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