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Merge tag 'pci-v6.16-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci
[linux-2.6-block.git] / drivers / scsi / iscsi_tcp.c
... / ...
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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * iSCSI Initiator over TCP/IP Data-Path
4 *
5 * Copyright (C) 2004 Dmitry Yusupov
6 * Copyright (C) 2004 Alex Aizman
7 * Copyright (C) 2005 - 2006 Mike Christie
8 * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
9 * maintained by open-iscsi@googlegroups.com
10 *
11 * See the file COPYING included with this distribution for more details.
12 *
13 * Credits:
14 * Christoph Hellwig
15 * FUJITA Tomonori
16 * Arne Redlich
17 * Zhenyu Wang
18 */
19
20#include <linux/types.h>
21#include <linux/inet.h>
22#include <linux/slab.h>
23#include <linux/sched/mm.h>
24#include <linux/file.h>
25#include <linux/blkdev.h>
26#include <linux/delay.h>
27#include <linux/kfifo.h>
28#include <linux/scatterlist.h>
29#include <linux/module.h>
30#include <linux/backing-dev.h>
31#include <net/tcp.h>
32#include <scsi/scsi_cmnd.h>
33#include <scsi/scsi_device.h>
34#include <scsi/scsi_host.h>
35#include <scsi/scsi.h>
36#include <scsi/scsi_transport_iscsi.h>
37#include <trace/events/iscsi.h>
38#include <trace/events/sock.h>
39
40#include "iscsi_tcp.h"
41
42MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
43 "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
44 "Alex Aizman <itn780@yahoo.com>");
45MODULE_DESCRIPTION("iSCSI/TCP data-path");
46MODULE_LICENSE("GPL");
47
48static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport;
49static const struct scsi_host_template iscsi_sw_tcp_sht;
50static struct iscsi_transport iscsi_sw_tcp_transport;
51
52static unsigned int iscsi_max_lun = ~0;
53module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
54
55static bool iscsi_recv_from_iscsi_q;
56module_param_named(recv_from_iscsi_q, iscsi_recv_from_iscsi_q, bool, 0644);
57MODULE_PARM_DESC(recv_from_iscsi_q, "Set to true to read iSCSI data/headers from the iscsi_q workqueue. The default is false which will perform reads from the network softirq context.");
58
59static int iscsi_sw_tcp_dbg;
60module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int,
61 S_IRUGO | S_IWUSR);
62MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
63 "Set to 1 to turn on, and zero to turn off. Default is off.");
64
65#define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \
66 do { \
67 if (iscsi_sw_tcp_dbg) \
68 iscsi_conn_printk(KERN_INFO, _conn, \
69 "%s " dbg_fmt, \
70 __func__, ##arg); \
71 iscsi_dbg_trace(trace_iscsi_dbg_sw_tcp, \
72 &(_conn)->cls_conn->dev, \
73 "%s " dbg_fmt, __func__, ##arg);\
74 } while (0);
75
76
77/**
78 * iscsi_sw_tcp_recv - TCP receive in sendfile fashion
79 * @rd_desc: read descriptor
80 * @skb: socket buffer
81 * @offset: offset in skb
82 * @len: skb->len - offset
83 */
84static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
85 unsigned int offset, size_t len)
86{
87 struct iscsi_conn *conn = rd_desc->arg.data;
88 unsigned int consumed, total_consumed = 0;
89 int status;
90
91 ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset);
92
93 do {
94 status = 0;
95 consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status);
96 offset += consumed;
97 total_consumed += consumed;
98 } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE);
99
100 ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n",
101 skb->len - offset, status);
102 return total_consumed;
103}
104
105/**
106 * iscsi_sw_sk_state_check - check socket state
107 * @sk: socket
108 *
109 * If the socket is in CLOSE or CLOSE_WAIT we should
110 * not close the connection if there is still some
111 * data pending.
112 *
113 * Must be called with sk_callback_lock.
114 */
115static inline int iscsi_sw_sk_state_check(struct sock *sk)
116{
117 struct iscsi_conn *conn = sk->sk_user_data;
118
119 if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) &&
120 (conn->session->state != ISCSI_STATE_LOGGING_OUT) &&
121 !atomic_read(&sk->sk_rmem_alloc)) {
122 ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n");
123 iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE);
124 return -ECONNRESET;
125 }
126 return 0;
127}
128
129static void iscsi_sw_tcp_recv_data(struct iscsi_conn *conn)
130{
131 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
132 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
133 struct sock *sk = tcp_sw_conn->sock->sk;
134 read_descriptor_t rd_desc;
135
136 /*
137 * Use rd_desc to pass 'conn' to iscsi_tcp_recv.
138 * We set count to 1 because we want the network layer to
139 * hand us all the skbs that are available. iscsi_tcp_recv
140 * handled pdus that cross buffers or pdus that still need data.
141 */
142 rd_desc.arg.data = conn;
143 rd_desc.count = 1;
144
145 tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
146
147 /* If we had to (atomically) map a highmem page,
148 * unmap it now. */
149 iscsi_tcp_segment_unmap(&tcp_conn->in.segment);
150
151 iscsi_sw_sk_state_check(sk);
152}
153
154static void iscsi_sw_tcp_recv_data_work(struct work_struct *work)
155{
156 struct iscsi_conn *conn = container_of(work, struct iscsi_conn,
157 recvwork);
158 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
159 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
160 struct sock *sk = tcp_sw_conn->sock->sk;
161
162 lock_sock(sk);
163 iscsi_sw_tcp_recv_data(conn);
164 release_sock(sk);
165}
166
167static void iscsi_sw_tcp_data_ready(struct sock *sk)
168{
169 struct iscsi_sw_tcp_conn *tcp_sw_conn;
170 struct iscsi_tcp_conn *tcp_conn;
171 struct iscsi_conn *conn;
172
173 trace_sk_data_ready(sk);
174
175 read_lock_bh(&sk->sk_callback_lock);
176 conn = sk->sk_user_data;
177 if (!conn) {
178 read_unlock_bh(&sk->sk_callback_lock);
179 return;
180 }
181 tcp_conn = conn->dd_data;
182 tcp_sw_conn = tcp_conn->dd_data;
183
184 if (tcp_sw_conn->queue_recv)
185 iscsi_conn_queue_recv(conn);
186 else
187 iscsi_sw_tcp_recv_data(conn);
188 read_unlock_bh(&sk->sk_callback_lock);
189}
190
191static void iscsi_sw_tcp_state_change(struct sock *sk)
192{
193 struct iscsi_tcp_conn *tcp_conn;
194 struct iscsi_sw_tcp_conn *tcp_sw_conn;
195 struct iscsi_conn *conn;
196 void (*old_state_change)(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 iscsi_sw_sk_state_check(sk);
206
207 tcp_conn = conn->dd_data;
208 tcp_sw_conn = tcp_conn->dd_data;
209 old_state_change = tcp_sw_conn->old_state_change;
210
211 read_unlock_bh(&sk->sk_callback_lock);
212
213 old_state_change(sk);
214}
215
216/**
217 * iscsi_sw_tcp_write_space - Called when more output buffer space is available
218 * @sk: socket space is available for
219 **/
220static void iscsi_sw_tcp_write_space(struct sock *sk)
221{
222 struct iscsi_conn *conn;
223 struct iscsi_tcp_conn *tcp_conn;
224 struct iscsi_sw_tcp_conn *tcp_sw_conn;
225 void (*old_write_space)(struct sock *);
226
227 read_lock_bh(&sk->sk_callback_lock);
228 conn = sk->sk_user_data;
229 if (!conn) {
230 read_unlock_bh(&sk->sk_callback_lock);
231 return;
232 }
233
234 tcp_conn = conn->dd_data;
235 tcp_sw_conn = tcp_conn->dd_data;
236 old_write_space = tcp_sw_conn->old_write_space;
237 read_unlock_bh(&sk->sk_callback_lock);
238
239 old_write_space(sk);
240
241 ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n");
242 iscsi_conn_queue_xmit(conn);
243}
244
245static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn)
246{
247 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
248 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
249 struct sock *sk = tcp_sw_conn->sock->sk;
250
251 /* assign new callbacks */
252 write_lock_bh(&sk->sk_callback_lock);
253 sk->sk_user_data = conn;
254 tcp_sw_conn->old_data_ready = sk->sk_data_ready;
255 tcp_sw_conn->old_state_change = sk->sk_state_change;
256 tcp_sw_conn->old_write_space = sk->sk_write_space;
257 sk->sk_data_ready = iscsi_sw_tcp_data_ready;
258 sk->sk_state_change = iscsi_sw_tcp_state_change;
259 sk->sk_write_space = iscsi_sw_tcp_write_space;
260 write_unlock_bh(&sk->sk_callback_lock);
261}
262
263static void
264iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn)
265{
266 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
267 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
268 struct sock *sk = tcp_sw_conn->sock->sk;
269
270 /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */
271 write_lock_bh(&sk->sk_callback_lock);
272 sk->sk_user_data = NULL;
273 sk->sk_data_ready = tcp_sw_conn->old_data_ready;
274 sk->sk_state_change = tcp_sw_conn->old_state_change;
275 sk->sk_write_space = tcp_sw_conn->old_write_space;
276 sk->sk_no_check_tx = 0;
277 write_unlock_bh(&sk->sk_callback_lock);
278}
279
280/**
281 * iscsi_sw_tcp_xmit_segment - transmit segment
282 * @tcp_conn: the iSCSI TCP connection
283 * @segment: the buffer to transmnit
284 *
285 * This function transmits as much of the buffer as
286 * the network layer will accept, and returns the number of
287 * bytes transmitted.
288 *
289 * If CRC hashing is enabled, the function will compute the
290 * hash as it goes. When the entire segment has been transmitted,
291 * it will retrieve the hash value and send it as well.
292 */
293static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
294 struct iscsi_segment *segment)
295{
296 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
297 struct socket *sk = tcp_sw_conn->sock;
298 unsigned int copied = 0;
299 int r = 0;
300
301 while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
302 struct scatterlist *sg;
303 struct msghdr msg = {};
304 struct bio_vec bv;
305 unsigned int offset, copy;
306
307 r = 0;
308 offset = segment->copied;
309 copy = segment->size - offset;
310
311 if (segment->total_copied + segment->size < segment->total_size)
312 msg.msg_flags |= MSG_MORE;
313
314 if (tcp_sw_conn->queue_recv)
315 msg.msg_flags |= MSG_DONTWAIT;
316
317 if (!segment->data) {
318 if (!tcp_conn->iscsi_conn->datadgst_en)
319 msg.msg_flags |= MSG_SPLICE_PAGES;
320 sg = segment->sg;
321 offset += segment->sg_offset + sg->offset;
322 bvec_set_page(&bv, sg_page(sg), copy, offset);
323 } else {
324 bvec_set_virt(&bv, segment->data + offset, copy);
325 }
326 iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bv, 1, copy);
327
328 r = sock_sendmsg(sk, &msg);
329 if (r < 0) {
330 iscsi_tcp_segment_unmap(segment);
331 return r;
332 }
333 copied += r;
334 }
335 return copied;
336}
337
338/**
339 * iscsi_sw_tcp_xmit - TCP transmit
340 * @conn: iscsi connection
341 **/
342static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn)
343{
344 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
345 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
346 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
347 unsigned int consumed = 0;
348 int rc = 0;
349
350 while (1) {
351 rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);
352 /*
353 * We may not have been able to send data because the conn
354 * is getting stopped. libiscsi will know so propagate err
355 * for it to do the right thing.
356 */
357 if (rc == -EAGAIN)
358 return rc;
359 else if (rc < 0) {
360 rc = ISCSI_ERR_XMIT_FAILED;
361 goto error;
362 } else if (rc == 0)
363 break;
364
365 consumed += rc;
366
367 if (segment->total_copied >= segment->total_size) {
368 if (segment->done != NULL) {
369 rc = segment->done(tcp_conn, segment);
370 if (rc != 0)
371 goto error;
372 }
373 }
374 }
375
376 ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed);
377
378 conn->txdata_octets += consumed;
379 return consumed;
380
381error:
382 /* Transmit error. We could initiate error recovery
383 * here. */
384 ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc);
385 iscsi_conn_failure(conn, rc);
386 return -EIO;
387}
388
389/**
390 * iscsi_sw_tcp_xmit_qlen - return the number of bytes queued for xmit
391 * @conn: iscsi connection
392 */
393static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn)
394{
395 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
396 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
397 struct iscsi_segment *segment = &tcp_sw_conn->out.segment;
398
399 return segment->total_copied - segment->total_size;
400}
401
402static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task)
403{
404 struct iscsi_conn *conn = task->conn;
405 unsigned int noreclaim_flag;
406 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
407 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
408 int rc = 0;
409
410 if (!tcp_sw_conn->sock) {
411 iscsi_conn_printk(KERN_ERR, conn,
412 "Transport not bound to socket!\n");
413 return -EINVAL;
414 }
415
416 noreclaim_flag = memalloc_noreclaim_save();
417
418 while (iscsi_sw_tcp_xmit_qlen(conn)) {
419 rc = iscsi_sw_tcp_xmit(conn);
420 if (rc == 0) {
421 rc = -EAGAIN;
422 break;
423 }
424 if (rc < 0)
425 break;
426 rc = 0;
427 }
428
429 memalloc_noreclaim_restore(noreclaim_flag);
430 return rc;
431}
432
433/*
434 * This is called when we're done sending the header.
435 * Simply copy the data_segment to the send segment, and return.
436 */
437static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn,
438 struct iscsi_segment *segment)
439{
440 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
441
442 tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment;
443 ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn,
444 "Header done. Next segment size %u total_size %u\n",
445 tcp_sw_conn->out.segment.size,
446 tcp_sw_conn->out.segment.total_size);
447 return 0;
448}
449
450static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr,
451 size_t hdrlen)
452{
453 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
454 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
455
456 ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ?
457 "digest enabled" : "digest disabled");
458
459 /* Clear the data segment - needs to be filled in by the
460 * caller using iscsi_tcp_send_data_prep() */
461 memset(&tcp_sw_conn->out.data_segment, 0,
462 sizeof(struct iscsi_segment));
463
464 /* If header digest is enabled, compute the CRC and
465 * place the digest into the same buffer. We make
466 * sure that both iscsi_tcp_task and mtask have
467 * sufficient room.
468 */
469 if (conn->hdrdgst_en) {
470 iscsi_tcp_dgst_header(hdr, hdrlen, hdr + hdrlen);
471 hdrlen += ISCSI_DIGEST_SIZE;
472 }
473
474 /* Remember header pointer for later, when we need
475 * to decide whether there's a payload to go along
476 * with the header. */
477 tcp_sw_conn->out.hdr = hdr;
478
479 iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen,
480 iscsi_sw_tcp_send_hdr_done, NULL);
481}
482
483/*
484 * Prepare the send buffer for the payload data.
485 * Padding and checksumming will all be taken care
486 * of by the iscsi_segment routines.
487 */
488static int
489iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg,
490 unsigned int count, unsigned int offset,
491 unsigned int len)
492{
493 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
494 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
495 u32 *tx_crcp = NULL;
496 unsigned int hdr_spec_len;
497
498 ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len,
499 conn->datadgst_en ?
500 "digest enabled" : "digest disabled");
501
502 /* Make sure the datalen matches what the caller
503 said he would send. */
504 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
505 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
506
507 if (conn->datadgst_en)
508 tx_crcp = &tcp_sw_conn->tx_crc;
509
510 return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment,
511 sg, count, offset, len, NULL, tx_crcp);
512}
513
514static void
515iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data,
516 size_t len)
517{
518 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
519 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
520 u32 *tx_crcp = NULL;
521 unsigned int hdr_spec_len;
522
523 ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ?
524 "digest enabled" : "digest disabled");
525
526 /* Make sure the datalen matches what the caller
527 said he would send. */
528 hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength);
529 WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len));
530
531 if (conn->datadgst_en)
532 tx_crcp = &tcp_sw_conn->tx_crc;
533
534 iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment,
535 data, len, NULL, tx_crcp);
536}
537
538static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task,
539 unsigned int offset, unsigned int count)
540{
541 struct iscsi_conn *conn = task->conn;
542 int err = 0;
543
544 iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len);
545
546 if (!count)
547 return 0;
548
549 if (!task->sc)
550 iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
551 else {
552 struct scsi_data_buffer *sdb = &task->sc->sdb;
553
554 err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
555 sdb->table.nents, offset,
556 count);
557 }
558
559 if (err) {
560 /* got invalid offset/len */
561 return -EIO;
562 }
563 return 0;
564}
565
566static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
567{
568 struct iscsi_tcp_task *tcp_task = task->dd_data;
569
570 task->hdr = task->dd_data + sizeof(*tcp_task);
571 task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE;
572 return 0;
573}
574
575static struct iscsi_cls_conn *
576iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session,
577 uint32_t conn_idx)
578{
579 struct iscsi_conn *conn;
580 struct iscsi_cls_conn *cls_conn;
581 struct iscsi_tcp_conn *tcp_conn;
582 struct iscsi_sw_tcp_conn *tcp_sw_conn;
583
584 cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn),
585 conn_idx);
586 if (!cls_conn)
587 return NULL;
588 conn = cls_conn->dd_data;
589 tcp_conn = conn->dd_data;
590 tcp_sw_conn = tcp_conn->dd_data;
591 INIT_WORK(&conn->recvwork, iscsi_sw_tcp_recv_data_work);
592 tcp_sw_conn->queue_recv = iscsi_recv_from_iscsi_q;
593
594 mutex_init(&tcp_sw_conn->sock_lock);
595 tcp_conn->rx_crcp = &tcp_sw_conn->rx_crc;
596
597 return cls_conn;
598}
599
600static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
601{
602 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
603 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
604 struct socket *sock = tcp_sw_conn->sock;
605
606 /*
607 * The iscsi transport class will make sure we are not called in
608 * parallel with start, stop, bind and destroys. However, this can be
609 * called twice if userspace does a stop then a destroy.
610 */
611 if (!sock)
612 return;
613
614 /*
615 * Make sure we start socket shutdown now in case userspace is up
616 * but delayed in releasing the socket.
617 */
618 kernel_sock_shutdown(sock, SHUT_RDWR);
619
620 sock_hold(sock->sk);
621 iscsi_sw_tcp_conn_restore_callbacks(conn);
622 sock_put(sock->sk);
623
624 iscsi_suspend_rx(conn);
625
626 mutex_lock(&tcp_sw_conn->sock_lock);
627 tcp_sw_conn->sock = NULL;
628 mutex_unlock(&tcp_sw_conn->sock_lock);
629 sockfd_put(sock);
630}
631
632static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
633{
634 struct iscsi_conn *conn = cls_conn->dd_data;
635
636 iscsi_sw_tcp_release_conn(conn);
637 iscsi_tcp_conn_teardown(cls_conn);
638}
639
640static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
641{
642 struct iscsi_conn *conn = cls_conn->dd_data;
643 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
644 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
645 struct socket *sock = tcp_sw_conn->sock;
646
647 /* userspace may have goofed up and not bound us */
648 if (!sock)
649 return;
650
651 sock->sk->sk_err = EIO;
652 wake_up_interruptible(sk_sleep(sock->sk));
653
654 /* stop xmit side */
655 iscsi_suspend_tx(conn);
656
657 /* stop recv side and release socket */
658 iscsi_sw_tcp_release_conn(conn);
659
660 iscsi_conn_stop(cls_conn, flag);
661}
662
663static int
664iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
665 struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
666 int is_leading)
667{
668 struct iscsi_conn *conn = cls_conn->dd_data;
669 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
670 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
671 struct sock *sk;
672 struct socket *sock;
673 int err;
674
675 /* lookup for existing socket */
676 sock = sockfd_lookup((int)transport_eph, &err);
677 if (!sock) {
678 iscsi_conn_printk(KERN_ERR, conn,
679 "sockfd_lookup failed %d\n", err);
680 return -EEXIST;
681 }
682
683 err = -EINVAL;
684 if (!sk_is_tcp(sock->sk))
685 goto free_socket;
686
687 err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
688 if (err)
689 goto free_socket;
690
691 mutex_lock(&tcp_sw_conn->sock_lock);
692 /* bind iSCSI connection and socket */
693 tcp_sw_conn->sock = sock;
694 mutex_unlock(&tcp_sw_conn->sock_lock);
695
696 /* setup Socket parameters */
697 sk = sock->sk;
698 sk->sk_reuse = SK_CAN_REUSE;
699 sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
700 sk->sk_allocation = GFP_ATOMIC;
701 sk->sk_use_task_frag = false;
702 sk_set_memalloc(sk);
703 sock_no_linger(sk);
704
705 iscsi_sw_tcp_conn_set_callbacks(conn);
706 /*
707 * set receive state machine into initial state
708 */
709 iscsi_tcp_hdr_recv_prep(tcp_conn);
710 return 0;
711
712free_socket:
713 sockfd_put(sock);
714 return err;
715}
716
717static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
718 enum iscsi_param param, char *buf,
719 int buflen)
720{
721 struct iscsi_conn *conn = cls_conn->dd_data;
722 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
723 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
724
725 switch(param) {
726 case ISCSI_PARAM_HDRDGST_EN:
727 iscsi_set_param(cls_conn, param, buf, buflen);
728 break;
729 case ISCSI_PARAM_DATADGST_EN:
730 mutex_lock(&tcp_sw_conn->sock_lock);
731 if (!tcp_sw_conn->sock) {
732 mutex_unlock(&tcp_sw_conn->sock_lock);
733 return -ENOTCONN;
734 }
735 iscsi_set_param(cls_conn, param, buf, buflen);
736 mutex_unlock(&tcp_sw_conn->sock_lock);
737 break;
738 case ISCSI_PARAM_MAX_R2T:
739 return iscsi_tcp_set_max_r2t(conn, buf);
740 default:
741 return iscsi_set_param(cls_conn, param, buf, buflen);
742 }
743
744 return 0;
745}
746
747static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
748 enum iscsi_param param, char *buf)
749{
750 struct iscsi_conn *conn = cls_conn->dd_data;
751 struct iscsi_sw_tcp_conn *tcp_sw_conn;
752 struct iscsi_tcp_conn *tcp_conn;
753 struct sockaddr_in6 addr;
754 struct socket *sock;
755 int rc;
756
757 switch(param) {
758 case ISCSI_PARAM_CONN_PORT:
759 case ISCSI_PARAM_CONN_ADDRESS:
760 case ISCSI_PARAM_LOCAL_PORT:
761 spin_lock_bh(&conn->session->frwd_lock);
762 if (!conn->session->leadconn) {
763 spin_unlock_bh(&conn->session->frwd_lock);
764 return -ENOTCONN;
765 }
766 /*
767 * The conn has been setup and bound, so just grab a ref
768 * incase a destroy runs while we are in the net layer.
769 */
770 iscsi_get_conn(conn->cls_conn);
771 spin_unlock_bh(&conn->session->frwd_lock);
772
773 tcp_conn = conn->dd_data;
774 tcp_sw_conn = tcp_conn->dd_data;
775
776 mutex_lock(&tcp_sw_conn->sock_lock);
777 sock = tcp_sw_conn->sock;
778 if (!sock) {
779 rc = -ENOTCONN;
780 goto sock_unlock;
781 }
782
783 if (param == ISCSI_PARAM_LOCAL_PORT)
784 rc = kernel_getsockname(sock,
785 (struct sockaddr *)&addr);
786 else
787 rc = kernel_getpeername(sock,
788 (struct sockaddr *)&addr);
789sock_unlock:
790 mutex_unlock(&tcp_sw_conn->sock_lock);
791 iscsi_put_conn(conn->cls_conn);
792 if (rc < 0)
793 return rc;
794
795 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
796 &addr, param, buf);
797 default:
798 return iscsi_conn_get_param(cls_conn, param, buf);
799 }
800
801 return 0;
802}
803
804static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
805 enum iscsi_host_param param, char *buf)
806{
807 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
808 struct iscsi_session *session;
809 struct iscsi_conn *conn;
810 struct iscsi_tcp_conn *tcp_conn;
811 struct iscsi_sw_tcp_conn *tcp_sw_conn;
812 struct sockaddr_in6 addr;
813 struct socket *sock;
814 int rc;
815
816 switch (param) {
817 case ISCSI_HOST_PARAM_IPADDRESS:
818 session = tcp_sw_host->session;
819 if (!session)
820 return -ENOTCONN;
821
822 spin_lock_bh(&session->frwd_lock);
823 conn = session->leadconn;
824 if (!conn) {
825 spin_unlock_bh(&session->frwd_lock);
826 return -ENOTCONN;
827 }
828 tcp_conn = conn->dd_data;
829 tcp_sw_conn = tcp_conn->dd_data;
830 /*
831 * The conn has been setup and bound, so just grab a ref
832 * incase a destroy runs while we are in the net layer.
833 */
834 iscsi_get_conn(conn->cls_conn);
835 spin_unlock_bh(&session->frwd_lock);
836
837 mutex_lock(&tcp_sw_conn->sock_lock);
838 sock = tcp_sw_conn->sock;
839 if (!sock)
840 rc = -ENOTCONN;
841 else
842 rc = kernel_getsockname(sock, (struct sockaddr *)&addr);
843 mutex_unlock(&tcp_sw_conn->sock_lock);
844 iscsi_put_conn(conn->cls_conn);
845 if (rc < 0)
846 return rc;
847
848 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
849 &addr,
850 (enum iscsi_param)param, buf);
851 default:
852 return iscsi_host_get_param(shost, param, buf);
853 }
854
855 return 0;
856}
857
858static void
859iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
860 struct iscsi_stats *stats)
861{
862 struct iscsi_conn *conn = cls_conn->dd_data;
863 struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
864 struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
865
866 stats->custom_length = 3;
867 strcpy(stats->custom[0].desc, "tx_sendpage_failures");
868 stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt;
869 strcpy(stats->custom[1].desc, "rx_discontiguous_hdr");
870 stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt;
871 strcpy(stats->custom[2].desc, "eh_abort_cnt");
872 stats->custom[2].value = conn->eh_abort_cnt;
873
874 iscsi_tcp_conn_get_stats(cls_conn, stats);
875}
876
877static struct iscsi_cls_session *
878iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
879 uint16_t qdepth, uint32_t initial_cmdsn)
880{
881 struct iscsi_cls_session *cls_session;
882 struct iscsi_session *session;
883 struct iscsi_sw_tcp_host *tcp_sw_host;
884 struct Scsi_Host *shost;
885 int rc;
886
887 if (ep) {
888 printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep);
889 return NULL;
890 }
891
892 shost = iscsi_host_alloc(&iscsi_sw_tcp_sht,
893 sizeof(struct iscsi_sw_tcp_host), 1);
894 if (!shost)
895 return NULL;
896 shost->transportt = iscsi_sw_tcp_scsi_transport;
897 shost->cmd_per_lun = qdepth;
898 shost->max_lun = iscsi_max_lun;
899 shost->max_id = 0;
900 shost->max_channel = 0;
901 shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
902 shost->dma_alignment = 0;
903
904 rc = iscsi_host_get_max_scsi_cmds(shost, cmds_max);
905 if (rc < 0)
906 goto free_host;
907 shost->can_queue = rc;
908
909 if (iscsi_host_add(shost, NULL))
910 goto free_host;
911
912 cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
913 cmds_max, 0,
914 sizeof(struct iscsi_tcp_task) +
915 sizeof(struct iscsi_sw_tcp_hdrbuf),
916 initial_cmdsn, 0);
917 if (!cls_session)
918 goto remove_host;
919 session = cls_session->dd_data;
920
921 if (iscsi_tcp_r2tpool_alloc(session))
922 goto remove_session;
923
924 /* We are now fully setup so expose the session to sysfs. */
925 tcp_sw_host = iscsi_host_priv(shost);
926 tcp_sw_host->session = session;
927 return cls_session;
928
929remove_session:
930 iscsi_session_teardown(cls_session);
931remove_host:
932 iscsi_host_remove(shost, false);
933free_host:
934 iscsi_host_free(shost);
935 return NULL;
936}
937
938static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
939{
940 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
941 struct iscsi_session *session = cls_session->dd_data;
942
943 if (WARN_ON_ONCE(session->leadconn))
944 return;
945
946 iscsi_session_remove(cls_session);
947 /*
948 * Our get_host_param needs to access the session, so remove the
949 * host from sysfs before freeing the session to make sure userspace
950 * is no longer accessing the callout.
951 */
952 iscsi_host_remove(shost, false);
953
954 iscsi_tcp_r2tpool_free(cls_session->dd_data);
955
956 iscsi_session_free(cls_session);
957 iscsi_host_free(shost);
958}
959
960static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param)
961{
962 switch (param_type) {
963 case ISCSI_HOST_PARAM:
964 switch (param) {
965 case ISCSI_HOST_PARAM_NETDEV_NAME:
966 case ISCSI_HOST_PARAM_HWADDRESS:
967 case ISCSI_HOST_PARAM_IPADDRESS:
968 case ISCSI_HOST_PARAM_INITIATOR_NAME:
969 return S_IRUGO;
970 default:
971 return 0;
972 }
973 case ISCSI_PARAM:
974 switch (param) {
975 case ISCSI_PARAM_MAX_RECV_DLENGTH:
976 case ISCSI_PARAM_MAX_XMIT_DLENGTH:
977 case ISCSI_PARAM_HDRDGST_EN:
978 case ISCSI_PARAM_DATADGST_EN:
979 case ISCSI_PARAM_CONN_ADDRESS:
980 case ISCSI_PARAM_CONN_PORT:
981 case ISCSI_PARAM_LOCAL_PORT:
982 case ISCSI_PARAM_EXP_STATSN:
983 case ISCSI_PARAM_PERSISTENT_ADDRESS:
984 case ISCSI_PARAM_PERSISTENT_PORT:
985 case ISCSI_PARAM_PING_TMO:
986 case ISCSI_PARAM_RECV_TMO:
987 case ISCSI_PARAM_INITIAL_R2T_EN:
988 case ISCSI_PARAM_MAX_R2T:
989 case ISCSI_PARAM_IMM_DATA_EN:
990 case ISCSI_PARAM_FIRST_BURST:
991 case ISCSI_PARAM_MAX_BURST:
992 case ISCSI_PARAM_PDU_INORDER_EN:
993 case ISCSI_PARAM_DATASEQ_INORDER_EN:
994 case ISCSI_PARAM_ERL:
995 case ISCSI_PARAM_TARGET_NAME:
996 case ISCSI_PARAM_TPGT:
997 case ISCSI_PARAM_USERNAME:
998 case ISCSI_PARAM_PASSWORD:
999 case ISCSI_PARAM_USERNAME_IN:
1000 case ISCSI_PARAM_PASSWORD_IN:
1001 case ISCSI_PARAM_FAST_ABORT:
1002 case ISCSI_PARAM_ABORT_TMO:
1003 case ISCSI_PARAM_LU_RESET_TMO:
1004 case ISCSI_PARAM_TGT_RESET_TMO:
1005 case ISCSI_PARAM_IFACE_NAME:
1006 case ISCSI_PARAM_INITIATOR_NAME:
1007 return S_IRUGO;
1008 default:
1009 return 0;
1010 }
1011 }
1012
1013 return 0;
1014}
1015
1016static int iscsi_sw_tcp_sdev_configure(struct scsi_device *sdev,
1017 struct queue_limits *lim)
1018{
1019 struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(sdev->host);
1020 struct iscsi_session *session = tcp_sw_host->session;
1021 struct iscsi_conn *conn = session->leadconn;
1022
1023 if (conn->datadgst_en)
1024 lim->features |= BLK_FEAT_STABLE_WRITES;
1025 return 0;
1026}
1027
1028static const struct scsi_host_template iscsi_sw_tcp_sht = {
1029 .module = THIS_MODULE,
1030 .name = "iSCSI Initiator over TCP/IP",
1031 .queuecommand = iscsi_queuecommand,
1032 .change_queue_depth = scsi_change_queue_depth,
1033 .can_queue = ISCSI_TOTAL_CMDS_MAX,
1034 .sg_tablesize = 4096,
1035 .max_sectors = 0xFFFF,
1036 .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN,
1037 .eh_timed_out = iscsi_eh_cmd_timed_out,
1038 .eh_abort_handler = iscsi_eh_abort,
1039 .eh_device_reset_handler= iscsi_eh_device_reset,
1040 .eh_target_reset_handler = iscsi_eh_recover_target,
1041 .dma_boundary = PAGE_SIZE - 1,
1042 .sdev_configure = iscsi_sw_tcp_sdev_configure,
1043 .proc_name = "iscsi_tcp",
1044 .this_id = -1,
1045 .track_queue_depth = 1,
1046 .cmd_size = sizeof(struct iscsi_cmd),
1047};
1048
1049static struct iscsi_transport iscsi_sw_tcp_transport = {
1050 .owner = THIS_MODULE,
1051 .name = "tcp",
1052 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
1053 | CAP_DATADGST,
1054 /* session management */
1055 .create_session = iscsi_sw_tcp_session_create,
1056 .destroy_session = iscsi_sw_tcp_session_destroy,
1057 /* connection management */
1058 .create_conn = iscsi_sw_tcp_conn_create,
1059 .bind_conn = iscsi_sw_tcp_conn_bind,
1060 .destroy_conn = iscsi_sw_tcp_conn_destroy,
1061 .attr_is_visible = iscsi_sw_tcp_attr_is_visible,
1062 .set_param = iscsi_sw_tcp_conn_set_param,
1063 .get_conn_param = iscsi_sw_tcp_conn_get_param,
1064 .get_session_param = iscsi_session_get_param,
1065 .start_conn = iscsi_conn_start,
1066 .stop_conn = iscsi_sw_tcp_conn_stop,
1067 /* iscsi host params */
1068 .get_host_param = iscsi_sw_tcp_host_get_param,
1069 .set_host_param = iscsi_host_set_param,
1070 /* IO */
1071 .send_pdu = iscsi_conn_send_pdu,
1072 .get_stats = iscsi_sw_tcp_conn_get_stats,
1073 /* iscsi task/cmd helpers */
1074 .init_task = iscsi_tcp_task_init,
1075 .xmit_task = iscsi_tcp_task_xmit,
1076 .cleanup_task = iscsi_tcp_cleanup_task,
1077 /* low level pdu helpers */
1078 .xmit_pdu = iscsi_sw_tcp_pdu_xmit,
1079 .init_pdu = iscsi_sw_tcp_pdu_init,
1080 .alloc_pdu = iscsi_sw_tcp_pdu_alloc,
1081 /* recovery */
1082 .session_recovery_timedout = iscsi_session_recovery_timedout,
1083};
1084
1085static int __init iscsi_sw_tcp_init(void)
1086{
1087 if (iscsi_max_lun < 1) {
1088 printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n",
1089 iscsi_max_lun);
1090 return -EINVAL;
1091 }
1092
1093 iscsi_sw_tcp_scsi_transport = iscsi_register_transport(
1094 &iscsi_sw_tcp_transport);
1095 if (!iscsi_sw_tcp_scsi_transport)
1096 return -ENODEV;
1097
1098 return 0;
1099}
1100
1101static void __exit iscsi_sw_tcp_exit(void)
1102{
1103 iscsi_unregister_transport(&iscsi_sw_tcp_transport);
1104}
1105
1106module_init(iscsi_sw_tcp_init);
1107module_exit(iscsi_sw_tcp_exit);
Linux 6.x block layer and io_uring tree(s)