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09345f65 FT |
1 | /* |
2 | * SCSI RDMA (SRP) transport class | |
3 | * | |
4 | * Copyright (C) 2007 FUJITA Tomonori <tomof@acm.org> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License as | |
8 | * published by the Free Software Foundation, version 2 of the | |
9 | * License. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, but | |
12 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | * General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA | |
19 | * 02110-1301 USA | |
20 | */ | |
21 | #include <linux/init.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/jiffies.h> | |
24 | #include <linux/err.h> | |
25 | #include <linux/slab.h> | |
26 | #include <linux/string.h> | |
29c17324 | 27 | #include <linux/delay.h> |
09345f65 FT |
28 | |
29 | #include <scsi/scsi.h> | |
29c17324 | 30 | #include <scsi/scsi_cmnd.h> |
09345f65 FT |
31 | #include <scsi/scsi_device.h> |
32 | #include <scsi/scsi_host.h> | |
33 | #include <scsi/scsi_transport.h> | |
34 | #include <scsi/scsi_transport_srp.h> | |
29c17324 | 35 | #include "scsi_priv.h" |
09345f65 FT |
36 | |
37 | struct 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 | |
8c64e453 | 43 | #define SRP_RPORT_ATTRS 8 |
09345f65 FT |
44 | |
45 | struct srp_internal { | |
46 | struct scsi_transport_template t; | |
47 | struct srp_function_template *f; | |
48 | ||
ee959b00 | 49 | struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1]; |
09345f65 | 50 | |
ee959b00 | 51 | struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1]; |
09345f65 FT |
52 | 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) | |
ee959b00 | 58 | #define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent) |
29c17324 BVA |
59 | static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r) |
60 | { | |
61 | return dev_to_shost(r->dev.parent); | |
62 | } | |
63 | ||
e68ca752 BVA |
64 | static inline struct srp_rport *shost_to_rport(struct Scsi_Host *shost) |
65 | { | |
66 | return transport_class_to_srp_rport(&shost->shost_gendev); | |
67 | } | |
68 | ||
29c17324 BVA |
69 | /** |
70 | * srp_tmo_valid() - check timeout combination validity | |
0c7f8218 BVA |
71 | * @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. | |
29c17324 BVA |
74 | * |
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 | |
18cc4e02 BVA |
77 | * 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 | |
29c17324 | 79 | * parameters must be such that multipath can detect failed paths timely. |
8c64e453 | 80 | * Hence do not allow all three parameters to be disabled simultaneously. |
29c17324 | 81 | */ |
8c64e453 | 82 | int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, int dev_loss_tmo) |
29c17324 | 83 | { |
8c64e453 BVA |
84 | if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0) |
85 | return -EINVAL; | |
86 | if (reconnect_delay == 0) | |
29c17324 BVA |
87 | return -EINVAL; |
88 | if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT) | |
89 | return -EINVAL; | |
18cc4e02 BVA |
90 | if (fast_io_fail_tmo < 0 && |
91 | dev_loss_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT) | |
92 | return -EINVAL; | |
29c17324 BVA |
93 | 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 | } | |
100 | EXPORT_SYMBOL_GPL(srp_tmo_valid); | |
09345f65 FT |
101 | |
102 | static int srp_host_setup(struct transport_container *tc, struct device *dev, | |
ee959b00 | 103 | struct device *cdev) |
09345f65 FT |
104 | { |
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 | ||
112 | static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup, | |
113 | NULL, NULL); | |
114 | ||
115 | static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports", | |
116 | NULL, NULL, NULL); | |
117 | ||
09345f65 FT |
118 | #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 | ||
127 | static ssize_t | |
ee959b00 TJ |
128 | show_srp_rport_id(struct device *dev, struct device_attribute *attr, |
129 | char *buf) | |
09345f65 | 130 | { |
ee959b00 | 131 | struct srp_rport *rport = transport_class_to_srp_rport(dev); |
09345f65 FT |
132 | return sprintf(buf, SRP_PID_FMT "\n", SRP_PID(rport)); |
133 | } | |
134 | ||
ee959b00 | 135 | static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL); |
09345f65 | 136 | |
aebd5e47 FT |
137 | static 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 | ||
145 | static ssize_t | |
ee959b00 TJ |
146 | show_srp_rport_roles(struct device *dev, struct device_attribute *attr, |
147 | char *buf) | |
aebd5e47 | 148 | { |
ee959b00 | 149 | struct srp_rport *rport = transport_class_to_srp_rport(dev); |
aebd5e47 FT |
150 | 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 | ||
ee959b00 | 161 | static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL); |
aebd5e47 | 162 | |
dc1bdbd9 BVA |
163 | static 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 | ||
179 | static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete); | |
180 | ||
29c17324 BVA |
181 | static 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 | ||
199 | static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL); | |
200 | ||
201 | static 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 | ||
206 | static int srp_parse_tmo(int *tmo, const char *buf) | |
207 | { | |
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 | } | |
217 | ||
8c64e453 BVA |
218 | static ssize_t show_reconnect_delay(struct device *dev, |
219 | struct device_attribute *attr, char *buf) | |
220 | { | |
221 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
222 | ||
223 | return srp_show_tmo(buf, rport->reconnect_delay); | |
224 | } | |
225 | ||
226 | static ssize_t store_reconnect_delay(struct device *dev, | |
227 | struct device_attribute *attr, | |
228 | const char *buf, const size_t count) | |
229 | { | |
230 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
231 | int res, delay; | |
232 | ||
233 | res = srp_parse_tmo(&delay, buf); | |
234 | if (res) | |
235 | goto out; | |
236 | res = srp_tmo_valid(delay, rport->fast_io_fail_tmo, | |
237 | rport->dev_loss_tmo); | |
238 | if (res) | |
239 | goto out; | |
240 | ||
241 | if (rport->reconnect_delay <= 0 && delay > 0 && | |
242 | rport->state != SRP_RPORT_RUNNING) { | |
243 | queue_delayed_work(system_long_wq, &rport->reconnect_work, | |
244 | delay * HZ); | |
245 | } else if (delay <= 0) { | |
246 | cancel_delayed_work(&rport->reconnect_work); | |
247 | } | |
248 | rport->reconnect_delay = delay; | |
249 | res = count; | |
250 | ||
251 | out: | |
252 | return res; | |
253 | } | |
254 | ||
255 | static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay, | |
256 | store_reconnect_delay); | |
257 | ||
258 | static ssize_t show_failed_reconnects(struct device *dev, | |
259 | struct device_attribute *attr, char *buf) | |
260 | { | |
261 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
262 | ||
263 | return sprintf(buf, "%d\n", rport->failed_reconnects); | |
264 | } | |
265 | ||
266 | static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL); | |
267 | ||
29c17324 BVA |
268 | static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev, |
269 | struct device_attribute *attr, | |
270 | char *buf) | |
271 | { | |
272 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
273 | ||
274 | return srp_show_tmo(buf, rport->fast_io_fail_tmo); | |
275 | } | |
276 | ||
277 | static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev, | |
278 | struct device_attribute *attr, | |
279 | const char *buf, size_t count) | |
280 | { | |
281 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
282 | int res; | |
283 | int fast_io_fail_tmo; | |
284 | ||
285 | res = srp_parse_tmo(&fast_io_fail_tmo, buf); | |
286 | if (res) | |
287 | goto out; | |
8c64e453 BVA |
288 | res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo, |
289 | rport->dev_loss_tmo); | |
29c17324 BVA |
290 | if (res) |
291 | goto out; | |
292 | rport->fast_io_fail_tmo = fast_io_fail_tmo; | |
293 | res = count; | |
294 | ||
295 | out: | |
296 | return res; | |
297 | } | |
298 | ||
299 | static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR, | |
300 | show_srp_rport_fast_io_fail_tmo, | |
301 | store_srp_rport_fast_io_fail_tmo); | |
302 | ||
303 | static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev, | |
304 | struct device_attribute *attr, | |
305 | char *buf) | |
306 | { | |
307 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
308 | ||
309 | return srp_show_tmo(buf, rport->dev_loss_tmo); | |
310 | } | |
311 | ||
312 | static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev, | |
313 | struct device_attribute *attr, | |
314 | const char *buf, size_t count) | |
315 | { | |
316 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
317 | int res; | |
318 | int dev_loss_tmo; | |
319 | ||
320 | res = srp_parse_tmo(&dev_loss_tmo, buf); | |
321 | if (res) | |
322 | goto out; | |
8c64e453 BVA |
323 | res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo, |
324 | dev_loss_tmo); | |
29c17324 BVA |
325 | if (res) |
326 | goto out; | |
327 | rport->dev_loss_tmo = dev_loss_tmo; | |
328 | res = count; | |
329 | ||
330 | out: | |
331 | return res; | |
332 | } | |
333 | ||
334 | static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR, | |
335 | show_srp_rport_dev_loss_tmo, | |
336 | store_srp_rport_dev_loss_tmo); | |
337 | ||
338 | static int srp_rport_set_state(struct srp_rport *rport, | |
339 | enum srp_rport_state new_state) | |
340 | { | |
341 | enum srp_rport_state old_state = rport->state; | |
342 | ||
343 | lockdep_assert_held(&rport->mutex); | |
344 | ||
345 | switch (new_state) { | |
346 | case SRP_RPORT_RUNNING: | |
347 | switch (old_state) { | |
348 | case SRP_RPORT_LOST: | |
349 | goto invalid; | |
350 | default: | |
351 | break; | |
352 | } | |
353 | break; | |
354 | case SRP_RPORT_BLOCKED: | |
355 | switch (old_state) { | |
356 | case SRP_RPORT_RUNNING: | |
357 | break; | |
358 | default: | |
359 | goto invalid; | |
360 | } | |
361 | break; | |
362 | case SRP_RPORT_FAIL_FAST: | |
363 | switch (old_state) { | |
364 | case SRP_RPORT_LOST: | |
365 | goto invalid; | |
366 | default: | |
367 | break; | |
368 | } | |
369 | break; | |
370 | case SRP_RPORT_LOST: | |
371 | break; | |
372 | } | |
373 | rport->state = new_state; | |
374 | return 0; | |
375 | ||
376 | invalid: | |
377 | return -EINVAL; | |
378 | } | |
379 | ||
8c64e453 BVA |
380 | /** |
381 | * srp_reconnect_work() - reconnect and schedule a new attempt if necessary | |
0c7f8218 | 382 | * @work: Work structure used for scheduling this operation. |
8c64e453 BVA |
383 | */ |
384 | static void srp_reconnect_work(struct work_struct *work) | |
385 | { | |
386 | struct srp_rport *rport = container_of(to_delayed_work(work), | |
387 | struct srp_rport, reconnect_work); | |
388 | struct Scsi_Host *shost = rport_to_shost(rport); | |
389 | int delay, res; | |
390 | ||
391 | res = srp_reconnect_rport(rport); | |
392 | if (res != 0) { | |
393 | shost_printk(KERN_ERR, shost, | |
394 | "reconnect attempt %d failed (%d)\n", | |
395 | ++rport->failed_reconnects, res); | |
396 | delay = rport->reconnect_delay * | |
397 | min(100, max(1, rport->failed_reconnects - 10)); | |
398 | if (delay > 0) | |
399 | queue_delayed_work(system_long_wq, | |
400 | &rport->reconnect_work, delay * HZ); | |
401 | } | |
402 | } | |
403 | ||
be34c62d BVA |
404 | /** |
405 | * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn() | |
406 | * @shost: SCSI host for which to count the number of scsi_request_fn() callers. | |
407 | * | |
408 | * To do: add support for scsi-mq in this function. | |
409 | */ | |
410 | static int scsi_request_fn_active(struct Scsi_Host *shost) | |
411 | { | |
412 | struct scsi_device *sdev; | |
413 | struct request_queue *q; | |
414 | int request_fn_active = 0; | |
415 | ||
416 | shost_for_each_device(sdev, shost) { | |
417 | q = sdev->request_queue; | |
418 | ||
419 | spin_lock_irq(q->queue_lock); | |
420 | request_fn_active += q->request_fn_active; | |
421 | spin_unlock_irq(q->queue_lock); | |
422 | } | |
423 | ||
424 | return request_fn_active; | |
425 | } | |
426 | ||
427 | /* Wait until ongoing shost->hostt->queuecommand() calls have finished. */ | |
428 | static void srp_wait_for_queuecommand(struct Scsi_Host *shost) | |
429 | { | |
430 | while (scsi_request_fn_active(shost)) | |
431 | msleep(20); | |
432 | } | |
433 | ||
29c17324 BVA |
434 | static void __rport_fail_io_fast(struct srp_rport *rport) |
435 | { | |
436 | struct Scsi_Host *shost = rport_to_shost(rport); | |
437 | struct srp_internal *i; | |
438 | ||
439 | lockdep_assert_held(&rport->mutex); | |
440 | ||
441 | if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST)) | |
442 | return; | |
443 | scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE); | |
444 | ||
445 | /* Involve the LLD if possible to terminate all I/O on the rport. */ | |
446 | i = to_srp_internal(shost->transportt); | |
535fb906 BVA |
447 | if (i->f->terminate_rport_io) { |
448 | srp_wait_for_queuecommand(shost); | |
29c17324 | 449 | i->f->terminate_rport_io(rport); |
535fb906 | 450 | } |
29c17324 BVA |
451 | } |
452 | ||
453 | /** | |
454 | * rport_fast_io_fail_timedout() - fast I/O failure timeout handler | |
0c7f8218 | 455 | * @work: Work structure used for scheduling this operation. |
29c17324 BVA |
456 | */ |
457 | static void rport_fast_io_fail_timedout(struct work_struct *work) | |
458 | { | |
459 | struct srp_rport *rport = container_of(to_delayed_work(work), | |
460 | struct srp_rport, fast_io_fail_work); | |
461 | struct Scsi_Host *shost = rport_to_shost(rport); | |
462 | ||
463 | pr_info("fast_io_fail_tmo expired for SRP %s / %s.\n", | |
464 | dev_name(&rport->dev), dev_name(&shost->shost_gendev)); | |
465 | ||
466 | mutex_lock(&rport->mutex); | |
467 | if (rport->state == SRP_RPORT_BLOCKED) | |
468 | __rport_fail_io_fast(rport); | |
469 | mutex_unlock(&rport->mutex); | |
470 | } | |
471 | ||
472 | /** | |
473 | * rport_dev_loss_timedout() - device loss timeout handler | |
0c7f8218 | 474 | * @work: Work structure used for scheduling this operation. |
29c17324 BVA |
475 | */ |
476 | static void rport_dev_loss_timedout(struct work_struct *work) | |
477 | { | |
478 | struct srp_rport *rport = container_of(to_delayed_work(work), | |
479 | struct srp_rport, dev_loss_work); | |
480 | struct Scsi_Host *shost = rport_to_shost(rport); | |
481 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
482 | ||
483 | pr_info("dev_loss_tmo expired for SRP %s / %s.\n", | |
484 | dev_name(&rport->dev), dev_name(&shost->shost_gendev)); | |
485 | ||
486 | mutex_lock(&rport->mutex); | |
487 | WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0); | |
488 | scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE); | |
489 | mutex_unlock(&rport->mutex); | |
490 | ||
491 | i->f->rport_delete(rport); | |
492 | } | |
493 | ||
494 | static void __srp_start_tl_fail_timers(struct srp_rport *rport) | |
495 | { | |
496 | struct Scsi_Host *shost = rport_to_shost(rport); | |
8c64e453 | 497 | int delay, fast_io_fail_tmo, dev_loss_tmo; |
29c17324 BVA |
498 | |
499 | lockdep_assert_held(&rport->mutex); | |
500 | ||
93079162 BVA |
501 | delay = rport->reconnect_delay; |
502 | fast_io_fail_tmo = rport->fast_io_fail_tmo; | |
503 | dev_loss_tmo = rport->dev_loss_tmo; | |
504 | pr_debug("%s current state: %d\n", dev_name(&shost->shost_gendev), | |
505 | rport->state); | |
29c17324 | 506 | |
93079162 BVA |
507 | if (rport->state == SRP_RPORT_LOST) |
508 | return; | |
509 | if (delay > 0) | |
510 | queue_delayed_work(system_long_wq, &rport->reconnect_work, | |
511 | 1UL * delay * HZ); | |
cd53eb68 BVA |
512 | if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) && |
513 | srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) { | |
93079162 BVA |
514 | pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev), |
515 | rport->state); | |
516 | scsi_target_block(&shost->shost_gendev); | |
517 | if (fast_io_fail_tmo >= 0) | |
8c64e453 | 518 | queue_delayed_work(system_long_wq, |
93079162 BVA |
519 | &rport->fast_io_fail_work, |
520 | 1UL * fast_io_fail_tmo * HZ); | |
521 | if (dev_loss_tmo >= 0) | |
522 | queue_delayed_work(system_long_wq, | |
523 | &rport->dev_loss_work, | |
524 | 1UL * dev_loss_tmo * HZ); | |
29c17324 BVA |
525 | } |
526 | } | |
527 | ||
528 | /** | |
529 | * srp_start_tl_fail_timers() - start the transport layer failure timers | |
0c7f8218 | 530 | * @rport: SRP target port. |
29c17324 BVA |
531 | * |
532 | * Start the transport layer fast I/O failure and device loss timers. Do not | |
533 | * modify a timer that was already started. | |
534 | */ | |
535 | void srp_start_tl_fail_timers(struct srp_rport *rport) | |
536 | { | |
537 | mutex_lock(&rport->mutex); | |
538 | __srp_start_tl_fail_timers(rport); | |
539 | mutex_unlock(&rport->mutex); | |
540 | } | |
541 | EXPORT_SYMBOL(srp_start_tl_fail_timers); | |
542 | ||
29c17324 BVA |
543 | /** |
544 | * srp_reconnect_rport() - reconnect to an SRP target port | |
0c7f8218 | 545 | * @rport: SRP target port. |
29c17324 BVA |
546 | * |
547 | * Blocks SCSI command queueing before invoking reconnect() such that | |
548 | * queuecommand() won't be invoked concurrently with reconnect() from outside | |
549 | * the SCSI EH. This is important since a reconnect() implementation may | |
550 | * reallocate resources needed by queuecommand(). | |
551 | * | |
552 | * Notes: | |
553 | * - This function neither waits until outstanding requests have finished nor | |
554 | * tries to abort these. It is the responsibility of the reconnect() | |
555 | * function to finish outstanding commands before reconnecting to the target | |
556 | * port. | |
557 | * - It is the responsibility of the caller to ensure that the resources | |
558 | * reallocated by the reconnect() function won't be used while this function | |
559 | * is in progress. One possible strategy is to invoke this function from | |
560 | * the context of the SCSI EH thread only. Another possible strategy is to | |
561 | * lock the rport mutex inside each SCSI LLD callback that can be invoked by | |
562 | * the SCSI EH (the scsi_host_template.eh_*() functions and also the | |
563 | * scsi_host_template.queuecommand() function). | |
564 | */ | |
565 | int srp_reconnect_rport(struct srp_rport *rport) | |
566 | { | |
567 | struct Scsi_Host *shost = rport_to_shost(rport); | |
568 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
569 | struct scsi_device *sdev; | |
570 | int res; | |
571 | ||
572 | pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev)); | |
573 | ||
574 | res = mutex_lock_interruptible(&rport->mutex); | |
575 | if (res) | |
576 | goto out; | |
577 | scsi_target_block(&shost->shost_gendev); | |
be34c62d | 578 | srp_wait_for_queuecommand(shost); |
93079162 | 579 | res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV; |
29c17324 BVA |
580 | pr_debug("%s (state %d): transport.reconnect() returned %d\n", |
581 | dev_name(&shost->shost_gendev), rport->state, res); | |
582 | if (res == 0) { | |
583 | cancel_delayed_work(&rport->fast_io_fail_work); | |
584 | cancel_delayed_work(&rport->dev_loss_work); | |
585 | ||
8c64e453 | 586 | rport->failed_reconnects = 0; |
29c17324 BVA |
587 | srp_rport_set_state(rport, SRP_RPORT_RUNNING); |
588 | scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING); | |
589 | /* | |
590 | * If the SCSI error handler has offlined one or more devices, | |
591 | * invoking scsi_target_unblock() won't change the state of | |
592 | * these devices into running so do that explicitly. | |
593 | */ | |
594 | spin_lock_irq(shost->host_lock); | |
595 | __shost_for_each_device(sdev, shost) | |
596 | if (sdev->sdev_state == SDEV_OFFLINE) | |
597 | sdev->sdev_state = SDEV_RUNNING; | |
598 | spin_unlock_irq(shost->host_lock); | |
599 | } else if (rport->state == SRP_RPORT_RUNNING) { | |
600 | /* | |
18cc4e02 BVA |
601 | * srp_reconnect_rport() has been invoked with fast_io_fail |
602 | * and dev_loss off. Mark the port as failed and start the TL | |
603 | * failure timers if these had not yet been started. | |
29c17324 BVA |
604 | */ |
605 | __rport_fail_io_fast(rport); | |
606 | scsi_target_unblock(&shost->shost_gendev, | |
607 | SDEV_TRANSPORT_OFFLINE); | |
608 | __srp_start_tl_fail_timers(rport); | |
609 | } else if (rport->state != SRP_RPORT_BLOCKED) { | |
610 | scsi_target_unblock(&shost->shost_gendev, | |
611 | SDEV_TRANSPORT_OFFLINE); | |
612 | } | |
613 | mutex_unlock(&rport->mutex); | |
614 | ||
615 | out: | |
616 | return res; | |
617 | } | |
618 | EXPORT_SYMBOL(srp_reconnect_rport); | |
619 | ||
620 | /** | |
621 | * srp_timed_out() - SRP transport intercept of the SCSI timeout EH | |
0c7f8218 | 622 | * @scmd: SCSI command. |
29c17324 BVA |
623 | * |
624 | * If a timeout occurs while an rport is in the blocked state, ask the SCSI | |
625 | * EH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI core | |
626 | * handle the timeout (BLK_EH_NOT_HANDLED). | |
627 | * | |
628 | * Note: This function is called from soft-IRQ context and with the request | |
629 | * queue lock held. | |
630 | */ | |
631 | static enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd) | |
632 | { | |
633 | struct scsi_device *sdev = scmd->device; | |
634 | struct Scsi_Host *shost = sdev->host; | |
635 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
e68ca752 | 636 | struct srp_rport *rport = shost_to_rport(shost); |
29c17324 BVA |
637 | |
638 | pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev)); | |
e68ca752 BVA |
639 | return rport->fast_io_fail_tmo < 0 && rport->dev_loss_tmo < 0 && |
640 | i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ? | |
29c17324 BVA |
641 | BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED; |
642 | } | |
643 | ||
09345f65 FT |
644 | static void srp_rport_release(struct device *dev) |
645 | { | |
646 | struct srp_rport *rport = dev_to_rport(dev); | |
647 | ||
648 | put_device(dev->parent); | |
649 | kfree(rport); | |
650 | } | |
651 | ||
652 | static int scsi_is_srp_rport(const struct device *dev) | |
653 | { | |
654 | return dev->release == srp_rport_release; | |
655 | } | |
656 | ||
657 | static int srp_rport_match(struct attribute_container *cont, | |
658 | struct device *dev) | |
659 | { | |
660 | struct Scsi_Host *shost; | |
661 | struct srp_internal *i; | |
662 | ||
663 | if (!scsi_is_srp_rport(dev)) | |
664 | return 0; | |
665 | ||
666 | shost = dev_to_shost(dev->parent); | |
667 | if (!shost->transportt) | |
668 | return 0; | |
669 | if (shost->transportt->host_attrs.ac.class != &srp_host_class.class) | |
670 | return 0; | |
671 | ||
672 | i = to_srp_internal(shost->transportt); | |
673 | return &i->rport_attr_cont.ac == cont; | |
674 | } | |
675 | ||
676 | static int srp_host_match(struct attribute_container *cont, struct device *dev) | |
677 | { | |
678 | struct Scsi_Host *shost; | |
679 | struct srp_internal *i; | |
680 | ||
681 | if (!scsi_is_host_device(dev)) | |
682 | return 0; | |
683 | ||
684 | shost = dev_to_shost(dev); | |
685 | if (!shost->transportt) | |
686 | return 0; | |
687 | if (shost->transportt->host_attrs.ac.class != &srp_host_class.class) | |
688 | return 0; | |
689 | ||
690 | i = to_srp_internal(shost->transportt); | |
691 | return &i->t.host_attrs.ac == cont; | |
692 | } | |
693 | ||
9dd69a60 BVA |
694 | /** |
695 | * srp_rport_get() - increment rport reference count | |
0c7f8218 | 696 | * @rport: SRP target port. |
9dd69a60 BVA |
697 | */ |
698 | void srp_rport_get(struct srp_rport *rport) | |
699 | { | |
700 | get_device(&rport->dev); | |
701 | } | |
702 | EXPORT_SYMBOL(srp_rport_get); | |
703 | ||
704 | /** | |
705 | * srp_rport_put() - decrement rport reference count | |
0c7f8218 | 706 | * @rport: SRP target port. |
9dd69a60 BVA |
707 | */ |
708 | void srp_rport_put(struct srp_rport *rport) | |
709 | { | |
710 | put_device(&rport->dev); | |
711 | } | |
712 | EXPORT_SYMBOL(srp_rport_put); | |
713 | ||
09345f65 FT |
714 | /** |
715 | * srp_rport_add - add a SRP remote port to the device hierarchy | |
09345f65 FT |
716 | * @shost: scsi host the remote port is connected to. |
717 | * @ids: The port id for the remote port. | |
718 | * | |
dc8875e1 | 719 | * Publishes a port to the rest of the system. |
09345f65 FT |
720 | */ |
721 | struct srp_rport *srp_rport_add(struct Scsi_Host *shost, | |
722 | struct srp_rport_identifiers *ids) | |
723 | { | |
724 | struct srp_rport *rport; | |
725 | struct device *parent = &shost->shost_gendev; | |
29c17324 | 726 | struct srp_internal *i = to_srp_internal(shost->transportt); |
09345f65 FT |
727 | int id, ret; |
728 | ||
729 | rport = kzalloc(sizeof(*rport), GFP_KERNEL); | |
730 | if (!rport) | |
731 | return ERR_PTR(-ENOMEM); | |
732 | ||
29c17324 BVA |
733 | mutex_init(&rport->mutex); |
734 | ||
09345f65 FT |
735 | device_initialize(&rport->dev); |
736 | ||
737 | rport->dev.parent = get_device(parent); | |
738 | rport->dev.release = srp_rport_release; | |
739 | ||
740 | memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id)); | |
aebd5e47 | 741 | rport->roles = ids->roles; |
09345f65 | 742 | |
8c64e453 BVA |
743 | if (i->f->reconnect) |
744 | rport->reconnect_delay = i->f->reconnect_delay ? | |
745 | *i->f->reconnect_delay : 10; | |
746 | INIT_DELAYED_WORK(&rport->reconnect_work, srp_reconnect_work); | |
29c17324 BVA |
747 | rport->fast_io_fail_tmo = i->f->fast_io_fail_tmo ? |
748 | *i->f->fast_io_fail_tmo : 15; | |
749 | rport->dev_loss_tmo = i->f->dev_loss_tmo ? *i->f->dev_loss_tmo : 60; | |
750 | INIT_DELAYED_WORK(&rport->fast_io_fail_work, | |
751 | rport_fast_io_fail_timedout); | |
752 | INIT_DELAYED_WORK(&rport->dev_loss_work, rport_dev_loss_timedout); | |
753 | ||
09345f65 | 754 | id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id); |
71610f55 | 755 | dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id); |
09345f65 FT |
756 | |
757 | transport_setup_device(&rport->dev); | |
758 | ||
759 | ret = device_add(&rport->dev); | |
760 | if (ret) { | |
761 | transport_destroy_device(&rport->dev); | |
762 | put_device(&rport->dev); | |
763 | return ERR_PTR(ret); | |
764 | } | |
765 | ||
766 | transport_add_device(&rport->dev); | |
767 | transport_configure_device(&rport->dev); | |
768 | ||
769 | return rport; | |
770 | } | |
771 | EXPORT_SYMBOL_GPL(srp_rport_add); | |
772 | ||
773 | /** | |
eb44820c RL |
774 | * srp_rport_del - remove a SRP remote port |
775 | * @rport: SRP remote port to remove | |
09345f65 FT |
776 | * |
777 | * Removes the specified SRP remote port. | |
778 | */ | |
779 | void srp_rport_del(struct srp_rport *rport) | |
780 | { | |
781 | struct device *dev = &rport->dev; | |
62fe8826 | 782 | |
09345f65 FT |
783 | transport_remove_device(dev); |
784 | device_del(dev); | |
785 | transport_destroy_device(dev); | |
29c17324 | 786 | |
09345f65 FT |
787 | put_device(dev); |
788 | } | |
789 | EXPORT_SYMBOL_GPL(srp_rport_del); | |
790 | ||
791 | static int do_srp_rport_del(struct device *dev, void *data) | |
792 | { | |
91183344 DD |
793 | if (scsi_is_srp_rport(dev)) |
794 | srp_rport_del(dev_to_rport(dev)); | |
09345f65 FT |
795 | return 0; |
796 | } | |
797 | ||
798 | /** | |
eb44820c | 799 | * srp_remove_host - tear down a Scsi_Host's SRP data structures |
09345f65 FT |
800 | * @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 | */ | |
805 | void srp_remove_host(struct Scsi_Host *shost) | |
806 | { | |
807 | device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del); | |
808 | } | |
809 | EXPORT_SYMBOL_GPL(srp_remove_host); | |
810 | ||
93079162 BVA |
811 | /** |
812 | * srp_stop_rport_timers - stop the transport layer recovery timers | |
67513605 | 813 | * @rport: SRP remote port for which to stop the timers. |
93079162 BVA |
814 | * |
815 | * Must be called after srp_remove_host() and scsi_remove_host(). The caller | |
816 | * must hold a reference on the rport (rport->dev) and on the SCSI host | |
817 | * (rport->dev.parent). | |
818 | */ | |
819 | void srp_stop_rport_timers(struct srp_rport *rport) | |
820 | { | |
821 | mutex_lock(&rport->mutex); | |
822 | if (rport->state == SRP_RPORT_BLOCKED) | |
823 | __rport_fail_io_fast(rport); | |
824 | srp_rport_set_state(rport, SRP_RPORT_LOST); | |
825 | mutex_unlock(&rport->mutex); | |
826 | ||
827 | cancel_delayed_work_sync(&rport->reconnect_work); | |
828 | cancel_delayed_work_sync(&rport->fast_io_fail_work); | |
829 | cancel_delayed_work_sync(&rport->dev_loss_work); | |
830 | } | |
831 | EXPORT_SYMBOL_GPL(srp_stop_rport_timers); | |
832 | ||
bfb74374 FT |
833 | static int srp_tsk_mgmt_response(struct Scsi_Host *shost, u64 nexus, u64 tm_id, |
834 | int result) | |
62fe8826 FT |
835 | { |
836 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
bfb74374 FT |
837 | return i->f->tsk_mgmt_response(shost, nexus, tm_id, result); |
838 | } | |
839 | ||
840 | static int srp_it_nexus_response(struct Scsi_Host *shost, u64 nexus, int result) | |
841 | { | |
842 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
843 | return i->f->it_nexus_response(shost, nexus, result); | |
62fe8826 FT |
844 | } |
845 | ||
09345f65 | 846 | /** |
eb44820c | 847 | * srp_attach_transport - instantiate SRP transport template |
09345f65 FT |
848 | * @ft: SRP transport class function template |
849 | */ | |
850 | struct scsi_transport_template * | |
851 | srp_attach_transport(struct srp_function_template *ft) | |
852 | { | |
853 | int count; | |
854 | struct srp_internal *i; | |
855 | ||
856 | i = kzalloc(sizeof(*i), GFP_KERNEL); | |
857 | if (!i) | |
858 | return NULL; | |
859 | ||
29c17324 BVA |
860 | i->t.eh_timed_out = srp_timed_out; |
861 | ||
bfb74374 | 862 | i->t.tsk_mgmt_response = srp_tsk_mgmt_response; |
62fe8826 FT |
863 | i->t.it_nexus_response = srp_it_nexus_response; |
864 | ||
09345f65 FT |
865 | i->t.host_size = sizeof(struct srp_host_attrs); |
866 | i->t.host_attrs.ac.attrs = &i->host_attrs[0]; | |
867 | i->t.host_attrs.ac.class = &srp_host_class.class; | |
868 | i->t.host_attrs.ac.match = srp_host_match; | |
869 | i->host_attrs[0] = NULL; | |
870 | transport_container_register(&i->t.host_attrs); | |
871 | ||
872 | i->rport_attr_cont.ac.attrs = &i->rport_attrs[0]; | |
873 | i->rport_attr_cont.ac.class = &srp_rport_class.class; | |
874 | i->rport_attr_cont.ac.match = srp_rport_match; | |
09345f65 FT |
875 | |
876 | count = 0; | |
9134a855 BVA |
877 | i->rport_attrs[count++] = &dev_attr_port_id; |
878 | i->rport_attrs[count++] = &dev_attr_roles; | |
29c17324 BVA |
879 | if (ft->has_rport_state) { |
880 | i->rport_attrs[count++] = &dev_attr_state; | |
881 | i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo; | |
882 | i->rport_attrs[count++] = &dev_attr_dev_loss_tmo; | |
883 | } | |
8c64e453 BVA |
884 | if (ft->reconnect) { |
885 | i->rport_attrs[count++] = &dev_attr_reconnect_delay; | |
886 | i->rport_attrs[count++] = &dev_attr_failed_reconnects; | |
887 | } | |
dc1bdbd9 BVA |
888 | if (ft->rport_delete) |
889 | i->rport_attrs[count++] = &dev_attr_delete; | |
9134a855 BVA |
890 | i->rport_attrs[count++] = NULL; |
891 | BUG_ON(count > ARRAY_SIZE(i->rport_attrs)); | |
09345f65 | 892 | |
ac9be30e BVA |
893 | transport_container_register(&i->rport_attr_cont); |
894 | ||
09345f65 FT |
895 | i->f = ft; |
896 | ||
897 | return &i->t; | |
898 | } | |
899 | EXPORT_SYMBOL_GPL(srp_attach_transport); | |
900 | ||
901 | /** | |
eb44820c | 902 | * srp_release_transport - release SRP transport template instance |
09345f65 FT |
903 | * @t: transport template instance |
904 | */ | |
905 | void srp_release_transport(struct scsi_transport_template *t) | |
906 | { | |
907 | struct srp_internal *i = to_srp_internal(t); | |
908 | ||
909 | transport_container_unregister(&i->t.host_attrs); | |
910 | transport_container_unregister(&i->rport_attr_cont); | |
911 | ||
912 | kfree(i); | |
913 | } | |
914 | EXPORT_SYMBOL_GPL(srp_release_transport); | |
915 | ||
916 | static __init int srp_transport_init(void) | |
917 | { | |
918 | int ret; | |
919 | ||
920 | ret = transport_class_register(&srp_host_class); | |
921 | if (ret) | |
922 | return ret; | |
923 | ret = transport_class_register(&srp_rport_class); | |
924 | if (ret) | |
925 | goto unregister_host_class; | |
926 | ||
927 | return 0; | |
928 | unregister_host_class: | |
929 | transport_class_unregister(&srp_host_class); | |
930 | return ret; | |
931 | } | |
932 | ||
933 | static void __exit srp_transport_exit(void) | |
934 | { | |
935 | transport_class_unregister(&srp_host_class); | |
936 | transport_class_unregister(&srp_rport_class); | |
937 | } | |
938 | ||
939 | MODULE_AUTHOR("FUJITA Tomonori"); | |
940 | MODULE_DESCRIPTION("SRP Transport Attributes"); | |
941 | MODULE_LICENSE("GPL"); | |
942 | ||
943 | module_init(srp_transport_init); | |
944 | module_exit(srp_transport_exit); |