fs/ocfs2/suballoc.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * suballoc.c
   5  *
   6  * metadata alloc and free
   7  * Inspired by ext3 block groups.
   8  *
   9  * Copyright (C) 2002, 2004 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 #include <linux/slab.h>
  30 #include <linux/highmem.h>
  31
  32 #define MLOG_MASK_PREFIX ML_DISK_ALLOC
  33 #include <cluster/masklog.h>
  34
  35 #include "ocfs2.h"
  36
  37 #include "alloc.h"
  38 #include "dlmglue.h"
  39 #include "inode.h"
  40 #include "journal.h"
  41 #include "localalloc.h"
  42 #include "suballoc.h"
  43 #include "super.h"
  44 #include "sysfile.h"
  45 #include "uptodate.h"
  46
  47 #include "buffer_head_io.h"
  48
  49 #define NOT_ALLOC_NEW_GROUP             0
  50 #define ALLOC_NEW_GROUP                 1
  51
  52 #define OCFS2_MAX_INODES_TO_STEAL       1024
  53
  54 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
  55 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
  56 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  57 static int ocfs2_block_group_fill(handle_t *handle,
  58                                   struct inode *alloc_inode,
  59                                   struct buffer_head *bg_bh,
  60                                   u64 group_blkno,
  61                                   u16 my_chain,
  62                                   struct ocfs2_chain_list *cl);
  63 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  64                                    struct inode *alloc_inode,
  65                                    struct buffer_head *bh);
  66
  67 static int ocfs2_cluster_group_search(struct inode *inode,
  68                                       struct buffer_head *group_bh,
  69                                       u32 bits_wanted, u32 min_bits,
  70                                       u16 *bit_off, u16 *bits_found);
  71 static int ocfs2_block_group_search(struct inode *inode,
  72                                     struct buffer_head *group_bh,
  73                                     u32 bits_wanted, u32 min_bits,
  74                                     u16 *bit_off, u16 *bits_found);
  75 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
  76                                      struct ocfs2_alloc_context *ac,
  77                                      handle_t *handle,
  78                                      u32 bits_wanted,
  79                                      u32 min_bits,
  80                                      u16 *bit_off,
  81                                      unsigned int *num_bits,
  82                                      u64 *bg_blkno);
  83 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  84                                          int nr);
  85 static inline int ocfs2_block_group_set_bits(handle_t *handle,
  86                                              struct inode *alloc_inode,
  87                                              struct ocfs2_group_desc *bg,
  88                                              struct buffer_head *group_bh,
  89                                              unsigned int bit_off,
  90                                              unsigned int num_bits);
  91 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
  92                                                struct inode *alloc_inode,
  93                                                struct ocfs2_group_desc *bg,
  94                                                struct buffer_head *group_bh,
  95                                                unsigned int bit_off,
  96                                                unsigned int num_bits);
  97
  98 static int ocfs2_relink_block_group(handle_t *handle,
  99                                     struct inode *alloc_inode,
 100                                     struct buffer_head *fe_bh,
 101                                     struct buffer_head *bg_bh,
 102                                     struct buffer_head *prev_bg_bh,
 103                                     u16 chain);
 104 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 105                                                      u32 wanted);
 106 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 107                                                    u64 bg_blkno,
 108                                                    u16 bg_bit_off);
 109 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 110                                                 u64 data_blkno,
 111                                                 u64 *bg_blkno,
 112                                                 u16 *bg_bit_off);
 113
 114 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 115 {
 116         struct inode *inode = ac->ac_inode;
 117
 118         if (inode) {
 119                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 120                         ocfs2_inode_unlock(inode, 1);
 121
 122                 mutex_unlock(&inode->i_mutex);
 123
 124                 iput(inode);
 125                 ac->ac_inode = NULL;
 126         }
 127         if (ac->ac_bh) {
 128                 brelse(ac->ac_bh);
 129                 ac->ac_bh = NULL;
 130         }
 131 }
 132
 133 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 134 {
 135         ocfs2_free_ac_resource(ac);
 136         kfree(ac);
 137 }
 138
 139 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 140 {
 141         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 142 }
 143
 144 /* somewhat more expensive than our other checks, so use sparingly. */
 145 int ocfs2_check_group_descriptor(struct super_block *sb,
 146                                  struct ocfs2_dinode *di,
 147                                  struct ocfs2_group_desc *gd)
 148 {
 149         unsigned int max_bits;
 150
 151         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 152                 OCFS2_RO_ON_INVALID_GROUP_DESC(sb, gd);
 153                 return -EIO;
 154         }
 155
 156         if (di->i_blkno != gd->bg_parent_dinode) {
 157                 ocfs2_error(sb, "Group descriptor # %llu has bad parent "
 158                             "pointer (%llu, expected %llu)",
 159                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 160                             (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 161                             (unsigned long long)le64_to_cpu(di->i_blkno));
 162                 return -EIO;
 163         }
 164
 165         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 166         if (le16_to_cpu(gd->bg_bits) > max_bits) {
 167                 ocfs2_error(sb, "Group descriptor # %llu has bit count of %u",
 168                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 169                             le16_to_cpu(gd->bg_bits));
 170                 return -EIO;
 171         }
 172
 173         if (le16_to_cpu(gd->bg_chain) >=
 174             le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) {
 175                 ocfs2_error(sb, "Group descriptor # %llu has bad chain %u",
 176                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 177                             le16_to_cpu(gd->bg_chain));
 178                 return -EIO;
 179         }
 180
 181         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 182                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 183                             "claims that %u are free",
 184                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 185                             le16_to_cpu(gd->bg_bits),
 186                             le16_to_cpu(gd->bg_free_bits_count));
 187                 return -EIO;
 188         }
 189
 190         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 191                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 192                             "max bitmap bits of %u",
 193                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 194                             le16_to_cpu(gd->bg_bits),
 195                             8 * le16_to_cpu(gd->bg_size));
 196                 return -EIO;
 197         }
 198
 199         return 0;
 200 }
 201
 202 static int ocfs2_block_group_fill(handle_t *handle,
 203                                   struct inode *alloc_inode,
 204                                   struct buffer_head *bg_bh,
 205                                   u64 group_blkno,
 206                                   u16 my_chain,
 207                                   struct ocfs2_chain_list *cl)
 208 {
 209         int status = 0;
 210         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 211         struct super_block * sb = alloc_inode->i_sb;
 212
 213         mlog_entry_void();
 214
 215         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 216                 ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
 217                             "b_blocknr (%llu)",
 218                             (unsigned long long)group_blkno,
 219                             (unsigned long long) bg_bh->b_blocknr);
 220                 status = -EIO;
 221                 goto bail;
 222         }
 223
 224         status = ocfs2_journal_access(handle,
 225                                       alloc_inode,
 226                                       bg_bh,
 227                                       OCFS2_JOURNAL_ACCESS_CREATE);
 228         if (status < 0) {
 229                 mlog_errno(status);
 230                 goto bail;
 231         }
 232
 233         memset(bg, 0, sb->s_blocksize);
 234         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 235         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 236         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
 237         bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 238         bg->bg_chain = cpu_to_le16(my_chain);
 239         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 240         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 241         bg->bg_blkno = cpu_to_le64(group_blkno);
 242         /* set the 1st bit in the bitmap to account for the descriptor block */
 243         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 244         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 245
 246         status = ocfs2_journal_dirty(handle, bg_bh);
 247         if (status < 0)
 248                 mlog_errno(status);
 249
 250         /* There is no need to zero out or otherwise initialize the
 251          * other blocks in a group - All valid FS metadata in a block
 252          * group stores the superblock fs_generation value at
 253          * allocation time. */
 254
 255 bail:
 256         mlog_exit(status);
 257         return status;
 258 }
 259
 260 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 261 {
 262         u16 curr, best;
 263
 264         best = curr = 0;
 265         while (curr < le16_to_cpu(cl->cl_count)) {
 266                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 267                     le32_to_cpu(cl->cl_recs[curr].c_total))
 268                         best = curr;
 269                 curr++;
 270         }
 271         return best;
 272 }
 273
 274 /*
 275  * We expect the block group allocator to already be locked.
 276  */
 277 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 278                                    struct inode *alloc_inode,
 279                                    struct buffer_head *bh)
 280 {
 281         int status, credits;
 282         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 283         struct ocfs2_chain_list *cl;
 284         struct ocfs2_alloc_context *ac = NULL;
 285         handle_t *handle = NULL;
 286         u32 bit_off, num_bits;
 287         u16 alloc_rec;
 288         u64 bg_blkno;
 289         struct buffer_head *bg_bh = NULL;
 290         struct ocfs2_group_desc *bg;
 291
 292         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 293
 294         mlog_entry_void();
 295
 296         cl = &fe->id2.i_chain;
 297         status = ocfs2_reserve_clusters(osb,
 298                                         le16_to_cpu(cl->cl_cpg),
 299                                         &ac);
 300         if (status < 0) {
 301                 if (status != -ENOSPC)
 302                         mlog_errno(status);
 303                 goto bail;
 304         }
 305
 306         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 307                                                  le16_to_cpu(cl->cl_cpg));
 308         handle = ocfs2_start_trans(osb, credits);
 309         if (IS_ERR(handle)) {
 310                 status = PTR_ERR(handle);
 311                 handle = NULL;
 312                 mlog_errno(status);
 313                 goto bail;
 314         }
 315
 316         status = ocfs2_claim_clusters(osb,
 317                                       handle,
 318                                       ac,
 319                                       le16_to_cpu(cl->cl_cpg),
 320                                       &bit_off,
 321                                       &num_bits);
 322         if (status < 0) {
 323                 if (status != -ENOSPC)
 324                         mlog_errno(status);
 325                 goto bail;
 326         }
 327
 328         alloc_rec = ocfs2_find_smallest_chain(cl);
 329
 330         /* setup the group */
 331         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 332         mlog(0, "new descriptor, record %u, at block %llu\n",
 333              alloc_rec, (unsigned long long)bg_blkno);
 334
 335         bg_bh = sb_getblk(osb->sb, bg_blkno);
 336         if (!bg_bh) {
 337                 status = -EIO;
 338                 mlog_errno(status);
 339                 goto bail;
 340         }
 341         ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);
 342
 343         status = ocfs2_block_group_fill(handle,
 344                                         alloc_inode,
 345                                         bg_bh,
 346                                         bg_blkno,
 347                                         alloc_rec,
 348                                         cl);
 349         if (status < 0) {
 350                 mlog_errno(status);
 351                 goto bail;
 352         }
 353
 354         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 355
 356         status = ocfs2_journal_access(handle, alloc_inode,
 357                                       bh, OCFS2_JOURNAL_ACCESS_WRITE);
 358         if (status < 0) {
 359                 mlog_errno(status);
 360                 goto bail;
 361         }
 362
 363         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 364                      le16_to_cpu(bg->bg_free_bits_count));
 365         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
 366         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
 367         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 368                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 369
 370         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 371                                         le16_to_cpu(bg->bg_free_bits_count));
 372         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 373         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 374
 375         status = ocfs2_journal_dirty(handle, bh);
 376         if (status < 0) {
 377                 mlog_errno(status);
 378                 goto bail;
 379         }
 380
 381         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 382         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 383         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 384                                              le32_to_cpu(fe->i_clusters)));
 385         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 386         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 387         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 388
 389         status = 0;
 390 bail:
 391         if (handle)
 392                 ocfs2_commit_trans(osb, handle);
 393
 394         if (ac)
 395                 ocfs2_free_alloc_context(ac);
 396
 397         if (bg_bh)
 398                 brelse(bg_bh);
 399
 400         mlog_exit(status);
 401         return status;
 402 }
 403
 404 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 405                                        struct ocfs2_alloc_context *ac,
 406                                        int type,
 407                                        u32 slot,
 408                                        int alloc_new_group)
 409 {
 410         int status;
 411         u32 bits_wanted = ac->ac_bits_wanted;
 412         struct inode *alloc_inode;
 413         struct buffer_head *bh = NULL;
 414         struct ocfs2_dinode *fe;
 415         u32 free_bits;
 416
 417         mlog_entry_void();
 418
 419         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 420         if (!alloc_inode) {
 421                 mlog_errno(-EINVAL);
 422                 return -EINVAL;
 423         }
 424
 425         mutex_lock(&alloc_inode->i_mutex);
 426
 427         status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 428         if (status < 0) {
 429                 mutex_unlock(&alloc_inode->i_mutex);
 430                 iput(alloc_inode);
 431
 432                 mlog_errno(status);
 433                 return status;
 434         }
 435
 436         ac->ac_inode = alloc_inode;
 437         ac->ac_alloc_slot = slot;
 438
 439         fe = (struct ocfs2_dinode *) bh->b_data;
 440         if (!OCFS2_IS_VALID_DINODE(fe)) {
 441                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 442                 status = -EIO;
 443                 goto bail;
 444         }
 445         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 446                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 447                             (unsigned long long)le64_to_cpu(fe->i_blkno));
 448                 status = -EIO;
 449                 goto bail;
 450         }
 451
 452         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 453                 le32_to_cpu(fe->id1.bitmap1.i_used);
 454
 455         if (bits_wanted > free_bits) {
 456                 /* cluster bitmap never grows */
 457                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 458                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
 459                              bits_wanted, free_bits);
 460                         status = -ENOSPC;
 461                         goto bail;
 462                 }
 463
 464                 if (alloc_new_group != ALLOC_NEW_GROUP) {
 465                         mlog(0, "Alloc File %u Full: wanted=%u, free_bits=%u, "
 466                              "and we don't alloc a new group for it.\n",
 467                              slot, bits_wanted, free_bits);
 468                         status = -ENOSPC;
 469                         goto bail;
 470                 }
 471
 472                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh);
 473                 if (status < 0) {
 474                         if (status != -ENOSPC)
 475                                 mlog_errno(status);
 476                         goto bail;
 477                 }
 478                 atomic_inc(&osb->alloc_stats.bg_extends);
 479
 480                 /* You should never ask for this much metadata */
 481                 BUG_ON(bits_wanted >
 482                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 483                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 484         }
 485
 486         get_bh(bh);
 487         ac->ac_bh = bh;
 488 bail:
 489         if (bh)
 490                 brelse(bh);
 491
 492         mlog_exit(status);
 493         return status;
 494 }
 495
 496 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
 497                                struct ocfs2_extent_list *root_el,
 498                                struct ocfs2_alloc_context **ac)
 499 {
 500         int status;
 501         u32 slot;
 502
 503         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 504         if (!(*ac)) {
 505                 status = -ENOMEM;
 506                 mlog_errno(status);
 507                 goto bail;
 508         }
 509
 510         (*ac)->ac_bits_wanted = ocfs2_extend_meta_needed(root_el);
 511         (*ac)->ac_which = OCFS2_AC_USE_META;
 512         slot = osb->slot_num;
 513         (*ac)->ac_group_search = ocfs2_block_group_search;
 514
 515         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 516                                              EXTENT_ALLOC_SYSTEM_INODE,
 517                                              slot, ALLOC_NEW_GROUP);
 518         if (status < 0) {
 519                 if (status != -ENOSPC)
 520                         mlog_errno(status);
 521                 goto bail;
 522         }
 523
 524         status = 0;
 525 bail:
 526         if ((status < 0) && *ac) {
 527                 ocfs2_free_alloc_context(*ac);
 528                 *ac = NULL;
 529         }
 530
 531         mlog_exit(status);
 532         return status;
 533 }
 534
 535 static int ocfs2_steal_inode_from_other_nodes(struct ocfs2_super *osb,
 536                                               struct ocfs2_alloc_context *ac)
 537 {
 538         int i, status = -ENOSPC;
 539         s16 slot = ocfs2_get_inode_steal_slot(osb);
 540
 541         /* Start to steal inodes from the first slot after ours. */
 542         if (slot == OCFS2_INVALID_SLOT)
 543                 slot = osb->slot_num + 1;
 544
 545         for (i = 0; i < osb->max_slots; i++, slot++) {
 546                 if (slot == osb->max_slots)
 547                         slot = 0;
 548
 549                 if (slot == osb->slot_num)
 550                         continue;
 551
 552                 status = ocfs2_reserve_suballoc_bits(osb, ac,
 553                                                      INODE_ALLOC_SYSTEM_INODE,
 554                                                      slot, NOT_ALLOC_NEW_GROUP);
 555                 if (status >= 0) {
 556                         ocfs2_set_inode_steal_slot(osb, slot);
 557                         break;
 558                 }
 559
 560                 ocfs2_free_ac_resource(ac);
 561         }
 562
 563         return status;
 564 }
 565
 566 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 567                             struct ocfs2_alloc_context **ac)
 568 {
 569         int status;
 570         s16 slot = ocfs2_get_inode_steal_slot(osb);
 571
 572         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 573         if (!(*ac)) {
 574                 status = -ENOMEM;
 575                 mlog_errno(status);
 576                 goto bail;
 577         }
 578
 579         (*ac)->ac_bits_wanted = 1;
 580         (*ac)->ac_which = OCFS2_AC_USE_INODE;
 581
 582         (*ac)->ac_group_search = ocfs2_block_group_search;
 583
 584         /*
 585          * slot is set when we successfully steal inode from other nodes.
 586          * It is reset in 3 places:
 587          * 1. when we flush the truncate log
 588          * 2. when we complete local alloc recovery.
 589          * 3. when we successfully allocate from our own slot.
 590          * After it is set, we will go on stealing inodes until we find the
 591          * need to check our slots to see whether there is some space for us.
 592          */
 593         if (slot != OCFS2_INVALID_SLOT &&
 594             atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_INODES_TO_STEAL)
 595                 goto inode_steal;
 596
 597         atomic_set(&osb->s_num_inodes_stolen, 0);
 598         status = ocfs2_reserve_suballoc_bits(osb, *ac,
 599                                              INODE_ALLOC_SYSTEM_INODE,
 600                                              osb->slot_num, ALLOC_NEW_GROUP);
 601         if (status >= 0) {
 602                 status = 0;
 603
 604                 /*
 605                  * Some inodes must be freed by us, so try to allocate
 606                  * from our own next time.
 607                  */
 608                 if (slot != OCFS2_INVALID_SLOT)
 609                         ocfs2_init_inode_steal_slot(osb);
 610                 goto bail;
 611         } else if (status < 0 && status != -ENOSPC) {
 612                 mlog_errno(status);
 613                 goto bail;
 614         }
 615
 616         ocfs2_free_ac_resource(*ac);
 617
 618 inode_steal:
 619         status = ocfs2_steal_inode_from_other_nodes(osb, *ac);
 620         atomic_inc(&osb->s_num_inodes_stolen);
 621         if (status < 0) {
 622                 if (status != -ENOSPC)
 623                         mlog_errno(status);
 624                 goto bail;
 625         }
 626
 627         status = 0;
 628 bail:
 629         if ((status < 0) && *ac) {
 630                 ocfs2_free_alloc_context(*ac);
 631                 *ac = NULL;
 632         }
 633
 634         mlog_exit(status);
 635         return status;
 636 }
 637
 638 /* local alloc code has to do the same thing, so rather than do this
 639  * twice.. */
 640 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
 641                                       struct ocfs2_alloc_context *ac)
 642 {
 643         int status;
 644
 645         ac->ac_which = OCFS2_AC_USE_MAIN;
 646         ac->ac_group_search = ocfs2_cluster_group_search;
 647
 648         status = ocfs2_reserve_suballoc_bits(osb, ac,
 649                                              GLOBAL_BITMAP_SYSTEM_INODE,
 650                                              OCFS2_INVALID_SLOT,
 651                                              ALLOC_NEW_GROUP);
 652         if (status < 0 && status != -ENOSPC) {
 653                 mlog_errno(status);
 654                 goto bail;
 655         }
 656
 657 bail:
 658         return status;
 659 }
 660
 661 /* Callers don't need to care which bitmap (local alloc or main) to
 662  * use so we figure it out for them, but unfortunately this clutters
 663  * things a bit. */
 664 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
 665                            u32 bits_wanted,
 666                            struct ocfs2_alloc_context **ac)
 667 {
 668         int status;
 669
 670         mlog_entry_void();
 671
 672         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 673         if (!(*ac)) {
 674                 status = -ENOMEM;
 675                 mlog_errno(status);
 676                 goto bail;
 677         }
 678
 679         (*ac)->ac_bits_wanted = bits_wanted;
 680
 681         status = -ENOSPC;
 682         if (ocfs2_alloc_should_use_local(osb, bits_wanted)) {
 683                 status = ocfs2_reserve_local_alloc_bits(osb,
 684                                                         bits_wanted,
 685                                                         *ac);
 686                 if ((status < 0) && (status != -ENOSPC)) {
 687                         mlog_errno(status);
 688                         goto bail;
 689                 }
 690         }
 691
 692         if (status == -ENOSPC) {
 693                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 694                 if (status < 0) {
 695                         if (status != -ENOSPC)
 696                                 mlog_errno(status);
 697                         goto bail;
 698                 }
 699         }
 700
 701         status = 0;
 702 bail:
 703         if ((status < 0) && *ac) {
 704                 ocfs2_free_alloc_context(*ac);
 705                 *ac = NULL;
 706         }
 707
 708         mlog_exit(status);
 709         return status;
 710 }
 711
 712 /*
 713  * More or less lifted from ext3. I'll leave their description below:
 714  *
 715  * "For ext3 allocations, we must not reuse any blocks which are
 716  * allocated in the bitmap buffer's "last committed data" copy.  This
 717  * prevents deletes from freeing up the page for reuse until we have
 718  * committed the delete transaction.
 719  *
 720  * If we didn't do this, then deleting something and reallocating it as
 721  * data would allow the old block to be overwritten before the
 722  * transaction committed (because we force data to disk before commit).
 723  * This would lead to corruption if we crashed between overwriting the
 724  * data and committing the delete.
 725  *
 726  * @@@ We may want to make this allocation behaviour conditional on
 727  * data-writes at some point, and disable it for metadata allocations or
 728  * sync-data inodes."
 729  *
 730  * Note: OCFS2 already does this differently for metadata vs data
 731  * allocations, as those bitmaps are separate and undo access is never
 732  * called on a metadata group descriptor.
 733  */
 734 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 735                                          int nr)
 736 {
 737         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 738
 739         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
 740                 return 0;
 741         if (!buffer_jbd(bg_bh) || !bh2jh(bg_bh)->b_committed_data)
 742                 return 1;
 743
 744         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
 745         return !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
 746 }
 747
 748 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
 749                                              struct buffer_head *bg_bh,
 750                                              unsigned int bits_wanted,
 751                                              unsigned int total_bits,
 752                                              u16 *bit_off,
 753                                              u16 *bits_found)
 754 {
 755         void *bitmap;
 756         u16 best_offset, best_size;
 757         int offset, start, found, status = 0;
 758         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 759
 760         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 761                 OCFS2_RO_ON_INVALID_GROUP_DESC(osb->sb, bg);
 762                 return -EIO;
 763         }
 764
 765         found = start = best_offset = best_size = 0;
 766         bitmap = bg->bg_bitmap;
 767
 768         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
 769                 if (offset == total_bits)
 770                         break;
 771
 772                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
 773                         /* We found a zero, but we can't use it as it
 774                          * hasn't been put to disk yet! */
 775                         found = 0;
 776                         start = offset + 1;
 777                 } else if (offset == start) {
 778                         /* we found a zero */
 779                         found++;
 780                         /* move start to the next bit to test */
 781                         start++;
 782                 } else {
 783                         /* got a zero after some ones */
 784                         found = 1;
 785                         start = offset + 1;
 786                 }
 787                 if (found > best_size) {
 788                         best_size = found;
 789                         best_offset = start - found;
 790                 }
 791                 /* we got everything we needed */
 792                 if (found == bits_wanted) {
 793                         /* mlog(0, "Found it all!\n"); */
 794                         break;
 795                 }
 796         }
 797
 798         /* XXX: I think the first clause is equivalent to the second
 799          *      - jlbec */
 800         if (found == bits_wanted) {
 801                 *bit_off = start - found;
 802                 *bits_found = found;
 803         } else if (best_size) {
 804                 *bit_off = best_offset;
 805                 *bits_found = best_size;
 806         } else {
 807                 status = -ENOSPC;
 808                 /* No error log here -- see the comment above
 809                  * ocfs2_test_bg_bit_allocatable */
 810         }
 811
 812         return status;
 813 }
 814
 815 static inline int ocfs2_block_group_set_bits(handle_t *handle,
 816                                              struct inode *alloc_inode,
 817                                              struct ocfs2_group_desc *bg,
 818                                              struct buffer_head *group_bh,
 819                                              unsigned int bit_off,
 820                                              unsigned int num_bits)
 821 {
 822         int status;
 823         void *bitmap = bg->bg_bitmap;
 824         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
 825
 826         mlog_entry_void();
 827
 828         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 829                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 830                 status = -EIO;
 831                 goto bail;
 832         }
 833         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
 834
 835         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
 836              num_bits);
 837
 838         if (ocfs2_is_cluster_bitmap(alloc_inode))
 839                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
 840
 841         status = ocfs2_journal_access(handle,
 842                                       alloc_inode,
 843                                       group_bh,
 844                                       journal_type);
 845         if (status < 0) {
 846                 mlog_errno(status);
 847                 goto bail;
 848         }
 849
 850         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
 851
 852         while(num_bits--)
 853                 ocfs2_set_bit(bit_off++, bitmap);
 854
 855         status = ocfs2_journal_dirty(handle,
 856                                      group_bh);
 857         if (status < 0) {
 858                 mlog_errno(status);
 859                 goto bail;
 860         }
 861
 862 bail:
 863         mlog_exit(status);
 864         return status;
 865 }
 866
 867 /* find the one with the most empty bits */
 868 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
 869 {
 870         u16 curr, best;
 871
 872         BUG_ON(!cl->cl_next_free_rec);
 873
 874         best = curr = 0;
 875         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
 876                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
 877                     le32_to_cpu(cl->cl_recs[best].c_free))
 878                         best = curr;
 879                 curr++;
 880         }
 881
 882         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
 883         return best;
 884 }
 885
 886 static int ocfs2_relink_block_group(handle_t *handle,
 887                                     struct inode *alloc_inode,
 888                                     struct buffer_head *fe_bh,
 889                                     struct buffer_head *bg_bh,
 890                                     struct buffer_head *prev_bg_bh,
 891                                     u16 chain)
 892 {
 893         int status;
 894         /* there is a really tiny chance the journal calls could fail,
 895          * but we wouldn't want inconsistent blocks in *any* case. */
 896         u64 fe_ptr, bg_ptr, prev_bg_ptr;
 897         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
 898         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 899         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
 900
 901         if (!OCFS2_IS_VALID_DINODE(fe)) {
 902                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 903                 status = -EIO;
 904                 goto out;
 905         }
 906         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 907                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 908                 status = -EIO;
 909                 goto out;
 910         }
 911         if (!OCFS2_IS_VALID_GROUP_DESC(prev_bg)) {
 912                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, prev_bg);
 913                 status = -EIO;
 914                 goto out;
 915         }
 916
 917         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
 918              (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
 919              (unsigned long long)le64_to_cpu(bg->bg_blkno),
 920              (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
 921
 922         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
 923         bg_ptr = le64_to_cpu(bg->bg_next_group);
 924         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
 925
 926         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
 927                                       OCFS2_JOURNAL_ACCESS_WRITE);
 928         if (status < 0) {
 929                 mlog_errno(status);
 930                 goto out_rollback;
 931         }
 932
 933         prev_bg->bg_next_group = bg->bg_next_group;
 934
 935         status = ocfs2_journal_dirty(handle, prev_bg_bh);
 936         if (status < 0) {
 937                 mlog_errno(status);
 938                 goto out_rollback;
 939         }
 940
 941         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
 942                                       OCFS2_JOURNAL_ACCESS_WRITE);
 943         if (status < 0) {
 944                 mlog_errno(status);
 945                 goto out_rollback;
 946         }
 947
 948         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
 949
 950         status = ocfs2_journal_dirty(handle, bg_bh);
 951         if (status < 0) {
 952                 mlog_errno(status);
 953                 goto out_rollback;
 954         }
 955
 956         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
 957                                       OCFS2_JOURNAL_ACCESS_WRITE);
 958         if (status < 0) {
 959                 mlog_errno(status);
 960                 goto out_rollback;
 961         }
 962
 963         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
 964
 965         status = ocfs2_journal_dirty(handle, fe_bh);
 966         if (status < 0) {
 967                 mlog_errno(status);
 968                 goto out_rollback;
 969         }
 970
 971         status = 0;
 972 out_rollback:
 973         if (status < 0) {
 974                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
 975                 bg->bg_next_group = cpu_to_le64(bg_ptr);
 976                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
 977         }
 978 out:
 979         mlog_exit(status);
 980         return status;
 981 }
 982
 983 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 984                                                      u32 wanted)
 985 {
 986         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
 987 }
 988
 989 /* return 0 on success, -ENOSPC to keep searching and any other < 0
 990  * value on error. */
 991 static int ocfs2_cluster_group_search(struct inode *inode,
 992                                       struct buffer_head *group_bh,
 993                                       u32 bits_wanted, u32 min_bits,
 994                                       u16 *bit_off, u16 *bits_found)
 995 {
 996         int search = -ENOSPC;
 997         int ret;
 998         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
 999         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1000         u16 tmp_off, tmp_found;
1001         unsigned int max_bits, gd_cluster_off;
1002
1003         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1004
1005         if (gd->bg_free_bits_count) {
1006                 max_bits = le16_to_cpu(gd->bg_bits);
1007
1008                 /* Tail groups in cluster bitmaps which aren't cpg
1009                  * aligned are prone to partial extention by a failed
1010                  * fs resize. If the file system resize never got to
1011                  * update the dinode cluster count, then we don't want
1012                  * to trust any clusters past it, regardless of what
1013                  * the group descriptor says. */
1014                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1015                                                           le64_to_cpu(gd->bg_blkno));
1016                 if ((gd_cluster_off + max_bits) >
1017                     OCFS2_I(inode)->ip_clusters) {
1018                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1019                         mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
1020                              (unsigned long long)le64_to_cpu(gd->bg_blkno),
1021                              le16_to_cpu(gd->bg_bits),
1022                              OCFS2_I(inode)->ip_clusters, max_bits);
1023                 }
1024
1025                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1026                                                         group_bh, bits_wanted,
1027                                                         max_bits,
1028                                                         &tmp_off, &tmp_found);
1029                 if (ret)
1030                         return ret;
1031
1032                 /* ocfs2_block_group_find_clear_bits() might
1033                  * return success, but we still want to return
1034                  * -ENOSPC unless it found the minimum number
1035                  * of bits. */
1036                 if (min_bits <= tmp_found) {
1037                         *bit_off = tmp_off;
1038                         *bits_found = tmp_found;
1039                         search = 0; /* success */
1040                 } else if (tmp_found) {
1041                         /*
1042                          * Don't show bits which we'll be returning
1043                          * for allocation to the local alloc bitmap.
1044                          */
1045                         ocfs2_local_alloc_seen_free_bits(osb, tmp_found);
1046                 }
1047         }
1048
1049         return search;
1050 }
1051
1052 static int ocfs2_block_group_search(struct inode *inode,
1053                                     struct buffer_head *group_bh,
1054                                     u32 bits_wanted, u32 min_bits,
1055                                     u16 *bit_off, u16 *bits_found)
1056 {
1057         int ret = -ENOSPC;
1058         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1059
1060         BUG_ON(min_bits != 1);
1061         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1062
1063         if (bg->bg_free_bits_count)
1064                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1065                                                         group_bh, bits_wanted,
1066                                                         le16_to_cpu(bg->bg_bits),
1067                                                         bit_off, bits_found);
1068
1069         return ret;
1070 }
1071
1072 static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1073                                        handle_t *handle,
1074                                        struct buffer_head *di_bh,
1075                                        u32 num_bits,
1076                                        u16 chain)
1077 {
1078         int ret;
1079         u32 tmp_used;
1080         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1081         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1082
1083         ret = ocfs2_journal_access(handle, inode, di_bh,
1084                                    OCFS2_JOURNAL_ACCESS_WRITE);
1085         if (ret < 0) {
1086                 mlog_errno(ret);
1087                 goto out;
1088         }
1089
1090         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1091         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1092         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1093
1094         ret = ocfs2_journal_dirty(handle, di_bh);
1095         if (ret < 0)
1096                 mlog_errno(ret);
1097
1098 out:
1099         return ret;
1100 }
1101
1102 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1103                                   handle_t *handle,
1104                                   u32 bits_wanted,
1105                                   u32 min_bits,
1106                                   u16 *bit_off,
1107                                   unsigned int *num_bits,
1108                                   u64 gd_blkno,
1109                                   u16 *bits_left)
1110 {
1111         int ret;
1112         u16 found;
1113         struct buffer_head *group_bh = NULL;
1114         struct ocfs2_group_desc *gd;
1115         struct inode *alloc_inode = ac->ac_inode;
1116
1117         ret = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb), gd_blkno,
1118                                &group_bh, OCFS2_BH_CACHED, alloc_inode);
1119         if (ret < 0) {
1120                 mlog_errno(ret);
1121                 return ret;
1122         }
1123
1124         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1125         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
1126                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, gd);
1127                 ret = -EIO;
1128                 goto out;
1129         }
1130
1131         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1132                                   bit_off, &found);
1133         if (ret < 0) {
1134                 if (ret != -ENOSPC)
1135                         mlog_errno(ret);
1136                 goto out;
1137         }
1138
1139         *num_bits = found;
1140
1141         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1142                                                *num_bits,
1143                                                le16_to_cpu(gd->bg_chain));
1144         if (ret < 0) {
1145                 mlog_errno(ret);
1146                 goto out;
1147         }
1148
1149         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1150                                          *bit_off, *num_bits);
1151         if (ret < 0)
1152                 mlog_errno(ret);
1153
1154         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1155
1156 out:
1157         brelse(group_bh);
1158
1159         return ret;
1160 }
1161
1162 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1163                               handle_t *handle,
1164                               u32 bits_wanted,
1165                               u32 min_bits,
1166                               u16 *bit_off,
1167                               unsigned int *num_bits,
1168                               u64 *bg_blkno,
1169                               u16 *bits_left)
1170 {
1171         int status;
1172         u16 chain, tmp_bits;
1173         u32 tmp_used;
1174         u64 next_group;
1175         struct inode *alloc_inode = ac->ac_inode;
1176         struct buffer_head *group_bh = NULL;
1177         struct buffer_head *prev_group_bh = NULL;
1178         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1179         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1180         struct ocfs2_group_desc *bg;
1181
1182         chain = ac->ac_chain;
1183         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
1184              bits_wanted, chain,
1185              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
1186
1187         status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1188                                   le64_to_cpu(cl->cl_recs[chain].c_blkno),
1189                                   &group_bh, OCFS2_BH_CACHED, alloc_inode);
1190         if (status < 0) {
1191                 mlog_errno(status);
1192                 goto bail;
1193         }
1194         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1195         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1196         if (status) {
1197                 mlog_errno(status);
1198                 goto bail;
1199         }
1200
1201         status = -ENOSPC;
1202         /* for now, the chain search is a bit simplistic. We just use
1203          * the 1st group with any empty bits. */
1204         while ((status = ac->ac_group_search(alloc_inode, group_bh, bits_wanted,
1205                                              min_bits, bit_off, &tmp_bits)) == -ENOSPC) {
1206                 if (!bg->bg_next_group)
1207                         break;
1208
1209                 if (prev_group_bh) {
1210                         brelse(prev_group_bh);
1211                         prev_group_bh = NULL;
1212                 }
1213                 next_group = le64_to_cpu(bg->bg_next_group);
1214                 prev_group_bh = group_bh;
1215                 group_bh = NULL;
1216                 status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1217                                           next_group, &group_bh,
1218                                           OCFS2_BH_CACHED, alloc_inode);
1219                 if (status < 0) {
1220                         mlog_errno(status);
1221                         goto bail;
1222                 }
1223                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1224                 status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1225                 if (status) {
1226                         mlog_errno(status);
1227                         goto bail;
1228                 }
1229         }
1230         if (status < 0) {
1231                 if (status != -ENOSPC)
1232                         mlog_errno(status);
1233                 goto bail;
1234         }
1235
1236         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1237              tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
1238
1239         *num_bits = tmp_bits;
1240
1241         BUG_ON(*num_bits == 0);
1242
1243         /*
1244          * Keep track of previous block descriptor read. When
1245          * we find a target, if we have read more than X
1246          * number of descriptors, and the target is reasonably
1247          * empty, relink him to top of his chain.
1248          *
1249          * We've read 0 extra blocks and only send one more to
1250          * the transaction, yet the next guy to search has a
1251          * much easier time.
1252          *
1253          * Do this *after* figuring out how many bits we're taking out
1254          * of our target group.
1255          */
1256         if (ac->ac_allow_chain_relink &&
1257             (prev_group_bh) &&
1258             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1259                 status = ocfs2_relink_block_group(handle, alloc_inode,
1260                                                   ac->ac_bh, group_bh,
1261                                                   prev_group_bh, chain);
1262                 if (status < 0) {
1263                         mlog_errno(status);
1264                         goto bail;
1265                 }
1266         }
1267
1268         /* Ok, claim our bits now: set the info on dinode, chainlist
1269          * and then the group */
1270         status = ocfs2_journal_access(handle,
1271                                       alloc_inode,
1272                                       ac->ac_bh,
1273                                       OCFS2_JOURNAL_ACCESS_WRITE);
1274         if (status < 0) {
1275                 mlog_errno(status);
1276                 goto bail;
1277         }
1278
1279         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1280         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1281         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1282
1283         status = ocfs2_journal_dirty(handle,
1284                                      ac->ac_bh);
1285         if (status < 0) {
1286                 mlog_errno(status);
1287                 goto bail;
1288         }
1289
1290         status = ocfs2_block_group_set_bits(handle,
1291                                             alloc_inode,
1292                                             bg,
1293                                             group_bh,
1294                                             *bit_off,
1295                                             *num_bits);
1296         if (status < 0) {
1297                 mlog_errno(status);
1298                 goto bail;
1299         }
1300
1301         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1302              (unsigned long long)le64_to_cpu(fe->i_blkno));
1303
1304         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1305         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1306 bail:
1307         if (group_bh)
1308                 brelse(group_bh);
1309         if (prev_group_bh)
1310                 brelse(prev_group_bh);
1311
1312         mlog_exit(status);
1313         return status;
1314 }
1315
1316 /* will give out up to bits_wanted contiguous bits. */
1317 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1318                                      struct ocfs2_alloc_context *ac,
1319                                      handle_t *handle,
1320                                      u32 bits_wanted,
1321                                      u32 min_bits,
1322                                      u16 *bit_off,
1323                                      unsigned int *num_bits,
1324                                      u64 *bg_blkno)
1325 {
1326         int status;
1327         u16 victim, i;
1328         u16 bits_left = 0;
1329         u64 hint_blkno = ac->ac_last_group;
1330         struct ocfs2_chain_list *cl;
1331         struct ocfs2_dinode *fe;
1332
1333         mlog_entry_void();
1334
1335         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1336         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1337         BUG_ON(!ac->ac_bh);
1338
1339         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1340         if (!OCFS2_IS_VALID_DINODE(fe)) {
1341                 OCFS2_RO_ON_INVALID_DINODE(osb->sb, fe);
1342                 status = -EIO;
1343                 goto bail;
1344         }
1345         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1346             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1347                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1348                             "bits but only %u total.",
1349                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1350                             le32_to_cpu(fe->id1.bitmap1.i_used),
1351                             le32_to_cpu(fe->id1.bitmap1.i_total));
1352                 status = -EIO;
1353                 goto bail;
1354         }
1355
1356         if (hint_blkno) {
1357                 /* Attempt to short-circuit the usual search mechanism
1358                  * by jumping straight to the most recently used
1359                  * allocation group. This helps us mantain some
1360                  * contiguousness across allocations. */
1361                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1362                                                 min_bits, bit_off, num_bits,
1363                                                 hint_blkno, &bits_left);
1364                 if (!status) {
1365                         /* Be careful to update *bg_blkno here as the
1366                          * caller is expecting it to be filled in, and
1367                          * ocfs2_search_one_group() won't do that for
1368                          * us. */
1369                         *bg_blkno = hint_blkno;
1370                         goto set_hint;
1371                 }
1372                 if (status < 0 && status != -ENOSPC) {
1373                         mlog_errno(status);
1374                         goto bail;
1375                 }
1376         }
1377
1378         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1379
1380         victim = ocfs2_find_victim_chain(cl);
1381         ac->ac_chain = victim;
1382         ac->ac_allow_chain_relink = 1;
1383
1384         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, bit_off,
1385                                     num_bits, bg_blkno, &bits_left);
1386         if (!status)
1387                 goto set_hint;
1388         if (status < 0 && status != -ENOSPC) {
1389                 mlog_errno(status);
1390                 goto bail;
1391         }
1392
1393         mlog(0, "Search of victim chain %u came up with nothing, "
1394              "trying all chains now.\n", victim);
1395
1396         /* If we didn't pick a good victim, then just default to
1397          * searching each chain in order. Don't allow chain relinking
1398          * because we only calculate enough journal credits for one
1399          * relink per alloc. */
1400         ac->ac_allow_chain_relink = 0;
1401         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1402                 if (i == victim)
1403                         continue;
1404                 if (!cl->cl_recs[i].c_free)
1405                         continue;
1406
1407                 ac->ac_chain = i;
1408                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1409                                             bit_off, num_bits, bg_blkno,
1410                                             &bits_left);
1411                 if (!status)
1412                         break;
1413                 if (status < 0 && status != -ENOSPC) {
1414                         mlog_errno(status);
1415                         goto bail;
1416                 }
1417         }
1418
1419 set_hint:
1420         if (status != -ENOSPC) {
1421                 /* If the next search of this group is not likely to
1422                  * yield a suitable extent, then we reset the last
1423                  * group hint so as to not waste a disk read */
1424                 if (bits_left < min_bits)
1425                         ac->ac_last_group = 0;
1426                 else
1427                         ac->ac_last_group = *bg_blkno;
1428         }
1429
1430 bail:
1431         mlog_exit(status);
1432         return status;
1433 }
1434
1435 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1436                          handle_t *handle,
1437                          struct ocfs2_alloc_context *ac,
1438                          u32 bits_wanted,
1439                          u16 *suballoc_bit_start,
1440                          unsigned int *num_bits,
1441                          u64 *blkno_start)
1442 {
1443         int status;
1444         u64 bg_blkno;
1445
1446         BUG_ON(!ac);
1447         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1448         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1449
1450         status = ocfs2_claim_suballoc_bits(osb,
1451                                            ac,
1452                                            handle,
1453                                            bits_wanted,
1454                                            1,
1455                                            suballoc_bit_start,
1456                                            num_bits,
1457                                            &bg_blkno);
1458         if (status < 0) {
1459                 mlog_errno(status);
1460                 goto bail;
1461         }
1462         atomic_inc(&osb->alloc_stats.bg_allocs);
1463
1464         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1465         ac->ac_bits_given += (*num_bits);
1466         status = 0;
1467 bail:
1468         mlog_exit(status);
1469         return status;
1470 }
1471
1472 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1473                           handle_t *handle,
1474                           struct ocfs2_alloc_context *ac,
1475                           u16 *suballoc_bit,
1476                           u64 *fe_blkno)
1477 {
1478         int status;
1479         unsigned int num_bits;
1480         u64 bg_blkno;
1481
1482         mlog_entry_void();
1483
1484         BUG_ON(!ac);
1485         BUG_ON(ac->ac_bits_given != 0);
1486         BUG_ON(ac->ac_bits_wanted != 1);
1487         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1488
1489         status = ocfs2_claim_suballoc_bits(osb,
1490                                            ac,
1491                                            handle,
1492                                            1,
1493                                            1,
1494                                            suballoc_bit,
1495                                            &num_bits,
1496                                            &bg_blkno);
1497         if (status < 0) {
1498                 mlog_errno(status);
1499                 goto bail;
1500         }
1501         atomic_inc(&osb->alloc_stats.bg_allocs);
1502
1503         BUG_ON(num_bits != 1);
1504
1505         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1506         ac->ac_bits_given++;
1507         status = 0;
1508 bail:
1509         mlog_exit(status);
1510         return status;
1511 }
1512
1513 /* translate a group desc. blkno and it's bitmap offset into
1514  * disk cluster offset. */
1515 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1516                                                    u64 bg_blkno,
1517                                                    u16 bg_bit_off)
1518 {
1519         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1520         u32 cluster = 0;
1521
1522         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1523
1524         if (bg_blkno != osb->first_cluster_group_blkno)
1525                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1526         cluster += (u32) bg_bit_off;
1527         return cluster;
1528 }
1529
1530 /* given a cluster offset, calculate which block group it belongs to
1531  * and return that block offset. */
1532 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
1533 {
1534         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1535         u32 group_no;
1536
1537         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1538
1539         group_no = cluster / osb->bitmap_cpg;
1540         if (!group_no)
1541                 return osb->first_cluster_group_blkno;
1542         return ocfs2_clusters_to_blocks(inode->i_sb,
1543                                         group_no * osb->bitmap_cpg);
1544 }
1545
1546 /* given the block number of a cluster start, calculate which cluster
1547  * group and descriptor bitmap offset that corresponds to. */
1548 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1549                                                 u64 data_blkno,
1550                                                 u64 *bg_blkno,
1551                                                 u16 *bg_bit_off)
1552 {
1553         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1554         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1555
1556         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1557
1558         *bg_blkno = ocfs2_which_cluster_group(inode,
1559                                               data_cluster);
1560
1561         if (*bg_blkno == osb->first_cluster_group_blkno)
1562                 *bg_bit_off = (u16) data_cluster;
1563         else
1564                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1565                                                              data_blkno - *bg_blkno);
1566 }
1567
1568 /*
1569  * min_bits - minimum contiguous chunk from this total allocation we
1570  * can handle. set to what we asked for originally for a full
1571  * contig. allocation, set to '1' to indicate we can deal with extents
1572  * of any size.
1573  */
1574 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
1575                            handle_t *handle,
1576                            struct ocfs2_alloc_context *ac,
1577                            u32 min_clusters,
1578                            u32 max_clusters,
1579                            u32 *cluster_start,
1580                            u32 *num_clusters)
1581 {
1582         int status;
1583         unsigned int bits_wanted = max_clusters;
1584         u64 bg_blkno = 0;
1585         u16 bg_bit_off;
1586
1587         mlog_entry_void();
1588
1589         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1590
1591         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1592                && ac->ac_which != OCFS2_AC_USE_MAIN);
1593
1594         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1595                 status = ocfs2_claim_local_alloc_bits(osb,
1596                                                       handle,
1597                                                       ac,
1598                                                       bits_wanted,
1599                                                       cluster_start,
1600                                                       num_clusters);
1601                 if (!status)
1602                         atomic_inc(&osb->alloc_stats.local_data);
1603         } else {
1604                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1605                         /* The only paths asking for contiguousness
1606                          * should know about this already. */
1607                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
1608                              "group bitmap size %u!\n", min_clusters,
1609                              osb->bitmap_cpg);
1610                         status = -ENOSPC;
1611                         goto bail;
1612                 }
1613                 /* clamp the current request down to a realistic size. */
1614                 if (bits_wanted > (osb->bitmap_cpg - 1))
1615                         bits_wanted = osb->bitmap_cpg - 1;
1616
1617                 status = ocfs2_claim_suballoc_bits(osb,
1618                                                    ac,
1619                                                    handle,
1620                                                    bits_wanted,
1621                                                    min_clusters,
1622                                                    &bg_bit_off,
1623                                                    num_clusters,
1624                                                    &bg_blkno);
1625                 if (!status) {
1626                         *cluster_start =
1627                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1628                                                                  bg_blkno,
1629                                                                  bg_bit_off);
1630                         atomic_inc(&osb->alloc_stats.bitmap_data);
1631                 }
1632         }
1633         if (status < 0) {
1634                 if (status != -ENOSPC)
1635                         mlog_errno(status);
1636                 goto bail;
1637         }
1638
1639         ac->ac_bits_given += *num_clusters;
1640
1641 bail:
1642         mlog_exit(status);
1643         return status;
1644 }
1645
1646 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1647                          handle_t *handle,
1648                          struct ocfs2_alloc_context *ac,
1649                          u32 min_clusters,
1650                          u32 *cluster_start,
1651                          u32 *num_clusters)
1652 {
1653         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1654
1655         return __ocfs2_claim_clusters(osb, handle, ac, min_clusters,
1656                                       bits_wanted, cluster_start, num_clusters);
1657 }
1658
1659 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
1660                                                struct inode *alloc_inode,
1661                                                struct ocfs2_group_desc *bg,
1662                                                struct buffer_head *group_bh,
1663                                                unsigned int bit_off,
1664                                                unsigned int num_bits)
1665 {
1666         int status;
1667         unsigned int tmp;
1668         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1669         struct ocfs2_group_desc *undo_bg = NULL;
1670
1671         mlog_entry_void();
1672
1673         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1674                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1675                 status = -EIO;
1676                 goto bail;
1677         }
1678
1679         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1680
1681         if (ocfs2_is_cluster_bitmap(alloc_inode))
1682                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1683
1684         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1685                                       journal_type);
1686         if (status < 0) {
1687                 mlog_errno(status);
1688                 goto bail;
1689         }
1690
1691         if (ocfs2_is_cluster_bitmap(alloc_inode))
1692                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1693
1694         tmp = num_bits;
1695         while(tmp--) {
1696                 ocfs2_clear_bit((bit_off + tmp),
1697                                 (unsigned long *) bg->bg_bitmap);
1698                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1699                         ocfs2_set_bit(bit_off + tmp,
1700                                       (unsigned long *) undo_bg->bg_bitmap);
1701         }
1702         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1703
1704         status = ocfs2_journal_dirty(handle, group_bh);
1705         if (status < 0)
1706                 mlog_errno(status);
1707 bail:
1708         return status;
1709 }
1710
1711 /*
1712  * expects the suballoc inode to already be locked.
1713  */
1714 int ocfs2_free_suballoc_bits(handle_t *handle,
1715                              struct inode *alloc_inode,
1716                              struct buffer_head *alloc_bh,
1717                              unsigned int start_bit,
1718                              u64 bg_blkno,
1719                              unsigned int count)
1720 {
1721         int status = 0;
1722         u32 tmp_used;
1723         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
1724         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1725         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1726         struct buffer_head *group_bh = NULL;
1727         struct ocfs2_group_desc *group;
1728
1729         mlog_entry_void();
1730
1731         if (!OCFS2_IS_VALID_DINODE(fe)) {
1732                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
1733                 status = -EIO;
1734                 goto bail;
1735         }
1736         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1737
1738         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1739              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1740              (unsigned long long)bg_blkno, start_bit);
1741
1742         status = ocfs2_read_block(osb, bg_blkno, &group_bh, OCFS2_BH_CACHED,
1743                                   alloc_inode);
1744         if (status < 0) {
1745                 mlog_errno(status);
1746                 goto bail;
1747         }
1748
1749         group = (struct ocfs2_group_desc *) group_bh->b_data;
1750         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, group);
1751         if (status) {
1752                 mlog_errno(status);
1753                 goto bail;
1754         }
1755         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1756
1757         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1758                                               group, group_bh,
1759                                               start_bit, count);
1760         if (status < 0) {
1761                 mlog_errno(status);
1762                 goto bail;
1763         }
1764
1765         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1766                                       OCFS2_JOURNAL_ACCESS_WRITE);
1767         if (status < 0) {
1768                 mlog_errno(status);
1769                 goto bail;
1770         }
1771
1772         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1773                      count);
1774         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1775         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1776
1777         status = ocfs2_journal_dirty(handle, alloc_bh);
1778         if (status < 0) {
1779                 mlog_errno(status);
1780                 goto bail;
1781         }
1782
1783 bail:
1784         if (group_bh)
1785                 brelse(group_bh);
1786
1787         mlog_exit(status);
1788         return status;
1789 }
1790
1791 int ocfs2_free_dinode(handle_t *handle,
1792                       struct inode *inode_alloc_inode,
1793                       struct buffer_head *inode_alloc_bh,
1794                       struct ocfs2_dinode *di)
1795 {
1796         u64 blk = le64_to_cpu(di->i_blkno);
1797         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1798         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1799
1800         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1801                                         inode_alloc_bh, bit, bg_blkno, 1);
1802 }
1803
1804 int ocfs2_free_clusters(handle_t *handle,
1805                        struct inode *bitmap_inode,
1806                        struct buffer_head *bitmap_bh,
1807                        u64 start_blk,
1808                        unsigned int num_clusters)
1809 {
1810         int status;
1811         u16 bg_start_bit;
1812         u64 bg_blkno;
1813         struct ocfs2_dinode *fe;
1814
1815         /* You can't ever have a contiguous set of clusters
1816          * bigger than a block group bitmap so we never have to worry
1817          * about looping on them. */
1818
1819         mlog_entry_void();
1820
1821         /* This is expensive. We can safely remove once this stuff has
1822          * gotten tested really well. */
1823         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1824
1825         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1826
1827         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1828                                      &bg_start_bit);
1829
1830         mlog(0, "want to free %u clusters starting at block %llu\n",
1831              num_clusters, (unsigned long long)start_blk);
1832         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1833              (unsigned long long)bg_blkno, bg_start_bit);
1834
1835         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1836                                           bg_start_bit, bg_blkno,
1837                                           num_clusters);
1838         if (status < 0) {
1839                 mlog_errno(status);
1840                 goto out;
1841         }
1842
1843         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
1844                                          num_clusters);
1845
1846 out:
1847         mlog_exit(status);
1848         return status;
1849 }
1850
1851 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1852 {
1853         printk("Block Group:\n");
1854         printk("bg_signature:       %s\n", bg->bg_signature);
1855         printk("bg_size:            %u\n", bg->bg_size);
1856         printk("bg_bits:            %u\n", bg->bg_bits);
1857         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1858         printk("bg_chain:           %u\n", bg->bg_chain);
1859         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1860         printk("bg_next_group:      %llu\n",
1861                (unsigned long long)bg->bg_next_group);
1862         printk("bg_parent_dinode:   %llu\n",
1863                (unsigned long long)bg->bg_parent_dinode);
1864         printk("bg_blkno:           %llu\n",
1865                (unsigned long long)bg->bg_blkno);
1866 }
1867
1868 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
1869 {
1870         int i;
1871
1872         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
1873         printk("i_signature:                  %s\n", fe->i_signature);
1874         printk("i_size:                       %llu\n",
1875                (unsigned long long)fe->i_size);
1876         printk("i_clusters:                   %u\n", fe->i_clusters);
1877         printk("i_generation:                 %u\n",
1878                le32_to_cpu(fe->i_generation));
1879         printk("id1.bitmap1.i_used:           %u\n",
1880                le32_to_cpu(fe->id1.bitmap1.i_used));
1881         printk("id1.bitmap1.i_total:          %u\n",
1882                le32_to_cpu(fe->id1.bitmap1.i_total));
1883         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
1884         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
1885         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
1886         printk("id2.i_chain.cl_next_free_rec: %u\n",
1887                fe->id2.i_chain.cl_next_free_rec);
1888         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
1889                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
1890                        fe->id2.i_chain.cl_recs[i].c_free);
1891                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
1892                        fe->id2.i_chain.cl_recs[i].c_total);
1893                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
1894                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
1895         }
1896 }
1897
1898 /*
1899  * For a given allocation, determine which allocators will need to be
1900  * accessed, and lock them, reserving the appropriate number of bits.
1901  *
1902  * Sparse file systems call this from ocfs2_write_begin_nolock()
1903  * and ocfs2_allocate_unwritten_extents().
1904  *
1905  * File systems which don't support holes call this from
1906  * ocfs2_extend_allocation().
1907  */
1908 int ocfs2_lock_allocators(struct inode *inode, struct buffer_head *root_bh,
1909                           struct ocfs2_extent_list *root_el,
1910                           u32 clusters_to_add, u32 extents_to_split,
1911                           struct ocfs2_alloc_context **data_ac,
1912                           struct ocfs2_alloc_context **meta_ac,
1913                           enum ocfs2_extent_tree_type type, void *private)
1914 {
1915         int ret = 0, num_free_extents;
1916         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
1917         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1918
1919         *meta_ac = NULL;
1920         if (data_ac)
1921                 *data_ac = NULL;
1922
1923         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
1924
1925         num_free_extents = ocfs2_num_free_extents(osb, inode, root_bh,
1926                                                   type, private);
1927         if (num_free_extents < 0) {
1928                 ret = num_free_extents;
1929                 mlog_errno(ret);
1930                 goto out;
1931         }
1932
1933         /*
1934          * Sparse allocation file systems need to be more conservative
1935          * with reserving room for expansion - the actual allocation
1936          * happens while we've got a journal handle open so re-taking
1937          * a cluster lock (because we ran out of room for another
1938          * extent) will violate ordering rules.
1939          *
1940          * Most of the time we'll only be seeing this 1 cluster at a time
1941          * anyway.
1942          *
1943          * Always lock for any unwritten extents - we might want to
1944          * add blocks during a split.
1945          */
1946         if (!num_free_extents ||
1947             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
1948                 ret = ocfs2_reserve_new_metadata(osb, root_el, meta_ac);
1949                 if (ret < 0) {
1950                         if (ret != -ENOSPC)
1951                                 mlog_errno(ret);
1952                         goto out;
1953                 }
1954         }
1955
1956         if (clusters_to_add == 0)
1957                 goto out;
1958
1959         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
1960         if (ret < 0) {
1961                 if (ret != -ENOSPC)
1962                         mlog_errno(ret);
1963                 goto out;
1964         }
1965
1966 out:
1967         if (ret) {
1968                 if (*meta_ac) {
1969                         ocfs2_free_alloc_context(*meta_ac);
1970                         *meta_ac = NULL;
1971                 }
1972
1973                 /*
1974                  * We cannot have an error and a non null *data_ac.
1975                  */
1976         }
1977
1978         return ret;
1979 }