lustre/lov/lov_lock.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) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2011, 2012, Whamcloud, 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  * Implementation of cl_lock for LOV layer.
  37  *
  38  *   Author: Nikita Danilov <nikita.danilov@sun.com>
  39  */
  40
  41 #define DEBUG_SUBSYSTEM S_LOV
  42
  43 #include "lov_cl_internal.h"
  44
  45 /** \addtogroup lov
  46  *  @{
  47  */
  48
  49 static struct cl_lock_closure *lov_closure_get(const struct lu_env *env,
  50                                                struct cl_lock *parent);
  51
  52 static int lov_lock_unuse(const struct lu_env *env,
  53                           const struct cl_lock_slice *slice);
  54 /*****************************************************************************
  55  *
  56  * Lov lock operations.
  57  *
  58  */
  59
  60 static struct lov_sublock_env *lov_sublock_env_get(const struct lu_env *env,
  61                                                    struct cl_lock *parent,
  62                                                    struct lov_lock_sub *lls)
  63 {
  64         struct lov_sublock_env *subenv;
  65         struct lov_io          *lio    = lov_env_io(env);
  66         struct cl_io           *io     = lio->lis_cl.cis_io;
  67         struct lov_io_sub      *sub;
  68
  69         subenv = &lov_env_session(env)->ls_subenv;
  70
  71         /*
  72          * FIXME: We tend to use the subio's env & io to call the sublock
  73          * lock operations because osc lock sometimes stores some control
  74          * variables in thread's IO infomation(Now only lockless information).
  75          * However, if the lock's host(object) is different from the object
  76          * for current IO, we have no way to get the subenv and subio because
  77          * they are not initialized at all. As a temp fix, in this case,
  78          * we still borrow the parent's env to call sublock operations.
  79          */
  80         if (!io || !cl_object_same(io->ci_obj, parent->cll_descr.cld_obj)) {
  81                 subenv->lse_env = env;
  82                 subenv->lse_io  = io;
  83                 subenv->lse_sub = NULL;
  84         } else {
  85                 sub = lov_sub_get(env, lio, lls->sub_stripe);
  86                 if (!IS_ERR(sub)) {
  87                         subenv->lse_env = sub->sub_env;
  88                         subenv->lse_io  = sub->sub_io;
  89                         subenv->lse_sub = sub;
  90                 } else {
  91                         subenv = (void*)sub;
  92                 }
  93         }
  94         return subenv;
  95 }
  96
  97 static void lov_sublock_env_put(struct lov_sublock_env *subenv)
  98 {
  99         if (subenv && subenv->lse_sub)
 100                 lov_sub_put(subenv->lse_sub);
 101 }
 102
 103 static void lov_sublock_adopt(const struct lu_env *env, struct lov_lock *lck,
 104                               struct cl_lock *sublock, int idx,
 105                               struct lov_lock_link *link)
 106 {
 107         struct lovsub_lock *lsl;
 108         struct cl_lock     *parent = lck->lls_cl.cls_lock;
 109         int                 rc;
 110
 111         LASSERT(cl_lock_is_mutexed(parent));
 112         LASSERT(cl_lock_is_mutexed(sublock));
 113         ENTRY;
 114
 115         lsl = cl2sub_lock(sublock);
 116         /*
 117          * check that sub-lock doesn't have lock link to this top-lock.
 118          */
 119         LASSERT(lov_lock_link_find(env, lck, lsl) == NULL);
 120         LASSERT(idx < lck->lls_nr);
 121
 122         lck->lls_sub[idx].sub_lock = lsl;
 123         lck->lls_nr_filled++;
 124         LASSERT(lck->lls_nr_filled <= lck->lls_nr);
 125         cfs_list_add_tail(&link->lll_list, &lsl->lss_parents);
 126         link->lll_idx = idx;
 127         link->lll_super = lck;
 128         cl_lock_get(parent);
 129         lu_ref_add(&parent->cll_reference, "lov-child", sublock);
 130         lck->lls_sub[idx].sub_flags |= LSF_HELD;
 131         cl_lock_user_add(env, sublock);
 132
 133         rc = lov_sublock_modify(env, lck, lsl, &sublock->cll_descr, idx);
 134         LASSERT(rc == 0); /* there is no way this can fail, currently */
 135         EXIT;
 136 }
 137
 138 static struct cl_lock *lov_sublock_alloc(const struct lu_env *env,
 139                                          const struct cl_io *io,
 140                                          struct lov_lock *lck,
 141                                          int idx, struct lov_lock_link **out)
 142 {
 143         struct cl_lock       *sublock;
 144         struct cl_lock       *parent;
 145         struct lov_lock_link *link;
 146
 147         LASSERT(idx < lck->lls_nr);
 148         ENTRY;
 149
 150         OBD_SLAB_ALLOC_PTR_GFP(link, lov_lock_link_kmem, CFS_ALLOC_IO);
 151         if (link != NULL) {
 152                 struct lov_sublock_env *subenv;
 153                 struct lov_lock_sub  *lls;
 154                 struct cl_lock_descr *descr;
 155
 156                 parent = lck->lls_cl.cls_lock;
 157                 lls    = &lck->lls_sub[idx];
 158                 descr  = &lls->sub_descr;
 159
 160                 subenv = lov_sublock_env_get(env, parent, lls);
 161                 if (!IS_ERR(subenv)) {
 162                         /* CAVEAT: Don't try to add a field in lov_lock_sub
 163                          * to remember the subio. This is because lock is able
 164                          * to be cached, but this is not true for IO. This
 165                          * further means a sublock might be referenced in
 166                          * different io context. -jay */
 167
 168                         sublock = cl_lock_hold(subenv->lse_env, subenv->lse_io,
 169                                                descr, "lov-parent", parent);
 170                         lov_sublock_env_put(subenv);
 171                 } else {
 172                         /* error occurs. */
 173                         sublock = (void*)subenv;
 174                 }
 175
 176                 if (!IS_ERR(sublock))
 177                         *out = link;
 178                 else
 179                         OBD_SLAB_FREE_PTR(link, lov_lock_link_kmem);
 180         } else
 181                 sublock = ERR_PTR(-ENOMEM);
 182         RETURN(sublock);
 183 }
 184
 185 static void lov_sublock_unlock(const struct lu_env *env,
 186                                struct lovsub_lock *lsl,
 187                                struct cl_lock_closure *closure,
 188                                struct lov_sublock_env *subenv)
 189 {
 190         ENTRY;
 191         lov_sublock_env_put(subenv);
 192         lsl->lss_active = NULL;
 193         cl_lock_disclosure(env, closure);
 194         EXIT;
 195 }
 196
 197 static int lov_sublock_lock(const struct lu_env *env,
 198                             struct lov_lock *lck,
 199                             struct lov_lock_sub *lls,
 200                             struct cl_lock_closure *closure,
 201                             struct lov_sublock_env **lsep)
 202 {
 203         struct lovsub_lock *sublock;
 204         struct cl_lock     *child;
 205         int                 result = 0;
 206         ENTRY;
 207
 208         LASSERT(cfs_list_empty(&closure->clc_list));
 209
 210         sublock = lls->sub_lock;
 211         child = sublock->lss_cl.cls_lock;
 212         result = cl_lock_closure_build(env, child, closure);
 213         if (result == 0) {
 214                 struct cl_lock *parent = closure->clc_origin;
 215
 216                 LASSERT(cl_lock_is_mutexed(child));
 217                 sublock->lss_active = parent;
 218
 219                 if (unlikely((child->cll_state == CLS_FREEING) ||
 220                              (child->cll_flags & CLF_CANCELLED))) {
 221                         struct lov_lock_link *link;
 222                         /*
 223                          * we could race with lock deletion which temporarily
 224                          * put the lock in freeing state, bug 19080.
 225                          */
 226                         LASSERT(!(lls->sub_flags & LSF_HELD));
 227
 228                         link = lov_lock_link_find(env, lck, sublock);
 229                         LASSERT(link != NULL);
 230                         lov_lock_unlink(env, link, sublock);
 231                         lov_sublock_unlock(env, sublock, closure, NULL);
 232                         lck->lls_cancel_race = 1;
 233                         result = CLO_REPEAT;
 234                 } else if (lsep) {
 235                         struct lov_sublock_env *subenv;
 236                         subenv = lov_sublock_env_get(env, parent, lls);
 237                         if (IS_ERR(subenv)) {
 238                                 lov_sublock_unlock(env, sublock,
 239                                                    closure, NULL);
 240                                 result = PTR_ERR(subenv);
 241                         } else {
 242                                 *lsep = subenv;
 243                         }
 244                 }
 245         }
 246         RETURN(result);
 247 }
 248
 249 /**
 250  * Updates the result of a top-lock operation from a result of sub-lock
 251  * sub-operations. Top-operations like lov_lock_{enqueue,use,unuse}() iterate
 252  * over sub-locks and lov_subresult() is used to calculate return value of a
 253  * top-operation. To this end, possible return values of sub-operations are
 254  * ordered as
 255  *
 256  *     - 0                  success
 257  *     - CLO_WAIT           wait for event
 258  *     - CLO_REPEAT         repeat top-operation
 259  *     - -ne                fundamental error
 260  *
 261  * Top-level return code can only go down through this list. CLO_REPEAT
 262  * overwrites CLO_WAIT, because lock mutex was released and sleeping condition
 263  * has to be rechecked by the upper layer.
 264  */
 265 static int lov_subresult(int result, int rc)
 266 {
 267         int result_rank;
 268         int rc_rank;
 269
 270         ENTRY;
 271
 272         LASSERTF(result <= 0 || result == CLO_REPEAT || result == CLO_WAIT,
 273                  "result = %d", result);
 274         LASSERTF(rc <= 0 || rc == CLO_REPEAT || rc == CLO_WAIT,
 275                  "rc = %d\n", rc);
 276         CLASSERT(CLO_WAIT < CLO_REPEAT);
 277
 278         /* calculate ranks in the ordering above */
 279         result_rank = result < 0 ? 1 + CLO_REPEAT : result;
 280         rc_rank = rc < 0 ? 1 + CLO_REPEAT : rc;
 281
 282         if (result_rank < rc_rank)
 283                 result = rc;
 284         RETURN(result);
 285 }
 286
 287 /**
 288  * Creates sub-locks for a given lov_lock for the first time.
 289  *
 290  * Goes through all sub-objects of top-object, and creates sub-locks on every
 291  * sub-object intersecting with top-lock extent. This is complicated by the
 292  * fact that top-lock (that is being created) can be accessed concurrently
 293  * through already created sub-locks (possibly shared with other top-locks).
 294  */
 295 static int lov_lock_sub_init(const struct lu_env *env,
 296                              struct lov_lock *lck, const struct cl_io *io)
 297 {
 298         int result = 0;
 299         int i;
 300         int nr;
 301         obd_off start;
 302         obd_off end;
 303         obd_off file_start;
 304         obd_off file_end;
 305
 306         struct lov_object       *loo    = cl2lov(lck->lls_cl.cls_obj);
 307         struct lov_layout_raid0 *r0     = lov_r0(loo);
 308         struct cl_lock          *parent = lck->lls_cl.cls_lock;
 309
 310         ENTRY;
 311
 312         lck->lls_orig = parent->cll_descr;
 313         file_start = cl_offset(lov2cl(loo), parent->cll_descr.cld_start);
 314         file_end   = cl_offset(lov2cl(loo), parent->cll_descr.cld_end + 1) - 1;
 315
 316         for (i = 0, nr = 0; i < r0->lo_nr; i++) {
 317                 /*
 318                  * XXX for wide striping smarter algorithm is desirable,
 319                  * breaking out of the loop, early.
 320                  */
 321                 if (lov_stripe_intersects(loo->lo_lsm, i,
 322                                           file_start, file_end, &start, &end))
 323                         nr++;
 324         }
 325         LASSERT(nr > 0);
 326         OBD_ALLOC_LARGE(lck->lls_sub, nr * sizeof lck->lls_sub[0]);
 327         if (lck->lls_sub == NULL)
 328                 RETURN(-ENOMEM);
 329
 330         lck->lls_nr = nr;
 331         /*
 332          * First, fill in sub-lock descriptions in
 333          * lck->lls_sub[].sub_descr. They are used by lov_sublock_alloc()
 334          * (called below in this function, and by lov_lock_enqueue()) to
 335          * create sub-locks. At this moment, no other thread can access
 336          * top-lock.
 337          */
 338         for (i = 0, nr = 0; i < r0->lo_nr; ++i) {
 339                 if (lov_stripe_intersects(loo->lo_lsm, i,
 340                                           file_start, file_end, &start, &end)) {
 341                         struct cl_lock_descr *descr;
 342
 343                         descr = &lck->lls_sub[nr].sub_descr;
 344
 345                         LASSERT(descr->cld_obj == NULL);
 346                         descr->cld_obj   = lovsub2cl(r0->lo_sub[i]);
 347                         descr->cld_start = cl_index(descr->cld_obj, start);
 348                         descr->cld_end   = cl_index(descr->cld_obj, end);
 349                         descr->cld_mode  = parent->cll_descr.cld_mode;
 350                         descr->cld_gid   = parent->cll_descr.cld_gid;
 351                         descr->cld_enq_flags   = parent->cll_descr.cld_enq_flags;
 352                         /* XXX has no effect */
 353                         lck->lls_sub[nr].sub_got = *descr;
 354                         lck->lls_sub[nr].sub_stripe = i;
 355                         nr++;
 356                 }
 357         }
 358         LASSERT(nr == lck->lls_nr);
 359         /*
 360          * Then, create sub-locks. Once at least one sub-lock was created,
 361          * top-lock can be reached by other threads.
 362          */
 363         for (i = 0; i < lck->lls_nr; ++i) {
 364                 struct cl_lock       *sublock;
 365                 struct lov_lock_link *link;
 366
 367                 if (lck->lls_sub[i].sub_lock == NULL) {
 368                         sublock = lov_sublock_alloc(env, io, lck, i, &link);
 369                         if (IS_ERR(sublock)) {
 370                                 result = PTR_ERR(sublock);
 371                                 break;
 372                         }
 373                         cl_lock_get_trust(sublock);
 374                         cl_lock_mutex_get(env, sublock);
 375                         cl_lock_mutex_get(env, parent);
 376                         /*
 377                          * recheck under mutex that sub-lock wasn't created
 378                          * concurrently, and that top-lock is still alive.
 379                          */
 380                         if (lck->lls_sub[i].sub_lock == NULL &&
 381                             parent->cll_state < CLS_FREEING) {
 382                                 lov_sublock_adopt(env, lck, sublock, i, link);
 383                                 cl_lock_mutex_put(env, parent);
 384                         } else {
 385                                 OBD_SLAB_FREE_PTR(link, lov_lock_link_kmem);
 386                                 cl_lock_mutex_put(env, parent);
 387                                 cl_lock_unhold(env, sublock,
 388                                                "lov-parent", parent);
 389                         }
 390                         cl_lock_mutex_put(env, sublock);
 391                         cl_lock_put(env, sublock);
 392                 }
 393         }
 394         /*
 395          * Some sub-locks can be missing at this point. This is not a problem,
 396          * because enqueue will create them anyway. Main duty of this function
 397          * is to fill in sub-lock descriptions in a race free manner.
 398          */
 399         RETURN(result);
 400 }
 401
 402 static int lov_sublock_release(const struct lu_env *env, struct lov_lock *lck,
 403                                int i, int deluser, int rc)
 404 {
 405         struct cl_lock *parent = lck->lls_cl.cls_lock;
 406
 407         LASSERT(cl_lock_is_mutexed(parent));
 408         ENTRY;
 409
 410         if (lck->lls_sub[i].sub_flags & LSF_HELD) {
 411                 struct cl_lock    *sublock;
 412                 int dying;
 413
 414                 LASSERT(lck->lls_sub[i].sub_lock != NULL);
 415                 sublock = lck->lls_sub[i].sub_lock->lss_cl.cls_lock;
 416                 LASSERT(cl_lock_is_mutexed(sublock));
 417
 418                 lck->lls_sub[i].sub_flags &= ~LSF_HELD;
 419                 if (deluser)
 420                         cl_lock_user_del(env, sublock);
 421                 /*
 422                  * If the last hold is released, and cancellation is pending
 423                  * for a sub-lock, release parent mutex, to avoid keeping it
 424                  * while sub-lock is being paged out.
 425                  */
 426                 dying = (sublock->cll_descr.cld_mode == CLM_PHANTOM ||
 427                          sublock->cll_descr.cld_mode == CLM_GROUP ||
 428                          (sublock->cll_flags & (CLF_CANCELPEND|CLF_DOOMED))) &&
 429                         sublock->cll_holds == 1;
 430                 if (dying)
 431                         cl_lock_mutex_put(env, parent);
 432                 cl_lock_unhold(env, sublock, "lov-parent", parent);
 433                 if (dying) {
 434                         cl_lock_mutex_get(env, parent);
 435                         rc = lov_subresult(rc, CLO_REPEAT);
 436                 }
 437                 /*
 438                  * From now on lck->lls_sub[i].sub_lock is a "weak" pointer,
 439                  * not backed by a reference on a
 440                  * sub-lock. lovsub_lock_delete() will clear
 441                  * lck->lls_sub[i].sub_lock under semaphores, just before
 442                  * sub-lock is destroyed.
 443                  */
 444         }
 445         RETURN(rc);
 446 }
 447
 448 static void lov_sublock_hold(const struct lu_env *env, struct lov_lock *lck,
 449                              int i)
 450 {
 451         struct cl_lock *parent = lck->lls_cl.cls_lock;
 452
 453         LASSERT(cl_lock_is_mutexed(parent));
 454         ENTRY;
 455
 456         if (!(lck->lls_sub[i].sub_flags & LSF_HELD)) {
 457                 struct cl_lock *sublock;
 458
 459                 LASSERT(lck->lls_sub[i].sub_lock != NULL);
 460                 sublock = lck->lls_sub[i].sub_lock->lss_cl.cls_lock;
 461                 LASSERT(cl_lock_is_mutexed(sublock));
 462                 LASSERT(sublock->cll_state != CLS_FREEING);
 463
 464                 lck->lls_sub[i].sub_flags |= LSF_HELD;
 465
 466                 cl_lock_get_trust(sublock);
 467                 cl_lock_hold_add(env, sublock, "lov-parent", parent);
 468                 cl_lock_user_add(env, sublock);
 469                 cl_lock_put(env, sublock);
 470         }
 471         EXIT;
 472 }
 473
 474 static void lov_lock_fini(const struct lu_env *env,
 475                           struct cl_lock_slice *slice)
 476 {
 477         struct lov_lock *lck;
 478         int i;
 479
 480         ENTRY;
 481         lck = cl2lov_lock(slice);
 482         LASSERT(lck->lls_nr_filled == 0);
 483         if (lck->lls_sub != NULL) {
 484                 for (i = 0; i < lck->lls_nr; ++i)
 485                         /*
 486                          * No sub-locks exists at this point, as sub-lock has
 487                          * a reference on its parent.
 488                          */
 489                         LASSERT(lck->lls_sub[i].sub_lock == NULL);
 490                 OBD_FREE_LARGE(lck->lls_sub,
 491                                lck->lls_nr * sizeof lck->lls_sub[0]);
 492         }
 493         OBD_SLAB_FREE_PTR(lck, lov_lock_kmem);
 494         EXIT;
 495 }
 496
 497 static int lov_lock_enqueue_wait(const struct lu_env *env,
 498                                  struct lov_lock *lck,
 499                                  struct cl_lock *sublock)
 500 {
 501         struct cl_lock *lock = lck->lls_cl.cls_lock;
 502         int             result;
 503         ENTRY;
 504
 505         LASSERT(cl_lock_is_mutexed(lock));
 506
 507         cl_lock_mutex_put(env, lock);
 508         result = cl_lock_enqueue_wait(env, sublock, 0);
 509         cl_lock_mutex_get(env, lock);
 510         RETURN(result ?: CLO_REPEAT);
 511 }
 512
 513 /**
 514  * Tries to advance a state machine of a given sub-lock toward enqueuing of
 515  * the top-lock.
 516  *
 517  * \retval 0 if state-transition can proceed
 518  * \retval -ve otherwise.
 519  */
 520 static int lov_lock_enqueue_one(const struct lu_env *env, struct lov_lock *lck,
 521                                 struct cl_lock *sublock,
 522                                 struct cl_io *io, __u32 enqflags, int last)
 523 {
 524         int result;
 525         ENTRY;
 526
 527         /* first, try to enqueue a sub-lock ... */
 528         result = cl_enqueue_try(env, sublock, io, enqflags);
 529         if ((sublock->cll_state == CLS_ENQUEUED) && !(enqflags & CEF_AGL)) {
 530                 /* if it is enqueued, try to `wait' on it---maybe it's already
 531                  * granted */
 532                 result = cl_wait_try(env, sublock);
 533                 if (result == CLO_REENQUEUED)
 534                         result = CLO_WAIT;
 535         }
 536         /*
 537          * If CEF_ASYNC flag is set, then all sub-locks can be enqueued in
 538          * parallel, otherwise---enqueue has to wait until sub-lock is granted
 539          * before proceeding to the next one.
 540          */
 541         if ((result == CLO_WAIT) && (sublock->cll_state <= CLS_HELD) &&
 542             (enqflags & CEF_ASYNC) && (!last || (enqflags & CEF_AGL)))
 543                 result = 0;
 544         RETURN(result);
 545 }
 546
 547 /**
 548  * Helper function for lov_lock_enqueue() that creates missing sub-lock.
 549  */
 550 static int lov_sublock_fill(const struct lu_env *env, struct cl_lock *parent,
 551                             struct cl_io *io, struct lov_lock *lck, int idx)
 552 {
 553         struct lov_lock_link *link;
 554         struct cl_lock       *sublock;
 555         int                   result;
 556
 557         LASSERT(parent->cll_depth == 1);
 558         cl_lock_mutex_put(env, parent);
 559         sublock = lov_sublock_alloc(env, io, lck, idx, &link);
 560         if (!IS_ERR(sublock))
 561                 cl_lock_mutex_get(env, sublock);
 562         cl_lock_mutex_get(env, parent);
 563
 564         if (!IS_ERR(sublock)) {
 565                 cl_lock_get_trust(sublock);
 566                 if (parent->cll_state == CLS_QUEUING &&
 567                     lck->lls_sub[idx].sub_lock == NULL) {
 568                         lov_sublock_adopt(env, lck, sublock, idx, link);
 569                 } else {
 570                         OBD_SLAB_FREE_PTR(link, lov_lock_link_kmem);
 571                         /* other thread allocated sub-lock, or enqueue is no
 572                          * longer going on */
 573                         cl_lock_mutex_put(env, parent);
 574                         cl_lock_unhold(env, sublock, "lov-parent", parent);
 575                         cl_lock_mutex_get(env, parent);
 576                 }
 577                 cl_lock_mutex_put(env, sublock);
 578                 cl_lock_put(env, sublock);
 579                 result = CLO_REPEAT;
 580         } else
 581                 result = PTR_ERR(sublock);
 582         return result;
 583 }
 584
 585 /**
 586  * Implementation of cl_lock_operations::clo_enqueue() for lov layer. This
 587  * function is rather subtle, as it enqueues top-lock (i.e., advances top-lock
 588  * state machine from CLS_QUEUING to CLS_ENQUEUED states) by juggling sub-lock
 589  * state machines in the face of sub-locks sharing (by multiple top-locks),
 590  * and concurrent sub-lock cancellations.
 591  */
 592 static int lov_lock_enqueue(const struct lu_env *env,
 593                             const struct cl_lock_slice *slice,
 594                             struct cl_io *io, __u32 enqflags)
 595 {
 596         struct cl_lock         *lock    = slice->cls_lock;
 597         struct lov_lock        *lck     = cl2lov_lock(slice);
 598         struct cl_lock_closure *closure = lov_closure_get(env, lock);
 599         int i;
 600         int result;
 601         enum cl_lock_state minstate;
 602
 603         ENTRY;
 604
 605         for (result = 0, minstate = CLS_FREEING, i = 0; i < lck->lls_nr; ++i) {
 606                 int rc;
 607                 struct lovsub_lock     *sub;
 608                 struct lov_lock_sub    *lls;
 609                 struct cl_lock         *sublock;
 610                 struct lov_sublock_env *subenv;
 611
 612                 if (lock->cll_state != CLS_QUEUING) {
 613                         /*
 614                          * Lock might have left QUEUING state if previous
 615                          * iteration released its mutex. Stop enqueing in this
 616                          * case and let the upper layer to decide what to do.
 617                          */
 618                         LASSERT(i > 0 && result != 0);
 619                         break;
 620                 }
 621
 622                 lls = &lck->lls_sub[i];
 623                 sub = lls->sub_lock;
 624                 /*
 625                  * Sub-lock might have been canceled, while top-lock was
 626                  * cached.
 627                  */
 628                 if (sub == NULL) {
 629                         result = lov_sublock_fill(env, lock, io, lck, i);
 630                         /* lov_sublock_fill() released @lock mutex,
 631                          * restart. */
 632                         break;
 633                 }
 634                 sublock = sub->lss_cl.cls_lock;
 635                 rc = lov_sublock_lock(env, lck, lls, closure, &subenv);
 636                 if (rc == 0) {
 637                         lov_sublock_hold(env, lck, i);
 638                         rc = lov_lock_enqueue_one(subenv->lse_env, lck, sublock,
 639                                                   subenv->lse_io, enqflags,
 640                                                   i == lck->lls_nr - 1);
 641                         minstate = min(minstate, sublock->cll_state);
 642                         if (rc == CLO_WAIT) {
 643                                 switch (sublock->cll_state) {
 644                                 case CLS_QUEUING:
 645                                         /* take recursive mutex, the lock is
 646                                          * released in lov_lock_enqueue_wait.
 647                                          */
 648                                         cl_lock_mutex_get(env, sublock);
 649                                         lov_sublock_unlock(env, sub, closure,
 650                                                            subenv);
 651                                         rc = lov_lock_enqueue_wait(env, lck,
 652                                                                    sublock);
 653                                         break;
 654                                 case CLS_CACHED:
 655                                         rc = lov_sublock_release(env, lck, i,
 656                                                                  1, rc);
 657                                 default:
 658                                         lov_sublock_unlock(env, sub, closure,
 659                                                            subenv);
 660                                         break;
 661                                 }
 662                         } else {
 663                                 LASSERT(sublock->cll_conflict == NULL);
 664                                 lov_sublock_unlock(env, sub, closure, subenv);
 665                         }
 666                 }
 667                 result = lov_subresult(result, rc);
 668                 if (result != 0)
 669                         break;
 670         }
 671         cl_lock_closure_fini(closure);
 672         RETURN(result ?: minstate >= CLS_ENQUEUED ? 0 : CLO_WAIT);
 673 }
 674
 675 static int lov_lock_unuse(const struct lu_env *env,
 676                           const struct cl_lock_slice *slice)
 677 {
 678         struct lov_lock        *lck     = cl2lov_lock(slice);
 679         struct cl_lock_closure *closure = lov_closure_get(env, slice->cls_lock);
 680         int i;
 681         int result;
 682
 683         ENTRY;
 684
 685         for (result = 0, i = 0; i < lck->lls_nr; ++i) {
 686                 int rc;
 687                 struct lovsub_lock     *sub;
 688                 struct cl_lock         *sublock;
 689                 struct lov_lock_sub    *lls;
 690                 struct lov_sublock_env *subenv;
 691
 692                 /* top-lock state cannot change concurrently, because single
 693                  * thread (one that released the last hold) carries unlocking
 694                  * to the completion. */
 695                 LASSERT(slice->cls_lock->cll_state == CLS_INTRANSIT);
 696                 lls = &lck->lls_sub[i];
 697                 sub = lls->sub_lock;
 698                 if (sub == NULL)
 699                         continue;
 700
 701                 sublock = sub->lss_cl.cls_lock;
 702                 rc = lov_sublock_lock(env, lck, lls, closure, &subenv);
 703                 if (rc == 0) {
 704                         if (lls->sub_flags & LSF_HELD) {
 705                                 LASSERT(sublock->cll_state == CLS_HELD ||
 706                                         sublock->cll_state == CLS_ENQUEUED);
 707                                 rc = cl_unuse_try(subenv->lse_env, sublock);
 708                                 rc = lov_sublock_release(env, lck, i, 0, rc);
 709                         }
 710                         lov_sublock_unlock(env, sub, closure, subenv);
 711                 }
 712                 result = lov_subresult(result, rc);
 713         }
 714
 715         if (result == 0 && lck->lls_cancel_race) {
 716                 lck->lls_cancel_race = 0;
 717                 result = -ESTALE;
 718         }
 719         cl_lock_closure_fini(closure);
 720         RETURN(result);
 721 }
 722
 723
 724 static void lov_lock_cancel(const struct lu_env *env,
 725                            const struct cl_lock_slice *slice)
 726 {
 727         struct lov_lock        *lck     = cl2lov_lock(slice);
 728         struct cl_lock_closure *closure = lov_closure_get(env, slice->cls_lock);
 729         int i;
 730         int result;
 731
 732         ENTRY;
 733
 734         for (result = 0, i = 0; i < lck->lls_nr; ++i) {
 735                 int rc;
 736                 struct lovsub_lock     *sub;
 737                 struct cl_lock         *sublock;
 738                 struct lov_lock_sub    *lls;
 739                 struct lov_sublock_env *subenv;
 740
 741                 /* top-lock state cannot change concurrently, because single
 742                  * thread (one that released the last hold) carries unlocking
 743                  * to the completion. */
 744                 lls = &lck->lls_sub[i];
 745                 sub = lls->sub_lock;
 746                 if (sub == NULL)
 747                         continue;
 748
 749                 sublock = sub->lss_cl.cls_lock;
 750                 rc = lov_sublock_lock(env, lck, lls, closure, &subenv);
 751                 if (rc == 0) {
 752                         if (!(lls->sub_flags & LSF_HELD)) {
 753                                 lov_sublock_unlock(env, sub, closure, subenv);
 754                                 continue;
 755                         }
 756
 757                         switch(sublock->cll_state) {
 758                         case CLS_HELD:
 759                                 rc = cl_unuse_try(subenv->lse_env, sublock);
 760                                 lov_sublock_release(env, lck, i, 0, 0);
 761                                 break;
 762                         default:
 763                                 lov_sublock_release(env, lck, i, 1, 0);
 764                                 break;
 765                         }
 766                         lov_sublock_unlock(env, sub, closure, subenv);
 767                 }
 768
 769                 if (rc == CLO_REPEAT) {
 770                         --i;
 771                         continue;
 772                 }
 773
 774                 result = lov_subresult(result, rc);
 775         }
 776
 777         if (result)
 778                 CL_LOCK_DEBUG(D_ERROR, env, slice->cls_lock,
 779                               "lov_lock_cancel fails with %d.\n", result);
 780
 781         cl_lock_closure_fini(closure);
 782 }
 783
 784 static int lov_lock_wait(const struct lu_env *env,
 785                          const struct cl_lock_slice *slice)
 786 {
 787         struct lov_lock        *lck     = cl2lov_lock(slice);
 788         struct cl_lock_closure *closure = lov_closure_get(env, slice->cls_lock);
 789         enum cl_lock_state      minstate;
 790         int                     reenqueued;
 791         int                     result;
 792         int                     i;
 793
 794         ENTRY;
 795
 796 again:
 797         for (result = 0, minstate = CLS_FREEING, i = 0, reenqueued = 0;
 798              i < lck->lls_nr; ++i) {
 799                 int rc;
 800                 struct lovsub_lock     *sub;
 801                 struct cl_lock         *sublock;
 802                 struct lov_lock_sub    *lls;
 803                 struct lov_sublock_env *subenv;
 804
 805                 lls = &lck->lls_sub[i];
 806                 sub = lls->sub_lock;
 807                 LASSERT(sub != NULL);
 808                 sublock = sub->lss_cl.cls_lock;
 809                 rc = lov_sublock_lock(env, lck, lls, closure, &subenv);
 810                 if (rc == 0) {
 811                         LASSERT(sublock->cll_state >= CLS_ENQUEUED);
 812                         if (sublock->cll_state < CLS_HELD)
 813                                 rc = cl_wait_try(env, sublock);
 814
 815                         minstate = min(minstate, sublock->cll_state);
 816                         lov_sublock_unlock(env, sub, closure, subenv);
 817                 }
 818                 if (rc == CLO_REENQUEUED) {
 819                         reenqueued++;
 820                         rc = 0;
 821                 }
 822                 result = lov_subresult(result, rc);
 823                 if (result != 0)
 824                         break;
 825         }
 826         /* Each sublock only can be reenqueued once, so will not loop for
 827          * ever. */
 828         if (result == 0 && reenqueued != 0)
 829                 goto again;
 830         cl_lock_closure_fini(closure);
 831         RETURN(result ?: minstate >= CLS_HELD ? 0 : CLO_WAIT);
 832 }
 833
 834 static int lov_lock_use(const struct lu_env *env,
 835                         const struct cl_lock_slice *slice)
 836 {
 837         struct lov_lock        *lck     = cl2lov_lock(slice);
 838         struct cl_lock_closure *closure = lov_closure_get(env, slice->cls_lock);
 839         int                     result;
 840         int                     i;
 841
 842         LASSERT(slice->cls_lock->cll_state == CLS_INTRANSIT);
 843         ENTRY;
 844
 845         for (result = 0, i = 0; i < lck->lls_nr; ++i) {
 846                 int rc;
 847                 struct lovsub_lock     *sub;
 848                 struct cl_lock         *sublock;
 849                 struct lov_lock_sub    *lls;
 850                 struct lov_sublock_env *subenv;
 851
 852                 LASSERT(slice->cls_lock->cll_state == CLS_INTRANSIT);
 853
 854                 lls = &lck->lls_sub[i];
 855                 sub = lls->sub_lock;
 856                 if (sub == NULL) {
 857                         /*
 858                          * Sub-lock might have been canceled, while top-lock was
 859                          * cached.
 860                          */
 861                         result = -ESTALE;
 862                         break;
 863                 }
 864
 865                 sublock = sub->lss_cl.cls_lock;
 866                 rc = lov_sublock_lock(env, lck, lls, closure, &subenv);
 867                 if (rc == 0) {
 868                         LASSERT(sublock->cll_state != CLS_FREEING);
 869                         lov_sublock_hold(env, lck, i);
 870                         if (sublock->cll_state == CLS_CACHED) {
 871                                 rc = cl_use_try(subenv->lse_env, sublock, 0);
 872                                 if (rc != 0)
 873                                         rc = lov_sublock_release(env, lck,
 874                                                                  i, 1, rc);
 875                         } else if (sublock->cll_state == CLS_NEW) {
 876                                 /* Sub-lock might have been canceled, while
 877                                  * top-lock was cached. */
 878                                 result = -ESTALE;
 879                                 lov_sublock_release(env, lck, i, 1, result);
 880                         }
 881                         lov_sublock_unlock(env, sub, closure, subenv);
 882                 }
 883                 result = lov_subresult(result, rc);
 884                 if (result != 0)
 885                         break;
 886         }
 887
 888         if (lck->lls_cancel_race) {
 889                 /*
 890                  * If there is unlocking happened at the same time, then
 891                  * sublock_lock state should be FREEING, and lov_sublock_lock
 892                  * should return CLO_REPEAT. In this case, it should return
 893                  * ESTALE, and up layer should reset the lock state to be NEW.
 894                  */
 895                 lck->lls_cancel_race = 0;
 896                 LASSERT(result != 0);
 897                 result = -ESTALE;
 898         }
 899         cl_lock_closure_fini(closure);
 900         RETURN(result);
 901 }
 902
 903 #if 0
 904 static int lock_lock_multi_match()
 905 {
 906         struct cl_lock          *lock    = slice->cls_lock;
 907         struct cl_lock_descr    *subneed = &lov_env_info(env)->lti_ldescr;
 908         struct lov_object       *loo     = cl2lov(lov->lls_cl.cls_obj);
 909         struct lov_layout_raid0 *r0      = lov_r0(loo);
 910         struct lov_lock_sub     *sub;
 911         struct cl_object        *subobj;
 912         obd_off  fstart;
 913         obd_off  fend;
 914         obd_off  start;
 915         obd_off  end;
 916         int i;
 917
 918         fstart = cl_offset(need->cld_obj, need->cld_start);
 919         fend   = cl_offset(need->cld_obj, need->cld_end + 1) - 1;
 920         subneed->cld_mode = need->cld_mode;
 921         cl_lock_mutex_get(env, lock);
 922         for (i = 0; i < lov->lls_nr; ++i) {
 923                 sub = &lov->lls_sub[i];
 924                 if (sub->sub_lock == NULL)
 925                         continue;
 926                 subobj = sub->sub_descr.cld_obj;
 927                 if (!lov_stripe_intersects(loo->lo_lsm, sub->sub_stripe,
 928                                            fstart, fend, &start, &end))
 929                         continue;
 930                 subneed->cld_start = cl_index(subobj, start);
 931                 subneed->cld_end   = cl_index(subobj, end);
 932                 subneed->cld_obj   = subobj;
 933                 if (!cl_lock_ext_match(&sub->sub_got, subneed)) {
 934                         result = 0;
 935                         break;
 936                 }
 937         }
 938         cl_lock_mutex_put(env, lock);
 939 }
 940 #endif
 941
 942 /**
 943  * Check if the extent region \a descr is covered by \a child against the
 944  * specific \a stripe.
 945  */
 946 static int lov_lock_stripe_is_matching(const struct lu_env *env,
 947                                        struct lov_object *lov, int stripe,
 948                                        const struct cl_lock_descr *child,
 949                                        const struct cl_lock_descr *descr)
 950 {
 951         struct lov_stripe_md *lsm = lov->lo_lsm;
 952         obd_off start;
 953         obd_off end;
 954         int result;
 955
 956         if (lov_r0(lov)->lo_nr == 1)
 957                 return cl_lock_ext_match(child, descr);
 958
 959         /*
 960          * For a multi-stripes object:
 961          * - make sure the descr only covers child's stripe, and
 962          * - check if extent is matching.
 963          */
 964         start = cl_offset(&lov->lo_cl, descr->cld_start);
 965         end   = cl_offset(&lov->lo_cl, descr->cld_end + 1) - 1;
 966         result = end - start <= lsm->lsm_stripe_size &&
 967                  stripe == lov_stripe_number(lsm, start) &&
 968                  stripe == lov_stripe_number(lsm, end);
 969         if (result) {
 970                 struct cl_lock_descr *subd = &lov_env_info(env)->lti_ldescr;
 971                 obd_off sub_start;
 972                 obd_off sub_end;
 973
 974                 subd->cld_obj  = NULL;   /* don't need sub object at all */
 975                 subd->cld_mode = descr->cld_mode;
 976                 subd->cld_gid  = descr->cld_gid;
 977                 result = lov_stripe_intersects(lsm, stripe, start, end,
 978                                                &sub_start, &sub_end);
 979                 LASSERT(result);
 980                 subd->cld_start = cl_index(child->cld_obj, sub_start);
 981                 subd->cld_end   = cl_index(child->cld_obj, sub_end);
 982                 result = cl_lock_ext_match(child, subd);
 983         }
 984         return result;
 985 }
 986
 987 /**
 988  * An implementation of cl_lock_operations::clo_fits_into() method.
 989  *
 990  * Checks whether a lock (given by \a slice) is suitable for \a
 991  * io. Multi-stripe locks can be used only for "quick" io, like truncate, or
 992  * O_APPEND write.
 993  *
 994  * \see ccc_lock_fits_into().
 995  */
 996 static int lov_lock_fits_into(const struct lu_env *env,
 997                               const struct cl_lock_slice *slice,
 998                               const struct cl_lock_descr *need,
 999                               const struct cl_io *io)
1000 {
1001         struct lov_lock   *lov = cl2lov_lock(slice);
1002         struct lov_object *obj = cl2lov(slice->cls_obj);
1003         int result;
1004
1005         LASSERT(cl_object_same(need->cld_obj, slice->cls_obj));
1006         LASSERT(lov->lls_nr > 0);
1007
1008         ENTRY;
1009
1010         if (need->cld_mode == CLM_GROUP)
1011                 /*
1012                  * always allow to match group lock.
1013                  */
1014                 result = cl_lock_ext_match(&lov->lls_orig, need);
1015         else if (lov->lls_nr == 1) {
1016                 struct cl_lock_descr *got = &lov->lls_sub[0].sub_got;
1017                 result = lov_lock_stripe_is_matching(env,
1018                                                      cl2lov(slice->cls_obj),
1019                                                      lov->lls_sub[0].sub_stripe,
1020                                                      got, need);
1021         } else if (io->ci_type != CIT_SETATTR && io->ci_type != CIT_MISC &&
1022                    !cl_io_is_append(io) && need->cld_mode != CLM_PHANTOM)
1023                 /*
1024                  * Multi-stripe locks are only suitable for `quick' IO and for
1025                  * glimpse.
1026                  */
1027                 result = 0;
1028         else
1029                 /*
1030                  * Most general case: multi-stripe existing lock, and
1031                  * (potentially) multi-stripe @need lock. Check that @need is
1032                  * covered by @lov's sub-locks.
1033                  *
1034                  * For now, ignore lock expansions made by the server, and
1035                  * match against original lock extent.
1036                  */
1037                 result = cl_lock_ext_match(&lov->lls_orig, need);
1038         CDEBUG(D_DLMTRACE, DDESCR"/"DDESCR" %d %d/%d: %d\n",
1039                PDESCR(&lov->lls_orig), PDESCR(&lov->lls_sub[0].sub_got),
1040                lov->lls_sub[0].sub_stripe, lov->lls_nr, lov_r0(obj)->lo_nr,
1041                result);
1042         RETURN(result);
1043 }
1044
1045 void lov_lock_unlink(const struct lu_env *env,
1046                      struct lov_lock_link *link, struct lovsub_lock *sub)
1047 {
1048         struct lov_lock *lck    = link->lll_super;
1049         struct cl_lock  *parent = lck->lls_cl.cls_lock;
1050
1051         LASSERT(cl_lock_is_mutexed(parent));
1052         LASSERT(cl_lock_is_mutexed(sub->lss_cl.cls_lock));
1053         ENTRY;
1054
1055         cfs_list_del_init(&link->lll_list);
1056         LASSERT(lck->lls_sub[link->lll_idx].sub_lock == sub);
1057         /* yank this sub-lock from parent's array */
1058         lck->lls_sub[link->lll_idx].sub_lock = NULL;
1059         LASSERT(lck->lls_nr_filled > 0);
1060         lck->lls_nr_filled--;
1061         lu_ref_del(&parent->cll_reference, "lov-child", sub->lss_cl.cls_lock);
1062         cl_lock_put(env, parent);
1063         OBD_SLAB_FREE_PTR(link, lov_lock_link_kmem);
1064         EXIT;
1065 }
1066
1067 struct lov_lock_link *lov_lock_link_find(const struct lu_env *env,
1068                                          struct lov_lock *lck,
1069                                          struct lovsub_lock *sub)
1070 {
1071         struct lov_lock_link *scan;
1072
1073         LASSERT(cl_lock_is_mutexed(sub->lss_cl.cls_lock));
1074         ENTRY;
1075
1076         cfs_list_for_each_entry(scan, &sub->lss_parents, lll_list) {
1077                 if (scan->lll_super == lck)
1078                         RETURN(scan);
1079         }
1080         RETURN(NULL);
1081 }
1082
1083 /**
1084  * An implementation of cl_lock_operations::clo_delete() method. This is
1085  * invoked for "top-to-bottom" delete, when lock destruction starts from the
1086  * top-lock, e.g., as a result of inode destruction.
1087  *
1088  * Unlinks top-lock from all its sub-locks. Sub-locks are not deleted there:
1089  * this is done separately elsewhere:
1090  *
1091  *     - for inode destruction, lov_object_delete() calls cl_object_kill() for
1092  *       each sub-object, purging its locks;
1093  *
1094  *     - in other cases (e.g., a fatal error with a top-lock) sub-locks are
1095  *       left in the cache.
1096  */
1097 static void lov_lock_delete(const struct lu_env *env,
1098                             const struct cl_lock_slice *slice)
1099 {
1100         struct lov_lock        *lck     = cl2lov_lock(slice);
1101         struct cl_lock_closure *closure = lov_closure_get(env, slice->cls_lock);
1102         struct lov_lock_link   *link;
1103         int                     rc;
1104         int                     i;
1105
1106         LASSERT(slice->cls_lock->cll_state == CLS_FREEING);
1107         ENTRY;
1108
1109         for (i = 0; i < lck->lls_nr; ++i) {
1110                 struct lov_lock_sub *lls = &lck->lls_sub[i];
1111                 struct lovsub_lock  *lsl = lls->sub_lock;
1112
1113                 if (lsl == NULL) /* already removed */
1114                         continue;
1115
1116                 rc = lov_sublock_lock(env, lck, lls, closure, NULL);
1117                 if (rc == CLO_REPEAT) {
1118                         --i;
1119                         continue;
1120                 }
1121
1122                 LASSERT(rc == 0);
1123                 LASSERT(lsl->lss_cl.cls_lock->cll_state < CLS_FREEING);
1124
1125                 if (lls->sub_flags & LSF_HELD)
1126                         lov_sublock_release(env, lck, i, 1, 0);
1127
1128                 link = lov_lock_link_find(env, lck, lsl);
1129                 LASSERT(link != NULL);
1130                 lov_lock_unlink(env, link, lsl);
1131                 LASSERT(lck->lls_sub[i].sub_lock == NULL);
1132
1133                 lov_sublock_unlock(env, lsl, closure, NULL);
1134         }
1135
1136         cl_lock_closure_fini(closure);
1137         EXIT;
1138 }
1139
1140 static int lov_lock_print(const struct lu_env *env, void *cookie,
1141                           lu_printer_t p, const struct cl_lock_slice *slice)
1142 {
1143         struct lov_lock *lck = cl2lov_lock(slice);
1144         int              i;
1145
1146         (*p)(env, cookie, "%d\n", lck->lls_nr);
1147         for (i = 0; i < lck->lls_nr; ++i) {
1148                 struct lov_lock_sub *sub;
1149
1150                 sub = &lck->lls_sub[i];
1151                 (*p)(env, cookie, "    %d %x: ", i, sub->sub_flags);
1152                 if (sub->sub_lock != NULL)
1153                         cl_lock_print(env, cookie, p,
1154                                       sub->sub_lock->lss_cl.cls_lock);
1155                 else
1156                         (*p)(env, cookie, "---\n");
1157         }
1158         return 0;
1159 }
1160
1161 static const struct cl_lock_operations lov_lock_ops = {
1162         .clo_fini      = lov_lock_fini,
1163         .clo_enqueue   = lov_lock_enqueue,
1164         .clo_wait      = lov_lock_wait,
1165         .clo_use       = lov_lock_use,
1166         .clo_unuse     = lov_lock_unuse,
1167         .clo_cancel    = lov_lock_cancel,
1168         .clo_fits_into = lov_lock_fits_into,
1169         .clo_delete    = lov_lock_delete,
1170         .clo_print     = lov_lock_print
1171 };
1172
1173 int lov_lock_init_raid0(const struct lu_env *env, struct cl_object *obj,
1174                         struct cl_lock *lock, const struct cl_io *io)
1175 {
1176         struct lov_lock *lck;
1177         int result;
1178
1179         ENTRY;
1180         OBD_SLAB_ALLOC_PTR_GFP(lck, lov_lock_kmem, CFS_ALLOC_IO);
1181         if (lck != NULL) {
1182                 cl_lock_slice_add(lock, &lck->lls_cl, obj, &lov_lock_ops);
1183                 result = lov_lock_sub_init(env, lck, io);
1184         } else
1185                 result = -ENOMEM;
1186         RETURN(result);
1187 }
1188
1189 static struct cl_lock_closure *lov_closure_get(const struct lu_env *env,
1190                                                struct cl_lock *parent)
1191 {
1192         struct cl_lock_closure *closure;
1193
1194         closure = &lov_env_info(env)->lti_closure;
1195         LASSERT(cfs_list_empty(&closure->clc_list));
1196         cl_lock_closure_init(env, closure, parent, 1);
1197         return closure;
1198 }
1199
1200
1201 /** @} lov */