xref: /linux/drivers/target/iscsi/iscsi_target.c (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
1 /*******************************************************************************
2  * This file contains main functions related to the iSCSI Target Core Driver.
3  *
4  * (c) Copyright 2007-2013 Datera, Inc.
5  *
6  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  ******************************************************************************/
18 
19 #include <crypto/hash.h>
20 #include <linux/string.h>
21 #include <linux/kthread.h>
22 #include <linux/completion.h>
23 #include <linux/module.h>
24 #include <linux/vmalloc.h>
25 #include <linux/idr.h>
26 #include <linux/delay.h>
27 #include <linux/sched/signal.h>
28 #include <asm/unaligned.h>
29 #include <net/ipv6.h>
30 #include <scsi/scsi_proto.h>
31 #include <scsi/iscsi_proto.h>
32 #include <scsi/scsi_tcq.h>
33 #include <target/target_core_base.h>
34 #include <target/target_core_fabric.h>
35 
36 #include <target/iscsi/iscsi_target_core.h>
37 #include "iscsi_target_parameters.h"
38 #include "iscsi_target_seq_pdu_list.h"
39 #include "iscsi_target_datain_values.h"
40 #include "iscsi_target_erl0.h"
41 #include "iscsi_target_erl1.h"
42 #include "iscsi_target_erl2.h"
43 #include "iscsi_target_login.h"
44 #include "iscsi_target_tmr.h"
45 #include "iscsi_target_tpg.h"
46 #include "iscsi_target_util.h"
47 #include "iscsi_target.h"
48 #include "iscsi_target_device.h"
49 #include <target/iscsi/iscsi_target_stat.h>
50 
51 #include <target/iscsi/iscsi_transport.h>
52 
53 static LIST_HEAD(g_tiqn_list);
54 static LIST_HEAD(g_np_list);
55 static DEFINE_SPINLOCK(tiqn_lock);
56 static DEFINE_MUTEX(np_lock);
57 
58 static struct idr tiqn_idr;
59 struct idr sess_idr;
60 struct mutex auth_id_lock;
61 spinlock_t sess_idr_lock;
62 
63 struct iscsit_global *iscsit_global;
64 
65 struct kmem_cache *lio_qr_cache;
66 struct kmem_cache *lio_dr_cache;
67 struct kmem_cache *lio_ooo_cache;
68 struct kmem_cache *lio_r2t_cache;
69 
70 static int iscsit_handle_immediate_data(struct iscsi_cmd *,
71 			struct iscsi_scsi_req *, u32);
72 
73 struct iscsi_tiqn *iscsit_get_tiqn_for_login(unsigned char *buf)
74 {
75 	struct iscsi_tiqn *tiqn = NULL;
76 
77 	spin_lock(&tiqn_lock);
78 	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
79 		if (!strcmp(tiqn->tiqn, buf)) {
80 
81 			spin_lock(&tiqn->tiqn_state_lock);
82 			if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
83 				tiqn->tiqn_access_count++;
84 				spin_unlock(&tiqn->tiqn_state_lock);
85 				spin_unlock(&tiqn_lock);
86 				return tiqn;
87 			}
88 			spin_unlock(&tiqn->tiqn_state_lock);
89 		}
90 	}
91 	spin_unlock(&tiqn_lock);
92 
93 	return NULL;
94 }
95 
96 static int iscsit_set_tiqn_shutdown(struct iscsi_tiqn *tiqn)
97 {
98 	spin_lock(&tiqn->tiqn_state_lock);
99 	if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
100 		tiqn->tiqn_state = TIQN_STATE_SHUTDOWN;
101 		spin_unlock(&tiqn->tiqn_state_lock);
102 		return 0;
103 	}
104 	spin_unlock(&tiqn->tiqn_state_lock);
105 
106 	return -1;
107 }
108 
109 void iscsit_put_tiqn_for_login(struct iscsi_tiqn *tiqn)
110 {
111 	spin_lock(&tiqn->tiqn_state_lock);
112 	tiqn->tiqn_access_count--;
113 	spin_unlock(&tiqn->tiqn_state_lock);
114 }
115 
116 /*
117  * Note that IQN formatting is expected to be done in userspace, and
118  * no explict IQN format checks are done here.
119  */
120 struct iscsi_tiqn *iscsit_add_tiqn(unsigned char *buf)
121 {
122 	struct iscsi_tiqn *tiqn = NULL;
123 	int ret;
124 
125 	if (strlen(buf) >= ISCSI_IQN_LEN) {
126 		pr_err("Target IQN exceeds %d bytes\n",
127 				ISCSI_IQN_LEN);
128 		return ERR_PTR(-EINVAL);
129 	}
130 
131 	tiqn = kzalloc(sizeof(*tiqn), GFP_KERNEL);
132 	if (!tiqn)
133 		return ERR_PTR(-ENOMEM);
134 
135 	sprintf(tiqn->tiqn, "%s", buf);
136 	INIT_LIST_HEAD(&tiqn->tiqn_list);
137 	INIT_LIST_HEAD(&tiqn->tiqn_tpg_list);
138 	spin_lock_init(&tiqn->tiqn_state_lock);
139 	spin_lock_init(&tiqn->tiqn_tpg_lock);
140 	spin_lock_init(&tiqn->sess_err_stats.lock);
141 	spin_lock_init(&tiqn->login_stats.lock);
142 	spin_lock_init(&tiqn->logout_stats.lock);
143 
144 	tiqn->tiqn_state = TIQN_STATE_ACTIVE;
145 
146 	idr_preload(GFP_KERNEL);
147 	spin_lock(&tiqn_lock);
148 
149 	ret = idr_alloc(&tiqn_idr, NULL, 0, 0, GFP_NOWAIT);
150 	if (ret < 0) {
151 		pr_err("idr_alloc() failed for tiqn->tiqn_index\n");
152 		spin_unlock(&tiqn_lock);
153 		idr_preload_end();
154 		kfree(tiqn);
155 		return ERR_PTR(ret);
156 	}
157 	tiqn->tiqn_index = ret;
158 	list_add_tail(&tiqn->tiqn_list, &g_tiqn_list);
159 
160 	spin_unlock(&tiqn_lock);
161 	idr_preload_end();
162 
163 	pr_debug("CORE[0] - Added iSCSI Target IQN: %s\n", tiqn->tiqn);
164 
165 	return tiqn;
166 
167 }
168 
169 static void iscsit_wait_for_tiqn(struct iscsi_tiqn *tiqn)
170 {
171 	/*
172 	 * Wait for accesses to said struct iscsi_tiqn to end.
173 	 */
174 	spin_lock(&tiqn->tiqn_state_lock);
175 	while (tiqn->tiqn_access_count != 0) {
176 		spin_unlock(&tiqn->tiqn_state_lock);
177 		msleep(10);
178 		spin_lock(&tiqn->tiqn_state_lock);
179 	}
180 	spin_unlock(&tiqn->tiqn_state_lock);
181 }
182 
183 void iscsit_del_tiqn(struct iscsi_tiqn *tiqn)
184 {
185 	/*
186 	 * iscsit_set_tiqn_shutdown sets tiqn->tiqn_state = TIQN_STATE_SHUTDOWN
187 	 * while holding tiqn->tiqn_state_lock.  This means that all subsequent
188 	 * attempts to access this struct iscsi_tiqn will fail from both transport
189 	 * fabric and control code paths.
190 	 */
191 	if (iscsit_set_tiqn_shutdown(tiqn) < 0) {
192 		pr_err("iscsit_set_tiqn_shutdown() failed\n");
193 		return;
194 	}
195 
196 	iscsit_wait_for_tiqn(tiqn);
197 
198 	spin_lock(&tiqn_lock);
199 	list_del(&tiqn->tiqn_list);
200 	idr_remove(&tiqn_idr, tiqn->tiqn_index);
201 	spin_unlock(&tiqn_lock);
202 
203 	pr_debug("CORE[0] - Deleted iSCSI Target IQN: %s\n",
204 			tiqn->tiqn);
205 	kfree(tiqn);
206 }
207 
208 int iscsit_access_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
209 {
210 	int ret;
211 	/*
212 	 * Determine if the network portal is accepting storage traffic.
213 	 */
214 	spin_lock_bh(&np->np_thread_lock);
215 	if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
216 		spin_unlock_bh(&np->np_thread_lock);
217 		return -1;
218 	}
219 	spin_unlock_bh(&np->np_thread_lock);
220 	/*
221 	 * Determine if the portal group is accepting storage traffic.
222 	 */
223 	spin_lock_bh(&tpg->tpg_state_lock);
224 	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
225 		spin_unlock_bh(&tpg->tpg_state_lock);
226 		return -1;
227 	}
228 	spin_unlock_bh(&tpg->tpg_state_lock);
229 
230 	/*
231 	 * Here we serialize access across the TIQN+TPG Tuple.
232 	 */
233 	ret = down_interruptible(&tpg->np_login_sem);
234 	if (ret != 0)
235 		return -1;
236 
237 	spin_lock_bh(&tpg->tpg_state_lock);
238 	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
239 		spin_unlock_bh(&tpg->tpg_state_lock);
240 		up(&tpg->np_login_sem);
241 		return -1;
242 	}
243 	spin_unlock_bh(&tpg->tpg_state_lock);
244 
245 	return 0;
246 }
247 
248 void iscsit_login_kref_put(struct kref *kref)
249 {
250 	struct iscsi_tpg_np *tpg_np = container_of(kref,
251 				struct iscsi_tpg_np, tpg_np_kref);
252 
253 	complete(&tpg_np->tpg_np_comp);
254 }
255 
256 int iscsit_deaccess_np(struct iscsi_np *np, struct iscsi_portal_group *tpg,
257 		       struct iscsi_tpg_np *tpg_np)
258 {
259 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
260 
261 	up(&tpg->np_login_sem);
262 
263 	if (tpg_np)
264 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
265 
266 	if (tiqn)
267 		iscsit_put_tiqn_for_login(tiqn);
268 
269 	return 0;
270 }
271 
272 bool iscsit_check_np_match(
273 	struct sockaddr_storage *sockaddr,
274 	struct iscsi_np *np,
275 	int network_transport)
276 {
277 	struct sockaddr_in *sock_in, *sock_in_e;
278 	struct sockaddr_in6 *sock_in6, *sock_in6_e;
279 	bool ip_match = false;
280 	u16 port, port_e;
281 
282 	if (sockaddr->ss_family == AF_INET6) {
283 		sock_in6 = (struct sockaddr_in6 *)sockaddr;
284 		sock_in6_e = (struct sockaddr_in6 *)&np->np_sockaddr;
285 
286 		if (!memcmp(&sock_in6->sin6_addr.in6_u,
287 			    &sock_in6_e->sin6_addr.in6_u,
288 			    sizeof(struct in6_addr)))
289 			ip_match = true;
290 
291 		port = ntohs(sock_in6->sin6_port);
292 		port_e = ntohs(sock_in6_e->sin6_port);
293 	} else {
294 		sock_in = (struct sockaddr_in *)sockaddr;
295 		sock_in_e = (struct sockaddr_in *)&np->np_sockaddr;
296 
297 		if (sock_in->sin_addr.s_addr == sock_in_e->sin_addr.s_addr)
298 			ip_match = true;
299 
300 		port = ntohs(sock_in->sin_port);
301 		port_e = ntohs(sock_in_e->sin_port);
302 	}
303 
304 	if (ip_match && (port_e == port) &&
305 	    (np->np_network_transport == network_transport))
306 		return true;
307 
308 	return false;
309 }
310 
311 /*
312  * Called with mutex np_lock held
313  */
314 static struct iscsi_np *iscsit_get_np(
315 	struct sockaddr_storage *sockaddr,
316 	int network_transport)
317 {
318 	struct iscsi_np *np;
319 	bool match;
320 
321 	list_for_each_entry(np, &g_np_list, np_list) {
322 		spin_lock_bh(&np->np_thread_lock);
323 		if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
324 			spin_unlock_bh(&np->np_thread_lock);
325 			continue;
326 		}
327 
328 		match = iscsit_check_np_match(sockaddr, np, network_transport);
329 		if (match) {
330 			/*
331 			 * Increment the np_exports reference count now to
332 			 * prevent iscsit_del_np() below from being called
333 			 * while iscsi_tpg_add_network_portal() is called.
334 			 */
335 			np->np_exports++;
336 			spin_unlock_bh(&np->np_thread_lock);
337 			return np;
338 		}
339 		spin_unlock_bh(&np->np_thread_lock);
340 	}
341 
342 	return NULL;
343 }
344 
345 struct iscsi_np *iscsit_add_np(
346 	struct sockaddr_storage *sockaddr,
347 	int network_transport)
348 {
349 	struct iscsi_np *np;
350 	int ret;
351 
352 	mutex_lock(&np_lock);
353 
354 	/*
355 	 * Locate the existing struct iscsi_np if already active..
356 	 */
357 	np = iscsit_get_np(sockaddr, network_transport);
358 	if (np) {
359 		mutex_unlock(&np_lock);
360 		return np;
361 	}
362 
363 	np = kzalloc(sizeof(*np), GFP_KERNEL);
364 	if (!np) {
365 		mutex_unlock(&np_lock);
366 		return ERR_PTR(-ENOMEM);
367 	}
368 
369 	np->np_flags |= NPF_IP_NETWORK;
370 	np->np_network_transport = network_transport;
371 	spin_lock_init(&np->np_thread_lock);
372 	init_completion(&np->np_restart_comp);
373 	INIT_LIST_HEAD(&np->np_list);
374 
375 	ret = iscsi_target_setup_login_socket(np, sockaddr);
376 	if (ret != 0) {
377 		kfree(np);
378 		mutex_unlock(&np_lock);
379 		return ERR_PTR(ret);
380 	}
381 
382 	np->np_thread = kthread_run(iscsi_target_login_thread, np, "iscsi_np");
383 	if (IS_ERR(np->np_thread)) {
384 		pr_err("Unable to create kthread: iscsi_np\n");
385 		ret = PTR_ERR(np->np_thread);
386 		kfree(np);
387 		mutex_unlock(&np_lock);
388 		return ERR_PTR(ret);
389 	}
390 	/*
391 	 * Increment the np_exports reference count now to prevent
392 	 * iscsit_del_np() below from being run while a new call to
393 	 * iscsi_tpg_add_network_portal() for a matching iscsi_np is
394 	 * active.  We don't need to hold np->np_thread_lock at this
395 	 * point because iscsi_np has not been added to g_np_list yet.
396 	 */
397 	np->np_exports = 1;
398 	np->np_thread_state = ISCSI_NP_THREAD_ACTIVE;
399 
400 	list_add_tail(&np->np_list, &g_np_list);
401 	mutex_unlock(&np_lock);
402 
403 	pr_debug("CORE[0] - Added Network Portal: %pISpc on %s\n",
404 		&np->np_sockaddr, np->np_transport->name);
405 
406 	return np;
407 }
408 
409 int iscsit_reset_np_thread(
410 	struct iscsi_np *np,
411 	struct iscsi_tpg_np *tpg_np,
412 	struct iscsi_portal_group *tpg,
413 	bool shutdown)
414 {
415 	spin_lock_bh(&np->np_thread_lock);
416 	if (np->np_thread_state == ISCSI_NP_THREAD_INACTIVE) {
417 		spin_unlock_bh(&np->np_thread_lock);
418 		return 0;
419 	}
420 	np->np_thread_state = ISCSI_NP_THREAD_RESET;
421 
422 	if (np->np_thread) {
423 		spin_unlock_bh(&np->np_thread_lock);
424 		send_sig(SIGINT, np->np_thread, 1);
425 		wait_for_completion(&np->np_restart_comp);
426 		spin_lock_bh(&np->np_thread_lock);
427 	}
428 	spin_unlock_bh(&np->np_thread_lock);
429 
430 	if (tpg_np && shutdown) {
431 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
432 
433 		wait_for_completion(&tpg_np->tpg_np_comp);
434 	}
435 
436 	return 0;
437 }
438 
439 static void iscsit_free_np(struct iscsi_np *np)
440 {
441 	if (np->np_socket)
442 		sock_release(np->np_socket);
443 }
444 
445 int iscsit_del_np(struct iscsi_np *np)
446 {
447 	spin_lock_bh(&np->np_thread_lock);
448 	np->np_exports--;
449 	if (np->np_exports) {
450 		np->enabled = true;
451 		spin_unlock_bh(&np->np_thread_lock);
452 		return 0;
453 	}
454 	np->np_thread_state = ISCSI_NP_THREAD_SHUTDOWN;
455 	spin_unlock_bh(&np->np_thread_lock);
456 
457 	if (np->np_thread) {
458 		/*
459 		 * We need to send the signal to wakeup Linux/Net
460 		 * which may be sleeping in sock_accept()..
461 		 */
462 		send_sig(SIGINT, np->np_thread, 1);
463 		kthread_stop(np->np_thread);
464 		np->np_thread = NULL;
465 	}
466 
467 	np->np_transport->iscsit_free_np(np);
468 
469 	mutex_lock(&np_lock);
470 	list_del(&np->np_list);
471 	mutex_unlock(&np_lock);
472 
473 	pr_debug("CORE[0] - Removed Network Portal: %pISpc on %s\n",
474 		&np->np_sockaddr, np->np_transport->name);
475 
476 	iscsit_put_transport(np->np_transport);
477 	kfree(np);
478 	return 0;
479 }
480 
481 static void iscsit_get_rx_pdu(struct iscsi_conn *);
482 
483 int iscsit_queue_rsp(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
484 {
485 	return iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
486 }
487 EXPORT_SYMBOL(iscsit_queue_rsp);
488 
489 void iscsit_aborted_task(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
490 {
491 	bool scsi_cmd = (cmd->iscsi_opcode == ISCSI_OP_SCSI_CMD);
492 
493 	spin_lock_bh(&conn->cmd_lock);
494 	if (!list_empty(&cmd->i_conn_node) &&
495 	    !(cmd->se_cmd.transport_state & CMD_T_FABRIC_STOP))
496 		list_del_init(&cmd->i_conn_node);
497 	spin_unlock_bh(&conn->cmd_lock);
498 
499 	__iscsit_free_cmd(cmd, scsi_cmd, true);
500 }
501 EXPORT_SYMBOL(iscsit_aborted_task);
502 
503 static void iscsit_do_crypto_hash_buf(struct ahash_request *, const void *,
504 				      u32, u32, u8 *, u8 *);
505 static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *);
506 
507 static int
508 iscsit_xmit_nondatain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
509 			  const void *data_buf, u32 data_buf_len)
510 {
511 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)cmd->pdu;
512 	struct kvec *iov;
513 	u32 niov = 0, tx_size = ISCSI_HDR_LEN;
514 	int ret;
515 
516 	iov = &cmd->iov_misc[0];
517 	iov[niov].iov_base	= cmd->pdu;
518 	iov[niov++].iov_len	= ISCSI_HDR_LEN;
519 
520 	if (conn->conn_ops->HeaderDigest) {
521 		u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];
522 
523 		iscsit_do_crypto_hash_buf(conn->conn_tx_hash, hdr,
524 					  ISCSI_HDR_LEN, 0, NULL,
525 					  (u8 *)header_digest);
526 
527 		iov[0].iov_len += ISCSI_CRC_LEN;
528 		tx_size += ISCSI_CRC_LEN;
529 		pr_debug("Attaching CRC32C HeaderDigest"
530 			 " to opcode 0x%x 0x%08x\n",
531 			 hdr->opcode, *header_digest);
532 	}
533 
534 	if (data_buf_len) {
535 		u32 padding = ((-data_buf_len) & 3);
536 
537 		iov[niov].iov_base	= (void *)data_buf;
538 		iov[niov++].iov_len	= data_buf_len;
539 		tx_size += data_buf_len;
540 
541 		if (padding != 0) {
542 			iov[niov].iov_base = &cmd->pad_bytes;
543 			iov[niov++].iov_len = padding;
544 			tx_size += padding;
545 			pr_debug("Attaching %u additional"
546 				 " padding bytes.\n", padding);
547 		}
548 
549 		if (conn->conn_ops->DataDigest) {
550 			iscsit_do_crypto_hash_buf(conn->conn_tx_hash,
551 						  data_buf, data_buf_len,
552 						  padding,
553 						  (u8 *)&cmd->pad_bytes,
554 						  (u8 *)&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 					  (u8 *)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 	spin_lock_init(&sess_idr_lock);
703 	idr_init(&tiqn_idr);
704 	idr_init(&sess_idr);
705 
706 	ret = target_register_template(&iscsi_ops);
707 	if (ret)
708 		goto out;
709 
710 	size = BITS_TO_LONGS(ISCSIT_BITMAP_BITS) * sizeof(long);
711 	iscsit_global->ts_bitmap = vzalloc(size);
712 	if (!iscsit_global->ts_bitmap)
713 		goto configfs_out;
714 
715 	lio_qr_cache = kmem_cache_create("lio_qr_cache",
716 			sizeof(struct iscsi_queue_req),
717 			__alignof__(struct iscsi_queue_req), 0, NULL);
718 	if (!lio_qr_cache) {
719 		pr_err("nable to kmem_cache_create() for"
720 				" lio_qr_cache\n");
721 		goto bitmap_out;
722 	}
723 
724 	lio_dr_cache = kmem_cache_create("lio_dr_cache",
725 			sizeof(struct iscsi_datain_req),
726 			__alignof__(struct iscsi_datain_req), 0, NULL);
727 	if (!lio_dr_cache) {
728 		pr_err("Unable to kmem_cache_create() for"
729 				" lio_dr_cache\n");
730 		goto qr_out;
731 	}
732 
733 	lio_ooo_cache = kmem_cache_create("lio_ooo_cache",
734 			sizeof(struct iscsi_ooo_cmdsn),
735 			__alignof__(struct iscsi_ooo_cmdsn), 0, NULL);
736 	if (!lio_ooo_cache) {
737 		pr_err("Unable to kmem_cache_create() for"
738 				" lio_ooo_cache\n");
739 		goto dr_out;
740 	}
741 
742 	lio_r2t_cache = kmem_cache_create("lio_r2t_cache",
743 			sizeof(struct iscsi_r2t), __alignof__(struct iscsi_r2t),
744 			0, NULL);
745 	if (!lio_r2t_cache) {
746 		pr_err("Unable to kmem_cache_create() for"
747 				" lio_r2t_cache\n");
748 		goto ooo_out;
749 	}
750 
751 	iscsit_register_transport(&iscsi_target_transport);
752 
753 	if (iscsit_load_discovery_tpg() < 0)
754 		goto r2t_out;
755 
756 	return ret;
757 r2t_out:
758 	iscsit_unregister_transport(&iscsi_target_transport);
759 	kmem_cache_destroy(lio_r2t_cache);
760 ooo_out:
761 	kmem_cache_destroy(lio_ooo_cache);
762 dr_out:
763 	kmem_cache_destroy(lio_dr_cache);
764 qr_out:
765 	kmem_cache_destroy(lio_qr_cache);
766 bitmap_out:
767 	vfree(iscsit_global->ts_bitmap);
768 configfs_out:
769 	/* XXX: this probably wants it to be it's own unwind step.. */
770 	if (iscsit_global->discovery_tpg)
771 		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
772 	target_unregister_template(&iscsi_ops);
773 out:
774 	kfree(iscsit_global);
775 	return -ENOMEM;
776 }
777 
778 static void __exit iscsi_target_cleanup_module(void)
779 {
780 	iscsit_release_discovery_tpg();
781 	iscsit_unregister_transport(&iscsi_target_transport);
782 	kmem_cache_destroy(lio_qr_cache);
783 	kmem_cache_destroy(lio_dr_cache);
784 	kmem_cache_destroy(lio_ooo_cache);
785 	kmem_cache_destroy(lio_r2t_cache);
786 
787 	/*
788 	 * Shutdown discovery sessions and disable discovery TPG
789 	 */
790 	if (iscsit_global->discovery_tpg)
791 		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
792 
793 	target_unregister_template(&iscsi_ops);
794 
795 	vfree(iscsit_global->ts_bitmap);
796 	kfree(iscsit_global);
797 }
798 
799 int iscsit_add_reject(
800 	struct iscsi_conn *conn,
801 	u8 reason,
802 	unsigned char *buf)
803 {
804 	struct iscsi_cmd *cmd;
805 
806 	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
807 	if (!cmd)
808 		return -1;
809 
810 	cmd->iscsi_opcode = ISCSI_OP_REJECT;
811 	cmd->reject_reason = reason;
812 
813 	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
814 	if (!cmd->buf_ptr) {
815 		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
816 		iscsit_free_cmd(cmd, false);
817 		return -1;
818 	}
819 
820 	spin_lock_bh(&conn->cmd_lock);
821 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
822 	spin_unlock_bh(&conn->cmd_lock);
823 
824 	cmd->i_state = ISTATE_SEND_REJECT;
825 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
826 
827 	return -1;
828 }
829 EXPORT_SYMBOL(iscsit_add_reject);
830 
831 static int iscsit_add_reject_from_cmd(
832 	struct iscsi_cmd *cmd,
833 	u8 reason,
834 	bool add_to_conn,
835 	unsigned char *buf)
836 {
837 	struct iscsi_conn *conn;
838 
839 	if (!cmd->conn) {
840 		pr_err("cmd->conn is NULL for ITT: 0x%08x\n",
841 				cmd->init_task_tag);
842 		return -1;
843 	}
844 	conn = cmd->conn;
845 
846 	cmd->iscsi_opcode = ISCSI_OP_REJECT;
847 	cmd->reject_reason = reason;
848 
849 	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
850 	if (!cmd->buf_ptr) {
851 		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
852 		iscsit_free_cmd(cmd, false);
853 		return -1;
854 	}
855 
856 	if (add_to_conn) {
857 		spin_lock_bh(&conn->cmd_lock);
858 		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
859 		spin_unlock_bh(&conn->cmd_lock);
860 	}
861 
862 	cmd->i_state = ISTATE_SEND_REJECT;
863 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
864 	/*
865 	 * Perform the kref_put now if se_cmd has already been setup by
866 	 * scsit_setup_scsi_cmd()
867 	 */
868 	if (cmd->se_cmd.se_tfo != NULL) {
869 		pr_debug("iscsi reject: calling target_put_sess_cmd >>>>>>\n");
870 		target_put_sess_cmd(&cmd->se_cmd);
871 	}
872 	return -1;
873 }
874 
875 static int iscsit_add_reject_cmd(struct iscsi_cmd *cmd, u8 reason,
876 				 unsigned char *buf)
877 {
878 	return iscsit_add_reject_from_cmd(cmd, reason, true, buf);
879 }
880 
881 int iscsit_reject_cmd(struct iscsi_cmd *cmd, u8 reason, unsigned char *buf)
882 {
883 	return iscsit_add_reject_from_cmd(cmd, reason, false, buf);
884 }
885 EXPORT_SYMBOL(iscsit_reject_cmd);
886 
887 /*
888  * Map some portion of the allocated scatterlist to an iovec, suitable for
889  * kernel sockets to copy data in/out.
890  */
891 static int iscsit_map_iovec(
892 	struct iscsi_cmd *cmd,
893 	struct kvec *iov,
894 	u32 data_offset,
895 	u32 data_length)
896 {
897 	u32 i = 0;
898 	struct scatterlist *sg;
899 	unsigned int page_off;
900 
901 	/*
902 	 * We know each entry in t_data_sg contains a page.
903 	 */
904 	u32 ent = data_offset / PAGE_SIZE;
905 
906 	if (ent >= cmd->se_cmd.t_data_nents) {
907 		pr_err("Initial page entry out-of-bounds\n");
908 		return -1;
909 	}
910 
911 	sg = &cmd->se_cmd.t_data_sg[ent];
912 	page_off = (data_offset % PAGE_SIZE);
913 
914 	cmd->first_data_sg = sg;
915 	cmd->first_data_sg_off = page_off;
916 
917 	while (data_length) {
918 		u32 cur_len = min_t(u32, data_length, sg->length - page_off);
919 
920 		iov[i].iov_base = kmap(sg_page(sg)) + sg->offset + page_off;
921 		iov[i].iov_len = cur_len;
922 
923 		data_length -= cur_len;
924 		page_off = 0;
925 		sg = sg_next(sg);
926 		i++;
927 	}
928 
929 	cmd->kmapped_nents = i;
930 
931 	return i;
932 }
933 
934 static void iscsit_unmap_iovec(struct iscsi_cmd *cmd)
935 {
936 	u32 i;
937 	struct scatterlist *sg;
938 
939 	sg = cmd->first_data_sg;
940 
941 	for (i = 0; i < cmd->kmapped_nents; i++)
942 		kunmap(sg_page(&sg[i]));
943 }
944 
945 static void iscsit_ack_from_expstatsn(struct iscsi_conn *conn, u32 exp_statsn)
946 {
947 	LIST_HEAD(ack_list);
948 	struct iscsi_cmd *cmd, *cmd_p;
949 
950 	conn->exp_statsn = exp_statsn;
951 
952 	if (conn->sess->sess_ops->RDMAExtensions)
953 		return;
954 
955 	spin_lock_bh(&conn->cmd_lock);
956 	list_for_each_entry_safe(cmd, cmd_p, &conn->conn_cmd_list, i_conn_node) {
957 		spin_lock(&cmd->istate_lock);
958 		if ((cmd->i_state == ISTATE_SENT_STATUS) &&
959 		    iscsi_sna_lt(cmd->stat_sn, exp_statsn)) {
960 			cmd->i_state = ISTATE_REMOVE;
961 			spin_unlock(&cmd->istate_lock);
962 			list_move_tail(&cmd->i_conn_node, &ack_list);
963 			continue;
964 		}
965 		spin_unlock(&cmd->istate_lock);
966 	}
967 	spin_unlock_bh(&conn->cmd_lock);
968 
969 	list_for_each_entry_safe(cmd, cmd_p, &ack_list, i_conn_node) {
970 		list_del_init(&cmd->i_conn_node);
971 		iscsit_free_cmd(cmd, false);
972 	}
973 }
974 
975 static int iscsit_allocate_iovecs(struct iscsi_cmd *cmd)
976 {
977 	u32 iov_count = max(1UL, DIV_ROUND_UP(cmd->se_cmd.data_length, PAGE_SIZE));
978 
979 	iov_count += ISCSI_IOV_DATA_BUFFER;
980 	cmd->iov_data = kcalloc(iov_count, sizeof(*cmd->iov_data), GFP_KERNEL);
981 	if (!cmd->iov_data)
982 		return -ENOMEM;
983 
984 	cmd->orig_iov_data_count = iov_count;
985 	return 0;
986 }
987 
988 int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
989 			  unsigned char *buf)
990 {
991 	int data_direction, payload_length;
992 	struct iscsi_scsi_req *hdr;
993 	int iscsi_task_attr;
994 	int sam_task_attr;
995 
996 	atomic_long_inc(&conn->sess->cmd_pdus);
997 
998 	hdr			= (struct iscsi_scsi_req *) buf;
999 	payload_length		= ntoh24(hdr->dlength);
1000 
1001 	/* FIXME; Add checks for AdditionalHeaderSegment */
1002 
1003 	if (!(hdr->flags & ISCSI_FLAG_CMD_WRITE) &&
1004 	    !(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
1005 		pr_err("ISCSI_FLAG_CMD_WRITE & ISCSI_FLAG_CMD_FINAL"
1006 				" not set. Bad iSCSI Initiator.\n");
1007 		return iscsit_add_reject_cmd(cmd,
1008 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1009 	}
1010 
1011 	if (((hdr->flags & ISCSI_FLAG_CMD_READ) ||
1012 	     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) && !hdr->data_length) {
1013 		/*
1014 		 * From RFC-3720 Section 10.3.1:
1015 		 *
1016 		 * "Either or both of R and W MAY be 1 when either the
1017 		 *  Expected Data Transfer Length and/or Bidirectional Read
1018 		 *  Expected Data Transfer Length are 0"
1019 		 *
1020 		 * For this case, go ahead and clear the unnecssary bits
1021 		 * to avoid any confusion with ->data_direction.
1022 		 */
1023 		hdr->flags &= ~ISCSI_FLAG_CMD_READ;
1024 		hdr->flags &= ~ISCSI_FLAG_CMD_WRITE;
1025 
1026 		pr_warn("ISCSI_FLAG_CMD_READ or ISCSI_FLAG_CMD_WRITE"
1027 			" set when Expected Data Transfer Length is 0 for"
1028 			" CDB: 0x%02x, Fixing up flags\n", hdr->cdb[0]);
1029 	}
1030 
1031 	if (!(hdr->flags & ISCSI_FLAG_CMD_READ) &&
1032 	    !(hdr->flags & ISCSI_FLAG_CMD_WRITE) && (hdr->data_length != 0)) {
1033 		pr_err("ISCSI_FLAG_CMD_READ and/or ISCSI_FLAG_CMD_WRITE"
1034 			" MUST be set if Expected Data Transfer Length is not 0."
1035 			" Bad iSCSI Initiator\n");
1036 		return iscsit_add_reject_cmd(cmd,
1037 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1038 	}
1039 
1040 	if ((hdr->flags & ISCSI_FLAG_CMD_READ) &&
1041 	    (hdr->flags & ISCSI_FLAG_CMD_WRITE)) {
1042 		pr_err("Bidirectional operations not supported!\n");
1043 		return iscsit_add_reject_cmd(cmd,
1044 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1045 	}
1046 
1047 	if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
1048 		pr_err("Illegally set Immediate Bit in iSCSI Initiator"
1049 				" Scsi Command PDU.\n");
1050 		return iscsit_add_reject_cmd(cmd,
1051 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1052 	}
1053 
1054 	if (payload_length && !conn->sess->sess_ops->ImmediateData) {
1055 		pr_err("ImmediateData=No but DataSegmentLength=%u,"
1056 			" protocol error.\n", payload_length);
1057 		return iscsit_add_reject_cmd(cmd,
1058 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1059 	}
1060 
1061 	if ((be32_to_cpu(hdr->data_length) == payload_length) &&
1062 	    (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))) {
1063 		pr_err("Expected Data Transfer Length and Length of"
1064 			" Immediate Data are the same, but ISCSI_FLAG_CMD_FINAL"
1065 			" bit is not set protocol error\n");
1066 		return iscsit_add_reject_cmd(cmd,
1067 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1068 	}
1069 
1070 	if (payload_length > be32_to_cpu(hdr->data_length)) {
1071 		pr_err("DataSegmentLength: %u is greater than"
1072 			" EDTL: %u, protocol error.\n", payload_length,
1073 				hdr->data_length);
1074 		return iscsit_add_reject_cmd(cmd,
1075 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1076 	}
1077 
1078 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1079 		pr_err("DataSegmentLength: %u is greater than"
1080 			" MaxXmitDataSegmentLength: %u, protocol error.\n",
1081 			payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
1082 		return iscsit_add_reject_cmd(cmd,
1083 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1084 	}
1085 
1086 	if (payload_length > conn->sess->sess_ops->FirstBurstLength) {
1087 		pr_err("DataSegmentLength: %u is greater than"
1088 			" FirstBurstLength: %u, protocol error.\n",
1089 			payload_length, conn->sess->sess_ops->FirstBurstLength);
1090 		return iscsit_add_reject_cmd(cmd,
1091 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1092 	}
1093 
1094 	data_direction = (hdr->flags & ISCSI_FLAG_CMD_WRITE) ? DMA_TO_DEVICE :
1095 			 (hdr->flags & ISCSI_FLAG_CMD_READ) ? DMA_FROM_DEVICE :
1096 			  DMA_NONE;
1097 
1098 	cmd->data_direction = data_direction;
1099 	iscsi_task_attr = hdr->flags & ISCSI_FLAG_CMD_ATTR_MASK;
1100 	/*
1101 	 * Figure out the SAM Task Attribute for the incoming SCSI CDB
1102 	 */
1103 	if ((iscsi_task_attr == ISCSI_ATTR_UNTAGGED) ||
1104 	    (iscsi_task_attr == ISCSI_ATTR_SIMPLE))
1105 		sam_task_attr = TCM_SIMPLE_TAG;
1106 	else if (iscsi_task_attr == ISCSI_ATTR_ORDERED)
1107 		sam_task_attr = TCM_ORDERED_TAG;
1108 	else if (iscsi_task_attr == ISCSI_ATTR_HEAD_OF_QUEUE)
1109 		sam_task_attr = TCM_HEAD_TAG;
1110 	else if (iscsi_task_attr == ISCSI_ATTR_ACA)
1111 		sam_task_attr = TCM_ACA_TAG;
1112 	else {
1113 		pr_debug("Unknown iSCSI Task Attribute: 0x%02x, using"
1114 			" TCM_SIMPLE_TAG\n", iscsi_task_attr);
1115 		sam_task_attr = TCM_SIMPLE_TAG;
1116 	}
1117 
1118 	cmd->iscsi_opcode	= ISCSI_OP_SCSI_CMD;
1119 	cmd->i_state		= ISTATE_NEW_CMD;
1120 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
1121 	cmd->immediate_data	= (payload_length) ? 1 : 0;
1122 	cmd->unsolicited_data	= ((!(hdr->flags & ISCSI_FLAG_CMD_FINAL) &&
1123 				     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) ? 1 : 0);
1124 	if (cmd->unsolicited_data)
1125 		cmd->cmd_flags |= ICF_NON_IMMEDIATE_UNSOLICITED_DATA;
1126 
1127 	conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
1128 	if (hdr->flags & ISCSI_FLAG_CMD_READ)
1129 		cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
1130 	else
1131 		cmd->targ_xfer_tag = 0xFFFFFFFF;
1132 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
1133 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
1134 	cmd->first_burst_len	= payload_length;
1135 
1136 	if (!conn->sess->sess_ops->RDMAExtensions &&
1137 	     cmd->data_direction == DMA_FROM_DEVICE) {
1138 		struct iscsi_datain_req *dr;
1139 
1140 		dr = iscsit_allocate_datain_req();
1141 		if (!dr)
1142 			return iscsit_add_reject_cmd(cmd,
1143 					ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1144 
1145 		iscsit_attach_datain_req(cmd, dr);
1146 	}
1147 
1148 	/*
1149 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
1150 	 */
1151 	transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
1152 			conn->sess->se_sess, be32_to_cpu(hdr->data_length),
1153 			cmd->data_direction, sam_task_attr,
1154 			cmd->sense_buffer + 2);
1155 
1156 	pr_debug("Got SCSI Command, ITT: 0x%08x, CmdSN: 0x%08x,"
1157 		" ExpXferLen: %u, Length: %u, CID: %hu\n", hdr->itt,
1158 		hdr->cmdsn, be32_to_cpu(hdr->data_length), payload_length,
1159 		conn->cid);
1160 
1161 	target_get_sess_cmd(&cmd->se_cmd, true);
1162 
1163 	cmd->sense_reason = transport_lookup_cmd_lun(&cmd->se_cmd,
1164 						     scsilun_to_int(&hdr->lun));
1165 	if (cmd->sense_reason)
1166 		goto attach_cmd;
1167 
1168 	/* only used for printks or comparing with ->ref_task_tag */
1169 	cmd->se_cmd.tag = (__force u32)cmd->init_task_tag;
1170 	cmd->sense_reason = target_setup_cmd_from_cdb(&cmd->se_cmd, hdr->cdb);
1171 	if (cmd->sense_reason) {
1172 		if (cmd->sense_reason == TCM_OUT_OF_RESOURCES) {
1173 			return iscsit_add_reject_cmd(cmd,
1174 					ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1175 		}
1176 
1177 		goto attach_cmd;
1178 	}
1179 
1180 	if (iscsit_build_pdu_and_seq_lists(cmd, payload_length) < 0) {
1181 		return iscsit_add_reject_cmd(cmd,
1182 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1183 	}
1184 
1185 attach_cmd:
1186 	spin_lock_bh(&conn->cmd_lock);
1187 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
1188 	spin_unlock_bh(&conn->cmd_lock);
1189 	/*
1190 	 * Check if we need to delay processing because of ALUA
1191 	 * Active/NonOptimized primary access state..
1192 	 */
1193 	core_alua_check_nonop_delay(&cmd->se_cmd);
1194 
1195 	return 0;
1196 }
1197 EXPORT_SYMBOL(iscsit_setup_scsi_cmd);
1198 
1199 void iscsit_set_unsoliticed_dataout(struct iscsi_cmd *cmd)
1200 {
1201 	iscsit_set_dataout_sequence_values(cmd);
1202 
1203 	spin_lock_bh(&cmd->dataout_timeout_lock);
1204 	iscsit_start_dataout_timer(cmd, cmd->conn);
1205 	spin_unlock_bh(&cmd->dataout_timeout_lock);
1206 }
1207 EXPORT_SYMBOL(iscsit_set_unsoliticed_dataout);
1208 
1209 int iscsit_process_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1210 			    struct iscsi_scsi_req *hdr)
1211 {
1212 	int cmdsn_ret = 0;
1213 	/*
1214 	 * Check the CmdSN against ExpCmdSN/MaxCmdSN here if
1215 	 * the Immediate Bit is not set, and no Immediate
1216 	 * Data is attached.
1217 	 *
1218 	 * A PDU/CmdSN carrying Immediate Data can only
1219 	 * be processed after the DataCRC has passed.
1220 	 * If the DataCRC fails, the CmdSN MUST NOT
1221 	 * be acknowledged. (See below)
1222 	 */
1223 	if (!cmd->immediate_data) {
1224 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
1225 					(unsigned char *)hdr, hdr->cmdsn);
1226 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1227 			return -1;
1228 		else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
1229 			target_put_sess_cmd(&cmd->se_cmd);
1230 			return 0;
1231 		}
1232 	}
1233 
1234 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
1235 
1236 	/*
1237 	 * If no Immediate Data is attached, it's OK to return now.
1238 	 */
1239 	if (!cmd->immediate_data) {
1240 		if (!cmd->sense_reason && cmd->unsolicited_data)
1241 			iscsit_set_unsoliticed_dataout(cmd);
1242 		if (!cmd->sense_reason)
1243 			return 0;
1244 
1245 		target_put_sess_cmd(&cmd->se_cmd);
1246 		return 0;
1247 	}
1248 
1249 	/*
1250 	 * Early CHECK_CONDITIONs with ImmediateData never make it to command
1251 	 * execution.  These exceptions are processed in CmdSN order using
1252 	 * iscsit_check_received_cmdsn() in iscsit_get_immediate_data() below.
1253 	 */
1254 	if (cmd->sense_reason) {
1255 		if (cmd->reject_reason)
1256 			return 0;
1257 
1258 		return 1;
1259 	}
1260 	/*
1261 	 * Call directly into transport_generic_new_cmd() to perform
1262 	 * the backend memory allocation.
1263 	 */
1264 	cmd->sense_reason = transport_generic_new_cmd(&cmd->se_cmd);
1265 	if (cmd->sense_reason)
1266 		return 1;
1267 
1268 	return 0;
1269 }
1270 EXPORT_SYMBOL(iscsit_process_scsi_cmd);
1271 
1272 static int
1273 iscsit_get_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
1274 			  bool dump_payload)
1275 {
1276 	int cmdsn_ret = 0, immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
1277 	/*
1278 	 * Special case for Unsupported SAM WRITE Opcodes and ImmediateData=Yes.
1279 	 */
1280 	if (dump_payload)
1281 		goto after_immediate_data;
1282 
1283 	immed_ret = iscsit_handle_immediate_data(cmd, hdr,
1284 					cmd->first_burst_len);
1285 after_immediate_data:
1286 	if (immed_ret == IMMEDIATE_DATA_NORMAL_OPERATION) {
1287 		/*
1288 		 * A PDU/CmdSN carrying Immediate Data passed
1289 		 * DataCRC, check against ExpCmdSN/MaxCmdSN if
1290 		 * Immediate Bit is not set.
1291 		 */
1292 		cmdsn_ret = iscsit_sequence_cmd(cmd->conn, cmd,
1293 					(unsigned char *)hdr, hdr->cmdsn);
1294 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1295 			return -1;
1296 
1297 		if (cmd->sense_reason || cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
1298 			int rc;
1299 
1300 			rc = iscsit_dump_data_payload(cmd->conn,
1301 						      cmd->first_burst_len, 1);
1302 			target_put_sess_cmd(&cmd->se_cmd);
1303 			return rc;
1304 		} else if (cmd->unsolicited_data)
1305 			iscsit_set_unsoliticed_dataout(cmd);
1306 
1307 	} else if (immed_ret == IMMEDIATE_DATA_ERL1_CRC_FAILURE) {
1308 		/*
1309 		 * Immediate Data failed DataCRC and ERL>=1,
1310 		 * silently drop this PDU and let the initiator
1311 		 * plug the CmdSN gap.
1312 		 *
1313 		 * FIXME: Send Unsolicited NOPIN with reserved
1314 		 * TTT here to help the initiator figure out
1315 		 * the missing CmdSN, although they should be
1316 		 * intelligent enough to determine the missing
1317 		 * CmdSN and issue a retry to plug the sequence.
1318 		 */
1319 		cmd->i_state = ISTATE_REMOVE;
1320 		iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, cmd->i_state);
1321 	} else /* immed_ret == IMMEDIATE_DATA_CANNOT_RECOVER */
1322 		return -1;
1323 
1324 	return 0;
1325 }
1326 
1327 static int
1328 iscsit_handle_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1329 			   unsigned char *buf)
1330 {
1331 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)buf;
1332 	int rc, immed_data;
1333 	bool dump_payload = false;
1334 
1335 	rc = iscsit_setup_scsi_cmd(conn, cmd, buf);
1336 	if (rc < 0)
1337 		return 0;
1338 	/*
1339 	 * Allocation iovecs needed for struct socket operations for
1340 	 * traditional iSCSI block I/O.
1341 	 */
1342 	if (iscsit_allocate_iovecs(cmd) < 0) {
1343 		return iscsit_reject_cmd(cmd,
1344 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1345 	}
1346 	immed_data = cmd->immediate_data;
1347 
1348 	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
1349 	if (rc < 0)
1350 		return rc;
1351 	else if (rc > 0)
1352 		dump_payload = true;
1353 
1354 	if (!immed_data)
1355 		return 0;
1356 
1357 	return iscsit_get_immediate_data(cmd, hdr, dump_payload);
1358 }
1359 
1360 static u32 iscsit_do_crypto_hash_sg(
1361 	struct ahash_request *hash,
1362 	struct iscsi_cmd *cmd,
1363 	u32 data_offset,
1364 	u32 data_length,
1365 	u32 padding,
1366 	u8 *pad_bytes)
1367 {
1368 	u32 data_crc;
1369 	struct scatterlist *sg;
1370 	unsigned int page_off;
1371 
1372 	crypto_ahash_init(hash);
1373 
1374 	sg = cmd->first_data_sg;
1375 	page_off = cmd->first_data_sg_off;
1376 
1377 	while (data_length) {
1378 		u32 cur_len = min_t(u32, data_length, (sg->length - page_off));
1379 
1380 		ahash_request_set_crypt(hash, sg, NULL, cur_len);
1381 		crypto_ahash_update(hash);
1382 
1383 		data_length -= cur_len;
1384 		page_off = 0;
1385 		/* iscsit_map_iovec has already checked for invalid sg pointers */
1386 		sg = sg_next(sg);
1387 	}
1388 
1389 	if (padding) {
1390 		struct scatterlist pad_sg;
1391 
1392 		sg_init_one(&pad_sg, pad_bytes, padding);
1393 		ahash_request_set_crypt(hash, &pad_sg, (u8 *)&data_crc,
1394 					padding);
1395 		crypto_ahash_finup(hash);
1396 	} else {
1397 		ahash_request_set_crypt(hash, NULL, (u8 *)&data_crc, 0);
1398 		crypto_ahash_final(hash);
1399 	}
1400 
1401 	return data_crc;
1402 }
1403 
1404 static void iscsit_do_crypto_hash_buf(
1405 	struct ahash_request *hash,
1406 	const void *buf,
1407 	u32 payload_length,
1408 	u32 padding,
1409 	u8 *pad_bytes,
1410 	u8 *data_crc)
1411 {
1412 	struct scatterlist sg[2];
1413 
1414 	sg_init_table(sg, ARRAY_SIZE(sg));
1415 	sg_set_buf(sg, buf, payload_length);
1416 	sg_set_buf(sg + 1, pad_bytes, padding);
1417 
1418 	ahash_request_set_crypt(hash, sg, data_crc, payload_length + padding);
1419 
1420 	crypto_ahash_digest(hash);
1421 }
1422 
1423 int
1424 __iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
1425 			   struct iscsi_cmd *cmd, u32 payload_length,
1426 			   bool *success)
1427 {
1428 	struct iscsi_data *hdr = buf;
1429 	struct se_cmd *se_cmd;
1430 	int rc;
1431 
1432 	/* iSCSI write */
1433 	atomic_long_add(payload_length, &conn->sess->rx_data_octets);
1434 
1435 	pr_debug("Got DataOut ITT: 0x%08x, TTT: 0x%08x,"
1436 		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
1437 		hdr->itt, hdr->ttt, hdr->datasn, ntohl(hdr->offset),
1438 		payload_length, conn->cid);
1439 
1440 	if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
1441 		pr_err("Command ITT: 0x%08x received DataOUT after"
1442 			" last DataOUT received, dumping payload\n",
1443 			cmd->init_task_tag);
1444 		return iscsit_dump_data_payload(conn, payload_length, 1);
1445 	}
1446 
1447 	if (cmd->data_direction != DMA_TO_DEVICE) {
1448 		pr_err("Command ITT: 0x%08x received DataOUT for a"
1449 			" NON-WRITE command.\n", cmd->init_task_tag);
1450 		return iscsit_dump_data_payload(conn, payload_length, 1);
1451 	}
1452 	se_cmd = &cmd->se_cmd;
1453 	iscsit_mod_dataout_timer(cmd);
1454 
1455 	if ((be32_to_cpu(hdr->offset) + payload_length) > cmd->se_cmd.data_length) {
1456 		pr_err("DataOut Offset: %u, Length %u greater than"
1457 			" iSCSI Command EDTL %u, protocol error.\n",
1458 			hdr->offset, payload_length, cmd->se_cmd.data_length);
1459 		return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_INVALID, buf);
1460 	}
1461 
1462 	if (cmd->unsolicited_data) {
1463 		int dump_unsolicited_data = 0;
1464 
1465 		if (conn->sess->sess_ops->InitialR2T) {
1466 			pr_err("Received unexpected unsolicited data"
1467 				" while InitialR2T=Yes, protocol error.\n");
1468 			transport_send_check_condition_and_sense(&cmd->se_cmd,
1469 					TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
1470 			return -1;
1471 		}
1472 		/*
1473 		 * Special case for dealing with Unsolicited DataOUT
1474 		 * and Unsupported SAM WRITE Opcodes and SE resource allocation
1475 		 * failures;
1476 		 */
1477 
1478 		/* Something's amiss if we're not in WRITE_PENDING state... */
1479 		WARN_ON(se_cmd->t_state != TRANSPORT_WRITE_PENDING);
1480 		if (!(se_cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE))
1481 			dump_unsolicited_data = 1;
1482 
1483 		if (dump_unsolicited_data) {
1484 			/*
1485 			 * Check if a delayed TASK_ABORTED status needs to
1486 			 * be sent now if the ISCSI_FLAG_CMD_FINAL has been
1487 			 * received with the unsolicited data out.
1488 			 */
1489 			if (hdr->flags & ISCSI_FLAG_CMD_FINAL)
1490 				iscsit_stop_dataout_timer(cmd);
1491 
1492 			transport_check_aborted_status(se_cmd,
1493 					(hdr->flags & ISCSI_FLAG_CMD_FINAL));
1494 			return iscsit_dump_data_payload(conn, payload_length, 1);
1495 		}
1496 	} else {
1497 		/*
1498 		 * For the normal solicited data path:
1499 		 *
1500 		 * Check for a delayed TASK_ABORTED status and dump any
1501 		 * incoming data out payload if one exists.  Also, when the
1502 		 * ISCSI_FLAG_CMD_FINAL is set to denote the end of the current
1503 		 * data out sequence, we decrement outstanding_r2ts.  Once
1504 		 * outstanding_r2ts reaches zero, go ahead and send the delayed
1505 		 * TASK_ABORTED status.
1506 		 */
1507 		if (se_cmd->transport_state & CMD_T_ABORTED) {
1508 			if (hdr->flags & ISCSI_FLAG_CMD_FINAL)
1509 				if (--cmd->outstanding_r2ts < 1) {
1510 					iscsit_stop_dataout_timer(cmd);
1511 					transport_check_aborted_status(
1512 							se_cmd, 1);
1513 				}
1514 
1515 			return iscsit_dump_data_payload(conn, payload_length, 1);
1516 		}
1517 	}
1518 	/*
1519 	 * Perform DataSN, DataSequenceInOrder, DataPDUInOrder, and
1520 	 * within-command recovery checks before receiving the payload.
1521 	 */
1522 	rc = iscsit_check_pre_dataout(cmd, buf);
1523 	if (rc == DATAOUT_WITHIN_COMMAND_RECOVERY)
1524 		return 0;
1525 	else if (rc == DATAOUT_CANNOT_RECOVER)
1526 		return -1;
1527 	*success = true;
1528 	return 0;
1529 }
1530 EXPORT_SYMBOL(__iscsit_check_dataout_hdr);
1531 
1532 int
1533 iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
1534 			 struct iscsi_cmd **out_cmd)
1535 {
1536 	struct iscsi_data *hdr = buf;
1537 	struct iscsi_cmd *cmd;
1538 	u32 payload_length = ntoh24(hdr->dlength);
1539 	int rc;
1540 	bool success = false;
1541 
1542 	if (!payload_length) {
1543 		pr_warn_ratelimited("DataOUT payload is ZERO, ignoring.\n");
1544 		return 0;
1545 	}
1546 
1547 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1548 		pr_err_ratelimited("DataSegmentLength: %u is greater than"
1549 			" MaxXmitDataSegmentLength: %u\n", payload_length,
1550 			conn->conn_ops->MaxXmitDataSegmentLength);
1551 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR, buf);
1552 	}
1553 
1554 	cmd = iscsit_find_cmd_from_itt_or_dump(conn, hdr->itt, payload_length);
1555 	if (!cmd)
1556 		return 0;
1557 
1558 	rc = __iscsit_check_dataout_hdr(conn, buf, cmd, payload_length, &success);
1559 
1560 	if (success)
1561 		*out_cmd = cmd;
1562 
1563 	return rc;
1564 }
1565 EXPORT_SYMBOL(iscsit_check_dataout_hdr);
1566 
1567 static int
1568 iscsit_get_dataout(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1569 		   struct iscsi_data *hdr)
1570 {
1571 	struct kvec *iov;
1572 	u32 checksum, iov_count = 0, padding = 0, rx_got = 0, rx_size = 0;
1573 	u32 payload_length = ntoh24(hdr->dlength);
1574 	int iov_ret, data_crc_failed = 0;
1575 
1576 	rx_size += payload_length;
1577 	iov = &cmd->iov_data[0];
1578 
1579 	iov_ret = iscsit_map_iovec(cmd, iov, be32_to_cpu(hdr->offset),
1580 				   payload_length);
1581 	if (iov_ret < 0)
1582 		return -1;
1583 
1584 	iov_count += iov_ret;
1585 
1586 	padding = ((-payload_length) & 3);
1587 	if (padding != 0) {
1588 		iov[iov_count].iov_base	= cmd->pad_bytes;
1589 		iov[iov_count++].iov_len = padding;
1590 		rx_size += padding;
1591 		pr_debug("Receiving %u padding bytes.\n", padding);
1592 	}
1593 
1594 	if (conn->conn_ops->DataDigest) {
1595 		iov[iov_count].iov_base = &checksum;
1596 		iov[iov_count++].iov_len = ISCSI_CRC_LEN;
1597 		rx_size += ISCSI_CRC_LEN;
1598 	}
1599 
1600 	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
1601 
1602 	iscsit_unmap_iovec(cmd);
1603 
1604 	if (rx_got != rx_size)
1605 		return -1;
1606 
1607 	if (conn->conn_ops->DataDigest) {
1608 		u32 data_crc;
1609 
1610 		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
1611 						    be32_to_cpu(hdr->offset),
1612 						    payload_length, padding,
1613 						    cmd->pad_bytes);
1614 
1615 		if (checksum != data_crc) {
1616 			pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
1617 				" DataSN: 0x%08x, CRC32C DataDigest 0x%08x"
1618 				" does not match computed 0x%08x\n",
1619 				hdr->itt, hdr->offset, payload_length,
1620 				hdr->datasn, checksum, data_crc);
1621 			data_crc_failed = 1;
1622 		} else {
1623 			pr_debug("Got CRC32C DataDigest 0x%08x for"
1624 				" %u bytes of Data Out\n", checksum,
1625 				payload_length);
1626 		}
1627 	}
1628 
1629 	return data_crc_failed;
1630 }
1631 
1632 int
1633 iscsit_check_dataout_payload(struct iscsi_cmd *cmd, struct iscsi_data *hdr,
1634 			     bool data_crc_failed)
1635 {
1636 	struct iscsi_conn *conn = cmd->conn;
1637 	int rc, ooo_cmdsn;
1638 	/*
1639 	 * Increment post receive data and CRC values or perform
1640 	 * within-command recovery.
1641 	 */
1642 	rc = iscsit_check_post_dataout(cmd, (unsigned char *)hdr, data_crc_failed);
1643 	if ((rc == DATAOUT_NORMAL) || (rc == DATAOUT_WITHIN_COMMAND_RECOVERY))
1644 		return 0;
1645 	else if (rc == DATAOUT_SEND_R2T) {
1646 		iscsit_set_dataout_sequence_values(cmd);
1647 		conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
1648 	} else if (rc == DATAOUT_SEND_TO_TRANSPORT) {
1649 		/*
1650 		 * Handle extra special case for out of order
1651 		 * Unsolicited Data Out.
1652 		 */
1653 		spin_lock_bh(&cmd->istate_lock);
1654 		ooo_cmdsn = (cmd->cmd_flags & ICF_OOO_CMDSN);
1655 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
1656 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
1657 		spin_unlock_bh(&cmd->istate_lock);
1658 
1659 		iscsit_stop_dataout_timer(cmd);
1660 		if (ooo_cmdsn)
1661 			return 0;
1662 		target_execute_cmd(&cmd->se_cmd);
1663 		return 0;
1664 	} else /* DATAOUT_CANNOT_RECOVER */
1665 		return -1;
1666 
1667 	return 0;
1668 }
1669 EXPORT_SYMBOL(iscsit_check_dataout_payload);
1670 
1671 static int iscsit_handle_data_out(struct iscsi_conn *conn, unsigned char *buf)
1672 {
1673 	struct iscsi_cmd *cmd = NULL;
1674 	struct iscsi_data *hdr = (struct iscsi_data *)buf;
1675 	int rc;
1676 	bool data_crc_failed = false;
1677 
1678 	rc = iscsit_check_dataout_hdr(conn, buf, &cmd);
1679 	if (rc < 0)
1680 		return 0;
1681 	else if (!cmd)
1682 		return 0;
1683 
1684 	rc = iscsit_get_dataout(conn, cmd, hdr);
1685 	if (rc < 0)
1686 		return rc;
1687 	else if (rc > 0)
1688 		data_crc_failed = true;
1689 
1690 	return iscsit_check_dataout_payload(cmd, hdr, data_crc_failed);
1691 }
1692 
1693 int iscsit_setup_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1694 			 struct iscsi_nopout *hdr)
1695 {
1696 	u32 payload_length = ntoh24(hdr->dlength);
1697 
1698 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
1699 		pr_err("NopOUT Flag's, Left Most Bit not set, protocol error.\n");
1700 		if (!cmd)
1701 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1702 						 (unsigned char *)hdr);
1703 
1704 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1705 					 (unsigned char *)hdr);
1706 	}
1707 
1708 	if (hdr->itt == RESERVED_ITT && !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
1709 		pr_err("NOPOUT ITT is reserved, but Immediate Bit is"
1710 			" not set, protocol error.\n");
1711 		if (!cmd)
1712 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1713 						 (unsigned char *)hdr);
1714 
1715 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1716 					 (unsigned char *)hdr);
1717 	}
1718 
1719 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1720 		pr_err("NOPOUT Ping Data DataSegmentLength: %u is"
1721 			" greater than MaxXmitDataSegmentLength: %u, protocol"
1722 			" error.\n", payload_length,
1723 			conn->conn_ops->MaxXmitDataSegmentLength);
1724 		if (!cmd)
1725 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1726 						 (unsigned char *)hdr);
1727 
1728 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1729 					 (unsigned char *)hdr);
1730 	}
1731 
1732 	pr_debug("Got NOPOUT Ping %s ITT: 0x%08x, TTT: 0x%08x,"
1733 		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, Length: %u\n",
1734 		hdr->itt == RESERVED_ITT ? "Response" : "Request",
1735 		hdr->itt, hdr->ttt, hdr->cmdsn, hdr->exp_statsn,
1736 		payload_length);
1737 	/*
1738 	 * This is not a response to a Unsolicited NopIN, which means
1739 	 * it can either be a NOPOUT ping request (with a valid ITT),
1740 	 * or a NOPOUT not requesting a NOPIN (with a reserved ITT).
1741 	 * Either way, make sure we allocate an struct iscsi_cmd, as both
1742 	 * can contain ping data.
1743 	 */
1744 	if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1745 		cmd->iscsi_opcode	= ISCSI_OP_NOOP_OUT;
1746 		cmd->i_state		= ISTATE_SEND_NOPIN;
1747 		cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ?
1748 						1 : 0);
1749 		conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
1750 		cmd->targ_xfer_tag	= 0xFFFFFFFF;
1751 		cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
1752 		cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
1753 		cmd->data_direction	= DMA_NONE;
1754 	}
1755 
1756 	return 0;
1757 }
1758 EXPORT_SYMBOL(iscsit_setup_nop_out);
1759 
1760 int iscsit_process_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1761 			   struct iscsi_nopout *hdr)
1762 {
1763 	struct iscsi_cmd *cmd_p = NULL;
1764 	int cmdsn_ret = 0;
1765 	/*
1766 	 * Initiator is expecting a NopIN ping reply..
1767 	 */
1768 	if (hdr->itt != RESERVED_ITT) {
1769 		if (!cmd)
1770 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1771 						(unsigned char *)hdr);
1772 
1773 		spin_lock_bh(&conn->cmd_lock);
1774 		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
1775 		spin_unlock_bh(&conn->cmd_lock);
1776 
1777 		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
1778 
1779 		if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
1780 			iscsit_add_cmd_to_response_queue(cmd, conn,
1781 							 cmd->i_state);
1782 			return 0;
1783 		}
1784 
1785 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
1786 				(unsigned char *)hdr, hdr->cmdsn);
1787                 if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
1788 			return 0;
1789 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1790 			return -1;
1791 
1792 		return 0;
1793 	}
1794 	/*
1795 	 * This was a response to a unsolicited NOPIN ping.
1796 	 */
1797 	if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
1798 		cmd_p = iscsit_find_cmd_from_ttt(conn, be32_to_cpu(hdr->ttt));
1799 		if (!cmd_p)
1800 			return -EINVAL;
1801 
1802 		iscsit_stop_nopin_response_timer(conn);
1803 
1804 		cmd_p->i_state = ISTATE_REMOVE;
1805 		iscsit_add_cmd_to_immediate_queue(cmd_p, conn, cmd_p->i_state);
1806 
1807 		iscsit_start_nopin_timer(conn);
1808 		return 0;
1809 	}
1810 	/*
1811 	 * Otherwise, initiator is not expecting a NOPIN is response.
1812 	 * Just ignore for now.
1813 	 */
1814 
1815 	if (cmd)
1816 		iscsit_free_cmd(cmd, false);
1817 
1818         return 0;
1819 }
1820 EXPORT_SYMBOL(iscsit_process_nop_out);
1821 
1822 static int iscsit_handle_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1823 				 unsigned char *buf)
1824 {
1825 	unsigned char *ping_data = NULL;
1826 	struct iscsi_nopout *hdr = (struct iscsi_nopout *)buf;
1827 	struct kvec *iov = NULL;
1828 	u32 payload_length = ntoh24(hdr->dlength);
1829 	int ret;
1830 
1831 	ret = iscsit_setup_nop_out(conn, cmd, hdr);
1832 	if (ret < 0)
1833 		return 0;
1834 	/*
1835 	 * Handle NOP-OUT payload for traditional iSCSI sockets
1836 	 */
1837 	if (payload_length && hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1838 		u32 checksum, data_crc, padding = 0;
1839 		int niov = 0, rx_got, rx_size = payload_length;
1840 
1841 		ping_data = kzalloc(payload_length + 1, GFP_KERNEL);
1842 		if (!ping_data) {
1843 			ret = -1;
1844 			goto out;
1845 		}
1846 
1847 		iov = &cmd->iov_misc[0];
1848 		iov[niov].iov_base	= ping_data;
1849 		iov[niov++].iov_len	= payload_length;
1850 
1851 		padding = ((-payload_length) & 3);
1852 		if (padding != 0) {
1853 			pr_debug("Receiving %u additional bytes"
1854 				" for padding.\n", padding);
1855 			iov[niov].iov_base	= &cmd->pad_bytes;
1856 			iov[niov++].iov_len	= padding;
1857 			rx_size += padding;
1858 		}
1859 		if (conn->conn_ops->DataDigest) {
1860 			iov[niov].iov_base	= &checksum;
1861 			iov[niov++].iov_len	= ISCSI_CRC_LEN;
1862 			rx_size += ISCSI_CRC_LEN;
1863 		}
1864 
1865 		rx_got = rx_data(conn, &cmd->iov_misc[0], niov, rx_size);
1866 		if (rx_got != rx_size) {
1867 			ret = -1;
1868 			goto out;
1869 		}
1870 
1871 		if (conn->conn_ops->DataDigest) {
1872 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash,
1873 					ping_data, payload_length,
1874 					padding, cmd->pad_bytes,
1875 					(u8 *)&data_crc);
1876 
1877 			if (checksum != data_crc) {
1878 				pr_err("Ping data CRC32C DataDigest"
1879 				" 0x%08x does not match computed 0x%08x\n",
1880 					checksum, data_crc);
1881 				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1882 					pr_err("Unable to recover from"
1883 					" NOPOUT Ping DataCRC failure while in"
1884 						" ERL=0.\n");
1885 					ret = -1;
1886 					goto out;
1887 				} else {
1888 					/*
1889 					 * Silently drop this PDU and let the
1890 					 * initiator plug the CmdSN gap.
1891 					 */
1892 					pr_debug("Dropping NOPOUT"
1893 					" Command CmdSN: 0x%08x due to"
1894 					" DataCRC error.\n", hdr->cmdsn);
1895 					ret = 0;
1896 					goto out;
1897 				}
1898 			} else {
1899 				pr_debug("Got CRC32C DataDigest"
1900 				" 0x%08x for %u bytes of ping data.\n",
1901 					checksum, payload_length);
1902 			}
1903 		}
1904 
1905 		ping_data[payload_length] = '\0';
1906 		/*
1907 		 * Attach ping data to struct iscsi_cmd->buf_ptr.
1908 		 */
1909 		cmd->buf_ptr = ping_data;
1910 		cmd->buf_ptr_size = payload_length;
1911 
1912 		pr_debug("Got %u bytes of NOPOUT ping"
1913 			" data.\n", payload_length);
1914 		pr_debug("Ping Data: \"%s\"\n", ping_data);
1915 	}
1916 
1917 	return iscsit_process_nop_out(conn, cmd, hdr);
1918 out:
1919 	if (cmd)
1920 		iscsit_free_cmd(cmd, false);
1921 
1922 	kfree(ping_data);
1923 	return ret;
1924 }
1925 
1926 static enum tcm_tmreq_table iscsit_convert_tmf(u8 iscsi_tmf)
1927 {
1928 	switch (iscsi_tmf) {
1929 	case ISCSI_TM_FUNC_ABORT_TASK:
1930 		return TMR_ABORT_TASK;
1931 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
1932 		return TMR_ABORT_TASK_SET;
1933 	case ISCSI_TM_FUNC_CLEAR_ACA:
1934 		return TMR_CLEAR_ACA;
1935 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
1936 		return TMR_CLEAR_TASK_SET;
1937 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
1938 		return TMR_LUN_RESET;
1939 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
1940 		return TMR_TARGET_WARM_RESET;
1941 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
1942 		return TMR_TARGET_COLD_RESET;
1943 	default:
1944 		return TMR_UNKNOWN;
1945 	}
1946 }
1947 
1948 int
1949 iscsit_handle_task_mgt_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1950 			   unsigned char *buf)
1951 {
1952 	struct se_tmr_req *se_tmr;
1953 	struct iscsi_tmr_req *tmr_req;
1954 	struct iscsi_tm *hdr;
1955 	int out_of_order_cmdsn = 0, ret;
1956 	bool sess_ref = false;
1957 	u8 function, tcm_function = TMR_UNKNOWN;
1958 
1959 	hdr			= (struct iscsi_tm *) buf;
1960 	hdr->flags &= ~ISCSI_FLAG_CMD_FINAL;
1961 	function = hdr->flags;
1962 
1963 	pr_debug("Got Task Management Request ITT: 0x%08x, CmdSN:"
1964 		" 0x%08x, Function: 0x%02x, RefTaskTag: 0x%08x, RefCmdSN:"
1965 		" 0x%08x, CID: %hu\n", hdr->itt, hdr->cmdsn, function,
1966 		hdr->rtt, hdr->refcmdsn, conn->cid);
1967 
1968 	if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
1969 	    ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
1970 	     hdr->rtt != RESERVED_ITT)) {
1971 		pr_err("RefTaskTag should be set to 0xFFFFFFFF.\n");
1972 		hdr->rtt = RESERVED_ITT;
1973 	}
1974 
1975 	if ((function == ISCSI_TM_FUNC_TASK_REASSIGN) &&
1976 			!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
1977 		pr_err("Task Management Request TASK_REASSIGN not"
1978 			" issued as immediate command, bad iSCSI Initiator"
1979 				"implementation\n");
1980 		return iscsit_add_reject_cmd(cmd,
1981 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1982 	}
1983 	if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
1984 	    be32_to_cpu(hdr->refcmdsn) != ISCSI_RESERVED_TAG)
1985 		hdr->refcmdsn = cpu_to_be32(ISCSI_RESERVED_TAG);
1986 
1987 	cmd->data_direction = DMA_NONE;
1988 	cmd->tmr_req = kzalloc(sizeof(*cmd->tmr_req), GFP_KERNEL);
1989 	if (!cmd->tmr_req)
1990 		return iscsit_add_reject_cmd(cmd,
1991 					     ISCSI_REASON_BOOKMARK_NO_RESOURCES,
1992 					     buf);
1993 
1994 	/*
1995 	 * TASK_REASSIGN for ERL=2 / connection stays inside of
1996 	 * LIO-Target $FABRIC_MOD
1997 	 */
1998 	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
1999 		transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
2000 				      conn->sess->se_sess, 0, DMA_NONE,
2001 				      TCM_SIMPLE_TAG, cmd->sense_buffer + 2);
2002 
2003 		target_get_sess_cmd(&cmd->se_cmd, true);
2004 		sess_ref = true;
2005 		tcm_function = iscsit_convert_tmf(function);
2006 		if (tcm_function == TMR_UNKNOWN) {
2007 			pr_err("Unknown iSCSI TMR Function:"
2008 			       " 0x%02x\n", function);
2009 			return iscsit_add_reject_cmd(cmd,
2010 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
2011 		}
2012 	}
2013 	ret = core_tmr_alloc_req(&cmd->se_cmd, cmd->tmr_req, tcm_function,
2014 				 GFP_KERNEL);
2015 	if (ret < 0)
2016 		return iscsit_add_reject_cmd(cmd,
2017 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
2018 
2019 	cmd->tmr_req->se_tmr_req = cmd->se_cmd.se_tmr_req;
2020 
2021 	cmd->iscsi_opcode	= ISCSI_OP_SCSI_TMFUNC;
2022 	cmd->i_state		= ISTATE_SEND_TASKMGTRSP;
2023 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2024 	cmd->init_task_tag	= hdr->itt;
2025 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2026 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
2027 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
2028 	se_tmr			= cmd->se_cmd.se_tmr_req;
2029 	tmr_req			= cmd->tmr_req;
2030 	/*
2031 	 * Locate the struct se_lun for all TMRs not related to ERL=2 TASK_REASSIGN
2032 	 */
2033 	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
2034 		ret = transport_lookup_tmr_lun(&cmd->se_cmd,
2035 					       scsilun_to_int(&hdr->lun));
2036 		if (ret < 0) {
2037 			se_tmr->response = ISCSI_TMF_RSP_NO_LUN;
2038 			goto attach;
2039 		}
2040 	}
2041 
2042 	switch (function) {
2043 	case ISCSI_TM_FUNC_ABORT_TASK:
2044 		se_tmr->response = iscsit_tmr_abort_task(cmd, buf);
2045 		if (se_tmr->response)
2046 			goto attach;
2047 		break;
2048 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
2049 	case ISCSI_TM_FUNC_CLEAR_ACA:
2050 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
2051 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
2052 		break;
2053 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
2054 		if (iscsit_tmr_task_warm_reset(conn, tmr_req, buf) < 0) {
2055 			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
2056 			goto attach;
2057 		}
2058 		break;
2059 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
2060 		if (iscsit_tmr_task_cold_reset(conn, tmr_req, buf) < 0) {
2061 			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
2062 			goto attach;
2063 		}
2064 		break;
2065 	case ISCSI_TM_FUNC_TASK_REASSIGN:
2066 		se_tmr->response = iscsit_tmr_task_reassign(cmd, buf);
2067 		/*
2068 		 * Perform sanity checks on the ExpDataSN only if the
2069 		 * TASK_REASSIGN was successful.
2070 		 */
2071 		if (se_tmr->response)
2072 			break;
2073 
2074 		if (iscsit_check_task_reassign_expdatasn(tmr_req, conn) < 0)
2075 			return iscsit_add_reject_cmd(cmd,
2076 					ISCSI_REASON_BOOKMARK_INVALID, buf);
2077 		break;
2078 	default:
2079 		pr_err("Unknown TMR function: 0x%02x, protocol"
2080 			" error.\n", function);
2081 		se_tmr->response = ISCSI_TMF_RSP_NOT_SUPPORTED;
2082 		goto attach;
2083 	}
2084 
2085 	if ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
2086 	    (se_tmr->response == ISCSI_TMF_RSP_COMPLETE))
2087 		se_tmr->call_transport = 1;
2088 attach:
2089 	spin_lock_bh(&conn->cmd_lock);
2090 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2091 	spin_unlock_bh(&conn->cmd_lock);
2092 
2093 	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
2094 		int cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
2095 		if (cmdsn_ret == CMDSN_HIGHER_THAN_EXP)
2096 			out_of_order_cmdsn = 1;
2097 		else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
2098 			return 0;
2099 		else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2100 			return -1;
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 	if (sess_ref) {
2121 		pr_debug("Handle TMR, using sess_ref=true check\n");
2122 		target_put_sess_cmd(&cmd->se_cmd);
2123 	}
2124 
2125 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2126 	return 0;
2127 }
2128 EXPORT_SYMBOL(iscsit_handle_task_mgt_cmd);
2129 
2130 /* #warning FIXME: Support Text Command parameters besides SendTargets */
2131 int
2132 iscsit_setup_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2133 		      struct iscsi_text *hdr)
2134 {
2135 	u32 payload_length = ntoh24(hdr->dlength);
2136 
2137 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
2138 		pr_err("Unable to accept text parameter length: %u"
2139 			"greater than MaxXmitDataSegmentLength %u.\n",
2140 		       payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
2141 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
2142 					 (unsigned char *)hdr);
2143 	}
2144 
2145 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL) ||
2146 	     (hdr->flags & ISCSI_FLAG_TEXT_CONTINUE)) {
2147 		pr_err("Multi sequence text commands currently not supported\n");
2148 		return iscsit_reject_cmd(cmd, ISCSI_REASON_CMD_NOT_SUPPORTED,
2149 					(unsigned char *)hdr);
2150 	}
2151 
2152 	pr_debug("Got Text Request: ITT: 0x%08x, CmdSN: 0x%08x,"
2153 		" ExpStatSN: 0x%08x, Length: %u\n", hdr->itt, hdr->cmdsn,
2154 		hdr->exp_statsn, payload_length);
2155 
2156 	cmd->iscsi_opcode	= ISCSI_OP_TEXT;
2157 	cmd->i_state		= ISTATE_SEND_TEXTRSP;
2158 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2159 	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
2160 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2161 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
2162 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
2163 	cmd->data_direction	= DMA_NONE;
2164 	cmd->text_in_ptr	= NULL;
2165 
2166 	return 0;
2167 }
2168 EXPORT_SYMBOL(iscsit_setup_text_cmd);
2169 
2170 int
2171 iscsit_process_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2172 			struct iscsi_text *hdr)
2173 {
2174 	unsigned char *text_in = cmd->text_in_ptr, *text_ptr;
2175 	int cmdsn_ret;
2176 
2177 	if (!text_in) {
2178 		cmd->targ_xfer_tag = be32_to_cpu(hdr->ttt);
2179 		if (cmd->targ_xfer_tag == 0xFFFFFFFF) {
2180 			pr_err("Unable to locate text_in buffer for sendtargets"
2181 			       " discovery\n");
2182 			goto reject;
2183 		}
2184 		goto empty_sendtargets;
2185 	}
2186 	if (strncmp("SendTargets", text_in, 11) != 0) {
2187 		pr_err("Received Text Data that is not"
2188 			" SendTargets, cannot continue.\n");
2189 		goto reject;
2190 	}
2191 	text_ptr = strchr(text_in, '=');
2192 	if (!text_ptr) {
2193 		pr_err("No \"=\" separator found in Text Data,"
2194 			"  cannot continue.\n");
2195 		goto reject;
2196 	}
2197 	if (!strncmp("=All", text_ptr, 4)) {
2198 		cmd->cmd_flags |= ICF_SENDTARGETS_ALL;
2199 	} else if (!strncmp("=iqn.", text_ptr, 5) ||
2200 		   !strncmp("=eui.", text_ptr, 5)) {
2201 		cmd->cmd_flags |= ICF_SENDTARGETS_SINGLE;
2202 	} else {
2203 		pr_err("Unable to locate valid SendTargets=%s value\n", text_ptr);
2204 		goto reject;
2205 	}
2206 
2207 	spin_lock_bh(&conn->cmd_lock);
2208 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2209 	spin_unlock_bh(&conn->cmd_lock);
2210 
2211 empty_sendtargets:
2212 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2213 
2214 	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
2215 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
2216 				(unsigned char *)hdr, hdr->cmdsn);
2217 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2218 			return -1;
2219 
2220 		return 0;
2221 	}
2222 
2223 	return iscsit_execute_cmd(cmd, 0);
2224 
2225 reject:
2226 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
2227 				 (unsigned char *)hdr);
2228 }
2229 EXPORT_SYMBOL(iscsit_process_text_cmd);
2230 
2231 static int
2232 iscsit_handle_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2233 		       unsigned char *buf)
2234 {
2235 	struct iscsi_text *hdr = (struct iscsi_text *)buf;
2236 	char *text_in = NULL;
2237 	u32 payload_length = ntoh24(hdr->dlength);
2238 	int rx_size, rc;
2239 
2240 	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
2241 	if (rc < 0)
2242 		return 0;
2243 
2244 	rx_size = payload_length;
2245 	if (payload_length) {
2246 		u32 checksum = 0, data_crc = 0;
2247 		u32 padding = 0, pad_bytes = 0;
2248 		int niov = 0, rx_got;
2249 		struct kvec iov[3];
2250 
2251 		text_in = kzalloc(payload_length, GFP_KERNEL);
2252 		if (!text_in)
2253 			goto reject;
2254 
2255 		cmd->text_in_ptr = text_in;
2256 
2257 		memset(iov, 0, 3 * sizeof(struct kvec));
2258 		iov[niov].iov_base	= text_in;
2259 		iov[niov++].iov_len	= payload_length;
2260 
2261 		padding = ((-payload_length) & 3);
2262 		if (padding != 0) {
2263 			iov[niov].iov_base = &pad_bytes;
2264 			iov[niov++].iov_len  = padding;
2265 			rx_size += padding;
2266 			pr_debug("Receiving %u additional bytes"
2267 					" for padding.\n", padding);
2268 		}
2269 		if (conn->conn_ops->DataDigest) {
2270 			iov[niov].iov_base	= &checksum;
2271 			iov[niov++].iov_len	= ISCSI_CRC_LEN;
2272 			rx_size += ISCSI_CRC_LEN;
2273 		}
2274 
2275 		rx_got = rx_data(conn, &iov[0], niov, rx_size);
2276 		if (rx_got != rx_size)
2277 			goto reject;
2278 
2279 		if (conn->conn_ops->DataDigest) {
2280 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash,
2281 					text_in, payload_length,
2282 					padding, (u8 *)&pad_bytes,
2283 					(u8 *)&data_crc);
2284 
2285 			if (checksum != data_crc) {
2286 				pr_err("Text data CRC32C DataDigest"
2287 					" 0x%08x does not match computed"
2288 					" 0x%08x\n", checksum, data_crc);
2289 				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2290 					pr_err("Unable to recover from"
2291 					" Text Data digest failure while in"
2292 						" ERL=0.\n");
2293 					goto reject;
2294 				} else {
2295 					/*
2296 					 * Silently drop this PDU and let the
2297 					 * initiator plug the CmdSN gap.
2298 					 */
2299 					pr_debug("Dropping Text"
2300 					" Command CmdSN: 0x%08x due to"
2301 					" DataCRC error.\n", hdr->cmdsn);
2302 					kfree(text_in);
2303 					return 0;
2304 				}
2305 			} else {
2306 				pr_debug("Got CRC32C DataDigest"
2307 					" 0x%08x for %u bytes of text data.\n",
2308 						checksum, payload_length);
2309 			}
2310 		}
2311 		text_in[payload_length - 1] = '\0';
2312 		pr_debug("Successfully read %d bytes of text"
2313 				" data.\n", payload_length);
2314 	}
2315 
2316 	return iscsit_process_text_cmd(conn, cmd, hdr);
2317 
2318 reject:
2319 	kfree(cmd->text_in_ptr);
2320 	cmd->text_in_ptr = NULL;
2321 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
2322 }
2323 
2324 int iscsit_logout_closesession(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2325 {
2326 	struct iscsi_conn *conn_p;
2327 	struct iscsi_session *sess = conn->sess;
2328 
2329 	pr_debug("Received logout request CLOSESESSION on CID: %hu"
2330 		" for SID: %u.\n", conn->cid, conn->sess->sid);
2331 
2332 	atomic_set(&sess->session_logout, 1);
2333 	atomic_set(&conn->conn_logout_remove, 1);
2334 	conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_SESSION;
2335 
2336 	iscsit_inc_conn_usage_count(conn);
2337 	iscsit_inc_session_usage_count(sess);
2338 
2339 	spin_lock_bh(&sess->conn_lock);
2340 	list_for_each_entry(conn_p, &sess->sess_conn_list, conn_list) {
2341 		if (conn_p->conn_state != TARG_CONN_STATE_LOGGED_IN)
2342 			continue;
2343 
2344 		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
2345 		conn_p->conn_state = TARG_CONN_STATE_IN_LOGOUT;
2346 	}
2347 	spin_unlock_bh(&sess->conn_lock);
2348 
2349 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2350 
2351 	return 0;
2352 }
2353 
2354 int iscsit_logout_closeconnection(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2355 {
2356 	struct iscsi_conn *l_conn;
2357 	struct iscsi_session *sess = conn->sess;
2358 
2359 	pr_debug("Received logout request CLOSECONNECTION for CID:"
2360 		" %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
2361 
2362 	/*
2363 	 * A Logout Request with a CLOSECONNECTION reason code for a CID
2364 	 * can arrive on a connection with a differing CID.
2365 	 */
2366 	if (conn->cid == cmd->logout_cid) {
2367 		spin_lock_bh(&conn->state_lock);
2368 		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
2369 		conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
2370 
2371 		atomic_set(&conn->conn_logout_remove, 1);
2372 		conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_CONNECTION;
2373 		iscsit_inc_conn_usage_count(conn);
2374 
2375 		spin_unlock_bh(&conn->state_lock);
2376 	} else {
2377 		/*
2378 		 * Handle all different cid CLOSECONNECTION requests in
2379 		 * iscsit_logout_post_handler_diffcid() as to give enough
2380 		 * time for any non immediate command's CmdSN to be
2381 		 * acknowledged on the connection in question.
2382 		 *
2383 		 * Here we simply make sure the CID is still around.
2384 		 */
2385 		l_conn = iscsit_get_conn_from_cid(sess,
2386 				cmd->logout_cid);
2387 		if (!l_conn) {
2388 			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
2389 			iscsit_add_cmd_to_response_queue(cmd, conn,
2390 					cmd->i_state);
2391 			return 0;
2392 		}
2393 
2394 		iscsit_dec_conn_usage_count(l_conn);
2395 	}
2396 
2397 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2398 
2399 	return 0;
2400 }
2401 
2402 int iscsit_logout_removeconnforrecovery(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2403 {
2404 	struct iscsi_session *sess = conn->sess;
2405 
2406 	pr_debug("Received explicit REMOVECONNFORRECOVERY logout for"
2407 		" CID: %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
2408 
2409 	if (sess->sess_ops->ErrorRecoveryLevel != 2) {
2410 		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
2411 			" while ERL!=2.\n");
2412 		cmd->logout_response = ISCSI_LOGOUT_RECOVERY_UNSUPPORTED;
2413 		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2414 		return 0;
2415 	}
2416 
2417 	if (conn->cid == cmd->logout_cid) {
2418 		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
2419 			" with CID: %hu on CID: %hu, implementation error.\n",
2420 				cmd->logout_cid, conn->cid);
2421 		cmd->logout_response = ISCSI_LOGOUT_CLEANUP_FAILED;
2422 		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2423 		return 0;
2424 	}
2425 
2426 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2427 
2428 	return 0;
2429 }
2430 
2431 int
2432 iscsit_handle_logout_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2433 			unsigned char *buf)
2434 {
2435 	int cmdsn_ret, logout_remove = 0;
2436 	u8 reason_code = 0;
2437 	struct iscsi_logout *hdr;
2438 	struct iscsi_tiqn *tiqn = iscsit_snmp_get_tiqn(conn);
2439 
2440 	hdr			= (struct iscsi_logout *) buf;
2441 	reason_code		= (hdr->flags & 0x7f);
2442 
2443 	if (tiqn) {
2444 		spin_lock(&tiqn->logout_stats.lock);
2445 		if (reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION)
2446 			tiqn->logout_stats.normal_logouts++;
2447 		else
2448 			tiqn->logout_stats.abnormal_logouts++;
2449 		spin_unlock(&tiqn->logout_stats.lock);
2450 	}
2451 
2452 	pr_debug("Got Logout Request ITT: 0x%08x CmdSN: 0x%08x"
2453 		" ExpStatSN: 0x%08x Reason: 0x%02x CID: %hu on CID: %hu\n",
2454 		hdr->itt, hdr->cmdsn, hdr->exp_statsn, reason_code,
2455 		hdr->cid, conn->cid);
2456 
2457 	if (conn->conn_state != TARG_CONN_STATE_LOGGED_IN) {
2458 		pr_err("Received logout request on connection that"
2459 			" is not in logged in state, ignoring request.\n");
2460 		iscsit_free_cmd(cmd, false);
2461 		return 0;
2462 	}
2463 
2464 	cmd->iscsi_opcode       = ISCSI_OP_LOGOUT;
2465 	cmd->i_state            = ISTATE_SEND_LOGOUTRSP;
2466 	cmd->immediate_cmd      = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2467 	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
2468 	cmd->targ_xfer_tag      = 0xFFFFFFFF;
2469 	cmd->cmd_sn             = be32_to_cpu(hdr->cmdsn);
2470 	cmd->exp_stat_sn        = be32_to_cpu(hdr->exp_statsn);
2471 	cmd->logout_cid         = be16_to_cpu(hdr->cid);
2472 	cmd->logout_reason      = reason_code;
2473 	cmd->data_direction     = DMA_NONE;
2474 
2475 	/*
2476 	 * We need to sleep in these cases (by returning 1) until the Logout
2477 	 * Response gets sent in the tx thread.
2478 	 */
2479 	if ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION) ||
2480 	   ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION) &&
2481 	    be16_to_cpu(hdr->cid) == conn->cid))
2482 		logout_remove = 1;
2483 
2484 	spin_lock_bh(&conn->cmd_lock);
2485 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2486 	spin_unlock_bh(&conn->cmd_lock);
2487 
2488 	if (reason_code != ISCSI_LOGOUT_REASON_RECOVERY)
2489 		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2490 
2491 	/*
2492 	 * Immediate commands are executed, well, immediately.
2493 	 * Non-Immediate Logout Commands are executed in CmdSN order.
2494 	 */
2495 	if (cmd->immediate_cmd) {
2496 		int ret = iscsit_execute_cmd(cmd, 0);
2497 
2498 		if (ret < 0)
2499 			return ret;
2500 	} else {
2501 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
2502 		if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
2503 			logout_remove = 0;
2504 		else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2505 			return -1;
2506 	}
2507 
2508 	return logout_remove;
2509 }
2510 EXPORT_SYMBOL(iscsit_handle_logout_cmd);
2511 
2512 int iscsit_handle_snack(
2513 	struct iscsi_conn *conn,
2514 	unsigned char *buf)
2515 {
2516 	struct iscsi_snack *hdr;
2517 
2518 	hdr			= (struct iscsi_snack *) buf;
2519 	hdr->flags		&= ~ISCSI_FLAG_CMD_FINAL;
2520 
2521 	pr_debug("Got ISCSI_INIT_SNACK, ITT: 0x%08x, ExpStatSN:"
2522 		" 0x%08x, Type: 0x%02x, BegRun: 0x%08x, RunLength: 0x%08x,"
2523 		" CID: %hu\n", hdr->itt, hdr->exp_statsn, hdr->flags,
2524 			hdr->begrun, hdr->runlength, conn->cid);
2525 
2526 	if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2527 		pr_err("Initiator sent SNACK request while in"
2528 			" ErrorRecoveryLevel=0.\n");
2529 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2530 					 buf);
2531 	}
2532 	/*
2533 	 * SNACK_DATA and SNACK_R2T are both 0,  so check which function to
2534 	 * call from inside iscsi_send_recovery_datain_or_r2t().
2535 	 */
2536 	switch (hdr->flags & ISCSI_FLAG_SNACK_TYPE_MASK) {
2537 	case 0:
2538 		return iscsit_handle_recovery_datain_or_r2t(conn, buf,
2539 			hdr->itt,
2540 			be32_to_cpu(hdr->ttt),
2541 			be32_to_cpu(hdr->begrun),
2542 			be32_to_cpu(hdr->runlength));
2543 	case ISCSI_FLAG_SNACK_TYPE_STATUS:
2544 		return iscsit_handle_status_snack(conn, hdr->itt,
2545 			be32_to_cpu(hdr->ttt),
2546 			be32_to_cpu(hdr->begrun), be32_to_cpu(hdr->runlength));
2547 	case ISCSI_FLAG_SNACK_TYPE_DATA_ACK:
2548 		return iscsit_handle_data_ack(conn, be32_to_cpu(hdr->ttt),
2549 			be32_to_cpu(hdr->begrun),
2550 			be32_to_cpu(hdr->runlength));
2551 	case ISCSI_FLAG_SNACK_TYPE_RDATA:
2552 		/* FIXME: Support R-Data SNACK */
2553 		pr_err("R-Data SNACK Not Supported.\n");
2554 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2555 					 buf);
2556 	default:
2557 		pr_err("Unknown SNACK type 0x%02x, protocol"
2558 			" error.\n", hdr->flags & 0x0f);
2559 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2560 					 buf);
2561 	}
2562 
2563 	return 0;
2564 }
2565 EXPORT_SYMBOL(iscsit_handle_snack);
2566 
2567 static void iscsit_rx_thread_wait_for_tcp(struct iscsi_conn *conn)
2568 {
2569 	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
2570 	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
2571 		wait_for_completion_interruptible_timeout(
2572 					&conn->rx_half_close_comp,
2573 					ISCSI_RX_THREAD_TCP_TIMEOUT * HZ);
2574 	}
2575 }
2576 
2577 static int iscsit_handle_immediate_data(
2578 	struct iscsi_cmd *cmd,
2579 	struct iscsi_scsi_req *hdr,
2580 	u32 length)
2581 {
2582 	int iov_ret, rx_got = 0, rx_size = 0;
2583 	u32 checksum, iov_count = 0, padding = 0;
2584 	struct iscsi_conn *conn = cmd->conn;
2585 	struct kvec *iov;
2586 
2587 	iov_ret = iscsit_map_iovec(cmd, cmd->iov_data, cmd->write_data_done, length);
2588 	if (iov_ret < 0)
2589 		return IMMEDIATE_DATA_CANNOT_RECOVER;
2590 
2591 	rx_size = length;
2592 	iov_count = iov_ret;
2593 	iov = &cmd->iov_data[0];
2594 
2595 	padding = ((-length) & 3);
2596 	if (padding != 0) {
2597 		iov[iov_count].iov_base	= cmd->pad_bytes;
2598 		iov[iov_count++].iov_len = padding;
2599 		rx_size += padding;
2600 	}
2601 
2602 	if (conn->conn_ops->DataDigest) {
2603 		iov[iov_count].iov_base		= &checksum;
2604 		iov[iov_count++].iov_len	= ISCSI_CRC_LEN;
2605 		rx_size += ISCSI_CRC_LEN;
2606 	}
2607 
2608 	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
2609 
2610 	iscsit_unmap_iovec(cmd);
2611 
2612 	if (rx_got != rx_size) {
2613 		iscsit_rx_thread_wait_for_tcp(conn);
2614 		return IMMEDIATE_DATA_CANNOT_RECOVER;
2615 	}
2616 
2617 	if (conn->conn_ops->DataDigest) {
2618 		u32 data_crc;
2619 
2620 		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
2621 						    cmd->write_data_done, length, padding,
2622 						    cmd->pad_bytes);
2623 
2624 		if (checksum != data_crc) {
2625 			pr_err("ImmediateData CRC32C DataDigest 0x%08x"
2626 				" does not match computed 0x%08x\n", checksum,
2627 				data_crc);
2628 
2629 			if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2630 				pr_err("Unable to recover from"
2631 					" Immediate Data digest failure while"
2632 					" in ERL=0.\n");
2633 				iscsit_reject_cmd(cmd,
2634 						ISCSI_REASON_DATA_DIGEST_ERROR,
2635 						(unsigned char *)hdr);
2636 				return IMMEDIATE_DATA_CANNOT_RECOVER;
2637 			} else {
2638 				iscsit_reject_cmd(cmd,
2639 						ISCSI_REASON_DATA_DIGEST_ERROR,
2640 						(unsigned char *)hdr);
2641 				return IMMEDIATE_DATA_ERL1_CRC_FAILURE;
2642 			}
2643 		} else {
2644 			pr_debug("Got CRC32C DataDigest 0x%08x for"
2645 				" %u bytes of Immediate Data\n", checksum,
2646 				length);
2647 		}
2648 	}
2649 
2650 	cmd->write_data_done += length;
2651 
2652 	if (cmd->write_data_done == cmd->se_cmd.data_length) {
2653 		spin_lock_bh(&cmd->istate_lock);
2654 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
2655 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
2656 		spin_unlock_bh(&cmd->istate_lock);
2657 	}
2658 
2659 	return IMMEDIATE_DATA_NORMAL_OPERATION;
2660 }
2661 
2662 /*
2663  *	Called with sess->conn_lock held.
2664  */
2665 /* #warning iscsi_build_conn_drop_async_message() only sends out on connections
2666 	with active network interface */
2667 static void iscsit_build_conn_drop_async_message(struct iscsi_conn *conn)
2668 {
2669 	struct iscsi_cmd *cmd;
2670 	struct iscsi_conn *conn_p;
2671 	bool found = false;
2672 
2673 	/*
2674 	 * Only send a Asynchronous Message on connections whos network
2675 	 * interface is still functional.
2676 	 */
2677 	list_for_each_entry(conn_p, &conn->sess->sess_conn_list, conn_list) {
2678 		if (conn_p->conn_state == TARG_CONN_STATE_LOGGED_IN) {
2679 			iscsit_inc_conn_usage_count(conn_p);
2680 			found = true;
2681 			break;
2682 		}
2683 	}
2684 
2685 	if (!found)
2686 		return;
2687 
2688 	cmd = iscsit_allocate_cmd(conn_p, TASK_RUNNING);
2689 	if (!cmd) {
2690 		iscsit_dec_conn_usage_count(conn_p);
2691 		return;
2692 	}
2693 
2694 	cmd->logout_cid = conn->cid;
2695 	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
2696 	cmd->i_state = ISTATE_SEND_ASYNCMSG;
2697 
2698 	spin_lock_bh(&conn_p->cmd_lock);
2699 	list_add_tail(&cmd->i_conn_node, &conn_p->conn_cmd_list);
2700 	spin_unlock_bh(&conn_p->cmd_lock);
2701 
2702 	iscsit_add_cmd_to_response_queue(cmd, conn_p, cmd->i_state);
2703 	iscsit_dec_conn_usage_count(conn_p);
2704 }
2705 
2706 static int iscsit_send_conn_drop_async_message(
2707 	struct iscsi_cmd *cmd,
2708 	struct iscsi_conn *conn)
2709 {
2710 	struct iscsi_async *hdr;
2711 
2712 	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
2713 
2714 	hdr			= (struct iscsi_async *) cmd->pdu;
2715 	hdr->opcode		= ISCSI_OP_ASYNC_EVENT;
2716 	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
2717 	cmd->init_task_tag	= RESERVED_ITT;
2718 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2719 	put_unaligned_be64(0xFFFFFFFFFFFFFFFFULL, &hdr->rsvd4[0]);
2720 	cmd->stat_sn		= conn->stat_sn++;
2721 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2722 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2723 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2724 	hdr->async_event	= ISCSI_ASYNC_MSG_DROPPING_CONNECTION;
2725 	hdr->param1		= cpu_to_be16(cmd->logout_cid);
2726 	hdr->param2		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Wait);
2727 	hdr->param3		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Retain);
2728 
2729 	pr_debug("Sending Connection Dropped Async Message StatSN:"
2730 		" 0x%08x, for CID: %hu on CID: %hu\n", cmd->stat_sn,
2731 			cmd->logout_cid, conn->cid);
2732 
2733 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
2734 }
2735 
2736 static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *conn)
2737 {
2738 	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
2739 	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
2740 		wait_for_completion_interruptible_timeout(
2741 					&conn->tx_half_close_comp,
2742 					ISCSI_TX_THREAD_TCP_TIMEOUT * HZ);
2743 	}
2744 }
2745 
2746 void
2747 iscsit_build_datain_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2748 			struct iscsi_datain *datain, struct iscsi_data_rsp *hdr,
2749 			bool set_statsn)
2750 {
2751 	hdr->opcode		= ISCSI_OP_SCSI_DATA_IN;
2752 	hdr->flags		= datain->flags;
2753 	if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
2754 		if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
2755 			hdr->flags |= ISCSI_FLAG_DATA_OVERFLOW;
2756 			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
2757 		} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
2758 			hdr->flags |= ISCSI_FLAG_DATA_UNDERFLOW;
2759 			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
2760 		}
2761 	}
2762 	hton24(hdr->dlength, datain->length);
2763 	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
2764 		int_to_scsilun(cmd->se_cmd.orig_fe_lun,
2765 				(struct scsi_lun *)&hdr->lun);
2766 	else
2767 		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
2768 
2769 	hdr->itt		= cmd->init_task_tag;
2770 
2771 	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
2772 		hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
2773 	else
2774 		hdr->ttt		= cpu_to_be32(0xFFFFFFFF);
2775 	if (set_statsn)
2776 		hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2777 	else
2778 		hdr->statsn		= cpu_to_be32(0xFFFFFFFF);
2779 
2780 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2781 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2782 	hdr->datasn		= cpu_to_be32(datain->data_sn);
2783 	hdr->offset		= cpu_to_be32(datain->offset);
2784 
2785 	pr_debug("Built DataIN ITT: 0x%08x, StatSN: 0x%08x,"
2786 		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
2787 		cmd->init_task_tag, ntohl(hdr->statsn), ntohl(hdr->datasn),
2788 		ntohl(hdr->offset), datain->length, conn->cid);
2789 }
2790 EXPORT_SYMBOL(iscsit_build_datain_pdu);
2791 
2792 static int iscsit_send_datain(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2793 {
2794 	struct iscsi_data_rsp *hdr = (struct iscsi_data_rsp *)&cmd->pdu[0];
2795 	struct iscsi_datain datain;
2796 	struct iscsi_datain_req *dr;
2797 	int eodr = 0, ret;
2798 	bool set_statsn = false;
2799 
2800 	memset(&datain, 0, sizeof(struct iscsi_datain));
2801 	dr = iscsit_get_datain_values(cmd, &datain);
2802 	if (!dr) {
2803 		pr_err("iscsit_get_datain_values failed for ITT: 0x%08x\n",
2804 				cmd->init_task_tag);
2805 		return -1;
2806 	}
2807 	/*
2808 	 * Be paranoid and double check the logic for now.
2809 	 */
2810 	if ((datain.offset + datain.length) > cmd->se_cmd.data_length) {
2811 		pr_err("Command ITT: 0x%08x, datain.offset: %u and"
2812 			" datain.length: %u exceeds cmd->data_length: %u\n",
2813 			cmd->init_task_tag, datain.offset, datain.length,
2814 			cmd->se_cmd.data_length);
2815 		return -1;
2816 	}
2817 
2818 	atomic_long_add(datain.length, &conn->sess->tx_data_octets);
2819 	/*
2820 	 * Special case for successfully execution w/ both DATAIN
2821 	 * and Sense Data.
2822 	 */
2823 	if ((datain.flags & ISCSI_FLAG_DATA_STATUS) &&
2824 	    (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE))
2825 		datain.flags &= ~ISCSI_FLAG_DATA_STATUS;
2826 	else {
2827 		if ((dr->dr_complete == DATAIN_COMPLETE_NORMAL) ||
2828 		    (dr->dr_complete == DATAIN_COMPLETE_CONNECTION_RECOVERY)) {
2829 			iscsit_increment_maxcmdsn(cmd, conn->sess);
2830 			cmd->stat_sn = conn->stat_sn++;
2831 			set_statsn = true;
2832 		} else if (dr->dr_complete ==
2833 			   DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY)
2834 			set_statsn = true;
2835 	}
2836 
2837 	iscsit_build_datain_pdu(cmd, conn, &datain, hdr, set_statsn);
2838 
2839 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, dr, &datain, 0);
2840 	if (ret < 0)
2841 		return ret;
2842 
2843 	if (dr->dr_complete) {
2844 		eodr = (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ?
2845 				2 : 1;
2846 		iscsit_free_datain_req(cmd, dr);
2847 	}
2848 
2849 	return eodr;
2850 }
2851 
2852 int
2853 iscsit_build_logout_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2854 			struct iscsi_logout_rsp *hdr)
2855 {
2856 	struct iscsi_conn *logout_conn = NULL;
2857 	struct iscsi_conn_recovery *cr = NULL;
2858 	struct iscsi_session *sess = conn->sess;
2859 	/*
2860 	 * The actual shutting down of Sessions and/or Connections
2861 	 * for CLOSESESSION and CLOSECONNECTION Logout Requests
2862 	 * is done in scsi_logout_post_handler().
2863 	 */
2864 	switch (cmd->logout_reason) {
2865 	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
2866 		pr_debug("iSCSI session logout successful, setting"
2867 			" logout response to ISCSI_LOGOUT_SUCCESS.\n");
2868 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2869 		break;
2870 	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
2871 		if (cmd->logout_response == ISCSI_LOGOUT_CID_NOT_FOUND)
2872 			break;
2873 		/*
2874 		 * For CLOSECONNECTION logout requests carrying
2875 		 * a matching logout CID -> local CID, the reference
2876 		 * for the local CID will have been incremented in
2877 		 * iscsi_logout_closeconnection().
2878 		 *
2879 		 * For CLOSECONNECTION logout requests carrying
2880 		 * a different CID than the connection it arrived
2881 		 * on, the connection responding to cmd->logout_cid
2882 		 * is stopped in iscsit_logout_post_handler_diffcid().
2883 		 */
2884 
2885 		pr_debug("iSCSI CID: %hu logout on CID: %hu"
2886 			" successful.\n", cmd->logout_cid, conn->cid);
2887 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2888 		break;
2889 	case ISCSI_LOGOUT_REASON_RECOVERY:
2890 		if ((cmd->logout_response == ISCSI_LOGOUT_RECOVERY_UNSUPPORTED) ||
2891 		    (cmd->logout_response == ISCSI_LOGOUT_CLEANUP_FAILED))
2892 			break;
2893 		/*
2894 		 * If the connection is still active from our point of view
2895 		 * force connection recovery to occur.
2896 		 */
2897 		logout_conn = iscsit_get_conn_from_cid_rcfr(sess,
2898 				cmd->logout_cid);
2899 		if (logout_conn) {
2900 			iscsit_connection_reinstatement_rcfr(logout_conn);
2901 			iscsit_dec_conn_usage_count(logout_conn);
2902 		}
2903 
2904 		cr = iscsit_get_inactive_connection_recovery_entry(
2905 				conn->sess, cmd->logout_cid);
2906 		if (!cr) {
2907 			pr_err("Unable to locate CID: %hu for"
2908 			" REMOVECONNFORRECOVERY Logout Request.\n",
2909 				cmd->logout_cid);
2910 			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
2911 			break;
2912 		}
2913 
2914 		iscsit_discard_cr_cmds_by_expstatsn(cr, cmd->exp_stat_sn);
2915 
2916 		pr_debug("iSCSI REMOVECONNFORRECOVERY logout"
2917 			" for recovery for CID: %hu on CID: %hu successful.\n",
2918 				cmd->logout_cid, conn->cid);
2919 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2920 		break;
2921 	default:
2922 		pr_err("Unknown cmd->logout_reason: 0x%02x\n",
2923 				cmd->logout_reason);
2924 		return -1;
2925 	}
2926 
2927 	hdr->opcode		= ISCSI_OP_LOGOUT_RSP;
2928 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
2929 	hdr->response		= cmd->logout_response;
2930 	hdr->itt		= cmd->init_task_tag;
2931 	cmd->stat_sn		= conn->stat_sn++;
2932 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2933 
2934 	iscsit_increment_maxcmdsn(cmd, conn->sess);
2935 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2936 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2937 
2938 	pr_debug("Built Logout Response ITT: 0x%08x StatSN:"
2939 		" 0x%08x Response: 0x%02x CID: %hu on CID: %hu\n",
2940 		cmd->init_task_tag, cmd->stat_sn, hdr->response,
2941 		cmd->logout_cid, conn->cid);
2942 
2943 	return 0;
2944 }
2945 EXPORT_SYMBOL(iscsit_build_logout_rsp);
2946 
2947 static int
2948 iscsit_send_logout(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2949 {
2950 	int rc;
2951 
2952 	rc = iscsit_build_logout_rsp(cmd, conn,
2953 			(struct iscsi_logout_rsp *)&cmd->pdu[0]);
2954 	if (rc < 0)
2955 		return rc;
2956 
2957 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
2958 }
2959 
2960 void
2961 iscsit_build_nopin_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2962 		       struct iscsi_nopin *hdr, bool nopout_response)
2963 {
2964 	hdr->opcode		= ISCSI_OP_NOOP_IN;
2965 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
2966         hton24(hdr->dlength, cmd->buf_ptr_size);
2967 	if (nopout_response)
2968 		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
2969 	hdr->itt		= cmd->init_task_tag;
2970 	hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
2971 	cmd->stat_sn		= (nopout_response) ? conn->stat_sn++ :
2972 				  conn->stat_sn;
2973 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2974 
2975 	if (nopout_response)
2976 		iscsit_increment_maxcmdsn(cmd, conn->sess);
2977 
2978 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2979 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2980 
2981 	pr_debug("Built NOPIN %s Response ITT: 0x%08x, TTT: 0x%08x,"
2982 		" StatSN: 0x%08x, Length %u\n", (nopout_response) ?
2983 		"Solicited" : "Unsolicited", cmd->init_task_tag,
2984 		cmd->targ_xfer_tag, cmd->stat_sn, cmd->buf_ptr_size);
2985 }
2986 EXPORT_SYMBOL(iscsit_build_nopin_rsp);
2987 
2988 /*
2989  *	Unsolicited NOPIN, either requesting a response or not.
2990  */
2991 static int iscsit_send_unsolicited_nopin(
2992 	struct iscsi_cmd *cmd,
2993 	struct iscsi_conn *conn,
2994 	int want_response)
2995 {
2996 	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
2997 	int ret;
2998 
2999 	iscsit_build_nopin_rsp(cmd, conn, hdr, false);
3000 
3001 	pr_debug("Sending Unsolicited NOPIN TTT: 0x%08x StatSN:"
3002 		" 0x%08x CID: %hu\n", hdr->ttt, cmd->stat_sn, conn->cid);
3003 
3004 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3005 	if (ret < 0)
3006 		return ret;
3007 
3008 	spin_lock_bh(&cmd->istate_lock);
3009 	cmd->i_state = want_response ?
3010 		ISTATE_SENT_NOPIN_WANT_RESPONSE : ISTATE_SENT_STATUS;
3011 	spin_unlock_bh(&cmd->istate_lock);
3012 
3013 	return 0;
3014 }
3015 
3016 static int
3017 iscsit_send_nopin(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3018 {
3019 	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
3020 
3021 	iscsit_build_nopin_rsp(cmd, conn, hdr, true);
3022 
3023 	/*
3024 	 * NOPOUT Ping Data is attached to struct iscsi_cmd->buf_ptr.
3025 	 * NOPOUT DataSegmentLength is at struct iscsi_cmd->buf_ptr_size.
3026 	 */
3027 	pr_debug("Echoing back %u bytes of ping data.\n", cmd->buf_ptr_size);
3028 
3029 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3030 						     cmd->buf_ptr,
3031 						     cmd->buf_ptr_size);
3032 }
3033 
3034 static int iscsit_send_r2t(
3035 	struct iscsi_cmd *cmd,
3036 	struct iscsi_conn *conn)
3037 {
3038 	struct iscsi_r2t *r2t;
3039 	struct iscsi_r2t_rsp *hdr;
3040 	int ret;
3041 
3042 	r2t = iscsit_get_r2t_from_list(cmd);
3043 	if (!r2t)
3044 		return -1;
3045 
3046 	hdr			= (struct iscsi_r2t_rsp *) cmd->pdu;
3047 	memset(hdr, 0, ISCSI_HDR_LEN);
3048 	hdr->opcode		= ISCSI_OP_R2T;
3049 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3050 	int_to_scsilun(cmd->se_cmd.orig_fe_lun,
3051 			(struct scsi_lun *)&hdr->lun);
3052 	hdr->itt		= cmd->init_task_tag;
3053 	if (conn->conn_transport->iscsit_get_r2t_ttt)
3054 		conn->conn_transport->iscsit_get_r2t_ttt(conn, cmd, r2t);
3055 	else
3056 		r2t->targ_xfer_tag = session_get_next_ttt(conn->sess);
3057 	hdr->ttt		= cpu_to_be32(r2t->targ_xfer_tag);
3058 	hdr->statsn		= cpu_to_be32(conn->stat_sn);
3059 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3060 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3061 	hdr->r2tsn		= cpu_to_be32(r2t->r2t_sn);
3062 	hdr->data_offset	= cpu_to_be32(r2t->offset);
3063 	hdr->data_length	= cpu_to_be32(r2t->xfer_len);
3064 
3065 	pr_debug("Built %sR2T, ITT: 0x%08x, TTT: 0x%08x, StatSN:"
3066 		" 0x%08x, R2TSN: 0x%08x, Offset: %u, DDTL: %u, CID: %hu\n",
3067 		(!r2t->recovery_r2t) ? "" : "Recovery ", cmd->init_task_tag,
3068 		r2t->targ_xfer_tag, ntohl(hdr->statsn), r2t->r2t_sn,
3069 			r2t->offset, r2t->xfer_len, conn->cid);
3070 
3071 	spin_lock_bh(&cmd->r2t_lock);
3072 	r2t->sent_r2t = 1;
3073 	spin_unlock_bh(&cmd->r2t_lock);
3074 
3075 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3076 	if (ret < 0) {
3077 		return ret;
3078 	}
3079 
3080 	spin_lock_bh(&cmd->dataout_timeout_lock);
3081 	iscsit_start_dataout_timer(cmd, conn);
3082 	spin_unlock_bh(&cmd->dataout_timeout_lock);
3083 
3084 	return 0;
3085 }
3086 
3087 /*
3088  *	@recovery: If called from iscsi_task_reassign_complete_write() for
3089  *		connection recovery.
3090  */
3091 int iscsit_build_r2ts_for_cmd(
3092 	struct iscsi_conn *conn,
3093 	struct iscsi_cmd *cmd,
3094 	bool recovery)
3095 {
3096 	int first_r2t = 1;
3097 	u32 offset = 0, xfer_len = 0;
3098 
3099 	spin_lock_bh(&cmd->r2t_lock);
3100 	if (cmd->cmd_flags & ICF_SENT_LAST_R2T) {
3101 		spin_unlock_bh(&cmd->r2t_lock);
3102 		return 0;
3103 	}
3104 
3105 	if (conn->sess->sess_ops->DataSequenceInOrder &&
3106 	    !recovery)
3107 		cmd->r2t_offset = max(cmd->r2t_offset, cmd->write_data_done);
3108 
3109 	while (cmd->outstanding_r2ts < conn->sess->sess_ops->MaxOutstandingR2T) {
3110 		if (conn->sess->sess_ops->DataSequenceInOrder) {
3111 			offset = cmd->r2t_offset;
3112 
3113 			if (first_r2t && recovery) {
3114 				int new_data_end = offset +
3115 					conn->sess->sess_ops->MaxBurstLength -
3116 					cmd->next_burst_len;
3117 
3118 				if (new_data_end > cmd->se_cmd.data_length)
3119 					xfer_len = cmd->se_cmd.data_length - offset;
3120 				else
3121 					xfer_len =
3122 						conn->sess->sess_ops->MaxBurstLength -
3123 						cmd->next_burst_len;
3124 			} else {
3125 				int new_data_end = offset +
3126 					conn->sess->sess_ops->MaxBurstLength;
3127 
3128 				if (new_data_end > cmd->se_cmd.data_length)
3129 					xfer_len = cmd->se_cmd.data_length - offset;
3130 				else
3131 					xfer_len = conn->sess->sess_ops->MaxBurstLength;
3132 			}
3133 			cmd->r2t_offset += xfer_len;
3134 
3135 			if (cmd->r2t_offset == cmd->se_cmd.data_length)
3136 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3137 		} else {
3138 			struct iscsi_seq *seq;
3139 
3140 			seq = iscsit_get_seq_holder_for_r2t(cmd);
3141 			if (!seq) {
3142 				spin_unlock_bh(&cmd->r2t_lock);
3143 				return -1;
3144 			}
3145 
3146 			offset = seq->offset;
3147 			xfer_len = seq->xfer_len;
3148 
3149 			if (cmd->seq_send_order == cmd->seq_count)
3150 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3151 		}
3152 		cmd->outstanding_r2ts++;
3153 		first_r2t = 0;
3154 
3155 		if (iscsit_add_r2t_to_list(cmd, offset, xfer_len, 0, 0) < 0) {
3156 			spin_unlock_bh(&cmd->r2t_lock);
3157 			return -1;
3158 		}
3159 
3160 		if (cmd->cmd_flags & ICF_SENT_LAST_R2T)
3161 			break;
3162 	}
3163 	spin_unlock_bh(&cmd->r2t_lock);
3164 
3165 	return 0;
3166 }
3167 EXPORT_SYMBOL(iscsit_build_r2ts_for_cmd);
3168 
3169 void iscsit_build_rsp_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3170 			bool inc_stat_sn, struct iscsi_scsi_rsp *hdr)
3171 {
3172 	if (inc_stat_sn)
3173 		cmd->stat_sn = conn->stat_sn++;
3174 
3175 	atomic_long_inc(&conn->sess->rsp_pdus);
3176 
3177 	memset(hdr, 0, ISCSI_HDR_LEN);
3178 	hdr->opcode		= ISCSI_OP_SCSI_CMD_RSP;
3179 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3180 	if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
3181 		hdr->flags |= ISCSI_FLAG_CMD_OVERFLOW;
3182 		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
3183 	} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
3184 		hdr->flags |= ISCSI_FLAG_CMD_UNDERFLOW;
3185 		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
3186 	}
3187 	hdr->response		= cmd->iscsi_response;
3188 	hdr->cmd_status		= cmd->se_cmd.scsi_status;
3189 	hdr->itt		= cmd->init_task_tag;
3190 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3191 
3192 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3193 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3194 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3195 
3196 	pr_debug("Built SCSI Response, ITT: 0x%08x, StatSN: 0x%08x,"
3197 		" Response: 0x%02x, SAM Status: 0x%02x, CID: %hu\n",
3198 		cmd->init_task_tag, cmd->stat_sn, cmd->se_cmd.scsi_status,
3199 		cmd->se_cmd.scsi_status, conn->cid);
3200 }
3201 EXPORT_SYMBOL(iscsit_build_rsp_pdu);
3202 
3203 static int iscsit_send_response(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3204 {
3205 	struct iscsi_scsi_rsp *hdr = (struct iscsi_scsi_rsp *)&cmd->pdu[0];
3206 	bool inc_stat_sn = (cmd->i_state == ISTATE_SEND_STATUS);
3207 	void *data_buf = NULL;
3208 	u32 padding = 0, data_buf_len = 0;
3209 
3210 	iscsit_build_rsp_pdu(cmd, conn, inc_stat_sn, hdr);
3211 
3212 	/*
3213 	 * Attach SENSE DATA payload to iSCSI Response PDU
3214 	 */
3215 	if (cmd->se_cmd.sense_buffer &&
3216 	   ((cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
3217 	    (cmd->se_cmd.se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
3218 		put_unaligned_be16(cmd->se_cmd.scsi_sense_length, cmd->sense_buffer);
3219 		cmd->se_cmd.scsi_sense_length += sizeof (__be16);
3220 
3221 		padding		= -(cmd->se_cmd.scsi_sense_length) & 3;
3222 		hton24(hdr->dlength, (u32)cmd->se_cmd.scsi_sense_length);
3223 		data_buf = cmd->sense_buffer;
3224 		data_buf_len = cmd->se_cmd.scsi_sense_length + padding;
3225 
3226 		if (padding) {
3227 			memset(cmd->sense_buffer +
3228 				cmd->se_cmd.scsi_sense_length, 0, padding);
3229 			pr_debug("Adding %u bytes of padding to"
3230 				" SENSE.\n", padding);
3231 		}
3232 
3233 		pr_debug("Attaching SENSE DATA: %u bytes to iSCSI"
3234 				" Response PDU\n",
3235 				cmd->se_cmd.scsi_sense_length);
3236 	}
3237 
3238 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, data_buf,
3239 						     data_buf_len);
3240 }
3241 
3242 static u8 iscsit_convert_tcm_tmr_rsp(struct se_tmr_req *se_tmr)
3243 {
3244 	switch (se_tmr->response) {
3245 	case TMR_FUNCTION_COMPLETE:
3246 		return ISCSI_TMF_RSP_COMPLETE;
3247 	case TMR_TASK_DOES_NOT_EXIST:
3248 		return ISCSI_TMF_RSP_NO_TASK;
3249 	case TMR_LUN_DOES_NOT_EXIST:
3250 		return ISCSI_TMF_RSP_NO_LUN;
3251 	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
3252 		return ISCSI_TMF_RSP_NOT_SUPPORTED;
3253 	case TMR_FUNCTION_REJECTED:
3254 	default:
3255 		return ISCSI_TMF_RSP_REJECTED;
3256 	}
3257 }
3258 
3259 void
3260 iscsit_build_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3261 			  struct iscsi_tm_rsp *hdr)
3262 {
3263 	struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req;
3264 
3265 	hdr->opcode		= ISCSI_OP_SCSI_TMFUNC_RSP;
3266 	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
3267 	hdr->response		= iscsit_convert_tcm_tmr_rsp(se_tmr);
3268 	hdr->itt		= cmd->init_task_tag;
3269 	cmd->stat_sn		= conn->stat_sn++;
3270 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3271 
3272 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3273 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3274 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3275 
3276 	pr_debug("Built Task Management Response ITT: 0x%08x,"
3277 		" StatSN: 0x%08x, Response: 0x%02x, CID: %hu\n",
3278 		cmd->init_task_tag, cmd->stat_sn, hdr->response, conn->cid);
3279 }
3280 EXPORT_SYMBOL(iscsit_build_task_mgt_rsp);
3281 
3282 static int
3283 iscsit_send_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3284 {
3285 	struct iscsi_tm_rsp *hdr = (struct iscsi_tm_rsp *)&cmd->pdu[0];
3286 
3287 	iscsit_build_task_mgt_rsp(cmd, conn, hdr);
3288 
3289 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3290 }
3291 
3292 static bool iscsit_check_inaddr_any(struct iscsi_np *np)
3293 {
3294 	bool ret = false;
3295 
3296 	if (np->np_sockaddr.ss_family == AF_INET6) {
3297 		const struct sockaddr_in6 sin6 = {
3298 			.sin6_addr = IN6ADDR_ANY_INIT };
3299 		struct sockaddr_in6 *sock_in6 =
3300 			 (struct sockaddr_in6 *)&np->np_sockaddr;
3301 
3302 		if (!memcmp(sock_in6->sin6_addr.s6_addr,
3303 				sin6.sin6_addr.s6_addr, 16))
3304 			ret = true;
3305 	} else {
3306 		struct sockaddr_in * sock_in =
3307 			(struct sockaddr_in *)&np->np_sockaddr;
3308 
3309 		if (sock_in->sin_addr.s_addr == htonl(INADDR_ANY))
3310 			ret = true;
3311 	}
3312 
3313 	return ret;
3314 }
3315 
3316 #define SENDTARGETS_BUF_LIMIT 32768U
3317 
3318 static int
3319 iscsit_build_sendtargets_response(struct iscsi_cmd *cmd,
3320 				  enum iscsit_transport_type network_transport,
3321 				  int skip_bytes, bool *completed)
3322 {
3323 	char *payload = NULL;
3324 	struct iscsi_conn *conn = cmd->conn;
3325 	struct iscsi_portal_group *tpg;
3326 	struct iscsi_tiqn *tiqn;
3327 	struct iscsi_tpg_np *tpg_np;
3328 	int buffer_len, end_of_buf = 0, len = 0, payload_len = 0;
3329 	int target_name_printed;
3330 	unsigned char buf[ISCSI_IQN_LEN+12]; /* iqn + "TargetName=" + \0 */
3331 	unsigned char *text_in = cmd->text_in_ptr, *text_ptr = NULL;
3332 	bool active;
3333 
3334 	buffer_len = min(conn->conn_ops->MaxRecvDataSegmentLength,
3335 			 SENDTARGETS_BUF_LIMIT);
3336 
3337 	payload = kzalloc(buffer_len, GFP_KERNEL);
3338 	if (!payload)
3339 		return -ENOMEM;
3340 
3341 	/*
3342 	 * Locate pointer to iqn./eui. string for ICF_SENDTARGETS_SINGLE
3343 	 * explicit case..
3344 	 */
3345 	if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) {
3346 		text_ptr = strchr(text_in, '=');
3347 		if (!text_ptr) {
3348 			pr_err("Unable to locate '=' string in text_in:"
3349 			       " %s\n", text_in);
3350 			kfree(payload);
3351 			return -EINVAL;
3352 		}
3353 		/*
3354 		 * Skip over '=' character..
3355 		 */
3356 		text_ptr += 1;
3357 	}
3358 
3359 	spin_lock(&tiqn_lock);
3360 	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
3361 		if ((cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) &&
3362 		     strcmp(tiqn->tiqn, text_ptr)) {
3363 			continue;
3364 		}
3365 
3366 		target_name_printed = 0;
3367 
3368 		spin_lock(&tiqn->tiqn_tpg_lock);
3369 		list_for_each_entry(tpg, &tiqn->tiqn_tpg_list, tpg_list) {
3370 
3371 			/* If demo_mode_discovery=0 and generate_node_acls=0
3372 			 * (demo mode dislabed) do not return
3373 			 * TargetName+TargetAddress unless a NodeACL exists.
3374 			 */
3375 
3376 			if ((tpg->tpg_attrib.generate_node_acls == 0) &&
3377 			    (tpg->tpg_attrib.demo_mode_discovery == 0) &&
3378 			    (!target_tpg_has_node_acl(&tpg->tpg_se_tpg,
3379 				cmd->conn->sess->sess_ops->InitiatorName))) {
3380 				continue;
3381 			}
3382 
3383 			spin_lock(&tpg->tpg_state_lock);
3384 			active = (tpg->tpg_state == TPG_STATE_ACTIVE);
3385 			spin_unlock(&tpg->tpg_state_lock);
3386 
3387 			if (!active && tpg->tpg_attrib.tpg_enabled_sendtargets)
3388 				continue;
3389 
3390 			spin_lock(&tpg->tpg_np_lock);
3391 			list_for_each_entry(tpg_np, &tpg->tpg_gnp_list,
3392 						tpg_np_list) {
3393 				struct iscsi_np *np = tpg_np->tpg_np;
3394 				bool inaddr_any = iscsit_check_inaddr_any(np);
3395 				struct sockaddr_storage *sockaddr;
3396 
3397 				if (np->np_network_transport != network_transport)
3398 					continue;
3399 
3400 				if (!target_name_printed) {
3401 					len = sprintf(buf, "TargetName=%s",
3402 						      tiqn->tiqn);
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 						target_name_printed = 1;
3418 						if (len > skip_bytes)
3419 							skip_bytes = 0;
3420 					}
3421 				}
3422 
3423 				if (inaddr_any)
3424 					sockaddr = &conn->local_sockaddr;
3425 				else
3426 					sockaddr = &np->np_sockaddr;
3427 
3428 				len = sprintf(buf, "TargetAddress="
3429 					      "%pISpc,%hu",
3430 					      sockaddr,
3431 					      tpg->tpgt);
3432 				len += 1;
3433 
3434 				if ((len + payload_len) > buffer_len) {
3435 					spin_unlock(&tpg->tpg_np_lock);
3436 					spin_unlock(&tiqn->tiqn_tpg_lock);
3437 					end_of_buf = 1;
3438 					goto eob;
3439 				}
3440 
3441 				if (skip_bytes && len <= skip_bytes) {
3442 					skip_bytes -= len;
3443 				} else {
3444 					memcpy(payload + payload_len, buf, len);
3445 					payload_len += len;
3446 					if (len > skip_bytes)
3447 						skip_bytes = 0;
3448 				}
3449 			}
3450 			spin_unlock(&tpg->tpg_np_lock);
3451 		}
3452 		spin_unlock(&tiqn->tiqn_tpg_lock);
3453 eob:
3454 		if (end_of_buf) {
3455 			*completed = false;
3456 			break;
3457 		}
3458 
3459 		if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE)
3460 			break;
3461 	}
3462 	spin_unlock(&tiqn_lock);
3463 
3464 	cmd->buf_ptr = payload;
3465 
3466 	return payload_len;
3467 }
3468 
3469 int
3470 iscsit_build_text_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3471 		      struct iscsi_text_rsp *hdr,
3472 		      enum iscsit_transport_type network_transport)
3473 {
3474 	int text_length, padding;
3475 	bool completed = true;
3476 
3477 	text_length = iscsit_build_sendtargets_response(cmd, network_transport,
3478 							cmd->read_data_done,
3479 							&completed);
3480 	if (text_length < 0)
3481 		return text_length;
3482 
3483 	if (completed) {
3484 		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
3485 	} else {
3486 		hdr->flags |= ISCSI_FLAG_TEXT_CONTINUE;
3487 		cmd->read_data_done += text_length;
3488 		if (cmd->targ_xfer_tag == 0xFFFFFFFF)
3489 			cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
3490 	}
3491 	hdr->opcode = ISCSI_OP_TEXT_RSP;
3492 	padding = ((-text_length) & 3);
3493 	hton24(hdr->dlength, text_length);
3494 	hdr->itt = cmd->init_task_tag;
3495 	hdr->ttt = cpu_to_be32(cmd->targ_xfer_tag);
3496 	cmd->stat_sn = conn->stat_sn++;
3497 	hdr->statsn = cpu_to_be32(cmd->stat_sn);
3498 
3499 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3500 	/*
3501 	 * Reset maxcmdsn_inc in multi-part text payload exchanges to
3502 	 * correctly increment MaxCmdSN for each response answering a
3503 	 * non immediate text request with a valid CmdSN.
3504 	 */
3505 	cmd->maxcmdsn_inc = 0;
3506 	hdr->exp_cmdsn = cpu_to_be32(conn->sess->exp_cmd_sn);
3507 	hdr->max_cmdsn = cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3508 
3509 	pr_debug("Built Text Response: ITT: 0x%08x, TTT: 0x%08x, StatSN: 0x%08x,"
3510 		" Length: %u, CID: %hu F: %d C: %d\n", cmd->init_task_tag,
3511 		cmd->targ_xfer_tag, cmd->stat_sn, text_length, conn->cid,
3512 		!!(hdr->flags & ISCSI_FLAG_CMD_FINAL),
3513 		!!(hdr->flags & ISCSI_FLAG_TEXT_CONTINUE));
3514 
3515 	return text_length + padding;
3516 }
3517 EXPORT_SYMBOL(iscsit_build_text_rsp);
3518 
3519 static int iscsit_send_text_rsp(
3520 	struct iscsi_cmd *cmd,
3521 	struct iscsi_conn *conn)
3522 {
3523 	struct iscsi_text_rsp *hdr = (struct iscsi_text_rsp *)cmd->pdu;
3524 	int text_length;
3525 
3526 	text_length = iscsit_build_text_rsp(cmd, conn, hdr,
3527 				conn->conn_transport->transport_type);
3528 	if (text_length < 0)
3529 		return text_length;
3530 
3531 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3532 						     cmd->buf_ptr,
3533 						     text_length);
3534 }
3535 
3536 void
3537 iscsit_build_reject(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3538 		    struct iscsi_reject *hdr)
3539 {
3540 	hdr->opcode		= ISCSI_OP_REJECT;
3541 	hdr->reason		= cmd->reject_reason;
3542 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3543 	hton24(hdr->dlength, ISCSI_HDR_LEN);
3544 	hdr->ffffffff		= cpu_to_be32(0xffffffff);
3545 	cmd->stat_sn		= conn->stat_sn++;
3546 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3547 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3548 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3549 
3550 }
3551 EXPORT_SYMBOL(iscsit_build_reject);
3552 
3553 static int iscsit_send_reject(
3554 	struct iscsi_cmd *cmd,
3555 	struct iscsi_conn *conn)
3556 {
3557 	struct iscsi_reject *hdr = (struct iscsi_reject *)&cmd->pdu[0];
3558 
3559 	iscsit_build_reject(cmd, conn, hdr);
3560 
3561 	pr_debug("Built Reject PDU StatSN: 0x%08x, Reason: 0x%02x,"
3562 		" CID: %hu\n", ntohl(hdr->statsn), hdr->reason, conn->cid);
3563 
3564 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3565 						     cmd->buf_ptr,
3566 						     ISCSI_HDR_LEN);
3567 }
3568 
3569 void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
3570 {
3571 	int ord, cpu;
3572 	/*
3573 	 * bitmap_id is assigned from iscsit_global->ts_bitmap from
3574 	 * within iscsit_start_kthreads()
3575 	 *
3576 	 * Here we use bitmap_id to determine which CPU that this
3577 	 * iSCSI connection's RX/TX threads will be scheduled to
3578 	 * execute upon.
3579 	 */
3580 	ord = conn->bitmap_id % cpumask_weight(cpu_online_mask);
3581 	for_each_online_cpu(cpu) {
3582 		if (ord-- == 0) {
3583 			cpumask_set_cpu(cpu, conn->conn_cpumask);
3584 			return;
3585 		}
3586 	}
3587 	/*
3588 	 * This should never be reached..
3589 	 */
3590 	dump_stack();
3591 	cpumask_setall(conn->conn_cpumask);
3592 }
3593 
3594 int
3595 iscsit_immediate_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
3596 {
3597 	int ret;
3598 
3599 	switch (state) {
3600 	case ISTATE_SEND_R2T:
3601 		ret = iscsit_send_r2t(cmd, conn);
3602 		if (ret < 0)
3603 			goto err;
3604 		break;
3605 	case ISTATE_REMOVE:
3606 		spin_lock_bh(&conn->cmd_lock);
3607 		list_del_init(&cmd->i_conn_node);
3608 		spin_unlock_bh(&conn->cmd_lock);
3609 
3610 		iscsit_free_cmd(cmd, false);
3611 		break;
3612 	case ISTATE_SEND_NOPIN_WANT_RESPONSE:
3613 		iscsit_mod_nopin_response_timer(conn);
3614 		ret = iscsit_send_unsolicited_nopin(cmd, conn, 1);
3615 		if (ret < 0)
3616 			goto err;
3617 		break;
3618 	case ISTATE_SEND_NOPIN_NO_RESPONSE:
3619 		ret = iscsit_send_unsolicited_nopin(cmd, conn, 0);
3620 		if (ret < 0)
3621 			goto err;
3622 		break;
3623 	default:
3624 		pr_err("Unknown Opcode: 0x%02x ITT:"
3625 		       " 0x%08x, i_state: %d on CID: %hu\n",
3626 		       cmd->iscsi_opcode, cmd->init_task_tag, state,
3627 		       conn->cid);
3628 		goto err;
3629 	}
3630 
3631 	return 0;
3632 
3633 err:
3634 	return -1;
3635 }
3636 EXPORT_SYMBOL(iscsit_immediate_queue);
3637 
3638 static int
3639 iscsit_handle_immediate_queue(struct iscsi_conn *conn)
3640 {
3641 	struct iscsit_transport *t = conn->conn_transport;
3642 	struct iscsi_queue_req *qr;
3643 	struct iscsi_cmd *cmd;
3644 	u8 state;
3645 	int ret;
3646 
3647 	while ((qr = iscsit_get_cmd_from_immediate_queue(conn))) {
3648 		atomic_set(&conn->check_immediate_queue, 0);
3649 		cmd = qr->cmd;
3650 		state = qr->state;
3651 		kmem_cache_free(lio_qr_cache, qr);
3652 
3653 		ret = t->iscsit_immediate_queue(conn, cmd, state);
3654 		if (ret < 0)
3655 			return ret;
3656 	}
3657 
3658 	return 0;
3659 }
3660 
3661 int
3662 iscsit_response_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
3663 {
3664 	int ret;
3665 
3666 check_rsp_state:
3667 	switch (state) {
3668 	case ISTATE_SEND_DATAIN:
3669 		ret = iscsit_send_datain(cmd, conn);
3670 		if (ret < 0)
3671 			goto err;
3672 		else if (!ret)
3673 			/* more drs */
3674 			goto check_rsp_state;
3675 		else if (ret == 1) {
3676 			/* all done */
3677 			spin_lock_bh(&cmd->istate_lock);
3678 			cmd->i_state = ISTATE_SENT_STATUS;
3679 			spin_unlock_bh(&cmd->istate_lock);
3680 
3681 			if (atomic_read(&conn->check_immediate_queue))
3682 				return 1;
3683 
3684 			return 0;
3685 		} else if (ret == 2) {
3686 			/* Still must send status,
3687 			   SCF_TRANSPORT_TASK_SENSE was set */
3688 			spin_lock_bh(&cmd->istate_lock);
3689 			cmd->i_state = ISTATE_SEND_STATUS;
3690 			spin_unlock_bh(&cmd->istate_lock);
3691 			state = ISTATE_SEND_STATUS;
3692 			goto check_rsp_state;
3693 		}
3694 
3695 		break;
3696 	case ISTATE_SEND_STATUS:
3697 	case ISTATE_SEND_STATUS_RECOVERY:
3698 		ret = iscsit_send_response(cmd, conn);
3699 		break;
3700 	case ISTATE_SEND_LOGOUTRSP:
3701 		ret = iscsit_send_logout(cmd, conn);
3702 		break;
3703 	case ISTATE_SEND_ASYNCMSG:
3704 		ret = iscsit_send_conn_drop_async_message(
3705 			cmd, conn);
3706 		break;
3707 	case ISTATE_SEND_NOPIN:
3708 		ret = iscsit_send_nopin(cmd, conn);
3709 		break;
3710 	case ISTATE_SEND_REJECT:
3711 		ret = iscsit_send_reject(cmd, conn);
3712 		break;
3713 	case ISTATE_SEND_TASKMGTRSP:
3714 		ret = iscsit_send_task_mgt_rsp(cmd, conn);
3715 		if (ret != 0)
3716 			break;
3717 		ret = iscsit_tmr_post_handler(cmd, conn);
3718 		if (ret != 0)
3719 			iscsit_fall_back_to_erl0(conn->sess);
3720 		break;
3721 	case ISTATE_SEND_TEXTRSP:
3722 		ret = iscsit_send_text_rsp(cmd, conn);
3723 		break;
3724 	default:
3725 		pr_err("Unknown Opcode: 0x%02x ITT:"
3726 		       " 0x%08x, i_state: %d on CID: %hu\n",
3727 		       cmd->iscsi_opcode, cmd->init_task_tag,
3728 		       state, conn->cid);
3729 		goto err;
3730 	}
3731 	if (ret < 0)
3732 		goto err;
3733 
3734 	switch (state) {
3735 	case ISTATE_SEND_LOGOUTRSP:
3736 		if (!iscsit_logout_post_handler(cmd, conn))
3737 			return -ECONNRESET;
3738 		/* fall through */
3739 	case ISTATE_SEND_STATUS:
3740 	case ISTATE_SEND_ASYNCMSG:
3741 	case ISTATE_SEND_NOPIN:
3742 	case ISTATE_SEND_STATUS_RECOVERY:
3743 	case ISTATE_SEND_TEXTRSP:
3744 	case ISTATE_SEND_TASKMGTRSP:
3745 	case ISTATE_SEND_REJECT:
3746 		spin_lock_bh(&cmd->istate_lock);
3747 		cmd->i_state = ISTATE_SENT_STATUS;
3748 		spin_unlock_bh(&cmd->istate_lock);
3749 		break;
3750 	default:
3751 		pr_err("Unknown Opcode: 0x%02x ITT:"
3752 		       " 0x%08x, i_state: %d on CID: %hu\n",
3753 		       cmd->iscsi_opcode, cmd->init_task_tag,
3754 		       cmd->i_state, conn->cid);
3755 		goto err;
3756 	}
3757 
3758 	if (atomic_read(&conn->check_immediate_queue))
3759 		return 1;
3760 
3761 	return 0;
3762 
3763 err:
3764 	return -1;
3765 }
3766 EXPORT_SYMBOL(iscsit_response_queue);
3767 
3768 static int iscsit_handle_response_queue(struct iscsi_conn *conn)
3769 {
3770 	struct iscsit_transport *t = conn->conn_transport;
3771 	struct iscsi_queue_req *qr;
3772 	struct iscsi_cmd *cmd;
3773 	u8 state;
3774 	int ret;
3775 
3776 	while ((qr = iscsit_get_cmd_from_response_queue(conn))) {
3777 		cmd = qr->cmd;
3778 		state = qr->state;
3779 		kmem_cache_free(lio_qr_cache, qr);
3780 
3781 		ret = t->iscsit_response_queue(conn, cmd, state);
3782 		if (ret == 1 || ret < 0)
3783 			return ret;
3784 	}
3785 
3786 	return 0;
3787 }
3788 
3789 int iscsi_target_tx_thread(void *arg)
3790 {
3791 	int ret = 0;
3792 	struct iscsi_conn *conn = arg;
3793 	bool conn_freed = false;
3794 
3795 	/*
3796 	 * Allow ourselves to be interrupted by SIGINT so that a
3797 	 * connection recovery / failure event can be triggered externally.
3798 	 */
3799 	allow_signal(SIGINT);
3800 
3801 	while (!kthread_should_stop()) {
3802 		/*
3803 		 * Ensure that both TX and RX per connection kthreads
3804 		 * are scheduled to run on the same CPU.
3805 		 */
3806 		iscsit_thread_check_cpumask(conn, current, 1);
3807 
3808 		wait_event_interruptible(conn->queues_wq,
3809 					 !iscsit_conn_all_queues_empty(conn));
3810 
3811 		if (signal_pending(current))
3812 			goto transport_err;
3813 
3814 get_immediate:
3815 		ret = iscsit_handle_immediate_queue(conn);
3816 		if (ret < 0)
3817 			goto transport_err;
3818 
3819 		ret = iscsit_handle_response_queue(conn);
3820 		if (ret == 1) {
3821 			goto get_immediate;
3822 		} else if (ret == -ECONNRESET) {
3823 			conn_freed = true;
3824 			goto out;
3825 		} else if (ret < 0) {
3826 			goto transport_err;
3827 		}
3828 	}
3829 
3830 transport_err:
3831 	/*
3832 	 * Avoid the normal connection failure code-path if this connection
3833 	 * is still within LOGIN mode, and iscsi_np process context is
3834 	 * responsible for cleaning up the early connection failure.
3835 	 */
3836 	if (conn->conn_state != TARG_CONN_STATE_IN_LOGIN)
3837 		iscsit_take_action_for_connection_exit(conn, &conn_freed);
3838 out:
3839 	if (!conn_freed) {
3840 		while (!kthread_should_stop()) {
3841 			msleep(100);
3842 		}
3843 	}
3844 	return 0;
3845 }
3846 
3847 static int iscsi_target_rx_opcode(struct iscsi_conn *conn, unsigned char *buf)
3848 {
3849 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)buf;
3850 	struct iscsi_cmd *cmd;
3851 	int ret = 0;
3852 
3853 	switch (hdr->opcode & ISCSI_OPCODE_MASK) {
3854 	case ISCSI_OP_SCSI_CMD:
3855 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3856 		if (!cmd)
3857 			goto reject;
3858 
3859 		ret = iscsit_handle_scsi_cmd(conn, cmd, buf);
3860 		break;
3861 	case ISCSI_OP_SCSI_DATA_OUT:
3862 		ret = iscsit_handle_data_out(conn, buf);
3863 		break;
3864 	case ISCSI_OP_NOOP_OUT:
3865 		cmd = NULL;
3866 		if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
3867 			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3868 			if (!cmd)
3869 				goto reject;
3870 		}
3871 		ret = iscsit_handle_nop_out(conn, cmd, buf);
3872 		break;
3873 	case ISCSI_OP_SCSI_TMFUNC:
3874 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3875 		if (!cmd)
3876 			goto reject;
3877 
3878 		ret = iscsit_handle_task_mgt_cmd(conn, cmd, buf);
3879 		break;
3880 	case ISCSI_OP_TEXT:
3881 		if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
3882 			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
3883 			if (!cmd)
3884 				goto reject;
3885 		} else {
3886 			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3887 			if (!cmd)
3888 				goto reject;
3889 		}
3890 
3891 		ret = iscsit_handle_text_cmd(conn, cmd, buf);
3892 		break;
3893 	case ISCSI_OP_LOGOUT:
3894 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3895 		if (!cmd)
3896 			goto reject;
3897 
3898 		ret = iscsit_handle_logout_cmd(conn, cmd, buf);
3899 		if (ret > 0)
3900 			wait_for_completion_timeout(&conn->conn_logout_comp,
3901 					SECONDS_FOR_LOGOUT_COMP * HZ);
3902 		break;
3903 	case ISCSI_OP_SNACK:
3904 		ret = iscsit_handle_snack(conn, buf);
3905 		break;
3906 	default:
3907 		pr_err("Got unknown iSCSI OpCode: 0x%02x\n", hdr->opcode);
3908 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
3909 			pr_err("Cannot recover from unknown"
3910 			" opcode while ERL=0, closing iSCSI connection.\n");
3911 			return -1;
3912 		}
3913 		pr_err("Unable to recover from unknown opcode while OFMarker=No,"
3914 		       " closing iSCSI connection.\n");
3915 		ret = -1;
3916 		break;
3917 	}
3918 
3919 	return ret;
3920 reject:
3921 	return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
3922 }
3923 
3924 static bool iscsi_target_check_conn_state(struct iscsi_conn *conn)
3925 {
3926 	bool ret;
3927 
3928 	spin_lock_bh(&conn->state_lock);
3929 	ret = (conn->conn_state != TARG_CONN_STATE_LOGGED_IN);
3930 	spin_unlock_bh(&conn->state_lock);
3931 
3932 	return ret;
3933 }
3934 
3935 static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
3936 {
3937 	int ret;
3938 	u8 buffer[ISCSI_HDR_LEN], opcode;
3939 	u32 checksum = 0, digest = 0;
3940 	struct kvec iov;
3941 
3942 	while (!kthread_should_stop()) {
3943 		/*
3944 		 * Ensure that both TX and RX per connection kthreads
3945 		 * are scheduled to run on the same CPU.
3946 		 */
3947 		iscsit_thread_check_cpumask(conn, current, 0);
3948 
3949 		memset(buffer, 0, ISCSI_HDR_LEN);
3950 		memset(&iov, 0, sizeof(struct kvec));
3951 
3952 		iov.iov_base	= buffer;
3953 		iov.iov_len	= ISCSI_HDR_LEN;
3954 
3955 		ret = rx_data(conn, &iov, 1, ISCSI_HDR_LEN);
3956 		if (ret != ISCSI_HDR_LEN) {
3957 			iscsit_rx_thread_wait_for_tcp(conn);
3958 			return;
3959 		}
3960 
3961 		if (conn->conn_ops->HeaderDigest) {
3962 			iov.iov_base	= &digest;
3963 			iov.iov_len	= ISCSI_CRC_LEN;
3964 
3965 			ret = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
3966 			if (ret != ISCSI_CRC_LEN) {
3967 				iscsit_rx_thread_wait_for_tcp(conn);
3968 				return;
3969 			}
3970 
3971 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash,
3972 					buffer, ISCSI_HDR_LEN,
3973 					0, NULL, (u8 *)&checksum);
3974 
3975 			if (digest != checksum) {
3976 				pr_err("HeaderDigest CRC32C failed,"
3977 					" received 0x%08x, computed 0x%08x\n",
3978 					digest, checksum);
3979 				/*
3980 				 * Set the PDU to 0xff so it will intentionally
3981 				 * hit default in the switch below.
3982 				 */
3983 				memset(buffer, 0xff, ISCSI_HDR_LEN);
3984 				atomic_long_inc(&conn->sess->conn_digest_errors);
3985 			} else {
3986 				pr_debug("Got HeaderDigest CRC32C"
3987 						" 0x%08x\n", checksum);
3988 			}
3989 		}
3990 
3991 		if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
3992 			return;
3993 
3994 		opcode = buffer[0] & ISCSI_OPCODE_MASK;
3995 
3996 		if (conn->sess->sess_ops->SessionType &&
3997 		   ((!(opcode & ISCSI_OP_TEXT)) ||
3998 		    (!(opcode & ISCSI_OP_LOGOUT)))) {
3999 			pr_err("Received illegal iSCSI Opcode: 0x%02x"
4000 			" while in Discovery Session, rejecting.\n", opcode);
4001 			iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
4002 					  buffer);
4003 			return;
4004 		}
4005 
4006 		ret = iscsi_target_rx_opcode(conn, buffer);
4007 		if (ret < 0)
4008 			return;
4009 	}
4010 }
4011 
4012 int iscsi_target_rx_thread(void *arg)
4013 {
4014 	int rc;
4015 	struct iscsi_conn *conn = arg;
4016 	bool conn_freed = false;
4017 
4018 	/*
4019 	 * Allow ourselves to be interrupted by SIGINT so that a
4020 	 * connection recovery / failure event can be triggered externally.
4021 	 */
4022 	allow_signal(SIGINT);
4023 	/*
4024 	 * Wait for iscsi_post_login_handler() to complete before allowing
4025 	 * incoming iscsi/tcp socket I/O, and/or failing the connection.
4026 	 */
4027 	rc = wait_for_completion_interruptible(&conn->rx_login_comp);
4028 	if (rc < 0 || iscsi_target_check_conn_state(conn))
4029 		goto out;
4030 
4031 	if (!conn->conn_transport->iscsit_get_rx_pdu)
4032 		return 0;
4033 
4034 	conn->conn_transport->iscsit_get_rx_pdu(conn);
4035 
4036 	if (!signal_pending(current))
4037 		atomic_set(&conn->transport_failed, 1);
4038 	iscsit_take_action_for_connection_exit(conn, &conn_freed);
4039 
4040 out:
4041 	if (!conn_freed) {
4042 		while (!kthread_should_stop()) {
4043 			msleep(100);
4044 		}
4045 	}
4046 
4047 	return 0;
4048 }
4049 
4050 static void iscsit_release_commands_from_conn(struct iscsi_conn *conn)
4051 {
4052 	LIST_HEAD(tmp_list);
4053 	struct iscsi_cmd *cmd = NULL, *cmd_tmp = NULL;
4054 	struct iscsi_session *sess = conn->sess;
4055 	/*
4056 	 * We expect this function to only ever be called from either RX or TX
4057 	 * thread context via iscsit_close_connection() once the other context
4058 	 * has been reset -> returned sleeping pre-handler state.
4059 	 */
4060 	spin_lock_bh(&conn->cmd_lock);
4061 	list_splice_init(&conn->conn_cmd_list, &tmp_list);
4062 
4063 	list_for_each_entry(cmd, &tmp_list, i_conn_node) {
4064 		struct se_cmd *se_cmd = &cmd->se_cmd;
4065 
4066 		if (se_cmd->se_tfo != NULL) {
4067 			spin_lock(&se_cmd->t_state_lock);
4068 			se_cmd->transport_state |= CMD_T_FABRIC_STOP;
4069 			spin_unlock(&se_cmd->t_state_lock);
4070 		}
4071 	}
4072 	spin_unlock_bh(&conn->cmd_lock);
4073 
4074 	list_for_each_entry_safe(cmd, cmd_tmp, &tmp_list, i_conn_node) {
4075 		list_del_init(&cmd->i_conn_node);
4076 
4077 		iscsit_increment_maxcmdsn(cmd, sess);
4078 		iscsit_free_cmd(cmd, true);
4079 
4080 	}
4081 }
4082 
4083 static void iscsit_stop_timers_for_cmds(
4084 	struct iscsi_conn *conn)
4085 {
4086 	struct iscsi_cmd *cmd;
4087 
4088 	spin_lock_bh(&conn->cmd_lock);
4089 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
4090 		if (cmd->data_direction == DMA_TO_DEVICE)
4091 			iscsit_stop_dataout_timer(cmd);
4092 	}
4093 	spin_unlock_bh(&conn->cmd_lock);
4094 }
4095 
4096 int iscsit_close_connection(
4097 	struct iscsi_conn *conn)
4098 {
4099 	int conn_logout = (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT);
4100 	struct iscsi_session	*sess = conn->sess;
4101 
4102 	pr_debug("Closing iSCSI connection CID %hu on SID:"
4103 		" %u\n", conn->cid, sess->sid);
4104 	/*
4105 	 * Always up conn_logout_comp for the traditional TCP and HW_OFFLOAD
4106 	 * case just in case the RX Thread in iscsi_target_rx_opcode() is
4107 	 * sleeping and the logout response never got sent because the
4108 	 * connection failed.
4109 	 *
4110 	 * However for iser-target, isert_wait4logout() is using conn_logout_comp
4111 	 * to signal logout response TX interrupt completion.  Go ahead and skip
4112 	 * this for iser since isert_rx_opcode() does not wait on logout failure,
4113 	 * and to avoid iscsi_conn pointer dereference in iser-target code.
4114 	 */
4115 	if (!conn->conn_transport->rdma_shutdown)
4116 		complete(&conn->conn_logout_comp);
4117 
4118 	if (!strcmp(current->comm, ISCSI_RX_THREAD_NAME)) {
4119 		if (conn->tx_thread &&
4120 		    cmpxchg(&conn->tx_thread_active, true, false)) {
4121 			send_sig(SIGINT, conn->tx_thread, 1);
4122 			kthread_stop(conn->tx_thread);
4123 		}
4124 	} else if (!strcmp(current->comm, ISCSI_TX_THREAD_NAME)) {
4125 		if (conn->rx_thread &&
4126 		    cmpxchg(&conn->rx_thread_active, true, false)) {
4127 			send_sig(SIGINT, conn->rx_thread, 1);
4128 			kthread_stop(conn->rx_thread);
4129 		}
4130 	}
4131 
4132 	spin_lock(&iscsit_global->ts_bitmap_lock);
4133 	bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
4134 			      get_order(1));
4135 	spin_unlock(&iscsit_global->ts_bitmap_lock);
4136 
4137 	iscsit_stop_timers_for_cmds(conn);
4138 	iscsit_stop_nopin_response_timer(conn);
4139 	iscsit_stop_nopin_timer(conn);
4140 
4141 	if (conn->conn_transport->iscsit_wait_conn)
4142 		conn->conn_transport->iscsit_wait_conn(conn);
4143 
4144 	/*
4145 	 * During Connection recovery drop unacknowledged out of order
4146 	 * commands for this connection, and prepare the other commands
4147 	 * for reallegiance.
4148 	 *
4149 	 * During normal operation clear the out of order commands (but
4150 	 * do not free the struct iscsi_ooo_cmdsn's) and release all
4151 	 * struct iscsi_cmds.
4152 	 */
4153 	if (atomic_read(&conn->connection_recovery)) {
4154 		iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(conn);
4155 		iscsit_prepare_cmds_for_reallegiance(conn);
4156 	} else {
4157 		iscsit_clear_ooo_cmdsns_for_conn(conn);
4158 		iscsit_release_commands_from_conn(conn);
4159 	}
4160 	iscsit_free_queue_reqs_for_conn(conn);
4161 
4162 	/*
4163 	 * Handle decrementing session or connection usage count if
4164 	 * a logout response was not able to be sent because the
4165 	 * connection failed.  Fall back to Session Recovery here.
4166 	 */
4167 	if (atomic_read(&conn->conn_logout_remove)) {
4168 		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_SESSION) {
4169 			iscsit_dec_conn_usage_count(conn);
4170 			iscsit_dec_session_usage_count(sess);
4171 		}
4172 		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION)
4173 			iscsit_dec_conn_usage_count(conn);
4174 
4175 		atomic_set(&conn->conn_logout_remove, 0);
4176 		atomic_set(&sess->session_reinstatement, 0);
4177 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4178 	}
4179 
4180 	spin_lock_bh(&sess->conn_lock);
4181 	list_del(&conn->conn_list);
4182 
4183 	/*
4184 	 * Attempt to let the Initiator know this connection failed by
4185 	 * sending an Connection Dropped Async Message on another
4186 	 * active connection.
4187 	 */
4188 	if (atomic_read(&conn->connection_recovery))
4189 		iscsit_build_conn_drop_async_message(conn);
4190 
4191 	spin_unlock_bh(&sess->conn_lock);
4192 
4193 	/*
4194 	 * If connection reinstatement is being performed on this connection,
4195 	 * up the connection reinstatement semaphore that is being blocked on
4196 	 * in iscsit_cause_connection_reinstatement().
4197 	 */
4198 	spin_lock_bh(&conn->state_lock);
4199 	if (atomic_read(&conn->sleep_on_conn_wait_comp)) {
4200 		spin_unlock_bh(&conn->state_lock);
4201 		complete(&conn->conn_wait_comp);
4202 		wait_for_completion(&conn->conn_post_wait_comp);
4203 		spin_lock_bh(&conn->state_lock);
4204 	}
4205 
4206 	/*
4207 	 * If connection reinstatement is being performed on this connection
4208 	 * by receiving a REMOVECONNFORRECOVERY logout request, up the
4209 	 * connection wait rcfr semaphore that is being blocked on
4210 	 * an iscsit_connection_reinstatement_rcfr().
4211 	 */
4212 	if (atomic_read(&conn->connection_wait_rcfr)) {
4213 		spin_unlock_bh(&conn->state_lock);
4214 		complete(&conn->conn_wait_rcfr_comp);
4215 		wait_for_completion(&conn->conn_post_wait_comp);
4216 		spin_lock_bh(&conn->state_lock);
4217 	}
4218 	atomic_set(&conn->connection_reinstatement, 1);
4219 	spin_unlock_bh(&conn->state_lock);
4220 
4221 	/*
4222 	 * If any other processes are accessing this connection pointer we
4223 	 * must wait until they have completed.
4224 	 */
4225 	iscsit_check_conn_usage_count(conn);
4226 
4227 	ahash_request_free(conn->conn_tx_hash);
4228 	if (conn->conn_rx_hash) {
4229 		struct crypto_ahash *tfm;
4230 
4231 		tfm = crypto_ahash_reqtfm(conn->conn_rx_hash);
4232 		ahash_request_free(conn->conn_rx_hash);
4233 		crypto_free_ahash(tfm);
4234 	}
4235 
4236 	free_cpumask_var(conn->conn_cpumask);
4237 
4238 	kfree(conn->conn_ops);
4239 	conn->conn_ops = NULL;
4240 
4241 	if (conn->sock)
4242 		sock_release(conn->sock);
4243 
4244 	if (conn->conn_transport->iscsit_free_conn)
4245 		conn->conn_transport->iscsit_free_conn(conn);
4246 
4247 	iscsit_put_transport(conn->conn_transport);
4248 
4249 	pr_debug("Moving to TARG_CONN_STATE_FREE.\n");
4250 	conn->conn_state = TARG_CONN_STATE_FREE;
4251 	kfree(conn);
4252 
4253 	spin_lock_bh(&sess->conn_lock);
4254 	atomic_dec(&sess->nconn);
4255 	pr_debug("Decremented iSCSI connection count to %hu from node:"
4256 		" %s\n", atomic_read(&sess->nconn),
4257 		sess->sess_ops->InitiatorName);
4258 	/*
4259 	 * Make sure that if one connection fails in an non ERL=2 iSCSI
4260 	 * Session that they all fail.
4261 	 */
4262 	if ((sess->sess_ops->ErrorRecoveryLevel != 2) && !conn_logout &&
4263 	     !atomic_read(&sess->session_logout))
4264 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4265 
4266 	/*
4267 	 * If this was not the last connection in the session, and we are
4268 	 * performing session reinstatement or falling back to ERL=0, call
4269 	 * iscsit_stop_session() without sleeping to shutdown the other
4270 	 * active connections.
4271 	 */
4272 	if (atomic_read(&sess->nconn)) {
4273 		if (!atomic_read(&sess->session_reinstatement) &&
4274 		    !atomic_read(&sess->session_fall_back_to_erl0)) {
4275 			spin_unlock_bh(&sess->conn_lock);
4276 			return 0;
4277 		}
4278 		if (!atomic_read(&sess->session_stop_active)) {
4279 			atomic_set(&sess->session_stop_active, 1);
4280 			spin_unlock_bh(&sess->conn_lock);
4281 			iscsit_stop_session(sess, 0, 0);
4282 			return 0;
4283 		}
4284 		spin_unlock_bh(&sess->conn_lock);
4285 		return 0;
4286 	}
4287 
4288 	/*
4289 	 * If this was the last connection in the session and one of the
4290 	 * following is occurring:
4291 	 *
4292 	 * Session Reinstatement is not being performed, and are falling back
4293 	 * to ERL=0 call iscsit_close_session().
4294 	 *
4295 	 * Session Logout was requested.  iscsit_close_session() will be called
4296 	 * elsewhere.
4297 	 *
4298 	 * Session Continuation is not being performed, start the Time2Retain
4299 	 * handler and check if sleep_on_sess_wait_sem is active.
4300 	 */
4301 	if (!atomic_read(&sess->session_reinstatement) &&
4302 	     atomic_read(&sess->session_fall_back_to_erl0)) {
4303 		spin_unlock_bh(&sess->conn_lock);
4304 		iscsit_close_session(sess);
4305 
4306 		return 0;
4307 	} else if (atomic_read(&sess->session_logout)) {
4308 		pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
4309 		sess->session_state = TARG_SESS_STATE_FREE;
4310 		spin_unlock_bh(&sess->conn_lock);
4311 
4312 		if (atomic_read(&sess->sleep_on_sess_wait_comp))
4313 			complete(&sess->session_wait_comp);
4314 
4315 		return 0;
4316 	} else {
4317 		pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
4318 		sess->session_state = TARG_SESS_STATE_FAILED;
4319 
4320 		if (!atomic_read(&sess->session_continuation)) {
4321 			spin_unlock_bh(&sess->conn_lock);
4322 			iscsit_start_time2retain_handler(sess);
4323 		} else
4324 			spin_unlock_bh(&sess->conn_lock);
4325 
4326 		if (atomic_read(&sess->sleep_on_sess_wait_comp))
4327 			complete(&sess->session_wait_comp);
4328 
4329 		return 0;
4330 	}
4331 }
4332 
4333 /*
4334  * If the iSCSI Session for the iSCSI Initiator Node exists,
4335  * forcefully shutdown the iSCSI NEXUS.
4336  */
4337 int iscsit_close_session(struct iscsi_session *sess)
4338 {
4339 	struct iscsi_portal_group *tpg = sess->tpg;
4340 	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
4341 
4342 	if (atomic_read(&sess->nconn)) {
4343 		pr_err("%d connection(s) still exist for iSCSI session"
4344 			" to %s\n", atomic_read(&sess->nconn),
4345 			sess->sess_ops->InitiatorName);
4346 		BUG();
4347 	}
4348 
4349 	spin_lock_bh(&se_tpg->session_lock);
4350 	atomic_set(&sess->session_logout, 1);
4351 	atomic_set(&sess->session_reinstatement, 1);
4352 	iscsit_stop_time2retain_timer(sess);
4353 	spin_unlock_bh(&se_tpg->session_lock);
4354 
4355 	/*
4356 	 * transport_deregister_session_configfs() will clear the
4357 	 * struct se_node_acl->nacl_sess pointer now as a iscsi_np process context
4358 	 * can be setting it again with __transport_register_session() in
4359 	 * iscsi_post_login_handler() again after the iscsit_stop_session()
4360 	 * completes in iscsi_np context.
4361 	 */
4362 	transport_deregister_session_configfs(sess->se_sess);
4363 
4364 	/*
4365 	 * If any other processes are accessing this session pointer we must
4366 	 * wait until they have completed.  If we are in an interrupt (the
4367 	 * time2retain handler) and contain and active session usage count we
4368 	 * restart the timer and exit.
4369 	 */
4370 	if (!in_interrupt()) {
4371 		if (iscsit_check_session_usage_count(sess) == 1)
4372 			iscsit_stop_session(sess, 1, 1);
4373 	} else {
4374 		if (iscsit_check_session_usage_count(sess) == 2) {
4375 			atomic_set(&sess->session_logout, 0);
4376 			iscsit_start_time2retain_handler(sess);
4377 			return 0;
4378 		}
4379 	}
4380 
4381 	transport_deregister_session(sess->se_sess);
4382 
4383 	if (sess->sess_ops->ErrorRecoveryLevel == 2)
4384 		iscsit_free_connection_recovery_entires(sess);
4385 
4386 	iscsit_free_all_ooo_cmdsns(sess);
4387 
4388 	spin_lock_bh(&se_tpg->session_lock);
4389 	pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
4390 	sess->session_state = TARG_SESS_STATE_FREE;
4391 	pr_debug("Released iSCSI session from node: %s\n",
4392 			sess->sess_ops->InitiatorName);
4393 	tpg->nsessions--;
4394 	if (tpg->tpg_tiqn)
4395 		tpg->tpg_tiqn->tiqn_nsessions--;
4396 
4397 	pr_debug("Decremented number of active iSCSI Sessions on"
4398 		" iSCSI TPG: %hu to %u\n", tpg->tpgt, tpg->nsessions);
4399 
4400 	spin_lock(&sess_idr_lock);
4401 	idr_remove(&sess_idr, sess->session_index);
4402 	spin_unlock(&sess_idr_lock);
4403 
4404 	kfree(sess->sess_ops);
4405 	sess->sess_ops = NULL;
4406 	spin_unlock_bh(&se_tpg->session_lock);
4407 
4408 	kfree(sess);
4409 	return 0;
4410 }
4411 
4412 static void iscsit_logout_post_handler_closesession(
4413 	struct iscsi_conn *conn)
4414 {
4415 	struct iscsi_session *sess = conn->sess;
4416 	int sleep = 1;
4417 	/*
4418 	 * Traditional iscsi/tcp will invoke this logic from TX thread
4419 	 * context during session logout, so clear tx_thread_active and
4420 	 * sleep if iscsit_close_connection() has not already occured.
4421 	 *
4422 	 * Since iser-target invokes this logic from it's own workqueue,
4423 	 * always sleep waiting for RX/TX thread shutdown to complete
4424 	 * within iscsit_close_connection().
4425 	 */
4426 	if (!conn->conn_transport->rdma_shutdown)
4427 		sleep = cmpxchg(&conn->tx_thread_active, true, false);
4428 
4429 	atomic_set(&conn->conn_logout_remove, 0);
4430 	complete(&conn->conn_logout_comp);
4431 
4432 	iscsit_dec_conn_usage_count(conn);
4433 	iscsit_stop_session(sess, sleep, sleep);
4434 	iscsit_dec_session_usage_count(sess);
4435 	iscsit_close_session(sess);
4436 }
4437 
4438 static void iscsit_logout_post_handler_samecid(
4439 	struct iscsi_conn *conn)
4440 {
4441 	int sleep = 1;
4442 
4443 	if (!conn->conn_transport->rdma_shutdown)
4444 		sleep = cmpxchg(&conn->tx_thread_active, true, false);
4445 
4446 	atomic_set(&conn->conn_logout_remove, 0);
4447 	complete(&conn->conn_logout_comp);
4448 
4449 	iscsit_cause_connection_reinstatement(conn, sleep);
4450 	iscsit_dec_conn_usage_count(conn);
4451 }
4452 
4453 static void iscsit_logout_post_handler_diffcid(
4454 	struct iscsi_conn *conn,
4455 	u16 cid)
4456 {
4457 	struct iscsi_conn *l_conn;
4458 	struct iscsi_session *sess = conn->sess;
4459 	bool conn_found = false;
4460 
4461 	if (!sess)
4462 		return;
4463 
4464 	spin_lock_bh(&sess->conn_lock);
4465 	list_for_each_entry(l_conn, &sess->sess_conn_list, conn_list) {
4466 		if (l_conn->cid == cid) {
4467 			iscsit_inc_conn_usage_count(l_conn);
4468 			conn_found = true;
4469 			break;
4470 		}
4471 	}
4472 	spin_unlock_bh(&sess->conn_lock);
4473 
4474 	if (!conn_found)
4475 		return;
4476 
4477 	if (l_conn->sock)
4478 		l_conn->sock->ops->shutdown(l_conn->sock, RCV_SHUTDOWN);
4479 
4480 	spin_lock_bh(&l_conn->state_lock);
4481 	pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
4482 	l_conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
4483 	spin_unlock_bh(&l_conn->state_lock);
4484 
4485 	iscsit_cause_connection_reinstatement(l_conn, 1);
4486 	iscsit_dec_conn_usage_count(l_conn);
4487 }
4488 
4489 /*
4490  *	Return of 0 causes the TX thread to restart.
4491  */
4492 int iscsit_logout_post_handler(
4493 	struct iscsi_cmd *cmd,
4494 	struct iscsi_conn *conn)
4495 {
4496 	int ret = 0;
4497 
4498 	switch (cmd->logout_reason) {
4499 	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
4500 		switch (cmd->logout_response) {
4501 		case ISCSI_LOGOUT_SUCCESS:
4502 		case ISCSI_LOGOUT_CLEANUP_FAILED:
4503 		default:
4504 			iscsit_logout_post_handler_closesession(conn);
4505 			break;
4506 		}
4507 		ret = 0;
4508 		break;
4509 	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
4510 		if (conn->cid == cmd->logout_cid) {
4511 			switch (cmd->logout_response) {
4512 			case ISCSI_LOGOUT_SUCCESS:
4513 			case ISCSI_LOGOUT_CLEANUP_FAILED:
4514 			default:
4515 				iscsit_logout_post_handler_samecid(conn);
4516 				break;
4517 			}
4518 			ret = 0;
4519 		} else {
4520 			switch (cmd->logout_response) {
4521 			case ISCSI_LOGOUT_SUCCESS:
4522 				iscsit_logout_post_handler_diffcid(conn,
4523 					cmd->logout_cid);
4524 				break;
4525 			case ISCSI_LOGOUT_CID_NOT_FOUND:
4526 			case ISCSI_LOGOUT_CLEANUP_FAILED:
4527 			default:
4528 				break;
4529 			}
4530 			ret = 1;
4531 		}
4532 		break;
4533 	case ISCSI_LOGOUT_REASON_RECOVERY:
4534 		switch (cmd->logout_response) {
4535 		case ISCSI_LOGOUT_SUCCESS:
4536 		case ISCSI_LOGOUT_CID_NOT_FOUND:
4537 		case ISCSI_LOGOUT_RECOVERY_UNSUPPORTED:
4538 		case ISCSI_LOGOUT_CLEANUP_FAILED:
4539 		default:
4540 			break;
4541 		}
4542 		ret = 1;
4543 		break;
4544 	default:
4545 		break;
4546 
4547 	}
4548 	return ret;
4549 }
4550 EXPORT_SYMBOL(iscsit_logout_post_handler);
4551 
4552 void iscsit_fail_session(struct iscsi_session *sess)
4553 {
4554 	struct iscsi_conn *conn;
4555 
4556 	spin_lock_bh(&sess->conn_lock);
4557 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
4558 		pr_debug("Moving to TARG_CONN_STATE_CLEANUP_WAIT.\n");
4559 		conn->conn_state = TARG_CONN_STATE_CLEANUP_WAIT;
4560 	}
4561 	spin_unlock_bh(&sess->conn_lock);
4562 
4563 	pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
4564 	sess->session_state = TARG_SESS_STATE_FAILED;
4565 }
4566 
4567 int iscsit_free_session(struct iscsi_session *sess)
4568 {
4569 	u16 conn_count = atomic_read(&sess->nconn);
4570 	struct iscsi_conn *conn, *conn_tmp = NULL;
4571 	int is_last;
4572 
4573 	spin_lock_bh(&sess->conn_lock);
4574 	atomic_set(&sess->sleep_on_sess_wait_comp, 1);
4575 
4576 	list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
4577 			conn_list) {
4578 		if (conn_count == 0)
4579 			break;
4580 
4581 		if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
4582 			is_last = 1;
4583 		} else {
4584 			iscsit_inc_conn_usage_count(conn_tmp);
4585 			is_last = 0;
4586 		}
4587 		iscsit_inc_conn_usage_count(conn);
4588 
4589 		spin_unlock_bh(&sess->conn_lock);
4590 		iscsit_cause_connection_reinstatement(conn, 1);
4591 		spin_lock_bh(&sess->conn_lock);
4592 
4593 		iscsit_dec_conn_usage_count(conn);
4594 		if (is_last == 0)
4595 			iscsit_dec_conn_usage_count(conn_tmp);
4596 
4597 		conn_count--;
4598 	}
4599 
4600 	if (atomic_read(&sess->nconn)) {
4601 		spin_unlock_bh(&sess->conn_lock);
4602 		wait_for_completion(&sess->session_wait_comp);
4603 	} else
4604 		spin_unlock_bh(&sess->conn_lock);
4605 
4606 	iscsit_close_session(sess);
4607 	return 0;
4608 }
4609 
4610 void iscsit_stop_session(
4611 	struct iscsi_session *sess,
4612 	int session_sleep,
4613 	int connection_sleep)
4614 {
4615 	u16 conn_count = atomic_read(&sess->nconn);
4616 	struct iscsi_conn *conn, *conn_tmp = NULL;
4617 	int is_last;
4618 
4619 	spin_lock_bh(&sess->conn_lock);
4620 	if (session_sleep)
4621 		atomic_set(&sess->sleep_on_sess_wait_comp, 1);
4622 
4623 	if (connection_sleep) {
4624 		list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
4625 				conn_list) {
4626 			if (conn_count == 0)
4627 				break;
4628 
4629 			if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
4630 				is_last = 1;
4631 			} else {
4632 				iscsit_inc_conn_usage_count(conn_tmp);
4633 				is_last = 0;
4634 			}
4635 			iscsit_inc_conn_usage_count(conn);
4636 
4637 			spin_unlock_bh(&sess->conn_lock);
4638 			iscsit_cause_connection_reinstatement(conn, 1);
4639 			spin_lock_bh(&sess->conn_lock);
4640 
4641 			iscsit_dec_conn_usage_count(conn);
4642 			if (is_last == 0)
4643 				iscsit_dec_conn_usage_count(conn_tmp);
4644 			conn_count--;
4645 		}
4646 	} else {
4647 		list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
4648 			iscsit_cause_connection_reinstatement(conn, 0);
4649 	}
4650 
4651 	if (session_sleep && atomic_read(&sess->nconn)) {
4652 		spin_unlock_bh(&sess->conn_lock);
4653 		wait_for_completion(&sess->session_wait_comp);
4654 	} else
4655 		spin_unlock_bh(&sess->conn_lock);
4656 }
4657 
4658 int iscsit_release_sessions_for_tpg(struct iscsi_portal_group *tpg, int force)
4659 {
4660 	struct iscsi_session *sess;
4661 	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
4662 	struct se_session *se_sess, *se_sess_tmp;
4663 	LIST_HEAD(free_list);
4664 	int session_count = 0;
4665 
4666 	spin_lock_bh(&se_tpg->session_lock);
4667 	if (tpg->nsessions && !force) {
4668 		spin_unlock_bh(&se_tpg->session_lock);
4669 		return -1;
4670 	}
4671 
4672 	list_for_each_entry_safe(se_sess, se_sess_tmp, &se_tpg->tpg_sess_list,
4673 			sess_list) {
4674 		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
4675 
4676 		spin_lock(&sess->conn_lock);
4677 		if (atomic_read(&sess->session_fall_back_to_erl0) ||
4678 		    atomic_read(&sess->session_logout) ||
4679 		    (sess->time2retain_timer_flags & ISCSI_TF_EXPIRED)) {
4680 			spin_unlock(&sess->conn_lock);
4681 			continue;
4682 		}
4683 		atomic_set(&sess->session_reinstatement, 1);
4684 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4685 		spin_unlock(&sess->conn_lock);
4686 
4687 		list_move_tail(&se_sess->sess_list, &free_list);
4688 	}
4689 	spin_unlock_bh(&se_tpg->session_lock);
4690 
4691 	list_for_each_entry_safe(se_sess, se_sess_tmp, &free_list, sess_list) {
4692 		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
4693 
4694 		iscsit_free_session(sess);
4695 		session_count++;
4696 	}
4697 
4698 	pr_debug("Released %d iSCSI Session(s) from Target Portal"
4699 			" Group: %hu\n", session_count, tpg->tpgt);
4700 	return 0;
4701 }
4702 
4703 MODULE_DESCRIPTION("iSCSI-Target Driver for mainline target infrastructure");
4704 MODULE_VERSION("4.1.x");
4705 MODULE_AUTHOR("nab@Linux-iSCSI.org");
4706 MODULE_LICENSE("GPL");
4707 
4708 module_init(iscsi_target_init_module);
4709 module_exit(iscsi_target_cleanup_module);
4710