lustre/obdclass/local_storage.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,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License version 2 for more details.  A copy is
  14  * included in the COPYING file that accompanied this code.
  15
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2012 Whamcloud, Inc.
  24  */
  25 /*
  26  * lustre/obdclass/local_storage.c
  27  *
  28  * Local storage for file/objects with fid generation. Works on top of OSD.
  29  *
  30  * Author: Mikhail Pershin <mike.pershin@intel.com>
  31  */
  32
  33 #define DEBUG_SUBSYSTEM S_CLASS
  34
  35 #include "local_storage.h"
  36
  37 /* all initialized local storages on this node are linked on this */
  38 static CFS_LIST_HEAD(ls_list_head);
  39 static CFS_DEFINE_MUTEX(ls_list_mutex);
  40
  41 static int ls_object_init(const struct lu_env *env, struct lu_object *o,
  42                           const struct lu_object_conf *unused)
  43 {
  44         struct ls_device        *ls;
  45         struct lu_object        *below;
  46         struct lu_device        *under;
  47
  48         ENTRY;
  49
  50         ls = container_of0(o->lo_dev, struct ls_device, ls_top_dev.dd_lu_dev);
  51         under = &ls->ls_osd->dd_lu_dev;
  52         below = under->ld_ops->ldo_object_alloc(env, o->lo_header, under);
  53         if (below == NULL)
  54                 RETURN(-ENOMEM);
  55
  56         lu_object_add(o, below);
  57
  58         RETURN(0);
  59 }
  60
  61 static void ls_object_free(const struct lu_env *env, struct lu_object *o)
  62 {
  63         struct ls_object        *obj = lu2ls_obj(o);
  64         struct lu_object_header *h = o->lo_header;
  65
  66         dt_object_fini(&obj->ls_obj);
  67         lu_object_header_fini(h);
  68         OBD_FREE_PTR(obj);
  69 }
  70
  71 struct lu_object_operations ls_lu_obj_ops = {
  72         .loo_object_init  = ls_object_init,
  73         .loo_object_free  = ls_object_free,
  74 };
  75
  76 struct lu_object *ls_object_alloc(const struct lu_env *env,
  77                                   const struct lu_object_header *_h,
  78                                   struct lu_device *d)
  79 {
  80         struct lu_object_header *h;
  81         struct ls_object        *o;
  82         struct lu_object        *l;
  83
  84         LASSERT(_h == NULL);
  85
  86         OBD_ALLOC_PTR(o);
  87         if (o != NULL) {
  88                 l = &o->ls_obj.do_lu;
  89                 h = &o->ls_header;
  90
  91                 lu_object_header_init(h);
  92                 dt_object_init(&o->ls_obj, h, d);
  93                 lu_object_add_top(h, l);
  94
  95                 l->lo_ops = &ls_lu_obj_ops;
  96
  97                 return l;
  98         } else {
  99                 return NULL;
 100         }
 101 }
 102
 103 static struct lu_device_operations ls_lu_dev_ops = {
 104         .ldo_object_alloc =     ls_object_alloc
 105 };
 106
 107 static struct ls_device *__ls_find_dev(struct dt_device *dev)
 108 {
 109         struct ls_device *ls, *ret = NULL;
 110
 111         cfs_list_for_each_entry(ls, &ls_list_head, ls_linkage) {
 112                 if (ls->ls_osd == dev) {
 113                         cfs_atomic_inc(&ls->ls_refcount);
 114                         ret = ls;
 115                         break;
 116                 }
 117         }
 118         return ret;
 119 }
 120
 121 struct ls_device *ls_find_dev(struct dt_device *dev)
 122 {
 123         struct ls_device *ls;
 124
 125         cfs_mutex_lock(&ls_list_mutex);
 126         ls = __ls_find_dev(dev);
 127         cfs_mutex_unlock(&ls_list_mutex);
 128
 129         return ls;
 130 }
 131
 132 static struct lu_device_type_operations ls_device_type_ops = {
 133         .ldto_start = NULL,
 134         .ldto_stop  = NULL,
 135 };
 136
 137 static struct lu_device_type ls_lu_type = {
 138         .ldt_name = "local_storage",
 139         .ldt_ops  = &ls_device_type_ops,
 140 };
 141
 142 static struct ls_device *ls_device_get(const struct lu_env *env,
 143                                        struct dt_device *dev)
 144 {
 145         struct ls_device *ls;
 146
 147         ENTRY;
 148
 149         cfs_mutex_lock(&ls_list_mutex);
 150         ls = __ls_find_dev(dev);
 151         if (ls)
 152                 GOTO(out_ls, ls);
 153
 154         /* not found, then create */
 155         OBD_ALLOC_PTR(ls);
 156         if (ls == NULL)
 157                 GOTO(out_ls, ls = ERR_PTR(-ENOMEM));
 158
 159         cfs_atomic_set(&ls->ls_refcount, 1);
 160         CFS_INIT_LIST_HEAD(&ls->ls_los_list);
 161         cfs_mutex_init(&ls->ls_los_mutex);
 162
 163         ls->ls_osd = dev;
 164
 165         LASSERT(dev->dd_lu_dev.ld_site);
 166         lu_device_init(&ls->ls_top_dev.dd_lu_dev, &ls_lu_type);
 167         ls->ls_top_dev.dd_lu_dev.ld_ops = &ls_lu_dev_ops;
 168         ls->ls_top_dev.dd_lu_dev.ld_site = dev->dd_lu_dev.ld_site;
 169
 170         /* finally add ls to the list */
 171         cfs_list_add(&ls->ls_linkage, &ls_list_head);
 172 out_ls:
 173         cfs_mutex_unlock(&ls_list_mutex);
 174         RETURN(ls);
 175 }
 176
 177 static void ls_device_put(const struct lu_env *env, struct ls_device *ls)
 178 {
 179         LASSERT(env);
 180         if (!cfs_atomic_dec_and_test(&ls->ls_refcount))
 181                 return;
 182
 183         cfs_mutex_lock(&ls_list_mutex);
 184         if (cfs_atomic_read(&ls->ls_refcount) == 0) {
 185                 LASSERT(cfs_list_empty(&ls->ls_los_list));
 186                 cfs_list_del(&ls->ls_linkage);
 187                 lu_site_purge(env, ls->ls_top_dev.dd_lu_dev.ld_site, ~0);
 188                 lu_device_fini(&ls->ls_top_dev.dd_lu_dev);
 189                 OBD_FREE_PTR(ls);
 190         }
 191         cfs_mutex_unlock(&ls_list_mutex);
 192 }
 193
 194 /**
 195  * local file fid generation
 196  */
 197 int local_object_fid_generate(const struct lu_env *env,
 198                               struct local_oid_storage *los,
 199                               struct lu_fid *fid)
 200 {
 201         LASSERT(los->los_dev);
 202         LASSERT(los->los_obj);
 203
 204         /* take next OID */
 205
 206         /* to make it unique after reboot we store
 207          * the latest generated fid atomically with
 208          * object creation see local_object_create() */
 209
 210         cfs_mutex_lock(&los->los_id_lock);
 211         fid->f_seq = los->los_seq;
 212         fid->f_oid = los->los_last_oid++;
 213         fid->f_ver = 0;
 214         cfs_mutex_unlock(&los->los_id_lock);
 215
 216         return 0;
 217 }
 218
 219 int local_object_declare_create(const struct lu_env *env,
 220                                 struct local_oid_storage *los,
 221                                 struct dt_object *o, struct lu_attr *attr,
 222                                 struct dt_object_format *dof,
 223                                 struct thandle *th)
 224 {
 225         struct dt_thread_info   *dti = dt_info(env);
 226         int                      rc;
 227
 228         ENTRY;
 229
 230         /* update fid generation file */
 231         if (los != NULL) {
 232                 LASSERT(dt_object_exists(los->los_obj));
 233                 rc = dt_declare_record_write(env, los->los_obj,
 234                                              sizeof(struct los_ondisk), 0, th);
 235                 if (rc)
 236                         RETURN(rc);
 237         }
 238
 239         rc = dt_declare_create(env, o, attr, NULL, dof, th);
 240         if (rc)
 241                 RETURN(rc);
 242
 243         dti->dti_lb.lb_buf = NULL;
 244         dti->dti_lb.lb_len = sizeof(dti->dti_lma);
 245         rc = dt_declare_xattr_set(env, o, &dti->dti_lb, XATTR_NAME_LMA, 0, th);
 246
 247         RETURN(rc);
 248 }
 249
 250 int local_object_create(const struct lu_env *env,
 251                         struct local_oid_storage *los,
 252                         struct dt_object *o, struct lu_attr *attr,
 253                         struct dt_object_format *dof, struct thandle *th)
 254 {
 255         struct dt_thread_info   *dti = dt_info(env);
 256         struct los_ondisk        losd;
 257         int                      rc;
 258
 259         ENTRY;
 260
 261         rc = dt_create(env, o, attr, NULL, dof, th);
 262         if (rc)
 263                 RETURN(rc);
 264
 265         lustre_lma_init(&dti->dti_lma, lu_object_fid(&o->do_lu));
 266         lustre_lma_swab(&dti->dti_lma);
 267         dti->dti_lb.lb_buf = &dti->dti_lma;
 268         dti->dti_lb.lb_len = sizeof(dti->dti_lma);
 269         rc = dt_xattr_set(env, o, &dti->dti_lb, XATTR_NAME_LMA, 0, th,
 270                           BYPASS_CAPA);
 271
 272         if (los == NULL)
 273                 RETURN(rc);
 274
 275         LASSERT(los->los_obj);
 276         LASSERT(dt_object_exists(los->los_obj));
 277
 278         /* many threads can be updated this, serialize
 279          * them here to avoid the race where one thread
 280          * takes the value first, but writes it last */
 281         cfs_mutex_lock(&los->los_id_lock);
 282
 283         /* update local oid number on disk so that
 284          * we know the last one used after reboot */
 285         losd.lso_magic = cpu_to_le32(LOS_MAGIC);
 286         losd.lso_next_oid = cpu_to_le32(los->los_last_oid);
 287
 288         dti->dti_off = 0;
 289         dti->dti_lb.lb_buf = &losd;
 290         dti->dti_lb.lb_len = sizeof(losd);
 291         rc = dt_record_write(env, los->los_obj, &dti->dti_lb, &dti->dti_off,
 292                              th);
 293         cfs_mutex_unlock(&los->los_id_lock);
 294
 295         RETURN(rc);
 296 }
 297
 298 /*
 299  * Create local named object (file, directory or index) in parent directory.
 300  */
 301 struct dt_object *__local_file_create(const struct lu_env *env,
 302                                       const struct lu_fid *fid,
 303                                       struct local_oid_storage *los,
 304                                       struct ls_device *ls,
 305                                       struct dt_object *parent,
 306                                       const char *name, struct lu_attr *attr,
 307                                       struct dt_object_format *dof)
 308 {
 309         struct dt_thread_info   *dti = dt_info(env);
 310         struct dt_object        *dto;
 311         struct thandle          *th;
 312         int                      rc;
 313
 314         dto = ls_locate(env, ls, fid);
 315         if (unlikely(IS_ERR(dto)))
 316                 RETURN(dto);
 317
 318         LASSERT(dto != NULL);
 319         if (dt_object_exists(dto))
 320                 GOTO(out, rc = -EEXIST);
 321
 322         th = dt_trans_create(env, ls->ls_osd);
 323         if (IS_ERR(th))
 324                 GOTO(out, rc = PTR_ERR(th));
 325
 326         rc = local_object_declare_create(env, los, dto, attr, dof, th);
 327         if (rc)
 328                 GOTO(trans_stop, rc);
 329
 330         if (dti->dti_dof.dof_type == DFT_DIR) {
 331                 dt_declare_ref_add(env, dto, th);
 332                 dt_declare_ref_add(env, parent, th);
 333         }
 334
 335         rc = dt_declare_insert(env, parent, (void *)fid, (void *)name, th);
 336         if (rc)
 337                 GOTO(trans_stop, rc);
 338
 339         rc = dt_trans_start_local(env, ls->ls_osd, th);
 340         if (rc)
 341                 GOTO(trans_stop, rc);
 342
 343         dt_write_lock(env, dto, 0);
 344         if (dt_object_exists(dto))
 345                 GOTO(unlock, rc = 0);
 346
 347         CDEBUG(D_OTHER, "create new object "DFID"\n",
 348                PFID(lu_object_fid(&dto->do_lu)));
 349         rc = local_object_create(env, los, dto, attr, dof, th);
 350         if (rc)
 351                 GOTO(unlock, rc);
 352         LASSERT(dt_object_exists(dto));
 353
 354         if (dti->dti_dof.dof_type == DFT_DIR) {
 355                 if (!dt_try_as_dir(env, dto))
 356                         GOTO(destroy, rc = -ENOTDIR);
 357                 /* Add "." and ".." for newly created dir */
 358                 rc = dt_insert(env, dto, (void *)fid, (void *)".", th,
 359                                BYPASS_CAPA, 1);
 360                 if (rc)
 361                         GOTO(destroy, rc);
 362                 dt_ref_add(env, dto, th);
 363                 rc = dt_insert(env, dto, (void *)lu_object_fid(&parent->do_lu),
 364                                (void *)"..", th, BYPASS_CAPA, 1);
 365                 if (rc)
 366                         GOTO(destroy, rc);
 367         }
 368
 369         dt_write_lock(env, parent, 0);
 370         rc = dt_insert(env, parent, (const struct dt_rec *)fid,
 371                        (const struct dt_key *)name, th, BYPASS_CAPA, 1);
 372         if (dti->dti_dof.dof_type == DFT_DIR)
 373                 dt_ref_add(env, parent, th);
 374         dt_write_unlock(env, parent);
 375         if (rc)
 376                 GOTO(destroy, rc);
 377 destroy:
 378         if (rc)
 379                 dt_destroy(env, dto, th);
 380 unlock:
 381         dt_write_unlock(env, dto);
 382 trans_stop:
 383         dt_trans_stop(env, ls->ls_osd, th);
 384 out:
 385         if (rc) {
 386                 lu_object_put_nocache(env, &dto->do_lu);
 387                 dto = ERR_PTR(rc);
 388         } else {
 389                 struct lu_fid dti_fid;
 390                 /* since local files FIDs are not in OI the directory entry
 391                  * is used to get inode number/generation, we need to do lookup
 392                  * again to cache this data after create */
 393                 rc = dt_lookup_dir(env, parent, name, &dti_fid);
 394                 LASSERT(rc == 0);
 395         }
 396         RETURN(dto);
 397 }
 398
 399 /*
 400  * Look up and create (if it does not exist) a local named file or directory in
 401  * parent directory.
 402  */
 403 struct dt_object *local_file_find_or_create(const struct lu_env *env,
 404                                             struct local_oid_storage *los,
 405                                             struct dt_object *parent,
 406                                             const char *name, __u32 mode)
 407 {
 408         struct dt_thread_info   *dti = dt_info(env);
 409         struct dt_object        *dto;
 410         int                      rc;
 411
 412         LASSERT(parent);
 413
 414         rc = dt_lookup_dir(env, parent, name, &dti->dti_fid);
 415         if (rc == 0)
 416                 /* name is found, get the object */
 417                 dto = ls_locate(env, dt2ls_dev(los->los_dev), &dti->dti_fid);
 418         else if (rc != -ENOENT)
 419                 dto = ERR_PTR(rc);
 420         else {
 421                 rc = local_object_fid_generate(env, los, &dti->dti_fid);
 422                 if (rc < 0) {
 423                         dto = ERR_PTR(rc);
 424                 } else {
 425                         /* create the object */
 426                         dti->dti_attr.la_valid  = LA_MODE;
 427                         dti->dti_attr.la_mode   = mode;
 428                         dti->dti_dof.dof_type   = dt_mode_to_dft(mode & S_IFMT);
 429                         dto = __local_file_create(env, &dti->dti_fid, los,
 430                                                   dt2ls_dev(los->los_dev),
 431                                                   parent, name, &dti->dti_attr,
 432                                                   &dti->dti_dof);
 433                 }
 434         }
 435         return dto;
 436 }
 437 EXPORT_SYMBOL(local_file_find_or_create);
 438
 439 struct dt_object *local_file_find_or_create_with_fid(const struct lu_env *env,
 440                                                      struct dt_device *dt,
 441                                                      const struct lu_fid *fid,
 442                                                      struct dt_object *parent,
 443                                                      const char *name,
 444                                                      __u32 mode)
 445 {
 446         struct dt_thread_info   *dti = dt_info(env);
 447         struct dt_object        *dto;
 448         int                      rc;
 449
 450         LASSERT(parent);
 451
 452         rc = dt_lookup_dir(env, parent, name, &dti->dti_fid);
 453         if (rc == 0) {
 454                 /* name is found, get the object */
 455                 if (!lu_fid_eq(fid, &dti->dti_fid))
 456                         dto = ERR_PTR(-EINVAL);
 457                 else
 458                         dto = dt_locate(env, dt, fid);
 459         } else if (rc != -ENOENT) {
 460                 dto = ERR_PTR(rc);
 461         } else {
 462                 struct ls_device *ls;
 463
 464                 ls = ls_device_get(env, dt);
 465                 if (IS_ERR(ls)) {
 466                         dto = ERR_PTR(PTR_ERR(ls));
 467                 } else {
 468                         /* create the object */
 469                         dti->dti_attr.la_valid  = LA_MODE;
 470                         dti->dti_attr.la_mode   = mode;
 471                         dti->dti_dof.dof_type   = dt_mode_to_dft(mode & S_IFMT);
 472                         dto = __local_file_create(env, fid, NULL, ls, parent,
 473                                                   name, &dti->dti_attr,
 474                                                   &dti->dti_dof);
 475                         /* ls_device_put() will finalize the ls device, we
 476                          * have to open the object in other device stack */
 477                         if (!IS_ERR(dto)) {
 478                                 dti->dti_fid = dto->do_lu.lo_header->loh_fid;
 479                                 lu_object_put_nocache(env, &dto->do_lu);
 480                                 dto = dt_locate(env, dt, &dti->dti_fid);
 481                         }
 482                         ls_device_put(env, ls);
 483                 }
 484         }
 485         return dto;
 486 }
 487 EXPORT_SYMBOL(local_file_find_or_create_with_fid);
 488
 489 /*
 490  * Look up and create (if it does not exist) a local named index file in parent
 491  * directory.
 492  */
 493 struct dt_object *local_index_find_or_create(const struct lu_env *env,
 494                                              struct local_oid_storage *los,
 495                                              struct dt_object *parent,
 496                                              const char *name, __u32 mode,
 497                                              const struct dt_index_features *ft)
 498 {
 499         struct dt_thread_info   *dti = dt_info(env);
 500         struct dt_object        *dto;
 501         int                      rc;
 502
 503         LASSERT(parent);
 504
 505         rc = dt_lookup_dir(env, parent, name, &dti->dti_fid);
 506         if (rc == 0) {
 507                 /* name is found, get the object */
 508                 dto = ls_locate(env, dt2ls_dev(los->los_dev), &dti->dti_fid);
 509         } else if (rc != -ENOENT) {
 510                 dto = ERR_PTR(rc);
 511         } else {
 512                 rc = local_object_fid_generate(env, los, &dti->dti_fid);
 513                 if (rc < 0) {
 514                         dto = ERR_PTR(rc);
 515                 } else {
 516                         /* create the object */
 517                         dti->dti_attr.la_valid          = LA_MODE;
 518                         dti->dti_attr.la_mode           = mode;
 519                         dti->dti_dof.dof_type           = DFT_INDEX;
 520                         dti->dti_dof.u.dof_idx.di_feat  = ft;
 521                         dto = __local_file_create(env, &dti->dti_fid, los,
 522                                                   dt2ls_dev(los->los_dev),
 523                                                   parent, name, &dti->dti_attr,
 524                                                   &dti->dti_dof);
 525                 }
 526         }
 527         return dto;
 528
 529 }
 530 EXPORT_SYMBOL(local_index_find_or_create);
 531
 532 struct dt_object *
 533 local_index_find_or_create_with_fid(const struct lu_env *env,
 534                                     struct dt_device *dt,
 535                                     const struct lu_fid *fid,
 536                                     struct dt_object *parent,
 537                                     const char *name, __u32 mode,
 538                                     const struct dt_index_features *ft)
 539 {
 540         struct dt_thread_info   *dti = dt_info(env);
 541         struct dt_object        *dto;
 542         int                      rc;
 543
 544         LASSERT(parent);
 545
 546         rc = dt_lookup_dir(env, parent, name, &dti->dti_fid);
 547         if (rc == 0) {
 548                 /* name is found, get the object */
 549                 if (!lu_fid_eq(fid, &dti->dti_fid))
 550                         dto = ERR_PTR(-EINVAL);
 551                 else
 552                         dto = dt_locate(env, dt, fid);
 553         } else if (rc != -ENOENT) {
 554                 dto = ERR_PTR(rc);
 555         } else {
 556                 struct ls_device *ls;
 557
 558                 ls = ls_device_get(env, dt);
 559                 if (IS_ERR(ls)) {
 560                         dto = ERR_PTR(PTR_ERR(ls));
 561                 } else {
 562                         /* create the object */
 563                         dti->dti_attr.la_valid          = LA_MODE;
 564                         dti->dti_attr.la_mode           = mode;
 565                         dti->dti_dof.dof_type           = DFT_INDEX;
 566                         dti->dti_dof.u.dof_idx.di_feat  = ft;
 567                         dto = __local_file_create(env, fid, NULL, ls, parent,
 568                                                   name, &dti->dti_attr,
 569                                                   &dti->dti_dof);
 570                         /* ls_device_put() will finalize the ls device, we
 571                          * have to open the object in other device stack */
 572                         if (!IS_ERR(dto)) {
 573                                 dti->dti_fid = dto->do_lu.lo_header->loh_fid;
 574                                 lu_object_put_nocache(env, &dto->do_lu);
 575                                 dto = dt_locate(env, dt, &dti->dti_fid);
 576                         }
 577                         ls_device_put(env, ls);
 578                 }
 579         }
 580         return dto;
 581 }
 582 EXPORT_SYMBOL(local_index_find_or_create_with_fid);
 583
 584 static struct local_oid_storage *dt_los_find(struct ls_device *ls, __u64 seq)
 585 {
 586         struct local_oid_storage *los, *ret = NULL;
 587
 588         cfs_list_for_each_entry(los, &ls->ls_los_list, los_list) {
 589                 if (los->los_seq == seq) {
 590                         cfs_atomic_inc(&los->los_refcount);
 591                         ret = los;
 592                         break;
 593                 }
 594         }
 595         return ret;
 596 }
 597
 598 /**
 599  * Initialize local OID storage for required sequence.
 600  * That may be needed for services that uses local files and requires
 601  * dynamic OID allocation for them.
 602  *
 603  * Per each sequence we have an object with 'first_fid' identificator
 604  * containing the counter for OIDs of locally created files with that
 605  * sequence.
 606  *
 607  * It is used now by llog subsystem and MGS for NID tables
 608  *
 609  * Function gets first_fid to create counter object.
 610  * All dynamic fids will be generated with the same sequence and incremented
 611  * OIDs
 612  *
 613  * Returned local_oid_storage is in-memory representaion of OID storage
 614  */
 615 int local_oid_storage_init(const struct lu_env *env, struct dt_device *dev,
 616                            const struct lu_fid *first_fid,
 617                            struct local_oid_storage **los)
 618 {
 619         struct dt_thread_info   *dti = dt_info(env);
 620         struct ls_device        *ls;
 621         struct los_ondisk        losd;
 622         struct dt_object        *o;
 623         struct dt_object        *root = NULL;
 624         struct thandle          *th;
 625         int                      rc;
 626
 627         ENTRY;
 628
 629         ls = ls_device_get(env, dev);
 630         if (IS_ERR(ls))
 631                 RETURN(PTR_ERR(ls));
 632
 633         cfs_mutex_lock(&ls->ls_los_mutex);
 634         *los = dt_los_find(ls, fid_seq(first_fid));
 635         if (*los != NULL)
 636                 GOTO(out, rc = 0);
 637
 638         /* not found, then create */
 639         OBD_ALLOC_PTR(*los);
 640         if (*los == NULL)
 641                 GOTO(out, rc = -ENOMEM);
 642
 643         cfs_atomic_set(&(*los)->los_refcount, 1);
 644         cfs_mutex_init(&(*los)->los_id_lock);
 645         (*los)->los_dev = &ls->ls_top_dev;
 646         cfs_atomic_inc(&ls->ls_refcount);
 647         cfs_list_add(&(*los)->los_list, &ls->ls_los_list);
 648
 649         /* initialize data allowing to generate new fids,
 650          * literally we need a sequence */
 651         o = ls_locate(env, ls, first_fid);
 652         if (IS_ERR(o))
 653                 GOTO(out_los, rc = PTR_ERR(o));
 654
 655         rc = dt_root_get(env, dev, &dti->dti_fid);
 656         if (rc)
 657                 GOTO(out_los, rc);
 658
 659         root = ls_locate(env, ls, &dti->dti_fid);
 660         if (IS_ERR(root))
 661                 GOTO(out_los, rc = PTR_ERR(root));
 662
 663         if (dt_try_as_dir(env, root) == 0)
 664                 GOTO(out_los, rc = -ENOTDIR);
 665
 666         dt_write_lock(env, o, 0);
 667         if (!dt_object_exists(o)) {
 668                 th = dt_trans_create(env, dev);
 669                 if (IS_ERR(th))
 670                         GOTO(out_lock, rc = PTR_ERR(th));
 671
 672                 dti->dti_attr.la_valid = LA_MODE | LA_TYPE;
 673                 dti->dti_attr.la_mode = S_IFREG | S_IRUGO | S_IWUSR;
 674                 dti->dti_dof.dof_type = dt_mode_to_dft(S_IFREG);
 675
 676                 rc = dt_declare_create(env, o, &dti->dti_attr, NULL,
 677                                        &dti->dti_dof, th);
 678                 if (rc)
 679                         GOTO(out_trans, rc);
 680
 681                 snprintf(dti->dti_buf, sizeof(dti->dti_buf),
 682                         "seq-%Lx-lastid", fid_seq(first_fid));
 683                 rc = dt_declare_insert(env, root,
 684                                        (const struct dt_rec *)lu_object_fid(&o->do_lu),
 685                                        (const struct dt_key *)dti->dti_buf,
 686                                        th);
 687                 if (rc)
 688                         GOTO(out_trans, rc);
 689
 690                 dti->dti_lb.lb_buf = NULL;
 691                 dti->dti_lb.lb_len = sizeof(dti->dti_lma);
 692                 rc = dt_declare_xattr_set(env, o, &dti->dti_lb, XATTR_NAME_LMA,
 693                                           0, th);
 694                 if (rc)
 695                         GOTO(out_trans, rc);
 696
 697                 rc = dt_declare_record_write(env, o, sizeof(losd), 0, th);
 698                 if (rc)
 699                         GOTO(out_trans, rc);
 700
 701                 rc = dt_trans_start_local(env, dev, th);
 702                 if (rc)
 703                         GOTO(out_trans, rc);
 704
 705                 LASSERT(!dt_object_exists(o));
 706                 rc = dt_create(env, o, &dti->dti_attr, NULL, &dti->dti_dof, th);
 707                 if (rc)
 708                         GOTO(out_trans, rc);
 709                 LASSERT(dt_object_exists(o));
 710
 711                 lustre_lma_init(&dti->dti_lma, lu_object_fid(&o->do_lu));
 712                 lustre_lma_swab(&dti->dti_lma);
 713                 dti->dti_lb.lb_buf = &dti->dti_lma;
 714                 dti->dti_lb.lb_len = sizeof(dti->dti_lma);
 715                 rc = dt_xattr_set(env, o, &dti->dti_lb, XATTR_NAME_LMA, 0,
 716                                   th, BYPASS_CAPA);
 717                 if (rc)
 718                         GOTO(out_trans, rc);
 719
 720                 losd.lso_magic = cpu_to_le32(LOS_MAGIC);
 721                 losd.lso_next_oid = cpu_to_le32(fid_oid(first_fid) + 1);
 722
 723                 dti->dti_off = 0;
 724                 dti->dti_lb.lb_buf = &losd;
 725                 dti->dti_lb.lb_len = sizeof(losd);
 726                 rc = dt_record_write(env, o, &dti->dti_lb, &dti->dti_off, th);
 727                 if (rc)
 728                         GOTO(out_trans, rc);
 729                 rc = dt_insert(env, root,
 730                                (const struct dt_rec *)lu_object_fid(&o->do_lu),
 731                                (const struct dt_key *)dti->dti_buf, th,
 732                                BYPASS_CAPA, 1);
 733                 if (rc)
 734                         GOTO(out_trans, rc);
 735 out_trans:
 736                 dt_trans_stop(env, dev, th);
 737         } else {
 738                 dti->dti_off = 0;
 739                 dti->dti_lb.lb_buf = &losd;
 740                 dti->dti_lb.lb_len = sizeof(losd);
 741                 rc = dt_record_read(env, o, &dti->dti_lb, &dti->dti_off);
 742                 if (rc == 0 && le32_to_cpu(losd.lso_magic) != LOS_MAGIC) {
 743                         CERROR("local storage file "DFID" is corrupted\n",
 744                                PFID(first_fid));
 745                         rc = -EINVAL;
 746                 }
 747         }
 748 out_lock:
 749         dt_write_unlock(env, o);
 750 out_los:
 751         if (root)
 752                 lu_object_put_nocache(env, &root->do_lu);
 753         if (rc) {
 754                 OBD_FREE_PTR(*los);
 755                 *los = NULL;
 756                 if (o)
 757                         lu_object_put_nocache(env, &o->do_lu);
 758         } else {
 759                 (*los)->los_seq = fid_seq(first_fid);
 760                 (*los)->los_last_oid = le32_to_cpu(losd.lso_next_oid);
 761                 (*los)->los_obj = o;
 762         }
 763 out:
 764         cfs_mutex_unlock(&ls->ls_los_mutex);
 765         ls_device_put(env, ls);
 766         return rc;
 767 }
 768 EXPORT_SYMBOL(local_oid_storage_init);
 769
 770 void local_oid_storage_fini(const struct lu_env *env,
 771                             struct local_oid_storage *los)
 772 {
 773         struct ls_device *ls;
 774
 775         if (!cfs_atomic_dec_and_test(&los->los_refcount))
 776                 return;
 777
 778         LASSERT(env);
 779         LASSERT(los->los_dev);
 780         ls = dt2ls_dev(los->los_dev);
 781
 782         cfs_mutex_lock(&ls->ls_los_mutex);
 783         if (cfs_atomic_read(&los->los_refcount) == 0) {
 784                 if (los->los_obj)
 785                         lu_object_put_nocache(env, &los->los_obj->do_lu);
 786                 cfs_list_del(&los->los_list);
 787                 OBD_FREE_PTR(los);
 788         }
 789         cfs_mutex_unlock(&ls->ls_los_mutex);
 790         ls_device_put(env, ls);
 791 }
 792 EXPORT_SYMBOL(local_oid_storage_fini);