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   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                                    u64 max_block);
  67
  68 static int ocfs2_cluster_group_search(struct inode *inode,
  69                                       struct buffer_head *group_bh,
  70                                       u32 bits_wanted, u32 min_bits,
  71                                       u64 max_block,
  72                                       u16 *bit_off, u16 *bits_found);
  73 static int ocfs2_block_group_search(struct inode *inode,
  74                                     struct buffer_head *group_bh,
  75                                     u32 bits_wanted, u32 min_bits,
  76                                     u64 max_block,
  77                                     u16 *bit_off, u16 *bits_found);
  78 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
  79                                      struct ocfs2_alloc_context *ac,
  80                                      handle_t *handle,
  81                                      u32 bits_wanted,
  82                                      u32 min_bits,
  83                                      u16 *bit_off,
  84                                      unsigned int *num_bits,
  85                                      u64 *bg_blkno);
  86 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  87                                          int nr);
  88 static inline int ocfs2_block_group_set_bits(handle_t *handle,
  89                                              struct inode *alloc_inode,
  90                                              struct ocfs2_group_desc *bg,
  91                                              struct buffer_head *group_bh,
  92                                              unsigned int bit_off,
  93                                              unsigned int num_bits);
  94 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
  95                                                struct inode *alloc_inode,
  96                                                struct ocfs2_group_desc *bg,
  97                                                struct buffer_head *group_bh,
  98                                                unsigned int bit_off,
  99                                                unsigned int num_bits);
 100
 101 static int ocfs2_relink_block_group(handle_t *handle,
 102                                     struct inode *alloc_inode,
 103                                     struct buffer_head *fe_bh,
 104                                     struct buffer_head *bg_bh,
 105                                     struct buffer_head *prev_bg_bh,
 106                                     u16 chain);
 107 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 108                                                      u32 wanted);
 109 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 110                                                    u64 bg_blkno,
 111                                                    u16 bg_bit_off);
 112 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 113                                                 u64 data_blkno,
 114                                                 u64 *bg_blkno,
 115                                                 u16 *bg_bit_off);
 116 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 117                                              u32 bits_wanted, u64 max_block,
 118                                              struct ocfs2_alloc_context **ac);
 119
 120 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 121 {
 122         struct inode *inode = ac->ac_inode;
 123
 124         if (inode) {
 125                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 126                         ocfs2_inode_unlock(inode, 1);
 127
 128                 mutex_unlock(&inode->i_mutex);
 129
 130                 iput(inode);
 131                 ac->ac_inode = NULL;
 132         }
 133         brelse(ac->ac_bh);
 134         ac->ac_bh = NULL;
 135 }
 136
 137 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 138 {
 139         ocfs2_free_ac_resource(ac);
 140         kfree(ac);
 141 }
 142
 143 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 144 {
 145         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 146 }
 147
 148 /* somewhat more expensive than our other checks, so use sparingly. */
 149 int ocfs2_check_group_descriptor(struct super_block *sb,
 150                                  struct ocfs2_dinode *di,
 151                                  struct ocfs2_group_desc *gd)
 152 {
 153         unsigned int max_bits;
 154
 155         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 156                 OCFS2_RO_ON_INVALID_GROUP_DESC(sb, gd);
 157                 return -EIO;
 158         }
 159
 160         if (di->i_blkno != gd->bg_parent_dinode) {
 161                 ocfs2_error(sb, "Group descriptor # %llu has bad parent "
 162                             "pointer (%llu, expected %llu)",
 163                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 164                             (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 165                             (unsigned long long)le64_to_cpu(di->i_blkno));
 166                 return -EIO;
 167         }
 168
 169         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 170         if (le16_to_cpu(gd->bg_bits) > max_bits) {
 171                 ocfs2_error(sb, "Group descriptor # %llu has bit count of %u",
 172                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 173                             le16_to_cpu(gd->bg_bits));
 174                 return -EIO;
 175         }
 176
 177         if (le16_to_cpu(gd->bg_chain) >=
 178             le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) {
 179                 ocfs2_error(sb, "Group descriptor # %llu has bad chain %u",
 180                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 181                             le16_to_cpu(gd->bg_chain));
 182                 return -EIO;
 183         }
 184
 185         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 186                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 187                             "claims that %u are free",
 188                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 189                             le16_to_cpu(gd->bg_bits),
 190                             le16_to_cpu(gd->bg_free_bits_count));
 191                 return -EIO;
 192         }
 193
 194         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 195                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 196                             "max bitmap bits of %u",
 197                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 198                             le16_to_cpu(gd->bg_bits),
 199                             8 * le16_to_cpu(gd->bg_size));
 200                 return -EIO;
 201         }
 202
 203         return 0;
 204 }
 205
 206 static int ocfs2_block_group_fill(handle_t *handle,
 207                                   struct inode *alloc_inode,
 208                                   struct buffer_head *bg_bh,
 209                                   u64 group_blkno,
 210                                   u16 my_chain,
 211                                   struct ocfs2_chain_list *cl)
 212 {
 213         int status = 0;
 214         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 215         struct super_block * sb = alloc_inode->i_sb;
 216
 217         mlog_entry_void();
 218
 219         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 220                 ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
 221                             "b_blocknr (%llu)",
 222                             (unsigned long long)group_blkno,
 223                             (unsigned long long) bg_bh->b_blocknr);
 224                 status = -EIO;
 225                 goto bail;
 226         }
 227
 228         status = ocfs2_journal_access(handle,
 229                                       alloc_inode,
 230                                       bg_bh,
 231                                       OCFS2_JOURNAL_ACCESS_CREATE);
 232         if (status < 0) {
 233                 mlog_errno(status);
 234                 goto bail;
 235         }
 236
 237         memset(bg, 0, sb->s_blocksize);
 238         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 239         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 240         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
 241         bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 242         bg->bg_chain = cpu_to_le16(my_chain);
 243         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 244         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 245         bg->bg_blkno = cpu_to_le64(group_blkno);
 246         /* set the 1st bit in the bitmap to account for the descriptor block */
 247         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 248         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 249
 250         status = ocfs2_journal_dirty(handle, bg_bh);
 251         if (status < 0)
 252                 mlog_errno(status);
 253
 254         /* There is no need to zero out or otherwise initialize the
 255          * other blocks in a group - All valid FS metadata in a block
 256          * group stores the superblock fs_generation value at
 257          * allocation time. */
 258
 259 bail:
 260         mlog_exit(status);
 261         return status;
 262 }
 263
 264 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 265 {
 266         u16 curr, best;
 267
 268         best = curr = 0;
 269         while (curr < le16_to_cpu(cl->cl_count)) {
 270                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 271                     le32_to_cpu(cl->cl_recs[curr].c_total))
 272                         best = curr;
 273                 curr++;
 274         }
 275         return best;
 276 }
 277
 278 /*
 279  * We expect the block group allocator to already be locked.
 280  */
 281 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 282                                    struct inode *alloc_inode,
 283                                    struct buffer_head *bh,
 284                                    u64 max_block)
 285 {
 286         int status, credits;
 287         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 288         struct ocfs2_chain_list *cl;
 289         struct ocfs2_alloc_context *ac = NULL;
 290         handle_t *handle = NULL;
 291         u32 bit_off, num_bits;
 292         u16 alloc_rec;
 293         u64 bg_blkno;
 294         struct buffer_head *bg_bh = NULL;
 295         struct ocfs2_group_desc *bg;
 296
 297         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 298
 299         mlog_entry_void();
 300
 301         cl = &fe->id2.i_chain;
 302         status = ocfs2_reserve_clusters_with_limit(osb,
 303                                                    le16_to_cpu(cl->cl_cpg),
 304                                                    max_block, &ac);
 305         if (status < 0) {
 306                 if (status != -ENOSPC)
 307                         mlog_errno(status);
 308                 goto bail;
 309         }
 310
 311         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 312                                                  le16_to_cpu(cl->cl_cpg));
 313         handle = ocfs2_start_trans(osb, credits);
 314         if (IS_ERR(handle)) {
 315                 status = PTR_ERR(handle);
 316                 handle = NULL;
 317                 mlog_errno(status);
 318                 goto bail;
 319         }
 320
 321         status = ocfs2_claim_clusters(osb,
 322                                       handle,
 323                                       ac,
 324                                       le16_to_cpu(cl->cl_cpg),
 325                                       &bit_off,
 326                                       &num_bits);
 327         if (status < 0) {
 328                 if (status != -ENOSPC)
 329                         mlog_errno(status);
 330                 goto bail;
 331         }
 332
 333         alloc_rec = ocfs2_find_smallest_chain(cl);
 334
 335         /* setup the group */
 336         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 337         mlog(0, "new descriptor, record %u, at block %llu\n",
 338              alloc_rec, (unsigned long long)bg_blkno);
 339
 340         bg_bh = sb_getblk(osb->sb, bg_blkno);
 341         if (!bg_bh) {
 342                 status = -EIO;
 343                 mlog_errno(status);
 344                 goto bail;
 345         }
 346         ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);
 347
 348         status = ocfs2_block_group_fill(handle,
 349                                         alloc_inode,
 350                                         bg_bh,
 351                                         bg_blkno,
 352                                         alloc_rec,
 353                                         cl);
 354         if (status < 0) {
 355                 mlog_errno(status);
 356                 goto bail;
 357         }
 358
 359         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 360
 361         status = ocfs2_journal_access(handle, alloc_inode,
 362                                       bh, OCFS2_JOURNAL_ACCESS_WRITE);
 363         if (status < 0) {
 364                 mlog_errno(status);
 365                 goto bail;
 366         }
 367
 368         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 369                      le16_to_cpu(bg->bg_free_bits_count));
 370         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
 371         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
 372         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 373                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 374
 375         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 376                                         le16_to_cpu(bg->bg_free_bits_count));
 377         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 378         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 379
 380         status = ocfs2_journal_dirty(handle, bh);
 381         if (status < 0) {
 382                 mlog_errno(status);
 383                 goto bail;
 384         }
 385
 386         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 387         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 388         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 389                                              le32_to_cpu(fe->i_clusters)));
 390         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 391         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 392         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 393
 394         status = 0;
 395 bail:
 396         if (handle)
 397                 ocfs2_commit_trans(osb, handle);
 398
 399         if (ac)
 400                 ocfs2_free_alloc_context(ac);
 401
 402         brelse(bg_bh);
 403
 404         mlog_exit(status);
 405         return status;
 406 }
 407
 408 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 409                                        struct ocfs2_alloc_context *ac,
 410                                        int type,
 411                                        u32 slot,
 412                                        int alloc_new_group)
 413 {
 414         int status;
 415         u32 bits_wanted = ac->ac_bits_wanted;
 416         struct inode *alloc_inode;
 417         struct buffer_head *bh = NULL;
 418         struct ocfs2_dinode *fe;
 419         u32 free_bits;
 420
 421         mlog_entry_void();
 422
 423         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 424         if (!alloc_inode) {
 425                 mlog_errno(-EINVAL);
 426                 return -EINVAL;
 427         }
 428
 429         mutex_lock(&alloc_inode->i_mutex);
 430
 431         status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 432         if (status < 0) {
 433                 mutex_unlock(&alloc_inode->i_mutex);
 434                 iput(alloc_inode);
 435
 436                 mlog_errno(status);
 437                 return status;
 438         }
 439
 440         ac->ac_inode = alloc_inode;
 441         ac->ac_alloc_slot = slot;
 442
 443         fe = (struct ocfs2_dinode *) bh->b_data;
 444         if (!OCFS2_IS_VALID_DINODE(fe)) {
 445                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 446                 status = -EIO;
 447                 goto bail;
 448         }
 449         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 450                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 451                             (unsigned long long)le64_to_cpu(fe->i_blkno));
 452                 status = -EIO;
 453                 goto bail;
 454         }
 455
 456         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 457                 le32_to_cpu(fe->id1.bitmap1.i_used);
 458
 459         if (bits_wanted > free_bits) {
 460                 /* cluster bitmap never grows */
 461                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 462                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
 463                              bits_wanted, free_bits);
 464                         status = -ENOSPC;
 465                         goto bail;
 466                 }
 467
 468                 if (alloc_new_group != ALLOC_NEW_GROUP) {
 469                         mlog(0, "Alloc File %u Full: wanted=%u, free_bits=%u, "
 470                              "and we don't alloc a new group for it.\n",
 471                              slot, bits_wanted, free_bits);
 472                         status = -ENOSPC;
 473                         goto bail;
 474                 }
 475
 476                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 477                                                  ac->ac_max_block);
 478                 if (status < 0) {
 479                         if (status != -ENOSPC)
 480                                 mlog_errno(status);
 481                         goto bail;
 482                 }
 483                 atomic_inc(&osb->alloc_stats.bg_extends);
 484
 485                 /* You should never ask for this much metadata */
 486                 BUG_ON(bits_wanted >
 487                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 488                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 489         }
 490
 491         get_bh(bh);
 492         ac->ac_bh = bh;
 493 bail:
 494         brelse(bh);
 495
 496         mlog_exit(status);
 497         return status;
 498 }
 499
 500 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 501                                       int blocks,
 502                                       struct ocfs2_alloc_context **ac)
 503 {
 504         int status;
 505         u32 slot;
 506
 507         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 508         if (!(*ac)) {
 509                 status = -ENOMEM;
 510                 mlog_errno(status);
 511                 goto bail;
 512         }
 513
 514         (*ac)->ac_bits_wanted = blocks;
 515         (*ac)->ac_which = OCFS2_AC_USE_META;
 516         slot = osb->slot_num;
 517         (*ac)->ac_group_search = ocfs2_block_group_search;
 518
 519         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 520                                              EXTENT_ALLOC_SYSTEM_INODE,
 521                                              slot, ALLOC_NEW_GROUP);
 522         if (status < 0) {
 523                 if (status != -ENOSPC)
 524                         mlog_errno(status);
 525                 goto bail;
 526         }
 527
 528         status = 0;
 529 bail:
 530         if ((status < 0) && *ac) {
 531                 ocfs2_free_alloc_context(*ac);
 532                 *ac = NULL;
 533         }
 534
 535         mlog_exit(status);
 536         return status;
 537 }
 538
 539 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
 540                                struct ocfs2_extent_list *root_el,
 541                                struct ocfs2_alloc_context **ac)
 542 {
 543         return ocfs2_reserve_new_metadata_blocks(osb,
 544                                         ocfs2_extend_meta_needed(root_el),
 545                                         ac);
 546 }
 547
 548 static int ocfs2_steal_inode_from_other_nodes(struct ocfs2_super *osb,
 549                                               struct ocfs2_alloc_context *ac)
 550 {
 551         int i, status = -ENOSPC;
 552         s16 slot = ocfs2_get_inode_steal_slot(osb);
 553
 554         /* Start to steal inodes from the first slot after ours. */
 555         if (slot == OCFS2_INVALID_SLOT)
 556                 slot = osb->slot_num + 1;
 557
 558         for (i = 0; i < osb->max_slots; i++, slot++) {
 559                 if (slot == osb->max_slots)
 560                         slot = 0;
 561
 562                 if (slot == osb->slot_num)
 563                         continue;
 564
 565                 status = ocfs2_reserve_suballoc_bits(osb, ac,
 566                                                      INODE_ALLOC_SYSTEM_INODE,
 567                                                      slot, NOT_ALLOC_NEW_GROUP);
 568                 if (status >= 0) {
 569                         ocfs2_set_inode_steal_slot(osb, slot);
 570                         break;
 571                 }
 572
 573                 ocfs2_free_ac_resource(ac);
 574         }
 575
 576         return status;
 577 }
 578
 579 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 580                             struct ocfs2_alloc_context **ac)
 581 {
 582         int status;
 583         s16 slot = ocfs2_get_inode_steal_slot(osb);
 584
 585         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 586         if (!(*ac)) {
 587                 status = -ENOMEM;
 588                 mlog_errno(status);
 589                 goto bail;
 590         }
 591
 592         (*ac)->ac_bits_wanted = 1;
 593         (*ac)->ac_which = OCFS2_AC_USE_INODE;
 594
 595         (*ac)->ac_group_search = ocfs2_block_group_search;
 596
 597         /*
 598          * stat(2) can't handle i_ino > 32bits, so we tell the
 599          * lower levels not to allocate us a block group past that
 600          * limit.  The 'inode64' mount option avoids this behavior.
 601          */
 602         if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
 603                 (*ac)->ac_max_block = (u32)~0U;
 604
 605         /*
 606          * slot is set when we successfully steal inode from other nodes.
 607          * It is reset in 3 places:
 608          * 1. when we flush the truncate log
 609          * 2. when we complete local alloc recovery.
 610          * 3. when we successfully allocate from our own slot.
 611          * After it is set, we will go on stealing inodes until we find the
 612          * need to check our slots to see whether there is some space for us.
 613          */
 614         if (slot != OCFS2_INVALID_SLOT &&
 615             atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_INODES_TO_STEAL)
 616                 goto inode_steal;
 617
 618         atomic_set(&osb->s_num_inodes_stolen, 0);
 619         status = ocfs2_reserve_suballoc_bits(osb, *ac,
 620                                              INODE_ALLOC_SYSTEM_INODE,
 621                                              osb->slot_num, ALLOC_NEW_GROUP);
 622         if (status >= 0) {
 623                 status = 0;
 624
 625                 /*
 626                  * Some inodes must be freed by us, so try to allocate
 627                  * from our own next time.
 628                  */
 629                 if (slot != OCFS2_INVALID_SLOT)
 630                         ocfs2_init_inode_steal_slot(osb);
 631                 goto bail;
 632         } else if (status < 0 && status != -ENOSPC) {
 633                 mlog_errno(status);
 634                 goto bail;
 635         }
 636
 637         ocfs2_free_ac_resource(*ac);
 638
 639 inode_steal:
 640         status = ocfs2_steal_inode_from_other_nodes(osb, *ac);
 641         atomic_inc(&osb->s_num_inodes_stolen);
 642         if (status < 0) {
 643                 if (status != -ENOSPC)
 644                         mlog_errno(status);
 645                 goto bail;
 646         }
 647
 648         status = 0;
 649 bail:
 650         if ((status < 0) && *ac) {
 651                 ocfs2_free_alloc_context(*ac);
 652                 *ac = NULL;
 653         }
 654
 655         mlog_exit(status);
 656         return status;
 657 }
 658
 659 /* local alloc code has to do the same thing, so rather than do this
 660  * twice.. */
 661 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
 662                                       struct ocfs2_alloc_context *ac)
 663 {
 664         int status;
 665
 666         ac->ac_which = OCFS2_AC_USE_MAIN;
 667         ac->ac_group_search = ocfs2_cluster_group_search;
 668
 669         status = ocfs2_reserve_suballoc_bits(osb, ac,
 670                                              GLOBAL_BITMAP_SYSTEM_INODE,
 671                                              OCFS2_INVALID_SLOT,
 672                                              ALLOC_NEW_GROUP);
 673         if (status < 0 && status != -ENOSPC) {
 674                 mlog_errno(status);
 675                 goto bail;
 676         }
 677
 678 bail:
 679         return status;
 680 }
 681
 682 /* Callers don't need to care which bitmap (local alloc or main) to
 683  * use so we figure it out for them, but unfortunately this clutters
 684  * things a bit. */
 685 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 686                                              u32 bits_wanted, u64 max_block,
 687                                              struct ocfs2_alloc_context **ac)
 688 {
 689         int status;
 690
 691         mlog_entry_void();
 692
 693         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 694         if (!(*ac)) {
 695                 status = -ENOMEM;
 696                 mlog_errno(status);
 697                 goto bail;
 698         }
 699
 700         (*ac)->ac_bits_wanted = bits_wanted;
 701         (*ac)->ac_max_block = max_block;
 702
 703         status = -ENOSPC;
 704         if (ocfs2_alloc_should_use_local(osb, bits_wanted)) {
 705                 status = ocfs2_reserve_local_alloc_bits(osb,
 706                                                         bits_wanted,
 707                                                         *ac);
 708                 if (status == -EFBIG) {
 709                         /* The local alloc window is outside ac_max_block.
 710                          * use the main bitmap. */
 711                         status = -ENOSPC;
 712                 } else if ((status < 0) && (status != -ENOSPC)) {
 713                         mlog_errno(status);
 714                         goto bail;
 715                 }
 716         }
 717
 718         if (status == -ENOSPC) {
 719                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 720                 if (status < 0) {
 721                         if (status != -ENOSPC)
 722                                 mlog_errno(status);
 723                         goto bail;
 724                 }
 725         }
 726
 727         status = 0;
 728 bail:
 729         if ((status < 0) && *ac) {
 730                 ocfs2_free_alloc_context(*ac);
 731                 *ac = NULL;
 732         }
 733
 734         mlog_exit(status);
 735         return status;
 736 }
 737
 738 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
 739                            u32 bits_wanted,
 740                            struct ocfs2_alloc_context **ac)
 741 {
 742         return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0, ac);
 743 }
 744
 745 /*
 746  * More or less lifted from ext3. I'll leave their description below:
 747  *
 748  * "For ext3 allocations, we must not reuse any blocks which are
 749  * allocated in the bitmap buffer's "last committed data" copy.  This
 750  * prevents deletes from freeing up the page for reuse until we have
 751  * committed the delete transaction.
 752  *
 753  * If we didn't do this, then deleting something and reallocating it as
 754  * data would allow the old block to be overwritten before the
 755  * transaction committed (because we force data to disk before commit).
 756  * This would lead to corruption if we crashed between overwriting the
 757  * data and committing the delete.
 758  *
 759  * @@@ We may want to make this allocation behaviour conditional on
 760  * data-writes at some point, and disable it for metadata allocations or
 761  * sync-data inodes."
 762  *
 763  * Note: OCFS2 already does this differently for metadata vs data
 764  * allocations, as those bitmaps are separate and undo access is never
 765  * called on a metadata group descriptor.
 766  */
 767 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 768                                          int nr)
 769 {
 770         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 771
 772         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
 773                 return 0;
 774         if (!buffer_jbd(bg_bh) || !bh2jh(bg_bh)->b_committed_data)
 775                 return 1;
 776
 777         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
 778         return !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
 779 }
 780
 781 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
 782                                              struct buffer_head *bg_bh,
 783                                              unsigned int bits_wanted,
 784                                              unsigned int total_bits,
 785                                              u16 *bit_off,
 786                                              u16 *bits_found)
 787 {
 788         void *bitmap;
 789         u16 best_offset, best_size;
 790         int offset, start, found, status = 0;
 791         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 792
 793         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 794                 OCFS2_RO_ON_INVALID_GROUP_DESC(osb->sb, bg);
 795                 return -EIO;
 796         }
 797
 798         found = start = best_offset = best_size = 0;
 799         bitmap = bg->bg_bitmap;
 800
 801         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
 802                 if (offset == total_bits)
 803                         break;
 804
 805                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
 806                         /* We found a zero, but we can't use it as it
 807                          * hasn't been put to disk yet! */
 808                         found = 0;
 809                         start = offset + 1;
 810                 } else if (offset == start) {
 811                         /* we found a zero */
 812                         found++;
 813                         /* move start to the next bit to test */
 814                         start++;
 815                 } else {
 816                         /* got a zero after some ones */
 817                         found = 1;
 818                         start = offset + 1;
 819                 }
 820                 if (found > best_size) {
 821                         best_size = found;
 822                         best_offset = start - found;
 823                 }
 824                 /* we got everything we needed */
 825                 if (found == bits_wanted) {
 826                         /* mlog(0, "Found it all!\n"); */
 827                         break;
 828                 }
 829         }
 830
 831         /* XXX: I think the first clause is equivalent to the second
 832          *      - jlbec */
 833         if (found == bits_wanted) {
 834                 *bit_off = start - found;
 835                 *bits_found = found;
 836         } else if (best_size) {
 837                 *bit_off = best_offset;
 838                 *bits_found = best_size;
 839         } else {
 840                 status = -ENOSPC;
 841                 /* No error log here -- see the comment above
 842                  * ocfs2_test_bg_bit_allocatable */
 843         }
 844
 845         return status;
 846 }
 847
 848 static inline int ocfs2_block_group_set_bits(handle_t *handle,
 849                                              struct inode *alloc_inode,
 850                                              struct ocfs2_group_desc *bg,
 851                                              struct buffer_head *group_bh,
 852                                              unsigned int bit_off,
 853                                              unsigned int num_bits)
 854 {
 855         int status;
 856         void *bitmap = bg->bg_bitmap;
 857         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
 858
 859         mlog_entry_void();
 860
 861         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 862                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 863                 status = -EIO;
 864                 goto bail;
 865         }
 866         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
 867
 868         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
 869              num_bits);
 870
 871         if (ocfs2_is_cluster_bitmap(alloc_inode))
 872                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
 873
 874         status = ocfs2_journal_access(handle,
 875                                       alloc_inode,
 876                                       group_bh,
 877                                       journal_type);
 878         if (status < 0) {
 879                 mlog_errno(status);
 880                 goto bail;
 881         }
 882
 883         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
 884
 885         while(num_bits--)
 886                 ocfs2_set_bit(bit_off++, bitmap);
 887
 888         status = ocfs2_journal_dirty(handle,
 889                                      group_bh);
 890         if (status < 0) {
 891                 mlog_errno(status);
 892                 goto bail;
 893         }
 894
 895 bail:
 896         mlog_exit(status);
 897         return status;
 898 }
 899
 900 /* find the one with the most empty bits */
 901 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
 902 {
 903         u16 curr, best;
 904
 905         BUG_ON(!cl->cl_next_free_rec);
 906
 907         best = curr = 0;
 908         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
 909                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
 910                     le32_to_cpu(cl->cl_recs[best].c_free))
 911                         best = curr;
 912                 curr++;
 913         }
 914
 915         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
 916         return best;
 917 }
 918
 919 static int ocfs2_relink_block_group(handle_t *handle,
 920                                     struct inode *alloc_inode,
 921                                     struct buffer_head *fe_bh,
 922                                     struct buffer_head *bg_bh,
 923                                     struct buffer_head *prev_bg_bh,
 924                                     u16 chain)
 925 {
 926         int status;
 927         /* there is a really tiny chance the journal calls could fail,
 928          * but we wouldn't want inconsistent blocks in *any* case. */
 929         u64 fe_ptr, bg_ptr, prev_bg_ptr;
 930         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
 931         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 932         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
 933
 934         if (!OCFS2_IS_VALID_DINODE(fe)) {
 935                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 936                 status = -EIO;
 937                 goto out;
 938         }
 939         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 940                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 941                 status = -EIO;
 942                 goto out;
 943         }
 944         if (!OCFS2_IS_VALID_GROUP_DESC(prev_bg)) {
 945                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, prev_bg);
 946                 status = -EIO;
 947                 goto out;
 948         }
 949
 950         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
 951              (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
 952              (unsigned long long)le64_to_cpu(bg->bg_blkno),
 953              (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
 954
 955         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
 956         bg_ptr = le64_to_cpu(bg->bg_next_group);
 957         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
 958
 959         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
 960                                       OCFS2_JOURNAL_ACCESS_WRITE);
 961         if (status < 0) {
 962                 mlog_errno(status);
 963                 goto out_rollback;
 964         }
 965
 966         prev_bg->bg_next_group = bg->bg_next_group;
 967
 968         status = ocfs2_journal_dirty(handle, prev_bg_bh);
 969         if (status < 0) {
 970                 mlog_errno(status);
 971                 goto out_rollback;
 972         }
 973
 974         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
 975                                       OCFS2_JOURNAL_ACCESS_WRITE);
 976         if (status < 0) {
 977                 mlog_errno(status);
 978                 goto out_rollback;
 979         }
 980
 981         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
 982
 983         status = ocfs2_journal_dirty(handle, bg_bh);
 984         if (status < 0) {
 985                 mlog_errno(status);
 986                 goto out_rollback;
 987         }
 988
 989         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
 990                                       OCFS2_JOURNAL_ACCESS_WRITE);
 991         if (status < 0) {
 992                 mlog_errno(status);
 993                 goto out_rollback;
 994         }
 995
 996         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
 997
 998         status = ocfs2_journal_dirty(handle, fe_bh);
 999         if (status < 0) {
1000                 mlog_errno(status);
1001                 goto out_rollback;
1002         }
1003
1004         status = 0;
1005 out_rollback:
1006         if (status < 0) {
1007                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
1008                 bg->bg_next_group = cpu_to_le64(bg_ptr);
1009                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1010         }
1011 out:
1012         mlog_exit(status);
1013         return status;
1014 }
1015
1016 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1017                                                      u32 wanted)
1018 {
1019         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1020 }
1021
1022 /* return 0 on success, -ENOSPC to keep searching and any other < 0
1023  * value on error. */
1024 static int ocfs2_cluster_group_search(struct inode *inode,
1025                                       struct buffer_head *group_bh,
1026                                       u32 bits_wanted, u32 min_bits,
1027                                       u64 max_block,
1028                                       u16 *bit_off, u16 *bits_found)
1029 {
1030         int search = -ENOSPC;
1031         int ret;
1032         u64 blkoff;
1033         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1034         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1035         u16 tmp_off, tmp_found;
1036         unsigned int max_bits, gd_cluster_off;
1037
1038         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1039
1040         if (gd->bg_free_bits_count) {
1041                 max_bits = le16_to_cpu(gd->bg_bits);
1042
1043                 /* Tail groups in cluster bitmaps which aren't cpg
1044                  * aligned are prone to partial extention by a failed
1045                  * fs resize. If the file system resize never got to
1046                  * update the dinode cluster count, then we don't want
1047                  * to trust any clusters past it, regardless of what
1048                  * the group descriptor says. */
1049                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1050                                                           le64_to_cpu(gd->bg_blkno));
1051                 if ((gd_cluster_off + max_bits) >
1052                     OCFS2_I(inode)->ip_clusters) {
1053                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1054                         mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
1055                              (unsigned long long)le64_to_cpu(gd->bg_blkno),
1056                              le16_to_cpu(gd->bg_bits),
1057                              OCFS2_I(inode)->ip_clusters, max_bits);
1058                 }
1059
1060                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1061                                                         group_bh, bits_wanted,
1062                                                         max_bits,
1063                                                         &tmp_off, &tmp_found);
1064                 if (ret)
1065                         return ret;
1066
1067                 if (max_block) {
1068                         blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1069                                                           gd_cluster_off +
1070                                                           tmp_off + tmp_found);
1071                         mlog(0, "Checking %llu against %llu\n",
1072                              (unsigned long long)blkoff,
1073                              (unsigned long long)max_block);
1074                         if (blkoff > max_block)
1075                                 return -ENOSPC;
1076                 }
1077
1078                 /* ocfs2_block_group_find_clear_bits() might
1079                  * return success, but we still want to return
1080                  * -ENOSPC unless it found the minimum number
1081                  * of bits. */
1082                 if (min_bits <= tmp_found) {
1083                         *bit_off = tmp_off;
1084                         *bits_found = tmp_found;
1085                         search = 0; /* success */
1086                 } else if (tmp_found) {
1087                         /*
1088                          * Don't show bits which we'll be returning
1089                          * for allocation to the local alloc bitmap.
1090                          */
1091                         ocfs2_local_alloc_seen_free_bits(osb, tmp_found);
1092                 }
1093         }
1094
1095         return search;
1096 }
1097
1098 static int ocfs2_block_group_search(struct inode *inode,
1099                                     struct buffer_head *group_bh,
1100                                     u32 bits_wanted, u32 min_bits,
1101                                     u64 max_block,
1102                                     u16 *bit_off, u16 *bits_found)
1103 {
1104         int ret = -ENOSPC;
1105         u64 blkoff;
1106         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1107
1108         BUG_ON(min_bits != 1);
1109         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1110
1111         if (bg->bg_free_bits_count) {
1112                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1113                                                         group_bh, bits_wanted,
1114                                                         le16_to_cpu(bg->bg_bits),
1115                                                         bit_off, bits_found);
1116                 if (!ret && max_block) {
1117                         blkoff = le64_to_cpu(bg->bg_blkno) + *bit_off +
1118                                 *bits_found;
1119                         mlog(0, "Checking %llu against %llu\n",
1120                              (unsigned long long)blkoff,
1121                              (unsigned long long)max_block);
1122                         if (blkoff > max_block)
1123                                 ret = -ENOSPC;
1124                 }
1125         }
1126
1127         return ret;
1128 }
1129
1130 static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1131                                        handle_t *handle,
1132                                        struct buffer_head *di_bh,
1133                                        u32 num_bits,
1134                                        u16 chain)
1135 {
1136         int ret;
1137         u32 tmp_used;
1138         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1139         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1140
1141         ret = ocfs2_journal_access(handle, inode, di_bh,
1142                                    OCFS2_JOURNAL_ACCESS_WRITE);
1143         if (ret < 0) {
1144                 mlog_errno(ret);
1145                 goto out;
1146         }
1147
1148         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1149         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1150         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1151
1152         ret = ocfs2_journal_dirty(handle, di_bh);
1153         if (ret < 0)
1154                 mlog_errno(ret);
1155
1156 out:
1157         return ret;
1158 }
1159
1160 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1161                                   handle_t *handle,
1162                                   u32 bits_wanted,
1163                                   u32 min_bits,
1164                                   u16 *bit_off,
1165                                   unsigned int *num_bits,
1166                                   u64 gd_blkno,
1167                                   u16 *bits_left)
1168 {
1169         int ret;
1170         u16 found;
1171         struct buffer_head *group_bh = NULL;
1172         struct ocfs2_group_desc *gd;
1173         struct inode *alloc_inode = ac->ac_inode;
1174
1175         ret = ocfs2_read_block(alloc_inode, gd_blkno,
1176                                &group_bh, OCFS2_BH_CACHED);
1177         if (ret < 0) {
1178                 mlog_errno(ret);
1179                 return ret;
1180         }
1181
1182         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1183         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
1184                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, gd);
1185                 ret = -EIO;
1186                 goto out;
1187         }
1188
1189         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1190                                   ac->ac_max_block, bit_off, &found);
1191         if (ret < 0) {
1192                 if (ret != -ENOSPC)
1193                         mlog_errno(ret);
1194                 goto out;
1195         }
1196
1197         *num_bits = found;
1198
1199         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1200                                                *num_bits,
1201                                                le16_to_cpu(gd->bg_chain));
1202         if (ret < 0) {
1203                 mlog_errno(ret);
1204                 goto out;
1205         }
1206
1207         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1208                                          *bit_off, *num_bits);
1209         if (ret < 0)
1210                 mlog_errno(ret);
1211
1212         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1213
1214 out:
1215         brelse(group_bh);
1216
1217         return ret;
1218 }
1219
1220 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1221                               handle_t *handle,
1222                               u32 bits_wanted,
1223                               u32 min_bits,
1224                               u16 *bit_off,
1225                               unsigned int *num_bits,
1226                               u64 *bg_blkno,
1227                               u16 *bits_left)
1228 {
1229         int status;
1230         u16 chain, tmp_bits;
1231         u32 tmp_used;
1232         u64 next_group;
1233         struct inode *alloc_inode = ac->ac_inode;
1234         struct buffer_head *group_bh = NULL;
1235         struct buffer_head *prev_group_bh = NULL;
1236         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1237         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1238         struct ocfs2_group_desc *bg;
1239
1240         chain = ac->ac_chain;
1241         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
1242              bits_wanted, chain,
1243              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
1244
1245         status = ocfs2_read_block(alloc_inode,
1246                                   le64_to_cpu(cl->cl_recs[chain].c_blkno),
1247                                   &group_bh, OCFS2_BH_CACHED);
1248         if (status < 0) {
1249                 mlog_errno(status);
1250                 goto bail;
1251         }
1252         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1253         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1254         if (status) {
1255                 mlog_errno(status);
1256                 goto bail;
1257         }
1258
1259         status = -ENOSPC;
1260         /* for now, the chain search is a bit simplistic. We just use
1261          * the 1st group with any empty bits. */
1262         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1263                                              bits_wanted, min_bits,
1264                                              ac->ac_max_block, bit_off,
1265                                              &tmp_bits)) == -ENOSPC) {
1266                 if (!bg->bg_next_group)
1267                         break;
1268
1269                 brelse(prev_group_bh);
1270                 prev_group_bh = NULL;
1271
1272                 next_group = le64_to_cpu(bg->bg_next_group);
1273                 prev_group_bh = group_bh;
1274                 group_bh = NULL;
1275                 status = ocfs2_read_block(alloc_inode,
1276                                           next_group, &group_bh,
1277                                           OCFS2_BH_CACHED);
1278                 if (status < 0) {
1279                         mlog_errno(status);
1280                         goto bail;
1281                 }
1282                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1283                 status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1284                 if (status) {
1285                         mlog_errno(status);
1286                         goto bail;
1287                 }
1288         }
1289         if (status < 0) {
1290                 if (status != -ENOSPC)
1291                         mlog_errno(status);
1292                 goto bail;
1293         }
1294
1295         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1296              tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
1297
1298         *num_bits = tmp_bits;
1299
1300         BUG_ON(*num_bits == 0);
1301
1302         /*
1303          * Keep track of previous block descriptor read. When
1304          * we find a target, if we have read more than X
1305          * number of descriptors, and the target is reasonably
1306          * empty, relink him to top of his chain.
1307          *
1308          * We've read 0 extra blocks and only send one more to
1309          * the transaction, yet the next guy to search has a
1310          * much easier time.
1311          *
1312          * Do this *after* figuring out how many bits we're taking out
1313          * of our target group.
1314          */
1315         if (ac->ac_allow_chain_relink &&
1316             (prev_group_bh) &&
1317             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1318                 status = ocfs2_relink_block_group(handle, alloc_inode,
1319                                                   ac->ac_bh, group_bh,
1320                                                   prev_group_bh, chain);
1321                 if (status < 0) {
1322                         mlog_errno(status);
1323                         goto bail;
1324                 }
1325         }
1326
1327         /* Ok, claim our bits now: set the info on dinode, chainlist
1328          * and then the group */
1329         status = ocfs2_journal_access(handle,
1330                                       alloc_inode,
1331                                       ac->ac_bh,
1332                                       OCFS2_JOURNAL_ACCESS_WRITE);
1333         if (status < 0) {
1334                 mlog_errno(status);
1335                 goto bail;
1336         }
1337
1338         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1339         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1340         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1341
1342         status = ocfs2_journal_dirty(handle,
1343                                      ac->ac_bh);
1344         if (status < 0) {
1345                 mlog_errno(status);
1346                 goto bail;
1347         }
1348
1349         status = ocfs2_block_group_set_bits(handle,
1350                                             alloc_inode,
1351                                             bg,
1352                                             group_bh,
1353                                             *bit_off,
1354                                             *num_bits);
1355         if (status < 0) {
1356                 mlog_errno(status);
1357                 goto bail;
1358         }
1359
1360         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1361              (unsigned long long)le64_to_cpu(fe->i_blkno));
1362
1363         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1364         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1365 bail:
1366         brelse(group_bh);
1367         brelse(prev_group_bh);
1368
1369         mlog_exit(status);
1370         return status;
1371 }
1372
1373 /* will give out up to bits_wanted contiguous bits. */
1374 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1375                                      struct ocfs2_alloc_context *ac,
1376                                      handle_t *handle,
1377                                      u32 bits_wanted,
1378                                      u32 min_bits,
1379                                      u16 *bit_off,
1380                                      unsigned int *num_bits,
1381                                      u64 *bg_blkno)
1382 {
1383         int status;
1384         u16 victim, i;
1385         u16 bits_left = 0;
1386         u64 hint_blkno = ac->ac_last_group;
1387         struct ocfs2_chain_list *cl;
1388         struct ocfs2_dinode *fe;
1389
1390         mlog_entry_void();
1391
1392         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1393         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1394         BUG_ON(!ac->ac_bh);
1395
1396         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1397         if (!OCFS2_IS_VALID_DINODE(fe)) {
1398                 OCFS2_RO_ON_INVALID_DINODE(osb->sb, fe);
1399                 status = -EIO;
1400                 goto bail;
1401         }
1402         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1403             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1404                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1405                             "bits but only %u total.",
1406                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1407                             le32_to_cpu(fe->id1.bitmap1.i_used),
1408                             le32_to_cpu(fe->id1.bitmap1.i_total));
1409                 status = -EIO;
1410                 goto bail;
1411         }
1412
1413         if (hint_blkno) {
1414                 /* Attempt to short-circuit the usual search mechanism
1415                  * by jumping straight to the most recently used
1416                  * allocation group. This helps us mantain some
1417                  * contiguousness across allocations. */
1418                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1419                                                 min_bits, bit_off, num_bits,
1420                                                 hint_blkno, &bits_left);
1421                 if (!status) {
1422                         /* Be careful to update *bg_blkno here as the
1423                          * caller is expecting it to be filled in, and
1424                          * ocfs2_search_one_group() won't do that for
1425                          * us. */
1426                         *bg_blkno = hint_blkno;
1427                         goto set_hint;
1428                 }
1429                 if (status < 0 && status != -ENOSPC) {
1430                         mlog_errno(status);
1431                         goto bail;
1432                 }
1433         }
1434
1435         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1436
1437         victim = ocfs2_find_victim_chain(cl);
1438         ac->ac_chain = victim;
1439         ac->ac_allow_chain_relink = 1;
1440
1441         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, bit_off,
1442                                     num_bits, bg_blkno, &bits_left);
1443         if (!status)
1444                 goto set_hint;
1445         if (status < 0 && status != -ENOSPC) {
1446                 mlog_errno(status);
1447                 goto bail;
1448         }
1449
1450         mlog(0, "Search of victim chain %u came up with nothing, "
1451              "trying all chains now.\n", victim);
1452
1453         /* If we didn't pick a good victim, then just default to
1454          * searching each chain in order. Don't allow chain relinking
1455          * because we only calculate enough journal credits for one
1456          * relink per alloc. */
1457         ac->ac_allow_chain_relink = 0;
1458         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1459                 if (i == victim)
1460                         continue;
1461                 if (!cl->cl_recs[i].c_free)
1462                         continue;
1463
1464                 ac->ac_chain = i;
1465                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1466                                             bit_off, num_bits, bg_blkno,
1467                                             &bits_left);
1468                 if (!status)
1469                         break;
1470                 if (status < 0 && status != -ENOSPC) {
1471                         mlog_errno(status);
1472                         goto bail;
1473                 }
1474         }
1475
1476 set_hint:
1477         if (status != -ENOSPC) {
1478                 /* If the next search of this group is not likely to
1479                  * yield a suitable extent, then we reset the last
1480                  * group hint so as to not waste a disk read */
1481                 if (bits_left < min_bits)
1482                         ac->ac_last_group = 0;
1483                 else
1484                         ac->ac_last_group = *bg_blkno;
1485         }
1486
1487 bail:
1488         mlog_exit(status);
1489         return status;
1490 }
1491
1492 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1493                          handle_t *handle,
1494                          struct ocfs2_alloc_context *ac,
1495                          u32 bits_wanted,
1496                          u16 *suballoc_bit_start,
1497                          unsigned int *num_bits,
1498                          u64 *blkno_start)
1499 {
1500         int status;
1501         u64 bg_blkno;
1502
1503         BUG_ON(!ac);
1504         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1505         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1506
1507         status = ocfs2_claim_suballoc_bits(osb,
1508                                            ac,
1509                                            handle,
1510                                            bits_wanted,
1511                                            1,
1512                                            suballoc_bit_start,
1513                                            num_bits,
1514                                            &bg_blkno);
1515         if (status < 0) {
1516                 mlog_errno(status);
1517                 goto bail;
1518         }
1519         atomic_inc(&osb->alloc_stats.bg_allocs);
1520
1521         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1522         ac->ac_bits_given += (*num_bits);
1523         status = 0;
1524 bail:
1525         mlog_exit(status);
1526         return status;
1527 }
1528
1529 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1530                           handle_t *handle,
1531                           struct ocfs2_alloc_context *ac,
1532                           u16 *suballoc_bit,
1533                           u64 *fe_blkno)
1534 {
1535         int status;
1536         unsigned int num_bits;
1537         u64 bg_blkno;
1538
1539         mlog_entry_void();
1540
1541         BUG_ON(!ac);
1542         BUG_ON(ac->ac_bits_given != 0);
1543         BUG_ON(ac->ac_bits_wanted != 1);
1544         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1545
1546         status = ocfs2_claim_suballoc_bits(osb,
1547                                            ac,
1548                                            handle,
1549                                            1,
1550                                            1,
1551                                            suballoc_bit,
1552                                            &num_bits,
1553                                            &bg_blkno);
1554         if (status < 0) {
1555                 mlog_errno(status);
1556                 goto bail;
1557         }
1558         atomic_inc(&osb->alloc_stats.bg_allocs);
1559
1560         BUG_ON(num_bits != 1);
1561
1562         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1563         ac->ac_bits_given++;
1564         status = 0;
1565 bail:
1566         mlog_exit(status);
1567         return status;
1568 }
1569
1570 /* translate a group desc. blkno and it's bitmap offset into
1571  * disk cluster offset. */
1572 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1573                                                    u64 bg_blkno,
1574                                                    u16 bg_bit_off)
1575 {
1576         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1577         u32 cluster = 0;
1578
1579         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1580
1581         if (bg_blkno != osb->first_cluster_group_blkno)
1582                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1583         cluster += (u32) bg_bit_off;
1584         return cluster;
1585 }
1586
1587 /* given a cluster offset, calculate which block group it belongs to
1588  * and return that block offset. */
1589 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
1590 {
1591         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1592         u32 group_no;
1593
1594         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1595
1596         group_no = cluster / osb->bitmap_cpg;
1597         if (!group_no)
1598                 return osb->first_cluster_group_blkno;
1599         return ocfs2_clusters_to_blocks(inode->i_sb,
1600                                         group_no * osb->bitmap_cpg);
1601 }
1602
1603 /* given the block number of a cluster start, calculate which cluster
1604  * group and descriptor bitmap offset that corresponds to. */
1605 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1606                                                 u64 data_blkno,
1607                                                 u64 *bg_blkno,
1608                                                 u16 *bg_bit_off)
1609 {
1610         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1611         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1612
1613         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1614
1615         *bg_blkno = ocfs2_which_cluster_group(inode,
1616                                               data_cluster);
1617
1618         if (*bg_blkno == osb->first_cluster_group_blkno)
1619                 *bg_bit_off = (u16) data_cluster;
1620         else
1621                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1622                                                              data_blkno - *bg_blkno);
1623 }
1624
1625 /*
1626  * min_bits - minimum contiguous chunk from this total allocation we
1627  * can handle. set to what we asked for originally for a full
1628  * contig. allocation, set to '1' to indicate we can deal with extents
1629  * of any size.
1630  */
1631 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
1632                            handle_t *handle,
1633                            struct ocfs2_alloc_context *ac,
1634                            u32 min_clusters,
1635                            u32 max_clusters,
1636                            u32 *cluster_start,
1637                            u32 *num_clusters)
1638 {
1639         int status;
1640         unsigned int bits_wanted = max_clusters;
1641         u64 bg_blkno = 0;
1642         u16 bg_bit_off;
1643
1644         mlog_entry_void();
1645
1646         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1647
1648         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1649                && ac->ac_which != OCFS2_AC_USE_MAIN);
1650
1651         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1652                 status = ocfs2_claim_local_alloc_bits(osb,
1653                                                       handle,
1654                                                       ac,
1655                                                       bits_wanted,
1656                                                       cluster_start,
1657                                                       num_clusters);
1658                 if (!status)
1659                         atomic_inc(&osb->alloc_stats.local_data);
1660         } else {
1661                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1662                         /* The only paths asking for contiguousness
1663                          * should know about this already. */
1664                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
1665                              "group bitmap size %u!\n", min_clusters,
1666                              osb->bitmap_cpg);
1667                         status = -ENOSPC;
1668                         goto bail;
1669                 }
1670                 /* clamp the current request down to a realistic size. */
1671                 if (bits_wanted > (osb->bitmap_cpg - 1))
1672                         bits_wanted = osb->bitmap_cpg - 1;
1673
1674                 status = ocfs2_claim_suballoc_bits(osb,
1675                                                    ac,
1676                                                    handle,
1677                                                    bits_wanted,
1678                                                    min_clusters,
1679                                                    &bg_bit_off,
1680                                                    num_clusters,
1681                                                    &bg_blkno);
1682                 if (!status) {
1683                         *cluster_start =
1684                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1685                                                                  bg_blkno,
1686                                                                  bg_bit_off);
1687                         atomic_inc(&osb->alloc_stats.bitmap_data);
1688                 }
1689         }
1690         if (status < 0) {
1691                 if (status != -ENOSPC)
1692                         mlog_errno(status);
1693                 goto bail;
1694         }
1695
1696         ac->ac_bits_given += *num_clusters;
1697
1698 bail:
1699         mlog_exit(status);
1700         return status;
1701 }
1702
1703 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1704                          handle_t *handle,
1705                          struct ocfs2_alloc_context *ac,
1706                          u32 min_clusters,
1707                          u32 *cluster_start,
1708                          u32 *num_clusters)
1709 {
1710         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1711
1712         return __ocfs2_claim_clusters(osb, handle, ac, min_clusters,
1713                                       bits_wanted, cluster_start, num_clusters);
1714 }
1715
1716 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
1717                                                struct inode *alloc_inode,
1718                                                struct ocfs2_group_desc *bg,
1719                                                struct buffer_head *group_bh,
1720                                                unsigned int bit_off,
1721                                                unsigned int num_bits)
1722 {
1723         int status;
1724         unsigned int tmp;
1725         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1726         struct ocfs2_group_desc *undo_bg = NULL;
1727
1728         mlog_entry_void();
1729
1730         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1731                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1732                 status = -EIO;
1733                 goto bail;
1734         }
1735
1736         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1737
1738         if (ocfs2_is_cluster_bitmap(alloc_inode))
1739                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1740
1741         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1742                                       journal_type);
1743         if (status < 0) {
1744                 mlog_errno(status);
1745                 goto bail;
1746         }
1747
1748         if (ocfs2_is_cluster_bitmap(alloc_inode))
1749                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1750
1751         tmp = num_bits;
1752         while(tmp--) {
1753                 ocfs2_clear_bit((bit_off + tmp),
1754                                 (unsigned long *) bg->bg_bitmap);
1755                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1756                         ocfs2_set_bit(bit_off + tmp,
1757                                       (unsigned long *) undo_bg->bg_bitmap);
1758         }
1759         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1760
1761         status = ocfs2_journal_dirty(handle, group_bh);
1762         if (status < 0)
1763                 mlog_errno(status);
1764 bail:
1765         return status;
1766 }
1767
1768 /*
1769  * expects the suballoc inode to already be locked.
1770  */
1771 int ocfs2_free_suballoc_bits(handle_t *handle,
1772                              struct inode *alloc_inode,
1773                              struct buffer_head *alloc_bh,
1774                              unsigned int start_bit,
1775                              u64 bg_blkno,
1776                              unsigned int count)
1777 {
1778         int status = 0;
1779         u32 tmp_used;
1780         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1781         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1782         struct buffer_head *group_bh = NULL;
1783         struct ocfs2_group_desc *group;
1784
1785         mlog_entry_void();
1786
1787         if (!OCFS2_IS_VALID_DINODE(fe)) {
1788                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
1789                 status = -EIO;
1790                 goto bail;
1791         }
1792         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1793
1794         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1795              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1796              (unsigned long long)bg_blkno, start_bit);
1797
1798         status = ocfs2_read_block(alloc_inode, bg_blkno, &group_bh,
1799                                   OCFS2_BH_CACHED);
1800         if (status < 0) {
1801                 mlog_errno(status);
1802                 goto bail;
1803         }
1804
1805         group = (struct ocfs2_group_desc *) group_bh->b_data;
1806         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, group);
1807         if (status) {
1808                 mlog_errno(status);
1809                 goto bail;
1810         }
1811         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1812
1813         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1814                                               group, group_bh,
1815                                               start_bit, count);
1816         if (status < 0) {
1817                 mlog_errno(status);
1818                 goto bail;
1819         }
1820
1821         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1822                                       OCFS2_JOURNAL_ACCESS_WRITE);
1823         if (status < 0) {
1824                 mlog_errno(status);
1825                 goto bail;
1826         }
1827
1828         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1829                      count);
1830         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1831         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1832
1833         status = ocfs2_journal_dirty(handle, alloc_bh);
1834         if (status < 0) {
1835                 mlog_errno(status);
1836                 goto bail;
1837         }
1838
1839 bail:
1840         brelse(group_bh);
1841
1842         mlog_exit(status);
1843         return status;
1844 }
1845
1846 int ocfs2_free_dinode(handle_t *handle,
1847                       struct inode *inode_alloc_inode,
1848                       struct buffer_head *inode_alloc_bh,
1849                       struct ocfs2_dinode *di)
1850 {
1851         u64 blk = le64_to_cpu(di->i_blkno);
1852         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1853         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1854
1855         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1856                                         inode_alloc_bh, bit, bg_blkno, 1);
1857 }
1858
1859 int ocfs2_free_clusters(handle_t *handle,
1860                        struct inode *bitmap_inode,
1861                        struct buffer_head *bitmap_bh,
1862                        u64 start_blk,
1863                        unsigned int num_clusters)
1864 {
1865         int status;
1866         u16 bg_start_bit;
1867         u64 bg_blkno;
1868         struct ocfs2_dinode *fe;
1869
1870         /* You can't ever have a contiguous set of clusters
1871          * bigger than a block group bitmap so we never have to worry
1872          * about looping on them. */
1873
1874         mlog_entry_void();
1875
1876         /* This is expensive. We can safely remove once this stuff has
1877          * gotten tested really well. */
1878         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1879
1880         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1881
1882         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1883                                      &bg_start_bit);
1884
1885         mlog(0, "want to free %u clusters starting at block %llu\n",
1886              num_clusters, (unsigned long long)start_blk);
1887         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1888              (unsigned long long)bg_blkno, bg_start_bit);
1889
1890         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1891                                           bg_start_bit, bg_blkno,
1892                                           num_clusters);
1893         if (status < 0) {
1894                 mlog_errno(status);
1895                 goto out;
1896         }
1897
1898         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
1899                                          num_clusters);
1900
1901 out:
1902         mlog_exit(status);
1903         return status;
1904 }
1905
1906 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1907 {
1908         printk("Block Group:\n");
1909         printk("bg_signature:       %s\n", bg->bg_signature);
1910         printk("bg_size:            %u\n", bg->bg_size);
1911         printk("bg_bits:            %u\n", bg->bg_bits);
1912         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1913         printk("bg_chain:           %u\n", bg->bg_chain);
1914         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1915         printk("bg_next_group:      %llu\n",
1916                (unsigned long long)bg->bg_next_group);
1917         printk("bg_parent_dinode:   %llu\n",
1918                (unsigned long long)bg->bg_parent_dinode);
1919         printk("bg_blkno:           %llu\n",
1920                (unsigned long long)bg->bg_blkno);
1921 }
1922
1923 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
1924 {
1925         int i;
1926
1927         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
1928         printk("i_signature:                  %s\n", fe->i_signature);
1929         printk("i_size:                       %llu\n",
1930                (unsigned long long)fe->i_size);
1931         printk("i_clusters:                   %u\n", fe->i_clusters);
1932         printk("i_generation:                 %u\n",
1933                le32_to_cpu(fe->i_generation));
1934         printk("id1.bitmap1.i_used:           %u\n",
1935                le32_to_cpu(fe->id1.bitmap1.i_used));
1936         printk("id1.bitmap1.i_total:          %u\n",
1937                le32_to_cpu(fe->id1.bitmap1.i_total));
1938         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
1939         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
1940         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
1941         printk("id2.i_chain.cl_next_free_rec: %u\n",
1942                fe->id2.i_chain.cl_next_free_rec);
1943         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
1944                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
1945                        fe->id2.i_chain.cl_recs[i].c_free);
1946                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
1947                        fe->id2.i_chain.cl_recs[i].c_total);
1948                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
1949                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
1950         }
1951 }
1952
1953 /*
1954  * For a given allocation, determine which allocators will need to be
1955  * accessed, and lock them, reserving the appropriate number of bits.
1956  *
1957  * Sparse file systems call this from ocfs2_write_begin_nolock()
1958  * and ocfs2_allocate_unwritten_extents().
1959  *
1960  * File systems which don't support holes call this from
1961  * ocfs2_extend_allocation().
1962  */
1963 int ocfs2_lock_allocators(struct inode *inode,
1964                           struct ocfs2_extent_tree *et,
1965                           u32 clusters_to_add, u32 extents_to_split,
1966                           struct ocfs2_alloc_context **data_ac,
1967                           struct ocfs2_alloc_context **meta_ac)
1968 {
1969         int ret = 0, num_free_extents;
1970         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
1971         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1972
1973         *meta_ac = NULL;
1974         if (data_ac)
1975                 *data_ac = NULL;
1976
1977         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
1978
1979         num_free_extents = ocfs2_num_free_extents(osb, inode, et);
1980         if (num_free_extents < 0) {
1981                 ret = num_free_extents;
1982                 mlog_errno(ret);
1983                 goto out;
1984         }
1985
1986         /*
1987          * Sparse allocation file systems need to be more conservative
1988          * with reserving room for expansion - the actual allocation
1989          * happens while we've got a journal handle open so re-taking
1990          * a cluster lock (because we ran out of room for another
1991          * extent) will violate ordering rules.
1992          *
1993          * Most of the time we'll only be seeing this 1 cluster at a time
1994          * anyway.
1995          *
1996          * Always lock for any unwritten extents - we might want to
1997          * add blocks during a split.
1998          */
1999         if (!num_free_extents ||
2000             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2001                 ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2002                 if (ret < 0) {
2003                         if (ret != -ENOSPC)
2004                                 mlog_errno(ret);
2005                         goto out;
2006                 }
2007         }
2008
2009         if (clusters_to_add == 0)
2010                 goto out;
2011
2012         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2013         if (ret < 0) {
2014                 if (ret != -ENOSPC)
2015                         mlog_errno(ret);
2016                 goto out;
2017         }
2018
2019 out:
2020         if (ret) {
2021                 if (*meta_ac) {
2022                         ocfs2_free_alloc_context(*meta_ac);
2023                         *meta_ac = NULL;
2024                 }
2025
2026                 /*
2027                  * We cannot have an error and a non null *data_ac.
2028                  */
2029         }
2030
2031         return ret;
2032 }