SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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                                    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
 445         /* The bh was validated by the inode read inside
 446          * ocfs2_inode_lock().  Any corruption is a code bug. */
 447         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 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_GROUP_DESC(bg)) {
 935                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 936                 status = -EIO;
 937                 goto out;
 938         }
 939         if (!OCFS2_IS_VALID_GROUP_DESC(prev_bg)) {
 940                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, prev_bg);
 941                 status = -EIO;
 942                 goto out;
 943         }
 944
 945         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
 946              (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
 947              (unsigned long long)le64_to_cpu(bg->bg_blkno),
 948              (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
 949
 950         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
 951         bg_ptr = le64_to_cpu(bg->bg_next_group);
 952         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
 953
 954         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
 955                                       OCFS2_JOURNAL_ACCESS_WRITE);
 956         if (status < 0) {
 957                 mlog_errno(status);
 958                 goto out_rollback;
 959         }
 960
 961         prev_bg->bg_next_group = bg->bg_next_group;
 962
 963         status = ocfs2_journal_dirty(handle, prev_bg_bh);
 964         if (status < 0) {
 965                 mlog_errno(status);
 966                 goto out_rollback;
 967         }
 968
 969         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
 970                                       OCFS2_JOURNAL_ACCESS_WRITE);
 971         if (status < 0) {
 972                 mlog_errno(status);
 973                 goto out_rollback;
 974         }
 975
 976         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
 977
 978         status = ocfs2_journal_dirty(handle, bg_bh);
 979         if (status < 0) {
 980                 mlog_errno(status);
 981                 goto out_rollback;
 982         }
 983
 984         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
 985                                       OCFS2_JOURNAL_ACCESS_WRITE);
 986         if (status < 0) {
 987                 mlog_errno(status);
 988                 goto out_rollback;
 989         }
 990
 991         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
 992
 993         status = ocfs2_journal_dirty(handle, fe_bh);
 994         if (status < 0) {
 995                 mlog_errno(status);
 996                 goto out_rollback;
 997         }
 998
 999         status = 0;
1000 out_rollback:
1001         if (status < 0) {
1002                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
1003                 bg->bg_next_group = cpu_to_le64(bg_ptr);
1004                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1005         }
1006 out:
1007         mlog_exit(status);
1008         return status;
1009 }
1010
1011 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1012                                                      u32 wanted)
1013 {
1014         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1015 }
1016
1017 /* return 0 on success, -ENOSPC to keep searching and any other < 0
1018  * value on error. */
1019 static int ocfs2_cluster_group_search(struct inode *inode,
1020                                       struct buffer_head *group_bh,
1021                                       u32 bits_wanted, u32 min_bits,
1022                                       u64 max_block,
1023                                       u16 *bit_off, u16 *bits_found)
1024 {
1025         int search = -ENOSPC;
1026         int ret;
1027         u64 blkoff;
1028         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1029         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1030         u16 tmp_off, tmp_found;
1031         unsigned int max_bits, gd_cluster_off;
1032
1033         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1034
1035         if (gd->bg_free_bits_count) {
1036                 max_bits = le16_to_cpu(gd->bg_bits);
1037
1038                 /* Tail groups in cluster bitmaps which aren't cpg
1039                  * aligned are prone to partial extention by a failed
1040                  * fs resize. If the file system resize never got to
1041                  * update the dinode cluster count, then we don't want
1042                  * to trust any clusters past it, regardless of what
1043                  * the group descriptor says. */
1044                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1045                                                           le64_to_cpu(gd->bg_blkno));
1046                 if ((gd_cluster_off + max_bits) >
1047                     OCFS2_I(inode)->ip_clusters) {
1048                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1049                         mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
1050                              (unsigned long long)le64_to_cpu(gd->bg_blkno),
1051                              le16_to_cpu(gd->bg_bits),
1052                              OCFS2_I(inode)->ip_clusters, max_bits);
1053                 }
1054
1055                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1056                                                         group_bh, bits_wanted,
1057                                                         max_bits,
1058                                                         &tmp_off, &tmp_found);
1059                 if (ret)
1060                         return ret;
1061
1062                 if (max_block) {
1063                         blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1064                                                           gd_cluster_off +
1065                                                           tmp_off + tmp_found);
1066                         mlog(0, "Checking %llu against %llu\n",
1067                              (unsigned long long)blkoff,
1068                              (unsigned long long)max_block);
1069                         if (blkoff > max_block)
1070                                 return -ENOSPC;
1071                 }
1072
1073                 /* ocfs2_block_group_find_clear_bits() might
1074                  * return success, but we still want to return
1075                  * -ENOSPC unless it found the minimum number
1076                  * of bits. */
1077                 if (min_bits <= tmp_found) {
1078                         *bit_off = tmp_off;
1079                         *bits_found = tmp_found;
1080                         search = 0; /* success */
1081                 } else if (tmp_found) {
1082                         /*
1083                          * Don't show bits which we'll be returning
1084                          * for allocation to the local alloc bitmap.
1085                          */
1086                         ocfs2_local_alloc_seen_free_bits(osb, tmp_found);
1087                 }
1088         }
1089
1090         return search;
1091 }
1092
1093 static int ocfs2_block_group_search(struct inode *inode,
1094                                     struct buffer_head *group_bh,
1095                                     u32 bits_wanted, u32 min_bits,
1096                                     u64 max_block,
1097                                     u16 *bit_off, u16 *bits_found)
1098 {
1099         int ret = -ENOSPC;
1100         u64 blkoff;
1101         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1102
1103         BUG_ON(min_bits != 1);
1104         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1105
1106         if (bg->bg_free_bits_count) {
1107                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1108                                                         group_bh, bits_wanted,
1109                                                         le16_to_cpu(bg->bg_bits),
1110                                                         bit_off, bits_found);
1111                 if (!ret && max_block) {
1112                         blkoff = le64_to_cpu(bg->bg_blkno) + *bit_off +
1113                                 *bits_found;
1114                         mlog(0, "Checking %llu against %llu\n",
1115                              (unsigned long long)blkoff,
1116                              (unsigned long long)max_block);
1117                         if (blkoff > max_block)
1118                                 ret = -ENOSPC;
1119                 }
1120         }
1121
1122         return ret;
1123 }
1124
1125 static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1126                                        handle_t *handle,
1127                                        struct buffer_head *di_bh,
1128                                        u32 num_bits,
1129                                        u16 chain)
1130 {
1131         int ret;
1132         u32 tmp_used;
1133         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1134         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1135
1136         ret = ocfs2_journal_access(handle, inode, di_bh,
1137                                    OCFS2_JOURNAL_ACCESS_WRITE);
1138         if (ret < 0) {
1139                 mlog_errno(ret);
1140                 goto out;
1141         }
1142
1143         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1144         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1145         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1146
1147         ret = ocfs2_journal_dirty(handle, di_bh);
1148         if (ret < 0)
1149                 mlog_errno(ret);
1150
1151 out:
1152         return ret;
1153 }
1154
1155 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1156                                   handle_t *handle,
1157                                   u32 bits_wanted,
1158                                   u32 min_bits,
1159                                   u16 *bit_off,
1160                                   unsigned int *num_bits,
1161                                   u64 gd_blkno,
1162                                   u16 *bits_left)
1163 {
1164         int ret;
1165         u16 found;
1166         struct buffer_head *group_bh = NULL;
1167         struct ocfs2_group_desc *gd;
1168         struct inode *alloc_inode = ac->ac_inode;
1169
1170         ret = ocfs2_read_block(alloc_inode, gd_blkno, &group_bh);
1171         if (ret < 0) {
1172                 mlog_errno(ret);
1173                 return ret;
1174         }
1175
1176         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1177         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
1178                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, gd);
1179                 ret = -EIO;
1180                 goto out;
1181         }
1182
1183         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1184                                   ac->ac_max_block, bit_off, &found);
1185         if (ret < 0) {
1186                 if (ret != -ENOSPC)
1187                         mlog_errno(ret);
1188                 goto out;
1189         }
1190
1191         *num_bits = found;
1192
1193         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1194                                                *num_bits,
1195                                                le16_to_cpu(gd->bg_chain));
1196         if (ret < 0) {
1197                 mlog_errno(ret);
1198                 goto out;
1199         }
1200
1201         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1202                                          *bit_off, *num_bits);
1203         if (ret < 0)
1204                 mlog_errno(ret);
1205
1206         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1207
1208 out:
1209         brelse(group_bh);
1210
1211         return ret;
1212 }
1213
1214 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1215                               handle_t *handle,
1216                               u32 bits_wanted,
1217                               u32 min_bits,
1218                               u16 *bit_off,
1219                               unsigned int *num_bits,
1220                               u64 *bg_blkno,
1221                               u16 *bits_left)
1222 {
1223         int status;
1224         u16 chain, tmp_bits;
1225         u32 tmp_used;
1226         u64 next_group;
1227         struct inode *alloc_inode = ac->ac_inode;
1228         struct buffer_head *group_bh = NULL;
1229         struct buffer_head *prev_group_bh = NULL;
1230         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1231         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1232         struct ocfs2_group_desc *bg;
1233
1234         chain = ac->ac_chain;
1235         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
1236              bits_wanted, chain,
1237              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
1238
1239         status = ocfs2_read_block(alloc_inode,
1240                                   le64_to_cpu(cl->cl_recs[chain].c_blkno),
1241                                   &group_bh);
1242         if (status < 0) {
1243                 mlog_errno(status);
1244                 goto bail;
1245         }
1246         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1247         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1248         if (status) {
1249                 mlog_errno(status);
1250                 goto bail;
1251         }
1252
1253         status = -ENOSPC;
1254         /* for now, the chain search is a bit simplistic. We just use
1255          * the 1st group with any empty bits. */
1256         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1257                                              bits_wanted, min_bits,
1258                                              ac->ac_max_block, bit_off,
1259                                              &tmp_bits)) == -ENOSPC) {
1260                 if (!bg->bg_next_group)
1261                         break;
1262
1263                 brelse(prev_group_bh);
1264                 prev_group_bh = NULL;
1265
1266                 next_group = le64_to_cpu(bg->bg_next_group);
1267                 prev_group_bh = group_bh;
1268                 group_bh = NULL;
1269                 status = ocfs2_read_block(alloc_inode,
1270                                           next_group, &group_bh);
1271                 if (status < 0) {
1272                         mlog_errno(status);
1273                         goto bail;
1274                 }
1275                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1276                 status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1277                 if (status) {
1278                         mlog_errno(status);
1279                         goto bail;
1280                 }
1281         }
1282         if (status < 0) {
1283                 if (status != -ENOSPC)
1284                         mlog_errno(status);
1285                 goto bail;
1286         }
1287
1288         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1289              tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
1290
1291         *num_bits = tmp_bits;
1292
1293         BUG_ON(*num_bits == 0);
1294
1295         /*
1296          * Keep track of previous block descriptor read. When
1297          * we find a target, if we have read more than X
1298          * number of descriptors, and the target is reasonably
1299          * empty, relink him to top of his chain.
1300          *
1301          * We've read 0 extra blocks and only send one more to
1302          * the transaction, yet the next guy to search has a
1303          * much easier time.
1304          *
1305          * Do this *after* figuring out how many bits we're taking out
1306          * of our target group.
1307          */
1308         if (ac->ac_allow_chain_relink &&
1309             (prev_group_bh) &&
1310             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1311                 status = ocfs2_relink_block_group(handle, alloc_inode,
1312                                                   ac->ac_bh, group_bh,
1313                                                   prev_group_bh, chain);
1314                 if (status < 0) {
1315                         mlog_errno(status);
1316                         goto bail;
1317                 }
1318         }
1319
1320         /* Ok, claim our bits now: set the info on dinode, chainlist
1321          * and then the group */
1322         status = ocfs2_journal_access(handle,
1323                                       alloc_inode,
1324                                       ac->ac_bh,
1325                                       OCFS2_JOURNAL_ACCESS_WRITE);
1326         if (status < 0) {
1327                 mlog_errno(status);
1328                 goto bail;
1329         }
1330
1331         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1332         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1333         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1334
1335         status = ocfs2_journal_dirty(handle,
1336                                      ac->ac_bh);
1337         if (status < 0) {
1338                 mlog_errno(status);
1339                 goto bail;
1340         }
1341
1342         status = ocfs2_block_group_set_bits(handle,
1343                                             alloc_inode,
1344                                             bg,
1345                                             group_bh,
1346                                             *bit_off,
1347                                             *num_bits);
1348         if (status < 0) {
1349                 mlog_errno(status);
1350                 goto bail;
1351         }
1352
1353         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1354              (unsigned long long)le64_to_cpu(fe->i_blkno));
1355
1356         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1357         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1358 bail:
1359         brelse(group_bh);
1360         brelse(prev_group_bh);
1361
1362         mlog_exit(status);
1363         return status;
1364 }
1365
1366 /* will give out up to bits_wanted contiguous bits. */
1367 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1368                                      struct ocfs2_alloc_context *ac,
1369                                      handle_t *handle,
1370                                      u32 bits_wanted,
1371                                      u32 min_bits,
1372                                      u16 *bit_off,
1373                                      unsigned int *num_bits,
1374                                      u64 *bg_blkno)
1375 {
1376         int status;
1377         u16 victim, i;
1378         u16 bits_left = 0;
1379         u64 hint_blkno = ac->ac_last_group;
1380         struct ocfs2_chain_list *cl;
1381         struct ocfs2_dinode *fe;
1382
1383         mlog_entry_void();
1384
1385         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1386         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1387         BUG_ON(!ac->ac_bh);
1388
1389         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1390
1391         /* The bh was validated by the inode read during
1392          * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1393         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1394
1395         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1396             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1397                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1398                             "bits but only %u total.",
1399                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1400                             le32_to_cpu(fe->id1.bitmap1.i_used),
1401                             le32_to_cpu(fe->id1.bitmap1.i_total));
1402                 status = -EIO;
1403                 goto bail;
1404         }
1405
1406         if (hint_blkno) {
1407                 /* Attempt to short-circuit the usual search mechanism
1408                  * by jumping straight to the most recently used
1409                  * allocation group. This helps us mantain some
1410                  * contiguousness across allocations. */
1411                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1412                                                 min_bits, bit_off, num_bits,
1413                                                 hint_blkno, &bits_left);
1414                 if (!status) {
1415                         /* Be careful to update *bg_blkno here as the
1416                          * caller is expecting it to be filled in, and
1417                          * ocfs2_search_one_group() won't do that for
1418                          * us. */
1419                         *bg_blkno = hint_blkno;
1420                         goto set_hint;
1421                 }
1422                 if (status < 0 && status != -ENOSPC) {
1423                         mlog_errno(status);
1424                         goto bail;
1425                 }
1426         }
1427
1428         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1429
1430         victim = ocfs2_find_victim_chain(cl);
1431         ac->ac_chain = victim;
1432         ac->ac_allow_chain_relink = 1;
1433
1434         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, bit_off,
1435                                     num_bits, bg_blkno, &bits_left);
1436         if (!status)
1437                 goto set_hint;
1438         if (status < 0 && status != -ENOSPC) {
1439                 mlog_errno(status);
1440                 goto bail;
1441         }
1442
1443         mlog(0, "Search of victim chain %u came up with nothing, "
1444              "trying all chains now.\n", victim);
1445
1446         /* If we didn't pick a good victim, then just default to
1447          * searching each chain in order. Don't allow chain relinking
1448          * because we only calculate enough journal credits for one
1449          * relink per alloc. */
1450         ac->ac_allow_chain_relink = 0;
1451         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1452                 if (i == victim)
1453                         continue;
1454                 if (!cl->cl_recs[i].c_free)
1455                         continue;
1456
1457                 ac->ac_chain = i;
1458                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1459                                             bit_off, num_bits, bg_blkno,
1460                                             &bits_left);
1461                 if (!status)
1462                         break;
1463                 if (status < 0 && status != -ENOSPC) {
1464                         mlog_errno(status);
1465                         goto bail;
1466                 }
1467         }
1468
1469 set_hint:
1470         if (status != -ENOSPC) {
1471                 /* If the next search of this group is not likely to
1472                  * yield a suitable extent, then we reset the last
1473                  * group hint so as to not waste a disk read */
1474                 if (bits_left < min_bits)
1475                         ac->ac_last_group = 0;
1476                 else
1477                         ac->ac_last_group = *bg_blkno;
1478         }
1479
1480 bail:
1481         mlog_exit(status);
1482         return status;
1483 }
1484
1485 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1486                          handle_t *handle,
1487                          struct ocfs2_alloc_context *ac,
1488                          u32 bits_wanted,
1489                          u16 *suballoc_bit_start,
1490                          unsigned int *num_bits,
1491                          u64 *blkno_start)
1492 {
1493         int status;
1494         u64 bg_blkno;
1495
1496         BUG_ON(!ac);
1497         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1498         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1499
1500         status = ocfs2_claim_suballoc_bits(osb,
1501                                            ac,
1502                                            handle,
1503                                            bits_wanted,
1504                                            1,
1505                                            suballoc_bit_start,
1506                                            num_bits,
1507                                            &bg_blkno);
1508         if (status < 0) {
1509                 mlog_errno(status);
1510                 goto bail;
1511         }
1512         atomic_inc(&osb->alloc_stats.bg_allocs);
1513
1514         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1515         ac->ac_bits_given += (*num_bits);
1516         status = 0;
1517 bail:
1518         mlog_exit(status);
1519         return status;
1520 }
1521
1522 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1523                           handle_t *handle,
1524                           struct ocfs2_alloc_context *ac,
1525                           u16 *suballoc_bit,
1526                           u64 *fe_blkno)
1527 {
1528         int status;
1529         unsigned int num_bits;
1530         u64 bg_blkno;
1531
1532         mlog_entry_void();
1533
1534         BUG_ON(!ac);
1535         BUG_ON(ac->ac_bits_given != 0);
1536         BUG_ON(ac->ac_bits_wanted != 1);
1537         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1538
1539         status = ocfs2_claim_suballoc_bits(osb,
1540                                            ac,
1541                                            handle,
1542                                            1,
1543                                            1,
1544                                            suballoc_bit,
1545                                            &num_bits,
1546                                            &bg_blkno);
1547         if (status < 0) {
1548                 mlog_errno(status);
1549                 goto bail;
1550         }
1551         atomic_inc(&osb->alloc_stats.bg_allocs);
1552
1553         BUG_ON(num_bits != 1);
1554
1555         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1556         ac->ac_bits_given++;
1557         status = 0;
1558 bail:
1559         mlog_exit(status);
1560         return status;
1561 }
1562
1563 /* translate a group desc. blkno and it's bitmap offset into
1564  * disk cluster offset. */
1565 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1566                                                    u64 bg_blkno,
1567                                                    u16 bg_bit_off)
1568 {
1569         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1570         u32 cluster = 0;
1571
1572         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1573
1574         if (bg_blkno != osb->first_cluster_group_blkno)
1575                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1576         cluster += (u32) bg_bit_off;
1577         return cluster;
1578 }
1579
1580 /* given a cluster offset, calculate which block group it belongs to
1581  * and return that block offset. */
1582 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
1583 {
1584         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1585         u32 group_no;
1586
1587         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1588
1589         group_no = cluster / osb->bitmap_cpg;
1590         if (!group_no)
1591                 return osb->first_cluster_group_blkno;
1592         return ocfs2_clusters_to_blocks(inode->i_sb,
1593                                         group_no * osb->bitmap_cpg);
1594 }
1595
1596 /* given the block number of a cluster start, calculate which cluster
1597  * group and descriptor bitmap offset that corresponds to. */
1598 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1599                                                 u64 data_blkno,
1600                                                 u64 *bg_blkno,
1601                                                 u16 *bg_bit_off)
1602 {
1603         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1604         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1605
1606         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1607
1608         *bg_blkno = ocfs2_which_cluster_group(inode,
1609                                               data_cluster);
1610
1611         if (*bg_blkno == osb->first_cluster_group_blkno)
1612                 *bg_bit_off = (u16) data_cluster;
1613         else
1614                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1615                                                              data_blkno - *bg_blkno);
1616 }
1617
1618 /*
1619  * min_bits - minimum contiguous chunk from this total allocation we
1620  * can handle. set to what we asked for originally for a full
1621  * contig. allocation, set to '1' to indicate we can deal with extents
1622  * of any size.
1623  */
1624 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
1625                            handle_t *handle,
1626                            struct ocfs2_alloc_context *ac,
1627                            u32 min_clusters,
1628                            u32 max_clusters,
1629                            u32 *cluster_start,
1630                            u32 *num_clusters)
1631 {
1632         int status;
1633         unsigned int bits_wanted = max_clusters;
1634         u64 bg_blkno = 0;
1635         u16 bg_bit_off;
1636
1637         mlog_entry_void();
1638
1639         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1640
1641         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1642                && ac->ac_which != OCFS2_AC_USE_MAIN);
1643
1644         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1645                 status = ocfs2_claim_local_alloc_bits(osb,
1646                                                       handle,
1647                                                       ac,
1648                                                       bits_wanted,
1649                                                       cluster_start,
1650                                                       num_clusters);
1651                 if (!status)
1652                         atomic_inc(&osb->alloc_stats.local_data);
1653         } else {
1654                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1655                         /* The only paths asking for contiguousness
1656                          * should know about this already. */
1657                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
1658                              "group bitmap size %u!\n", min_clusters,
1659                              osb->bitmap_cpg);
1660                         status = -ENOSPC;
1661                         goto bail;
1662                 }
1663                 /* clamp the current request down to a realistic size. */
1664                 if (bits_wanted > (osb->bitmap_cpg - 1))
1665                         bits_wanted = osb->bitmap_cpg - 1;
1666
1667                 status = ocfs2_claim_suballoc_bits(osb,
1668                                                    ac,
1669                                                    handle,
1670                                                    bits_wanted,
1671                                                    min_clusters,
1672                                                    &bg_bit_off,
1673                                                    num_clusters,
1674                                                    &bg_blkno);
1675                 if (!status) {
1676                         *cluster_start =
1677                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1678                                                                  bg_blkno,
1679                                                                  bg_bit_off);
1680                         atomic_inc(&osb->alloc_stats.bitmap_data);
1681                 }
1682         }
1683         if (status < 0) {
1684                 if (status != -ENOSPC)
1685                         mlog_errno(status);
1686                 goto bail;
1687         }
1688
1689         ac->ac_bits_given += *num_clusters;
1690
1691 bail:
1692         mlog_exit(status);
1693         return status;
1694 }
1695
1696 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1697                          handle_t *handle,
1698                          struct ocfs2_alloc_context *ac,
1699                          u32 min_clusters,
1700                          u32 *cluster_start,
1701                          u32 *num_clusters)
1702 {
1703         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1704
1705         return __ocfs2_claim_clusters(osb, handle, ac, min_clusters,
1706                                       bits_wanted, cluster_start, num_clusters);
1707 }
1708
1709 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
1710                                                struct inode *alloc_inode,
1711                                                struct ocfs2_group_desc *bg,
1712                                                struct buffer_head *group_bh,
1713                                                unsigned int bit_off,
1714                                                unsigned int num_bits)
1715 {
1716         int status;
1717         unsigned int tmp;
1718         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1719         struct ocfs2_group_desc *undo_bg = NULL;
1720
1721         mlog_entry_void();
1722
1723         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1724                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1725                 status = -EIO;
1726                 goto bail;
1727         }
1728
1729         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1730
1731         if (ocfs2_is_cluster_bitmap(alloc_inode))
1732                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1733
1734         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1735                                       journal_type);
1736         if (status < 0) {
1737                 mlog_errno(status);
1738                 goto bail;
1739         }
1740
1741         if (ocfs2_is_cluster_bitmap(alloc_inode))
1742                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1743
1744         tmp = num_bits;
1745         while(tmp--) {
1746                 ocfs2_clear_bit((bit_off + tmp),
1747                                 (unsigned long *) bg->bg_bitmap);
1748                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1749                         ocfs2_set_bit(bit_off + tmp,
1750                                       (unsigned long *) undo_bg->bg_bitmap);
1751         }
1752         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1753
1754         status = ocfs2_journal_dirty(handle, group_bh);
1755         if (status < 0)
1756                 mlog_errno(status);
1757 bail:
1758         return status;
1759 }
1760
1761 /*
1762  * expects the suballoc inode to already be locked.
1763  */
1764 int ocfs2_free_suballoc_bits(handle_t *handle,
1765                              struct inode *alloc_inode,
1766                              struct buffer_head *alloc_bh,
1767                              unsigned int start_bit,
1768                              u64 bg_blkno,
1769                              unsigned int count)
1770 {
1771         int status = 0;
1772         u32 tmp_used;
1773         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1774         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1775         struct buffer_head *group_bh = NULL;
1776         struct ocfs2_group_desc *group;
1777
1778         mlog_entry_void();
1779
1780         /* The alloc_bh comes from ocfs2_free_dinode() or
1781          * ocfs2_free_clusters().  The callers have all locked the
1782          * allocator and gotten alloc_bh from the lock call.  This
1783          * validates the dinode buffer.  Any corruption that has happended
1784          * is a code bug. */
1785         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1786         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1787
1788         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1789              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1790              (unsigned long long)bg_blkno, start_bit);
1791
1792         status = ocfs2_read_block(alloc_inode, bg_blkno, &group_bh);
1793         if (status < 0) {
1794                 mlog_errno(status);
1795                 goto bail;
1796         }
1797
1798         group = (struct ocfs2_group_desc *) group_bh->b_data;
1799         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, group);
1800         if (status) {
1801                 mlog_errno(status);
1802                 goto bail;
1803         }
1804         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1805
1806         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1807                                               group, group_bh,
1808                                               start_bit, count);
1809         if (status < 0) {
1810                 mlog_errno(status);
1811                 goto bail;
1812         }
1813
1814         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1815                                       OCFS2_JOURNAL_ACCESS_WRITE);
1816         if (status < 0) {
1817                 mlog_errno(status);
1818                 goto bail;
1819         }
1820
1821         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1822                      count);
1823         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1824         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1825
1826         status = ocfs2_journal_dirty(handle, alloc_bh);
1827         if (status < 0) {
1828                 mlog_errno(status);
1829                 goto bail;
1830         }
1831
1832 bail:
1833         brelse(group_bh);
1834
1835         mlog_exit(status);
1836         return status;
1837 }
1838
1839 int ocfs2_free_dinode(handle_t *handle,
1840                       struct inode *inode_alloc_inode,
1841                       struct buffer_head *inode_alloc_bh,
1842                       struct ocfs2_dinode *di)
1843 {
1844         u64 blk = le64_to_cpu(di->i_blkno);
1845         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1846         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1847
1848         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1849                                         inode_alloc_bh, bit, bg_blkno, 1);
1850 }
1851
1852 int ocfs2_free_clusters(handle_t *handle,
1853                        struct inode *bitmap_inode,
1854                        struct buffer_head *bitmap_bh,
1855                        u64 start_blk,
1856                        unsigned int num_clusters)
1857 {
1858         int status;
1859         u16 bg_start_bit;
1860         u64 bg_blkno;
1861         struct ocfs2_dinode *fe;
1862
1863         /* You can't ever have a contiguous set of clusters
1864          * bigger than a block group bitmap so we never have to worry
1865          * about looping on them. */
1866
1867         mlog_entry_void();
1868
1869         /* This is expensive. We can safely remove once this stuff has
1870          * gotten tested really well. */
1871         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1872
1873         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1874
1875         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1876                                      &bg_start_bit);
1877
1878         mlog(0, "want to free %u clusters starting at block %llu\n",
1879              num_clusters, (unsigned long long)start_blk);
1880         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1881              (unsigned long long)bg_blkno, bg_start_bit);
1882
1883         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1884                                           bg_start_bit, bg_blkno,
1885                                           num_clusters);
1886         if (status < 0) {
1887                 mlog_errno(status);
1888                 goto out;
1889         }
1890
1891         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
1892                                          num_clusters);
1893
1894 out:
1895         mlog_exit(status);
1896         return status;
1897 }
1898
1899 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1900 {
1901         printk("Block Group:\n");
1902         printk("bg_signature:       %s\n", bg->bg_signature);
1903         printk("bg_size:            %u\n", bg->bg_size);
1904         printk("bg_bits:            %u\n", bg->bg_bits);
1905         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1906         printk("bg_chain:           %u\n", bg->bg_chain);
1907         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1908         printk("bg_next_group:      %llu\n",
1909                (unsigned long long)bg->bg_next_group);
1910         printk("bg_parent_dinode:   %llu\n",
1911                (unsigned long long)bg->bg_parent_dinode);
1912         printk("bg_blkno:           %llu\n",
1913                (unsigned long long)bg->bg_blkno);
1914 }
1915
1916 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
1917 {
1918         int i;
1919
1920         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
1921         printk("i_signature:                  %s\n", fe->i_signature);
1922         printk("i_size:                       %llu\n",
1923                (unsigned long long)fe->i_size);
1924         printk("i_clusters:                   %u\n", fe->i_clusters);
1925         printk("i_generation:                 %u\n",
1926                le32_to_cpu(fe->i_generation));
1927         printk("id1.bitmap1.i_used:           %u\n",
1928                le32_to_cpu(fe->id1.bitmap1.i_used));
1929         printk("id1.bitmap1.i_total:          %u\n",
1930                le32_to_cpu(fe->id1.bitmap1.i_total));
1931         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
1932         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
1933         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
1934         printk("id2.i_chain.cl_next_free_rec: %u\n",
1935                fe->id2.i_chain.cl_next_free_rec);
1936         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
1937                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
1938                        fe->id2.i_chain.cl_recs[i].c_free);
1939                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
1940                        fe->id2.i_chain.cl_recs[i].c_total);
1941                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
1942                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
1943         }
1944 }
1945
1946 /*
1947  * For a given allocation, determine which allocators will need to be
1948  * accessed, and lock them, reserving the appropriate number of bits.
1949  *
1950  * Sparse file systems call this from ocfs2_write_begin_nolock()
1951  * and ocfs2_allocate_unwritten_extents().
1952  *
1953  * File systems which don't support holes call this from
1954  * ocfs2_extend_allocation().
1955  */
1956 int ocfs2_lock_allocators(struct inode *inode,
1957                           struct ocfs2_extent_tree *et,
1958                           u32 clusters_to_add, u32 extents_to_split,
1959                           struct ocfs2_alloc_context **data_ac,
1960                           struct ocfs2_alloc_context **meta_ac)
1961 {
1962         int ret = 0, num_free_extents;
1963         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
1964         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1965
1966         *meta_ac = NULL;
1967         if (data_ac)
1968                 *data_ac = NULL;
1969
1970         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
1971
1972         num_free_extents = ocfs2_num_free_extents(osb, inode, et);
1973         if (num_free_extents < 0) {
1974                 ret = num_free_extents;
1975                 mlog_errno(ret);
1976                 goto out;
1977         }
1978
1979         /*
1980          * Sparse allocation file systems need to be more conservative
1981          * with reserving room for expansion - the actual allocation
1982          * happens while we've got a journal handle open so re-taking
1983          * a cluster lock (because we ran out of room for another
1984          * extent) will violate ordering rules.
1985          *
1986          * Most of the time we'll only be seeing this 1 cluster at a time
1987          * anyway.
1988          *
1989          * Always lock for any unwritten extents - we might want to
1990          * add blocks during a split.
1991          */
1992         if (!num_free_extents ||
1993             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
1994                 ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
1995                 if (ret < 0) {
1996                         if (ret != -ENOSPC)
1997                                 mlog_errno(ret);
1998                         goto out;
1999                 }
2000         }
2001
2002         if (clusters_to_add == 0)
2003                 goto out;
2004
2005         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2006         if (ret < 0) {
2007                 if (ret != -ENOSPC)
2008                         mlog_errno(ret);
2009                 goto out;
2010         }
2011
2012 out:
2013         if (ret) {
2014                 if (*meta_ac) {
2015                         ocfs2_free_alloc_context(*meta_ac);
2016                         *meta_ac = NULL;
2017                 }
2018
2019                 /*
2020                  * We cannot have an error and a non null *data_ac.
2021                  */
2022         }
2023
2024         return ret;
2025 }