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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" |
0012fdf9 | 36 | #include "scsi_transport_srp_internal.h" |
09345f65 FT |
37 | |
38 | struct 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 | |
8c64e453 | 44 | #define SRP_RPORT_ATTRS 8 |
09345f65 FT |
45 | |
46 | struct srp_internal { | |
47 | struct scsi_transport_template t; | |
48 | struct srp_function_template *f; | |
49 | ||
ee959b00 | 50 | struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1]; |
09345f65 | 51 | |
ee959b00 | 52 | struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1]; |
09345f65 FT |
53 | 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) | |
ee959b00 | 59 | #define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent) |
29c17324 BVA |
60 | static 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 | |
67 | * | |
68 | * The combination of the timeout parameters must be such that SCSI commands | |
69 | * are finished in a reasonable time. Hence do not allow the fast I/O fail | |
70 | * timeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT. Furthermore, these | |
71 | * parameters must be such that multipath can detect failed paths timely. | |
8c64e453 | 72 | * Hence do not allow all three parameters to be disabled simultaneously. |
29c17324 | 73 | */ |
8c64e453 | 74 | int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, int dev_loss_tmo) |
29c17324 | 75 | { |
8c64e453 BVA |
76 | if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0) |
77 | return -EINVAL; | |
78 | if (reconnect_delay == 0) | |
29c17324 BVA |
79 | return -EINVAL; |
80 | if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT) | |
81 | return -EINVAL; | |
82 | if (dev_loss_tmo >= LONG_MAX / HZ) | |
83 | return -EINVAL; | |
84 | if (fast_io_fail_tmo >= 0 && dev_loss_tmo >= 0 && | |
85 | fast_io_fail_tmo >= dev_loss_tmo) | |
86 | return -EINVAL; | |
87 | return 0; | |
88 | } | |
89 | EXPORT_SYMBOL_GPL(srp_tmo_valid); | |
09345f65 FT |
90 | |
91 | static int srp_host_setup(struct transport_container *tc, struct device *dev, | |
ee959b00 | 92 | struct device *cdev) |
09345f65 FT |
93 | { |
94 | struct Scsi_Host *shost = dev_to_shost(dev); | |
95 | struct srp_host_attrs *srp_host = to_srp_host_attrs(shost); | |
96 | ||
97 | atomic_set(&srp_host->next_port_id, 0); | |
98 | return 0; | |
99 | } | |
100 | ||
101 | static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup, | |
102 | NULL, NULL); | |
103 | ||
104 | static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports", | |
105 | NULL, NULL, NULL); | |
106 | ||
09345f65 FT |
107 | #define SRP_PID(p) \ |
108 | (p)->port_id[0], (p)->port_id[1], (p)->port_id[2], (p)->port_id[3], \ | |
109 | (p)->port_id[4], (p)->port_id[5], (p)->port_id[6], (p)->port_id[7], \ | |
110 | (p)->port_id[8], (p)->port_id[9], (p)->port_id[10], (p)->port_id[11], \ | |
111 | (p)->port_id[12], (p)->port_id[13], (p)->port_id[14], (p)->port_id[15] | |
112 | ||
113 | #define SRP_PID_FMT "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:" \ | |
114 | "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x" | |
115 | ||
116 | static ssize_t | |
ee959b00 TJ |
117 | show_srp_rport_id(struct device *dev, struct device_attribute *attr, |
118 | char *buf) | |
09345f65 | 119 | { |
ee959b00 | 120 | struct srp_rport *rport = transport_class_to_srp_rport(dev); |
09345f65 FT |
121 | return sprintf(buf, SRP_PID_FMT "\n", SRP_PID(rport)); |
122 | } | |
123 | ||
ee959b00 | 124 | static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL); |
09345f65 | 125 | |
aebd5e47 FT |
126 | static const struct { |
127 | u32 value; | |
128 | char *name; | |
129 | } srp_rport_role_names[] = { | |
130 | {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"}, | |
131 | {SRP_RPORT_ROLE_TARGET, "SRP Target"}, | |
132 | }; | |
133 | ||
134 | static ssize_t | |
ee959b00 TJ |
135 | show_srp_rport_roles(struct device *dev, struct device_attribute *attr, |
136 | char *buf) | |
aebd5e47 | 137 | { |
ee959b00 | 138 | struct srp_rport *rport = transport_class_to_srp_rport(dev); |
aebd5e47 FT |
139 | int i; |
140 | char *name = NULL; | |
141 | ||
142 | for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++) | |
143 | if (srp_rport_role_names[i].value == rport->roles) { | |
144 | name = srp_rport_role_names[i].name; | |
145 | break; | |
146 | } | |
147 | return sprintf(buf, "%s\n", name ? : "unknown"); | |
148 | } | |
149 | ||
ee959b00 | 150 | static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL); |
aebd5e47 | 151 | |
dc1bdbd9 BVA |
152 | static ssize_t store_srp_rport_delete(struct device *dev, |
153 | struct device_attribute *attr, | |
154 | const char *buf, size_t count) | |
155 | { | |
156 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
157 | struct Scsi_Host *shost = dev_to_shost(dev); | |
158 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
159 | ||
160 | if (i->f->rport_delete) { | |
161 | i->f->rport_delete(rport); | |
162 | return count; | |
163 | } else { | |
164 | return -ENOSYS; | |
165 | } | |
166 | } | |
167 | ||
168 | static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete); | |
169 | ||
29c17324 BVA |
170 | static ssize_t show_srp_rport_state(struct device *dev, |
171 | struct device_attribute *attr, | |
172 | char *buf) | |
173 | { | |
174 | static const char *const state_name[] = { | |
175 | [SRP_RPORT_RUNNING] = "running", | |
176 | [SRP_RPORT_BLOCKED] = "blocked", | |
177 | [SRP_RPORT_FAIL_FAST] = "fail-fast", | |
178 | [SRP_RPORT_LOST] = "lost", | |
179 | }; | |
180 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
181 | enum srp_rport_state state = rport->state; | |
182 | ||
183 | return sprintf(buf, "%s\n", | |
184 | (unsigned)state < ARRAY_SIZE(state_name) ? | |
185 | state_name[state] : "???"); | |
186 | } | |
187 | ||
188 | static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL); | |
189 | ||
190 | static ssize_t srp_show_tmo(char *buf, int tmo) | |
191 | { | |
192 | return tmo >= 0 ? sprintf(buf, "%d\n", tmo) : sprintf(buf, "off\n"); | |
193 | } | |
194 | ||
195 | static int srp_parse_tmo(int *tmo, const char *buf) | |
196 | { | |
197 | int res = 0; | |
198 | ||
199 | if (strncmp(buf, "off", 3) != 0) | |
200 | res = kstrtoint(buf, 0, tmo); | |
201 | else | |
202 | *tmo = -1; | |
203 | ||
204 | return res; | |
205 | } | |
206 | ||
8c64e453 BVA |
207 | static ssize_t show_reconnect_delay(struct device *dev, |
208 | struct device_attribute *attr, char *buf) | |
209 | { | |
210 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
211 | ||
212 | return srp_show_tmo(buf, rport->reconnect_delay); | |
213 | } | |
214 | ||
215 | static ssize_t store_reconnect_delay(struct device *dev, | |
216 | struct device_attribute *attr, | |
217 | const char *buf, const size_t count) | |
218 | { | |
219 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
220 | int res, delay; | |
221 | ||
222 | res = srp_parse_tmo(&delay, buf); | |
223 | if (res) | |
224 | goto out; | |
225 | res = srp_tmo_valid(delay, rport->fast_io_fail_tmo, | |
226 | rport->dev_loss_tmo); | |
227 | if (res) | |
228 | goto out; | |
229 | ||
230 | if (rport->reconnect_delay <= 0 && delay > 0 && | |
231 | rport->state != SRP_RPORT_RUNNING) { | |
232 | queue_delayed_work(system_long_wq, &rport->reconnect_work, | |
233 | delay * HZ); | |
234 | } else if (delay <= 0) { | |
235 | cancel_delayed_work(&rport->reconnect_work); | |
236 | } | |
237 | rport->reconnect_delay = delay; | |
238 | res = count; | |
239 | ||
240 | out: | |
241 | return res; | |
242 | } | |
243 | ||
244 | static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay, | |
245 | store_reconnect_delay); | |
246 | ||
247 | static ssize_t show_failed_reconnects(struct device *dev, | |
248 | struct device_attribute *attr, char *buf) | |
249 | { | |
250 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
251 | ||
252 | return sprintf(buf, "%d\n", rport->failed_reconnects); | |
253 | } | |
254 | ||
255 | static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL); | |
256 | ||
29c17324 BVA |
257 | static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev, |
258 | struct device_attribute *attr, | |
259 | char *buf) | |
260 | { | |
261 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
262 | ||
263 | return srp_show_tmo(buf, rport->fast_io_fail_tmo); | |
264 | } | |
265 | ||
266 | static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev, | |
267 | struct device_attribute *attr, | |
268 | const char *buf, size_t count) | |
269 | { | |
270 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
271 | int res; | |
272 | int fast_io_fail_tmo; | |
273 | ||
274 | res = srp_parse_tmo(&fast_io_fail_tmo, buf); | |
275 | if (res) | |
276 | goto out; | |
8c64e453 BVA |
277 | res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo, |
278 | rport->dev_loss_tmo); | |
29c17324 BVA |
279 | if (res) |
280 | goto out; | |
281 | rport->fast_io_fail_tmo = fast_io_fail_tmo; | |
282 | res = count; | |
283 | ||
284 | out: | |
285 | return res; | |
286 | } | |
287 | ||
288 | static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR, | |
289 | show_srp_rport_fast_io_fail_tmo, | |
290 | store_srp_rport_fast_io_fail_tmo); | |
291 | ||
292 | static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev, | |
293 | struct device_attribute *attr, | |
294 | char *buf) | |
295 | { | |
296 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
297 | ||
298 | return srp_show_tmo(buf, rport->dev_loss_tmo); | |
299 | } | |
300 | ||
301 | static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev, | |
302 | struct device_attribute *attr, | |
303 | const char *buf, size_t count) | |
304 | { | |
305 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
306 | int res; | |
307 | int dev_loss_tmo; | |
308 | ||
309 | res = srp_parse_tmo(&dev_loss_tmo, buf); | |
310 | if (res) | |
311 | goto out; | |
8c64e453 BVA |
312 | res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo, |
313 | dev_loss_tmo); | |
29c17324 BVA |
314 | if (res) |
315 | goto out; | |
316 | rport->dev_loss_tmo = dev_loss_tmo; | |
317 | res = count; | |
318 | ||
319 | out: | |
320 | return res; | |
321 | } | |
322 | ||
323 | static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR, | |
324 | show_srp_rport_dev_loss_tmo, | |
325 | store_srp_rport_dev_loss_tmo); | |
326 | ||
327 | static int srp_rport_set_state(struct srp_rport *rport, | |
328 | enum srp_rport_state new_state) | |
329 | { | |
330 | enum srp_rport_state old_state = rport->state; | |
331 | ||
332 | lockdep_assert_held(&rport->mutex); | |
333 | ||
334 | switch (new_state) { | |
335 | case SRP_RPORT_RUNNING: | |
336 | switch (old_state) { | |
337 | case SRP_RPORT_LOST: | |
338 | goto invalid; | |
339 | default: | |
340 | break; | |
341 | } | |
342 | break; | |
343 | case SRP_RPORT_BLOCKED: | |
344 | switch (old_state) { | |
345 | case SRP_RPORT_RUNNING: | |
346 | break; | |
347 | default: | |
348 | goto invalid; | |
349 | } | |
350 | break; | |
351 | case SRP_RPORT_FAIL_FAST: | |
352 | switch (old_state) { | |
353 | case SRP_RPORT_LOST: | |
354 | goto invalid; | |
355 | default: | |
356 | break; | |
357 | } | |
358 | break; | |
359 | case SRP_RPORT_LOST: | |
360 | break; | |
361 | } | |
362 | rport->state = new_state; | |
363 | return 0; | |
364 | ||
365 | invalid: | |
366 | return -EINVAL; | |
367 | } | |
368 | ||
8c64e453 BVA |
369 | /** |
370 | * srp_reconnect_work() - reconnect and schedule a new attempt if necessary | |
371 | */ | |
372 | static void srp_reconnect_work(struct work_struct *work) | |
373 | { | |
374 | struct srp_rport *rport = container_of(to_delayed_work(work), | |
375 | struct srp_rport, reconnect_work); | |
376 | struct Scsi_Host *shost = rport_to_shost(rport); | |
377 | int delay, res; | |
378 | ||
379 | res = srp_reconnect_rport(rport); | |
380 | if (res != 0) { | |
381 | shost_printk(KERN_ERR, shost, | |
382 | "reconnect attempt %d failed (%d)\n", | |
383 | ++rport->failed_reconnects, res); | |
384 | delay = rport->reconnect_delay * | |
385 | min(100, max(1, rport->failed_reconnects - 10)); | |
386 | if (delay > 0) | |
387 | queue_delayed_work(system_long_wq, | |
388 | &rport->reconnect_work, delay * HZ); | |
389 | } | |
390 | } | |
391 | ||
29c17324 BVA |
392 | static void __rport_fail_io_fast(struct srp_rport *rport) |
393 | { | |
394 | struct Scsi_Host *shost = rport_to_shost(rport); | |
395 | struct srp_internal *i; | |
396 | ||
397 | lockdep_assert_held(&rport->mutex); | |
398 | ||
399 | if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST)) | |
400 | return; | |
401 | scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE); | |
402 | ||
403 | /* Involve the LLD if possible to terminate all I/O on the rport. */ | |
404 | i = to_srp_internal(shost->transportt); | |
405 | if (i->f->terminate_rport_io) | |
406 | i->f->terminate_rport_io(rport); | |
407 | } | |
408 | ||
409 | /** | |
410 | * rport_fast_io_fail_timedout() - fast I/O failure timeout handler | |
411 | */ | |
412 | static void rport_fast_io_fail_timedout(struct work_struct *work) | |
413 | { | |
414 | struct srp_rport *rport = container_of(to_delayed_work(work), | |
415 | struct srp_rport, fast_io_fail_work); | |
416 | struct Scsi_Host *shost = rport_to_shost(rport); | |
417 | ||
418 | pr_info("fast_io_fail_tmo expired for SRP %s / %s.\n", | |
419 | dev_name(&rport->dev), dev_name(&shost->shost_gendev)); | |
420 | ||
421 | mutex_lock(&rport->mutex); | |
422 | if (rport->state == SRP_RPORT_BLOCKED) | |
423 | __rport_fail_io_fast(rport); | |
424 | mutex_unlock(&rport->mutex); | |
425 | } | |
426 | ||
427 | /** | |
428 | * rport_dev_loss_timedout() - device loss timeout handler | |
429 | */ | |
430 | static void rport_dev_loss_timedout(struct work_struct *work) | |
431 | { | |
432 | struct srp_rport *rport = container_of(to_delayed_work(work), | |
433 | struct srp_rport, dev_loss_work); | |
434 | struct Scsi_Host *shost = rport_to_shost(rport); | |
435 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
436 | ||
437 | pr_info("dev_loss_tmo expired for SRP %s / %s.\n", | |
438 | dev_name(&rport->dev), dev_name(&shost->shost_gendev)); | |
439 | ||
440 | mutex_lock(&rport->mutex); | |
441 | WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0); | |
442 | scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE); | |
443 | mutex_unlock(&rport->mutex); | |
444 | ||
445 | i->f->rport_delete(rport); | |
446 | } | |
447 | ||
448 | static void __srp_start_tl_fail_timers(struct srp_rport *rport) | |
449 | { | |
450 | struct Scsi_Host *shost = rport_to_shost(rport); | |
8c64e453 | 451 | int delay, fast_io_fail_tmo, dev_loss_tmo; |
29c17324 BVA |
452 | |
453 | lockdep_assert_held(&rport->mutex); | |
454 | ||
455 | if (!rport->deleted) { | |
8c64e453 | 456 | delay = rport->reconnect_delay; |
29c17324 BVA |
457 | fast_io_fail_tmo = rport->fast_io_fail_tmo; |
458 | dev_loss_tmo = rport->dev_loss_tmo; | |
459 | pr_debug("%s current state: %d\n", | |
460 | dev_name(&shost->shost_gendev), rport->state); | |
461 | ||
8c64e453 BVA |
462 | if (delay > 0) |
463 | queue_delayed_work(system_long_wq, | |
464 | &rport->reconnect_work, | |
465 | 1UL * delay * HZ); | |
29c17324 BVA |
466 | if (fast_io_fail_tmo >= 0 && |
467 | srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) { | |
468 | pr_debug("%s new state: %d\n", | |
469 | dev_name(&shost->shost_gendev), | |
470 | rport->state); | |
471 | scsi_target_block(&shost->shost_gendev); | |
472 | queue_delayed_work(system_long_wq, | |
473 | &rport->fast_io_fail_work, | |
474 | 1UL * fast_io_fail_tmo * HZ); | |
475 | } | |
476 | if (dev_loss_tmo >= 0) | |
477 | queue_delayed_work(system_long_wq, | |
478 | &rport->dev_loss_work, | |
479 | 1UL * dev_loss_tmo * HZ); | |
480 | } else { | |
481 | pr_debug("%s has already been deleted\n", | |
482 | dev_name(&shost->shost_gendev)); | |
483 | srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST); | |
484 | scsi_target_unblock(&shost->shost_gendev, | |
485 | SDEV_TRANSPORT_OFFLINE); | |
486 | } | |
487 | } | |
488 | ||
489 | /** | |
490 | * srp_start_tl_fail_timers() - start the transport layer failure timers | |
491 | * | |
492 | * Start the transport layer fast I/O failure and device loss timers. Do not | |
493 | * modify a timer that was already started. | |
494 | */ | |
495 | void srp_start_tl_fail_timers(struct srp_rport *rport) | |
496 | { | |
497 | mutex_lock(&rport->mutex); | |
498 | __srp_start_tl_fail_timers(rport); | |
499 | mutex_unlock(&rport->mutex); | |
500 | } | |
501 | EXPORT_SYMBOL(srp_start_tl_fail_timers); | |
502 | ||
503 | /** | |
504 | * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn() | |
505 | */ | |
506 | static int scsi_request_fn_active(struct Scsi_Host *shost) | |
507 | { | |
508 | struct scsi_device *sdev; | |
509 | struct request_queue *q; | |
510 | int request_fn_active = 0; | |
511 | ||
512 | shost_for_each_device(sdev, shost) { | |
513 | q = sdev->request_queue; | |
514 | ||
515 | spin_lock_irq(q->queue_lock); | |
516 | request_fn_active += q->request_fn_active; | |
517 | spin_unlock_irq(q->queue_lock); | |
518 | } | |
519 | ||
520 | return request_fn_active; | |
521 | } | |
522 | ||
523 | /** | |
524 | * srp_reconnect_rport() - reconnect to an SRP target port | |
525 | * | |
526 | * Blocks SCSI command queueing before invoking reconnect() such that | |
527 | * queuecommand() won't be invoked concurrently with reconnect() from outside | |
528 | * the SCSI EH. This is important since a reconnect() implementation may | |
529 | * reallocate resources needed by queuecommand(). | |
530 | * | |
531 | * Notes: | |
532 | * - This function neither waits until outstanding requests have finished nor | |
533 | * tries to abort these. It is the responsibility of the reconnect() | |
534 | * function to finish outstanding commands before reconnecting to the target | |
535 | * port. | |
536 | * - It is the responsibility of the caller to ensure that the resources | |
537 | * reallocated by the reconnect() function won't be used while this function | |
538 | * is in progress. One possible strategy is to invoke this function from | |
539 | * the context of the SCSI EH thread only. Another possible strategy is to | |
540 | * lock the rport mutex inside each SCSI LLD callback that can be invoked by | |
541 | * the SCSI EH (the scsi_host_template.eh_*() functions and also the | |
542 | * scsi_host_template.queuecommand() function). | |
543 | */ | |
544 | int srp_reconnect_rport(struct srp_rport *rport) | |
545 | { | |
546 | struct Scsi_Host *shost = rport_to_shost(rport); | |
547 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
548 | struct scsi_device *sdev; | |
549 | int res; | |
550 | ||
551 | pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev)); | |
552 | ||
553 | res = mutex_lock_interruptible(&rport->mutex); | |
554 | if (res) | |
555 | goto out; | |
556 | scsi_target_block(&shost->shost_gendev); | |
557 | while (scsi_request_fn_active(shost)) | |
558 | msleep(20); | |
559 | res = i->f->reconnect(rport); | |
560 | pr_debug("%s (state %d): transport.reconnect() returned %d\n", | |
561 | dev_name(&shost->shost_gendev), rport->state, res); | |
562 | if (res == 0) { | |
563 | cancel_delayed_work(&rport->fast_io_fail_work); | |
564 | cancel_delayed_work(&rport->dev_loss_work); | |
565 | ||
8c64e453 | 566 | rport->failed_reconnects = 0; |
29c17324 BVA |
567 | srp_rport_set_state(rport, SRP_RPORT_RUNNING); |
568 | scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING); | |
569 | /* | |
570 | * If the SCSI error handler has offlined one or more devices, | |
571 | * invoking scsi_target_unblock() won't change the state of | |
572 | * these devices into running so do that explicitly. | |
573 | */ | |
574 | spin_lock_irq(shost->host_lock); | |
575 | __shost_for_each_device(sdev, shost) | |
576 | if (sdev->sdev_state == SDEV_OFFLINE) | |
577 | sdev->sdev_state = SDEV_RUNNING; | |
578 | spin_unlock_irq(shost->host_lock); | |
579 | } else if (rport->state == SRP_RPORT_RUNNING) { | |
580 | /* | |
581 | * srp_reconnect_rport() was invoked with fast_io_fail | |
582 | * off. Mark the port as failed and start the TL failure | |
583 | * timers if these had not yet been started. | |
584 | */ | |
585 | __rport_fail_io_fast(rport); | |
586 | scsi_target_unblock(&shost->shost_gendev, | |
587 | SDEV_TRANSPORT_OFFLINE); | |
588 | __srp_start_tl_fail_timers(rport); | |
589 | } else if (rport->state != SRP_RPORT_BLOCKED) { | |
590 | scsi_target_unblock(&shost->shost_gendev, | |
591 | SDEV_TRANSPORT_OFFLINE); | |
592 | } | |
593 | mutex_unlock(&rport->mutex); | |
594 | ||
595 | out: | |
596 | return res; | |
597 | } | |
598 | EXPORT_SYMBOL(srp_reconnect_rport); | |
599 | ||
600 | /** | |
601 | * srp_timed_out() - SRP transport intercept of the SCSI timeout EH | |
602 | * | |
603 | * If a timeout occurs while an rport is in the blocked state, ask the SCSI | |
604 | * EH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI core | |
605 | * handle the timeout (BLK_EH_NOT_HANDLED). | |
606 | * | |
607 | * Note: This function is called from soft-IRQ context and with the request | |
608 | * queue lock held. | |
609 | */ | |
610 | static enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd) | |
611 | { | |
612 | struct scsi_device *sdev = scmd->device; | |
613 | struct Scsi_Host *shost = sdev->host; | |
614 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
615 | ||
616 | pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev)); | |
617 | return i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ? | |
618 | BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED; | |
619 | } | |
620 | ||
09345f65 FT |
621 | static void srp_rport_release(struct device *dev) |
622 | { | |
623 | struct srp_rport *rport = dev_to_rport(dev); | |
624 | ||
8c64e453 | 625 | cancel_delayed_work_sync(&rport->reconnect_work); |
29c17324 BVA |
626 | cancel_delayed_work_sync(&rport->fast_io_fail_work); |
627 | cancel_delayed_work_sync(&rport->dev_loss_work); | |
628 | ||
09345f65 FT |
629 | put_device(dev->parent); |
630 | kfree(rport); | |
631 | } | |
632 | ||
633 | static int scsi_is_srp_rport(const struct device *dev) | |
634 | { | |
635 | return dev->release == srp_rport_release; | |
636 | } | |
637 | ||
638 | static int srp_rport_match(struct attribute_container *cont, | |
639 | struct device *dev) | |
640 | { | |
641 | struct Scsi_Host *shost; | |
642 | struct srp_internal *i; | |
643 | ||
644 | if (!scsi_is_srp_rport(dev)) | |
645 | return 0; | |
646 | ||
647 | shost = dev_to_shost(dev->parent); | |
648 | if (!shost->transportt) | |
649 | return 0; | |
650 | if (shost->transportt->host_attrs.ac.class != &srp_host_class.class) | |
651 | return 0; | |
652 | ||
653 | i = to_srp_internal(shost->transportt); | |
654 | return &i->rport_attr_cont.ac == cont; | |
655 | } | |
656 | ||
657 | static int srp_host_match(struct attribute_container *cont, struct device *dev) | |
658 | { | |
659 | struct Scsi_Host *shost; | |
660 | struct srp_internal *i; | |
661 | ||
662 | if (!scsi_is_host_device(dev)) | |
663 | return 0; | |
664 | ||
665 | shost = dev_to_shost(dev); | |
666 | if (!shost->transportt) | |
667 | return 0; | |
668 | if (shost->transportt->host_attrs.ac.class != &srp_host_class.class) | |
669 | return 0; | |
670 | ||
671 | i = to_srp_internal(shost->transportt); | |
672 | return &i->t.host_attrs.ac == cont; | |
673 | } | |
674 | ||
9dd69a60 BVA |
675 | /** |
676 | * srp_rport_get() - increment rport reference count | |
677 | */ | |
678 | void srp_rport_get(struct srp_rport *rport) | |
679 | { | |
680 | get_device(&rport->dev); | |
681 | } | |
682 | EXPORT_SYMBOL(srp_rport_get); | |
683 | ||
684 | /** | |
685 | * srp_rport_put() - decrement rport reference count | |
686 | */ | |
687 | void srp_rport_put(struct srp_rport *rport) | |
688 | { | |
689 | put_device(&rport->dev); | |
690 | } | |
691 | EXPORT_SYMBOL(srp_rport_put); | |
692 | ||
09345f65 FT |
693 | /** |
694 | * srp_rport_add - add a SRP remote port to the device hierarchy | |
09345f65 FT |
695 | * @shost: scsi host the remote port is connected to. |
696 | * @ids: The port id for the remote port. | |
697 | * | |
dc8875e1 | 698 | * Publishes a port to the rest of the system. |
09345f65 FT |
699 | */ |
700 | struct srp_rport *srp_rport_add(struct Scsi_Host *shost, | |
701 | struct srp_rport_identifiers *ids) | |
702 | { | |
703 | struct srp_rport *rport; | |
704 | struct device *parent = &shost->shost_gendev; | |
29c17324 | 705 | struct srp_internal *i = to_srp_internal(shost->transportt); |
09345f65 FT |
706 | int id, ret; |
707 | ||
708 | rport = kzalloc(sizeof(*rport), GFP_KERNEL); | |
709 | if (!rport) | |
710 | return ERR_PTR(-ENOMEM); | |
711 | ||
29c17324 BVA |
712 | mutex_init(&rport->mutex); |
713 | ||
09345f65 FT |
714 | device_initialize(&rport->dev); |
715 | ||
716 | rport->dev.parent = get_device(parent); | |
717 | rport->dev.release = srp_rport_release; | |
718 | ||
719 | memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id)); | |
aebd5e47 | 720 | rport->roles = ids->roles; |
09345f65 | 721 | |
8c64e453 BVA |
722 | if (i->f->reconnect) |
723 | rport->reconnect_delay = i->f->reconnect_delay ? | |
724 | *i->f->reconnect_delay : 10; | |
725 | INIT_DELAYED_WORK(&rport->reconnect_work, srp_reconnect_work); | |
29c17324 BVA |
726 | rport->fast_io_fail_tmo = i->f->fast_io_fail_tmo ? |
727 | *i->f->fast_io_fail_tmo : 15; | |
728 | rport->dev_loss_tmo = i->f->dev_loss_tmo ? *i->f->dev_loss_tmo : 60; | |
729 | INIT_DELAYED_WORK(&rport->fast_io_fail_work, | |
730 | rport_fast_io_fail_timedout); | |
731 | INIT_DELAYED_WORK(&rport->dev_loss_work, rport_dev_loss_timedout); | |
732 | ||
09345f65 | 733 | id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id); |
71610f55 | 734 | dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id); |
09345f65 FT |
735 | |
736 | transport_setup_device(&rport->dev); | |
737 | ||
738 | ret = device_add(&rport->dev); | |
739 | if (ret) { | |
740 | transport_destroy_device(&rport->dev); | |
741 | put_device(&rport->dev); | |
742 | return ERR_PTR(ret); | |
743 | } | |
744 | ||
72e39ea7 FT |
745 | if (shost->active_mode & MODE_TARGET && |
746 | ids->roles == SRP_RPORT_ROLE_INITIATOR) { | |
0012fdf9 FT |
747 | ret = srp_tgt_it_nexus_create(shost, (unsigned long)rport, |
748 | rport->port_id); | |
62fe8826 FT |
749 | if (ret) { |
750 | device_del(&rport->dev); | |
751 | transport_destroy_device(&rport->dev); | |
752 | put_device(&rport->dev); | |
753 | return ERR_PTR(ret); | |
754 | } | |
755 | } | |
756 | ||
09345f65 FT |
757 | transport_add_device(&rport->dev); |
758 | transport_configure_device(&rport->dev); | |
759 | ||
760 | return rport; | |
761 | } | |
762 | EXPORT_SYMBOL_GPL(srp_rport_add); | |
763 | ||
764 | /** | |
eb44820c RL |
765 | * srp_rport_del - remove a SRP remote port |
766 | * @rport: SRP remote port to remove | |
09345f65 FT |
767 | * |
768 | * Removes the specified SRP remote port. | |
769 | */ | |
770 | void srp_rport_del(struct srp_rport *rport) | |
771 | { | |
772 | struct device *dev = &rport->dev; | |
72e39ea7 | 773 | struct Scsi_Host *shost = dev_to_shost(dev->parent); |
09345f65 | 774 | |
72e39ea7 FT |
775 | if (shost->active_mode & MODE_TARGET && |
776 | rport->roles == SRP_RPORT_ROLE_INITIATOR) | |
777 | srp_tgt_it_nexus_destroy(shost, (unsigned long)rport); | |
62fe8826 | 778 | |
09345f65 FT |
779 | transport_remove_device(dev); |
780 | device_del(dev); | |
781 | transport_destroy_device(dev); | |
29c17324 BVA |
782 | |
783 | mutex_lock(&rport->mutex); | |
784 | if (rport->state == SRP_RPORT_BLOCKED) | |
785 | __rport_fail_io_fast(rport); | |
786 | rport->deleted = true; | |
787 | mutex_unlock(&rport->mutex); | |
788 | ||
09345f65 FT |
789 | put_device(dev); |
790 | } | |
791 | EXPORT_SYMBOL_GPL(srp_rport_del); | |
792 | ||
793 | static int do_srp_rport_del(struct device *dev, void *data) | |
794 | { | |
91183344 DD |
795 | if (scsi_is_srp_rport(dev)) |
796 | srp_rport_del(dev_to_rport(dev)); | |
09345f65 FT |
797 | return 0; |
798 | } | |
799 | ||
800 | /** | |
eb44820c | 801 | * srp_remove_host - tear down a Scsi_Host's SRP data structures |
09345f65 FT |
802 | * @shost: Scsi Host that is torn down |
803 | * | |
804 | * Removes all SRP remote ports for a given Scsi_Host. | |
805 | * Must be called just before scsi_remove_host for SRP HBAs. | |
806 | */ | |
807 | void srp_remove_host(struct Scsi_Host *shost) | |
808 | { | |
809 | device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del); | |
810 | } | |
811 | EXPORT_SYMBOL_GPL(srp_remove_host); | |
812 | ||
bfb74374 FT |
813 | static int srp_tsk_mgmt_response(struct Scsi_Host *shost, u64 nexus, u64 tm_id, |
814 | int result) | |
62fe8826 FT |
815 | { |
816 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
bfb74374 FT |
817 | return i->f->tsk_mgmt_response(shost, nexus, tm_id, result); |
818 | } | |
819 | ||
820 | static int srp_it_nexus_response(struct Scsi_Host *shost, u64 nexus, int result) | |
821 | { | |
822 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
823 | return i->f->it_nexus_response(shost, nexus, result); | |
62fe8826 FT |
824 | } |
825 | ||
09345f65 | 826 | /** |
eb44820c | 827 | * srp_attach_transport - instantiate SRP transport template |
09345f65 FT |
828 | * @ft: SRP transport class function template |
829 | */ | |
830 | struct scsi_transport_template * | |
831 | srp_attach_transport(struct srp_function_template *ft) | |
832 | { | |
833 | int count; | |
834 | struct srp_internal *i; | |
835 | ||
836 | i = kzalloc(sizeof(*i), GFP_KERNEL); | |
837 | if (!i) | |
838 | return NULL; | |
839 | ||
29c17324 BVA |
840 | i->t.eh_timed_out = srp_timed_out; |
841 | ||
bfb74374 | 842 | i->t.tsk_mgmt_response = srp_tsk_mgmt_response; |
62fe8826 FT |
843 | i->t.it_nexus_response = srp_it_nexus_response; |
844 | ||
09345f65 FT |
845 | i->t.host_size = sizeof(struct srp_host_attrs); |
846 | i->t.host_attrs.ac.attrs = &i->host_attrs[0]; | |
847 | i->t.host_attrs.ac.class = &srp_host_class.class; | |
848 | i->t.host_attrs.ac.match = srp_host_match; | |
849 | i->host_attrs[0] = NULL; | |
850 | transport_container_register(&i->t.host_attrs); | |
851 | ||
852 | i->rport_attr_cont.ac.attrs = &i->rport_attrs[0]; | |
853 | i->rport_attr_cont.ac.class = &srp_rport_class.class; | |
854 | i->rport_attr_cont.ac.match = srp_rport_match; | |
09345f65 FT |
855 | |
856 | count = 0; | |
9134a855 BVA |
857 | i->rport_attrs[count++] = &dev_attr_port_id; |
858 | i->rport_attrs[count++] = &dev_attr_roles; | |
29c17324 BVA |
859 | if (ft->has_rport_state) { |
860 | i->rport_attrs[count++] = &dev_attr_state; | |
861 | i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo; | |
862 | i->rport_attrs[count++] = &dev_attr_dev_loss_tmo; | |
863 | } | |
8c64e453 BVA |
864 | if (ft->reconnect) { |
865 | i->rport_attrs[count++] = &dev_attr_reconnect_delay; | |
866 | i->rport_attrs[count++] = &dev_attr_failed_reconnects; | |
867 | } | |
dc1bdbd9 BVA |
868 | if (ft->rport_delete) |
869 | i->rport_attrs[count++] = &dev_attr_delete; | |
9134a855 BVA |
870 | i->rport_attrs[count++] = NULL; |
871 | BUG_ON(count > ARRAY_SIZE(i->rport_attrs)); | |
09345f65 | 872 | |
ac9be30e BVA |
873 | transport_container_register(&i->rport_attr_cont); |
874 | ||
09345f65 FT |
875 | i->f = ft; |
876 | ||
877 | return &i->t; | |
878 | } | |
879 | EXPORT_SYMBOL_GPL(srp_attach_transport); | |
880 | ||
881 | /** | |
eb44820c | 882 | * srp_release_transport - release SRP transport template instance |
09345f65 FT |
883 | * @t: transport template instance |
884 | */ | |
885 | void srp_release_transport(struct scsi_transport_template *t) | |
886 | { | |
887 | struct srp_internal *i = to_srp_internal(t); | |
888 | ||
889 | transport_container_unregister(&i->t.host_attrs); | |
890 | transport_container_unregister(&i->rport_attr_cont); | |
891 | ||
892 | kfree(i); | |
893 | } | |
894 | EXPORT_SYMBOL_GPL(srp_release_transport); | |
895 | ||
896 | static __init int srp_transport_init(void) | |
897 | { | |
898 | int ret; | |
899 | ||
900 | ret = transport_class_register(&srp_host_class); | |
901 | if (ret) | |
902 | return ret; | |
903 | ret = transport_class_register(&srp_rport_class); | |
904 | if (ret) | |
905 | goto unregister_host_class; | |
906 | ||
907 | return 0; | |
908 | unregister_host_class: | |
909 | transport_class_unregister(&srp_host_class); | |
910 | return ret; | |
911 | } | |
912 | ||
913 | static void __exit srp_transport_exit(void) | |
914 | { | |
915 | transport_class_unregister(&srp_host_class); | |
916 | transport_class_unregister(&srp_rport_class); | |
917 | } | |
918 | ||
919 | MODULE_AUTHOR("FUJITA Tomonori"); | |
920 | MODULE_DESCRIPTION("SRP Transport Attributes"); | |
921 | MODULE_LICENSE("GPL"); | |
922 | ||
923 | module_init(srp_transport_init); | |
924 | module_exit(srp_transport_exit); |