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Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm...
[linux-2.6.git] / drivers / scsi / iscsi_tcp.c
blobadd6d1566ec8331aa5e27963e13fefa74a117ffd
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/inet.h>
31 #include <linux/slab.h>
32 #include <linux/file.h>
33 #include <linux/blkdev.h>
34 #include <linux/crypto.h>
35 #include <linux/delay.h>
36 #include <linux/kfifo.h>
37 #include <linux/scatterlist.h>
38 #include <linux/module.h>
39 #include <net/tcp.h>
40 #include <scsi/scsi_cmnd.h>
41 #include <scsi/scsi_device.h>
42 #include <scsi/scsi_host.h>
43 #include <scsi/scsi.h>
44 #include <scsi/scsi_transport_iscsi.h>
45
46 #include "iscsi_tcp.h"
47
48 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
49 "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
50 "Alex Aizman <itn780@yahoo.com>");
51 MODULE_DESCRIPTION("iSCSI/TCP data-path");
52 MODULE_LICENSE("GPL");
53
54 static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
55 static struct scsi_host_template iscsi_sw_tcp_sht;
56 static struct iscsi_transport iscsi_sw_tcp_transport;
57
58 static unsigned int iscsi_max_lun = ~0;
59 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
60
61 static int iscsi_sw_tcp_dbg;
62 module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
63 S_IRUGO | S_IWUSR);
64 MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
65 "Set to 1 to turn on, and zero to turn off. Default is off.");
66
67 #define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \
68 do { \
69 if (iscsi_sw_tcp_dbg) \
70 iscsi_conn_printk(KERN_INFO, _conn, \
71 "%s " dbg_fmt, \
72 __func__, ##arg); \
73 } while (0);
74
75
76 /**
77 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
78 * @rd_desc: read descriptor
79 * @skb: socket buffer
80 * @offset: offset in skb
81 * @len: skb->len - offset
82 */
83 static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
84 unsigned int offset, size_t len)
85 {
86 struct iscsi_conn *conn = rd_desc->arg.data;
87 unsigned int consumed, total_consumed = 0;
88 int status;
89
90 ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
91
92 do {
93 status = 0;
94 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
95 offset += consumed;
96 total_consumed += consumed;
97 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
98
99 ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
100 skb->len - offset, status);
101 return total_consumed;
102 }
103
104 /**
105 * iscsi_sw_sk_state_check - check socket state
106 * @sk: socket
107 *
108 * If the socket is in CLOSE or CLOSE_WAIT we should
109 * not close the connection if there is still some
110 * data pending.
111 *
112 * Must be called with sk_callback_lock.
113 */
114 static inline int iscsi_sw_sk_state_check(struct sock *sk)
115 {
116 struct iscsi_conn *conn = sk->sk_user_data;
117
118 if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
119 (conn->session->state != ISCSI_STATE_LOGGING_OUT) &&
120 !atomic_read(&sk->sk_rmem_alloc)) {
121 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
122 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
123 return -ECONNRESET;
124 }
125 return 0;
126 }
127
128 static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag)
129 {
130 struct iscsi_conn *conn;
131 struct iscsi_tcp_conn *tcp_conn;
132 read_descriptor_t rd_desc;
133
134 read_lock(&sk->sk_callback_lock);
135 conn = sk->sk_user_data;
136 if (!conn) {
137 read_unlock(&sk->sk_callback_lock);
138 return;
139 }
140 tcp_conn = conn->dd_data;
141
142 /*
143 * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
144 * We set count to 1 because we want the network layer to
145 * hand us all the skbs that are available. iscsi_tcp_recv
146 * handled pdus that cross buffers or pdus that still need data.
147 */
148 rd_desc.arg.data = conn;
149 rd_desc.count = 1;
150 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
151
152 iscsi_sw_sk_state_check(sk);
153
154 /* If we had to (atomically) map a highmem page,
155 * unmap it now. */
156 iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
157 read_unlock(&sk->sk_callback_lock);
158 }
159
160 static void iscsi_sw_tcp_state_change(struct sock *sk)
161 {
162 struct iscsi_tcp_conn *tcp_conn;
163 struct iscsi_sw_tcp_conn *tcp_sw_conn;
164 struct iscsi_conn *conn;
165 struct iscsi_session *session;
166 void (*old_state_change)(struct sock *);
167
168 read_lock(&sk->sk_callback_lock);
169 conn = sk->sk_user_data;
170 if (!conn) {
171 read_unlock(&sk->sk_callback_lock);
172 return;
173 }
174 session = conn->session;
175
176 iscsi_sw_sk_state_check(sk);
177
178 tcp_conn = conn->dd_data;
179 tcp_sw_conn = tcp_conn->dd_data;
180 old_state_change = tcp_sw_conn->old_state_change;
181
182 read_unlock(&sk->sk_callback_lock);
183
184 old_state_change(sk);
185 }
186
187 /**
188 * iscsi_write_space - Called when more output buffer space is available
189 * @sk: socket space is available for
190 **/
191 static void iscsi_sw_tcp_write_space(struct sock *sk)
192 {
193 struct iscsi_conn *conn;
194 struct iscsi_tcp_conn *tcp_conn;
195 struct iscsi_sw_tcp_conn *tcp_sw_conn;
196 void (*old_write_space)(struct sock *);
197
198 read_lock_bh(&sk->sk_callback_lock);
199 conn = sk->sk_user_data;
200 if (!conn) {
201 read_unlock_bh(&sk->sk_callback_lock);
202 return;
203 }
204
205 tcp_conn = conn->dd_data;
206 tcp_sw_conn = tcp_conn->dd_data;
207 old_write_space = tcp_sw_conn->old_write_space;
208 read_unlock_bh(&sk->sk_callback_lock);
209
210 old_write_space(sk);
211
212 ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
213 iscsi_conn_queue_work(conn);
214 }
215
216 static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
217 {
218 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
219 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
220 struct sock *sk = tcp_sw_conn->sock->sk;
221
222 /* assign new callbacks */
223 write_lock_bh(&sk->sk_callback_lock);
224 sk->sk_user_data = conn;
225 tcp_sw_conn->old_data_ready = sk->sk_data_ready;
226 tcp_sw_conn->old_state_change = sk->sk_state_change;
227 tcp_sw_conn->old_write_space = sk->sk_write_space;
228 sk->sk_data_ready = iscsi_sw_tcp_data_ready;
229 sk->sk_state_change = iscsi_sw_tcp_state_change;
230 sk->sk_write_space = iscsi_sw_tcp_write_space;
231 write_unlock_bh(&sk->sk_callback_lock);
232 }
233
234 static void
235 iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn)
236 {
237 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
238 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
239 struct sock *sk = tcp_sw_conn->sock->sk;
240
241 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
242 write_lock_bh(&sk->sk_callback_lock);
243 sk->sk_user_data = NULL;
244 sk->sk_data_ready = tcp_sw_conn->old_data_ready;
245 sk->sk_state_change = tcp_sw_conn->old_state_change;
246 sk->sk_write_space = tcp_sw_conn->old_write_space;
247 sk->sk_no_check = 0;
248 write_unlock_bh(&sk->sk_callback_lock);
249 }
250
251 /**
252 * iscsi_sw_tcp_xmit_segment - transmit segment
253 * @tcp_conn: the iSCSI TCP connection
254 * @segment: the buffer to transmnit
255 *
256 * This function transmits as much of the buffer as
257 * the network layer will accept, and returns the number of
258 * bytes transmitted.
259 *
260 * If CRC hashing is enabled, the function will compute the
261 * hash as it goes. When the entire segment has been transmitted,
262 * it will retrieve the hash value and send it as well.
263 */
264 static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
265 struct iscsi_segment *segment)
266 {
267 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
268 struct socket *sk = tcp_sw_conn->sock;
269 unsigned int copied = 0;
270 int r = 0;
271
272 while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
273 struct scatterlist *sg;
274 unsigned int offset, copy;
275 int flags = 0;
276
277 r = 0;
278 offset = segment->copied;
279 copy = segment->size - offset;
280
281 if (segment->total_copied + segment->size < segment->total_size)
282 flags |= MSG_MORE;
283
284 /* Use sendpage if we can; else fall back to sendmsg */
285 if (!segment->data) {
286 sg = segment->sg;
287 offset += segment->sg_offset + sg->offset;
288 r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
289 copy, flags);
290 } else {
291 struct msghdr msg = { .msg_flags = flags };
292 struct kvec iov = {
293 .iov_base = segment->data + offset,
294 .iov_len = copy
295 };
296
297 r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
298 }
299
300 if (r < 0) {
301 iscsi_tcp_segment_unmap(segment);
302 return r;
303 }
304 copied += r;
305 }
306 return copied;
307 }
308
309 /**
310 * iscsi_sw_tcp_xmit - TCP transmit
311 **/
312 static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
313 {
314 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
315 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
316 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
317 unsigned int consumed = 0;
318 int rc = 0;
319
320 while (1) {
321 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
322 /*
323 * We may not have been able to send data because the conn
324 * is getting stopped. libiscsi will know so propagate err
325 * for it to do the right thing.
326 */
327 if (rc == -EAGAIN)
328 return rc;
329 else if (rc < 0) {
330 rc = ISCSI_ERR_XMIT_FAILED;
331 goto error;
332 } else if (rc == 0)
333 break;
334
335 consumed += rc;
336
337 if (segment->total_copied >= segment->total_size) {
338 if (segment->done != NULL) {
339 rc = segment->done(tcp_conn, segment);
340 if (rc != 0)
341 goto error;
342 }
343 }
344 }
345
346 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
347
348 conn->txdata_octets += consumed;
349 return consumed;
350
351 error:
352 /* Transmit error. We could initiate error recovery
353 * here. */
354 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
355 iscsi_conn_failure(conn, rc);
356 return -EIO;
357 }
358
359 /**
360 * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit
361 */
362 static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
363 {
364 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
365 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
366 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
367
368 return segment->total_copied - segment->total_size;
369 }
370
371 static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
372 {
373 struct iscsi_conn *conn = task->conn;
374 unsigned long pflags = current->flags;
375 int rc = 0;
376
377 current->flags |= PF_MEMALLOC;
378
379 while (iscsi_sw_tcp_xmit_qlen(conn)) {
380 rc = iscsi_sw_tcp_xmit(conn);
381 if (rc == 0) {
382 rc = -EAGAIN;
383 break;
384 }
385 if (rc < 0)
386 break;
387 rc = 0;
388 }
389
390 tsk_restore_flags(current, pflags, PF_MEMALLOC);
391 return rc;
392 }
393
394 /*
395 * This is called when we're done sending the header.
396 * Simply copy the data_segment to the send segment, and return.
397 */
398 static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
399 struct iscsi_segment *segment)
400 {
401 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
402
403 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
404 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
405 "Header done. Next segment size %u total_size %u\n",
406 tcp_sw_conn->out.segment.size,
407 tcp_sw_conn->out.segment.total_size);
408 return 0;
409 }
410
411 static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
412 size_t hdrlen)
413 {
414 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
415 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
416
417 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
418 "digest enabled" : "digest disabled");
419
420 /* Clear the data segment - needs to be filled in by the
421 * caller using iscsi_tcp_send_data_prep() */
422 memset(&tcp_sw_conn->out.data_segment, 0,
423 sizeof(struct iscsi_segment));
424
425 /* If header digest is enabled, compute the CRC and
426 * place the digest into the same buffer. We make
427 * sure that both iscsi_tcp_task and mtask have
428 * sufficient room.
429 */
430 if (conn->hdrdgst_en) {
431 iscsi_tcp_dgst_header(&tcp_sw_conn->tx_hash, hdr, hdrlen,
432 hdr + hdrlen);
433 hdrlen += ISCSI_DIGEST_SIZE;
434 }
435
436 /* Remember header pointer for later, when we need
437 * to decide whether there's a payload to go along
438 * with the header. */
439 tcp_sw_conn->out.hdr = hdr;
440
441 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
442 iscsi_sw_tcp_send_hdr_done, NULL);
443 }
444
445 /*
446 * Prepare the send buffer for the payload data.
447 * Padding and checksumming will all be taken care
448 * of by the iscsi_segment routines.
449 */
450 static int
451 iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
452 unsigned int count, unsigned int offset,
453 unsigned int len)
454 {
455 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
456 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
457 struct hash_desc *tx_hash = NULL;
458 unsigned int hdr_spec_len;
459
460 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
461 conn->datadgst_en ?
462 "digest enabled" : "digest disabled");
463
464 /* Make sure the datalen matches what the caller
465 said he would send. */
466 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
467 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
468
469 if (conn->datadgst_en)
470 tx_hash = &tcp_sw_conn->tx_hash;
471
472 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
473 sg, count, offset, len,
474 NULL, tx_hash);
475 }
476
477 static void
478 iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
479 size_t len)
480 {
481 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
482 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
483 struct hash_desc *tx_hash = NULL;
484 unsigned int hdr_spec_len;
485
486 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
487 "digest enabled" : "digest disabled");
488
489 /* Make sure the datalen matches what the caller
490 said he would send. */
491 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
492 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
493
494 if (conn->datadgst_en)
495 tx_hash = &tcp_sw_conn->tx_hash;
496
497 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
498 data, len, NULL, tx_hash);
499 }
500
501 static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
502 unsigned int offset, unsigned int count)
503 {
504 struct iscsi_conn *conn = task->conn;
505 int err = 0;
506
507 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
508
509 if (!count)
510 return 0;
511
512 if (!task->sc)
513 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
514 else {
515 struct scsi_data_buffer *sdb = scsi_out(task->sc);
516
517 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
518 sdb->table.nents, offset,
519 count);
520 }
521
522 if (err) {
523 /* got invalid offset/len */
524 return -EIO;
525 }
526 return 0;
527 }
528
529 static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
530 {
531 struct iscsi_tcp_task *tcp_task = task->dd_data;
532
533 task->hdr = task->dd_data + sizeof(*tcp_task);
534 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
535 return 0;
536 }
537
538 static struct iscsi_cls_conn *
539 iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
540 uint32_t conn_idx)
541 {
542 struct iscsi_conn *conn;
543 struct iscsi_cls_conn *cls_conn;
544 struct iscsi_tcp_conn *tcp_conn;
545 struct iscsi_sw_tcp_conn *tcp_sw_conn;
546
547 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
548 conn_idx);
549 if (!cls_conn)
550 return NULL;
551 conn = cls_conn->dd_data;
552 tcp_conn = conn->dd_data;
553 tcp_sw_conn = tcp_conn->dd_data;
554
555 tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
556 CRYPTO_ALG_ASYNC);
557 tcp_sw_conn->tx_hash.flags = 0;
558 if (IS_ERR(tcp_sw_conn->tx_hash.tfm))
559 goto free_conn;
560
561 tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
562 CRYPTO_ALG_ASYNC);
563 tcp_sw_conn->rx_hash.flags = 0;
564 if (IS_ERR(tcp_sw_conn->rx_hash.tfm))
565 goto free_tx_tfm;
566 tcp_conn->rx_hash = &tcp_sw_conn->rx_hash;
567
568 return cls_conn;
569
570 free_tx_tfm:
571 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
572 free_conn:
573 iscsi_conn_printk(KERN_ERR, conn,
574 "Could not create connection due to crc32c "
575 "loading error. Make sure the crc32c "
576 "module is built as a module or into the "
577 "kernel\n");
578 iscsi_tcp_conn_teardown(cls_conn);
579 return NULL;
580 }
581
582 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
583 {
584 struct iscsi_session *session = conn->session;
585 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
586 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
587 struct socket *sock = tcp_sw_conn->sock;
588
589 if (!sock)
590 return;
591
592 sock_hold(sock->sk);
593 iscsi_sw_tcp_conn_restore_callbacks(conn);
594 sock_put(sock->sk);
595
596 spin_lock_bh(&session->lock);
597 tcp_sw_conn->sock = NULL;
598 spin_unlock_bh(&session->lock);
599 sockfd_put(sock);
600 }
601
602 static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
603 {
604 struct iscsi_conn *conn = cls_conn->dd_data;
605 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
606 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
607
608 iscsi_sw_tcp_release_conn(conn);
609
610 if (tcp_sw_conn->tx_hash.tfm)
611 crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
612 if (tcp_sw_conn->rx_hash.tfm)
613 crypto_free_hash(tcp_sw_conn->rx_hash.tfm);
614
615 iscsi_tcp_conn_teardown(cls_conn);
616 }
617
618 static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
619 {
620 struct iscsi_conn *conn = cls_conn->dd_data;
621 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
622 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
623 struct socket *sock = tcp_sw_conn->sock;
624
625 /* userspace may have goofed up and not bound us */
626 if (!sock)
627 return;
628
629 sock->sk->sk_err = EIO;
630 wake_up_interruptible(sk_sleep(sock->sk));
631
632 /* stop xmit side */
633 iscsi_suspend_tx(conn);
634
635 /* stop recv side and release socket */
636 iscsi_sw_tcp_release_conn(conn);
637
638 iscsi_conn_stop(cls_conn, flag);
639 }
640
641 static int
642 iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
643 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
644 int is_leading)
645 {
646 struct iscsi_session *session = cls_session->dd_data;
647 struct iscsi_conn *conn = cls_conn->dd_data;
648 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
649 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
650 struct sock *sk;
651 struct socket *sock;
652 int err;
653
654 /* lookup for existing socket */
655 sock = sockfd_lookup((int)transport_eph, &err);
656 if (!sock) {
657 iscsi_conn_printk(KERN_ERR, conn,
658 "sockfd_lookup failed %d\n", err);
659 return -EEXIST;
660 }
661
662 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
663 if (err)
664 goto free_socket;
665
666 spin_lock_bh(&session->lock);
667 /* bind iSCSI connection and socket */
668 tcp_sw_conn->sock = sock;
669 spin_unlock_bh(&session->lock);
670
671 /* setup Socket parameters */
672 sk = sock->sk;
673 sk->sk_reuse = SK_CAN_REUSE;
674 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
675 sk->sk_allocation = GFP_ATOMIC;
676 sk_set_memalloc(sk);
677
678 iscsi_sw_tcp_conn_set_callbacks(conn);
679 tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
680 /*
681 * set receive state machine into initial state
682 */
683 iscsi_tcp_hdr_recv_prep(tcp_conn);
684 return 0;
685
686 free_socket:
687 sockfd_put(sock);
688 return err;
689 }
690
691 static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
692 enum iscsi_param param, char *buf,
693 int buflen)
694 {
695 struct iscsi_conn *conn = cls_conn->dd_data;
696 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
697 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
698
699 switch(param) {
700 case ISCSI_PARAM_HDRDGST_EN:
701 iscsi_set_param(cls_conn, param, buf, buflen);
702 break;
703 case ISCSI_PARAM_DATADGST_EN:
704 iscsi_set_param(cls_conn, param, buf, buflen);
705 tcp_sw_conn->sendpage = conn->datadgst_en ?
706 sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
707 break;
708 case ISCSI_PARAM_MAX_R2T:
709 return iscsi_tcp_set_max_r2t(conn, buf);
710 default:
711 return iscsi_set_param(cls_conn, param, buf, buflen);
712 }
713
714 return 0;
715 }
716
717 static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
718 enum iscsi_param param, char *buf)
719 {
720 struct iscsi_conn *conn = cls_conn->dd_data;
721 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
722 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
723 struct sockaddr_in6 addr;
724 int rc, len;
725
726 switch(param) {
727 case ISCSI_PARAM_CONN_PORT:
728 case ISCSI_PARAM_CONN_ADDRESS:
729 spin_lock_bh(&conn->session->lock);
730 if (!tcp_sw_conn || !tcp_sw_conn->sock) {
731 spin_unlock_bh(&conn->session->lock);
732 return -ENOTCONN;
733 }
734 rc = kernel_getpeername(tcp_sw_conn->sock,
735 (struct sockaddr *)&addr, &len);
736 spin_unlock_bh(&conn->session->lock);
737 if (rc)
738 return rc;
739
740 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
741 &addr, param, buf);
742 default:
743 return iscsi_conn_get_param(cls_conn, param, buf);
744 }
745
746 return 0;
747 }
748
749 static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
750 enum iscsi_host_param param, char *buf)
751 {
752 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
753 struct iscsi_session *session = tcp_sw_host->session;
754 struct iscsi_conn *conn;
755 struct iscsi_tcp_conn *tcp_conn;
756 struct iscsi_sw_tcp_conn *tcp_sw_conn;
757 struct sockaddr_in6 addr;
758 int rc, len;
759
760 switch (param) {
761 case ISCSI_HOST_PARAM_IPADDRESS:
762 spin_lock_bh(&session->lock);
763 conn = session->leadconn;
764 if (!conn) {
765 spin_unlock_bh(&session->lock);
766 return -ENOTCONN;
767 }
768 tcp_conn = conn->dd_data;
769
770 tcp_sw_conn = tcp_conn->dd_data;
771 if (!tcp_sw_conn->sock) {
772 spin_unlock_bh(&session->lock);
773 return -ENOTCONN;
774 }
775
776 rc = kernel_getsockname(tcp_sw_conn->sock,
777 (struct sockaddr *)&addr, &len);
778 spin_unlock_bh(&session->lock);
779 if (rc)
780 return rc;
781
782 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
783 &addr, param, buf);
784 default:
785 return iscsi_host_get_param(shost, param, buf);
786 }
787
788 return 0;
789 }
790
791 static void
792 iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
793 struct iscsi_stats *stats)
794 {
795 struct iscsi_conn *conn = cls_conn->dd_data;
796 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
797 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
798
799 stats->custom_length = 3;
800 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
801 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
802 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
803 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
804 strcpy(stats->custom[2].desc, "eh_abort_cnt");
805 stats->custom[2].value = conn->eh_abort_cnt;
806
807 iscsi_tcp_conn_get_stats(cls_conn, stats);
808 }
809
810 static struct iscsi_cls_session *
811 iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
812 uint16_t qdepth, uint32_t initial_cmdsn)
813 {
814 struct iscsi_cls_session *cls_session;
815 struct iscsi_session *session;
816 struct iscsi_sw_tcp_host *tcp_sw_host;
817 struct Scsi_Host *shost;
818
819 if (ep) {
820 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
821 return NULL;
822 }
823
824 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
825 sizeof(struct iscsi_sw_tcp_host), 1);
826 if (!shost)
827 return NULL;
828 shost->transportt = iscsi_sw_tcp_scsi_transport;
829 shost->cmd_per_lun = qdepth;
830 shost->max_lun = iscsi_max_lun;
831 shost->max_id = 0;
832 shost->max_channel = 0;
833 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
834
835 if (iscsi_host_add(shost, NULL))
836 goto free_host;
837
838 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
839 cmds_max, 0,
840 sizeof(struct iscsi_tcp_task) +
841 sizeof(struct iscsi_sw_tcp_hdrbuf),
842 initial_cmdsn, 0);
843 if (!cls_session)
844 goto remove_host;
845 session = cls_session->dd_data;
846 tcp_sw_host = iscsi_host_priv(shost);
847 tcp_sw_host->session = session;
848
849 shost->can_queue = session->scsi_cmds_max;
850 if (iscsi_tcp_r2tpool_alloc(session))
851 goto remove_session;
852 return cls_session;
853
854 remove_session:
855 iscsi_session_teardown(cls_session);
856 remove_host:
857 iscsi_host_remove(shost);
858 free_host:
859 iscsi_host_free(shost);
860 return NULL;
861 }
862
863 static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
864 {
865 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
866
867 iscsi_tcp_r2tpool_free(cls_session->dd_data);
868 iscsi_session_teardown(cls_session);
869
870 iscsi_host_remove(shost);
871 iscsi_host_free(shost);
872 }
873
874 static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param)
875 {
876 switch (param_type) {
877 case ISCSI_HOST_PARAM:
878 switch (param) {
879 case ISCSI_HOST_PARAM_NETDEV_NAME:
880 case ISCSI_HOST_PARAM_HWADDRESS:
881 case ISCSI_HOST_PARAM_IPADDRESS:
882 case ISCSI_HOST_PARAM_INITIATOR_NAME:
883 return S_IRUGO;
884 default:
885 return 0;
886 }
887 case ISCSI_PARAM:
888 switch (param) {
889 case ISCSI_PARAM_MAX_RECV_DLENGTH:
890 case ISCSI_PARAM_MAX_XMIT_DLENGTH:
891 case ISCSI_PARAM_HDRDGST_EN:
892 case ISCSI_PARAM_DATADGST_EN:
893 case ISCSI_PARAM_CONN_ADDRESS:
894 case ISCSI_PARAM_CONN_PORT:
895 case ISCSI_PARAM_EXP_STATSN:
896 case ISCSI_PARAM_PERSISTENT_ADDRESS:
897 case ISCSI_PARAM_PERSISTENT_PORT:
898 case ISCSI_PARAM_PING_TMO:
899 case ISCSI_PARAM_RECV_TMO:
900 case ISCSI_PARAM_INITIAL_R2T_EN:
901 case ISCSI_PARAM_MAX_R2T:
902 case ISCSI_PARAM_IMM_DATA_EN:
903 case ISCSI_PARAM_FIRST_BURST:
904 case ISCSI_PARAM_MAX_BURST:
905 case ISCSI_PARAM_PDU_INORDER_EN:
906 case ISCSI_PARAM_DATASEQ_INORDER_EN:
907 case ISCSI_PARAM_ERL:
908 case ISCSI_PARAM_TARGET_NAME:
909 case ISCSI_PARAM_TPGT:
910 case ISCSI_PARAM_USERNAME:
911 case ISCSI_PARAM_PASSWORD:
912 case ISCSI_PARAM_USERNAME_IN:
913 case ISCSI_PARAM_PASSWORD_IN:
914 case ISCSI_PARAM_FAST_ABORT:
915 case ISCSI_PARAM_ABORT_TMO:
916 case ISCSI_PARAM_LU_RESET_TMO:
917 case ISCSI_PARAM_TGT_RESET_TMO:
918 case ISCSI_PARAM_IFACE_NAME:
919 case ISCSI_PARAM_INITIATOR_NAME:
920 return S_IRUGO;
921 default:
922 return 0;
923 }
924 }
925
926 return 0;
927 }
928
929 static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
930 {
931 set_bit(QUEUE_FLAG_BIDI, &sdev->request_queue->queue_flags);
932 return 0;
933 }
934
935 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
936 {
937 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
938 blk_queue_dma_alignment(sdev->request_queue, 0);
939 return 0;
940 }
941
942 static struct scsi_host_template iscsi_sw_tcp_sht = {
943 .module = THIS_MODULE,
944 .name = "iSCSI Initiator over TCP/IP",
945 .queuecommand = iscsi_queuecommand,
946 .change_queue_depth = iscsi_change_queue_depth,
947 .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1,
948 .sg_tablesize = 4096,
949 .max_sectors = 0xFFFF,
950 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
951 .eh_abort_handler = iscsi_eh_abort,
952 .eh_device_reset_handler= iscsi_eh_device_reset,
953 .eh_target_reset_handler = iscsi_eh_recover_target,
954 .use_clustering = DISABLE_CLUSTERING,
955 .slave_alloc = iscsi_sw_tcp_slave_alloc,
956 .slave_configure = iscsi_sw_tcp_slave_configure,
957 .target_alloc = iscsi_target_alloc,
958 .proc_name = "iscsi_tcp",
959 .this_id = -1,
960 };
961
962 static struct iscsi_transport iscsi_sw_tcp_transport = {
963 .owner = THIS_MODULE,
964 .name = "tcp",
965 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
966 | CAP_DATADGST,
967 /* session management */
968 .create_session = iscsi_sw_tcp_session_create,
969 .destroy_session = iscsi_sw_tcp_session_destroy,
970 /* connection management */
971 .create_conn = iscsi_sw_tcp_conn_create,
972 .bind_conn = iscsi_sw_tcp_conn_bind,
973 .destroy_conn = iscsi_sw_tcp_conn_destroy,
974 .attr_is_visible = iscsi_sw_tcp_attr_is_visible,
975 .set_param = iscsi_sw_tcp_conn_set_param,
976 .get_conn_param = iscsi_sw_tcp_conn_get_param,
977 .get_session_param = iscsi_session_get_param,
978 .start_conn = iscsi_conn_start,
979 .stop_conn = iscsi_sw_tcp_conn_stop,
980 /* iscsi host params */
981 .get_host_param = iscsi_sw_tcp_host_get_param,
982 .set_host_param = iscsi_host_set_param,
983 /* IO */
984 .send_pdu = iscsi_conn_send_pdu,
985 .get_stats = iscsi_sw_tcp_conn_get_stats,
986 /* iscsi task/cmd helpers */
987 .init_task = iscsi_tcp_task_init,
988 .xmit_task = iscsi_tcp_task_xmit,
989 .cleanup_task = iscsi_tcp_cleanup_task,
990 /* low level pdu helpers */
991 .xmit_pdu = iscsi_sw_tcp_pdu_xmit,
992 .init_pdu = iscsi_sw_tcp_pdu_init,
993 .alloc_pdu = iscsi_sw_tcp_pdu_alloc,
994 /* recovery */
995 .session_recovery_timedout = iscsi_session_recovery_timedout,
996 };
997
998 static int __init iscsi_sw_tcp_init(void)
999 {
1000 if (iscsi_max_lun < 1) {
1001 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
1002 iscsi_max_lun);
1003 return -EINVAL;
1004 }
1005
1006 iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
1007 &iscsi_sw_tcp_transport);
1008 if (!iscsi_sw_tcp_scsi_transport)
1009 return -ENODEV;
1010
1011 return 0;
1012 }
1013
1014 static void __exit iscsi_sw_tcp_exit(void)
1015 {
1016 iscsi_unregister_transport(&iscsi_sw_tcp_transport);
1017 }
1018
1019 module_init(iscsi_sw_tcp_init);
1020 module_exit(iscsi_sw_tcp_exit);
Linus' kernel tree