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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 Tomonori0012fdf2007-08-02 00:20:34 +090036#include "scsi_transport_srp_internal.h"
FUJITA Tomonori09345f62007-06-27 16:32:39 +090037
38struct srp_host_attrs {
39 atomic_t next_port_id;
40};
41#define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data)
42
43#define SRP_HOST_ATTRS 0
Bart Van Assche8c64e452013-10-26 14:35:59 +020044#define SRP_RPORT_ATTRS 8
FUJITA Tomonori09345f62007-06-27 16:32:39 +090045
46struct srp_internal {
47 struct scsi_transport_template t;
48 struct srp_function_template *f;
49
Tony Jonesee959b02008-02-22 00:13:36 +010050 struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1];
FUJITA Tomonori09345f62007-06-27 16:32:39 +090051
Tony Jonesee959b02008-02-22 00:13:36 +010052 struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1];
FUJITA Tomonori09345f62007-06-27 16:32:39 +090053 struct transport_container rport_attr_cont;
54};
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)
Tony Jonesee959b02008-02-22 00:13:36 +010059#define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent)
Bart Van Assche29c17322013-10-26 14:33:30 +020060static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r)
61{
62 return dev_to_shost(r->dev.parent);
63}
64
65/**
66 * srp_tmo_valid() - check timeout combination validity
Bart Van Assche0c7f8212014-01-13 12:39:35 +010067 * @reconnect_delay: Reconnect delay in seconds.
68 * @fast_io_fail_tmo: Fast I/O fail timeout in seconds.
69 * @dev_loss_tmo: Device loss timeout in seconds.
Bart Van Assche29c17322013-10-26 14:33:30 +020070 *
71 * The combination of the timeout parameters must be such that SCSI commands
72 * are finished in a reasonable time. Hence do not allow the fast I/O fail
Bart Van Assche18cc4e02013-12-11 17:05:22 +010073 * timeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT nor allow dev_loss_tmo to
74 * exceed that limit if failing I/O fast has been disabled. Furthermore, these
Bart Van Assche29c17322013-10-26 14:33:30 +020075 * parameters must be such that multipath can detect failed paths timely.
Bart Van Assche8c64e452013-10-26 14:35:59 +020076 * Hence do not allow all three parameters to be disabled simultaneously.
Bart Van Assche29c17322013-10-26 14:33:30 +020077 */
Bart Van Assche8c64e452013-10-26 14:35:59 +020078int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, int dev_loss_tmo)
Bart Van Assche29c17322013-10-26 14:33:30 +020079{
Bart Van Assche8c64e452013-10-26 14:35:59 +020080 if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0)
81 return -EINVAL;
82 if (reconnect_delay == 0)
Bart Van Assche29c17322013-10-26 14:33:30 +020083 return -EINVAL;
84 if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
85 return -EINVAL;
Bart Van Assche18cc4e02013-12-11 17:05:22 +010086 if (fast_io_fail_tmo < 0 &&
87 dev_loss_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
88 return -EINVAL;
Bart Van Assche29c17322013-10-26 14:33:30 +020089 if (dev_loss_tmo >= LONG_MAX / HZ)
90 return -EINVAL;
91 if (fast_io_fail_tmo >= 0 && dev_loss_tmo >= 0 &&
92 fast_io_fail_tmo >= dev_loss_tmo)
93 return -EINVAL;
94 return 0;
95}
96EXPORT_SYMBOL_GPL(srp_tmo_valid);
FUJITA Tomonori09345f62007-06-27 16:32:39 +090097
98static int srp_host_setup(struct transport_container *tc, struct device *dev,
Tony Jonesee959b02008-02-22 00:13:36 +010099 struct device *cdev)
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900100{
101 struct Scsi_Host *shost = dev_to_shost(dev);
102 struct srp_host_attrs *srp_host = to_srp_host_attrs(shost);
103
104 atomic_set(&srp_host->next_port_id, 0);
105 return 0;
106}
107
108static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup,
109 NULL, NULL);
110
111static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports",
112 NULL, NULL, NULL);
113
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900114#define SRP_PID(p) \
115 (p)->port_id[0], (p)->port_id[1], (p)->port_id[2], (p)->port_id[3], \
116 (p)->port_id[4], (p)->port_id[5], (p)->port_id[6], (p)->port_id[7], \
117 (p)->port_id[8], (p)->port_id[9], (p)->port_id[10], (p)->port_id[11], \
118 (p)->port_id[12], (p)->port_id[13], (p)->port_id[14], (p)->port_id[15]
119
120#define SRP_PID_FMT "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:" \
121 "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x"
122
123static ssize_t
Tony Jonesee959b02008-02-22 00:13:36 +0100124show_srp_rport_id(struct device *dev, struct device_attribute *attr,
125 char *buf)
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900126{
Tony Jonesee959b02008-02-22 00:13:36 +0100127 struct srp_rport *rport = transport_class_to_srp_rport(dev);
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900128 return sprintf(buf, SRP_PID_FMT "\n", SRP_PID(rport));
129}
130
Tony Jonesee959b02008-02-22 00:13:36 +0100131static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900132
FUJITA Tomonoriaebd5e42007-07-11 15:08:15 +0900133static const struct {
134 u32 value;
135 char *name;
136} srp_rport_role_names[] = {
137 {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
138 {SRP_RPORT_ROLE_TARGET, "SRP Target"},
139};
140
141static ssize_t
Tony Jonesee959b02008-02-22 00:13:36 +0100142show_srp_rport_roles(struct device *dev, struct device_attribute *attr,
143 char *buf)
FUJITA Tomonoriaebd5e42007-07-11 15:08:15 +0900144{
Tony Jonesee959b02008-02-22 00:13:36 +0100145 struct srp_rport *rport = transport_class_to_srp_rport(dev);
FUJITA Tomonoriaebd5e42007-07-11 15:08:15 +0900146 int i;
147 char *name = NULL;
148
149 for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
150 if (srp_rport_role_names[i].value == rport->roles) {
151 name = srp_rport_role_names[i].name;
152 break;
153 }
154 return sprintf(buf, "%s\n", name ? : "unknown");
155}
156
Tony Jonesee959b02008-02-22 00:13:36 +0100157static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
FUJITA Tomonoriaebd5e42007-07-11 15:08:15 +0900158
Bart Van Asschedc1bdbd2011-09-16 20:41:13 +0200159static ssize_t store_srp_rport_delete(struct device *dev,
160 struct device_attribute *attr,
161 const char *buf, size_t count)
162{
163 struct srp_rport *rport = transport_class_to_srp_rport(dev);
164 struct Scsi_Host *shost = dev_to_shost(dev);
165 struct srp_internal *i = to_srp_internal(shost->transportt);
166
167 if (i->f->rport_delete) {
168 i->f->rport_delete(rport);
169 return count;
170 } else {
171 return -ENOSYS;
172 }
173}
174
175static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete);
176
Bart Van Assche29c17322013-10-26 14:33:30 +0200177static ssize_t show_srp_rport_state(struct device *dev,
178 struct device_attribute *attr,
179 char *buf)
180{
181 static const char *const state_name[] = {
182 [SRP_RPORT_RUNNING] = "running",
183 [SRP_RPORT_BLOCKED] = "blocked",
184 [SRP_RPORT_FAIL_FAST] = "fail-fast",
185 [SRP_RPORT_LOST] = "lost",
186 };
187 struct srp_rport *rport = transport_class_to_srp_rport(dev);
188 enum srp_rport_state state = rport->state;
189
190 return sprintf(buf, "%s\n",
191 (unsigned)state < ARRAY_SIZE(state_name) ?
192 state_name[state] : "???");
193}
194
195static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL);
196
197static ssize_t srp_show_tmo(char *buf, int tmo)
198{
199 return tmo >= 0 ? sprintf(buf, "%d\n", tmo) : sprintf(buf, "off\n");
200}
201
202static int srp_parse_tmo(int *tmo, const char *buf)
203{
204 int res = 0;
205
206 if (strncmp(buf, "off", 3) != 0)
207 res = kstrtoint(buf, 0, tmo);
208 else
209 *tmo = -1;
210
211 return res;
212}
213
Bart Van Assche8c64e452013-10-26 14:35:59 +0200214static ssize_t show_reconnect_delay(struct device *dev,
215 struct device_attribute *attr, char *buf)
216{
217 struct srp_rport *rport = transport_class_to_srp_rport(dev);
218
219 return srp_show_tmo(buf, rport->reconnect_delay);
220}
221
222static ssize_t store_reconnect_delay(struct device *dev,
223 struct device_attribute *attr,
224 const char *buf, const size_t count)
225{
226 struct srp_rport *rport = transport_class_to_srp_rport(dev);
227 int res, delay;
228
229 res = srp_parse_tmo(&delay, buf);
230 if (res)
231 goto out;
232 res = srp_tmo_valid(delay, rport->fast_io_fail_tmo,
233 rport->dev_loss_tmo);
234 if (res)
235 goto out;
236
237 if (rport->reconnect_delay <= 0 && delay > 0 &&
238 rport->state != SRP_RPORT_RUNNING) {
239 queue_delayed_work(system_long_wq, &rport->reconnect_work,
240 delay * HZ);
241 } else if (delay <= 0) {
242 cancel_delayed_work(&rport->reconnect_work);
243 }
244 rport->reconnect_delay = delay;
245 res = count;
246
247out:
248 return res;
249}
250
251static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay,
252 store_reconnect_delay);
253
254static ssize_t show_failed_reconnects(struct device *dev,
255 struct device_attribute *attr, char *buf)
256{
257 struct srp_rport *rport = transport_class_to_srp_rport(dev);
258
259 return sprintf(buf, "%d\n", rport->failed_reconnects);
260}
261
262static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL);
263
Bart Van Assche29c17322013-10-26 14:33:30 +0200264static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev,
265 struct device_attribute *attr,
266 char *buf)
267{
268 struct srp_rport *rport = transport_class_to_srp_rport(dev);
269
270 return srp_show_tmo(buf, rport->fast_io_fail_tmo);
271}
272
273static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev,
274 struct device_attribute *attr,
275 const char *buf, size_t count)
276{
277 struct srp_rport *rport = transport_class_to_srp_rport(dev);
278 int res;
279 int fast_io_fail_tmo;
280
281 res = srp_parse_tmo(&fast_io_fail_tmo, buf);
282 if (res)
283 goto out;
Bart Van Assche8c64e452013-10-26 14:35:59 +0200284 res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo,
285 rport->dev_loss_tmo);
Bart Van Assche29c17322013-10-26 14:33:30 +0200286 if (res)
287 goto out;
288 rport->fast_io_fail_tmo = fast_io_fail_tmo;
289 res = count;
290
291out:
292 return res;
293}
294
295static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR,
296 show_srp_rport_fast_io_fail_tmo,
297 store_srp_rport_fast_io_fail_tmo);
298
299static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev,
300 struct device_attribute *attr,
301 char *buf)
302{
303 struct srp_rport *rport = transport_class_to_srp_rport(dev);
304
305 return srp_show_tmo(buf, rport->dev_loss_tmo);
306}
307
308static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev,
309 struct device_attribute *attr,
310 const char *buf, size_t count)
311{
312 struct srp_rport *rport = transport_class_to_srp_rport(dev);
313 int res;
314 int dev_loss_tmo;
315
316 res = srp_parse_tmo(&dev_loss_tmo, buf);
317 if (res)
318 goto out;
Bart Van Assche8c64e452013-10-26 14:35:59 +0200319 res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo,
320 dev_loss_tmo);
Bart Van Assche29c17322013-10-26 14:33:30 +0200321 if (res)
322 goto out;
323 rport->dev_loss_tmo = dev_loss_tmo;
324 res = count;
325
326out:
327 return res;
328}
329
330static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR,
331 show_srp_rport_dev_loss_tmo,
332 store_srp_rport_dev_loss_tmo);
333
334static int srp_rport_set_state(struct srp_rport *rport,
335 enum srp_rport_state new_state)
336{
337 enum srp_rport_state old_state = rport->state;
338
339 lockdep_assert_held(&rport->mutex);
340
341 switch (new_state) {
342 case SRP_RPORT_RUNNING:
343 switch (old_state) {
344 case SRP_RPORT_LOST:
345 goto invalid;
346 default:
347 break;
348 }
349 break;
350 case SRP_RPORT_BLOCKED:
351 switch (old_state) {
352 case SRP_RPORT_RUNNING:
353 break;
354 default:
355 goto invalid;
356 }
357 break;
358 case SRP_RPORT_FAIL_FAST:
359 switch (old_state) {
360 case SRP_RPORT_LOST:
361 goto invalid;
362 default:
363 break;
364 }
365 break;
366 case SRP_RPORT_LOST:
367 break;
368 }
369 rport->state = new_state;
370 return 0;
371
372invalid:
373 return -EINVAL;
374}
375
Bart Van Assche8c64e452013-10-26 14:35:59 +0200376/**
377 * srp_reconnect_work() - reconnect and schedule a new attempt if necessary
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100378 * @work: Work structure used for scheduling this operation.
Bart Van Assche8c64e452013-10-26 14:35:59 +0200379 */
380static void srp_reconnect_work(struct work_struct *work)
381{
382 struct srp_rport *rport = container_of(to_delayed_work(work),
383 struct srp_rport, reconnect_work);
384 struct Scsi_Host *shost = rport_to_shost(rport);
385 int delay, res;
386
387 res = srp_reconnect_rport(rport);
388 if (res != 0) {
389 shost_printk(KERN_ERR, shost,
390 "reconnect attempt %d failed (%d)\n",
391 ++rport->failed_reconnects, res);
392 delay = rport->reconnect_delay *
393 min(100, max(1, rport->failed_reconnects - 10));
394 if (delay > 0)
395 queue_delayed_work(system_long_wq,
396 &rport->reconnect_work, delay * HZ);
397 }
398}
399
Bart Van Assche29c17322013-10-26 14:33:30 +0200400static void __rport_fail_io_fast(struct srp_rport *rport)
401{
402 struct Scsi_Host *shost = rport_to_shost(rport);
403 struct srp_internal *i;
404
405 lockdep_assert_held(&rport->mutex);
406
407 if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST))
408 return;
409 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
410
411 /* Involve the LLD if possible to terminate all I/O on the rport. */
412 i = to_srp_internal(shost->transportt);
413 if (i->f->terminate_rport_io)
414 i->f->terminate_rport_io(rport);
415}
416
417/**
418 * rport_fast_io_fail_timedout() - fast I/O failure timeout handler
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100419 * @work: Work structure used for scheduling this operation.
Bart Van Assche29c17322013-10-26 14:33:30 +0200420 */
421static void rport_fast_io_fail_timedout(struct work_struct *work)
422{
423 struct srp_rport *rport = container_of(to_delayed_work(work),
424 struct srp_rport, fast_io_fail_work);
425 struct Scsi_Host *shost = rport_to_shost(rport);
426
427 pr_info("fast_io_fail_tmo expired for SRP %s / %s.\n",
428 dev_name(&rport->dev), dev_name(&shost->shost_gendev));
429
430 mutex_lock(&rport->mutex);
431 if (rport->state == SRP_RPORT_BLOCKED)
432 __rport_fail_io_fast(rport);
433 mutex_unlock(&rport->mutex);
434}
435
436/**
437 * rport_dev_loss_timedout() - device loss timeout handler
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100438 * @work: Work structure used for scheduling this operation.
Bart Van Assche29c17322013-10-26 14:33:30 +0200439 */
440static void rport_dev_loss_timedout(struct work_struct *work)
441{
442 struct srp_rport *rport = container_of(to_delayed_work(work),
443 struct srp_rport, dev_loss_work);
444 struct Scsi_Host *shost = rport_to_shost(rport);
445 struct srp_internal *i = to_srp_internal(shost->transportt);
446
447 pr_info("dev_loss_tmo expired for SRP %s / %s.\n",
448 dev_name(&rport->dev), dev_name(&shost->shost_gendev));
449
450 mutex_lock(&rport->mutex);
451 WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0);
452 scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
453 mutex_unlock(&rport->mutex);
454
455 i->f->rport_delete(rport);
456}
457
458static void __srp_start_tl_fail_timers(struct srp_rport *rport)
459{
460 struct Scsi_Host *shost = rport_to_shost(rport);
Bart Van Assche8c64e452013-10-26 14:35:59 +0200461 int delay, fast_io_fail_tmo, dev_loss_tmo;
Bart Van Assche29c17322013-10-26 14:33:30 +0200462
463 lockdep_assert_held(&rport->mutex);
464
Bart Van Assche93079162013-12-11 17:06:14 +0100465 delay = rport->reconnect_delay;
466 fast_io_fail_tmo = rport->fast_io_fail_tmo;
467 dev_loss_tmo = rport->dev_loss_tmo;
468 pr_debug("%s current state: %d\n", dev_name(&shost->shost_gendev),
469 rport->state);
Bart Van Assche29c17322013-10-26 14:33:30 +0200470
Bart Van Assche93079162013-12-11 17:06:14 +0100471 if (rport->state == SRP_RPORT_LOST)
472 return;
473 if (delay > 0)
474 queue_delayed_work(system_long_wq, &rport->reconnect_work,
475 1UL * delay * HZ);
476 if (srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) {
477 pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev),
478 rport->state);
479 scsi_target_block(&shost->shost_gendev);
480 if (fast_io_fail_tmo >= 0)
Bart Van Assche8c64e452013-10-26 14:35:59 +0200481 queue_delayed_work(system_long_wq,
Bart Van Assche93079162013-12-11 17:06:14 +0100482 &rport->fast_io_fail_work,
483 1UL * fast_io_fail_tmo * HZ);
484 if (dev_loss_tmo >= 0)
485 queue_delayed_work(system_long_wq,
486 &rport->dev_loss_work,
487 1UL * dev_loss_tmo * HZ);
Bart Van Assche29c17322013-10-26 14:33:30 +0200488 }
489}
490
491/**
492 * srp_start_tl_fail_timers() - start the transport layer failure timers
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100493 * @rport: SRP target port.
Bart Van Assche29c17322013-10-26 14:33:30 +0200494 *
495 * Start the transport layer fast I/O failure and device loss timers. Do not
496 * modify a timer that was already started.
497 */
498void srp_start_tl_fail_timers(struct srp_rport *rport)
499{
500 mutex_lock(&rport->mutex);
501 __srp_start_tl_fail_timers(rport);
502 mutex_unlock(&rport->mutex);
503}
504EXPORT_SYMBOL(srp_start_tl_fail_timers);
505
506/**
507 * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100508 * @shost: SCSI host for which to count the number of scsi_request_fn() callers.
Bart Van Assche29c17322013-10-26 14:33:30 +0200509 */
510static int scsi_request_fn_active(struct Scsi_Host *shost)
511{
512 struct scsi_device *sdev;
513 struct request_queue *q;
514 int request_fn_active = 0;
515
516 shost_for_each_device(sdev, shost) {
517 q = sdev->request_queue;
518
519 spin_lock_irq(q->queue_lock);
520 request_fn_active += q->request_fn_active;
521 spin_unlock_irq(q->queue_lock);
522 }
523
524 return request_fn_active;
525}
526
527/**
528 * srp_reconnect_rport() - reconnect to an SRP target port
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100529 * @rport: SRP target port.
Bart Van Assche29c17322013-10-26 14:33:30 +0200530 *
531 * Blocks SCSI command queueing before invoking reconnect() such that
532 * queuecommand() won't be invoked concurrently with reconnect() from outside
533 * the SCSI EH. This is important since a reconnect() implementation may
534 * reallocate resources needed by queuecommand().
535 *
536 * Notes:
537 * - This function neither waits until outstanding requests have finished nor
538 * tries to abort these. It is the responsibility of the reconnect()
539 * function to finish outstanding commands before reconnecting to the target
540 * port.
541 * - It is the responsibility of the caller to ensure that the resources
542 * reallocated by the reconnect() function won't be used while this function
543 * is in progress. One possible strategy is to invoke this function from
544 * the context of the SCSI EH thread only. Another possible strategy is to
545 * lock the rport mutex inside each SCSI LLD callback that can be invoked by
546 * the SCSI EH (the scsi_host_template.eh_*() functions and also the
547 * scsi_host_template.queuecommand() function).
548 */
549int srp_reconnect_rport(struct srp_rport *rport)
550{
551 struct Scsi_Host *shost = rport_to_shost(rport);
552 struct srp_internal *i = to_srp_internal(shost->transportt);
553 struct scsi_device *sdev;
554 int res;
555
556 pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev));
557
558 res = mutex_lock_interruptible(&rport->mutex);
559 if (res)
560 goto out;
561 scsi_target_block(&shost->shost_gendev);
562 while (scsi_request_fn_active(shost))
563 msleep(20);
Bart Van Assche93079162013-12-11 17:06:14 +0100564 res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV;
Bart Van Assche29c17322013-10-26 14:33:30 +0200565 pr_debug("%s (state %d): transport.reconnect() returned %d\n",
566 dev_name(&shost->shost_gendev), rport->state, res);
567 if (res == 0) {
568 cancel_delayed_work(&rport->fast_io_fail_work);
569 cancel_delayed_work(&rport->dev_loss_work);
570
Bart Van Assche8c64e452013-10-26 14:35:59 +0200571 rport->failed_reconnects = 0;
Bart Van Assche29c17322013-10-26 14:33:30 +0200572 srp_rport_set_state(rport, SRP_RPORT_RUNNING);
573 scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING);
574 /*
575 * If the SCSI error handler has offlined one or more devices,
576 * invoking scsi_target_unblock() won't change the state of
577 * these devices into running so do that explicitly.
578 */
579 spin_lock_irq(shost->host_lock);
580 __shost_for_each_device(sdev, shost)
581 if (sdev->sdev_state == SDEV_OFFLINE)
582 sdev->sdev_state = SDEV_RUNNING;
583 spin_unlock_irq(shost->host_lock);
584 } else if (rport->state == SRP_RPORT_RUNNING) {
585 /*
Bart Van Assche18cc4e02013-12-11 17:05:22 +0100586 * srp_reconnect_rport() has been invoked with fast_io_fail
587 * and dev_loss off. Mark the port as failed and start the TL
588 * failure timers if these had not yet been started.
Bart Van Assche29c17322013-10-26 14:33:30 +0200589 */
590 __rport_fail_io_fast(rport);
591 scsi_target_unblock(&shost->shost_gendev,
592 SDEV_TRANSPORT_OFFLINE);
593 __srp_start_tl_fail_timers(rport);
594 } else if (rport->state != SRP_RPORT_BLOCKED) {
595 scsi_target_unblock(&shost->shost_gendev,
596 SDEV_TRANSPORT_OFFLINE);
597 }
598 mutex_unlock(&rport->mutex);
599
600out:
601 return res;
602}
603EXPORT_SYMBOL(srp_reconnect_rport);
604
605/**
606 * srp_timed_out() - SRP transport intercept of the SCSI timeout EH
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100607 * @scmd: SCSI command.
Bart Van Assche29c17322013-10-26 14:33:30 +0200608 *
609 * If a timeout occurs while an rport is in the blocked state, ask the SCSI
610 * EH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI core
611 * handle the timeout (BLK_EH_NOT_HANDLED).
612 *
613 * Note: This function is called from soft-IRQ context and with the request
614 * queue lock held.
615 */
616static enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd)
617{
618 struct scsi_device *sdev = scmd->device;
619 struct Scsi_Host *shost = sdev->host;
620 struct srp_internal *i = to_srp_internal(shost->transportt);
621
622 pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev));
623 return i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ?
624 BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
625}
626
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900627static 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/**
Bart Van Assche9dd69a62013-10-26 14:32:30 +0200678 * srp_rport_get() - increment rport reference count
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100679 * @rport: SRP target port.
Bart Van Assche9dd69a62013-10-26 14:32:30 +0200680 */
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
Bart Van Assche0c7f8212014-01-13 12:39:35 +0100689 * @rport: SRP target port.
Bart Van Assche9dd69a62013-10-26 14:32:30 +0200690 */
691void srp_rport_put(struct srp_rport *rport)
692{
693 put_device(&rport->dev);
694}
695EXPORT_SYMBOL(srp_rport_put);
696
697/**
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900698 * srp_rport_add - add a SRP remote port to the device hierarchy
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900699 * @shost: scsi host the remote port is connected to.
700 * @ids: The port id for the remote port.
701 *
Randy Dunlapdc8875e2007-11-15 15:42:30 -0800702 * Publishes a port to the rest of the system.
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900703 */
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;
Bart Van Assche29c17322013-10-26 14:33:30 +0200709 struct srp_internal *i = to_srp_internal(shost->transportt);
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900710 int id, ret;
711
712 rport = kzalloc(sizeof(*rport), GFP_KERNEL);
713 if (!rport)
714 return ERR_PTR(-ENOMEM);
715
Bart Van Assche29c17322013-10-26 14:33:30 +0200716 mutex_init(&rport->mutex);
717
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900718 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));
FUJITA Tomonoriaebd5e42007-07-11 15:08:15 +0900724 rport->roles = ids->roles;
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900725
Bart Van Assche8c64e452013-10-26 14:35:59 +0200726 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);
Bart Van Assche29c17322013-10-26 14:33:30 +0200730 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
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900737 id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id);
Kay Sievers71610f52008-12-03 22:41:36 +0100738 dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id);
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900739
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
FUJITA Tomonori72e39ea2007-09-01 02:03:39 +0900749 if (shost->active_mode & MODE_TARGET &&
750 ids->roles == SRP_RPORT_ROLE_INITIATOR) {
FUJITA Tomonori0012fdf2007-08-02 00:20:34 +0900751 ret = srp_tgt_it_nexus_create(shost, (unsigned long)rport,
752 rport->port_id);
FUJITA Tomonori62fe8822007-07-11 15:08:19 +0900753 if (ret) {
754 device_del(&rport->dev);
755 transport_destroy_device(&rport->dev);
756 put_device(&rport->dev);
757 return ERR_PTR(ret);
758 }
759 }
760
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900761 transport_add_device(&rport->dev);
762 transport_configure_device(&rport->dev);
763
764 return rport;
765}
766EXPORT_SYMBOL_GPL(srp_rport_add);
767
768/**
Rob Landleyeb448202007-11-03 13:30:39 -0500769 * srp_rport_del - remove a SRP remote port
770 * @rport: SRP remote port to remove
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900771 *
772 * Removes the specified SRP remote port.
773 */
774void srp_rport_del(struct srp_rport *rport)
775{
776 struct device *dev = &rport->dev;
FUJITA Tomonori72e39ea2007-09-01 02:03:39 +0900777 struct Scsi_Host *shost = dev_to_shost(dev->parent);
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900778
FUJITA Tomonori72e39ea2007-09-01 02:03:39 +0900779 if (shost->active_mode & MODE_TARGET &&
780 rport->roles == SRP_RPORT_ROLE_INITIATOR)
781 srp_tgt_it_nexus_destroy(shost, (unsigned long)rport);
FUJITA Tomonori62fe8822007-07-11 15:08:19 +0900782
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900783 transport_remove_device(dev);
784 device_del(dev);
785 transport_destroy_device(dev);
Bart Van Assche29c17322013-10-26 14:33:30 +0200786
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900787 put_device(dev);
788}
789EXPORT_SYMBOL_GPL(srp_rport_del);
790
791static int do_srp_rport_del(struct device *dev, void *data)
792{
Dave Dillow91183342008-01-03 21:34:49 -0500793 if (scsi_is_srp_rport(dev))
794 srp_rport_del(dev_to_rport(dev));
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900795 return 0;
796}
797
798/**
Rob Landleyeb448202007-11-03 13:30:39 -0500799 * srp_remove_host - tear down a Scsi_Host's SRP data structures
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900800 * @shost: Scsi Host that is torn down
801 *
802 * Removes all SRP remote ports for a given Scsi_Host.
803 * Must be called just before scsi_remove_host for SRP HBAs.
804 */
805void srp_remove_host(struct Scsi_Host *shost)
806{
807 device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
808}
809EXPORT_SYMBOL_GPL(srp_remove_host);
810
Bart Van Assche93079162013-12-11 17:06:14 +0100811/**
812 * srp_stop_rport_timers - stop the transport layer recovery timers
813 *
814 * Must be called after srp_remove_host() and scsi_remove_host(). The caller
815 * must hold a reference on the rport (rport->dev) and on the SCSI host
816 * (rport->dev.parent).
817 */
818void srp_stop_rport_timers(struct srp_rport *rport)
819{
820 mutex_lock(&rport->mutex);
821 if (rport->state == SRP_RPORT_BLOCKED)
822 __rport_fail_io_fast(rport);
823 srp_rport_set_state(rport, SRP_RPORT_LOST);
824 mutex_unlock(&rport->mutex);
825
826 cancel_delayed_work_sync(&rport->reconnect_work);
827 cancel_delayed_work_sync(&rport->fast_io_fail_work);
828 cancel_delayed_work_sync(&rport->dev_loss_work);
829}
830EXPORT_SYMBOL_GPL(srp_stop_rport_timers);
831
FUJITA Tomonoribfb74372007-07-11 15:08:22 +0900832static int srp_tsk_mgmt_response(struct Scsi_Host *shost, u64 nexus, u64 tm_id,
833 int result)
FUJITA Tomonori62fe8822007-07-11 15:08:19 +0900834{
835 struct srp_internal *i = to_srp_internal(shost->transportt);
FUJITA Tomonoribfb74372007-07-11 15:08:22 +0900836 return i->f->tsk_mgmt_response(shost, nexus, tm_id, result);
837}
838
839static int srp_it_nexus_response(struct Scsi_Host *shost, u64 nexus, int result)
840{
841 struct srp_internal *i = to_srp_internal(shost->transportt);
842 return i->f->it_nexus_response(shost, nexus, result);
FUJITA Tomonori62fe8822007-07-11 15:08:19 +0900843}
844
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900845/**
Rob Landleyeb448202007-11-03 13:30:39 -0500846 * srp_attach_transport - instantiate SRP transport template
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900847 * @ft: SRP transport class function template
848 */
849struct scsi_transport_template *
850srp_attach_transport(struct srp_function_template *ft)
851{
852 int count;
853 struct srp_internal *i;
854
855 i = kzalloc(sizeof(*i), GFP_KERNEL);
856 if (!i)
857 return NULL;
858
Bart Van Assche29c17322013-10-26 14:33:30 +0200859 i->t.eh_timed_out = srp_timed_out;
860
FUJITA Tomonoribfb74372007-07-11 15:08:22 +0900861 i->t.tsk_mgmt_response = srp_tsk_mgmt_response;
FUJITA Tomonori62fe8822007-07-11 15:08:19 +0900862 i->t.it_nexus_response = srp_it_nexus_response;
863
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900864 i->t.host_size = sizeof(struct srp_host_attrs);
865 i->t.host_attrs.ac.attrs = &i->host_attrs[0];
866 i->t.host_attrs.ac.class = &srp_host_class.class;
867 i->t.host_attrs.ac.match = srp_host_match;
868 i->host_attrs[0] = NULL;
869 transport_container_register(&i->t.host_attrs);
870
871 i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
872 i->rport_attr_cont.ac.class = &srp_rport_class.class;
873 i->rport_attr_cont.ac.match = srp_rport_match;
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900874
875 count = 0;
Bart Van Assche9134a852011-09-10 16:31:57 +0200876 i->rport_attrs[count++] = &dev_attr_port_id;
877 i->rport_attrs[count++] = &dev_attr_roles;
Bart Van Assche29c17322013-10-26 14:33:30 +0200878 if (ft->has_rport_state) {
879 i->rport_attrs[count++] = &dev_attr_state;
880 i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo;
881 i->rport_attrs[count++] = &dev_attr_dev_loss_tmo;
882 }
Bart Van Assche8c64e452013-10-26 14:35:59 +0200883 if (ft->reconnect) {
884 i->rport_attrs[count++] = &dev_attr_reconnect_delay;
885 i->rport_attrs[count++] = &dev_attr_failed_reconnects;
886 }
Bart Van Asschedc1bdbd2011-09-16 20:41:13 +0200887 if (ft->rport_delete)
888 i->rport_attrs[count++] = &dev_attr_delete;
Bart Van Assche9134a852011-09-10 16:31:57 +0200889 i->rport_attrs[count++] = NULL;
890 BUG_ON(count > ARRAY_SIZE(i->rport_attrs));
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900891
Bart Van Asscheac9be302011-10-21 19:31:07 +0200892 transport_container_register(&i->rport_attr_cont);
893
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900894 i->f = ft;
895
896 return &i->t;
897}
898EXPORT_SYMBOL_GPL(srp_attach_transport);
899
900/**
Rob Landleyeb448202007-11-03 13:30:39 -0500901 * srp_release_transport - release SRP transport template instance
FUJITA Tomonori09345f62007-06-27 16:32:39 +0900902 * @t: transport template instance
903 */
904void srp_release_transport(struct scsi_transport_template *t)
905{
906 struct srp_internal *i = to_srp_internal(t);
907
908 transport_container_unregister(&i->t.host_attrs);
909 transport_container_unregister(&i->rport_attr_cont);
910
911 kfree(i);
912}
913EXPORT_SYMBOL_GPL(srp_release_transport);
914
915static __init int srp_transport_init(void)
916{
917 int ret;
918
919 ret = transport_class_register(&srp_host_class);
920 if (ret)
921 return ret;
922 ret = transport_class_register(&srp_rport_class);
923 if (ret)
924 goto unregister_host_class;
925
926 return 0;
927unregister_host_class:
928 transport_class_unregister(&srp_host_class);
929 return ret;
930}
931
932static void __exit srp_transport_exit(void)
933{
934 transport_class_unregister(&srp_host_class);
935 transport_class_unregister(&srp_rport_class);
936}
937
938MODULE_AUTHOR("FUJITA Tomonori");
939MODULE_DESCRIPTION("SRP Transport Attributes");
940MODULE_LICENSE("GPL");
941
942module_init(srp_transport_init);
943module_exit(srp_transport_exit);