fs/ocfs2/resize.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * resize.c
   5  *
   6  * volume resize.
   7  * Inspired by ext3/resize.c.
   8  *
   9  * Copyright (C) 2007 Oracle.  All rights reserved.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public
  13  * License as published by the Free Software Foundation; either
  14  * version 2 of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public
  22  * License along with this program; if not, write to the
  23  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24  * Boston, MA 021110-1307, USA.
  25  */
  26
  27 #include <linux/fs.h>
  28 #include <linux/types.h>
  29
  30 #include <cluster/masklog.h>
  31
  32 #include "ocfs2.h"
  33
  34 #include "alloc.h"
  35 #include "dlmglue.h"
  36 #include "inode.h"
  37 #include "journal.h"
  38 #include "super.h"
  39 #include "sysfile.h"
  40 #include "uptodate.h"
  41 #include "ocfs2_trace.h"
  42
  43 #include "buffer_head_io.h"
  44 #include "suballoc.h"
  45 #include "resize.h"
  46
  47 /*
  48  * Check whether there are new backup superblocks exist
  49  * in the last group. If there are some, mark them or clear
  50  * them in the bitmap.
  51  *
  52  * Return how many backups we find in the last group.
  53  */
  54 static u16 ocfs2_calc_new_backup_super(struct inode *inode,
  55                                        struct ocfs2_group_desc *gd,
  56                                        int new_clusters,
  57                                        u32 first_new_cluster,
  58                                        u16 cl_cpg,
  59                                        int set)
  60 {
  61         int i;
  62         u16 backups = 0;
  63         u32 cluster;
  64         u64 blkno, gd_blkno, lgd_blkno = le64_to_cpu(gd->bg_blkno);
  65
  66         for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) {
  67                 blkno = ocfs2_backup_super_blkno(inode->i_sb, i);
  68                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, blkno);
  69
  70                 gd_blkno = ocfs2_which_cluster_group(inode, cluster);
  71                 if (gd_blkno < lgd_blkno)
  72                         continue;
  73                 else if (gd_blkno > lgd_blkno)
  74                         break;
  75
  76                 if (set)
  77                         ocfs2_set_bit(cluster % cl_cpg,
  78                                       (unsigned long *)gd->bg_bitmap);
  79                 else
  80                         ocfs2_clear_bit(cluster % cl_cpg,
  81                                         (unsigned long *)gd->bg_bitmap);
  82                 backups++;
  83         }
  84
  85         return backups;
  86 }
  87
  88 static int ocfs2_update_last_group_and_inode(handle_t *handle,
  89                                              struct inode *bm_inode,
  90                                              struct buffer_head *bm_bh,
  91                                              struct buffer_head *group_bh,
  92                                              u32 first_new_cluster,
  93                                              int new_clusters)
  94 {
  95         int ret = 0;
  96         struct ocfs2_super *osb = OCFS2_SB(bm_inode->i_sb);
  97         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bm_bh->b_data;
  98         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
  99         struct ocfs2_chain_rec *cr;
 100         struct ocfs2_group_desc *group;
 101         u16 chain, num_bits, backups = 0;
 102         u16 cl_bpc = le16_to_cpu(cl->cl_bpc);
 103         u16 cl_cpg = le16_to_cpu(cl->cl_cpg);
 104
 105         trace_ocfs2_update_last_group_and_inode(new_clusters,
 106                                                 first_new_cluster);
 107
 108         ret = ocfs2_journal_access_gd(handle, INODE_CACHE(bm_inode),
 109                                       group_bh, OCFS2_JOURNAL_ACCESS_WRITE);
 110         if (ret < 0) {
 111                 mlog_errno(ret);
 112                 goto out;
 113         }
 114
 115         group = (struct ocfs2_group_desc *)group_bh->b_data;
 116
 117         /* update the group first. */
 118         num_bits = new_clusters * cl_bpc;
 119         le16_add_cpu(&group->bg_bits, num_bits);
 120         le16_add_cpu(&group->bg_free_bits_count, num_bits);
 121
 122         /*
 123          * check whether there are some new backup superblocks exist in
 124          * this group and update the group bitmap accordingly.
 125          */
 126         if (OCFS2_HAS_COMPAT_FEATURE(osb->sb,
 127                                      OCFS2_FEATURE_COMPAT_BACKUP_SB)) {
 128                 backups = ocfs2_calc_new_backup_super(bm_inode,
 129                                                      group,
 130                                                      new_clusters,
 131                                                      first_new_cluster,
 132                                                      cl_cpg, 1);
 133                 le16_add_cpu(&group->bg_free_bits_count, -1 * backups);
 134         }
 135
 136         ocfs2_journal_dirty(handle, group_bh);
 137
 138         /* update the inode accordingly. */
 139         ret = ocfs2_journal_access_di(handle, INODE_CACHE(bm_inode), bm_bh,
 140                                       OCFS2_JOURNAL_ACCESS_WRITE);
 141         if (ret < 0) {
 142                 mlog_errno(ret);
 143                 goto out_rollback;
 144         }
 145
 146         chain = le16_to_cpu(group->bg_chain);
 147         cr = (&cl->cl_recs[chain]);
 148         le32_add_cpu(&cr->c_total, num_bits);
 149         le32_add_cpu(&cr->c_free, num_bits);
 150         le32_add_cpu(&fe->id1.bitmap1.i_total, num_bits);
 151         le32_add_cpu(&fe->i_clusters, new_clusters);
 152
 153         if (backups) {
 154                 le32_add_cpu(&cr->c_free, -1 * backups);
 155                 le32_add_cpu(&fe->id1.bitmap1.i_used, backups);
 156         }
 157
 158         spin_lock(&OCFS2_I(bm_inode)->ip_lock);
 159         OCFS2_I(bm_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 160         le64_add_cpu(&fe->i_size, new_clusters << osb->s_clustersize_bits);
 161         spin_unlock(&OCFS2_I(bm_inode)->ip_lock);
 162         i_size_write(bm_inode, le64_to_cpu(fe->i_size));
 163
 164         ocfs2_journal_dirty(handle, bm_bh);
 165
 166 out_rollback:
 167         if (ret < 0) {
 168                 ocfs2_calc_new_backup_super(bm_inode,
 169                                             group,
 170                                             new_clusters,
 171                                             first_new_cluster,
 172                                             cl_cpg, 0);
 173                 le16_add_cpu(&group->bg_free_bits_count, backups);
 174                 le16_add_cpu(&group->bg_bits, -1 * num_bits);
 175                 le16_add_cpu(&group->bg_free_bits_count, -1 * num_bits);
 176         }
 177 out:
 178         if (ret)
 179                 mlog_errno(ret);
 180         return ret;
 181 }
 182
 183 static int update_backups(struct inode * inode, u32 clusters, char *data)
 184 {
 185         int i, ret = 0;
 186         u32 cluster;
 187         u64 blkno;
 188         struct buffer_head *backup = NULL;
 189         struct ocfs2_dinode *backup_di = NULL;
 190         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 191
 192         /* calculate the real backups we need to update. */
 193         for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) {
 194                 blkno = ocfs2_backup_super_blkno(inode->i_sb, i);
 195                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, blkno);
 196                 if (cluster > clusters)
 197                         break;
 198
 199                 ret = ocfs2_read_blocks_sync(osb, blkno, 1, &backup);
 200                 if (ret < 0) {
 201                         mlog_errno(ret);
 202                         break;
 203                 }
 204
 205                 memcpy(backup->b_data, data, inode->i_sb->s_blocksize);
 206
 207                 backup_di = (struct ocfs2_dinode *)backup->b_data;
 208                 backup_di->i_blkno = cpu_to_le64(blkno);
 209
 210                 ret = ocfs2_write_super_or_backup(osb, backup);
 211                 brelse(backup);
 212                 backup = NULL;
 213                 if (ret < 0) {
 214                         mlog_errno(ret);
 215                         break;
 216                 }
 217         }
 218
 219         return ret;
 220 }
 221
 222 static void ocfs2_update_super_and_backups(struct inode *inode,
 223                                            int new_clusters)
 224 {
 225         int ret;
 226         u32 clusters = 0;
 227         struct buffer_head *super_bh = NULL;
 228         struct ocfs2_dinode *super_di = NULL;
 229         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 230
 231         /*
 232          * update the superblock last.
 233          * It doesn't matter if the write failed.
 234          */
 235         ret = ocfs2_read_blocks_sync(osb, OCFS2_SUPER_BLOCK_BLKNO, 1,
 236                                      &super_bh);
 237         if (ret < 0) {
 238                 mlog_errno(ret);
 239                 goto out;
 240         }
 241
 242         super_di = (struct ocfs2_dinode *)super_bh->b_data;
 243         le32_add_cpu(&super_di->i_clusters, new_clusters);
 244         clusters = le32_to_cpu(super_di->i_clusters);
 245
 246         ret = ocfs2_write_super_or_backup(osb, super_bh);
 247         if (ret < 0) {
 248                 mlog_errno(ret);
 249                 goto out;
 250         }
 251
 252         if (OCFS2_HAS_COMPAT_FEATURE(osb->sb, OCFS2_FEATURE_COMPAT_BACKUP_SB))
 253                 ret = update_backups(inode, clusters, super_bh->b_data);
 254
 255 out:
 256         brelse(super_bh);
 257         if (ret)
 258                 printk(KERN_WARNING "ocfs2: Failed to update super blocks on %s"
 259                         " during fs resize. This condition is not fatal,"
 260                         " but fsck.ocfs2 should be run to fix it\n",
 261                         osb->dev_str);
 262         return;
 263 }
 264
 265 /*
 266  * Extend the filesystem to the new number of clusters specified.  This entry
 267  * point is only used to extend the current filesystem to the end of the last
 268  * existing group.
 269  */
 270 int ocfs2_group_extend(struct inode * inode, int new_clusters)
 271 {
 272         int ret;
 273         handle_t *handle;
 274         struct buffer_head *main_bm_bh = NULL;
 275         struct buffer_head *group_bh = NULL;
 276         struct inode *main_bm_inode = NULL;
 277         struct ocfs2_dinode *fe = NULL;
 278         struct ocfs2_group_desc *group = NULL;
 279         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 280         u16 cl_bpc;
 281         u32 first_new_cluster;
 282         u64 lgd_blkno;
 283
 284         if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb))
 285                 return -EROFS;
 286
 287         if (new_clusters < 0)
 288                 return -EINVAL;
 289         else if (new_clusters == 0)
 290                 return 0;
 291
 292         main_bm_inode = ocfs2_get_system_file_inode(osb,
 293                                                     GLOBAL_BITMAP_SYSTEM_INODE,
 294                                                     OCFS2_INVALID_SLOT);
 295         if (!main_bm_inode) {
 296                 ret = -EINVAL;
 297                 mlog_errno(ret);
 298                 goto out;
 299         }
 300
 301         mutex_lock(&main_bm_inode->i_mutex);
 302
 303         ret = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
 304         if (ret < 0) {
 305                 mlog_errno(ret);
 306                 goto out_mutex;
 307         }
 308
 309         fe = (struct ocfs2_dinode *)main_bm_bh->b_data;
 310
 311         /* main_bm_bh is validated by inode read inside ocfs2_inode_lock(),
 312          * so any corruption is a code bug. */
 313         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 314
 315         if (le16_to_cpu(fe->id2.i_chain.cl_cpg) !=
 316                 ocfs2_group_bitmap_size(osb->sb, 0,
 317                                         osb->s_feature_incompat) * 8) {
 318                 mlog(ML_ERROR, "The disk is too old and small. "
 319                      "Force to do offline resize.");
 320                 ret = -EINVAL;
 321                 goto out_unlock;
 322         }
 323
 324         first_new_cluster = le32_to_cpu(fe->i_clusters);
 325         lgd_blkno = ocfs2_which_cluster_group(main_bm_inode,
 326                                               first_new_cluster - 1);
 327
 328         ret = ocfs2_read_group_descriptor(main_bm_inode, fe, lgd_blkno,
 329                                           &group_bh);
 330         if (ret < 0) {
 331                 mlog_errno(ret);
 332                 goto out_unlock;
 333         }
 334         group = (struct ocfs2_group_desc *)group_bh->b_data;
 335
 336         cl_bpc = le16_to_cpu(fe->id2.i_chain.cl_bpc);
 337         if (le16_to_cpu(group->bg_bits) / cl_bpc + new_clusters >
 338                 le16_to_cpu(fe->id2.i_chain.cl_cpg)) {
 339                 ret = -EINVAL;
 340                 goto out_unlock;
 341         }
 342
 343
 344         trace_ocfs2_group_extend(
 345              (unsigned long long)le64_to_cpu(group->bg_blkno), new_clusters);
 346
 347         handle = ocfs2_start_trans(osb, OCFS2_GROUP_EXTEND_CREDITS);
 348         if (IS_ERR(handle)) {
 349                 mlog_errno(PTR_ERR(handle));
 350                 ret = -EINVAL;
 351                 goto out_unlock;
 352         }
 353
 354         /* update the last group descriptor and inode. */
 355         ret = ocfs2_update_last_group_and_inode(handle, main_bm_inode,
 356                                                 main_bm_bh, group_bh,
 357                                                 first_new_cluster,
 358                                                 new_clusters);
 359         if (ret) {
 360                 mlog_errno(ret);
 361                 goto out_commit;
 362         }
 363
 364         ocfs2_update_super_and_backups(main_bm_inode, new_clusters);
 365
 366 out_commit:
 367         ocfs2_commit_trans(osb, handle);
 368 out_unlock:
 369         brelse(group_bh);
 370         brelse(main_bm_bh);
 371
 372         ocfs2_inode_unlock(main_bm_inode, 1);
 373
 374 out_mutex:
 375         mutex_unlock(&main_bm_inode->i_mutex);
 376         iput(main_bm_inode);
 377
 378 out:
 379         return ret;
 380 }
 381
 382 static int ocfs2_check_new_group(struct inode *inode,
 383                                  struct ocfs2_dinode *di,
 384                                  struct ocfs2_new_group_input *input,
 385                                  struct buffer_head *group_bh)
 386 {
 387         int ret;
 388         struct ocfs2_group_desc *gd =
 389                 (struct ocfs2_group_desc *)group_bh->b_data;
 390         u16 cl_bpc = le16_to_cpu(di->id2.i_chain.cl_bpc);
 391
 392         ret = ocfs2_check_group_descriptor(inode->i_sb, di, group_bh);
 393         if (ret)
 394                 goto out;
 395
 396         ret = -EINVAL;
 397         if (le16_to_cpu(gd->bg_chain) != input->chain)
 398                 mlog(ML_ERROR, "Group descriptor # %llu has bad chain %u "
 399                      "while input has %u set.\n",
 400                      (unsigned long long)le64_to_cpu(gd->bg_blkno),
 401                      le16_to_cpu(gd->bg_chain), input->chain);
 402         else if (le16_to_cpu(gd->bg_bits) != input->clusters * cl_bpc)
 403                 mlog(ML_ERROR, "Group descriptor # %llu has bit count %u but "
 404                      "input has %u clusters set\n",
 405                      (unsigned long long)le64_to_cpu(gd->bg_blkno),
 406                      le16_to_cpu(gd->bg_bits), input->clusters);
 407         else if (le16_to_cpu(gd->bg_free_bits_count) != input->frees * cl_bpc)
 408                 mlog(ML_ERROR, "Group descriptor # %llu has free bit count %u "
 409                      "but it should have %u set\n",
 410                      (unsigned long long)le64_to_cpu(gd->bg_blkno),
 411                      le16_to_cpu(gd->bg_bits),
 412                      input->frees * cl_bpc);
 413         else
 414                 ret = 0;
 415
 416 out:
 417         return ret;
 418 }
 419
 420 static int ocfs2_verify_group_and_input(struct inode *inode,
 421                                         struct ocfs2_dinode *di,
 422                                         struct ocfs2_new_group_input *input,
 423                                         struct buffer_head *group_bh)
 424 {
 425         u16 cl_count = le16_to_cpu(di->id2.i_chain.cl_count);
 426         u16 cl_cpg = le16_to_cpu(di->id2.i_chain.cl_cpg);
 427         u16 next_free = le16_to_cpu(di->id2.i_chain.cl_next_free_rec);
 428         u32 cluster = ocfs2_blocks_to_clusters(inode->i_sb, input->group);
 429         u32 total_clusters = le32_to_cpu(di->i_clusters);
 430         int ret = -EINVAL;
 431
 432         if (cluster < total_clusters)
 433                 mlog(ML_ERROR, "add a group which is in the current volume.\n");
 434         else if (input->chain >= cl_count)
 435                 mlog(ML_ERROR, "input chain exceeds the limit.\n");
 436         else if (next_free != cl_count && next_free != input->chain)
 437                 mlog(ML_ERROR,
 438                      "the add group should be in chain %u\n", next_free);
 439         else if (total_clusters + input->clusters < total_clusters)
 440                 mlog(ML_ERROR, "add group's clusters overflow.\n");
 441         else if (input->clusters > cl_cpg)
 442                 mlog(ML_ERROR, "the cluster exceeds the maximum of a group\n");
 443         else if (input->frees > input->clusters)
 444                 mlog(ML_ERROR, "the free cluster exceeds the total clusters\n");
 445         else if (total_clusters % cl_cpg != 0)
 446                 mlog(ML_ERROR,
 447                      "the last group isn't full. Use group extend first.\n");
 448         else if (input->group != ocfs2_which_cluster_group(inode, cluster))
 449                 mlog(ML_ERROR, "group blkno is invalid\n");
 450         else if ((ret = ocfs2_check_new_group(inode, di, input, group_bh)))
 451                 mlog(ML_ERROR, "group descriptor check failed.\n");
 452         else
 453                 ret = 0;
 454
 455         return ret;
 456 }
 457
 458 /* Add a new group descriptor to global_bitmap. */
 459 int ocfs2_group_add(struct inode *inode, struct ocfs2_new_group_input *input)
 460 {
 461         int ret;
 462         handle_t *handle;
 463         struct buffer_head *main_bm_bh = NULL;
 464         struct inode *main_bm_inode = NULL;
 465         struct ocfs2_dinode *fe = NULL;
 466         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 467         struct buffer_head *group_bh = NULL;
 468         struct ocfs2_group_desc *group = NULL;
 469         struct ocfs2_chain_list *cl;
 470         struct ocfs2_chain_rec *cr;
 471         u16 cl_bpc;
 472
 473         if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb))
 474                 return -EROFS;
 475
 476         main_bm_inode = ocfs2_get_system_file_inode(osb,
 477                                                     GLOBAL_BITMAP_SYSTEM_INODE,
 478                                                     OCFS2_INVALID_SLOT);
 479         if (!main_bm_inode) {
 480                 ret = -EINVAL;
 481                 mlog_errno(ret);
 482                 goto out;
 483         }
 484
 485         mutex_lock(&main_bm_inode->i_mutex);
 486
 487         ret = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
 488         if (ret < 0) {
 489                 mlog_errno(ret);
 490                 goto out_mutex;
 491         }
 492
 493         fe = (struct ocfs2_dinode *)main_bm_bh->b_data;
 494
 495         if (le16_to_cpu(fe->id2.i_chain.cl_cpg) !=
 496                 ocfs2_group_bitmap_size(osb->sb, 0,
 497                                         osb->s_feature_incompat) * 8) {
 498                 mlog(ML_ERROR, "The disk is too old and small."
 499                      " Force to do offline resize.");
 500                 ret = -EINVAL;
 501                 goto out_unlock;
 502         }
 503
 504         ret = ocfs2_read_blocks_sync(osb, input->group, 1, &group_bh);
 505         if (ret < 0) {
 506                 mlog(ML_ERROR, "Can't read the group descriptor # %llu "
 507                      "from the device.", (unsigned long long)input->group);
 508                 goto out_unlock;
 509         }
 510
 511         ocfs2_set_new_buffer_uptodate(INODE_CACHE(inode), group_bh);
 512
 513         ret = ocfs2_verify_group_and_input(main_bm_inode, fe, input, group_bh);
 514         if (ret) {
 515                 mlog_errno(ret);
 516                 goto out_unlock;
 517         }
 518
 519         trace_ocfs2_group_add((unsigned long long)input->group,
 520                                input->chain, input->clusters, input->frees);
 521
 522         handle = ocfs2_start_trans(osb, OCFS2_GROUP_ADD_CREDITS);
 523         if (IS_ERR(handle)) {
 524                 mlog_errno(PTR_ERR(handle));
 525                 ret = -EINVAL;
 526                 goto out_unlock;
 527         }
 528
 529         cl_bpc = le16_to_cpu(fe->id2.i_chain.cl_bpc);
 530         cl = &fe->id2.i_chain;
 531         cr = &cl->cl_recs[input->chain];
 532
 533         ret = ocfs2_journal_access_gd(handle, INODE_CACHE(main_bm_inode),
 534                                       group_bh, OCFS2_JOURNAL_ACCESS_WRITE);
 535         if (ret < 0) {
 536                 mlog_errno(ret);
 537                 goto out_commit;
 538         }
 539
 540         group = (struct ocfs2_group_desc *)group_bh->b_data;
 541         group->bg_next_group = cr->c_blkno;
 542         ocfs2_journal_dirty(handle, group_bh);
 543
 544         ret = ocfs2_journal_access_di(handle, INODE_CACHE(main_bm_inode),
 545                                       main_bm_bh, OCFS2_JOURNAL_ACCESS_WRITE);
 546         if (ret < 0) {
 547                 mlog_errno(ret);
 548                 goto out_commit;
 549         }
 550
 551         if (input->chain == le16_to_cpu(cl->cl_next_free_rec)) {
 552                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 553                 memset(cr, 0, sizeof(struct ocfs2_chain_rec));
 554         }
 555
 556         cr->c_blkno = cpu_to_le64(input->group);
 557         le32_add_cpu(&cr->c_total, input->clusters * cl_bpc);
 558         le32_add_cpu(&cr->c_free, input->frees * cl_bpc);
 559
 560         le32_add_cpu(&fe->id1.bitmap1.i_total, input->clusters *cl_bpc);
 561         le32_add_cpu(&fe->id1.bitmap1.i_used,
 562                      (input->clusters - input->frees) * cl_bpc);
 563         le32_add_cpu(&fe->i_clusters, input->clusters);
 564
 565         ocfs2_journal_dirty(handle, main_bm_bh);
 566
 567         spin_lock(&OCFS2_I(main_bm_inode)->ip_lock);
 568         OCFS2_I(main_bm_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 569         le64_add_cpu(&fe->i_size, input->clusters << osb->s_clustersize_bits);
 570         spin_unlock(&OCFS2_I(main_bm_inode)->ip_lock);
 571         i_size_write(main_bm_inode, le64_to_cpu(fe->i_size));
 572
 573         ocfs2_update_super_and_backups(main_bm_inode, input->clusters);
 574
 575 out_commit:
 576         ocfs2_commit_trans(osb, handle);
 577 out_unlock:
 578         brelse(group_bh);
 579         brelse(main_bm_bh);
 580
 581         ocfs2_inode_unlock(main_bm_inode, 1);
 582
 583 out_mutex:
 584         mutex_unlock(&main_bm_inode->i_mutex);
 585         iput(main_bm_inode);
 586
 587 out:
 588         return ret;
 589 }