lustre/ptlrpc/service.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  30  * Use is subject to license terms.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  */
  36
  37 #define DEBUG_SUBSYSTEM S_RPC
  38 #ifndef __KERNEL__
  39 #include <liblustre.h>
  40 #include <libcfs/kp30.h>
  41 #endif
  42 #include <obd_support.h>
  43 #include <obd_class.h>
  44 #include <lustre_net.h>
  45 #include <lnet/types.h>
  46 #include "ptlrpc_internal.h"
  47
  48 /* The following are visible and mutable through /sys/module/ptlrpc */
  49 int test_req_buffer_pressure = 0;
  50 CFS_MODULE_PARM(test_req_buffer_pressure, "i", int, 0444,
  51                 "set non-zero to put pressure on request buffer pools");
  52
  53 CFS_MODULE_PARM(at_min, "i", int, 0644,
  54                 "Adaptive timeout minimum (sec)");
  55 CFS_MODULE_PARM(at_max, "i", int, 0644,
  56                 "Adaptive timeout maximum (sec)");
  57 CFS_MODULE_PARM(at_history, "i", int, 0644,
  58                 "Adaptive timeouts remember the slowest event that took place "
  59                 "within this period (sec)");
  60 CFS_MODULE_PARM(at_early_margin, "i", int, 0644,
  61                 "How soon before an RPC deadline to send an early reply");
  62 CFS_MODULE_PARM(at_extra, "i", int, 0644,
  63                 "How much extra time to give with each early reply");
  64
  65 /* forward ref */
  66 static int ptlrpc_server_post_idle_rqbds (struct ptlrpc_service *svc);
  67
  68 static CFS_LIST_HEAD (ptlrpc_all_services);
  69 spinlock_t ptlrpc_all_services_lock;
  70
  71 static char *
  72 ptlrpc_alloc_request_buffer (int size)
  73 {
  74         char *ptr;
  75
  76         if (size > SVC_BUF_VMALLOC_THRESHOLD)
  77                 OBD_VMALLOC(ptr, size);
  78         else
  79                 OBD_ALLOC(ptr, size);
  80
  81         return (ptr);
  82 }
  83
  84 static void
  85 ptlrpc_free_request_buffer (char *ptr, int size)
  86 {
  87         if (size > SVC_BUF_VMALLOC_THRESHOLD)
  88                 OBD_VFREE(ptr, size);
  89         else
  90                 OBD_FREE(ptr, size);
  91 }
  92
  93 struct ptlrpc_request_buffer_desc *
  94 ptlrpc_alloc_rqbd (struct ptlrpc_service *svc)
  95 {
  96         struct ptlrpc_request_buffer_desc *rqbd;
  97
  98         OBD_ALLOC(rqbd, sizeof (*rqbd));
  99         if (rqbd == NULL)
 100                 return (NULL);
 101
 102         rqbd->rqbd_service = svc;
 103         rqbd->rqbd_refcount = 0;
 104         rqbd->rqbd_cbid.cbid_fn = request_in_callback;
 105         rqbd->rqbd_cbid.cbid_arg = rqbd;
 106         CFS_INIT_LIST_HEAD(&rqbd->rqbd_reqs);
 107         rqbd->rqbd_buffer = ptlrpc_alloc_request_buffer(svc->srv_buf_size);
 108
 109         if (rqbd->rqbd_buffer == NULL) {
 110                 OBD_FREE(rqbd, sizeof (*rqbd));
 111                 return (NULL);
 112         }
 113
 114         spin_lock(&svc->srv_lock);
 115         list_add(&rqbd->rqbd_list, &svc->srv_idle_rqbds);
 116         svc->srv_nbufs++;
 117         spin_unlock(&svc->srv_lock);
 118
 119         return (rqbd);
 120 }
 121
 122 void
 123 ptlrpc_free_rqbd (struct ptlrpc_request_buffer_desc *rqbd)
 124 {
 125         struct ptlrpc_service *svc = rqbd->rqbd_service;
 126
 127         LASSERT (rqbd->rqbd_refcount == 0);
 128         LASSERT (list_empty(&rqbd->rqbd_reqs));
 129
 130         spin_lock(&svc->srv_lock);
 131         list_del(&rqbd->rqbd_list);
 132         svc->srv_nbufs--;
 133         spin_unlock(&svc->srv_lock);
 134
 135         ptlrpc_free_request_buffer (rqbd->rqbd_buffer, svc->srv_buf_size);
 136         OBD_FREE (rqbd, sizeof (*rqbd));
 137 }
 138
 139 int
 140 ptlrpc_grow_req_bufs(struct ptlrpc_service *svc)
 141 {
 142         struct ptlrpc_request_buffer_desc *rqbd;
 143         int                                i;
 144
 145         CDEBUG(D_RPCTRACE, "%s: allocate %d new %d-byte reqbufs (%d/%d left)\n",
 146                svc->srv_name, svc->srv_nbuf_per_group, svc->srv_buf_size,
 147                svc->srv_nrqbd_receiving, svc->srv_nbufs);
 148         for (i = 0; i < svc->srv_nbuf_per_group; i++) {
 149                 rqbd = ptlrpc_alloc_rqbd(svc);
 150
 151                 if (rqbd == NULL) {
 152                         CERROR ("%s: Can't allocate request buffer\n",
 153                                 svc->srv_name);
 154                         return (-ENOMEM);
 155                 }
 156
 157                 if (ptlrpc_server_post_idle_rqbds(svc) < 0)
 158                         return (-EAGAIN);
 159         }
 160
 161         return (0);
 162 }
 163
 164 void
 165 ptlrpc_save_lock(struct ptlrpc_request *req,
 166                  struct lustre_handle *lock, int mode)
 167 {
 168         struct ptlrpc_reply_state *rs = req->rq_reply_state;
 169         int                        idx;
 170
 171         LASSERT(rs != NULL);
 172         LASSERT(rs->rs_nlocks < RS_MAX_LOCKS);
 173
 174         if (req->rq_export->exp_disconnected) {
 175                 ldlm_lock_decref(lock, mode);
 176         } else {
 177                 idx = rs->rs_nlocks++;
 178                 rs->rs_locks[idx] = *lock;
 179                 rs->rs_modes[idx] = mode;
 180                 rs->rs_difficult = 1;
 181         }
 182 }
 183
 184 void
 185 ptlrpc_schedule_difficult_reply (struct ptlrpc_reply_state *rs)
 186 {
 187         struct ptlrpc_service *svc = rs->rs_service;
 188
 189         LASSERT_SPIN_LOCKED (&svc->srv_lock);
 190         LASSERT (rs->rs_difficult);
 191         rs->rs_scheduled_ever = 1;              /* flag any notification attempt */
 192
 193         if (rs->rs_scheduled)                   /* being set up or already notified */
 194                 return;
 195
 196         rs->rs_scheduled = 1;
 197         list_del (&rs->rs_list);
 198         list_add (&rs->rs_list, &svc->srv_reply_queue);
 199         cfs_waitq_signal (&svc->srv_waitq);
 200 }
 201
 202 void
 203 ptlrpc_commit_replies (struct obd_export *exp)
 204 {
 205         struct list_head   *tmp;
 206         struct list_head   *nxt;
 207
 208         /* Find any replies that have been committed and get their service
 209          * to attend to complete them. */
 210
 211         /* CAVEAT EMPTOR: spinlock ordering!!! */
 212         spin_lock(&exp->exp_uncommitted_replies_lock);
 213
 214         list_for_each_safe(tmp, nxt, &exp->exp_uncommitted_replies) {
 215                 struct ptlrpc_reply_state *rs =
 216                         list_entry(tmp, struct ptlrpc_reply_state, rs_obd_list);
 217
 218                 LASSERT(rs->rs_difficult);
 219                 /* VBR: per-export last_committed */
 220                 LASSERT(rs->rs_export);
 221                 if (rs->rs_transno <= rs->rs_export->exp_last_committed) {
 222                         struct ptlrpc_service *svc = rs->rs_service;
 223
 224                         spin_lock (&svc->srv_lock);
 225                         list_del_init (&rs->rs_obd_list);
 226                         ptlrpc_schedule_difficult_reply (rs);
 227                         spin_unlock (&svc->srv_lock);
 228                 }
 229         }
 230
 231         spin_unlock(&exp->exp_uncommitted_replies_lock);
 232 }
 233
 234 static int
 235 ptlrpc_server_post_idle_rqbds (struct ptlrpc_service *svc)
 236 {
 237         struct ptlrpc_request_buffer_desc *rqbd;
 238         int                                rc;
 239         int                                posted = 0;
 240
 241         for (;;) {
 242                 spin_lock(&svc->srv_lock);
 243
 244                 if (list_empty (&svc->srv_idle_rqbds)) {
 245                         spin_unlock(&svc->srv_lock);
 246                         return (posted);
 247                 }
 248
 249                 rqbd = list_entry(svc->srv_idle_rqbds.next,
 250                                   struct ptlrpc_request_buffer_desc,
 251                                   rqbd_list);
 252                 list_del (&rqbd->rqbd_list);
 253
 254                 /* assume we will post successfully */
 255                 svc->srv_nrqbd_receiving++;
 256                 list_add (&rqbd->rqbd_list, &svc->srv_active_rqbds);
 257
 258                 spin_unlock(&svc->srv_lock);
 259
 260                 rc = ptlrpc_register_rqbd(rqbd);
 261                 if (rc != 0)
 262                         break;
 263
 264                 posted = 1;
 265         }
 266
 267         spin_lock(&svc->srv_lock);
 268
 269         svc->srv_nrqbd_receiving--;
 270         list_del(&rqbd->rqbd_list);
 271         list_add_tail(&rqbd->rqbd_list, &svc->srv_idle_rqbds);
 272
 273         /* Don't complain if no request buffers are posted right now; LNET
 274          * won't drop requests because we set the portal lazy! */
 275
 276         spin_unlock(&svc->srv_lock);
 277
 278         return (-1);
 279 }
 280
 281 static void ptlrpc_at_timer(unsigned long castmeharder)
 282 {
 283         struct ptlrpc_service *svc = (struct ptlrpc_service *)castmeharder;
 284         svc->srv_at_check = 1;
 285         svc->srv_at_checktime = cfs_time_current();
 286         cfs_waitq_signal(&svc->srv_waitq);
 287 }
 288
 289 /* @threadname should be 11 characters or less - 3 will be added on */
 290 struct ptlrpc_service *
 291 ptlrpc_init_svc(int nbufs, int bufsize, int max_req_size, int max_reply_size,
 292                 int req_portal, int rep_portal, int watchdog_factor,
 293                 svc_handler_t handler, char *name,
 294                 cfs_proc_dir_entry_t *proc_entry,
 295                 svcreq_printfn_t svcreq_printfn,
 296                 int min_threads, int max_threads, char *threadname,
 297                 svc_hpreq_handler_t hp_handler)
 298 {
 299         int                     rc;
 300         struct ptlrpc_at_array *array;
 301         struct ptlrpc_service  *service;
 302         unsigned int            size, index;
 303         ENTRY;
 304
 305         LASSERT (nbufs > 0);
 306         LASSERT (bufsize >= max_req_size);
 307
 308         OBD_ALLOC(service, sizeof(*service));
 309         if (service == NULL)
 310                 RETURN(NULL);
 311
 312         /* First initialise enough for early teardown */
 313
 314         service->srv_name = name;
 315         spin_lock_init(&service->srv_lock);
 316         CFS_INIT_LIST_HEAD(&service->srv_threads);
 317         cfs_waitq_init(&service->srv_waitq);
 318
 319         service->srv_nbuf_per_group = test_req_buffer_pressure ? 1 : nbufs;
 320         service->srv_max_req_size = max_req_size;
 321         service->srv_buf_size = bufsize;
 322         service->srv_rep_portal = rep_portal;
 323         service->srv_req_portal = req_portal;
 324         service->srv_watchdog_factor = watchdog_factor;
 325         service->srv_handler = handler;
 326         service->srv_request_history_print_fn = svcreq_printfn;
 327         service->srv_request_seq = 1;           /* valid seq #s start at 1 */
 328         service->srv_request_max_cull_seq = 0;
 329         service->srv_threads_min = min_threads;
 330         service->srv_threads_max = max_threads;
 331         service->srv_thread_name = threadname;
 332         service->srv_hpreq_handler = hp_handler;
 333         service->srv_hpreq_ratio = PTLRPC_SVC_HP_RATIO;
 334         service->srv_hpreq_count = 0;
 335         service->srv_n_hpreq = 0;
 336
 337         rc = LNetSetLazyPortal(service->srv_req_portal);
 338         LASSERT (rc == 0);
 339
 340         CFS_INIT_LIST_HEAD(&service->srv_request_queue);
 341         CFS_INIT_LIST_HEAD(&service->srv_request_hpq);
 342         CFS_INIT_LIST_HEAD(&service->srv_idle_rqbds);
 343         CFS_INIT_LIST_HEAD(&service->srv_active_rqbds);
 344         CFS_INIT_LIST_HEAD(&service->srv_history_rqbds);
 345         CFS_INIT_LIST_HEAD(&service->srv_request_history);
 346         CFS_INIT_LIST_HEAD(&service->srv_active_replies);
 347         CFS_INIT_LIST_HEAD(&service->srv_reply_queue);
 348         CFS_INIT_LIST_HEAD(&service->srv_free_rs_list);
 349         cfs_waitq_init(&service->srv_free_rs_waitq);
 350
 351         spin_lock_init(&service->srv_at_lock);
 352         CFS_INIT_LIST_HEAD(&service->srv_req_in_queue);
 353
 354         array = &service->srv_at_array;
 355         size = at_est2timeout(at_max);
 356         array->paa_size = size;
 357         array->paa_count = 0;
 358         array->paa_deadline = -1;
 359
 360         /* allocate memory for srv_at_array (ptlrpc_at_array) */
 361         OBD_ALLOC(array->paa_reqs_array, sizeof(struct list_head) * size);
 362         if (array->paa_reqs_array == NULL)
 363                 GOTO(failed, NULL);
 364
 365         for (index = 0; index < size; index++)
 366                 CFS_INIT_LIST_HEAD(&array->paa_reqs_array[index]);
 367
 368         OBD_ALLOC(array->paa_reqs_count, sizeof(__u32) * size);
 369         if (array->paa_reqs_count == NULL)
 370                 GOTO(failed, NULL);
 371
 372         cfs_timer_init(&service->srv_at_timer, ptlrpc_at_timer, service);
 373         /* At SOW, service time should be quick; 10s seems generous. If client
 374            timeout is less than this, we'll be sending an early reply. */
 375         at_init(&service->srv_at_estimate, 10, 0);
 376
 377         spin_lock (&ptlrpc_all_services_lock);
 378         list_add (&service->srv_list, &ptlrpc_all_services);
 379         spin_unlock (&ptlrpc_all_services_lock);
 380
 381         /* Now allocate the request buffers */
 382         rc = ptlrpc_grow_req_bufs(service);
 383         /* We shouldn't be under memory pressure at startup, so
 384          * fail if we can't post all our buffers at this time. */
 385         if (rc != 0)
 386                 GOTO(failed, NULL);
 387
 388         /* Now allocate pool of reply buffers */
 389         /* Increase max reply size to next power of two */
 390         service->srv_max_reply_size = 1;
 391         while (service->srv_max_reply_size < max_reply_size)
 392                 service->srv_max_reply_size <<= 1;
 393
 394         if (proc_entry != NULL)
 395                 ptlrpc_lprocfs_register_service(proc_entry, service);
 396
 397         CDEBUG(D_NET, "%s: Started, listening on portal %d\n",
 398                service->srv_name, service->srv_req_portal);
 399
 400         RETURN(service);
 401 failed:
 402         ptlrpc_unregister_service(service);
 403         return NULL;
 404 }
 405
 406 /**
 407  * to actually free the request, must be called without holding svc_lock.
 408  * note it's caller's responsibility to unlink req->rq_list.
 409  */
 410 static void ptlrpc_server_free_request(struct ptlrpc_request *req)
 411 {
 412         LASSERT(atomic_read(&req->rq_refcount) == 0);
 413         LASSERT(list_empty(&req->rq_timed_list));
 414
 415         /* DEBUG_REQ() assumes the reply state of a request with a valid
 416          * ref will not be destroyed until that reference is dropped. */
 417         ptlrpc_req_drop_rs(req);
 418
 419         if (req != &req->rq_rqbd->rqbd_req) {
 420                 /* NB request buffers use an embedded
 421                  * req if the incoming req unlinked the
 422                  * MD; this isn't one of them! */
 423                 OBD_FREE(req, sizeof(*req));
 424         }
 425 }
 426
 427 /**
 428  * increment the number of active requests consuming service threads.
 429  */
 430 void ptlrpc_server_active_request_inc(struct ptlrpc_request *req)
 431 {
 432         struct ptlrpc_request_buffer_desc *rqbd = req->rq_rqbd;
 433         struct ptlrpc_service *svc = rqbd->rqbd_service;
 434
 435         spin_lock(&svc->srv_lock);
 436         svc->srv_n_active_reqs++;
 437         spin_unlock(&svc->srv_lock);
 438 }
 439
 440 /**
 441  * decrement the number of active requests consuming service threads.
 442  */
 443 void ptlrpc_server_active_request_dec(struct ptlrpc_request *req)
 444 {
 445         struct ptlrpc_request_buffer_desc *rqbd = req->rq_rqbd;
 446         struct ptlrpc_service *svc = rqbd->rqbd_service;
 447
 448         spin_lock(&svc->srv_lock);
 449         svc->srv_n_active_reqs--;
 450         spin_unlock(&svc->srv_lock);
 451 }
 452
 453 /**
 454  * drop a reference count of the request. if it reaches 0, we either
 455  * put it into history list, or free it immediately.
 456  */
 457 void ptlrpc_server_drop_request(struct ptlrpc_request *req)
 458 {
 459         struct ptlrpc_request_buffer_desc *rqbd = req->rq_rqbd;
 460         struct ptlrpc_service             *svc = rqbd->rqbd_service;
 461         int                                refcount;
 462         struct list_head                  *tmp;
 463         struct list_head                  *nxt;
 464
 465         if (!atomic_dec_and_test(&req->rq_refcount))
 466                 return;
 467
 468         spin_lock(&svc->srv_at_lock);
 469         list_del_init(&req->rq_timed_list);
 470         if (req->rq_at_linked) {
 471                 struct ptlrpc_at_array *array = &svc->srv_at_array;
 472                 __u32 index = req->rq_at_index;
 473
 474                 spin_lock(&req->rq_lock);
 475                 req->rq_at_linked = 0;
 476                 spin_unlock(&req->rq_lock);
 477                 array->paa_reqs_count[index]--;
 478                 array->paa_count--;
 479         }
 480         spin_unlock(&svc->srv_at_lock);
 481
 482         /* finalize request */
 483         if (req->rq_export) {
 484                 class_export_put(req->rq_export);
 485                 req->rq_export = NULL;
 486         }
 487
 488         spin_lock(&svc->srv_lock);
 489
 490         svc->srv_n_active_reqs--;
 491         list_add(&req->rq_list, &rqbd->rqbd_reqs);
 492
 493         refcount = --(rqbd->rqbd_refcount);
 494         if (refcount == 0) {
 495                 /* request buffer is now idle: add to history */
 496                 list_del(&rqbd->rqbd_list);
 497                 list_add_tail(&rqbd->rqbd_list, &svc->srv_history_rqbds);
 498                 svc->srv_n_history_rqbds++;
 499
 500                 /* cull some history?
 501                  * I expect only about 1 or 2 rqbds need to be recycled here */
 502                 while (svc->srv_n_history_rqbds > svc->srv_max_history_rqbds) {
 503                         rqbd = list_entry(svc->srv_history_rqbds.next,
 504                                           struct ptlrpc_request_buffer_desc,
 505                                           rqbd_list);
 506
 507                         list_del(&rqbd->rqbd_list);
 508                         svc->srv_n_history_rqbds--;
 509
 510                         /* remove rqbd's reqs from svc's req history while
 511                          * I've got the service lock */
 512                         list_for_each(tmp, &rqbd->rqbd_reqs) {
 513                                 req = list_entry(tmp, struct ptlrpc_request,
 514                                                  rq_list);
 515                                 /* Track the highest culled req seq */
 516                                 if (req->rq_history_seq >
 517                                     svc->srv_request_max_cull_seq)
 518                                         svc->srv_request_max_cull_seq =
 519                                                 req->rq_history_seq;
 520                                 list_del(&req->rq_history_list);
 521                         }
 522
 523                         spin_unlock(&svc->srv_lock);
 524
 525                         list_for_each_safe(tmp, nxt, &rqbd->rqbd_reqs) {
 526                                 req = list_entry(rqbd->rqbd_reqs.next,
 527                                                  struct ptlrpc_request,
 528                                                  rq_list);
 529                                 list_del(&req->rq_list);
 530                                 ptlrpc_server_free_request(req);
 531                         }
 532
 533                         spin_lock(&svc->srv_lock);
 534                         /*
 535                          * now all reqs including the embedded req has been
 536                          * disposed, schedule request buffer for re-use.
 537                          */
 538                         LASSERT(atomic_read(&rqbd->rqbd_req.rq_refcount) == 0);
 539                         list_add_tail(&rqbd->rqbd_list, &svc->srv_idle_rqbds);
 540                 }
 541
 542                 spin_unlock(&svc->srv_lock);
 543         } else if (req->rq_reply_state && req->rq_reply_state->rs_prealloc) {
 544                  /* If we are low on memory, we are not interested in history */
 545                 list_del(&req->rq_list);
 546                 list_del_init(&req->rq_history_list);
 547                 spin_unlock(&svc->srv_lock);
 548
 549                 ptlrpc_server_free_request(req);
 550         } else {
 551                 spin_unlock(&svc->srv_lock);
 552         }
 553 }
 554
 555 /**
 556  * to finish a request: stop sending more early replies, and release
 557  * the request. should be called after we finished handling the request.
 558  */
 559 static void ptlrpc_server_finish_request(struct ptlrpc_request *req)
 560 {
 561         ptlrpc_server_drop_request(req);
 562 }
 563
 564 /* This function makes sure dead exports are evicted in a timely manner.
 565    This function is only called when some export receives a message (i.e.,
 566    the network is up.) */
 567 static void ptlrpc_update_export_timer(struct obd_export *exp, long extra_delay)
 568 {
 569         struct obd_export *oldest_exp;
 570         time_t oldest_time, new_time;
 571
 572         ENTRY;
 573
 574         LASSERT(exp);
 575
 576         /* Compensate for slow machines, etc, by faking our request time
 577            into the future.  Although this can break the strict time-ordering
 578            of the list, we can be really lazy here - we don't have to evict
 579            at the exact right moment.  Eventually, all silent exports
 580            will make it to the top of the list. */
 581
 582         /* Do not pay attention on 1sec or smaller renewals. */
 583         new_time = cfs_time_current_sec() + extra_delay;
 584         if (exp->exp_last_request_time + 1 /*second */ >= new_time)
 585                 RETURN_EXIT;
 586
 587         exp->exp_last_request_time = new_time;
 588         CDEBUG(D_INFO, "updating export %s at %ld\n",
 589                exp->exp_client_uuid.uuid,
 590                exp->exp_last_request_time);
 591
 592         /* exports may get disconnected from the chain even though the
 593            export has references, so we must keep the spin lock while
 594            manipulating the lists */
 595         spin_lock(&exp->exp_obd->obd_dev_lock);
 596
 597         if (list_empty(&exp->exp_obd_chain_timed)) {
 598                 /* this one is not timed */
 599                 spin_unlock(&exp->exp_obd->obd_dev_lock);
 600                 RETURN_EXIT;
 601         }
 602
 603         list_move_tail(&exp->exp_obd_chain_timed,
 604                        &exp->exp_obd->obd_exports_timed);
 605
 606         oldest_exp = list_entry(exp->exp_obd->obd_exports_timed.next,
 607                                 struct obd_export, exp_obd_chain_timed);
 608         oldest_time = oldest_exp->exp_last_request_time;
 609         spin_unlock(&exp->exp_obd->obd_dev_lock);
 610
 611         if (exp->exp_obd->obd_recovering) {
 612                 /* be nice to everyone during recovery */
 613                 EXIT;
 614                 return;
 615         }
 616
 617         /* Note - racing to start/reset the obd_eviction timer is safe */
 618         if (exp->exp_obd->obd_eviction_timer == 0) {
 619                 /* Check if the oldest entry is expired. */
 620                 if (cfs_time_current_sec() > (oldest_time + PING_EVICT_TIMEOUT +
 621                                               extra_delay)) {
 622                         /* We need a second timer, in case the net was down and
 623                          * it just came back. Since the pinger may skip every
 624                          * other PING_INTERVAL (see note in ptlrpc_pinger_main),
 625                          * we better wait for 3. */
 626                         exp->exp_obd->obd_eviction_timer =
 627                                 cfs_time_current_sec() + 3 * PING_INTERVAL;
 628                         CDEBUG(D_HA, "%s: Think about evicting %s from %ld\n",
 629                                exp->exp_obd->obd_name,
 630                                obd_export_nid2str(oldest_exp), oldest_time);
 631                 }
 632         } else {
 633                 if (cfs_time_current_sec() >
 634                     (exp->exp_obd->obd_eviction_timer + extra_delay)) {
 635                         /* The evictor won't evict anyone who we've heard from
 636                          * recently, so we don't have to check before we start
 637                          * it. */
 638                         if (!ping_evictor_wake(exp))
 639                                 exp->exp_obd->obd_eviction_timer = 0;
 640                 }
 641         }
 642
 643         EXIT;
 644 }
 645
 646 static int ptlrpc_check_req(struct ptlrpc_request *req)
 647 {
 648         if (lustre_msg_get_conn_cnt(req->rq_reqmsg) <
 649             req->rq_export->exp_conn_cnt) {
 650                 DEBUG_REQ(D_ERROR, req,
 651                           "DROPPING req from old connection %d < %d",
 652                           lustre_msg_get_conn_cnt(req->rq_reqmsg),
 653                           req->rq_export->exp_conn_cnt);
 654                 return -EEXIST;
 655         }
 656         if (req->rq_export->exp_obd && req->rq_export->exp_obd->obd_fail) {
 657              /* Failing over, don't handle any more reqs, send
 658                 error response instead. */
 659                 CDEBUG(D_RPCTRACE, "Dropping req %p for failed obd %s\n",
 660                        req, req->rq_export->exp_obd->obd_name);
 661                 req->rq_status = -ENODEV;
 662                 ptlrpc_error(req);
 663                 return -ENODEV;
 664         }
 665         return 0;
 666 }
 667
 668 static void ptlrpc_at_set_timer(struct ptlrpc_service *svc)
 669 {
 670         struct ptlrpc_at_array *array = &svc->srv_at_array;
 671         __s32 next;
 672
 673         spin_lock(&svc->srv_at_lock);
 674         if (array->paa_count == 0) {
 675                 cfs_timer_disarm(&svc->srv_at_timer);
 676                 spin_unlock(&svc->srv_at_lock);
 677                 return;
 678         }
 679
 680         /* Set timer for closest deadline */
 681         next = (__s32)(array->paa_deadline - cfs_time_current_sec() -
 682                        at_early_margin);
 683         if (next <= 0)
 684                 ptlrpc_at_timer((unsigned long)svc);
 685         else
 686                 cfs_timer_arm(&svc->srv_at_timer, cfs_time_shift(next));
 687         spin_unlock(&svc->srv_at_lock);
 688         CDEBUG(D_INFO, "armed %s at %+ds\n", svc->srv_name, next);
 689 }
 690
 691 /* Add rpc to early reply check list */
 692 static int ptlrpc_at_add_timed(struct ptlrpc_request *req)
 693 {
 694         struct ptlrpc_service *svc = req->rq_rqbd->rqbd_service;
 695         struct ptlrpc_request *rq = NULL;
 696         struct ptlrpc_at_array *array = &svc->srv_at_array;
 697         __u32 index;
 698         int found = 0;
 699
 700         if (AT_OFF)
 701                 return(0);
 702
 703         if ((lustre_msghdr_get_flags(req->rq_reqmsg) & MSGHDR_AT_SUPPORT) == 0)
 704                 return(-ENOSYS);
 705
 706         spin_lock(&svc->srv_at_lock);
 707         LASSERT(list_empty(&req->rq_timed_list));
 708
 709         index = (unsigned long)req->rq_deadline % array->paa_size;
 710         if (array->paa_reqs_count[index] > 0) {
 711                 /* latest rpcs will have the latest deadlines in the list,
 712                  * so search backward. */
 713                 list_for_each_entry_reverse(rq, &array->paa_reqs_array[index],
 714                                             rq_timed_list) {
 715                         if (req->rq_deadline >= rq->rq_deadline) {
 716                                 list_add(&req->rq_timed_list,
 717                                          &rq->rq_timed_list);
 718                                 break;
 719                         }
 720                 }
 721         }
 722
 723         /* Add the request at the head of the list */
 724         if (list_empty(&req->rq_timed_list))
 725                 list_add(&req->rq_timed_list, &array->paa_reqs_array[index]);
 726
 727         spin_lock(&req->rq_lock);
 728         req->rq_at_linked = 1;
 729         spin_unlock(&req->rq_lock);
 730
 731         req->rq_at_index = index;
 732         array->paa_reqs_count[index]++;
 733         array->paa_count++;
 734         if (array->paa_count == 1 || array->paa_deadline > req->rq_deadline) {
 735                 array->paa_deadline = req->rq_deadline;
 736                 found = 1;
 737         }
 738         spin_unlock(&svc->srv_at_lock);
 739
 740         if (found)
 741                 ptlrpc_at_set_timer(svc);
 742
 743         return 0;
 744 }
 745
 746 static int ptlrpc_at_send_early_reply(struct ptlrpc_request *req)
 747 {
 748         struct ptlrpc_service *svc = req->rq_rqbd->rqbd_service;
 749         struct ptlrpc_request *reqcopy;
 750         struct lustre_msg *reqmsg;
 751         long olddl = req->rq_deadline - cfs_time_current_sec();
 752         time_t newdl;
 753         int rc;
 754         ENTRY;
 755
 756         /* deadline is when the client expects us to reply, margin is the
 757            difference between clients' and servers' expectations */
 758         DEBUG_REQ(D_ADAPTTO, req,
 759                   "%ssending early reply (deadline %+lds, margin %+lds) for "
 760                   "%d+%d", AT_OFF ? "AT off - not " : "",
 761                   olddl, olddl - at_get(&svc->srv_at_estimate),
 762                   at_get(&svc->srv_at_estimate), at_extra);
 763
 764         if (AT_OFF)
 765                 RETURN(0);
 766
 767         if (olddl < 0) {
 768                 DEBUG_REQ(D_WARNING, req, "Already past deadline (%+lds), "
 769                           "not sending early reply. Consider increasing "
 770                           "at_early_margin (%d)?", olddl, at_early_margin);
 771
 772                 /* Return an error so we're not re-added to the timed list. */
 773                 RETURN(-ETIMEDOUT);
 774         }
 775
 776         if ((lustre_msghdr_get_flags(req->rq_reqmsg) & MSGHDR_AT_SUPPORT) == 0){
 777                 DEBUG_REQ(D_INFO, req, "Wanted to ask client for more time, "
 778                           "but no AT support");
 779                 RETURN(-ENOSYS);
 780         }
 781
 782         if (req->rq_export &&
 783             lustre_msg_get_flags(req->rq_reqmsg) &
 784             (MSG_REPLAY | MSG_LAST_REPLAY)) {
 785                 /* During recovery, we don't want to send too many early
 786                  * replies, but on the other hand we want to make sure the
 787                  * client has enough time to resend if the rpc is lost. So
 788                  * during the recovery period send at least 4 early replies,
 789                  * spacing them every at_extra if we can. at_estimate should
 790                  * always equal this fixed value during recovery. */
 791                 at_measured(&svc->srv_at_estimate, min(at_extra,
 792                             req->rq_export->exp_obd->obd_recovery_timeout / 4));
 793         } else {
 794                 /* Fake our processing time into the future to ask the
 795                  * clients for some extra amount of time */
 796                 at_measured(&svc->srv_at_estimate, at_extra +
 797                             cfs_time_current_sec() -
 798                             req->rq_arrival_time.tv_sec);
 799
 800                 /* Check to see if we've actually increased the deadline -
 801                  * we may be past adaptive_max */
 802                 if (req->rq_deadline >= req->rq_arrival_time.tv_sec +
 803                     at_get(&svc->srv_at_estimate)) {
 804                         DEBUG_REQ(D_WARNING, req, "Couldn't add any time "
 805                                   "(%ld/%ld), not sending early reply\n",
 806                                   olddl, req->rq_arrival_time.tv_sec +
 807                                   at_get(&svc->srv_at_estimate) -
 808                                   cfs_time_current_sec());
 809                         RETURN(-ETIMEDOUT);
 810                 }
 811         }
 812         newdl = cfs_time_current_sec() + at_get(&svc->srv_at_estimate);
 813
 814         OBD_ALLOC(reqcopy, sizeof *reqcopy);
 815         if (reqcopy == NULL)
 816                 RETURN(-ENOMEM);
 817         OBD_ALLOC(reqmsg, req->rq_reqlen);
 818         if (!reqmsg) {
 819                 OBD_FREE(reqcopy, sizeof *reqcopy);
 820                 RETURN(-ENOMEM);
 821         }
 822
 823         *reqcopy = *req;
 824         reqcopy->rq_reply_state = NULL;
 825         reqcopy->rq_rep_swab_mask = 0;
 826         /* We only need the reqmsg for the magic */
 827         reqcopy->rq_reqmsg = reqmsg;
 828         memcpy(reqmsg, req->rq_reqmsg, req->rq_reqlen);
 829
 830         LASSERT(atomic_read(&req->rq_refcount));
 831         /** if it is last refcount then early reply isn't needed */
 832         if (atomic_read(&req->rq_refcount) == 1) {
 833                 DEBUG_REQ(D_ADAPTTO, reqcopy, "Normal reply already sent out, "
 834                           "abort sending early reply\n");
 835                 GOTO(out, rc = -EINVAL);
 836         }
 837
 838         /* Connection ref */
 839         reqcopy->rq_export = class_conn2export(
 840                                      lustre_msg_get_handle(reqcopy->rq_reqmsg));
 841         if (reqcopy->rq_export == NULL)
 842                 GOTO(out, rc = -ENODEV);
 843
 844         /* RPC ref */
 845         class_export_rpc_get(reqcopy->rq_export);
 846         if (reqcopy->rq_export->exp_obd &&
 847             reqcopy->rq_export->exp_obd->obd_fail)
 848                 GOTO(out_put, rc = -ENODEV);
 849
 850         rc = lustre_pack_reply_flags(reqcopy, 1, NULL, NULL, LPRFL_EARLY_REPLY);
 851         if (rc)
 852                 GOTO(out_put, rc);
 853
 854         rc = ptlrpc_send_reply(reqcopy, PTLRPC_REPLY_EARLY);
 855
 856         if (!rc) {
 857                 /* Adjust our own deadline to what we told the client */
 858                 req->rq_deadline = newdl;
 859                 req->rq_early_count++; /* number sent, server side */
 860         } else {
 861                 DEBUG_REQ(D_ERROR, req, "Early reply send failed %d", rc);
 862         }
 863
 864         /* Free the (early) reply state from lustre_pack_reply.
 865            (ptlrpc_send_reply takes it's own rs ref, so this is safe here) */
 866         ptlrpc_req_drop_rs(reqcopy);
 867
 868 out_put:
 869         class_export_rpc_put(reqcopy->rq_export);
 870         class_export_put(reqcopy->rq_export);
 871 out:
 872         OBD_FREE(reqmsg, req->rq_reqlen);
 873         OBD_FREE(reqcopy, sizeof *reqcopy);
 874         RETURN(rc);
 875 }
 876
 877 /* Send early replies to everybody expiring within at_early_margin
 878    asking for at_extra time */
 879 static int ptlrpc_at_check_timed(struct ptlrpc_service *svc)
 880 {
 881         struct ptlrpc_request *rq, *n;
 882         struct list_head work_list;
 883         struct ptlrpc_at_array *array = &svc->srv_at_array;
 884         __u32  index, count;
 885         time_t deadline;
 886         time_t now = cfs_time_current_sec();
 887         cfs_duration_t delay;
 888         int first, counter = 0;
 889         ENTRY;
 890
 891         spin_lock(&svc->srv_at_lock);
 892         if (svc->srv_at_check == 0) {
 893                 spin_unlock(&svc->srv_at_lock);
 894                 RETURN(0);
 895         }
 896         delay = cfs_time_sub(cfs_time_current(), svc->srv_at_checktime);
 897         svc->srv_at_check = 0;
 898
 899         if (array->paa_count == 0) {
 900                 spin_unlock(&svc->srv_at_lock);
 901                 RETURN(0);
 902         }
 903
 904         /* The timer went off, but maybe the nearest rpc already completed. */
 905         first = array->paa_deadline - now;
 906         if (first > at_early_margin) {
 907                 /* We've still got plenty of time.  Reset the timer. */
 908                 spin_unlock(&svc->srv_at_lock);
 909                 ptlrpc_at_set_timer(svc);
 910                 RETURN(0);
 911         }
 912
 913         /* We're close to a timeout, and we don't know how much longer the
 914            server will take. Send early replies to everyone expiring soon. */
 915         CFS_INIT_LIST_HEAD(&work_list);
 916         deadline = -1;
 917         index = (unsigned long)array->paa_deadline % array->paa_size;
 918         count = array->paa_count;
 919         while (count > 0) {
 920                 count -= array->paa_reqs_count[index];
 921                 list_for_each_entry_safe(rq, n, &array->paa_reqs_array[index],
 922                                          rq_timed_list) {
 923                         if (rq->rq_deadline <= now + at_early_margin) {
 924                                 list_del_init(&rq->rq_timed_list);
 925                                 /**
 926                                  * ptlrpc_server_drop_request() may drop
 927                                  * refcount to 0 already. Let's check this and
 928                                  * don't add entry to work_list
 929                                  */
 930                                 if (likely(atomic_inc_not_zero(&rq->rq_refcount)))
 931                                         list_add(&rq->rq_timed_list, &work_list);
 932                                 counter++;
 933                                 array->paa_reqs_count[index]--;
 934                                 array->paa_count--;
 935                                 spin_lock(&rq->rq_lock);
 936                                 rq->rq_at_linked = 0;
 937                                 spin_unlock(&rq->rq_lock);
 938                                 continue;
 939                         }
 940
 941                         /* update the earliest deadline */
 942                         if (deadline == -1 || rq->rq_deadline < deadline)
 943                                 deadline = rq->rq_deadline;
 944
 945                         break;
 946                 }
 947
 948                 if (++index >= array->paa_size)
 949                         index = 0;
 950         }
 951         array->paa_deadline = deadline;
 952         spin_unlock(&svc->srv_at_lock);
 953
 954         /* we have a new earliest deadline, restart the timer */
 955         ptlrpc_at_set_timer(svc);
 956
 957         CDEBUG(D_ADAPTTO, "timeout in %+ds, asking for %d secs on %d early "
 958                "replies\n", first, at_extra, counter);
 959
 960         if (first < 0) {
 961                 /* We're already past request deadlines before we even get a
 962                    chance to send early replies */
 963                 LCONSOLE_WARN("%s: This server is not able to keep up with "
 964                               "request traffic (cpu-bound).\n",  svc->srv_name);
 965                 CWARN("earlyQ=%d reqQ=%d recA=%d, svcEst=%d, "
 966                       "delay="CFS_DURATION_T"(jiff)\n",
 967                       counter, svc->srv_n_queued_reqs, svc->srv_n_active_reqs,
 968                       at_get(&svc->srv_at_estimate), delay);
 969         }
 970
 971         /* we took additional refcount so entries can't be deleted from list, no
 972          * locking is needed */
 973         while (!list_empty(&work_list)) {
 974                 rq = list_entry(work_list.next, struct ptlrpc_request,
 975                                 rq_timed_list);
 976                 list_del_init(&rq->rq_timed_list);
 977
 978                 if (ptlrpc_at_send_early_reply(rq) == 0)
 979                         ptlrpc_at_add_timed(rq);
 980
 981                 ptlrpc_server_drop_request(rq);
 982         }
 983
 984         RETURN(0);
 985 }
 986
 987 /**
 988  * Put the request to the export list if the request may become
 989  * a high priority one.
 990  */
 991 static int ptlrpc_hpreq_init(struct ptlrpc_service *svc,
 992                              struct ptlrpc_request *req)
 993 {
 994         int rc;
 995         ENTRY;
 996
 997         if (svc->srv_hpreq_handler) {
 998                 rc = svc->srv_hpreq_handler(req);
 999                 if (rc)
1000                         RETURN(rc);
1001         }
1002         if (req->rq_export && req->rq_ops) {
1003                 spin_lock(&req->rq_export->exp_lock);
1004                 list_add(&req->rq_exp_list, &req->rq_export->exp_queued_rpc);
1005                 spin_unlock(&req->rq_export->exp_lock);
1006         }
1007
1008         RETURN(0);
1009 }
1010
1011 /** Remove the request from the export list. */
1012 static void ptlrpc_hpreq_fini(struct ptlrpc_request *req)
1013 {
1014         ENTRY;
1015         if (req->rq_export && req->rq_ops) {
1016                 spin_lock(&req->rq_export->exp_lock);
1017                 list_del_init(&req->rq_exp_list);
1018                 spin_unlock(&req->rq_export->exp_lock);
1019         }
1020         EXIT;
1021 }
1022
1023 /**
1024  * Make the request a high priority one.
1025  *
1026  * All the high priority requests are queued in a separate FIFO
1027  * ptlrpc_service::srv_request_hpq list which is parallel to
1028  * ptlrpc_service::srv_request_queue list but has a higher priority
1029  * for handling.
1030  *
1031  * \see ptlrpc_server_handle_request().
1032  */
1033 static void ptlrpc_hpreq_reorder_nolock(struct ptlrpc_service *svc,
1034                                         struct ptlrpc_request *req)
1035 {
1036         ENTRY;
1037         LASSERT(svc != NULL);
1038         spin_lock(&req->rq_lock);
1039         if (req->rq_hp == 0) {
1040                 int opc = lustre_msg_get_opc(req->rq_reqmsg);
1041
1042                 /* Add to the high priority queue. */
1043                 list_move_tail(&req->rq_list, &svc->srv_request_hpq);
1044                 req->rq_hp = 1;
1045                 if (opc != OBD_PING)
1046                         DEBUG_REQ(D_NET, req, "high priority req");
1047         }
1048         spin_unlock(&req->rq_lock);
1049         EXIT;
1050 }
1051
1052 void ptlrpc_hpreq_reorder(struct ptlrpc_request *req)
1053 {
1054         struct ptlrpc_service *svc = req->rq_rqbd->rqbd_service;
1055         ENTRY;
1056
1057         spin_lock(&svc->srv_lock);
1058         /* It may happen that the request is already taken for the processing
1059          * but still in the export list, do not re-add it into the HP list. */
1060         if (req->rq_phase == RQ_PHASE_NEW)
1061                 ptlrpc_hpreq_reorder_nolock(svc, req);
1062         spin_unlock(&svc->srv_lock);
1063         EXIT;
1064 }
1065
1066 /** Check if the request if a high priority one. */
1067 static int ptlrpc_server_hpreq_check(struct ptlrpc_request *req)
1068 {
1069         int opc, rc = 0;
1070         ENTRY;
1071
1072         /* Check by request opc. */
1073         opc = lustre_msg_get_opc(req->rq_reqmsg);
1074         if (opc == OBD_PING)
1075                 RETURN(1);
1076
1077         /* Perform request specific check. */
1078         if (req->rq_ops && req->rq_ops->hpreq_check)
1079                 rc = req->rq_ops->hpreq_check(req);
1080         RETURN(rc);
1081 }
1082
1083 /** Check if a request is a high priority one. */
1084 static int ptlrpc_server_request_add(struct ptlrpc_service *svc,
1085                                      struct ptlrpc_request *req)
1086 {
1087         int rc;
1088         ENTRY;
1089
1090         rc = ptlrpc_server_hpreq_check(req);
1091         if (rc < 0)
1092                 RETURN(rc);
1093
1094         spin_lock(&svc->srv_lock);
1095         /* Before inserting the request into the queue, check if it is not
1096          * inserted yet, or even already handled -- it may happen due to
1097          * a racing ldlm_server_blocking_ast(). */
1098         if (req->rq_phase == RQ_PHASE_NEW && list_empty(&req->rq_list)) {
1099                 if (rc)
1100                         ptlrpc_hpreq_reorder_nolock(svc, req);
1101                 else
1102                         list_add_tail(&req->rq_list, &svc->srv_request_queue);
1103         }
1104         spin_unlock(&svc->srv_lock);
1105
1106         RETURN(0);
1107 }
1108
1109 /* Only allow normal priority requests on a service that has a high-priority
1110  * queue if forced (i.e. cleanup), if there are other high priority requests
1111  * already being processed (i.e. those threads can service more high-priority
1112  * requests), or if there are enough idle threads that a later thread can do
1113  * a high priority request. */
1114 static int ptlrpc_server_allow_normal(struct ptlrpc_service *svc, int force)
1115 {
1116         return force || !svc->srv_hpreq_handler || svc->srv_n_hpreq > 0 ||
1117                svc->srv_n_active_reqs < svc->srv_threads_running - 2;
1118 }
1119
1120 static struct ptlrpc_request *
1121 ptlrpc_server_request_get(struct ptlrpc_service *svc, int force)
1122 {
1123         struct ptlrpc_request *req = NULL;
1124         ENTRY;
1125
1126         if (ptlrpc_server_allow_normal(svc, force) &&
1127             !list_empty(&svc->srv_request_queue) &&
1128             (list_empty(&svc->srv_request_hpq) ||
1129              svc->srv_hpreq_count >= svc->srv_hpreq_ratio)) {
1130                 req = list_entry(svc->srv_request_queue.next,
1131                                  struct ptlrpc_request, rq_list);
1132                 svc->srv_hpreq_count = 0;
1133         } else if (!list_empty(&svc->srv_request_hpq)) {
1134                 req = list_entry(svc->srv_request_hpq.next,
1135                                  struct ptlrpc_request, rq_list);
1136                 svc->srv_hpreq_count++;
1137         }
1138         RETURN(req);
1139 }
1140
1141 static int ptlrpc_server_request_pending(struct ptlrpc_service *svc, int force)
1142 {
1143         return ((ptlrpc_server_allow_normal(svc, force) &&
1144                  !list_empty(&svc->srv_request_queue)) ||
1145                 !list_empty(&svc->srv_request_hpq));
1146 }
1147
1148 /* Handle freshly incoming reqs, add to timed early reply list,
1149    pass on to regular request queue */
1150 static int
1151 ptlrpc_server_handle_req_in(struct ptlrpc_service *svc)
1152 {
1153         struct ptlrpc_request *req;
1154         __u32                  deadline;
1155         int                    rc;
1156         ENTRY;
1157
1158         LASSERT(svc);
1159
1160         spin_lock(&svc->srv_lock);
1161         if (list_empty(&svc->srv_req_in_queue)) {
1162                 spin_unlock(&svc->srv_lock);
1163                 RETURN(0);
1164         }
1165
1166         req = list_entry(svc->srv_req_in_queue.next,
1167                          struct ptlrpc_request, rq_list);
1168         list_del_init (&req->rq_list);
1169         /* Consider this still a "queued" request as far as stats are
1170            concerned */
1171         spin_unlock(&svc->srv_lock);
1172
1173         /* Clear request swab mask; this is a new request */
1174         req->rq_req_swab_mask = 0;
1175
1176         rc = lustre_unpack_msg(req->rq_reqmsg, req->rq_reqlen);
1177         if (rc < 0) {
1178                 CERROR ("error unpacking request: ptl %d from %s"
1179                         " xid "LPU64"\n", svc->srv_req_portal,
1180                         libcfs_id2str(req->rq_peer), req->rq_xid);
1181                 goto err_req;
1182         }
1183
1184         if (rc > 0)
1185                 lustre_set_req_swabbed(req, MSG_PTLRPC_HEADER_OFF);
1186
1187         rc = lustre_unpack_req_ptlrpc_body(req, MSG_PTLRPC_BODY_OFF);
1188         if (rc) {
1189                 CERROR ("error unpacking ptlrpc body: ptl %d from %s"
1190                         " xid "LPU64"\n", svc->srv_req_portal,
1191                         libcfs_id2str(req->rq_peer), req->rq_xid);
1192                 goto err_req;
1193         }
1194
1195         rc = -EINVAL;
1196         if (lustre_msg_get_type(req->rq_reqmsg) != PTL_RPC_MSG_REQUEST) {
1197                 CERROR("wrong packet type received (type=%u) from %s\n",
1198                        lustre_msg_get_type(req->rq_reqmsg),
1199                        libcfs_id2str(req->rq_peer));
1200                 goto err_req;
1201         }
1202
1203         CDEBUG(D_NET, "got req "LPU64"\n", req->rq_xid);
1204
1205         req->rq_export = class_conn2export(
1206                 lustre_msg_get_handle(req->rq_reqmsg));
1207         if (req->rq_export) {
1208                 rc = ptlrpc_check_req(req);
1209                 if (rc)
1210                         goto err_req;
1211                 ptlrpc_update_export_timer(req->rq_export, 0);
1212         }
1213
1214         /* req_in handling should/must be fast */
1215         if (cfs_time_current_sec() - req->rq_arrival_time.tv_sec > 5)
1216                 DEBUG_REQ(D_WARNING, req, "Slow req_in handling %lus",
1217                           cfs_time_current_sec() - req->rq_arrival_time.tv_sec);
1218
1219         /* Set rpc server deadline and add it to the timed list */
1220         deadline = (lustre_msghdr_get_flags(req->rq_reqmsg) &
1221                     MSGHDR_AT_SUPPORT) ?
1222                    /* The max time the client expects us to take */
1223                    lustre_msg_get_timeout(req->rq_reqmsg) : obd_timeout;
1224         req->rq_deadline = req->rq_arrival_time.tv_sec + deadline;
1225         if (unlikely(deadline == 0)) {
1226                 DEBUG_REQ(D_ERROR, req, "Dropping request with 0 timeout");
1227                 goto err_req;
1228         }
1229
1230         ptlrpc_at_add_timed(req);
1231         rc = ptlrpc_hpreq_init(svc, req);
1232         if (rc)
1233                 GOTO(err_req, rc);
1234
1235         /* Move it over to the request processing queue */
1236         rc = ptlrpc_server_request_add(svc, req);
1237         if (rc)
1238                 GOTO(err_req, rc);
1239         cfs_waitq_signal(&svc->srv_waitq);
1240         RETURN(1);
1241
1242 err_req:
1243         spin_lock(&svc->srv_lock);
1244         svc->srv_n_queued_reqs--;
1245         svc->srv_n_active_reqs++;
1246         spin_unlock(&svc->srv_lock);
1247         ptlrpc_server_finish_request(req);
1248
1249         RETURN(1);
1250 }
1251
1252 /*
1253  * The sole purpose of these functions is to avoid unreasonable stack frame
1254  * sizes such as assigned by the gcc compiler. Should NOT be inlined.
1255  */
1256 static void noinline
1257 ptlrpc_server_log_handling_request(struct ptlrpc_request *request)
1258 {
1259         CDEBUG(D_RPCTRACE, "Handling RPC pname:cluuid+ref:pid:xid:nid:opc "
1260                "%s:%s+%d:%d:x"LPU64":%s:%d\n", cfs_curproc_comm(),
1261                (request->rq_export ?
1262                 (char *)request->rq_export->exp_client_uuid.uuid : "0"),
1263                (request->rq_export ?
1264                 atomic_read(&request->rq_export->exp_refcount) : -99),
1265                lustre_msg_get_status(request->rq_reqmsg), request->rq_xid,
1266                libcfs_id2str(request->rq_peer),
1267                lustre_msg_get_opc(request->rq_reqmsg));
1268 }
1269
1270 static void noinline
1271 ptlrpc_server_log_handled_request(struct ptlrpc_request *request,
1272                                   long timediff,
1273                                   struct timeval *work_end)
1274 {
1275         CDEBUG(D_RPCTRACE, "Handled RPC pname:cluuid+ref:pid:xid:nid:opc "
1276                "%s:%s+%d:%d:x"LPU64":%s:%d Request procesed in "
1277                "%ldus (%ldus total) trans "LPU64" rc %d/%d\n",
1278                cfs_curproc_comm(),
1279                (request->rq_export ?
1280                 (char *)request->rq_export->exp_client_uuid.uuid : "0"),
1281                (request->rq_export ?
1282                 atomic_read(&request->rq_export->exp_refcount) : -99),
1283                lustre_msg_get_status(request->rq_reqmsg),
1284                request->rq_xid,
1285                libcfs_id2str(request->rq_peer),
1286                lustre_msg_get_opc(request->rq_reqmsg),
1287                timediff,
1288                cfs_timeval_sub(work_end, &request->rq_arrival_time, NULL),
1289                (request->rq_repmsg ?
1290                 lustre_msg_get_transno(request->rq_repmsg) :
1291                 request->rq_transno),
1292                request->rq_status,
1293                (request->rq_repmsg ?
1294                 lustre_msg_get_status(request->rq_repmsg) : -999));
1295 }
1296
1297 static int
1298 ptlrpc_server_handle_request(struct ptlrpc_service *svc,
1299                              struct ptlrpc_thread *thread)
1300 {
1301         struct obd_export     *export = NULL;
1302         struct ptlrpc_request *request;
1303         struct timeval         work_start;
1304         struct timeval         work_end;
1305         long                   timediff;
1306         int                    opc, rc;
1307         int                    fail_opc = 0;
1308         ENTRY;
1309
1310         LASSERT(svc);
1311
1312         spin_lock(&svc->srv_lock);
1313         if (!ptlrpc_server_request_pending(svc, 0) ||
1314             (
1315 #ifndef __KERNEL__
1316              /* !@%$# liblustre only has 1 thread */
1317              svc->srv_n_difficult_replies != 0 &&
1318 #endif
1319              svc->srv_n_active_reqs >= (svc->srv_threads_running - 1))) {
1320                 /* Don't handle regular requests in the last thread, in order
1321                  * to handle difficult replies (which might block other threads)
1322                  * as well as handle any incoming reqs, early replies, etc.
1323                  * That means we always need at least 2 service threads. */
1324                 spin_unlock(&svc->srv_lock);
1325                 RETURN(0);
1326         }
1327
1328         request = ptlrpc_server_request_get(svc, 0);
1329         if  (request == NULL) {
1330                 spin_unlock(&svc->srv_lock);
1331                 RETURN(0);
1332         }
1333
1334         opc = lustre_msg_get_opc(request->rq_reqmsg);
1335         if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_HPREQ_NOTIMEOUT))
1336                 fail_opc = OBD_FAIL_PTLRPC_HPREQ_NOTIMEOUT;
1337         else if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_HPREQ_TIMEOUT))
1338                 fail_opc = OBD_FAIL_PTLRPC_HPREQ_TIMEOUT;
1339
1340         if (unlikely(fail_opc)) {
1341                 if (request->rq_export && request->rq_ops) {
1342                         spin_unlock(&svc->srv_lock);
1343                         OBD_FAIL_TIMEOUT(fail_opc, 4);
1344                         spin_lock(&svc->srv_lock);
1345                         request = ptlrpc_server_request_get(svc, 0);
1346                         if  (request == NULL) {
1347                                 spin_unlock(&svc->srv_lock);
1348                                 RETURN(0);
1349                         }
1350                         LASSERT(ptlrpc_server_request_pending(svc, 0));
1351                 }
1352         }
1353
1354         list_del_init(&request->rq_list);
1355         svc->srv_n_queued_reqs--;
1356         svc->srv_n_active_reqs++;
1357
1358         if (request->rq_hp)
1359                 svc->srv_n_hpreq++;
1360
1361         /* The phase is changed under the lock here because we need to know
1362          * the request is under processing (see ptlrpc_hpreq_reorder()). */
1363         ptlrpc_rqphase_move(request, RQ_PHASE_INTERPRET);
1364         spin_unlock(&svc->srv_lock);
1365
1366         ptlrpc_hpreq_fini(request);
1367
1368         if(OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_DUMP_LOG))
1369                 libcfs_debug_dumplog();
1370
1371         do_gettimeofday(&work_start);
1372         timediff = cfs_timeval_sub(&work_start, &request->rq_arrival_time,NULL);
1373         if (svc->srv_stats != NULL) {
1374                 lprocfs_counter_add(svc->srv_stats, PTLRPC_REQWAIT_CNTR,
1375                                     timediff);
1376                 lprocfs_counter_add(svc->srv_stats, PTLRPC_REQQDEPTH_CNTR,
1377                                     svc->srv_n_queued_reqs);
1378                 lprocfs_counter_add(svc->srv_stats, PTLRPC_REQACTIVE_CNTR,
1379                                     svc->srv_n_active_reqs);
1380                 lprocfs_counter_add(svc->srv_stats, PTLRPC_TIMEOUT,
1381                                     at_get(&svc->srv_at_estimate));
1382         }
1383
1384         CDEBUG(D_NET, "got req "LPU64"\n", request->rq_xid);
1385
1386         request->rq_svc_thread = thread;
1387         if (request->rq_export) {
1388                 if (ptlrpc_check_req(request))
1389                         goto put_conn;
1390                 ptlrpc_update_export_timer(request->rq_export, timediff >> 19);
1391                 export = class_export_rpc_get(request->rq_export);
1392         }
1393
1394         /* Discard requests queued for longer than the deadline.
1395            The deadline is increased if we send an early reply. */
1396         if (cfs_time_current_sec() > request->rq_deadline) {
1397                 DEBUG_REQ(D_ERROR, request, "Dropping timed-out request from %s"
1398                           ": deadline %ld%+lds ago\n",
1399                           libcfs_id2str(request->rq_peer),
1400                           request->rq_deadline -
1401                           request->rq_arrival_time.tv_sec,
1402                           cfs_time_current_sec() - request->rq_deadline);
1403                 goto put_rpc_export;
1404         }
1405
1406         ptlrpc_server_log_handling_request(request);
1407
1408         if (lustre_msg_get_opc(request->rq_reqmsg) != OBD_PING)
1409                 OBD_FAIL_TIMEOUT_MS(OBD_FAIL_PTLRPC_PAUSE_REQ, obd_fail_val);
1410
1411         rc = svc->srv_handler(request);
1412
1413         ptlrpc_rqphase_move(request, RQ_PHASE_COMPLETE);
1414
1415 put_rpc_export:
1416         if (export != NULL && !request->rq_copy_queued)
1417                 class_export_rpc_put(export);
1418
1419 put_conn:
1420         if (cfs_time_current_sec() > request->rq_deadline) {
1421                 DEBUG_REQ(D_WARNING, request, "Request x"LPU64" took longer "
1422                           "than estimated (%ld%+lds); client may timeout.",
1423                           request->rq_xid, request->rq_deadline -
1424                           request->rq_arrival_time.tv_sec,
1425                           cfs_time_current_sec() - request->rq_deadline);
1426         }
1427
1428         do_gettimeofday(&work_end);
1429         timediff = cfs_timeval_sub(&work_end, &work_start, NULL);
1430
1431         ptlrpc_server_log_handled_request(request, timediff, &work_end);
1432
1433         if (svc->srv_stats != NULL) {
1434                 __u32 op = lustre_msg_get_opc(request->rq_reqmsg);
1435                 int opc = opcode_offset(op);
1436                 if (opc > 0 && !(op == LDLM_ENQUEUE || op == MDS_REINT)) {
1437                         LASSERT(opc < LUSTRE_MAX_OPCODES);
1438                         lprocfs_counter_add(svc->srv_stats,
1439                                             opc + EXTRA_MAX_OPCODES,
1440                                             timediff);
1441                 }
1442         }
1443         if (request->rq_early_count) {
1444                 DEBUG_REQ(D_ADAPTTO, request,
1445                           "sent %d early replies before finishing in %lds",
1446                           request->rq_early_count,
1447                           work_end.tv_sec - request->rq_arrival_time.tv_sec);
1448         }
1449
1450         spin_lock(&svc->srv_lock);
1451         if (request->rq_hp)
1452                 svc->srv_n_hpreq--;
1453         spin_unlock(&svc->srv_lock);
1454         ptlrpc_server_finish_request(request);
1455
1456         RETURN(1);
1457 }
1458
1459 static int
1460 ptlrpc_server_handle_reply (struct ptlrpc_service *svc)
1461 {
1462         struct ptlrpc_reply_state *rs;
1463         struct obd_export         *exp;
1464         struct obd_device         *obd;
1465         int                        nlocks;
1466         int                        been_handled;
1467         ENTRY;
1468
1469         spin_lock(&svc->srv_lock);
1470         if (list_empty (&svc->srv_reply_queue)) {
1471                 spin_unlock(&svc->srv_lock);
1472                 RETURN(0);
1473         }
1474
1475         rs = list_entry (svc->srv_reply_queue.next,
1476                          struct ptlrpc_reply_state, rs_list);
1477
1478         exp = rs->rs_export;
1479         obd = exp->exp_obd;
1480
1481         LASSERT (rs->rs_difficult);
1482         LASSERT (rs->rs_scheduled);
1483
1484         list_del_init (&rs->rs_list);
1485
1486         /* Disengage from notifiers carefully (lock order - irqrestore below!)*/
1487         spin_unlock(&svc->srv_lock);
1488
1489         spin_lock (&exp->exp_uncommitted_replies_lock);
1490         /* Noop if removed already */
1491         list_del_init (&rs->rs_obd_list);
1492         spin_unlock (&exp->exp_uncommitted_replies_lock);
1493
1494         spin_lock (&exp->exp_lock);
1495         /* Noop if removed already */
1496         list_del_init (&rs->rs_exp_list);
1497         spin_unlock (&exp->exp_lock);
1498
1499         spin_lock(&svc->srv_lock);
1500
1501         been_handled = rs->rs_handled;
1502         rs->rs_handled = 1;
1503
1504         nlocks = rs->rs_nlocks;                 /* atomic "steal", but */
1505         rs->rs_nlocks = 0;                      /* locks still on rs_locks! */
1506
1507         if (nlocks == 0 && !been_handled) {
1508                 /* If we see this, we should already have seen the warning
1509                  * in mds_steal_ack_locks()  */
1510                 CWARN("All locks stolen from rs %p x"LPD64".t"LPD64
1511                       " o%d NID %s\n", rs, rs->rs_xid, rs->rs_transno,
1512                       lustre_msg_get_opc(rs->rs_msg),
1513                       libcfs_nid2str(exp->exp_connection->c_peer.nid));
1514         }
1515
1516         if ((!been_handled && rs->rs_on_net) || nlocks > 0) {
1517                 spin_unlock(&svc->srv_lock);
1518
1519                 if (!been_handled && rs->rs_on_net) {
1520                         LNetMDUnlink(rs->rs_md_h);
1521                         /* Ignore return code; we're racing with
1522                          * completion... */
1523                 }
1524
1525                 while (nlocks-- > 0)
1526                         ldlm_lock_decref(&rs->rs_locks[nlocks],
1527                                          rs->rs_modes[nlocks]);
1528
1529                 spin_lock(&svc->srv_lock);
1530         }
1531
1532         rs->rs_scheduled = 0;
1533
1534         if (!rs->rs_on_net) {
1535                 /* Off the net */
1536                 svc->srv_n_difficult_replies--;
1537                 spin_unlock(&svc->srv_lock);
1538
1539                 class_export_put (exp);
1540                 rs->rs_export = NULL;
1541                 ptlrpc_rs_decref (rs);
1542                 atomic_dec (&svc->srv_outstanding_replies);
1543                 RETURN(1);
1544         }
1545
1546         /* still on the net; callback will schedule */
1547         spin_unlock(&svc->srv_lock);
1548         RETURN(1);
1549 }
1550
1551 #ifndef __KERNEL__
1552 /* FIXME make use of timeout later */
1553 int
1554 liblustre_check_services (void *arg)
1555 {
1556         int  did_something = 0;
1557         int  rc;
1558         struct list_head *tmp, *nxt;
1559         ENTRY;
1560
1561         /* I'm relying on being single threaded, not to have to lock
1562          * ptlrpc_all_services etc */
1563         list_for_each_safe (tmp, nxt, &ptlrpc_all_services) {
1564                 struct ptlrpc_service *svc =
1565                         list_entry (tmp, struct ptlrpc_service, srv_list);
1566
1567                 if (svc->srv_threads_running != 0)     /* I've recursed */
1568                         continue;
1569
1570                 /* service threads can block for bulk, so this limits us
1571                  * (arbitrarily) to recursing 1 stack frame per service.
1572                  * Note that the problem with recursion is that we have to
1573                  * unwind completely before our caller can resume. */
1574
1575                 svc->srv_threads_running++;
1576
1577                 do {
1578                         rc = ptlrpc_server_handle_req_in(svc);
1579                         rc |= ptlrpc_server_handle_reply(svc);
1580                         rc |= ptlrpc_at_check_timed(svc);
1581                         rc |= ptlrpc_server_handle_request(svc, NULL);
1582                         rc |= (ptlrpc_server_post_idle_rqbds(svc) > 0);
1583                         did_something |= rc;
1584                 } while (rc);
1585
1586                 svc->srv_threads_running--;
1587         }
1588
1589         RETURN(did_something);
1590 }
1591 #define ptlrpc_stop_all_threads(s) do {} while (0)
1592
1593 #else /* __KERNEL__ */
1594
1595 static void
1596 ptlrpc_check_rqbd_pool(struct ptlrpc_service *svc)
1597 {
1598         int avail = svc->srv_nrqbd_receiving;
1599         int low_water = test_req_buffer_pressure ? 0 :
1600                         svc->srv_nbuf_per_group/2;
1601
1602         /* NB I'm not locking; just looking. */
1603
1604         /* CAVEAT EMPTOR: We might be allocating buffers here because we've
1605          * allowed the request history to grow out of control.  We could put a
1606          * sanity check on that here and cull some history if we need the
1607          * space. */
1608
1609         if (avail <= low_water)
1610                 ptlrpc_grow_req_bufs(svc);
1611
1612         if (svc->srv_stats)
1613                 lprocfs_counter_add(svc->srv_stats, PTLRPC_REQBUF_AVAIL_CNTR,
1614                                     avail);
1615 }
1616
1617 static int
1618 ptlrpc_retry_rqbds(void *arg)
1619 {
1620         struct ptlrpc_service *svc = (struct ptlrpc_service *)arg;
1621
1622         svc->srv_rqbd_timeout = 0;
1623         return (-ETIMEDOUT);
1624 }
1625
1626 static int ptlrpc_main(void *arg)
1627 {
1628         struct ptlrpc_svc_data *data = (struct ptlrpc_svc_data *)arg;
1629         struct ptlrpc_service  *svc = data->svc;
1630         struct ptlrpc_thread   *thread = data->thread;
1631         struct obd_device      *dev = data->dev;
1632         struct ptlrpc_reply_state *rs;
1633 #ifdef WITH_GROUP_INFO
1634         struct group_info *ginfo = NULL;
1635 #endif
1636         int counter = 0, rc = 0;
1637         ENTRY;
1638
1639         cfs_daemonize_ctxt(data->name);
1640
1641 #if defined(HAVE_NODE_TO_CPUMASK) && defined(CONFIG_NUMA)
1642         /* we need to do this before any per-thread allocation is done so that
1643          * we get the per-thread allocations on local node.  bug 7342 */
1644         if (svc->srv_cpu_affinity) {
1645                 int cpu, num_cpu;
1646
1647                 for (cpu = 0, num_cpu = 0; cpu < num_possible_cpus(); cpu++) {
1648                         if (!cpu_online(cpu))
1649                                 continue;
1650                         if (num_cpu == thread->t_id % num_online_cpus())
1651                                 break;
1652                         num_cpu++;
1653                 }
1654                 set_cpus_allowed(cfs_current(), node_to_cpumask(cpu_to_node(cpu)));
1655         }
1656 #endif
1657
1658 #ifdef WITH_GROUP_INFO
1659         ginfo = groups_alloc(0);
1660         if (!ginfo) {
1661                 rc = -ENOMEM;
1662                 goto out;
1663         }
1664
1665         set_current_groups(ginfo);
1666         put_group_info(ginfo);
1667 #endif
1668
1669         if (svc->srv_init != NULL) {
1670                 rc = svc->srv_init(thread);
1671                 if (rc)
1672                         goto out;
1673         }
1674
1675         /* Alloc reply state structure for this one */
1676         OBD_ALLOC_GFP(rs, svc->srv_max_reply_size, CFS_ALLOC_STD);
1677         if (!rs) {
1678                 rc = -ENOMEM;
1679                 goto out_srv_init;
1680         }
1681
1682         spin_lock(&svc->srv_lock);
1683         /* SVC_STOPPING may already be set here if someone else is trying
1684          * to stop the service while this new thread has been dynamically
1685          * forked. We still set SVC_RUNNING to let our creator know that
1686          * we are now running, however we will exit as soon as possible */
1687         thread->t_flags |= SVC_RUNNING;
1688         spin_unlock(&svc->srv_lock);
1689
1690         /*
1691          * wake up our creator. Note: @data is invalid after this point,
1692          * because it's allocated on ptlrpc_start_thread() stack.
1693          */
1694         cfs_waitq_signal(&thread->t_ctl_waitq);
1695
1696         thread->t_watchdog = lc_watchdog_add(GET_TIMEOUT(svc), NULL, NULL);
1697
1698         spin_lock(&svc->srv_lock);
1699         svc->srv_threads_running++;
1700         list_add(&rs->rs_list, &svc->srv_free_rs_list);
1701         spin_unlock(&svc->srv_lock);
1702         cfs_waitq_signal(&svc->srv_free_rs_waitq);
1703
1704         CDEBUG(D_NET, "service thread %d (#%d) started\n", thread->t_id,
1705                svc->srv_threads_running);
1706
1707         /* XXX maintain a list of all managed devices: insert here */
1708
1709         while ((thread->t_flags & SVC_STOPPING) == 0 ||
1710                svc->srv_n_difficult_replies != 0) {
1711                 /* Don't exit while there are replies to be handled */
1712                 struct l_wait_info lwi = LWI_TIMEOUT(svc->srv_rqbd_timeout,
1713                                                      ptlrpc_retry_rqbds, svc);
1714
1715                 lc_watchdog_disable(thread->t_watchdog);
1716
1717                 cfs_cond_resched();
1718
1719                 l_wait_event_exclusive (svc->srv_waitq,
1720                               ((thread->t_flags & SVC_STOPPING) != 0 &&
1721                                svc->srv_n_difficult_replies == 0) ||
1722                               (!list_empty(&svc->srv_idle_rqbds) &&
1723                                svc->srv_rqbd_timeout == 0) ||
1724                               !list_empty(&svc->srv_req_in_queue) ||
1725                               !list_empty(&svc->srv_reply_queue) ||
1726                               (ptlrpc_server_request_pending(svc, 0) &&
1727                                (svc->srv_n_active_reqs <
1728                                 (svc->srv_threads_running - 1))) ||
1729                               svc->srv_at_check,
1730                               &lwi);
1731
1732                 lc_watchdog_touch(thread->t_watchdog, GET_TIMEOUT(svc));
1733
1734                 ptlrpc_check_rqbd_pool(svc);
1735
1736                 if ((svc->srv_threads_started < svc->srv_threads_max) &&
1737                     (svc->srv_n_active_reqs >= (svc->srv_threads_started - 1))){
1738                         /* Ignore return code - we tried... */
1739                         ptlrpc_start_thread(dev, svc);
1740                 }
1741
1742                 if (!list_empty(&svc->srv_reply_queue))
1743                         ptlrpc_server_handle_reply (svc);
1744
1745                 if (!list_empty(&svc->srv_req_in_queue)) {
1746                         /* Process all incoming reqs before handling any */
1747                         ptlrpc_server_handle_req_in(svc);
1748                         /* but limit ourselves in case of flood */
1749                         if (counter++ < 1000)
1750                                 continue;
1751                         counter = 0;
1752                 }
1753
1754                 if (svc->srv_at_check)
1755                         ptlrpc_at_check_timed(svc);
1756
1757                 /* don't handle requests in the last thread */
1758                 if (ptlrpc_server_request_pending(svc, 0) &&
1759                     (svc->srv_n_active_reqs < (svc->srv_threads_running - 1)))
1760                         ptlrpc_server_handle_request(svc, thread);
1761
1762                 if (!list_empty(&svc->srv_idle_rqbds) &&
1763                     ptlrpc_server_post_idle_rqbds(svc) < 0) {
1764                         /* I just failed to repost request buffers.  Wait
1765                          * for a timeout (unless something else happens)
1766                          * before I try again */
1767                         svc->srv_rqbd_timeout = cfs_time_seconds(1)/10;
1768                         CDEBUG(D_RPCTRACE,"Posted buffers: %d\n",
1769                                svc->srv_nrqbd_receiving);
1770                 }
1771         }
1772
1773         lc_watchdog_delete(thread->t_watchdog);
1774         thread->t_watchdog = NULL;
1775
1776 out_srv_init:
1777         /*
1778          * deconstruct service specific state created by ptlrpc_start_thread()
1779          */
1780         if (svc->srv_done != NULL)
1781                 svc->srv_done(thread);
1782
1783 out:
1784         CDEBUG(D_NET, "service thread %d exiting: rc %d\n", thread->t_id, rc);
1785
1786         spin_lock(&svc->srv_lock);
1787         svc->srv_threads_running--;              /* must know immediately */
1788         thread->t_id = rc;
1789         thread->t_flags = SVC_STOPPED;
1790
1791         cfs_waitq_signal(&thread->t_ctl_waitq);
1792         spin_unlock(&svc->srv_lock);
1793
1794         return rc;
1795 }
1796
1797 static void ptlrpc_stop_thread(struct ptlrpc_service *svc,
1798                                struct ptlrpc_thread *thread)
1799 {
1800         struct l_wait_info lwi = { 0 };
1801
1802         spin_lock(&svc->srv_lock);
1803         /* let the thread know that we would like it to stop asap */
1804         thread->t_flags |= SVC_STOPPING;
1805         spin_unlock(&svc->srv_lock);
1806
1807         cfs_waitq_broadcast(&svc->srv_waitq);
1808         l_wait_event(thread->t_ctl_waitq, (thread->t_flags & SVC_STOPPED),
1809                      &lwi);
1810
1811         spin_lock(&svc->srv_lock);
1812         list_del(&thread->t_link);
1813         spin_unlock(&svc->srv_lock);
1814
1815         OBD_FREE(thread, sizeof(*thread));
1816 }
1817
1818 void ptlrpc_stop_all_threads(struct ptlrpc_service *svc)
1819 {
1820         struct ptlrpc_thread *thread;
1821
1822         spin_lock(&svc->srv_lock);
1823         while (!list_empty(&svc->srv_threads)) {
1824                 thread = list_entry(svc->srv_threads.next,
1825                                     struct ptlrpc_thread, t_link);
1826
1827                 spin_unlock(&svc->srv_lock);
1828                 ptlrpc_stop_thread(svc, thread);
1829                 spin_lock(&svc->srv_lock);
1830         }
1831
1832         spin_unlock(&svc->srv_lock);
1833 }
1834
1835 int ptlrpc_start_threads(struct obd_device *dev, struct ptlrpc_service *svc)
1836 {
1837         int i, rc = 0;
1838         ENTRY;
1839
1840         /* We require 2 threads min - see note in
1841          * ptlrpc_server_handle_request() */
1842
1843         LASSERT(svc->srv_threads_min >= 2);
1844         for (i = 0; i < svc->srv_threads_min; i++) {
1845                 rc = ptlrpc_start_thread(dev, svc);
1846                 /* We have enough threads, don't start more.  b=15759 */
1847                 if (rc == -EMFILE)
1848                         break;
1849                 if (rc) {
1850                         CERROR("cannot start %s thread #%d: rc %d\n",
1851                                svc->srv_thread_name, i, rc);
1852                         ptlrpc_stop_all_threads(svc);
1853                 }
1854         }
1855         RETURN(rc);
1856 }
1857
1858 int ptlrpc_start_thread(struct obd_device *dev, struct ptlrpc_service *svc)
1859 {
1860         struct l_wait_info lwi = { 0 };
1861         struct ptlrpc_svc_data d;
1862         struct ptlrpc_thread *thread;
1863         char name[32];
1864         int id, rc;
1865         ENTRY;
1866
1867         CDEBUG(D_RPCTRACE, "%s started %d min %d max %d running %d\n",
1868                svc->srv_name, svc->srv_threads_started, svc->srv_threads_min,
1869                svc->srv_threads_max, svc->srv_threads_running);
1870         if (unlikely(svc->srv_threads_started >= svc->srv_threads_max) ||
1871             (OBD_FAIL_CHECK(OBD_FAIL_TGT_TOOMANY_THREADS) &&
1872              svc->srv_threads_started == svc->srv_threads_min - 1))
1873                 RETURN(-EMFILE);
1874
1875         OBD_ALLOC(thread, sizeof(*thread));
1876         if (thread == NULL)
1877                 RETURN(-ENOMEM);
1878         cfs_waitq_init(&thread->t_ctl_waitq);
1879
1880         spin_lock(&svc->srv_lock);
1881         if (svc->srv_threads_started >= svc->srv_threads_max) {
1882                 spin_unlock(&svc->srv_lock);
1883                 OBD_FREE(thread, sizeof(*thread));
1884                 RETURN(-EMFILE);
1885         }
1886         list_add(&thread->t_link, &svc->srv_threads);
1887         id = svc->srv_threads_started++;
1888         spin_unlock(&svc->srv_lock);
1889
1890         thread->t_svc = svc;
1891         thread->t_id = id;
1892         sprintf(name, "%s_%02d", svc->srv_thread_name, id);
1893         d.dev = dev;
1894         d.svc = svc;
1895         d.name = name;
1896         d.thread = thread;
1897
1898         CDEBUG(D_RPCTRACE, "starting thread '%s'\n", name);
1899
1900         /* CLONE_VM and CLONE_FILES just avoid a needless copy, because we
1901          * just drop the VM and FILES in cfs_daemonize_ctxt() right away.
1902          */
1903         rc = cfs_kernel_thread(ptlrpc_main, &d, CLONE_VM | CLONE_FILES);
1904         if (rc < 0) {
1905                 CERROR("cannot start thread '%s': rc %d\n", name, rc);
1906
1907                 spin_lock(&svc->srv_lock);
1908                 list_del(&thread->t_link);
1909                 --svc->srv_threads_started;
1910                 spin_unlock(&svc->srv_lock);
1911
1912                 OBD_FREE(thread, sizeof(*thread));
1913                 RETURN(rc);
1914         }
1915         l_wait_event(thread->t_ctl_waitq,
1916                      thread->t_flags & (SVC_RUNNING | SVC_STOPPED), &lwi);
1917
1918         rc = (thread->t_flags & SVC_STOPPED) ? thread->t_id : 0;
1919         RETURN(rc);
1920 }
1921 #endif
1922
1923 int ptlrpc_unregister_service(struct ptlrpc_service *service)
1924 {
1925         int                   rc;
1926         struct l_wait_info    lwi;
1927         struct list_head     *tmp;
1928         struct ptlrpc_reply_state *rs, *t;
1929         struct ptlrpc_at_array *array = &service->srv_at_array;
1930
1931         cfs_timer_disarm(&service->srv_at_timer);
1932
1933         ptlrpc_stop_all_threads(service);
1934         LASSERT(list_empty(&service->srv_threads));
1935
1936         spin_lock (&ptlrpc_all_services_lock);
1937         list_del_init (&service->srv_list);
1938         spin_unlock (&ptlrpc_all_services_lock);
1939
1940         ptlrpc_lprocfs_unregister_service(service);
1941
1942         /* All history will be culled when the next request buffer is
1943          * freed */
1944         service->srv_max_history_rqbds = 0;
1945
1946         CDEBUG(D_NET, "%s: tearing down\n", service->srv_name);
1947
1948         rc = LNetClearLazyPortal(service->srv_req_portal);
1949         LASSERT (rc == 0);
1950
1951         /* Unlink all the request buffers.  This forces a 'final' event with
1952          * its 'unlink' flag set for each posted rqbd */
1953         list_for_each(tmp, &service->srv_active_rqbds) {
1954                 struct ptlrpc_request_buffer_desc *rqbd =
1955                         list_entry(tmp, struct ptlrpc_request_buffer_desc,
1956                                    rqbd_list);
1957
1958                 rc = LNetMDUnlink(rqbd->rqbd_md_h);
1959                 LASSERT (rc == 0 || rc == -ENOENT);
1960         }
1961
1962         /* Wait for the network to release any buffers it's currently
1963          * filling */
1964         for (;;) {
1965                 spin_lock(&service->srv_lock);
1966                 rc = service->srv_nrqbd_receiving;
1967                 spin_unlock(&service->srv_lock);
1968
1969                 if (rc == 0)
1970                         break;
1971
1972                 /* Network access will complete in finite time but the HUGE
1973                  * timeout lets us CWARN for visibility of sluggish NALs */
1974                 lwi = LWI_TIMEOUT_INTERVAL(cfs_time_seconds(LONG_UNLINK),
1975                                            cfs_time_seconds(1), NULL, NULL);
1976                 rc = l_wait_event(service->srv_waitq,
1977                                   service->srv_nrqbd_receiving == 0,
1978                                   &lwi);
1979                 if (rc == -ETIMEDOUT)
1980                         CWARN("Service %s waiting for request buffers\n",
1981                               service->srv_name);
1982         }
1983
1984         /* schedule all outstanding replies to terminate them */
1985         spin_lock(&service->srv_lock);
1986         while (!list_empty(&service->srv_active_replies)) {
1987                 struct ptlrpc_reply_state *rs =
1988                         list_entry(service->srv_active_replies.next,
1989                                    struct ptlrpc_reply_state, rs_list);
1990                 ptlrpc_schedule_difficult_reply(rs);
1991         }
1992         spin_unlock(&service->srv_lock);
1993
1994         /* purge the request queue.  NB No new replies (rqbds all unlinked)
1995          * and no service threads, so I'm the only thread noodling the
1996          * request queue now */
1997         while (!list_empty(&service->srv_req_in_queue)) {
1998                 struct ptlrpc_request *req =
1999                         list_entry(service->srv_req_in_queue.next,
2000                                    struct ptlrpc_request,
2001                                    rq_list);
2002
2003                 list_del(&req->rq_list);
2004                 service->srv_n_queued_reqs--;
2005                 service->srv_n_active_reqs++;
2006                 ptlrpc_server_finish_request(req);
2007         }
2008         while (ptlrpc_server_request_pending(service, 1)) {
2009                 struct ptlrpc_request *req;
2010
2011                 req = ptlrpc_server_request_get(service, 1);
2012                 list_del(&req->rq_list);
2013                 service->srv_n_queued_reqs--;
2014                 service->srv_n_active_reqs++;
2015                 ptlrpc_hpreq_fini(req);
2016                 ptlrpc_server_finish_request(req);
2017         }
2018         LASSERT(service->srv_n_queued_reqs == 0);
2019         LASSERT(service->srv_n_active_reqs == 0);
2020         LASSERT(service->srv_n_history_rqbds == 0);
2021         LASSERT(list_empty(&service->srv_active_rqbds));
2022
2023         /* Now free all the request buffers since nothing references them
2024          * any more... */
2025         while (!list_empty(&service->srv_idle_rqbds)) {
2026                 struct ptlrpc_request_buffer_desc *rqbd =
2027                         list_entry(service->srv_idle_rqbds.next,
2028                                    struct ptlrpc_request_buffer_desc,
2029                                    rqbd_list);
2030
2031                 ptlrpc_free_rqbd(rqbd);
2032         }
2033
2034         /* wait for all outstanding replies to complete (they were
2035          * scheduled having been flagged to abort above) */
2036         while (atomic_read(&service->srv_outstanding_replies) != 0) {
2037                 struct l_wait_info lwi = LWI_TIMEOUT(cfs_time_seconds(10), NULL, NULL);
2038
2039                 rc = l_wait_event(service->srv_waitq,
2040                                   !list_empty(&service->srv_reply_queue), &lwi);
2041                 LASSERT(rc == 0 || rc == -ETIMEDOUT);
2042
2043                 if (rc == 0) {
2044                         ptlrpc_server_handle_reply(service);
2045                         continue;
2046                 }
2047                 CWARN("Unexpectedly long timeout %p\n", service);
2048         }
2049
2050         list_for_each_entry_safe(rs, t, &service->srv_free_rs_list, rs_list) {
2051                 list_del(&rs->rs_list);
2052                 OBD_FREE(rs, service->srv_max_reply_size);
2053         }
2054
2055         /* In case somebody rearmed this in the meantime */
2056         cfs_timer_disarm(&service->srv_at_timer);
2057
2058         if (array->paa_reqs_array != NULL) {
2059                 OBD_FREE(array->paa_reqs_array,
2060                          sizeof(struct list_head) * array->paa_size);
2061                 array->paa_reqs_array = NULL;
2062         }
2063
2064         if (array->paa_reqs_count != NULL) {
2065                 OBD_FREE(array->paa_reqs_count,
2066                          sizeof(__u32) * array->paa_size);
2067                 array->paa_reqs_count= NULL;
2068         }
2069
2070         OBD_FREE(service, sizeof(*service));
2071         return 0;
2072 }
2073
2074 /* Returns 0 if the service is healthy.
2075  *
2076  * Right now, it just checks to make sure that requests aren't languishing
2077  * in the queue.  We'll use this health check to govern whether a node needs
2078  * to be shot, so it's intentionally non-aggressive. */
2079 int ptlrpc_service_health_check(struct ptlrpc_service *svc)
2080 {
2081         struct ptlrpc_request *request;
2082         struct timeval         right_now;
2083         long                   timediff;
2084
2085         if (svc == NULL)
2086                 return 0;
2087
2088         do_gettimeofday(&right_now);
2089
2090         spin_lock(&svc->srv_lock);
2091         if (!ptlrpc_server_request_pending(svc, 1)) {
2092                 spin_unlock(&svc->srv_lock);
2093                 return 0;
2094         }
2095
2096         /* How long has the next entry been waiting? */
2097         if (list_empty(&svc->srv_request_queue))
2098                 request = list_entry(svc->srv_request_hpq.next,
2099                                      struct ptlrpc_request, rq_list);
2100         else
2101                 request = list_entry(svc->srv_request_queue.next,
2102                                      struct ptlrpc_request, rq_list);
2103         timediff = cfs_timeval_sub(&right_now, &request->rq_arrival_time, NULL);
2104         spin_unlock(&svc->srv_lock);
2105
2106         if ((timediff / ONE_MILLION) > (AT_OFF ? obd_timeout * 3/2 :
2107                                         at_max)) {
2108                 CERROR("%s: unhealthy - request has been waiting %lds\n",
2109                        svc->srv_name, timediff / ONE_MILLION);
2110                 return (-1);
2111         }
2112
2113         return 0;
2114 }