmd->istate_lock);
2650 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
2651 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
2652 		spin_unlock_bh(&cmd->istate_lock);
2653 	}
2654 
2655 	return IMMEDIATE_DATA_NORMAL_OPERATION;
2656 }
2657 
2658 /*
2659  *	Called with sess->conn_lock held.
2660  */
2661 /* #warning iscsi_build_conn_drop_async_message() only sends out on connections
2662 	with active network interface */
2663 static void iscsit_build_conn_drop_async_message(struct iscsi_conn *conn)
2664 {
2665 	struct iscsi_cmd *cmd;
2666 	struct iscsi_conn *conn_p;
2667 	bool found = false;
2668 
2669 	/*
2670 	 * Only send a Asynchronous Message on connections whos network
2671 	 * interface is still functional.
2672 	 */
2673 	list_for_each_entry(conn_p, &conn->sess->sess_conn_list, conn_list) {
2674 		if (conn_p->conn_state == TARG_CONN_STATE_LOGGED_IN) {
2675 			iscsit_inc_conn_usage_count(conn_p);
2676 			found = true;
2677 			break;
2678 		}
2679 	}
2680 
2681 	if (!found)
2682 		return;
2683 
2684 	cmd = iscsit_allocate_cmd(conn_p, TASK_RUNNING);
2685 	if (!cmd) {
2686 		iscsit_dec_conn_usage_count(conn_p);
2687 		return;
2688 	}
2689 
2690 	cmd->logout_cid = conn->cid;
2691 	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
2692 	cmd->i_state = ISTATE_SEND_ASYNCMSG;
2693 
2694 	spin_lock_bh(&conn_p->cmd_lock);
2695 	list_add_tail(&cmd->i_conn_node, &conn_p->conn_cmd_list);
2696 	spin_unlock_bh(&conn_p->cmd_lock);
2697 
2698 	iscsit_add_cmd_to_response_queue(cmd, conn_p, cmd->i_state);
2699 	iscsit_dec_conn_usage_count(conn_p);
2700 }
2701 
2702 static int iscsit_send_conn_drop_async_message(
2703 	struct iscsi_cmd *cmd,
2704 	struct iscsi_conn *conn)
2705 {
2706 	struct iscsi_async *hdr;
2707 
2708 	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
2709 
2710 	hdr			= (struct iscsi_async *) cmd->pdu;
2711 	hdr->opcode		= ISCSI_OP_ASYNC_EVENT;
2712 	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
2713 	cmd->init_task_tag	= RESERVED_ITT;
2714 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2715 	put_unaligned_be64(0xFFFFFFFFFFFFFFFFULL, &hdr->rsvd4[0]);
2716 	cmd->stat_sn		= conn->stat_sn++;
2717 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2718 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2719 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2720 	hdr->async_event	= ISCSI_ASYNC_MSG_DROPPING_CONNECTION;
2721 	hdr->param1		= cpu_to_be16(cmd->logout_cid);
2722 	hdr->param2		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Wait);
2723 	hdr->param3		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Retain);
2724 
2725 	pr_debug("Sending Connection Dropped Async Message StatSN:"
2726 		" 0x%08x, for CID: %hu on CID: %hu\n", cmd->stat_sn,
2727 			cmd->logout_cid, conn->cid);
2728 
2729 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
2730 }
2731 
2732 static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *conn)
2733 {
2734 	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
2735 	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
2736 		wait_for_completion_interruptible_timeout(
2737 					&conn->tx_half_close_comp,
2738 					ISCSI_TX_THREAD_TCP_TIMEOUT * HZ);
2739 	}
2740 }
2741 
2742 void
2743 iscsit_build_datain_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2744 			struct iscsi_datain *datain, struct iscsi_data_rsp *hdr,
2745 			bool set_statsn)
2746 {
2747 	hdr->opcode		= ISCSI_OP_SCSI_DATA_IN;
2748 	hdr->flags		= datain->flags;
2749 	if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
2750 		if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
2751 			hdr->flags |= ISCSI_FLAG_DATA_OVERFLOW;
2752 			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
2753 		} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
2754 			hdr->flags |= ISCSI_FLAG_DATA_UNDERFLOW;
2755 			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
2756 		}
2757 	}
2758 	hton24(hdr->dlength, datain->length);
2759 	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
2760 		int_to_scsilun(cmd->se_cmd.orig_fe_lun,
2761 				(struct scsi_lun *)&hdr->lun);
2762 	else
2763 		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
2764 
2765 	hdr->itt		= cmd->init_task_tag;
2766 
2767 	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
2768 		hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
2769 	else
2770 		hdr->ttt		= cpu_to_be32(0xFFFFFFFF);
2771 	if (set_statsn)
2772 		hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2773 	else
2774 		hdr->statsn		= cpu_to_be32(0xFFFFFFFF);
2775 
2776 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2777 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2778 	hdr->datasn		= cpu_to_be32(datain->data_sn);
2779 	hdr->offset		= cpu_to_be32(datain->offset);
2780 
2781 	pr_debug("Built DataIN ITT: 0x%08x, StatSN: 0x%08x,"
2782 		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
2783 		cmd->init_task_tag, ntohl(hdr->statsn), ntohl(hdr->datasn),
2784 		ntohl(hdr->offset), datain->length, conn->cid);
2785 }
2786 EXPORT_SYMBOL(iscsit_build_datain_pdu);
2787 
2788 static int iscsit_send_datain(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2789 {
2790 	struct iscsi_data_rsp *hdr = (struct iscsi_data_rsp *)&cmd->pdu[0];
2791 	struct iscsi_datain datain;
2792 	struct iscsi_datain_req *dr;
2793 	int eodr = 0, ret;
2794 	bool set_statsn = false;
2795 
2796 	memset(&datain, 0, sizeof(struct iscsi_datain));
2797 	dr = iscsit_get_datain_values(cmd, &datain);
2798 	if (!dr) {
2799 		pr_err("iscsit_get_datain_values failed for ITT: 0x%08x\n",
2800 				cmd->init_task_tag);
2801 		return -1;
2802 	}
2803 	/*
2804 	 * Be paranoid and double check the logic for now.
2805 	 */
2806 	if ((datain.offset + datain.length) > cmd->se_cmd.data_length) {
2807 		pr_err("Command ITT: 0x%08x, datain.offset: %u and"
2808 			" datain.length: %u exceeds cmd->data_length: %u\n",
2809 			cmd->init_task_tag, datain.offset, datain.length,
2810 			cmd->se_cmd.data_length);
2811 		return -1;
2812 	}
2813 
2814 	atomic_long_add(datain.length, &conn->sess->tx_data_octets);
2815 	/*
2816 	 * Special case for successfully execution w/ both DATAIN
2817 	 * and Sense Data.
2818 	 */
2819 	if ((datain.flags & ISCSI_FLAG_DATA_STATUS) &&
2820 	    (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE))
2821 		datain.flags &= ~ISCSI_FLAG_DATA_STATUS;
2822 	else {
2823 		if ((dr->dr_complete == DATAIN_COMPLETE_NORMAL) ||
2824 		    (dr->dr_complete == DATAIN_COMPLETE_CONNECTION_RECOVERY)) {
2825 			iscsit_increment_maxcmdsn(cmd, conn->sess);
2826 			cmd->stat_sn = conn->stat_sn++;
2827 			set_statsn = true;
2828 		} else if (dr->dr_complete ==
2829 			   DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY)
2830 			set_statsn = true;
2831 	}
2832 
2833 	iscsit_build_datain_pdu(cmd, conn, &datain, hdr, set_statsn);
2834 
2835 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, dr, &datain, 0);
2836 	if (ret < 0)
2837 		return ret;
2838 
2839 	if (dr->dr_complete) {
2840 		eodr = (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ?
2841 				2 : 1;
2842 		iscsit_free_datain_req(cmd, dr);
2843 	}
2844 
2845 	return eodr;
2846 }
2847 
2848 int
2849 iscsit_build_logout_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2850 			struct iscsi_logout_rsp *hdr)
2851 {
2852 	struct iscsi_conn *logout_conn = NULL;
2853 	struct iscsi_conn_recovery *cr = NULL;
2854 	struct iscsi_session *sess = conn->sess;
2855 	/*
2856 	 * The actual shutting down of Sessions and/or Connections
2857 	 * for CLOSESESSION and CLOSECONNECTION Logout Requests
2858 	 * is done in scsi_logout_post_handler().
2859 	 */
2860 	switch (cmd->logout_reason) {
2861 	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
2862 		pr_debug("iSCSI session logout successful, setting"
2863 			" logout response to ISCSI_LOGOUT_SUCCESS.\n");
2864 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2865 		break;
2866 	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
2867 		if (cmd->logout_response == ISCSI_LOGOUT_CID_NOT_FOUND)
2868 			break;
2869 		/*
2870 		 * For CLOSECONNECTION logout requests carrying
2871 		 * a matching logout CID -> local CID, the reference
2872 		 * for the local CID will have been incremented in
2873 		 * iscsi_logout_closeconnection().
2874 		 *
2875 		 * For CLOSECONNECTION logout requests carrying
2876 		 * a different CID than the connection it arrived
2877 		 * on, the connection responding to cmd->logout_cid
2878 		 * is stopped in iscsit_logout_post_handler_diffcid().
2879 		 */
2880 
2881 		pr_debug("iSCSI CID: %hu logout on CID: %hu"
2882 			" successful.\n", cmd->logout_cid, conn->cid);
2883 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2884 		break;
2885 	case ISCSI_LOGOUT_REASON_RECOVERY:
2886 		if ((cmd->logout_response == ISCSI_LOGOUT_RECOVERY_UNSUPPORTED) ||
2887 		    (cmd->logout_response == ISCSI_LOGOUT_CLEANUP_FAILED))
2888 			break;
2889 		/*
2890 		 * If the connection is still active from our point of view
2891 		 * force connection recovery to occur.
2892 		 */
2893 		logout_conn = iscsit_get_conn_from_cid_rcfr(sess,
2894 				cmd->logout_cid);
2895 		if (logout_conn) {
2896 			iscsit_connection_reinstatement_rcfr(logout_conn);
2897 			iscsit_dec_conn_usage_count(logout_conn);
2898 		}
2899 
2900 		cr = iscsit_get_inactive_connection_recovery_entry(
2901 				conn->sess, cmd->logout_cid);
2902 		if (!cr) {
2903 			pr_err("Unable to locate CID: %hu for"
2904 			" REMOVECONNFORRECOVERY Logout Request.\n",
2905 				cmd->logout_cid);
2906 			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
2907 			break;
2908 		}
2909 
2910 		iscsit_discard_cr_cmds_by_expstatsn(cr, cmd->exp_stat_sn);
2911 
2912 		pr_debug("iSCSI REMOVECONNFORRECOVERY logout"
2913 			" for recovery for CID: %hu on CID: %hu successful.\n",
2914 				cmd->logout_cid, conn->cid);
2915 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2916 		break;
2917 	default:
2918 		pr_err("Unknown cmd->logout_reason: 0x%02x\n",
2919 				cmd->logout_reason);
2920 		return -1;
2921 	}
2922 
2923 	hdr->opcode		= ISCSI_OP_LOGOUT_RSP;
2924 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
2925 	hdr->response		= cmd->logout_response;
2926 	hdr->itt		= cmd->init_task_tag;
2927 	cmd->stat_sn		= conn->stat_sn++;
2928 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2929 
2930 	iscsit_increment_maxcmdsn(cmd, conn->sess);
2931 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2932 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2933 
2934 	pr_debug("Built Logout Response ITT: 0x%08x StatSN:"
2935 		" 0x%08x Response: 0x%02x CID: %hu on CID: %hu\n",
2936 		cmd->init_task_tag, cmd->stat_sn, hdr->response,
2937 		cmd->logout_cid, conn->cid);
2938 
2939 	return 0;
2940 }
2941 EXPORT_SYMBOL(iscsit_build_logout_rsp);
2942 
2943 static int
2944 iscsit_send_logout(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2945 {
2946 	int rc;
2947 
2948 	rc = iscsit_build_logout_rsp(cmd, conn,
2949 			(struct iscsi_logout_rsp *)&cmd->pdu[0]);
2950 	if (rc < 0)
2951 		return rc;
2952 
2953 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
2954 }
2955 
2956 void
2957 iscsit_build_nopin_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2958 		       struct iscsi_nopin *hdr, bool nopout_response)
2959 {
2960 	hdr->opcode		= ISCSI_OP_NOOP_IN;
2961 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
2962         hton24(hdr->dlength, cmd->buf_ptr_size);
2963 	if (nopout_response)
2964 		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
2965 	hdr->itt		= cmd->init_task_tag;
2966 	hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
2967 	cmd->stat_sn		= (nopout_response) ? conn->stat_sn++ :
2968 				  conn->stat_sn;
2969 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2970 
2971 	if (nopout_response)
2972 		iscsit_increment_maxcmdsn(cmd, conn->sess);
2973 
2974 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2975 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2976 
2977 	pr_debug("Built NOPIN %s Response ITT: 0x%08x, TTT: 0x%08x,"
2978 		" StatSN: 0x%08x, Length %u\n", (nopout_response) ?
2979 		"Solicited" : "Unsolicited", cmd->init_task_tag,
2980 		cmd->targ_xfer_tag, cmd->stat_sn, cmd->buf_ptr_size);
2981 }
2982 EXPORT_SYMBOL(iscsit_build_nopin_rsp);
2983 
2984 /*
2985  *	Unsolicited NOPIN, either requesting a response or not.
2986  */
2987 static int iscsit_send_unsolicited_nopin(
2988 	struct iscsi_cmd *cmd,
2989 	struct iscsi_conn *conn,
2990 	int want_response)
2991 {
2992 	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
2993 	int ret;
2994 
2995 	iscsit_build_nopin_rsp(cmd, conn, hdr, false);
2996 
2997 	pr_debug("Sending Unsolicited NOPIN TTT: 0x%08x StatSN:"
2998 		" 0x%08x CID: %hu\n", hdr->ttt, cmd->stat_sn, conn->cid);
2999 
3000 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3001 	if (ret < 0)
3002 		return ret;
3003 
3004 	spin_lock_bh(&cmd->istate_lock);
3005 	cmd->i_state = want_response ?
3006 		ISTATE_SENT_NOPIN_WANT_RESPONSE : ISTATE_SENT_STATUS;
3007 	spin_unlock_bh(&cmd->istate_lock);
3008 
3009 	return 0;
3010 }
3011 
3012 static int
3013 iscsit_send_nopin(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3014 {
3015 	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
3016 
3017 	iscsit_build_nopin_rsp(cmd, conn, hdr, true);
3018 
3019 	/*
3020 	 * NOPOUT Ping Data is attached to struct iscsi_cmd->buf_ptr.
3021 	 * NOPOUT DataSegmentLength is at struct iscsi_cmd->buf_ptr_size.
3022 	 */
3023 	pr_debug("Echoing back %u bytes of ping data.\n", cmd->buf_ptr_size);
3024 
3025 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3026 						     cmd->buf_ptr,
3027 						     cmd->buf_ptr_size);
3028 }
3029 
3030 static int iscsit_send_r2t(
3031 	struct iscsi_cmd *cmd,
3032 	struct iscsi_conn *conn)
3033 {
3034 	struct iscsi_r2t *r2t;
3035 	struct iscsi_r2t_rsp *hdr;
3036 	int ret;
3037 
3038 	r2t = iscsit_get_r2t_from_list(cmd);
3039 	if (!r2t)
3040 		return -1;
3041 
3042 	hdr			= (struct iscsi_r2t_rsp *) cmd->pdu;
3043 	memset(hdr, 0, ISCSI_HDR_LEN);
3044 	hdr->opcode		= ISCSI_OP_R2T;
3045 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3046 	int_to_scsilun(cmd->se_cmd.orig_fe_lun,
3047 			(struct scsi_lun *)&hdr->lun);
3048 	hdr->itt		= cmd->init_task_tag;
3049 	if (conn->conn_transport->iscsit_get_r2t_ttt)
3050 		conn->conn_transport->iscsit_get_r2t_ttt(conn, cmd, r2t);
3051 	else
3052 		r2t->targ_xfer_tag = session_get_next_ttt(conn->sess);
3053 	hdr->ttt		= cpu_to_be32(r2t->targ_xfer_tag);
3054 	hdr->statsn		= cpu_to_be32(conn->stat_sn);
3055 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3056 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3057 	hdr->r2tsn		= cpu_to_be32(r2t->r2t_sn);
3058 	hdr->data_offset	= cpu_to_be32(r2t->offset);
3059 	hdr->data_length	= cpu_to_be32(r2t->xfer_len);
3060 
3061 	pr_debug("Built %sR2T, ITT: 0x%08x, TTT: 0x%08x, StatSN:"
3062 		" 0x%08x, R2TSN: 0x%08x, Offset: %u, DDTL: %u, CID: %hu\n",
3063 		(!r2t->recovery_r2t) ? "" : "Recovery ", cmd->init_task_tag,
3064 		r2t->targ_xfer_tag, ntohl(hdr->statsn), r2t->r2t_sn,
3065 			r2t->offset, r2t->xfer_len, conn->cid);
3066 
3067 	spin_lock_bh(&cmd->r2t_lock);
3068 	r2t->sent_r2t = 1;
3069 	spin_unlock_bh(&cmd->r2t_lock);
3070 
3071 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3072 	if (ret < 0) {
3073 		return ret;
3074 	}
3075 
3076 	spin_lock_bh(&cmd->dataout_timeout_lock);
3077 	iscsit_start_dataout_timer(cmd, conn);
3078 	spin_unlock_bh(&cmd->dataout_timeout_lock);
3079 
3080 	return 0;
3081 }
3082 
3083 /*
3084  *	@recovery: If called from iscsi_task_reassign_complete_write() for
3085  *		connection recovery.
3086  */
3087 int iscsit_build_r2ts_for_cmd(
3088 	struct iscsi_conn *conn,
3089 	struct iscsi_cmd *cmd,
3090 	bool recovery)
3091 {
3092 	int first_r2t = 1;
3093 	u32 offset = 0, xfer_len = 0;
3094 
3095 	spin_lock_bh(&cmd->r2t_lock);
3096 	if (cmd->cmd_flags & ICF_SENT_LAST_R2T) {
3097 		spin_unlock_bh(&cmd->r2t_lock);
3098 		return 0;
3099 	}
3100 
3101 	if (conn->sess->sess_ops->DataSequenceInOrder &&
3102 	    !recovery)
3103 		cmd->r2t_offset = max(cmd->r2t_offset, cmd->write_data_done);
3104 
3105 	while (cmd->outstanding_r2ts < conn->sess->sess_ops->MaxOutstandingR2T) {
3106 		if (conn->sess->sess_ops->DataSequenceInOrder) {
3107 			offset = cmd->r2t_offset;
3108 
3109 			if (first_r2t && recovery) {
3110 				int new_data_end = offset +
3111 					conn->sess->sess_ops->MaxBurstLength -
3112 					cmd->next_burst_len;
3113 
3114 				if (new_data_end > cmd->se_cmd.data_length)
3115 					xfer_len = cmd->se_cmd.data_length - offset;
3116 				else
3117 					xfer_len =
3118 						conn->sess->sess_ops->MaxBurstLength -
3119 						cmd->next_burst_len;
3120 			} else {
3121 				int new_data_end = offset +
3122 					conn->sess->sess_ops->MaxBurstLength;
3123 
3124 				if (new_data_end > cmd->se_cmd.data_length)
3125 					xfer_len = cmd->se_cmd.data_length - offset;
3126 				else
3127 					xfer_len = conn->sess->sess_ops->MaxBurstLength;
3128 			}
3129 			cmd->r2t_offset += xfer_len;
3130 
3131 			if (cmd->r2t_offset == cmd->se_cmd.data_length)
3132 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3133 		} else {
3134 			struct iscsi_seq *seq;
3135 
3136 			seq = iscsit_get_seq_holder_for_r2t(cmd);
3137 			if (!seq) {
3138 				spin_unlock_bh(&cmd->r2t_lock);
3139 				return -1;
3140 			}
3141 
3142 			offset = seq->offset;
3143 			xfer_len = seq->xfer_len;
3144 
3145 			if (cmd->seq_send_order == cmd->seq_count)
3146 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3147 		}
3148 		cmd->outstanding_r2ts++;
3149 		first_r2t = 0;
3150 
3151 		if (iscsit_add_r2t_to_list(cmd, offset, xfer_len, 0, 0) < 0) {
3152 			spin_unlock_bh(&cmd->r2t_lock);
3153 			return -1;
3154 		}
3155 
3156 		if (cmd->cmd_flags & ICF_SENT_LAST_R2T)
3157 			break;
3158 	}
3159 	spin_unlock_bh(&cmd->r2t_lock);
3160 
3161 	return 0;
3162 }
3163 EXPORT_SYMBOL(iscsit_build_r2ts_for_cmd);
3164 
3165 void iscsit_build_rsp_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3166 			bool inc_stat_sn, struct iscsi_scsi_rsp *hdr)
3167 {
3168 	if (inc_stat_sn)
3169 		cmd->stat_sn = conn->stat_sn++;
3170 
3171 	atomic_long_inc(&conn->sess->rsp_pdus);
3172 
3173 	memset(hdr, 0, ISCSI_HDR_LEN);
3174 	hdr->opcode		= ISCSI_OP_SCSI_CMD_RSP;
3175 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3176 	if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
3177 		hdr->flags |= ISCSI_FLAG_CMD_OVERFLOW;
3178 		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
3179 	} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
3180 		hdr->flags |= ISCSI_FLAG_CMD_UNDERFLOW;
3181 		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
3182 	}
3183 	hdr->response		= cmd->iscsi_response;
3184 	hdr->cmd_status		= cmd->se_cmd.scsi_status;
3185 	hdr->itt		= cmd->init_task_tag;
3186 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3187 
3188 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3189 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3190 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3191 
3192 	pr_debug("Built SCSI Response, ITT: 0x%08x, StatSN: 0x%08x,"
3193 		" Response: 0x%02x, SAM Status: 0x%02x, CID: %hu\n",
3194 		cmd->init_task_tag, cmd->stat_sn, cmd->se_cmd.scsi_status,
3195 		cmd->se_cmd.scsi_status, conn->cid);
3196 }
3197 EXPORT_SYMBOL(iscsit_build_rsp_pdu);
3198 
3199 static int iscsit_send_response(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3200 {
3201 	struct iscsi_scsi_rsp *hdr = (struct iscsi_scsi_rsp *)&cmd->pdu[0];
3202 	bool inc_stat_sn = (cmd->i_state == ISTATE_SEND_STATUS);
3203 	void *data_buf = NULL;
3204 	u32 padding = 0, data_buf_len = 0;
3205 
3206 	iscsit_build_rsp_pdu(cmd, conn, inc_stat_sn, hdr);
3207 
3208 	/*
3209 	 * Attach SENSE DATA payload to iSCSI Response PDU
3210 	 */
3211 	if (cmd->se_cmd.sense_buffer &&
3212 	   ((cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
3213 	    (cmd->se_cmd.se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
3214 		put_unaligned_be16(cmd->se_cmd.scsi_sense_length, cmd->sense_buffer);
3215 		cmd->se_cmd.scsi_sense_length += sizeof (__be16);
3216 
3217 		padding		= -(cmd->se_cmd.scsi_sense_length) & 3;
3218 		hton24(hdr->dlength, (u32)cmd->se_cmd.scsi_sense_length);
3219 		data_buf = cmd->sense_buffer;
3220 		data_buf_len = cmd->se_cmd.scsi_sense_length + padding;
3221 
3222 		if (padding) {
3223 			memset(cmd->sense_buffer +
3224 				cmd->se_cmd.scsi_sense_length, 0, padding);
3225 			pr_debug("Adding %u bytes of padding to"
3226 				" SENSE.\n", padding);
3227 		}
3228 
3229 		pr_debug("Attaching SENSE DATA: %u bytes to iSCSI"
3230 				" Response PDU\n",
3231 				cmd->se_cmd.scsi_sense_length);
3232 	}
3233 
3234 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, data_buf,
3235 						     data_buf_len);
3236 }
3237 
3238 static u8 iscsit_convert_tcm_tmr_rsp(struct se_tmr_req *se_tmr)
3239 {
3240 	switch (se_tmr->response) {
3241 	case TMR_FUNCTION_COMPLETE:
3242 		return ISCSI_TMF_RSP_COMPLETE;
3243 	case TMR_TASK_DOES_NOT_EXIST:
3244 		return ISCSI_TMF_RSP_NO_TASK;
3245 	case TMR_LUN_DOES_NOT_EXIST:
3246 		return ISCSI_TMF_RSP_NO_LUN;
3247 	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
3248 		return ISCSI_TMF_RSP_NOT_SUPPORTED;
3249 	case TMR_FUNCTION_REJECTED:
3250 	default:
3251 		return ISCSI_TMF_RSP_REJECTED;
3252 	}
3253 }
3254 
3255 void
3256 iscsit_build_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3257 			  struct iscsi_tm_rsp *hdr)
3258 {
3259 	struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req;
3260 
3261 	hdr->opcode		= ISCSI_OP_SCSI_TMFUNC_RSP;
3262 	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
3263 	hdr->response		= iscsit_convert_tcm_tmr_rsp(se_tmr);
3264 	hdr->itt		= cmd->init_task_tag;
3265 	cmd->stat_sn		= conn->stat_sn++;
3266 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3267 
3268 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3269 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3270 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3271 
3272 	pr_debug("Built Task Management Response ITT: 0x%08x,"
3273 		" StatSN: 0x%08x, Response: 0x%02x, CID: %hu\n",
3274 		cmd->init_task_tag, cmd->stat_sn, hdr->response, conn->cid);
3275 }
3276 EXPORT_SYMBOL(iscsit_build_task_mgt_rsp);
3277 
3278 static int
3279 iscsit_send_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3280 {
3281 	struct iscsi_tm_rsp *hdr = (struct iscsi_tm_rsp *)&cmd->pdu[0];
3282 
3283 	iscsit_build_task_mgt_rsp(cmd, conn, hdr);
3284 
3285 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3286 }
3287 
3288 #define SENDTARGETS_BUF_LIMIT 32768U
3289 
3290 static int
3291 iscsit_build_sendtargets_response(struct iscsi_cmd *cmd,
3292 				  enum iscsit_transport_type network_transport,
3293 				  int skip_bytes, bool *completed)
3294 {
3295 	char *payload = NULL;
3296 	struct iscsi_conn *conn = cmd->conn;
3297 	struct iscsi_portal_group *tpg;
3298 	struct iscsi_tiqn *tiqn;
3299 	struct iscsi_tpg_np *tpg_np;
3300 	int buffer_len, end_of_buf = 0, len = 0, payload_len = 0;
3301 	int target_name_printed;
3302 	unsigned char buf[ISCSI_IQN_LEN+12]; /* iqn + "TargetName=" + \0 */
3303 	unsigned char *text_in = cmd->text_in_ptr, *text_ptr = NULL;
3304 	bool active;
3305 
3306 	buffer_len = min(conn->conn_ops->MaxRecvDataSegmentLength,
3307 			 SENDTARGETS_BUF_LIMIT);
3308 
3309 	payload = kzalloc(buffer_len, GFP_KERNEL);
3310 	if (!payload)
3311 		return -ENOMEM;
3312 
3313 	/*
3314 	 * Locate pointer to iqn./eui. string for ICF_SENDTARGETS_SINGLE
3315 	 * explicit case..
3316 	 */
3317 	if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) {
3318 		text_ptr = strchr(text_in, '=');
3319 		if (!text_ptr) {
3320 			pr_err("Unable to locate '=' string in text_in:"
3321 			       " %s\n", text_in);
3322 			kfree(payload);
3323 			return -EINVAL;
3324 		}
3325 		/*
3326 		 * Skip over '=' character..
3327 		 */
3328 		text_ptr += 1;
3329 	}
3330 
3331 	spin_lock(&tiqn_lock);
3332 	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
3333 		if ((cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) &&
3334 		     strcmp(tiqn->tiqn, text_ptr)) {
3335 			continue;
3336 		}
3337 
3338 		target_name_printed = 0;
3339 
3340 		spin_lock(&tiqn->tiqn_tpg_lock);
3341 		list_for_each_entry(tpg, &tiqn->tiqn_tpg_list, tpg_list) {
3342 
3343 			/* If demo_mode_discovery=0 and generate_node_acls=0
3344 			 * (demo mode dislabed) do not return
3345 			 * TargetName+TargetAddress unless a NodeACL exists.
3346 			 */
3347 
3348 			if ((tpg->tpg_attrib.generate_node_acls == 0) &&
3349 			    (tpg->tpg_attrib.demo_mode_discovery == 0) &&
3350 			    (!target_tpg_has_node_acl(&tpg->tpg_se_tpg,
3351 				cmd->conn->sess->sess_ops->InitiatorName))) {
3352 				continue;
3353 			}
3354 
3355 			spin_lock(&tpg->tpg_state_lock);
3356 			active = (tpg->tpg_state == TPG_STATE_ACTIVE);
3357 			spin_unlock(&tpg->tpg_state_lock);
3358 
3359 			if (!active && tpg->tpg_attrib.tpg_enabled_sendtargets)
3360 				continue;
3361 
3362 			spin_lock(&tpg->tpg_np_lock);
3363 			list_for_each_entry(tpg_np, &tpg->tpg_gnp_list,
3364 						tpg_np_list) {
3365 				struct iscsi_np *np = tpg_np->tpg_np;
3366 				struct sockaddr_storage *sockaddr;
3367 
3368 				if (np->np_network_transport != network_transport)
3369 					continue;
3370 
3371 				if (!target_name_printed) {
3372 					len = sprintf(buf, "TargetName=%s",
3373 						      tiqn->tiqn);
3374 					len += 1;
3375 
3376 					if ((len + payload_len) > buffer_len) {
3377 						spin_unlock(&tpg->tpg_np_lock);
3378 						spin_unlock(&tiqn->tiqn_tpg_lock);
3379 						end_of_buf = 1;
3380 						goto eob;
3381 					}
3382 
3383 					if (skip_bytes && len <= skip_bytes) {
3384 						skip_bytes -= len;
3385 					} else {
3386 						memcpy(payload + payload_len, buf, len);
3387 						payload_len += len;
3388 						target_name_printed = 1;
3389 						if (len > skip_bytes)
3390 							skip_bytes = 0;
3391 					}
3392 				}
3393 
3394 				if (inet_addr_is_any((struct sockaddr *)&np->np_sockaddr))
3395 					sockaddr = &conn->local_sockaddr;
3396 				else
3397 					sockaddr = &np->np_sockaddr;
3398 
3399 				len = sprintf(buf, "TargetAddress="
3400 					      "%pISpc,%hu",
3401 					      sockaddr,
3402 					      tpg->tpgt);
3403 				len += 1;
3404 
3405 				if ((len + payload_len) > buffer_len) {
3406 					spin_unlock(&tpg->tpg_np_lock);
3407 					spin_unlock(&tiqn->tiqn_tpg_lock);
3408 					end_of_buf = 1;
3409 					goto eob;
3410 				}
3411 
3412 				if (skip_bytes && len <= skip_bytes) {
3413 					skip_bytes -= len;
3414 				} else {
3415 					memcpy(payload + payload_len, buf, len);
3416 					payload_len += len;
3417 					if (len > skip_bytes)
3418 						skip_bytes = 0;
3419 				}
3420 			}
3421 			spin_unlock(&tpg->tpg_np_lock);
3422 		}
3423 		spin_unlock(&tiqn->tiqn_tpg_lock);
3424 eob:
3425 		if (end_of_buf) {
3426 			*completed = false;
3427 			break;
3428 		}
3429 
3430 		if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE)
3431 			break;
3432 	}
3433 	spin_unlock(&tiqn_lock);
3434 
3435 	cmd->buf_ptr = payload;
3436 
3437 	return payload_len;
3438 }
3439 
3440 int
3441 iscsit_build_text_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3442 		      struct iscsi_text_rsp *hdr,
3443 		      enum iscsit_transport_type network_transport)
3444 {
3445 	int text_length, padding;
3446 	bool completed = true;
3447 
3448 	text_length = iscsit_build_sendtargets_response(cmd, network_transport,
3449 							cmd->read_data_done,
3450 							&completed);
3451 	if (text_length < 0)
3452 		return text_length;
3453 
3454 	if (completed) {
3455 		hdr->flags = ISCSI_FLAG_CMD_FINAL;
3456 	} else {
3457 		hdr->flags = ISCSI_FLAG_TEXT_CONTINUE;
3458 		cmd->read_data_done += text_length;
3459 		if (cmd->targ_xfer_tag == 0xFFFFFFFF)
3460 			cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
3461 	}
3462 	hdr->opcode = ISCSI_OP_TEXT_RSP;
3463 	padding = ((-text_length) & 3);
3464 	hton24(hdr->dlength, text_length);
3465 	hdr->itt = cmd->init_task_tag;
3466 	hdr->ttt = cpu_to_be32(cmd->targ_xfer_tag);
3467 	cmd->stat_sn = conn->stat_sn++;
3468 	hdr->statsn = cpu_to_be32(cmd->stat_sn);
3469 
3470 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3471 	/*
3472 	 * Reset maxcmdsn_inc in multi-part text payload exchanges to
3473 	 * correctly increment MaxCmdSN for each response answering a
3474 	 * non immediate text request with a valid CmdSN.
3475 	 */
3476 	cmd->maxcmdsn_inc = 0;
3477 	hdr->exp_cmdsn = cpu_to_be32(conn->sess->exp_cmd_sn);
3478 	hdr->max_cmdsn = cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3479 
3480 	pr_debug("Built Text Response: ITT: 0x%08x, TTT: 0x%08x, StatSN: 0x%08x,"
3481 		" Length: %u, CID: %hu F: %d C: %d\n", cmd->init_task_tag,
3482 		cmd->targ_xfer_tag, cmd->stat_sn, text_length, conn->cid,
3483 		!!(hdr->flags & ISCSI_FLAG_CMD_FINAL),
3484 		!!(hdr->flags & ISCSI_FLAG_TEXT_CONTINUE));
3485 
3486 	return text_length + padding;
3487 }
3488 EXPORT_SYMBOL(iscsit_build_text_rsp);
3489 
3490 static int iscsit_send_text_rsp(
3491 	struct iscsi_cmd *cmd,
3492 	struct iscsi_conn *conn)
3493 {
3494 	struct iscsi_text_rsp *hdr = (struct iscsi_text_rsp *)cmd->pdu;
3495 	int text_length;
3496 
3497 	text_length = iscsit_build_text_rsp(cmd, conn, hdr,
3498 				conn->conn_transport->transport_type);
3499 	if (text_length < 0)
3500 		return text_length;
3501 
3502 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3503 						     cmd->buf_ptr,
3504 						     text_length);
3505 }
3506 
3507 void
3508 iscsit_build_reject(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3509 		    struct iscsi_reject *hdr)
3510 {
3511 	hdr->opcode		= ISCSI_OP_REJECT;
3512 	hdr->reason		= cmd->reject_reason;
3513 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3514 	hton24(hdr->dlength, ISCSI_HDR_LEN);
3515 	hdr->ffffffff		= cpu_to_be32(0xffffffff);
3516 	cmd->stat_sn		= conn->stat_sn++;
3517 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3518 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3519 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3520 
3521 }
3522 EXPORT_SYMBOL(iscsit_build_reject);
3523 
3524 static int iscsit_send_reject(
3525 	struct iscsi_cmd *cmd,
3526 	struct iscsi_conn *conn)
3527 {
3528 	struct iscsi_reject *hdr = (struct iscsi_reject *)&cmd->pdu[0];
3529 
3530 	iscsit_build_reject(cmd, conn, hdr);
3531 
3532 	pr_debug("Built Reject PDU StatSN: 0x%08x, Reason: 0x%02x,"
3533 		" CID: %hu\n", ntohl(hdr->statsn), hdr->reason, conn->cid);
3534 
3535 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3536 						     cmd->buf_ptr,
3537 						     ISCSI_HDR_LEN);
3538 }
3539 
3540 void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
3541 {
3542 	int ord, cpu;
3543 	/*
3544 	 * bitmap_id is assigned from iscsit_global->ts_bitmap from
3545 	 * within iscsit_start_kthreads()
3546 	 *
3547 	 * Here we use bitmap_id to determine which CPU that this
3548 	 * iSCSI connection's RX/TX threads will be scheduled to
3549 	 * execute upon.
3550 	 */
3551 	ord = conn->bitmap_id % cpumask_weight(cpu_online_mask);
3552 	for_each_online_cpu(cpu) {
3553 		if (ord-- == 0) {
3554 			cpumask_set_cpu(cpu, conn->conn_cpumask);
3555 			return;
3556 		}
3557 	}
3558 	/*
3559 	 * This should never be reached..
3560 	 */
3561 	dump_stack();
3562 	cpumask_setall(conn->conn_cpumask);
3563 }
3564 
3565 int
3566 iscsit_immediate_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
3567 {
3568 	int ret;
3569 
3570 	switch (state) {
3571 	case ISTATE_SEND_R2T:
3572 		ret = iscsit_send_r2t(cmd, conn);
3573 		if (ret < 0)
3574 			goto err;
3575 		break;
3576 	case ISTATE_REMOVE:
3577 		spin_lock_bh(&conn->cmd_lock);
3578 		list_del_init(&cmd->i_conn_node);
3579 		spin_unlock_bh(&conn->cmd_lock);
3580 
3581 		iscsit_free_cmd(cmd, false);
3582 		break;
3583 	case ISTATE_SEND_NOPIN_WANT_RESPONSE:
3584 		iscsit_mod_nopin_response_timer(conn);
3585 		ret = iscsit_send_unsolicited_nopin(cmd, conn, 1);
3586 		if (ret < 0)
3587 			goto err;
3588 		break;
3589 	case ISTATE_SEND_NOPIN_NO_RESPONSE:
3590 		ret = iscsit_send_unsolicited_nopin(cmd, conn, 0);
3591 		if (ret < 0)
3592 			goto err;
3593 		break;
3594 	default:
3595 		pr_err("Unknown Opcode: 0x%02x ITT:"
3596 		       " 0x%08x, i_state: %d on CID: %hu\n",
3597 		       cmd->iscsi_opcode, cmd->init_task_tag, state,
3598 		       conn->cid);
3599 		goto err;
3600 	}
3601 
3602 	return 0;
3603 
3604 err:
3605 	return -1;
3606 }
3607 EXPORT_SYMBOL(iscsit_immediate_queue);
3608 
3609 static int
3610 iscsit_handle_immediate_queue(struct iscsi_conn *conn)
3611 {
3612 	struct iscsit_transport *t = conn->conn_transport;
3613 	struct iscsi_queue_req *qr;
3614 	struct iscsi_cmd *cmd;
3615 	u8 state;
3616 	int ret;
3617 
3618 	while ((qr = iscsit_get_cmd_from_immediate_queue(conn))) {
3619 		atomic_set(&conn->check_immediate_queue, 0);
3620 		cmd = qr->cmd;
3621 		state = qr->state;
3622 		kmem_cache_free(lio_qr_cache, qr);
3623 
3624 		ret = t->iscsit_immediate_queue(conn, cmd, state);
3625 		if (ret < 0)
3626 			return ret;
3627 	}
3628 
3629 	return 0;
3630 }
3631 
3632 int
3633 iscsit_response_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
3634 {
3635 	int ret;
3636 
3637 check_rsp_state:
3638 	switch (state) {
3639 	case ISTATE_SEND_DATAIN:
3640 		ret = iscsit_send_datain(cmd, conn);
3641 		if (ret < 0)
3642 			goto err;
3643 		else if (!ret)
3644 			/* more drs */
3645 			goto check_rsp_state;
3646 		else if (ret == 1) {
3647 			/* all done */
3648 			spin_lock_bh(&cmd->istate_lock);
3649 			cmd->i_state = ISTATE_SENT_STATUS;
3650 			spin_unlock_bh(&cmd->istate_lock);
3651 
3652 			if (atomic_read(&conn->check_immediate_queue))
3653 				return 1;
3654 
3655 			return 0;
3656 		} else if (ret == 2) {
3657 			/* Still must send status,
3658 			   SCF_TRANSPORT_TASK_SENSE was set */
3659 			spin_lock_bh(&cmd->istate_lock);
3660 			cmd->i_state = ISTATE_SEND_STATUS;
3661 			spin_unlock_bh(&cmd->istate_lock);
3662 			state = ISTATE_SEND_STATUS;
3663 			goto check_rsp_state;
3664 		}
3665 
3666 		break;
3667 	case ISTATE_SEND_STATUS:
3668 	case ISTATE_SEND_STATUS_RECOVERY:
3669 		ret = iscsit_send_response(cmd, conn);
3670 		break;
3671 	case ISTATE_SEND_LOGOUTRSP:
3672 		ret = iscsit_send_logout(cmd, conn);
3673 		break;
3674 	case ISTATE_SEND_ASYNCMSG:
3675 		ret = iscsit_send_conn_drop_async_message(
3676 			cmd, conn);
3677 		break;
3678 	case ISTATE_SEND_NOPIN:
3679 		ret = iscsit_send_nopin(cmd, conn);
3680 		break;
3681 	case ISTATE_SEND_REJECT:
3682 		ret = iscsit_send_reject(cmd, conn);
3683 		break;
3684 	case ISTATE_SEND_TASKMGTRSP:
3685 		ret = iscsit_send_task_mgt_rsp(cmd, conn);
3686 		if (ret != 0)
3687 			break;
3688 		ret = iscsit_tmr_post_handler(cmd, conn);
3689 		if (ret != 0)
3690 			iscsit_fall_back_to_erl0(conn->sess);
3691 		break;
3692 	case ISTATE_SEND_TEXTRSP:
3693 		ret = iscsit_send_text_rsp(cmd, conn);
3694 		break;
3695 	default:
3696 		pr_err("Unknown Opcode: 0x%02x ITT:"
3697 		       " 0x%08x, i_state: %d on CID: %hu\n",
3698 		       cmd->iscsi_opcode, cmd->init_task_tag,
3699 		       state, conn->cid);
3700 		goto err;
3701 	}
3702 	if (ret < 0)
3703 		goto err;
3704 
3705 	switch (state) {
3706 	case ISTATE_SEND_LOGOUTRSP:
3707 		if (!iscsit_logout_post_handler(cmd, conn))
3708 			return -ECONNRESET;
3709 		/* fall through */
3710 	case ISTATE_SEND_STATUS:
3711 	case ISTATE_SEND_ASYNCMSG:
3712 	case ISTATE_SEND_NOPIN:
3713 	case ISTATE_SEND_STATUS_RECOVERY:
3714 	case ISTATE_SEND_TEXTRSP:
3715 	case ISTATE_SEND_TASKMGTRSP:
3716 	case ISTATE_SEND_REJECT:
3717 		spin_lock_bh(&cmd->istate_lock);
3718 		cmd->i_state = ISTATE_SENT_STATUS;
3719 		spin_unlock_bh(&cmd->istate_lock);
3720 		break;
3721 	default:
3722 		pr_err("Unknown Opcode: 0x%02x ITT:"
3723 		       " 0x%08x, i_state: %d on CID: %hu\n",
3724 		       cmd->iscsi_opcode, cmd->init_task_tag,
3725 		       cmd->i_state, conn->cid);
3726 		goto err;
3727 	}
3728 
3729 	if (atomic_read(&conn->check_immediate_queue))
3730 		return 1;
3731 
3732 	return 0;
3733 
3734 err:
3735 	return -1;
3736 }
3737 EXPORT_SYMBOL(iscsit_response_queue);
3738 
3739 static int iscsit_handle_response_queue(struct iscsi_conn *conn)
3740 {
3741 	struct iscsit_transport *t = conn->conn_transport;
3742 	struct iscsi_queue_req *qr;
3743 	struct iscsi_cmd *cmd;
3744 	u8 state;
3745 	int ret;
3746 
3747 	while ((qr = iscsit_get_cmd_from_response_queue(conn))) {
3748 		cmd = qr->cmd;
3749 		state = qr->state;
3750 		kmem_cache_free(lio_qr_cache, qr);
3751 
3752 		ret = t->iscsit_response_queue(conn, cmd, state);
3753 		if (ret == 1 || ret < 0)
3754 			return ret;
3755 	}
3756 
3757 	return 0;
3758 }
3759 
3760 int iscsi_target_tx_thread(void *arg)
3761 {
3762 	int ret = 0;
3763 	struct iscsi_conn *conn = arg;
3764 	bool conn_freed = false;
3765 
3766 	/*
3767 	 * Allow ourselves to be interrupted by SIGINT so that a
3768 	 * connection recovery / failure event can be triggered externally.
3769 	 */
3770 	allow_signal(SIGINT);
3771 
3772 	while (!kthread_should_stop()) {
3773 		/*
3774 		 * Ensure that both TX and RX per connection kthreads
3775 		 * are scheduled to run on the same CPU.
3776 		 */
3777 		iscsit_thread_check_cpumask(conn, current, 1);
3778 
3779 		wait_event_interruptible(conn->queues_wq,
3780 					 !iscsit_conn_all_queues_empty(conn));
3781 
3782 		if (signal_pending(current))
3783 			goto transport_err;
3784 
3785 get_immediate:
3786 		ret = iscsit_handle_immediate_queue(conn);
3787 		if (ret < 0)
3788 			goto transport_err;
3789 
3790 		ret = iscsit_handle_response_queue(conn);
3791 		if (ret == 1) {
3792 			goto get_immediate;
3793 		} else if (ret == -ECONNRESET) {
3794 			conn_freed = true;
3795 			goto out;
3796 		} else if (ret < 0) {
3797 			goto transport_err;
3798 		}
3799 	}
3800 
3801 transport_err:
3802 	/*
3803 	 * Avoid the normal connection failure code-path if this connection
3804 	 * is still within LOGIN mode, and iscsi_np process context is
3805 	 * responsible for cleaning up the early connection failure.
3806 	 */
3807 	if (conn->conn_state != TARG_CONN_STATE_IN_LOGIN)
3808 		iscsit_take_action_for_connection_exit(conn, &conn_freed);
3809 out:
3810 	if (!conn_freed) {
3811 		while (!kthread_should_stop()) {
3812 			msleep(100);
3813 		}
3814 	}
3815 	return 0;
3816 }
3817 
3818 static int iscsi_target_rx_opcode(struct iscsi_conn *conn, unsigned char *buf)
3819 {
3820 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)buf;
3821 	struct iscsi_cmd *cmd;
3822 	int ret = 0;
3823 
3824 	switch (hdr->opcode & ISCSI_OPCODE_MASK) {
3825 	case ISCSI_OP_SCSI_CMD:
3826 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3827 		if (!cmd)
3828 			goto reject;
3829 
3830 		ret = iscsit_handle_scsi_cmd(conn, cmd, buf);
3831 		break;
3832 	case ISCSI_OP_SCSI_DATA_OUT:
3833 		ret = iscsit_handle_data_out(conn, buf);
3834 		break;
3835 	case ISCSI_OP_NOOP_OUT:
3836 		cmd = NULL;
3837 		if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
3838 			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3839 			if (!cmd)
3840 				goto reject;
3841 		}
3842 		ret = iscsit_handle_nop_out(conn, cmd, buf);
3843 		break;
3844 	case ISCSI_OP_SCSI_TMFUNC:
3845 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3846 		if (!cmd)
3847 			goto reject;
3848 
3849 		ret = iscsit_handle_task_mgt_cmd(conn, cmd, buf);
3850 		break;
3851 	case ISCSI_OP_TEXT:
3852 		if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
3853 			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
3854 			if (!cmd)
3855 				goto reject;
3856 		} else {
3857 			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3858 			if (!cmd)
3859 				goto reject;
3860 		}
3861 
3862 		ret = iscsit_handle_text_cmd(conn, cmd, buf);
3863 		break;
3864 	case ISCSI_OP_LOGOUT:
3865 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3866 		if (!cmd)
3867 			goto reject;
3868 
3869 		ret = iscsit_handle_logout_cmd(conn, cmd, buf);
3870 		if (ret > 0)
3871 			wait_for_completion_timeout(&conn->conn_logout_comp,
3872 					SECONDS_FOR_LOGOUT_COMP * HZ);
3873 		break;
3874 	case ISCSI_OP_SNACK:
3875 		ret = iscsit_handle_snack(conn, buf);
3876 		break;
3877 	default:
3878 		pr_err("Got unknown iSCSI OpCode: 0x%02x\n", hdr->opcode);
3879 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
3880 			pr_err("Cannot recover from unknown"
3881 			" opcode while ERL=0, closing iSCSI connection.\n");
3882 			return -1;
3883 		}
3884 		pr_err("Unable to recover from unknown opcode while OFMarker=No,"
3885 		       " closing iSCSI connection.\n");
3886 		ret = -1;
3887 		break;
3888 	}
3889 
3890 	return ret;
3891 reject:
3892 	return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
3893 }
3894 
3895 static bool iscsi_target_check_conn_state(struct iscsi_conn *conn)
3896 {
3897 	bool ret;
3898 
3899 	spin_lock_bh(&conn->state_lock);
3900 	ret = (conn->conn_state != TARG_CONN_STATE_LOGGED_IN);
3901 	spin_unlock_bh(&conn->state_lock);
3902 
3903 	return ret;
3904 }
3905 
3906 static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
3907 {
3908 	int ret;
3909 	u8 *buffer, opcode;
3910 	u32 checksum = 0, digest = 0;
3911 	struct kvec iov;
3912 
3913 	buffer = kcalloc(ISCSI_HDR_LEN, sizeof(*buffer), GFP_KERNEL);
3914 	if (!buffer)
3915 		return;
3916 
3917 	while (!kthread_should_stop()) {
3918 		/*
3919 		 * Ensure that both TX and RX per connection kthreads
3920 		 * are scheduled to run on the same CPU.
3921 		 */
3922 		iscsit_thread_check_cpumask(conn, current, 0);
3923 
3924 		memset(&iov, 0, sizeof(struct kvec));
3925 
3926 		iov.iov_base	= buffer;
3927 		iov.iov_len	= ISCSI_HDR_LEN;
3928 
3929 		ret = rx_data(conn, &iov, 1, ISCSI_HDR_LEN);
3930 		if (ret != ISCSI_HDR_LEN) {
3931 			iscsit_rx_thread_wait_for_tcp(conn);
3932 			break;
3933 		}
3934 
3935 		if (conn->conn_ops->HeaderDigest) {
3936 			iov.iov_base	= &digest;
3937 			iov.iov_len	= ISCSI_CRC_LEN;
3938 
3939 			ret = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
3940 			if (ret != ISCSI_CRC_LEN) {
3941 				iscsit_rx_thread_wait_for_tcp(conn);
3942 				break;
3943 			}
3944 
3945 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash, buffer,
3946 						  ISCSI_HDR_LEN, 0, NULL,
3947 						  &checksum);
3948 
3949 			if (digest != checksum) {
3950 				pr_err("HeaderDigest CRC32C failed,"
3951 					" received 0x%08x, computed 0x%08x\n",
3952 					digest, checksum);
3953 				/*
3954 				 * Set the PDU to 0xff so it will intentionally
3955 				 * hit default in the switch below.
3956 				 */
3957 				memset(buffer, 0xff, ISCSI_HDR_LEN);
3958 				atomic_long_inc(&conn->sess->conn_digest_errors);
3959 			} else {
3960 				pr_debug("Got HeaderDigest CRC32C"
3961 						" 0x%08x\n", checksum);
3962 			}
3963 		}
3964 
3965 		if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
3966 			break;
3967 
3968 		opcode = buffer[0] & ISCSI_OPCODE_MASK;
3969 
3970 		if (conn->sess->sess_ops->SessionType &&
3971 		   ((!(opcode & ISCSI_OP_TEXT)) ||
3972 		    (!(opcode & ISCSI_OP_LOGOUT)))) {
3973 			pr_err("Received illegal iSCSI Opcode: 0x%02x"
3974 			" while in Discovery Session, rejecting.\n", opcode);
3975 			iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
3976 					  buffer);
3977 			break;
3978 		}
3979 
3980 		ret = iscsi_target_rx_opcode(conn, buffer);
3981 		if (ret < 0)
3982 			break;
3983 	}
3984 
3985 	kfree(buffer);
3986 }
3987 
3988 int iscsi_target_rx_thread(void *arg)
3989 {
3990 	int rc;
3991 	struct iscsi_conn *conn = arg;
3992 	bool conn_freed = false;
3993 
3994 	/*
3995 	 * Allow ourselves to be interrupted by SIGINT so that a
3996 	 * connection recovery / failure event can be triggered externally.
3997 	 */
3998 	allow_signal(SIGINT);
3999 	/*
4000 	 * Wait for iscsi_post_login_handler() to complete before allowing
4001 	 * incoming iscsi/tcp socket I/O, and/or failing the connection.
4002 	 */
4003 	rc = wait_for_completion_interruptible(&conn->rx_login_comp);
4004 	if (rc < 0 || iscsi_target_check_conn_state(conn))
4005 		goto out;
4006 
4007 	if (!conn->conn_transport->iscsit_get_rx_pdu)
4008 		return 0;
4009 
4010 	conn->conn_transport->iscsit_get_rx_pdu(conn);
4011 
4012 	if (!signal_pending(current))
4013 		atomic_set(&conn->transport_failed, 1);
4014 	iscsit_take_action_for_connection_exit(conn, &conn_freed);
4015 
4016 out:
4017 	if (!conn_freed) {
4018 		while (!kthread_should_stop()) {
4019 			msleep(100);
4020 		}
4021 	}
4022 
4023 	return 0;
4024 }
4025 
4026 static void iscsit_release_commands_from_conn(struct iscsi_conn *conn)
4027 {
4028 	LIST_HEAD(tmp_list);
4029 	struct iscsi_cmd *cmd = NULL, *cmd_tmp = NULL;
4030 	struct iscsi_session *sess = conn->sess;
4031 	/*
4032 	 * We expect this function to only ever be called from either RX or TX
4033 	 * thread context via iscsit_close_connection() once the other context
4034 	 * has been reset -> returned sleeping pre-handler state.
4035 	 */
4036 	spin_lock_bh(&conn->cmd_lock);
4037 	list_splice_init(&conn->conn_cmd_list, &tmp_list);
4038 
4039 	list_for_each_entry(cmd, &tmp_list, i_conn_node) {
4040 		struct se_cmd *se_cmd = &cmd->se_cmd;
4041 
4042 		if (se_cmd->se_tfo != NULL) {
4043 			spin_lock(&se_cmd->t_state_lock);
4044 			se_cmd->transport_state |= CMD_T_FABRIC_STOP;
4045 			spin_unlock(&se_cmd->t_state_lock);
4046 		}
4047 	}
4048 	spin_unlock_bh(&conn->cmd_lock);
4049 
4050 	list_for_each_entry_safe(cmd, cmd_tmp, &tmp_list, i_conn_node) {
4051 		list_del_init(&cmd->i_conn_node);
4052 
4053 		iscsit_increment_maxcmdsn(cmd, sess);
4054 		iscsit_free_cmd(cmd, true);
4055 
4056 	}
4057 }
4058 
4059 static void iscsit_stop_timers_for_cmds(
4060 	struct iscsi_conn *conn)
4061 {
4062 	struct iscsi_cmd *cmd;
4063 
4064 	spin_lock_bh(&conn->cmd_lock);
4065 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
4066 		if (cmd->data_direction == DMA_TO_DEVICE)
4067 			iscsit_stop_dataout_timer(cmd);
4068 	}
4069 	spin_unlock_bh(&conn->cmd_lock);
4070 }
4071 
4072 int iscsit_close_connection(
4073 	struct iscsi_conn *conn)
4074 {
4075 	int conn_logout = (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT);
4076 	struct iscsi_session	*sess = conn->sess;
4077 
4078 	pr_debug("Closing iSCSI connection CID %hu on SID:"
4079 		" %u\n", conn->cid, sess->sid);
4080 	/*
4081 	 * Always up conn_logout_comp for the traditional TCP and HW_OFFLOAD
4082 	 * case just in case the RX Thread in iscsi_target_rx_opcode() is
4083 	 * sleeping and the logout response never got sent because the
4084 	 * connection failed.
4085 	 *
4086 	 * However for iser-target, isert_wait4logout() is using conn_logout_comp
4087 	 * to signal logout response TX interrupt completion.  Go ahead and skip
4088 	 * this for iser since isert_rx_opcode() does not wait on logout failure,
4089 	 * and to avoid iscsi_conn pointer dereference in iser-target code.
4090 	 */
4091 	if (!conn->conn_transport->rdma_shutdown)
4092 		complete(&conn->conn_logout_comp);
4093 
4094 	if (!strcmp(current->comm, ISCSI_RX_THREAD_NAME)) {
4095 		if (conn->tx_thread &&
4096 		    cmpxchg(&conn->tx_thread_active, true, false)) {
4097 			send_sig(SIGINT, conn->tx_thread, 1);
4098 			kthread_stop(conn->tx_thread);
4099 		}
4100 	} else if (!strcmp(current->comm, ISCSI_TX_THREAD_NAME)) {
4101 		if (conn->rx_thread &&
4102 		    cmpxchg(&conn->rx_thread_active, true, false)) {
4103 			send_sig(SIGINT, conn->rx_thread, 1);
4104 			kthread_stop(conn->rx_thread);
4105 		}
4106 	}
4107 
4108 	spin_lock(&iscsit_global->ts_bitmap_lock);
4109 	bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
4110 			      get_order(1));
4111 	spin_unlock(&iscsit_global->ts_bitmap_lock);
4112 
4113 	iscsit_stop_timers_for_cmds(conn);
4114 	iscsit_stop_nopin_response_timer(conn);
4115 	iscsit_stop_nopin_timer(conn);
4116 
4117 	if (conn->conn_transport->iscsit_wait_conn)
4118 		conn->conn_transport->iscsit_wait_conn(conn);
4119 
4120 	/*
4121 	 * During Connection recovery drop unacknowledged out of order
4122 	 * commands for this connection, and prepare the other commands
4123 	 * for reallegiance.
4124 	 *
4125 	 * During normal operation clear the out of order commands (but
4126 	 * do not free the struct iscsi_ooo_cmdsn's) and release all
4127 	 * struct iscsi_cmds.
4128 	 */
4129 	if (atomic_read(&conn->connection_recovery)) {
4130 		iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(conn);
4131 		iscsit_prepare_cmds_for_reallegiance(conn);
4132 	} else {
4133 		iscsit_clear_ooo_cmdsns_for_conn(conn);
4134 		iscsit_release_commands_from_conn(conn);
4135 	}
4136 	iscsit_free_queue_reqs_for_conn(conn);
4137 
4138 	/*
4139 	 * Handle decrementing session or connection usage count if
4140 	 * a logout response was not able to be sent because the
4141 	 * connection failed.  Fall back to Session Recovery here.
4142 	 */
4143 	if (atomic_read(&conn->conn_logout_remove)) {
4144 		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_SESSION) {
4145 			iscsit_dec_conn_usage_count(conn);
4146 			iscsit_dec_session_usage_count(sess);
4147 		}
4148 		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION)
4149 			iscsit_dec_conn_usage_count(conn);
4150 
4151 		atomic_set(&conn->conn_logout_remove, 0);
4152 		atomic_set(&sess->session_reinstatement, 0);
4153 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4154 	}
4155 
4156 	spin_lock_bh(&sess->conn_lock);
4157 	list_del(&conn->conn_list);
4158 
4159 	/*
4160 	 * Attempt to let the Initiator know this connection failed by
4161 	 * sending an Connection Dropped Async Message on another
4162 	 * active connection.
4163 	 */
4164 	if (atomic_read(&conn->connection_recovery))
4165 		iscsit_build_conn_drop_async_message(conn);
4166 
4167 	spin_unlock_bh(&sess->conn_lock);
4168 
4169 	/*
4170 	 * If connection reinstatement is being performed on this connection,
4171 	 * up the connection reinstatement semaphore that is being blocked on
4172 	 * in iscsit_cause_connection_reinstatement().
4173 	 */
4174 	spin_lock_bh(&conn->state_lock);
4175 	if (atomic_read(&conn->sleep_on_conn_wait_comp)) {
4176 		spin_unlock_bh(&conn->state_lock);
4177 		complete(&conn->conn_wait_comp);
4178 		wait_for_completion(&conn->conn_post_wait_comp);
4179 		spin_lock_bh(&conn->state_lock);
4180 	}
4181 
4182 	/*
4183 	 * If connection reinstatement is being performed on this connection
4184 	 * by receiving a REMOVECONNFORRECOVERY logout request, up the
4185 	 * connection wait rcfr semaphore that is being blocked on
4186 	 * an iscsit_connection_reinstatement_rcfr().
4187 	 */
4188 	if (atomic_read(&conn->connection_wait_rcfr)) {
4189 		spin_unlock_bh(&conn->state_lock);
4190 		complete(&conn->conn_wait_rcfr_comp);
4191 		wait_for_completion(&conn->conn_post_wait_comp);
4192 		spin_lock_bh(&conn->state_lock);
4193 	}
4194 	atomic_set(&conn->connection_reinstatement, 1);
4195 	spin_unlock_bh(&conn->state_lock);
4196 
4197 	/*
4198 	 * If any other processes are accessing this connection pointer we
4199 	 * must wait until they have completed.
4200 	 */
4201 	iscsit_check_conn_usage_count(conn);
4202 
4203 	ahash_request_free(conn->conn_tx_hash);
4204 	if (conn->conn_rx_hash) {
4205 		struct crypto_ahash *tfm;
4206 
4207 		tfm = crypto_ahash_reqtfm(conn->conn_rx_hash);
4208 		ahash_request_free(conn->conn_rx_hash);
4209 		crypto_free_ahash(tfm);
4210 	}
4211 
4212 	if (conn->sock)
4213 		sock_release(conn->sock);
4214 
4215 	if (conn->conn_transport->iscsit_free_conn)
4216 		conn->conn_transport->iscsit_free_conn(conn);
4217 
4218 	pr_debug("Moving to TARG_CONN_STATE_FREE.\n");
4219 	conn->conn_state = TARG_CONN_STATE_FREE;
4220 	iscsit_free_conn(conn);
4221 
4222 	spin_lock_bh(&sess->conn_lock);
4223 	atomic_dec(&sess->nconn);
4224 	pr_debug("Decremented iSCSI connection count to %hu from node:"
4225 		" %s\n", atomic_read(&sess->nconn),
4226 		sess->sess_ops->InitiatorName);
4227 	/*
4228 	 * Make sure that if one connection fails in an non ERL=2 iSCSI
4229 	 * Session that they all fail.
4230 	 */
4231 	if ((sess->sess_ops->ErrorRecoveryLevel != 2) && !conn_logout &&
4232 	     !atomic_read(&sess->session_logout))
4233 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4234 
4235 	/*
4236 	 * If this was not the last connection in the session, and we are
4237 	 * performing session reinstatement or falling back to ERL=0, call
4238 	 * iscsit_stop_session() without sleeping to shutdown the other
4239 	 * active connections.
4240 	 */
4241 	if (atomic_read(&sess->nconn)) {
4242 		if (!atomic_read(&sess->session_reinstatement) &&
4243 		    !atomic_read(&sess->session_fall_back_to_erl0)) {
4244 			spin_unlock_bh(&sess->conn_lock);
4245 			return 0;
4246 		}
4247 		if (!atomic_read(&sess->session_stop_active)) {
4248 			atomic_set(&sess->session_stop_active, 1);
4249 			spin_unlock_bh(&sess->conn_lock);
4250 			iscsit_stop_session(sess, 0, 0);
4251 			return 0;
4252 		}
4253 		spin_unlock_bh(&sess->conn_lock);
4254 		return 0;
4255 	}
4256 
4257 	/*
4258 	 * If this was the last connection in the session and one of the
4259 	 * following is occurring:
4260 	 *
4261 	 * Session Reinstatement is not being performed, and are falling back
4262 	 * to ERL=0 call iscsit_close_session().
4263 	 *
4264 	 * Session Logout was requested.  iscsit_close_session() will be called
4265 	 * elsewhere.
4266 	 *
4267 	 * Session Continuation is not being performed, start the Time2Retain
4268 	 * handler and check if sleep_on_sess_wait_sem is active.
4269 	 */
4270 	if (!atomic_read(&sess->session_reinstatement) &&
4271 	     atomic_read(&sess->session_fall_back_to_erl0)) {
4272 		spin_unlock_bh(&sess->conn_lock);
4273 		iscsit_close_session(sess);
4274 
4275 		return 0;
4276 	} else if (atomic_read(&sess->session_logout)) {
4277 		pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
4278 		sess->session_state = TARG_SESS_STATE_FREE;
4279 		spin_unlock_bh(&sess->conn_lock);
4280 
4281 		if (atomic_read(&sess->sleep_on_sess_wait_comp))
4282 			complete(&sess->session_wait_comp);
4283 
4284 		return 0;
4285 	} else {
4286 		pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
4287 		sess->session_state = TARG_SESS_STATE_FAILED;
4288 
4289 		if (!atomic_read(&sess->session_continuation)) {
4290 			spin_unlock_bh(&sess->conn_lock);
4291 			iscsit_start_time2retain_handler(sess);
4292 		} else
4293 			spin_unlock_bh(&sess->conn_lock);
4294 
4295 		if (atomic_read(&sess->sleep_on_sess_wait_comp))
4296 			complete(&sess->session_wait_comp);
4297 
4298 		return 0;
4299 	}
4300 }
4301 
4302 /*
4303  * If the iSCSI Session for the iSCSI Initiator Node exists,
4304  * forcefully shutdown the iSCSI NEXUS.
4305  */
4306 int iscsit_close_session(struct iscsi_session *sess)
4307 {
4308 	struct iscsi_portal_group *tpg = sess->tpg;
4309 	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
4310 
4311 	if (atomic_read(&sess->nconn)) {
4312 		pr_err("%d connection(s) still exist for iSCSI session"
4313 			" to %s\n", atomic_read(&sess->nconn),
4314 			sess->sess_ops->InitiatorName);
4315 		BUG();
4316 	}
4317 
4318 	spin_lock_bh(&se_tpg->session_lock);
4319 	atomic_set(&sess->session_logout, 1);
4320 	atomic_set(&sess->session_reinstatement, 1);
4321 	iscsit_stop_time2retain_timer(sess);
4322 	spin_unlock_bh(&se_tpg->session_lock);
4323 
4324 	/*
4325 	 * transport_deregister_session_configfs() will clear the
4326 	 * struct se_node_acl->nacl_sess pointer now as a iscsi_np process context
4327 	 * can be setting it again with __transport_register_session() in
4328 	 * iscsi_post_login_handler() again after the iscsit_stop_session()
4329 	 * completes in iscsi_np context.
4330 	 */
4331 	transport_deregister_session_configfs(sess->se_sess);
4332 
4333 	/*
4334 	 * If any other processes are accessing this session pointer we must
4335 	 * wait until they have completed.  If we are in an interrupt (the
4336 	 * time2retain handler) and contain and active session usage count we
4337 	 * restart the timer and exit.
4338 	 */
4339 	if (!in_interrupt()) {
4340 		if (iscsit_check_session_usage_count(sess) == 1)
4341 			iscsit_stop_session(sess, 1, 1);
4342 	} else {
4343 		if (iscsit_check_session_usage_count(sess) == 2) {
4344 			atomic_set(&sess->session_logout, 0);
4345 			iscsit_start_time2retain_handler(sess);
4346 			return 0;
4347 		}
4348 	}
4349 
4350 	transport_deregister_session(sess->se_sess);
4351 
4352 	if (sess->sess_ops->ErrorRecoveryLevel == 2)
4353 		iscsit_free_connection_recovery_entries(sess);
4354 
4355 	iscsit_free_all_ooo_cmdsns(sess);
4356 
4357 	spin_lock_bh(&se_tpg->session_lock);
4358 	pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
4359 	sess->session_state = TARG_SESS_STATE_FREE;
4360 	pr_debug("Released iSCSI session from node: %s\n",
4361 			sess->sess_ops->InitiatorName);
4362 	tpg->nsessions--;
4363 	if (tpg->tpg_tiqn)
4364 		tpg->tpg_tiqn->tiqn_nsessions--;
4365 
4366 	pr_debug("Decremented number of active iSCSI Sessions on"
4367 		" iSCSI TPG: %hu to %u\n", tpg->tpgt, tpg->nsessions);
4368 
4369 	ida_free(&sess_ida, sess->session_index);
4370 	kfree(sess->sess_ops);
4371 	sess->sess_ops = NULL;
4372 	spin_unlock_bh(&se_tpg->session_lock);
4373 
4374 	kfree(sess);
4375 	return 0;
4376 }
4377 
4378 static void iscsit_logout_post_handler_closesession(
4379 	struct iscsi_conn *conn)
4380 {
4381 	struct iscsi_session *sess = conn->sess;
4382 	int sleep = 1;
4383 	/*
4384 	 * Traditional iscsi/tcp will invoke this logic from TX thread
4385 	 * context during session logout, so clear tx_thread_active and
4386 	 * sleep if iscsit_close_connection() has not already occured.
4387 	 *
4388 	 * Since iser-target invokes this logic from it's own workqueue,
4389 	 * always sleep waiting for RX/TX thread shutdown to complete
4390 	 * within iscsit_close_connection().
4391 	 */
4392 	if (!conn->conn_transport->rdma_shutdown) {
4393 		sleep = cmpxchg(&conn->tx_thread_active, true, false);
4394 		if (!sleep)
4395 			return;
4396 	}
4397 
4398 	atomic_set(&conn->conn_logout_remove, 0);
4399 	complete(&conn->conn_logout_comp);
4400 
4401 	iscsit_dec_conn_usage_count(conn);
4402 	iscsit_stop_session(sess, sleep, sleep);
4403 	iscsit_dec_session_usage_count(sess);
4404 	iscsit_close_session(sess);
4405 }
4406 
4407 static void iscsit_logout_post_handler_samecid(
4408 	struct iscsi_conn *conn)
4409 {
4410 	int sleep = 1;
4411 
4412 	if (!conn->conn_transport->rdma_shutdown) {
4413 		sleep = cmpxchg(&conn->tx_thread_active, true, false);
4414 		if (!sleep)
4415 			return;
4416 	}
4417 
4418 	atomic_set(&conn->conn_logout_remove, 0);
4419 	complete(&conn->conn_logout_comp);
4420 
4421 	iscsit_cause_connection_reinstatement(conn, sleep);
4422 	iscsit_dec_conn_usage_count(conn);
4423 }
4424 
4425 static void iscsit_logout_post_handler_diffcid(
4426 	struct iscsi_conn *conn,
4427 	u16 cid)
4428 {
4429 	struct iscsi_conn *l_conn;
4430 	struct iscsi_session *sess = conn->sess;
4431 	bool conn_found = false;
4432 
4433 	if (!sess)
4434 		return;
4435 
4436 	spin_lock_bh(&sess->conn_lock);
4437 	list_for_each_entry(l_conn, &sess->sess_conn_list, conn_list) {
4438 		if (l_conn->cid == cid) {
4439 			iscsit_inc_conn_usage_count(l_conn);
4440 			conn_found = true;
4441 			break;
4442 		}
4443 	}
4444 	spin_unlock_bh(&sess->conn_lock);
4445 
4446 	if (!conn_found)
4447 		return;
4448 
4449 	if (l_conn->sock)
4450 		l_conn->sock->ops->shutdown(l_conn->sock, RCV_SHUTDOWN);
4451 
4452 	spin_lock_bh(&l_conn->state_lock);
4453 	pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
4454 	l_conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
4455 	spin_unlock_bh(&l_conn->state_lock);
4456 
4457 	iscsit_cause_connection_reinstatement(l_conn, 1);
4458 	iscsit_dec_conn_usage_count(l_conn);
4459 }
4460 
4461 /*
4462  *	Return of 0 causes the TX thread to restart.
4463  */
4464 int iscsit_logout_post_handler(
4465 	struct iscsi_cmd *cmd,
4466 	struct iscsi_conn *conn)
4467 {
4468 	int ret = 0;
4469 
4470 	switch (cmd->logout_reason) {
4471 	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
4472 		switch (cmd->logout_response) {
4473 		case ISCSI_LOGOUT_SUCCESS:
4474 		case ISCSI_LOGOUT_CLEANUP_FAILED:
4475 		default:
4476 			iscsit_logout_post_handler_closesession(conn);
4477 			break;
4478 		}
4479 		ret = 0;
4480 		break;
4481 	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
4482 		if (conn->cid == cmd->logout_cid) {
4483 			switch (cmd->logout_response) {
4484 			case ISCSI_LOGOUT_SUCCESS:
4485 			case ISCSI_LOGOUT_CLEANUP_FAILED:
4486 			default:
4487 				iscsit_logout_post_handler_samecid(conn);
4488 				break;
4489 			}
4490 			ret = 0;
4491 		} else {
4492 			switch (cmd->logout_response) {
4493 			case ISCSI_LOGOUT_SUCCESS:
4494 				iscsit_logout_post_handler_diffcid(conn,
4495 					cmd->logout_cid);
4496 				break;
4497 			case ISCSI_LOGOUT_CID_NOT_FOUND:
4498 			case ISCSI_LOGOUT_CLEANUP_FAILED:
4499 			default:
4500 				break;
4501 			}
4502 			ret = 1;
4503 		}
4504 		break;
4505 	case ISCSI_LOGOUT_REASON_RECOVERY:
4506 		switch (cmd->logout_response) {
4507 		case ISCSI_LOGOUT_SUCCESS:
4508 		case ISCSI_LOGOUT_CID_NOT_FOUND:
4509 		case ISCSI_LOGOUT_RECOVERY_UNSUPPORTED:
4510 		case ISCSI_LOGOUT_CLEANUP_FAILED:
4511 		default:
4512 			break;
4513 		}
4514 		ret = 1;
4515 		break;
4516 	default:
4517 		break;
4518 
4519 	}
4520 	return ret;
4521 }
4522 EXPORT_SYMBOL(iscsit_logout_post_handler);
4523 
4524 void iscsit_fail_session(struct iscsi_session *sess)
4525 {
4526 	struct iscsi_conn *conn;
4527 
4528 	spin_lock_bh(&sess->conn_lock);
4529 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
4530 		pr_debug("Moving to TARG_CONN_STATE_CLEANUP_WAIT.\n");
4531 		conn->conn_state = TARG_CONN_STATE_CLEANUP_WAIT;
4532 	}
4533 	spin_unlock_bh(&sess->conn_lock);
4534 
4535 	pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
4536 	sess->session_state = TARG_SESS_STATE_FAILED;
4537 }
4538 
4539 int iscsit_free_session(struct iscsi_session *sess)
4540 {
4541 	u16 conn_count = atomic_read(&sess->nconn);
4542 	struct iscsi_conn *conn, *conn_tmp = NULL;
4543 	int is_last;
4544 
4545 	spin_lock_bh(&sess->conn_lock);
4546 	atomic_set(&sess->sleep_on_sess_wait_comp, 1);
4547 
4548 	list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
4549 			conn_list) {
4550 		if (conn_count == 0)
4551 			break;
4552 
4553 		if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
4554 			is_last = 1;
4555 		} else {
4556 			iscsit_inc_conn_usage_count(conn_tmp);
4557 			is_last = 0;
4558 		}
4559 		iscsit_inc_conn_usage_count(conn);
4560 
4561 		spin_unlock_bh(&sess->conn_lock);
4562 		iscsit_cause_connection_reinstatement(conn, 1);
4563 		spin_lock_bh(&sess->conn_lock);
4564 
4565 		iscsit_dec_conn_usage_count(conn);
4566 		if (is_last == 0)
4567 			iscsit_dec_conn_usage_count(conn_tmp);
4568 
4569 		conn_count--;
4570 	}
4571 
4572 	if (atomic_read(&sess->nconn)) {
4573 		spin_unlock_bh(&sess->conn_lock);
4574 		wait_for_completion(&sess->session_wait_comp);
4575 	} else
4576 		spin_unlock_bh(&sess->conn_lock);
4577 
4578 	iscsit_close_session(sess);
4579 	return 0;
4580 }
4581 
4582 void iscsit_stop_session(
4583 	struct iscsi_session *sess,
4584 	int session_sleep,
4585 	int connection_sleep)
4586 {
4587 	u16 conn_count = atomic_read(&sess->nconn);
4588 	struct iscsi_conn *conn, *conn_tmp = NULL;
4589 	int is_last;
4590 
4591 	spin_lock_bh(&sess->conn_lock);
4592 	if (session_sleep)
4593 		atomic_set(&sess->sleep_on_sess_wait_comp, 1);
4594 
4595 	if (connection_sleep) {
4596 		list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
4597 				conn_list) {
4598 			if (conn_count == 0)
4599 				break;
4600 
4601 			if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
4602 				is_last = 1;
4603 			} else {
4604 				iscsit_inc_conn_usage_count(conn_tmp);
4605 				is_last = 0;
4606 			}
4607 			iscsit_inc_conn_usage_count(conn);
4608 
4609 			spin_unlock_bh(&sess->conn_lock);
4610 			iscsit_cause_connection_reinstatement(conn, 1);
4611 			spin_lock_bh(&sess->conn_lock);
4612 
4613 			iscsit_dec_conn_usage_count(conn);
4614 			if (is_last == 0)
4615 				iscsit_dec_conn_usage_count(conn_tmp);
4616 			conn_count--;
4617 		}
4618 	} else {
4619 		list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
4620 			iscsit_cause_connection_reinstatement(conn, 0);
4621 	}
4622 
4623 	if (session_sleep && atomic_read(&sess->nconn)) {
4624 		spin_unlock_bh(&sess->conn_lock);
4625 		wait_for_completion(&sess->session_wait_comp);
4626 	} else
4627 		spin_unlock_bh(&sess->conn_lock);
4628 }
4629 
4630 int iscsit_release_sessions_for_tpg(struct iscsi_portal_group *tpg, int force)
4631 {
4632 	struct iscsi_session *sess;
4633 	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
4634 	struct se_session *se_sess, *se_sess_tmp;
4635 	LIST_HEAD(free_list);
4636 	int session_count = 0;
4637 
4638 	spin_lock_bh(&se_tpg->session_lock);
4639 	if (tpg->nsessions && !force) {
4640 		spin_unlock_bh(&se_tpg->session_lock);
4641 		return -1;
4642 	}
4643 
4644 	list_for_each_entry_safe(se_sess, se_sess_tmp, &se_tpg->tpg_sess_list,
4645 			sess_list) {
4646 		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
4647 
4648 		spin_lock(&sess->conn_lock);
4649 		if (atomic_read(&sess->session_fall_back_to_erl0) ||
4650 		    atomic_read(&sess->session_logout) ||
4651 		    (sess->time2retain_timer_flags & ISCSI_TF_EXPIRED)) {
4652 			spin_unlock(&sess->conn_lock);
4653 			continue;
4654 		}
4655 		atomic_set(&sess->session_reinstatement, 1);
4656 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4657 		spin_unlock(&sess->conn_lock);
4658 
4659 		list_move_tail(&se_sess->sess_list, &free_list);
4660 	}
4661 	spin_unlock_bh(&se_tpg->session_lock);
4662 
4663 	list_for_each_entry_safe(se_sess, se_sess_tmp, &free_list, sess_list) {
4664 		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
4665 
4666 		iscsit_free_session(sess);
4667 		session_count++;
4668 	}
4669 
4670 	pr_debug("Released %d iSCSI Session(s) from Target Portal"
4671 			" Group: %hu\n", session_count, tpg->tpgt);
4672 	return 0;
4673 }
4674 
4675 MODULE_DESCRIPTION("iSCSI-Target Driver for mainline target infrastructure");
4676 MODULE_VERSION("4.1.x");
4677 MODULE_AUTHOR("nab@Linux-iSCSI.org");
4678 MODULE_LICENSE("GPL");
4679 
4680 module_init(iscsi_target_init_module);
4681 module_exit(iscsi_target_cleanup_module);
4682