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[SCSI] iscsi bugfixes: reduce memory allocations
[linux-2.6/linux-loongson.git] / drivers / scsi / iscsi_tcp.c
blobaa20adc79f0279c321990080b504377d2bd4ba90
1 /*
2 * iSCSI Initiator over TCP/IP Data-Path
3 *
4 * Copyright (C) 2004 Dmitry Yusupov
5 * Copyright (C) 2004 Alex Aizman
6 * Copyright (C) 2005 - 2006 Mike Christie
7 * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
8 * maintained by open-iscsi@googlegroups.com
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published
12 * by the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * See the file COPYING included with this distribution for more details.
21 *
22 * Credits:
23 * Christoph Hellwig
24 * FUJITA Tomonori
25 * Arne Redlich
26 * Zhenyu Wang
27 */
28
29 #include <linux/types.h>
30 #include <linux/list.h>
31 #include <linux/inet.h>
32 #include <linux/blkdev.h>
33 #include <linux/crypto.h>
34 #include <linux/delay.h>
35 #include <linux/kfifo.h>
36 #include <linux/scatterlist.h>
37 #include <linux/mutex.h>
38 #include <net/tcp.h>
39 #include <scsi/scsi_cmnd.h>
40 #include <scsi/scsi_host.h>
41 #include <scsi/scsi.h>
42 #include <scsi/scsi_transport_iscsi.h>
43
44 #include "iscsi_tcp.h"
45
46 #define ISCSI_TCP_VERSION "1.0-595"
47
48 MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, "
49 "Alex Aizman <itn780@yahoo.com>");
50 MODULE_DESCRIPTION("iSCSI/TCP data-path");
51 MODULE_LICENSE("GPL");
52 MODULE_VERSION(ISCSI_TCP_VERSION);
53 /* #define DEBUG_TCP */
54 #define DEBUG_ASSERT
55
56 #ifdef DEBUG_TCP
57 #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt)
58 #else
59 #define debug_tcp(fmt...)
60 #endif
61
62 #ifndef DEBUG_ASSERT
63 #ifdef BUG_ON
64 #undef BUG_ON
65 #endif
66 #define BUG_ON(expr)
67 #endif
68
69 static unsigned int iscsi_max_lun = 512;
70 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
71
72 static inline void
73 iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
74 {
75 ibuf->sg.page = virt_to_page(vbuf);
76 ibuf->sg.offset = offset_in_page(vbuf);
77 ibuf->sg.length = size;
78 ibuf->sent = 0;
79 ibuf->use_sendmsg = 1;
80 }
81
82 static inline void
83 iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
84 {
85 ibuf->sg.page = sg->page;
86 ibuf->sg.offset = sg->offset;
87 ibuf->sg.length = sg->length;
88 /*
89 * Fastpath: sg element fits into single page
90 */
91 if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg->page))
92 ibuf->use_sendmsg = 0;
93 else
94 ibuf->use_sendmsg = 1;
95 ibuf->sent = 0;
96 }
97
98 static inline int
99 iscsi_buf_left(struct iscsi_buf *ibuf)
100 {
101 int rc;
102
103 rc = ibuf->sg.length - ibuf->sent;
104 BUG_ON(rc < 0);
105 return rc;
106 }
107
108 static inline void
109 iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
110 u8* crc)
111 {
112 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
113
114 crypto_digest_digest(tcp_conn->tx_tfm, &buf->sg, 1, crc);
115 buf->sg.length += sizeof(uint32_t);
116 }
117
118 static inline int
119 iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
120 {
121 struct sk_buff *skb = tcp_conn->in.skb;
122
123 tcp_conn->in.zero_copy_hdr = 0;
124
125 if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
126 tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
127 /*
128 * Zero-copy PDU Header: using connection context
129 * to store header pointer.
130 */
131 if (skb_shinfo(skb)->frag_list == NULL &&
132 !skb_shinfo(skb)->nr_frags) {
133 tcp_conn->in.hdr = (struct iscsi_hdr *)
134 ((char*)skb->data + tcp_conn->in.offset);
135 tcp_conn->in.zero_copy_hdr = 1;
136 } else {
137 /* ignoring return code since we checked
138 * in.copy before */
139 skb_copy_bits(skb, tcp_conn->in.offset,
140 &tcp_conn->hdr, tcp_conn->hdr_size);
141 tcp_conn->in.hdr = &tcp_conn->hdr;
142 }
143 tcp_conn->in.offset += tcp_conn->hdr_size;
144 tcp_conn->in.copy -= tcp_conn->hdr_size;
145 } else {
146 int hdr_remains;
147 int copylen;
148
149 /*
150 * PDU header scattered across SKB's,
151 * copying it... This'll happen quite rarely.
152 */
153
154 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
155 tcp_conn->in.hdr_offset = 0;
156
157 hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
158 BUG_ON(hdr_remains <= 0);
159
160 copylen = min(tcp_conn->in.copy, hdr_remains);
161 skb_copy_bits(skb, tcp_conn->in.offset,
162 (char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset,
163 copylen);
164
165 debug_tcp("PDU gather offset %d bytes %d in.offset %d "
166 "in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
167 tcp_conn->in.offset, tcp_conn->in.copy);
168
169 tcp_conn->in.offset += copylen;
170 tcp_conn->in.copy -= copylen;
171 if (copylen < hdr_remains) {
172 tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
173 tcp_conn->in.hdr_offset += copylen;
174 return -EAGAIN;
175 }
176 tcp_conn->in.hdr = &tcp_conn->hdr;
177 tcp_conn->discontiguous_hdr_cnt++;
178 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
179 }
180
181 return 0;
182 }
183
184 /*
185 * must be called with session lock
186 */
187 static void
188 iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
189 {
190 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
191 struct iscsi_r2t_info *r2t;
192 struct scsi_cmnd *sc;
193
194 /* flush ctask's r2t queues */
195 while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
196 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t,
197 sizeof(void*));
198 debug_scsi("iscsi_tcp_cleanup_ctask pending r2t dropped\n");
199 }
200
201 sc = ctask->sc;
202 if (unlikely(!sc))
203 return;
204
205 tcp_ctask->xmstate = XMSTATE_IDLE;
206 tcp_ctask->r2t = NULL;
207 }
208
209 /**
210 * iscsi_data_rsp - SCSI Data-In Response processing
211 * @conn: iscsi connection
212 * @ctask: scsi command task
213 **/
214 static int
215 iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
216 {
217 int rc;
218 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
219 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
220 struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
221 struct iscsi_session *session = conn->session;
222 int datasn = be32_to_cpu(rhdr->datasn);
223
224 rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
225 if (rc)
226 return rc;
227 /*
228 * setup Data-In byte counter (gets decremented..)
229 */
230 ctask->data_count = tcp_conn->in.datalen;
231
232 if (tcp_conn->in.datalen == 0)
233 return 0;
234
235 if (ctask->datasn != datasn)
236 return ISCSI_ERR_DATASN;
237
238 ctask->datasn++;
239
240 tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
241 if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
242 return ISCSI_ERR_DATA_OFFSET;
243
244 if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
245 struct scsi_cmnd *sc = ctask->sc;
246
247 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
248 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
249 int res_count = be32_to_cpu(rhdr->residual_count);
250
251 if (res_count > 0 &&
252 res_count <= sc->request_bufflen) {
253 sc->resid = res_count;
254 sc->result = (DID_OK << 16) | rhdr->cmd_status;
255 } else
256 sc->result = (DID_BAD_TARGET << 16) |
257 rhdr->cmd_status;
258 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
259 sc->resid = be32_to_cpu(rhdr->residual_count);
260 sc->result = (DID_OK << 16) | rhdr->cmd_status;
261 } else
262 sc->result = (DID_OK << 16) | rhdr->cmd_status;
263 }
264
265 conn->datain_pdus_cnt++;
266 return 0;
267 }
268
269 /**
270 * iscsi_solicit_data_init - initialize first Data-Out
271 * @conn: iscsi connection
272 * @ctask: scsi command task
273 * @r2t: R2T info
274 *
275 * Notes:
276 * Initialize first Data-Out within this R2T sequence and finds
277 * proper data_offset within this SCSI command.
278 *
279 * This function is called with connection lock taken.
280 **/
281 static void
282 iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
283 struct iscsi_r2t_info *r2t)
284 {
285 struct iscsi_data *hdr;
286 struct scsi_cmnd *sc = ctask->sc;
287 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
288
289 hdr = &r2t->dtask.hdr;
290 memset(hdr, 0, sizeof(struct iscsi_data));
291 hdr->ttt = r2t->ttt;
292 hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
293 r2t->solicit_datasn++;
294 hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
295 memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
296 hdr->itt = ctask->hdr->itt;
297 hdr->exp_statsn = r2t->exp_statsn;
298 hdr->offset = cpu_to_be32(r2t->data_offset);
299 if (r2t->data_length > conn->max_xmit_dlength) {
300 hton24(hdr->dlength, conn->max_xmit_dlength);
301 r2t->data_count = conn->max_xmit_dlength;
302 hdr->flags = 0;
303 } else {
304 hton24(hdr->dlength, r2t->data_length);
305 r2t->data_count = r2t->data_length;
306 hdr->flags = ISCSI_FLAG_CMD_FINAL;
307 }
308 conn->dataout_pdus_cnt++;
309
310 r2t->sent = 0;
311
312 iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
313 sizeof(struct iscsi_hdr));
314
315 if (sc->use_sg) {
316 int i, sg_count = 0;
317 struct scatterlist *sg = sc->request_buffer;
318
319 r2t->sg = NULL;
320 for (i = 0; i < sc->use_sg; i++, sg += 1) {
321 /* FIXME: prefetch ? */
322 if (sg_count + sg->length > r2t->data_offset) {
323 int page_offset;
324
325 /* sg page found! */
326
327 /* offset within this page */
328 page_offset = r2t->data_offset - sg_count;
329
330 /* fill in this buffer */
331 iscsi_buf_init_sg(&r2t->sendbuf, sg);
332 r2t->sendbuf.sg.offset += page_offset;
333 r2t->sendbuf.sg.length -= page_offset;
334
335 /* xmit logic will continue with next one */
336 r2t->sg = sg + 1;
337 break;
338 }
339 sg_count += sg->length;
340 }
341 BUG_ON(r2t->sg == NULL);
342 } else
343 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
344 (char*)sc->request_buffer + r2t->data_offset,
345 r2t->data_count);
346 }
347
348 /**
349 * iscsi_r2t_rsp - iSCSI R2T Response processing
350 * @conn: iscsi connection
351 * @ctask: scsi command task
352 **/
353 static int
354 iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
355 {
356 struct iscsi_r2t_info *r2t;
357 struct iscsi_session *session = conn->session;
358 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
359 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
360 struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
361 int r2tsn = be32_to_cpu(rhdr->r2tsn);
362 int rc;
363
364 if (tcp_conn->in.datalen)
365 return ISCSI_ERR_DATALEN;
366
367 if (tcp_ctask->exp_r2tsn && tcp_ctask->exp_r2tsn != r2tsn)
368 return ISCSI_ERR_R2TSN;
369
370 rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
371 if (rc)
372 return rc;
373
374 /* FIXME: use R2TSN to detect missing R2T */
375
376 /* fill-in new R2T associated with the task */
377 spin_lock(&session->lock);
378 if (!ctask->sc || ctask->mtask ||
379 session->state != ISCSI_STATE_LOGGED_IN) {
380 printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in "
381 "recovery...\n", ctask->itt);
382 spin_unlock(&session->lock);
383 return 0;
384 }
385
386 rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
387 BUG_ON(!rc);
388
389 r2t->exp_statsn = rhdr->statsn;
390 r2t->data_length = be32_to_cpu(rhdr->data_length);
391 if (r2t->data_length == 0 ||
392 r2t->data_length > session->max_burst) {
393 spin_unlock(&session->lock);
394 return ISCSI_ERR_DATALEN;
395 }
396
397 r2t->data_offset = be32_to_cpu(rhdr->data_offset);
398 if (r2t->data_offset + r2t->data_length > ctask->total_length) {
399 spin_unlock(&session->lock);
400 return ISCSI_ERR_DATALEN;
401 }
402
403 r2t->ttt = rhdr->ttt; /* no flip */
404 r2t->solicit_datasn = 0;
405
406 iscsi_solicit_data_init(conn, ctask, r2t);
407
408 tcp_ctask->exp_r2tsn = r2tsn + 1;
409 tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
410 __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
411 list_move_tail(&ctask->running, &conn->xmitqueue);
412
413 scsi_queue_work(session->host, &conn->xmitwork);
414 conn->r2t_pdus_cnt++;
415 spin_unlock(&session->lock);
416
417 return 0;
418 }
419
420 static int
421 iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
422 {
423 int rc = 0, opcode, ahslen;
424 struct iscsi_hdr *hdr;
425 struct iscsi_session *session = conn->session;
426 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
427 uint32_t cdgst, rdgst = 0, itt;
428
429 hdr = tcp_conn->in.hdr;
430
431 /* verify PDU length */
432 tcp_conn->in.datalen = ntoh24(hdr->dlength);
433 if (tcp_conn->in.datalen > conn->max_recv_dlength) {
434 printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n",
435 tcp_conn->in.datalen, conn->max_recv_dlength);
436 return ISCSI_ERR_DATALEN;
437 }
438 tcp_conn->data_copied = 0;
439
440 /* read AHS */
441 ahslen = hdr->hlength << 2;
442 tcp_conn->in.offset += ahslen;
443 tcp_conn->in.copy -= ahslen;
444 if (tcp_conn->in.copy < 0) {
445 printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
446 "%d bytes\n", ahslen);
447 return ISCSI_ERR_AHSLEN;
448 }
449
450 /* calculate read padding */
451 tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
452 if (tcp_conn->in.padding) {
453 tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
454 debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
455 }
456
457 if (conn->hdrdgst_en) {
458 struct scatterlist sg;
459
460 sg_init_one(&sg, (u8 *)hdr,
461 sizeof(struct iscsi_hdr) + ahslen);
462 crypto_digest_digest(tcp_conn->rx_tfm, &sg, 1, (u8 *)&cdgst);
463 rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
464 ahslen);
465 if (cdgst != rdgst) {
466 printk(KERN_ERR "iscsi_tcp: hdrdgst error "
467 "recv 0x%x calc 0x%x\n", rdgst, cdgst);
468 return ISCSI_ERR_HDR_DGST;
469 }
470 }
471
472 opcode = hdr->opcode & ISCSI_OPCODE_MASK;
473 /* verify itt (itt encoding: age+cid+itt) */
474 rc = iscsi_verify_itt(conn, hdr, &itt);
475 if (rc == ISCSI_ERR_NO_SCSI_CMD) {
476 tcp_conn->in.datalen = 0; /* force drop */
477 return 0;
478 } else if (rc)
479 return rc;
480
481 debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
482 opcode, tcp_conn->in.offset, tcp_conn->in.copy,
483 ahslen, tcp_conn->in.datalen);
484
485 switch(opcode) {
486 case ISCSI_OP_SCSI_DATA_IN:
487 tcp_conn->in.ctask = session->cmds[itt];
488 rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
489 if (rc)
490 return rc;
491 /* fall through */
492 case ISCSI_OP_SCSI_CMD_RSP:
493 tcp_conn->in.ctask = session->cmds[itt];
494 if (tcp_conn->in.datalen)
495 goto copy_hdr;
496
497 spin_lock(&session->lock);
498 iscsi_tcp_cleanup_ctask(conn, tcp_conn->in.ctask);
499 rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
500 spin_unlock(&session->lock);
501 break;
502 case ISCSI_OP_R2T:
503 tcp_conn->in.ctask = session->cmds[itt];
504 if (ahslen)
505 rc = ISCSI_ERR_AHSLEN;
506 else if (tcp_conn->in.ctask->sc->sc_data_direction ==
507 DMA_TO_DEVICE)
508 rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
509 else
510 rc = ISCSI_ERR_PROTO;
511 break;
512 case ISCSI_OP_LOGIN_RSP:
513 case ISCSI_OP_TEXT_RSP:
514 case ISCSI_OP_REJECT:
515 case ISCSI_OP_ASYNC_EVENT:
516 /*
517 * It is possible that we could get a PDU with a buffer larger
518 * than 8K, but there are no targets that currently do this.
519 * For now we fail until we find a vendor that needs it
520 */
521 if (DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH <
522 tcp_conn->in.datalen) {
523 printk(KERN_ERR "iscsi_tcp: received buffer of len %u "
524 "but conn buffer is only %u (opcode %0x)\n",
525 tcp_conn->in.datalen,
526 DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, opcode);
527 rc = ISCSI_ERR_PROTO;
528 break;
529 }
530
531 if (tcp_conn->in.datalen)
532 goto copy_hdr;
533 /* fall through */
534 case ISCSI_OP_LOGOUT_RSP:
535 case ISCSI_OP_NOOP_IN:
536 case ISCSI_OP_SCSI_TMFUNC_RSP:
537 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
538 break;
539 default:
540 rc = ISCSI_ERR_BAD_OPCODE;
541 break;
542 }
543
544 return rc;
545
546 copy_hdr:
547 /*
548 * if we did zero copy for the header but we will need multiple
549 * skbs to complete the command then we have to copy the header
550 * for later use
551 */
552 if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <=
553 (tcp_conn->in.datalen + tcp_conn->in.padding +
554 (conn->datadgst_en ? 4 : 0))) {
555 debug_tcp("Copying header for later use. in.copy %d in.datalen"
556 " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
557 memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
558 sizeof(struct iscsi_hdr));
559 tcp_conn->in.hdr = &tcp_conn->hdr;
560 tcp_conn->in.zero_copy_hdr = 0;
561 }
562 return 0;
563 }
564
565 /**
566 * iscsi_ctask_copy - copy skb bits to the destanation cmd task
567 * @conn: iscsi tcp connection
568 * @ctask: scsi command task
569 * @buf: buffer to copy to
570 * @buf_size: size of buffer
571 * @offset: offset within the buffer
572 *
573 * Notes:
574 * The function calls skb_copy_bits() and updates per-connection and
575 * per-cmd byte counters.
576 *
577 * Read counters (in bytes):
578 *
579 * conn->in.offset offset within in progress SKB
580 * conn->in.copy left to copy from in progress SKB
581 * including padding
582 * conn->in.copied copied already from in progress SKB
583 * conn->data_copied copied already from in progress buffer
584 * ctask->sent total bytes sent up to the MidLayer
585 * ctask->data_count left to copy from in progress Data-In
586 * buf_left left to copy from in progress buffer
587 **/
588 static inline int
589 iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
590 void *buf, int buf_size, int offset)
591 {
592 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
593 int buf_left = buf_size - (tcp_conn->data_copied + offset);
594 int size = min(tcp_conn->in.copy, buf_left);
595 int rc;
596
597 size = min(size, ctask->data_count);
598
599 debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
600 size, tcp_conn->in.offset, tcp_conn->in.copied);
601
602 BUG_ON(size <= 0);
603 BUG_ON(tcp_ctask->sent + size > ctask->total_length);
604
605 rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
606 (char*)buf + (offset + tcp_conn->data_copied), size);
607 /* must fit into skb->len */
608 BUG_ON(rc);
609
610 tcp_conn->in.offset += size;
611 tcp_conn->in.copy -= size;
612 tcp_conn->in.copied += size;
613 tcp_conn->data_copied += size;
614 tcp_ctask->sent += size;
615 ctask->data_count -= size;
616
617 BUG_ON(tcp_conn->in.copy < 0);
618 BUG_ON(ctask->data_count < 0);
619
620 if (buf_size != (tcp_conn->data_copied + offset)) {
621 if (!ctask->data_count) {
622 BUG_ON(buf_size - tcp_conn->data_copied < 0);
623 /* done with this PDU */
624 return buf_size - tcp_conn->data_copied;
625 }
626 return -EAGAIN;
627 }
628
629 /* done with this buffer or with both - PDU and buffer */
630 tcp_conn->data_copied = 0;
631 return 0;
632 }
633
634 /**
635 * iscsi_tcp_copy - copy skb bits to the destanation buffer
636 * @conn: iscsi tcp connection
637 *
638 * Notes:
639 * The function calls skb_copy_bits() and updates per-connection
640 * byte counters.
641 **/
642 static inline int
643 iscsi_tcp_copy(struct iscsi_conn *conn)
644 {
645 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
646 int buf_size = tcp_conn->in.datalen;
647 int buf_left = buf_size - tcp_conn->data_copied;
648 int size = min(tcp_conn->in.copy, buf_left);
649 int rc;
650
651 debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
652 size, tcp_conn->in.offset, tcp_conn->data_copied);
653 BUG_ON(size <= 0);
654
655 rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
656 (char*)conn->data + tcp_conn->data_copied, size);
657 BUG_ON(rc);
658
659 tcp_conn->in.offset += size;
660 tcp_conn->in.copy -= size;
661 tcp_conn->in.copied += size;
662 tcp_conn->data_copied += size;
663
664 if (buf_size != tcp_conn->data_copied)
665 return -EAGAIN;
666
667 return 0;
668 }
669
670 static inline void
671 partial_sg_digest_update(struct iscsi_tcp_conn *tcp_conn,
672 struct scatterlist *sg, int offset, int length)
673 {
674 struct scatterlist temp;
675
676 memcpy(&temp, sg, sizeof(struct scatterlist));
677 temp.offset = offset;
678 temp.length = length;
679 crypto_digest_update(tcp_conn->data_rx_tfm, &temp, 1);
680 }
681
682 static void
683 iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
684 {
685 struct scatterlist tmp;
686
687 sg_init_one(&tmp, buf, len);
688 crypto_digest_update(tcp_conn->data_rx_tfm, &tmp, 1);
689 }
690
691 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
692 {
693 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
694 struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
695 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
696 struct scsi_cmnd *sc = ctask->sc;
697 struct scatterlist *sg;
698 int i, offset, rc = 0;
699
700 BUG_ON((void*)ctask != sc->SCp.ptr);
701
702 /*
703 * copying Data-In into the Scsi_Cmnd
704 */
705 if (!sc->use_sg) {
706 i = ctask->data_count;
707 rc = iscsi_ctask_copy(tcp_conn, ctask, sc->request_buffer,
708 sc->request_bufflen,
709 tcp_ctask->data_offset);
710 if (rc == -EAGAIN)
711 return rc;
712 if (conn->datadgst_en)
713 iscsi_recv_digest_update(tcp_conn, sc->request_buffer,
714 i);
715 rc = 0;
716 goto done;
717 }
718
719 offset = tcp_ctask->data_offset;
720 sg = sc->request_buffer;
721
722 if (tcp_ctask->data_offset)
723 for (i = 0; i < tcp_ctask->sg_count; i++)
724 offset -= sg[i].length;
725 /* we've passed through partial sg*/
726 if (offset < 0)
727 offset = 0;
728
729 for (i = tcp_ctask->sg_count; i < sc->use_sg; i++) {
730 char *dest;
731
732 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
733 rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
734 sg[i].length, offset);
735 kunmap_atomic(dest, KM_SOFTIRQ0);
736 if (rc == -EAGAIN)
737 /* continue with the next SKB/PDU */
738 return rc;
739 if (!rc) {
740 if (conn->datadgst_en) {
741 if (!offset)
742 crypto_digest_update(
743 tcp_conn->data_rx_tfm,
744 &sg[i], 1);
745 else
746 partial_sg_digest_update(tcp_conn,
747 &sg[i],
748 sg[i].offset + offset,
749 sg[i].length - offset);
750 }
751 offset = 0;
752 tcp_ctask->sg_count++;
753 }
754
755 if (!ctask->data_count) {
756 if (rc && conn->datadgst_en)
757 /*
758 * data-in is complete, but buffer not...
759 */
760 partial_sg_digest_update(tcp_conn, &sg[i],
761 sg[i].offset, sg[i].length-rc);
762 rc = 0;
763 break;
764 }
765
766 if (!tcp_conn->in.copy)
767 return -EAGAIN;
768 }
769 BUG_ON(ctask->data_count);
770
771 done:
772 /* check for non-exceptional status */
773 if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
774 debug_scsi("done [sc %lx res %d itt 0x%x flags 0x%x]\n",
775 (long)sc, sc->result, ctask->itt,
776 tcp_conn->in.hdr->flags);
777 spin_lock(&conn->session->lock);
778 iscsi_tcp_cleanup_ctask(conn, ctask);
779 __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
780 spin_unlock(&conn->session->lock);
781 }
782
783 return rc;
784 }
785
786 static int
787 iscsi_data_recv(struct iscsi_conn *conn)
788 {
789 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
790 int rc = 0, opcode;
791
792 opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
793 switch (opcode) {
794 case ISCSI_OP_SCSI_DATA_IN:
795 rc = iscsi_scsi_data_in(conn);
796 break;
797 case ISCSI_OP_SCSI_CMD_RSP:
798 spin_lock(&conn->session->lock);
799 iscsi_tcp_cleanup_ctask(conn, tcp_conn->in.ctask);
800 spin_unlock(&conn->session->lock);
801 case ISCSI_OP_TEXT_RSP:
802 case ISCSI_OP_LOGIN_RSP:
803 case ISCSI_OP_ASYNC_EVENT:
804 case ISCSI_OP_REJECT:
805 /*
806 * Collect data segment to the connection's data
807 * placeholder
808 */
809 if (iscsi_tcp_copy(conn)) {
810 rc = -EAGAIN;
811 goto exit;
812 }
813
814 rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, conn->data,
815 tcp_conn->in.datalen);
816 if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
817 iscsi_recv_digest_update(tcp_conn, conn->data,
818 tcp_conn->in.datalen);
819 break;
820 default:
821 BUG_ON(1);
822 }
823 exit:
824 return rc;
825 }
826
827 /**
828 * iscsi_tcp_data_recv - TCP receive in sendfile fashion
829 * @rd_desc: read descriptor
830 * @skb: socket buffer
831 * @offset: offset in skb
832 * @len: skb->len - offset
833 **/
834 static int
835 iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
836 unsigned int offset, size_t len)
837 {
838 int rc;
839 struct iscsi_conn *conn = rd_desc->arg.data;
840 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
841 int processed;
842 char pad[ISCSI_PAD_LEN];
843 struct scatterlist sg;
844
845 /*
846 * Save current SKB and its offset in the corresponding
847 * connection context.
848 */
849 tcp_conn->in.copy = skb->len - offset;
850 tcp_conn->in.offset = offset;
851 tcp_conn->in.skb = skb;
852 tcp_conn->in.len = tcp_conn->in.copy;
853 BUG_ON(tcp_conn->in.copy <= 0);
854 debug_tcp("in %d bytes\n", tcp_conn->in.copy);
855
856 more:
857 tcp_conn->in.copied = 0;
858 rc = 0;
859
860 if (unlikely(conn->suspend_rx)) {
861 debug_tcp("conn %d Rx suspended!\n", conn->id);
862 return 0;
863 }
864
865 if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
866 tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
867 rc = iscsi_hdr_extract(tcp_conn);
868 if (rc) {
869 if (rc == -EAGAIN)
870 goto nomore;
871 else {
872 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
873 return 0;
874 }
875 }
876
877 /*
878 * Verify and process incoming PDU header.
879 */
880 rc = iscsi_tcp_hdr_recv(conn);
881 if (!rc && tcp_conn->in.datalen) {
882 if (conn->datadgst_en) {
883 BUG_ON(!tcp_conn->data_rx_tfm);
884 crypto_digest_init(tcp_conn->data_rx_tfm);
885 }
886 tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
887 } else if (rc) {
888 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
889 return 0;
890 }
891 }
892
893 if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
894 uint32_t recv_digest;
895
896 debug_tcp("extra data_recv offset %d copy %d\n",
897 tcp_conn->in.offset, tcp_conn->in.copy);
898 skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
899 &recv_digest, 4);
900 tcp_conn->in.offset += 4;
901 tcp_conn->in.copy -= 4;
902 if (recv_digest != tcp_conn->in.datadgst) {
903 debug_tcp("iscsi_tcp: data digest error!"
904 "0x%x != 0x%x\n", recv_digest,
905 tcp_conn->in.datadgst);
906 iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
907 return 0;
908 } else {
909 debug_tcp("iscsi_tcp: data digest match!"
910 "0x%x == 0x%x\n", recv_digest,
911 tcp_conn->in.datadgst);
912 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
913 }
914 }
915
916 if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
917 tcp_conn->in.copy) {
918
919 debug_tcp("data_recv offset %d copy %d\n",
920 tcp_conn->in.offset, tcp_conn->in.copy);
921
922 rc = iscsi_data_recv(conn);
923 if (rc) {
924 if (rc == -EAGAIN)
925 goto again;
926 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
927 return 0;
928 }
929 tcp_conn->in.copy -= tcp_conn->in.padding;
930 tcp_conn->in.offset += tcp_conn->in.padding;
931 if (conn->datadgst_en) {
932 if (tcp_conn->in.padding) {
933 debug_tcp("padding -> %d\n",
934 tcp_conn->in.padding);
935 memset(pad, 0, tcp_conn->in.padding);
936 sg_init_one(&sg, pad, tcp_conn->in.padding);
937 crypto_digest_update(tcp_conn->data_rx_tfm,
938 &sg, 1);
939 }
940 crypto_digest_final(tcp_conn->data_rx_tfm,
941 (u8 *) & tcp_conn->in.datadgst);
942 debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
943 tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
944 } else
945 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
946 }
947
948 debug_tcp("f, processed %d from out of %d padding %d\n",
949 tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
950 BUG_ON(tcp_conn->in.offset - offset > len);
951
952 if (tcp_conn->in.offset - offset != len) {
953 debug_tcp("continue to process %d bytes\n",
954 (int)len - (tcp_conn->in.offset - offset));
955 goto more;
956 }
957
958 nomore:
959 processed = tcp_conn->in.offset - offset;
960 BUG_ON(processed == 0);
961 return processed;
962
963 again:
964 processed = tcp_conn->in.offset - offset;
965 debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
966 processed, (int)len, (int)rd_desc->count);
967 BUG_ON(processed == 0);
968 BUG_ON(processed > len);
969
970 conn->rxdata_octets += processed;
971 return processed;
972 }
973
974 static void
975 iscsi_tcp_data_ready(struct sock *sk, int flag)
976 {
977 struct iscsi_conn *conn = sk->sk_user_data;
978 read_descriptor_t rd_desc;
979
980 read_lock(&sk->sk_callback_lock);
981
982 /*
983 * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
984 * We set count to 1 because we want the network layer to
985 * hand us all the skbs that are available. iscsi_tcp_data_recv
986 * handled pdus that cross buffers or pdus that still need data.
987 */
988 rd_desc.arg.data = conn;
989 rd_desc.count = 1;
990 tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv);
991
992 read_unlock(&sk->sk_callback_lock);
993 }
994
995 static void
996 iscsi_tcp_state_change(struct sock *sk)
997 {
998 struct iscsi_tcp_conn *tcp_conn;
999 struct iscsi_conn *conn;
1000 struct iscsi_session *session;
1001 void (*old_state_change)(struct sock *);
1002
1003 read_lock(&sk->sk_callback_lock);
1004
1005 conn = (struct iscsi_conn*)sk->sk_user_data;
1006 session = conn->session;
1007
1008 if ((sk->sk_state == TCP_CLOSE_WAIT ||
1009 sk->sk_state == TCP_CLOSE) &&
1010 !atomic_read(&sk->sk_rmem_alloc)) {
1011 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
1012 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1013 }
1014
1015 tcp_conn = conn->dd_data;
1016 old_state_change = tcp_conn->old_state_change;
1017
1018 read_unlock(&sk->sk_callback_lock);
1019
1020 old_state_change(sk);
1021 }
1022
1023 /**
1024 * iscsi_write_space - Called when more output buffer space is available
1025 * @sk: socket space is available for
1026 **/
1027 static void
1028 iscsi_write_space(struct sock *sk)
1029 {
1030 struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data;
1031 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1032
1033 tcp_conn->old_write_space(sk);
1034 debug_tcp("iscsi_write_space: cid %d\n", conn->id);
1035 scsi_queue_work(conn->session->host, &conn->xmitwork);
1036 }
1037
1038 static void
1039 iscsi_conn_set_callbacks(struct iscsi_conn *conn)
1040 {
1041 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1042 struct sock *sk = tcp_conn->sock->sk;
1043
1044 /* assign new callbacks */
1045 write_lock_bh(&sk->sk_callback_lock);
1046 sk->sk_user_data = conn;
1047 tcp_conn->old_data_ready = sk->sk_data_ready;
1048 tcp_conn->old_state_change = sk->sk_state_change;
1049 tcp_conn->old_write_space = sk->sk_write_space;
1050 sk->sk_data_ready = iscsi_tcp_data_ready;
1051 sk->sk_state_change = iscsi_tcp_state_change;
1052 sk->sk_write_space = iscsi_write_space;
1053 write_unlock_bh(&sk->sk_callback_lock);
1054 }
1055
1056 static void
1057 iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn)
1058 {
1059 struct sock *sk = tcp_conn->sock->sk;
1060
1061 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
1062 write_lock_bh(&sk->sk_callback_lock);
1063 sk->sk_user_data = NULL;
1064 sk->sk_data_ready = tcp_conn->old_data_ready;
1065 sk->sk_state_change = tcp_conn->old_state_change;
1066 sk->sk_write_space = tcp_conn->old_write_space;
1067 sk->sk_no_check = 0;
1068 write_unlock_bh(&sk->sk_callback_lock);
1069 }
1070
1071 /**
1072 * iscsi_send - generic send routine
1073 * @sk: kernel's socket
1074 * @buf: buffer to write from
1075 * @size: actual size to write
1076 * @flags: socket's flags
1077 */
1078 static inline int
1079 iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)
1080 {
1081 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1082 struct socket *sk = tcp_conn->sock;
1083 int offset = buf->sg.offset + buf->sent, res;
1084
1085 /*
1086 * if we got use_sg=0 or are sending something we kmallocd
1087 * then we did not have to do kmap (kmap returns page_address)
1088 *
1089 * if we got use_sg > 0, but had to drop down, we do not
1090 * set clustering so this should only happen for that
1091 * slab case.
1092 */
1093 if (buf->use_sendmsg)
1094 res = sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
1095 else
1096 res = tcp_conn->sendpage(sk, buf->sg.page, offset, size, flags);
1097
1098 if (res >= 0) {
1099 conn->txdata_octets += res;
1100 buf->sent += res;
1101 return res;
1102 }
1103
1104 tcp_conn->sendpage_failures_cnt++;
1105 if (res == -EAGAIN)
1106 res = -ENOBUFS;
1107 else
1108 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1109 return res;
1110 }
1111
1112 /**
1113 * iscsi_sendhdr - send PDU Header via tcp_sendpage()
1114 * @conn: iscsi connection
1115 * @buf: buffer to write from
1116 * @datalen: lenght of data to be sent after the header
1117 *
1118 * Notes:
1119 * (Tx, Fast Path)
1120 **/
1121 static inline int
1122 iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
1123 {
1124 int flags = 0; /* MSG_DONTWAIT; */
1125 int res, size;
1126
1127 size = buf->sg.length - buf->sent;
1128 BUG_ON(buf->sent + size > buf->sg.length);
1129 if (buf->sent + size != buf->sg.length || datalen)
1130 flags |= MSG_MORE;
1131
1132 res = iscsi_send(conn, buf, size, flags);
1133 debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
1134 if (res >= 0) {
1135 if (size != res)
1136 return -EAGAIN;
1137 return 0;
1138 }
1139
1140 return res;
1141 }
1142
1143 /**
1144 * iscsi_sendpage - send one page of iSCSI Data-Out.
1145 * @conn: iscsi connection
1146 * @buf: buffer to write from
1147 * @count: remaining data
1148 * @sent: number of bytes sent
1149 *
1150 * Notes:
1151 * (Tx, Fast Path)
1152 **/
1153 static inline int
1154 iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
1155 int *count, int *sent)
1156 {
1157 int flags = 0; /* MSG_DONTWAIT; */
1158 int res, size;
1159
1160 size = buf->sg.length - buf->sent;
1161 BUG_ON(buf->sent + size > buf->sg.length);
1162 if (size > *count)
1163 size = *count;
1164 if (buf->sent + size != buf->sg.length || *count != size)
1165 flags |= MSG_MORE;
1166
1167 res = iscsi_send(conn, buf, size, flags);
1168 debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
1169 size, buf->sent, *count, *sent, res);
1170 if (res >= 0) {
1171 *count -= res;
1172 *sent += res;
1173 if (size != res)
1174 return -EAGAIN;
1175 return 0;
1176 }
1177
1178 return res;
1179 }
1180
1181 static inline void
1182 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
1183 struct iscsi_cmd_task *ctask)
1184 {
1185 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1186
1187 BUG_ON(!tcp_conn->data_tx_tfm);
1188 crypto_digest_init(tcp_conn->data_tx_tfm);
1189 tcp_ctask->digest_count = 4;
1190 }
1191
1192 static int
1193 iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1194 struct iscsi_buf *buf, uint32_t *digest, int final)
1195 {
1196 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1197 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1198 int rc = 0;
1199 int sent = 0;
1200
1201 if (final)
1202 crypto_digest_final(tcp_conn->data_tx_tfm, (u8*)digest);
1203
1204 iscsi_buf_init_iov(buf, (char*)digest, 4);
1205 rc = iscsi_sendpage(conn, buf, &tcp_ctask->digest_count, &sent);
1206 if (rc) {
1207 tcp_ctask->datadigest = *digest;
1208 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1209 } else
1210 tcp_ctask->digest_count = 4;
1211 return rc;
1212 }
1213
1214 /**
1215 * iscsi_solicit_data_cont - initialize next Data-Out
1216 * @conn: iscsi connection
1217 * @ctask: scsi command task
1218 * @r2t: R2T info
1219 * @left: bytes left to transfer
1220 *
1221 * Notes:
1222 * Initialize next Data-Out within this R2T sequence and continue
1223 * to process next Scatter-Gather element(if any) of this SCSI command.
1224 *
1225 * Called under connection lock.
1226 **/
1227 static void
1228 iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1229 struct iscsi_r2t_info *r2t, int left)
1230 {
1231 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1232 struct iscsi_data *hdr;
1233 struct scsi_cmnd *sc = ctask->sc;
1234 int new_offset;
1235
1236 hdr = &r2t->dtask.hdr;
1237 memset(hdr, 0, sizeof(struct iscsi_data));
1238 hdr->ttt = r2t->ttt;
1239 hdr->datasn = cpu_to_be32(r2t->solicit_datasn);
1240 r2t->solicit_datasn++;
1241 hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
1242 memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1243 hdr->itt = ctask->hdr->itt;
1244 hdr->exp_statsn = r2t->exp_statsn;
1245 new_offset = r2t->data_offset + r2t->sent;
1246 hdr->offset = cpu_to_be32(new_offset);
1247 if (left > conn->max_xmit_dlength) {
1248 hton24(hdr->dlength, conn->max_xmit_dlength);
1249 r2t->data_count = conn->max_xmit_dlength;
1250 } else {
1251 hton24(hdr->dlength, left);
1252 r2t->data_count = left;
1253 hdr->flags = ISCSI_FLAG_CMD_FINAL;
1254 }
1255 conn->dataout_pdus_cnt++;
1256
1257 iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
1258 sizeof(struct iscsi_hdr));
1259
1260 if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) {
1261 BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1262 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1263 r2t->sg += 1;
1264 } else
1265 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1266 (char*)sc->request_buffer + new_offset,
1267 r2t->data_count);
1268 }
1269
1270 static void
1271 iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1272 {
1273 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1274 struct iscsi_data_task *dtask;
1275
1276 dtask = tcp_ctask->dtask = &tcp_ctask->unsol_dtask;
1277 iscsi_prep_unsolicit_data_pdu(ctask, &dtask->hdr,
1278 tcp_ctask->r2t_data_count);
1279 iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)&dtask->hdr,
1280 sizeof(struct iscsi_hdr));
1281 }
1282
1283 /**
1284 * iscsi_tcp_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
1285 * @conn: iscsi connection
1286 * @ctask: scsi command task
1287 * @sc: scsi command
1288 **/
1289 static void
1290 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
1291 {
1292 struct scsi_cmnd *sc = ctask->sc;
1293 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1294
1295 BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
1296
1297 tcp_ctask->sent = 0;
1298 tcp_ctask->sg_count = 0;
1299
1300 if (sc->sc_data_direction == DMA_TO_DEVICE) {
1301 tcp_ctask->xmstate = XMSTATE_W_HDR;
1302 tcp_ctask->exp_r2tsn = 0;
1303 BUG_ON(ctask->total_length == 0);
1304
1305 if (sc->use_sg) {
1306 struct scatterlist *sg = sc->request_buffer;
1307
1308 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1309 &sg[tcp_ctask->sg_count++]);
1310 tcp_ctask->sg = sg;
1311 tcp_ctask->bad_sg = sg + sc->use_sg;
1312 } else
1313 iscsi_buf_init_iov(&tcp_ctask->sendbuf,
1314 sc->request_buffer,
1315 sc->request_bufflen);
1316
1317 if (ctask->imm_count)
1318 tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1319
1320 tcp_ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1);
1321 if (tcp_ctask->pad_count) {
1322 tcp_ctask->pad_count = ISCSI_PAD_LEN -
1323 tcp_ctask->pad_count;
1324 debug_scsi("write padding %d bytes\n",
1325 tcp_ctask->pad_count);
1326 tcp_ctask->xmstate |= XMSTATE_W_PAD;
1327 }
1328
1329 if (ctask->unsol_count)
1330 tcp_ctask->xmstate |= XMSTATE_UNS_HDR |
1331 XMSTATE_UNS_INIT;
1332 tcp_ctask->r2t_data_count = ctask->total_length -
1333 ctask->imm_count -
1334 ctask->unsol_count;
1335
1336 debug_scsi("cmd [itt 0x%x total %d imm %d imm_data %d "
1337 "r2t_data %d]\n",
1338 ctask->itt, ctask->total_length, ctask->imm_count,
1339 ctask->unsol_count, tcp_ctask->r2t_data_count);
1340 } else
1341 tcp_ctask->xmstate = XMSTATE_R_HDR;
1342
1343 iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
1344 sizeof(struct iscsi_hdr));
1345 }
1346
1347 /**
1348 * iscsi_tcp_mtask_xmit - xmit management(immediate) task
1349 * @conn: iscsi connection
1350 * @mtask: task management task
1351 *
1352 * Notes:
1353 * The function can return -EAGAIN in which case caller must
1354 * call it again later, or recover. '0' return code means successful
1355 * xmit.
1356 *
1357 * Management xmit state machine consists of two states:
1358 * IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
1359 * IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
1360 **/
1361 static int
1362 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
1363 {
1364 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
1365 int rc;
1366
1367 debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
1368 conn->id, tcp_mtask->xmstate, mtask->itt);
1369
1370 if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
1371 tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
1372 if (mtask->data_count)
1373 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1374 if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
1375 conn->stop_stage != STOP_CONN_RECOVER &&
1376 conn->hdrdgst_en)
1377 iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
1378 (u8*)tcp_mtask->hdrext);
1379 rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
1380 mtask->data_count);
1381 if (rc) {
1382 tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
1383 if (mtask->data_count)
1384 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1385 return rc;
1386 }
1387 }
1388
1389 if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
1390 BUG_ON(!mtask->data_count);
1391 tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
1392 /* FIXME: implement.
1393 * Virtual buffer could be spreaded across multiple pages...
1394 */
1395 do {
1396 int rc;
1397
1398 rc = iscsi_sendpage(conn, &tcp_mtask->sendbuf,
1399 &mtask->data_count, &tcp_mtask->sent);
1400 if (rc) {
1401 tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
1402 return rc;
1403 }
1404 } while (mtask->data_count);
1405 }
1406
1407 BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
1408 if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1409 struct iscsi_session *session = conn->session;
1410
1411 spin_lock_bh(&session->lock);
1412 list_del(&conn->mtask->running);
1413 __kfifo_put(session->mgmtpool.queue, (void*)&conn->mtask,
1414 sizeof(void*));
1415 spin_unlock_bh(&session->lock);
1416 }
1417 return 0;
1418 }
1419
1420 static inline int
1421 handle_xmstate_r_hdr(struct iscsi_conn *conn,
1422 struct iscsi_tcp_cmd_task *tcp_ctask)
1423 {
1424 int rc;
1425
1426 tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
1427 if (conn->hdrdgst_en)
1428 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1429 (u8*)tcp_ctask->hdrext);
1430 rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0);
1431 if (!rc) {
1432 BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
1433 return 0; /* wait for Data-In */
1434 }
1435 tcp_ctask->xmstate |= XMSTATE_R_HDR;
1436 return rc;
1437 }
1438
1439 static inline int
1440 handle_xmstate_w_hdr(struct iscsi_conn *conn,
1441 struct iscsi_cmd_task *ctask)
1442 {
1443 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1444 int rc;
1445
1446 tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
1447 if (conn->hdrdgst_en)
1448 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1449 (u8*)tcp_ctask->hdrext);
1450 rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
1451 if (rc)
1452 tcp_ctask->xmstate |= XMSTATE_W_HDR;
1453 return rc;
1454 }
1455
1456 static inline int
1457 handle_xmstate_data_digest(struct iscsi_conn *conn,
1458 struct iscsi_cmd_task *ctask)
1459 {
1460 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1461 int rc;
1462
1463 tcp_ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
1464 debug_tcp("resent data digest 0x%x\n", tcp_ctask->datadigest);
1465 rc = iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1466 &tcp_ctask->datadigest, 0);
1467 if (rc) {
1468 tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
1469 debug_tcp("resent data digest 0x%x fail!\n",
1470 tcp_ctask->datadigest);
1471 }
1472
1473 return rc;
1474 }
1475
1476 static inline int
1477 handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1478 {
1479 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1480 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1481 int rc;
1482
1483 BUG_ON(!ctask->imm_count);
1484 tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
1485
1486 if (conn->datadgst_en) {
1487 iscsi_data_digest_init(tcp_conn, ctask);
1488 tcp_ctask->immdigest = 0;
1489 }
1490
1491 for (;;) {
1492 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1493 &ctask->imm_count, &tcp_ctask->sent);
1494 if (rc) {
1495 tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
1496 if (conn->datadgst_en) {
1497 crypto_digest_final(tcp_conn->data_tx_tfm,
1498 (u8*)&tcp_ctask->immdigest);
1499 debug_tcp("tx imm sendpage fail 0x%x\n",
1500 tcp_ctask->datadigest);
1501 }
1502 return rc;
1503 }
1504 if (conn->datadgst_en)
1505 crypto_digest_update(tcp_conn->data_tx_tfm,
1506 &tcp_ctask->sendbuf.sg, 1);
1507
1508 if (!ctask->imm_count)
1509 break;
1510 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1511 &tcp_ctask->sg[tcp_ctask->sg_count++]);
1512 }
1513
1514 if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1515 rc = iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
1516 &tcp_ctask->immdigest, 1);
1517 if (rc) {
1518 debug_tcp("sending imm digest 0x%x fail!\n",
1519 tcp_ctask->immdigest);
1520 return rc;
1521 }
1522 debug_tcp("sending imm digest 0x%x\n", tcp_ctask->immdigest);
1523 }
1524
1525 return 0;
1526 }
1527
1528 static inline int
1529 handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1530 {
1531 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1532 struct iscsi_data_task *dtask;
1533 int rc;
1534
1535 tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1536 if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
1537 iscsi_unsolicit_data_init(conn, ctask);
1538 dtask = tcp_ctask->dtask;
1539 if (conn->hdrdgst_en)
1540 iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
1541 (u8*)dtask->hdrext);
1542 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
1543 }
1544
1545 rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count);
1546 if (rc) {
1547 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1548 tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
1549 return rc;
1550 }
1551
1552 debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
1553 ctask->itt, ctask->unsol_count, tcp_ctask->sent);
1554 return 0;
1555 }
1556
1557 static inline int
1558 handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1559 {
1560 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1561 struct iscsi_data_task *dtask = tcp_ctask->dtask;
1562 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1563 int rc;
1564
1565 BUG_ON(!ctask->data_count);
1566 tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
1567
1568 if (conn->datadgst_en) {
1569 iscsi_data_digest_init(tcp_conn, ctask);
1570 dtask->digest = 0;
1571 }
1572
1573 for (;;) {
1574 int start = tcp_ctask->sent;
1575
1576 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf,
1577 &ctask->data_count, &tcp_ctask->sent);
1578 if (rc) {
1579 ctask->unsol_count -= tcp_ctask->sent - start;
1580 tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
1581 /* will continue with this ctask later.. */
1582 if (conn->datadgst_en) {
1583 crypto_digest_final(tcp_conn->data_tx_tfm,
1584 (u8 *)&dtask->digest);
1585 debug_tcp("tx uns data fail 0x%x\n",
1586 dtask->digest);
1587 }
1588 return rc;
1589 }
1590
1591 BUG_ON(tcp_ctask->sent > ctask->total_length);
1592 ctask->unsol_count -= tcp_ctask->sent - start;
1593
1594 /*
1595 * XXX:we may run here with un-initial sendbuf.
1596 * so pass it
1597 */
1598 if (conn->datadgst_en && tcp_ctask->sent - start > 0)
1599 crypto_digest_update(tcp_conn->data_tx_tfm,
1600 &tcp_ctask->sendbuf.sg, 1);
1601
1602 if (!ctask->data_count)
1603 break;
1604 iscsi_buf_init_sg(&tcp_ctask->sendbuf,
1605 &tcp_ctask->sg[tcp_ctask->sg_count++]);
1606 }
1607 BUG_ON(ctask->unsol_count < 0);
1608
1609 /*
1610 * Done with the Data-Out. Next, check if we need
1611 * to send another unsolicited Data-Out.
1612 */
1613 if (ctask->unsol_count) {
1614 if (conn->datadgst_en) {
1615 rc = iscsi_digest_final_send(conn, ctask,
1616 &dtask->digestbuf,
1617 &dtask->digest, 1);
1618 if (rc) {
1619 debug_tcp("send uns digest 0x%x fail\n",
1620 dtask->digest);
1621 return rc;
1622 }
1623 debug_tcp("sending uns digest 0x%x, more uns\n",
1624 dtask->digest);
1625 }
1626 tcp_ctask->xmstate |= XMSTATE_UNS_INIT;
1627 return 1;
1628 }
1629
1630 if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
1631 rc = iscsi_digest_final_send(conn, ctask,
1632 &dtask->digestbuf,
1633 &dtask->digest, 1);
1634 if (rc) {
1635 debug_tcp("send last uns digest 0x%x fail\n",
1636 dtask->digest);
1637 return rc;
1638 }
1639 debug_tcp("sending uns digest 0x%x\n",dtask->digest);
1640 }
1641
1642 return 0;
1643 }
1644
1645 static inline int
1646 handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1647 {
1648 struct iscsi_session *session = conn->session;
1649 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1650 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1651 struct iscsi_r2t_info *r2t = tcp_ctask->r2t;
1652 struct iscsi_data_task *dtask = &r2t->dtask;
1653 int left, rc;
1654
1655 tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1656 tcp_ctask->dtask = dtask;
1657
1658 if (conn->datadgst_en) {
1659 iscsi_data_digest_init(tcp_conn, ctask);
1660 dtask->digest = 0;
1661 }
1662 solicit_again:
1663 /*
1664 * send Data-Out within this R2T sequence.
1665 */
1666 if (!r2t->data_count)
1667 goto data_out_done;
1668
1669 rc = iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent);
1670 if (rc) {
1671 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1672 /* will continue with this ctask later.. */
1673 if (conn->datadgst_en) {
1674 crypto_digest_final(tcp_conn->data_tx_tfm,
1675 (u8 *)&dtask->digest);
1676 debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
1677 }
1678 return rc;
1679 }
1680
1681 BUG_ON(r2t->data_count < 0);
1682 if (conn->datadgst_en)
1683 crypto_digest_update(tcp_conn->data_tx_tfm, &r2t->sendbuf.sg,
1684 1);
1685
1686 if (r2t->data_count) {
1687 BUG_ON(ctask->sc->use_sg == 0);
1688 if (!iscsi_buf_left(&r2t->sendbuf)) {
1689 BUG_ON(tcp_ctask->bad_sg == r2t->sg);
1690 iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
1691 r2t->sg += 1;
1692 }
1693 goto solicit_again;
1694 }
1695
1696 data_out_done:
1697 /*
1698 * Done with this Data-Out. Next, check if we have
1699 * to send another Data-Out for this R2T.
1700 */
1701 BUG_ON(r2t->data_length - r2t->sent < 0);
1702 left = r2t->data_length - r2t->sent;
1703 if (left) {
1704 if (conn->datadgst_en) {
1705 rc = iscsi_digest_final_send(conn, ctask,
1706 &dtask->digestbuf,
1707 &dtask->digest, 1);
1708 if (rc) {
1709 debug_tcp("send r2t data digest 0x%x"
1710 "fail\n", dtask->digest);
1711 return rc;
1712 }
1713 debug_tcp("r2t data send digest 0x%x\n",
1714 dtask->digest);
1715 }
1716 iscsi_solicit_data_cont(conn, ctask, r2t, left);
1717 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1718 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1719 return 1;
1720 }
1721
1722 /*
1723 * Done with this R2T. Check if there are more
1724 * outstanding R2Ts ready to be processed.
1725 */
1726 BUG_ON(tcp_ctask->r2t_data_count - r2t->data_length < 0);
1727 if (conn->datadgst_en) {
1728 rc = iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
1729 &dtask->digest, 1);
1730 if (rc) {
1731 debug_tcp("send last r2t data digest 0x%x"
1732 "fail\n", dtask->digest);
1733 return rc;
1734 }
1735 debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
1736 }
1737
1738 tcp_ctask->r2t_data_count -= r2t->data_length;
1739 tcp_ctask->r2t = NULL;
1740 spin_lock_bh(&session->lock);
1741 __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*));
1742 spin_unlock_bh(&session->lock);
1743 if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) {
1744 tcp_ctask->r2t = r2t;
1745 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1746 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1747 return 1;
1748 }
1749
1750 return 0;
1751 }
1752
1753 static inline int
1754 handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1755 {
1756 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1757 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1758 struct iscsi_data_task *dtask = tcp_ctask->dtask;
1759 int sent = 0, rc;
1760
1761 tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
1762 iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
1763 tcp_ctask->pad_count);
1764 rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
1765 &sent);
1766 if (rc) {
1767 tcp_ctask->xmstate |= XMSTATE_W_PAD;
1768 return rc;
1769 }
1770
1771 if (conn->datadgst_en) {
1772 crypto_digest_update(tcp_conn->data_tx_tfm,
1773 &tcp_ctask->sendbuf.sg, 1);
1774 /* imm data? */
1775 if (!dtask) {
1776 rc = iscsi_digest_final_send(conn, ctask,
1777 &tcp_ctask->immbuf,
1778 &tcp_ctask->immdigest, 1);
1779 if (rc) {
1780 debug_tcp("send padding digest 0x%x"
1781 "fail!\n", tcp_ctask->immdigest);
1782 return rc;
1783 }
1784 debug_tcp("done with padding, digest 0x%x\n",
1785 tcp_ctask->datadigest);
1786 } else {
1787 rc = iscsi_digest_final_send(conn, ctask,
1788 &dtask->digestbuf,
1789 &dtask->digest, 1);
1790 if (rc) {
1791 debug_tcp("send padding digest 0x%x"
1792 "fail\n", dtask->digest);
1793 return rc;
1794 }
1795 debug_tcp("done with padding, digest 0x%x\n",
1796 dtask->digest);
1797 }
1798 }
1799
1800 return 0;
1801 }
1802
1803 static int
1804 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
1805 {
1806 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
1807 int rc = 0;
1808
1809 debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n",
1810 conn->id, tcp_ctask->xmstate, ctask->itt);
1811
1812 /*
1813 * serialize with TMF AbortTask
1814 */
1815 if (ctask->mtask)
1816 return rc;
1817
1818 if (tcp_ctask->xmstate & XMSTATE_R_HDR)
1819 return handle_xmstate_r_hdr(conn, tcp_ctask);
1820
1821 if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
1822 rc = handle_xmstate_w_hdr(conn, ctask);
1823 if (rc)
1824 return rc;
1825 }
1826
1827 /* XXX: for data digest xmit recover */
1828 if (tcp_ctask->xmstate & XMSTATE_DATA_DIGEST) {
1829 rc = handle_xmstate_data_digest(conn, ctask);
1830 if (rc)
1831 return rc;
1832 }
1833
1834 if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
1835 rc = handle_xmstate_imm_data(conn, ctask);
1836 if (rc)
1837 return rc;
1838 }
1839
1840 if (tcp_ctask->xmstate & XMSTATE_UNS_HDR) {
1841 BUG_ON(!ctask->unsol_count);
1842 tcp_ctask->xmstate &= ~XMSTATE_UNS_HDR;
1843 unsolicit_head_again:
1844 rc = handle_xmstate_uns_hdr(conn, ctask);
1845 if (rc)
1846 return rc;
1847 }
1848
1849 if (tcp_ctask->xmstate & XMSTATE_UNS_DATA) {
1850 rc = handle_xmstate_uns_data(conn, ctask);
1851 if (rc == 1)
1852 goto unsolicit_head_again;
1853 else if (rc)
1854 return rc;
1855 goto done;
1856 }
1857
1858 if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
1859 struct iscsi_r2t_info *r2t;
1860
1861 tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
1862 tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
1863 if (!tcp_ctask->r2t)
1864 __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
1865 sizeof(void*));
1866 solicit_head_again:
1867 r2t = tcp_ctask->r2t;
1868 if (conn->hdrdgst_en)
1869 iscsi_hdr_digest(conn, &r2t->headbuf,
1870 (u8*)r2t->dtask.hdrext);
1871 rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
1872 if (rc) {
1873 tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
1874 tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
1875 return rc;
1876 }
1877
1878 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
1879 r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
1880 r2t->sent);
1881 }
1882
1883 if (tcp_ctask->xmstate & XMSTATE_SOL_DATA) {
1884 rc = handle_xmstate_sol_data(conn, ctask);
1885 if (rc == 1)
1886 goto solicit_head_again;
1887 if (rc)
1888 return rc;
1889 }
1890
1891 done:
1892 /*
1893 * Last thing to check is whether we need to send write
1894 * padding. Note that we check for xmstate equality, not just the bit.
1895 */
1896 if (tcp_ctask->xmstate == XMSTATE_W_PAD)
1897 rc = handle_xmstate_w_pad(conn, ctask);
1898
1899 return rc;
1900 }
1901
1902 static struct iscsi_cls_conn *
1903 iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1904 {
1905 struct iscsi_conn *conn;
1906 struct iscsi_cls_conn *cls_conn;
1907 struct iscsi_tcp_conn *tcp_conn;
1908
1909 cls_conn = iscsi_conn_setup(cls_session, conn_idx);
1910 if (!cls_conn)
1911 return NULL;
1912 conn = cls_conn->dd_data;
1913 /*
1914 * due to strange issues with iser these are not set
1915 * in iscsi_conn_setup
1916 */
1917 conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
1918
1919 tcp_conn = kzalloc(sizeof(*tcp_conn), GFP_KERNEL);
1920 if (!tcp_conn)
1921 goto tcp_conn_alloc_fail;
1922
1923 conn->dd_data = tcp_conn;
1924 tcp_conn->iscsi_conn = conn;
1925 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
1926 /* initial operational parameters */
1927 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
1928
1929 return cls_conn;
1930
1931 tcp_conn_alloc_fail:
1932 iscsi_conn_teardown(cls_conn);
1933 return NULL;
1934 }
1935
1936 static void
1937 iscsi_tcp_release_conn(struct iscsi_conn *conn)
1938 {
1939 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1940
1941 if (!tcp_conn->sock)
1942 return;
1943
1944 sock_hold(tcp_conn->sock->sk);
1945 iscsi_conn_restore_callbacks(tcp_conn);
1946 sock_put(tcp_conn->sock->sk);
1947
1948 sock_release(tcp_conn->sock);
1949 tcp_conn->sock = NULL;
1950 conn->recv_lock = NULL;
1951 }
1952
1953 static void
1954 iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
1955 {
1956 struct iscsi_conn *conn = cls_conn->dd_data;
1957 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1958 int digest = 0;
1959
1960 if (conn->hdrdgst_en || conn->datadgst_en)
1961 digest = 1;
1962
1963 iscsi_tcp_release_conn(conn);
1964 iscsi_conn_teardown(cls_conn);
1965
1966 /* now free tcp_conn */
1967 if (digest) {
1968 if (tcp_conn->tx_tfm)
1969 crypto_free_tfm(tcp_conn->tx_tfm);
1970 if (tcp_conn->rx_tfm)
1971 crypto_free_tfm(tcp_conn->rx_tfm);
1972 if (tcp_conn->data_tx_tfm)
1973 crypto_free_tfm(tcp_conn->data_tx_tfm);
1974 if (tcp_conn->data_rx_tfm)
1975 crypto_free_tfm(tcp_conn->data_rx_tfm);
1976 }
1977
1978 kfree(tcp_conn);
1979 }
1980
1981 static void
1982 iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1983 {
1984 struct iscsi_conn *conn = cls_conn->dd_data;
1985
1986 iscsi_conn_stop(cls_conn, flag);
1987 iscsi_tcp_release_conn(conn);
1988 }
1989
1990 static int
1991 iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session,
1992 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
1993 int is_leading)
1994 {
1995 struct iscsi_conn *conn = cls_conn->dd_data;
1996 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
1997 struct sock *sk;
1998 struct socket *sock;
1999 int err;
2000
2001 /* lookup for existing socket */
2002 sock = sockfd_lookup((int)transport_eph, &err);
2003 if (!sock) {
2004 printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err);
2005 return -EEXIST;
2006 }
2007
2008 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
2009 if (err)
2010 return err;
2011
2012 /* bind iSCSI connection and socket */
2013 tcp_conn->sock = sock;
2014
2015 /* setup Socket parameters */
2016 sk = sock->sk;
2017 sk->sk_reuse = 1;
2018 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
2019 sk->sk_allocation = GFP_ATOMIC;
2020
2021 /* FIXME: disable Nagle's algorithm */
2022
2023 /*
2024 * Intercept TCP callbacks for sendfile like receive
2025 * processing.
2026 */
2027 conn->recv_lock = &sk->sk_callback_lock;
2028 iscsi_conn_set_callbacks(conn);
2029 tcp_conn->sendpage = tcp_conn->sock->ops->sendpage;
2030 /*
2031 * set receive state machine into initial state
2032 */
2033 tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
2034
2035 return 0;
2036 }
2037
2038 /* called with host lock */
2039 static void
2040 iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask,
2041 char *data, uint32_t data_size)
2042 {
2043 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2044
2045 iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
2046 sizeof(struct iscsi_hdr));
2047 tcp_mtask->xmstate = XMSTATE_IMM_HDR;
2048 tcp_mtask->sent = 0;
2049
2050 if (mtask->data_count)
2051 iscsi_buf_init_iov(&tcp_mtask->sendbuf, (char*)mtask->data,
2052 mtask->data_count);
2053 }
2054
2055 static int
2056 iscsi_r2tpool_alloc(struct iscsi_session *session)
2057 {
2058 int i;
2059 int cmd_i;
2060
2061 /*
2062 * initialize per-task: R2T pool and xmit queue
2063 */
2064 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2065 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2066 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2067
2068 /*
2069 * pre-allocated x4 as much r2ts to handle race when
2070 * target acks DataOut faster than we data_xmit() queues
2071 * could replenish r2tqueue.
2072 */
2073
2074 /* R2T pool */
2075 if (iscsi_pool_init(&tcp_ctask->r2tpool, session->max_r2t * 4,
2076 (void***)&tcp_ctask->r2ts,
2077 sizeof(struct iscsi_r2t_info))) {
2078 goto r2t_alloc_fail;
2079 }
2080
2081 /* R2T xmit queue */
2082 tcp_ctask->r2tqueue = kfifo_alloc(
2083 session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL);
2084 if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) {
2085 iscsi_pool_free(&tcp_ctask->r2tpool,
2086 (void**)tcp_ctask->r2ts);
2087 goto r2t_alloc_fail;
2088 }
2089 }
2090
2091 return 0;
2092
2093 r2t_alloc_fail:
2094 for (i = 0; i < cmd_i; i++) {
2095 struct iscsi_cmd_task *ctask = session->cmds[i];
2096 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2097
2098 kfifo_free(tcp_ctask->r2tqueue);
2099 iscsi_pool_free(&tcp_ctask->r2tpool,
2100 (void**)tcp_ctask->r2ts);
2101 }
2102 return -ENOMEM;
2103 }
2104
2105 static void
2106 iscsi_r2tpool_free(struct iscsi_session *session)
2107 {
2108 int i;
2109
2110 for (i = 0; i < session->cmds_max; i++) {
2111 struct iscsi_cmd_task *ctask = session->cmds[i];
2112 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2113
2114 kfifo_free(tcp_ctask->r2tqueue);
2115 iscsi_pool_free(&tcp_ctask->r2tpool,
2116 (void**)tcp_ctask->r2ts);
2117 }
2118 }
2119
2120 static int
2121 iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
2122 char *buf, int buflen)
2123 {
2124 struct iscsi_conn *conn = cls_conn->dd_data;
2125 struct iscsi_session *session = conn->session;
2126 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2127 int value;
2128
2129 switch(param) {
2130 case ISCSI_PARAM_HDRDGST_EN:
2131 iscsi_set_param(cls_conn, param, buf, buflen);
2132 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
2133 if (conn->hdrdgst_en) {
2134 tcp_conn->hdr_size += sizeof(__u32);
2135 if (!tcp_conn->tx_tfm)
2136 tcp_conn->tx_tfm = crypto_alloc_tfm("crc32c",
2137 0);
2138 if (!tcp_conn->tx_tfm)
2139 return -ENOMEM;
2140 if (!tcp_conn->rx_tfm)
2141 tcp_conn->rx_tfm = crypto_alloc_tfm("crc32c",
2142 0);
2143 if (!tcp_conn->rx_tfm) {
2144 crypto_free_tfm(tcp_conn->tx_tfm);
2145 return -ENOMEM;
2146 }
2147 } else {
2148 if (tcp_conn->tx_tfm)
2149 crypto_free_tfm(tcp_conn->tx_tfm);
2150 if (tcp_conn->rx_tfm)
2151 crypto_free_tfm(tcp_conn->rx_tfm);
2152 }
2153 break;
2154 case ISCSI_PARAM_DATADGST_EN:
2155 iscsi_set_param(cls_conn, param, buf, buflen);
2156 if (conn->datadgst_en) {
2157 if (!tcp_conn->data_tx_tfm)
2158 tcp_conn->data_tx_tfm =
2159 crypto_alloc_tfm("crc32c", 0);
2160 if (!tcp_conn->data_tx_tfm)
2161 return -ENOMEM;
2162 if (!tcp_conn->data_rx_tfm)
2163 tcp_conn->data_rx_tfm =
2164 crypto_alloc_tfm("crc32c", 0);
2165 if (!tcp_conn->data_rx_tfm) {
2166 crypto_free_tfm(tcp_conn->data_tx_tfm);
2167 return -ENOMEM;
2168 }
2169 } else {
2170 if (tcp_conn->data_tx_tfm)
2171 crypto_free_tfm(tcp_conn->data_tx_tfm);
2172 if (tcp_conn->data_rx_tfm)
2173 crypto_free_tfm(tcp_conn->data_rx_tfm);
2174 }
2175 tcp_conn->sendpage = conn->datadgst_en ?
2176 sock_no_sendpage : tcp_conn->sock->ops->sendpage;
2177 break;
2178 case ISCSI_PARAM_MAX_R2T:
2179 sscanf(buf, "%d", &value);
2180 if (session->max_r2t == roundup_pow_of_two(value))
2181 break;
2182 iscsi_r2tpool_free(session);
2183 iscsi_set_param(cls_conn, param, buf, buflen);
2184 if (session->max_r2t & (session->max_r2t - 1))
2185 session->max_r2t = roundup_pow_of_two(session->max_r2t);
2186 if (iscsi_r2tpool_alloc(session))
2187 return -ENOMEM;
2188 break;
2189 default:
2190 return iscsi_set_param(cls_conn, param, buf, buflen);
2191 }
2192
2193 return 0;
2194 }
2195
2196 static int
2197 iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
2198 enum iscsi_param param, char *buf)
2199 {
2200 struct iscsi_conn *conn = cls_conn->dd_data;
2201 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2202 struct inet_sock *inet;
2203 struct ipv6_pinfo *np;
2204 struct sock *sk;
2205 int len;
2206
2207 switch(param) {
2208 case ISCSI_PARAM_CONN_PORT:
2209 mutex_lock(&conn->xmitmutex);
2210 if (!tcp_conn->sock) {
2211 mutex_unlock(&conn->xmitmutex);
2212 return -EINVAL;
2213 }
2214
2215 inet = inet_sk(tcp_conn->sock->sk);
2216 len = sprintf(buf, "%hu\n", be16_to_cpu(inet->dport));
2217 mutex_unlock(&conn->xmitmutex);
2218 break;
2219 case ISCSI_PARAM_CONN_ADDRESS:
2220 mutex_lock(&conn->xmitmutex);
2221 if (!tcp_conn->sock) {
2222 mutex_unlock(&conn->xmitmutex);
2223 return -EINVAL;
2224 }
2225
2226 sk = tcp_conn->sock->sk;
2227 if (sk->sk_family == PF_INET) {
2228 inet = inet_sk(sk);
2229 len = sprintf(buf, "%u.%u.%u.%u\n",
2230 NIPQUAD(inet->daddr));
2231 } else {
2232 np = inet6_sk(sk);
2233 len = sprintf(buf,
2234 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
2235 NIP6(np->daddr));
2236 }
2237 mutex_unlock(&conn->xmitmutex);
2238 break;
2239 default:
2240 return iscsi_conn_get_param(cls_conn, param, buf);
2241 }
2242
2243 return len;
2244 }
2245
2246 static void
2247 iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
2248 {
2249 struct iscsi_conn *conn = cls_conn->dd_data;
2250 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
2251
2252 stats->txdata_octets = conn->txdata_octets;
2253 stats->rxdata_octets = conn->rxdata_octets;
2254 stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
2255 stats->dataout_pdus = conn->dataout_pdus_cnt;
2256 stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
2257 stats->datain_pdus = conn->datain_pdus_cnt;
2258 stats->r2t_pdus = conn->r2t_pdus_cnt;
2259 stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
2260 stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
2261 stats->custom_length = 3;
2262 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
2263 stats->custom[0].value = tcp_conn->sendpage_failures_cnt;
2264 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
2265 stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt;
2266 strcpy(stats->custom[2].desc, "eh_abort_cnt");
2267 stats->custom[2].value = conn->eh_abort_cnt;
2268 }
2269
2270 static struct iscsi_cls_session *
2271 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
2272 struct scsi_transport_template *scsit,
2273 uint32_t initial_cmdsn, uint32_t *hostno)
2274 {
2275 struct iscsi_cls_session *cls_session;
2276 struct iscsi_session *session;
2277 uint32_t hn;
2278 int cmd_i;
2279
2280 cls_session = iscsi_session_setup(iscsit, scsit,
2281 sizeof(struct iscsi_tcp_cmd_task),
2282 sizeof(struct iscsi_tcp_mgmt_task),
2283 initial_cmdsn, &hn);
2284 if (!cls_session)
2285 return NULL;
2286 *hostno = hn;
2287
2288 session = class_to_transport_session(cls_session);
2289 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2290 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
2291 struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
2292
2293 ctask->hdr = &tcp_ctask->hdr;
2294 }
2295
2296 for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
2297 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
2298 struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
2299
2300 mtask->hdr = &tcp_mtask->hdr;
2301 }
2302
2303 if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session)))
2304 goto r2tpool_alloc_fail;
2305
2306 return cls_session;
2307
2308 r2tpool_alloc_fail:
2309 iscsi_session_teardown(cls_session);
2310 return NULL;
2311 }
2312
2313 static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
2314 {
2315 iscsi_r2tpool_free(class_to_transport_session(cls_session));
2316 iscsi_session_teardown(cls_session);
2317 }
2318
2319 static struct scsi_host_template iscsi_sht = {
2320 .name = "iSCSI Initiator over TCP/IP, v"
2321 ISCSI_TCP_VERSION,
2322 .queuecommand = iscsi_queuecommand,
2323 .change_queue_depth = iscsi_change_queue_depth,
2324 .can_queue = ISCSI_XMIT_CMDS_MAX - 1,
2325 .sg_tablesize = ISCSI_SG_TABLESIZE,
2326 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
2327 .eh_abort_handler = iscsi_eh_abort,
2328 .eh_host_reset_handler = iscsi_eh_host_reset,
2329 .use_clustering = DISABLE_CLUSTERING,
2330 .proc_name = "iscsi_tcp",
2331 .this_id = -1,
2332 };
2333
2334 static struct iscsi_transport iscsi_tcp_transport = {
2335 .owner = THIS_MODULE,
2336 .name = "tcp",
2337 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
2338 | CAP_DATADGST,
2339 .param_mask = ISCSI_MAX_RECV_DLENGTH |
2340 ISCSI_MAX_XMIT_DLENGTH |
2341 ISCSI_HDRDGST_EN |
2342 ISCSI_DATADGST_EN |
2343 ISCSI_INITIAL_R2T_EN |
2344 ISCSI_MAX_R2T |
2345 ISCSI_IMM_DATA_EN |
2346 ISCSI_FIRST_BURST |
2347 ISCSI_MAX_BURST |
2348 ISCSI_PDU_INORDER_EN |
2349 ISCSI_DATASEQ_INORDER_EN |
2350 ISCSI_ERL |
2351 ISCSI_CONN_PORT |
2352 ISCSI_CONN_ADDRESS |
2353 ISCSI_EXP_STATSN |
2354 ISCSI_PERSISTENT_PORT |
2355 ISCSI_PERSISTENT_ADDRESS |
2356 ISCSI_TARGET_NAME |
2357 ISCSI_TPGT,
2358 .host_template = &iscsi_sht,
2359 .conndata_size = sizeof(struct iscsi_conn),
2360 .max_conn = 1,
2361 .max_cmd_len = ISCSI_TCP_MAX_CMD_LEN,
2362 /* session management */
2363 .create_session = iscsi_tcp_session_create,
2364 .destroy_session = iscsi_tcp_session_destroy,
2365 /* connection management */
2366 .create_conn = iscsi_tcp_conn_create,
2367 .bind_conn = iscsi_tcp_conn_bind,
2368 .destroy_conn = iscsi_tcp_conn_destroy,
2369 .set_param = iscsi_conn_set_param,
2370 .get_conn_param = iscsi_tcp_conn_get_param,
2371 .get_session_param = iscsi_session_get_param,
2372 .start_conn = iscsi_conn_start,
2373 .stop_conn = iscsi_tcp_conn_stop,
2374 /* IO */
2375 .send_pdu = iscsi_conn_send_pdu,
2376 .get_stats = iscsi_conn_get_stats,
2377 .init_cmd_task = iscsi_tcp_cmd_init,
2378 .init_mgmt_task = iscsi_tcp_mgmt_init,
2379 .xmit_cmd_task = iscsi_tcp_ctask_xmit,
2380 .xmit_mgmt_task = iscsi_tcp_mtask_xmit,
2381 .cleanup_cmd_task = iscsi_tcp_cleanup_ctask,
2382 /* recovery */
2383 .session_recovery_timedout = iscsi_session_recovery_timedout,
2384 };
2385
2386 static int __init
2387 iscsi_tcp_init(void)
2388 {
2389 if (iscsi_max_lun < 1) {
2390 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
2391 iscsi_max_lun);
2392 return -EINVAL;
2393 }
2394 iscsi_tcp_transport.max_lun = iscsi_max_lun;
2395
2396 if (!iscsi_register_transport(&iscsi_tcp_transport))
2397 return -ENODEV;
2398
2399 return 0;
2400 }
2401
2402 static void __exit
2403 iscsi_tcp_exit(void)
2404 {
2405 iscsi_unregister_transport(&iscsi_tcp_transport);
2406 }
2407
2408 module_init(iscsi_tcp_init);
2409 module_exit(iscsi_tcp_exit);
linux kernel for loongson