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[fs/lustre-release.git] / lustre / ptlrpc / service.c
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.gnu.org/licenses/gpl-2.0.html
19  *
20  * GPL HEADER END
21  */
22 /*
23  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Use is subject to license terms.
25  *
26  * Copyright (c) 2010, 2017, Intel Corporation.
27  */
28 /*
29  * This file is part of Lustre, http://www.lustre.org/
30  * Lustre is a trademark of Sun Microsystems, Inc.
31  */
32
33 #define DEBUG_SUBSYSTEM S_RPC
34
35 #include <linux/kthread.h>
36 #include <linux/ratelimit.h>
37
38 #include <obd_support.h>
39 #include <obd_class.h>
40 #include <lustre_net.h>
41 #include <lu_object.h>
42 #include <uapi/linux/lnet/lnet-types.h>
43 #include "ptlrpc_internal.h"
44
45 /* The following are visible and mutable through /sys/module/ptlrpc */
46 int test_req_buffer_pressure = 0;
47 module_param(test_req_buffer_pressure, int, 0444);
48 MODULE_PARM_DESC(test_req_buffer_pressure, "set non-zero to put pressure on request buffer pools");
49 module_param(at_min, int, 0644);
50 MODULE_PARM_DESC(at_min, "Adaptive timeout minimum (sec)");
51 module_param(at_max, int, 0644);
52 MODULE_PARM_DESC(at_max, "Adaptive timeout maximum (sec)");
53 module_param(at_history, int, 0644);
54 MODULE_PARM_DESC(at_history,
55                  "Adaptive timeouts remember the slowest event that took place within this period (sec)");
56 module_param(at_early_margin, int, 0644);
57 MODULE_PARM_DESC(at_early_margin, "How soon before an RPC deadline to send an early reply");
58 module_param(at_extra, int, 0644);
59 MODULE_PARM_DESC(at_extra, "How much extra time to give with each early reply");
60
61 /* forward ref */
62 static int ptlrpc_server_post_idle_rqbds(struct ptlrpc_service_part *svcpt);
63 static void ptlrpc_server_hpreq_fini(struct ptlrpc_request *req);
64 static void ptlrpc_at_remove_timed(struct ptlrpc_request *req);
65
66 /** Holds a list of all PTLRPC services */
67 struct list_head ptlrpc_all_services;
68 /** Used to protect the \e ptlrpc_all_services list */
69 struct mutex ptlrpc_all_services_mutex;
70
71 static struct ptlrpc_request_buffer_desc *
72 ptlrpc_alloc_rqbd(struct ptlrpc_service_part *svcpt)
73 {
74         struct ptlrpc_service             *svc = svcpt->scp_service;
75         struct ptlrpc_request_buffer_desc *rqbd;
76
77         OBD_CPT_ALLOC_PTR(rqbd, svc->srv_cptable, svcpt->scp_cpt);
78         if (rqbd == NULL)
79                 return NULL;
80
81         rqbd->rqbd_svcpt = svcpt;
82         rqbd->rqbd_refcount = 0;
83         rqbd->rqbd_cbid.cbid_fn = request_in_callback;
84         rqbd->rqbd_cbid.cbid_arg = rqbd;
85         INIT_LIST_HEAD(&rqbd->rqbd_reqs);
86         OBD_CPT_ALLOC_LARGE(rqbd->rqbd_buffer, svc->srv_cptable,
87                             svcpt->scp_cpt, svc->srv_buf_size);
88         if (rqbd->rqbd_buffer == NULL) {
89                 OBD_FREE_PTR(rqbd);
90                 return NULL;
91         }
92
93         spin_lock(&svcpt->scp_lock);
94         list_add(&rqbd->rqbd_list, &svcpt->scp_rqbd_idle);
95         svcpt->scp_nrqbds_total++;
96         spin_unlock(&svcpt->scp_lock);
97
98         return rqbd;
99 }
100
101 static void ptlrpc_free_rqbd(struct ptlrpc_request_buffer_desc *rqbd)
102 {
103         struct ptlrpc_service_part *svcpt = rqbd->rqbd_svcpt;
104
105         LASSERT(rqbd->rqbd_refcount == 0);
106         LASSERT(list_empty(&rqbd->rqbd_reqs));
107
108         spin_lock(&svcpt->scp_lock);
109         list_del(&rqbd->rqbd_list);
110         svcpt->scp_nrqbds_total--;
111         spin_unlock(&svcpt->scp_lock);
112
113         OBD_FREE_LARGE(rqbd->rqbd_buffer, svcpt->scp_service->srv_buf_size);
114         OBD_FREE_PTR(rqbd);
115 }
116
117 static int ptlrpc_grow_req_bufs(struct ptlrpc_service_part *svcpt, int post)
118 {
119         struct ptlrpc_service *svc = svcpt->scp_service;
120         struct ptlrpc_request_buffer_desc *rqbd;
121         int rc = 0;
122         int i;
123
124         if (svcpt->scp_rqbd_allocating)
125                 goto try_post;
126
127         spin_lock(&svcpt->scp_lock);
128         /* check again with lock */
129         if (svcpt->scp_rqbd_allocating) {
130                 /* NB: we might allow more than one thread in the future */
131                 LASSERT(svcpt->scp_rqbd_allocating == 1);
132                 spin_unlock(&svcpt->scp_lock);
133                 goto try_post;
134         }
135
136         svcpt->scp_rqbd_allocating++;
137         spin_unlock(&svcpt->scp_lock);
138
139
140         for (i = 0; i < svc->srv_nbuf_per_group; i++) {
141                 /*
142                  * NB: another thread might have recycled enough rqbds, we
143                  * need to make sure it wouldn't over-allocate, see LU-1212.
144                  */
145                 if (svcpt->scp_nrqbds_posted >= svc->srv_nbuf_per_group ||
146                     (svc->srv_nrqbds_max != 0 &&
147                      svcpt->scp_nrqbds_total > svc->srv_nrqbds_max))
148                         break;
149
150                 rqbd = ptlrpc_alloc_rqbd(svcpt);
151
152                 if (rqbd == NULL) {
153                         CERROR("%s: Can't allocate request buffer\n",
154                                svc->srv_name);
155                         rc = -ENOMEM;
156                         break;
157                 }
158         }
159
160         spin_lock(&svcpt->scp_lock);
161
162         LASSERT(svcpt->scp_rqbd_allocating == 1);
163         svcpt->scp_rqbd_allocating--;
164
165         spin_unlock(&svcpt->scp_lock);
166
167         CDEBUG(D_RPCTRACE,
168                "%s: allocate %d new %d-byte reqbufs (%d/%d left), rc = %d\n",
169                svc->srv_name, i, svc->srv_buf_size, svcpt->scp_nrqbds_posted,
170                svcpt->scp_nrqbds_total, rc);
171
172  try_post:
173         if (post && rc == 0)
174                 rc = ptlrpc_server_post_idle_rqbds(svcpt);
175
176         return rc;
177 }
178
179 /**
180  * Part of Rep-Ack logic.
181  * Puts a lock and its mode into reply state assotiated to request reply.
182  */
183 void ptlrpc_save_lock(struct ptlrpc_request *req, struct lustre_handle *lock,
184                       int mode, bool no_ack, bool convert_lock)
185 {
186         struct ptlrpc_reply_state *rs = req->rq_reply_state;
187         int idx;
188
189         LASSERT(rs != NULL);
190         LASSERT(rs->rs_nlocks < RS_MAX_LOCKS);
191
192         idx = rs->rs_nlocks++;
193         rs->rs_locks[idx] = *lock;
194         rs->rs_modes[idx] = mode;
195         rs->rs_difficult = 1;
196         rs->rs_no_ack = no_ack;
197         rs->rs_convert_lock = convert_lock;
198 }
199 EXPORT_SYMBOL(ptlrpc_save_lock);
200
201
202 struct ptlrpc_hr_partition;
203
204 struct ptlrpc_hr_thread {
205         int                             hrt_id;         /* thread ID */
206         spinlock_t                      hrt_lock;
207         wait_queue_head_t               hrt_waitq;
208         struct list_head                hrt_queue;
209         struct ptlrpc_hr_partition      *hrt_partition;
210 };
211
212 struct ptlrpc_hr_partition {
213         /* # of started threads */
214         atomic_t                        hrp_nstarted;
215         /* # of stopped threads */
216         atomic_t                        hrp_nstopped;
217         /* cpu partition id */
218         int                             hrp_cpt;
219         /* round-robin rotor for choosing thread */
220         int                             hrp_rotor;
221         /* total number of threads on this partition */
222         int                             hrp_nthrs;
223         /* threads table */
224         struct ptlrpc_hr_thread         *hrp_thrs;
225 };
226
227 #define HRT_RUNNING 0
228 #define HRT_STOPPING 1
229
230 struct ptlrpc_hr_service {
231         /* CPU partition table, it's just cfs_cpt_table for now */
232         struct cfs_cpt_table            *hr_cpt_table;
233         /** controller sleep waitq */
234         wait_queue_head_t               hr_waitq;
235         unsigned int                    hr_stopping;
236         /** roundrobin rotor for non-affinity service */
237         unsigned int                    hr_rotor;
238         /* partition data */
239         struct ptlrpc_hr_partition      **hr_partitions;
240 };
241
242 struct rs_batch {
243         struct list_head                        rsb_replies;
244         unsigned int                    rsb_n_replies;
245         struct ptlrpc_service_part      *rsb_svcpt;
246 };
247
248 /** reply handling service. */
249 static struct ptlrpc_hr_service         ptlrpc_hr;
250
251 /**
252  * maximum mumber of replies scheduled in one batch
253  */
254 #define MAX_SCHEDULED 256
255
256 /**
257  * Initialize a reply batch.
258  *
259  * \param b batch
260  */
261 static void rs_batch_init(struct rs_batch *b)
262 {
263         memset(b, 0, sizeof(*b));
264         INIT_LIST_HEAD(&b->rsb_replies);
265 }
266
267 /**
268  * Choose an hr thread to dispatch requests to.
269  */
270 static
271 struct ptlrpc_hr_thread *ptlrpc_hr_select(struct ptlrpc_service_part *svcpt)
272 {
273         struct ptlrpc_hr_partition      *hrp;
274         unsigned int                    rotor;
275
276         if (svcpt->scp_cpt >= 0 &&
277             svcpt->scp_service->srv_cptable == ptlrpc_hr.hr_cpt_table) {
278                 /* directly match partition */
279                 hrp = ptlrpc_hr.hr_partitions[svcpt->scp_cpt];
280
281         } else {
282                 rotor = ptlrpc_hr.hr_rotor++;
283                 rotor %= cfs_cpt_number(ptlrpc_hr.hr_cpt_table);
284
285                 hrp = ptlrpc_hr.hr_partitions[rotor];
286         }
287
288         rotor = hrp->hrp_rotor++;
289         return &hrp->hrp_thrs[rotor % hrp->hrp_nthrs];
290 }
291
292 /**
293  * Dispatch all replies accumulated in the batch to one from
294  * dedicated reply handling threads.
295  *
296  * \param b batch
297  */
298 static void rs_batch_dispatch(struct rs_batch *b)
299 {
300         if (b->rsb_n_replies != 0) {
301                 struct ptlrpc_hr_thread *hrt;
302
303                 hrt = ptlrpc_hr_select(b->rsb_svcpt);
304
305                 spin_lock(&hrt->hrt_lock);
306                 list_splice_init(&b->rsb_replies, &hrt->hrt_queue);
307                 spin_unlock(&hrt->hrt_lock);
308
309                 wake_up(&hrt->hrt_waitq);
310                 b->rsb_n_replies = 0;
311         }
312 }
313
314 /**
315  * Add a reply to a batch.
316  * Add one reply object to a batch, schedule batched replies if overload.
317  *
318  * \param b batch
319  * \param rs reply
320  */
321 static void rs_batch_add(struct rs_batch *b, struct ptlrpc_reply_state *rs)
322 {
323         struct ptlrpc_service_part *svcpt = rs->rs_svcpt;
324
325         if (svcpt != b->rsb_svcpt || b->rsb_n_replies >= MAX_SCHEDULED) {
326                 if (b->rsb_svcpt != NULL) {
327                         rs_batch_dispatch(b);
328                         spin_unlock(&b->rsb_svcpt->scp_rep_lock);
329                 }
330                 spin_lock(&svcpt->scp_rep_lock);
331                 b->rsb_svcpt = svcpt;
332         }
333         spin_lock(&rs->rs_lock);
334         rs->rs_scheduled_ever = 1;
335         if (rs->rs_scheduled == 0) {
336                 list_move(&rs->rs_list, &b->rsb_replies);
337                 rs->rs_scheduled = 1;
338                 b->rsb_n_replies++;
339         }
340         rs->rs_committed = 1;
341         spin_unlock(&rs->rs_lock);
342 }
343
344 /**
345  * Reply batch finalization.
346  * Dispatch remaining replies from the batch
347  * and release remaining spinlock.
348  *
349  * \param b batch
350  */
351 static void rs_batch_fini(struct rs_batch *b)
352 {
353         if (b->rsb_svcpt != NULL) {
354                 rs_batch_dispatch(b);
355                 spin_unlock(&b->rsb_svcpt->scp_rep_lock);
356         }
357 }
358
359 #define DECLARE_RS_BATCH(b)     struct rs_batch b
360
361
362 /**
363  * Put reply state into a queue for processing because we received
364  * ACK from the client
365  */
366 void ptlrpc_dispatch_difficult_reply(struct ptlrpc_reply_state *rs)
367 {
368         struct ptlrpc_hr_thread *hrt;
369
370         ENTRY;
371
372         LASSERT(list_empty(&rs->rs_list));
373
374         hrt = ptlrpc_hr_select(rs->rs_svcpt);
375
376         spin_lock(&hrt->hrt_lock);
377         list_add_tail(&rs->rs_list, &hrt->hrt_queue);
378         spin_unlock(&hrt->hrt_lock);
379
380         wake_up(&hrt->hrt_waitq);
381         EXIT;
382 }
383
384 void ptlrpc_schedule_difficult_reply(struct ptlrpc_reply_state *rs)
385 {
386         ENTRY;
387
388         assert_spin_locked(&rs->rs_svcpt->scp_rep_lock);
389         assert_spin_locked(&rs->rs_lock);
390         LASSERT(rs->rs_difficult);
391         rs->rs_scheduled_ever = 1;  /* flag any notification attempt */
392
393         if (rs->rs_scheduled) {     /* being set up or already notified */
394                 EXIT;
395                 return;
396         }
397
398         rs->rs_scheduled = 1;
399         list_del_init(&rs->rs_list);
400         ptlrpc_dispatch_difficult_reply(rs);
401         EXIT;
402 }
403 EXPORT_SYMBOL(ptlrpc_schedule_difficult_reply);
404
405 void ptlrpc_commit_replies(struct obd_export *exp)
406 {
407         struct ptlrpc_reply_state *rs, *nxt;
408         DECLARE_RS_BATCH(batch);
409
410         ENTRY;
411
412         rs_batch_init(&batch);
413         /*
414          * Find any replies that have been committed and get their service
415          * to attend to complete them.
416          */
417
418         /* CAVEAT EMPTOR: spinlock ordering!!! */
419         spin_lock(&exp->exp_uncommitted_replies_lock);
420         list_for_each_entry_safe(rs, nxt, &exp->exp_uncommitted_replies,
421                                  rs_obd_list) {
422                 LASSERT(rs->rs_difficult);
423                 /* VBR: per-export last_committed */
424                 LASSERT(rs->rs_export);
425                 if (rs->rs_transno <= exp->exp_last_committed) {
426                         list_del_init(&rs->rs_obd_list);
427                         rs_batch_add(&batch, rs);
428                 }
429         }
430         spin_unlock(&exp->exp_uncommitted_replies_lock);
431         rs_batch_fini(&batch);
432         EXIT;
433 }
434
435 static int ptlrpc_server_post_idle_rqbds(struct ptlrpc_service_part *svcpt)
436 {
437         struct ptlrpc_request_buffer_desc *rqbd;
438         int rc;
439         int posted = 0;
440
441         for (;;) {
442                 spin_lock(&svcpt->scp_lock);
443
444                 if (list_empty(&svcpt->scp_rqbd_idle)) {
445                         spin_unlock(&svcpt->scp_lock);
446                         return posted;
447                 }
448
449                 rqbd = list_entry(svcpt->scp_rqbd_idle.next,
450                                       struct ptlrpc_request_buffer_desc,
451                                       rqbd_list);
452                 list_del(&rqbd->rqbd_list);
453
454                 /* assume we will post successfully */
455                 svcpt->scp_nrqbds_posted++;
456                 list_add(&rqbd->rqbd_list, &svcpt->scp_rqbd_posted);
457
458                 spin_unlock(&svcpt->scp_lock);
459
460                 rc = ptlrpc_register_rqbd(rqbd);
461                 if (rc != 0)
462                         break;
463
464                 posted = 1;
465         }
466
467         spin_lock(&svcpt->scp_lock);
468
469         svcpt->scp_nrqbds_posted--;
470         list_del(&rqbd->rqbd_list);
471         list_add_tail(&rqbd->rqbd_list, &svcpt->scp_rqbd_idle);
472
473         /*
474          * Don't complain if no request buffers are posted right now; LNET
475          * won't drop requests because we set the portal lazy!
476          */
477
478         spin_unlock(&svcpt->scp_lock);
479
480         return -1;
481 }
482
483 static void ptlrpc_at_timer(cfs_timer_cb_arg_t data)
484 {
485         struct ptlrpc_service_part *svcpt;
486
487         svcpt = cfs_from_timer(svcpt, data, scp_at_timer);
488
489         svcpt->scp_at_check = 1;
490         svcpt->scp_at_checktime = ktime_get();
491         wake_up(&svcpt->scp_waitq);
492 }
493
494 static void ptlrpc_server_nthreads_check(struct ptlrpc_service *svc,
495                                          struct ptlrpc_service_conf *conf)
496 {
497         struct ptlrpc_service_thr_conf *tc = &conf->psc_thr;
498         unsigned int init;
499         unsigned int total;
500         unsigned int nthrs;
501         int weight;
502
503         /*
504          * Common code for estimating & validating threads number.
505          * CPT affinity service could have percpt thread-pool instead
506          * of a global thread-pool, which means user might not always
507          * get the threads number they give it in conf::tc_nthrs_user
508          * even they did set. It's because we need to validate threads
509          * number for each CPT to guarantee each pool will have enough
510          * threads to keep the service healthy.
511          */
512         init = PTLRPC_NTHRS_INIT + (svc->srv_ops.so_hpreq_handler != NULL);
513         init = max_t(int, init, tc->tc_nthrs_init);
514
515         /*
516          * NB: please see comments in lustre_lnet.h for definition
517          * details of these members
518          */
519         LASSERT(tc->tc_nthrs_max != 0);
520
521         if (tc->tc_nthrs_user != 0) {
522                 /*
523                  * In case there is a reason to test a service with many
524                  * threads, we give a less strict check here, it can
525                  * be up to 8 * nthrs_max
526                  */
527                 total = min(tc->tc_nthrs_max * 8, tc->tc_nthrs_user);
528                 nthrs = total / svc->srv_ncpts;
529                 init  = max(init, nthrs);
530                 goto out;
531         }
532
533         total = tc->tc_nthrs_max;
534         if (tc->tc_nthrs_base == 0) {
535                 /*
536                  * don't care about base threads number per partition,
537                  * this is most for non-affinity service
538                  */
539                 nthrs = total / svc->srv_ncpts;
540                 goto out;
541         }
542
543         nthrs = tc->tc_nthrs_base;
544         if (svc->srv_ncpts == 1) {
545                 int     i;
546
547                 /*
548                  * NB: Increase the base number if it's single partition
549                  * and total number of cores/HTs is larger or equal to 4.
550                  * result will always < 2 * nthrs_base
551                  */
552                 weight = cfs_cpt_weight(svc->srv_cptable, CFS_CPT_ANY);
553                 for (i = 1; (weight >> (i + 1)) != 0 && /* >= 4 cores/HTs */
554                             (tc->tc_nthrs_base >> i) != 0; i++)
555                         nthrs += tc->tc_nthrs_base >> i;
556         }
557
558         if (tc->tc_thr_factor != 0) {
559                 int       factor = tc->tc_thr_factor;
560                 const int fade = 4;
561
562                 /*
563                  * User wants to increase number of threads with for
564                  * each CPU core/HT, most likely the factor is larger than
565                  * one thread/core because service threads are supposed to
566                  * be blocked by lock or wait for IO.
567                  */
568                 /*
569                  * Amdahl's law says that adding processors wouldn't give
570                  * a linear increasing of parallelism, so it's nonsense to
571                  * have too many threads no matter how many cores/HTs
572                  * there are.
573                  */
574                 if (cpumask_weight
575                     (topology_sibling_cpumask(smp_processor_id())) > 1) {
576                         /* weight is # of HTs */
577                         /* depress thread factor for hyper-thread */
578                         factor = factor - (factor >> 1) + (factor >> 3);
579                 }
580
581                 weight = cfs_cpt_weight(svc->srv_cptable, 0);
582
583                 for (; factor > 0 && weight > 0; factor--, weight -= fade)
584                         nthrs += min(weight, fade) * factor;
585         }
586
587         if (nthrs * svc->srv_ncpts > tc->tc_nthrs_max) {
588                 nthrs = max(tc->tc_nthrs_base,
589                             tc->tc_nthrs_max / svc->srv_ncpts);
590         }
591  out:
592         nthrs = max(nthrs, tc->tc_nthrs_init);
593         svc->srv_nthrs_cpt_limit = nthrs;
594         svc->srv_nthrs_cpt_init = init;
595
596         if (nthrs * svc->srv_ncpts > tc->tc_nthrs_max) {
597                 CDEBUG(D_OTHER,
598                        "%s: This service may have more threads (%d) than the given soft limit (%d)\n",
599                        svc->srv_name, nthrs * svc->srv_ncpts,
600                        tc->tc_nthrs_max);
601         }
602 }
603
604 /**
605  * Initialize percpt data for a service
606  */
607 static int ptlrpc_service_part_init(struct ptlrpc_service *svc,
608                                     struct ptlrpc_service_part *svcpt, int cpt)
609 {
610         struct ptlrpc_at_array *array;
611         int size;
612         int index;
613         int rc;
614
615         svcpt->scp_cpt = cpt;
616         INIT_LIST_HEAD(&svcpt->scp_threads);
617
618         /* rqbd and incoming request queue */
619         spin_lock_init(&svcpt->scp_lock);
620         mutex_init(&svcpt->scp_mutex);
621         INIT_LIST_HEAD(&svcpt->scp_rqbd_idle);
622         INIT_LIST_HEAD(&svcpt->scp_rqbd_posted);
623         INIT_LIST_HEAD(&svcpt->scp_req_incoming);
624         init_waitqueue_head(&svcpt->scp_waitq);
625         /* history request & rqbd list */
626         INIT_LIST_HEAD(&svcpt->scp_hist_reqs);
627         INIT_LIST_HEAD(&svcpt->scp_hist_rqbds);
628
629         /* acitve requests and hp requests */
630         spin_lock_init(&svcpt->scp_req_lock);
631
632         /* reply states */
633         spin_lock_init(&svcpt->scp_rep_lock);
634         INIT_LIST_HEAD(&svcpt->scp_rep_active);
635         INIT_LIST_HEAD(&svcpt->scp_rep_idle);
636         init_waitqueue_head(&svcpt->scp_rep_waitq);
637         atomic_set(&svcpt->scp_nreps_difficult, 0);
638
639         /* adaptive timeout */
640         spin_lock_init(&svcpt->scp_at_lock);
641         array = &svcpt->scp_at_array;
642
643         size = at_est2timeout(at_max);
644         array->paa_size     = size;
645         array->paa_count    = 0;
646         array->paa_deadline = -1;
647
648         /* allocate memory for scp_at_array (ptlrpc_at_array) */
649         OBD_CPT_ALLOC(array->paa_reqs_array,
650                       svc->srv_cptable, cpt, sizeof(struct list_head) * size);
651         if (array->paa_reqs_array == NULL)
652                 return -ENOMEM;
653
654         for (index = 0; index < size; index++)
655                 INIT_LIST_HEAD(&array->paa_reqs_array[index]);
656
657         OBD_CPT_ALLOC(array->paa_reqs_count,
658                       svc->srv_cptable, cpt, sizeof(__u32) * size);
659         if (array->paa_reqs_count == NULL)
660                 goto failed;
661
662         cfs_timer_setup(&svcpt->scp_at_timer, ptlrpc_at_timer,
663                         (unsigned long)svcpt, 0);
664
665         /*
666          * At SOW, service time should be quick; 10s seems generous. If client
667          * timeout is less than this, we'll be sending an early reply.
668          */
669         at_init(&svcpt->scp_at_estimate, 10, 0);
670
671         /* assign this before call ptlrpc_grow_req_bufs */
672         svcpt->scp_service = svc;
673         /* Now allocate the request buffers, but don't post them now */
674         rc = ptlrpc_grow_req_bufs(svcpt, 0);
675         /*
676          * We shouldn't be under memory pressure at startup, so
677          * fail if we can't allocate all our buffers at this time.
678          */
679         if (rc != 0)
680                 goto failed;
681
682         return 0;
683
684  failed:
685         if (array->paa_reqs_count != NULL) {
686                 OBD_FREE(array->paa_reqs_count, sizeof(__u32) * size);
687                 array->paa_reqs_count = NULL;
688         }
689
690         if (array->paa_reqs_array != NULL) {
691                 OBD_FREE(array->paa_reqs_array,
692                          sizeof(struct list_head) * array->paa_size);
693                 array->paa_reqs_array = NULL;
694         }
695
696         return -ENOMEM;
697 }
698
699 /**
700  * Initialize service on a given portal.
701  * This includes starting serving threads , allocating and posting rqbds and
702  * so on.
703  */
704 struct ptlrpc_service *ptlrpc_register_service(struct ptlrpc_service_conf *conf,
705                                                struct kset *parent,
706                                                struct dentry *debugfs_entry)
707 {
708         struct ptlrpc_service_cpt_conf *cconf = &conf->psc_cpt;
709         struct ptlrpc_service *service;
710         struct ptlrpc_service_part *svcpt;
711         struct cfs_cpt_table *cptable;
712         __u32 *cpts = NULL;
713         int ncpts;
714         int cpt;
715         int rc;
716         int i;
717
718         ENTRY;
719
720         LASSERT(conf->psc_buf.bc_nbufs > 0);
721         LASSERT(conf->psc_buf.bc_buf_size >=
722                 conf->psc_buf.bc_req_max_size + SPTLRPC_MAX_PAYLOAD);
723         LASSERT(conf->psc_thr.tc_ctx_tags != 0);
724
725         cptable = cconf->cc_cptable;
726         if (cptable == NULL)
727                 cptable = cfs_cpt_table;
728
729         if (conf->psc_thr.tc_cpu_bind > 1) {
730                 CERROR("%s: Invalid cpu bind value %d, only 1 or 0 allowed\n",
731                        conf->psc_name, conf->psc_thr.tc_cpu_bind);
732                 RETURN(ERR_PTR(-EINVAL));
733         }
734
735         if (!cconf->cc_affinity) {
736                 ncpts = 1;
737         } else {
738                 ncpts = cfs_cpt_number(cptable);
739                 if (cconf->cc_pattern != NULL) {
740                         struct cfs_expr_list    *el;
741
742                         rc = cfs_expr_list_parse(cconf->cc_pattern,
743                                                  strlen(cconf->cc_pattern),
744                                                  0, ncpts - 1, &el);
745                         if (rc != 0) {
746                                 CERROR("%s: invalid CPT pattern string: %s",
747                                        conf->psc_name, cconf->cc_pattern);
748                                 RETURN(ERR_PTR(-EINVAL));
749                         }
750
751                         rc = cfs_expr_list_values(el, ncpts, &cpts);
752                         cfs_expr_list_free(el);
753                         if (rc <= 0) {
754                                 CERROR("%s: failed to parse CPT array %s: %d\n",
755                                        conf->psc_name, cconf->cc_pattern, rc);
756                                 if (cpts != NULL)
757                                         OBD_FREE(cpts, sizeof(*cpts) * ncpts);
758                                 RETURN(ERR_PTR(rc < 0 ? rc : -EINVAL));
759                         }
760                         ncpts = rc;
761                 }
762         }
763
764         OBD_ALLOC(service, offsetof(struct ptlrpc_service, srv_parts[ncpts]));
765         if (service == NULL) {
766                 if (cpts != NULL)
767                         OBD_FREE(cpts, sizeof(*cpts) * ncpts);
768                 RETURN(ERR_PTR(-ENOMEM));
769         }
770
771         service->srv_cptable            = cptable;
772         service->srv_cpts               = cpts;
773         service->srv_ncpts              = ncpts;
774         service->srv_cpt_bind           = conf->psc_thr.tc_cpu_bind;
775
776         service->srv_cpt_bits = 0; /* it's zero already, easy to read... */
777         while ((1 << service->srv_cpt_bits) < cfs_cpt_number(cptable))
778                 service->srv_cpt_bits++;
779
780         /* public members */
781         spin_lock_init(&service->srv_lock);
782         service->srv_name               = conf->psc_name;
783         service->srv_watchdog_factor    = conf->psc_watchdog_factor;
784         INIT_LIST_HEAD(&service->srv_list); /* for safty of cleanup */
785
786         /* buffer configuration */
787         service->srv_nbuf_per_group     = test_req_buffer_pressure ?
788                                           1 : conf->psc_buf.bc_nbufs;
789         /* do not limit max number of rqbds by default */
790         service->srv_nrqbds_max         = 0;
791
792         service->srv_max_req_size       = conf->psc_buf.bc_req_max_size +
793                                           SPTLRPC_MAX_PAYLOAD;
794         service->srv_buf_size           = conf->psc_buf.bc_buf_size;
795         service->srv_rep_portal         = conf->psc_buf.bc_rep_portal;
796         service->srv_req_portal         = conf->psc_buf.bc_req_portal;
797
798         /* With slab/alloc_pages buffer size will be rounded up to 2^n */
799         if (service->srv_buf_size & (service->srv_buf_size - 1)) {
800                 int round = size_roundup_power2(service->srv_buf_size);
801
802                 service->srv_buf_size = round;
803         }
804
805         /* Increase max reply size to next power of two */
806         service->srv_max_reply_size = 1;
807         while (service->srv_max_reply_size <
808                conf->psc_buf.bc_rep_max_size + SPTLRPC_MAX_PAYLOAD)
809                 service->srv_max_reply_size <<= 1;
810
811         service->srv_thread_name        = conf->psc_thr.tc_thr_name;
812         service->srv_ctx_tags           = conf->psc_thr.tc_ctx_tags;
813         service->srv_hpreq_ratio        = PTLRPC_SVC_HP_RATIO;
814         service->srv_ops                = conf->psc_ops;
815
816         for (i = 0; i < ncpts; i++) {
817                 if (!cconf->cc_affinity)
818                         cpt = CFS_CPT_ANY;
819                 else
820                         cpt = cpts != NULL ? cpts[i] : i;
821
822                 OBD_CPT_ALLOC(svcpt, cptable, cpt, sizeof(*svcpt));
823                 if (svcpt == NULL)
824                         GOTO(failed, rc = -ENOMEM);
825
826                 service->srv_parts[i] = svcpt;
827                 rc = ptlrpc_service_part_init(service, svcpt, cpt);
828                 if (rc != 0)
829                         GOTO(failed, rc);
830         }
831
832         ptlrpc_server_nthreads_check(service, conf);
833
834         rc = LNetSetLazyPortal(service->srv_req_portal);
835         LASSERT(rc == 0);
836
837         mutex_lock(&ptlrpc_all_services_mutex);
838         list_add(&service->srv_list, &ptlrpc_all_services);
839         mutex_unlock(&ptlrpc_all_services_mutex);
840
841         if (parent) {
842                 rc = ptlrpc_sysfs_register_service(parent, service);
843                 if (rc)
844                         GOTO(failed, rc);
845         }
846
847         if (debugfs_entry != NULL)
848                 ptlrpc_ldebugfs_register_service(debugfs_entry, service);
849
850         rc = ptlrpc_service_nrs_setup(service);
851         if (rc != 0)
852                 GOTO(failed, rc);
853
854         CDEBUG(D_NET, "%s: Started, listening on portal %d\n",
855                service->srv_name, service->srv_req_portal);
856
857         rc = ptlrpc_start_threads(service);
858         if (rc != 0) {
859                 CERROR("Failed to start threads for service %s: %d\n",
860                        service->srv_name, rc);
861                 GOTO(failed, rc);
862         }
863
864         RETURN(service);
865 failed:
866         ptlrpc_unregister_service(service);
867         RETURN(ERR_PTR(rc));
868 }
869 EXPORT_SYMBOL(ptlrpc_register_service);
870
871 /**
872  * to actually free the request, must be called without holding svc_lock.
873  * note it's caller's responsibility to unlink req->rq_list.
874  */
875 static void ptlrpc_server_free_request(struct ptlrpc_request *req)
876 {
877         LASSERT(atomic_read(&req->rq_refcount) == 0);
878         LASSERT(list_empty(&req->rq_timed_list));
879
880         /*
881          * DEBUG_REQ() assumes the reply state of a request with a valid
882          * ref will not be destroyed until that reference is dropped.
883          */
884         ptlrpc_req_drop_rs(req);
885
886         sptlrpc_svc_ctx_decref(req);
887
888         if (req != &req->rq_rqbd->rqbd_req) {
889                 /*
890                  * NB request buffers use an embedded
891                  * req if the incoming req unlinked the
892                  * MD; this isn't one of them!
893                  */
894                 ptlrpc_request_cache_free(req);
895         }
896 }
897
898 /**
899  * drop a reference count of the request. if it reaches 0, we either
900  * put it into history list, or free it immediately.
901  */
902 void ptlrpc_server_drop_request(struct ptlrpc_request *req)
903 {
904         struct ptlrpc_request_buffer_desc *rqbd = req->rq_rqbd;
905         struct ptlrpc_service_part        *svcpt = rqbd->rqbd_svcpt;
906         struct ptlrpc_service             *svc = svcpt->scp_service;
907         int                                refcount;
908         struct list_head                          *tmp;
909         struct list_head                          *nxt;
910
911         if (!atomic_dec_and_test(&req->rq_refcount))
912                 return;
913
914         if (req->rq_session.lc_state == LCS_ENTERED) {
915                 lu_context_exit(&req->rq_session);
916                 lu_context_fini(&req->rq_session);
917         }
918
919         if (req->rq_at_linked) {
920                 spin_lock(&svcpt->scp_at_lock);
921                 /*
922                  * recheck with lock, in case it's unlinked by
923                  * ptlrpc_at_check_timed()
924                  */
925                 if (likely(req->rq_at_linked))
926                         ptlrpc_at_remove_timed(req);
927                 spin_unlock(&svcpt->scp_at_lock);
928         }
929
930         LASSERT(list_empty(&req->rq_timed_list));
931
932         /* finalize request */
933         if (req->rq_export) {
934                 class_export_put(req->rq_export);
935                 req->rq_export = NULL;
936         }
937
938         spin_lock(&svcpt->scp_lock);
939
940         list_add(&req->rq_list, &rqbd->rqbd_reqs);
941
942         refcount = --(rqbd->rqbd_refcount);
943         if (refcount == 0) {
944                 /* request buffer is now idle: add to history */
945                 list_del(&rqbd->rqbd_list);
946
947                 list_add_tail(&rqbd->rqbd_list, &svcpt->scp_hist_rqbds);
948                 svcpt->scp_hist_nrqbds++;
949
950                 /*
951                  * cull some history?
952                  * I expect only about 1 or 2 rqbds need to be recycled here
953                  */
954                 while (svcpt->scp_hist_nrqbds > svc->srv_hist_nrqbds_cpt_max) {
955                         rqbd = list_entry(svcpt->scp_hist_rqbds.next,
956                                           struct ptlrpc_request_buffer_desc,
957                                           rqbd_list);
958
959                         list_del(&rqbd->rqbd_list);
960                         svcpt->scp_hist_nrqbds--;
961
962                         /*
963                          * remove rqbd's reqs from svc's req history while
964                          * I've got the service lock
965                          */
966                         list_for_each(tmp, &rqbd->rqbd_reqs) {
967                                 req = list_entry(tmp, struct ptlrpc_request,
968                                                  rq_list);
969                                 /* Track the highest culled req seq */
970                                 if (req->rq_history_seq >
971                                     svcpt->scp_hist_seq_culled) {
972                                         svcpt->scp_hist_seq_culled =
973                                                 req->rq_history_seq;
974                                 }
975                                 list_del(&req->rq_history_list);
976                         }
977
978                         spin_unlock(&svcpt->scp_lock);
979
980                         list_for_each_safe(tmp, nxt, &rqbd->rqbd_reqs) {
981                                 req = list_entry(rqbd->rqbd_reqs.next,
982                                                  struct ptlrpc_request,
983                                                  rq_list);
984                                 list_del(&req->rq_list);
985                                 ptlrpc_server_free_request(req);
986                         }
987
988                         spin_lock(&svcpt->scp_lock);
989                         /*
990                          * now all reqs including the embedded req has been
991                          * disposed, schedule request buffer for re-use
992                          * or free it to drain some in excess.
993                          */
994                         LASSERT(atomic_read(&rqbd->rqbd_req.rq_refcount) == 0);
995                         if (svcpt->scp_nrqbds_posted >=
996                             svc->srv_nbuf_per_group ||
997                             (svc->srv_nrqbds_max != 0 &&
998                              svcpt->scp_nrqbds_total > svc->srv_nrqbds_max) ||
999                             test_req_buffer_pressure) {
1000                                 /* like in ptlrpc_free_rqbd() */
1001                                 svcpt->scp_nrqbds_total--;
1002                                 OBD_FREE_LARGE(rqbd->rqbd_buffer,
1003                                                svc->srv_buf_size);
1004                                 OBD_FREE_PTR(rqbd);
1005                         } else {
1006                                 list_add_tail(&rqbd->rqbd_list,
1007                                               &svcpt->scp_rqbd_idle);
1008                         }
1009                 }
1010
1011                 spin_unlock(&svcpt->scp_lock);
1012         } else if (req->rq_reply_state && req->rq_reply_state->rs_prealloc) {
1013                 /* If we are low on memory, we are not interested in history */
1014                 list_del(&req->rq_list);
1015                 list_del_init(&req->rq_history_list);
1016
1017                 /* Track the highest culled req seq */
1018                 if (req->rq_history_seq > svcpt->scp_hist_seq_culled)
1019                         svcpt->scp_hist_seq_culled = req->rq_history_seq;
1020
1021                 spin_unlock(&svcpt->scp_lock);
1022
1023                 ptlrpc_server_free_request(req);
1024         } else {
1025                 spin_unlock(&svcpt->scp_lock);
1026         }
1027 }
1028
1029 /** Change request export and move hp request from old export to new */
1030 void ptlrpc_request_change_export(struct ptlrpc_request *req,
1031                                   struct obd_export *export)
1032 {
1033         if (req->rq_export != NULL) {
1034                 LASSERT(!list_empty(&req->rq_exp_list));
1035                 /* remove rq_exp_list from last export */
1036                 spin_lock(&req->rq_export->exp_rpc_lock);
1037                 list_del_init(&req->rq_exp_list);
1038                 spin_unlock(&req->rq_export->exp_rpc_lock);
1039                 /*
1040                  * export has one reference already, so it`s safe to
1041                  * add req to export queue here and get another
1042                  * reference for request later
1043                  */
1044                 spin_lock(&export->exp_rpc_lock);
1045                 if (req->rq_ops != NULL) /* hp request */
1046                         list_add(&req->rq_exp_list, &export->exp_hp_rpcs);
1047                 else
1048                         list_add(&req->rq_exp_list, &export->exp_reg_rpcs);
1049                 spin_unlock(&export->exp_rpc_lock);
1050
1051                 class_export_rpc_dec(req->rq_export);
1052                 class_export_put(req->rq_export);
1053         }
1054
1055         /* request takes one export refcount */
1056         req->rq_export = class_export_get(export);
1057         class_export_rpc_inc(export);
1058
1059         return;
1060 }
1061
1062 /**
1063  * to finish a request: stop sending more early replies, and release
1064  * the request.
1065  */
1066 static void ptlrpc_server_finish_request(struct ptlrpc_service_part *svcpt,
1067                                          struct ptlrpc_request *req)
1068 {
1069         ptlrpc_server_hpreq_fini(req);
1070
1071         ptlrpc_server_drop_request(req);
1072 }
1073
1074 /**
1075  * to finish an active request: stop sending more early replies, and release
1076  * the request. should be called after we finished handling the request.
1077  */
1078 static void ptlrpc_server_finish_active_request(
1079                                         struct ptlrpc_service_part *svcpt,
1080                                         struct ptlrpc_request *req)
1081 {
1082         spin_lock(&svcpt->scp_req_lock);
1083         ptlrpc_nrs_req_stop_nolock(req);
1084         svcpt->scp_nreqs_active--;
1085         if (req->rq_hp)
1086                 svcpt->scp_nhreqs_active--;
1087         spin_unlock(&svcpt->scp_req_lock);
1088
1089         ptlrpc_nrs_req_finalize(req);
1090
1091         if (req->rq_export != NULL)
1092                 class_export_rpc_dec(req->rq_export);
1093
1094         ptlrpc_server_finish_request(svcpt, req);
1095 }
1096
1097 /**
1098  * This function makes sure dead exports are evicted in a timely manner.
1099  * This function is only called when some export receives a message (i.e.,
1100  * the network is up.)
1101  */
1102 void ptlrpc_update_export_timer(struct obd_export *exp, time64_t extra_delay)
1103 {
1104         struct obd_export *oldest_exp;
1105         time64_t oldest_time, new_time;
1106
1107         ENTRY;
1108
1109         LASSERT(exp);
1110
1111         /*
1112          * Compensate for slow machines, etc, by faking our request time
1113          * into the future.  Although this can break the strict time-ordering
1114          * of the list, we can be really lazy here - we don't have to evict
1115          * at the exact right moment.  Eventually, all silent exports
1116          * will make it to the top of the list.
1117          */
1118
1119         /* Do not pay attention on 1sec or smaller renewals. */
1120         new_time = ktime_get_real_seconds() + extra_delay;
1121         if (exp->exp_last_request_time + 1 /*second */ >= new_time)
1122                 RETURN_EXIT;
1123
1124         exp->exp_last_request_time = new_time;
1125
1126         /*
1127          * exports may get disconnected from the chain even though the
1128          * export has references, so we must keep the spin lock while
1129          * manipulating the lists
1130          */
1131         spin_lock(&exp->exp_obd->obd_dev_lock);
1132
1133         if (list_empty(&exp->exp_obd_chain_timed)) {
1134                 /* this one is not timed */
1135                 spin_unlock(&exp->exp_obd->obd_dev_lock);
1136                 RETURN_EXIT;
1137         }
1138
1139         list_move_tail(&exp->exp_obd_chain_timed,
1140                        &exp->exp_obd->obd_exports_timed);
1141
1142         oldest_exp = list_entry(exp->exp_obd->obd_exports_timed.next,
1143                                 struct obd_export, exp_obd_chain_timed);
1144         oldest_time = oldest_exp->exp_last_request_time;
1145         spin_unlock(&exp->exp_obd->obd_dev_lock);
1146
1147         if (exp->exp_obd->obd_recovering) {
1148                 /* be nice to everyone during recovery */
1149                 EXIT;
1150                 return;
1151         }
1152
1153         /* Note - racing to start/reset the obd_eviction timer is safe */
1154         if (exp->exp_obd->obd_eviction_timer == 0) {
1155                 /* Check if the oldest entry is expired. */
1156                 if (ktime_get_real_seconds() >
1157                     oldest_time + PING_EVICT_TIMEOUT + extra_delay) {
1158                         /*
1159                          * We need a second timer, in case the net was down and
1160                          * it just came back. Since the pinger may skip every
1161                          * other PING_INTERVAL (see note in ptlrpc_pinger_main),
1162                          * we better wait for 3.
1163                          */
1164                         exp->exp_obd->obd_eviction_timer =
1165                                 ktime_get_real_seconds() + 3 * PING_INTERVAL;
1166                         CDEBUG(D_HA, "%s: Think about evicting %s from %lld\n",
1167                                exp->exp_obd->obd_name,
1168                                obd_export_nid2str(oldest_exp), oldest_time);
1169                 }
1170         } else {
1171                 if (ktime_get_real_seconds() >
1172                     (exp->exp_obd->obd_eviction_timer + extra_delay)) {
1173                         /*
1174                          * The evictor won't evict anyone who we've heard from
1175                          * recently, so we don't have to check before we start
1176                          * it.
1177                          */
1178                         if (!ping_evictor_wake(exp))
1179                                 exp->exp_obd->obd_eviction_timer = 0;
1180                 }
1181         }
1182
1183         EXIT;
1184 }
1185
1186 /**
1187  * Sanity check request \a req.
1188  * Return 0 if all is ok, error code otherwise.
1189  */
1190 static int ptlrpc_check_req(struct ptlrpc_request *req)
1191 {
1192         struct obd_device *obd = req->rq_export->exp_obd;
1193         int rc = 0;
1194
1195         if (unlikely(lustre_msg_get_conn_cnt(req->rq_reqmsg) <
1196                      req->rq_export->exp_conn_cnt)) {
1197                 DEBUG_REQ(D_RPCTRACE, req,
1198                           "DROPPING req from old connection %d < %d",
1199                           lustre_msg_get_conn_cnt(req->rq_reqmsg),
1200                           req->rq_export->exp_conn_cnt);
1201                 return -EEXIST;
1202         }
1203         if (unlikely(obd == NULL || obd->obd_fail)) {
1204                 /*
1205                  * Failing over, don't handle any more reqs,
1206                  * send error response instead.
1207                  */
1208                 CDEBUG(D_RPCTRACE, "Dropping req %p for failed obd %s\n",
1209                         req, (obd != NULL) ? obd->obd_name : "unknown");
1210                 rc = -ENODEV;
1211         } else if (lustre_msg_get_flags(req->rq_reqmsg) &
1212                    (MSG_REPLAY | MSG_REQ_REPLAY_DONE) &&
1213                    !obd->obd_recovering) {
1214                 DEBUG_REQ(D_ERROR, req,
1215                           "Invalid replay without recovery");
1216                 class_fail_export(req->rq_export);
1217                 rc = -ENODEV;
1218         } else if (lustre_msg_get_transno(req->rq_reqmsg) != 0 &&
1219                    !obd->obd_recovering) {
1220                 DEBUG_REQ(D_ERROR, req,
1221                           "Invalid req with transno %llu without recovery",
1222                           lustre_msg_get_transno(req->rq_reqmsg));
1223                 class_fail_export(req->rq_export);
1224                 rc = -ENODEV;
1225         }
1226
1227         if (unlikely(rc < 0)) {
1228                 req->rq_status = rc;
1229                 ptlrpc_error(req);
1230         }
1231         return rc;
1232 }
1233
1234 static void ptlrpc_at_set_timer(struct ptlrpc_service_part *svcpt)
1235 {
1236         struct ptlrpc_at_array *array = &svcpt->scp_at_array;
1237         time64_t next;
1238
1239         if (array->paa_count == 0) {
1240                 del_timer(&svcpt->scp_at_timer);
1241                 return;
1242         }
1243
1244         /* Set timer for closest deadline */
1245         next = array->paa_deadline - ktime_get_real_seconds() -
1246                at_early_margin;
1247         if (next <= 0) {
1248                 ptlrpc_at_timer(cfs_timer_cb_arg(svcpt, scp_at_timer));
1249         } else {
1250                 mod_timer(&svcpt->scp_at_timer,
1251                           jiffies + nsecs_to_jiffies(next * NSEC_PER_SEC));
1252                 CDEBUG(D_INFO, "armed %s at %+llds\n",
1253                        svcpt->scp_service->srv_name, next);
1254         }
1255 }
1256
1257 /* Add rpc to early reply check list */
1258 static int ptlrpc_at_add_timed(struct ptlrpc_request *req)
1259 {
1260         struct ptlrpc_service_part *svcpt = req->rq_rqbd->rqbd_svcpt;
1261         struct ptlrpc_at_array *array = &svcpt->scp_at_array;
1262         struct ptlrpc_request *rq = NULL;
1263         __u32 index;
1264
1265         if (AT_OFF)
1266                 return(0);
1267
1268         if (req->rq_no_reply)
1269                 return 0;
1270
1271         if ((lustre_msghdr_get_flags(req->rq_reqmsg) & MSGHDR_AT_SUPPORT) == 0)
1272                 return(-ENOSYS);
1273
1274         spin_lock(&svcpt->scp_at_lock);
1275         LASSERT(list_empty(&req->rq_timed_list));
1276
1277         div_u64_rem(req->rq_deadline, array->paa_size, &index);
1278         if (array->paa_reqs_count[index] > 0) {
1279                 /*
1280                  * latest rpcs will have the latest deadlines in the list,
1281                  * so search backward.
1282                  */
1283                 list_for_each_entry_reverse(rq, &array->paa_reqs_array[index],
1284                                             rq_timed_list) {
1285                         if (req->rq_deadline >= rq->rq_deadline) {
1286                                 list_add(&req->rq_timed_list,
1287                                          &rq->rq_timed_list);
1288                                 break;
1289                         }
1290                 }
1291         }
1292
1293         /* Add the request at the head of the list */
1294         if (list_empty(&req->rq_timed_list))
1295                 list_add(&req->rq_timed_list, &array->paa_reqs_array[index]);
1296
1297         spin_lock(&req->rq_lock);
1298         req->rq_at_linked = 1;
1299         spin_unlock(&req->rq_lock);
1300         req->rq_at_index = index;
1301         array->paa_reqs_count[index]++;
1302         array->paa_count++;
1303         if (array->paa_count == 1 || array->paa_deadline > req->rq_deadline) {
1304                 array->paa_deadline = req->rq_deadline;
1305                 ptlrpc_at_set_timer(svcpt);
1306         }
1307         spin_unlock(&svcpt->scp_at_lock);
1308
1309         return 0;
1310 }
1311
1312 static void ptlrpc_at_remove_timed(struct ptlrpc_request *req)
1313 {
1314         struct ptlrpc_at_array *array;
1315
1316         array = &req->rq_rqbd->rqbd_svcpt->scp_at_array;
1317
1318         /* NB: must call with hold svcpt::scp_at_lock */
1319         LASSERT(!list_empty(&req->rq_timed_list));
1320         list_del_init(&req->rq_timed_list);
1321
1322         spin_lock(&req->rq_lock);
1323         req->rq_at_linked = 0;
1324         spin_unlock(&req->rq_lock);
1325
1326         array->paa_reqs_count[req->rq_at_index]--;
1327         array->paa_count--;
1328 }
1329
1330 /*
1331  * Attempt to extend the request deadline by sending an early reply to the
1332  * client.
1333  */
1334 static int ptlrpc_at_send_early_reply(struct ptlrpc_request *req)
1335 {
1336         struct ptlrpc_service_part *svcpt = req->rq_rqbd->rqbd_svcpt;
1337         struct ptlrpc_request *reqcopy;
1338         struct lustre_msg *reqmsg;
1339         time64_t olddl = req->rq_deadline - ktime_get_real_seconds();
1340         time64_t newdl;
1341         int rc;
1342
1343         ENTRY;
1344
1345         if (CFS_FAIL_CHECK(OBD_FAIL_TGT_REPLAY_RECONNECT)) {
1346                 /* don't send early reply */
1347                 RETURN(1);
1348         }
1349
1350         /*
1351          * deadline is when the client expects us to reply, margin is the
1352          * difference between clients' and servers' expectations
1353          */
1354         DEBUG_REQ(D_ADAPTTO, req,
1355                   "%ssending early reply (deadline %+llds, margin %+llds) for %d+%d",
1356                   AT_OFF ? "AT off - not " : "",
1357                   (s64)olddl, (s64)(olddl - at_get(&svcpt->scp_at_estimate)),
1358                   at_get(&svcpt->scp_at_estimate), at_extra);
1359
1360         if (AT_OFF)
1361                 RETURN(0);
1362
1363         if (olddl < 0) {
1364                 DEBUG_REQ(D_WARNING, req,
1365                           "Already past deadline (%+llds), not sending early reply. Consider increasing at_early_margin (%d)?",
1366                           (s64)olddl, at_early_margin);
1367
1368                 /* Return an error so we're not re-added to the timed list. */
1369                 RETURN(-ETIMEDOUT);
1370         }
1371
1372         if ((lustre_msghdr_get_flags(req->rq_reqmsg) &
1373              MSGHDR_AT_SUPPORT) == 0) {
1374                 DEBUG_REQ(D_INFO, req,
1375                           "Wanted to ask client for more time, but no AT support");
1376                 RETURN(-ENOSYS);
1377         }
1378
1379         if (req->rq_export &&
1380             lustre_msg_get_flags(req->rq_reqmsg) &
1381             (MSG_REPLAY | MSG_REQ_REPLAY_DONE | MSG_LOCK_REPLAY_DONE)) {
1382                 struct obd_device *obd_exp = req->rq_export->exp_obd;
1383
1384                 /*
1385                  * During recovery, we don't want to send too many early
1386                  * replies, but on the other hand we want to make sure the
1387                  * client has enough time to resend if the rpc is lost. So
1388                  * during the recovery period send at least 4 early replies,
1389                  * spacing them every at_extra if we can. at_estimate should
1390                  * always equal this fixed value during recovery.
1391                  */
1392
1393                 /*
1394                  * Don't account request processing time into AT history
1395                  * during recovery, it is not service time we need but
1396                  * includes also waiting time for recovering clients
1397                  */
1398                 newdl = min_t(time64_t, at_extra,
1399                               obd_exp->obd_recovery_timeout / 4) +
1400                         ktime_get_real_seconds();
1401         } else {
1402                 /*
1403                  * We want to extend the request deadline by at_extra seconds,
1404                  * so we set our service estimate to reflect how much time has
1405                  * passed since this request arrived plus an additional
1406                  * at_extra seconds. The client will calculate the new deadline
1407                  * based on this service estimate (plus some additional time to
1408                  * account for network latency). See ptlrpc_at_recv_early_reply
1409                  */
1410                 at_measured(&svcpt->scp_at_estimate, at_extra +
1411                             ktime_get_real_seconds() -
1412                             req->rq_arrival_time.tv_sec);
1413                 newdl = req->rq_arrival_time.tv_sec +
1414                         at_get(&svcpt->scp_at_estimate);
1415         }
1416
1417         /*
1418          * Check to see if we've actually increased the deadline -
1419          * we may be past adaptive_max
1420          */
1421         if (req->rq_deadline >= newdl) {
1422                 DEBUG_REQ(D_WARNING, req, "Couldn't add any time (%lld/%lld), not sending early reply\n",
1423                           (s64)olddl, (s64)(newdl - ktime_get_real_seconds()));
1424                 RETURN(-ETIMEDOUT);
1425         }
1426
1427         reqcopy = ptlrpc_request_cache_alloc(GFP_NOFS);
1428         if (reqcopy == NULL)
1429                 RETURN(-ENOMEM);
1430         OBD_ALLOC_LARGE(reqmsg, req->rq_reqlen);
1431         if (!reqmsg)
1432                 GOTO(out_free, rc = -ENOMEM);
1433
1434         *reqcopy = *req;
1435         reqcopy->rq_reply_state = NULL;
1436         reqcopy->rq_rep_swab_mask = 0;
1437         reqcopy->rq_pack_bulk = 0;
1438         reqcopy->rq_pack_udesc = 0;
1439         reqcopy->rq_packed_final = 0;
1440         sptlrpc_svc_ctx_addref(reqcopy);
1441         /* We only need the reqmsg for the magic */
1442         reqcopy->rq_reqmsg = reqmsg;
1443         memcpy(reqmsg, req->rq_reqmsg, req->rq_reqlen);
1444
1445         /*
1446          * tgt_brw_read() and tgt_brw_write() may have decided not to reply.
1447          * Without this check, we would fail the rq_no_reply assertion in
1448          * ptlrpc_send_reply().
1449          */
1450         if (reqcopy->rq_no_reply)
1451                 GOTO(out, rc = -ETIMEDOUT);
1452
1453         LASSERT(atomic_read(&req->rq_refcount));
1454         /** if it is last refcount then early reply isn't needed */
1455         if (atomic_read(&req->rq_refcount) == 1) {
1456                 DEBUG_REQ(D_ADAPTTO, reqcopy,
1457                           "Normal reply already sent out, abort sending early reply\n");
1458                 GOTO(out, rc = -EINVAL);
1459         }
1460
1461         /* Connection ref */
1462         reqcopy->rq_export = class_conn2export(
1463                         lustre_msg_get_handle(reqcopy->rq_reqmsg));
1464         if (reqcopy->rq_export == NULL)
1465                 GOTO(out, rc = -ENODEV);
1466
1467         /* RPC ref */
1468         class_export_rpc_inc(reqcopy->rq_export);
1469         if (reqcopy->rq_export->exp_obd &&
1470             reqcopy->rq_export->exp_obd->obd_fail)
1471                 GOTO(out_put, rc = -ENODEV);
1472
1473         rc = lustre_pack_reply_flags(reqcopy, 1, NULL, NULL, LPRFL_EARLY_REPLY);
1474         if (rc)
1475                 GOTO(out_put, rc);
1476
1477         rc = ptlrpc_send_reply(reqcopy, PTLRPC_REPLY_EARLY);
1478
1479         if (!rc) {
1480                 /* Adjust our own deadline to what we told the client */
1481                 req->rq_deadline = newdl;
1482                 req->rq_early_count++; /* number sent, server side */
1483         } else {
1484                 DEBUG_REQ(D_ERROR, req, "Early reply send failed %d", rc);
1485         }
1486
1487         /*
1488          * Free the (early) reply state from lustre_pack_reply.
1489          * (ptlrpc_send_reply takes it's own rs ref, so this is safe here)
1490          */
1491         ptlrpc_req_drop_rs(reqcopy);
1492
1493 out_put:
1494         class_export_rpc_dec(reqcopy->rq_export);
1495         class_export_put(reqcopy->rq_export);
1496 out:
1497         sptlrpc_svc_ctx_decref(reqcopy);
1498         OBD_FREE_LARGE(reqmsg, req->rq_reqlen);
1499 out_free:
1500         ptlrpc_request_cache_free(reqcopy);
1501         RETURN(rc);
1502 }
1503
1504 /*
1505  * Send early replies to everybody expiring within at_early_margin
1506  * asking for at_extra time
1507  */
1508 static int ptlrpc_at_check_timed(struct ptlrpc_service_part *svcpt)
1509 {
1510         struct ptlrpc_at_array *array = &svcpt->scp_at_array;
1511         struct ptlrpc_request *rq, *n;
1512         struct list_head work_list;
1513         __u32 index, count;
1514         time64_t deadline;
1515         time64_t now = ktime_get_real_seconds();
1516         s64 delay;
1517         int first, counter = 0;
1518
1519         ENTRY;
1520         spin_lock(&svcpt->scp_at_lock);
1521         if (svcpt->scp_at_check == 0) {
1522                 spin_unlock(&svcpt->scp_at_lock);
1523                 RETURN(0);
1524         }
1525         delay = ktime_ms_delta(ktime_get(), svcpt->scp_at_checktime);
1526         svcpt->scp_at_check = 0;
1527
1528         if (array->paa_count == 0) {
1529                 spin_unlock(&svcpt->scp_at_lock);
1530                 RETURN(0);
1531         }
1532
1533         /* The timer went off, but maybe the nearest rpc already completed. */
1534         first = array->paa_deadline - now;
1535         if (first > at_early_margin) {
1536                 /* We've still got plenty of time.  Reset the timer. */
1537                 ptlrpc_at_set_timer(svcpt);
1538                 spin_unlock(&svcpt->scp_at_lock);
1539                 RETURN(0);
1540         }
1541
1542         /*
1543          * We're close to a timeout, and we don't know how much longer the
1544          * server will take. Send early replies to everyone expiring soon.
1545          */
1546         INIT_LIST_HEAD(&work_list);
1547         deadline = -1;
1548         div_u64_rem(array->paa_deadline, array->paa_size, &index);
1549         count = array->paa_count;
1550         while (count > 0) {
1551                 count -= array->paa_reqs_count[index];
1552                 list_for_each_entry_safe(rq, n,
1553                                          &array->paa_reqs_array[index],
1554                                          rq_timed_list) {
1555                         if (rq->rq_deadline > now + at_early_margin) {
1556                                 /* update the earliest deadline */
1557                                 if (deadline == -1 ||
1558                                     rq->rq_deadline < deadline)
1559                                         deadline = rq->rq_deadline;
1560                                 break;
1561                         }
1562
1563                         /**
1564                          * ptlrpc_server_drop_request() may drop
1565                          * refcount to 0 already. Let's check this and
1566                          * don't add entry to work_list
1567                          */
1568                         if (likely(atomic_inc_not_zero(&rq->rq_refcount))) {
1569                                 ptlrpc_at_remove_timed(rq);
1570                                 list_add(&rq->rq_timed_list, &work_list);
1571                         } else {
1572                                 ptlrpc_at_remove_timed(rq);
1573                         }
1574
1575                         counter++;
1576                 }
1577
1578                 if (++index >= array->paa_size)
1579                         index = 0;
1580         }
1581         array->paa_deadline = deadline;
1582         /* we have a new earliest deadline, restart the timer */
1583         ptlrpc_at_set_timer(svcpt);
1584
1585         spin_unlock(&svcpt->scp_at_lock);
1586
1587         CDEBUG(D_ADAPTTO,
1588                "timeout in %+ds, asking for %d secs on %d early replies\n",
1589                first, at_extra, counter);
1590         if (first < 0) {
1591                 /*
1592                  * We're already past request deadlines before we even get a
1593                  * chance to send early replies
1594                  */
1595                 LCONSOLE_WARN("%s: This server is not able to keep up with request traffic (cpu-bound).\n",
1596                               svcpt->scp_service->srv_name);
1597                 CWARN("earlyQ=%d reqQ=%d recA=%d, svcEst=%d, delay=%lld\n",
1598                       counter, svcpt->scp_nreqs_incoming,
1599                       svcpt->scp_nreqs_active,
1600                       at_get(&svcpt->scp_at_estimate), delay);
1601         }
1602
1603         /*
1604          * we took additional refcount so entries can't be deleted from list, no
1605          * locking is needed
1606          */
1607         while (!list_empty(&work_list)) {
1608                 rq = list_entry(work_list.next, struct ptlrpc_request,
1609                                 rq_timed_list);
1610                 list_del_init(&rq->rq_timed_list);
1611
1612                 if (ptlrpc_at_send_early_reply(rq) == 0)
1613                         ptlrpc_at_add_timed(rq);
1614
1615                 ptlrpc_server_drop_request(rq);
1616         }
1617
1618         RETURN(1); /* return "did_something" for liblustre */
1619 }
1620
1621 /*
1622  * Check if we are already handling earlier incarnation of this request.
1623  * Called under &req->rq_export->exp_rpc_lock locked
1624  */
1625 static struct ptlrpc_request*
1626 ptlrpc_server_check_resend_in_progress(struct ptlrpc_request *req)
1627 {
1628         struct ptlrpc_request *tmp = NULL;
1629
1630         if (!(lustre_msg_get_flags(req->rq_reqmsg) & MSG_RESENT) ||
1631             (atomic_read(&req->rq_export->exp_rpc_count) == 0))
1632                 return NULL;
1633
1634         /*
1635          * bulk request are aborted upon reconnect, don't try to
1636          * find a match
1637          */
1638         if (req->rq_bulk_write || req->rq_bulk_read)
1639                 return NULL;
1640
1641         /*
1642          * This list should not be longer than max_requests in
1643          * flights on the client, so it is not all that long.
1644          * Also we only hit this codepath in case of a resent
1645          * request which makes it even more rarely hit
1646          */
1647         list_for_each_entry(tmp, &req->rq_export->exp_reg_rpcs,
1648                                 rq_exp_list) {
1649                 /* Found duplicate one */
1650                 if (tmp->rq_xid == req->rq_xid)
1651                         goto found;
1652         }
1653         list_for_each_entry(tmp, &req->rq_export->exp_hp_rpcs,
1654                                 rq_exp_list) {
1655                 /* Found duplicate one */
1656                 if (tmp->rq_xid == req->rq_xid)
1657                         goto found;
1658         }
1659         return NULL;
1660
1661 found:
1662         DEBUG_REQ(D_HA, req, "Found duplicate req in processing");
1663         DEBUG_REQ(D_HA, tmp, "Request being processed");
1664         return tmp;
1665 }
1666
1667 /**
1668  * Check if a request should be assigned with a high priority.
1669  *
1670  * \retval      < 0: error occurred
1671  *                0: normal RPC request
1672  *               +1: high priority request
1673  */
1674 static int ptlrpc_server_hpreq_init(struct ptlrpc_service_part *svcpt,
1675                                     struct ptlrpc_request *req)
1676 {
1677         int rc = 0;
1678
1679         ENTRY;
1680         if (svcpt->scp_service->srv_ops.so_hpreq_handler != NULL) {
1681                 rc = svcpt->scp_service->srv_ops.so_hpreq_handler(req);
1682                 if (rc < 0)
1683                         RETURN(rc);
1684
1685                 LASSERT(rc == 0);
1686         }
1687
1688         if (req->rq_export != NULL && req->rq_ops != NULL) {
1689                 /*
1690                  * Perform request specific check. We should do this
1691                  * check before the request is added into exp_hp_rpcs
1692                  * list otherwise it may hit swab race at LU-1044.
1693                  */
1694                 if (req->rq_ops->hpreq_check != NULL) {
1695                         rc = req->rq_ops->hpreq_check(req);
1696                         if (rc == -ESTALE) {
1697                                 req->rq_status = rc;
1698                                 ptlrpc_error(req);
1699                         }
1700                         /*
1701                          * can only return error,
1702                          * 0 for normal request,
1703                          * or 1 for high priority request
1704                          */
1705                         LASSERT(rc <= 1);
1706                 }
1707         }
1708
1709         RETURN(rc);
1710 }
1711
1712 /** Remove the request from the export list. */
1713 static void ptlrpc_server_hpreq_fini(struct ptlrpc_request *req)
1714 {
1715         ENTRY;
1716         if (req->rq_export) {
1717                 /*
1718                  * refresh lock timeout again so that client has more
1719                  * room to send lock cancel RPC.
1720                  */
1721                 if (req->rq_ops && req->rq_ops->hpreq_fini)
1722                         req->rq_ops->hpreq_fini(req);
1723
1724                 spin_lock(&req->rq_export->exp_rpc_lock);
1725                 list_del_init(&req->rq_exp_list);
1726                 spin_unlock(&req->rq_export->exp_rpc_lock);
1727         }
1728         EXIT;
1729 }
1730
1731 static int ptlrpc_hpreq_check(struct ptlrpc_request *req)
1732 {
1733         return 1;
1734 }
1735
1736 static struct ptlrpc_hpreq_ops ptlrpc_hpreq_common = {
1737         .hpreq_check       = ptlrpc_hpreq_check,
1738 };
1739
1740 /* Hi-Priority RPC check by RPC operation code. */
1741 int ptlrpc_hpreq_handler(struct ptlrpc_request *req)
1742 {
1743         int opc = lustre_msg_get_opc(req->rq_reqmsg);
1744
1745         /*
1746          * Check for export to let only reconnects for not yet evicted
1747          * export to become a HP rpc.
1748          */
1749         if ((req->rq_export != NULL) &&
1750             (opc == OBD_PING || opc == MDS_CONNECT || opc == OST_CONNECT))
1751                 req->rq_ops = &ptlrpc_hpreq_common;
1752
1753         return 0;
1754 }
1755 EXPORT_SYMBOL(ptlrpc_hpreq_handler);
1756
1757 static int ptlrpc_server_request_add(struct ptlrpc_service_part *svcpt,
1758                                      struct ptlrpc_request *req)
1759 {
1760         int rc;
1761         bool hp;
1762         struct ptlrpc_request *orig;
1763
1764         ENTRY;
1765
1766         rc = ptlrpc_server_hpreq_init(svcpt, req);
1767         if (rc < 0)
1768                 RETURN(rc);
1769
1770         hp = rc > 0;
1771         ptlrpc_nrs_req_initialize(svcpt, req, hp);
1772
1773         if (req->rq_export != NULL) {
1774                 struct obd_export *exp = req->rq_export;
1775
1776                 /*
1777                  * do search for duplicated xid and the adding to the list
1778                  * atomically
1779                  */
1780                 spin_lock_bh(&exp->exp_rpc_lock);
1781                 orig = ptlrpc_server_check_resend_in_progress(req);
1782                 if (orig && likely(atomic_inc_not_zero(&orig->rq_refcount))) {
1783                         bool linked;
1784
1785                         spin_unlock_bh(&exp->exp_rpc_lock);
1786
1787                         /*
1788                          * When the client resend request and the server has
1789                          * the previous copy of it, we need to update deadlines,
1790                          * to be sure that the client and the server have equal
1791                          *  request deadlines.
1792                          */
1793
1794                         spin_lock(&orig->rq_rqbd->rqbd_svcpt->scp_at_lock);
1795                         linked = orig->rq_at_linked;
1796                         if (likely(linked))
1797                                 ptlrpc_at_remove_timed(orig);
1798                         spin_unlock(&orig->rq_rqbd->rqbd_svcpt->scp_at_lock);
1799                         orig->rq_deadline = req->rq_deadline;
1800                         if (likely(linked))
1801                                 ptlrpc_at_add_timed(orig);
1802                         ptlrpc_server_drop_request(orig);
1803                         ptlrpc_nrs_req_finalize(req);
1804                         RETURN(-EBUSY);
1805                 }
1806
1807                 if (hp || req->rq_ops != NULL)
1808                         list_add(&req->rq_exp_list, &exp->exp_hp_rpcs);
1809                 else
1810                         list_add(&req->rq_exp_list, &exp->exp_reg_rpcs);
1811                 spin_unlock_bh(&exp->exp_rpc_lock);
1812         }
1813
1814         /*
1815          * the current thread is not the processing thread for this request
1816          * since that, but request is in exp_hp_list and can be find there.
1817          * Remove all relations between request and old thread.
1818          */
1819         req->rq_svc_thread->t_env->le_ses = NULL;
1820         req->rq_svc_thread = NULL;
1821         req->rq_session.lc_thread = NULL;
1822
1823         ptlrpc_nrs_req_add(svcpt, req, hp);
1824
1825         RETURN(0);
1826 }
1827
1828 /**
1829  * Allow to handle high priority request
1830  * User can call it w/o any lock but need to hold
1831  * ptlrpc_service_part::scp_req_lock to get reliable result
1832  */
1833 static bool ptlrpc_server_allow_high(struct ptlrpc_service_part *svcpt,
1834                                      bool force)
1835 {
1836         int running = svcpt->scp_nthrs_running;
1837
1838         if (!nrs_svcpt_has_hp(svcpt))
1839                 return false;
1840
1841         if (force)
1842                 return true;
1843
1844         if (ptlrpc_nrs_req_throttling_nolock(svcpt, true))
1845                 return false;
1846
1847         if (unlikely(svcpt->scp_service->srv_req_portal == MDS_REQUEST_PORTAL &&
1848                      CFS_FAIL_PRECHECK(OBD_FAIL_PTLRPC_CANCEL_RESEND))) {
1849                 /* leave just 1 thread for normal RPCs */
1850                 running = PTLRPC_NTHRS_INIT;
1851                 if (svcpt->scp_service->srv_ops.so_hpreq_handler != NULL)
1852                         running += 1;
1853         }
1854
1855         if (svcpt->scp_nreqs_active >= running - 1)
1856                 return false;
1857
1858         if (svcpt->scp_nhreqs_active == 0)
1859                 return true;
1860
1861         return !ptlrpc_nrs_req_pending_nolock(svcpt, false) ||
1862                svcpt->scp_hreq_count < svcpt->scp_service->srv_hpreq_ratio;
1863 }
1864
1865 static bool ptlrpc_server_high_pending(struct ptlrpc_service_part *svcpt,
1866                                        bool force)
1867 {
1868         return ptlrpc_server_allow_high(svcpt, force) &&
1869                ptlrpc_nrs_req_pending_nolock(svcpt, true);
1870 }
1871
1872 /**
1873  * Only allow normal priority requests on a service that has a high-priority
1874  * queue if forced (i.e. cleanup), if there are other high priority requests
1875  * already being processed (i.e. those threads can service more high-priority
1876  * requests), or if there are enough idle threads that a later thread can do
1877  * a high priority request.
1878  * User can call it w/o any lock but need to hold
1879  * ptlrpc_service_part::scp_req_lock to get reliable result
1880  */
1881 static bool ptlrpc_server_allow_normal(struct ptlrpc_service_part *svcpt,
1882                                        bool force)
1883 {
1884         int running = svcpt->scp_nthrs_running;
1885
1886         if (unlikely(svcpt->scp_service->srv_req_portal == MDS_REQUEST_PORTAL &&
1887                      CFS_FAIL_PRECHECK(OBD_FAIL_PTLRPC_CANCEL_RESEND))) {
1888                 /* leave just 1 thread for normal RPCs */
1889                 running = PTLRPC_NTHRS_INIT;
1890                 if (svcpt->scp_service->srv_ops.so_hpreq_handler != NULL)
1891                         running += 1;
1892         }
1893
1894         if (force)
1895                 return true;
1896
1897         if (ptlrpc_nrs_req_throttling_nolock(svcpt, false))
1898                 return false;
1899
1900         if (svcpt->scp_nreqs_active < running - 2)
1901                 return true;
1902
1903         if (svcpt->scp_nreqs_active >= running - 1)
1904                 return false;
1905
1906         return svcpt->scp_nhreqs_active > 0 || !nrs_svcpt_has_hp(svcpt);
1907 }
1908
1909 static bool ptlrpc_server_normal_pending(struct ptlrpc_service_part *svcpt,
1910                                          bool force)
1911 {
1912         return ptlrpc_server_allow_normal(svcpt, force) &&
1913                ptlrpc_nrs_req_pending_nolock(svcpt, false);
1914 }
1915
1916 /**
1917  * Returns true if there are requests available in incoming
1918  * request queue for processing and it is allowed to fetch them.
1919  * User can call it w/o any lock but need to hold ptlrpc_service::scp_req_lock
1920  * to get reliable result
1921  * \see ptlrpc_server_allow_normal
1922  * \see ptlrpc_server_allow high
1923  */
1924 static inline
1925 bool ptlrpc_server_request_pending(struct ptlrpc_service_part *svcpt,
1926                                    bool force)
1927 {
1928         return ptlrpc_server_high_pending(svcpt, force) ||
1929                ptlrpc_server_normal_pending(svcpt, force);
1930 }
1931
1932 /**
1933  * Fetch a request for processing from queue of unprocessed requests.
1934  * Favors high-priority requests.
1935  * Returns a pointer to fetched request.
1936  */
1937 static struct ptlrpc_request *
1938 ptlrpc_server_request_get(struct ptlrpc_service_part *svcpt, bool force)
1939 {
1940         struct ptlrpc_request *req = NULL;
1941
1942         ENTRY;
1943
1944         spin_lock(&svcpt->scp_req_lock);
1945
1946         if (ptlrpc_server_high_pending(svcpt, force)) {
1947                 req = ptlrpc_nrs_req_get_nolock(svcpt, true, force);
1948                 if (req != NULL) {
1949                         svcpt->scp_hreq_count++;
1950                         goto got_request;
1951                 }
1952         }
1953
1954         if (ptlrpc_server_normal_pending(svcpt, force)) {
1955                 req = ptlrpc_nrs_req_get_nolock(svcpt, false, force);
1956                 if (req != NULL) {
1957                         svcpt->scp_hreq_count = 0;
1958                         goto got_request;
1959                 }
1960         }
1961
1962         spin_unlock(&svcpt->scp_req_lock);
1963         RETURN(NULL);
1964
1965 got_request:
1966         svcpt->scp_nreqs_active++;
1967         if (req->rq_hp)
1968                 svcpt->scp_nhreqs_active++;
1969
1970         spin_unlock(&svcpt->scp_req_lock);
1971
1972         if (likely(req->rq_export))
1973                 class_export_rpc_inc(req->rq_export);
1974
1975         RETURN(req);
1976 }
1977
1978 /**
1979  * Handle freshly incoming reqs, add to timed early reply list,
1980  * pass on to regular request queue.
1981  * All incoming requests pass through here before getting into
1982  * ptlrpc_server_handle_req later on.
1983  */
1984 static int ptlrpc_server_handle_req_in(struct ptlrpc_service_part *svcpt,
1985                                        struct ptlrpc_thread *thread)
1986 {
1987         struct ptlrpc_service *svc = svcpt->scp_service;
1988         struct ptlrpc_request *req;
1989         __u32 deadline;
1990         int rc;
1991
1992         ENTRY;
1993
1994         spin_lock(&svcpt->scp_lock);
1995         if (list_empty(&svcpt->scp_req_incoming)) {
1996                 spin_unlock(&svcpt->scp_lock);
1997                 RETURN(0);
1998         }
1999
2000         req = list_entry(svcpt->scp_req_incoming.next,
2001                              struct ptlrpc_request, rq_list);
2002         list_del_init(&req->rq_list);
2003         svcpt->scp_nreqs_incoming--;
2004         /*
2005          * Consider this still a "queued" request as far as stats are
2006          * concerned
2007          */
2008         spin_unlock(&svcpt->scp_lock);
2009
2010         /* go through security check/transform */
2011         rc = sptlrpc_svc_unwrap_request(req);
2012         switch (rc) {
2013         case SECSVC_OK:
2014                 break;
2015         case SECSVC_COMPLETE:
2016                 target_send_reply(req, 0, OBD_FAIL_MDS_ALL_REPLY_NET);
2017                 goto err_req;
2018         case SECSVC_DROP:
2019                 goto err_req;
2020         default:
2021                 LBUG();
2022         }
2023
2024         /*
2025          * for null-flavored rpc, msg has been unpacked by sptlrpc, although
2026          * redo it wouldn't be harmful.
2027          */
2028         if (SPTLRPC_FLVR_POLICY(req->rq_flvr.sf_rpc) != SPTLRPC_POLICY_NULL) {
2029                 rc = ptlrpc_unpack_req_msg(req, req->rq_reqlen);
2030                 if (rc != 0) {
2031                         CERROR("error unpacking request: ptl %d from %s x%llu\n",
2032                                svc->srv_req_portal, libcfs_id2str(req->rq_peer),
2033                                req->rq_xid);
2034                         goto err_req;
2035                 }
2036         }
2037
2038         rc = lustre_unpack_req_ptlrpc_body(req, MSG_PTLRPC_BODY_OFF);
2039         if (rc) {
2040                 CERROR("error unpacking ptlrpc body: ptl %d from %s x %llu\n",
2041                        svc->srv_req_portal, libcfs_id2str(req->rq_peer),
2042                        req->rq_xid);
2043                 goto err_req;
2044         }
2045
2046         if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_DROP_REQ_OPC) &&
2047             lustre_msg_get_opc(req->rq_reqmsg) == cfs_fail_val) {
2048                 CERROR("drop incoming rpc opc %u, x%llu\n",
2049                        cfs_fail_val, req->rq_xid);
2050                 goto err_req;
2051         }
2052
2053         rc = -EINVAL;
2054         if (lustre_msg_get_type(req->rq_reqmsg) != PTL_RPC_MSG_REQUEST) {
2055                 CERROR("wrong packet type received (type=%u) from %s\n",
2056                        lustre_msg_get_type(req->rq_reqmsg),
2057                        libcfs_id2str(req->rq_peer));
2058                 goto err_req;
2059         }
2060
2061         switch (lustre_msg_get_opc(req->rq_reqmsg)) {
2062         case MDS_WRITEPAGE:
2063         case OST_WRITE:
2064         case OUT_UPDATE:
2065                 req->rq_bulk_write = 1;
2066                 break;
2067         case MDS_READPAGE:
2068         case OST_READ:
2069         case MGS_CONFIG_READ:
2070                 req->rq_bulk_read = 1;
2071                 break;
2072         }
2073
2074         CDEBUG(D_RPCTRACE, "got req x%llu\n", req->rq_xid);
2075
2076         req->rq_export = class_conn2export(
2077                 lustre_msg_get_handle(req->rq_reqmsg));
2078         if (req->rq_export) {
2079                 rc = ptlrpc_check_req(req);
2080                 if (rc == 0) {
2081                         rc = sptlrpc_target_export_check(req->rq_export, req);
2082                         if (rc)
2083                                 DEBUG_REQ(D_ERROR, req,
2084                                           "DROPPING req with illegal security flavor,");
2085                 }
2086
2087                 if (rc)
2088                         goto err_req;
2089                 ptlrpc_update_export_timer(req->rq_export, 0);
2090         }
2091
2092         /* req_in handling should/must be fast */
2093         if (ktime_get_real_seconds() - req->rq_arrival_time.tv_sec > 5)
2094                 DEBUG_REQ(D_WARNING, req, "Slow req_in handling %llds",
2095                           (s64)(ktime_get_real_seconds() -
2096                                 req->rq_arrival_time.tv_sec));
2097
2098         /* Set rpc server deadline and add it to the timed list */
2099         deadline = (lustre_msghdr_get_flags(req->rq_reqmsg) &
2100                     MSGHDR_AT_SUPPORT) ?
2101                     /* The max time the client expects us to take */
2102                     lustre_msg_get_timeout(req->rq_reqmsg) : obd_timeout;
2103
2104         req->rq_deadline = req->rq_arrival_time.tv_sec + deadline;
2105         if (unlikely(deadline == 0)) {
2106                 DEBUG_REQ(D_ERROR, req, "Dropping request with 0 timeout");
2107                 goto err_req;
2108         }
2109
2110         /* Skip early reply */
2111         if (OBD_FAIL_PRECHECK(OBD_FAIL_MDS_RESEND))
2112                 req->rq_deadline += obd_timeout;
2113
2114         req->rq_svc_thread = thread;
2115         if (thread != NULL) {
2116                 /*
2117                  * initialize request session, it is needed for request
2118                  * processing by target
2119                  */
2120                 rc = lu_context_init(&req->rq_session, LCT_SERVER_SESSION |
2121                                                        LCT_NOREF);
2122                 if (rc) {
2123                         CERROR("%s: failure to initialize session: rc = %d\n",
2124                                thread->t_name, rc);
2125                         goto err_req;
2126                 }
2127                 req->rq_session.lc_thread = thread;
2128                 lu_context_enter(&req->rq_session);
2129                 thread->t_env->le_ses = &req->rq_session;
2130         }
2131
2132         ptlrpc_at_add_timed(req);
2133
2134         /* Move it over to the request processing queue */
2135         rc = ptlrpc_server_request_add(svcpt, req);
2136         if (rc)
2137                 GOTO(err_req, rc);
2138
2139         wake_up(&svcpt->scp_waitq);
2140         RETURN(1);
2141
2142 err_req:
2143         ptlrpc_server_finish_request(svcpt, req);
2144
2145         RETURN(1);
2146 }
2147
2148 /**
2149  * Main incoming request handling logic.
2150  * Calls handler function from service to do actual processing.
2151  */
2152 static int ptlrpc_server_handle_request(struct ptlrpc_service_part *svcpt,
2153                                         struct ptlrpc_thread *thread)
2154 {
2155         struct ptlrpc_service *svc = svcpt->scp_service;
2156         struct ptlrpc_request *request;
2157         ktime_t work_start;
2158         ktime_t work_end;
2159         ktime_t arrived;
2160         s64 timediff_usecs;
2161         s64 arrived_usecs;
2162         int fail_opc = 0;
2163
2164         ENTRY;
2165
2166         request = ptlrpc_server_request_get(svcpt, false);
2167         if (request == NULL)
2168                 RETURN(0);
2169
2170         if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_HPREQ_NOTIMEOUT))
2171                 fail_opc = OBD_FAIL_PTLRPC_HPREQ_NOTIMEOUT;
2172         else if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_HPREQ_TIMEOUT))
2173                 fail_opc = OBD_FAIL_PTLRPC_HPREQ_TIMEOUT;
2174
2175         if (unlikely(fail_opc)) {
2176                 if (request->rq_export && request->rq_ops)
2177                         OBD_FAIL_TIMEOUT(fail_opc, 4);
2178         }
2179
2180         ptlrpc_rqphase_move(request, RQ_PHASE_INTERPRET);
2181
2182         if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_DUMP_LOG))
2183                 libcfs_debug_dumplog();
2184
2185         work_start = ktime_get_real();
2186         arrived = timespec64_to_ktime(request->rq_arrival_time);
2187         timediff_usecs = ktime_us_delta(work_start, arrived);
2188         if (likely(svc->srv_stats != NULL)) {
2189                 lprocfs_counter_add(svc->srv_stats, PTLRPC_REQWAIT_CNTR,
2190                                     timediff_usecs);
2191                 lprocfs_counter_add(svc->srv_stats, PTLRPC_REQQDEPTH_CNTR,
2192                                     svcpt->scp_nreqs_incoming);
2193                 lprocfs_counter_add(svc->srv_stats, PTLRPC_REQACTIVE_CNTR,
2194                                     svcpt->scp_nreqs_active);
2195                 lprocfs_counter_add(svc->srv_stats, PTLRPC_TIMEOUT,
2196                                     at_get(&svcpt->scp_at_estimate));
2197         }
2198
2199         if (likely(request->rq_export)) {
2200                 if (unlikely(ptlrpc_check_req(request)))
2201                         goto put_conn;
2202                 ptlrpc_update_export_timer(request->rq_export,
2203                                            div_u64(timediff_usecs,
2204                                                    USEC_PER_SEC / 2));
2205         }
2206
2207         /*
2208          * Discard requests queued for longer than the deadline.
2209          * The deadline is increased if we send an early reply.
2210          */
2211         if (ktime_get_real_seconds() > request->rq_deadline) {
2212                 DEBUG_REQ(D_ERROR, request, "Dropping timed-out request from %s: deadline %lld:%llds ago\n",
2213                           libcfs_id2str(request->rq_peer),
2214                           request->rq_deadline -
2215                           request->rq_arrival_time.tv_sec,
2216                           ktime_get_real_seconds() - request->rq_deadline);
2217                 goto put_conn;
2218         }
2219
2220         CDEBUG(D_RPCTRACE,
2221                "Handling RPC pname:cluuid+ref:pid:xid:nid:opc %s:%s+%d:%d:x%llu:%s:%d\n",
2222                current_comm(),
2223                (request->rq_export ?
2224                 (char *)request->rq_export->exp_client_uuid.uuid : "0"),
2225                (request->rq_export ?
2226                 atomic_read(&request->rq_export->exp_refcount) : -99),
2227                lustre_msg_get_status(request->rq_reqmsg), request->rq_xid,
2228                libcfs_id2str(request->rq_peer),
2229                lustre_msg_get_opc(request->rq_reqmsg));
2230
2231         if (lustre_msg_get_opc(request->rq_reqmsg) != OBD_PING)
2232                 CFS_FAIL_TIMEOUT_MS(OBD_FAIL_PTLRPC_PAUSE_REQ, cfs_fail_val);
2233
2234         CDEBUG(D_NET, "got req %llu\n", request->rq_xid);
2235
2236         /* re-assign request and sesson thread to the current one */
2237         request->rq_svc_thread = thread;
2238         if (thread != NULL) {
2239                 LASSERT(request->rq_session.lc_thread == NULL);
2240                 request->rq_session.lc_thread = thread;
2241                 thread->t_env->le_ses = &request->rq_session;
2242         }
2243         svc->srv_ops.so_req_handler(request);
2244
2245         ptlrpc_rqphase_move(request, RQ_PHASE_COMPLETE);
2246
2247 put_conn:
2248         if (unlikely(ktime_get_real_seconds() > request->rq_deadline)) {
2249                 DEBUG_REQ(D_WARNING, request,
2250                           "Request took longer than estimated (%lld:%llds); "
2251                           "client may timeout.",
2252                           request->rq_deadline -
2253                           request->rq_arrival_time.tv_sec,
2254                           ktime_get_real_seconds() - request->rq_deadline);
2255         }
2256
2257         work_end = ktime_get_real();
2258         timediff_usecs = ktime_us_delta(work_end, work_start);
2259         arrived_usecs = ktime_us_delta(work_end, arrived);
2260         CDEBUG(D_RPCTRACE,
2261                "Handled RPC pname:cluuid+ref:pid:xid:nid:opc %s:%s+%d:%d:x%llu:%s:%d Request processed in %lldus (%lldus total) trans %llu rc %d/%d\n",
2262                current_comm(),
2263                (request->rq_export ?
2264                (char *)request->rq_export->exp_client_uuid.uuid : "0"),
2265                (request->rq_export ?
2266                atomic_read(&request->rq_export->exp_refcount) : -99),
2267                lustre_msg_get_status(request->rq_reqmsg),
2268                request->rq_xid,
2269                libcfs_id2str(request->rq_peer),
2270                lustre_msg_get_opc(request->rq_reqmsg),
2271                timediff_usecs,
2272                arrived_usecs,
2273                (request->rq_repmsg ?
2274                lustre_msg_get_transno(request->rq_repmsg) :
2275                request->rq_transno),
2276                request->rq_status,
2277                (request->rq_repmsg ?
2278                lustre_msg_get_status(request->rq_repmsg) : -999));
2279         if (likely(svc->srv_stats != NULL && request->rq_reqmsg != NULL)) {
2280                 __u32 op = lustre_msg_get_opc(request->rq_reqmsg);
2281                 int opc = opcode_offset(op);
2282
2283                 if (opc > 0 && !(op == LDLM_ENQUEUE || op == MDS_REINT)) {
2284                         LASSERT(opc < LUSTRE_MAX_OPCODES);
2285                         lprocfs_counter_add(svc->srv_stats,
2286                                             opc + EXTRA_MAX_OPCODES,
2287                                             timediff_usecs);
2288                 }
2289         }
2290         if (unlikely(request->rq_early_count)) {
2291                 DEBUG_REQ(D_ADAPTTO, request,
2292                           "sent %d early replies before finishing in %llds",
2293                           request->rq_early_count,
2294                           div_u64(arrived_usecs, USEC_PER_SEC));
2295         }
2296
2297         ptlrpc_server_finish_active_request(svcpt, request);
2298
2299         RETURN(1);
2300 }
2301
2302 /**
2303  * An internal function to process a single reply state object.
2304  */
2305 static int ptlrpc_handle_rs(struct ptlrpc_reply_state *rs)
2306 {
2307         struct ptlrpc_service_part *svcpt = rs->rs_svcpt;
2308         struct ptlrpc_service *svc = svcpt->scp_service;
2309         struct obd_export *exp;
2310         int nlocks;
2311         int been_handled;
2312
2313         ENTRY;
2314
2315         exp = rs->rs_export;
2316
2317         LASSERT(rs->rs_difficult);
2318         LASSERT(rs->rs_scheduled);
2319         LASSERT(list_empty(&rs->rs_list));
2320
2321         /*
2322          * The disk commit callback holds exp_uncommitted_replies_lock while it
2323          * iterates over newly committed replies, removing them from
2324          * exp_uncommitted_replies.  It then drops this lock and schedules the
2325          * replies it found for handling here.
2326          *
2327          * We can avoid contention for exp_uncommitted_replies_lock between the
2328          * HRT threads and further commit callbacks by checking rs_committed
2329          * which is set in the commit callback while it holds both
2330          * rs_lock and exp_uncommitted_reples.
2331          *
2332          * If we see rs_committed clear, the commit callback _may_ not have
2333          * handled this reply yet and we race with it to grab
2334          * exp_uncommitted_replies_lock before removing the reply from
2335          * exp_uncommitted_replies.  Note that if we lose the race and the
2336          * reply has already been removed, list_del_init() is a noop.
2337          *
2338          * If we see rs_committed set, we know the commit callback is handling,
2339          * or has handled this reply since store reordering might allow us to
2340          * see rs_committed set out of sequence.  But since this is done
2341          * holding rs_lock, we can be sure it has all completed once we hold
2342          * rs_lock, which we do right next.
2343          */
2344         if (!rs->rs_committed) {
2345                 /*
2346                  * if rs was commited, no need to convert locks, don't check
2347                  * rs_committed here because rs may never be added into
2348                  * exp_uncommitted_replies and this flag never be set, see
2349                  * target_send_reply()
2350                  */
2351                 if (rs->rs_convert_lock &&
2352                     rs->rs_transno > exp->exp_last_committed) {
2353                         struct ldlm_lock *lock;
2354                         struct ldlm_lock *ack_locks[RS_MAX_LOCKS] = { NULL };
2355
2356                         spin_lock(&rs->rs_lock);
2357                         if (rs->rs_convert_lock &&
2358                             rs->rs_transno > exp->exp_last_committed) {
2359                                 nlocks = rs->rs_nlocks;
2360                                 while (nlocks-- > 0) {
2361                                         /*
2362                                          * NB don't assume rs is always handled
2363                                          * by the same service thread (see
2364                                          * ptlrpc_hr_select, so REP-ACK hr may
2365                                          * race with trans commit, while the
2366                                          * latter will release locks, get locks
2367                                          * here early to convert to COS mode
2368                                          * safely.
2369                                          */
2370                                         lock = ldlm_handle2lock(
2371                                                         &rs->rs_locks[nlocks]);
2372                                         LASSERT(lock);
2373                                         ack_locks[nlocks] = lock;
2374                                         rs->rs_modes[nlocks] = LCK_COS;
2375                                 }
2376                                 nlocks = rs->rs_nlocks;
2377                                 rs->rs_convert_lock = 0;
2378                                 /*
2379                                  * clear rs_scheduled so that commit callback
2380                                  * can schedule again
2381                                  */
2382                                 rs->rs_scheduled = 0;
2383                                 spin_unlock(&rs->rs_lock);
2384
2385                                 while (nlocks-- > 0) {
2386                                         lock = ack_locks[nlocks];
2387                                         ldlm_lock_mode_downgrade(lock, LCK_COS);
2388                                         LDLM_LOCK_PUT(lock);
2389                                 }
2390                                 RETURN(0);
2391                         }
2392                         spin_unlock(&rs->rs_lock);
2393                 }
2394
2395                 spin_lock(&exp->exp_uncommitted_replies_lock);
2396                 list_del_init(&rs->rs_obd_list);
2397                 spin_unlock(&exp->exp_uncommitted_replies_lock);
2398         }
2399
2400         spin_lock(&exp->exp_lock);
2401         /* Noop if removed already */
2402         list_del_init(&rs->rs_exp_list);
2403         spin_unlock(&exp->exp_lock);
2404
2405         spin_lock(&rs->rs_lock);
2406
2407         been_handled = rs->rs_handled;
2408         rs->rs_handled = 1;
2409
2410         nlocks = rs->rs_nlocks; /* atomic "steal", but */
2411         rs->rs_nlocks = 0; /* locks still on rs_locks! */
2412
2413         if (nlocks == 0 && !been_handled) {
2414                 /*
2415                  * If we see this, we should already have seen the warning
2416                  * in mds_steal_ack_locks()
2417                  */
2418                 CDEBUG(D_HA,
2419                        "All locks stolen from rs %p x%lld.t%lld o%d NID %s\n",
2420                        rs, rs->rs_xid, rs->rs_transno, rs->rs_opc,
2421                        libcfs_nid2str(exp->exp_connection->c_peer.nid));
2422         }
2423
2424         if ((!been_handled && rs->rs_on_net) || nlocks > 0) {
2425                 spin_unlock(&rs->rs_lock);
2426
2427                 if (!been_handled && rs->rs_on_net) {
2428                         LNetMDUnlink(rs->rs_md_h);
2429                         /* Ignore return code; we're racing with completion */
2430                 }
2431
2432                 while (nlocks-- > 0)
2433                         ldlm_lock_decref(&rs->rs_locks[nlocks],
2434                                          rs->rs_modes[nlocks]);
2435
2436                 spin_lock(&rs->rs_lock);
2437         }
2438
2439         rs->rs_scheduled = 0;
2440         rs->rs_convert_lock = 0;
2441
2442         if (!rs->rs_on_net) {
2443                 /* Off the net */
2444                 spin_unlock(&rs->rs_lock);
2445
2446                 class_export_put(exp);
2447                 rs->rs_export = NULL;
2448                 ptlrpc_rs_decref(rs);
2449                 if (atomic_dec_and_test(&svcpt->scp_nreps_difficult) &&
2450                     svc->srv_is_stopping)
2451                         wake_up_all(&svcpt->scp_waitq);
2452                 RETURN(1);
2453         }
2454
2455         /* still on the net; callback will schedule */
2456         spin_unlock(&rs->rs_lock);
2457         RETURN(1);
2458 }
2459
2460
2461 static void ptlrpc_check_rqbd_pool(struct ptlrpc_service_part *svcpt)
2462 {
2463         int avail = svcpt->scp_nrqbds_posted;
2464         int low_water = test_req_buffer_pressure ? 0 :
2465                         svcpt->scp_service->srv_nbuf_per_group / 2;
2466
2467         /* NB I'm not locking; just looking. */
2468
2469         /*
2470          * CAVEAT EMPTOR: We might be allocating buffers here because we've
2471          * allowed the request history to grow out of control.  We could put a
2472          * sanity check on that here and cull some history if we need the
2473          * space.
2474          */
2475
2476         if (avail <= low_water)
2477                 ptlrpc_grow_req_bufs(svcpt, 1);
2478
2479         if (svcpt->scp_service->srv_stats) {
2480                 lprocfs_counter_add(svcpt->scp_service->srv_stats,
2481                                     PTLRPC_REQBUF_AVAIL_CNTR, avail);
2482         }
2483 }
2484
2485 static int ptlrpc_retry_rqbds(void *arg)
2486 {
2487         struct ptlrpc_service_part *svcpt = (struct ptlrpc_service_part *)arg;
2488
2489         svcpt->scp_rqbd_timeout = 0;
2490         return -ETIMEDOUT;
2491 }
2492
2493 static inline int ptlrpc_threads_enough(struct ptlrpc_service_part *svcpt)
2494 {
2495         return svcpt->scp_nreqs_active <
2496                svcpt->scp_nthrs_running - 1 -
2497                (svcpt->scp_service->srv_ops.so_hpreq_handler != NULL);
2498 }
2499
2500 /**
2501  * allowed to create more threads
2502  * user can call it w/o any lock but need to hold
2503  * ptlrpc_service_part::scp_lock to get reliable result
2504  */
2505 static inline int ptlrpc_threads_increasable(struct ptlrpc_service_part *svcpt)
2506 {
2507         return svcpt->scp_nthrs_running +
2508                svcpt->scp_nthrs_starting <
2509                svcpt->scp_service->srv_nthrs_cpt_limit;
2510 }
2511
2512 /**
2513  * too many requests and allowed to create more threads
2514  */
2515 static inline int ptlrpc_threads_need_create(struct ptlrpc_service_part *svcpt)
2516 {
2517         return !ptlrpc_threads_enough(svcpt) &&
2518                 ptlrpc_threads_increasable(svcpt);
2519 }
2520
2521 static inline int ptlrpc_thread_stopping(struct ptlrpc_thread *thread)
2522 {
2523         return thread_is_stopping(thread) ||
2524                thread->t_svcpt->scp_service->srv_is_stopping;
2525 }
2526
2527 /* stop the highest numbered thread if there are too many threads running */
2528 static inline bool ptlrpc_thread_should_stop(struct ptlrpc_thread *thread)
2529 {
2530         struct ptlrpc_service_part *svcpt = thread->t_svcpt;
2531
2532         return thread->t_id >= svcpt->scp_service->srv_nthrs_cpt_limit &&
2533                 thread->t_id == svcpt->scp_thr_nextid - 1;
2534 }
2535
2536 static void ptlrpc_stop_thread(struct ptlrpc_thread *thread)
2537 {
2538         CDEBUG(D_INFO, "Stopping thread %s #%u\n",
2539                thread->t_svcpt->scp_service->srv_thread_name, thread->t_id);
2540         thread_add_flags(thread, SVC_STOPPING);
2541 }
2542
2543 static inline void ptlrpc_thread_stop(struct ptlrpc_thread *thread)
2544 {
2545         struct ptlrpc_service_part *svcpt = thread->t_svcpt;
2546
2547         spin_lock(&svcpt->scp_lock);
2548         if (ptlrpc_thread_should_stop(thread)) {
2549                 ptlrpc_stop_thread(thread);
2550                 svcpt->scp_thr_nextid--;
2551         }
2552         spin_unlock(&svcpt->scp_lock);
2553 }
2554
2555 static inline int ptlrpc_rqbd_pending(struct ptlrpc_service_part *svcpt)
2556 {
2557         return !list_empty(&svcpt->scp_rqbd_idle) &&
2558                svcpt->scp_rqbd_timeout == 0;
2559 }
2560
2561 static inline int
2562 ptlrpc_at_check(struct ptlrpc_service_part *svcpt)
2563 {
2564         return svcpt->scp_at_check;
2565 }
2566
2567 /*
2568  * If a thread runs too long or spends to much time on a single request,
2569  * we want to know about it, so we set up a delayed work item as a watchdog.
2570  * If it fires, we display a stack trace of the delayed thread,
2571  * providing we aren't rate-limited
2572  *
2573  * Watchdog stack traces are limited to 3 per 'libcfs_watchdog_ratelimit'
2574  * seconds
2575  */
2576 static struct ratelimit_state watchdog_limit;
2577
2578 static void ptlrpc_watchdog_fire(struct work_struct *w)
2579 {
2580         struct ptlrpc_thread *thread = container_of(w, struct ptlrpc_thread,
2581                                                     t_watchdog.work);
2582         u64 ms_lapse = ktime_ms_delta(ktime_get(), thread->t_touched);
2583         u32 ms_frac = do_div(ms_lapse, MSEC_PER_SEC);
2584
2585         if (!__ratelimit(&watchdog_limit)) {
2586                 LCONSOLE_WARN("%s: service thread pid %u was inactive for %llu.%03u seconds. The thread might be hung, or it might only be slow and will resume later. Dumping the stack trace for debugging purposes:\n",
2587                               thread->t_task->comm, thread->t_task->pid,
2588                               ms_lapse, ms_frac);
2589
2590                 libcfs_debug_dumpstack(thread->t_task);
2591         } else {
2592                 LCONSOLE_WARN("%s: service thread pid %u was inactive for %llu.%03u seconds. Watchdog stack traces are limited to 3 per %u seconds, skipping this one.\n",
2593                               thread->t_task->comm, thread->t_task->pid,
2594                               ms_lapse, ms_frac, libcfs_watchdog_ratelimit);
2595         }
2596 }
2597
2598 static void ptlrpc_watchdog_init(struct delayed_work *work, time_t time)
2599 {
2600         INIT_DELAYED_WORK(work, ptlrpc_watchdog_fire);
2601         schedule_delayed_work(work, cfs_time_seconds(time));
2602 }
2603
2604 static void ptlrpc_watchdog_disable(struct delayed_work *work)
2605 {
2606         cancel_delayed_work_sync(work);
2607 }
2608
2609 static void ptlrpc_watchdog_touch(struct delayed_work *work, time_t time)
2610 {
2611         struct ptlrpc_thread *thread = container_of(&work->work,
2612                                                     struct ptlrpc_thread,
2613                                                     t_watchdog.work);
2614         thread->t_touched = ktime_get();
2615         mod_delayed_work(system_wq, work, cfs_time_seconds(time));
2616 }
2617
2618 /**
2619  * requests wait on preprocessing
2620  * user can call it w/o any lock but need to hold
2621  * ptlrpc_service_part::scp_lock to get reliable result
2622  */
2623 static inline int
2624 ptlrpc_server_request_incoming(struct ptlrpc_service_part *svcpt)
2625 {
2626         return !list_empty(&svcpt->scp_req_incoming);
2627 }
2628
2629 static __attribute__((__noinline__)) int
2630 ptlrpc_wait_event(struct ptlrpc_service_part *svcpt,
2631                   struct ptlrpc_thread *thread)
2632 {
2633         /* Don't exit while there are replies to be handled */
2634         struct l_wait_info lwi = LWI_TIMEOUT(svcpt->scp_rqbd_timeout,
2635                                              ptlrpc_retry_rqbds, svcpt);
2636
2637         ptlrpc_watchdog_disable(&thread->t_watchdog);
2638
2639         cond_resched();
2640
2641         l_wait_event_exclusive_head(svcpt->scp_waitq,
2642                                 ptlrpc_thread_stopping(thread) ||
2643                                 ptlrpc_server_request_incoming(svcpt) ||
2644                                 ptlrpc_server_request_pending(svcpt, false) ||
2645                                 ptlrpc_rqbd_pending(svcpt) ||
2646                                 ptlrpc_at_check(svcpt), &lwi);
2647
2648         if (ptlrpc_thread_stopping(thread))
2649                 return -EINTR;
2650
2651         ptlrpc_watchdog_touch(&thread->t_watchdog,
2652                               ptlrpc_server_get_timeout(svcpt));
2653         return 0;
2654 }
2655
2656 /**
2657  * Main thread body for service threads.
2658  * Waits in a loop waiting for new requests to process to appear.
2659  * Every time an incoming requests is added to its queue, a waitq
2660  * is woken up and one of the threads will handle it.
2661  */
2662 static int ptlrpc_main(void *arg)
2663 {
2664         struct ptlrpc_thread *thread = (struct ptlrpc_thread *)arg;
2665         struct ptlrpc_service_part *svcpt = thread->t_svcpt;
2666         struct ptlrpc_service *svc = svcpt->scp_service;
2667         struct ptlrpc_reply_state *rs;
2668         struct group_info *ginfo = NULL;
2669         struct lu_env *env;
2670         int counter = 0, rc = 0;
2671
2672         ENTRY;
2673
2674         thread->t_task = current;
2675         thread->t_pid = current_pid();
2676         unshare_fs_struct();
2677
2678         if (svc->srv_cpt_bind) {
2679                 rc = cfs_cpt_bind(svc->srv_cptable, svcpt->scp_cpt);
2680                 if (rc != 0) {
2681                         CWARN("%s: failed to bind %s on CPT %d\n",
2682                               svc->srv_name, thread->t_name, svcpt->scp_cpt);
2683                 }
2684         }
2685
2686         ginfo = groups_alloc(0);
2687         if (!ginfo)
2688                 GOTO(out, rc = -ENOMEM);
2689
2690         set_current_groups(ginfo);
2691         put_group_info(ginfo);
2692
2693         if (svc->srv_ops.so_thr_init != NULL) {
2694                 rc = svc->srv_ops.so_thr_init(thread);
2695                 if (rc)
2696                         GOTO(out, rc);
2697         }
2698
2699         OBD_ALLOC_PTR(env);
2700         if (env == NULL)
2701                 GOTO(out_srv_fini, rc = -ENOMEM);
2702         rc = lu_env_add(env);
2703         if (rc)
2704                 GOTO(out_env, rc);
2705
2706         rc = lu_context_init(&env->le_ctx,
2707                              svc->srv_ctx_tags|LCT_REMEMBER|LCT_NOREF);
2708         if (rc)
2709                 GOTO(out_env_remove, rc);
2710
2711         thread->t_env = env;
2712         env->le_ctx.lc_thread = thread;
2713         env->le_ctx.lc_cookie = 0x6;
2714
2715         while (!list_empty(&svcpt->scp_rqbd_idle)) {
2716                 rc = ptlrpc_server_post_idle_rqbds(svcpt);
2717                 if (rc >= 0)
2718                         continue;
2719
2720                 CERROR("Failed to post rqbd for %s on CPT %d: %d\n",
2721                         svc->srv_name, svcpt->scp_cpt, rc);
2722                 GOTO(out_ctx_fini, rc);
2723         }
2724
2725         /* Alloc reply state structure for this one */
2726         OBD_ALLOC_LARGE(rs, svc->srv_max_reply_size);
2727         if (!rs)
2728                 GOTO(out_ctx_fini, rc = -ENOMEM);
2729
2730         spin_lock(&svcpt->scp_lock);
2731
2732         LASSERT(thread_is_starting(thread));
2733         thread_clear_flags(thread, SVC_STARTING);
2734
2735         LASSERT(svcpt->scp_nthrs_starting == 1);
2736         svcpt->scp_nthrs_starting--;
2737
2738         /*
2739          * SVC_STOPPING may already be set here if someone else is trying
2740          * to stop the service while this new thread has been dynamically
2741          * forked. We still set SVC_RUNNING to let our creator know that
2742          * we are now running, however we will exit as soon as possible
2743          */
2744         thread_add_flags(thread, SVC_RUNNING);
2745         svcpt->scp_nthrs_running++;
2746         spin_unlock(&svcpt->scp_lock);
2747
2748         /* wake up our creator in case he's still waiting. */
2749         wake_up(&thread->t_ctl_waitq);
2750
2751         thread->t_touched = ktime_get();
2752         ptlrpc_watchdog_init(&thread->t_watchdog,
2753                          ptlrpc_server_get_timeout(svcpt));
2754
2755         spin_lock(&svcpt->scp_rep_lock);
2756         list_add(&rs->rs_list, &svcpt->scp_rep_idle);
2757         wake_up(&svcpt->scp_rep_waitq);
2758         spin_unlock(&svcpt->scp_rep_lock);
2759
2760         CDEBUG(D_NET, "service thread %d (#%d) started\n", thread->t_id,
2761                svcpt->scp_nthrs_running);
2762
2763         /* XXX maintain a list of all managed devices: insert here */
2764         while (!ptlrpc_thread_stopping(thread)) {
2765                 if (ptlrpc_wait_event(svcpt, thread))
2766                         break;
2767
2768                 ptlrpc_check_rqbd_pool(svcpt);
2769
2770                 if (ptlrpc_threads_need_create(svcpt)) {
2771                         /* Ignore return code - we tried... */
2772                         ptlrpc_start_thread(svcpt, 0);
2773                 }
2774
2775                 /* reset le_ses to initial state */
2776                 env->le_ses = NULL;
2777                 /* Process all incoming reqs before handling any */
2778                 if (ptlrpc_server_request_incoming(svcpt)) {
2779                         lu_context_enter(&env->le_ctx);
2780                         ptlrpc_server_handle_req_in(svcpt, thread);
2781                         lu_context_exit(&env->le_ctx);
2782
2783                         /* but limit ourselves in case of flood */
2784                         if (counter++ < 100)
2785                                 continue;
2786                         counter = 0;
2787                 }
2788
2789                 if (ptlrpc_at_check(svcpt))
2790                         ptlrpc_at_check_timed(svcpt);
2791
2792                 if (ptlrpc_server_request_pending(svcpt, false)) {
2793                         lu_context_enter(&env->le_ctx);
2794                         ptlrpc_server_handle_request(svcpt, thread);
2795                         lu_context_exit(&env->le_ctx);
2796                 }
2797
2798                 if (ptlrpc_rqbd_pending(svcpt) &&
2799                     ptlrpc_server_post_idle_rqbds(svcpt) < 0) {
2800                         /*
2801                          * I just failed to repost request buffers.
2802                          * Wait for a timeout (unless something else
2803                          * happens) before I try again
2804                          */
2805                         svcpt->scp_rqbd_timeout = cfs_time_seconds(1) / 10;
2806                         CDEBUG(D_RPCTRACE, "Posted buffers: %d\n",
2807                                svcpt->scp_nrqbds_posted);
2808                 }
2809                 /*
2810                  * If the number of threads has been tuned downward and this
2811                  * thread should be stopped, then stop in reverse order so the
2812                  * the threads always have contiguous thread index values.
2813                  */
2814                 if (unlikely(ptlrpc_thread_should_stop(thread)))
2815                         ptlrpc_thread_stop(thread);
2816         }
2817
2818         ptlrpc_watchdog_disable(&thread->t_watchdog);
2819
2820 out_ctx_fini:
2821         lu_context_fini(&env->le_ctx);
2822 out_env_remove:
2823         lu_env_remove(env);
2824 out_env:
2825         OBD_FREE_PTR(env);
2826 out_srv_fini:
2827         /* deconstruct service thread state created by ptlrpc_start_thread() */
2828         if (svc->srv_ops.so_thr_done != NULL)
2829                 svc->srv_ops.so_thr_done(thread);
2830 out:
2831         CDEBUG(D_RPCTRACE, "%s: service thread [%p:%u] %d exiting: rc = %d\n",
2832                thread->t_name, thread, thread->t_pid, thread->t_id, rc);
2833         spin_lock(&svcpt->scp_lock);
2834         if (thread_test_and_clear_flags(thread, SVC_STARTING))
2835                 svcpt->scp_nthrs_starting--;
2836
2837         if (thread_test_and_clear_flags(thread, SVC_RUNNING)) {
2838                 /* must know immediately */
2839                 svcpt->scp_nthrs_running--;
2840         }
2841
2842         thread->t_id = rc;
2843         thread_add_flags(thread, SVC_STOPPED);
2844
2845         wake_up(&thread->t_ctl_waitq);
2846         spin_unlock(&svcpt->scp_lock);
2847
2848         return rc;
2849 }
2850
2851 static int hrt_dont_sleep(struct ptlrpc_hr_thread *hrt,
2852                           struct list_head *replies)
2853 {
2854         int result;
2855
2856         spin_lock(&hrt->hrt_lock);
2857
2858         list_splice_init(&hrt->hrt_queue, replies);
2859         result = ptlrpc_hr.hr_stopping || !list_empty(replies);
2860
2861         spin_unlock(&hrt->hrt_lock);
2862         return result;
2863 }
2864
2865 /**
2866  * Main body of "handle reply" function.
2867  * It processes acked reply states
2868  */
2869 static int ptlrpc_hr_main(void *arg)
2870 {
2871         struct ptlrpc_hr_thread *hrt = (struct ptlrpc_hr_thread *)arg;
2872         struct ptlrpc_hr_partition *hrp = hrt->hrt_partition;
2873         struct list_head replies;
2874         struct lu_env *env;
2875         int rc;
2876
2877         OBD_ALLOC_PTR(env);
2878         if (env == NULL)
2879                 RETURN(-ENOMEM);
2880
2881         INIT_LIST_HEAD(&replies);
2882         unshare_fs_struct();
2883
2884         rc = cfs_cpt_bind(ptlrpc_hr.hr_cpt_table, hrp->hrp_cpt);
2885         if (rc != 0) {
2886                 char threadname[20];
2887
2888                 snprintf(threadname, sizeof(threadname), "ptlrpc_hr%02d_%03d",
2889                          hrp->hrp_cpt, hrt->hrt_id);
2890                 CWARN("Failed to bind %s on CPT %d of CPT table %p: rc = %d\n",
2891                       threadname, hrp->hrp_cpt, ptlrpc_hr.hr_cpt_table, rc);
2892         }
2893
2894         rc = lu_context_init(&env->le_ctx, LCT_MD_THREAD | LCT_DT_THREAD |
2895                              LCT_REMEMBER | LCT_NOREF);
2896         if (rc)
2897                 GOTO(out_env, rc);
2898
2899         rc = lu_env_add(env);
2900         if (rc)
2901                 GOTO(out_ctx_fini, rc);
2902
2903         atomic_inc(&hrp->hrp_nstarted);
2904         wake_up(&ptlrpc_hr.hr_waitq);
2905
2906         while (!ptlrpc_hr.hr_stopping) {
2907                 l_wait_condition(hrt->hrt_waitq, hrt_dont_sleep(hrt, &replies));
2908
2909                 while (!list_empty(&replies)) {
2910                         struct ptlrpc_reply_state *rs;
2911
2912                         rs = list_entry(replies.prev,
2913                                         struct ptlrpc_reply_state,
2914                                         rs_list);
2915                         list_del_init(&rs->rs_list);
2916                         /* refill keys if needed */
2917                         lu_env_refill(env);
2918                         lu_context_enter(&env->le_ctx);
2919                         ptlrpc_handle_rs(rs);
2920                         lu_context_exit(&env->le_ctx);
2921                 }
2922         }
2923
2924         atomic_inc(&hrp->hrp_nstopped);
2925         wake_up(&ptlrpc_hr.hr_waitq);
2926
2927         lu_env_remove(env);
2928 out_ctx_fini:
2929         lu_context_fini(&env->le_ctx);
2930 out_env:
2931         OBD_FREE_PTR(env);
2932         return 0;
2933 }
2934
2935 static void ptlrpc_stop_hr_threads(void)
2936 {
2937         struct ptlrpc_hr_partition *hrp;
2938         int i;
2939         int j;
2940
2941         ptlrpc_hr.hr_stopping = 1;
2942
2943         cfs_percpt_for_each(hrp, i, ptlrpc_hr.hr_partitions) {
2944                 if (hrp->hrp_thrs == NULL)
2945                         continue; /* uninitialized */
2946                 for (j = 0; j < hrp->hrp_nthrs; j++)
2947                         wake_up_all(&hrp->hrp_thrs[j].hrt_waitq);
2948         }
2949
2950         cfs_percpt_for_each(hrp, i, ptlrpc_hr.hr_partitions) {
2951                 if (hrp->hrp_thrs == NULL)
2952                         continue; /* uninitialized */
2953                 wait_event(ptlrpc_hr.hr_waitq,
2954                                atomic_read(&hrp->hrp_nstopped) ==
2955                                atomic_read(&hrp->hrp_nstarted));
2956         }
2957 }
2958
2959 static int ptlrpc_start_hr_threads(void)
2960 {
2961         struct ptlrpc_hr_partition *hrp;
2962         int i;
2963         int j;
2964
2965         ENTRY;
2966
2967         cfs_percpt_for_each(hrp, i, ptlrpc_hr.hr_partitions) {
2968                 int     rc = 0;
2969
2970                 for (j = 0; j < hrp->hrp_nthrs; j++) {
2971                         struct ptlrpc_hr_thread *hrt = &hrp->hrp_thrs[j];
2972                         struct task_struct *task;
2973
2974                         task = kthread_run(ptlrpc_hr_main,
2975                                            &hrp->hrp_thrs[j],
2976                                            "ptlrpc_hr%02d_%03d",
2977                                            hrp->hrp_cpt,
2978                                            hrt->hrt_id);
2979                         if (IS_ERR(task)) {
2980                                 rc = PTR_ERR(task);
2981                                 break;
2982                         }
2983                 }
2984
2985                 wait_event(ptlrpc_hr.hr_waitq,
2986                            atomic_read(&hrp->hrp_nstarted) == j);
2987
2988                 if (rc < 0) {
2989                         CERROR("cannot start reply handler thread %d:%d: rc = %d\n",
2990                                i, j, rc);
2991                         ptlrpc_stop_hr_threads();
2992                         RETURN(rc);
2993                 }
2994         }
2995
2996         RETURN(0);
2997 }
2998
2999 static void ptlrpc_svcpt_stop_threads(struct ptlrpc_service_part *svcpt)
3000 {
3001         struct l_wait_info lwi = { 0 };
3002         struct ptlrpc_thread *thread;
3003         struct list_head zombie;
3004
3005         ENTRY;
3006
3007         CDEBUG(D_INFO, "Stopping threads for service %s\n",
3008                svcpt->scp_service->srv_name);
3009
3010         INIT_LIST_HEAD(&zombie);
3011         spin_lock(&svcpt->scp_lock);
3012         /* let the thread know that we would like it to stop asap */
3013         list_for_each_entry(thread, &svcpt->scp_threads, t_link)
3014                 ptlrpc_stop_thread(thread);
3015
3016         wake_up_all(&svcpt->scp_waitq);
3017
3018         while (!list_empty(&svcpt->scp_threads)) {
3019                 thread = list_entry(svcpt->scp_threads.next,
3020                                         struct ptlrpc_thread, t_link);
3021                 if (thread_is_stopped(thread)) {
3022                         list_del(&thread->t_link);
3023                         list_add(&thread->t_link, &zombie);
3024                         continue;
3025                 }
3026                 spin_unlock(&svcpt->scp_lock);
3027
3028                 CDEBUG(D_INFO, "waiting for stopping-thread %s #%u\n",
3029                        svcpt->scp_service->srv_thread_name, thread->t_id);
3030                 l_wait_event(thread->t_ctl_waitq,
3031                              thread_is_stopped(thread), &lwi);
3032
3033                 spin_lock(&svcpt->scp_lock);
3034         }
3035
3036         spin_unlock(&svcpt->scp_lock);
3037
3038         while (!list_empty(&zombie)) {
3039                 thread = list_entry(zombie.next,
3040                                         struct ptlrpc_thread, t_link);
3041                 list_del(&thread->t_link);
3042                 OBD_FREE_PTR(thread);
3043         }
3044         EXIT;
3045 }
3046
3047 /**
3048  * Stops all threads of a particular service \a svc
3049  */
3050 void ptlrpc_stop_all_threads(struct ptlrpc_service *svc)
3051 {
3052         struct ptlrpc_service_part *svcpt;
3053         int i;
3054
3055         ENTRY;
3056
3057         ptlrpc_service_for_each_part(svcpt, i, svc) {
3058                 if (svcpt->scp_service != NULL)
3059                         ptlrpc_svcpt_stop_threads(svcpt);
3060         }
3061
3062         EXIT;
3063 }
3064
3065 int ptlrpc_start_threads(struct ptlrpc_service *svc)
3066 {
3067         int rc = 0;
3068         int i;
3069         int j;
3070
3071         ENTRY;
3072
3073         /* We require 2 threads min, see note in ptlrpc_server_handle_request */
3074         LASSERT(svc->srv_nthrs_cpt_init >= PTLRPC_NTHRS_INIT);
3075
3076         for (i = 0; i < svc->srv_ncpts; i++) {
3077                 for (j = 0; j < svc->srv_nthrs_cpt_init; j++) {
3078                         rc = ptlrpc_start_thread(svc->srv_parts[i], 1);
3079                         if (rc == 0)
3080                                 continue;
3081
3082                         if (rc != -EMFILE)
3083                                 goto failed;
3084                         /* We have enough threads, don't start more. b=15759 */
3085                         break;
3086                 }
3087         }
3088
3089         RETURN(0);
3090  failed:
3091         CERROR("cannot start %s thread #%d_%d: rc %d\n",
3092                svc->srv_thread_name, i, j, rc);
3093         ptlrpc_stop_all_threads(svc);
3094         RETURN(rc);
3095 }
3096
3097 int ptlrpc_start_thread(struct ptlrpc_service_part *svcpt, int wait)
3098 {
3099         struct l_wait_info lwi = { 0 };
3100         struct ptlrpc_thread *thread;
3101         struct ptlrpc_service *svc;
3102         struct task_struct *task;
3103         int rc;
3104
3105         ENTRY;
3106
3107         LASSERT(svcpt != NULL);
3108
3109         svc = svcpt->scp_service;
3110
3111         CDEBUG(D_RPCTRACE, "%s[%d] started %d min %d max %d\n",
3112                svc->srv_name, svcpt->scp_cpt, svcpt->scp_nthrs_running,
3113                svc->srv_nthrs_cpt_init, svc->srv_nthrs_cpt_limit);
3114
3115  again:
3116         if (unlikely(svc->srv_is_stopping))
3117                 RETURN(-ESRCH);
3118
3119         if (!ptlrpc_threads_increasable(svcpt) ||
3120             (OBD_FAIL_CHECK(OBD_FAIL_TGT_TOOMANY_THREADS) &&
3121              svcpt->scp_nthrs_running == svc->srv_nthrs_cpt_init - 1))
3122                 RETURN(-EMFILE);
3123
3124         OBD_CPT_ALLOC_PTR(thread, svc->srv_cptable, svcpt->scp_cpt);
3125         if (thread == NULL)
3126                 RETURN(-ENOMEM);
3127         init_waitqueue_head(&thread->t_ctl_waitq);
3128
3129         spin_lock(&svcpt->scp_lock);
3130         if (!ptlrpc_threads_increasable(svcpt)) {
3131                 spin_unlock(&svcpt->scp_lock);
3132                 OBD_FREE_PTR(thread);
3133                 RETURN(-EMFILE);
3134         }
3135
3136         if (svcpt->scp_nthrs_starting != 0) {
3137                 /*
3138                  * serialize starting because some modules (obdfilter)
3139                  * might require unique and contiguous t_id
3140                  */
3141                 LASSERT(svcpt->scp_nthrs_starting == 1);
3142                 spin_unlock(&svcpt->scp_lock);
3143                 OBD_FREE_PTR(thread);
3144                 if (wait) {
3145                         CDEBUG(D_INFO, "Waiting for creating thread %s #%d\n",
3146                                svc->srv_thread_name, svcpt->scp_thr_nextid);
3147                         schedule();
3148                         goto again;
3149                 }
3150
3151                 CDEBUG(D_INFO, "Creating thread %s #%d race, retry later\n",
3152                        svc->srv_thread_name, svcpt->scp_thr_nextid);
3153                 RETURN(-EAGAIN);
3154         }
3155
3156         svcpt->scp_nthrs_starting++;
3157         thread->t_id = svcpt->scp_thr_nextid++;
3158         thread_add_flags(thread, SVC_STARTING);
3159         thread->t_svcpt = svcpt;
3160
3161         list_add(&thread->t_link, &svcpt->scp_threads);
3162         spin_unlock(&svcpt->scp_lock);
3163
3164         if (svcpt->scp_cpt >= 0) {
3165                 snprintf(thread->t_name, PTLRPC_THR_NAME_LEN, "%s%02d_%03d",
3166                          svc->srv_thread_name, svcpt->scp_cpt, thread->t_id);
3167         } else {
3168                 snprintf(thread->t_name, PTLRPC_THR_NAME_LEN, "%s_%04d",
3169                          svc->srv_thread_name, thread->t_id);
3170         }
3171
3172         CDEBUG(D_RPCTRACE, "starting thread '%s'\n", thread->t_name);
3173         task = kthread_run(ptlrpc_main, thread, "%s", thread->t_name);
3174         if (IS_ERR(task)) {
3175                 rc = PTR_ERR(task);
3176                 CERROR("cannot start thread '%s': rc = %d\n",
3177                        thread->t_name, rc);
3178                 spin_lock(&svcpt->scp_lock);
3179                 --svcpt->scp_nthrs_starting;
3180                 if (thread_is_stopping(thread)) {
3181                         /*
3182                          * this ptlrpc_thread is being hanled
3183                          * by ptlrpc_svcpt_stop_threads now
3184                          */
3185                         thread_add_flags(thread, SVC_STOPPED);
3186                         wake_up(&thread->t_ctl_waitq);
3187                         spin_unlock(&svcpt->scp_lock);
3188                 } else {
3189                         list_del(&thread->t_link);
3190                         spin_unlock(&svcpt->scp_lock);
3191                         OBD_FREE_PTR(thread);
3192                 }
3193                 RETURN(rc);
3194         }
3195
3196         if (!wait)
3197                 RETURN(0);
3198
3199         l_wait_event(thread->t_ctl_waitq,
3200                      thread_is_running(thread) || thread_is_stopped(thread),
3201                      &lwi);
3202
3203         rc = thread_is_stopped(thread) ? thread->t_id : 0;
3204         RETURN(rc);
3205 }
3206
3207 int ptlrpc_hr_init(void)
3208 {
3209         struct ptlrpc_hr_partition *hrp;
3210         struct ptlrpc_hr_thread *hrt;
3211         int rc;
3212         int cpt;
3213         int i;
3214         int weight;
3215
3216         ENTRY;
3217
3218         memset(&ptlrpc_hr, 0, sizeof(ptlrpc_hr));
3219         ptlrpc_hr.hr_cpt_table = cfs_cpt_table;
3220
3221         ptlrpc_hr.hr_partitions = cfs_percpt_alloc(ptlrpc_hr.hr_cpt_table,
3222                                                    sizeof(*hrp));
3223         if (ptlrpc_hr.hr_partitions == NULL)
3224                 RETURN(-ENOMEM);
3225
3226         ratelimit_state_init(&watchdog_limit,
3227                              cfs_time_seconds(libcfs_watchdog_ratelimit), 3);
3228
3229         init_waitqueue_head(&ptlrpc_hr.hr_waitq);
3230
3231         weight = cpumask_weight(topology_sibling_cpumask(smp_processor_id()));
3232
3233         cfs_percpt_for_each(hrp, cpt, ptlrpc_hr.hr_partitions) {
3234                 hrp->hrp_cpt = cpt;
3235
3236                 atomic_set(&hrp->hrp_nstarted, 0);
3237                 atomic_set(&hrp->hrp_nstopped, 0);
3238
3239                 hrp->hrp_nthrs = cfs_cpt_weight(ptlrpc_hr.hr_cpt_table, cpt);
3240                 hrp->hrp_nthrs /= weight;
3241                 if (hrp->hrp_nthrs == 0)
3242                         hrp->hrp_nthrs = 1;
3243
3244                 OBD_CPT_ALLOC(hrp->hrp_thrs, ptlrpc_hr.hr_cpt_table, cpt,
3245                               hrp->hrp_nthrs * sizeof(*hrt));
3246                 if (hrp->hrp_thrs == NULL)
3247                         GOTO(out, rc = -ENOMEM);
3248
3249                 for (i = 0; i < hrp->hrp_nthrs; i++) {
3250                         hrt = &hrp->hrp_thrs[i];
3251
3252                         hrt->hrt_id = i;
3253                         hrt->hrt_partition = hrp;
3254                         init_waitqueue_head(&hrt->hrt_waitq);
3255                         spin_lock_init(&hrt->hrt_lock);
3256                         INIT_LIST_HEAD(&hrt->hrt_queue);
3257                 }
3258         }
3259
3260         rc = ptlrpc_start_hr_threads();
3261 out:
3262         if (rc != 0)
3263                 ptlrpc_hr_fini();
3264         RETURN(rc);
3265 }
3266
3267 void ptlrpc_hr_fini(void)
3268 {
3269         struct ptlrpc_hr_partition *hrp;
3270         int cpt;
3271
3272         if (ptlrpc_hr.hr_partitions == NULL)
3273                 return;
3274
3275         ptlrpc_stop_hr_threads();
3276
3277         cfs_percpt_for_each(hrp, cpt, ptlrpc_hr.hr_partitions) {
3278                 if (hrp->hrp_thrs != NULL) {
3279                         OBD_FREE(hrp->hrp_thrs,
3280                                  hrp->hrp_nthrs * sizeof(hrp->hrp_thrs[0]));
3281                 }
3282         }
3283
3284         cfs_percpt_free(ptlrpc_hr.hr_partitions);
3285         ptlrpc_hr.hr_partitions = NULL;
3286 }
3287
3288
3289 /**
3290  * Wait until all already scheduled replies are processed.
3291  */
3292 static void ptlrpc_wait_replies(struct ptlrpc_service_part *svcpt)
3293 {
3294         while (1) {
3295                 int rc;
3296                 struct l_wait_info lwi = LWI_TIMEOUT(cfs_time_seconds(10),
3297                                                      NULL, NULL);
3298
3299                 rc = l_wait_event(svcpt->scp_waitq,
3300                      atomic_read(&svcpt->scp_nreps_difficult) == 0, &lwi);
3301                 if (rc == 0)
3302                         break;
3303                 CWARN("Unexpectedly long timeout %s %p\n",
3304                       svcpt->scp_service->srv_name, svcpt->scp_service);
3305         }
3306 }
3307
3308 static void
3309 ptlrpc_service_del_atimer(struct ptlrpc_service *svc)
3310 {
3311         struct ptlrpc_service_part *svcpt;
3312         int i;
3313
3314         /* early disarm AT timer... */
3315         ptlrpc_service_for_each_part(svcpt, i, svc) {
3316                 if (svcpt->scp_service != NULL)
3317                         del_timer(&svcpt->scp_at_timer);
3318         }
3319 }
3320
3321 static void
3322 ptlrpc_service_unlink_rqbd(struct ptlrpc_service *svc)
3323 {
3324         struct ptlrpc_service_part *svcpt;
3325         struct ptlrpc_request_buffer_desc *rqbd;
3326         struct l_wait_info lwi;
3327         int rc;
3328         int i;
3329
3330         /*
3331          * All history will be culled when the next request buffer is
3332          * freed in ptlrpc_service_purge_all()
3333          */
3334         svc->srv_hist_nrqbds_cpt_max = 0;
3335
3336         rc = LNetClearLazyPortal(svc->srv_req_portal);
3337         LASSERT(rc == 0);
3338
3339         ptlrpc_service_for_each_part(svcpt, i, svc) {
3340                 if (svcpt->scp_service == NULL)
3341                         break;
3342
3343                 /*
3344                  * Unlink all the request buffers.  This forces a 'final'
3345                  * event with its 'unlink' flag set for each posted rqbd
3346                  */
3347                 list_for_each_entry(rqbd, &svcpt->scp_rqbd_posted,
3348                                         rqbd_list) {
3349                         rc = LNetMDUnlink(rqbd->rqbd_md_h);
3350                         LASSERT(rc == 0 || rc == -ENOENT);
3351                 }
3352         }
3353
3354         ptlrpc_service_for_each_part(svcpt, i, svc) {
3355                 if (svcpt->scp_service == NULL)
3356                         break;
3357
3358                 /*
3359                  * Wait for the network to release any buffers
3360                  * it's currently filling
3361                  */
3362                 spin_lock(&svcpt->scp_lock);
3363                 while (svcpt->scp_nrqbds_posted != 0) {
3364                         spin_unlock(&svcpt->scp_lock);
3365                         /*
3366                          * Network access will complete in finite time but
3367                          * the HUGE timeout lets us CWARN for visibility
3368                          * of sluggish NALs
3369                          */
3370                         lwi = LWI_TIMEOUT_INTERVAL(
3371                                         cfs_time_seconds(LONG_UNLINK),
3372                                         cfs_time_seconds(1), NULL, NULL);
3373                         rc = l_wait_event(svcpt->scp_waitq,
3374                                           svcpt->scp_nrqbds_posted == 0, &lwi);
3375                         if (rc == -ETIMEDOUT) {
3376                                 CWARN("Service %s waiting for request buffers\n",
3377                                       svcpt->scp_service->srv_name);
3378                         }
3379                         spin_lock(&svcpt->scp_lock);
3380                 }
3381                 spin_unlock(&svcpt->scp_lock);
3382         }
3383 }
3384
3385 static void
3386 ptlrpc_service_purge_all(struct ptlrpc_service *svc)
3387 {
3388         struct ptlrpc_service_part *svcpt;
3389         struct ptlrpc_request_buffer_desc *rqbd;
3390         struct ptlrpc_request *req;
3391         struct ptlrpc_reply_state *rs;
3392         int i;
3393
3394         ptlrpc_service_for_each_part(svcpt, i, svc) {
3395                 if (svcpt->scp_service == NULL)
3396                         break;
3397
3398                 spin_lock(&svcpt->scp_rep_lock);
3399                 while (!list_empty(&svcpt->scp_rep_active)) {
3400                         rs = list_entry(svcpt->scp_rep_active.next,
3401                                             struct ptlrpc_reply_state, rs_list);
3402                         spin_lock(&rs->rs_lock);
3403                         ptlrpc_schedule_difficult_reply(rs);
3404                         spin_unlock(&rs->rs_lock);
3405                 }
3406                 spin_unlock(&svcpt->scp_rep_lock);
3407
3408                 /*
3409                  * purge the request queue.  NB No new replies (rqbds
3410                  * all unlinked) and no service threads, so I'm the only
3411                  * thread noodling the request queue now
3412                  */
3413                 while (!list_empty(&svcpt->scp_req_incoming)) {
3414                         req = list_entry(svcpt->scp_req_incoming.next,
3415                                              struct ptlrpc_request, rq_list);
3416
3417                         list_del(&req->rq_list);
3418                         svcpt->scp_nreqs_incoming--;
3419                         ptlrpc_server_finish_request(svcpt, req);
3420                 }
3421
3422                 while (ptlrpc_server_request_pending(svcpt, true)) {
3423                         req = ptlrpc_server_request_get(svcpt, true);
3424                         ptlrpc_server_finish_active_request(svcpt, req);
3425                 }
3426
3427                 LASSERT(list_empty(&svcpt->scp_rqbd_posted));
3428                 LASSERT(svcpt->scp_nreqs_incoming == 0);
3429                 LASSERT(svcpt->scp_nreqs_active == 0);
3430                 /*
3431                  * history should have been culled by
3432                  * ptlrpc_server_finish_request
3433                  */
3434                 LASSERT(svcpt->scp_hist_nrqbds == 0);
3435
3436                 /*
3437                  * Now free all the request buffers since nothing
3438                  * references them any more...
3439                  */
3440
3441                 while (!list_empty(&svcpt->scp_rqbd_idle)) {
3442                         rqbd = list_entry(svcpt->scp_rqbd_idle.next,
3443                                               struct ptlrpc_request_buffer_desc,
3444                                               rqbd_list);
3445                         ptlrpc_free_rqbd(rqbd);
3446                 }
3447                 ptlrpc_wait_replies(svcpt);
3448
3449                 while (!list_empty(&svcpt->scp_rep_idle)) {
3450                         rs = list_entry(svcpt->scp_rep_idle.next,
3451                                             struct ptlrpc_reply_state,
3452                                             rs_list);
3453                         list_del(&rs->rs_list);
3454                         OBD_FREE_LARGE(rs, svc->srv_max_reply_size);
3455                 }
3456         }
3457 }
3458
3459 static void
3460 ptlrpc_service_free(struct ptlrpc_service *svc)
3461 {
3462         struct ptlrpc_service_part      *svcpt;
3463         struct ptlrpc_at_array          *array;
3464         int                             i;
3465
3466         ptlrpc_service_for_each_part(svcpt, i, svc) {
3467                 if (svcpt->scp_service == NULL)
3468                         break;
3469
3470                 /* In case somebody rearmed this in the meantime */
3471                 del_timer(&svcpt->scp_at_timer);
3472                 array = &svcpt->scp_at_array;
3473
3474                 if (array->paa_reqs_array != NULL) {
3475                         OBD_FREE(array->paa_reqs_array,
3476                                  sizeof(struct list_head) * array->paa_size);
3477                         array->paa_reqs_array = NULL;
3478                 }
3479
3480                 if (array->paa_reqs_count != NULL) {
3481                         OBD_FREE(array->paa_reqs_count,
3482                                  sizeof(__u32) * array->paa_size);
3483                         array->paa_reqs_count = NULL;
3484                 }
3485         }
3486
3487         ptlrpc_service_for_each_part(svcpt, i, svc)
3488                 OBD_FREE_PTR(svcpt);
3489
3490         if (svc->srv_cpts != NULL)
3491                 cfs_expr_list_values_free(svc->srv_cpts, svc->srv_ncpts);
3492
3493         OBD_FREE(svc, offsetof(struct ptlrpc_service,
3494                                srv_parts[svc->srv_ncpts]));
3495 }
3496
3497 int ptlrpc_unregister_service(struct ptlrpc_service *service)
3498 {
3499         ENTRY;
3500
3501         CDEBUG(D_NET, "%s: tearing down\n", service->srv_name);
3502
3503         service->srv_is_stopping = 1;
3504
3505         mutex_lock(&ptlrpc_all_services_mutex);
3506         list_del_init(&service->srv_list);
3507         mutex_unlock(&ptlrpc_all_services_mutex);
3508
3509         ptlrpc_service_del_atimer(service);
3510         ptlrpc_stop_all_threads(service);
3511
3512         ptlrpc_service_unlink_rqbd(service);
3513         ptlrpc_service_purge_all(service);
3514         ptlrpc_service_nrs_cleanup(service);
3515
3516         ptlrpc_lprocfs_unregister_service(service);
3517         ptlrpc_sysfs_unregister_service(service);
3518
3519         ptlrpc_service_free(service);
3520
3521         RETURN(0);
3522 }
3523 EXPORT_SYMBOL(ptlrpc_unregister_service);
3524
3525 /**
3526  * Returns 0 if the service is healthy.
3527  *
3528  * Right now, it just checks to make sure that requests aren't languishing
3529  * in the queue.  We'll use this health check to govern whether a node needs
3530  * to be shot, so it's intentionally non-aggressive.
3531  */
3532 static int ptlrpc_svcpt_health_check(struct ptlrpc_service_part *svcpt)
3533 {
3534         struct ptlrpc_request *request = NULL;
3535         struct timespec64 right_now;
3536         struct timespec64 timediff;
3537
3538         ktime_get_real_ts64(&right_now);
3539
3540         spin_lock(&svcpt->scp_req_lock);
3541         /* How long has the next entry been waiting? */
3542         if (ptlrpc_server_high_pending(svcpt, true))
3543                 request = ptlrpc_nrs_req_peek_nolock(svcpt, true);
3544         else if (ptlrpc_server_normal_pending(svcpt, true))
3545                 request = ptlrpc_nrs_req_peek_nolock(svcpt, false);
3546
3547         if (request == NULL) {
3548                 spin_unlock(&svcpt->scp_req_lock);
3549                 return 0;
3550         }
3551
3552         timediff = timespec64_sub(right_now, request->rq_arrival_time);
3553         spin_unlock(&svcpt->scp_req_lock);
3554
3555         if ((timediff.tv_sec) >
3556             (AT_OFF ? obd_timeout * 3 / 2 : at_max)) {
3557                 CERROR("%s: unhealthy - request has been waiting %llds\n",
3558                        svcpt->scp_service->srv_name, (s64)timediff.tv_sec);
3559                 return -1;
3560         }
3561
3562         return 0;
3563 }
3564
3565 int
3566 ptlrpc_service_health_check(struct ptlrpc_service *svc)
3567 {
3568         struct ptlrpc_service_part      *svcpt;
3569         int                             i;
3570
3571         if (svc == NULL)
3572                 return 0;
3573
3574         ptlrpc_service_for_each_part(svcpt, i, svc) {
3575                 int rc = ptlrpc_svcpt_health_check(svcpt);
3576
3577                 if (rc != 0)
3578                         return rc;
3579         }
3580         return 0;
3581 }
3582 EXPORT_SYMBOL(ptlrpc_service_health_check);