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) 2011, 2012, Intel, Inc.
  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                 cfs_spin_lock(&d->opd_syn_lock);
 272                 d->opd_syn_changes++;
 273                 cfs_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
 320         CDEBUG(D_HA, "commit req %p, transno "LPU64"\n", req, req->rq_transno);
 321
 322         if (unlikely(req->rq_transno == 0))
 323                 return;
 324
 325         /* XXX: what if request isn't committed for very long? */
 326         LASSERT(d);
 327         LASSERT(req->rq_svc_thread == (void *) OSP_JOB_MAGIC);
 328         LASSERT(cfs_list_empty(&req->rq_exp_list));
 329
 330         ptlrpc_request_addref(req);
 331
 332         cfs_spin_lock(&d->opd_syn_lock);
 333         cfs_list_add(&req->rq_exp_list, &d->opd_syn_committed_there);
 334         cfs_spin_unlock(&d->opd_syn_lock);
 335
 336         /* XXX: some batching wouldn't hurt */
 337         cfs_waitq_signal(&d->opd_syn_waitq);
 338 }
 339
 340 static int osp_sync_interpret(const struct lu_env *env,
 341                               struct ptlrpc_request *req, void *aa, int rc)
 342 {
 343         struct osp_device *d = req->rq_cb_data;
 344
 345         /* XXX: error handling here */
 346         if (req->rq_svc_thread != (void *) OSP_JOB_MAGIC)
 347                 DEBUG_REQ(D_ERROR, req, "bad magic %p\n", req->rq_svc_thread);
 348         LASSERT(req->rq_svc_thread == (void *) OSP_JOB_MAGIC);
 349         LASSERT(d);
 350
 351         CDEBUG(D_HA, "reply req %p/%d, rc %d, transno %u\n", req,
 352                cfs_atomic_read(&req->rq_refcount),
 353                rc, (unsigned) req->rq_transno);
 354         LASSERT(rc || req->rq_transno);
 355
 356         if (rc == -ENOENT) {
 357                 /*
 358                  * we tried to destroy object or update attributes,
 359                  * but object doesn't exist anymore - cancell llog record
 360                  */
 361                 LASSERT(req->rq_transno == 0);
 362                 LASSERT(cfs_list_empty(&req->rq_exp_list));
 363
 364                 ptlrpc_request_addref(req);
 365
 366                 cfs_spin_lock(&d->opd_syn_lock);
 367                 cfs_list_add(&req->rq_exp_list, &d->opd_syn_committed_there);
 368                 cfs_spin_unlock(&d->opd_syn_lock);
 369
 370                 cfs_waitq_signal(&d->opd_syn_waitq);
 371         } else if (rc) {
 372                 struct obd_import *imp = req->rq_import;
 373                 /*
 374                  * error happened, we'll try to repeat on next boot ?
 375                  */
 376                 LASSERTF(req->rq_transno == 0 ||
 377                          req->rq_import_generation < imp->imp_generation,
 378                          "transno "LPU64", rc %d, gen: req %d, imp %d\n",
 379                          req->rq_transno, rc, req->rq_import_generation,
 380                          imp->imp_generation);
 381                 LASSERT(d->opd_syn_rpc_in_progress > 0);
 382                 if (req->rq_transno == 0) {
 383                         /* this is the last time we see the request
 384                          * if transno is not zero, then commit cb
 385                          * will be called at some point */
 386                         cfs_spin_lock(&d->opd_syn_lock);
 387                         d->opd_syn_rpc_in_progress--;
 388                         cfs_spin_unlock(&d->opd_syn_lock);
 389                 }
 390
 391                 cfs_waitq_signal(&d->opd_syn_waitq);
 392         } else if (unlikely(d->opd_pre_status == -ENOSPC)) {
 393                 /*
 394                  * if current status is -ENOSPC (lack of free space on OST)
 395                  * then we should poll OST immediately once object destroy
 396                  * is replied
 397                  */
 398                 osp_statfs_need_now(d);
 399         }
 400
 401         LASSERT(d->opd_syn_rpc_in_flight > 0);
 402         cfs_spin_lock(&d->opd_syn_lock);
 403         d->opd_syn_rpc_in_flight--;
 404         cfs_spin_unlock(&d->opd_syn_lock);
 405         CDEBUG(D_OTHER, "%s: %d in flight, %d in progress\n",
 406                d->opd_obd->obd_name, d->opd_syn_rpc_in_flight,
 407                d->opd_syn_rpc_in_progress);
 408
 409         osp_sync_check_for_work(d);
 410
 411         return 0;
 412 }
 413
 414 /*
 415  * the function walks through list of committed locally changes
 416  * and send them to RPC until the pipe is full
 417  */
 418 static void osp_sync_send_new_rpc(struct osp_device *d,
 419                                   struct ptlrpc_request *req)
 420 {
 421         LASSERT(d->opd_syn_rpc_in_flight <= d->opd_syn_max_rpc_in_flight);
 422         LASSERT(req->rq_svc_thread == (void *) OSP_JOB_MAGIC);
 423
 424         ptlrpcd_add_req(req, PDL_POLICY_ROUND, -1);
 425 }
 426
 427 static struct ptlrpc_request *osp_sync_new_job(struct osp_device *d,
 428                                                struct llog_handle *llh,
 429                                                struct llog_rec_hdr *h,
 430                                                ost_cmd_t op,
 431                                                const struct req_format *format)
 432 {
 433         struct ptlrpc_request   *req;
 434         struct ost_body         *body;
 435         struct obd_import       *imp;
 436         int                      rc;
 437
 438         /* Prepare the request */
 439         imp = d->opd_obd->u.cli.cl_import;
 440         LASSERT(imp);
 441         req = ptlrpc_request_alloc(imp, format);
 442         if (req == NULL)
 443                 RETURN(ERR_PTR(-ENOMEM));
 444
 445         rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, op);
 446         if (rc) {
 447                 ptlrpc_req_finished(req);
 448                 return ERR_PTR(rc);
 449         }
 450
 451         /*
 452          * this is a trick: to save on memory allocations we put cookie
 453          * into the request, but don't set corresponded flag in o_valid
 454          * so that OST doesn't interpret this cookie. once the request
 455          * is committed on OST we take cookie from the request and cancel
 456          */
 457         body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
 458         LASSERT(body);
 459         body->oa.o_lcookie.lgc_lgl = llh->lgh_id;
 460         body->oa.o_lcookie.lgc_subsys = LLOG_MDS_OST_ORIG_CTXT;
 461         body->oa.o_lcookie.lgc_index = h->lrh_index;
 462         CFS_INIT_LIST_HEAD(&req->rq_exp_list);
 463         req->rq_svc_thread = (void *) OSP_JOB_MAGIC;
 464
 465         req->rq_interpret_reply = osp_sync_interpret;
 466         req->rq_commit_cb = osp_sync_request_commit_cb;
 467         req->rq_cb_data = d;
 468
 469         ptlrpc_request_set_replen(req);
 470
 471         return req;
 472 }
 473
 474 static int osp_sync_new_setattr_job(struct osp_device *d,
 475                                     struct llog_handle *llh,
 476                                     struct llog_rec_hdr *h)
 477 {
 478         struct llog_setattr64_rec       *rec = (struct llog_setattr64_rec *)h;
 479         struct ptlrpc_request           *req;
 480         struct ost_body                 *body;
 481
 482         ENTRY;
 483         LASSERT(h->lrh_type == MDS_SETATTR64_REC);
 484
 485         req = osp_sync_new_job(d, llh, h, OST_SETATTR, &RQF_OST_SETATTR);
 486         if (IS_ERR(req))
 487                 RETURN(PTR_ERR(req));
 488
 489         body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
 490         LASSERT(body);
 491         body->oa.o_id  = rec->lsr_oid;
 492         body->oa.o_seq = rec->lsr_oseq;
 493         body->oa.o_uid = rec->lsr_uid;
 494         body->oa.o_gid = rec->lsr_gid;
 495         body->oa.o_valid = OBD_MD_FLGROUP | OBD_MD_FLID |
 496                            OBD_MD_FLUID | OBD_MD_FLGID;
 497
 498         osp_sync_send_new_rpc(d, req);
 499         RETURN(0);
 500 }
 501
 502 /* Old records may be in old format, so we handle that too */
 503 static int osp_sync_new_unlink_job(struct osp_device *d,
 504                                    struct llog_handle *llh,
 505                                    struct llog_rec_hdr *h)
 506 {
 507         struct llog_unlink_rec  *rec = (struct llog_unlink_rec *)h;
 508         struct ptlrpc_request   *req;
 509         struct ost_body         *body;
 510
 511         ENTRY;
 512         LASSERT(h->lrh_type == MDS_UNLINK_REC);
 513
 514         req = osp_sync_new_job(d, llh, h, OST_DESTROY, &RQF_OST_DESTROY);
 515         if (IS_ERR(req))
 516                 RETURN(PTR_ERR(req));
 517
 518         body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
 519         LASSERT(body);
 520         body->oa.o_id  = rec->lur_oid;
 521         body->oa.o_seq = rec->lur_oseq;
 522         body->oa.o_misc = rec->lur_count;
 523         body->oa.o_valid = OBD_MD_FLGROUP | OBD_MD_FLID;
 524         if (rec->lur_count)
 525                 body->oa.o_valid |= OBD_MD_FLOBJCOUNT;
 526
 527         osp_sync_send_new_rpc(d, req);
 528         RETURN(0);
 529 }
 530
 531 static int osp_sync_new_unlink64_job(struct osp_device *d,
 532                                      struct llog_handle *llh,
 533                                      struct llog_rec_hdr *h)
 534 {
 535         struct llog_unlink64_rec        *rec = (struct llog_unlink64_rec *)h;
 536         struct ptlrpc_request           *req;
 537         struct ost_body                 *body;
 538         int                              rc;
 539
 540         ENTRY;
 541         LASSERT(h->lrh_type == MDS_UNLINK64_REC);
 542
 543         req = osp_sync_new_job(d, llh, h, OST_DESTROY, &RQF_OST_DESTROY);
 544         if (IS_ERR(req))
 545                 RETURN(PTR_ERR(req));
 546
 547         body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
 548         if (body == NULL)
 549                 RETURN(-EFAULT);
 550         rc = fid_ostid_pack(&rec->lur_fid, &body->oa.o_oi);
 551         if (rc < 0)
 552                 RETURN(rc);
 553         body->oa.o_misc = rec->lur_count;
 554         body->oa.o_valid = OBD_MD_FLGROUP | OBD_MD_FLID | OBD_MD_FLOBJCOUNT;
 555
 556         osp_sync_send_new_rpc(d, req);
 557         RETURN(0);
 558 }
 559
 560 static int osp_sync_process_record(const struct lu_env *env,
 561                                    struct osp_device *d,
 562                                    struct llog_handle *llh,
 563                                    struct llog_rec_hdr *rec)
 564 {
 565         struct llog_cookie       cookie;
 566         int                      rc = 0;
 567
 568         cookie.lgc_lgl = llh->lgh_id;
 569         cookie.lgc_subsys = LLOG_MDS_OST_ORIG_CTXT;
 570         cookie.lgc_index = rec->lrh_index;
 571
 572         if (unlikely(rec->lrh_type == LLOG_GEN_REC)) {
 573                 struct llog_gen_rec *gen = (struct llog_gen_rec *)rec;
 574
 575                 /* we're waiting for the record generated by this instance */
 576                 LASSERT(d->opd_syn_prev_done == 0);
 577                 if (!memcmp(&d->opd_syn_generation, &gen->lgr_gen,
 578                             sizeof(gen->lgr_gen))) {
 579                         CDEBUG(D_HA, "processed all old entries\n");
 580                         d->opd_syn_prev_done = 1;
 581                 }
 582
 583                 /* cancel any generation record */
 584                 rc = llog_cat_cancel_records(env, llh->u.phd.phd_cat_handle,
 585                                              1, &cookie);
 586
 587                 return rc;
 588         }
 589
 590         /*
 591          * now we prepare and fill requests to OST, put them on the queue
 592          * and fire after next commit callback
 593          */
 594
 595         /* notice we increment counters before sending RPC, to be consistent
 596          * in RPC interpret callback which may happen very quickly */
 597         cfs_spin_lock(&d->opd_syn_lock);
 598         d->opd_syn_rpc_in_flight++;
 599         d->opd_syn_rpc_in_progress++;
 600         cfs_spin_unlock(&d->opd_syn_lock);
 601
 602         switch (rec->lrh_type) {
 603         /* case MDS_UNLINK_REC is kept for compatibility */
 604         case MDS_UNLINK_REC:
 605                 rc = osp_sync_new_unlink_job(d, llh, rec);
 606                 break;
 607         case MDS_UNLINK64_REC:
 608                 rc = osp_sync_new_unlink64_job(d, llh, rec);
 609                 break;
 610         case MDS_SETATTR64_REC:
 611                 rc = osp_sync_new_setattr_job(d, llh, rec);
 612                 break;
 613         default:
 614                 CERROR("unknown record type: %x\n", rec->lrh_type);
 615                        rc = -EINVAL;
 616                        break;
 617         }
 618
 619         if (likely(rc == 0)) {
 620                 cfs_spin_lock(&d->opd_syn_lock);
 621                 if (d->opd_syn_prev_done) {
 622                         LASSERT(d->opd_syn_changes > 0);
 623                         LASSERT(rec->lrh_id <= d->opd_syn_last_committed_id);
 624                         /*
 625                          * NOTE: it's possible to meet same id if
 626                          * OST stores few stripes of same file
 627                          */
 628                         if (rec->lrh_id > d->opd_syn_last_processed_id)
 629                                 d->opd_syn_last_processed_id = rec->lrh_id;
 630
 631                         d->opd_syn_changes--;
 632                 }
 633                 CDEBUG(D_OTHER, "%s: %d in flight, %d in progress\n",
 634                        d->opd_obd->obd_name, d->opd_syn_rpc_in_flight,
 635                        d->opd_syn_rpc_in_progress);
 636                 cfs_spin_unlock(&d->opd_syn_lock);
 637         } else {
 638                 cfs_spin_lock(&d->opd_syn_lock);
 639                 d->opd_syn_rpc_in_flight--;
 640                 d->opd_syn_rpc_in_progress--;
 641                 cfs_spin_unlock(&d->opd_syn_lock);
 642         }
 643
 644         CDEBUG(D_HA, "found record %x, %d, idx %u, id %u: %d\n",
 645                rec->lrh_type, rec->lrh_len, rec->lrh_index, rec->lrh_id, rc);
 646         return rc;
 647 }
 648
 649 static void osp_sync_process_committed(const struct lu_env *env,
 650                                        struct osp_device *d)
 651 {
 652         struct obd_device       *obd = d->opd_obd;
 653         struct obd_import       *imp = obd->u.cli.cl_import;
 654         struct ost_body         *body;
 655         struct ptlrpc_request   *req, *tmp;
 656         struct llog_ctxt        *ctxt;
 657         struct llog_handle      *llh;
 658         cfs_list_t               list;
 659         int                      rc, done = 0;
 660
 661         ENTRY;
 662
 663         if (cfs_list_empty(&d->opd_syn_committed_there))
 664                 return;
 665
 666         /*
 667          * if current status is -ENOSPC (lack of free space on OST)
 668          * then we should poll OST immediately once object destroy
 669          * is committed.
 670          * notice: we do this upon commit as well because some backends
 671          * (like DMU) do not release space right away.
 672          */
 673         if (unlikely(d->opd_pre_status == -ENOSPC))
 674                 osp_statfs_need_now(d);
 675
 676         /*
 677          * now cancel them all
 678          * XXX: can we improve this using some batching?
 679          *      with batch RPC that'll happen automatically?
 680          * XXX: can we store ctxt in lod_device and save few cycles ?
 681          */
 682         ctxt = llog_get_context(obd, LLOG_MDS_OST_ORIG_CTXT);
 683         LASSERT(ctxt);
 684
 685         llh = ctxt->loc_handle;
 686         LASSERT(llh);
 687
 688         CFS_INIT_LIST_HEAD(&list);
 689         cfs_spin_lock(&d->opd_syn_lock);
 690         cfs_list_splice(&d->opd_syn_committed_there, &list);
 691         CFS_INIT_LIST_HEAD(&d->opd_syn_committed_there);
 692         cfs_spin_unlock(&d->opd_syn_lock);
 693
 694         cfs_list_for_each_entry_safe(req, tmp, &list, rq_exp_list) {
 695                 LASSERT(req->rq_svc_thread == (void *) OSP_JOB_MAGIC);
 696                 cfs_list_del_init(&req->rq_exp_list);
 697
 698                 body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
 699                 LASSERT(body);
 700
 701                 /* import can be closing, thus all commit cb's are
 702                  * called we can check committness directly */
 703                 if (req->rq_transno <= imp->imp_peer_committed_transno) {
 704                         rc = llog_cat_cancel_records(env, llh, 1,
 705                                                      &body->oa.o_lcookie);
 706                         if (rc)
 707                                 CERROR("%s: can't cancel record: %d\n",
 708                                        obd->obd_name, rc);
 709                 } else {
 710                         DEBUG_REQ(D_HA, req, "not committed");
 711                 }
 712
 713                 ptlrpc_req_finished(req);
 714                 done++;
 715         }
 716
 717         llog_ctxt_put(ctxt);
 718
 719         LASSERT(d->opd_syn_rpc_in_progress >= done);
 720         cfs_spin_lock(&d->opd_syn_lock);
 721         d->opd_syn_rpc_in_progress -= done;
 722         cfs_spin_unlock(&d->opd_syn_lock);
 723         CDEBUG(D_OTHER, "%s: %d in flight, %d in progress\n",
 724                d->opd_obd->obd_name, d->opd_syn_rpc_in_flight,
 725                d->opd_syn_rpc_in_progress);
 726
 727         osp_sync_check_for_work(d);
 728
 729         EXIT;
 730 }
 731
 732 /*
 733  * this is where most of queues processing happens
 734  */
 735 static int osp_sync_process_queues(const struct lu_env *env,
 736                                    struct llog_handle *llh,
 737                                    struct llog_rec_hdr *rec,
 738                                    void *data)
 739 {
 740         struct osp_device       *d = data;
 741         int                      rc;
 742
 743         do {
 744                 struct l_wait_info lwi = { 0 };
 745
 746                 if (!osp_sync_running(d)) {
 747                         CDEBUG(D_HA, "stop llog processing\n");
 748                         return LLOG_PROC_BREAK;
 749                 }
 750
 751                 /* process requests committed by OST */
 752                 osp_sync_process_committed(env, d);
 753
 754                 /* if we there are changes to be processed and we have
 755                  * resources for this ... do now */
 756                 if (osp_sync_can_process_new(d, rec)) {
 757                         if (llh == NULL) {
 758                                 /* ask llog for another record */
 759                                 CDEBUG(D_HA, "%lu changes, %u in progress, %u in flight\n",
 760                                        d->opd_syn_changes,
 761                                        d->opd_syn_rpc_in_progress,
 762                                        d->opd_syn_rpc_in_flight);
 763                                 return 0;
 764                         }
 765
 766                         /*
 767                          * try to send, in case of disconnection, suspend
 768                          * processing till we can send this request
 769                          */
 770                         do {
 771                                 rc = osp_sync_process_record(env, d, llh, rec);
 772                                 /*
 773                                  * XXX: probably different handling is needed
 774                                  * for some bugs, like immediate exit or if
 775                                  * OSP gets inactive
 776                                  */
 777                                 if (rc) {
 778                                         CERROR("can't send: %d\n", rc);
 779                                         l_wait_event(d->opd_syn_waitq,
 780                                                      !osp_sync_running(d) ||
 781                                                      osp_sync_has_work(d),
 782                                                      &lwi);
 783                                 }
 784                         } while (rc != 0 && osp_sync_running(d));
 785
 786                         llh = NULL;
 787                         rec = NULL;
 788                 }
 789
 790                 if (d->opd_syn_last_processed_id == d->opd_syn_last_used_id)
 791                         osp_sync_remove_from_tracker(d);
 792
 793                 l_wait_event(d->opd_syn_waitq,
 794                              !osp_sync_running(d) ||
 795                              osp_sync_can_process_new(d, rec) ||
 796                              !cfs_list_empty(&d->opd_syn_committed_there),
 797                              &lwi);
 798         } while (1);
 799 }
 800
 801 /*
 802  * this thread runs llog_cat_process() scanner calling our callback
 803  * to process llog records. in the callback we implement tricky
 804  * state machine as we don't want to start scanning of the llog again
 805  * and again, also we don't want to process too many records and send
 806  * too many RPCs a time. so, depending on current load (num of changes
 807  * being synced to OST) the callback can suspend awaiting for some
 808  * new conditions, like syncs completed.
 809  *
 810  * in order to process llog records left by previous boots and to allow
 811  * llog_process_thread() to find something (otherwise it'd just exit
 812  * immediately) we add a special GENERATATION record on each boot.
 813  */
 814 static int osp_sync_thread(void *_arg)
 815 {
 816         struct osp_device       *d = _arg;
 817         struct ptlrpc_thread    *thread = &d->opd_syn_thread;
 818         struct l_wait_info       lwi = { 0 };
 819         struct llog_ctxt        *ctxt;
 820         struct obd_device       *obd = d->opd_obd;
 821         struct llog_handle      *llh;
 822         struct lu_env            env;
 823         int                      rc;
 824         char                     pname[16];
 825
 826         ENTRY;
 827
 828         rc = lu_env_init(&env, LCT_LOCAL);
 829         if (rc) {
 830                 CERROR("%s: can't initialize env: rc = %d\n",
 831                        obd->obd_name, rc);
 832                 RETURN(rc);
 833         }
 834
 835         sprintf(pname, "osp-syn-%u\n", d->opd_index);
 836         cfs_daemonize(pname);
 837
 838         cfs_spin_lock(&d->opd_syn_lock);
 839         thread->t_flags = SVC_RUNNING;
 840         cfs_spin_unlock(&d->opd_syn_lock);
 841         cfs_waitq_signal(&thread->t_ctl_waitq);
 842
 843         ctxt = llog_get_context(obd, LLOG_MDS_OST_ORIG_CTXT);
 844         if (ctxt == NULL) {
 845                 CERROR("can't get appropriate context\n");
 846                 GOTO(out, rc = -EINVAL);
 847         }
 848
 849         llh = ctxt->loc_handle;
 850         if (llh == NULL) {
 851                 CERROR("can't get llh\n");
 852                 llog_ctxt_put(ctxt);
 853                 GOTO(out, rc = -EINVAL);
 854         }
 855
 856         rc = llog_cat_process(&env, llh, osp_sync_process_queues, d, 0, 0);
 857         LASSERTF(rc == 0 || rc == LLOG_PROC_BREAK,
 858                  "%lu changes, %u in progress, %u in flight: %d\n",
 859                  d->opd_syn_changes, d->opd_syn_rpc_in_progress,
 860                  d->opd_syn_rpc_in_flight, rc);
 861
 862         /* we don't expect llog_process_thread() to exit till umount */
 863         LASSERTF(thread->t_flags != SVC_RUNNING,
 864                  "%lu changes, %u in progress, %u in flight\n",
 865                  d->opd_syn_changes, d->opd_syn_rpc_in_progress,
 866                  d->opd_syn_rpc_in_flight);
 867
 868         osp_sync_process_committed(&env, d);
 869
 870         llog_cat_close(&env, llh);
 871         rc = llog_cleanup(&env, ctxt);
 872         if (rc)
 873                 CERROR("can't cleanup llog: %d\n", rc);
 874 out:
 875         thread->t_flags = SVC_STOPPED;
 876
 877         /*
 878          * there might be a race between osp sync thread sending RPCs and
 879          * import invalidation. this can result in RPCs being in ptlrpcd
 880          * till this point. for safete reason let's wait till they are done
 881          */
 882         l_wait_event(d->opd_syn_waitq, d->opd_syn_rpc_in_flight == 0, &lwi);
 883
 884         cfs_waitq_signal(&thread->t_ctl_waitq);
 885         LASSERTF(d->opd_syn_rpc_in_progress == 0,
 886                  "%s: %d %d %sempty\n",
 887                  d->opd_obd->obd_name, d->opd_syn_rpc_in_progress,
 888                  d->opd_syn_rpc_in_flight,
 889                  cfs_list_empty(&d->opd_syn_committed_there) ? "" : "!");
 890
 891         lu_env_fini(&env);
 892
 893         RETURN(0);
 894 }
 895
 896 static struct llog_operations osp_mds_ost_orig_logops;
 897
 898 static int osp_sync_llog_init(const struct lu_env *env, struct osp_device *d)
 899 {
 900         struct osp_thread_info *osi = osp_env_info(env);
 901         struct llog_handle     *lgh;
 902         struct obd_device      *obd = d->opd_obd;
 903         struct llog_ctxt       *ctxt;
 904         int                     rc;
 905
 906         ENTRY;
 907
 908         LASSERT(obd);
 909
 910         /*
 911          * open llog corresponding to our OST
 912          */
 913         OBD_SET_CTXT_MAGIC(&obd->obd_lvfs_ctxt);
 914         obd->obd_lvfs_ctxt.dt = d->opd_storage;
 915
 916         rc = llog_osd_get_cat_list(env, d->opd_storage, d->opd_index, 1,
 917                                    &osi->osi_cid);
 918         if (rc) {
 919                 CERROR("%s: can't get id from catalogs: rc = %d\n",
 920                        obd->obd_name, rc);
 921                 RETURN(rc);
 922         }
 923
 924         CDEBUG(D_INFO, "%s: Init llog for %d - catid "LPX64"/"LPX64":%x\n",
 925                obd->obd_name, d->opd_index, osi->osi_cid.lci_logid.lgl_oid,
 926                osi->osi_cid.lci_logid.lgl_oseq,
 927                osi->osi_cid.lci_logid.lgl_ogen);
 928
 929         osp_mds_ost_orig_logops = llog_osd_ops;
 930         rc = llog_setup(env, obd, &obd->obd_olg, LLOG_MDS_OST_ORIG_CTXT, obd,
 931                         &osp_mds_ost_orig_logops);
 932         if (rc)
 933                 RETURN(rc);
 934
 935         ctxt = llog_get_context(obd, LLOG_MDS_OST_ORIG_CTXT);
 936         LASSERT(ctxt);
 937
 938         if (likely(osi->osi_cid.lci_logid.lgl_oid != 0)) {
 939                 rc = llog_open(env, ctxt, &lgh, &osi->osi_cid.lci_logid, NULL,
 940                                LLOG_OPEN_EXISTS);
 941                 /* re-create llog if it is missing */
 942                 if (rc == -ENOENT)
 943                         osi->osi_cid.lci_logid.lgl_oid = 0;
 944                 else if (rc < 0)
 945                         GOTO(out_cleanup, rc);
 946         }
 947
 948         if (unlikely(osi->osi_cid.lci_logid.lgl_oid == 0)) {
 949                 rc = llog_open_create(env, ctxt, &lgh, NULL, NULL);
 950                 if (rc < 0)
 951                         GOTO(out_cleanup, rc);
 952                 osi->osi_cid.lci_logid = lgh->lgh_id;
 953         }
 954
 955         ctxt->loc_handle = lgh;
 956         lgh->lgh_logops->lop_add = llog_cat_add_rec;
 957         lgh->lgh_logops->lop_declare_add = llog_cat_declare_add_rec;
 958
 959         rc = llog_cat_init_and_process(env, lgh);
 960         if (rc)
 961                 GOTO(out_close, rc);
 962
 963         rc = llog_osd_put_cat_list(env, d->opd_storage, d->opd_index, 1,
 964                                    &osi->osi_cid);
 965         if (rc)
 966                 GOTO(out_close, rc);
 967
 968         /*
 969          * put a mark in the llog till which we'll be processing
 970          * old records restless
 971          */
 972         d->opd_syn_generation.mnt_cnt = cfs_time_current();
 973         d->opd_syn_generation.conn_cnt = cfs_time_current();
 974
 975         osi->osi_hdr.lrh_type = LLOG_GEN_REC;
 976         osi->osi_hdr.lrh_len = sizeof(osi->osi_gen);
 977
 978         memcpy(&osi->osi_gen.lgr_gen, &d->opd_syn_generation,
 979                sizeof(osi->osi_gen.lgr_gen));
 980
 981         rc = llog_cat_add(env, lgh, &osi->osi_gen.lgr_hdr, &osi->osi_cookie,
 982                           NULL);
 983         if (rc < 0)
 984                 GOTO(out_close, rc);
 985         llog_ctxt_put(ctxt);
 986         RETURN(0);
 987 out_close:
 988         llog_cat_close(env, lgh);
 989 out_cleanup:
 990         llog_cleanup(env, ctxt);
 991         RETURN(rc);
 992 }
 993
 994 static void osp_sync_llog_fini(const struct lu_env *env, struct osp_device *d)
 995 {
 996         struct llog_ctxt *ctxt;
 997
 998         ctxt = llog_get_context(d->opd_obd, LLOG_MDS_OST_ORIG_CTXT);
 999         llog_cat_close(env, ctxt->loc_handle);
1000         llog_cleanup(env, ctxt);
1001 }
1002
1003 /*
1004  * initializes sync component of OSP
1005  */
1006 int osp_sync_init(const struct lu_env *env, struct osp_device *d)
1007 {
1008         struct l_wait_info       lwi = { 0 };
1009         int                      rc;
1010
1011         ENTRY;
1012
1013         rc = osp_sync_id_traction_init(d);
1014         if (rc)
1015                 RETURN(rc);
1016
1017         /*
1018          * initialize llog storing changes
1019          */
1020         rc = osp_sync_llog_init(env, d);
1021         if (rc) {
1022                 CERROR("%s: can't initialize llog: rc = %d\n",
1023                        d->opd_obd->obd_name, rc);
1024                 GOTO(err_id, rc);
1025         }
1026
1027         /*
1028          * Start synchronization thread
1029          */
1030         d->opd_syn_max_rpc_in_flight = OSP_MAX_IN_FLIGHT;
1031         d->opd_syn_max_rpc_in_progress = OSP_MAX_IN_PROGRESS;
1032         cfs_spin_lock_init(&d->opd_syn_lock);
1033         cfs_waitq_init(&d->opd_syn_waitq);
1034         cfs_waitq_init(&d->opd_syn_thread.t_ctl_waitq);
1035         CFS_INIT_LIST_HEAD(&d->opd_syn_committed_there);
1036
1037         rc = cfs_create_thread(osp_sync_thread, d, 0);
1038         if (rc < 0) {
1039                 CERROR("%s: can't start sync thread: rc = %d\n",
1040                        d->opd_obd->obd_name, rc);
1041                 GOTO(err_llog, rc);
1042         }
1043
1044         l_wait_event(d->opd_syn_thread.t_ctl_waitq,
1045                      osp_sync_running(d) || osp_sync_stopped(d), &lwi);
1046
1047         RETURN(0);
1048 err_llog:
1049         osp_sync_llog_fini(env, d);
1050 err_id:
1051         osp_sync_id_traction_fini(d);
1052         return rc;
1053 }
1054
1055 int osp_sync_fini(struct osp_device *d)
1056 {
1057         struct ptlrpc_thread *thread = &d->opd_syn_thread;
1058
1059         ENTRY;
1060
1061         thread->t_flags = SVC_STOPPING;
1062         cfs_waitq_signal(&d->opd_syn_waitq);
1063         cfs_wait_event(thread->t_ctl_waitq, thread->t_flags & SVC_STOPPED);
1064
1065         /*
1066          * unregister transaction callbacks only when sync thread
1067          * has finished operations with llog
1068          */
1069         osp_sync_id_traction_fini(d);
1070
1071         RETURN(0);
1072 }
1073
1074 static CFS_DEFINE_MUTEX(osp_id_tracker_sem);
1075 static CFS_LIST_HEAD(osp_id_tracker_list);
1076
1077 static void osp_sync_tracker_commit_cb(struct thandle *th, void *cookie)
1078 {
1079         struct osp_id_tracker   *tr = cookie;
1080         struct osp_device       *d;
1081         struct osp_txn_info     *txn;
1082
1083         LASSERT(tr);
1084
1085         txn = osp_txn_info(&th->th_ctx);
1086         if (txn == NULL || txn->oti_current_id < tr->otr_committed_id)
1087                 return;
1088
1089         cfs_spin_lock(&tr->otr_lock);
1090         if (likely(txn->oti_current_id > tr->otr_committed_id)) {
1091                 CDEBUG(D_OTHER, "committed: %u -> %u\n",
1092                        tr->otr_committed_id, txn->oti_current_id);
1093                 tr->otr_committed_id = txn->oti_current_id;
1094
1095                 cfs_list_for_each_entry(d, &tr->otr_wakeup_list,
1096                                         opd_syn_ontrack) {
1097                         d->opd_syn_last_committed_id = tr->otr_committed_id;
1098                         cfs_waitq_signal(&d->opd_syn_waitq);
1099                 }
1100         }
1101         cfs_spin_unlock(&tr->otr_lock);
1102 }
1103
1104 static int osp_sync_id_traction_init(struct osp_device *d)
1105 {
1106         struct osp_id_tracker   *tr, *found = NULL;
1107         int                      rc = 0;
1108
1109         LASSERT(d);
1110         LASSERT(d->opd_storage);
1111         LASSERT(d->opd_syn_tracker == NULL);
1112         CFS_INIT_LIST_HEAD(&d->opd_syn_ontrack);
1113
1114         cfs_mutex_lock(&osp_id_tracker_sem);
1115         cfs_list_for_each_entry(tr, &osp_id_tracker_list, otr_list) {
1116                 if (tr->otr_dev == d->opd_storage) {
1117                         LASSERT(cfs_atomic_read(&tr->otr_refcount));
1118                         cfs_atomic_inc(&tr->otr_refcount);
1119                         d->opd_syn_tracker = tr;
1120                         found = tr;
1121                         break;
1122                 }
1123         }
1124
1125         if (found == NULL) {
1126                 rc = -ENOMEM;
1127                 OBD_ALLOC_PTR(tr);
1128                 if (tr) {
1129                         d->opd_syn_tracker = tr;
1130                         cfs_spin_lock_init(&tr->otr_lock);
1131                         tr->otr_dev = d->opd_storage;
1132                         tr->otr_next_id = 1;
1133                         tr->otr_committed_id = 0;
1134                         cfs_atomic_set(&tr->otr_refcount, 1);
1135                         CFS_INIT_LIST_HEAD(&tr->otr_wakeup_list);
1136                         cfs_list_add(&tr->otr_list, &osp_id_tracker_list);
1137                         tr->otr_tx_cb.dtc_txn_commit =
1138                                                 osp_sync_tracker_commit_cb;
1139                         tr->otr_tx_cb.dtc_cookie = tr;
1140                         tr->otr_tx_cb.dtc_tag = LCT_MD_THREAD;
1141                         dt_txn_callback_add(d->opd_storage, &tr->otr_tx_cb);
1142                         rc = 0;
1143                 }
1144         }
1145         cfs_mutex_unlock(&osp_id_tracker_sem);
1146
1147         return rc;
1148 }
1149
1150 static void osp_sync_id_traction_fini(struct osp_device *d)
1151 {
1152         struct osp_id_tracker *tr;
1153
1154         ENTRY;
1155
1156         LASSERT(d);
1157         tr = d->opd_syn_tracker;
1158         if (tr == NULL) {
1159                 EXIT;
1160                 return;
1161         }
1162
1163         osp_sync_remove_from_tracker(d);
1164
1165         cfs_mutex_lock(&osp_id_tracker_sem);
1166         if (cfs_atomic_dec_and_test(&tr->otr_refcount)) {
1167                 dt_txn_callback_del(d->opd_storage, &tr->otr_tx_cb);
1168                 LASSERT(cfs_list_empty(&tr->otr_wakeup_list));
1169                 cfs_list_del(&tr->otr_list);
1170                 OBD_FREE_PTR(tr);
1171                 d->opd_syn_tracker = NULL;
1172         }
1173         cfs_mutex_unlock(&osp_id_tracker_sem);
1174
1175         EXIT;
1176 }
1177
1178 /*
1179  * generates id for the tracker
1180  */
1181 static __u32 osp_sync_id_get(struct osp_device *d, __u32 id)
1182 {
1183         struct osp_id_tracker *tr;
1184
1185         tr = d->opd_syn_tracker;
1186         LASSERT(tr);
1187
1188         /* XXX: we can improve this introducing per-cpu preallocated ids? */
1189         cfs_spin_lock(&tr->otr_lock);
1190         if (unlikely(tr->otr_next_id <= d->opd_syn_last_used_id)) {
1191                 cfs_spin_unlock(&tr->otr_lock);
1192                 CERROR("%s: next %u, last synced %lu\n",
1193                        d->opd_obd->obd_name, tr->otr_next_id,
1194                        d->opd_syn_last_used_id);
1195                 LBUG();
1196         }
1197
1198         if (id == 0)
1199                 id = tr->otr_next_id++;
1200         if (id > d->opd_syn_last_used_id)
1201                 d->opd_syn_last_used_id = id;
1202         if (cfs_list_empty(&d->opd_syn_ontrack))
1203                 cfs_list_add(&d->opd_syn_ontrack, &tr->otr_wakeup_list);
1204         cfs_spin_unlock(&tr->otr_lock);
1205         CDEBUG(D_OTHER, "new id %u\n", (unsigned) id);
1206
1207         return id;
1208 }
1209
1210 static void osp_sync_remove_from_tracker(struct osp_device *d)
1211 {
1212         struct osp_id_tracker *tr;
1213
1214         tr = d->opd_syn_tracker;
1215         LASSERT(tr);
1216
1217         if (cfs_list_empty(&d->opd_syn_ontrack))
1218                 return;
1219
1220         cfs_spin_lock(&tr->otr_lock);
1221         cfs_list_del_init(&d->opd_syn_ontrack);
1222         cfs_spin_unlock(&tr->otr_lock);
1223 }
1224