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Merge branch 'pm-cpuidle'
[linux-block.git] / drivers / staging / lustre / lustre / ptlrpc / pinger.c
CommitLineData
d7e09d03
PT		 1/*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19 *
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26/*
27 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 *
30 * Copyright (c) 2011, 2012, Intel Corporation.
31 */
32/*
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
35 *
36 * lustre/ptlrpc/pinger.c
37 *
38 * Portal-RPC reconnection and replay operations, for use in recovery.
39 */
40
41#define DEBUG_SUBSYSTEM S_RPC
42
43#include <obd_support.h>
44#include <obd_class.h>
45#include "ptlrpc_internal.h"
46
47static int suppress_pings;
48CFS_MODULE_PARM(suppress_pings, "i", int, 0644, "Suppress pings");
49
50struct mutex pinger_mutex;
51static LIST_HEAD(pinger_imports);
52static struct list_head timeout_list = LIST_HEAD_INIT(timeout_list);
53
7d46a21a 54int ptlrpc_pinger_suppress_pings(void)
d7e09d03
PT		 55{
56 return suppress_pings;
57}
58EXPORT_SYMBOL(ptlrpc_pinger_suppress_pings);
59
60struct ptlrpc_request *
61ptlrpc_prep_ping(struct obd_import *imp)
62{
63 struct ptlrpc_request *req;
64
65 req = ptlrpc_request_alloc_pack(imp, &RQF_OBD_PING,
66 LUSTRE_OBD_VERSION, OBD_PING);
67 if (req) {
68 ptlrpc_request_set_replen(req);
69 req->rq_no_resend = req->rq_no_delay = 1;
70 }
71 return req;
72}
73
74int ptlrpc_obd_ping(struct obd_device *obd)
75{
76 int rc;
77 struct ptlrpc_request *req;
d7e09d03
PT		 78
79 req = ptlrpc_prep_ping(obd->u.cli.cl_import);
80 if (req == NULL)
0a3bdb00 81 return -ENOMEM;
d7e09d03
PT		 82
83 req->rq_send_state = LUSTRE_IMP_FULL;
84
85 rc = ptlrpc_queue_wait(req);
86
87 ptlrpc_req_finished(req);
88
0a3bdb00 89 return rc;
d7e09d03
PT		 90}
91EXPORT_SYMBOL(ptlrpc_obd_ping);
92
93int ptlrpc_ping(struct obd_import *imp)
94{
95 struct ptlrpc_request *req;
d7e09d03
PT		 96
97 req = ptlrpc_prep_ping(imp);
98 if (req == NULL) {
99 CERROR("OOM trying to ping %s->%s\n",
100 imp->imp_obd->obd_uuid.uuid,
101 obd2cli_tgt(imp->imp_obd));
0a3bdb00 102 return -ENOMEM;
d7e09d03
PT		 103 }
104
105 DEBUG_REQ(D_INFO, req, "pinging %s->%s",
106 imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
107 ptlrpcd_add_req(req, PDL_POLICY_ROUND, -1);
108
0a3bdb00 109 return 0;
d7e09d03
PT		 110}
111
112void ptlrpc_update_next_ping(struct obd_import *imp, int soon)
113{
114 int time = soon ? PING_INTERVAL_SHORT : PING_INTERVAL;
115 if (imp->imp_state == LUSTRE_IMP_DISCON) {
116 int dtime = max_t(int, CONNECTION_SWITCH_MIN,
117 AT_OFF ? 0 :
118 at_get(&imp->imp_at.iat_net_latency));
119 time = min(time, dtime);
120 }
121 imp->imp_next_ping = cfs_time_shift(time);
122}
123
124void ptlrpc_ping_import_soon(struct obd_import *imp)
125{
126 imp->imp_next_ping = cfs_time_current();
127}
128
129static inline int imp_is_deactive(struct obd_import *imp)
130{
131 return (imp->imp_deactive ||
132 OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_IMP_DEACTIVE));
133}
134
135static inline int ptlrpc_next_reconnect(struct obd_import *imp)
136{
137 if (imp->imp_server_timeout)
138 return cfs_time_shift(obd_timeout / 2);
139 else
140 return cfs_time_shift(obd_timeout);
141}
142
143static atomic_t suspend_timeouts = ATOMIC_INIT(0);
144static cfs_time_t suspend_wakeup_time = 0;
145
146cfs_duration_t pinger_check_timeout(cfs_time_t time)
147{
148 struct timeout_item *item;
149 cfs_time_t timeout = PING_INTERVAL;
150
151 /* The timeout list is a increase order sorted list */
152 mutex_lock(&pinger_mutex);
153 list_for_each_entry(item, &timeout_list, ti_chain) {
154 int ti_timeout = item->ti_timeout;
155 if (timeout > ti_timeout)
156 timeout = ti_timeout;
157 break;
158 }
159 mutex_unlock(&pinger_mutex);
160
161 return cfs_time_sub(cfs_time_add(time, cfs_time_seconds(timeout)),
162 cfs_time_current());
163}
164
165static wait_queue_head_t suspend_timeouts_waitq;
166
167cfs_time_t ptlrpc_suspend_wakeup_time(void)
168{
169 return suspend_wakeup_time;
170}
171
172void ptlrpc_deactivate_timeouts(struct obd_import *imp)
173{
174 /*XXX: disabled for now, will be replaced by adaptive timeouts */
175#if 0
176 if (imp->imp_no_timeout)
177 return;
178 imp->imp_no_timeout = 1;
179 atomic_inc(&suspend_timeouts);
180 CDEBUG(D_HA|D_WARNING, "deactivate timeouts %u\n",
181 atomic_read(&suspend_timeouts));
182#endif
183}
184
185void ptlrpc_activate_timeouts(struct obd_import *imp)
186{
187 /*XXX: disabled for now, will be replaced by adaptive timeouts */
188#if 0
189 if (!imp->imp_no_timeout)
190 return;
191 imp->imp_no_timeout = 0;
192 LASSERT(atomic_read(&suspend_timeouts) > 0);
193 if (atomic_dec_and_test(&suspend_timeouts)) {
194 suspend_wakeup_time = cfs_time_current();
195 wake_up(&suspend_timeouts_waitq);
196 }
197 CDEBUG(D_HA|D_WARNING, "activate timeouts %u\n",
198 atomic_read(&suspend_timeouts));
199#endif
200}
201
202int ptlrpc_check_suspend(void)
203{
204 if (atomic_read(&suspend_timeouts))
205 return 1;
206 return 0;
207}
208
209int ptlrpc_check_and_wait_suspend(struct ptlrpc_request *req)
210{
211 struct l_wait_info lwi;
212
213 if (atomic_read(&suspend_timeouts)) {
214 DEBUG_REQ(D_NET, req, "-- suspend %d regular timeout",
215 atomic_read(&suspend_timeouts));
216 lwi = LWI_INTR(NULL, NULL);
217 l_wait_event(suspend_timeouts_waitq,
218 atomic_read(&suspend_timeouts) == 0, &lwi);
219 DEBUG_REQ(D_NET, req, "-- recharge regular timeout");
220 return 1;
221 }
222 return 0;
223}
224
225
226static bool ir_up;
227
228void ptlrpc_pinger_ir_up(void)
229{
230 CDEBUG(D_HA, "IR up\n");
231 ir_up = true;
232}
233EXPORT_SYMBOL(ptlrpc_pinger_ir_up);
234
235void ptlrpc_pinger_ir_down(void)
236{
237 CDEBUG(D_HA, "IR down\n");
238 ir_up = false;
239}
240EXPORT_SYMBOL(ptlrpc_pinger_ir_down);
241
242static void ptlrpc_pinger_process_import(struct obd_import *imp,
243 unsigned long this_ping)
244{
245 int level;
246 int force;
247 int force_next;
248 int suppress;
249
250 spin_lock(&imp->imp_lock);
251
252 level = imp->imp_state;
253 force = imp->imp_force_verify;
254 force_next = imp->imp_force_next_verify;
255 /*
256 * This will be used below only if the import is "FULL".
257 */
258 suppress = ir_up && OCD_HAS_FLAG(&imp->imp_connect_data, PINGLESS);
259
260 imp->imp_force_verify = 0;
261
262 if (cfs_time_aftereq(imp->imp_next_ping - 5 * CFS_TICK, this_ping) &&
263 !force) {
264 spin_unlock(&imp->imp_lock);
265 return;
266 }
267
268 imp->imp_force_next_verify = 0;
269
270 spin_unlock(&imp->imp_lock);
271
272 CDEBUG(level == LUSTRE_IMP_FULL ? D_INFO : D_HA, "%s->%s: level %s/%u "
273 "force %u force_next %u deactive %u pingable %u suppress %u\n",
274 imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd),
275 ptlrpc_import_state_name(level), level, force, force_next,
276 imp->imp_deactive, imp->imp_pingable, suppress);
277
278 if (level == LUSTRE_IMP_DISCON && !imp_is_deactive(imp)) {
279 /* wait for a while before trying recovery again */
280 imp->imp_next_ping = ptlrpc_next_reconnect(imp);
281 if (!imp->imp_no_pinger_recover)
282 ptlrpc_initiate_recovery(imp);
283 } else if (level != LUSTRE_IMP_FULL ||
284 imp->imp_obd->obd_no_recov ||
285 imp_is_deactive(imp)) {
286 CDEBUG(D_HA, "%s->%s: not pinging (in recovery "
287 "or recovery disabled: %s)\n",
288 imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd),
289 ptlrpc_import_state_name(level));
290 } else if ((imp->imp_pingable && !suppress) || force_next || force) {
291 ptlrpc_ping(imp);
292 }
293}
294
295static int ptlrpc_pinger_main(void *arg)
296{
297 struct ptlrpc_thread *thread = (struct ptlrpc_thread *)arg;
d7e09d03
PT		 298
299 /* Record that the thread is running */
300 thread_set_flags(thread, SVC_RUNNING);
301 wake_up(&thread->t_ctl_waitq);
302
303 /* And now, loop forever, pinging as needed. */
304 while (1) {
305 cfs_time_t this_ping = cfs_time_current();
306 struct l_wait_info lwi;
307 cfs_duration_t time_to_next_wake;
308 struct timeout_item *item;
309 struct list_head *iter;
310
311 mutex_lock(&pinger_mutex);
312 list_for_each_entry(item, &timeout_list, ti_chain) {
313 item->ti_cb(item, item->ti_cb_data);
314 }
315 list_for_each(iter, &pinger_imports) {
316 struct obd_import *imp =
317 list_entry(iter, struct obd_import,
318 imp_pinger_chain);
319
320 ptlrpc_pinger_process_import(imp, this_ping);
321 /* obd_timeout might have changed */
322 if (imp->imp_pingable && imp->imp_next_ping &&
323 cfs_time_after(imp->imp_next_ping,
324 cfs_time_add(this_ping,
325 cfs_time_seconds(PING_INTERVAL))))
326 ptlrpc_update_next_ping(imp, 0);
327 }
328 mutex_unlock(&pinger_mutex);
329 /* update memory usage info */
330 obd_update_maxusage();
331
332 /* Wait until the next ping time, or until we're stopped. */
333 time_to_next_wake = pinger_check_timeout(this_ping);
334 /* The ping sent by ptlrpc_send_rpc may get sent out
335 say .01 second after this.
336 ptlrpc_pinger_sending_on_import will then set the
337 next ping time to next_ping + .01 sec, which means
338 we will SKIP the next ping at next_ping, and the
339 ping will get sent 2 timeouts from now! Beware. */
340 CDEBUG(D_INFO, "next wakeup in "CFS_DURATION_T" ("
341 CFS_TIME_T")\n", time_to_next_wake,
342 cfs_time_add(this_ping,cfs_time_seconds(PING_INTERVAL)));
343 if (time_to_next_wake > 0) {
344 lwi = LWI_TIMEOUT(max_t(cfs_duration_t,
345 time_to_next_wake,
346 cfs_time_seconds(1)),
347 NULL, NULL);
348 l_wait_event(thread->t_ctl_waitq,
349 thread_is_stopping(thread) ||
350 thread_is_event(thread),
351 &lwi);
352 if (thread_test_and_clear_flags(thread, SVC_STOPPING)) {
d7e09d03
PT		 353 break;
354 } else {
355 /* woken after adding import to reset timer */
356 thread_test_and_clear_flags(thread, SVC_EVENT);
357 }
358 }
359 }
360
361 thread_set_flags(thread, SVC_STOPPED);
362 wake_up(&thread->t_ctl_waitq);
363
364 CDEBUG(D_NET, "pinger thread exiting, process %d\n", current_pid());
365 return 0;
366}
367
20802057 368static struct ptlrpc_thread pinger_thread;
d7e09d03
PT		 369
370int ptlrpc_start_pinger(void)
371{
372 struct l_wait_info lwi = { 0 };
373 int rc;
d7e09d03 374
20802057
DE		 375 if (!thread_is_init(&pinger_thread) &&
376 !thread_is_stopped(&pinger_thread))
0a3bdb00 377 return -EALREADY;
d7e09d03 378
20802057 379 init_waitqueue_head(&pinger_thread.t_ctl_waitq);
d7e09d03
PT		 380 init_waitqueue_head(&suspend_timeouts_waitq);
381
20802057 382 strcpy(pinger_thread.t_name, "ll_ping");
d7e09d03
PT		 383
384 /* CLONE_VM and CLONE_FILES just avoid a needless copy, because we
385 * just drop the VM and FILES in cfs_daemonize_ctxt() right away. */
386 rc = PTR_ERR(kthread_run(ptlrpc_pinger_main,
20802057 387 &pinger_thread, pinger_thread.t_name));
d7e09d03
PT		 388 if (IS_ERR_VALUE(rc)) {
389 CERROR("cannot start thread: %d\n", rc);
0a3bdb00 390 return rc;
d7e09d03 391 }
20802057
DE		 392 l_wait_event(pinger_thread.t_ctl_waitq,
393 thread_is_running(&pinger_thread), &lwi);
d7e09d03
PT		 394
395 if (suppress_pings)
396 CWARN("Pings will be suppressed at the request of the "
397 "administrator. The configuration shall meet the "
398 "additional requirements described in the manual. "
399 "(Search for the \"suppress_pings\" kernel module "
400 "parameter.)\n");
401
0a3bdb00 402 return 0;
d7e09d03
PT		 403}
404
405int ptlrpc_pinger_remove_timeouts(void);
406
407int ptlrpc_stop_pinger(void)
408{
409 struct l_wait_info lwi = { 0 };
410 int rc = 0;
d7e09d03 411
20802057
DE		 412 if (!thread_is_init(&pinger_thread) &&
413 !thread_is_stopped(&pinger_thread))
0a3bdb00 414 return -EALREADY;
d7e09d03
PT		 415
416 ptlrpc_pinger_remove_timeouts();
20802057
DE		 417 thread_set_flags(&pinger_thread, SVC_STOPPING);
418 wake_up(&pinger_thread.t_ctl_waitq);
d7e09d03 419
20802057
DE		 420 l_wait_event(pinger_thread.t_ctl_waitq,
421 thread_is_stopped(&pinger_thread), &lwi);
d7e09d03 422
0a3bdb00 423 return rc;
d7e09d03
PT		 424}
425
426void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
427{
428 ptlrpc_update_next_ping(imp, 0);
429}
430EXPORT_SYMBOL(ptlrpc_pinger_sending_on_import);
431
432void ptlrpc_pinger_commit_expected(struct obd_import *imp)
433{
434 ptlrpc_update_next_ping(imp, 1);
435 LASSERT(spin_is_locked(&imp->imp_lock));
436 /*
437 * Avoid reading stale imp_connect_data. When not sure if pings are
438 * expected or not on next connection, we assume they are not and force
439 * one anyway to guarantee the chance of updating
440 * imp_peer_committed_transno.
441 */
442 if (imp->imp_state != LUSTRE_IMP_FULL ||
443 OCD_HAS_FLAG(&imp->imp_connect_data, PINGLESS))
444 imp->imp_force_next_verify = 1;
445}
446
447int ptlrpc_pinger_add_import(struct obd_import *imp)
448{
d7e09d03 449 if (!list_empty(&imp->imp_pinger_chain))
0a3bdb00 450 return -EALREADY;
d7e09d03
PT		 451
452 mutex_lock(&pinger_mutex);
453 CDEBUG(D_HA, "adding pingable import %s->%s\n",
454 imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
455 /* if we add to pinger we want recovery on this import */
456 imp->imp_obd->obd_no_recov = 0;
457 ptlrpc_update_next_ping(imp, 0);
458 /* XXX sort, blah blah */
459 list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
460 class_import_get(imp);
461
462 ptlrpc_pinger_wake_up();
463 mutex_unlock(&pinger_mutex);
464
0a3bdb00 465 return 0;
d7e09d03
PT		 466}
467EXPORT_SYMBOL(ptlrpc_pinger_add_import);
468
469int ptlrpc_pinger_del_import(struct obd_import *imp)
470{
d7e09d03 471 if (list_empty(&imp->imp_pinger_chain))
0a3bdb00 472 return -ENOENT;
d7e09d03
PT		 473
474 mutex_lock(&pinger_mutex);
475 list_del_init(&imp->imp_pinger_chain);
476 CDEBUG(D_HA, "removing pingable import %s->%s\n",
477 imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
478 /* if we remove from pinger we don't want recovery on this import */
479 imp->imp_obd->obd_no_recov = 1;
480 class_import_put(imp);
481 mutex_unlock(&pinger_mutex);
0a3bdb00 482 return 0;
d7e09d03
PT		 483}
484EXPORT_SYMBOL(ptlrpc_pinger_del_import);
485
486/**
487 * Register a timeout callback to the pinger list, and the callback will
488 * be called when timeout happens.
489 */
490struct timeout_item* ptlrpc_new_timeout(int time, enum timeout_event event,
491 timeout_cb_t cb, void *data)
492{
493 struct timeout_item *ti;
494
495 OBD_ALLOC_PTR(ti);
496 if (!ti)
497 return(NULL);
498
499 INIT_LIST_HEAD(&ti->ti_obd_list);
500 INIT_LIST_HEAD(&ti->ti_chain);
501 ti->ti_timeout = time;
502 ti->ti_event = event;
503 ti->ti_cb = cb;
504 ti->ti_cb_data = data;
505
506 return ti;
507}
508
509/**
510 * Register timeout event on the the pinger thread.
511 * Note: the timeout list is an sorted list with increased timeout value.
512 */
513static struct timeout_item*
514ptlrpc_pinger_register_timeout(int time, enum timeout_event event,
515 timeout_cb_t cb, void *data)
516{
517 struct timeout_item *item, *tmp;
518
519 LASSERT(mutex_is_locked(&pinger_mutex));
520
521 list_for_each_entry(item, &timeout_list, ti_chain)
522 if (item->ti_event == event)
523 goto out;
524
525 item = ptlrpc_new_timeout(time, event, cb, data);
526 if (item) {
527 list_for_each_entry_reverse(tmp, &timeout_list, ti_chain) {
528 if (tmp->ti_timeout < time) {
529 list_add(&item->ti_chain, &tmp->ti_chain);
530 goto out;
531 }
532 }
533 list_add(&item->ti_chain, &timeout_list);
534 }
535out:
536 return item;
537}
538
539/* Add a client_obd to the timeout event list, when timeout(@time)
540 * happens, the callback(@cb) will be called.
541 */
542int ptlrpc_add_timeout_client(int time, enum timeout_event event,
543 timeout_cb_t cb, void *data,
544 struct list_head *obd_list)
545{
546 struct timeout_item *ti;
547
548 mutex_lock(&pinger_mutex);
549 ti = ptlrpc_pinger_register_timeout(time, event, cb, data);
550 if (!ti) {
551 mutex_unlock(&pinger_mutex);
552 return (-EINVAL);
553 }
554 list_add(obd_list, &ti->ti_obd_list);
555 mutex_unlock(&pinger_mutex);
556 return 0;
557}
558EXPORT_SYMBOL(ptlrpc_add_timeout_client);
559
560int ptlrpc_del_timeout_client(struct list_head *obd_list,
561 enum timeout_event event)
562{
563 struct timeout_item *ti = NULL, *item;
564
565 if (list_empty(obd_list))
566 return 0;
567 mutex_lock(&pinger_mutex);
568 list_del_init(obd_list);
569 /**
570 * If there are no obd attached to the timeout event
571 * list, remove this timeout event from the pinger
572 */
573 list_for_each_entry(item, &timeout_list, ti_chain) {
574 if (item->ti_event == event) {
575 ti = item;
576 break;
577 }
578 }
579 LASSERTF(ti != NULL, "ti is NULL ! \n");
580 if (list_empty(&ti->ti_obd_list)) {
581 list_del(&ti->ti_chain);
582 OBD_FREE_PTR(ti);
583 }
584 mutex_unlock(&pinger_mutex);
585 return 0;
586}
587EXPORT_SYMBOL(ptlrpc_del_timeout_client);
588
589int ptlrpc_pinger_remove_timeouts(void)
590{
591 struct timeout_item *item, *tmp;
592
593 mutex_lock(&pinger_mutex);
594 list_for_each_entry_safe(item, tmp, &timeout_list, ti_chain) {
595 LASSERT(list_empty(&item->ti_obd_list));
596 list_del(&item->ti_chain);
597 OBD_FREE_PTR(item);
598 }
599 mutex_unlock(&pinger_mutex);
600 return 0;
601}
602
7d46a21a 603void ptlrpc_pinger_wake_up(void)
d7e09d03 604{
20802057
DE		 605 thread_add_flags(&pinger_thread, SVC_EVENT);
606 wake_up(&pinger_thread.t_ctl_waitq);
d7e09d03
PT		 607}
608
609/* Ping evictor thread */
610#define PET_READY 1
611#define PET_TERMINATE 2
612
613static int pet_refcount = 0;
614static int pet_state;
615static wait_queue_head_t pet_waitq;
616LIST_HEAD(pet_list);
617static DEFINE_SPINLOCK(pet_lock);
618
619int ping_evictor_wake(struct obd_export *exp)
620{
621 struct obd_device *obd;
622
623 spin_lock(&pet_lock);
624 if (pet_state != PET_READY) {
625 /* eventually the new obd will call here again. */
626 spin_unlock(&pet_lock);
627 return 1;
628 }
629
630 obd = class_exp2obd(exp);
631 if (list_empty(&obd->obd_evict_list)) {
632 class_incref(obd, "evictor", obd);
633 list_add(&obd->obd_evict_list, &pet_list);
634 }
635 spin_unlock(&pet_lock);
636
637 wake_up(&pet_waitq);
638 return 0;
639}
640
641static int ping_evictor_main(void *arg)
642{
643 struct obd_device *obd;
644 struct obd_export *exp;
645 struct l_wait_info lwi = { 0 };
646 time_t expire_time;
d7e09d03
PT		 647
648 unshare_fs_struct();
649
650 CDEBUG(D_HA, "Starting Ping Evictor\n");
651 pet_state = PET_READY;
652 while (1) {
653 l_wait_event(pet_waitq, (!list_empty(&pet_list)) ||
654 (pet_state == PET_TERMINATE), &lwi);
655
656 /* loop until all obd's will be removed */
657 if ((pet_state == PET_TERMINATE) && list_empty(&pet_list))
658 break;
659
660 /* we only get here if pet_exp != NULL, and the end of this
661 * loop is the only place which sets it NULL again, so lock
662 * is not strictly necessary. */
663 spin_lock(&pet_lock);
664 obd = list_entry(pet_list.next, struct obd_device,
665 obd_evict_list);
666 spin_unlock(&pet_lock);
667
668 expire_time = cfs_time_current_sec() - PING_EVICT_TIMEOUT;
669
670 CDEBUG(D_HA, "evicting all exports of obd %s older than %ld\n",
671 obd->obd_name, expire_time);
672
673 /* Exports can't be deleted out of the list while we hold
674 * the obd lock (class_unlink_export), which means we can't
675 * lose the last ref on the export. If they've already been
676 * removed from the list, we won't find them here. */
677 spin_lock(&obd->obd_dev_lock);
678 while (!list_empty(&obd->obd_exports_timed)) {
679 exp = list_entry(obd->obd_exports_timed.next,
680 struct obd_export,
681 exp_obd_chain_timed);
682 if (expire_time > exp->exp_last_request_time) {
683 class_export_get(exp);
684 spin_unlock(&obd->obd_dev_lock);
685 LCONSOLE_WARN("%s: haven't heard from client %s"
686 " (at %s) in %ld seconds. I think"
687 " it's dead, and I am evicting"
688 " it. exp %p, cur %ld expire %ld"
689 " last %ld\n",
690 obd->obd_name,
691 obd_uuid2str(&exp->exp_client_uuid),
692 obd_export_nid2str(exp),
693 (long)(cfs_time_current_sec() -
694 exp->exp_last_request_time),
695 exp, (long)cfs_time_current_sec(),
696 (long)expire_time,
697 (long)exp->exp_last_request_time);
698 CDEBUG(D_HA, "Last request was at %ld\n",
699 exp->exp_last_request_time);
700 class_fail_export(exp);
701 class_export_put(exp);
702 spin_lock(&obd->obd_dev_lock);
703 } else {
704 /* List is sorted, so everyone below is ok */
705 break;
706 }
707 }
708 spin_unlock(&obd->obd_dev_lock);
709
710 spin_lock(&pet_lock);
711 list_del_init(&obd->obd_evict_list);
712 spin_unlock(&pet_lock);
713
714 class_decref(obd, "evictor", obd);
715 }
716 CDEBUG(D_HA, "Exiting Ping Evictor\n");
717
0a3bdb00 718 return 0;
d7e09d03
PT		 719}
720
721void ping_evictor_start(void)
722{
68b636b6 723 struct task_struct *task;
d7e09d03
PT		 724
725 if (++pet_refcount > 1)
726 return;
727
728 init_waitqueue_head(&pet_waitq);
729
730 task = kthread_run(ping_evictor_main, NULL, "ll_evictor");
731 if (IS_ERR(task)) {
732 pet_refcount--;
733 CERROR("Cannot start ping evictor thread: %ld\n",
734 PTR_ERR(task));
735 }
736}
737EXPORT_SYMBOL(ping_evictor_start);
738
739void ping_evictor_stop(void)
740{
741 if (--pet_refcount > 0)
742 return;
743
744 pet_state = PET_TERMINATE;
745 wake_up(&pet_waitq);
746}
747EXPORT_SYMBOL(ping_evictor_stop);
Linux 6.x block layer and io_uring tree(s)