lustre/ptlrpc/ptlrpcd.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 [sun.com URL with a
  20  * copy of GPLv2].
  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  2008 Sun Microsystems, Inc. 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  * lustre/ptlrpc/ptlrpcd.c
  37  */
  38
  39 #define DEBUG_SUBSYSTEM S_RPC
  40
  41 #ifdef __KERNEL__
  42 # include <libcfs/libcfs.h>
  43 #else /* __KERNEL__ */
  44 # include <liblustre.h>
  45 # include <ctype.h>
  46 #endif
  47
  48 #include <lustre_net.h>
  49 # include <lustre_lib.h>
  50
  51 #include <lustre_ha.h>
  52 #include <obd_class.h>   /* for obd_zombie */
  53 #include <obd_support.h> /* for OBD_FAIL_CHECK */
  54 #include <lprocfs_status.h>
  55
  56 #define LIOD_STOP 0
  57 struct ptlrpcd_ctl {
  58         unsigned long             pc_flags;
  59         spinlock_t                pc_lock;
  60         struct completion         pc_starting;
  61         struct completion         pc_finishing;
  62         struct ptlrpc_request_set *pc_set;
  63         char                      pc_name[16];
  64 #ifndef __KERNEL__
  65         int                       pc_recurred;
  66         void                     *pc_callback;
  67         void                     *pc_wait_callback;
  68         void                     *pc_idle_callback;
  69 #endif
  70 };
  71
  72 static struct ptlrpcd_ctl ptlrpcd_pc;
  73 static struct ptlrpcd_ctl ptlrpcd_recovery_pc;
  74
  75 struct semaphore ptlrpcd_sem;
  76 static int ptlrpcd_users = 0;
  77
  78 void ptlrpcd_wake(struct ptlrpc_request *req)
  79 {
  80         struct ptlrpc_request_set *rq_set = req->rq_set;
  81
  82         LASSERT(rq_set != NULL);
  83
  84         cfs_waitq_signal(&rq_set->set_waitq);
  85 }
  86
  87 /* requests that are added to the ptlrpcd queue are sent via
  88  * ptlrpcd_check->ptlrpc_check_set() */
  89 void ptlrpcd_add_req(struct ptlrpc_request *req)
  90 {
  91         struct ptlrpcd_ctl *pc;
  92
  93         if (req->rq_send_state == LUSTRE_IMP_FULL)
  94                 pc = &ptlrpcd_pc;
  95         else
  96                 pc = &ptlrpcd_recovery_pc;
  97
  98         ptlrpc_set_add_new_req(pc->pc_set, req);
  99         cfs_waitq_signal(&pc->pc_set->set_waitq);
 100 }
 101
 102 static int ptlrpcd_check(struct ptlrpcd_ctl *pc)
 103 {
 104         struct list_head *tmp, *pos;
 105         struct ptlrpc_request *req;
 106         int rc = 0;
 107         ENTRY;
 108
 109         if (test_bit(LIOD_STOP, &pc->pc_flags))
 110                 RETURN(1);
 111
 112         spin_lock(&pc->pc_set->set_new_req_lock);
 113         list_for_each_safe(pos, tmp, &pc->pc_set->set_new_requests) {
 114                 req = list_entry(pos, struct ptlrpc_request, rq_set_chain);
 115                 list_del_init(&req->rq_set_chain);
 116                 ptlrpc_set_add_req(pc->pc_set, req);
 117                 rc = 1; /* need to calculate its timeout */
 118         }
 119         spin_unlock(&pc->pc_set->set_new_req_lock);
 120
 121         if (pc->pc_set->set_remaining) {
 122                 rc = rc | ptlrpc_check_set(pc->pc_set);
 123
 124                 /* XXX our set never completes, so we prune the completed
 125                  * reqs after each iteration. boy could this be smarter. */
 126                 list_for_each_safe(pos, tmp, &pc->pc_set->set_requests) {
 127                         req = list_entry(pos, struct ptlrpc_request,
 128                                          rq_set_chain);
 129                         if (req->rq_phase != RQ_PHASE_COMPLETE)
 130                                 continue;
 131
 132                         list_del_init(&req->rq_set_chain);
 133                         req->rq_set = NULL;
 134                         ptlrpc_req_finished (req);
 135                 }
 136         }
 137
 138         if (rc == 0) {
 139                 /* If new requests have been added, make sure to wake up */
 140                 spin_lock(&pc->pc_set->set_new_req_lock);
 141                 rc = !list_empty(&pc->pc_set->set_new_requests);
 142                 spin_unlock(&pc->pc_set->set_new_req_lock);
 143         }
 144
 145         RETURN(rc);
 146 }
 147
 148 #ifdef __KERNEL__
 149 /* ptlrpc's code paths like to execute in process context, so we have this
 150  * thread which spins on a set which contains the io rpcs.  llite specifies
 151  * ptlrpcd's set when it pushes pages down into the oscs */
 152 static int ptlrpcd(void *arg)
 153 {
 154         struct ptlrpcd_ctl *pc = arg;
 155         int rc;
 156         ENTRY;
 157
 158         if ((rc = cfs_daemonize_ctxt(pc->pc_name))) {
 159                 complete(&pc->pc_starting);
 160                 return rc;
 161         }
 162
 163         complete(&pc->pc_starting);
 164
 165         /* this mainloop strongly resembles ptlrpc_set_wait except
 166          * that our set never completes.  ptlrpcd_check calls ptlrpc_check_set
 167          * when there are requests in the set.  new requests come in
 168          * on the set's new_req_list and ptlrpcd_check moves them into
 169          * the set. */
 170         while (1) {
 171                 struct l_wait_info lwi;
 172                 cfs_duration_t timeout;
 173
 174                 timeout = cfs_time_seconds(ptlrpc_set_next_timeout(pc->pc_set));
 175                 lwi = LWI_TIMEOUT(timeout, ptlrpc_expired_set, pc->pc_set);
 176
 177                 l_wait_event(pc->pc_set->set_waitq, ptlrpcd_check(pc), &lwi);
 178
 179                 if (test_bit(LIOD_STOP, &pc->pc_flags))
 180                         break;
 181         }
 182         /* wait for inflight requests to drain */
 183         if (!list_empty(&pc->pc_set->set_requests))
 184                 ptlrpc_set_wait(pc->pc_set);
 185         complete(&pc->pc_finishing);
 186         return 0;
 187 }
 188
 189 #else
 190
 191 int ptlrpcd_check_async_rpcs(void *arg)
 192 {
 193         struct ptlrpcd_ctl *pc = arg;
 194         int                  rc = 0;
 195
 196         /* single threaded!! */
 197         pc->pc_recurred++;
 198
 199         if (pc->pc_recurred == 1) {
 200                 rc = ptlrpcd_check(pc);
 201                 if (!rc)
 202                         ptlrpc_expired_set(pc->pc_set);
 203                 /*XXX send replay requests */
 204                 if (pc == &ptlrpcd_recovery_pc)
 205                         rc = ptlrpcd_check(pc);
 206         }
 207
 208         pc->pc_recurred--;
 209         return rc;
 210 }
 211
 212 int ptlrpcd_idle(void *arg)
 213 {
 214         struct ptlrpcd_ctl *pc = arg;
 215
 216         return (list_empty(&pc->pc_set->set_new_requests) &&
 217                 pc->pc_set->set_remaining == 0);
 218 }
 219
 220 #endif
 221
 222 static int ptlrpcd_start(char *name, struct ptlrpcd_ctl *pc)
 223 {
 224         int rc;
 225
 226         ENTRY;
 227         memset(pc, 0, sizeof(*pc));
 228         init_completion(&pc->pc_starting);
 229         init_completion(&pc->pc_finishing);
 230         pc->pc_flags = 0;
 231         spin_lock_init(&pc->pc_lock);
 232         snprintf (pc->pc_name, sizeof (pc->pc_name), name);
 233
 234         pc->pc_set = ptlrpc_prep_set();
 235         if (pc->pc_set == NULL)
 236                 RETURN(-ENOMEM);
 237
 238 #ifdef __KERNEL__
 239         rc = cfs_kernel_thread(ptlrpcd, pc, 0);
 240         if (rc < 0)  {
 241                 ptlrpc_set_destroy(pc->pc_set);
 242                 RETURN(rc);
 243         }
 244
 245         wait_for_completion(&pc->pc_starting);
 246 #else
 247         pc->pc_wait_callback =
 248                 liblustre_register_wait_callback("ptlrpcd_check_async_rpcs",
 249                                                  &ptlrpcd_check_async_rpcs, pc);
 250         pc->pc_idle_callback =
 251                 liblustre_register_idle_callback("ptlrpcd_check_idle_rpcs",
 252                                                  &ptlrpcd_idle, pc);
 253         (void)rc;
 254 #endif
 255         RETURN(0);
 256 }
 257
 258 static void ptlrpcd_stop(struct ptlrpcd_ctl *pc)
 259 {
 260         set_bit(LIOD_STOP, &pc->pc_flags);
 261         cfs_waitq_signal(&pc->pc_set->set_waitq);
 262 #ifdef __KERNEL__
 263         wait_for_completion(&pc->pc_finishing);
 264 #else
 265         liblustre_deregister_wait_callback(pc->pc_wait_callback);
 266         liblustre_deregister_idle_callback(pc->pc_idle_callback);
 267 #endif
 268         ptlrpc_set_destroy(pc->pc_set);
 269 }
 270
 271 int ptlrpcd_addref(void)
 272 {
 273         int rc = 0;
 274         ENTRY;
 275
 276         mutex_down(&ptlrpcd_sem);
 277         if (++ptlrpcd_users != 1)
 278                 GOTO(out, rc);
 279
 280         rc = ptlrpcd_start("ptlrpcd", &ptlrpcd_pc);
 281         if (rc) {
 282                 --ptlrpcd_users;
 283                 GOTO(out, rc);
 284         }
 285
 286         rc = ptlrpcd_start("ptlrpcd-recov", &ptlrpcd_recovery_pc);
 287         if (rc) {
 288                 ptlrpcd_stop(&ptlrpcd_pc);
 289                 --ptlrpcd_users;
 290                 GOTO(out, rc);
 291         }
 292 out:
 293         mutex_up(&ptlrpcd_sem);
 294         RETURN(rc);
 295 }
 296
 297 void ptlrpcd_decref(void)
 298 {
 299         mutex_down(&ptlrpcd_sem);
 300         if (--ptlrpcd_users == 0) {
 301                 ptlrpcd_stop(&ptlrpcd_pc);
 302                 ptlrpcd_stop(&ptlrpcd_recovery_pc);
 303         }
 304         mutex_up(&ptlrpcd_sem);
 305 }