lustre/ptlrpc/ptlrpcd.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (C) 2001-2003 Cluster File Systems, Inc.
   5  *   Author Peter Braam <braam@clusterfs.com>
   6  *
   7  *   This file is part of the Lustre file system, http://www.lustre.org
   8  *   Lustre is a trademark of Cluster File Systems, Inc.
   9  *
  10  *   You may have signed or agreed to another license before downloading
  11  *   this software.  If so, you are bound by the terms and conditions
  12  *   of that agreement, and the following does not apply to you.  See the
  13  *   LICENSE file included with this distribution for more information.
  14  *
  15  *   If you did not agree to a different license, then this copy of Lustre
  16  *   is open source software; you can redistribute it and/or modify it
  17  *   under the terms of version 2 of the GNU General Public License as
  18  *   published by the Free Software Foundation.
  19  *
  20  *   In either case, Lustre is distributed in the hope that it will be
  21  *   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  22  *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  *   license text for more details.
  24  *
  25  */
  26
  27 #define DEBUG_SUBSYSTEM S_RPC
  28
  29 #ifdef __KERNEL__
  30 # include <libcfs/libcfs.h>
  31 #else /* __KERNEL__ */
  32 # include <liblustre.h>
  33 # include <ctype.h>
  34 #endif
  35
  36 #include <libcfs/kp30.h>
  37 #include <lustre_net.h>
  38 # include <lustre_lib.h>
  39
  40 #include <lustre_ha.h>
  41 #include <obd_class.h>   /* for obd_zombie */
  42 #include <obd_support.h> /* for OBD_FAIL_CHECK */
  43 #include <lprocfs_status.h>
  44
  45 #define LIOD_STOP 0
  46 struct ptlrpcd_ctl {
  47         unsigned long             pc_flags;
  48         spinlock_t                pc_lock;
  49         struct completion         pc_starting;
  50         struct completion         pc_finishing;
  51         struct ptlrpc_request_set *pc_set;
  52         char                      pc_name[16];
  53 #ifndef __KERNEL__
  54         int                       pc_recurred;
  55         void                     *pc_callback;
  56         void                     *pc_wait_callback;
  57         void                     *pc_idle_callback;
  58 #endif
  59 };
  60
  61 static struct ptlrpcd_ctl ptlrpcd_pc;
  62 static struct ptlrpcd_ctl ptlrpcd_recovery_pc;
  63
  64 struct semaphore ptlrpcd_sem;
  65 static int ptlrpcd_users = 0;
  66
  67 void ptlrpcd_wake(struct ptlrpc_request *req)
  68 {
  69         struct ptlrpc_request_set *rq_set = req->rq_set;
  70
  71         LASSERT(rq_set != NULL);
  72
  73         cfs_waitq_signal(&rq_set->set_waitq);
  74 }
  75
  76 /* requests that are added to the ptlrpcd queue are sent via
  77  * ptlrpcd_check->ptlrpc_check_set() */
  78 void ptlrpcd_add_req(struct ptlrpc_request *req)
  79 {
  80         struct ptlrpcd_ctl *pc;
  81
  82         if (req->rq_send_state == LUSTRE_IMP_FULL)
  83                 pc = &ptlrpcd_pc;
  84         else
  85                 pc = &ptlrpcd_recovery_pc;
  86
  87         ptlrpc_set_add_new_req(pc->pc_set, req);
  88         cfs_waitq_signal(&pc->pc_set->set_waitq);
  89 }
  90
  91 static int ptlrpcd_check(struct ptlrpcd_ctl *pc)
  92 {
  93         struct list_head *tmp, *pos;
  94         struct ptlrpc_request *req;
  95         int rc = 0;
  96         ENTRY;
  97
  98         if (test_bit(LIOD_STOP, &pc->pc_flags))
  99                 RETURN(1);
 100
 101         obd_zombie_impexp_cull();
 102
 103         spin_lock(&pc->pc_set->set_new_req_lock);
 104         list_for_each_safe(pos, tmp, &pc->pc_set->set_new_requests) {
 105                 req = list_entry(pos, struct ptlrpc_request, rq_set_chain);
 106                 list_del_init(&req->rq_set_chain);
 107                 ptlrpc_set_add_req(pc->pc_set, req);
 108                 rc = 1; /* need to calculate its timeout */
 109         }
 110         spin_unlock(&pc->pc_set->set_new_req_lock);
 111
 112         if (pc->pc_set->set_remaining) {
 113                 rc = rc | ptlrpc_check_set(pc->pc_set);
 114
 115                 /* XXX our set never completes, so we prune the completed
 116                  * reqs after each iteration. boy could this be smarter. */
 117                 list_for_each_safe(pos, tmp, &pc->pc_set->set_requests) {
 118                         req = list_entry(pos, struct ptlrpc_request,
 119                                          rq_set_chain);
 120                         if (req->rq_phase != RQ_PHASE_COMPLETE)
 121                                 continue;
 122
 123                         list_del_init(&req->rq_set_chain);
 124                         req->rq_set = NULL;
 125                         ptlrpc_req_finished (req);
 126                 }
 127         }
 128
 129         if (rc == 0) {
 130                 /* If new requests have been added, make sure to wake up */
 131                 spin_lock(&pc->pc_set->set_new_req_lock);
 132                 rc = !list_empty(&pc->pc_set->set_new_requests);
 133                 spin_unlock(&pc->pc_set->set_new_req_lock);
 134         }
 135
 136         RETURN(rc);
 137 }
 138
 139 #ifdef __KERNEL__
 140 /* ptlrpc's code paths like to execute in process context, so we have this
 141  * thread which spins on a set which contains the io rpcs.  llite specifies
 142  * ptlrpcd's set when it pushes pages down into the oscs */
 143 static int ptlrpcd(void *arg)
 144 {
 145         struct ptlrpcd_ctl *pc = arg;
 146         int rc;
 147         ENTRY;
 148
 149         if ((rc = cfs_daemonize_ctxt(pc->pc_name))) {
 150                 complete(&pc->pc_starting);
 151                 return rc;
 152         }
 153
 154         complete(&pc->pc_starting);
 155
 156         /* this mainloop strongly resembles ptlrpc_set_wait except
 157          * that our set never completes.  ptlrpcd_check calls ptlrpc_check_set
 158          * when there are requests in the set.  new requests come in
 159          * on the set's new_req_list and ptlrpcd_check moves them into
 160          * the set. */
 161         while (1) {
 162                 struct l_wait_info lwi;
 163                 cfs_duration_t timeout;
 164
 165                 timeout = cfs_time_seconds(ptlrpc_set_next_timeout(pc->pc_set));
 166                 lwi = LWI_TIMEOUT(timeout, ptlrpc_expired_set, pc->pc_set);
 167
 168                 l_wait_event(pc->pc_set->set_waitq, ptlrpcd_check(pc), &lwi);
 169
 170                 if (test_bit(LIOD_STOP, &pc->pc_flags))
 171                         break;
 172         }
 173         /* wait for inflight requests to drain */
 174         if (!list_empty(&pc->pc_set->set_requests))
 175                 ptlrpc_set_wait(pc->pc_set);
 176         complete(&pc->pc_finishing);
 177         return 0;
 178 }
 179
 180 static void ptlrpcd_zombie_impexp_notify(void)
 181 {
 182         LASSERT(ptlrpcd_pc.pc_set != NULL); // call before ptlrpcd inited ?
 183
 184         cfs_waitq_signal(&ptlrpcd_pc.pc_set->set_waitq);
 185 }
 186
 187 #else
 188
 189 int ptlrpcd_check_async_rpcs(void *arg)
 190 {
 191         struct ptlrpcd_ctl *pc = arg;
 192         int                  rc = 0;
 193
 194         /* single threaded!! */
 195         pc->pc_recurred++;
 196
 197         if (pc->pc_recurred == 1) {
 198                 rc = ptlrpcd_check(pc);
 199                 if (!rc)
 200                         ptlrpc_expired_set(pc->pc_set);
 201                 /*XXX send replay requests */
 202                 if (pc == &ptlrpcd_recovery_pc)
 203                         rc = ptlrpcd_check(pc);
 204         }
 205
 206         pc->pc_recurred--;
 207         return rc;
 208 }
 209
 210 int ptlrpcd_idle(void *arg)
 211 {
 212         struct ptlrpcd_ctl *pc = arg;
 213
 214         return (list_empty(&pc->pc_set->set_new_requests) &&
 215                 pc->pc_set->set_remaining == 0);
 216 }
 217
 218 #endif
 219
 220 static int ptlrpcd_start(char *name, struct ptlrpcd_ctl *pc)
 221 {
 222         int rc;
 223
 224         ENTRY;
 225         memset(pc, 0, sizeof(*pc));
 226         init_completion(&pc->pc_starting);
 227         init_completion(&pc->pc_finishing);
 228         pc->pc_flags = 0;
 229         spin_lock_init(&pc->pc_lock);
 230         snprintf (pc->pc_name, sizeof (pc->pc_name), name);
 231
 232         pc->pc_set = ptlrpc_prep_set();
 233         if (pc->pc_set == NULL)
 234                 RETURN(-ENOMEM);
 235
 236 #ifdef __KERNEL__
 237         /* wake ptlrpcd when zombie imports or exports exist */
 238         obd_zombie_impexp_notify = ptlrpcd_zombie_impexp_notify;
 239
 240         rc = cfs_kernel_thread(ptlrpcd, pc, 0);
 241         if (rc < 0)  {
 242                 ptlrpc_set_destroy(pc->pc_set);
 243                 RETURN(rc);
 244         }
 245
 246         wait_for_completion(&pc->pc_starting);
 247 #else
 248         pc->pc_wait_callback =
 249                 liblustre_register_wait_callback("ptlrpcd_check_async_rpcs",
 250                                                  &ptlrpcd_check_async_rpcs, pc);
 251         pc->pc_idle_callback =
 252                 liblustre_register_idle_callback("ptlrpcd_check_idle_rpcs",
 253                                                  &ptlrpcd_idle, pc);
 254         (void)rc;
 255 #endif
 256         RETURN(0);
 257 }
 258
 259 static void ptlrpcd_stop(struct ptlrpcd_ctl *pc)
 260 {
 261         set_bit(LIOD_STOP, &pc->pc_flags);
 262         cfs_waitq_signal(&pc->pc_set->set_waitq);
 263 #ifdef __KERNEL__
 264         obd_zombie_impexp_notify = NULL;
 265         wait_for_completion(&pc->pc_finishing);
 266 #else
 267         liblustre_deregister_wait_callback(pc->pc_wait_callback);
 268         liblustre_deregister_idle_callback(pc->pc_idle_callback);
 269 #endif
 270         ptlrpc_set_destroy(pc->pc_set);
 271 }
 272
 273 int ptlrpcd_addref(void)
 274 {
 275         int rc = 0;
 276         ENTRY;
 277
 278         mutex_down(&ptlrpcd_sem);
 279         if (++ptlrpcd_users != 1)
 280                 GOTO(out, rc);
 281
 282         rc = ptlrpcd_start("ptlrpcd", &ptlrpcd_pc);
 283         if (rc) {
 284                 --ptlrpcd_users;
 285                 GOTO(out, rc);
 286         }
 287
 288         rc = ptlrpcd_start("ptlrpcd-recov", &ptlrpcd_recovery_pc);
 289         if (rc) {
 290                 ptlrpcd_stop(&ptlrpcd_pc);
 291                 --ptlrpcd_users;
 292                 GOTO(out, rc);
 293         }
 294 out:
 295         mutex_up(&ptlrpcd_sem);
 296         RETURN(rc);
 297 }
 298
 299 void ptlrpcd_decref(void)
 300 {
 301         mutex_down(&ptlrpcd_sem);
 302         if (--ptlrpcd_users == 0) {
 303                 ptlrpcd_stop(&ptlrpcd_pc);
 304                 ptlrpcd_stop(&ptlrpcd_recovery_pc);
 305         }
 306         mutex_up(&ptlrpcd_sem);
 307 }