lustre/ptlrpc/pinger.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * Portal-RPC reconnection and replay operations, for use in recovery.
   5  *
   6  *  Copyright (c) 2003 Cluster File Systems, Inc.
   7  *   Authors: Phil Schwan <phil@clusterfs.com>
   8  *            Mike Shaver <shaver@clusterfs.com>
   9  *
  10  *   This file is part of Lustre, http://www.lustre.org.
  11  *
  12  *   Lustre is free software; you can redistribute it and/or
  13  *   modify it under the terms of version 2 of the GNU General Public
  14  *   License as published by the Free Software Foundation.
  15  *
  16  *   Lustre is distributed in the hope that it will be useful,
  17  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *   GNU General Public License for more details.
  20  *
  21  *   You should have received a copy of the GNU General Public License
  22  *   along with Lustre; if not, write to the Free Software
  23  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26 #ifndef __KERNEL__
  27 #include <liblustre.h>
  28 #else
  29 #include <linux/version.h>
  30 #include <asm/semaphore.h>
  31 #define DEBUG_SUBSYSTEM S_RPC
  32 #endif
  33
  34 #include <linux/obd_support.h>
  35 #include <linux/obd_class.h>
  36 #include "ptlrpc_internal.h"
  37
  38 static DECLARE_MUTEX(pinger_sem);
  39 static struct list_head pinger_imports = LIST_HEAD_INIT(pinger_imports);
  40
  41 int ptlrpc_ping(struct obd_import *imp)
  42 {
  43         struct ptlrpc_request *req;
  44         int rc = 0;
  45         ENTRY;
  46
  47         req = ptlrpc_prep_req(imp, OBD_PING, 0, NULL,
  48                               NULL);
  49         if (req) {
  50                 DEBUG_REQ(D_HA, req, "pinging %s->%s",
  51                           imp->imp_obd->obd_uuid.uuid,
  52                           imp->imp_target_uuid.uuid);
  53                 req->rq_no_resend = req->rq_no_delay = 1;
  54                 req->rq_replen = lustre_msg_size(0,
  55                                                  NULL);
  56                 ptlrpcd_add_req(req);
  57         } else {
  58                 CERROR("OOM trying to ping %s->%s\n",
  59                           imp->imp_obd->obd_uuid.uuid,
  60                           imp->imp_target_uuid.uuid);
  61                 rc = -ENOMEM;
  62         }
  63
  64         RETURN(rc);
  65 }
  66
  67 #ifdef __KERNEL__
  68 static int ptlrpc_pinger_main(void *arg)
  69 {
  70         struct ptlrpc_svc_data *data = (struct ptlrpc_svc_data *)arg;
  71         struct ptlrpc_thread *thread = data->thread;
  72         unsigned long flags;
  73         ENTRY;
  74
  75         lock_kernel();
  76         ptlrpc_daemonize();
  77
  78         SIGNAL_MASK_LOCK(current, flags);
  79         sigfillset(&current->blocked);
  80         RECALC_SIGPENDING;
  81         SIGNAL_MASK_UNLOCK(current, flags);
  82
  83         LASSERTF(strlen(data->name) < sizeof(current->comm),
  84                  "name %d > len %d\n",
  85                  (int)strlen(data->name), (int)sizeof(current->comm));
  86         THREAD_NAME(current->comm, sizeof(current->comm) - 1, "%s", data->name);
  87         unlock_kernel();
  88
  89         /* Record that the thread is running */
  90         thread->t_flags = SVC_RUNNING;
  91         wake_up(&thread->t_ctl_waitq);
  92
  93         /* And now, loop forever, pinging as needed. */
  94         while (1) {
  95                 unsigned long this_ping = jiffies;
  96                 long time_to_next_ping;
  97                 struct l_wait_info lwi = LWI_TIMEOUT(obd_timeout * HZ,
  98                                                      NULL, NULL);
  99                 struct list_head *iter;
 100
 101                 down(&pinger_sem);
 102                 list_for_each(iter, &pinger_imports) {
 103                         struct obd_import *imp =
 104                                 list_entry(iter, struct obd_import,
 105                                            imp_pinger_chain);
 106                         int force, level;
 107                         unsigned long flags;
 108
 109
 110                         spin_lock_irqsave(&imp->imp_lock, flags);
 111                         level = imp->imp_state;
 112                         force = imp->imp_force_verify;
 113                         if (force)
 114                                 imp->imp_force_verify = 0;
 115                         spin_unlock_irqrestore(&imp->imp_lock, flags);
 116
 117                         if (imp->imp_next_ping <= this_ping || force) {
 118                                 if (level == LUSTRE_IMP_DISCON &&
 119                                     !imp->imp_deactive) {
 120                                         /* wait at least a timeout before
 121                                            trying recovery again. */
 122                                         imp->imp_next_ping = jiffies +
 123                                                 (obd_timeout * HZ);
 124                                         ptlrpc_initiate_recovery(imp);
 125                                 }
 126                                 else if (level != LUSTRE_IMP_FULL ||
 127                                          imp->imp_obd->obd_no_recov) {
 128                                         CDEBUG(D_HA,
 129                                                "not pinging %s (in recovery "
 130                                                " or recovery disabled: %s)\n",
 131                                                imp->imp_target_uuid.uuid,
 132                                                ptlrpc_import_state_name(level));
 133                                 }
 134                                 else if (imp->imp_pingable || force) {
 135                                         ptlrpc_ping(imp);
 136                                 }
 137
 138                         } else {
 139                                 if (imp->imp_pingable)
 140                                         CDEBUG(D_HA, "don't need to ping %s "
 141                                                "(%lu > %lu)\n",
 142                                                imp->imp_target_uuid.uuid,
 143                                                imp->imp_next_ping, this_ping);
 144                         }
 145                 }
 146                 up(&pinger_sem);
 147
 148                 /* Wait until the next ping time, or until we're stopped. */
 149                 time_to_next_ping = this_ping + (obd_timeout * HZ) - jiffies;
 150                 CDEBUG(D_HA, "next ping in %lu (%lu)\n", time_to_next_ping,
 151                        this_ping + (obd_timeout * HZ));
 152                 if (time_to_next_ping > 0) {
 153                         lwi = LWI_TIMEOUT(time_to_next_ping, NULL, NULL);
 154                         l_wait_event(thread->t_ctl_waitq,
 155                                      thread->t_flags & (SVC_STOPPING|SVC_EVENT),
 156                                      &lwi);
 157                         if (thread->t_flags & SVC_STOPPING) {
 158                                 thread->t_flags &= ~SVC_STOPPING;
 159                                 EXIT;
 160                                 break;
 161                         } else if (thread->t_flags & SVC_EVENT) {
 162                                 /* woken after adding import to reset timer */
 163                                 thread->t_flags &= ~SVC_EVENT;
 164                         }
 165                 }
 166         }
 167
 168         thread->t_flags = SVC_STOPPED;
 169         wake_up(&thread->t_ctl_waitq);
 170
 171         CDEBUG(D_NET, "pinger thread exiting, process %d\n", current->pid);
 172         return 0;
 173 }
 174
 175 static struct ptlrpc_thread *pinger_thread = NULL;
 176
 177 int ptlrpc_start_pinger(void)
 178 {
 179         struct l_wait_info lwi = { 0 };
 180         struct ptlrpc_svc_data d;
 181         int rc;
 182 #ifndef ENABLE_PINGER
 183         return 0;
 184 #endif
 185         ENTRY;
 186
 187         if (pinger_thread != NULL)
 188                 RETURN(-EALREADY);
 189
 190         OBD_ALLOC(pinger_thread, sizeof(*pinger_thread));
 191         if (pinger_thread == NULL)
 192                 RETURN(-ENOMEM);
 193         init_waitqueue_head(&pinger_thread->t_ctl_waitq);
 194
 195         d.name = "ll_ping";
 196         d.thread = pinger_thread;
 197
 198         /* CLONE_VM and CLONE_FILES just avoid a needless copy, because we
 199          * just drop the VM and FILES in ptlrpc_daemonize() right away. */
 200         rc = kernel_thread(ptlrpc_pinger_main, &d, CLONE_VM | CLONE_FILES);
 201         if (rc < 0) {
 202                 CERROR("cannot start thread: %d\n", rc);
 203                 OBD_FREE(pinger_thread, sizeof(*pinger_thread));
 204                 RETURN(rc);
 205         }
 206         l_wait_event(pinger_thread->t_ctl_waitq,
 207                      pinger_thread->t_flags & SVC_RUNNING, &lwi);
 208
 209         RETURN(rc);
 210 }
 211
 212 int ptlrpc_stop_pinger(void)
 213 {
 214         struct l_wait_info lwi = { 0 };
 215         int rc = 0;
 216 #ifndef ENABLE_PINGER
 217         return 0;
 218 #endif
 219         ENTRY;
 220
 221         if (pinger_thread == NULL)
 222                 RETURN(-EALREADY);
 223         down(&pinger_sem);
 224         pinger_thread->t_flags = SVC_STOPPING;
 225         wake_up(&pinger_thread->t_ctl_waitq);
 226         up(&pinger_sem);
 227
 228         l_wait_event(pinger_thread->t_ctl_waitq,
 229                      (pinger_thread->t_flags & SVC_STOPPED), &lwi);
 230
 231         OBD_FREE(pinger_thread, sizeof(*pinger_thread));
 232         pinger_thread = NULL;
 233         RETURN(rc);
 234 }
 235
 236 void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
 237 {
 238         down(&pinger_sem);
 239         imp->imp_next_ping = jiffies + (obd_timeout * HZ);
 240         up(&pinger_sem);
 241 }
 242
 243 int ptlrpc_pinger_add_import(struct obd_import *imp)
 244 {
 245         ENTRY;
 246         if (!list_empty(&imp->imp_pinger_chain))
 247                 RETURN(-EALREADY);
 248
 249         down(&pinger_sem);
 250         CDEBUG(D_HA, "adding pingable import %s->%s\n",
 251                imp->imp_obd->obd_uuid.uuid, imp->imp_target_uuid.uuid);
 252         imp->imp_next_ping = jiffies + (obd_timeout * HZ);
 253         /* XXX sort, blah blah */
 254         list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
 255         class_import_get(imp);
 256
 257         ptlrpc_pinger_wake_up();
 258         up(&pinger_sem);
 259
 260         RETURN(0);
 261 }
 262
 263 int ptlrpc_pinger_del_import(struct obd_import *imp)
 264 {
 265         ENTRY;
 266         if (list_empty(&imp->imp_pinger_chain))
 267                 RETURN(-ENOENT);
 268
 269         down(&pinger_sem);
 270         list_del_init(&imp->imp_pinger_chain);
 271         CDEBUG(D_HA, "removing pingable import %s->%s\n",
 272                imp->imp_obd->obd_uuid.uuid, imp->imp_target_uuid.uuid);
 273         class_import_put(imp);
 274         up(&pinger_sem);
 275         RETURN(0);
 276 }
 277
 278 void ptlrpc_pinger_wake_up()
 279 {
 280 #ifdef ENABLE_PINGER
 281         pinger_thread->t_flags |= SVC_EVENT;
 282         wake_up(&pinger_thread->t_ctl_waitq);
 283 #endif
 284 }
 285
 286 #else /* !__KERNEL__ */
 287
 288 /* XXX
 289  * the current implementation of pinger in liblustre is not optimized
 290  */
 291
 292 static struct pinger_data {
 293         int             pd_recursion;
 294         unsigned long   pd_this_ping;
 295         unsigned long   pd_next_ping;
 296         struct ptlrpc_request_set *pd_set;
 297 } pinger_args;
 298
 299 static int pinger_check_rpcs(void *arg)
 300 {
 301         unsigned long curtime = time(NULL);
 302         struct ptlrpc_request *req;
 303         struct ptlrpc_request_set *set;
 304         struct list_head *iter;
 305         struct pinger_data *pd = &pinger_args;
 306         int rc;
 307
 308         /* prevent recursion */
 309         if (pd->pd_recursion++) {
 310                 CDEBUG(D_HA, "pinger: recursion! quit\n");
 311                 LASSERT(pd->pd_set);
 312                 pd->pd_recursion--;
 313                 return 0;
 314         }
 315
 316         /* have we reached ping point? */
 317         if (!pd->pd_set && pd->pd_next_ping > curtime) {
 318                 pd->pd_recursion--;
 319                 return 0;
 320         }
 321
 322         /* if we have rpc_set already, continue processing it */
 323         if (pd->pd_set) {
 324                 LASSERT(pd->pd_this_ping);
 325                 set = pd->pd_set;
 326                 goto do_check_set;
 327         }
 328
 329         pd->pd_this_ping = curtime;
 330         pd->pd_set = ptlrpc_prep_set();
 331         set = pd->pd_set;
 332
 333         /* add rpcs into set */
 334         down(&pinger_sem);
 335         list_for_each(iter, &pinger_imports) {
 336                 struct obd_import *imp =
 337                         list_entry(iter, struct obd_import,
 338                                    imp_pinger_chain);
 339                 int generation, level;
 340                 unsigned long flags;
 341
 342                 if (imp->imp_next_ping <= pd->pd_this_ping) {
 343                         /* Add a ping. */
 344                         spin_lock_irqsave(&imp->imp_lock, flags);
 345                         generation = imp->imp_generation;
 346                         level = imp->imp_state;
 347                         spin_unlock_irqrestore(&imp->imp_lock, flags);
 348
 349                         if (level != LUSTRE_IMP_FULL) {
 350                                 CDEBUG(D_HA,
 351                                        "not pinging %s (in recovery)\n",
 352                                        imp->imp_target_uuid.uuid);
 353                                 continue;
 354                         }
 355
 356                         req = ptlrpc_prep_req(imp, OBD_PING, 0, NULL,
 357                                               NULL);
 358                         if (!req) {
 359                                 CERROR("out of memory\n");
 360                                 break;
 361                         }
 362                         req->rq_no_resend = 1;
 363                         req->rq_replen = lustre_msg_size(0, NULL);
 364                         req->rq_send_state = LUSTRE_IMP_FULL;
 365                         req->rq_phase = RQ_PHASE_RPC;
 366                         req->rq_import_generation = generation;
 367                         ptlrpc_set_add_req(set, req);
 368                 } else {
 369                         CDEBUG(D_HA, "don't need to ping %s (%lu > "
 370                                "%lu)\n", imp->imp_target_uuid.uuid,
 371                                imp->imp_next_ping, pd->pd_this_ping);
 372                 }
 373         }
 374         pd->pd_this_ping = curtime;
 375         up(&pinger_sem);
 376
 377         /* Might be empty, that's OK. */
 378         if (set->set_remaining == 0)
 379                 CDEBUG(D_HA, "nothing to ping\n");
 380
 381         list_for_each(iter, &set->set_requests) {
 382                 struct ptlrpc_request *req =
 383                         list_entry(iter, struct ptlrpc_request,
 384                                    rq_set_chain);
 385                 DEBUG_REQ(D_HA, req, "pinging %s->%s",
 386                           req->rq_import->imp_obd->obd_uuid.uuid,
 387                           req->rq_import->imp_target_uuid.uuid);
 388                 (void)ptl_send_rpc(req);
 389         }
 390
 391 do_check_set:
 392         rc = ptlrpc_check_set(set);
 393
 394         /* not finished, and we are not expired, simply return */
 395         if (!rc && curtime < pd->pd_this_ping + obd_timeout) {
 396                 CDEBUG(D_HA, "not finished, but also not expired\n");
 397                 pd->pd_recursion--;
 398                 return 0;
 399         }
 400
 401         /* Expire all the requests that didn't come back. */
 402         down(&pinger_sem);
 403         list_for_each(iter, &set->set_requests) {
 404                 req = list_entry(iter, struct ptlrpc_request,
 405                                  rq_set_chain);
 406
 407                 if (req->rq_replied)
 408                         continue;
 409
 410                 req->rq_phase = RQ_PHASE_COMPLETE;
 411                 set->set_remaining--;
 412                 /* If it was disconnected, don't sweat it. */
 413                 if (list_empty(&req->rq_import->imp_pinger_chain)) {
 414                         ptlrpc_unregister_reply(req);
 415                         continue;
 416                 }
 417
 418                 CDEBUG(D_HA, "pinger initiate expire_one_request\n");
 419                 ptlrpc_expire_one_request(req);
 420         }
 421         up(&pinger_sem);
 422
 423         ptlrpc_set_destroy(set);
 424         pd->pd_set = NULL;
 425
 426         pd->pd_next_ping = pd->pd_this_ping + obd_timeout;
 427         pd->pd_this_ping = 0; /* XXX for debug */
 428
 429         CDEBUG(D_HA, "finished a round ping\n");
 430         pd->pd_recursion--;
 431         return 0;
 432 }
 433
 434 static void *pinger_callback = NULL;
 435
 436 int ptlrpc_start_pinger(void)
 437 {
 438         memset(&pinger_args, 0, sizeof(pinger_args));
 439 #ifdef ENABLE_PINGER
 440         pinger_callback =
 441                 liblustre_register_wait_callback(&pinger_check_rpcs, &pinger_args);
 442 #endif
 443         return 0;
 444 }
 445
 446 int ptlrpc_stop_pinger(void)
 447 {
 448 #ifdef ENABLE_PINGER
 449         if (pinger_callback)
 450                 liblustre_deregister_wait_callback(pinger_callback);
 451 #endif
 452         return 0;
 453 }
 454
 455 void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
 456 {
 457         down(&pinger_sem);
 458         imp->imp_next_ping = time(NULL) + obd_timeout;
 459         if (pinger_args.pd_set == NULL &&
 460             pinger_args.pd_next_ping > imp->imp_next_ping) {
 461                 CDEBUG(D_HA, "set next ping to %ld(cur %ld)\n",
 462                         imp->imp_next_ping, time(NULL));
 463                 pinger_args.pd_next_ping = imp->imp_next_ping;
 464         }
 465         up(&pinger_sem);
 466 }
 467
 468 int ptlrpc_pinger_add_import(struct obd_import *imp)
 469 {
 470         ENTRY;
 471         if (!list_empty(&imp->imp_pinger_chain))
 472                 RETURN(-EALREADY);
 473
 474         CDEBUG(D_HA, "adding pingable import %s->%s\n",
 475                imp->imp_obd->obd_uuid.uuid, imp->imp_target_uuid.uuid);
 476         ptlrpc_pinger_sending_on_import(imp);
 477
 478         down(&pinger_sem);
 479         list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
 480         class_import_get(imp);
 481         up(&pinger_sem);
 482
 483         RETURN(0);
 484 }
 485
 486 int ptlrpc_pinger_del_import(struct obd_import *imp)
 487 {
 488         ENTRY;
 489         if (list_empty(&imp->imp_pinger_chain))
 490                 RETURN(-ENOENT);
 491
 492         down(&pinger_sem);
 493         list_del_init(&imp->imp_pinger_chain);
 494         CDEBUG(D_HA, "removing pingable import %s->%s\n",
 495                imp->imp_obd->obd_uuid.uuid, imp->imp_target_uuid.uuid);
 496         class_import_put(imp);
 497         up(&pinger_sem);
 498         RETURN(0);
 499 }
 500
 501 void ptlrpc_pinger_wake_up()
 502 {
 503 #ifdef ENABLE_PINGER
 504         /* XXX force pinger to run, if needed */
 505 #endif
 506 }
 507 #endif /* !__KERNEL__ */