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FUJITA Tomonori09345f62007-06-27 16:32:39 +09001/*
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>
Bart Van Assche29c17322013-10-26 14:33:30 +020027#include <linux/delay.h>
FUJITA Tomonori09345f62007-06-27 16:32:39 +090028
29#include <scsi/scsi.h>
Bart Van Assche29c17322013-10-26 14:33:30 +020030#include <scsi/scsi_cmnd.h>
FUJITA Tomonori09345f62007-06-27 16:32:39 +090031#include <scsi/scsi_device.h>
32#include <scsi/scsi_host.h>
33#include <scsi/scsi_transport.h>
34#include <scsi/scsi_transport_srp.h>
Bart Van Assche29c17322013-10-26 14:33:30 +020035#include "scsi_priv.h"
FUJITA Tomonori09345f62007-06-27 16:32:39 +090036
37struct srp_host_attrs {
38 atomic_t next_port_id;
39};
40#define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data)
41
42#define SRP_HOST_ATTRS 0
Bart Van Assche8c64e452013-10-26 14:35:59 +020043#define SRP_RPORT_ATTRS 8
FUJITA Tomonori09345f62007-06-27 16:32:39 +090044
45struct srp_internal {
46 struct scsi_transport_template t;
47 struct srp_function_template *f;
48
Tony Jonesee959b02008-02-22 00:13:36 +010049 struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1];
FUJITA Tomonori09345f62007-06-27 16:32:39 +090050
Tony Jonesee959b02008-02-22 00:13:36 +010051 struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1];
FUJITA Tomonori09345f62007-06-27 16:32:39 +090052 struct transport_container rport_attr_cont;
53};
54
55#define to_srp_internal(tmpl) container_of(tmpl, struct srp_internal, t)
56
57#define dev_to_rport(d) container_of(d, struct srp_rport, dev)
Tony Jonesee959b02008-02-22 00:13:36 +010058#define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent)
Bart Van Assche29c17322013-10-26 14:33:30 +020059static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r)
60{
61 return dev_to_shost(r->dev.parent);
62}
63
Bart Van Asschee68ca752015-05-18 13:24:38 +020064static inline struct srp_rport *shost_to_rport(struct Scsi_Host *shost)
65{
66 return transport_class_to_srp_rport(&shost->shost_gendev);
67}
68
Bart Van Assche29c17322013-10-26 14:33:30 +020069/**
70 * srp_tmo_valid() - check timeout combination validity
Bart Van Assche0c7f8212014-01-13 12:39:35 +010071 * @reconnect_delay: Reconnect delay in seconds.
72 * @fast_io_fail_tmo: Fast I/O fail timeout in seconds.
73 * @dev_loss_tmo: Device loss timeout in seconds.
Bart Van Assche29c17322013-10-26 14:33:30 +020074 *
75 * The combination of the timeout parameters must be such that SCSI commands
76 * are finished in a reasonable time. Hence do not allow the fast I/O fail
Bart Van Assche18cc4e02013-12-11 17:05:22 +010077 * timeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT nor allow dev_loss_tmo to
78 * exceed that limit if failing I/O fast has been disabled. Furthermore, these
Bart Van Assche29c17322013-10-26 14:33:30 +020079 * parameters must be such that multipath can detect failed paths timely.
Bart Van Assche8c64e452013-10-26 14:35:59 +020080 * Hence do not allow all three parameters to be disabled simultaneously.
Bart Van Assche29c17322013-10-26 14:33:30 +020081 */
Bart Van Assche8c64e452013-10-26 14:35:59 +020082int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, int dev_loss_tmo)
Bart Van Assche29c17322013-10-26 14:33:30 +020083{
Bart Van Assche8c64e452013-10-26 14:35:59 +020084 if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0)
85 return -EINVAL;
86 if (reconnect_delay == 0)
Bart Van Assche29c17322013-10-26 14:33:30 +020087 return -EINVAL;
88 if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
89 return -EINVAL;
Bart Van Assche18cc4e02013-12-11 17:05:22 +010090 if (fast_io_fail_tmo < 0 &&
91 dev_loss_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
92 return -EINVAL;
Bart Van Assche29c17322013-10-26 14:33:30 +020093 if (dev_loss_tmo >= LONG_MAX / HZ)
94 return -EINVAL;
95 if (fast_io_fail_tmo >= 0 && dev_loss_tmo >= 0 &&
96 fast_io_fail_tmo >= dev_loss_tmo)
97 return -EINVAL;
98 return 0;
99}
100EXPORT_SYMBOL_GPL(srp_tmo_valid);
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900101
102static int srp_host_setup(struct transport_container *tc, struct device *dev,
Tony Jonesee959b02008-02-22 00:13:36 +0100103 struct device *cdev)
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900104{
105 struct Scsi_Host *shost = dev_to_shost(dev);
106 struct srp_host_attrs *srp_host = to_srp_host_attrs(shost);
107
108 atomic_set(&srp_host->next_port_id, 0);
109 return 0;
110}
111
112static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup,
113 NULL, NULL);
114
115static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports",
116 NULL, NULL, NULL);
117
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900118#define SRP_PID(p) \
119 (p)->port_id[0], (p)->port_id[1], (p)->port_id[2], (p)->port_id[3], \
120 (p)->port_id[4], (p)->port_id[5], (p)->port_id[6], (p)->port_id[7], \
121 (p)->port_id[8], (p)->port_id[9], (p)->port_id[10], (p)->port_id[11], \
122 (p)->port_id[12], (p)->port_id[13], (p)->port_id[14], (p)->port_id[15]
123
124#define SRP_PID_FMT "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:" \
125 "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x"
126
127static ssize_t
Tony Jonesee959b02008-02-22 00:13:36 +0100128show_srp_rport_id(struct device *dev, struct device_attribute *attr,
129 char *buf)
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900130{
Tony Jonesee959b02008-02-22 00:13:36 +0100131 struct srp_rport *rport = transport_class_to_srp_rport(dev);
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900132 return sprintf(buf, SRP_PID_FMT "\n", SRP_PID(rport));
133}
134
Tony Jonesee959b02008-02-22 00:13:36 +0100135static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900136
FUJITA Tomonoriaebd5e42007-07-11 15:08:15 +0900137static const struct {
138 u32 value;
139 char *name;
140} srp_rport_role_names[] = {
141 {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
142 {SRP_RPORT_ROLE_TARGET, "SRP Target"},
143};
144
145static ssize_t
Tony Jonesee959b02008-02-22 00:13:36 +0100146show_srp_rport_roles(struct device *dev, struct device_attribute *attr,
147 char *buf)
FUJITA Tomonoriaebd5e42007-07-11 15:08:15 +0900148{
Tony Jonesee959b02008-02-22 00:13:36 +0100149 struct srp_rport *rport = transport_class_to_srp_rport(dev);
FUJITA Tomonoriaebd5e42007-07-11 15:08:15 +0900150 int i;
151 char *name = NULL;
152
153 for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
154 if (srp_rport_role_names[i].value == rport->roles) {
155 name = srp_rport_role_names[i].name;
156 break;
157 }
158 return sprintf(buf, "%s\n", name ? : "unknown");
159}
160
Tony Jonesee959b02008-02-22 00:13:36 +0100161static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
FUJITA Tomonoriaebd5e42007-07-11 15:08:15 +0900162
Bart Van Asschedc1bdbd2011-09-16 20:41:13 +0200163static ssize_t store_srp_rport_delete(struct device *dev,
164 struct device_attribute *attr,
165 const char *buf, size_t count)
166{
167 struct srp_rport *rport = transport_class_to_srp_rport(dev);
168 struct Scsi_Host *shost = dev_to_shost(dev);
169 struct srp_internal *i = to_srp_internal(shost->transportt);
170
171 if (i->f->rport_delete) {
172 i->f->rport_delete(rport);
173 return count;
174 } else {
175 return -ENOSYS;
176 }
177}
178
179static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete);
180
Bart Van Assche29c17322013-10-26 14:33:30 +0200181static ssize_t show_srp_rport_state(struct device *dev,
182 struct device_attribute *attr,
183 char *buf)
184{
185 static const char *const state_name[] = {
186 [SRP_RPORT_RUNNING] = "running",
187 [SRP_RPORT_BLOCKED] = "blocked",
188 [SRP_RPORT_FAIL_FAST] = "fail-fast",
189 [SRP_RPORT_LOST] = "lost",
190 };
191 struct srp_rport *rport = transport_class_to_srp_rport(dev);
192 enum srp_rport_state state = rport->state;
193
194 return sprintf(buf, "%s\n",
195 (unsigned)state < ARRAY_SIZE(state_name) ?
196 state_name[state] : "???");
197}
198
199static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL);
200
201static ssize_t srp_show_tmo(char *buf, int tmo)
202{
203 return tmo >= 0 ? sprintf(buf, "%d\n", tmo) : sprintf(buf, "off\n");
204}
205
Sagi Grimberg3fdf70a2015-06-25 13:34:15 +0300206int srp_parse_tmo(int *tmo, const char *buf)
Bart Van Assche29c17322013-10-26 14:33:30 +0200207{
208 int res = 0;
209
210 if (strncmp(buf, "off", 3) != 0)
211 res = kstrtoint(buf, 0, tmo);
212 else
213 *tmo = -1;
214
215 return res;
216}
Sagi Grimberg3fdf70a2015-06-25 13:34:15 +0300217EXPORT_SYMBOL(srp_parse_tmo);
Bart Van Assche29c17322013-10-26 14:33:30 +0200218
Bart Van Assche8c64e452013-10-26 14:35:59 +0200219static ssize_t show_reconnect_delay(struct device *dev,
220 struct device_attribute *attr, char *buf)
221{
222 struct srp_rport *rport = transport_class_to_srp_rport(dev);
223
224 return srp_show_tmo(buf, rport->reconnect_delay);
225}
226
227static ssize_t store_reconnect_delay(struct device *dev,
228 struct device_attribute *attr,
229 const char *buf, const size_t count)
230{
231 struct srp_rport *rport = transport_class_to_srp_rport(dev);
232 int res, delay;
233
234 res = srp_parse_tmo(&delay, buf);
235 if (res)
236 goto out;
237 res = srp_tmo_valid(delay, rport->fast_io_fail_tmo,
238 rport->dev_loss_tmo);
239 if (res)
240 goto out;
241
242 if (rport->reconnect_delay <= 0 && delay > 0 &&
243 rport->state != SRP_RPORT_RUNNING) {
244 queue_delayed_work(system_long_wq, &rport->reconnect_work,
245 delay * HZ);
246 } else if (delay <= 0) {
247 cancel_delayed_work(&rport->reconnect_work);
248 }
249 rport->reconnect_delay = delay;
250 res = count;
251
252out:
253 return res;
254}
255
256static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay,
257 store_reconnect_delay);
258
259static ssize_t show_failed_reconnects(struct device *dev,
260 struct device_attribute *attr, char *buf)
261{
262 struct srp_rport *rport = transport_class_to_srp_rport(dev);
263
264 return sprintf(buf, "%d\n", rport->failed_reconnects);
265}
266
267static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL);
268
Bart Van Assche29c17322013-10-26 14:33:30 +0200269static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev,
270 struct device_attribute *attr,
271 char *buf)
272{
273 struct srp_rport *rport = transport_class_to_srp_rport(dev);
274
275 return srp_show_tmo(buf, rport->fast_io_fail_tmo);
276}
277
278static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev,
279 struct device_attribute *attr,
280 const char *buf, size_t count)
281{
282 struct srp_rport *rport = transport_class_to_srp_rport(dev);
283 int res;
284 int fast_io_fail_tmo;
285
286 res = srp_parse_tmo(&fast_io_fail_tmo, buf);
287 if (res)
288 goto out;
Bart Van Assche8c64e452013-10-26 14:35:59 +0200289 res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo,
290 rport->dev_loss_tmo);
Bart Van Assche29c17322013-10-26 14:33:30 +0200291 if (res)
292 goto out;
293 rport->fast_io_fail_tmo = fast_io_fail_tmo;
294 res = count;
295
296out:
297 return res;
298}
299
300static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR,
301 show_srp_rport_fast_io_fail_tmo,
302 store_srp_rport_fast_io_fail_tmo);
303
304static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev,
305 struct device_attribute *attr,
306 char *buf)
307{
308 struct srp_rport *rport = transport_class_to_srp_rport(dev);
309
310 return srp_show_tmo(buf, rport->dev_loss_tmo);
311}
312
313static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev,
314 struct device_attribute *attr,
315 const char *buf, size_t count)
316{
317 struct srp_rport *rport = transport_class_to_srp_rport(dev);
318 int res;
319 int dev_loss_tmo;
320
321 res = srp_parse_tmo(&dev_loss_tmo, buf);
322 if (res)
323 goto out;
Bart Van Assche8c64e452013-10-26 14:35:59 +0200324 res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo,
325 dev_loss_tmo);
Bart Van Assche29c17322013-10-26 14:33:30 +0200326 if (res)
327 goto out;
328 rport->dev_loss_tmo = dev_loss_tmo;
329 res = count;
330
331out:
332 return res;
333}
334
335static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR,
336 show_srp_rport_dev_loss_tmo,
337 store_srp_rport_dev_loss_tmo);
338
339static int srp_rport_set_state(struct srp_rport *rport,
340 enum srp_rport_state new_state)
341{
342 enum srp_rport_state old_state = rport->state;
343
344 lockdep_assert_held(&rport->mutex);
345
346 switch (new_state) {
347 case SRP_RPORT_RUNNING:
348 switch (old_state) {
349 case SRP_RPORT_LOST:
350 goto invalid;
351 default:
352 break;
353 }
354 break;
355 case SRP_RPORT_BLOCKED:
356 switch (old_state) {
357 case SRP_RPORT_RUNNING:
358 break;
359 default:
360 goto invalid;
361 }
362 break;
363 case SRP_RPORT_FAIL_FAST:
364 switch (old_state) {
365 case SRP_RPORT_LOST:
366 goto invalid;
367 default:
368 break;
369 }
370 break;
371 case SRP_RPORT_LOST:
372 break;
373 }
374 rport->state = new_state;
375 return 0;
376
377invalid:
378 return -EINVAL;
379}
380
Bart Van Assche8c64e452013-10-26 14:35:59 +0200381/**
382 * srp_reconnect_work() - reconnect and schedule a new attempt if necessary
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100383 * @work: Work structure used for scheduling this operation.
Bart Van Assche8c64e452013-10-26 14:35:59 +0200384 */
385static void srp_reconnect_work(struct work_struct *work)
386{
387 struct srp_rport *rport = container_of(to_delayed_work(work),
388 struct srp_rport, reconnect_work);
389 struct Scsi_Host *shost = rport_to_shost(rport);
390 int delay, res;
391
392 res = srp_reconnect_rport(rport);
393 if (res != 0) {
394 shost_printk(KERN_ERR, shost,
395 "reconnect attempt %d failed (%d)\n",
396 ++rport->failed_reconnects, res);
397 delay = rport->reconnect_delay *
398 min(100, max(1, rport->failed_reconnects - 10));
399 if (delay > 0)
400 queue_delayed_work(system_long_wq,
401 &rport->reconnect_work, delay * HZ);
402 }
403}
404
Bart Van Asschebe34c622015-05-18 13:22:19 +0200405/**
406 * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()
407 * @shost: SCSI host for which to count the number of scsi_request_fn() callers.
408 *
409 * To do: add support for scsi-mq in this function.
410 */
411static int scsi_request_fn_active(struct Scsi_Host *shost)
412{
413 struct scsi_device *sdev;
414 struct request_queue *q;
415 int request_fn_active = 0;
416
417 shost_for_each_device(sdev, shost) {
418 q = sdev->request_queue;
419
420 spin_lock_irq(q->queue_lock);
421 request_fn_active += q->request_fn_active;
422 spin_unlock_irq(q->queue_lock);
423 }
424
425 return request_fn_active;
426}
427
428/* Wait until ongoing shost->hostt->queuecommand() calls have finished. */
429static void srp_wait_for_queuecommand(struct Scsi_Host *shost)
430{
431 while (scsi_request_fn_active(shost))
432 msleep(20);
433}
434
Bart Van Assche29c17322013-10-26 14:33:30 +0200435static void __rport_fail_io_fast(struct srp_rport *rport)
436{
437 struct Scsi_Host *shost = rport_to_shost(rport);
438 struct srp_internal *i;
439
440 lockdep_assert_held(&rport->mutex);
441
442 if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST))
443 return;
444 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
445
446 /* Involve the LLD if possible to terminate all I/O on the rport. */
447 i = to_srp_internal(shost->transportt);
Bart Van Assche535fb902015-05-18 13:22:44 +0200448 if (i->f->terminate_rport_io) {
449 srp_wait_for_queuecommand(shost);
Bart Van Assche29c17322013-10-26 14:33:30 +0200450 i->f->terminate_rport_io(rport);
Bart Van Assche535fb902015-05-18 13:22:44 +0200451 }
Bart Van Assche29c17322013-10-26 14:33:30 +0200452}
453
454/**
455 * rport_fast_io_fail_timedout() - fast I/O failure timeout handler
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100456 * @work: Work structure used for scheduling this operation.
Bart Van Assche29c17322013-10-26 14:33:30 +0200457 */
458static void rport_fast_io_fail_timedout(struct work_struct *work)
459{
460 struct srp_rport *rport = container_of(to_delayed_work(work),
461 struct srp_rport, fast_io_fail_work);
462 struct Scsi_Host *shost = rport_to_shost(rport);
463
464 pr_info("fast_io_fail_tmo expired for SRP %s / %s.\n",
465 dev_name(&rport->dev), dev_name(&shost->shost_gendev));
466
467 mutex_lock(&rport->mutex);
468 if (rport->state == SRP_RPORT_BLOCKED)
469 __rport_fail_io_fast(rport);
470 mutex_unlock(&rport->mutex);
471}
472
473/**
474 * rport_dev_loss_timedout() - device loss timeout handler
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100475 * @work: Work structure used for scheduling this operation.
Bart Van Assche29c17322013-10-26 14:33:30 +0200476 */
477static void rport_dev_loss_timedout(struct work_struct *work)
478{
479 struct srp_rport *rport = container_of(to_delayed_work(work),
480 struct srp_rport, dev_loss_work);
481 struct Scsi_Host *shost = rport_to_shost(rport);
482 struct srp_internal *i = to_srp_internal(shost->transportt);
483
484 pr_info("dev_loss_tmo expired for SRP %s / %s.\n",
485 dev_name(&rport->dev), dev_name(&shost->shost_gendev));
486
487 mutex_lock(&rport->mutex);
488 WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0);
489 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
490 mutex_unlock(&rport->mutex);
491
492 i->f->rport_delete(rport);
493}
494
495static void __srp_start_tl_fail_timers(struct srp_rport *rport)
496{
497 struct Scsi_Host *shost = rport_to_shost(rport);
Bart Van Assche8c64e452013-10-26 14:35:59 +0200498 int delay, fast_io_fail_tmo, dev_loss_tmo;
Bart Van Assche29c17322013-10-26 14:33:30 +0200499
500 lockdep_assert_held(&rport->mutex);
501
Bart Van Assche93079162013-12-11 17:06:14 +0100502 delay = rport->reconnect_delay;
503 fast_io_fail_tmo = rport->fast_io_fail_tmo;
504 dev_loss_tmo = rport->dev_loss_tmo;
505 pr_debug("%s current state: %d\n", dev_name(&shost->shost_gendev),
506 rport->state);
Bart Van Assche29c17322013-10-26 14:33:30 +0200507
Bart Van Assche93079162013-12-11 17:06:14 +0100508 if (rport->state == SRP_RPORT_LOST)
509 return;
510 if (delay > 0)
511 queue_delayed_work(system_long_wq, &rport->reconnect_work,
512 1UL * delay * HZ);
Bart Van Asschecd53eb62014-07-09 15:56:43 +0200513 if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) &&
514 srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) {
Bart Van Assche93079162013-12-11 17:06:14 +0100515 pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev),
516 rport->state);
517 scsi_target_block(&shost->shost_gendev);
518 if (fast_io_fail_tmo >= 0)
Bart Van Assche8c64e452013-10-26 14:35:59 +0200519 queue_delayed_work(system_long_wq,
Bart Van Assche93079162013-12-11 17:06:14 +0100520 &rport->fast_io_fail_work,
521 1UL * fast_io_fail_tmo * HZ);
522 if (dev_loss_tmo >= 0)
523 queue_delayed_work(system_long_wq,
524 &rport->dev_loss_work,
525 1UL * dev_loss_tmo * HZ);
Bart Van Assche29c17322013-10-26 14:33:30 +0200526 }
527}
528
529/**
530 * srp_start_tl_fail_timers() - start the transport layer failure timers
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100531 * @rport: SRP target port.
Bart Van Assche29c17322013-10-26 14:33:30 +0200532 *
533 * Start the transport layer fast I/O failure and device loss timers. Do not
534 * modify a timer that was already started.
535 */
536void srp_start_tl_fail_timers(struct srp_rport *rport)
537{
538 mutex_lock(&rport->mutex);
539 __srp_start_tl_fail_timers(rport);
540 mutex_unlock(&rport->mutex);
541}
542EXPORT_SYMBOL(srp_start_tl_fail_timers);
543
544/**
Bart Van Assche29c17322013-10-26 14:33:30 +0200545 * srp_reconnect_rport() - reconnect to an SRP target port
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100546 * @rport: SRP target port.
Bart Van Assche29c17322013-10-26 14:33:30 +0200547 *
548 * Blocks SCSI command queueing before invoking reconnect() such that
549 * queuecommand() won't be invoked concurrently with reconnect() from outside
550 * the SCSI EH. This is important since a reconnect() implementation may
551 * reallocate resources needed by queuecommand().
552 *
553 * Notes:
554 * - This function neither waits until outstanding requests have finished nor
555 * tries to abort these. It is the responsibility of the reconnect()
556 * function to finish outstanding commands before reconnecting to the target
557 * port.
558 * - It is the responsibility of the caller to ensure that the resources
559 * reallocated by the reconnect() function won't be used while this function
560 * is in progress. One possible strategy is to invoke this function from
561 * the context of the SCSI EH thread only. Another possible strategy is to
562 * lock the rport mutex inside each SCSI LLD callback that can be invoked by
563 * the SCSI EH (the scsi_host_template.eh_*() functions and also the
564 * scsi_host_template.queuecommand() function).
565 */
566int srp_reconnect_rport(struct srp_rport *rport)
567{
568 struct Scsi_Host *shost = rport_to_shost(rport);
569 struct srp_internal *i = to_srp_internal(shost->transportt);
570 struct scsi_device *sdev;
571 int res;
572
573 pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev));
574
575 res = mutex_lock_interruptible(&rport->mutex);
576 if (res)
577 goto out;
578 scsi_target_block(&shost->shost_gendev);
Bart Van Asschebe34c622015-05-18 13:22:19 +0200579 srp_wait_for_queuecommand(shost);
Bart Van Assche93079162013-12-11 17:06:14 +0100580 res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV;
Bart Van Assche29c17322013-10-26 14:33:30 +0200581 pr_debug("%s (state %d): transport.reconnect() returned %d\n",
582 dev_name(&shost->shost_gendev), rport->state, res);
583 if (res == 0) {
584 cancel_delayed_work(&rport->fast_io_fail_work);
585 cancel_delayed_work(&rport->dev_loss_work);
586
Bart Van Assche8c64e452013-10-26 14:35:59 +0200587 rport->failed_reconnects = 0;
Bart Van Assche29c17322013-10-26 14:33:30 +0200588 srp_rport_set_state(rport, SRP_RPORT_RUNNING);
589 scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING);
590 /*
591 * If the SCSI error handler has offlined one or more devices,
592 * invoking scsi_target_unblock() won't change the state of
593 * these devices into running so do that explicitly.
594 */
595 spin_lock_irq(shost->host_lock);
596 __shost_for_each_device(sdev, shost)
597 if (sdev->sdev_state == SDEV_OFFLINE)
598 sdev->sdev_state = SDEV_RUNNING;
599 spin_unlock_irq(shost->host_lock);
600 } else if (rport->state == SRP_RPORT_RUNNING) {
601 /*
Bart Van Assche18cc4e02013-12-11 17:05:22 +0100602 * srp_reconnect_rport() has been invoked with fast_io_fail
603 * and dev_loss off. Mark the port as failed and start the TL
604 * failure timers if these had not yet been started.
Bart Van Assche29c17322013-10-26 14:33:30 +0200605 */
606 __rport_fail_io_fast(rport);
607 scsi_target_unblock(&shost->shost_gendev,
608 SDEV_TRANSPORT_OFFLINE);
609 __srp_start_tl_fail_timers(rport);
610 } else if (rport->state != SRP_RPORT_BLOCKED) {
611 scsi_target_unblock(&shost->shost_gendev,
612 SDEV_TRANSPORT_OFFLINE);
613 }
614 mutex_unlock(&rport->mutex);
615
616out:
617 return res;
618}
619EXPORT_SYMBOL(srp_reconnect_rport);
620
621/**
622 * srp_timed_out() - SRP transport intercept of the SCSI timeout EH
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100623 * @scmd: SCSI command.
Bart Van Assche29c17322013-10-26 14:33:30 +0200624 *
625 * If a timeout occurs while an rport is in the blocked state, ask the SCSI
626 * EH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI core
627 * handle the timeout (BLK_EH_NOT_HANDLED).
628 *
629 * Note: This function is called from soft-IRQ context and with the request
630 * queue lock held.
631 */
632static enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd)
633{
634 struct scsi_device *sdev = scmd->device;
635 struct Scsi_Host *shost = sdev->host;
636 struct srp_internal *i = to_srp_internal(shost->transportt);
Bart Van Asschee68ca752015-05-18 13:24:38 +0200637 struct srp_rport *rport = shost_to_rport(shost);
Bart Van Assche29c17322013-10-26 14:33:30 +0200638
639 pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev));
Bart Van Asschee68ca752015-05-18 13:24:38 +0200640 return rport->fast_io_fail_tmo < 0 && rport->dev_loss_tmo < 0 &&
641 i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ?
Bart Van Assche29c17322013-10-26 14:33:30 +0200642 BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
643}
644
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900645static void srp_rport_release(struct device *dev)
646{
647 struct srp_rport *rport = dev_to_rport(dev);
648
649 put_device(dev->parent);
650 kfree(rport);
651}
652
653static int scsi_is_srp_rport(const struct device *dev)
654{
655 return dev->release == srp_rport_release;
656}
657
658static int srp_rport_match(struct attribute_container *cont,
659 struct device *dev)
660{
661 struct Scsi_Host *shost;
662 struct srp_internal *i;
663
664 if (!scsi_is_srp_rport(dev))
665 return 0;
666
667 shost = dev_to_shost(dev->parent);
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->rport_attr_cont.ac == cont;
675}
676
677static int srp_host_match(struct attribute_container *cont, struct device *dev)
678{
679 struct Scsi_Host *shost;
680 struct srp_internal *i;
681
682 if (!scsi_is_host_device(dev))
683 return 0;
684
685 shost = dev_to_shost(dev);
686 if (!shost->transportt)
687 return 0;
688 if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
689 return 0;
690
691 i = to_srp_internal(shost->transportt);
692 return &i->t.host_attrs.ac == cont;
693}
694
695/**
Bart Van Assche9dd69a62013-10-26 14:32:30 +0200696 * srp_rport_get() - increment rport reference count
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100697 * @rport: SRP target port.
Bart Van Assche9dd69a62013-10-26 14:32:30 +0200698 */
699void srp_rport_get(struct srp_rport *rport)
700{
701 get_device(&rport->dev);
702}
703EXPORT_SYMBOL(srp_rport_get);
704
705/**
706 * srp_rport_put() - decrement rport reference count
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100707 * @rport: SRP target port.
Bart Van Assche9dd69a62013-10-26 14:32:30 +0200708 */
709void srp_rport_put(struct srp_rport *rport)
710{
711 put_device(&rport->dev);
712}
713EXPORT_SYMBOL(srp_rport_put);
714
715/**
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900716 * srp_rport_add - add a SRP remote port to the device hierarchy
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900717 * @shost: scsi host the remote port is connected to.
718 * @ids: The port id for the remote port.
719 *
Randy Dunlapdc8875e2007-11-15 15:42:30 -0800720 * Publishes a port to the rest of the system.
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900721 */
722struct srp_rport *srp_rport_add(struct Scsi_Host *shost,
723 struct srp_rport_identifiers *ids)
724{
725 struct srp_rport *rport;
726 struct device *parent = &shost->shost_gendev;
Bart Van Assche29c17322013-10-26 14:33:30 +0200727 struct srp_internal *i = to_srp_internal(shost->transportt);
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900728 int id, ret;
729
730 rport = kzalloc(sizeof(*rport), GFP_KERNEL);
731 if (!rport)
732 return ERR_PTR(-ENOMEM);
733
Bart Van Assche29c17322013-10-26 14:33:30 +0200734 mutex_init(&rport->mutex);
735
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900736 device_initialize(&rport->dev);
737
738 rport->dev.parent = get_device(parent);
739 rport->dev.release = srp_rport_release;
740
741 memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id));
FUJITA Tomonoriaebd5e42007-07-11 15:08:15 +0900742 rport->roles = ids->roles;
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900743
Bart Van Assche8c64e452013-10-26 14:35:59 +0200744 if (i->f->reconnect)
745 rport->reconnect_delay = i->f->reconnect_delay ?
746 *i->f->reconnect_delay : 10;
747 INIT_DELAYED_WORK(&rport->reconnect_work, srp_reconnect_work);
Bart Van Assche29c17322013-10-26 14:33:30 +0200748 rport->fast_io_fail_tmo = i->f->fast_io_fail_tmo ?
749 *i->f->fast_io_fail_tmo : 15;
750 rport->dev_loss_tmo = i->f->dev_loss_tmo ? *i->f->dev_loss_tmo : 60;
751 INIT_DELAYED_WORK(&rport->fast_io_fail_work,
752 rport_fast_io_fail_timedout);
753 INIT_DELAYED_WORK(&rport->dev_loss_work, rport_dev_loss_timedout);
754
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900755 id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id);
Kay Sievers71610f52008-12-03 22:41:36 +0100756 dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id);
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900757
758 transport_setup_device(&rport->dev);
759
760 ret = device_add(&rport->dev);
761 if (ret) {
762 transport_destroy_device(&rport->dev);
763 put_device(&rport->dev);
764 return ERR_PTR(ret);
765 }
766
767 transport_add_device(&rport->dev);
768 transport_configure_device(&rport->dev);
769
770 return rport;
771}
772EXPORT_SYMBOL_GPL(srp_rport_add);
773
774/**
Rob Landleyeb448202007-11-03 13:30:39 -0500775 * srp_rport_del - remove a SRP remote port
776 * @rport: SRP remote port to remove
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900777 *
778 * Removes the specified SRP remote port.
779 */
780void srp_rport_del(struct srp_rport *rport)
781{
782 struct device *dev = &rport->dev;
FUJITA Tomonori62fe8822007-07-11 15:08:19 +0900783
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900784 transport_remove_device(dev);
785 device_del(dev);
786 transport_destroy_device(dev);
Bart Van Assche29c17322013-10-26 14:33:30 +0200787
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900788 put_device(dev);
789}
790EXPORT_SYMBOL_GPL(srp_rport_del);
791
792static int do_srp_rport_del(struct device *dev, void *data)
793{
Dave Dillow91183342008-01-03 21:34:49 -0500794 if (scsi_is_srp_rport(dev))
795 srp_rport_del(dev_to_rport(dev));
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900796 return 0;
797}
798
799/**
Rob Landleyeb448202007-11-03 13:30:39 -0500800 * srp_remove_host - tear down a Scsi_Host's SRP data structures
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900801 * @shost: Scsi Host that is torn down
802 *
803 * Removes all SRP remote ports for a given Scsi_Host.
804 * Must be called just before scsi_remove_host for SRP HBAs.
805 */
806void srp_remove_host(struct Scsi_Host *shost)
807{
808 device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
809}
810EXPORT_SYMBOL_GPL(srp_remove_host);
811
Bart Van Assche93079162013-12-11 17:06:14 +0100812/**
813 * srp_stop_rport_timers - stop the transport layer recovery timers
Bart Van Assche67513602014-03-14 13:51:19 +0100814 * @rport: SRP remote port for which to stop the timers.
Bart Van Assche93079162013-12-11 17:06:14 +0100815 *
816 * Must be called after srp_remove_host() and scsi_remove_host(). The caller
817 * must hold a reference on the rport (rport->dev) and on the SCSI host
818 * (rport->dev.parent).
819 */
820void srp_stop_rport_timers(struct srp_rport *rport)
821{
822 mutex_lock(&rport->mutex);
823 if (rport->state == SRP_RPORT_BLOCKED)
824 __rport_fail_io_fast(rport);
825 srp_rport_set_state(rport, SRP_RPORT_LOST);
826 mutex_unlock(&rport->mutex);
827
828 cancel_delayed_work_sync(&rport->reconnect_work);
829 cancel_delayed_work_sync(&rport->fast_io_fail_work);
830 cancel_delayed_work_sync(&rport->dev_loss_work);
831}
832EXPORT_SYMBOL_GPL(srp_stop_rport_timers);
833
FUJITA Tomonoribfb74372007-07-11 15:08:22 +0900834static int srp_tsk_mgmt_response(struct Scsi_Host *shost, u64 nexus, u64 tm_id,
835 int result)
FUJITA Tomonori62fe8822007-07-11 15:08:19 +0900836{
837 struct srp_internal *i = to_srp_internal(shost->transportt);
FUJITA Tomonoribfb74372007-07-11 15:08:22 +0900838 return i->f->tsk_mgmt_response(shost, nexus, tm_id, result);
839}
840
841static int srp_it_nexus_response(struct Scsi_Host *shost, u64 nexus, int result)
842{
843 struct srp_internal *i = to_srp_internal(shost->transportt);
844 return i->f->it_nexus_response(shost, nexus, result);
FUJITA Tomonori62fe8822007-07-11 15:08:19 +0900845}
846
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900847/**
Rob Landleyeb448202007-11-03 13:30:39 -0500848 * srp_attach_transport - instantiate SRP transport template
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900849 * @ft: SRP transport class function template
850 */
851struct scsi_transport_template *
852srp_attach_transport(struct srp_function_template *ft)
853{
854 int count;
855 struct srp_internal *i;
856
857 i = kzalloc(sizeof(*i), GFP_KERNEL);
858 if (!i)
859 return NULL;
860
Bart Van Assche29c17322013-10-26 14:33:30 +0200861 i->t.eh_timed_out = srp_timed_out;
862
FUJITA Tomonoribfb74372007-07-11 15:08:22 +0900863 i->t.tsk_mgmt_response = srp_tsk_mgmt_response;
FUJITA Tomonori62fe8822007-07-11 15:08:19 +0900864 i->t.it_nexus_response = srp_it_nexus_response;
865
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900866 i->t.host_size = sizeof(struct srp_host_attrs);
867 i->t.host_attrs.ac.attrs = &i->host_attrs[0];
868 i->t.host_attrs.ac.class = &srp_host_class.class;
869 i->t.host_attrs.ac.match = srp_host_match;
870 i->host_attrs[0] = NULL;
871 transport_container_register(&i->t.host_attrs);
872
873 i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
874 i->rport_attr_cont.ac.class = &srp_rport_class.class;
875 i->rport_attr_cont.ac.match = srp_rport_match;
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900876
877 count = 0;
Bart Van Assche9134a852011-09-10 16:31:57 +0200878 i->rport_attrs[count++] = &dev_attr_port_id;
879 i->rport_attrs[count++] = &dev_attr_roles;
Bart Van Assche29c17322013-10-26 14:33:30 +0200880 if (ft->has_rport_state) {
881 i->rport_attrs[count++] = &dev_attr_state;
882 i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo;
883 i->rport_attrs[count++] = &dev_attr_dev_loss_tmo;
884 }
Bart Van Assche8c64e452013-10-26 14:35:59 +0200885 if (ft->reconnect) {
886 i->rport_attrs[count++] = &dev_attr_reconnect_delay;
887 i->rport_attrs[count++] = &dev_attr_failed_reconnects;
888 }
Bart Van Asschedc1bdbd2011-09-16 20:41:13 +0200889 if (ft->rport_delete)
890 i->rport_attrs[count++] = &dev_attr_delete;
Bart Van Assche9134a852011-09-10 16:31:57 +0200891 i->rport_attrs[count++] = NULL;
892 BUG_ON(count > ARRAY_SIZE(i->rport_attrs));
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900893
Bart Van Asscheac9be302011-10-21 19:31:07 +0200894 transport_container_register(&i->rport_attr_cont);
895
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900896 i->f = ft;
897
898 return &i->t;
899}
900EXPORT_SYMBOL_GPL(srp_attach_transport);
901
902/**
Rob Landleyeb448202007-11-03 13:30:39 -0500903 * srp_release_transport - release SRP transport template instance
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900904 * @t: transport template instance
905 */
906void srp_release_transport(struct scsi_transport_template *t)
907{
908 struct srp_internal *i = to_srp_internal(t);
909
910 transport_container_unregister(&i->t.host_attrs);
911 transport_container_unregister(&i->rport_attr_cont);
912
913 kfree(i);
914}
915EXPORT_SYMBOL_GPL(srp_release_transport);
916
917static __init int srp_transport_init(void)
918{
919 int ret;
920
921 ret = transport_class_register(&srp_host_class);
922 if (ret)
923 return ret;
924 ret = transport_class_register(&srp_rport_class);
925 if (ret)
926 goto unregister_host_class;
927
928 return 0;
929unregister_host_class:
930 transport_class_unregister(&srp_host_class);
931 return ret;
932}
933
934static void __exit srp_transport_exit(void)
935{
936 transport_class_unregister(&srp_host_class);
937 transport_class_unregister(&srp_rport_class);
938}
939
940MODULE_AUTHOR("FUJITA Tomonori");
941MODULE_DESCRIPTION("SRP Transport Attributes");
942MODULE_LICENSE("GPL");
943
944module_init(srp_transport_init);
945module_exit(srp_transport_exit);