lustre/ldlm/ldlm_request.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (C) 2002, 2003 Cluster File Systems, Inc.
   5  *
   6  *   This file is part of the Lustre file system, http://www.lustre.org
   7  *   Lustre is a trademark of Cluster File Systems, Inc.
   8  *
   9  *   You may have signed or agreed to another license before downloading
  10  *   this software.  If so, you are bound by the terms and conditions
  11  *   of that agreement, and the following does not apply to you.  See the
  12  *   LICENSE file included with this distribution for more information.
  13  *
  14  *   If you did not agree to a different license, then this copy of Lustre
  15  *   is open source software; you can redistribute it and/or modify it
  16  *   under the terms of version 2 of the GNU General Public License as
  17  *   published by the Free Software Foundation.
  18  *
  19  *   In either case, Lustre is distributed in the hope that it will be
  20  *   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  21  *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  *   license text for more details.
  23  */
  24
  25 #define DEBUG_SUBSYSTEM S_LDLM
  26 #ifndef __KERNEL__
  27 #include <signal.h>
  28 #include <liblustre.h>
  29 #endif
  30
  31 #include <lustre_dlm.h>
  32 #include <obd_class.h>
  33 #include <obd.h>
  34
  35 #include "ldlm_internal.h"
  36
  37 static void interrupted_completion_wait(void *data)
  38 {
  39 }
  40
  41 struct lock_wait_data {
  42         struct ldlm_lock *lwd_lock;
  43         __u32             lwd_conn_cnt;
  44 };
  45
  46 struct ldlm_async_args {
  47         struct lustre_handle lock_handle;
  48 };
  49
  50 int ldlm_expired_completion_wait(void *data)
  51 {
  52         struct lock_wait_data *lwd = data;
  53         struct ldlm_lock *lock = lwd->lwd_lock;
  54         struct obd_import *imp;
  55         struct obd_device *obd;
  56
  57         ENTRY;
  58         if (lock->l_conn_export == NULL) {
  59                 static cfs_time_t next_dump = 0, last_dump = 0;
  60
  61                 if (ptlrpc_check_suspend())
  62                         RETURN(0);
  63
  64                 LDLM_ERROR(lock, "lock timed out (enqueued at %lu, %lus ago); "
  65                            "not entering recovery in server code, just going "
  66                            "back to sleep", lock->l_enqueued_time.tv_sec,
  67                            CURRENT_SECONDS - lock->l_enqueued_time.tv_sec);
  68                 if (cfs_time_after(cfs_time_current(), next_dump)) {
  69                         last_dump = next_dump;
  70                         next_dump = cfs_time_shift(300);
  71                         ldlm_namespace_dump(D_DLMTRACE,
  72                                             lock->l_resource->lr_namespace);
  73                         if (last_dump == 0)
  74                                 libcfs_debug_dumplog();
  75                 }
  76                 RETURN(0);
  77         }
  78
  79         obd = lock->l_conn_export->exp_obd;
  80         imp = obd->u.cli.cl_import;
  81         ptlrpc_fail_import(imp, lwd->lwd_conn_cnt);
  82         LDLM_ERROR(lock, "lock timed out (enqueued at %lu, %lus ago), entering "
  83                    "recovery for %s@%s", lock->l_enqueued_time.tv_sec,
  84                    CURRENT_SECONDS - lock->l_enqueued_time.tv_sec,
  85                    obd2cli_tgt(obd), imp->imp_connection->c_remote_uuid.uuid);
  86
  87         RETURN(0);
  88 }
  89
  90 int ldlm_completion_ast(struct ldlm_lock *lock, int flags, void *data)
  91 {
  92         /* XXX ALLOCATE - 160 bytes */
  93         struct lock_wait_data lwd;
  94         struct obd_device *obd;
  95         struct obd_import *imp = NULL;
  96         struct l_wait_info lwi;
  97         int rc = 0;
  98         ENTRY;
  99
 100         if (flags == LDLM_FL_WAIT_NOREPROC) {
 101                 LDLM_DEBUG(lock, "client-side enqueue waiting on pending lock");
 102                 goto noreproc;
 103         }
 104
 105         if (!(flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED |
 106                        LDLM_FL_BLOCK_CONV))) {
 107                 cfs_waitq_signal(&lock->l_waitq);
 108                 RETURN(0);
 109         }
 110
 111         LDLM_DEBUG(lock, "client-side enqueue returned a blocked lock, "
 112                    "sleeping");
 113         ldlm_lock_dump(D_OTHER, lock, 0);
 114         ldlm_reprocess_all(lock->l_resource);
 115
 116 noreproc:
 117
 118         obd = class_exp2obd(lock->l_conn_export);
 119
 120         /* if this is a local lock, then there is no import */
 121         if (obd != NULL)
 122                 imp = obd->u.cli.cl_import;
 123
 124         lwd.lwd_lock = lock;
 125
 126         if (lock->l_flags & LDLM_FL_NO_TIMEOUT) {
 127                 LDLM_DEBUG(lock, "waiting indefinitely because of NO_TIMEOUT");
 128                 lwi = LWI_INTR(interrupted_completion_wait, &lwd);
 129         } else {
 130                 lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(obd_timeout),
 131                                        ldlm_expired_completion_wait,
 132                                        interrupted_completion_wait, &lwd);
 133         }
 134
 135         if (imp != NULL) {
 136                 spin_lock(&imp->imp_lock);
 137                 lwd.lwd_conn_cnt = imp->imp_conn_cnt;
 138                 spin_unlock(&imp->imp_lock);
 139         }
 140
 141         /* Go to sleep until the lock is granted or cancelled. */
 142         rc = l_wait_event(lock->l_waitq,
 143                           ((lock->l_req_mode == lock->l_granted_mode) ||
 144                            (lock->l_flags & LDLM_FL_FAILED)), &lwi);
 145
 146         if (lock->l_destroyed || lock->l_flags & LDLM_FL_FAILED) {
 147                 LDLM_DEBUG(lock, "client-side enqueue waking up: destroyed");
 148                 RETURN(-EIO);
 149         }
 150
 151         if (rc) {
 152                 LDLM_DEBUG(lock, "client-side enqueue waking up: failed (%d)",
 153                            rc);
 154                 RETURN(rc);
 155         }
 156
 157         LDLM_DEBUG(lock, "client-side enqueue waking up: granted");
 158         RETURN(0);
 159 }
 160
 161 /*
 162  * ->l_blocking_ast() callback for LDLM locks acquired by server-side OBDs.
 163  */
 164 int ldlm_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock_desc *desc,
 165                       void *data, int flag)
 166 {
 167         int do_ast;
 168         ENTRY;
 169
 170         if (flag == LDLM_CB_CANCELING) {
 171                 /* Don't need to do anything here. */
 172                 RETURN(0);
 173         }
 174
 175         lock_res_and_lock(lock);
 176         /* Get this: if ldlm_blocking_ast is racing with intent_policy, such
 177          * that ldlm_blocking_ast is called just before intent_policy method
 178          * takes the ns_lock, then by the time we get the lock, we might not
 179          * be the correct blocking function anymore.  So check, and return
 180          * early, if so. */
 181         if (lock->l_blocking_ast != ldlm_blocking_ast) {
 182                 unlock_res_and_lock(lock);
 183                 RETURN(0);
 184         }
 185
 186         lock->l_flags |= LDLM_FL_CBPENDING;
 187         do_ast = (!lock->l_readers && !lock->l_writers);
 188         unlock_res_and_lock(lock);
 189
 190         if (do_ast) {
 191                 struct lustre_handle lockh;
 192                 int rc;
 193
 194                 LDLM_DEBUG(lock, "already unused, calling ldlm_cli_cancel");
 195                 ldlm_lock2handle(lock, &lockh);
 196                 rc = ldlm_cli_cancel(&lockh);
 197                 if (rc < 0)
 198                         CERROR("ldlm_cli_cancel: %d\n", rc);
 199         } else {
 200                 LDLM_DEBUG(lock, "Lock still has references, will be "
 201                            "cancelled later");
 202         }
 203         RETURN(0);
 204 }
 205
 206 /*
 207  * ->l_glimpse_ast() for DLM extent locks acquired on the server-side. See
 208  * comment in filter_intent_policy() on why you may need this.
 209  */
 210 int ldlm_glimpse_ast(struct ldlm_lock *lock, void *reqp)
 211 {
 212         /*
 213          * Returning -ELDLM_NO_LOCK_DATA actually works, but the reason for
 214          * that is rather subtle: with OST-side locking, it may so happen that
 215          * _all_ extent locks are held by the OST. If client wants to obtain
 216          * current file size it calls ll{,u}_glimpse_size(), and (as locks are
 217          * on the server), dummy glimpse callback fires and does
 218          * nothing. Client still receives correct file size due to the
 219          * following fragment in filter_intent_policy():
 220          *
 221          * rc = l->l_glimpse_ast(l, NULL); // this will update the LVB
 222          * if (rc != 0 && res->lr_namespace->ns_lvbo &&
 223          *     res->lr_namespace->ns_lvbo->lvbo_update) {
 224          *         res->lr_namespace->ns_lvbo->lvbo_update(res, NULL, 0, 1);
 225          * }
 226          *
 227          * that is, after glimpse_ast() fails, filter_lvbo_update() runs, and
 228          * returns correct file size to the client.
 229          */
 230         return -ELDLM_NO_LOCK_DATA;
 231 }
 232
 233 int ldlm_cli_enqueue_local(struct ldlm_namespace *ns,
 234                            const struct ldlm_res_id *res_id,
 235                            ldlm_type_t type, ldlm_policy_data_t *policy,
 236                            ldlm_mode_t mode, int *flags,
 237                            ldlm_blocking_callback blocking,
 238                            ldlm_completion_callback completion,
 239                            ldlm_glimpse_callback glimpse,
 240                            void *data, __u32 lvb_len, void *lvb_swabber,
 241                            struct lustre_handle *lockh)
 242 {
 243         struct ldlm_lock *lock;
 244         int err;
 245         ENTRY;
 246
 247         LASSERT(!(*flags & LDLM_FL_REPLAY));
 248         if (unlikely(ns->ns_client)) {
 249                 CERROR("Trying to enqueue local lock in a shadow namespace\n");
 250                 LBUG();
 251         }
 252
 253         lock = ldlm_lock_create(ns, res_id, type, mode, blocking,
 254                                 completion, glimpse, data, lvb_len);
 255         if (unlikely(!lock))
 256                 GOTO(out_nolock, err = -ENOMEM);
 257         LDLM_DEBUG(lock, "client-side local enqueue handler, new lock created");
 258
 259         ldlm_lock_addref_internal(lock, mode);
 260         ldlm_lock2handle(lock, lockh);
 261         lock_res_and_lock(lock);
 262         lock->l_flags |= LDLM_FL_LOCAL;
 263         if (*flags & LDLM_FL_ATOMIC_CB)
 264                 lock->l_flags |= LDLM_FL_ATOMIC_CB;
 265         lock->l_lvb_swabber = lvb_swabber;
 266         unlock_res_and_lock(lock);
 267         if (policy != NULL)
 268                 lock->l_policy_data = *policy;
 269         if (type == LDLM_EXTENT)
 270                 lock->l_req_extent = policy->l_extent;
 271
 272         err = ldlm_lock_enqueue(ns, &lock, policy, flags);
 273         if (unlikely(err != ELDLM_OK))
 274                 GOTO(out, err);
 275
 276         if (policy != NULL)
 277                 *policy = lock->l_policy_data;
 278
 279         LDLM_DEBUG_NOLOCK("client-side local enqueue handler END (lock %p)",
 280                           lock);
 281
 282         if (lock->l_completion_ast)
 283                 lock->l_completion_ast(lock, *flags, NULL);
 284
 285         LDLM_DEBUG(lock, "client-side local enqueue END");
 286         EXIT;
 287  out:
 288         LDLM_LOCK_PUT(lock);
 289  out_nolock:
 290         return err;
 291 }
 292
 293 static void failed_lock_cleanup(struct ldlm_namespace *ns,
 294                                 struct ldlm_lock *lock,
 295                                 struct lustre_handle *lockh, int mode)
 296 {
 297         /* Set a flag to prevent us from sending a CANCEL (bug 407) */
 298         lock_res_and_lock(lock);
 299         lock->l_flags |= LDLM_FL_LOCAL_ONLY;
 300         unlock_res_and_lock(lock);
 301         LDLM_DEBUG(lock, "setting FL_LOCAL_ONLY");
 302
 303         ldlm_lock_decref_and_cancel(lockh, mode);
 304
 305         /* XXX - HACK because we shouldn't call ldlm_lock_destroy()
 306          *       from llite/file.c/ll_file_flock(). */
 307         if (lock->l_resource->lr_type == LDLM_FLOCK) {
 308                 ldlm_lock_destroy(lock);
 309         }
 310 }
 311
 312 int ldlm_cli_enqueue_fini(struct obd_export *exp, struct ptlrpc_request *req,
 313                           ldlm_type_t type, __u8 with_policy, ldlm_mode_t mode,
 314                           int *flags, void *lvb, __u32 lvb_len,
 315                           void *lvb_swabber, struct lustre_handle *lockh,int rc)
 316 {
 317         struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
 318         int is_replay = *flags & LDLM_FL_REPLAY;
 319         struct ldlm_lock *lock;
 320         struct ldlm_reply *reply;
 321         int cleanup_phase = 1;
 322         ENTRY;
 323
 324         lock = ldlm_handle2lock(lockh);
 325         /* ldlm_cli_enqueue is holding a reference on this lock. */
 326         if (!lock) {
 327                 LASSERT(type == LDLM_FLOCK);
 328                 RETURN(-ENOLCK);
 329         }
 330
 331         if (rc != ELDLM_OK) {
 332                 LASSERT(!is_replay);
 333                 LDLM_DEBUG(lock, "client-side enqueue END (%s)",
 334                            rc == ELDLM_LOCK_ABORTED ? "ABORTED" : "FAILED");
 335                 if (rc == ELDLM_LOCK_ABORTED) {
 336                         /* Before we return, swab the reply */
 337                         reply = lustre_swab_repbuf(req, DLM_LOCKREPLY_OFF,
 338                                                    sizeof(*reply),
 339                                                    lustre_swab_ldlm_reply);
 340                         if (reply == NULL) {
 341                                 CERROR("Can't unpack ldlm_reply\n");
 342                                 rc = -EPROTO;
 343                         }
 344                         if (lvb_len) {
 345                                 void *tmplvb;
 346                                 tmplvb = lustre_swab_repbuf(req,
 347                                                             DLM_REPLY_REC_OFF,
 348                                                             lvb_len,
 349                                                             lvb_swabber);
 350                                 if (tmplvb == NULL)
 351                                         GOTO(cleanup, rc = -EPROTO);
 352                                 if (lvb != NULL)
 353                                         memcpy(lvb, tmplvb, lvb_len);
 354                         }
 355                 }
 356                 GOTO(cleanup, rc);
 357         }
 358
 359         reply = lustre_swab_repbuf(req, DLM_LOCKREPLY_OFF, sizeof(*reply),
 360                                    lustre_swab_ldlm_reply);
 361         if (reply == NULL) {
 362                 CERROR("Can't unpack ldlm_reply\n");
 363                 GOTO(cleanup, rc = -EPROTO);
 364         }
 365
 366         /* lock enqueued on the server */
 367         cleanup_phase = 0;
 368
 369         lock_res_and_lock(lock);
 370         lock->l_remote_handle = reply->lock_handle;
 371         *flags = reply->lock_flags;
 372         lock->l_flags |= reply->lock_flags & LDLM_INHERIT_FLAGS;
 373         /* move NO_TIMEOUT flag to the lock to force ldlm_lock_match()
 374          * to wait with no timeout as well */
 375         lock->l_flags |= reply->lock_flags & LDLM_FL_NO_TIMEOUT;
 376         unlock_res_and_lock(lock);
 377
 378         CDEBUG(D_INFO, "local: %p, remote cookie: "LPX64", flags: 0x%x\n",
 379                lock, reply->lock_handle.cookie, *flags);
 380
 381         /* If enqueue returned a blocked lock but the completion handler has
 382          * already run, then it fixed up the resource and we don't need to do it
 383          * again. */
 384         if ((*flags) & LDLM_FL_LOCK_CHANGED) {
 385                 int newmode = reply->lock_desc.l_req_mode;
 386                 LASSERT(!is_replay);
 387                 if (newmode && newmode != lock->l_req_mode) {
 388                         LDLM_DEBUG(lock, "server returned different mode %s",
 389                                    ldlm_lockname[newmode]);
 390                         lock->l_req_mode = newmode;
 391                 }
 392
 393                 if (memcmp(reply->lock_desc.l_resource.lr_name.name,
 394                           lock->l_resource->lr_name.name,
 395                           sizeof(struct ldlm_res_id))) {
 396                         CDEBUG(D_INFO, "remote intent success, locking "
 397                                         "(%ld,%ld,%ld) instead of "
 398                                         "(%ld,%ld,%ld)\n",
 399                               (long)reply->lock_desc.l_resource.lr_name.name[0],
 400                               (long)reply->lock_desc.l_resource.lr_name.name[1],
 401                               (long)reply->lock_desc.l_resource.lr_name.name[2],
 402                               (long)lock->l_resource->lr_name.name[0],
 403                               (long)lock->l_resource->lr_name.name[1],
 404                               (long)lock->l_resource->lr_name.name[2]);
 405
 406                         ldlm_lock_change_resource(ns, lock,
 407                                           &reply->lock_desc.l_resource.lr_name);
 408                         if (lock->l_resource == NULL) {
 409                                 LBUG();
 410                                 GOTO(cleanup, rc = -ENOMEM);
 411                         }
 412                         LDLM_DEBUG(lock, "client-side enqueue, new resource");
 413                 }
 414                 if (with_policy)
 415                         if (!(type == LDLM_IBITS && !(exp->exp_connect_flags &
 416                                                     OBD_CONNECT_IBITS)))
 417                                 lock->l_policy_data =
 418                                                  reply->lock_desc.l_policy_data;
 419                 if (type != LDLM_PLAIN)
 420                         LDLM_DEBUG(lock,"client-side enqueue, new policy data");
 421         }
 422
 423         if ((*flags) & LDLM_FL_AST_SENT ||
 424             /* Cancel extent locks as soon as possible on a liblustre client,
 425              * because it cannot handle asynchronous ASTs robustly (see
 426              * bug 7311). */
 427             (LIBLUSTRE_CLIENT && type == LDLM_EXTENT)) {
 428                 lock_res_and_lock(lock);
 429                 lock->l_flags |= LDLM_FL_CBPENDING;
 430                 unlock_res_and_lock(lock);
 431                 LDLM_DEBUG(lock, "enqueue reply includes blocking AST");
 432         }
 433
 434         /* If the lock has already been granted by a completion AST, don't
 435          * clobber the LVB with an older one. */
 436         if (lvb_len && (lock->l_req_mode != lock->l_granted_mode)) {
 437                 void *tmplvb;
 438                 tmplvb = lustre_swab_repbuf(req, DLM_REPLY_REC_OFF, lvb_len,
 439                                             lvb_swabber);
 440                 if (tmplvb == NULL)
 441                         GOTO(cleanup, rc = -EPROTO);
 442                 memcpy(lock->l_lvb_data, tmplvb, lvb_len);
 443         }
 444
 445         if (!is_replay) {
 446                 rc = ldlm_lock_enqueue(ns, &lock, NULL, flags);
 447                 if (lock->l_completion_ast != NULL) {
 448                         int err = lock->l_completion_ast(lock, *flags, NULL);
 449                         if (!rc)
 450                                 rc = err;
 451                         if (rc && type != LDLM_FLOCK) /* bug 9425, bug 10250 */
 452                                 cleanup_phase = 1;
 453                 }
 454         }
 455
 456         if (lvb_len && lvb != NULL) {
 457                 /* Copy the LVB here, and not earlier, because the completion
 458                  * AST (if any) can override what we got in the reply */
 459                 memcpy(lvb, lock->l_lvb_data, lvb_len);
 460         }
 461
 462         LDLM_DEBUG(lock, "client-side enqueue END");
 463         EXIT;
 464 cleanup:
 465         if (cleanup_phase == 1 && rc)
 466                 failed_lock_cleanup(ns, lock, lockh, mode);
 467         /* Put lock 2 times, the second reference is held by ldlm_cli_enqueue */
 468         LDLM_LOCK_PUT(lock);
 469         LDLM_LOCK_PUT(lock);
 470         return rc;
 471 }
 472
 473 /* PAGE_SIZE-512 is to allow TCP/IP and LNET headers to fit into
 474  * a single page on the send/receive side. XXX: 512 should be changed
 475  * to more adequate value. */
 476 static inline int ldlm_req_handles_avail(struct obd_export *exp,
 477                                          int *size, int bufcount, int off)
 478 {
 479         int avail = min_t(int, LDLM_MAXREQSIZE, PAGE_SIZE - 512);
 480         int old_size = size[DLM_LOCKREQ_OFF];
 481
 482         size[DLM_LOCKREQ_OFF] = sizeof(struct ldlm_request);
 483         avail -= lustre_msg_size(class_exp2cliimp(exp)->imp_msg_magic,
 484                                  bufcount, size);
 485         avail /= sizeof(struct lustre_handle);
 486         avail += LDLM_LOCKREQ_HANDLES - off;
 487         size[DLM_LOCKREQ_OFF] = old_size;
 488
 489         return avail;
 490 }
 491
 492 static inline int ldlm_cancel_handles_avail(struct obd_export *exp)
 493 {
 494         int size[2] = { sizeof(struct ptlrpc_body),
 495                         sizeof(struct ldlm_request) };
 496         return ldlm_req_handles_avail(exp, size, 2, 0);
 497 }
 498
 499 /* Cancel lru locks and pack them into the enqueue request. Pack there the given
 500  * @count locks in @cancels. */
 501 struct ptlrpc_request *ldlm_prep_enqueue_req(struct obd_export *exp,
 502                                              int bufcount, int *size,
 503                                              struct list_head *cancels,
 504                                              int count)
 505 {
 506         struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
 507         struct ldlm_request *dlm = NULL;
 508         struct ptlrpc_request *req;
 509         CFS_LIST_HEAD(head);
 510         ENTRY;
 511
 512         if (cancels == NULL)
 513                 cancels = &head;
 514         if (exp_connect_cancelset(exp)) {
 515                 /* Estimate the amount of available space in the request. */
 516                 int avail = ldlm_req_handles_avail(exp, size, bufcount,
 517                                                    LDLM_ENQUEUE_CANCEL_OFF);
 518                 LASSERT(avail >= count);
 519
 520                 /* Cancel lru locks here _only_ if the server supports
 521                  * EARLY_CANCEL. Otherwise we have to send extra CANCEL
 522                  * rpc right on enqueue, what will make it slower, vs.
 523                  * asynchronous rpc in blocking thread. */
 524                 count += ldlm_cancel_lru_local(ns, cancels,
 525                                                exp_connect_lru_resize(exp) ? 0 : 1,
 526                                                avail - count, LDLM_CANCEL_AGED);
 527                 size[DLM_LOCKREQ_OFF] =
 528                         ldlm_request_bufsize(count, LDLM_ENQUEUE);
 529         }
 530         req = ptlrpc_prep_req(class_exp2cliimp(exp), LUSTRE_DLM_VERSION,
 531                               LDLM_ENQUEUE, bufcount, size, NULL);
 532         if (exp_connect_cancelset(exp) && req) {
 533                 dlm = lustre_msg_buf(req->rq_reqmsg,
 534                                      DLM_LOCKREQ_OFF, sizeof(*dlm));
 535                 /* Skip first lock handler in ldlm_request_pack(), this method
 536                  * will incrment @lock_count according to the lock handle amount
 537                  * actually written to the buffer. */
 538                 dlm->lock_count = LDLM_ENQUEUE_CANCEL_OFF;
 539                 ldlm_cli_cancel_list(cancels, count, req, DLM_LOCKREQ_OFF, 0);
 540         } else {
 541                 ldlm_lock_list_put(cancels, l_bl_ast, count);
 542         }
 543         RETURN(req);
 544 }
 545
 546 /* If a request has some specific initialisation it is passed in @reqp,
 547  * otherwise it is created in ldlm_cli_enqueue.
 548  *
 549  * Supports sync and async requests, pass @async flag accordingly. If a
 550  * request was created in ldlm_cli_enqueue and it is the async request,
 551  * pass it to the caller in @reqp. */
 552 int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp,
 553                      struct ldlm_enqueue_info *einfo,
 554                      const struct ldlm_res_id *res_id,
 555                      ldlm_policy_data_t *policy, int *flags,
 556                      void *lvb, __u32 lvb_len, void *lvb_swabber,
 557                      struct lustre_handle *lockh, int async)
 558 {
 559         struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
 560         struct ldlm_lock *lock;
 561         struct ldlm_request *body;
 562         struct ldlm_reply *reply;
 563         int size[3] = { [MSG_PTLRPC_BODY_OFF] = sizeof(struct ptlrpc_body),
 564                         [DLM_LOCKREQ_OFF]     = sizeof(*body),
 565                         [DLM_REPLY_REC_OFF]   = lvb_len };
 566         int is_replay = *flags & LDLM_FL_REPLAY;
 567         int req_passed_in = 1, rc, err;
 568         struct ptlrpc_request *req;
 569         ENTRY;
 570
 571         LASSERT(exp != NULL);
 572
 573         /* If we're replaying this lock, just check some invariants.
 574          * If we're creating a new lock, get everything all setup nice. */
 575         if (is_replay) {
 576                 lock = ldlm_handle2lock(lockh);
 577                 LASSERT(lock != NULL);
 578                 LDLM_DEBUG(lock, "client-side enqueue START");
 579                 LASSERT(exp == lock->l_conn_export);
 580         } else {
 581                 lock = ldlm_lock_create(ns, res_id, einfo->ei_type,
 582                                         einfo->ei_mode, einfo->ei_cb_bl,
 583                                         einfo->ei_cb_cp, einfo->ei_cb_gl,
 584                                         einfo->ei_cbdata, lvb_len);
 585                 if (lock == NULL)
 586                         RETURN(-ENOMEM);
 587                 /* for the local lock, add the reference */
 588                 ldlm_lock_addref_internal(lock, einfo->ei_mode);
 589                 ldlm_lock2handle(lock, lockh);
 590                 lock->l_lvb_swabber = lvb_swabber;
 591                 if (policy != NULL) {
 592                         /* INODEBITS_INTEROP: If the server does not support
 593                          * inodebits, we will request a plain lock in the
 594                          * descriptor (ldlm_lock2desc() below) but use an
 595                          * inodebits lock internally with both bits set.
 596                          */
 597                         if (einfo->ei_type == LDLM_IBITS &&
 598                             !(exp->exp_connect_flags & OBD_CONNECT_IBITS))
 599                                 lock->l_policy_data.l_inodebits.bits =
 600                                         MDS_INODELOCK_LOOKUP |
 601                                         MDS_INODELOCK_UPDATE;
 602                         else
 603                                 lock->l_policy_data = *policy;
 604                 }
 605
 606                 if (einfo->ei_type == LDLM_EXTENT)
 607                         lock->l_req_extent = policy->l_extent;
 608                 LDLM_DEBUG(lock, "client-side enqueue START");
 609         }
 610
 611         /* lock not sent to server yet */
 612
 613         if (reqp == NULL || *reqp == NULL) {
 614                 req = ldlm_prep_enqueue_req(exp, 2, size, NULL, 0);
 615                 if (req == NULL) {
 616                         failed_lock_cleanup(ns, lock, lockh, einfo->ei_mode);
 617                         LDLM_LOCK_PUT(lock);
 618                         RETURN(-ENOMEM);
 619                 }
 620                 req_passed_in = 0;
 621                 if (reqp)
 622                         *reqp = req;
 623         } else {
 624                 req = *reqp;
 625                 LASSERTF(lustre_msg_buflen(req->rq_reqmsg, DLM_LOCKREQ_OFF) >=
 626                          sizeof(*body), "buflen[%d] = %d, not "LPSZ"\n",
 627                          DLM_LOCKREQ_OFF,
 628                          lustre_msg_buflen(req->rq_reqmsg, DLM_LOCKREQ_OFF),
 629                          sizeof(*body));
 630         }
 631
 632         lock->l_conn_export = exp;
 633         lock->l_export = NULL;
 634         lock->l_blocking_ast = einfo->ei_cb_bl;
 635
 636         /* Dump lock data into the request buffer */
 637         body = lustre_msg_buf(req->rq_reqmsg, DLM_LOCKREQ_OFF, sizeof(*body));
 638         ldlm_lock2desc(lock, &body->lock_desc);
 639         body->lock_flags = *flags;
 640         body->lock_handle[0] = *lockh;
 641
 642         /* Continue as normal. */
 643         if (!req_passed_in) {
 644                 size[DLM_LOCKREPLY_OFF] = sizeof(*reply);
 645                 ptlrpc_req_set_repsize(req, 2 + (lvb_len > 0), size);
 646         }
 647
 648         /*
 649          * Liblustre client doesn't get extent locks, except for O_APPEND case
 650          * where [0, OBD_OBJECT_EOF] lock is taken, or truncate, where
 651          * [i_size, OBD_OBJECT_EOF] lock is taken.
 652          */
 653         LASSERT(ergo(LIBLUSTRE_CLIENT, einfo->ei_type != LDLM_EXTENT ||
 654                      policy->l_extent.end == OBD_OBJECT_EOF));
 655
 656         if (async) {
 657                 LASSERT(reqp != NULL);
 658                 RETURN(0);
 659         }
 660
 661         LDLM_DEBUG(lock, "sending request");
 662         rc = ptlrpc_queue_wait(req);
 663         err = ldlm_cli_enqueue_fini(exp, req, einfo->ei_type, policy ? 1 : 0,
 664                                     einfo->ei_mode, flags, lvb, lvb_len,
 665                                     lvb_swabber, lockh, rc);
 666
 667         /* If ldlm_cli_enqueue_fini did not find the lock, we need to free
 668          * one reference that we took */
 669         if (err == -ENOLCK)
 670                 LDLM_LOCK_PUT(lock);
 671         else
 672                 rc = err;
 673
 674         if (!req_passed_in && req != NULL) {
 675                 ptlrpc_req_finished(req);
 676                 if (reqp)
 677                         *reqp = NULL;
 678         }
 679
 680         RETURN(rc);
 681 }
 682
 683 static int ldlm_cli_convert_local(struct ldlm_lock *lock, int new_mode,
 684                                   int *flags)
 685 {
 686         struct ldlm_resource *res;
 687         int rc;
 688         ENTRY;
 689         if (lock->l_resource->lr_namespace->ns_client) {
 690                 CERROR("Trying to cancel local lock\n");
 691                 LBUG();
 692         }
 693         LDLM_DEBUG(lock, "client-side local convert");
 694
 695         res = ldlm_lock_convert(lock, new_mode, flags);
 696         if (res) {
 697                 ldlm_reprocess_all(res);
 698                 rc = 0;
 699         } else {
 700                 rc = EDEADLOCK;
 701         }
 702         LDLM_DEBUG(lock, "client-side local convert handler END");
 703         LDLM_LOCK_PUT(lock);
 704         RETURN(rc);
 705 }
 706
 707 /* FIXME: one of ldlm_cli_convert or the server side should reject attempted
 708  * conversion of locks which are on the waiting or converting queue */
 709 /* Caller of this code is supposed to take care of lock readers/writers
 710    accounting */
 711 int ldlm_cli_convert(struct lustre_handle *lockh, int new_mode, int *flags)
 712 {
 713         struct ldlm_request *body;
 714         struct ldlm_reply *reply;
 715         struct ldlm_lock *lock;
 716         struct ldlm_resource *res;
 717         struct ptlrpc_request *req;
 718         int size[2] = { [MSG_PTLRPC_BODY_OFF] = sizeof(struct ptlrpc_body),
 719                         [DLM_LOCKREQ_OFF]     = sizeof(*body) };
 720         int rc;
 721         ENTRY;
 722
 723         lock = ldlm_handle2lock(lockh);
 724         if (!lock) {
 725                 LBUG();
 726                 RETURN(-EINVAL);
 727         }
 728         *flags = 0;
 729
 730         if (lock->l_conn_export == NULL)
 731                 RETURN(ldlm_cli_convert_local(lock, new_mode, flags));
 732
 733         LDLM_DEBUG(lock, "client-side convert");
 734
 735         req = ptlrpc_prep_req(class_exp2cliimp(lock->l_conn_export),
 736                               LUSTRE_DLM_VERSION, LDLM_CONVERT, 2, size, NULL);
 737         if (!req)
 738                 GOTO(out, rc = -ENOMEM);
 739
 740         body = lustre_msg_buf(req->rq_reqmsg, DLM_LOCKREQ_OFF, sizeof(*body));
 741         body->lock_handle[0] = lock->l_remote_handle;
 742
 743         body->lock_desc.l_req_mode = new_mode;
 744         body->lock_flags = *flags;
 745
 746         size[DLM_LOCKREPLY_OFF] = sizeof(*reply);
 747         ptlrpc_req_set_repsize(req, 2, size);
 748
 749         rc = ptlrpc_queue_wait(req);
 750         if (rc != ELDLM_OK)
 751                 GOTO(out, rc);
 752
 753         reply = lustre_swab_repbuf(req, DLM_LOCKREPLY_OFF, sizeof(*reply),
 754                                    lustre_swab_ldlm_reply);
 755         if (reply == NULL) {
 756                 CERROR ("Can't unpack ldlm_reply\n");
 757                 GOTO (out, rc = -EPROTO);
 758         }
 759
 760         if (req->rq_status)
 761                 GOTO(out, rc = req->rq_status);
 762
 763         res = ldlm_lock_convert(lock, new_mode, &reply->lock_flags);
 764         if (res != NULL) {
 765                 ldlm_reprocess_all(res);
 766                 /* Go to sleep until the lock is granted. */
 767                 /* FIXME: or cancelled. */
 768                 if (lock->l_completion_ast) {
 769                         rc = lock->l_completion_ast(lock, LDLM_FL_WAIT_NOREPROC,
 770                                                     NULL);
 771                         if (rc)
 772                                 GOTO(out, rc);
 773                 }
 774         } else {
 775                 rc = EDEADLOCK;
 776         }
 777         EXIT;
 778  out:
 779         LDLM_LOCK_PUT(lock);
 780         ptlrpc_req_finished(req);
 781         return rc;
 782 }
 783
 784 /* Cancel locks locally.
 785  * Returns:
 786  * LDLM_FL_LOCAL_ONLY if tere is no need in a CANCEL rpc to the server;
 787  * LDLM_FL_CANCELING otherwise;
 788  * LDLM_FL_BL_AST if there is a need in a separate CANCEL rpc. */
 789 static int ldlm_cli_cancel_local(struct ldlm_lock *lock)
 790 {
 791         int rc = LDLM_FL_LOCAL_ONLY;
 792         ENTRY;
 793
 794         if (lock->l_conn_export) {
 795                 int local_only;
 796
 797                 LDLM_DEBUG(lock, "client-side cancel");
 798                 /* Set this flag to prevent others from getting new references*/
 799                 lock_res_and_lock(lock);
 800                 lock->l_flags |= LDLM_FL_CBPENDING;
 801                 local_only = (lock->l_flags &
 802                               (LDLM_FL_LOCAL_ONLY|LDLM_FL_CANCEL_ON_BLOCK));
 803                 ldlm_cancel_callback(lock);
 804                 rc = (lock->l_flags & LDLM_FL_BL_AST) ?
 805                         LDLM_FL_BL_AST : LDLM_FL_CANCELING;
 806                 unlock_res_and_lock(lock);
 807
 808                 if (local_only) {
 809                         CDEBUG(D_DLMTRACE, "not sending request (at caller's "
 810                                "instruction)\n");
 811                         rc = LDLM_FL_LOCAL_ONLY;
 812                 }
 813                 ldlm_lock_cancel(lock);
 814         } else {
 815                 if (lock->l_resource->lr_namespace->ns_client) {
 816                         LDLM_ERROR(lock, "Trying to cancel local lock");
 817                         LBUG();
 818                 }
 819                 LDLM_DEBUG(lock, "server-side local cancel");
 820                 ldlm_lock_cancel(lock);
 821                 ldlm_reprocess_all(lock->l_resource);
 822                 LDLM_DEBUG(lock, "server-side local cancel handler END");
 823         }
 824
 825         RETURN(rc);
 826 }
 827
 828 /* Pack @count locks in @head into ldlm_request buffer at the offset @off,
 829    of the request @req. */
 830 static void ldlm_cancel_pack(struct ptlrpc_request *req, int off,
 831                              struct list_head *head, int count)
 832 {
 833         struct ldlm_request *dlm;
 834         struct ldlm_lock *lock;
 835         int max, packed = 0;
 836         ENTRY;
 837
 838         dlm = lustre_msg_buf(req->rq_reqmsg, off, sizeof(*dlm));
 839         LASSERT(dlm != NULL);
 840
 841         /* Check the room in the request buffer. */
 842         max = lustre_msg_buflen(req->rq_reqmsg, off) -
 843                 sizeof(struct ldlm_request);
 844         max /= sizeof(struct lustre_handle);
 845         max += LDLM_LOCKREQ_HANDLES;
 846         LASSERT(max >= dlm->lock_count + count);
 847
 848         /* XXX: it would be better to pack lock handles grouped by resource.
 849          * so that the server cancel would call filter_lvbo_update() less
 850          * frequently. */
 851         list_for_each_entry(lock, head, l_bl_ast) {
 852                 if (!count--)
 853                         break;
 854                 LASSERT(lock->l_conn_export);
 855                 /* Pack the lock handle to the given request buffer. */
 856                 LDLM_DEBUG(lock, "packing");
 857                 dlm->lock_handle[dlm->lock_count++] = lock->l_remote_handle;
 858                 packed++;
 859         }
 860         CDEBUG(D_DLMTRACE, "%d locks packed\n", packed);
 861         EXIT;
 862 }
 863
 864 /* Prepare and send a batched cancel rpc, it will include count lock handles
 865  * of locks given in @head. */
 866 int ldlm_cli_cancel_req(struct obd_export *exp, struct list_head *cancels,
 867                         int count, int flags)
 868 {
 869         struct ptlrpc_request *req = NULL;
 870         struct ldlm_request *body;
 871         int size[2] = { [MSG_PTLRPC_BODY_OFF] = sizeof(struct ptlrpc_body),
 872                 [DLM_LOCKREQ_OFF]     = sizeof(*body) };
 873         struct obd_import *imp;
 874         int free, sent = 0;
 875         int rc = 0;
 876         ENTRY;
 877
 878         LASSERT(exp != NULL);
 879         LASSERT(count > 0);
 880
 881         if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_CANCEL_RACE))
 882                 RETURN(count);
 883
 884         free = ldlm_req_handles_avail(exp, size, 2, 0);
 885         if (count > free)
 886                 count = free;
 887
 888         size[DLM_LOCKREQ_OFF] = ldlm_request_bufsize(count, LDLM_CANCEL);
 889         while (1) {
 890                 imp = class_exp2cliimp(exp);
 891                 if (imp == NULL || imp->imp_invalid) {
 892                         CDEBUG(D_HA, "skipping cancel on invalid import %p\n",
 893                                imp);
 894                         break;
 895                 }
 896
 897                 req = ptlrpc_prep_req(imp, LUSTRE_DLM_VERSION, LDLM_CANCEL, 2,
 898                                       size, NULL);
 899                 if (!req)
 900                         GOTO(out, rc = -ENOMEM);
 901
 902                 req->rq_no_resend = 1;
 903                 req->rq_no_delay = 1;
 904
 905                 /* XXX FIXME bug 249 */
 906                 req->rq_request_portal = LDLM_CANCEL_REQUEST_PORTAL;
 907                 req->rq_reply_portal = LDLM_CANCEL_REPLY_PORTAL;
 908
 909                 body = lustre_msg_buf(req->rq_reqmsg, DLM_LOCKREQ_OFF,
 910                                       sizeof(*body));
 911                 ldlm_cancel_pack(req, DLM_LOCKREQ_OFF, cancels, count);
 912
 913                 ptlrpc_req_set_repsize(req, 1, NULL);
 914                 if (flags & LDLM_FL_ASYNC) {
 915                         ptlrpcd_add_req(req);
 916                         sent = count;
 917                         GOTO(out, 0);
 918                 } else {
 919                         rc = ptlrpc_queue_wait(req);
 920                 }
 921                 if (rc == ESTALE) {
 922                         CDEBUG(D_DLMTRACE, "client/server (nid %s) "
 923                                "out of sync -- not fatal\n",
 924                                libcfs_nid2str(req->rq_import->
 925                                               imp_connection->c_peer.nid));
 926                         rc = 0;
 927                 } else if (rc == -ETIMEDOUT && /* check there was no reconnect*/
 928                            req->rq_import_generation == imp->imp_generation) {
 929                         ptlrpc_req_finished(req);
 930                         continue;
 931                 } else if (rc != ELDLM_OK) {
 932                         CERROR("Got rc %d from cancel RPC: canceling "
 933                                "anyway\n", rc);
 934                         break;
 935                 }
 936                 sent = count;
 937                 break;
 938         }
 939
 940         ptlrpc_req_finished(req);
 941         EXIT;
 942 out:
 943         return sent ? sent : rc;
 944 }
 945
 946 static inline struct ldlm_pool *ldlm_imp2pl(struct obd_import *imp)
 947 {
 948         LASSERT(imp != NULL);
 949         return &imp->imp_obd->obd_namespace->ns_pool;
 950 }
 951
 952 int ldlm_cli_update_pool(struct ptlrpc_request *req)
 953 {
 954         struct ldlm_pool *pl;
 955         ENTRY;
 956
 957         if (!imp_connect_lru_resize(req->rq_import))
 958                 RETURN(0);
 959
 960         pl = ldlm_imp2pl(req->rq_import);
 961
 962         spin_lock(&pl->pl_lock);
 963 #ifdef __KERNEL__
 964         {
 965                 __u64 old_slv, fast_slv_change;
 966
 967                 old_slv = ldlm_pool_get_slv(pl);
 968                 fast_slv_change = old_slv * LDLM_POOLS_FAST_SLV_CHANGE;
 969                 do_div(fast_slv_change, 100);
 970 #endif
 971                 pl->pl_update_time = cfs_time_current();
 972                 ldlm_pool_set_slv(pl, lustre_msg_get_slv(req->rq_repmsg));
 973                 ldlm_pool_set_limit(pl, lustre_msg_get_limit(req->rq_repmsg));
 974 #ifdef __KERNEL__
 975                 /* Wake up pools thread only if SLV has changed more than
 976                  * 5% since last update. In this case we want to react asap.
 977                  * Otherwise it is no sense to wake up pools as they are
 978                  * re-calculated every 1s anyways. */
 979                 if (old_slv > ldlm_pool_get_slv(pl) &&
 980                     old_slv - ldlm_pool_get_slv(pl) > fast_slv_change)
 981                         ldlm_pools_wakeup();
 982         }
 983 #endif
 984         spin_unlock(&pl->pl_lock);
 985
 986         RETURN(0);
 987 }
 988 EXPORT_SYMBOL(ldlm_cli_update_pool);
 989
 990 int ldlm_cli_cancel(struct lustre_handle *lockh)
 991 {
 992         struct ldlm_lock *lock;
 993         CFS_LIST_HEAD(cancels);
 994         int rc = 0;
 995         ENTRY;
 996
 997         /* concurrent cancels on the same handle can happen */
 998         lock = __ldlm_handle2lock(lockh, LDLM_FL_CANCELING);
 999         if (lock == NULL) {
1000                 LDLM_DEBUG_NOLOCK("lock is already being destroyed\n");
1001                 RETURN(0);
1002         }
1003
1004         rc = ldlm_cli_cancel_local(lock);
1005         list_add(&lock->l_bl_ast, &cancels);
1006
1007         if (rc == LDLM_FL_BL_AST) {
1008                 rc = ldlm_cli_cancel_req(lock->l_conn_export, &cancels, 1, 0);
1009         } else if (rc == LDLM_FL_CANCELING) {
1010                 int avail = ldlm_cancel_handles_avail(lock->l_conn_export);
1011                 int count = 1;
1012                 LASSERT(avail > 0);
1013                 count += ldlm_cancel_lru_local(lock->l_resource->lr_namespace,
1014                                                &cancels, 0, avail - 1,
1015                                                LDLM_CANCEL_AGED);
1016                 ldlm_cli_cancel_list(&cancels, count, NULL, 0, 0);
1017         }
1018         if (rc != LDLM_FL_CANCELING)
1019                 LDLM_LOCK_PUT(lock);
1020         RETURN(rc < 0 ? rc : 0);
1021 }
1022
1023 /* - Free space in lru for @count new locks,
1024  *   redundant unused locks are canceled locally;
1025  * - also cancel locally unused aged locks;
1026  * - do not cancel more than @max locks;
1027  * - GET the found locks and add them into the @cancels list.
1028  *
1029  * A client lock can be added to the l_bl_ast list only when it is
1030  * marked LDLM_FL_CANCELING. Otherwise, somebody is already doing CANCEL.
1031  * There are the following use cases: ldlm_cancel_resource_local(),
1032  * ldlm_cancel_lru_local() and ldlm_cli_cancel(), which check&set this
1033  * flag properly. As any attempt to cancel a lock rely on this flag,
1034  * l_bl_ast list is accessed later without any special locking. */
1035 int ldlm_cancel_lru_local(struct ldlm_namespace *ns, struct list_head *cancels,
1036                           int count, int max, int flags)
1037 {
1038         cfs_time_t cur = cfs_time_current();
1039         int rc, added = 0, left, unused;
1040         struct ldlm_lock *lock, *next;
1041         __u64 slv, lvf, lv;
1042         ENTRY;
1043
1044         spin_lock(&ns->ns_unused_lock);
1045         unused = ns->ns_nr_unused;
1046
1047         if (!ns_connect_lru_resize(ns))
1048                 count += unused - ns->ns_max_unused;
1049
1050         while (!list_empty(&ns->ns_unused_list)) {
1051                 struct ldlm_pool *pl = &ns->ns_pool;
1052
1053                 if (max && added >= max)
1054                         break;
1055
1056                 list_for_each_entry(lock, &ns->ns_unused_list, l_lru) {
1057                         /* somebody is already doing CANCEL or there is a
1058                          * blocking request will send cancel. */
1059                         if (!(lock->l_flags & LDLM_FL_CANCELING) &&
1060                             !(lock->l_flags & LDLM_FL_BL_AST))
1061                                 break;
1062                 }
1063                 if (&lock->l_lru == &ns->ns_unused_list)
1064                         break;
1065
1066                 if (ns_connect_lru_resize(ns)) {
1067                         cfs_time_t la;
1068
1069                         /* Take into account SLV only if cpount == 0. */
1070                         if (count == 0) {
1071                                 /* Calculate lv for every lock. */
1072                                 spin_lock(&pl->pl_lock);
1073                                 slv = ldlm_pool_get_slv(pl);
1074                                 lvf = atomic_read(&pl->pl_lock_volume_factor);
1075                                 spin_unlock(&pl->pl_lock);
1076
1077                                 la = cfs_duration_sec(cfs_time_sub(cur,
1078                                                       lock->l_last_used));
1079                                 if (la == 0)
1080                                         la = 1;
1081
1082                                 /* Stop when slv is not yet come from server
1083                                  * or lv is smaller than it is. */
1084                                 lv = lvf * la * unused;
1085                                 if (slv == 1 || lv < slv)
1086                                         break;
1087                         } else {
1088                                 if (added >= count)
1089                                         break;
1090                         }
1091                 } else {
1092                         if ((added >= count) &&
1093                             (!(flags & LDLM_CANCEL_AGED) ||
1094                              cfs_time_before_64(cur, ns->ns_max_age +
1095                                                 lock->l_last_used)))
1096                                 break;
1097                 }
1098
1099                 LDLM_LOCK_GET(lock); /* dropped by bl thread */
1100                 spin_unlock(&ns->ns_unused_lock);
1101
1102                 lock_res_and_lock(lock);
1103                 /* Check flags again under the lock. */
1104                 if ((lock->l_flags & LDLM_FL_CANCELING) ||
1105                     (lock->l_flags & LDLM_FL_BL_AST) ||
1106                     (ldlm_lock_remove_from_lru(lock) == 0)) {
1107                         /* other thread is removing lock from lru or
1108                          * somebody is already doing CANCEL or
1109                          * there is a blocking request which will send
1110                          * cancel by itseft. */
1111                         unlock_res_and_lock(lock);
1112                         LDLM_LOCK_PUT(lock);
1113                         spin_lock(&ns->ns_unused_lock);
1114                         continue;
1115                 }
1116                 LASSERT(!lock->l_readers && !lock->l_writers);
1117
1118                 /* If we have chosen to canecl this lock voluntarily, we better
1119                    send cancel notification to server, so that it frees
1120                    appropriate state. This might lead to a race where while
1121                    we are doing cancel here, server is also silently
1122                    cancelling this lock. */
1123                 lock->l_flags &= ~LDLM_FL_CANCEL_ON_BLOCK;
1124
1125                 /* Setting the CBPENDING flag is a little misleading, but
1126                  * prevents an important race; namely, once CBPENDING is set,
1127                  * the lock can accumulate no more readers/writers.  Since
1128                  * readers and writers are already zero here, ldlm_lock_decref
1129                  * won't see this flag and call l_blocking_ast */
1130                 lock->l_flags |= LDLM_FL_CBPENDING | LDLM_FL_CANCELING;
1131                 /* We can't re-add to l_lru as it confuses the refcounting in
1132                  * ldlm_lock_remove_from_lru() if an AST arrives after we drop
1133                  * ns_lock below. We use l_bl_ast and can't use l_pending_chain
1134                  * as it is used both on server and client nevertheles bug 5666
1135                  * says it is used only on server. --umka */
1136
1137                 LASSERT(list_empty(&lock->l_bl_ast));
1138                 list_add(&lock->l_bl_ast, cancels);
1139                 unlock_res_and_lock(lock);
1140                 spin_lock(&ns->ns_unused_lock);
1141                 added++;
1142                 unused--;
1143         }
1144         spin_unlock(&ns->ns_unused_lock);
1145
1146         /* Handle only @added inserted locks. */
1147         left = added;
1148         list_for_each_entry_safe(lock, next, cancels, l_bl_ast) {
1149                 if (left-- == 0)
1150                         break;
1151
1152                 rc = ldlm_cli_cancel_local(lock);
1153                 if (rc == LDLM_FL_BL_AST) {
1154                         CFS_LIST_HEAD(head);
1155
1156                         LDLM_DEBUG(lock, "Cancel lock separately");
1157                         list_del_init(&lock->l_bl_ast);
1158                         list_add(&lock->l_bl_ast, &head);
1159                         ldlm_cli_cancel_req(lock->l_conn_export, &head, 1, 0);
1160                         rc = LDLM_FL_LOCAL_ONLY;
1161                 }
1162                 if (rc == LDLM_FL_LOCAL_ONLY) {
1163                         /* CANCEL RPC should not be sent to server. */
1164                         list_del_init(&lock->l_bl_ast);
1165                         LDLM_LOCK_PUT(lock);
1166                         added--;
1167                 }
1168
1169         }
1170         RETURN(added);
1171 }
1172
1173 /* when called with LDLM_ASYNC the blocking callback will be handled
1174  * in a thread and this function will return after the thread has been
1175  * asked to call the callback.  when called with LDLM_SYNC the blocking
1176  * callback will be performed in this function. */
1177 int ldlm_cancel_lru(struct ldlm_namespace *ns, int nr, ldlm_sync_t sync)
1178 {
1179         CFS_LIST_HEAD(cancels);
1180         int count, rc;
1181         ENTRY;
1182
1183 #ifndef __KERNEL__
1184         sync = LDLM_SYNC; /* force to be sync in user space */
1185 #endif
1186         count = ldlm_cancel_lru_local(ns, &cancels, nr, 0, 0);
1187         if (sync == LDLM_ASYNC) {
1188                 rc = ldlm_bl_to_thread_list(ns, NULL, &cancels, count);
1189                 if (rc == 0)
1190                         RETURN(count);
1191         }
1192
1193         /* If an error occured in ASYNC mode, or
1194          * this is SYNC mode, cancel the list. */
1195         ldlm_cli_cancel_list(&cancels, count, NULL, 0, 0);
1196         RETURN(count);
1197 }
1198
1199 /* Find and cancel locally unused locks found on resource, matched to the
1200  * given policy, mode. GET the found locks and add them into the @cancels
1201  * list. */
1202 int ldlm_cancel_resource_local(struct ldlm_resource *res,
1203                                struct list_head *cancels,
1204                                ldlm_policy_data_t *policy,
1205                                ldlm_mode_t mode, int lock_flags,
1206                                int flags, void *opaque)
1207 {
1208         struct ldlm_lock *lock, *next;
1209         int count = 0, left;
1210         ENTRY;
1211
1212         lock_res(res);
1213         list_for_each_entry(lock, &res->lr_granted, l_res_link) {
1214                 if (opaque != NULL && lock->l_ast_data != opaque) {
1215                         LDLM_ERROR(lock, "data %p doesn't match opaque %p",
1216                                    lock->l_ast_data, opaque);
1217                         //LBUG();
1218                         continue;
1219                 }
1220
1221                 if (lock->l_readers || lock->l_writers) {
1222                         if (flags & LDLM_FL_WARN) {
1223                                 LDLM_ERROR(lock, "lock in use");
1224                                 //LBUG();
1225                         }
1226                         continue;
1227                 }
1228
1229                 /* If somebody is already doing CANCEL, or blocking ast came,
1230                  * skip this lock. */
1231                 if (lock->l_flags & LDLM_FL_BL_AST ||
1232                     lock->l_flags & LDLM_FL_CANCELING)
1233                         continue;
1234
1235                 if (lockmode_compat(lock->l_granted_mode, mode))
1236                         continue;
1237
1238                 /* If policy is given and this is IBITS lock, add to list only
1239                  * those locks that match by policy. */
1240                 if (policy && (lock->l_resource->lr_type == LDLM_IBITS) &&
1241                     !(lock->l_policy_data.l_inodebits.bits &
1242                       policy->l_inodebits.bits))
1243                         continue;
1244
1245                 /* See CBPENDING comment in ldlm_cancel_lru */
1246                 lock->l_flags |= LDLM_FL_CBPENDING | LDLM_FL_CANCELING |
1247                         lock_flags;
1248
1249                 LASSERT(list_empty(&lock->l_bl_ast));
1250                 list_add(&lock->l_bl_ast, cancels);
1251                 LDLM_LOCK_GET(lock);
1252                 count++;
1253         }
1254         unlock_res(res);
1255
1256         /* Handle only @count inserted locks. */
1257         left = count;
1258         list_for_each_entry_safe(lock, next, cancels, l_bl_ast) {
1259                 int rc = LDLM_FL_LOCAL_ONLY;
1260
1261                 if (left-- == 0)
1262                         break;
1263                 if (flags & LDLM_FL_LOCAL_ONLY)
1264                         ldlm_lock_cancel(lock);
1265                 else
1266                         rc = ldlm_cli_cancel_local(lock);
1267
1268                 if (rc == LDLM_FL_BL_AST) {
1269                         CFS_LIST_HEAD(head);
1270
1271                         LDLM_DEBUG(lock, "Cancel lock separately");
1272                         list_del_init(&lock->l_bl_ast);
1273                         list_add(&lock->l_bl_ast, &head);
1274                         ldlm_cli_cancel_req(lock->l_conn_export, &head, 1, 0);
1275                         rc = LDLM_FL_LOCAL_ONLY;
1276                 }
1277                 if (rc == LDLM_FL_LOCAL_ONLY) {
1278                         /* CANCEL RPC should not be sent to server. */
1279                         list_del_init(&lock->l_bl_ast);
1280                         LDLM_LOCK_PUT(lock);
1281                         count--;
1282                 }
1283         }
1284         RETURN(count);
1285 }
1286
1287 /* If @req is NULL, send CANCEL request to server with handles of locks
1288  * in the @cancels. If EARLY_CANCEL is not supported, send CANCEL requests
1289  * separately per lock.
1290  * If @req is not NULL, put handles of locks in @cancels into the request
1291  * buffer at the offset @off.
1292  * Destroy @cancels at the end. */
1293 int ldlm_cli_cancel_list(struct list_head *cancels, int count,
1294                          struct ptlrpc_request *req, int off, int flags)
1295 {
1296         struct ldlm_lock *lock;
1297         int res = 0;
1298         ENTRY;
1299
1300         if (list_empty(cancels) || count == 0)
1301                 RETURN(0);
1302
1303         /* XXX: requests (both batched and not) could be sent in parallel.
1304          * Usually it is enough to have just 1 RPC, but it is possible that
1305          * there are to many locks to be cancelled in LRU or on a resource.
1306          * It would also speed up the case when the server does not support
1307          * the feature. */
1308         while (count > 0) {
1309                 LASSERT(!list_empty(cancels));
1310                 lock = list_entry(cancels->next, struct ldlm_lock, l_bl_ast);
1311                 LASSERT(lock->l_conn_export);
1312
1313                 if (exp_connect_cancelset(lock->l_conn_export)) {
1314                         res = count;
1315                         if (req)
1316                                 ldlm_cancel_pack(req, off, cancels, count);
1317                         else
1318                                 res = ldlm_cli_cancel_req(lock->l_conn_export,
1319                                                           cancels, count, flags);
1320                 } else {
1321                         res = ldlm_cli_cancel_req(lock->l_conn_export,
1322                                                   cancels, 1, flags);
1323                 }
1324
1325                 if (res < 0) {
1326                         CERROR("ldlm_cli_cancel_list: %d\n", res);
1327                         res = count;
1328                 }
1329
1330                 count -= res;
1331                 ldlm_lock_list_put(cancels, l_bl_ast, res);
1332         }
1333         LASSERT(list_empty(cancels));
1334         LASSERT(count == 0);
1335         RETURN(0);
1336 }
1337
1338 int ldlm_cli_cancel_unused_resource(struct ldlm_namespace *ns,
1339                                     const struct ldlm_res_id *res_id,
1340                                     ldlm_policy_data_t *policy,
1341                                     ldlm_mode_t mode, int flags, void *opaque)
1342 {
1343         struct ldlm_resource *res;
1344         CFS_LIST_HEAD(cancels);
1345         int count;
1346         int rc;
1347         ENTRY;
1348
1349         res = ldlm_resource_get(ns, NULL, res_id, 0, 0);
1350         if (res == NULL) {
1351                 /* This is not a problem. */
1352                 CDEBUG(D_INFO, "No resource "LPU64"\n", res_id->name[0]);
1353                 RETURN(0);
1354         }
1355
1356         count = ldlm_cancel_resource_local(res, &cancels, policy, mode,
1357                                            0, flags, opaque);
1358         rc = ldlm_cli_cancel_list(&cancels, count, NULL, 0, flags);
1359         if (rc != ELDLM_OK)
1360                 CERROR("ldlm_cli_cancel_unused_resource: %d\n", rc);
1361
1362         ldlm_resource_putref(res);
1363         RETURN(0);
1364 }
1365
1366 static inline int have_no_nsresource(struct ldlm_namespace *ns)
1367 {
1368         int no_resource = 0;
1369
1370         spin_lock(&ns->ns_hash_lock);
1371         if (ns->ns_resources == 0)
1372                 no_resource = 1;
1373         spin_unlock(&ns->ns_hash_lock);
1374
1375         RETURN(no_resource);
1376 }
1377
1378 /* Cancel all locks on a namespace (or a specific resource, if given)
1379  * that have 0 readers/writers.
1380  *
1381  * If flags & LDLM_FL_LOCAL_ONLY, throw the locks away without trying
1382  * to notify the server. */
1383 int ldlm_cli_cancel_unused(struct ldlm_namespace *ns,
1384                            const struct ldlm_res_id *res_id,
1385                            int flags, void *opaque)
1386 {
1387         int i;
1388         ENTRY;
1389
1390         if (ns == NULL)
1391                 RETURN(ELDLM_OK);
1392
1393         if (res_id)
1394                 RETURN(ldlm_cli_cancel_unused_resource(ns, res_id, NULL,
1395                                                        LCK_MINMODE, flags,
1396                                                        opaque));
1397
1398         spin_lock(&ns->ns_hash_lock);
1399         for (i = 0; i < RES_HASH_SIZE; i++) {
1400                 struct list_head *tmp;
1401                 tmp = ns->ns_hash[i].next;
1402                 while (tmp != &(ns->ns_hash[i])) {
1403                         struct ldlm_resource *res;
1404                         int rc;
1405
1406                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
1407                         ldlm_resource_getref(res);
1408                         spin_unlock(&ns->ns_hash_lock);
1409
1410                         rc = ldlm_cli_cancel_unused_resource(ns, &res->lr_name,
1411                                                              NULL, LCK_MINMODE,
1412                                                              flags, opaque);
1413
1414                         if (rc)
1415                                 CERROR("ldlm_cli_cancel_unused ("LPU64"): %d\n",
1416                                        res->lr_name.name[0], rc);
1417
1418                         spin_lock(&ns->ns_hash_lock);
1419                         tmp = tmp->next;
1420                         ldlm_resource_putref_locked(res);
1421                 }
1422         }
1423         spin_unlock(&ns->ns_hash_lock);
1424
1425         RETURN(ELDLM_OK);
1426 }
1427
1428 /* join/split resource locks to/from lru list */
1429 int ldlm_cli_join_lru(struct ldlm_namespace *ns,
1430                       const struct ldlm_res_id *res_id, int join)
1431 {
1432         struct ldlm_resource *res;
1433         struct ldlm_lock *lock, *n;
1434         int count = 0;
1435         ENTRY;
1436
1437         LASSERT(ns->ns_client == LDLM_NAMESPACE_CLIENT);
1438
1439         res = ldlm_resource_get(ns, NULL, res_id, LDLM_EXTENT, 0);
1440         if (res == NULL)
1441                 RETURN(count);
1442         LASSERT(res->lr_type == LDLM_EXTENT);
1443
1444         lock_res(res);
1445         if (!join)
1446                 goto split;
1447
1448         list_for_each_entry_safe (lock, n, &res->lr_granted, l_res_link) {
1449                 if (list_empty(&lock->l_lru) &&
1450                     !lock->l_readers && !lock->l_writers &&
1451                     !(lock->l_flags & LDLM_FL_LOCAL) &&
1452                     !(lock->l_flags & LDLM_FL_CBPENDING)) {
1453                         ldlm_lock_add_to_lru(lock);
1454                         lock->l_flags &= ~LDLM_FL_NO_LRU;
1455                         LDLM_DEBUG(lock, "join lock to lru");
1456                         count++;
1457                 }
1458         }
1459         goto unlock;
1460 split:
1461         spin_lock(&ns->ns_unused_lock);
1462         list_for_each_entry_safe (lock, n, &ns->ns_unused_list, l_lru) {
1463                 if (lock->l_resource == res) {
1464                         ldlm_lock_remove_from_lru_nolock(lock);
1465                         lock->l_flags |= LDLM_FL_NO_LRU;
1466                         LDLM_DEBUG(lock, "split lock from lru");
1467                         count++;
1468                 }
1469         }
1470         spin_unlock(&ns->ns_unused_lock);
1471 unlock:
1472         unlock_res(res);
1473         ldlm_resource_putref(res);
1474         RETURN(count);
1475 }
1476
1477 /* Lock iterators. */
1478
1479 int ldlm_resource_foreach(struct ldlm_resource *res, ldlm_iterator_t iter,
1480                           void *closure)
1481 {
1482         struct list_head *tmp, *next;
1483         struct ldlm_lock *lock;
1484         int rc = LDLM_ITER_CONTINUE;
1485
1486         ENTRY;
1487
1488         if (!res)
1489                 RETURN(LDLM_ITER_CONTINUE);
1490
1491         lock_res(res);
1492         list_for_each_safe(tmp, next, &res->lr_granted) {
1493                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
1494
1495                 if (iter(lock, closure) == LDLM_ITER_STOP)
1496                         GOTO(out, rc = LDLM_ITER_STOP);
1497         }
1498
1499         list_for_each_safe(tmp, next, &res->lr_converting) {
1500                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
1501
1502                 if (iter(lock, closure) == LDLM_ITER_STOP)
1503                         GOTO(out, rc = LDLM_ITER_STOP);
1504         }
1505
1506         list_for_each_safe(tmp, next, &res->lr_waiting) {
1507                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
1508
1509                 if (iter(lock, closure) == LDLM_ITER_STOP)
1510                         GOTO(out, rc = LDLM_ITER_STOP);
1511         }
1512  out:
1513         unlock_res(res);
1514         RETURN(rc);
1515 }
1516
1517 struct iter_helper_data {
1518         ldlm_iterator_t iter;
1519         void *closure;
1520 };
1521
1522 static int ldlm_iter_helper(struct ldlm_lock *lock, void *closure)
1523 {
1524         struct iter_helper_data *helper = closure;
1525         return helper->iter(lock, helper->closure);
1526 }
1527
1528 static int ldlm_res_iter_helper(struct ldlm_resource *res, void *closure)
1529 {
1530         return ldlm_resource_foreach(res, ldlm_iter_helper, closure);
1531 }
1532
1533 int ldlm_namespace_foreach(struct ldlm_namespace *ns, ldlm_iterator_t iter,
1534                            void *closure)
1535 {
1536         struct iter_helper_data helper = { iter: iter, closure: closure };
1537         return ldlm_namespace_foreach_res(ns, ldlm_res_iter_helper, &helper);
1538 }
1539
1540 int ldlm_namespace_foreach_res(struct ldlm_namespace *ns,
1541                                ldlm_res_iterator_t iter, void *closure)
1542 {
1543         int i, rc = LDLM_ITER_CONTINUE;
1544         struct ldlm_resource *res;
1545         struct list_head *tmp;
1546
1547         ENTRY;
1548         spin_lock(&ns->ns_hash_lock);
1549         for (i = 0; i < RES_HASH_SIZE; i++) {
1550                 tmp = ns->ns_hash[i].next;
1551                 while (tmp != &(ns->ns_hash[i])) {
1552                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
1553                         ldlm_resource_getref(res);
1554                         spin_unlock(&ns->ns_hash_lock);
1555
1556                         rc = iter(res, closure);
1557
1558                         spin_lock(&ns->ns_hash_lock);
1559                         tmp = tmp->next;
1560                         ldlm_resource_putref_locked(res);
1561                         if (rc == LDLM_ITER_STOP)
1562                                 GOTO(out, rc);
1563                 }
1564         }
1565  out:
1566         spin_unlock(&ns->ns_hash_lock);
1567         RETURN(rc);
1568 }
1569
1570 /* non-blocking function to manipulate a lock whose cb_data is being put away.*/
1571 void ldlm_resource_iterate(struct ldlm_namespace *ns,
1572                            const struct ldlm_res_id *res_id,
1573                            ldlm_iterator_t iter, void *data)
1574 {
1575         struct ldlm_resource *res;
1576         ENTRY;
1577
1578         if (ns == NULL) {
1579                 CERROR("must pass in namespace\n");
1580                 LBUG();
1581         }
1582
1583         res = ldlm_resource_get(ns, NULL, res_id, 0, 0);
1584         if (res == NULL) {
1585                 EXIT;
1586                 return;
1587         }
1588
1589         ldlm_resource_foreach(res, iter, data);
1590         ldlm_resource_putref(res);
1591         EXIT;
1592 }
1593
1594 /* Lock replay */
1595
1596 static int ldlm_chain_lock_for_replay(struct ldlm_lock *lock, void *closure)
1597 {
1598         struct list_head *list = closure;
1599
1600         /* we use l_pending_chain here, because it's unused on clients. */
1601         LASSERTF(list_empty(&lock->l_pending_chain),"lock %p next %p prev %p\n",
1602                  lock, &lock->l_pending_chain.next,&lock->l_pending_chain.prev);
1603         /* bug 9573: don't replay locks left after eviction */
1604         if (!(lock->l_flags & LDLM_FL_FAILED))
1605                 list_add(&lock->l_pending_chain, list);
1606         return LDLM_ITER_CONTINUE;
1607 }
1608
1609 static int replay_lock_interpret(struct ptlrpc_request *req,
1610                                  struct ldlm_async_args *aa, int rc)
1611 {
1612         struct ldlm_lock *lock;
1613         struct ldlm_reply *reply;
1614
1615         ENTRY;
1616         atomic_dec(&req->rq_import->imp_replay_inflight);
1617         if (rc != ELDLM_OK)
1618                 GOTO(out, rc);
1619
1620
1621         reply = lustre_swab_repbuf(req, DLM_LOCKREPLY_OFF, sizeof(*reply),
1622                                    lustre_swab_ldlm_reply);
1623         if (reply == NULL) {
1624                 CERROR("Can't unpack ldlm_reply\n");
1625                 GOTO (out, rc = -EPROTO);
1626         }
1627
1628         lock = ldlm_handle2lock(&aa->lock_handle);
1629         if (!lock) {
1630                 CERROR("received replay ack for unknown local cookie "LPX64
1631                        " remote cookie "LPX64 " from server %s id %s\n",
1632                        aa->lock_handle.cookie, reply->lock_handle.cookie,
1633                        req->rq_export->exp_client_uuid.uuid,
1634                        libcfs_id2str(req->rq_peer));
1635                 GOTO(out, rc = -ESTALE);
1636         }
1637
1638         lock->l_remote_handle = reply->lock_handle;
1639         LDLM_DEBUG(lock, "replayed lock:");
1640         ptlrpc_import_recovery_state_machine(req->rq_import);
1641         LDLM_LOCK_PUT(lock);
1642 out:
1643         if (rc != ELDLM_OK)
1644                 ptlrpc_connect_import(req->rq_import, NULL);
1645
1646
1647         RETURN(rc);
1648 }
1649
1650 static int replay_one_lock(struct obd_import *imp, struct ldlm_lock *lock)
1651 {
1652         struct ptlrpc_request *req;
1653         struct ldlm_request *body;
1654         struct ldlm_reply *reply;
1655         struct ldlm_async_args *aa;
1656         int buffers = 2;
1657         int size[3] = { sizeof(struct ptlrpc_body) };
1658         int flags;
1659         ENTRY;
1660
1661
1662         /* Bug 11974: Do not replay a lock which is actively being canceled */
1663         if (lock->l_flags & LDLM_FL_CANCELING) {
1664                 LDLM_DEBUG(lock, "Not replaying canceled lock:");
1665                 RETURN(0);
1666         }
1667
1668         /* If this is reply-less callback lock, we cannot replay it, since
1669          * server might have long dropped it, but notification of that event was
1670          * lost by network. (and server granted conflicting lock already) */
1671         if (lock->l_flags & LDLM_FL_CANCEL_ON_BLOCK) {
1672                 LDLM_DEBUG(lock, "Not replaying reply-less lock:");
1673                 ldlm_lock_cancel(lock);
1674                 RETURN(0);
1675         }
1676         /*
1677          * If granted mode matches the requested mode, this lock is granted.
1678          *
1679          * If they differ, but we have a granted mode, then we were granted
1680          * one mode and now want another: ergo, converting.
1681          *
1682          * If we haven't been granted anything and are on a resource list,
1683          * then we're blocked/waiting.
1684          *
1685          * If we haven't been granted anything and we're NOT on a resource list,
1686          * then we haven't got a reply yet and don't have a known disposition.
1687          * This happens whenever a lock enqueue is the request that triggers
1688          * recovery.
1689          */
1690         if (lock->l_granted_mode == lock->l_req_mode)
1691                 flags = LDLM_FL_REPLAY | LDLM_FL_BLOCK_GRANTED;
1692         else if (lock->l_granted_mode)
1693                 flags = LDLM_FL_REPLAY | LDLM_FL_BLOCK_CONV;
1694         else if (!list_empty(&lock->l_res_link))
1695                 flags = LDLM_FL_REPLAY | LDLM_FL_BLOCK_WAIT;
1696         else
1697                 flags = LDLM_FL_REPLAY;
1698
1699         size[DLM_LOCKREQ_OFF] = sizeof(*body);
1700         req = ptlrpc_prep_req(imp, LUSTRE_DLM_VERSION, LDLM_ENQUEUE, 2, size,
1701                               NULL);
1702         if (!req)
1703                 RETURN(-ENOMEM);
1704
1705         /* We're part of recovery, so don't wait for it. */
1706         req->rq_send_state = LUSTRE_IMP_REPLAY_LOCKS;
1707
1708         body = lustre_msg_buf(req->rq_reqmsg, DLM_LOCKREQ_OFF, sizeof(*body));
1709         ldlm_lock2desc(lock, &body->lock_desc);
1710         body->lock_flags = flags;
1711
1712         ldlm_lock2handle(lock, &body->lock_handle[0]);
1713         size[DLM_LOCKREPLY_OFF] = sizeof(*reply);
1714         if (lock->l_lvb_len != 0) {
1715                 buffers = 3;
1716                 size[DLM_REPLY_REC_OFF] = lock->l_lvb_len;
1717         }
1718         ptlrpc_req_set_repsize(req, buffers, size);
1719         /* notify the server we've replayed all requests.
1720          * also, we mark the request to be put on a dedicated
1721          * queue to be processed after all request replayes.
1722          * bug 6063 */
1723         lustre_msg_set_flags(req->rq_reqmsg, MSG_REQ_REPLAY_DONE);
1724
1725         LDLM_DEBUG(lock, "replaying lock:");
1726
1727         atomic_inc(&req->rq_import->imp_replay_inflight);
1728         CLASSERT(sizeof(*aa) <= sizeof(req->rq_async_args));
1729         aa = (struct ldlm_async_args *)&req->rq_async_args;
1730         aa->lock_handle = body->lock_handle[0];
1731         req->rq_interpret_reply = replay_lock_interpret;
1732         ptlrpcd_add_req(req);
1733
1734         RETURN(0);
1735 }
1736
1737 int ldlm_replay_locks(struct obd_import *imp)
1738 {
1739         struct ldlm_namespace *ns = imp->imp_obd->obd_namespace;
1740         struct list_head list;
1741         struct ldlm_lock *lock, *next;
1742         int rc = 0;
1743
1744         ENTRY;
1745         CFS_INIT_LIST_HEAD(&list);
1746
1747         LASSERT(atomic_read(&imp->imp_replay_inflight) == 0);
1748
1749         /* ensure this doesn't fall to 0 before all have been queued */
1750         atomic_inc(&imp->imp_replay_inflight);
1751
1752         (void)ldlm_namespace_foreach(ns, ldlm_chain_lock_for_replay, &list);
1753
1754         list_for_each_entry_safe(lock, next, &list, l_pending_chain) {
1755                 list_del_init(&lock->l_pending_chain);
1756                 if (rc)
1757                         continue; /* or try to do the rest? */
1758                 rc = replay_one_lock(imp, lock);
1759         }
1760
1761         atomic_dec(&imp->imp_replay_inflight);
1762
1763         RETURN(rc);
1764 }