lustre/ptlrpc/service.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (C) 2002 Cluster File Systems, Inc.
   5  *
   6  *   This file is part of Lustre, http://www.lustre.org.
   7  *
   8  *   Lustre is free software; you can redistribute it and/or
   9  *   modify it under the terms of version 2 of the GNU General Public
  10  *   License as published by the Free Software Foundation.
  11  *
  12  *   Lustre is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with Lustre; if not, write to the Free Software
  19  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  *
  21  */
  22
  23 #define DEBUG_SUBSYSTEM S_RPC
  24
  25 #include <linux/obd_support.h>
  26 #include <linux/obd_class.h>
  27 #include <linux/lustre_net.h>
  28
  29 extern int request_in_callback(ptl_event_t *ev);
  30
  31 static int ptlrpc_check_event(struct ptlrpc_service *svc,
  32                               struct ptlrpc_thread *thread, ptl_event_t *event)
  33 {
  34         int rc;
  35         ENTRY;
  36
  37         spin_lock(&svc->srv_lock);
  38
  39         if (thread->t_flags & SVC_STOPPING)
  40                 GOTO(out, rc = 1);
  41
  42         LASSERT ((thread->t_flags & SVC_EVENT) == 0);
  43         LASSERT (ptl_is_valid_handle (&svc->srv_eq_h));
  44
  45         rc = PtlEQGet(svc->srv_eq_h, event);
  46         switch (rc)
  47         {
  48         case PTL_OK:
  49                 thread->t_flags |= SVC_EVENT;
  50                 GOTO(out, rc = 1);
  51
  52         case PTL_EQ_EMPTY:
  53                 GOTO(out, rc = 0);
  54
  55         default:
  56                 CERROR("BUG: PtlEQGet returned %d\n", rc);
  57                 LBUG();
  58         }
  59  out:
  60         spin_unlock(&svc->srv_lock);
  61         return rc;
  62 }
  63
  64 struct ptlrpc_service *
  65 ptlrpc_init_svc(__u32 nevents, __u32 nbufs,
  66                 __u32 bufsize, __u32 max_req_size,
  67                 int req_portal, int rep_portal,
  68                 obd_uuid_t uuid, svc_handler_t handler, char *name)
  69 {
  70         int err;
  71         int rc, i;
  72         struct ptlrpc_service *service;
  73         ENTRY;
  74
  75         OBD_ALLOC(service, sizeof(*service));
  76         if (!service)
  77                 RETURN(NULL);
  78
  79         service->srv_name = name;
  80         spin_lock_init(&service->srv_lock);
  81         INIT_LIST_HEAD(&service->srv_threads);
  82         init_waitqueue_head(&service->srv_waitq);
  83
  84         service->srv_max_req_size = max_req_size;
  85         service->srv_buf_size = bufsize;
  86         INIT_LIST_HEAD(&service->srv_rqbds);
  87         service->srv_nrqbds = 0;
  88         atomic_set(&service->srv_nrqbds_receiving, 0);
  89
  90         service->srv_rep_portal = rep_portal;
  91         service->srv_req_portal = req_portal;
  92         service->srv_handler = handler;
  93
  94         err = kportal_uuid_to_peer(uuid, &service->srv_self);
  95         if (err) {
  96                 CERROR("%s: cannot get peer for uuid '%s'\n", name, uuid);
  97                 OBD_FREE(service, sizeof(*service));
  98                 RETURN(NULL);
  99         }
 100
 101         rc = PtlEQAlloc(service->srv_self.peer_ni, nevents,
 102                         request_in_callback, &(service->srv_eq_h));
 103
 104         if (rc != PTL_OK) {
 105                 CERROR("%s: PtlEQAlloc failed: %d\n", name, rc);
 106                 OBD_FREE(service, sizeof(*service));
 107                 RETURN(NULL);
 108         }
 109
 110         for (i = 0; i < nbufs; i++) {
 111                 struct ptlrpc_request_buffer_desc *rqbd;
 112
 113                 OBD_ALLOC(rqbd, sizeof(*rqbd));
 114                 if (rqbd == NULL)
 115                         GOTO(failed, NULL);
 116
 117                 rqbd->rqbd_service = service;
 118                 ptl_set_inv_handle(&rqbd->rqbd_me_h);
 119                 atomic_set(&rqbd->rqbd_refcount, 0);
 120                 OBD_ALLOC(rqbd->rqbd_buffer, service->srv_buf_size);
 121                 if (rqbd->rqbd_buffer == NULL) {
 122                         OBD_FREE(rqbd, sizeof(*rqbd));
 123                         GOTO(failed, NULL);
 124                 }
 125                 list_add(&rqbd->rqbd_list, &service->srv_rqbds);
 126                 service->srv_nrqbds++;
 127
 128                 ptlrpc_link_svc_me(rqbd);
 129         }
 130
 131         CDEBUG(D_NET, "Starting service listening on portal %d (eq: %p)\n",
 132                service->srv_req_portal, service->srv_eq_h.handle_idx);
 133
 134         RETURN(service);
 135 failed:
 136         ptlrpc_unregister_service(service);
 137         return NULL;
 138 }
 139
 140 static int handle_incoming_request(struct obd_device *obddev,
 141                                    struct ptlrpc_service *svc,
 142                                    ptl_event_t *event,
 143                                    struct ptlrpc_request *request)
 144 {
 145         struct ptlrpc_request_buffer_desc *rqbd = event->mem_desc.user_ptr;
 146         int rc;
 147
 148         /* FIXME: If we move to an event-driven model, we should put the request
 149          * on the stack of mds_handle instead. */
 150
 151         LASSERT (atomic_read (&rqbd->rqbd_refcount) > 0);
 152         LASSERT ((event->mem_desc.options & PTL_MD_IOV) == 0);
 153         LASSERT (rqbd->rqbd_service == svc);
 154         LASSERT (rqbd->rqbd_buffer == event->mem_desc.start);
 155         LASSERT (event->offset + event->mlength <= svc->srv_buf_size);
 156
 157         memset(request, 0, sizeof(*request));
 158         request->rq_svc = svc;
 159         request->rq_obd = obddev;
 160         request->rq_xid = event->match_bits;
 161         request->rq_reqmsg = event->mem_desc.start + event->offset;
 162         request->rq_reqlen = event->mlength;
 163
 164         rc = -EINVAL;
 165
 166         if (request->rq_reqlen < sizeof(struct lustre_msg)) {
 167                 CERROR("incomplete request (%d): ptl %d from "LPX64" xid "
 168                        LPD64"\n",
 169                        request->rq_reqlen, svc->srv_req_portal,
 170                        event->initiator.nid, request->rq_xid);
 171                 goto out;
 172         }
 173
 174         if (NTOH__u32(request->rq_reqmsg->type) != PTL_RPC_MSG_REQUEST) {
 175                 CERROR("wrong packet type received (type=%u)\n",
 176                        request->rq_reqmsg->type);
 177                 goto out;
 178         }
 179
 180         if (request->rq_reqmsg->magic != PTLRPC_MSG_MAGIC) {
 181                 CERROR("wrong lustre_msg magic %d: ptl %d from "LPX64" xid "
 182                        LPD64"\n",
 183                        request->rq_reqmsg->magic, svc->srv_req_portal,
 184                        event->initiator.nid, request->rq_xid);
 185                 goto out;
 186         }
 187
 188         if (request->rq_reqmsg->version != PTLRPC_MSG_VERSION) {
 189                 CERROR("wrong lustre_msg version %d: ptl %d from "LPX64" xid "
 190                        LPD64"\n",
 191                        request->rq_reqmsg->version, svc->srv_req_portal,
 192                        event->initiator.nid, request->rq_xid);
 193                 goto out;
 194         }
 195
 196         CDEBUG(D_NET, "got req "LPD64" (md: %p + %d)\n", request->rq_xid,
 197                event->mem_desc.start, event->offset);
 198
 199         request->rq_peer.peer_nid = event->initiator.nid;
 200         /* FIXME: this NI should be the incoming NI.
 201          * We don't know how to find that from here. */
 202         request->rq_peer.peer_ni = svc->srv_self.peer_ni;
 203
 204         request->rq_export = class_conn2export((struct lustre_handle *)
 205                                                request->rq_reqmsg);
 206
 207         if (request->rq_export) {
 208                 request->rq_connection = request->rq_export->exp_connection;
 209                 ptlrpc_connection_addref(request->rq_connection);
 210         } else {
 211                 /* create a (hopefully temporary) connection that will be used
 212                  * to send the reply if this call doesn't create an export.
 213                  * XXX revisit this when we revamp ptlrpc */
 214                 request->rq_connection =
 215                         ptlrpc_get_connection(&request->rq_peer, NULL);
 216         }
 217
 218         rc = svc->srv_handler(request);
 219         ptlrpc_put_connection(request->rq_connection);
 220
 221  out:
 222         if (atomic_dec_and_test (&rqbd->rqbd_refcount)) /* last reference? */
 223                 ptlrpc_link_svc_me (rqbd);
 224
 225         return rc;
 226 }
 227
 228 static int ptlrpc_main(void *arg)
 229 {
 230         struct ptlrpc_svc_data *data = (struct ptlrpc_svc_data *)arg;
 231         struct obd_device *obddev = data->dev;
 232         struct ptlrpc_service *svc = data->svc;
 233         struct ptlrpc_thread *thread = data->thread;
 234         struct ptlrpc_request *request;
 235         ptl_event_t *event;
 236         int rc = 0;
 237
 238         ENTRY;
 239
 240         lock_kernel();
 241         daemonize();
 242         spin_lock_irq(&current->sigmask_lock);
 243         sigfillset(&current->blocked);
 244         recalc_sigpending(current);
 245         spin_unlock_irq(&current->sigmask_lock);
 246
 247         strcpy(current->comm, data->name);
 248         unlock_kernel();
 249
 250         OBD_ALLOC(event, sizeof(*event));
 251         if (!event)
 252                 GOTO(out, rc = -ENOMEM);
 253         OBD_ALLOC(request, sizeof(*request));
 254         if (!request)
 255                 GOTO(out_event, rc = -ENOMEM);
 256
 257         /* Record that the thread is running */
 258         thread->t_flags = SVC_RUNNING;
 259         wake_up(&thread->t_ctl_waitq);
 260
 261         /* XXX maintain a list of all managed devices: insert here */
 262
 263         /* And now, loop forever on requests */
 264         while (1) {
 265                 wait_event(svc->srv_waitq,
 266                            ptlrpc_check_event(svc, thread, event));
 267
 268                 if (thread->t_flags & SVC_STOPPING) {
 269                         spin_lock(&svc->srv_lock);
 270                         thread->t_flags &= ~SVC_STOPPING;
 271                         spin_unlock(&svc->srv_lock);
 272
 273                         EXIT;
 274                         break;
 275                 }
 276
 277                 if (thread->t_flags & SVC_EVENT) {
 278                         spin_lock(&svc->srv_lock);
 279                         thread->t_flags &= ~SVC_EVENT;
 280                         spin_unlock(&svc->srv_lock);
 281
 282                         rc = handle_incoming_request(obddev, svc, event,
 283                                                      request);
 284                         continue;
 285                 }
 286
 287                 CERROR("unknown break in service");
 288                 LBUG();
 289                 EXIT;
 290                 break;
 291         }
 292
 293         OBD_FREE(request, sizeof(*request));
 294 out_event:
 295         OBD_FREE(event, sizeof(*event));
 296 out:
 297         thread->t_flags = SVC_STOPPED;
 298         wake_up(&thread->t_ctl_waitq);
 299
 300         CDEBUG(D_NET, "service thread exiting, process %d: rc = %d\n",
 301                current->pid, rc);
 302         return rc;
 303 }
 304
 305 static void ptlrpc_stop_thread(struct ptlrpc_service *svc,
 306                                struct ptlrpc_thread *thread)
 307 {
 308         spin_lock(&svc->srv_lock);
 309         thread->t_flags = SVC_STOPPING;
 310         spin_unlock(&svc->srv_lock);
 311
 312         wake_up(&svc->srv_waitq);
 313         wait_event(thread->t_ctl_waitq, (thread->t_flags & SVC_STOPPED));
 314 }
 315
 316 void ptlrpc_stop_all_threads(struct ptlrpc_service *svc)
 317 {
 318         spin_lock(&svc->srv_lock);
 319         while (!list_empty(&svc->srv_threads)) {
 320                 struct ptlrpc_thread *thread;
 321                 thread = list_entry(svc->srv_threads.next, struct ptlrpc_thread,
 322                                     t_link);
 323                 spin_unlock(&svc->srv_lock);
 324                 ptlrpc_stop_thread(svc, thread);
 325                 spin_lock(&svc->srv_lock);
 326                 list_del(&thread->t_link);
 327                 OBD_FREE(thread, sizeof(*thread));
 328         }
 329         spin_unlock(&svc->srv_lock);
 330 }
 331
 332 int ptlrpc_start_thread(struct obd_device *dev, struct ptlrpc_service *svc,
 333                         char *name)
 334 {
 335         struct ptlrpc_svc_data d;
 336         struct ptlrpc_thread *thread;
 337         int rc;
 338         ENTRY;
 339
 340         OBD_ALLOC(thread, sizeof(*thread));
 341         if (thread == NULL) {
 342                 LBUG();
 343                 RETURN(-ENOMEM);
 344         }
 345         init_waitqueue_head(&thread->t_ctl_waitq);
 346
 347         d.dev = dev;
 348         d.svc = svc;
 349         d.name = name;
 350         d.thread = thread;
 351
 352         spin_lock(&svc->srv_lock);
 353         list_add(&thread->t_link, &svc->srv_threads);
 354         spin_unlock(&svc->srv_lock);
 355
 356         /* XXX should we really be cloning open file handles here? */
 357         rc = kernel_thread(ptlrpc_main, (void *) &d,
 358                            CLONE_VM | CLONE_FS | CLONE_FILES);
 359         if (rc < 0) {
 360                 CERROR("cannot start thread\n");
 361                 OBD_FREE(thread, sizeof(*thread));
 362                 RETURN(rc);
 363         }
 364         wait_event(thread->t_ctl_waitq, thread->t_flags & SVC_RUNNING);
 365
 366         RETURN(0);
 367 }
 368
 369 int ptlrpc_unregister_service(struct ptlrpc_service *service)
 370 {
 371         int rc;
 372
 373         LASSERT (list_empty (&service->srv_threads));
 374
 375         /* XXX We could reply (with failure) to all buffered requests
 376          * _after_ unlinking _all_ the request buffers, but _before_
 377          * freeing them.
 378          */
 379
 380         while (!list_empty (&service->srv_rqbds)) {
 381                 struct ptlrpc_request_buffer_desc *rqbd =
 382                         list_entry (service->srv_rqbds.next,
 383                                     struct ptlrpc_request_buffer_desc,
 384                                     rqbd_list);
 385
 386                 list_del (&rqbd->rqbd_list);
 387
 388                 LASSERT (atomic_read (&rqbd->rqbd_refcount) > 0);
 389                 /* refcount could be anything; it's possible for the
 390                  * buffers to continued to get filled after all the server
 391                  * threads exited.  But we know they _have_ exited.
 392                  */
 393
 394                 (void) PtlMEUnlink(rqbd->rqbd_me_h);
 395                 /* The callback handler could have unlinked this ME already
 396                  * (we're racing with her) but it's safe to ensure it _has_
 397                  * been unlinked.
 398                  */
 399
 400                 OBD_FREE (rqbd->rqbd_buffer, service->srv_buf_size);
 401                 OBD_FREE (rqbd, sizeof (*rqbd));
 402                 service->srv_nrqbds--;
 403         }
 404
 405         LASSERT (service->srv_nrqbds == 0);
 406
 407         rc = PtlEQFree(service->srv_eq_h);
 408         if (rc)
 409                 CERROR("PtlEQFree failed: %d\n", rc);
 410
 411         OBD_FREE(service, sizeof(*service));
 412         if (rc)
 413                 LBUG();
 414         return rc;
 415 }