lustre/osp/osp_sync.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2012, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/osp/osp_sync.c
  37  *
  38  * Lustre OST Proxy Device
  39  *
  40  * Author: Alex Zhuravlev <alexey.zhuravlev@intel.com>
  41  * Author: Mikhail Pershin <mike.pershin@intel.com>
  42  */
  43
  44 #ifndef EXPORT_SYMTAB
  45 # define EXPORT_SYMTAB
  46 #endif
  47 #define DEBUG_SUBSYSTEM S_MDS
  48
  49 #include <lustre_log.h>
  50 #include "osp_internal.h"
  51
  52 static int osp_sync_id_traction_init(struct osp_device *d);
  53 static void osp_sync_id_traction_fini(struct osp_device *d);
  54 static __u32 osp_sync_id_get(struct osp_device *d, __u32 id);
  55 static void osp_sync_remove_from_tracker(struct osp_device *d);
  56
  57 /*
  58  * this is a components of OSP implementing synchronization between MDS and OST
  59  * it llogs all interesting changes (currently it's uig/gid change and object
  60  * destroy) atomically, then makes sure changes hit OST storage
  61  *
  62  * we have 4 queues of work:
  63  *
  64  * the first queue is llog itself, once read a change is stored in 2nd queue
  65  * in form of RPC (but RPC isn't fired yet).
  66  *
  67  * the second queue (opd_syn_waiting_for_commit) holds changes awaiting local
  68  * commit. once change is committed locally it migrates onto 3rd queue.
  69  *
  70  * the third queue (opd_syn_committed_here) holds changes committed locally,
  71  * but not sent to OST (as the pipe can be full). once pipe becomes non-full
  72  * we take a change from the queue and fire corresponded RPC.
  73  *
  74  * once RPC is reported committed by OST (using regular last_committed mech.)
  75  * the change jumps into 4th queue (opd_syn_committed_there), now we can
  76  * cancel corresponded llog record and release RPC
  77  *
  78  * opd_syn_changes is a number of unread llog records (to be processed).
  79  * notice this number doesn't include llog records from previous boots.
  80  * with OSP_SYN_THRESHOLD we try to batch processing a bit (TO BE IMPLEMENTED)
  81  *
  82  * opd_syn_rpc_in_progress is a number of requests in 2-4 queues.
  83  * we control this with OSP_MAX_IN_PROGRESS so that OSP don't consume
  84  * too much memory -- how to deal with 1000th OSTs ? batching could help?
  85  *
  86  * opd_syn_rpc_in_flight is a number of RPC in flight.
  87  * we control this with OSP_MAX_IN_FLIGHT
  88  */
  89
  90 /* XXX: do math to learn reasonable threshold
  91  * should it be ~ number of changes fitting bulk? */
  92
  93 #define OSP_SYN_THRESHOLD       10
  94 #define OSP_MAX_IN_FLIGHT       8
  95 #define OSP_MAX_IN_PROGRESS     4096
  96
  97 #define OSP_JOB_MAGIC           0x26112005
  98
  99 static inline int osp_sync_running(struct osp_device *d)
 100 {
 101         return !!(d->opd_syn_thread.t_flags & SVC_RUNNING);
 102 }
 103
 104 static inline int osp_sync_stopped(struct osp_device *d)
 105 {
 106         return !!(d->opd_syn_thread.t_flags & SVC_STOPPED);
 107 }
 108
 109 static inline int osp_sync_has_new_job(struct osp_device *d)
 110 {
 111         return ((d->opd_syn_last_processed_id < d->opd_syn_last_used_id) &&
 112                 (d->opd_syn_last_processed_id < d->opd_syn_last_committed_id))
 113                 || (d->opd_syn_prev_done == 0);
 114 }
 115
 116 static inline int osp_sync_low_in_progress(struct osp_device *d)
 117 {
 118         return d->opd_syn_rpc_in_progress < d->opd_syn_max_rpc_in_progress;
 119 }
 120
 121 static inline int osp_sync_low_in_flight(struct osp_device *d)
 122 {
 123         return d->opd_syn_rpc_in_flight < d->opd_syn_max_rpc_in_flight;
 124 }
 125
 126 static inline int osp_sync_has_work(struct osp_device *d)
 127 {
 128         /* has new/old changes and low in-progress? */
 129         if (osp_sync_has_new_job(d) && osp_sync_low_in_progress(d) &&
 130             osp_sync_low_in_flight(d) && d->opd_imp_connected)
 131                 return 1;
 132
 133         /* has remotely committed? */
 134         if (!cfs_list_empty(&d->opd_syn_committed_there))
 135                 return 1;
 136
 137         return 0;
 138 }
 139
 140 #define osp_sync_check_for_work(d)                      \
 141 {                                                       \
 142         if (osp_sync_has_work(d)) {                     \
 143                 cfs_waitq_signal(&d->opd_syn_waitq);    \
 144         }                                               \
 145 }
 146
 147 void __osp_sync_check_for_work(struct osp_device *d)
 148 {
 149         osp_sync_check_for_work(d);
 150 }
 151
 152 static inline int osp_sync_can_process_new(struct osp_device *d,
 153                                            struct llog_rec_hdr *rec)
 154 {
 155         LASSERT(d);
 156
 157         if (!osp_sync_low_in_progress(d))
 158                 return 0;
 159         if (!osp_sync_low_in_flight(d))
 160                 return 0;
 161         if (!d->opd_imp_connected)
 162                 return 0;
 163         if (d->opd_syn_prev_done == 0)
 164                 return 1;
 165         if (d->opd_syn_changes == 0)
 166                 return 0;
 167         if (rec == NULL || rec->lrh_id <= d->opd_syn_last_committed_id)
 168                 return 1;
 169         return 0;
 170 }
 171
 172 int osp_sync_declare_add(const struct lu_env *env, struct osp_object *o,
 173                          llog_op_type type, struct thandle *th)
 174 {
 175         struct osp_thread_info  *osi = osp_env_info(env);
 176         struct osp_device       *d = lu2osp_dev(o->opo_obj.do_lu.lo_dev);
 177         struct llog_ctxt        *ctxt;
 178         int                      rc;
 179
 180         ENTRY;
 181
 182         /* it's a layering violation, to access internals of th,
 183          * but we can do this as a sanity check, for a while */
 184         LASSERT(th->th_dev == d->opd_storage);
 185
 186         switch (type) {
 187         case MDS_UNLINK64_REC:
 188                 osi->osi_hdr.lrh_len = sizeof(struct llog_unlink64_rec);
 189                 break;
 190         case MDS_SETATTR64_REC:
 191                 osi->osi_hdr.lrh_len = sizeof(struct llog_setattr64_rec);
 192                 break;
 193         default:
 194                 LBUG();
 195         }
 196
 197         /* we want ->dt_trans_start() to allocate per-thandle structure */
 198         th->th_tags |= LCT_OSP_THREAD;
 199
 200         ctxt = llog_get_context(d->opd_obd, LLOG_MDS_OST_ORIG_CTXT);
 201         LASSERT(ctxt);
 202
 203         rc = llog_declare_add(env, ctxt->loc_handle, &osi->osi_hdr, th);
 204         llog_ctxt_put(ctxt);
 205
 206         RETURN(rc);
 207 }
 208
 209 static int osp_sync_add_rec(const struct lu_env *env, struct osp_device *d,
 210                             const struct lu_fid *fid, llog_op_type type,
 211                             int count, struct thandle *th,
 212                             const struct lu_attr *attr)
 213 {
 214         struct osp_thread_info  *osi = osp_env_info(env);
 215         struct llog_ctxt        *ctxt;
 216         struct osp_txn_info     *txn;
 217         int                      rc;
 218
 219         ENTRY;
 220
 221         /* it's a layering violation, to access internals of th,
 222          * but we can do this as a sanity check, for a while */
 223         LASSERT(th->th_dev == d->opd_storage);
 224
 225         switch (type) {
 226         case MDS_UNLINK64_REC:
 227                 osi->osi_hdr.lrh_len = sizeof(osi->osi_unlink);
 228                 osi->osi_hdr.lrh_type = MDS_UNLINK64_REC;
 229                 osi->osi_unlink.lur_fid  = *fid;
 230                 osi->osi_unlink.lur_count = count;
 231                 break;
 232         case MDS_SETATTR64_REC:
 233                 rc = fid_ostid_pack(fid, &osi->osi_oi);
 234                 LASSERT(rc == 0);
 235                 osi->osi_hdr.lrh_len = sizeof(osi->osi_setattr);
 236                 osi->osi_hdr.lrh_type = MDS_SETATTR64_REC;
 237                 osi->osi_setattr.lsr_oid  = osi->osi_oi.oi_id;
 238                 osi->osi_setattr.lsr_oseq = osi->osi_oi.oi_seq;
 239                 LASSERT(attr);
 240                 osi->osi_setattr.lsr_uid = attr->la_uid;
 241                 osi->osi_setattr.lsr_gid = attr->la_gid;
 242                 break;
 243         default:
 244                 LBUG();
 245         }
 246
 247         txn = osp_txn_info(&th->th_ctx);
 248         LASSERT(txn);
 249
 250         txn->oti_current_id = osp_sync_id_get(d, txn->oti_current_id);
 251         osi->osi_hdr.lrh_id = txn->oti_current_id;
 252
 253         ctxt = llog_get_context(d->opd_obd, LLOG_MDS_OST_ORIG_CTXT);
 254         if (ctxt == NULL)
 255                 RETURN(-ENOMEM);
 256         rc = llog_add(env, ctxt->loc_handle, &osi->osi_hdr, &osi->osi_cookie,
 257                       NULL, th);
 258         llog_ctxt_put(ctxt);
 259
 260         CDEBUG(D_OTHER, "%s: new record %lu:%lu:%lu/%lu: %d\n",
 261                d->opd_obd->obd_name,
 262                (unsigned long) osi->osi_cookie.lgc_lgl.lgl_oid,
 263                (unsigned long) osi->osi_cookie.lgc_lgl.lgl_oseq,
 264                (unsigned long) osi->osi_cookie.lgc_lgl.lgl_ogen,
 265                (unsigned long) osi->osi_cookie.lgc_index, rc);
 266
 267         if (rc > 0)
 268                 rc = 0;
 269
 270         if (likely(rc == 0)) {
 271                 spin_lock(&d->opd_syn_lock);
 272                 d->opd_syn_changes++;
 273                 spin_unlock(&d->opd_syn_lock);
 274         }
 275
 276         RETURN(rc);
 277 }
 278
 279 int osp_sync_add(const struct lu_env *env, struct osp_object *o,
 280                  llog_op_type type, struct thandle *th,
 281                  const struct lu_attr *attr)
 282 {
 283         return osp_sync_add_rec(env, lu2osp_dev(o->opo_obj.do_lu.lo_dev),
 284                                 lu_object_fid(&o->opo_obj.do_lu), type, 1,
 285                                 th, attr);
 286 }
 287
 288 int osp_sync_gap(const struct lu_env *env, struct osp_device *d,
 289                  struct lu_fid *fid, int lost, struct thandle *th)
 290 {
 291         return osp_sync_add_rec(env, d, fid, MDS_UNLINK64_REC, lost, th, NULL);
 292 }
 293
 294 /*
 295  * it's quite obvious we can't maintain all the structures in the memory:
 296  * while OST is down, MDS can be processing thousands and thousands of unlinks
 297  * filling persistent llogs and in-core respresentation
 298  *
 299  * this doesn't scale at all. so we need basically the following:
 300  * a) destroy/setattr append llog records
 301  * b) once llog has grown to X records, we process first Y committed records
 302  *
 303  *  once record R is found via llog_process(), it becomes committed after any
 304  *  subsequent commit callback (at the most)
 305  */
 306
 307 /*
 308  * called for each atomic on-disk change (not once per transaction batch)
 309  * and goes over the list
 310  * XXX: should be optimized?
 311  */
 312
 313 /**
 314  * called for each RPC reported committed
 315  */
 316 static void osp_sync_request_commit_cb(struct ptlrpc_request *req)
 317 {
 318         struct osp_device *d = req->rq_cb_data;
 319         struct obd_import *imp = req->rq_import;
 320
 321         CDEBUG(D_HA, "commit req %p, transno "LPU64"\n", req, req->rq_transno);
 322
 323         if (unlikely(req->rq_transno == 0))
 324                 return;
 325
 326         if (unlikely(req->rq_transno > imp->imp_peer_committed_transno)) {
 327                 /* this request was aborted by the shutdown procedure,
 328                  * not committed by the peer.  we should preserve llog
 329                  * record */
 330                 spin_lock(&d->opd_syn_lock);
 331                 d->opd_syn_rpc_in_progress--;
 332                 spin_unlock(&d->opd_syn_lock);
 333                 cfs_waitq_signal(&d->opd_syn_waitq);
 334                 return;
 335         }
 336
 337         /* XXX: what if request isn't committed for very long? */
 338         LASSERT(d);
 339         LASSERT(req->rq_svc_thread == (void *) OSP_JOB_MAGIC);
 340         LASSERT(cfs_list_empty(&req->rq_exp_list));
 341
 342         ptlrpc_request_addref(req);
 343
 344         spin_lock(&d->opd_syn_lock);
 345         cfs_list_add(&req->rq_exp_list, &d->opd_syn_committed_there);
 346         spin_unlock(&d->opd_syn_lock);
 347
 348         /* XXX: some batching wouldn't hurt */
 349         cfs_waitq_signal(&d->opd_syn_waitq);
 350 }
 351
 352 static int osp_sync_interpret(const struct lu_env *env,
 353                               struct ptlrpc_request *req, void *aa, int rc)
 354 {
 355         struct osp_device *d = req->rq_cb_data;
 356
 357         /* XXX: error handling here */
 358         if (req->rq_svc_thread != (void *) OSP_JOB_MAGIC)
 359                 DEBUG_REQ(D_ERROR, req, "bad magic %p\n", req->rq_svc_thread);
 360         LASSERT(req->rq_svc_thread == (void *) OSP_JOB_MAGIC);
 361         LASSERT(d);
 362
 363         CDEBUG(D_HA, "reply req %p/%d, rc %d, transno %u\n", req,
 364                cfs_atomic_read(&req->rq_refcount),
 365                rc, (unsigned) req->rq_transno);
 366         LASSERT(rc || req->rq_transno);
 367
 368         if (rc == -ENOENT) {
 369                 /*
 370                  * we tried to destroy object or update attributes,
 371                  * but object doesn't exist anymore - cancell llog record
 372                  */
 373                 LASSERT(req->rq_transno == 0);
 374                 LASSERT(cfs_list_empty(&req->rq_exp_list));
 375
 376                 ptlrpc_request_addref(req);
 377
 378                 spin_lock(&d->opd_syn_lock);
 379                 cfs_list_add(&req->rq_exp_list, &d->opd_syn_committed_there);
 380                 spin_unlock(&d->opd_syn_lock);
 381
 382                 cfs_waitq_signal(&d->opd_syn_waitq);
 383         } else if (rc) {
 384                 struct obd_import *imp = req->rq_import;
 385                 /*
 386                  * error happened, we'll try to repeat on next boot ?
 387                  */
 388                 LASSERTF(req->rq_transno == 0 ||
 389                          req->rq_import_generation < imp->imp_generation,
 390                          "transno "LPU64", rc %d, gen: req %d, imp %d\n",
 391                          req->rq_transno, rc, req->rq_import_generation,
 392                          imp->imp_generation);
 393                 LASSERT(d->opd_syn_rpc_in_progress > 0);
 394                 if (req->rq_transno == 0) {
 395                         /* this is the last time we see the request
 396                          * if transno is not zero, then commit cb
 397                          * will be called at some point */
 398                         spin_lock(&d->opd_syn_lock);
 399                         d->opd_syn_rpc_in_progress--;
 400                         spin_unlock(&d->opd_syn_lock);
 401                 }
 402
 403                 cfs_waitq_signal(&d->opd_syn_waitq);
 404         } else if (unlikely(d->opd_pre_status == -ENOSPC)) {
 405                 /*
 406                  * if current status is -ENOSPC (lack of free space on OST)
 407                  * then we should poll OST immediately once object destroy
 408                  * is replied
 409                  */
 410                 osp_statfs_need_now(d);
 411         }
 412
 413         LASSERT(d->opd_syn_rpc_in_flight > 0);
 414         spin_lock(&d->opd_syn_lock);
 415         d->opd_syn_rpc_in_flight--;
 416         spin_unlock(&d->opd_syn_lock);
 417         CDEBUG(D_OTHER, "%s: %d in flight, %d in progress\n",
 418                d->opd_obd->obd_name, d->opd_syn_rpc_in_flight,
 419                d->opd_syn_rpc_in_progress);
 420
 421         osp_sync_check_for_work(d);
 422
 423         return 0;
 424 }
 425
 426 /*
 427  * the function walks through list of committed locally changes
 428  * and send them to RPC until the pipe is full
 429  */
 430 static void osp_sync_send_new_rpc(struct osp_device *d,
 431                                   struct ptlrpc_request *req)
 432 {
 433         LASSERT(d->opd_syn_rpc_in_flight <= d->opd_syn_max_rpc_in_flight);
 434         LASSERT(req->rq_svc_thread == (void *) OSP_JOB_MAGIC);
 435
 436         ptlrpcd_add_req(req, PDL_POLICY_ROUND, -1);
 437 }
 438
 439 static struct ptlrpc_request *osp_sync_new_job(struct osp_device *d,
 440                                                struct llog_handle *llh,
 441                                                struct llog_rec_hdr *h,
 442                                                ost_cmd_t op,
 443                                                const struct req_format *format)
 444 {
 445         struct ptlrpc_request   *req;
 446         struct ost_body         *body;
 447         struct obd_import       *imp;
 448         int                      rc;
 449
 450         /* Prepare the request */
 451         imp = d->opd_obd->u.cli.cl_import;
 452         LASSERT(imp);
 453         req = ptlrpc_request_alloc(imp, format);
 454         if (req == NULL)
 455                 RETURN(ERR_PTR(-ENOMEM));
 456
 457         rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, op);
 458         if (rc) {
 459                 ptlrpc_req_finished(req);
 460                 return ERR_PTR(rc);
 461         }
 462
 463         /*
 464          * this is a trick: to save on memory allocations we put cookie
 465          * into the request, but don't set corresponded flag in o_valid
 466          * so that OST doesn't interpret this cookie. once the request
 467          * is committed on OST we take cookie from the request and cancel
 468          */
 469         body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
 470         LASSERT(body);
 471         body->oa.o_lcookie.lgc_lgl = llh->lgh_id;
 472         body->oa.o_lcookie.lgc_subsys = LLOG_MDS_OST_ORIG_CTXT;
 473         body->oa.o_lcookie.lgc_index = h->lrh_index;
 474         CFS_INIT_LIST_HEAD(&req->rq_exp_list);
 475         req->rq_svc_thread = (void *) OSP_JOB_MAGIC;
 476
 477         req->rq_interpret_reply = osp_sync_interpret;
 478         req->rq_commit_cb = osp_sync_request_commit_cb;
 479         req->rq_cb_data = d;
 480
 481         ptlrpc_request_set_replen(req);
 482
 483         return req;
 484 }
 485
 486 static int osp_sync_new_setattr_job(struct osp_device *d,
 487                                     struct llog_handle *llh,
 488                                     struct llog_rec_hdr *h)
 489 {
 490         struct llog_setattr64_rec       *rec = (struct llog_setattr64_rec *)h;
 491         struct ptlrpc_request           *req;
 492         struct ost_body                 *body;
 493
 494         ENTRY;
 495         LASSERT(h->lrh_type == MDS_SETATTR64_REC);
 496
 497         req = osp_sync_new_job(d, llh, h, OST_SETATTR, &RQF_OST_SETATTR);
 498         if (IS_ERR(req))
 499                 RETURN(PTR_ERR(req));
 500
 501         body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
 502         LASSERT(body);
 503         body->oa.o_id  = rec->lsr_oid;
 504         body->oa.o_seq = rec->lsr_oseq;
 505         body->oa.o_uid = rec->lsr_uid;
 506         body->oa.o_gid = rec->lsr_gid;
 507         body->oa.o_valid = OBD_MD_FLGROUP | OBD_MD_FLID |
 508                            OBD_MD_FLUID | OBD_MD_FLGID;
 509
 510         osp_sync_send_new_rpc(d, req);
 511         RETURN(0);
 512 }
 513
 514 /* Old records may be in old format, so we handle that too */
 515 static int osp_sync_new_unlink_job(struct osp_device *d,
 516                                    struct llog_handle *llh,
 517                                    struct llog_rec_hdr *h)
 518 {
 519         struct llog_unlink_rec  *rec = (struct llog_unlink_rec *)h;
 520         struct ptlrpc_request   *req;
 521         struct ost_body         *body;
 522
 523         ENTRY;
 524         LASSERT(h->lrh_type == MDS_UNLINK_REC);
 525
 526         req = osp_sync_new_job(d, llh, h, OST_DESTROY, &RQF_OST_DESTROY);
 527         if (IS_ERR(req))
 528                 RETURN(PTR_ERR(req));
 529
 530         body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
 531         LASSERT(body);
 532         body->oa.o_id  = rec->lur_oid;
 533         body->oa.o_seq = rec->lur_oseq;
 534         body->oa.o_misc = rec->lur_count;
 535         body->oa.o_valid = OBD_MD_FLGROUP | OBD_MD_FLID;
 536         if (rec->lur_count)
 537                 body->oa.o_valid |= OBD_MD_FLOBJCOUNT;
 538
 539         osp_sync_send_new_rpc(d, req);
 540         RETURN(0);
 541 }
 542
 543 static int osp_sync_new_unlink64_job(struct osp_device *d,
 544                                      struct llog_handle *llh,
 545                                      struct llog_rec_hdr *h)
 546 {
 547         struct llog_unlink64_rec        *rec = (struct llog_unlink64_rec *)h;
 548         struct ptlrpc_request           *req;
 549         struct ost_body                 *body;
 550         int                              rc;
 551
 552         ENTRY;
 553         LASSERT(h->lrh_type == MDS_UNLINK64_REC);
 554
 555         req = osp_sync_new_job(d, llh, h, OST_DESTROY, &RQF_OST_DESTROY);
 556         if (IS_ERR(req))
 557                 RETURN(PTR_ERR(req));
 558
 559         body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
 560         if (body == NULL)
 561                 RETURN(-EFAULT);
 562         rc = fid_ostid_pack(&rec->lur_fid, &body->oa.o_oi);
 563         if (rc < 0)
 564                 RETURN(rc);
 565         body->oa.o_misc = rec->lur_count;
 566         body->oa.o_valid = OBD_MD_FLGROUP | OBD_MD_FLID | OBD_MD_FLOBJCOUNT;
 567
 568         osp_sync_send_new_rpc(d, req);
 569         RETURN(0);
 570 }
 571
 572 static int osp_sync_process_record(const struct lu_env *env,
 573                                    struct osp_device *d,
 574                                    struct llog_handle *llh,
 575                                    struct llog_rec_hdr *rec)
 576 {
 577         struct llog_cookie       cookie;
 578         int                      rc = 0;
 579
 580         cookie.lgc_lgl = llh->lgh_id;
 581         cookie.lgc_subsys = LLOG_MDS_OST_ORIG_CTXT;
 582         cookie.lgc_index = rec->lrh_index;
 583
 584         if (unlikely(rec->lrh_type == LLOG_GEN_REC)) {
 585                 struct llog_gen_rec *gen = (struct llog_gen_rec *)rec;
 586
 587                 /* we're waiting for the record generated by this instance */
 588                 LASSERT(d->opd_syn_prev_done == 0);
 589                 if (!memcmp(&d->opd_syn_generation, &gen->lgr_gen,
 590                             sizeof(gen->lgr_gen))) {
 591                         CDEBUG(D_HA, "processed all old entries\n");
 592                         d->opd_syn_prev_done = 1;
 593                 }
 594
 595                 /* cancel any generation record */
 596                 rc = llog_cat_cancel_records(env, llh->u.phd.phd_cat_handle,
 597                                              1, &cookie);
 598
 599                 return rc;
 600         }
 601
 602         /*
 603          * now we prepare and fill requests to OST, put them on the queue
 604          * and fire after next commit callback
 605          */
 606
 607         /* notice we increment counters before sending RPC, to be consistent
 608          * in RPC interpret callback which may happen very quickly */
 609         spin_lock(&d->opd_syn_lock);
 610         d->opd_syn_rpc_in_flight++;
 611         d->opd_syn_rpc_in_progress++;
 612         spin_unlock(&d->opd_syn_lock);
 613
 614         switch (rec->lrh_type) {
 615         /* case MDS_UNLINK_REC is kept for compatibility */
 616         case MDS_UNLINK_REC:
 617                 rc = osp_sync_new_unlink_job(d, llh, rec);
 618                 break;
 619         case MDS_UNLINK64_REC:
 620                 rc = osp_sync_new_unlink64_job(d, llh, rec);
 621                 break;
 622         case MDS_SETATTR64_REC:
 623                 rc = osp_sync_new_setattr_job(d, llh, rec);
 624                 break;
 625         default:
 626                 CERROR("unknown record type: %x\n", rec->lrh_type);
 627                        rc = -EINVAL;
 628                        break;
 629         }
 630
 631         if (likely(rc == 0)) {
 632                 spin_lock(&d->opd_syn_lock);
 633                 if (d->opd_syn_prev_done) {
 634                         LASSERT(d->opd_syn_changes > 0);
 635                         LASSERT(rec->lrh_id <= d->opd_syn_last_committed_id);
 636                         /*
 637                          * NOTE: it's possible to meet same id if
 638                          * OST stores few stripes of same file
 639                          */
 640                         if (rec->lrh_id > d->opd_syn_last_processed_id)
 641                                 d->opd_syn_last_processed_id = rec->lrh_id;
 642
 643                         d->opd_syn_changes--;
 644                 }
 645                 CDEBUG(D_OTHER, "%s: %d in flight, %d in progress\n",
 646                        d->opd_obd->obd_name, d->opd_syn_rpc_in_flight,
 647                        d->opd_syn_rpc_in_progress);
 648                 spin_unlock(&d->opd_syn_lock);
 649         } else {
 650                 spin_lock(&d->opd_syn_lock);
 651                 d->opd_syn_rpc_in_flight--;
 652                 d->opd_syn_rpc_in_progress--;
 653                 spin_unlock(&d->opd_syn_lock);
 654         }
 655
 656         CDEBUG(D_HA, "found record %x, %d, idx %u, id %u: %d\n",
 657                rec->lrh_type, rec->lrh_len, rec->lrh_index, rec->lrh_id, rc);
 658         return rc;
 659 }
 660
 661 static void osp_sync_process_committed(const struct lu_env *env,
 662                                        struct osp_device *d)
 663 {
 664         struct obd_device       *obd = d->opd_obd;
 665         struct obd_import       *imp = obd->u.cli.cl_import;
 666         struct ost_body         *body;
 667         struct ptlrpc_request   *req, *tmp;
 668         struct llog_ctxt        *ctxt;
 669         struct llog_handle      *llh;
 670         cfs_list_t               list;
 671         int                      rc, done = 0;
 672
 673         ENTRY;
 674
 675         if (cfs_list_empty(&d->opd_syn_committed_there))
 676                 return;
 677
 678         /*
 679          * if current status is -ENOSPC (lack of free space on OST)
 680          * then we should poll OST immediately once object destroy
 681          * is committed.
 682          * notice: we do this upon commit as well because some backends
 683          * (like DMU) do not release space right away.
 684          */
 685         if (unlikely(d->opd_pre_status == -ENOSPC))
 686                 osp_statfs_need_now(d);
 687
 688         /*
 689          * now cancel them all
 690          * XXX: can we improve this using some batching?
 691          *      with batch RPC that'll happen automatically?
 692          * XXX: can we store ctxt in lod_device and save few cycles ?
 693          */
 694         ctxt = llog_get_context(obd, LLOG_MDS_OST_ORIG_CTXT);
 695         LASSERT(ctxt);
 696
 697         llh = ctxt->loc_handle;
 698         LASSERT(llh);
 699
 700         CFS_INIT_LIST_HEAD(&list);
 701         spin_lock(&d->opd_syn_lock);
 702         cfs_list_splice(&d->opd_syn_committed_there, &list);
 703         CFS_INIT_LIST_HEAD(&d->opd_syn_committed_there);
 704         spin_unlock(&d->opd_syn_lock);
 705
 706         cfs_list_for_each_entry_safe(req, tmp, &list, rq_exp_list) {
 707                 LASSERT(req->rq_svc_thread == (void *) OSP_JOB_MAGIC);
 708                 cfs_list_del_init(&req->rq_exp_list);
 709
 710                 body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
 711                 LASSERT(body);
 712
 713                 /* import can be closing, thus all commit cb's are
 714                  * called we can check committness directly */
 715                 if (req->rq_transno <= imp->imp_peer_committed_transno) {
 716                         rc = llog_cat_cancel_records(env, llh, 1,
 717                                                      &body->oa.o_lcookie);
 718                         if (rc)
 719                                 CERROR("%s: can't cancel record: %d\n",
 720                                        obd->obd_name, rc);
 721                 } else {
 722                         DEBUG_REQ(D_HA, req, "not committed");
 723                 }
 724
 725                 ptlrpc_req_finished(req);
 726                 done++;
 727         }
 728
 729         llog_ctxt_put(ctxt);
 730
 731         LASSERT(d->opd_syn_rpc_in_progress >= done);
 732         spin_lock(&d->opd_syn_lock);
 733         d->opd_syn_rpc_in_progress -= done;
 734         spin_unlock(&d->opd_syn_lock);
 735         CDEBUG(D_OTHER, "%s: %d in flight, %d in progress\n",
 736                d->opd_obd->obd_name, d->opd_syn_rpc_in_flight,
 737                d->opd_syn_rpc_in_progress);
 738
 739         osp_sync_check_for_work(d);
 740
 741         EXIT;
 742 }
 743
 744 /*
 745  * this is where most of queues processing happens
 746  */
 747 static int osp_sync_process_queues(const struct lu_env *env,
 748                                    struct llog_handle *llh,
 749                                    struct llog_rec_hdr *rec,
 750                                    void *data)
 751 {
 752         struct osp_device       *d = data;
 753         int                      rc;
 754
 755         do {
 756                 struct l_wait_info lwi = { 0 };
 757
 758                 if (!osp_sync_running(d)) {
 759                         CDEBUG(D_HA, "stop llog processing\n");
 760                         return LLOG_PROC_BREAK;
 761                 }
 762
 763                 /* process requests committed by OST */
 764                 osp_sync_process_committed(env, d);
 765
 766                 /* if we there are changes to be processed and we have
 767                  * resources for this ... do now */
 768                 if (osp_sync_can_process_new(d, rec)) {
 769                         if (llh == NULL) {
 770                                 /* ask llog for another record */
 771                                 CDEBUG(D_HA, "%lu changes, %u in progress, %u in flight\n",
 772                                        d->opd_syn_changes,
 773                                        d->opd_syn_rpc_in_progress,
 774                                        d->opd_syn_rpc_in_flight);
 775                                 return 0;
 776                         }
 777
 778                         /*
 779                          * try to send, in case of disconnection, suspend
 780                          * processing till we can send this request
 781                          */
 782                         do {
 783                                 rc = osp_sync_process_record(env, d, llh, rec);
 784                                 /*
 785                                  * XXX: probably different handling is needed
 786                                  * for some bugs, like immediate exit or if
 787                                  * OSP gets inactive
 788                                  */
 789                                 if (rc) {
 790                                         CERROR("can't send: %d\n", rc);
 791                                         l_wait_event(d->opd_syn_waitq,
 792                                                      !osp_sync_running(d) ||
 793                                                      osp_sync_has_work(d),
 794                                                      &lwi);
 795                                 }
 796                         } while (rc != 0 && osp_sync_running(d));
 797
 798                         llh = NULL;
 799                         rec = NULL;
 800                 }
 801
 802                 if (d->opd_syn_last_processed_id == d->opd_syn_last_used_id)
 803                         osp_sync_remove_from_tracker(d);
 804
 805                 l_wait_event(d->opd_syn_waitq,
 806                              !osp_sync_running(d) ||
 807                              osp_sync_can_process_new(d, rec) ||
 808                              !cfs_list_empty(&d->opd_syn_committed_there),
 809                              &lwi);
 810         } while (1);
 811 }
 812
 813 /*
 814  * this thread runs llog_cat_process() scanner calling our callback
 815  * to process llog records. in the callback we implement tricky
 816  * state machine as we don't want to start scanning of the llog again
 817  * and again, also we don't want to process too many records and send
 818  * too many RPCs a time. so, depending on current load (num of changes
 819  * being synced to OST) the callback can suspend awaiting for some
 820  * new conditions, like syncs completed.
 821  *
 822  * in order to process llog records left by previous boots and to allow
 823  * llog_process_thread() to find something (otherwise it'd just exit
 824  * immediately) we add a special GENERATATION record on each boot.
 825  */
 826 static int osp_sync_thread(void *_arg)
 827 {
 828         struct osp_device       *d = _arg;
 829         struct ptlrpc_thread    *thread = &d->opd_syn_thread;
 830         struct l_wait_info       lwi = { 0 };
 831         struct llog_ctxt        *ctxt;
 832         struct obd_device       *obd = d->opd_obd;
 833         struct llog_handle      *llh;
 834         struct lu_env            env;
 835         int                      rc;
 836         char                     pname[16];
 837
 838         ENTRY;
 839
 840         rc = lu_env_init(&env, LCT_LOCAL);
 841         if (rc) {
 842                 CERROR("%s: can't initialize env: rc = %d\n",
 843                        obd->obd_name, rc);
 844                 RETURN(rc);
 845         }
 846
 847         sprintf(pname, "osp-syn-%u", d->opd_index);
 848         cfs_daemonize(pname);
 849
 850         spin_lock(&d->opd_syn_lock);
 851         thread->t_flags = SVC_RUNNING;
 852         spin_unlock(&d->opd_syn_lock);
 853         cfs_waitq_signal(&thread->t_ctl_waitq);
 854
 855         ctxt = llog_get_context(obd, LLOG_MDS_OST_ORIG_CTXT);
 856         if (ctxt == NULL) {
 857                 CERROR("can't get appropriate context\n");
 858                 GOTO(out, rc = -EINVAL);
 859         }
 860
 861         llh = ctxt->loc_handle;
 862         if (llh == NULL) {
 863                 CERROR("can't get llh\n");
 864                 llog_ctxt_put(ctxt);
 865                 GOTO(out, rc = -EINVAL);
 866         }
 867
 868         rc = llog_cat_process(&env, llh, osp_sync_process_queues, d, 0, 0);
 869         LASSERTF(rc == 0 || rc == LLOG_PROC_BREAK,
 870                  "%lu changes, %u in progress, %u in flight: %d\n",
 871                  d->opd_syn_changes, d->opd_syn_rpc_in_progress,
 872                  d->opd_syn_rpc_in_flight, rc);
 873
 874         /* we don't expect llog_process_thread() to exit till umount */
 875         LASSERTF(thread->t_flags != SVC_RUNNING,
 876                  "%lu changes, %u in progress, %u in flight\n",
 877                  d->opd_syn_changes, d->opd_syn_rpc_in_progress,
 878                  d->opd_syn_rpc_in_flight);
 879
 880         /* wait till all the requests are completed */
 881         while (d->opd_syn_rpc_in_progress > 0) {
 882                 osp_sync_process_committed(&env, d);
 883                 l_wait_event(d->opd_syn_waitq,
 884                              d->opd_syn_rpc_in_progress == 0,
 885                              &lwi);
 886         }
 887
 888         llog_cat_close(&env, llh);
 889         rc = llog_cleanup(&env, ctxt);
 890         if (rc)
 891                 CERROR("can't cleanup llog: %d\n", rc);
 892 out:
 893         thread->t_flags = SVC_STOPPED;
 894
 895         cfs_waitq_signal(&thread->t_ctl_waitq);
 896         LASSERTF(d->opd_syn_rpc_in_progress == 0,
 897                  "%s: %d %d %sempty\n",
 898                  d->opd_obd->obd_name, d->opd_syn_rpc_in_progress,
 899                  d->opd_syn_rpc_in_flight,
 900                  cfs_list_empty(&d->opd_syn_committed_there) ? "" : "!");
 901
 902         lu_env_fini(&env);
 903
 904         RETURN(0);
 905 }
 906
 907 static int osp_sync_llog_init(const struct lu_env *env, struct osp_device *d)
 908 {
 909         struct osp_thread_info *osi = osp_env_info(env);
 910         struct llog_handle     *lgh;
 911         struct obd_device      *obd = d->opd_obd;
 912         struct llog_ctxt       *ctxt;
 913         int                     rc;
 914
 915         ENTRY;
 916
 917         LASSERT(obd);
 918
 919         /*
 920          * open llog corresponding to our OST
 921          */
 922         OBD_SET_CTXT_MAGIC(&obd->obd_lvfs_ctxt);
 923         obd->obd_lvfs_ctxt.dt = d->opd_storage;
 924
 925         rc = llog_osd_get_cat_list(env, d->opd_storage, d->opd_index, 1,
 926                                    &osi->osi_cid);
 927         if (rc) {
 928                 CERROR("%s: can't get id from catalogs: rc = %d\n",
 929                        obd->obd_name, rc);
 930                 RETURN(rc);
 931         }
 932
 933         CDEBUG(D_INFO, "%s: Init llog for %d - catid "LPX64"/"LPX64":%x\n",
 934                obd->obd_name, d->opd_index, osi->osi_cid.lci_logid.lgl_oid,
 935                osi->osi_cid.lci_logid.lgl_oseq,
 936                osi->osi_cid.lci_logid.lgl_ogen);
 937
 938         rc = llog_setup(env, obd, &obd->obd_olg, LLOG_MDS_OST_ORIG_CTXT, obd,
 939                         &osp_mds_ost_orig_logops);
 940         if (rc)
 941                 RETURN(rc);
 942
 943         ctxt = llog_get_context(obd, LLOG_MDS_OST_ORIG_CTXT);
 944         LASSERT(ctxt);
 945
 946         if (likely(osi->osi_cid.lci_logid.lgl_oid != 0)) {
 947                 rc = llog_open(env, ctxt, &lgh, &osi->osi_cid.lci_logid, NULL,
 948                                LLOG_OPEN_EXISTS);
 949                 /* re-create llog if it is missing */
 950                 if (rc == -ENOENT)
 951                         osi->osi_cid.lci_logid.lgl_oid = 0;
 952                 else if (rc < 0)
 953                         GOTO(out_cleanup, rc);
 954         }
 955
 956         if (unlikely(osi->osi_cid.lci_logid.lgl_oid == 0)) {
 957                 rc = llog_open_create(env, ctxt, &lgh, NULL, NULL);
 958                 if (rc < 0)
 959                         GOTO(out_cleanup, rc);
 960                 osi->osi_cid.lci_logid = lgh->lgh_id;
 961         }
 962
 963         ctxt->loc_handle = lgh;
 964
 965         rc = llog_cat_init_and_process(env, lgh);
 966         if (rc)
 967                 GOTO(out_close, rc);
 968
 969         rc = llog_osd_put_cat_list(env, d->opd_storage, d->opd_index, 1,
 970                                    &osi->osi_cid);
 971         if (rc)
 972                 GOTO(out_close, rc);
 973
 974         /*
 975          * put a mark in the llog till which we'll be processing
 976          * old records restless
 977          */
 978         d->opd_syn_generation.mnt_cnt = cfs_time_current();
 979         d->opd_syn_generation.conn_cnt = cfs_time_current();
 980
 981         osi->osi_hdr.lrh_type = LLOG_GEN_REC;
 982         osi->osi_hdr.lrh_len = sizeof(osi->osi_gen);
 983
 984         memcpy(&osi->osi_gen.lgr_gen, &d->opd_syn_generation,
 985                sizeof(osi->osi_gen.lgr_gen));
 986
 987         rc = llog_cat_add(env, lgh, &osi->osi_gen.lgr_hdr, &osi->osi_cookie,
 988                           NULL);
 989         if (rc < 0)
 990                 GOTO(out_close, rc);
 991         llog_ctxt_put(ctxt);
 992         RETURN(0);
 993 out_close:
 994         llog_cat_close(env, lgh);
 995 out_cleanup:
 996         llog_cleanup(env, ctxt);
 997         RETURN(rc);
 998 }
 999
1000 static void osp_sync_llog_fini(const struct lu_env *env, struct osp_device *d)
1001 {
1002         struct llog_ctxt *ctxt;
1003
1004         ctxt = llog_get_context(d->opd_obd, LLOG_MDS_OST_ORIG_CTXT);
1005         llog_cat_close(env, ctxt->loc_handle);
1006         llog_cleanup(env, ctxt);
1007 }
1008
1009 /*
1010  * initializes sync component of OSP
1011  */
1012 int osp_sync_init(const struct lu_env *env, struct osp_device *d)
1013 {
1014         struct l_wait_info       lwi = { 0 };
1015         int                      rc;
1016
1017         ENTRY;
1018
1019         rc = osp_sync_id_traction_init(d);
1020         if (rc)
1021                 RETURN(rc);
1022
1023         /*
1024          * initialize llog storing changes
1025          */
1026         rc = osp_sync_llog_init(env, d);
1027         if (rc) {
1028                 CERROR("%s: can't initialize llog: rc = %d\n",
1029                        d->opd_obd->obd_name, rc);
1030                 GOTO(err_id, rc);
1031         }
1032
1033         /*
1034          * Start synchronization thread
1035          */
1036         d->opd_syn_max_rpc_in_flight = OSP_MAX_IN_FLIGHT;
1037         d->opd_syn_max_rpc_in_progress = OSP_MAX_IN_PROGRESS;
1038         spin_lock_init(&d->opd_syn_lock);
1039         cfs_waitq_init(&d->opd_syn_waitq);
1040         cfs_waitq_init(&d->opd_syn_thread.t_ctl_waitq);
1041         CFS_INIT_LIST_HEAD(&d->opd_syn_committed_there);
1042
1043         rc = cfs_create_thread(osp_sync_thread, d, 0);
1044         if (rc < 0) {
1045                 CERROR("%s: can't start sync thread: rc = %d\n",
1046                        d->opd_obd->obd_name, rc);
1047                 GOTO(err_llog, rc);
1048         }
1049
1050         l_wait_event(d->opd_syn_thread.t_ctl_waitq,
1051                      osp_sync_running(d) || osp_sync_stopped(d), &lwi);
1052
1053         RETURN(0);
1054 err_llog:
1055         osp_sync_llog_fini(env, d);
1056 err_id:
1057         osp_sync_id_traction_fini(d);
1058         return rc;
1059 }
1060
1061 int osp_sync_fini(struct osp_device *d)
1062 {
1063         struct ptlrpc_thread *thread = &d->opd_syn_thread;
1064
1065         ENTRY;
1066
1067         thread->t_flags = SVC_STOPPING;
1068         cfs_waitq_signal(&d->opd_syn_waitq);
1069         cfs_wait_event(thread->t_ctl_waitq, thread->t_flags & SVC_STOPPED);
1070
1071         /*
1072          * unregister transaction callbacks only when sync thread
1073          * has finished operations with llog
1074          */
1075         osp_sync_id_traction_fini(d);
1076
1077         RETURN(0);
1078 }
1079
1080 static DEFINE_MUTEX(osp_id_tracker_sem);
1081 static CFS_LIST_HEAD(osp_id_tracker_list);
1082
1083 static void osp_sync_tracker_commit_cb(struct thandle *th, void *cookie)
1084 {
1085         struct osp_id_tracker   *tr = cookie;
1086         struct osp_device       *d;
1087         struct osp_txn_info     *txn;
1088
1089         LASSERT(tr);
1090
1091         txn = osp_txn_info(&th->th_ctx);
1092         if (txn == NULL || txn->oti_current_id < tr->otr_committed_id)
1093                 return;
1094
1095         spin_lock(&tr->otr_lock);
1096         if (likely(txn->oti_current_id > tr->otr_committed_id)) {
1097                 CDEBUG(D_OTHER, "committed: %u -> %u\n",
1098                        tr->otr_committed_id, txn->oti_current_id);
1099                 tr->otr_committed_id = txn->oti_current_id;
1100
1101                 cfs_list_for_each_entry(d, &tr->otr_wakeup_list,
1102                                         opd_syn_ontrack) {
1103                         d->opd_syn_last_committed_id = tr->otr_committed_id;
1104                         cfs_waitq_signal(&d->opd_syn_waitq);
1105                 }
1106         }
1107         spin_unlock(&tr->otr_lock);
1108 }
1109
1110 static int osp_sync_id_traction_init(struct osp_device *d)
1111 {
1112         struct osp_id_tracker   *tr, *found = NULL;
1113         int                      rc = 0;
1114
1115         LASSERT(d);
1116         LASSERT(d->opd_storage);
1117         LASSERT(d->opd_syn_tracker == NULL);
1118         CFS_INIT_LIST_HEAD(&d->opd_syn_ontrack);
1119
1120         mutex_lock(&osp_id_tracker_sem);
1121         cfs_list_for_each_entry(tr, &osp_id_tracker_list, otr_list) {
1122                 if (tr->otr_dev == d->opd_storage) {
1123                         LASSERT(cfs_atomic_read(&tr->otr_refcount));
1124                         cfs_atomic_inc(&tr->otr_refcount);
1125                         d->opd_syn_tracker = tr;
1126                         found = tr;
1127                         break;
1128                 }
1129         }
1130
1131         if (found == NULL) {
1132                 rc = -ENOMEM;
1133                 OBD_ALLOC_PTR(tr);
1134                 if (tr) {
1135                         d->opd_syn_tracker = tr;
1136                         spin_lock_init(&tr->otr_lock);
1137                         tr->otr_dev = d->opd_storage;
1138                         tr->otr_next_id = 1;
1139                         tr->otr_committed_id = 0;
1140                         cfs_atomic_set(&tr->otr_refcount, 1);
1141                         CFS_INIT_LIST_HEAD(&tr->otr_wakeup_list);
1142                         cfs_list_add(&tr->otr_list, &osp_id_tracker_list);
1143                         tr->otr_tx_cb.dtc_txn_commit =
1144                                                 osp_sync_tracker_commit_cb;
1145                         tr->otr_tx_cb.dtc_cookie = tr;
1146                         tr->otr_tx_cb.dtc_tag = LCT_MD_THREAD;
1147                         dt_txn_callback_add(d->opd_storage, &tr->otr_tx_cb);
1148                         rc = 0;
1149                 }
1150         }
1151         mutex_unlock(&osp_id_tracker_sem);
1152
1153         return rc;
1154 }
1155
1156 static void osp_sync_id_traction_fini(struct osp_device *d)
1157 {
1158         struct osp_id_tracker *tr;
1159
1160         ENTRY;
1161
1162         LASSERT(d);
1163         tr = d->opd_syn_tracker;
1164         if (tr == NULL) {
1165                 EXIT;
1166                 return;
1167         }
1168
1169         osp_sync_remove_from_tracker(d);
1170
1171         mutex_lock(&osp_id_tracker_sem);
1172         if (cfs_atomic_dec_and_test(&tr->otr_refcount)) {
1173                 dt_txn_callback_del(d->opd_storage, &tr->otr_tx_cb);
1174                 LASSERT(cfs_list_empty(&tr->otr_wakeup_list));
1175                 cfs_list_del(&tr->otr_list);
1176                 OBD_FREE_PTR(tr);
1177                 d->opd_syn_tracker = NULL;
1178         }
1179         mutex_unlock(&osp_id_tracker_sem);
1180
1181         EXIT;
1182 }
1183
1184 /*
1185  * generates id for the tracker
1186  */
1187 static __u32 osp_sync_id_get(struct osp_device *d, __u32 id)
1188 {
1189         struct osp_id_tracker *tr;
1190
1191         tr = d->opd_syn_tracker;
1192         LASSERT(tr);
1193
1194         /* XXX: we can improve this introducing per-cpu preallocated ids? */
1195         spin_lock(&tr->otr_lock);
1196         if (unlikely(tr->otr_next_id <= d->opd_syn_last_used_id)) {
1197                 spin_unlock(&tr->otr_lock);
1198                 CERROR("%s: next %u, last synced %lu\n",
1199                        d->opd_obd->obd_name, tr->otr_next_id,
1200                        d->opd_syn_last_used_id);
1201                 LBUG();
1202         }
1203
1204         if (id == 0)
1205                 id = tr->otr_next_id++;
1206         if (id > d->opd_syn_last_used_id)
1207                 d->opd_syn_last_used_id = id;
1208         if (cfs_list_empty(&d->opd_syn_ontrack))
1209                 cfs_list_add(&d->opd_syn_ontrack, &tr->otr_wakeup_list);
1210         spin_unlock(&tr->otr_lock);
1211         CDEBUG(D_OTHER, "new id %u\n", (unsigned) id);
1212
1213         return id;
1214 }
1215
1216 static void osp_sync_remove_from_tracker(struct osp_device *d)
1217 {
1218         struct osp_id_tracker *tr;
1219
1220         tr = d->opd_syn_tracker;
1221         LASSERT(tr);
1222
1223         if (cfs_list_empty(&d->opd_syn_ontrack))
1224                 return;
1225
1226         spin_lock(&tr->otr_lock);
1227         cfs_list_del_init(&d->opd_syn_ontrack);
1228         spin_unlock(&tr->otr_lock);
1229 }
1230