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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> | |
27 | ||
28 | #include <scsi/scsi.h> | |
29c17324 | 29 | #include <scsi/scsi_cmnd.h> |
09345f65 FT |
30 | #include <scsi/scsi_device.h> |
31 | #include <scsi/scsi_host.h> | |
32 | #include <scsi/scsi_transport.h> | |
33 | #include <scsi/scsi_transport_srp.h> | |
29c17324 | 34 | #include "scsi_priv.h" |
09345f65 FT |
35 | |
36 | struct srp_host_attrs { | |
37 | atomic_t next_port_id; | |
38 | }; | |
39 | #define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data) | |
40 | ||
41 | #define SRP_HOST_ATTRS 0 | |
8c64e453 | 42 | #define SRP_RPORT_ATTRS 8 |
09345f65 FT |
43 | |
44 | struct srp_internal { | |
45 | struct scsi_transport_template t; | |
46 | struct srp_function_template *f; | |
47 | ||
ee959b00 | 48 | struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1]; |
09345f65 | 49 | |
ee959b00 | 50 | struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1]; |
09345f65 FT |
51 | struct transport_container rport_attr_cont; |
52 | }; | |
53 | ||
54 | #define to_srp_internal(tmpl) container_of(tmpl, struct srp_internal, t) | |
55 | ||
56 | #define dev_to_rport(d) container_of(d, struct srp_rport, dev) | |
ee959b00 | 57 | #define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent) |
29c17324 BVA |
58 | static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r) |
59 | { | |
60 | return dev_to_shost(r->dev.parent); | |
61 | } | |
62 | ||
e68ca752 BVA |
63 | static inline struct srp_rport *shost_to_rport(struct Scsi_Host *shost) |
64 | { | |
65 | return transport_class_to_srp_rport(&shost->shost_gendev); | |
66 | } | |
67 | ||
29c17324 BVA |
68 | /** |
69 | * srp_tmo_valid() - check timeout combination validity | |
0c7f8218 BVA |
70 | * @reconnect_delay: Reconnect delay in seconds. |
71 | * @fast_io_fail_tmo: Fast I/O fail timeout in seconds. | |
72 | * @dev_loss_tmo: Device loss timeout in seconds. | |
29c17324 BVA |
73 | * |
74 | * The combination of the timeout parameters must be such that SCSI commands | |
75 | * are finished in a reasonable time. Hence do not allow the fast I/O fail | |
18cc4e02 BVA |
76 | * timeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT nor allow dev_loss_tmo to |
77 | * exceed that limit if failing I/O fast has been disabled. Furthermore, these | |
29c17324 | 78 | * parameters must be such that multipath can detect failed paths timely. |
8c64e453 | 79 | * Hence do not allow all three parameters to be disabled simultaneously. |
29c17324 | 80 | */ |
8c64e453 | 81 | int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, int dev_loss_tmo) |
29c17324 | 82 | { |
8c64e453 BVA |
83 | if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0) |
84 | return -EINVAL; | |
85 | if (reconnect_delay == 0) | |
29c17324 BVA |
86 | return -EINVAL; |
87 | if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT) | |
88 | return -EINVAL; | |
18cc4e02 BVA |
89 | if (fast_io_fail_tmo < 0 && |
90 | dev_loss_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT) | |
91 | return -EINVAL; | |
29c17324 BVA |
92 | if (dev_loss_tmo >= LONG_MAX / HZ) |
93 | return -EINVAL; | |
94 | if (fast_io_fail_tmo >= 0 && dev_loss_tmo >= 0 && | |
95 | fast_io_fail_tmo >= dev_loss_tmo) | |
96 | return -EINVAL; | |
97 | return 0; | |
98 | } | |
99 | EXPORT_SYMBOL_GPL(srp_tmo_valid); | |
09345f65 FT |
100 | |
101 | static int srp_host_setup(struct transport_container *tc, struct device *dev, | |
ee959b00 | 102 | struct device *cdev) |
09345f65 FT |
103 | { |
104 | struct Scsi_Host *shost = dev_to_shost(dev); | |
105 | struct srp_host_attrs *srp_host = to_srp_host_attrs(shost); | |
106 | ||
107 | atomic_set(&srp_host->next_port_id, 0); | |
108 | return 0; | |
109 | } | |
110 | ||
111 | static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup, | |
112 | NULL, NULL); | |
113 | ||
114 | static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports", | |
115 | NULL, NULL, NULL); | |
116 | ||
09345f65 | 117 | static ssize_t |
ee959b00 TJ |
118 | show_srp_rport_id(struct device *dev, struct device_attribute *attr, |
119 | char *buf) | |
09345f65 | 120 | { |
ee959b00 | 121 | struct srp_rport *rport = transport_class_to_srp_rport(dev); |
df441cc0 | 122 | return sprintf(buf, "%16phC\n", rport->port_id); |
09345f65 FT |
123 | } |
124 | ||
ee959b00 | 125 | static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL); |
09345f65 | 126 | |
aebd5e47 FT |
127 | static const struct { |
128 | u32 value; | |
129 | char *name; | |
130 | } srp_rport_role_names[] = { | |
131 | {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"}, | |
132 | {SRP_RPORT_ROLE_TARGET, "SRP Target"}, | |
133 | }; | |
134 | ||
135 | static ssize_t | |
ee959b00 TJ |
136 | show_srp_rport_roles(struct device *dev, struct device_attribute *attr, |
137 | char *buf) | |
aebd5e47 | 138 | { |
ee959b00 | 139 | struct srp_rport *rport = transport_class_to_srp_rport(dev); |
aebd5e47 FT |
140 | int i; |
141 | char *name = NULL; | |
142 | ||
143 | for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++) | |
144 | if (srp_rport_role_names[i].value == rport->roles) { | |
145 | name = srp_rport_role_names[i].name; | |
146 | break; | |
147 | } | |
148 | return sprintf(buf, "%s\n", name ? : "unknown"); | |
149 | } | |
150 | ||
ee959b00 | 151 | static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL); |
aebd5e47 | 152 | |
dc1bdbd9 BVA |
153 | static ssize_t store_srp_rport_delete(struct device *dev, |
154 | struct device_attribute *attr, | |
155 | const char *buf, size_t count) | |
156 | { | |
157 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
158 | struct Scsi_Host *shost = dev_to_shost(dev); | |
159 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
160 | ||
161 | if (i->f->rport_delete) { | |
162 | i->f->rport_delete(rport); | |
163 | return count; | |
164 | } else { | |
165 | return -ENOSYS; | |
166 | } | |
167 | } | |
168 | ||
169 | static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete); | |
170 | ||
29c17324 BVA |
171 | static ssize_t show_srp_rport_state(struct device *dev, |
172 | struct device_attribute *attr, | |
173 | char *buf) | |
174 | { | |
175 | static const char *const state_name[] = { | |
176 | [SRP_RPORT_RUNNING] = "running", | |
177 | [SRP_RPORT_BLOCKED] = "blocked", | |
178 | [SRP_RPORT_FAIL_FAST] = "fail-fast", | |
179 | [SRP_RPORT_LOST] = "lost", | |
180 | }; | |
181 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
182 | enum srp_rport_state state = rport->state; | |
183 | ||
184 | return sprintf(buf, "%s\n", | |
185 | (unsigned)state < ARRAY_SIZE(state_name) ? | |
186 | state_name[state] : "???"); | |
187 | } | |
188 | ||
189 | static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL); | |
190 | ||
191 | static ssize_t srp_show_tmo(char *buf, int tmo) | |
192 | { | |
193 | return tmo >= 0 ? sprintf(buf, "%d\n", tmo) : sprintf(buf, "off\n"); | |
194 | } | |
195 | ||
3fdf70ac | 196 | int srp_parse_tmo(int *tmo, const char *buf) |
29c17324 BVA |
197 | { |
198 | int res = 0; | |
199 | ||
200 | if (strncmp(buf, "off", 3) != 0) | |
201 | res = kstrtoint(buf, 0, tmo); | |
202 | else | |
203 | *tmo = -1; | |
204 | ||
205 | return res; | |
206 | } | |
3fdf70ac | 207 | EXPORT_SYMBOL(srp_parse_tmo); |
29c17324 | 208 | |
8c64e453 BVA |
209 | static ssize_t show_reconnect_delay(struct device *dev, |
210 | struct device_attribute *attr, char *buf) | |
211 | { | |
212 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
213 | ||
214 | return srp_show_tmo(buf, rport->reconnect_delay); | |
215 | } | |
216 | ||
217 | static ssize_t store_reconnect_delay(struct device *dev, | |
218 | struct device_attribute *attr, | |
219 | const char *buf, const size_t count) | |
220 | { | |
221 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
222 | int res, delay; | |
223 | ||
224 | res = srp_parse_tmo(&delay, buf); | |
225 | if (res) | |
226 | goto out; | |
227 | res = srp_tmo_valid(delay, rport->fast_io_fail_tmo, | |
228 | rport->dev_loss_tmo); | |
229 | if (res) | |
230 | goto out; | |
231 | ||
232 | if (rport->reconnect_delay <= 0 && delay > 0 && | |
233 | rport->state != SRP_RPORT_RUNNING) { | |
234 | queue_delayed_work(system_long_wq, &rport->reconnect_work, | |
235 | delay * HZ); | |
236 | } else if (delay <= 0) { | |
237 | cancel_delayed_work(&rport->reconnect_work); | |
238 | } | |
239 | rport->reconnect_delay = delay; | |
240 | res = count; | |
241 | ||
242 | out: | |
243 | return res; | |
244 | } | |
245 | ||
246 | static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay, | |
247 | store_reconnect_delay); | |
248 | ||
249 | static ssize_t show_failed_reconnects(struct device *dev, | |
250 | struct device_attribute *attr, char *buf) | |
251 | { | |
252 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
253 | ||
254 | return sprintf(buf, "%d\n", rport->failed_reconnects); | |
255 | } | |
256 | ||
257 | static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL); | |
258 | ||
29c17324 BVA |
259 | static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev, |
260 | struct device_attribute *attr, | |
261 | char *buf) | |
262 | { | |
263 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
264 | ||
265 | return srp_show_tmo(buf, rport->fast_io_fail_tmo); | |
266 | } | |
267 | ||
268 | static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev, | |
269 | struct device_attribute *attr, | |
270 | const char *buf, size_t count) | |
271 | { | |
272 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
273 | int res; | |
274 | int fast_io_fail_tmo; | |
275 | ||
276 | res = srp_parse_tmo(&fast_io_fail_tmo, buf); | |
277 | if (res) | |
278 | goto out; | |
8c64e453 BVA |
279 | res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo, |
280 | rport->dev_loss_tmo); | |
29c17324 BVA |
281 | if (res) |
282 | goto out; | |
283 | rport->fast_io_fail_tmo = fast_io_fail_tmo; | |
284 | res = count; | |
285 | ||
286 | out: | |
287 | return res; | |
288 | } | |
289 | ||
290 | static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR, | |
291 | show_srp_rport_fast_io_fail_tmo, | |
292 | store_srp_rport_fast_io_fail_tmo); | |
293 | ||
294 | static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev, | |
295 | struct device_attribute *attr, | |
296 | char *buf) | |
297 | { | |
298 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
299 | ||
300 | return srp_show_tmo(buf, rport->dev_loss_tmo); | |
301 | } | |
302 | ||
303 | static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev, | |
304 | struct device_attribute *attr, | |
305 | const char *buf, size_t count) | |
306 | { | |
307 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
308 | int res; | |
309 | int dev_loss_tmo; | |
310 | ||
311 | res = srp_parse_tmo(&dev_loss_tmo, buf); | |
312 | if (res) | |
313 | goto out; | |
8c64e453 BVA |
314 | res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo, |
315 | dev_loss_tmo); | |
29c17324 BVA |
316 | if (res) |
317 | goto out; | |
318 | rport->dev_loss_tmo = dev_loss_tmo; | |
319 | res = count; | |
320 | ||
321 | out: | |
322 | return res; | |
323 | } | |
324 | ||
325 | static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR, | |
326 | show_srp_rport_dev_loss_tmo, | |
327 | store_srp_rport_dev_loss_tmo); | |
328 | ||
329 | static int srp_rport_set_state(struct srp_rport *rport, | |
330 | enum srp_rport_state new_state) | |
331 | { | |
332 | enum srp_rport_state old_state = rport->state; | |
333 | ||
334 | lockdep_assert_held(&rport->mutex); | |
335 | ||
336 | switch (new_state) { | |
337 | case SRP_RPORT_RUNNING: | |
338 | switch (old_state) { | |
339 | case SRP_RPORT_LOST: | |
340 | goto invalid; | |
341 | default: | |
342 | break; | |
343 | } | |
344 | break; | |
345 | case SRP_RPORT_BLOCKED: | |
346 | switch (old_state) { | |
347 | case SRP_RPORT_RUNNING: | |
348 | break; | |
349 | default: | |
350 | goto invalid; | |
351 | } | |
352 | break; | |
353 | case SRP_RPORT_FAIL_FAST: | |
354 | switch (old_state) { | |
355 | case SRP_RPORT_LOST: | |
356 | goto invalid; | |
357 | default: | |
358 | break; | |
359 | } | |
360 | break; | |
361 | case SRP_RPORT_LOST: | |
362 | break; | |
363 | } | |
364 | rport->state = new_state; | |
365 | return 0; | |
366 | ||
367 | invalid: | |
368 | return -EINVAL; | |
369 | } | |
370 | ||
8c64e453 BVA |
371 | /** |
372 | * srp_reconnect_work() - reconnect and schedule a new attempt if necessary | |
0c7f8218 | 373 | * @work: Work structure used for scheduling this operation. |
8c64e453 BVA |
374 | */ |
375 | static void srp_reconnect_work(struct work_struct *work) | |
376 | { | |
377 | struct srp_rport *rport = container_of(to_delayed_work(work), | |
378 | struct srp_rport, reconnect_work); | |
379 | struct Scsi_Host *shost = rport_to_shost(rport); | |
380 | int delay, res; | |
381 | ||
382 | res = srp_reconnect_rport(rport); | |
383 | if (res != 0) { | |
384 | shost_printk(KERN_ERR, shost, | |
385 | "reconnect attempt %d failed (%d)\n", | |
386 | ++rport->failed_reconnects, res); | |
387 | delay = rport->reconnect_delay * | |
388 | min(100, max(1, rport->failed_reconnects - 10)); | |
389 | if (delay > 0) | |
390 | queue_delayed_work(system_long_wq, | |
391 | &rport->reconnect_work, delay * HZ); | |
392 | } | |
393 | } | |
394 | ||
29c17324 BVA |
395 | static void __rport_fail_io_fast(struct srp_rport *rport) |
396 | { | |
397 | struct Scsi_Host *shost = rport_to_shost(rport); | |
398 | struct srp_internal *i; | |
399 | ||
400 | lockdep_assert_held(&rport->mutex); | |
401 | ||
402 | if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST)) | |
403 | return; | |
669f0441 BVA |
404 | /* |
405 | * Call scsi_target_block() to wait for ongoing shost->queuecommand() | |
406 | * calls before invoking i->f->terminate_rport_io(). | |
407 | */ | |
408 | scsi_target_block(rport->dev.parent); | |
29c17324 BVA |
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); | |
669f0441 | 413 | if (i->f->terminate_rport_io) |
29c17324 BVA |
414 | i->f->terminate_rport_io(rport); |
415 | } | |
416 | ||
417 | /** | |
418 | * rport_fast_io_fail_timedout() - fast I/O failure timeout handler | |
0c7f8218 | 419 | * @work: Work structure used for scheduling this operation. |
29c17324 BVA |
420 | */ |
421 | static 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 | |
0c7f8218 | 438 | * @work: Work structure used for scheduling this operation. |
29c17324 BVA |
439 | */ |
440 | static 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 | ||
458 | static void __srp_start_tl_fail_timers(struct srp_rport *rport) | |
459 | { | |
460 | struct Scsi_Host *shost = rport_to_shost(rport); | |
8c64e453 | 461 | int delay, fast_io_fail_tmo, dev_loss_tmo; |
29c17324 BVA |
462 | |
463 | lockdep_assert_held(&rport->mutex); | |
464 | ||
93079162 BVA |
465 | 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); | |
29c17324 | 470 | |
93079162 BVA |
471 | 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); | |
cd53eb68 BVA |
476 | if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) && |
477 | srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) { | |
93079162 BVA |
478 | pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev), |
479 | rport->state); | |
480 | scsi_target_block(&shost->shost_gendev); | |
481 | if (fast_io_fail_tmo >= 0) | |
8c64e453 | 482 | queue_delayed_work(system_long_wq, |
93079162 BVA |
483 | &rport->fast_io_fail_work, |
484 | 1UL * fast_io_fail_tmo * HZ); | |
485 | if (dev_loss_tmo >= 0) | |
486 | queue_delayed_work(system_long_wq, | |
487 | &rport->dev_loss_work, | |
488 | 1UL * dev_loss_tmo * HZ); | |
29c17324 BVA |
489 | } |
490 | } | |
491 | ||
492 | /** | |
493 | * srp_start_tl_fail_timers() - start the transport layer failure timers | |
0c7f8218 | 494 | * @rport: SRP target port. |
29c17324 BVA |
495 | * |
496 | * Start the transport layer fast I/O failure and device loss timers. Do not | |
497 | * modify a timer that was already started. | |
498 | */ | |
499 | void srp_start_tl_fail_timers(struct srp_rport *rport) | |
500 | { | |
501 | mutex_lock(&rport->mutex); | |
502 | __srp_start_tl_fail_timers(rport); | |
503 | mutex_unlock(&rport->mutex); | |
504 | } | |
505 | EXPORT_SYMBOL(srp_start_tl_fail_timers); | |
506 | ||
29c17324 BVA |
507 | /** |
508 | * srp_reconnect_rport() - reconnect to an SRP target port | |
0c7f8218 | 509 | * @rport: SRP target port. |
29c17324 BVA |
510 | * |
511 | * Blocks SCSI command queueing before invoking reconnect() such that | |
512 | * queuecommand() won't be invoked concurrently with reconnect() from outside | |
513 | * the SCSI EH. This is important since a reconnect() implementation may | |
514 | * reallocate resources needed by queuecommand(). | |
515 | * | |
516 | * Notes: | |
517 | * - This function neither waits until outstanding requests have finished nor | |
518 | * tries to abort these. It is the responsibility of the reconnect() | |
519 | * function to finish outstanding commands before reconnecting to the target | |
520 | * port. | |
521 | * - It is the responsibility of the caller to ensure that the resources | |
522 | * reallocated by the reconnect() function won't be used while this function | |
523 | * is in progress. One possible strategy is to invoke this function from | |
524 | * the context of the SCSI EH thread only. Another possible strategy is to | |
525 | * lock the rport mutex inside each SCSI LLD callback that can be invoked by | |
526 | * the SCSI EH (the scsi_host_template.eh_*() functions and also the | |
527 | * scsi_host_template.queuecommand() function). | |
528 | */ | |
529 | int srp_reconnect_rport(struct srp_rport *rport) | |
530 | { | |
531 | struct Scsi_Host *shost = rport_to_shost(rport); | |
532 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
533 | struct scsi_device *sdev; | |
534 | int res; | |
535 | ||
536 | pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev)); | |
537 | ||
538 | res = mutex_lock_interruptible(&rport->mutex); | |
539 | if (res) | |
540 | goto out; | |
541 | scsi_target_block(&shost->shost_gendev); | |
93079162 | 542 | res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV; |
29c17324 BVA |
543 | pr_debug("%s (state %d): transport.reconnect() returned %d\n", |
544 | dev_name(&shost->shost_gendev), rport->state, res); | |
545 | if (res == 0) { | |
546 | cancel_delayed_work(&rport->fast_io_fail_work); | |
547 | cancel_delayed_work(&rport->dev_loss_work); | |
548 | ||
8c64e453 | 549 | rport->failed_reconnects = 0; |
29c17324 BVA |
550 | srp_rport_set_state(rport, SRP_RPORT_RUNNING); |
551 | scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING); | |
552 | /* | |
553 | * If the SCSI error handler has offlined one or more devices, | |
554 | * invoking scsi_target_unblock() won't change the state of | |
555 | * these devices into running so do that explicitly. | |
556 | */ | |
0db6ca8a BVA |
557 | shost_for_each_device(sdev, shost) { |
558 | mutex_lock(&sdev->state_mutex); | |
29c17324 BVA |
559 | if (sdev->sdev_state == SDEV_OFFLINE) |
560 | sdev->sdev_state = SDEV_RUNNING; | |
0db6ca8a BVA |
561 | mutex_unlock(&sdev->state_mutex); |
562 | } | |
29c17324 BVA |
563 | } else if (rport->state == SRP_RPORT_RUNNING) { |
564 | /* | |
18cc4e02 BVA |
565 | * srp_reconnect_rport() has been invoked with fast_io_fail |
566 | * and dev_loss off. Mark the port as failed and start the TL | |
567 | * failure timers if these had not yet been started. | |
29c17324 BVA |
568 | */ |
569 | __rport_fail_io_fast(rport); | |
570 | scsi_target_unblock(&shost->shost_gendev, | |
571 | SDEV_TRANSPORT_OFFLINE); | |
572 | __srp_start_tl_fail_timers(rport); | |
573 | } else if (rport->state != SRP_RPORT_BLOCKED) { | |
574 | scsi_target_unblock(&shost->shost_gendev, | |
575 | SDEV_TRANSPORT_OFFLINE); | |
576 | } | |
577 | mutex_unlock(&rport->mutex); | |
578 | ||
579 | out: | |
580 | return res; | |
581 | } | |
582 | EXPORT_SYMBOL(srp_reconnect_rport); | |
583 | ||
584 | /** | |
585 | * srp_timed_out() - SRP transport intercept of the SCSI timeout EH | |
0c7f8218 | 586 | * @scmd: SCSI command. |
29c17324 BVA |
587 | * |
588 | * If a timeout occurs while an rport is in the blocked state, ask the SCSI | |
589 | * EH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI core | |
590 | * handle the timeout (BLK_EH_NOT_HANDLED). | |
591 | * | |
592 | * Note: This function is called from soft-IRQ context and with the request | |
593 | * queue lock held. | |
594 | */ | |
b6a05c82 | 595 | enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd) |
29c17324 BVA |
596 | { |
597 | struct scsi_device *sdev = scmd->device; | |
598 | struct Scsi_Host *shost = sdev->host; | |
599 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
e68ca752 | 600 | struct srp_rport *rport = shost_to_rport(shost); |
29c17324 BVA |
601 | |
602 | pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev)); | |
e68ca752 BVA |
603 | return rport->fast_io_fail_tmo < 0 && rport->dev_loss_tmo < 0 && |
604 | i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ? | |
29c17324 BVA |
605 | BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED; |
606 | } | |
b6a05c82 | 607 | EXPORT_SYMBOL(srp_timed_out); |
29c17324 | 608 | |
09345f65 FT |
609 | static void srp_rport_release(struct device *dev) |
610 | { | |
611 | struct srp_rport *rport = dev_to_rport(dev); | |
612 | ||
613 | put_device(dev->parent); | |
614 | kfree(rport); | |
615 | } | |
616 | ||
617 | static int scsi_is_srp_rport(const struct device *dev) | |
618 | { | |
619 | return dev->release == srp_rport_release; | |
620 | } | |
621 | ||
622 | static int srp_rport_match(struct attribute_container *cont, | |
623 | struct device *dev) | |
624 | { | |
625 | struct Scsi_Host *shost; | |
626 | struct srp_internal *i; | |
627 | ||
628 | if (!scsi_is_srp_rport(dev)) | |
629 | return 0; | |
630 | ||
631 | shost = dev_to_shost(dev->parent); | |
632 | if (!shost->transportt) | |
633 | return 0; | |
634 | if (shost->transportt->host_attrs.ac.class != &srp_host_class.class) | |
635 | return 0; | |
636 | ||
637 | i = to_srp_internal(shost->transportt); | |
638 | return &i->rport_attr_cont.ac == cont; | |
639 | } | |
640 | ||
641 | static int srp_host_match(struct attribute_container *cont, struct device *dev) | |
642 | { | |
643 | struct Scsi_Host *shost; | |
644 | struct srp_internal *i; | |
645 | ||
646 | if (!scsi_is_host_device(dev)) | |
647 | return 0; | |
648 | ||
649 | shost = dev_to_shost(dev); | |
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->t.host_attrs.ac == cont; | |
657 | } | |
658 | ||
9dd69a60 BVA |
659 | /** |
660 | * srp_rport_get() - increment rport reference count | |
0c7f8218 | 661 | * @rport: SRP target port. |
9dd69a60 BVA |
662 | */ |
663 | void srp_rport_get(struct srp_rport *rport) | |
664 | { | |
665 | get_device(&rport->dev); | |
666 | } | |
667 | EXPORT_SYMBOL(srp_rport_get); | |
668 | ||
669 | /** | |
670 | * srp_rport_put() - decrement rport reference count | |
0c7f8218 | 671 | * @rport: SRP target port. |
9dd69a60 BVA |
672 | */ |
673 | void srp_rport_put(struct srp_rport *rport) | |
674 | { | |
675 | put_device(&rport->dev); | |
676 | } | |
677 | EXPORT_SYMBOL(srp_rport_put); | |
678 | ||
09345f65 FT |
679 | /** |
680 | * srp_rport_add - add a SRP remote port to the device hierarchy | |
09345f65 FT |
681 | * @shost: scsi host the remote port is connected to. |
682 | * @ids: The port id for the remote port. | |
683 | * | |
dc8875e1 | 684 | * Publishes a port to the rest of the system. |
09345f65 FT |
685 | */ |
686 | struct srp_rport *srp_rport_add(struct Scsi_Host *shost, | |
687 | struct srp_rport_identifiers *ids) | |
688 | { | |
689 | struct srp_rport *rport; | |
690 | struct device *parent = &shost->shost_gendev; | |
29c17324 | 691 | struct srp_internal *i = to_srp_internal(shost->transportt); |
09345f65 FT |
692 | int id, ret; |
693 | ||
694 | rport = kzalloc(sizeof(*rport), GFP_KERNEL); | |
695 | if (!rport) | |
696 | return ERR_PTR(-ENOMEM); | |
697 | ||
29c17324 BVA |
698 | mutex_init(&rport->mutex); |
699 | ||
09345f65 FT |
700 | device_initialize(&rport->dev); |
701 | ||
702 | rport->dev.parent = get_device(parent); | |
703 | rport->dev.release = srp_rport_release; | |
704 | ||
705 | memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id)); | |
aebd5e47 | 706 | rport->roles = ids->roles; |
09345f65 | 707 | |
8c64e453 BVA |
708 | if (i->f->reconnect) |
709 | rport->reconnect_delay = i->f->reconnect_delay ? | |
710 | *i->f->reconnect_delay : 10; | |
711 | INIT_DELAYED_WORK(&rport->reconnect_work, srp_reconnect_work); | |
29c17324 BVA |
712 | rport->fast_io_fail_tmo = i->f->fast_io_fail_tmo ? |
713 | *i->f->fast_io_fail_tmo : 15; | |
714 | rport->dev_loss_tmo = i->f->dev_loss_tmo ? *i->f->dev_loss_tmo : 60; | |
715 | INIT_DELAYED_WORK(&rport->fast_io_fail_work, | |
716 | rport_fast_io_fail_timedout); | |
717 | INIT_DELAYED_WORK(&rport->dev_loss_work, rport_dev_loss_timedout); | |
718 | ||
09345f65 | 719 | id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id); |
71610f55 | 720 | dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id); |
09345f65 FT |
721 | |
722 | transport_setup_device(&rport->dev); | |
723 | ||
724 | ret = device_add(&rport->dev); | |
725 | if (ret) { | |
726 | transport_destroy_device(&rport->dev); | |
727 | put_device(&rport->dev); | |
728 | return ERR_PTR(ret); | |
729 | } | |
730 | ||
731 | transport_add_device(&rport->dev); | |
732 | transport_configure_device(&rport->dev); | |
733 | ||
734 | return rport; | |
735 | } | |
736 | EXPORT_SYMBOL_GPL(srp_rport_add); | |
737 | ||
738 | /** | |
eb44820c RL |
739 | * srp_rport_del - remove a SRP remote port |
740 | * @rport: SRP remote port to remove | |
09345f65 FT |
741 | * |
742 | * Removes the specified SRP remote port. | |
743 | */ | |
744 | void srp_rport_del(struct srp_rport *rport) | |
745 | { | |
746 | struct device *dev = &rport->dev; | |
62fe8826 | 747 | |
09345f65 FT |
748 | transport_remove_device(dev); |
749 | device_del(dev); | |
750 | transport_destroy_device(dev); | |
29c17324 | 751 | |
09345f65 FT |
752 | put_device(dev); |
753 | } | |
754 | EXPORT_SYMBOL_GPL(srp_rport_del); | |
755 | ||
756 | static int do_srp_rport_del(struct device *dev, void *data) | |
757 | { | |
91183344 DD |
758 | if (scsi_is_srp_rport(dev)) |
759 | srp_rport_del(dev_to_rport(dev)); | |
09345f65 FT |
760 | return 0; |
761 | } | |
762 | ||
763 | /** | |
eb44820c | 764 | * srp_remove_host - tear down a Scsi_Host's SRP data structures |
09345f65 FT |
765 | * @shost: Scsi Host that is torn down |
766 | * | |
767 | * Removes all SRP remote ports for a given Scsi_Host. | |
768 | * Must be called just before scsi_remove_host for SRP HBAs. | |
769 | */ | |
770 | void srp_remove_host(struct Scsi_Host *shost) | |
771 | { | |
772 | device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del); | |
773 | } | |
774 | EXPORT_SYMBOL_GPL(srp_remove_host); | |
775 | ||
93079162 BVA |
776 | /** |
777 | * srp_stop_rport_timers - stop the transport layer recovery timers | |
67513605 | 778 | * @rport: SRP remote port for which to stop the timers. |
93079162 BVA |
779 | * |
780 | * Must be called after srp_remove_host() and scsi_remove_host(). The caller | |
781 | * must hold a reference on the rport (rport->dev) and on the SCSI host | |
782 | * (rport->dev.parent). | |
783 | */ | |
784 | void srp_stop_rport_timers(struct srp_rport *rport) | |
785 | { | |
786 | mutex_lock(&rport->mutex); | |
787 | if (rport->state == SRP_RPORT_BLOCKED) | |
788 | __rport_fail_io_fast(rport); | |
789 | srp_rport_set_state(rport, SRP_RPORT_LOST); | |
790 | mutex_unlock(&rport->mutex); | |
791 | ||
792 | cancel_delayed_work_sync(&rport->reconnect_work); | |
793 | cancel_delayed_work_sync(&rport->fast_io_fail_work); | |
794 | cancel_delayed_work_sync(&rport->dev_loss_work); | |
795 | } | |
796 | EXPORT_SYMBOL_GPL(srp_stop_rport_timers); | |
797 | ||
09345f65 | 798 | /** |
eb44820c | 799 | * srp_attach_transport - instantiate SRP transport template |
09345f65 FT |
800 | * @ft: SRP transport class function template |
801 | */ | |
802 | struct scsi_transport_template * | |
803 | srp_attach_transport(struct srp_function_template *ft) | |
804 | { | |
805 | int count; | |
806 | struct srp_internal *i; | |
807 | ||
808 | i = kzalloc(sizeof(*i), GFP_KERNEL); | |
809 | if (!i) | |
810 | return NULL; | |
811 | ||
812 | i->t.host_size = sizeof(struct srp_host_attrs); | |
813 | i->t.host_attrs.ac.attrs = &i->host_attrs[0]; | |
814 | i->t.host_attrs.ac.class = &srp_host_class.class; | |
815 | i->t.host_attrs.ac.match = srp_host_match; | |
816 | i->host_attrs[0] = NULL; | |
817 | transport_container_register(&i->t.host_attrs); | |
818 | ||
819 | i->rport_attr_cont.ac.attrs = &i->rport_attrs[0]; | |
820 | i->rport_attr_cont.ac.class = &srp_rport_class.class; | |
821 | i->rport_attr_cont.ac.match = srp_rport_match; | |
09345f65 FT |
822 | |
823 | count = 0; | |
9134a855 BVA |
824 | i->rport_attrs[count++] = &dev_attr_port_id; |
825 | i->rport_attrs[count++] = &dev_attr_roles; | |
29c17324 BVA |
826 | if (ft->has_rport_state) { |
827 | i->rport_attrs[count++] = &dev_attr_state; | |
828 | i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo; | |
829 | i->rport_attrs[count++] = &dev_attr_dev_loss_tmo; | |
830 | } | |
8c64e453 BVA |
831 | if (ft->reconnect) { |
832 | i->rport_attrs[count++] = &dev_attr_reconnect_delay; | |
833 | i->rport_attrs[count++] = &dev_attr_failed_reconnects; | |
834 | } | |
dc1bdbd9 BVA |
835 | if (ft->rport_delete) |
836 | i->rport_attrs[count++] = &dev_attr_delete; | |
9134a855 BVA |
837 | i->rport_attrs[count++] = NULL; |
838 | BUG_ON(count > ARRAY_SIZE(i->rport_attrs)); | |
09345f65 | 839 | |
ac9be30e BVA |
840 | transport_container_register(&i->rport_attr_cont); |
841 | ||
09345f65 FT |
842 | i->f = ft; |
843 | ||
844 | return &i->t; | |
845 | } | |
846 | EXPORT_SYMBOL_GPL(srp_attach_transport); | |
847 | ||
848 | /** | |
eb44820c | 849 | * srp_release_transport - release SRP transport template instance |
09345f65 FT |
850 | * @t: transport template instance |
851 | */ | |
852 | void srp_release_transport(struct scsi_transport_template *t) | |
853 | { | |
854 | struct srp_internal *i = to_srp_internal(t); | |
855 | ||
856 | transport_container_unregister(&i->t.host_attrs); | |
857 | transport_container_unregister(&i->rport_attr_cont); | |
858 | ||
859 | kfree(i); | |
860 | } | |
861 | EXPORT_SYMBOL_GPL(srp_release_transport); | |
862 | ||
863 | static __init int srp_transport_init(void) | |
864 | { | |
865 | int ret; | |
866 | ||
867 | ret = transport_class_register(&srp_host_class); | |
868 | if (ret) | |
869 | return ret; | |
870 | ret = transport_class_register(&srp_rport_class); | |
871 | if (ret) | |
872 | goto unregister_host_class; | |
873 | ||
874 | return 0; | |
875 | unregister_host_class: | |
876 | transport_class_unregister(&srp_host_class); | |
877 | return ret; | |
878 | } | |
879 | ||
880 | static void __exit srp_transport_exit(void) | |
881 | { | |
882 | transport_class_unregister(&srp_host_class); | |
883 | transport_class_unregister(&srp_rport_class); | |
884 | } | |
885 | ||
886 | MODULE_AUTHOR("FUJITA Tomonori"); | |
887 | MODULE_DESCRIPTION("SRP Transport Attributes"); | |
888 | MODULE_LICENSE("GPL"); | |
889 | ||
890 | module_init(srp_transport_init); | |
891 | module_exit(srp_transport_exit); |