1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * SCSI RDMA (SRP) transport class
4 *
5 * Copyright (C) 2007 FUJITA Tomonori <tomof@acm.org>
6 */
7#include <linux/init.h>
8#include <linux/module.h>
9#include <linux/jiffies.h>
10#include <linux/err.h>
11#include <linux/slab.h>
12#include <linux/string.h>
13
14#include <scsi/scsi.h>
15#include <scsi/scsi_cmnd.h>
16#include <scsi/scsi_device.h>
17#include <scsi/scsi_host.h>
18#include <scsi/scsi_transport.h>
19#include <scsi/scsi_transport_srp.h>
20#include "scsi_priv.h"
21
22struct srp_host_attrs {
23 atomic_t next_port_id;
24};
25#define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data)
26
27#define SRP_HOST_ATTRS 0
28#define SRP_RPORT_ATTRS 8
29
30struct srp_internal {
31 struct scsi_transport_template t;
32 struct srp_function_template *f;
33
34 struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1];
35
36 struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1];
37 struct transport_container rport_attr_cont;
38};
39
40static int scsi_is_srp_rport(const struct device *dev);
41
42#define to_srp_internal(tmpl) container_of(tmpl, struct srp_internal, t)
43
44#define dev_to_rport(d) container_of(d, struct srp_rport, dev)
45#define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent)
46static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r)
47{
48 return dev_to_shost(dev: r->dev.parent);
49}
50
51static int find_child_rport(struct device *dev, void *data)
52{
53 struct device **child = data;
54
55 if (scsi_is_srp_rport(dev)) {
56 WARN_ON_ONCE(*child);
57 *child = dev;
58 }
59 return 0;
60}
61
62static inline struct srp_rport *shost_to_rport(struct Scsi_Host *shost)
63{
64 struct device *child = NULL;
65
66 WARN_ON_ONCE(device_for_each_child(&shost->shost_gendev, &child,
67 find_child_rport) < 0);
68 return child ? dev_to_rport(child) : NULL;
69}
70
71/**
72 * srp_tmo_valid() - check timeout combination validity
73 * @reconnect_delay: Reconnect delay in seconds.
74 * @fast_io_fail_tmo: Fast I/O fail timeout in seconds.
75 * @dev_loss_tmo: Device loss timeout in seconds.
76 *
77 * The combination of the timeout parameters must be such that SCSI commands
78 * are finished in a reasonable time. Hence do not allow the fast I/O fail
79 * timeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT nor allow dev_loss_tmo to
80 * exceed that limit if failing I/O fast has been disabled. Furthermore, these
81 * parameters must be such that multipath can detect failed paths timely.
82 * Hence do not allow all three parameters to be disabled simultaneously.
83 */
84int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, long dev_loss_tmo)
85{
86 if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0)
87 return -EINVAL;
88 if (reconnect_delay == 0)
89 return -EINVAL;
90 if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
91 return -EINVAL;
92 if (fast_io_fail_tmo < 0 &&
93 dev_loss_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
94 return -EINVAL;
95 if (dev_loss_tmo >= LONG_MAX / HZ)
96 return -EINVAL;
97 if (fast_io_fail_tmo >= 0 && dev_loss_tmo >= 0 &&
98 fast_io_fail_tmo >= dev_loss_tmo)
99 return -EINVAL;
100 return 0;
101}
102EXPORT_SYMBOL_GPL(srp_tmo_valid);
103
104static int srp_host_setup(struct transport_container *tc, struct device *dev,
105 struct device *cdev)
106{
107 struct Scsi_Host *shost = dev_to_shost(dev);
108 struct srp_host_attrs *srp_host = to_srp_host_attrs(shost);
109
110 atomic_set(v: &srp_host->next_port_id, i: 0);
111 return 0;
112}
113
114static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup,
115 NULL, NULL);
116
117static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports",
118 NULL, NULL, NULL);
119
120static ssize_t
121show_srp_rport_id(struct device *dev, struct device_attribute *attr,
122 char *buf)
123{
124 struct srp_rport *rport = transport_class_to_srp_rport(dev);
125 return sprintf(buf, fmt: "%16phC\n", rport->port_id);
126}
127
128static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
129
130static const struct {
131 u32 value;
132 char *name;
133} srp_rport_role_names[] = {
134 {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
135 {SRP_RPORT_ROLE_TARGET, "SRP Target"},
136};
137
138static ssize_t
139show_srp_rport_roles(struct device *dev, struct device_attribute *attr,
140 char *buf)
141{
142 struct srp_rport *rport = transport_class_to_srp_rport(dev);
143 int i;
144 char *name = NULL;
145
146 for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
147 if (srp_rport_role_names[i].value == rport->roles) {
148 name = srp_rport_role_names[i].name;
149 break;
150 }
151 return sprintf(buf, fmt: "%s\n", name ? : "unknown");
152}
153
154static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
155
156static ssize_t store_srp_rport_delete(struct device *dev,
157 struct device_attribute *attr,
158 const char *buf, size_t count)
159{
160 struct srp_rport *rport = transport_class_to_srp_rport(dev);
161 struct Scsi_Host *shost = dev_to_shost(dev);
162 struct srp_internal *i = to_srp_internal(shost->transportt);
163
164 if (i->f->rport_delete) {
165 i->f->rport_delete(rport);
166 return count;
167 } else {
168 return -ENOSYS;
169 }
170}
171
172static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete);
173
174static ssize_t show_srp_rport_state(struct device *dev,
175 struct device_attribute *attr,
176 char *buf)
177{
178 static const char *const state_name[] = {
179 [SRP_RPORT_RUNNING] = "running",
180 [SRP_RPORT_BLOCKED] = "blocked",
181 [SRP_RPORT_FAIL_FAST] = "fail-fast",
182 [SRP_RPORT_LOST] = "lost",
183 };
184 struct srp_rport *rport = transport_class_to_srp_rport(dev);
185 enum srp_rport_state state = rport->state;
186
187 return sprintf(buf, fmt: "%s\n",
188 (unsigned)state < ARRAY_SIZE(state_name) ?
189 state_name[state] : "???");
190}
191
192static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL);
193
194static ssize_t srp_show_tmo(char *buf, int tmo)
195{
196 return tmo >= 0 ? sprintf(buf, fmt: "%d\n", tmo) : sprintf(buf, fmt: "off\n");
197}
198
199int srp_parse_tmo(int *tmo, const char *buf)
200{
201 int res = 0;
202
203 if (strncmp(buf, "off", 3) != 0)
204 res = kstrtoint(s: buf, base: 0, res: tmo);
205 else
206 *tmo = -1;
207
208 return res;
209}
210EXPORT_SYMBOL(srp_parse_tmo);
211
212static ssize_t show_reconnect_delay(struct device *dev,
213 struct device_attribute *attr, char *buf)
214{
215 struct srp_rport *rport = transport_class_to_srp_rport(dev);
216
217 return srp_show_tmo(buf, tmo: rport->reconnect_delay);
218}
219
220static ssize_t store_reconnect_delay(struct device *dev,
221 struct device_attribute *attr,
222 const char *buf, const size_t count)
223{
224 struct srp_rport *rport = transport_class_to_srp_rport(dev);
225 int res, delay;
226
227 res = srp_parse_tmo(&delay, buf);
228 if (res)
229 goto out;
230 res = srp_tmo_valid(delay, rport->fast_io_fail_tmo,
231 rport->dev_loss_tmo);
232 if (res)
233 goto out;
234
235 if (rport->reconnect_delay <= 0 && delay > 0 &&
236 rport->state != SRP_RPORT_RUNNING) {
237 queue_delayed_work(wq: system_long_wq, dwork: &rport->reconnect_work,
238 delay: delay * HZ);
239 } else if (delay <= 0) {
240 cancel_delayed_work(dwork: &rport->reconnect_work);
241 }
242 rport->reconnect_delay = delay;
243 res = count;
244
245out:
246 return res;
247}
248
249static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay,
250 store_reconnect_delay);
251
252static ssize_t show_failed_reconnects(struct device *dev,
253 struct device_attribute *attr, char *buf)
254{
255 struct srp_rport *rport = transport_class_to_srp_rport(dev);
256
257 return sprintf(buf, fmt: "%d\n", rport->failed_reconnects);
258}
259
260static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL);
261
262static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev,
263 struct device_attribute *attr,
264 char *buf)
265{
266 struct srp_rport *rport = transport_class_to_srp_rport(dev);
267
268 return srp_show_tmo(buf, tmo: rport->fast_io_fail_tmo);
269}
270
271static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev,
272 struct device_attribute *attr,
273 const char *buf, size_t count)
274{
275 struct srp_rport *rport = transport_class_to_srp_rport(dev);
276 int res;
277 int fast_io_fail_tmo;
278
279 res = srp_parse_tmo(&fast_io_fail_tmo, buf);
280 if (res)
281 goto out;
282 res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo,
283 rport->dev_loss_tmo);
284 if (res)
285 goto out;
286 rport->fast_io_fail_tmo = fast_io_fail_tmo;
287 res = count;
288
289out:
290 return res;
291}
292
293static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR,
294 show_srp_rport_fast_io_fail_tmo,
295 store_srp_rport_fast_io_fail_tmo);
296
297static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev,
298 struct device_attribute *attr,
299 char *buf)
300{
301 struct srp_rport *rport = transport_class_to_srp_rport(dev);
302
303 return srp_show_tmo(buf, tmo: rport->dev_loss_tmo);
304}
305
306static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev,
307 struct device_attribute *attr,
308 const char *buf, size_t count)
309{
310 struct srp_rport *rport = transport_class_to_srp_rport(dev);
311 int res;
312 int dev_loss_tmo;
313
314 res = srp_parse_tmo(&dev_loss_tmo, buf);
315 if (res)
316 goto out;
317 res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo,
318 dev_loss_tmo);
319 if (res)
320 goto out;
321 rport->dev_loss_tmo = dev_loss_tmo;
322 res = count;
323
324out:
325 return res;
326}
327
328static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR,
329 show_srp_rport_dev_loss_tmo,
330 store_srp_rport_dev_loss_tmo);
331
332static int srp_rport_set_state(struct srp_rport *rport,
333 enum srp_rport_state new_state)
334{
335 enum srp_rport_state old_state = rport->state;
336
337 lockdep_assert_held(&rport->mutex);
338
339 switch (new_state) {
340 case SRP_RPORT_RUNNING:
341 switch (old_state) {
342 case SRP_RPORT_LOST:
343 goto invalid;
344 default:
345 break;
346 }
347 break;
348 case SRP_RPORT_BLOCKED:
349 switch (old_state) {
350 case SRP_RPORT_RUNNING:
351 break;
352 default:
353 goto invalid;
354 }
355 break;
356 case SRP_RPORT_FAIL_FAST:
357 switch (old_state) {
358 case SRP_RPORT_LOST:
359 goto invalid;
360 default:
361 break;
362 }
363 break;
364 case SRP_RPORT_LOST:
365 break;
366 }
367 rport->state = new_state;
368 return 0;
369
370invalid:
371 return -EINVAL;
372}
373
374/**
375 * srp_reconnect_work() - reconnect and schedule a new attempt if necessary
376 * @work: Work structure used for scheduling this operation.
377 */
378static void srp_reconnect_work(struct work_struct *work)
379{
380 struct srp_rport *rport = container_of(to_delayed_work(work),
381 struct srp_rport, reconnect_work);
382 struct Scsi_Host *shost = rport_to_shost(r: rport);
383 int delay, res;
384
385 res = srp_reconnect_rport(rport);
386 if (res != 0) {
387 shost_printk(KERN_ERR, shost,
388 "reconnect attempt %d failed (%d)\n",
389 ++rport->failed_reconnects, res);
390 delay = rport->reconnect_delay *
391 min(100, max(1, rport->failed_reconnects - 10));
392 if (delay > 0)
393 queue_delayed_work(wq: system_long_wq,
394 dwork: &rport->reconnect_work, delay: delay * HZ);
395 }
396}
397
398/*
399 * scsi_block_targets() must have been called before this function is
400 * called to guarantee that no .queuecommand() calls are in progress.
401 */
402static void __rport_fail_io_fast(struct srp_rport *rport)
403{
404 struct Scsi_Host *shost = rport_to_shost(r: rport);
405 struct srp_internal *i;
406
407 lockdep_assert_held(&rport->mutex);
408
409 if (srp_rport_set_state(rport, new_state: SRP_RPORT_FAIL_FAST))
410 return;
411
412 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
413
414 /* Involve the LLD if possible to terminate all I/O on the rport. */
415 i = to_srp_internal(shost->transportt);
416 if (i->f->terminate_rport_io)
417 i->f->terminate_rport_io(rport);
418}
419
420/**
421 * rport_fast_io_fail_timedout() - fast I/O failure timeout handler
422 * @work: Work structure used for scheduling this operation.
423 */
424static void rport_fast_io_fail_timedout(struct work_struct *work)
425{
426 struct srp_rport *rport = container_of(to_delayed_work(work),
427 struct srp_rport, fast_io_fail_work);
428 struct Scsi_Host *shost = rport_to_shost(r: rport);
429
430 pr_info("fast_io_fail_tmo expired for SRP %s / %s.\n",
431 dev_name(&rport->dev), dev_name(&shost->shost_gendev));
432
433 mutex_lock(&rport->mutex);
434 if (rport->state == SRP_RPORT_BLOCKED)
435 __rport_fail_io_fast(rport);
436 mutex_unlock(lock: &rport->mutex);
437}
438
439/**
440 * rport_dev_loss_timedout() - device loss timeout handler
441 * @work: Work structure used for scheduling this operation.
442 */
443static void rport_dev_loss_timedout(struct work_struct *work)
444{
445 struct srp_rport *rport = container_of(to_delayed_work(work),
446 struct srp_rport, dev_loss_work);
447 struct Scsi_Host *shost = rport_to_shost(r: rport);
448 struct srp_internal *i = to_srp_internal(shost->transportt);
449
450 pr_info("dev_loss_tmo expired for SRP %s / %s.\n",
451 dev_name(&rport->dev), dev_name(&shost->shost_gendev));
452
453 mutex_lock(&rport->mutex);
454 WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0);
455 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
456 mutex_unlock(lock: &rport->mutex);
457
458 i->f->rport_delete(rport);
459}
460
461static void __srp_start_tl_fail_timers(struct srp_rport *rport)
462{
463 struct Scsi_Host *shost = rport_to_shost(r: rport);
464 int delay, fast_io_fail_tmo, dev_loss_tmo;
465
466 lockdep_assert_held(&rport->mutex);
467
468 delay = rport->reconnect_delay;
469 fast_io_fail_tmo = rport->fast_io_fail_tmo;
470 dev_loss_tmo = rport->dev_loss_tmo;
471 pr_debug("%s current state: %d\n", dev_name(&shost->shost_gendev),
472 rport->state);
473
474 if (rport->state == SRP_RPORT_LOST)
475 return;
476 if (delay > 0)
477 queue_delayed_work(wq: system_long_wq, dwork: &rport->reconnect_work,
478 delay: 1UL * delay * HZ);
479 if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) &&
480 srp_rport_set_state(rport, new_state: SRP_RPORT_BLOCKED) == 0) {
481 pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev),
482 rport->state);
483 scsi_block_targets(shost, dev: &shost->shost_gendev);
484 if (fast_io_fail_tmo >= 0)
485 queue_delayed_work(wq: system_long_wq,
486 dwork: &rport->fast_io_fail_work,
487 delay: 1UL * fast_io_fail_tmo * HZ);
488 if (dev_loss_tmo >= 0)
489 queue_delayed_work(wq: system_long_wq,
490 dwork: &rport->dev_loss_work,
491 delay: 1UL * dev_loss_tmo * HZ);
492 }
493}
494
495/**
496 * srp_start_tl_fail_timers() - start the transport layer failure timers
497 * @rport: SRP target port.
498 *
499 * Start the transport layer fast I/O failure and device loss timers. Do not
500 * modify a timer that was already started.
501 */
502void srp_start_tl_fail_timers(struct srp_rport *rport)
503{
504 mutex_lock(&rport->mutex);
505 __srp_start_tl_fail_timers(rport);
506 mutex_unlock(lock: &rport->mutex);
507}
508EXPORT_SYMBOL(srp_start_tl_fail_timers);
509
510/**
511 * srp_reconnect_rport() - reconnect to an SRP target port
512 * @rport: SRP target port.
513 *
514 * Blocks SCSI command queueing before invoking reconnect() such that
515 * queuecommand() won't be invoked concurrently with reconnect() from outside
516 * the SCSI EH. This is important since a reconnect() implementation may
517 * reallocate resources needed by queuecommand().
518 *
519 * Notes:
520 * - This function neither waits until outstanding requests have finished nor
521 * tries to abort these. It is the responsibility of the reconnect()
522 * function to finish outstanding commands before reconnecting to the target
523 * port.
524 * - It is the responsibility of the caller to ensure that the resources
525 * reallocated by the reconnect() function won't be used while this function
526 * is in progress. One possible strategy is to invoke this function from
527 * the context of the SCSI EH thread only. Another possible strategy is to
528 * lock the rport mutex inside each SCSI LLD callback that can be invoked by
529 * the SCSI EH (the scsi_host_template.eh_*() functions and also the
530 * scsi_host_template.queuecommand() function).
531 */
532int srp_reconnect_rport(struct srp_rport *rport)
533{
534 struct Scsi_Host *shost = rport_to_shost(r: rport);
535 struct srp_internal *i = to_srp_internal(shost->transportt);
536 struct scsi_device *sdev;
537 int res;
538
539 pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev));
540
541 res = mutex_lock_interruptible(&rport->mutex);
542 if (res)
543 goto out;
544 if (rport->state != SRP_RPORT_FAIL_FAST && rport->state != SRP_RPORT_LOST)
545 /*
546 * sdev state must be SDEV_TRANSPORT_OFFLINE, transition
547 * to SDEV_BLOCK is illegal. Calling scsi_target_unblock()
548 * later is ok though, scsi_internal_device_unblock_nowait()
549 * treats SDEV_TRANSPORT_OFFLINE like SDEV_BLOCK.
550 */
551 scsi_block_targets(shost, dev: &shost->shost_gendev);
552 res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV;
553 pr_debug("%s (state %d): transport.reconnect() returned %d\n",
554 dev_name(&shost->shost_gendev), rport->state, res);
555 if (res == 0) {
556 cancel_delayed_work(dwork: &rport->fast_io_fail_work);
557 cancel_delayed_work(dwork: &rport->dev_loss_work);
558
559 rport->failed_reconnects = 0;
560 srp_rport_set_state(rport, new_state: SRP_RPORT_RUNNING);
561 scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING);
562 /*
563 * If the SCSI error handler has offlined one or more devices,
564 * invoking scsi_target_unblock() won't change the state of
565 * these devices into running so do that explicitly.
566 */
567 shost_for_each_device(sdev, shost) {
568 mutex_lock(&sdev->state_mutex);
569 if (sdev->sdev_state == SDEV_OFFLINE)
570 sdev->sdev_state = SDEV_RUNNING;
571 mutex_unlock(lock: &sdev->state_mutex);
572 }
573 } else if (rport->state == SRP_RPORT_RUNNING) {
574 /*
575 * srp_reconnect_rport() has been invoked with fast_io_fail
576 * and dev_loss off. Mark the port as failed and start the TL
577 * failure timers if these had not yet been started.
578 */
579 __rport_fail_io_fast(rport);
580 __srp_start_tl_fail_timers(rport);
581 } else if (rport->state != SRP_RPORT_BLOCKED) {
582 scsi_target_unblock(&shost->shost_gendev,
583 SDEV_TRANSPORT_OFFLINE);
584 }
585 mutex_unlock(lock: &rport->mutex);
586
587out:
588 return res;
589}
590EXPORT_SYMBOL(srp_reconnect_rport);
591
592/**
593 * srp_timed_out() - SRP transport intercept of the SCSI timeout EH
594 * @scmd: SCSI command.
595 *
596 * If a timeout occurs while an rport is in the blocked state, ask the SCSI
597 * EH to continue waiting (SCSI_EH_RESET_TIMER). Otherwise let the SCSI core
598 * handle the timeout (SCSI_EH_NOT_HANDLED).
599 *
600 * Note: This function is called from soft-IRQ context and with the request
601 * queue lock held.
602 */
603enum scsi_timeout_action srp_timed_out(struct scsi_cmnd *scmd)
604{
605 struct scsi_device *sdev = scmd->device;
606 struct Scsi_Host *shost = sdev->host;
607 struct srp_internal *i = to_srp_internal(shost->transportt);
608 struct srp_rport *rport = shost_to_rport(shost);
609
610 pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev));
611 return rport && rport->fast_io_fail_tmo < 0 &&
612 rport->dev_loss_tmo < 0 &&
613 i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ?
614 SCSI_EH_RESET_TIMER : SCSI_EH_NOT_HANDLED;
615}
616EXPORT_SYMBOL(srp_timed_out);
617
618static void srp_rport_release(struct device *dev)
619{
620 struct srp_rport *rport = dev_to_rport(dev);
621
622 put_device(dev: dev->parent);
623 kfree(objp: rport);
624}
625
626static int scsi_is_srp_rport(const struct device *dev)
627{
628 return dev->release == srp_rport_release;
629}
630
631static int srp_rport_match(struct attribute_container *cont,
632 struct device *dev)
633{
634 struct Scsi_Host *shost;
635 struct srp_internal *i;
636
637 if (!scsi_is_srp_rport(dev))
638 return 0;
639
640 shost = dev_to_shost(dev: dev->parent);
641 if (!shost->transportt)
642 return 0;
643 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
644 return 0;
645
646 i = to_srp_internal(shost->transportt);
647 return &i->rport_attr_cont.ac == cont;
648}
649
650static int srp_host_match(struct attribute_container *cont, struct device *dev)
651{
652 struct Scsi_Host *shost;
653 struct srp_internal *i;
654
655 if (!scsi_is_host_device(dev))
656 return 0;
657
658 shost = dev_to_shost(dev);
659 if (!shost->transportt)
660 return 0;
661 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
662 return 0;
663
664 i = to_srp_internal(shost->transportt);
665 return &i->t.host_attrs.ac == cont;
666}
667
668/**
669 * srp_rport_get() - increment rport reference count
670 * @rport: SRP target port.
671 */
672void srp_rport_get(struct srp_rport *rport)
673{
674 get_device(dev: &rport->dev);
675}
676EXPORT_SYMBOL(srp_rport_get);
677
678/**
679 * srp_rport_put() - decrement rport reference count
680 * @rport: SRP target port.
681 */
682void srp_rport_put(struct srp_rport *rport)
683{
684 put_device(dev: &rport->dev);
685}
686EXPORT_SYMBOL(srp_rport_put);
687
688/**
689 * srp_rport_add - add a SRP remote port to the device hierarchy
690 * @shost: scsi host the remote port is connected to.
691 * @ids: The port id for the remote port.
692 *
693 * Publishes a port to the rest of the system.
694 */
695struct srp_rport *srp_rport_add(struct Scsi_Host *shost,
696 struct srp_rport_identifiers *ids)
697{
698 struct srp_rport *rport;
699 struct device *parent = &shost->shost_gendev;
700 struct srp_internal *i = to_srp_internal(shost->transportt);
701 int id, ret;
702
703 rport = kzalloc(size: sizeof(*rport), GFP_KERNEL);
704 if (!rport)
705 return ERR_PTR(error: -ENOMEM);
706
707 mutex_init(&rport->mutex);
708
709 device_initialize(dev: &rport->dev);
710
711 rport->dev.parent = get_device(dev: parent);
712 rport->dev.release = srp_rport_release;
713
714 memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id));
715 rport->roles = ids->roles;
716
717 if (i->f->reconnect)
718 rport->reconnect_delay = i->f->reconnect_delay ?
719 *i->f->reconnect_delay : 10;
720 INIT_DELAYED_WORK(&rport->reconnect_work, srp_reconnect_work);
721 rport->fast_io_fail_tmo = i->f->fast_io_fail_tmo ?
722 *i->f->fast_io_fail_tmo : 15;
723 rport->dev_loss_tmo = i->f->dev_loss_tmo ? *i->f->dev_loss_tmo : 60;
724 INIT_DELAYED_WORK(&rport->fast_io_fail_work,
725 rport_fast_io_fail_timedout);
726 INIT_DELAYED_WORK(&rport->dev_loss_work, rport_dev_loss_timedout);
727
728 id = atomic_inc_return(v: &to_srp_host_attrs(shost)->next_port_id);
729 dev_set_name(dev: &rport->dev, name: "port-%d:%d", shost->host_no, id);
730
731 transport_setup_device(&rport->dev);
732
733 ret = device_add(dev: &rport->dev);
734 if (ret) {
735 transport_destroy_device(&rport->dev);
736 put_device(dev: &rport->dev);
737 return ERR_PTR(error: ret);
738 }
739
740 transport_add_device(&rport->dev);
741 transport_configure_device(&rport->dev);
742
743 return rport;
744}
745EXPORT_SYMBOL_GPL(srp_rport_add);
746
747/**
748 * srp_rport_del - remove a SRP remote port
749 * @rport: SRP remote port to remove
750 *
751 * Removes the specified SRP remote port.
752 */
753void srp_rport_del(struct srp_rport *rport)
754{
755 struct device *dev = &rport->dev;
756
757 transport_remove_device(dev);
758 device_del(dev);
759 transport_destroy_device(dev);
760
761 put_device(dev);
762}
763EXPORT_SYMBOL_GPL(srp_rport_del);
764
765static int do_srp_rport_del(struct device *dev, void *data)
766{
767 if (scsi_is_srp_rport(dev))
768 srp_rport_del(dev_to_rport(dev));
769 return 0;
770}
771
772/**
773 * srp_remove_host - tear down a Scsi_Host's SRP data structures
774 * @shost: Scsi Host that is torn down
775 *
776 * Removes all SRP remote ports for a given Scsi_Host.
777 * Must be called just before scsi_remove_host for SRP HBAs.
778 */
779void srp_remove_host(struct Scsi_Host *shost)
780{
781 device_for_each_child(dev: &shost->shost_gendev, NULL, fn: do_srp_rport_del);
782}
783EXPORT_SYMBOL_GPL(srp_remove_host);
784
785/**
786 * srp_stop_rport_timers - stop the transport layer recovery timers
787 * @rport: SRP remote port for which to stop the timers.
788 *
789 * Must be called after srp_remove_host() and scsi_remove_host(). The caller
790 * must hold a reference on the rport (rport->dev) and on the SCSI host
791 * (rport->dev.parent).
792 */
793void srp_stop_rport_timers(struct srp_rport *rport)
794{
795 mutex_lock(&rport->mutex);
796 if (rport->state == SRP_RPORT_BLOCKED)
797 __rport_fail_io_fast(rport);
798 srp_rport_set_state(rport, new_state: SRP_RPORT_LOST);
799 mutex_unlock(lock: &rport->mutex);
800
801 cancel_delayed_work_sync(dwork: &rport->reconnect_work);
802 cancel_delayed_work_sync(dwork: &rport->fast_io_fail_work);
803 cancel_delayed_work_sync(dwork: &rport->dev_loss_work);
804}
805EXPORT_SYMBOL_GPL(srp_stop_rport_timers);
806
807/**
808 * srp_attach_transport - instantiate SRP transport template
809 * @ft: SRP transport class function template
810 */
811struct scsi_transport_template *
812srp_attach_transport(struct srp_function_template *ft)
813{
814 int count;
815 struct srp_internal *i;
816
817 i = kzalloc(size: sizeof(*i), GFP_KERNEL);
818 if (!i)
819 return NULL;
820
821 i->t.host_size = sizeof(struct srp_host_attrs);
822 i->t.host_attrs.ac.attrs = &i->host_attrs[0];
823 i->t.host_attrs.ac.class = &srp_host_class.class;
824 i->t.host_attrs.ac.match = srp_host_match;
825 i->host_attrs[0] = NULL;
826 transport_container_register(tc: &i->t.host_attrs);
827
828 i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
829 i->rport_attr_cont.ac.class = &srp_rport_class.class;
830 i->rport_attr_cont.ac.match = srp_rport_match;
831
832 count = 0;
833 i->rport_attrs[count++] = &dev_attr_port_id;
834 i->rport_attrs[count++] = &dev_attr_roles;
835 if (ft->has_rport_state) {
836 i->rport_attrs[count++] = &dev_attr_state;
837 i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo;
838 i->rport_attrs[count++] = &dev_attr_dev_loss_tmo;
839 }
840 if (ft->reconnect) {
841 i->rport_attrs[count++] = &dev_attr_reconnect_delay;
842 i->rport_attrs[count++] = &dev_attr_failed_reconnects;
843 }
844 if (ft->rport_delete)
845 i->rport_attrs[count++] = &dev_attr_delete;
846 i->rport_attrs[count++] = NULL;
847 BUG_ON(count > ARRAY_SIZE(i->rport_attrs));
848
849 transport_container_register(tc: &i->rport_attr_cont);
850
851 i->f = ft;
852
853 return &i->t;
854}
855EXPORT_SYMBOL_GPL(srp_attach_transport);
856
857/**
858 * srp_release_transport - release SRP transport template instance
859 * @t: transport template instance
860 */
861void srp_release_transport(struct scsi_transport_template *t)
862{
863 struct srp_internal *i = to_srp_internal(t);
864
865 transport_container_unregister(tc: &i->t.host_attrs);
866 transport_container_unregister(tc: &i->rport_attr_cont);
867
868 kfree(objp: i);
869}
870EXPORT_SYMBOL_GPL(srp_release_transport);
871
872static __init int srp_transport_init(void)
873{
874 int ret;
875
876 ret = transport_class_register(&srp_host_class);
877 if (ret)
878 return ret;
879 ret = transport_class_register(&srp_rport_class);
880 if (ret)
881 goto unregister_host_class;
882
883 return 0;
884unregister_host_class:
885 transport_class_unregister(&srp_host_class);
886 return ret;
887}
888
889static void __exit srp_transport_exit(void)
890{
891 transport_class_unregister(&srp_host_class);
892 transport_class_unregister(&srp_rport_class);
893}
894
895MODULE_AUTHOR("FUJITA Tomonori");
896MODULE_DESCRIPTION("SRP Transport Attributes");
897MODULE_LICENSE("GPL");
898
899module_init(srp_transport_init);
900module_exit(srp_transport_exit);
901

source code of linux/drivers/scsi/scsi_transport_srp.c