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                                         /* wait at least a timeout before
 120                                            trying recovery again. */
 121                                         imp->imp_next_ping = jiffies +
 122                                                 (obd_timeout * HZ);
 123                                         ptlrpc_initiate_recovery(imp);
 124                                 }
 125                                 else if (level != LUSTRE_IMP_FULL ||
 126                                          imp->imp_obd->obd_no_recov) {
 127                                         CDEBUG(D_HA,
 128                                                "not pinging %s (in recovery "
 129                                                " or recovery disabled: %s)\n",
 130                                                imp->imp_target_uuid.uuid,
 131                                                ptlrpc_import_state_name(level));
 132                                 }
 133                                 else if (imp->imp_pingable || force) {
 134                                         ptlrpc_ping(imp);
 135                                 }
 136
 137                         } else {
 138                                 if (imp->imp_pingable)
 139                                         CDEBUG(D_HA, "don't need to ping %s "
 140                                                "(%lu > %lu)\n",
 141                                                imp->imp_target_uuid.uuid,
 142                                                imp->imp_next_ping, this_ping);
 143                         }
 144                 }
 145                 up(&pinger_sem);
 146
 147                 /* Wait until the next ping time, or until we're stopped. */
 148                 time_to_next_ping = this_ping + (obd_timeout * HZ) - jiffies;
 149                 CDEBUG(D_HA, "next ping in %lu (%lu)\n", time_to_next_ping,
 150                        this_ping + (obd_timeout * HZ));
 151                 if (time_to_next_ping > 0) {
 152                         lwi = LWI_TIMEOUT(time_to_next_ping, NULL, NULL);
 153                         l_wait_event(thread->t_ctl_waitq,
 154                                      thread->t_flags & (SVC_STOPPING|SVC_EVENT),
 155                                      &lwi);
 156                         if (thread->t_flags & SVC_STOPPING) {
 157                                 thread->t_flags &= ~SVC_STOPPING;
 158                                 EXIT;
 159                                 break;
 160                         } else if (thread->t_flags & SVC_EVENT) {
 161                                 /* woken after adding import to reset timer */
 162                                 thread->t_flags &= ~SVC_EVENT;
 163                         }
 164                 }
 165         }
 166
 167         thread->t_flags = SVC_STOPPED;
 168         wake_up(&thread->t_ctl_waitq);
 169
 170         CDEBUG(D_NET, "pinger thread exiting, process %d\n", current->pid);
 171         return 0;
 172 }
 173
 174 static struct ptlrpc_thread *pinger_thread = NULL;
 175
 176 int ptlrpc_start_pinger(void)
 177 {
 178         struct l_wait_info lwi = { 0 };
 179         struct ptlrpc_svc_data d;
 180         int rc;
 181 #ifndef ENABLE_PINGER
 182         return 0;
 183 #endif
 184         ENTRY;
 185
 186         if (pinger_thread != NULL)
 187                 RETURN(-EALREADY);
 188
 189         OBD_ALLOC(pinger_thread, sizeof(*pinger_thread));
 190         if (pinger_thread == NULL)
 191                 RETURN(-ENOMEM);
 192         init_waitqueue_head(&pinger_thread->t_ctl_waitq);
 193
 194         d.name = "ll_ping";
 195         d.thread = pinger_thread;
 196
 197         /* CLONE_VM and CLONE_FILES just avoid a needless copy, because we
 198          * just drop the VM and FILES in ptlrpc_daemonize() right away. */
 199         rc = kernel_thread(ptlrpc_pinger_main, &d, CLONE_VM | CLONE_FILES);
 200         if (rc < 0) {
 201                 CERROR("cannot start thread: %d\n", rc);
 202                 OBD_FREE(pinger_thread, sizeof(*pinger_thread));
 203                 RETURN(rc);
 204         }
 205         l_wait_event(pinger_thread->t_ctl_waitq,
 206                      pinger_thread->t_flags & SVC_RUNNING, &lwi);
 207
 208         RETURN(rc);
 209 }
 210
 211 int ptlrpc_stop_pinger(void)
 212 {
 213         struct l_wait_info lwi = { 0 };
 214         int rc = 0;
 215 #ifndef ENABLE_PINGER
 216         return 0;
 217 #endif
 218         ENTRY;
 219
 220         if (pinger_thread == NULL)
 221                 RETURN(-EALREADY);
 222         down(&pinger_sem);
 223         pinger_thread->t_flags = SVC_STOPPING;
 224         wake_up(&pinger_thread->t_ctl_waitq);
 225         up(&pinger_sem);
 226
 227         l_wait_event(pinger_thread->t_ctl_waitq,
 228                      (pinger_thread->t_flags & SVC_STOPPED), &lwi);
 229
 230         OBD_FREE(pinger_thread, sizeof(*pinger_thread));
 231         pinger_thread = NULL;
 232         RETURN(rc);
 233 }
 234
 235 void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
 236 {
 237         down(&pinger_sem);
 238         imp->imp_next_ping = jiffies + (obd_timeout * HZ);
 239         up(&pinger_sem);
 240 }
 241
 242 int ptlrpc_pinger_add_import(struct obd_import *imp)
 243 {
 244         ENTRY;
 245         if (!list_empty(&imp->imp_pinger_chain))
 246                 RETURN(-EALREADY);
 247
 248         down(&pinger_sem);
 249         CDEBUG(D_HA, "adding pingable import %s->%s\n",
 250                imp->imp_obd->obd_uuid.uuid, imp->imp_target_uuid.uuid);
 251         imp->imp_next_ping = jiffies + (obd_timeout * HZ);
 252         /* XXX sort, blah blah */
 253         list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
 254         class_import_get(imp);
 255
 256         ptlrpc_pinger_wake_up();
 257         up(&pinger_sem);
 258
 259         RETURN(0);
 260 }
 261
 262 int ptlrpc_pinger_del_import(struct obd_import *imp)
 263 {
 264         ENTRY;
 265         if (list_empty(&imp->imp_pinger_chain))
 266                 RETURN(-ENOENT);
 267
 268         down(&pinger_sem);
 269         list_del_init(&imp->imp_pinger_chain);
 270         CDEBUG(D_HA, "removing pingable import %s->%s\n",
 271                imp->imp_obd->obd_uuid.uuid, imp->imp_target_uuid.uuid);
 272         class_import_put(imp);
 273         up(&pinger_sem);
 274         RETURN(0);
 275 }
 276
 277 void ptlrpc_pinger_wake_up()
 278 {
 279 #ifdef ENABLE_PINGER
 280         pinger_thread->t_flags |= SVC_EVENT;
 281         wake_up(&pinger_thread->t_ctl_waitq);
 282 #endif
 283 }
 284
 285 #else /* !__KERNEL__ */
 286
 287 /* XXX
 288  * the current implementation of pinger in liblustre is not optimized
 289  */
 290
 291 static struct pinger_data {
 292         int             pd_recursion;
 293         unsigned long   pd_this_ping;
 294         unsigned long   pd_next_ping;
 295         struct ptlrpc_request_set *pd_set;
 296 } pinger_args;
 297
 298 static int pinger_check_rpcs(void *arg)
 299 {
 300         unsigned long curtime = time(NULL);
 301         struct ptlrpc_request *req;
 302         struct ptlrpc_request_set *set;
 303         struct list_head *iter;
 304         struct pinger_data *pd = &pinger_args;
 305         int rc;
 306
 307         /* prevent recursion */
 308         if (pd->pd_recursion++) {
 309                 CDEBUG(D_HA, "pinger: recursion! quit\n");
 310                 LASSERT(pd->pd_set);
 311                 pd->pd_recursion--;
 312                 return 0;
 313         }
 314
 315         /* have we reached ping point? */
 316         if (!pd->pd_set && pd->pd_next_ping > curtime) {
 317                 pd->pd_recursion--;
 318                 return 0;
 319         }
 320
 321         /* if we have rpc_set already, continue processing it */
 322         if (pd->pd_set) {
 323                 LASSERT(pd->pd_this_ping);
 324                 set = pd->pd_set;
 325                 goto do_check_set;
 326         }
 327
 328         pd->pd_this_ping = curtime;
 329         pd->pd_set = ptlrpc_prep_set();
 330         set = pd->pd_set;
 331
 332         /* add rpcs into set */
 333         down(&pinger_sem);
 334         list_for_each(iter, &pinger_imports) {
 335                 struct obd_import *imp =
 336                         list_entry(iter, struct obd_import,
 337                                    imp_pinger_chain);
 338                 int generation, level;
 339                 unsigned long flags;
 340
 341                 if (imp->imp_next_ping <= pd->pd_this_ping) {
 342                         /* Add a ping. */
 343                         spin_lock_irqsave(&imp->imp_lock, flags);
 344                         generation = imp->imp_generation;
 345                         level = imp->imp_state;
 346                         spin_unlock_irqrestore(&imp->imp_lock, flags);
 347
 348                         if (level != LUSTRE_IMP_FULL) {
 349                                 CDEBUG(D_HA,
 350                                        "not pinging %s (in recovery)\n",
 351                                        imp->imp_target_uuid.uuid);
 352                                 continue;
 353                         }
 354
 355                         req = ptlrpc_prep_req(imp, OBD_PING, 0, NULL,
 356                                               NULL);
 357                         if (!req) {
 358                                 CERROR("out of memory\n");
 359                                 break;
 360                         }
 361                         req->rq_no_resend = 1;
 362                         req->rq_replen = lustre_msg_size(0, NULL);
 363                         req->rq_send_state = LUSTRE_IMP_FULL;
 364                         req->rq_phase = RQ_PHASE_RPC;
 365                         req->rq_import_generation = generation;
 366                         ptlrpc_set_add_req(set, req);
 367                 } else {
 368                         CDEBUG(D_HA, "don't need to ping %s (%lu > "
 369                                "%lu)\n", imp->imp_target_uuid.uuid,
 370                                imp->imp_next_ping, pd->pd_this_ping);
 371                 }
 372         }
 373         pd->pd_this_ping = curtime;
 374         up(&pinger_sem);
 375
 376         /* Might be empty, that's OK. */
 377         if (set->set_remaining == 0)
 378                 CDEBUG(D_HA, "nothing to ping\n");
 379
 380         list_for_each(iter, &set->set_requests) {
 381                 struct ptlrpc_request *req =
 382                         list_entry(iter, struct ptlrpc_request,
 383                                    rq_set_chain);
 384                 DEBUG_REQ(D_HA, req, "pinging %s->%s",
 385                           req->rq_import->imp_obd->obd_uuid.uuid,
 386                           req->rq_import->imp_target_uuid.uuid);
 387                 (void)ptl_send_rpc(req);
 388         }
 389
 390 do_check_set:
 391         rc = ptlrpc_check_set(set);
 392
 393         /* not finished, and we are not expired, simply return */
 394         if (!rc && curtime < pd->pd_this_ping + obd_timeout) {
 395                 CDEBUG(D_HA, "not finished, but also not expired\n");
 396                 pd->pd_recursion--;
 397                 return 0;
 398         }
 399
 400         /* Expire all the requests that didn't come back. */
 401         down(&pinger_sem);
 402         list_for_each(iter, &set->set_requests) {
 403                 req = list_entry(iter, struct ptlrpc_request,
 404                                  rq_set_chain);
 405
 406                 if (req->rq_replied)
 407                         continue;
 408
 409                 req->rq_phase = RQ_PHASE_COMPLETE;
 410                 set->set_remaining--;
 411                 /* If it was disconnected, don't sweat it. */
 412                 if (list_empty(&req->rq_import->imp_pinger_chain)) {
 413                         ptlrpc_unregister_reply(req);
 414                         continue;
 415                 }
 416
 417                 CDEBUG(D_HA, "pinger initiate expire_one_request\n");
 418                 ptlrpc_expire_one_request(req);
 419         }
 420         up(&pinger_sem);
 421
 422         ptlrpc_set_destroy(set);
 423         pd->pd_set = NULL;
 424
 425         pd->pd_next_ping = pd->pd_this_ping + obd_timeout;
 426         pd->pd_this_ping = 0; /* XXX for debug */
 427
 428         CDEBUG(D_HA, "finished a round ping\n");
 429         pd->pd_recursion--;
 430         return 0;
 431 }
 432
 433 static void *pinger_callback = NULL;
 434
 435 int ptlrpc_start_pinger(void)
 436 {
 437         memset(&pinger_args, 0, sizeof(pinger_args));
 438 #ifdef ENABLE_PINGER
 439         pinger_callback =
 440                 liblustre_register_wait_callback(&pinger_check_rpcs, &pinger_args);
 441 #endif
 442         return 0;
 443 }
 444
 445 int ptlrpc_stop_pinger(void)
 446 {
 447 #ifdef ENABLE_PINGER
 448         if (pinger_callback)
 449                 liblustre_deregister_wait_callback(pinger_callback);
 450 #endif
 451         return 0;
 452 }
 453
 454 void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
 455 {
 456         down(&pinger_sem);
 457         imp->imp_next_ping = time(NULL) + obd_timeout;
 458         if (pinger_args.pd_set == NULL &&
 459             pinger_args.pd_next_ping > imp->imp_next_ping) {
 460                 CDEBUG(D_HA, "set next ping to %ld(cur %ld)\n",
 461                         imp->imp_next_ping, time(NULL));
 462                 pinger_args.pd_next_ping = imp->imp_next_ping;
 463         }
 464         up(&pinger_sem);
 465 }
 466
 467 int ptlrpc_pinger_add_import(struct obd_import *imp)
 468 {
 469         ENTRY;
 470         if (!list_empty(&imp->imp_pinger_chain))
 471                 RETURN(-EALREADY);
 472
 473         CDEBUG(D_HA, "adding pingable import %s->%s\n",
 474                imp->imp_obd->obd_uuid.uuid, imp->imp_target_uuid.uuid);
 475         ptlrpc_pinger_sending_on_import(imp);
 476
 477         down(&pinger_sem);
 478         list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
 479         class_import_get(imp);
 480         up(&pinger_sem);
 481
 482         RETURN(0);
 483 }
 484
 485 int ptlrpc_pinger_del_import(struct obd_import *imp)
 486 {
 487         ENTRY;
 488         if (list_empty(&imp->imp_pinger_chain))
 489                 RETURN(-ENOENT);
 490
 491         down(&pinger_sem);
 492         list_del_init(&imp->imp_pinger_chain);
 493         CDEBUG(D_HA, "removing pingable import %s->%s\n",
 494                imp->imp_obd->obd_uuid.uuid, imp->imp_target_uuid.uuid);
 495         class_import_put(imp);
 496         up(&pinger_sem);
 497         RETURN(0);
 498 }
 499
 500 void ptlrpc_pinger_wake_up()
 501 {
 502 #ifdef ENABLE_PINGER
 503         /* XXX force pinger to run, if needed */
 504 #endif
 505 }
 506 #endif /* !__KERNEL__ */