1/*
2 * SCSI RDMA (SRP) transport class
3 *
4 * Copyright (C) 2007 FUJITA Tomonori <tomof@acm.org>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation, version 2 of the
9 * License.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19 * 02110-1301 USA
20 */
21#include <linux/init.h>
22#include <linux/module.h>
23#include <linux/jiffies.h>
24#include <linux/err.h>
25#include <linux/slab.h>
26#include <linux/string.h>
27
28#include <scsi/scsi.h>
29#include <scsi/scsi_cmnd.h>
30#include <scsi/scsi_device.h>
31#include <scsi/scsi_host.h>
32#include <scsi/scsi_transport.h>
33#include <scsi/scsi_transport_srp.h>
34#include "scsi_priv.h"
35
36struct srp_host_attrs {
37 atomic_t next_port_id;
38};
39#define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data)
40
41#define SRP_HOST_ATTRS 0
42#define SRP_RPORT_ATTRS 8
43
44struct srp_internal {
45 struct scsi_transport_template t;
46 struct srp_function_template *f;
47
48 struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1];
49
50 struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1];
51 struct transport_container rport_attr_cont;
52};
53
54static int scsi_is_srp_rport(const struct device *dev);
55
56#define to_srp_internal(tmpl) container_of(tmpl, struct srp_internal, t)
57
58#define dev_to_rport(d) container_of(d, struct srp_rport, dev)
59#define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent)
60static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r)
61{
62 return dev_to_shost(r->dev.parent);
63}
64
65static int find_child_rport(struct device *dev, void *data)
66{
67 struct device **child = data;
68
69 if (scsi_is_srp_rport(dev)) {
70 WARN_ON_ONCE(*child);
71 *child = dev;
72 }
73 return 0;
74}
75
76static inline struct srp_rport *shost_to_rport(struct Scsi_Host *shost)
77{
78 struct device *child = NULL;
79
80 WARN_ON_ONCE(device_for_each_child(&shost->shost_gendev, &child,
81 find_child_rport) < 0);
82 return child ? dev_to_rport(child) : NULL;
83}
84
85/**
86 * srp_tmo_valid() - check timeout combination validity
87 * @reconnect_delay: Reconnect delay in seconds.
88 * @fast_io_fail_tmo: Fast I/O fail timeout in seconds.
89 * @dev_loss_tmo: Device loss timeout in seconds.
90 *
91 * The combination of the timeout parameters must be such that SCSI commands
92 * are finished in a reasonable time. Hence do not allow the fast I/O fail
93 * timeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT nor allow dev_loss_tmo to
94 * exceed that limit if failing I/O fast has been disabled. Furthermore, these
95 * parameters must be such that multipath can detect failed paths timely.
96 * Hence do not allow all three parameters to be disabled simultaneously.
97 */
98int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, long dev_loss_tmo)
99{
100 if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0)
101 return -EINVAL;
102 if (reconnect_delay == 0)
103 return -EINVAL;
104 if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
105 return -EINVAL;
106 if (fast_io_fail_tmo < 0 &&
107 dev_loss_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
108 return -EINVAL;
109 if (dev_loss_tmo >= LONG_MAX / HZ)
110 return -EINVAL;
111 if (fast_io_fail_tmo >= 0 && dev_loss_tmo >= 0 &&
112 fast_io_fail_tmo >= dev_loss_tmo)
113 return -EINVAL;
114 return 0;
115}
116EXPORT_SYMBOL_GPL(srp_tmo_valid);
117
118static int srp_host_setup(struct transport_container *tc, struct device *dev,
119 struct device *cdev)
120{
121 struct Scsi_Host *shost = dev_to_shost(dev);
122 struct srp_host_attrs *srp_host = to_srp_host_attrs(shost);
123
124 atomic_set(&srp_host->next_port_id, 0);
125 return 0;
126}
127
128static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup,
129 NULL, NULL);
130
131static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports",
132 NULL, NULL, NULL);
133
134static ssize_t
135show_srp_rport_id(struct device *dev, struct device_attribute *attr,
136 char *buf)
137{
138 struct srp_rport *rport = transport_class_to_srp_rport(dev);
139 return sprintf(buf, "%16phC\n", rport->port_id);
140}
141
142static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
143
144static const struct {
145 u32 value;
146 char *name;
147} srp_rport_role_names[] = {
148 {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
149 {SRP_RPORT_ROLE_TARGET, "SRP Target"},
150};
151
152static ssize_t
153show_srp_rport_roles(struct device *dev, struct device_attribute *attr,
154 char *buf)
155{
156 struct srp_rport *rport = transport_class_to_srp_rport(dev);
157 int i;
158 char *name = NULL;
159
160 for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
161 if (srp_rport_role_names[i].value == rport->roles) {
162 name = srp_rport_role_names[i].name;
163 break;
164 }
165 return sprintf(buf, "%s\n", name ? : "unknown");
166}
167
168static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
169
170static ssize_t store_srp_rport_delete(struct device *dev,
171 struct device_attribute *attr,
172 const char *buf, size_t count)
173{
174 struct srp_rport *rport = transport_class_to_srp_rport(dev);
175 struct Scsi_Host *shost = dev_to_shost(dev);
176 struct srp_internal *i = to_srp_internal(shost->transportt);
177
178 if (i->f->rport_delete) {
179 i->f->rport_delete(rport);
180 return count;
181 } else {
182 return -ENOSYS;
183 }
184}
185
186static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete);
187
188static ssize_t show_srp_rport_state(struct device *dev,
189 struct device_attribute *attr,
190 char *buf)
191{
192 static const char *const state_name[] = {
193 [SRP_RPORT_RUNNING] = "running",
194 [SRP_RPORT_BLOCKED] = "blocked",
195 [SRP_RPORT_FAIL_FAST] = "fail-fast",
196 [SRP_RPORT_LOST] = "lost",
197 };
198 struct srp_rport *rport = transport_class_to_srp_rport(dev);
199 enum srp_rport_state state = rport->state;
200
201 return sprintf(buf, "%s\n",
202 (unsigned)state < ARRAY_SIZE(state_name) ?
203 state_name[state] : "???");
204}
205
206static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL);
207
208static ssize_t srp_show_tmo(char *buf, int tmo)
209{
210 return tmo >= 0 ? sprintf(buf, "%d\n", tmo) : sprintf(buf, "off\n");
211}
212
213int srp_parse_tmo(int *tmo, const char *buf)
214{
215 int res = 0;
216
217 if (strncmp(buf, "off", 3) != 0)
218 res = kstrtoint(buf, 0, tmo);
219 else
220 *tmo = -1;
221
222 return res;
223}
224EXPORT_SYMBOL(srp_parse_tmo);
225
226static ssize_t show_reconnect_delay(struct device *dev,
227 struct device_attribute *attr, char *buf)
228{
229 struct srp_rport *rport = transport_class_to_srp_rport(dev);
230
231 return srp_show_tmo(buf, rport->reconnect_delay);
232}
233
234static ssize_t store_reconnect_delay(struct device *dev,
235 struct device_attribute *attr,
236 const char *buf, const size_t count)
237{
238 struct srp_rport *rport = transport_class_to_srp_rport(dev);
239 int res, delay;
240
241 res = srp_parse_tmo(&delay, buf);
242 if (res)
243 goto out;
244 res = srp_tmo_valid(delay, rport->fast_io_fail_tmo,
245 rport->dev_loss_tmo);
246 if (res)
247 goto out;
248
249 if (rport->reconnect_delay <= 0 && delay > 0 &&
250 rport->state != SRP_RPORT_RUNNING) {
251 queue_delayed_work(system_long_wq, &rport->reconnect_work,
252 delay * HZ);
253 } else if (delay <= 0) {
254 cancel_delayed_work(&rport->reconnect_work);
255 }
256 rport->reconnect_delay = delay;
257 res = count;
258
259out:
260 return res;
261}
262
263static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay,
264 store_reconnect_delay);
265
266static ssize_t show_failed_reconnects(struct device *dev,
267 struct device_attribute *attr, char *buf)
268{
269 struct srp_rport *rport = transport_class_to_srp_rport(dev);
270
271 return sprintf(buf, "%d\n", rport->failed_reconnects);
272}
273
274static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL);
275
276static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev,
277 struct device_attribute *attr,
278 char *buf)
279{
280 struct srp_rport *rport = transport_class_to_srp_rport(dev);
281
282 return srp_show_tmo(buf, rport->fast_io_fail_tmo);
283}
284
285static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev,
286 struct device_attribute *attr,
287 const char *buf, size_t count)
288{
289 struct srp_rport *rport = transport_class_to_srp_rport(dev);
290 int res;
291 int fast_io_fail_tmo;
292
293 res = srp_parse_tmo(&fast_io_fail_tmo, buf);
294 if (res)
295 goto out;
296 res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo,
297 rport->dev_loss_tmo);
298 if (res)
299 goto out;
300 rport->fast_io_fail_tmo = fast_io_fail_tmo;
301 res = count;
302
303out:
304 return res;
305}
306
307static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR,
308 show_srp_rport_fast_io_fail_tmo,
309 store_srp_rport_fast_io_fail_tmo);
310
311static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev,
312 struct device_attribute *attr,
313 char *buf)
314{
315 struct srp_rport *rport = transport_class_to_srp_rport(dev);
316
317 return srp_show_tmo(buf, rport->dev_loss_tmo);
318}
319
320static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev,
321 struct device_attribute *attr,
322 const char *buf, size_t count)
323{
324 struct srp_rport *rport = transport_class_to_srp_rport(dev);
325 int res;
326 int dev_loss_tmo;
327
328 res = srp_parse_tmo(&dev_loss_tmo, buf);
329 if (res)
330 goto out;
331 res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo,
332 dev_loss_tmo);
333 if (res)
334 goto out;
335 rport->dev_loss_tmo = dev_loss_tmo;
336 res = count;
337
338out:
339 return res;
340}
341
342static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR,
343 show_srp_rport_dev_loss_tmo,
344 store_srp_rport_dev_loss_tmo);
345
346static int srp_rport_set_state(struct srp_rport *rport,
347 enum srp_rport_state new_state)
348{
349 enum srp_rport_state old_state = rport->state;
350
351 lockdep_assert_held(&rport->mutex);
352
353 switch (new_state) {
354 case SRP_RPORT_RUNNING:
355 switch (old_state) {
356 case SRP_RPORT_LOST:
357 goto invalid;
358 default:
359 break;
360 }
361 break;
362 case SRP_RPORT_BLOCKED:
363 switch (old_state) {
364 case SRP_RPORT_RUNNING:
365 break;
366 default:
367 goto invalid;
368 }
369 break;
370 case SRP_RPORT_FAIL_FAST:
371 switch (old_state) {
372 case SRP_RPORT_LOST:
373 goto invalid;
374 default:
375 break;
376 }
377 break;
378 case SRP_RPORT_LOST:
379 break;
380 }
381 rport->state = new_state;
382 return 0;
383
384invalid:
385 return -EINVAL;
386}
387
388/**
389 * srp_reconnect_work() - reconnect and schedule a new attempt if necessary
390 * @work: Work structure used for scheduling this operation.
391 */
392static void srp_reconnect_work(struct work_struct *work)
393{
394 struct srp_rport *rport = container_of(to_delayed_work(work),
395 struct srp_rport, reconnect_work);
396 struct Scsi_Host *shost = rport_to_shost(rport);
397 int delay, res;
398
399 res = srp_reconnect_rport(rport);
400 if (res != 0) {
401 shost_printk(KERN_ERR, shost,
402 "reconnect attempt %d failed (%d)\n",
403 ++rport->failed_reconnects, res);
404 delay = rport->reconnect_delay *
405 min(100, max(1, rport->failed_reconnects - 10));
406 if (delay > 0)
407 queue_delayed_work(system_long_wq,
408 &rport->reconnect_work, delay * HZ);
409 }
410}
411
412static void __rport_fail_io_fast(struct srp_rport *rport)
413{
414 struct Scsi_Host *shost = rport_to_shost(rport);
415 struct srp_internal *i;
416
417 lockdep_assert_held(&rport->mutex);
418
419 if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST))
420 return;
421 /*
422 * Call scsi_target_block() to wait for ongoing shost->queuecommand()
423 * calls before invoking i->f->terminate_rport_io().
424 */
425 scsi_target_block(rport->dev.parent);
426 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
427
428 /* Involve the LLD if possible to terminate all I/O on the rport. */
429 i = to_srp_internal(shost->transportt);
430 if (i->f->terminate_rport_io)
431 i->f->terminate_rport_io(rport);
432}
433
434/**
435 * rport_fast_io_fail_timedout() - fast I/O failure timeout handler
436 * @work: Work structure used for scheduling this operation.
437 */
438static void rport_fast_io_fail_timedout(struct work_struct *work)
439{
440 struct srp_rport *rport = container_of(to_delayed_work(work),
441 struct srp_rport, fast_io_fail_work);
442 struct Scsi_Host *shost = rport_to_shost(rport);
443
444 pr_info("fast_io_fail_tmo expired for SRP %s / %s.\n",
445 dev_name(&rport->dev), dev_name(&shost->shost_gendev));
446
447 mutex_lock(&rport->mutex);
448 if (rport->state == SRP_RPORT_BLOCKED)
449 __rport_fail_io_fast(rport);
450 mutex_unlock(&rport->mutex);
451}
452
453/**
454 * rport_dev_loss_timedout() - device loss timeout handler
455 * @work: Work structure used for scheduling this operation.
456 */
457static void rport_dev_loss_timedout(struct work_struct *work)
458{
459 struct srp_rport *rport = container_of(to_delayed_work(work),
460 struct srp_rport, dev_loss_work);
461 struct Scsi_Host *shost = rport_to_shost(rport);
462 struct srp_internal *i = to_srp_internal(shost->transportt);
463
464 pr_info("dev_loss_tmo expired for SRP %s / %s.\n",
465 dev_name(&rport->dev), dev_name(&shost->shost_gendev));
466
467 mutex_lock(&rport->mutex);
468 WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0);
469 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
470 mutex_unlock(&rport->mutex);
471
472 i->f->rport_delete(rport);
473}
474
475static void __srp_start_tl_fail_timers(struct srp_rport *rport)
476{
477 struct Scsi_Host *shost = rport_to_shost(rport);
478 int delay, fast_io_fail_tmo, dev_loss_tmo;
479
480 lockdep_assert_held(&rport->mutex);
481
482 delay = rport->reconnect_delay;
483 fast_io_fail_tmo = rport->fast_io_fail_tmo;
484 dev_loss_tmo = rport->dev_loss_tmo;
485 pr_debug("%s current state: %d\n", dev_name(&shost->shost_gendev),
486 rport->state);
487
488 if (rport->state == SRP_RPORT_LOST)
489 return;
490 if (delay > 0)
491 queue_delayed_work(system_long_wq, &rport->reconnect_work,
492 1UL * delay * HZ);
493 if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) &&
494 srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) {
495 pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev),
496 rport->state);
497 scsi_target_block(&shost->shost_gendev);
498 if (fast_io_fail_tmo >= 0)
499 queue_delayed_work(system_long_wq,
500 &rport->fast_io_fail_work,
501 1UL * fast_io_fail_tmo * HZ);
502 if (dev_loss_tmo >= 0)
503 queue_delayed_work(system_long_wq,
504 &rport->dev_loss_work,
505 1UL * dev_loss_tmo * HZ);
506 }
507}
508
509/**
510 * srp_start_tl_fail_timers() - start the transport layer failure timers
511 * @rport: SRP target port.
512 *
513 * Start the transport layer fast I/O failure and device loss timers. Do not
514 * modify a timer that was already started.
515 */
516void srp_start_tl_fail_timers(struct srp_rport *rport)
517{
518 mutex_lock(&rport->mutex);
519 __srp_start_tl_fail_timers(rport);
520 mutex_unlock(&rport->mutex);
521}
522EXPORT_SYMBOL(srp_start_tl_fail_timers);
523
524/**
525 * srp_reconnect_rport() - reconnect to an SRP target port
526 * @rport: SRP target port.
527 *
528 * Blocks SCSI command queueing before invoking reconnect() such that
529 * queuecommand() won't be invoked concurrently with reconnect() from outside
530 * the SCSI EH. This is important since a reconnect() implementation may
531 * reallocate resources needed by queuecommand().
532 *
533 * Notes:
534 * - This function neither waits until outstanding requests have finished nor
535 * tries to abort these. It is the responsibility of the reconnect()
536 * function to finish outstanding commands before reconnecting to the target
537 * port.
538 * - It is the responsibility of the caller to ensure that the resources
539 * reallocated by the reconnect() function won't be used while this function
540 * is in progress. One possible strategy is to invoke this function from
541 * the context of the SCSI EH thread only. Another possible strategy is to
542 * lock the rport mutex inside each SCSI LLD callback that can be invoked by
543 * the SCSI EH (the scsi_host_template.eh_*() functions and also the
544 * scsi_host_template.queuecommand() function).
545 */
546int srp_reconnect_rport(struct srp_rport *rport)
547{
548 struct Scsi_Host *shost = rport_to_shost(rport);
549 struct srp_internal *i = to_srp_internal(shost->transportt);
550 struct scsi_device *sdev;
551 int res;
552
553 pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev));
554
555 res = mutex_lock_interruptible(&rport->mutex);
556 if (res)
557 goto out;
558 scsi_target_block(&shost->shost_gendev);
559 res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV;
560 pr_debug("%s (state %d): transport.reconnect() returned %d\n",
561 dev_name(&shost->shost_gendev), rport->state, res);
562 if (res == 0) {
563 cancel_delayed_work(&rport->fast_io_fail_work);
564 cancel_delayed_work(&rport->dev_loss_work);
565
566 rport->failed_reconnects = 0;
567 srp_rport_set_state(rport, SRP_RPORT_RUNNING);
568 scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING);
569 /*
570 * If the SCSI error handler has offlined one or more devices,
571 * invoking scsi_target_unblock() won't change the state of
572 * these devices into running so do that explicitly.
573 */
574 shost_for_each_device(sdev, shost) {
575 mutex_lock(&sdev->state_mutex);
576 if (sdev->sdev_state == SDEV_OFFLINE)
577 sdev->sdev_state = SDEV_RUNNING;
578 mutex_unlock(&sdev->state_mutex);
579 }
580 } else if (rport->state == SRP_RPORT_RUNNING) {
581 /*
582 * srp_reconnect_rport() has been invoked with fast_io_fail
583 * and dev_loss off. Mark the port as failed and start the TL
584 * failure timers if these had not yet been started.
585 */
586 __rport_fail_io_fast(rport);
587 scsi_target_unblock(&shost->shost_gendev,
588 SDEV_TRANSPORT_OFFLINE);
589 __srp_start_tl_fail_timers(rport);
590 } else if (rport->state != SRP_RPORT_BLOCKED) {
591 scsi_target_unblock(&shost->shost_gendev,
592 SDEV_TRANSPORT_OFFLINE);
593 }
594 mutex_unlock(&rport->mutex);
595
596out:
597 return res;
598}
599EXPORT_SYMBOL(srp_reconnect_rport);
600
601/**
602 * srp_timed_out() - SRP transport intercept of the SCSI timeout EH
603 * @scmd: SCSI command.
604 *
605 * If a timeout occurs while an rport is in the blocked state, ask the SCSI
606 * EH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI core
607 * handle the timeout (BLK_EH_DONE).
608 *
609 * Note: This function is called from soft-IRQ context and with the request
610 * queue lock held.
611 */
612enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd)
613{
614 struct scsi_device *sdev = scmd->device;
615 struct Scsi_Host *shost = sdev->host;
616 struct srp_internal *i = to_srp_internal(shost->transportt);
617 struct srp_rport *rport = shost_to_rport(shost);
618
619 pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev));
620 return rport && rport->fast_io_fail_tmo < 0 &&
621 rport->dev_loss_tmo < 0 &&
622 i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ?
623 BLK_EH_RESET_TIMER : BLK_EH_DONE;
624}
625EXPORT_SYMBOL(srp_timed_out);
626
627static void srp_rport_release(struct device *dev)
628{
629 struct srp_rport *rport = dev_to_rport(dev);
630
631 put_device(dev->parent);
632 kfree(rport);
633}
634
635static int scsi_is_srp_rport(const struct device *dev)
636{
637 return dev->release == srp_rport_release;
638}
639
640static int srp_rport_match(struct attribute_container *cont,
641 struct device *dev)
642{
643 struct Scsi_Host *shost;
644 struct srp_internal *i;
645
646 if (!scsi_is_srp_rport(dev))
647 return 0;
648
649 shost = dev_to_shost(dev->parent);
650 if (!shost->transportt)
651 return 0;
652 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
653 return 0;
654
655 i = to_srp_internal(shost->transportt);
656 return &i->rport_attr_cont.ac == cont;
657}
658
659static int srp_host_match(struct attribute_container *cont, struct device *dev)
660{
661 struct Scsi_Host *shost;
662 struct srp_internal *i;
663
664 if (!scsi_is_host_device(dev))
665 return 0;
666
667 shost = dev_to_shost(dev);
668 if (!shost->transportt)
669 return 0;
670 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
671 return 0;
672
673 i = to_srp_internal(shost->transportt);
674 return &i->t.host_attrs.ac == cont;
675}
676
677/**
678 * srp_rport_get() - increment rport reference count
679 * @rport: SRP target port.
680 */
681void srp_rport_get(struct srp_rport *rport)
682{
683 get_device(&rport->dev);
684}
685EXPORT_SYMBOL(srp_rport_get);
686
687/**
688 * srp_rport_put() - decrement rport reference count
689 * @rport: SRP target port.
690 */
691void srp_rport_put(struct srp_rport *rport)
692{
693 put_device(&rport->dev);
694}
695EXPORT_SYMBOL(srp_rport_put);
696
697/**
698 * srp_rport_add - add a SRP remote port to the device hierarchy
699 * @shost: scsi host the remote port is connected to.
700 * @ids: The port id for the remote port.
701 *
702 * Publishes a port to the rest of the system.
703 */
704struct srp_rport *srp_rport_add(struct Scsi_Host *shost,
705 struct srp_rport_identifiers *ids)
706{
707 struct srp_rport *rport;
708 struct device *parent = &shost->shost_gendev;
709 struct srp_internal *i = to_srp_internal(shost->transportt);
710 int id, ret;
711
712 rport = kzalloc(sizeof(*rport), GFP_KERNEL);
713 if (!rport)
714 return ERR_PTR(-ENOMEM);
715
716 mutex_init(&rport->mutex);
717
718 device_initialize(&rport->dev);
719
720 rport->dev.parent = get_device(parent);
721 rport->dev.release = srp_rport_release;
722
723 memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id));
724 rport->roles = ids->roles;
725
726 if (i->f->reconnect)
727 rport->reconnect_delay = i->f->reconnect_delay ?
728 *i->f->reconnect_delay : 10;
729 INIT_DELAYED_WORK(&rport->reconnect_work, srp_reconnect_work);
730 rport->fast_io_fail_tmo = i->f->fast_io_fail_tmo ?
731 *i->f->fast_io_fail_tmo : 15;
732 rport->dev_loss_tmo = i->f->dev_loss_tmo ? *i->f->dev_loss_tmo : 60;
733 INIT_DELAYED_WORK(&rport->fast_io_fail_work,
734 rport_fast_io_fail_timedout);
735 INIT_DELAYED_WORK(&rport->dev_loss_work, rport_dev_loss_timedout);
736
737 id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id);
738 dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id);
739
740 transport_setup_device(&rport->dev);
741
742 ret = device_add(&rport->dev);
743 if (ret) {
744 transport_destroy_device(&rport->dev);
745 put_device(&rport->dev);
746 return ERR_PTR(ret);
747 }
748
749 transport_add_device(&rport->dev);
750 transport_configure_device(&rport->dev);
751
752 return rport;
753}
754EXPORT_SYMBOL_GPL(srp_rport_add);
755
756/**
757 * srp_rport_del - remove a SRP remote port
758 * @rport: SRP remote port to remove
759 *
760 * Removes the specified SRP remote port.
761 */
762void srp_rport_del(struct srp_rport *rport)
763{
764 struct device *dev = &rport->dev;
765
766 transport_remove_device(dev);
767 device_del(dev);
768 transport_destroy_device(dev);
769
770 put_device(dev);
771}
772EXPORT_SYMBOL_GPL(srp_rport_del);
773
774static int do_srp_rport_del(struct device *dev, void *data)
775{
776 if (scsi_is_srp_rport(dev))
777 srp_rport_del(dev_to_rport(dev));
778 return 0;
779}
780
781/**
782 * srp_remove_host - tear down a Scsi_Host's SRP data structures
783 * @shost: Scsi Host that is torn down
784 *
785 * Removes all SRP remote ports for a given Scsi_Host.
786 * Must be called just before scsi_remove_host for SRP HBAs.
787 */
788void srp_remove_host(struct Scsi_Host *shost)
789{
790 device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
791}
792EXPORT_SYMBOL_GPL(srp_remove_host);
793
794/**
795 * srp_stop_rport_timers - stop the transport layer recovery timers
796 * @rport: SRP remote port for which to stop the timers.
797 *
798 * Must be called after srp_remove_host() and scsi_remove_host(). The caller
799 * must hold a reference on the rport (rport->dev) and on the SCSI host
800 * (rport->dev.parent).
801 */
802void srp_stop_rport_timers(struct srp_rport *rport)
803{
804 mutex_lock(&rport->mutex);
805 if (rport->state == SRP_RPORT_BLOCKED)
806 __rport_fail_io_fast(rport);
807 srp_rport_set_state(rport, SRP_RPORT_LOST);
808 mutex_unlock(&rport->mutex);
809
810 cancel_delayed_work_sync(&rport->reconnect_work);
811 cancel_delayed_work_sync(&rport->fast_io_fail_work);
812 cancel_delayed_work_sync(&rport->dev_loss_work);
813}
814EXPORT_SYMBOL_GPL(srp_stop_rport_timers);
815
816/**
817 * srp_attach_transport - instantiate SRP transport template
818 * @ft: SRP transport class function template
819 */
820struct scsi_transport_template *
821srp_attach_transport(struct srp_function_template *ft)
822{
823 int count;
824 struct srp_internal *i;
825
826 i = kzalloc(sizeof(*i), GFP_KERNEL);
827 if (!i)
828 return NULL;
829
830 i->t.host_size = sizeof(struct srp_host_attrs);
831 i->t.host_attrs.ac.attrs = &i->host_attrs[0];
832 i->t.host_attrs.ac.class = &srp_host_class.class;
833 i->t.host_attrs.ac.match = srp_host_match;
834 i->host_attrs[0] = NULL;
835 transport_container_register(&i->t.host_attrs);
836
837 i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
838 i->rport_attr_cont.ac.class = &srp_rport_class.class;
839 i->rport_attr_cont.ac.match = srp_rport_match;
840
841 count = 0;
842 i->rport_attrs[count++] = &dev_attr_port_id;
843 i->rport_attrs[count++] = &dev_attr_roles;
844 if (ft->has_rport_state) {
845 i->rport_attrs[count++] = &dev_attr_state;
846 i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo;
847 i->rport_attrs[count++] = &dev_attr_dev_loss_tmo;
848 }
849 if (ft->reconnect) {
850 i->rport_attrs[count++] = &dev_attr_reconnect_delay;
851 i->rport_attrs[count++] = &dev_attr_failed_reconnects;
852 }
853 if (ft->rport_delete)
854 i->rport_attrs[count++] = &dev_attr_delete;
855 i->rport_attrs[count++] = NULL;
856 BUG_ON(count > ARRAY_SIZE(i->rport_attrs));
857
858 transport_container_register(&i->rport_attr_cont);
859
860 i->f = ft;
861
862 return &i->t;
863}
864EXPORT_SYMBOL_GPL(srp_attach_transport);
865
866/**
867 * srp_release_transport - release SRP transport template instance
868 * @t: transport template instance
869 */
870void srp_release_transport(struct scsi_transport_template *t)
871{
872 struct srp_internal *i = to_srp_internal(t);
873
874 transport_container_unregister(&i->t.host_attrs);
875 transport_container_unregister(&i->rport_attr_cont);
876
877 kfree(i);
878}
879EXPORT_SYMBOL_GPL(srp_release_transport);
880
881static __init int srp_transport_init(void)
882{
883 int ret;
884
885 ret = transport_class_register(&srp_host_class);
886 if (ret)
887 return ret;
888 ret = transport_class_register(&srp_rport_class);
889 if (ret)
890 goto unregister_host_class;
891
892 return 0;
893unregister_host_class:
894 transport_class_unregister(&srp_host_class);
895 return ret;
896}
897
898static void __exit srp_transport_exit(void)
899{
900 transport_class_unregister(&srp_host_class);
901 transport_class_unregister(&srp_rport_class);
902}
903
904MODULE_AUTHOR("FUJITA Tomonori");
905MODULE_DESCRIPTION("SRP Transport Attributes");
906MODULE_LICENSE("GPL");
907
908module_init(srp_transport_init);
909module_exit(srp_transport_exit);
910