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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 | ||
64 | /** | |
65 | * srp_tmo_valid() - check timeout combination validity | |
0c7f8218 BVA |
66 | * @reconnect_delay: Reconnect delay in seconds. |
67 | * @fast_io_fail_tmo: Fast I/O fail timeout in seconds. | |
68 | * @dev_loss_tmo: Device loss timeout in seconds. | |
29c17324 BVA |
69 | * |
70 | * The combination of the timeout parameters must be such that SCSI commands | |
71 | * are finished in a reasonable time. Hence do not allow the fast I/O fail | |
18cc4e02 BVA |
72 | * timeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT nor allow dev_loss_tmo to |
73 | * exceed that limit if failing I/O fast has been disabled. Furthermore, these | |
29c17324 | 74 | * parameters must be such that multipath can detect failed paths timely. |
8c64e453 | 75 | * Hence do not allow all three parameters to be disabled simultaneously. |
29c17324 | 76 | */ |
8c64e453 | 77 | int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, int dev_loss_tmo) |
29c17324 | 78 | { |
8c64e453 BVA |
79 | if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0) |
80 | return -EINVAL; | |
81 | if (reconnect_delay == 0) | |
29c17324 BVA |
82 | return -EINVAL; |
83 | if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT) | |
84 | return -EINVAL; | |
18cc4e02 BVA |
85 | if (fast_io_fail_tmo < 0 && |
86 | dev_loss_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT) | |
87 | return -EINVAL; | |
29c17324 BVA |
88 | if (dev_loss_tmo >= LONG_MAX / HZ) |
89 | return -EINVAL; | |
90 | if (fast_io_fail_tmo >= 0 && dev_loss_tmo >= 0 && | |
91 | fast_io_fail_tmo >= dev_loss_tmo) | |
92 | return -EINVAL; | |
93 | return 0; | |
94 | } | |
95 | EXPORT_SYMBOL_GPL(srp_tmo_valid); | |
09345f65 FT |
96 | |
97 | static int srp_host_setup(struct transport_container *tc, struct device *dev, | |
ee959b00 | 98 | struct device *cdev) |
09345f65 FT |
99 | { |
100 | struct Scsi_Host *shost = dev_to_shost(dev); | |
101 | struct srp_host_attrs *srp_host = to_srp_host_attrs(shost); | |
102 | ||
103 | atomic_set(&srp_host->next_port_id, 0); | |
104 | return 0; | |
105 | } | |
106 | ||
107 | static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup, | |
108 | NULL, NULL); | |
109 | ||
110 | static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports", | |
111 | NULL, NULL, NULL); | |
112 | ||
09345f65 FT |
113 | #define SRP_PID(p) \ |
114 | (p)->port_id[0], (p)->port_id[1], (p)->port_id[2], (p)->port_id[3], \ | |
115 | (p)->port_id[4], (p)->port_id[5], (p)->port_id[6], (p)->port_id[7], \ | |
116 | (p)->port_id[8], (p)->port_id[9], (p)->port_id[10], (p)->port_id[11], \ | |
117 | (p)->port_id[12], (p)->port_id[13], (p)->port_id[14], (p)->port_id[15] | |
118 | ||
119 | #define SRP_PID_FMT "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:" \ | |
120 | "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x" | |
121 | ||
122 | static ssize_t | |
ee959b00 TJ |
123 | show_srp_rport_id(struct device *dev, struct device_attribute *attr, |
124 | char *buf) | |
09345f65 | 125 | { |
ee959b00 | 126 | struct srp_rport *rport = transport_class_to_srp_rport(dev); |
09345f65 FT |
127 | return sprintf(buf, SRP_PID_FMT "\n", SRP_PID(rport)); |
128 | } | |
129 | ||
ee959b00 | 130 | static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL); |
09345f65 | 131 | |
aebd5e47 FT |
132 | static const struct { |
133 | u32 value; | |
134 | char *name; | |
135 | } srp_rport_role_names[] = { | |
136 | {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"}, | |
137 | {SRP_RPORT_ROLE_TARGET, "SRP Target"}, | |
138 | }; | |
139 | ||
140 | static ssize_t | |
ee959b00 TJ |
141 | show_srp_rport_roles(struct device *dev, struct device_attribute *attr, |
142 | char *buf) | |
aebd5e47 | 143 | { |
ee959b00 | 144 | struct srp_rport *rport = transport_class_to_srp_rport(dev); |
aebd5e47 FT |
145 | int i; |
146 | char *name = NULL; | |
147 | ||
148 | for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++) | |
149 | if (srp_rport_role_names[i].value == rport->roles) { | |
150 | name = srp_rport_role_names[i].name; | |
151 | break; | |
152 | } | |
153 | return sprintf(buf, "%s\n", name ? : "unknown"); | |
154 | } | |
155 | ||
ee959b00 | 156 | static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL); |
aebd5e47 | 157 | |
dc1bdbd9 BVA |
158 | static ssize_t store_srp_rport_delete(struct device *dev, |
159 | struct device_attribute *attr, | |
160 | const char *buf, size_t count) | |
161 | { | |
162 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
163 | struct Scsi_Host *shost = dev_to_shost(dev); | |
164 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
165 | ||
166 | if (i->f->rport_delete) { | |
167 | i->f->rport_delete(rport); | |
168 | return count; | |
169 | } else { | |
170 | return -ENOSYS; | |
171 | } | |
172 | } | |
173 | ||
174 | static DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete); | |
175 | ||
29c17324 BVA |
176 | static ssize_t show_srp_rport_state(struct device *dev, |
177 | struct device_attribute *attr, | |
178 | char *buf) | |
179 | { | |
180 | static const char *const state_name[] = { | |
181 | [SRP_RPORT_RUNNING] = "running", | |
182 | [SRP_RPORT_BLOCKED] = "blocked", | |
183 | [SRP_RPORT_FAIL_FAST] = "fail-fast", | |
184 | [SRP_RPORT_LOST] = "lost", | |
185 | }; | |
186 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
187 | enum srp_rport_state state = rport->state; | |
188 | ||
189 | return sprintf(buf, "%s\n", | |
190 | (unsigned)state < ARRAY_SIZE(state_name) ? | |
191 | state_name[state] : "???"); | |
192 | } | |
193 | ||
194 | static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL); | |
195 | ||
196 | static ssize_t srp_show_tmo(char *buf, int tmo) | |
197 | { | |
198 | return tmo >= 0 ? sprintf(buf, "%d\n", tmo) : sprintf(buf, "off\n"); | |
199 | } | |
200 | ||
201 | static int srp_parse_tmo(int *tmo, const char *buf) | |
202 | { | |
203 | int res = 0; | |
204 | ||
205 | if (strncmp(buf, "off", 3) != 0) | |
206 | res = kstrtoint(buf, 0, tmo); | |
207 | else | |
208 | *tmo = -1; | |
209 | ||
210 | return res; | |
211 | } | |
212 | ||
8c64e453 BVA |
213 | static ssize_t show_reconnect_delay(struct device *dev, |
214 | struct device_attribute *attr, char *buf) | |
215 | { | |
216 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
217 | ||
218 | return srp_show_tmo(buf, rport->reconnect_delay); | |
219 | } | |
220 | ||
221 | static ssize_t store_reconnect_delay(struct device *dev, | |
222 | struct device_attribute *attr, | |
223 | const char *buf, const size_t count) | |
224 | { | |
225 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
226 | int res, delay; | |
227 | ||
228 | res = srp_parse_tmo(&delay, buf); | |
229 | if (res) | |
230 | goto out; | |
231 | res = srp_tmo_valid(delay, rport->fast_io_fail_tmo, | |
232 | rport->dev_loss_tmo); | |
233 | if (res) | |
234 | goto out; | |
235 | ||
236 | if (rport->reconnect_delay <= 0 && delay > 0 && | |
237 | rport->state != SRP_RPORT_RUNNING) { | |
238 | queue_delayed_work(system_long_wq, &rport->reconnect_work, | |
239 | delay * HZ); | |
240 | } else if (delay <= 0) { | |
241 | cancel_delayed_work(&rport->reconnect_work); | |
242 | } | |
243 | rport->reconnect_delay = delay; | |
244 | res = count; | |
245 | ||
246 | out: | |
247 | return res; | |
248 | } | |
249 | ||
250 | static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay, | |
251 | store_reconnect_delay); | |
252 | ||
253 | static ssize_t show_failed_reconnects(struct device *dev, | |
254 | struct device_attribute *attr, char *buf) | |
255 | { | |
256 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
257 | ||
258 | return sprintf(buf, "%d\n", rport->failed_reconnects); | |
259 | } | |
260 | ||
261 | static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL); | |
262 | ||
29c17324 BVA |
263 | static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev, |
264 | struct device_attribute *attr, | |
265 | char *buf) | |
266 | { | |
267 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
268 | ||
269 | return srp_show_tmo(buf, rport->fast_io_fail_tmo); | |
270 | } | |
271 | ||
272 | static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev, | |
273 | struct device_attribute *attr, | |
274 | const char *buf, size_t count) | |
275 | { | |
276 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
277 | int res; | |
278 | int fast_io_fail_tmo; | |
279 | ||
280 | res = srp_parse_tmo(&fast_io_fail_tmo, buf); | |
281 | if (res) | |
282 | goto out; | |
8c64e453 BVA |
283 | res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo, |
284 | rport->dev_loss_tmo); | |
29c17324 BVA |
285 | if (res) |
286 | goto out; | |
287 | rport->fast_io_fail_tmo = fast_io_fail_tmo; | |
288 | res = count; | |
289 | ||
290 | out: | |
291 | return res; | |
292 | } | |
293 | ||
294 | static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR, | |
295 | show_srp_rport_fast_io_fail_tmo, | |
296 | store_srp_rport_fast_io_fail_tmo); | |
297 | ||
298 | static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev, | |
299 | struct device_attribute *attr, | |
300 | char *buf) | |
301 | { | |
302 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
303 | ||
304 | return srp_show_tmo(buf, rport->dev_loss_tmo); | |
305 | } | |
306 | ||
307 | static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev, | |
308 | struct device_attribute *attr, | |
309 | const char *buf, size_t count) | |
310 | { | |
311 | struct srp_rport *rport = transport_class_to_srp_rport(dev); | |
312 | int res; | |
313 | int dev_loss_tmo; | |
314 | ||
315 | res = srp_parse_tmo(&dev_loss_tmo, buf); | |
316 | if (res) | |
317 | goto out; | |
8c64e453 BVA |
318 | res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo, |
319 | dev_loss_tmo); | |
29c17324 BVA |
320 | if (res) |
321 | goto out; | |
322 | rport->dev_loss_tmo = dev_loss_tmo; | |
323 | res = count; | |
324 | ||
325 | out: | |
326 | return res; | |
327 | } | |
328 | ||
329 | static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR, | |
330 | show_srp_rport_dev_loss_tmo, | |
331 | store_srp_rport_dev_loss_tmo); | |
332 | ||
333 | static int srp_rport_set_state(struct srp_rport *rport, | |
334 | enum srp_rport_state new_state) | |
335 | { | |
336 | enum srp_rport_state old_state = rport->state; | |
337 | ||
338 | lockdep_assert_held(&rport->mutex); | |
339 | ||
340 | switch (new_state) { | |
341 | case SRP_RPORT_RUNNING: | |
342 | switch (old_state) { | |
343 | case SRP_RPORT_LOST: | |
344 | goto invalid; | |
345 | default: | |
346 | break; | |
347 | } | |
348 | break; | |
349 | case SRP_RPORT_BLOCKED: | |
350 | switch (old_state) { | |
351 | case SRP_RPORT_RUNNING: | |
352 | break; | |
353 | default: | |
354 | goto invalid; | |
355 | } | |
356 | break; | |
357 | case SRP_RPORT_FAIL_FAST: | |
358 | switch (old_state) { | |
359 | case SRP_RPORT_LOST: | |
360 | goto invalid; | |
361 | default: | |
362 | break; | |
363 | } | |
364 | break; | |
365 | case SRP_RPORT_LOST: | |
366 | break; | |
367 | } | |
368 | rport->state = new_state; | |
369 | return 0; | |
370 | ||
371 | invalid: | |
372 | return -EINVAL; | |
373 | } | |
374 | ||
8c64e453 BVA |
375 | /** |
376 | * srp_reconnect_work() - reconnect and schedule a new attempt if necessary | |
0c7f8218 | 377 | * @work: Work structure used for scheduling this operation. |
8c64e453 BVA |
378 | */ |
379 | static void srp_reconnect_work(struct work_struct *work) | |
380 | { | |
381 | struct srp_rport *rport = container_of(to_delayed_work(work), | |
382 | struct srp_rport, reconnect_work); | |
383 | struct Scsi_Host *shost = rport_to_shost(rport); | |
384 | int delay, res; | |
385 | ||
386 | res = srp_reconnect_rport(rport); | |
387 | if (res != 0) { | |
388 | shost_printk(KERN_ERR, shost, | |
389 | "reconnect attempt %d failed (%d)\n", | |
390 | ++rport->failed_reconnects, res); | |
391 | delay = rport->reconnect_delay * | |
392 | min(100, max(1, rport->failed_reconnects - 10)); | |
393 | if (delay > 0) | |
394 | queue_delayed_work(system_long_wq, | |
395 | &rport->reconnect_work, delay * HZ); | |
396 | } | |
397 | } | |
398 | ||
29c17324 BVA |
399 | static void __rport_fail_io_fast(struct srp_rport *rport) |
400 | { | |
401 | struct Scsi_Host *shost = rport_to_shost(rport); | |
402 | struct srp_internal *i; | |
403 | ||
404 | lockdep_assert_held(&rport->mutex); | |
405 | ||
406 | if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST)) | |
407 | return; | |
408 | scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE); | |
409 | ||
410 | /* Involve the LLD if possible to terminate all I/O on the rport. */ | |
411 | i = to_srp_internal(shost->transportt); | |
412 | if (i->f->terminate_rport_io) | |
413 | i->f->terminate_rport_io(rport); | |
414 | } | |
415 | ||
416 | /** | |
417 | * rport_fast_io_fail_timedout() - fast I/O failure timeout handler | |
0c7f8218 | 418 | * @work: Work structure used for scheduling this operation. |
29c17324 BVA |
419 | */ |
420 | static void rport_fast_io_fail_timedout(struct work_struct *work) | |
421 | { | |
422 | struct srp_rport *rport = container_of(to_delayed_work(work), | |
423 | struct srp_rport, fast_io_fail_work); | |
424 | struct Scsi_Host *shost = rport_to_shost(rport); | |
425 | ||
426 | pr_info("fast_io_fail_tmo expired for SRP %s / %s.\n", | |
427 | dev_name(&rport->dev), dev_name(&shost->shost_gendev)); | |
428 | ||
429 | mutex_lock(&rport->mutex); | |
430 | if (rport->state == SRP_RPORT_BLOCKED) | |
431 | __rport_fail_io_fast(rport); | |
432 | mutex_unlock(&rport->mutex); | |
433 | } | |
434 | ||
435 | /** | |
436 | * rport_dev_loss_timedout() - device loss timeout handler | |
0c7f8218 | 437 | * @work: Work structure used for scheduling this operation. |
29c17324 BVA |
438 | */ |
439 | static void rport_dev_loss_timedout(struct work_struct *work) | |
440 | { | |
441 | struct srp_rport *rport = container_of(to_delayed_work(work), | |
442 | struct srp_rport, dev_loss_work); | |
443 | struct Scsi_Host *shost = rport_to_shost(rport); | |
444 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
445 | ||
446 | pr_info("dev_loss_tmo expired for SRP %s / %s.\n", | |
447 | dev_name(&rport->dev), dev_name(&shost->shost_gendev)); | |
448 | ||
449 | mutex_lock(&rport->mutex); | |
450 | WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0); | |
451 | scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE); | |
452 | mutex_unlock(&rport->mutex); | |
453 | ||
454 | i->f->rport_delete(rport); | |
455 | } | |
456 | ||
457 | static void __srp_start_tl_fail_timers(struct srp_rport *rport) | |
458 | { | |
459 | struct Scsi_Host *shost = rport_to_shost(rport); | |
8c64e453 | 460 | int delay, fast_io_fail_tmo, dev_loss_tmo; |
29c17324 BVA |
461 | |
462 | lockdep_assert_held(&rport->mutex); | |
463 | ||
93079162 BVA |
464 | delay = rport->reconnect_delay; |
465 | fast_io_fail_tmo = rport->fast_io_fail_tmo; | |
466 | dev_loss_tmo = rport->dev_loss_tmo; | |
467 | pr_debug("%s current state: %d\n", dev_name(&shost->shost_gendev), | |
468 | rport->state); | |
29c17324 | 469 | |
93079162 BVA |
470 | if (rport->state == SRP_RPORT_LOST) |
471 | return; | |
472 | if (delay > 0) | |
473 | queue_delayed_work(system_long_wq, &rport->reconnect_work, | |
474 | 1UL * delay * HZ); | |
cd53eb68 BVA |
475 | if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) && |
476 | srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) { | |
93079162 BVA |
477 | pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev), |
478 | rport->state); | |
479 | scsi_target_block(&shost->shost_gendev); | |
480 | if (fast_io_fail_tmo >= 0) | |
8c64e453 | 481 | queue_delayed_work(system_long_wq, |
93079162 BVA |
482 | &rport->fast_io_fail_work, |
483 | 1UL * fast_io_fail_tmo * HZ); | |
484 | if (dev_loss_tmo >= 0) | |
485 | queue_delayed_work(system_long_wq, | |
486 | &rport->dev_loss_work, | |
487 | 1UL * dev_loss_tmo * HZ); | |
29c17324 BVA |
488 | } |
489 | } | |
490 | ||
491 | /** | |
492 | * srp_start_tl_fail_timers() - start the transport layer failure timers | |
0c7f8218 | 493 | * @rport: SRP target port. |
29c17324 BVA |
494 | * |
495 | * Start the transport layer fast I/O failure and device loss timers. Do not | |
496 | * modify a timer that was already started. | |
497 | */ | |
498 | void srp_start_tl_fail_timers(struct srp_rport *rport) | |
499 | { | |
500 | mutex_lock(&rport->mutex); | |
501 | __srp_start_tl_fail_timers(rport); | |
502 | mutex_unlock(&rport->mutex); | |
503 | } | |
504 | EXPORT_SYMBOL(srp_start_tl_fail_timers); | |
505 | ||
506 | /** | |
507 | * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn() | |
0c7f8218 | 508 | * @shost: SCSI host for which to count the number of scsi_request_fn() callers. |
29c17324 BVA |
509 | */ |
510 | static int scsi_request_fn_active(struct Scsi_Host *shost) | |
511 | { | |
512 | struct scsi_device *sdev; | |
513 | struct request_queue *q; | |
514 | int request_fn_active = 0; | |
515 | ||
516 | shost_for_each_device(sdev, shost) { | |
517 | q = sdev->request_queue; | |
518 | ||
519 | spin_lock_irq(q->queue_lock); | |
520 | request_fn_active += q->request_fn_active; | |
521 | spin_unlock_irq(q->queue_lock); | |
522 | } | |
523 | ||
524 | return request_fn_active; | |
525 | } | |
526 | ||
527 | /** | |
528 | * srp_reconnect_rport() - reconnect to an SRP target port | |
0c7f8218 | 529 | * @rport: SRP target port. |
29c17324 BVA |
530 | * |
531 | * Blocks SCSI command queueing before invoking reconnect() such that | |
532 | * queuecommand() won't be invoked concurrently with reconnect() from outside | |
533 | * the SCSI EH. This is important since a reconnect() implementation may | |
534 | * reallocate resources needed by queuecommand(). | |
535 | * | |
536 | * Notes: | |
537 | * - This function neither waits until outstanding requests have finished nor | |
538 | * tries to abort these. It is the responsibility of the reconnect() | |
539 | * function to finish outstanding commands before reconnecting to the target | |
540 | * port. | |
541 | * - It is the responsibility of the caller to ensure that the resources | |
542 | * reallocated by the reconnect() function won't be used while this function | |
543 | * is in progress. One possible strategy is to invoke this function from | |
544 | * the context of the SCSI EH thread only. Another possible strategy is to | |
545 | * lock the rport mutex inside each SCSI LLD callback that can be invoked by | |
546 | * the SCSI EH (the scsi_host_template.eh_*() functions and also the | |
547 | * scsi_host_template.queuecommand() function). | |
548 | */ | |
549 | int srp_reconnect_rport(struct srp_rport *rport) | |
550 | { | |
551 | struct Scsi_Host *shost = rport_to_shost(rport); | |
552 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
553 | struct scsi_device *sdev; | |
554 | int res; | |
555 | ||
556 | pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev)); | |
557 | ||
558 | res = mutex_lock_interruptible(&rport->mutex); | |
559 | if (res) | |
560 | goto out; | |
561 | scsi_target_block(&shost->shost_gendev); | |
562 | while (scsi_request_fn_active(shost)) | |
563 | msleep(20); | |
93079162 | 564 | res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV; |
29c17324 BVA |
565 | pr_debug("%s (state %d): transport.reconnect() returned %d\n", |
566 | dev_name(&shost->shost_gendev), rport->state, res); | |
567 | if (res == 0) { | |
568 | cancel_delayed_work(&rport->fast_io_fail_work); | |
569 | cancel_delayed_work(&rport->dev_loss_work); | |
570 | ||
8c64e453 | 571 | rport->failed_reconnects = 0; |
29c17324 BVA |
572 | srp_rport_set_state(rport, SRP_RPORT_RUNNING); |
573 | scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING); | |
574 | /* | |
575 | * If the SCSI error handler has offlined one or more devices, | |
576 | * invoking scsi_target_unblock() won't change the state of | |
577 | * these devices into running so do that explicitly. | |
578 | */ | |
579 | spin_lock_irq(shost->host_lock); | |
580 | __shost_for_each_device(sdev, shost) | |
581 | if (sdev->sdev_state == SDEV_OFFLINE) | |
582 | sdev->sdev_state = SDEV_RUNNING; | |
583 | spin_unlock_irq(shost->host_lock); | |
584 | } else if (rport->state == SRP_RPORT_RUNNING) { | |
585 | /* | |
18cc4e02 BVA |
586 | * srp_reconnect_rport() has been invoked with fast_io_fail |
587 | * and dev_loss off. Mark the port as failed and start the TL | |
588 | * failure timers if these had not yet been started. | |
29c17324 BVA |
589 | */ |
590 | __rport_fail_io_fast(rport); | |
591 | scsi_target_unblock(&shost->shost_gendev, | |
592 | SDEV_TRANSPORT_OFFLINE); | |
593 | __srp_start_tl_fail_timers(rport); | |
594 | } else if (rport->state != SRP_RPORT_BLOCKED) { | |
595 | scsi_target_unblock(&shost->shost_gendev, | |
596 | SDEV_TRANSPORT_OFFLINE); | |
597 | } | |
598 | mutex_unlock(&rport->mutex); | |
599 | ||
600 | out: | |
601 | return res; | |
602 | } | |
603 | EXPORT_SYMBOL(srp_reconnect_rport); | |
604 | ||
605 | /** | |
606 | * srp_timed_out() - SRP transport intercept of the SCSI timeout EH | |
0c7f8218 | 607 | * @scmd: SCSI command. |
29c17324 BVA |
608 | * |
609 | * If a timeout occurs while an rport is in the blocked state, ask the SCSI | |
610 | * EH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI core | |
611 | * handle the timeout (BLK_EH_NOT_HANDLED). | |
612 | * | |
613 | * Note: This function is called from soft-IRQ context and with the request | |
614 | * queue lock held. | |
615 | */ | |
616 | static enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd) | |
617 | { | |
618 | struct scsi_device *sdev = scmd->device; | |
619 | struct Scsi_Host *shost = sdev->host; | |
620 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
621 | ||
622 | pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev)); | |
623 | return i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ? | |
624 | BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED; | |
625 | } | |
626 | ||
09345f65 FT |
627 | static void srp_rport_release(struct device *dev) |
628 | { | |
629 | struct srp_rport *rport = dev_to_rport(dev); | |
630 | ||
631 | put_device(dev->parent); | |
632 | kfree(rport); | |
633 | } | |
634 | ||
635 | static int scsi_is_srp_rport(const struct device *dev) | |
636 | { | |
637 | return dev->release == srp_rport_release; | |
638 | } | |
639 | ||
640 | static int srp_rport_match(struct attribute_container *cont, | |
641 | struct device *dev) | |
642 | { | |
643 | struct Scsi_Host *shost; | |
644 | struct srp_internal *i; | |
645 | ||
646 | if (!scsi_is_srp_rport(dev)) | |
647 | return 0; | |
648 | ||
649 | shost = dev_to_shost(dev->parent); | |
650 | if (!shost->transportt) | |
651 | return 0; | |
652 | if (shost->transportt->host_attrs.ac.class != &srp_host_class.class) | |
653 | return 0; | |
654 | ||
655 | i = to_srp_internal(shost->transportt); | |
656 | return &i->rport_attr_cont.ac == cont; | |
657 | } | |
658 | ||
659 | static int srp_host_match(struct attribute_container *cont, struct device *dev) | |
660 | { | |
661 | struct Scsi_Host *shost; | |
662 | struct srp_internal *i; | |
663 | ||
664 | if (!scsi_is_host_device(dev)) | |
665 | return 0; | |
666 | ||
667 | shost = dev_to_shost(dev); | |
668 | if (!shost->transportt) | |
669 | return 0; | |
670 | if (shost->transportt->host_attrs.ac.class != &srp_host_class.class) | |
671 | return 0; | |
672 | ||
673 | i = to_srp_internal(shost->transportt); | |
674 | return &i->t.host_attrs.ac == cont; | |
675 | } | |
676 | ||
9dd69a60 BVA |
677 | /** |
678 | * srp_rport_get() - increment rport reference count | |
0c7f8218 | 679 | * @rport: SRP target port. |
9dd69a60 BVA |
680 | */ |
681 | void srp_rport_get(struct srp_rport *rport) | |
682 | { | |
683 | get_device(&rport->dev); | |
684 | } | |
685 | EXPORT_SYMBOL(srp_rport_get); | |
686 | ||
687 | /** | |
688 | * srp_rport_put() - decrement rport reference count | |
0c7f8218 | 689 | * @rport: SRP target port. |
9dd69a60 BVA |
690 | */ |
691 | void srp_rport_put(struct srp_rport *rport) | |
692 | { | |
693 | put_device(&rport->dev); | |
694 | } | |
695 | EXPORT_SYMBOL(srp_rport_put); | |
696 | ||
09345f65 FT |
697 | /** |
698 | * srp_rport_add - add a SRP remote port to the device hierarchy | |
09345f65 FT |
699 | * @shost: scsi host the remote port is connected to. |
700 | * @ids: The port id for the remote port. | |
701 | * | |
dc8875e1 | 702 | * Publishes a port to the rest of the system. |
09345f65 FT |
703 | */ |
704 | struct srp_rport *srp_rport_add(struct Scsi_Host *shost, | |
705 | struct srp_rport_identifiers *ids) | |
706 | { | |
707 | struct srp_rport *rport; | |
708 | struct device *parent = &shost->shost_gendev; | |
29c17324 | 709 | struct srp_internal *i = to_srp_internal(shost->transportt); |
09345f65 FT |
710 | int id, ret; |
711 | ||
712 | rport = kzalloc(sizeof(*rport), GFP_KERNEL); | |
713 | if (!rport) | |
714 | return ERR_PTR(-ENOMEM); | |
715 | ||
29c17324 BVA |
716 | mutex_init(&rport->mutex); |
717 | ||
09345f65 FT |
718 | device_initialize(&rport->dev); |
719 | ||
720 | rport->dev.parent = get_device(parent); | |
721 | rport->dev.release = srp_rport_release; | |
722 | ||
723 | memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id)); | |
aebd5e47 | 724 | rport->roles = ids->roles; |
09345f65 | 725 | |
8c64e453 BVA |
726 | if (i->f->reconnect) |
727 | rport->reconnect_delay = i->f->reconnect_delay ? | |
728 | *i->f->reconnect_delay : 10; | |
729 | INIT_DELAYED_WORK(&rport->reconnect_work, srp_reconnect_work); | |
29c17324 BVA |
730 | rport->fast_io_fail_tmo = i->f->fast_io_fail_tmo ? |
731 | *i->f->fast_io_fail_tmo : 15; | |
732 | rport->dev_loss_tmo = i->f->dev_loss_tmo ? *i->f->dev_loss_tmo : 60; | |
733 | INIT_DELAYED_WORK(&rport->fast_io_fail_work, | |
734 | rport_fast_io_fail_timedout); | |
735 | INIT_DELAYED_WORK(&rport->dev_loss_work, rport_dev_loss_timedout); | |
736 | ||
09345f65 | 737 | id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id); |
71610f55 | 738 | dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id); |
09345f65 FT |
739 | |
740 | transport_setup_device(&rport->dev); | |
741 | ||
742 | ret = device_add(&rport->dev); | |
743 | if (ret) { | |
744 | transport_destroy_device(&rport->dev); | |
745 | put_device(&rport->dev); | |
746 | return ERR_PTR(ret); | |
747 | } | |
748 | ||
749 | transport_add_device(&rport->dev); | |
750 | transport_configure_device(&rport->dev); | |
751 | ||
752 | return rport; | |
753 | } | |
754 | EXPORT_SYMBOL_GPL(srp_rport_add); | |
755 | ||
756 | /** | |
eb44820c RL |
757 | * srp_rport_del - remove a SRP remote port |
758 | * @rport: SRP remote port to remove | |
09345f65 FT |
759 | * |
760 | * Removes the specified SRP remote port. | |
761 | */ | |
762 | void srp_rport_del(struct srp_rport *rport) | |
763 | { | |
764 | struct device *dev = &rport->dev; | |
62fe8826 | 765 | |
09345f65 FT |
766 | transport_remove_device(dev); |
767 | device_del(dev); | |
768 | transport_destroy_device(dev); | |
29c17324 | 769 | |
09345f65 FT |
770 | put_device(dev); |
771 | } | |
772 | EXPORT_SYMBOL_GPL(srp_rport_del); | |
773 | ||
774 | static int do_srp_rport_del(struct device *dev, void *data) | |
775 | { | |
91183344 DD |
776 | if (scsi_is_srp_rport(dev)) |
777 | srp_rport_del(dev_to_rport(dev)); | |
09345f65 FT |
778 | return 0; |
779 | } | |
780 | ||
781 | /** | |
eb44820c | 782 | * srp_remove_host - tear down a Scsi_Host's SRP data structures |
09345f65 FT |
783 | * @shost: Scsi Host that is torn down |
784 | * | |
785 | * Removes all SRP remote ports for a given Scsi_Host. | |
786 | * Must be called just before scsi_remove_host for SRP HBAs. | |
787 | */ | |
788 | void srp_remove_host(struct Scsi_Host *shost) | |
789 | { | |
790 | device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del); | |
791 | } | |
792 | EXPORT_SYMBOL_GPL(srp_remove_host); | |
793 | ||
93079162 BVA |
794 | /** |
795 | * srp_stop_rport_timers - stop the transport layer recovery timers | |
67513605 | 796 | * @rport: SRP remote port for which to stop the timers. |
93079162 BVA |
797 | * |
798 | * Must be called after srp_remove_host() and scsi_remove_host(). The caller | |
799 | * must hold a reference on the rport (rport->dev) and on the SCSI host | |
800 | * (rport->dev.parent). | |
801 | */ | |
802 | void srp_stop_rport_timers(struct srp_rport *rport) | |
803 | { | |
804 | mutex_lock(&rport->mutex); | |
805 | if (rport->state == SRP_RPORT_BLOCKED) | |
806 | __rport_fail_io_fast(rport); | |
807 | srp_rport_set_state(rport, SRP_RPORT_LOST); | |
808 | mutex_unlock(&rport->mutex); | |
809 | ||
810 | cancel_delayed_work_sync(&rport->reconnect_work); | |
811 | cancel_delayed_work_sync(&rport->fast_io_fail_work); | |
812 | cancel_delayed_work_sync(&rport->dev_loss_work); | |
813 | } | |
814 | EXPORT_SYMBOL_GPL(srp_stop_rport_timers); | |
815 | ||
bfb74374 FT |
816 | static int srp_tsk_mgmt_response(struct Scsi_Host *shost, u64 nexus, u64 tm_id, |
817 | int result) | |
62fe8826 FT |
818 | { |
819 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
bfb74374 FT |
820 | return i->f->tsk_mgmt_response(shost, nexus, tm_id, result); |
821 | } | |
822 | ||
823 | static int srp_it_nexus_response(struct Scsi_Host *shost, u64 nexus, int result) | |
824 | { | |
825 | struct srp_internal *i = to_srp_internal(shost->transportt); | |
826 | return i->f->it_nexus_response(shost, nexus, result); | |
62fe8826 FT |
827 | } |
828 | ||
09345f65 | 829 | /** |
eb44820c | 830 | * srp_attach_transport - instantiate SRP transport template |
09345f65 FT |
831 | * @ft: SRP transport class function template |
832 | */ | |
833 | struct scsi_transport_template * | |
834 | srp_attach_transport(struct srp_function_template *ft) | |
835 | { | |
836 | int count; | |
837 | struct srp_internal *i; | |
838 | ||
839 | i = kzalloc(sizeof(*i), GFP_KERNEL); | |
840 | if (!i) | |
841 | return NULL; | |
842 | ||
29c17324 BVA |
843 | i->t.eh_timed_out = srp_timed_out; |
844 | ||
bfb74374 | 845 | i->t.tsk_mgmt_response = srp_tsk_mgmt_response; |
62fe8826 FT |
846 | i->t.it_nexus_response = srp_it_nexus_response; |
847 | ||
09345f65 FT |
848 | i->t.host_size = sizeof(struct srp_host_attrs); |
849 | i->t.host_attrs.ac.attrs = &i->host_attrs[0]; | |
850 | i->t.host_attrs.ac.class = &srp_host_class.class; | |
851 | i->t.host_attrs.ac.match = srp_host_match; | |
852 | i->host_attrs[0] = NULL; | |
853 | transport_container_register(&i->t.host_attrs); | |
854 | ||
855 | i->rport_attr_cont.ac.attrs = &i->rport_attrs[0]; | |
856 | i->rport_attr_cont.ac.class = &srp_rport_class.class; | |
857 | i->rport_attr_cont.ac.match = srp_rport_match; | |
09345f65 FT |
858 | |
859 | count = 0; | |
9134a855 BVA |
860 | i->rport_attrs[count++] = &dev_attr_port_id; |
861 | i->rport_attrs[count++] = &dev_attr_roles; | |
29c17324 BVA |
862 | if (ft->has_rport_state) { |
863 | i->rport_attrs[count++] = &dev_attr_state; | |
864 | i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo; | |
865 | i->rport_attrs[count++] = &dev_attr_dev_loss_tmo; | |
866 | } | |
8c64e453 BVA |
867 | if (ft->reconnect) { |
868 | i->rport_attrs[count++] = &dev_attr_reconnect_delay; | |
869 | i->rport_attrs[count++] = &dev_attr_failed_reconnects; | |
870 | } | |
dc1bdbd9 BVA |
871 | if (ft->rport_delete) |
872 | i->rport_attrs[count++] = &dev_attr_delete; | |
9134a855 BVA |
873 | i->rport_attrs[count++] = NULL; |
874 | BUG_ON(count > ARRAY_SIZE(i->rport_attrs)); | |
09345f65 | 875 | |
ac9be30e BVA |
876 | transport_container_register(&i->rport_attr_cont); |
877 | ||
09345f65 FT |
878 | i->f = ft; |
879 | ||
880 | return &i->t; | |
881 | } | |
882 | EXPORT_SYMBOL_GPL(srp_attach_transport); | |
883 | ||
884 | /** | |
eb44820c | 885 | * srp_release_transport - release SRP transport template instance |
09345f65 FT |
886 | * @t: transport template instance |
887 | */ | |
888 | void srp_release_transport(struct scsi_transport_template *t) | |
889 | { | |
890 | struct srp_internal *i = to_srp_internal(t); | |
891 | ||
892 | transport_container_unregister(&i->t.host_attrs); | |
893 | transport_container_unregister(&i->rport_attr_cont); | |
894 | ||
895 | kfree(i); | |
896 | } | |
897 | EXPORT_SYMBOL_GPL(srp_release_transport); | |
898 | ||
899 | static __init int srp_transport_init(void) | |
900 | { | |
901 | int ret; | |
902 | ||
903 | ret = transport_class_register(&srp_host_class); | |
904 | if (ret) | |
905 | return ret; | |
906 | ret = transport_class_register(&srp_rport_class); | |
907 | if (ret) | |
908 | goto unregister_host_class; | |
909 | ||
910 | return 0; | |
911 | unregister_host_class: | |
912 | transport_class_unregister(&srp_host_class); | |
913 | return ret; | |
914 | } | |
915 | ||
916 | static void __exit srp_transport_exit(void) | |
917 | { | |
918 | transport_class_unregister(&srp_host_class); | |
919 | transport_class_unregister(&srp_rport_class); | |
920 | } | |
921 | ||
922 | MODULE_AUTHOR("FUJITA Tomonori"); | |
923 | MODULE_DESCRIPTION("SRP Transport Attributes"); | |
924 | MODULE_LICENSE("GPL"); | |
925 | ||
926 | module_init(srp_transport_init); | |
927 | module_exit(srp_transport_exit); |