lustre/lov/lov_object.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  30  * Use is subject to license terms.
  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_object for LOV layer.
  37  *
  38  *   Author: Nikita Danilov <nikita.danilov@sun.com>
  39  */
  40
  41 /** \addtogroup lov lov @{ */
  42
  43 #define DEBUG_SUBSYSTEM S_LOV
  44
  45 #include "lov_cl_internal.h"
  46
  47 /*****************************************************************************
  48  *
  49  * Layout operations.
  50  *
  51  */
  52
  53 struct lov_layout_operations {
  54         int (*llo_init)(const struct lu_env *env, struct lov_device *dev,
  55                         struct lov_object *lov,
  56                         const struct cl_object_conf *conf,
  57                         union lov_layout_state *state);
  58         void (*llo_delete)(const struct lu_env *env, struct lov_object *lov,
  59                            union lov_layout_state *state);
  60         void (*llo_fini)(const struct lu_env *env, struct lov_object *lov,
  61                          union lov_layout_state *state);
  62         void (*llo_install)(const struct lu_env *env, struct lov_object *lov,
  63                             union lov_layout_state *state);
  64         int  (*llo_print)(const struct lu_env *env, void *cookie,
  65                           lu_printer_t p, const struct lu_object *o);
  66         struct cl_page *(*llo_page_init)(const struct lu_env *env,
  67                                          struct cl_object *obj,
  68                                          struct cl_page *page,
  69                                          cfs_page_t *vmpage);
  70         int  (*llo_lock_init)(const struct lu_env *env,
  71                               struct cl_object *obj, struct cl_lock *lock,
  72                               const struct cl_io *io);
  73         int  (*llo_io_init)(const struct lu_env *env,
  74                             struct cl_object *obj, struct cl_io *io);
  75         int  (*llo_getattr)(const struct lu_env *env, struct cl_object *obj,
  76                             struct cl_attr *attr);
  77 };
  78
  79 /*****************************************************************************
  80  *
  81  * Lov object layout operations.
  82  *
  83  */
  84
  85 static void lov_install_empty(const struct lu_env *env,
  86                               struct lov_object *lov,
  87                               union  lov_layout_state *state)
  88 {
  89         /*
  90          * File without objects.
  91          */
  92 }
  93
  94 static int lov_init_empty(const struct lu_env *env,
  95                           struct lov_device *dev, struct lov_object *lov,
  96                           const struct cl_object_conf *conf,
  97                           union  lov_layout_state *state)
  98 {
  99         return 0;
 100 }
 101
 102 static void lov_install_raid0(const struct lu_env *env,
 103                               struct lov_object *lov,
 104                               union  lov_layout_state *state)
 105 {
 106         lov->u = *state;
 107 }
 108
 109 static void oinfo_get_fid(const struct lov_oinfo *oinfo, struct lu_fid *fid)
 110 {
 111         __u64 idx = oinfo->loi_id;
 112
 113         /* See idif definition in wiki:CMD3_interoperability_architecture */
 114
 115         LASSERT(oinfo->loi_gr < 1ULL << 16);
 116         LASSERT(oinfo->loi_id < 1ULL << 49);
 117         ENTRY;
 118
 119         /*
 120          * Now that the fid of stripe is not unique now, ost_idx have to
 121          * be used to make it unique. This is ok because the stripe fids
 122          * are just used in client side(to locate the objects). -jay
 123          */
 124         fid->f_seq = ((__u64)oinfo->loi_ost_idx) << 32 |
 125                      oinfo->loi_gr << 16 | idx >> 32;
 126         fid->f_oid = idx; /* truncated to 32 bits by assignment */
 127         fid->f_ver = 0;
 128         EXIT;
 129 }
 130
 131 static struct cl_object *lov_sub_find(const struct lu_env *env,
 132                                       struct cl_device *dev,
 133                                       const struct lu_fid *fid,
 134                                       const struct cl_object_conf *conf)
 135 {
 136         struct lu_object *o;
 137
 138         ENTRY;
 139         o = lu_object_find_at(env, cl2lu_dev(dev), fid, &conf->coc_lu);
 140         LASSERT(ergo(!IS_ERR(o), o->lo_dev->ld_type == &lovsub_device_type));
 141         RETURN(lu2cl(o));
 142 }
 143
 144 static int lov_init_sub(const struct lu_env *env, struct lov_object *lov,
 145                         struct cl_object *stripe,
 146                         struct lov_layout_raid0 *r0, int idx)
 147 {
 148         struct cl_object_header *hdr;
 149         struct cl_object_header *subhdr;
 150         struct cl_object_header *parent;
 151         struct lov_oinfo        *oinfo;
 152         int result;
 153
 154         hdr    = cl_object_header(lov2cl(lov));
 155         subhdr = cl_object_header(stripe);
 156         parent = subhdr->coh_parent;
 157
 158         oinfo = r0->lo_lsm->lsm_oinfo[idx];
 159         CDEBUG(D_INODE, DFID"@%p[%d] -> "DFID"@%p: id: "LPU64" gr: "LPU64
 160                " idx: %d gen: %d\n",
 161                PFID(&subhdr->coh_lu.loh_fid), subhdr, idx,
 162                PFID(&hdr->coh_lu.loh_fid), hdr,
 163                oinfo->loi_id, oinfo->loi_gr,
 164                oinfo->loi_ost_idx, oinfo->loi_ost_gen);
 165
 166         if (parent == NULL) {
 167                 subhdr->coh_parent = hdr;
 168                 subhdr->coh_nesting = hdr->coh_nesting + 1;
 169                 lu_object_ref_add(&stripe->co_lu, "lov-parent", lov);
 170                 r0->lo_sub[idx] = cl2lovsub(stripe);
 171                 r0->lo_sub[idx]->lso_super = lov;
 172                 r0->lo_sub[idx]->lso_index = idx;
 173                 result = 0;
 174         } else {
 175                 CERROR("Stripe is already owned by other file (%i).\n", idx);
 176                 LU_OBJECT_DEBUG(D_ERROR, env, &stripe->co_lu, "\n");
 177                 LU_OBJECT_DEBUG(D_ERROR, env, lu_object_top(&parent->coh_lu),
 178                                 "old\n");
 179                 LU_OBJECT_HEADER(D_ERROR, env, lov2lu(lov), "new\n");
 180                 cl_object_put(env, stripe);
 181                 result = -EIO;
 182         }
 183         return result;
 184 }
 185
 186 static int lov_init_raid0(const struct lu_env *env,
 187                           struct lov_device *dev, struct lov_object *lov,
 188                           const struct cl_object_conf *conf,
 189                           union  lov_layout_state *state)
 190 {
 191         int result;
 192         int i;
 193
 194         struct cl_object        *stripe;
 195         struct lov_thread_info  *lti     = lov_env_info(env);
 196         struct cl_object_conf   *subconf = &lti->lti_stripe_conf;
 197         struct lov_stripe_md    *lsm     = conf->u.coc_md->lsm;
 198         struct lu_fid           *ofid    = &lti->lti_fid;
 199         struct lov_layout_raid0 *r0      = &state->raid0;
 200
 201         ENTRY;
 202         r0->lo_nr  = conf->u.coc_md->lsm->lsm_stripe_count;
 203         r0->lo_lsm = conf->u.coc_md->lsm;
 204         LASSERT(r0->lo_nr <= lov_targets_nr(dev));
 205
 206         OBD_ALLOC(r0->lo_sub, r0->lo_nr * sizeof r0->lo_sub[0]);
 207         if (r0->lo_sub != NULL) {
 208                 result = 0;
 209                 subconf->coc_inode = conf->coc_inode;
 210                 /*
 211                  * Create stripe cl_objects.
 212                  */
 213                 for (i = 0; i < r0->lo_nr && result == 0; ++i) {
 214                         struct cl_device *subdev;
 215                         struct lov_oinfo *oinfo = lsm->lsm_oinfo[i];
 216                         int ost_idx = oinfo->loi_ost_idx;
 217
 218                         oinfo_get_fid(oinfo, ofid);
 219                         subdev = lovsub2cl_dev(dev->ld_target[ost_idx]);
 220                         subconf->u.coc_oinfo = oinfo;
 221                         stripe = lov_sub_find(env, subdev, ofid, subconf);
 222                         if (!IS_ERR(stripe))
 223                                 result = lov_init_sub(env, lov, stripe, r0, i);
 224                         else
 225                                 result = PTR_ERR(stripe);
 226                 }
 227         } else
 228                 result = -ENOMEM;
 229         RETURN(result);
 230 }
 231
 232 static void lov_delete_empty(const struct lu_env *env, struct lov_object *lov,
 233                              union lov_layout_state *state)
 234 {
 235         LASSERT(lov->lo_type == LLT_EMPTY);
 236 }
 237
 238 static void lov_delete_raid0(const struct lu_env *env, struct lov_object *lov,
 239                              union lov_layout_state *state)
 240 {
 241         struct lov_layout_raid0 *r0 = &state->raid0;
 242         int                      i;
 243
 244         ENTRY;
 245         if (r0->lo_sub != NULL &&
 246             lu_object_is_dying(lov->lo_cl.co_lu.lo_header)) {
 247                 for (i = 0; i < r0->lo_nr; ++i) {
 248                         struct lovsub_object *sub = r0->lo_sub[i];
 249
 250                         if (sub != NULL)
 251                                 /*
 252                                  * If top-level object is to be evicted from
 253                                  * the cache, so are its sub-objects.
 254                                  */
 255                                 cl_object_kill(env, lovsub2cl(sub));
 256                 }
 257         }
 258         EXIT;
 259 }
 260
 261 static void lov_fini_empty(const struct lu_env *env, struct lov_object *lov,
 262                            union lov_layout_state *state)
 263 {
 264         LASSERT(lov->lo_type == LLT_EMPTY);
 265 }
 266
 267 static void lov_fini_raid0(const struct lu_env *env, struct lov_object *lov,
 268                            union lov_layout_state *state)
 269 {
 270         struct lov_layout_raid0 *r0 = &state->raid0;
 271
 272         ENTRY;
 273         if (r0->lo_sub != NULL) {
 274                 int i;
 275
 276                 for (i = 0; i < r0->lo_nr; ++i) {
 277                         struct cl_object *sub;
 278
 279                         if (r0->lo_sub[i] == NULL)
 280                                 continue;
 281                         sub = lovsub2cl(r0->lo_sub[i]);
 282                         cl_object_header(sub)->coh_parent = NULL;
 283                         lu_object_ref_del(&sub->co_lu, "lov-parent", lov);
 284                         cl_object_put(env, sub);
 285                         r0->lo_sub[i] = NULL;
 286                 }
 287                 OBD_FREE(r0->lo_sub, r0->lo_nr * sizeof r0->lo_sub[0]);
 288                 r0->lo_sub = NULL;
 289         }
 290         EXIT;
 291 }
 292
 293 static int lov_print_empty(const struct lu_env *env, void *cookie,
 294                            lu_printer_t p, const struct lu_object *o)
 295 {
 296         (*p)(env, cookie, "empty\n");
 297         return 0;
 298 }
 299
 300 static int lov_print_raid0(const struct lu_env *env, void *cookie,
 301                            lu_printer_t p, const struct lu_object *o)
 302 {
 303         struct lov_object       *lov = lu2lov(o);
 304         struct lov_layout_raid0 *r0  = lov_r0(lov);
 305         int i;
 306
 307         (*p)(env, cookie, "stripes: %d:\n", r0->lo_nr);
 308         for (i = 0; i < r0->lo_nr; ++i) {
 309                 struct lu_object *sub;
 310
 311                 if (r0->lo_sub[i] != NULL) {
 312                         sub = lovsub2lu(r0->lo_sub[i]);
 313                         lu_object_print(env, cookie, p, sub);
 314                 } else
 315                         (*p)(env, cookie, "sub %d absent\n", i);
 316         }
 317         return 0;
 318 }
 319
 320 /**
 321  * Implements cl_object_operations::coo_attr_get() method for an object
 322  * without stripes (LLT_EMPTY layout type).
 323  *
 324  * The only attributes this layer is authoritative in this case is
 325  * cl_attr::cat_blocks---it's 0.
 326  */
 327 static int lov_attr_get_empty(const struct lu_env *env, struct cl_object *obj,
 328                               struct cl_attr *attr)
 329 {
 330         attr->cat_blocks = 0;
 331         return 0;
 332 }
 333
 334 static int lov_attr_get_raid0(const struct lu_env *env, struct cl_object *obj,
 335                               struct cl_attr *attr)
 336 {
 337         struct lov_object       *lov = cl2lov(obj);
 338         struct lov_layout_raid0 *r0 = lov_r0(lov);
 339         struct lov_stripe_md    *lsm = lov->u.raid0.lo_lsm;
 340         struct ost_lvb          *lvb = &lov_env_info(env)->lti_lvb;
 341         __u64                    kms;
 342         int                      result = 0;
 343
 344         ENTRY;
 345         if (!r0->lo_attr_valid) {
 346                 /*
 347                  * Fill LVB with attributes already initialized by the upper
 348                  * layer.
 349                  */
 350                 cl_attr2lvb(lvb, attr);
 351                 kms = attr->cat_kms;
 352
 353                 /*
 354                  * XXX that should be replaced with a loop over sub-objects,
 355                  * doing cl_object_attr_get() on them. But for now, let's
 356                  * reuse old lov code.
 357                  */
 358
 359                 /*
 360                  * XXX take lsm spin-lock to keep lov_merge_lvb_kms()
 361                  * happy. It's not needed, because new code uses
 362                  * ->coh_attr_guard spin-lock to protect consistency of
 363                  * sub-object attributes.
 364                  */
 365                 lov_stripe_lock(lsm);
 366                 result = lov_merge_lvb_kms(lsm, lvb, &kms);
 367                 lov_stripe_unlock(lsm);
 368                 if (result == 0) {
 369                         cl_lvb2attr(attr, lvb);
 370                         attr->cat_kms = kms;
 371                         r0->lo_attr_valid = 1;
 372                         r0->lo_attr = *attr;
 373                 }
 374         } else
 375                 *attr = r0->lo_attr;
 376         RETURN(result);
 377 }
 378
 379 const static struct lov_layout_operations lov_dispatch[] = {
 380         [LLT_EMPTY] = {
 381                 .llo_init      = lov_init_empty,
 382                 .llo_delete    = lov_delete_empty,
 383                 .llo_fini      = lov_fini_empty,
 384                 .llo_install   = lov_install_empty,
 385                 .llo_print     = lov_print_empty,
 386                 .llo_page_init = lov_page_init_empty,
 387                 .llo_lock_init = NULL,
 388                 .llo_io_init   = lov_io_init_empty,
 389                 .llo_getattr   = lov_attr_get_empty
 390         },
 391         [LLT_RAID0] = {
 392                 .llo_init      = lov_init_raid0,
 393                 .llo_delete    = lov_delete_raid0,
 394                 .llo_fini      = lov_fini_raid0,
 395                 .llo_install   = lov_install_raid0,
 396                 .llo_print     = lov_print_raid0,
 397                 .llo_page_init = lov_page_init_raid0,
 398                 .llo_lock_init = lov_lock_init_raid0,
 399                 .llo_io_init   = lov_io_init_raid0,
 400                 .llo_getattr   = lov_attr_get_raid0
 401         }
 402 };
 403
 404
 405 /**
 406  * Performs a double-dispatch based on the layout type of an object.
 407  */
 408 #define LOV_2DISPATCH_NOLOCK(obj, op, ...)                              \
 409 ({                                                                      \
 410         struct lov_object                      *__obj = (obj);          \
 411         enum lov_layout_type                    __llt;                  \
 412                                                                         \
 413         __llt = __obj->lo_type;                                         \
 414         LASSERT(0 <= __llt && __llt < ARRAY_SIZE(lov_dispatch));        \
 415         lov_dispatch[__llt].op(__VA_ARGS__);                            \
 416 })
 417
 418 #define LOV_2DISPATCH_MAYLOCK(obj, op, lock, ...)                       \
 419 ({                                                                      \
 420         struct lov_object                      *__obj = (obj);          \
 421         int                                     __lock = !!(lock);      \
 422         typeof(lov_dispatch[0].op(__VA_ARGS__)) __result;               \
 423                                                                         \
 424         __lock &= __obj->lo_owner != cfs_current();                     \
 425         if (__lock)                                                     \
 426                 down_read(&__obj->lo_type_guard);                       \
 427         __result = LOV_2DISPATCH_NOLOCK(obj, op, __VA_ARGS__);          \
 428         if (__lock)                                                     \
 429                 up_read(&__obj->lo_type_guard);                         \
 430         __result;                                                       \
 431 })
 432
 433 /**
 434  * Performs a locked double-dispatch based on the layout type of an object.
 435  */
 436 #define LOV_2DISPATCH(obj, op, ...)                     \
 437         LOV_2DISPATCH_MAYLOCK(obj, op, 1, __VA_ARGS__)
 438
 439 #define LOV_2DISPATCH_VOID(obj, op, ...)                                \
 440 do {                                                                    \
 441         struct lov_object                      *__obj = (obj);          \
 442         enum lov_layout_type                    __llt;                  \
 443                                                                         \
 444         if (__obj->lo_owner != cfs_current())                           \
 445                 down_read(&__obj->lo_type_guard);                       \
 446         __llt = __obj->lo_type;                                         \
 447         LASSERT(0 <= __llt && __llt < ARRAY_SIZE(lov_dispatch));        \
 448         lov_dispatch[__llt].op(__VA_ARGS__);                            \
 449         if (__obj->lo_owner != cfs_current())                           \
 450                 up_read(&__obj->lo_type_guard);                         \
 451 } while (0)
 452
 453 static int lov_layout_change(const struct lu_env *env,
 454                              struct lov_object *obj, enum lov_layout_type llt,
 455                              const struct cl_object_conf *conf)
 456 {
 457         int result;
 458         union lov_layout_state       *state = &lov_env_info(env)->lti_state;
 459         const struct lov_layout_operations *old_ops;
 460         const struct lov_layout_operations *new_ops;
 461
 462         LASSERT(0 <= obj->lo_type && obj->lo_type < ARRAY_SIZE(lov_dispatch));
 463         LASSERT(0 <= llt && llt < ARRAY_SIZE(lov_dispatch));
 464         ENTRY;
 465
 466         old_ops = &lov_dispatch[obj->lo_type];
 467         new_ops = &lov_dispatch[llt];
 468
 469         result = new_ops->llo_init(env, lu2lov_dev(obj->lo_cl.co_lu.lo_dev),
 470                                    obj, conf, state);
 471         if (result == 0) {
 472                 struct cl_object_header *hdr = cl_object_header(&obj->lo_cl);
 473                 void                    *cookie;
 474                 struct lu_env           *nested;
 475                 int                      refcheck;
 476
 477                 cookie = cl_env_reenter();
 478                 nested = cl_env_get(&refcheck);
 479                 if (!IS_ERR(nested))
 480                         cl_object_prune(nested, &obj->lo_cl);
 481                 else
 482                         result = PTR_ERR(nested);
 483                 cl_env_put(nested, &refcheck);
 484                 cl_env_reexit(cookie);
 485
 486                 old_ops->llo_fini(env, obj, &obj->u);
 487                 LASSERT(list_empty(&hdr->coh_locks));
 488                 LASSERT(hdr->coh_tree.rnode == NULL);
 489                 LASSERT(hdr->coh_pages == 0);
 490
 491                 new_ops->llo_install(env, obj, state);
 492                 obj->lo_type = llt;
 493         } else
 494                 new_ops->llo_fini(env, obj, state);
 495         RETURN(result);
 496 }
 497
 498 /*****************************************************************************
 499  *
 500  * Lov object operations.
 501  *
 502  */
 503
 504 int lov_object_init(const struct lu_env *env, struct lu_object *obj,
 505                     const struct lu_object_conf *conf)
 506 {
 507         struct lov_device            *dev   = lu2lov_dev(obj->lo_dev);
 508         struct lov_object            *lov   = lu2lov(obj);
 509         const struct cl_object_conf  *cconf = lu2cl_conf(conf);
 510         union  lov_layout_state      *set   = &lov_env_info(env)->lti_state;
 511         const struct lov_layout_operations *ops;
 512         int result;
 513
 514         ENTRY;
 515         init_rwsem(&lov->lo_type_guard);
 516
 517         /* no locking is necessary, as object is being created */
 518         lov->lo_type = cconf->u.coc_md->lsm != NULL ? LLT_RAID0 : LLT_EMPTY;
 519         ops = &lov_dispatch[lov->lo_type];
 520         result = ops->llo_init(env, dev, lov, cconf, set);
 521         if (result == 0)
 522                 ops->llo_install(env, lov, set);
 523         else
 524                 ops->llo_fini(env, lov, set);
 525         RETURN(result);
 526 }
 527
 528 static int lov_conf_set(const struct lu_env *env, struct cl_object *obj,
 529                         const struct cl_object_conf *conf)
 530 {
 531         struct lov_object *lov = cl2lov(obj);
 532         int result;
 533
 534         ENTRY;
 535         /*
 536          * Currently only LLT_EMPTY -> LLT_RAID0 transition is supported.
 537          */
 538         LASSERT(lov->lo_owner != cfs_current());
 539         down_write(&lov->lo_type_guard);
 540         LASSERT(lov->lo_owner == NULL);
 541         lov->lo_owner = cfs_current();
 542         if (lov->lo_type == LLT_EMPTY && conf->u.coc_md->lsm != NULL)
 543                 result = lov_layout_change(env, lov, LLT_RAID0, conf);
 544         else
 545                 result = -EOPNOTSUPP;
 546         lov->lo_owner = NULL;
 547         up_write(&lov->lo_type_guard);
 548         RETURN(result);
 549 }
 550
 551 static void lov_object_delete(const struct lu_env *env, struct lu_object *obj)
 552 {
 553         struct lov_object *lov = lu2lov(obj);
 554
 555         ENTRY;
 556         LOV_2DISPATCH_VOID(lov, llo_delete, env, lov, &lov->u);
 557         EXIT;
 558 }
 559
 560 static void lov_object_free(const struct lu_env *env, struct lu_object *obj)
 561 {
 562         struct lov_object *lov = lu2lov(obj);
 563
 564         ENTRY;
 565         LOV_2DISPATCH_VOID(lov, llo_fini, env, lov, &lov->u);
 566         lu_object_fini(obj);
 567         OBD_SLAB_FREE_PTR(lov, lov_object_kmem);
 568         EXIT;
 569 }
 570
 571 static int lov_object_print(const struct lu_env *env, void *cookie,
 572                             lu_printer_t p, const struct lu_object *o)
 573 {
 574         return LOV_2DISPATCH(lu2lov(o), llo_print, env, cookie, p, o);
 575 }
 576
 577 struct cl_page *lov_page_init(const struct lu_env *env, struct cl_object *obj,
 578                               struct cl_page *page, cfs_page_t *vmpage)
 579 {
 580         return LOV_2DISPATCH(cl2lov(obj),
 581                              llo_page_init, env, obj, page, vmpage);
 582 }
 583
 584 /**
 585  * Implements cl_object_operations::clo_io_init() method for lov
 586  * layer. Dispatches to the appropriate layout io initialization method.
 587  */
 588 int lov_io_init(const struct lu_env *env, struct cl_object *obj,
 589                 struct cl_io *io)
 590 {
 591         CL_IO_SLICE_CLEAN(lov_env_io(env), lis_cl);
 592         /*
 593          * Do not take lock in case of CIT_MISC io, because
 594          *
 595          *     - if this is an io for a glimpse, then we don't care;
 596          *
 597          *     - if this not a glimpse (writepage or lock cancellation), then
 598          *       layout change cannot happen because a page or a lock
 599          *       already exist; and
 600          *
 601          *     - lock ordering (lock mutex nests within layout rw-semaphore)
 602          *       is obeyed in case of lock cancellation.
 603          */
 604         return LOV_2DISPATCH_MAYLOCK(cl2lov(obj), llo_io_init,
 605                                      io->ci_type != CIT_MISC, env, obj, io);
 606 }
 607
 608 /**
 609  * An implementation of cl_object_operations::clo_attr_get() method for lov
 610  * layer. For raid0 layout this collects and merges attributes of all
 611  * sub-objects.
 612  */
 613 static int lov_attr_get(const struct lu_env *env, struct cl_object *obj,
 614                         struct cl_attr *attr)
 615 {
 616         /* do not take lock, as this function is called under a
 617          * spin-lock. Layout is protected from changing by ongoing IO. */
 618         return LOV_2DISPATCH_NOLOCK(cl2lov(obj), llo_getattr, env, obj, attr);
 619 }
 620
 621 static int lov_attr_set(const struct lu_env *env, struct cl_object *obj,
 622                         const struct cl_attr *attr, unsigned valid)
 623 {
 624         /*
 625          * No dispatch is required here, as no layout implements this.
 626          */
 627         return 0;
 628 }
 629
 630 int lov_lock_init(const struct lu_env *env, struct cl_object *obj,
 631                   struct cl_lock *lock, const struct cl_io *io)
 632 {
 633         return LOV_2DISPATCH(cl2lov(obj), llo_lock_init, env, obj, lock, io);
 634 }
 635
 636 static const struct cl_object_operations lov_ops = {
 637         .coo_page_init = lov_page_init,
 638         .coo_lock_init = lov_lock_init,
 639         .coo_io_init   = lov_io_init,
 640         .coo_attr_get  = lov_attr_get,
 641         .coo_attr_set  = lov_attr_set,
 642         .coo_conf_set  = lov_conf_set
 643 };
 644
 645 static const struct lu_object_operations lov_lu_obj_ops = {
 646         .loo_object_init      = lov_object_init,
 647         .loo_object_delete    = lov_object_delete,
 648         .loo_object_release   = NULL,
 649         .loo_object_free      = lov_object_free,
 650         .loo_object_print     = lov_object_print,
 651         .loo_object_invariant = NULL
 652 };
 653
 654 struct lu_object *lov_object_alloc(const struct lu_env *env,
 655                                    const struct lu_object_header *_,
 656                                    struct lu_device *dev)
 657 {
 658         struct lov_object *lov;
 659         struct lu_object  *obj;
 660
 661         ENTRY;
 662         OBD_SLAB_ALLOC_PTR(lov, lov_object_kmem);
 663         if (lov != NULL) {
 664                 obj = lov2lu(lov);
 665                 lu_object_init(obj, NULL, dev);
 666                 lov->lo_cl.co_ops = &lov_ops;
 667                 lov->lo_type = -1; /* invalid, to catch uninitialized type */
 668                 /*
 669                  * object io operation vector (cl_object::co_iop) is installed
 670                  * later in lov_object_init(), as different vectors are used
 671                  * for object with different layouts.
 672                  */
 673                 obj->lo_ops = &lov_lu_obj_ops;
 674         } else
 675                 obj = NULL;
 676         RETURN(obj);
 677 }
 678
 679 /** @} lov */