lustre/osd-ldiskfs/osd_oi.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2012, 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  * lustre/osd/osd_oi.c
  37  *
  38  * Object Index.
  39  *
  40  * Author: Nikita Danilov <nikita@clusterfs.com>
  41  */
  42
  43 /*
  44  * oi uses two mechanisms to implement fid->cookie mapping:
  45  *
  46  *     - persistent index, where cookie is a record and fid is a key, and
  47  *
  48  *     - algorithmic mapping for "igif" fids.
  49  *
  50  */
  51
  52 #define DEBUG_SUBSYSTEM S_MDS
  53
  54 #include <linux/module.h>
  55
  56 /* LUSTRE_VERSION_CODE */
  57 #include <lustre_ver.h>
  58 /*
  59  * struct OBD_{ALLOC,FREE}*()
  60  * OBD_FAIL_CHECK
  61  */
  62 #include <obd.h>
  63 #include <obd_support.h>
  64
  65 /* fid_cpu_to_be() */
  66 #include <lustre_fid.h>
  67
  68 #include "osd_oi.h"
  69 /* osd_lookup(), struct osd_thread_info */
  70 #include "osd_internal.h"
  71 #include "osd_igif.h"
  72 #include "dt_object.h"
  73
  74 #define OSD_OI_FID_NR         (1UL << OSD_OI_FID_OID_BITS)
  75 #define OSD_OI_FID_NR_MAX     (1UL << OSD_OI_FID_OID_BITS_MAX)
  76
  77 static unsigned int osd_oi_count = OSD_OI_FID_NR;
  78 CFS_MODULE_PARM(osd_oi_count, "i", int, 0444,
  79                 "Number of Object Index containers to be created, "
  80                 "it's only valid for new filesystem.");
  81
  82 /** to serialize concurrent OI index initialization */
  83 static cfs_mutex_t oi_init_lock;
  84
  85 static struct dt_index_features oi_feat = {
  86         .dif_flags       = DT_IND_UPDATE,
  87         .dif_recsize_min = sizeof(struct osd_inode_id),
  88         .dif_recsize_max = sizeof(struct osd_inode_id),
  89         .dif_ptrsize     = 4
  90 };
  91
  92 #define OSD_OI_NAME_BASE        "oi.16"
  93
  94 static void osd_oi_table_put(struct osd_thread_info *info,
  95                              struct osd_oi **oi_table, unsigned oi_count)
  96 {
  97         struct iam_container *bag;
  98         int                   i;
  99
 100         for (i = 0; i < oi_count; i++) {
 101                 LASSERT(oi_table[i] != NULL);
 102                 LASSERT(oi_table[i]->oi_inode != NULL);
 103
 104                 bag = &(oi_table[i]->oi_dir.od_container);
 105                 if (bag->ic_object == oi_table[i]->oi_inode)
 106                         iam_container_fini(bag);
 107                 iput(oi_table[i]->oi_inode);
 108                 oi_table[i]->oi_inode = NULL;
 109                 OBD_FREE_PTR(oi_table[i]);
 110         }
 111 }
 112
 113 static int osd_oi_index_create_one(struct osd_thread_info *info,
 114                                    struct osd_device *osd, const char *name,
 115                                    struct dt_index_features *feat)
 116 {
 117         const struct lu_env             *env = info->oti_env;
 118         struct osd_inode_id             *id  = &info->oti_id;
 119         struct buffer_head              *bh;
 120         struct inode                    *inode;
 121         struct ldiskfs_dir_entry_2      *de;
 122         struct dentry                   *dentry;
 123         struct inode                    *dir;
 124         handle_t                        *jh;
 125         int                              rc;
 126
 127         dentry = osd_child_dentry_by_inode(env, osd_sb(osd)->s_root->d_inode,
 128                                            name, strlen(name));
 129         dir = osd_sb(osd)->s_root->d_inode;
 130         bh = osd_ldiskfs_find_entry(dir, dentry, &de, NULL);
 131         if (bh) {
 132                 brelse(bh);
 133
 134                 id->oii_ino = le32_to_cpu(de->inode);
 135                 id->oii_gen = OSD_OII_NOGEN;
 136
 137                 inode = osd_iget(info, osd, id);
 138                 if (!IS_ERR(inode)) {
 139                         iput(inode);
 140                         RETURN(-EEXIST);
 141                 }
 142                 RETURN(PTR_ERR(inode));
 143         }
 144
 145         jh = ldiskfs_journal_start_sb(osd_sb(osd), 100);
 146         LASSERT(!IS_ERR(jh));
 147
 148         inode = ldiskfs_create_inode(jh, osd_sb(osd)->s_root->d_inode,
 149                                      (S_IFREG | S_IRUGO | S_IWUSR));
 150         LASSERT(!IS_ERR(inode));
 151
 152         if (feat->dif_flags & DT_IND_VARKEY)
 153                 rc = iam_lvar_create(inode, feat->dif_keysize_max,
 154                                      feat->dif_ptrsize, feat->dif_recsize_max,
 155                                      jh);
 156         else
 157                 rc = iam_lfix_create(inode, feat->dif_keysize_max,
 158                                      feat->dif_ptrsize, feat->dif_recsize_max,
 159                                      jh);
 160
 161         dentry = osd_child_dentry_by_inode(env, osd_sb(osd)->s_root->d_inode,
 162                                            name, strlen(name));
 163         rc = osd_ldiskfs_add_entry(jh, dentry, inode, NULL);
 164         LASSERT(rc == 0);
 165
 166         ldiskfs_journal_stop(jh);
 167         iput(inode);
 168
 169         return rc;
 170 }
 171
 172 static struct inode *osd_oi_index_open(struct osd_thread_info *info,
 173                                        struct osd_device *osd,
 174                                        const char *name,
 175                                        struct dt_index_features *f,
 176                                        bool create)
 177 {
 178         struct dentry *dentry;
 179         struct inode  *inode;
 180         int            rc;
 181
 182         dentry = ll_lookup_one_len(name, osd_sb(osd)->s_root, strlen(name));
 183         if (IS_ERR(dentry))
 184                 return (void *) dentry;
 185
 186         if (dentry->d_inode) {
 187                 LASSERT(!is_bad_inode(dentry->d_inode));
 188                 inode = dentry->d_inode;
 189                 atomic_inc(&inode->i_count);
 190                 dput(dentry);
 191                 return inode;
 192         }
 193
 194         /* create */
 195         dput(dentry);
 196         shrink_dcache_parent(osd_sb(osd)->s_root);
 197         if (!create)
 198                 return ERR_PTR(-ENOENT);
 199
 200         rc = osd_oi_index_create_one(info, osd, name, f);
 201         if (rc)
 202                 RETURN(ERR_PTR(rc));
 203
 204         dentry = ll_lookup_one_len(name, osd_sb(osd)->s_root, strlen(name));
 205         if (IS_ERR(dentry))
 206                 return (void *) dentry;
 207
 208         if (dentry->d_inode) {
 209                 LASSERT(!is_bad_inode(dentry->d_inode));
 210                 inode = dentry->d_inode;
 211                 atomic_inc(&inode->i_count);
 212                 dput(dentry);
 213                 return inode;
 214         }
 215
 216         return ERR_PTR(-ENOENT);
 217 }
 218
 219 /**
 220  * Open an OI(Ojbect Index) container.
 221  *
 222  * \param       name    Name of OI container
 223  * \param       objp    Pointer of returned OI
 224  *
 225  * \retval      0       success
 226  * \retval      -ve     failure
 227  */
 228 static int osd_oi_open(struct osd_thread_info *info, struct osd_device *osd,
 229                        char *name, struct osd_oi **oi_slot, bool create)
 230 {
 231         struct osd_directory *dir;
 232         struct iam_container *bag;
 233         struct inode         *inode;
 234         struct osd_oi        *oi;
 235         int                   rc;
 236
 237         ENTRY;
 238
 239         oi_feat.dif_keysize_min = sizeof(struct lu_fid);
 240         oi_feat.dif_keysize_max = sizeof(struct lu_fid);
 241
 242         inode = osd_oi_index_open(info, osd, name, &oi_feat, create);
 243         if (IS_ERR(inode))
 244                 RETURN(PTR_ERR(inode));
 245
 246         OBD_ALLOC_PTR(oi);
 247         if (oi == NULL)
 248                 GOTO(out_inode, rc = -ENOMEM);
 249
 250         oi->oi_inode = inode;
 251         dir = &oi->oi_dir;
 252
 253         bag = &dir->od_container;
 254         rc = iam_container_init(bag, &dir->od_descr, inode);
 255         if (rc < 0)
 256                 GOTO(out_free, rc);
 257
 258         rc = iam_container_setup(bag);
 259         if (rc < 0)
 260                 GOTO(out_container, rc);
 261
 262         *oi_slot = oi;
 263         RETURN(0);
 264
 265 out_container:
 266         iam_container_fini(bag);
 267 out_free:
 268         OBD_FREE_PTR(oi);
 269 out_inode:
 270         iput(inode);
 271         return rc;
 272 }
 273
 274 /**
 275  * Open OI(Object Index) table.
 276  * If \a oi_count is zero, which means caller doesn't know how many OIs there
 277  * will be, this function can either return 0 for new filesystem, or number
 278  * of OIs on existed filesystem.
 279  *
 280  * If \a oi_count is non-zero, which means caller does know number of OIs on
 281  * filesystem, this function should return the exactly same number on
 282  * success, or error code in failure.
 283  *
 284  * \param     oi_count  Number of expected OI containers
 285  * \param     create    Create OIs if doesn't exist
 286  *
 287  * \retval    +ve       number of opened OI containers
 288  * \retval      0       no OI containers found
 289  * \retval    -ve       failure
 290  */
 291 static int
 292 osd_oi_table_open(struct osd_thread_info *info, struct osd_device *osd,
 293                   struct osd_oi **oi_table, unsigned oi_count, bool create)
 294 {
 295         struct dt_device *dev = &osd->od_dt_dev;
 296         int               count = 0;
 297         int               rc = 0;
 298         int               i;
 299
 300         /* NB: oi_count != 0 means that we have already created/known all OIs
 301          * and have known exact number of OIs. */
 302         LASSERT(oi_count <= OSD_OI_FID_NR_MAX);
 303
 304         for (i = 0; i < (oi_count != 0 ? oi_count : OSD_OI_FID_NR_MAX); i++) {
 305                 char name[12];
 306
 307                 sprintf(name, "%s.%d", OSD_OI_NAME_BASE, i);
 308                 rc = osd_oi_open(info, osd, name, &oi_table[i], create);
 309                 if (rc == 0) {
 310                         count++;
 311                         continue;
 312                 }
 313
 314                 if (rc == -ENOENT && oi_count == 0)
 315                         return count;
 316
 317                 CERROR("%s: can't open %s: rc = %d\n",
 318                        dev->dd_lu_dev.ld_obd->obd_name, name, rc);
 319                 if (oi_count > 0) {
 320                         CERROR("%s: expect to open total %d OI files.\n",
 321                                dev->dd_lu_dev.ld_obd->obd_name, oi_count);
 322                 }
 323                 break;
 324         }
 325
 326         if (rc < 0) {
 327                 osd_oi_table_put(info, oi_table, count);
 328                 return rc;
 329         }
 330
 331         return count;
 332 }
 333
 334 int osd_oi_init(struct osd_thread_info *info, struct osd_device *osd)
 335 {
 336         struct dt_device *dev = &osd->od_dt_dev;
 337         struct osd_oi   **oi;
 338         int               rc;
 339
 340         OBD_ALLOC(oi, sizeof(*oi) * OSD_OI_FID_NR_MAX);
 341         if (oi == NULL)
 342                 return -ENOMEM;
 343
 344         cfs_mutex_lock(&oi_init_lock);
 345         /* try to open existing multiple OIs first */
 346         rc = osd_oi_table_open(info, osd, oi, 0, false);
 347         if (rc != 0)
 348                 goto out;
 349
 350         /* if previous failed then try found single OI from old filesystem */
 351         rc = osd_oi_open(info, osd, OSD_OI_NAME_BASE, &oi[0], false);
 352         if (rc == 0) { /* found single OI from old filesystem */
 353                 rc = 1;
 354                 goto out;
 355         } else if (rc != -ENOENT) {
 356                 CERROR("%s: can't open %s: rc = %d\n",
 357                        dev->dd_lu_dev.ld_obd->obd_name, OSD_OI_NAME_BASE, rc);
 358                 goto out;
 359         }
 360
 361         /* No OIs exist, new filesystem, create OI objects */
 362         rc = osd_oi_table_open(info, osd, oi, osd_oi_count, true);
 363         LASSERT(ergo(rc >= 0, rc == osd_oi_count));
 364 out:
 365         if (rc < 0) {
 366                 OBD_FREE(oi, sizeof(*oi) * OSD_OI_FID_NR_MAX);
 367         } else {
 368                 LASSERT((rc & (rc - 1)) == 0);
 369                 osd->od_oi_table = oi;
 370                 osd->od_oi_count = rc;
 371                 rc = 0;
 372         }
 373
 374         cfs_mutex_unlock(&oi_init_lock);
 375         return rc;
 376 }
 377
 378 void osd_oi_fini(struct osd_thread_info *info, struct osd_device *osd)
 379 {
 380         osd_oi_table_put(info, osd->od_oi_table, osd->od_oi_count);
 381
 382         OBD_FREE(osd->od_oi_table,
 383                  sizeof(*(osd->od_oi_table)) * OSD_OI_FID_NR_MAX);
 384         osd->od_oi_table = NULL;
 385 }
 386
 387 static inline int fid_is_fs_root(const struct lu_fid *fid)
 388 {
 389         /* Map root inode to special local object FID */
 390         return (unlikely(fid_seq(fid) == FID_SEQ_LOCAL_FILE &&
 391                          fid_oid(fid) == OSD_FS_ROOT_OID));
 392 }
 393
 394 static int osd_oi_iam_lookup(struct osd_thread_info *oti,
 395                              struct osd_oi *oi, struct dt_rec *rec,
 396                              const struct dt_key *key)
 397 {
 398         struct iam_container  *bag;
 399         struct iam_iterator   *it = &oti->oti_idx_it;
 400         struct iam_rec        *iam_rec;
 401         struct iam_path_descr *ipd;
 402         int                    rc;
 403         ENTRY;
 404
 405         LASSERT(oi);
 406         LASSERT(oi->oi_inode);
 407
 408         bag = &oi->oi_dir.od_container;
 409         ipd = osd_idx_ipd_get(oti->oti_env, bag);
 410         if (IS_ERR(ipd))
 411                 RETURN(-ENOMEM);
 412
 413         /* got ipd now we can start iterator. */
 414         iam_it_init(it, bag, 0, ipd);
 415
 416         rc = iam_it_get(it, (struct iam_key *)key);
 417         if (rc >= 0) {
 418                 if (S_ISDIR(oi->oi_inode->i_mode))
 419                         iam_rec = (struct iam_rec *)oti->oti_ldp;
 420                 else
 421                         iam_rec = (struct iam_rec *)rec;
 422
 423                 iam_reccpy(&it->ii_path.ip_leaf, (struct iam_rec *)iam_rec);
 424                 if (S_ISDIR(oi->oi_inode->i_mode))
 425                         osd_fid_unpack((struct lu_fid *)rec,
 426                                        (struct osd_fid_pack *)iam_rec);
 427         }
 428         iam_it_put(it);
 429         iam_it_fini(it);
 430         osd_ipd_put(oti->oti_env, bag, ipd);
 431
 432         LINVRNT(osd_invariant(obj));
 433
 434         RETURN(rc);
 435 }
 436
 437 int osd_oi_lookup(struct osd_thread_info *info, struct osd_device *osd,
 438                   const struct lu_fid *fid, struct osd_inode_id *id)
 439 {
 440         struct lu_fid       *oi_fid = &info->oti_fid;
 441         const struct dt_key *key;
 442         int                  rc = 0;
 443
 444         if (fid_is_idif(fid) || fid_seq(fid) == FID_SEQ_LLOG) {
 445                 /* old OSD obj id */
 446                 rc = osd_compat_objid_lookup(info, osd, fid, id);
 447         } else if (fid_is_igif(fid)) {
 448                 lu_igif_to_id(fid, id);
 449                 rc = 0;
 450         } else if (fid_is_fs_root(fid)) {
 451                 struct inode *inode = osd_sb(osd)->s_root->d_inode;
 452
 453                 id->oii_ino = inode->i_ino;
 454                 id->oii_gen = inode->i_generation;
 455         } else {
 456                 if (unlikely(fid_seq(fid) == FID_SEQ_LOCAL_FILE)) {
 457                         rc = osd_compat_spec_lookup(info, osd, fid, id);
 458                         if (rc == 0 || rc != -ERESTART)
 459                                 goto out;
 460                 }
 461
 462                 fid_cpu_to_be(oi_fid, fid);
 463                 key = (struct dt_key *)oi_fid;
 464
 465                 rc = osd_oi_iam_lookup(info, osd_fid2oi(osd, fid),
 466                                        (struct dt_rec *)id, key);
 467
 468                 if (rc > 0) {
 469                         id->oii_ino = be32_to_cpu(id->oii_ino);
 470                         id->oii_gen = be32_to_cpu(id->oii_gen);
 471                         rc = 0;
 472                 } else if (rc == 0) {
 473                         rc = -ENOENT;
 474                 }
 475         }
 476
 477 out:
 478         return rc;
 479 }
 480
 481 static int osd_oi_iam_insert(struct osd_thread_info *oti, struct osd_oi *oi,
 482                              const struct dt_rec *rec, const struct dt_key *key,
 483                              struct thandle *th, int ignore_quota)
 484 {
 485         struct iam_container  *bag;
 486         struct iam_rec        *iam_rec = (struct iam_rec *)oti->oti_ldp;
 487         struct iam_path_descr *ipd;
 488         struct osd_thandle    *oh;
 489         int                    rc;
 490 #ifdef HAVE_QUOTA_SUPPORT
 491         cfs_cap_t              save    = cfs_curproc_cap_pack();
 492 #endif
 493         ENTRY;
 494
 495         LASSERT(oi);
 496         LASSERT(oi->oi_inode);
 497
 498         bag = &oi->oi_dir.od_container;
 499         ipd = osd_idx_ipd_get(oti->oti_env, bag);
 500         if (unlikely(ipd == NULL))
 501                 RETURN(-ENOMEM);
 502
 503         oh = container_of0(th, struct osd_thandle, ot_super);
 504         LASSERT(oh->ot_handle != NULL);
 505         LASSERT(oh->ot_handle->h_transaction != NULL);
 506 #ifdef HAVE_QUOTA_SUPPORT
 507         if (ignore_quota)
 508                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 509         else
 510                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 511 #endif
 512         if (S_ISDIR(oi->oi_inode->i_mode))
 513                 osd_fid_pack((struct osd_fid_pack *)iam_rec, rec,
 514                              &oti->oti_fid);
 515         else
 516                 iam_rec = (struct iam_rec *) rec;
 517         rc = iam_insert(oh->ot_handle, bag, (const struct iam_key *)key,
 518                         iam_rec, ipd);
 519 #ifdef HAVE_QUOTA_SUPPORT
 520         cfs_curproc_cap_unpack(save);
 521 #endif
 522         osd_ipd_put(oti->oti_env, bag, ipd);
 523         LINVRNT(osd_invariant(obj));
 524         RETURN(rc);
 525 }
 526
 527 int osd_oi_insert(struct osd_thread_info *info, struct osd_device *osd,
 528                   const struct lu_fid *fid, const struct osd_inode_id *id0,
 529                   struct thandle *th, int ignore_quota)
 530 {
 531         struct lu_fid       *oi_fid = &info->oti_fid;
 532         struct osd_inode_id *id;
 533         const struct dt_key *key;
 534
 535         if (fid_is_igif(fid))
 536                 return 0;
 537
 538         if (fid_is_idif(fid) || fid_seq(fid) == FID_SEQ_LLOG)
 539                 return osd_compat_objid_insert(info, osd, fid, id0, th);
 540
 541         /* notice we don't return immediately, but continue to get into OI */
 542         if (unlikely(fid_seq(fid) == FID_SEQ_LOCAL_FILE))
 543                 osd_compat_spec_insert(info, osd, fid, id0, th);
 544
 545         fid_cpu_to_be(oi_fid, fid);
 546         key = (struct dt_key *)oi_fid;
 547
 548         id  = &info->oti_id;
 549         id->oii_ino = cpu_to_be32(id0->oii_ino);
 550         id->oii_gen = cpu_to_be32(id0->oii_gen);
 551
 552         return osd_oi_iam_insert(info, osd_fid2oi(osd, fid),
 553                                  (struct dt_rec *)id, key, th, ignore_quota);
 554 }
 555
 556 static int osd_oi_iam_delete(struct osd_thread_info *oti, struct osd_oi *oi,
 557                              const struct dt_key *key, struct thandle *handle)
 558 {
 559         struct iam_container  *bag;
 560         struct iam_path_descr *ipd;
 561         struct osd_thandle    *oh;
 562         int                    rc;
 563         ENTRY;
 564
 565         LASSERT(oi);
 566
 567         bag = &oi->oi_dir.od_container;
 568         ipd = osd_idx_ipd_get(oti->oti_env, bag);
 569         if (unlikely(ipd == NULL))
 570                 RETURN(-ENOMEM);
 571
 572         oh = container_of0(handle, struct osd_thandle, ot_super);
 573         LASSERT(oh->ot_handle != NULL);
 574         LASSERT(oh->ot_handle->h_transaction != NULL);
 575
 576         rc = iam_delete(oh->ot_handle, bag, (const struct iam_key *)key, ipd);
 577         osd_ipd_put(oti->oti_env, bag, ipd);
 578         LINVRNT(osd_invariant(obj));
 579         RETURN(rc);
 580 }
 581
 582 int osd_oi_delete(struct osd_thread_info *info,
 583                   struct osd_device *osd, const struct lu_fid *fid,
 584                   struct thandle *th)
 585 {
 586         struct lu_fid       *oi_fid = &info->oti_fid;
 587         const struct dt_key *key;
 588
 589         if (!fid_is_norm(fid))
 590                 return 0;
 591
 592         LASSERT(fid_seq(fid) != FID_SEQ_LOCAL_FILE);
 593
 594         if (fid_is_idif(fid) || fid_seq(fid) == FID_SEQ_LLOG)
 595                 return osd_compat_objid_delete(info, osd, fid, th);
 596
 597         fid_cpu_to_be(oi_fid, fid);
 598         key = (struct dt_key *)oi_fid;
 599
 600         return osd_oi_iam_delete(info, osd_fid2oi(osd, fid), key, th);
 601 }
 602
 603 int osd_oi_mod_init()
 604 {
 605         if (osd_oi_count == 0 || osd_oi_count > OSD_OI_FID_NR_MAX)
 606                 osd_oi_count = OSD_OI_FID_NR;
 607
 608         if ((osd_oi_count & (osd_oi_count - 1)) != 0) {
 609                 LCONSOLE_WARN("Round up oi_count %d to power2 %d\n",
 610                               osd_oi_count, size_roundup_power2(osd_oi_count));
 611                 osd_oi_count = size_roundup_power2(osd_oi_count);
 612         }
 613
 614         cfs_mutex_init(&oi_init_lock);
 615         return 0;
 616 }