git.oblomov.eu Git - 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         if (ac->ac_bh) {
 134                 brelse(ac->ac_bh);
 135                 ac->ac_bh = NULL;
 136         }
 137 }
 138
 139 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 140 {
 141         ocfs2_free_ac_resource(ac);
 142         kfree(ac);
 143 }
 144
 145 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 146 {
 147         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 148 }
 149
 150 /* somewhat more expensive than our other checks, so use sparingly. */
 151 int ocfs2_check_group_descriptor(struct super_block *sb,
 152                                  struct ocfs2_dinode *di,
 153                                  struct ocfs2_group_desc *gd)
 154 {
 155         unsigned int max_bits;
 156
 157         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 158                 OCFS2_RO_ON_INVALID_GROUP_DESC(sb, gd);
 159                 return -EIO;
 160         }
 161
 162         if (di->i_blkno != gd->bg_parent_dinode) {
 163                 ocfs2_error(sb, "Group descriptor # %llu has bad parent "
 164                             "pointer (%llu, expected %llu)",
 165                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 166                             (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 167                             (unsigned long long)le64_to_cpu(di->i_blkno));
 168                 return -EIO;
 169         }
 170
 171         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 172         if (le16_to_cpu(gd->bg_bits) > max_bits) {
 173                 ocfs2_error(sb, "Group descriptor # %llu has bit count of %u",
 174                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 175                             le16_to_cpu(gd->bg_bits));
 176                 return -EIO;
 177         }
 178
 179         if (le16_to_cpu(gd->bg_chain) >=
 180             le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) {
 181                 ocfs2_error(sb, "Group descriptor # %llu has bad chain %u",
 182                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 183                             le16_to_cpu(gd->bg_chain));
 184                 return -EIO;
 185         }
 186
 187         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 188                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 189                             "claims that %u are free",
 190                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 191                             le16_to_cpu(gd->bg_bits),
 192                             le16_to_cpu(gd->bg_free_bits_count));
 193                 return -EIO;
 194         }
 195
 196         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 197                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 198                             "max bitmap bits of %u",
 199                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 200                             le16_to_cpu(gd->bg_bits),
 201                             8 * le16_to_cpu(gd->bg_size));
 202                 return -EIO;
 203         }
 204
 205         return 0;
 206 }
 207
 208 static int ocfs2_block_group_fill(handle_t *handle,
 209                                   struct inode *alloc_inode,
 210                                   struct buffer_head *bg_bh,
 211                                   u64 group_blkno,
 212                                   u16 my_chain,
 213                                   struct ocfs2_chain_list *cl)
 214 {
 215         int status = 0;
 216         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 217         struct super_block * sb = alloc_inode->i_sb;
 218
 219         mlog_entry_void();
 220
 221         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 222                 ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
 223                             "b_blocknr (%llu)",
 224                             (unsigned long long)group_blkno,
 225                             (unsigned long long) bg_bh->b_blocknr);
 226                 status = -EIO;
 227                 goto bail;
 228         }
 229
 230         status = ocfs2_journal_access(handle,
 231                                       alloc_inode,
 232                                       bg_bh,
 233                                       OCFS2_JOURNAL_ACCESS_CREATE);
 234         if (status < 0) {
 235                 mlog_errno(status);
 236                 goto bail;
 237         }
 238
 239         memset(bg, 0, sb->s_blocksize);
 240         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 241         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 242         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
 243         bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 244         bg->bg_chain = cpu_to_le16(my_chain);
 245         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 246         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 247         bg->bg_blkno = cpu_to_le64(group_blkno);
 248         /* set the 1st bit in the bitmap to account for the descriptor block */
 249         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 250         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 251
 252         status = ocfs2_journal_dirty(handle, bg_bh);
 253         if (status < 0)
 254                 mlog_errno(status);
 255
 256         /* There is no need to zero out or otherwise initialize the
 257          * other blocks in a group - All valid FS metadata in a block
 258          * group stores the superblock fs_generation value at
 259          * allocation time. */
 260
 261 bail:
 262         mlog_exit(status);
 263         return status;
 264 }
 265
 266 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 267 {
 268         u16 curr, best;
 269
 270         best = curr = 0;
 271         while (curr < le16_to_cpu(cl->cl_count)) {
 272                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 273                     le32_to_cpu(cl->cl_recs[curr].c_total))
 274                         best = curr;
 275                 curr++;
 276         }
 277         return best;
 278 }
 279
 280 /*
 281  * We expect the block group allocator to already be locked.
 282  */
 283 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 284                                    struct inode *alloc_inode,
 285                                    struct buffer_head *bh,
 286                                    u64 max_block)
 287 {
 288         int status, credits;
 289         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 290         struct ocfs2_chain_list *cl;
 291         struct ocfs2_alloc_context *ac = NULL;
 292         handle_t *handle = NULL;
 293         u32 bit_off, num_bits;
 294         u16 alloc_rec;
 295         u64 bg_blkno;
 296         struct buffer_head *bg_bh = NULL;
 297         struct ocfs2_group_desc *bg;
 298
 299         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 300
 301         mlog_entry_void();
 302
 303         cl = &fe->id2.i_chain;
 304         status = ocfs2_reserve_clusters_with_limit(osb,
 305                                                    le16_to_cpu(cl->cl_cpg),
 306                                                    max_block, &ac);
 307         if (status < 0) {
 308                 if (status != -ENOSPC)
 309                         mlog_errno(status);
 310                 goto bail;
 311         }
 312
 313         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 314                                                  le16_to_cpu(cl->cl_cpg));
 315         handle = ocfs2_start_trans(osb, credits);
 316         if (IS_ERR(handle)) {
 317                 status = PTR_ERR(handle);
 318                 handle = NULL;
 319                 mlog_errno(status);
 320                 goto bail;
 321         }
 322
 323         status = ocfs2_claim_clusters(osb,
 324                                       handle,
 325                                       ac,
 326                                       le16_to_cpu(cl->cl_cpg),
 327                                       &bit_off,
 328                                       &num_bits);
 329         if (status < 0) {
 330                 if (status != -ENOSPC)
 331                         mlog_errno(status);
 332                 goto bail;
 333         }
 334
 335         alloc_rec = ocfs2_find_smallest_chain(cl);
 336
 337         /* setup the group */
 338         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 339         mlog(0, "new descriptor, record %u, at block %llu\n",
 340              alloc_rec, (unsigned long long)bg_blkno);
 341
 342         bg_bh = sb_getblk(osb->sb, bg_blkno);
 343         if (!bg_bh) {
 344                 status = -EIO;
 345                 mlog_errno(status);
 346                 goto bail;
 347         }
 348         ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);
 349
 350         status = ocfs2_block_group_fill(handle,
 351                                         alloc_inode,
 352                                         bg_bh,
 353                                         bg_blkno,
 354                                         alloc_rec,
 355                                         cl);
 356         if (status < 0) {
 357                 mlog_errno(status);
 358                 goto bail;
 359         }
 360
 361         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 362
 363         status = ocfs2_journal_access(handle, alloc_inode,
 364                                       bh, OCFS2_JOURNAL_ACCESS_WRITE);
 365         if (status < 0) {
 366                 mlog_errno(status);
 367                 goto bail;
 368         }
 369
 370         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 371                      le16_to_cpu(bg->bg_free_bits_count));
 372         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
 373         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
 374         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 375                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 376
 377         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 378                                         le16_to_cpu(bg->bg_free_bits_count));
 379         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 380         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 381
 382         status = ocfs2_journal_dirty(handle, bh);
 383         if (status < 0) {
 384                 mlog_errno(status);
 385                 goto bail;
 386         }
 387
 388         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 389         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 390         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 391                                              le32_to_cpu(fe->i_clusters)));
 392         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 393         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 394         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 395
 396         status = 0;
 397 bail:
 398         if (handle)
 399                 ocfs2_commit_trans(osb, handle);
 400
 401         if (ac)
 402                 ocfs2_free_alloc_context(ac);
 403
 404         if (bg_bh)
 405                 brelse(bg_bh);
 406
 407         mlog_exit(status);
 408         return status;
 409 }
 410
 411 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 412                                        struct ocfs2_alloc_context *ac,
 413                                        int type,
 414                                        u32 slot,
 415                                        int alloc_new_group)
 416 {
 417         int status;
 418         u32 bits_wanted = ac->ac_bits_wanted;
 419         struct inode *alloc_inode;
 420         struct buffer_head *bh = NULL;
 421         struct ocfs2_dinode *fe;
 422         u32 free_bits;
 423
 424         mlog_entry_void();
 425
 426         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 427         if (!alloc_inode) {
 428                 mlog_errno(-EINVAL);
 429                 return -EINVAL;
 430         }
 431
 432         mutex_lock(&alloc_inode->i_mutex);
 433
 434         status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 435         if (status < 0) {
 436                 mutex_unlock(&alloc_inode->i_mutex);
 437                 iput(alloc_inode);
 438
 439                 mlog_errno(status);
 440                 return status;
 441         }
 442
 443         ac->ac_inode = alloc_inode;
 444         ac->ac_alloc_slot = slot;
 445
 446         fe = (struct ocfs2_dinode *) bh->b_data;
 447         if (!OCFS2_IS_VALID_DINODE(fe)) {
 448                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 449                 status = -EIO;
 450                 goto bail;
 451         }
 452         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 453                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 454                             (unsigned long long)le64_to_cpu(fe->i_blkno));
 455                 status = -EIO;
 456                 goto bail;
 457         }
 458
 459         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 460                 le32_to_cpu(fe->id1.bitmap1.i_used);
 461
 462         if (bits_wanted > free_bits) {
 463                 /* cluster bitmap never grows */
 464                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 465                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
 466                              bits_wanted, free_bits);
 467                         status = -ENOSPC;
 468                         goto bail;
 469                 }
 470
 471                 if (alloc_new_group != ALLOC_NEW_GROUP) {
 472                         mlog(0, "Alloc File %u Full: wanted=%u, free_bits=%u, "
 473                              "and we don't alloc a new group for it.\n",
 474                              slot, bits_wanted, free_bits);
 475                         status = -ENOSPC;
 476                         goto bail;
 477                 }
 478
 479                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 480                                                  ac->ac_max_block);
 481                 if (status < 0) {
 482                         if (status != -ENOSPC)
 483                                 mlog_errno(status);
 484                         goto bail;
 485                 }
 486                 atomic_inc(&osb->alloc_stats.bg_extends);
 487
 488                 /* You should never ask for this much metadata */
 489                 BUG_ON(bits_wanted >
 490                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 491                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 492         }
 493
 494         get_bh(bh);
 495         ac->ac_bh = bh;
 496 bail:
 497         if (bh)
 498                 brelse(bh);
 499
 500         mlog_exit(status);
 501         return status;
 502 }
 503
 504 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 505                                       int blocks,
 506                                       struct ocfs2_alloc_context **ac)
 507 {
 508         int status;
 509         u32 slot;
 510
 511         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 512         if (!(*ac)) {
 513                 status = -ENOMEM;
 514                 mlog_errno(status);
 515                 goto bail;
 516         }
 517
 518         (*ac)->ac_bits_wanted = blocks;
 519         (*ac)->ac_which = OCFS2_AC_USE_META;
 520         slot = osb->slot_num;
 521         (*ac)->ac_group_search = ocfs2_block_group_search;
 522
 523         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 524                                              EXTENT_ALLOC_SYSTEM_INODE,
 525                                              slot, ALLOC_NEW_GROUP);
 526         if (status < 0) {
 527                 if (status != -ENOSPC)
 528                         mlog_errno(status);
 529                 goto bail;
 530         }
 531
 532         status = 0;
 533 bail:
 534         if ((status < 0) && *ac) {
 535                 ocfs2_free_alloc_context(*ac);
 536                 *ac = NULL;
 537         }
 538
 539         mlog_exit(status);
 540         return status;
 541 }
 542
 543 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
 544                                struct ocfs2_extent_list *root_el,
 545                                struct ocfs2_alloc_context **ac)
 546 {
 547         return ocfs2_reserve_new_metadata_blocks(osb,
 548                                         ocfs2_extend_meta_needed(root_el),
 549                                         ac);
 550 }
 551
 552 static int ocfs2_steal_inode_from_other_nodes(struct ocfs2_super *osb,
 553                                               struct ocfs2_alloc_context *ac)
 554 {
 555         int i, status = -ENOSPC;
 556         s16 slot = ocfs2_get_inode_steal_slot(osb);
 557
 558         /* Start to steal inodes from the first slot after ours. */
 559         if (slot == OCFS2_INVALID_SLOT)
 560                 slot = osb->slot_num + 1;
 561
 562         for (i = 0; i < osb->max_slots; i++, slot++) {
 563                 if (slot == osb->max_slots)
 564                         slot = 0;
 565
 566                 if (slot == osb->slot_num)
 567                         continue;
 568
 569                 status = ocfs2_reserve_suballoc_bits(osb, ac,
 570                                                      INODE_ALLOC_SYSTEM_INODE,
 571                                                      slot, NOT_ALLOC_NEW_GROUP);
 572                 if (status >= 0) {
 573                         ocfs2_set_inode_steal_slot(osb, slot);
 574                         break;
 575                 }
 576
 577                 ocfs2_free_ac_resource(ac);
 578         }
 579
 580         return status;
 581 }
 582
 583 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 584                             struct ocfs2_alloc_context **ac)
 585 {
 586         int status;
 587         s16 slot = ocfs2_get_inode_steal_slot(osb);
 588
 589         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 590         if (!(*ac)) {
 591                 status = -ENOMEM;
 592                 mlog_errno(status);
 593                 goto bail;
 594         }
 595
 596         (*ac)->ac_bits_wanted = 1;
 597         (*ac)->ac_which = OCFS2_AC_USE_INODE;
 598
 599         (*ac)->ac_group_search = ocfs2_block_group_search;
 600
 601         /*
 602          * stat(2) can't handle i_ino > 32bits, so we tell the
 603          * lower levels not to allocate us a block group past that
 604          * limit.  The 'inode64' mount option avoids this behavior.
 605          */
 606         if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
 607                 (*ac)->ac_max_block = (u32)~0U;
 608
 609         /*
 610          * slot is set when we successfully steal inode from other nodes.
 611          * It is reset in 3 places:
 612          * 1. when we flush the truncate log
 613          * 2. when we complete local alloc recovery.
 614          * 3. when we successfully allocate from our own slot.
 615          * After it is set, we will go on stealing inodes until we find the
 616          * need to check our slots to see whether there is some space for us.
 617          */
 618         if (slot != OCFS2_INVALID_SLOT &&
 619             atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_INODES_TO_STEAL)
 620                 goto inode_steal;
 621
 622         atomic_set(&osb->s_num_inodes_stolen, 0);
 623         status = ocfs2_reserve_suballoc_bits(osb, *ac,
 624                                              INODE_ALLOC_SYSTEM_INODE,
 625                                              osb->slot_num, ALLOC_NEW_GROUP);
 626         if (status >= 0) {
 627                 status = 0;
 628
 629                 /*
 630                  * Some inodes must be freed by us, so try to allocate
 631                  * from our own next time.
 632                  */
 633                 if (slot != OCFS2_INVALID_SLOT)
 634                         ocfs2_init_inode_steal_slot(osb);
 635                 goto bail;
 636         } else if (status < 0 && status != -ENOSPC) {
 637                 mlog_errno(status);
 638                 goto bail;
 639         }
 640
 641         ocfs2_free_ac_resource(*ac);
 642
 643 inode_steal:
 644         status = ocfs2_steal_inode_from_other_nodes(osb, *ac);
 645         atomic_inc(&osb->s_num_inodes_stolen);
 646         if (status < 0) {
 647                 if (status != -ENOSPC)
 648                         mlog_errno(status);
 649                 goto bail;
 650         }
 651
 652         status = 0;
 653 bail:
 654         if ((status < 0) && *ac) {
 655                 ocfs2_free_alloc_context(*ac);
 656                 *ac = NULL;
 657         }
 658
 659         mlog_exit(status);
 660         return status;
 661 }
 662
 663 /* local alloc code has to do the same thing, so rather than do this
 664  * twice.. */
 665 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
 666                                       struct ocfs2_alloc_context *ac)
 667 {
 668         int status;
 669
 670         ac->ac_which = OCFS2_AC_USE_MAIN;
 671         ac->ac_group_search = ocfs2_cluster_group_search;
 672
 673         status = ocfs2_reserve_suballoc_bits(osb, ac,
 674                                              GLOBAL_BITMAP_SYSTEM_INODE,
 675                                              OCFS2_INVALID_SLOT,
 676                                              ALLOC_NEW_GROUP);
 677         if (status < 0 && status != -ENOSPC) {
 678                 mlog_errno(status);
 679                 goto bail;
 680         }
 681
 682 bail:
 683         return status;
 684 }
 685
 686 /* Callers don't need to care which bitmap (local alloc or main) to
 687  * use so we figure it out for them, but unfortunately this clutters
 688  * things a bit. */
 689 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 690                                              u32 bits_wanted, u64 max_block,
 691                                              struct ocfs2_alloc_context **ac)
 692 {
 693         int status;
 694
 695         mlog_entry_void();
 696
 697         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 698         if (!(*ac)) {
 699                 status = -ENOMEM;
 700                 mlog_errno(status);
 701                 goto bail;
 702         }
 703
 704         (*ac)->ac_bits_wanted = bits_wanted;
 705         (*ac)->ac_max_block = max_block;
 706
 707         status = -ENOSPC;
 708         if (ocfs2_alloc_should_use_local(osb, bits_wanted)) {
 709                 status = ocfs2_reserve_local_alloc_bits(osb,
 710                                                         bits_wanted,
 711                                                         *ac);
 712                 if (status == -EFBIG) {
 713                         /* The local alloc window is outside ac_max_block.
 714                          * use the main bitmap. */
 715                         status = -ENOSPC;
 716                 } else if ((status < 0) && (status != -ENOSPC)) {
 717                         mlog_errno(status);
 718                         goto bail;
 719                 }
 720         }
 721
 722         if (status == -ENOSPC) {
 723                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 724                 if (status < 0) {
 725                         if (status != -ENOSPC)
 726                                 mlog_errno(status);
 727                         goto bail;
 728                 }
 729         }
 730
 731         status = 0;
 732 bail:
 733         if ((status < 0) && *ac) {
 734                 ocfs2_free_alloc_context(*ac);
 735                 *ac = NULL;
 736         }
 737
 738         mlog_exit(status);
 739         return status;
 740 }
 741
 742 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
 743                            u32 bits_wanted,
 744                            struct ocfs2_alloc_context **ac)
 745 {
 746         return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0, ac);
 747 }
 748
 749 /*
 750  * More or less lifted from ext3. I'll leave their description below:
 751  *
 752  * "For ext3 allocations, we must not reuse any blocks which are
 753  * allocated in the bitmap buffer's "last committed data" copy.  This
 754  * prevents deletes from freeing up the page for reuse until we have
 755  * committed the delete transaction.
 756  *
 757  * If we didn't do this, then deleting something and reallocating it as
 758  * data would allow the old block to be overwritten before the
 759  * transaction committed (because we force data to disk before commit).
 760  * This would lead to corruption if we crashed between overwriting the
 761  * data and committing the delete.
 762  *
 763  * @@@ We may want to make this allocation behaviour conditional on
 764  * data-writes at some point, and disable it for metadata allocations or
 765  * sync-data inodes."
 766  *
 767  * Note: OCFS2 already does this differently for metadata vs data
 768  * allocations, as those bitmaps are separate and undo access is never
 769  * called on a metadata group descriptor.
 770  */
 771 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 772                                          int nr)
 773 {
 774         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 775
 776         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
 777                 return 0;
 778         if (!buffer_jbd(bg_bh) || !bh2jh(bg_bh)->b_committed_data)
 779                 return 1;
 780
 781         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
 782         return !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
 783 }
 784
 785 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
 786                                              struct buffer_head *bg_bh,
 787                                              unsigned int bits_wanted,
 788                                              unsigned int total_bits,
 789                                              u16 *bit_off,
 790                                              u16 *bits_found)
 791 {
 792         void *bitmap;
 793         u16 best_offset, best_size;
 794         int offset, start, found, status = 0;
 795         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 796
 797         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 798                 OCFS2_RO_ON_INVALID_GROUP_DESC(osb->sb, bg);
 799                 return -EIO;
 800         }
 801
 802         found = start = best_offset = best_size = 0;
 803         bitmap = bg->bg_bitmap;
 804
 805         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
 806                 if (offset == total_bits)
 807                         break;
 808
 809                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
 810                         /* We found a zero, but we can't use it as it
 811                          * hasn't been put to disk yet! */
 812                         found = 0;
 813                         start = offset + 1;
 814                 } else if (offset == start) {
 815                         /* we found a zero */
 816                         found++;
 817                         /* move start to the next bit to test */
 818                         start++;
 819                 } else {
 820                         /* got a zero after some ones */
 821                         found = 1;
 822                         start = offset + 1;
 823                 }
 824                 if (found > best_size) {
 825                         best_size = found;
 826                         best_offset = start - found;
 827                 }
 828                 /* we got everything we needed */
 829                 if (found == bits_wanted) {
 830                         /* mlog(0, "Found it all!\n"); */
 831                         break;
 832                 }
 833         }
 834
 835         /* XXX: I think the first clause is equivalent to the second
 836          *      - jlbec */
 837         if (found == bits_wanted) {
 838                 *bit_off = start - found;
 839                 *bits_found = found;
 840         } else if (best_size) {
 841                 *bit_off = best_offset;
 842                 *bits_found = best_size;
 843         } else {
 844                 status = -ENOSPC;
 845                 /* No error log here -- see the comment above
 846                  * ocfs2_test_bg_bit_allocatable */
 847         }
 848
 849         return status;
 850 }
 851
 852 static inline int ocfs2_block_group_set_bits(handle_t *handle,
 853                                              struct inode *alloc_inode,
 854                                              struct ocfs2_group_desc *bg,
 855                                              struct buffer_head *group_bh,
 856                                              unsigned int bit_off,
 857                                              unsigned int num_bits)
 858 {
 859         int status;
 860         void *bitmap = bg->bg_bitmap;
 861         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
 862
 863         mlog_entry_void();
 864
 865         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 866                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 867                 status = -EIO;
 868                 goto bail;
 869         }
 870         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
 871
 872         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
 873              num_bits);
 874
 875         if (ocfs2_is_cluster_bitmap(alloc_inode))
 876                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
 877
 878         status = ocfs2_journal_access(handle,
 879                                       alloc_inode,
 880                                       group_bh,
 881                                       journal_type);
 882         if (status < 0) {
 883                 mlog_errno(status);
 884                 goto bail;
 885         }
 886
 887         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
 888
 889         while(num_bits--)
 890                 ocfs2_set_bit(bit_off++, bitmap);
 891
 892         status = ocfs2_journal_dirty(handle,
 893                                      group_bh);
 894         if (status < 0) {
 895                 mlog_errno(status);
 896                 goto bail;
 897         }
 898
 899 bail:
 900         mlog_exit(status);
 901         return status;
 902 }
 903
 904 /* find the one with the most empty bits */
 905 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
 906 {
 907         u16 curr, best;
 908
 909         BUG_ON(!cl->cl_next_free_rec);
 910
 911         best = curr = 0;
 912         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
 913                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
 914                     le32_to_cpu(cl->cl_recs[best].c_free))
 915                         best = curr;
 916                 curr++;
 917         }
 918
 919         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
 920         return best;
 921 }
 922
 923 static int ocfs2_relink_block_group(handle_t *handle,
 924                                     struct inode *alloc_inode,
 925                                     struct buffer_head *fe_bh,
 926                                     struct buffer_head *bg_bh,
 927                                     struct buffer_head *prev_bg_bh,
 928                                     u16 chain)
 929 {
 930         int status;
 931         /* there is a really tiny chance the journal calls could fail,
 932          * but we wouldn't want inconsistent blocks in *any* case. */
 933         u64 fe_ptr, bg_ptr, prev_bg_ptr;
 934         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
 935         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 936         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
 937
 938         if (!OCFS2_IS_VALID_DINODE(fe)) {
 939                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 940                 status = -EIO;
 941                 goto out;
 942         }
 943         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 944                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 945                 status = -EIO;
 946                 goto out;
 947         }
 948         if (!OCFS2_IS_VALID_GROUP_DESC(prev_bg)) {
 949                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, prev_bg);
 950                 status = -EIO;
 951                 goto out;
 952         }
 953
 954         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
 955              (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
 956              (unsigned long long)le64_to_cpu(bg->bg_blkno),
 957              (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
 958
 959         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
 960         bg_ptr = le64_to_cpu(bg->bg_next_group);
 961         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
 962
 963         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
 964                                       OCFS2_JOURNAL_ACCESS_WRITE);
 965         if (status < 0) {
 966                 mlog_errno(status);
 967                 goto out_rollback;
 968         }
 969
 970         prev_bg->bg_next_group = bg->bg_next_group;
 971
 972         status = ocfs2_journal_dirty(handle, prev_bg_bh);
 973         if (status < 0) {
 974                 mlog_errno(status);
 975                 goto out_rollback;
 976         }
 977
 978         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
 979                                       OCFS2_JOURNAL_ACCESS_WRITE);
 980         if (status < 0) {
 981                 mlog_errno(status);
 982                 goto out_rollback;
 983         }
 984
 985         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
 986
 987         status = ocfs2_journal_dirty(handle, bg_bh);
 988         if (status < 0) {
 989                 mlog_errno(status);
 990                 goto out_rollback;
 991         }
 992
 993         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
 994                                       OCFS2_JOURNAL_ACCESS_WRITE);
 995         if (status < 0) {
 996                 mlog_errno(status);
 997                 goto out_rollback;
 998         }
 999
1000         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1001
1002         status = ocfs2_journal_dirty(handle, fe_bh);
1003         if (status < 0) {
1004                 mlog_errno(status);
1005                 goto out_rollback;
1006         }
1007
1008         status = 0;
1009 out_rollback:
1010         if (status < 0) {
1011                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
1012                 bg->bg_next_group = cpu_to_le64(bg_ptr);
1013                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1014         }
1015 out:
1016         mlog_exit(status);
1017         return status;
1018 }
1019
1020 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1021                                                      u32 wanted)
1022 {
1023         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1024 }
1025
1026 /* return 0 on success, -ENOSPC to keep searching and any other < 0
1027  * value on error. */
1028 static int ocfs2_cluster_group_search(struct inode *inode,
1029                                       struct buffer_head *group_bh,
1030                                       u32 bits_wanted, u32 min_bits,
1031                                       u64 max_block,
1032                                       u16 *bit_off, u16 *bits_found)
1033 {
1034         int search = -ENOSPC;
1035         int ret;
1036         u64 blkoff;
1037         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1038         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1039         u16 tmp_off, tmp_found;
1040         unsigned int max_bits, gd_cluster_off;
1041
1042         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1043
1044         if (gd->bg_free_bits_count) {
1045                 max_bits = le16_to_cpu(gd->bg_bits);
1046
1047                 /* Tail groups in cluster bitmaps which aren't cpg
1048                  * aligned are prone to partial extention by a failed
1049                  * fs resize. If the file system resize never got to
1050                  * update the dinode cluster count, then we don't want
1051                  * to trust any clusters past it, regardless of what
1052                  * the group descriptor says. */
1053                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1054                                                           le64_to_cpu(gd->bg_blkno));
1055                 if ((gd_cluster_off + max_bits) >
1056                     OCFS2_I(inode)->ip_clusters) {
1057                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1058                         mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
1059                              (unsigned long long)le64_to_cpu(gd->bg_blkno),
1060                              le16_to_cpu(gd->bg_bits),
1061                              OCFS2_I(inode)->ip_clusters, max_bits);
1062                 }
1063
1064                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1065                                                         group_bh, bits_wanted,
1066                                                         max_bits,
1067                                                         &tmp_off, &tmp_found);
1068                 if (ret)
1069                         return ret;
1070
1071                 if (max_block) {
1072                         blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1073                                                           gd_cluster_off +
1074                                                           tmp_off + tmp_found);
1075                         mlog(0, "Checking %llu against %llu\n",
1076                              (unsigned long long)blkoff,
1077                              (unsigned long long)max_block);
1078                         if (blkoff > max_block)
1079                                 return -ENOSPC;
1080                 }
1081
1082                 /* ocfs2_block_group_find_clear_bits() might
1083                  * return success, but we still want to return
1084                  * -ENOSPC unless it found the minimum number
1085                  * of bits. */
1086                 if (min_bits <= tmp_found) {
1087                         *bit_off = tmp_off;
1088                         *bits_found = tmp_found;
1089                         search = 0; /* success */
1090                 } else if (tmp_found) {
1091                         /*
1092                          * Don't show bits which we'll be returning
1093                          * for allocation to the local alloc bitmap.
1094                          */
1095                         ocfs2_local_alloc_seen_free_bits(osb, tmp_found);
1096                 }
1097         }
1098
1099         return search;
1100 }
1101
1102 static int ocfs2_block_group_search(struct inode *inode,
1103                                     struct buffer_head *group_bh,
1104                                     u32 bits_wanted, u32 min_bits,
1105                                     u64 max_block,
1106                                     u16 *bit_off, u16 *bits_found)
1107 {
1108         int ret = -ENOSPC;
1109         u64 blkoff;
1110         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1111
1112         BUG_ON(min_bits != 1);
1113         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1114
1115         if (bg->bg_free_bits_count) {
1116                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1117                                                         group_bh, bits_wanted,
1118                                                         le16_to_cpu(bg->bg_bits),
1119                                                         bit_off, bits_found);
1120                 if (!ret && max_block) {
1121                         blkoff = le64_to_cpu(bg->bg_blkno) + *bit_off +
1122                                 *bits_found;
1123                         mlog(0, "Checking %llu against %llu\n",
1124                              (unsigned long long)blkoff,
1125                              (unsigned long long)max_block);
1126                         if (blkoff > max_block)
1127                                 ret = -ENOSPC;
1128                 }
1129         }
1130
1131         return ret;
1132 }
1133
1134 static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1135                                        handle_t *handle,
1136                                        struct buffer_head *di_bh,
1137                                        u32 num_bits,
1138                                        u16 chain)
1139 {
1140         int ret;
1141         u32 tmp_used;
1142         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1143         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1144
1145         ret = ocfs2_journal_access(handle, inode, di_bh,
1146                                    OCFS2_JOURNAL_ACCESS_WRITE);
1147         if (ret < 0) {
1148                 mlog_errno(ret);
1149                 goto out;
1150         }
1151
1152         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1153         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1154         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1155
1156         ret = ocfs2_journal_dirty(handle, di_bh);
1157         if (ret < 0)
1158                 mlog_errno(ret);
1159
1160 out:
1161         return ret;
1162 }
1163
1164 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1165                                   handle_t *handle,
1166                                   u32 bits_wanted,
1167                                   u32 min_bits,
1168                                   u16 *bit_off,
1169                                   unsigned int *num_bits,
1170                                   u64 gd_blkno,
1171                                   u16 *bits_left)
1172 {
1173         int ret;
1174         u16 found;
1175         struct buffer_head *group_bh = NULL;
1176         struct ocfs2_group_desc *gd;
1177         struct inode *alloc_inode = ac->ac_inode;
1178
1179         ret = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb), gd_blkno,
1180                                &group_bh, OCFS2_BH_CACHED, alloc_inode);
1181         if (ret < 0) {
1182                 mlog_errno(ret);
1183                 return ret;
1184         }
1185
1186         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1187         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
1188                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, gd);
1189                 ret = -EIO;
1190                 goto out;
1191         }
1192
1193         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1194                                   ac->ac_max_block, bit_off, &found);
1195         if (ret < 0) {
1196                 if (ret != -ENOSPC)
1197                         mlog_errno(ret);
1198                 goto out;
1199         }
1200
1201         *num_bits = found;
1202
1203         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1204                                                *num_bits,
1205                                                le16_to_cpu(gd->bg_chain));
1206         if (ret < 0) {
1207                 mlog_errno(ret);
1208                 goto out;
1209         }
1210
1211         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1212                                          *bit_off, *num_bits);
1213         if (ret < 0)
1214                 mlog_errno(ret);
1215
1216         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1217
1218 out:
1219         brelse(group_bh);
1220
1221         return ret;
1222 }
1223
1224 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1225                               handle_t *handle,
1226                               u32 bits_wanted,
1227                               u32 min_bits,
1228                               u16 *bit_off,
1229                               unsigned int *num_bits,
1230                               u64 *bg_blkno,
1231                               u16 *bits_left)
1232 {
1233         int status;
1234         u16 chain, tmp_bits;
1235         u32 tmp_used;
1236         u64 next_group;
1237         struct inode *alloc_inode = ac->ac_inode;
1238         struct buffer_head *group_bh = NULL;
1239         struct buffer_head *prev_group_bh = NULL;
1240         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1241         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1242         struct ocfs2_group_desc *bg;
1243
1244         chain = ac->ac_chain;
1245         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
1246              bits_wanted, chain,
1247              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
1248
1249         status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1250                                   le64_to_cpu(cl->cl_recs[chain].c_blkno),
1251                                   &group_bh, OCFS2_BH_CACHED, alloc_inode);
1252         if (status < 0) {
1253                 mlog_errno(status);
1254                 goto bail;
1255         }
1256         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1257         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1258         if (status) {
1259                 mlog_errno(status);
1260                 goto bail;
1261         }
1262
1263         status = -ENOSPC;
1264         /* for now, the chain search is a bit simplistic. We just use
1265          * the 1st group with any empty bits. */
1266         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1267                                              bits_wanted, min_bits,
1268                                              ac->ac_max_block, bit_off,
1269                                              &tmp_bits)) == -ENOSPC) {
1270                 if (!bg->bg_next_group)
1271                         break;
1272                 if (prev_group_bh) {
1273                         brelse(prev_group_bh);
1274                         prev_group_bh = NULL;
1275                 }
1276                 next_group = le64_to_cpu(bg->bg_next_group);
1277                 prev_group_bh = group_bh;
1278                 group_bh = NULL;
1279                 status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1280                                           next_group, &group_bh,
1281                                           OCFS2_BH_CACHED, alloc_inode);
1282                 if (status < 0) {
1283                         mlog_errno(status);
1284                         goto bail;
1285                 }
1286                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1287                 status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1288                 if (status) {
1289                         mlog_errno(status);
1290                         goto bail;
1291                 }
1292         }
1293         if (status < 0) {
1294                 if (status != -ENOSPC)
1295                         mlog_errno(status);
1296                 goto bail;
1297         }
1298
1299         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1300              tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
1301
1302         *num_bits = tmp_bits;
1303
1304         BUG_ON(*num_bits == 0);
1305
1306         /*
1307          * Keep track of previous block descriptor read. When
1308          * we find a target, if we have read more than X
1309          * number of descriptors, and the target is reasonably
1310          * empty, relink him to top of his chain.
1311          *
1312          * We've read 0 extra blocks and only send one more to
1313          * the transaction, yet the next guy to search has a
1314          * much easier time.
1315          *
1316          * Do this *after* figuring out how many bits we're taking out
1317          * of our target group.
1318          */
1319         if (ac->ac_allow_chain_relink &&
1320             (prev_group_bh) &&
1321             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1322                 status = ocfs2_relink_block_group(handle, alloc_inode,
1323                                                   ac->ac_bh, group_bh,
1324                                                   prev_group_bh, chain);
1325                 if (status < 0) {
1326                         mlog_errno(status);
1327                         goto bail;
1328                 }
1329         }
1330
1331         /* Ok, claim our bits now: set the info on dinode, chainlist
1332          * and then the group */
1333         status = ocfs2_journal_access(handle,
1334                                       alloc_inode,
1335                                       ac->ac_bh,
1336                                       OCFS2_JOURNAL_ACCESS_WRITE);
1337         if (status < 0) {
1338                 mlog_errno(status);
1339                 goto bail;
1340         }
1341
1342         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1343         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1344         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1345
1346         status = ocfs2_journal_dirty(handle,
1347                                      ac->ac_bh);
1348         if (status < 0) {
1349                 mlog_errno(status);
1350                 goto bail;
1351         }
1352
1353         status = ocfs2_block_group_set_bits(handle,
1354                                             alloc_inode,
1355                                             bg,
1356                                             group_bh,
1357                                             *bit_off,
1358                                             *num_bits);
1359         if (status < 0) {
1360                 mlog_errno(status);
1361                 goto bail;
1362         }
1363
1364         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1365              (unsigned long long)le64_to_cpu(fe->i_blkno));
1366
1367         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1368         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1369 bail:
1370         if (group_bh)
1371                 brelse(group_bh);
1372         if (prev_group_bh)
1373                 brelse(prev_group_bh);
1374
1375         mlog_exit(status);
1376         return status;
1377 }
1378
1379 /* will give out up to bits_wanted contiguous bits. */
1380 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1381                                      struct ocfs2_alloc_context *ac,
1382                                      handle_t *handle,
1383                                      u32 bits_wanted,
1384                                      u32 min_bits,
1385                                      u16 *bit_off,
1386                                      unsigned int *num_bits,
1387                                      u64 *bg_blkno)
1388 {
1389         int status;
1390         u16 victim, i;
1391         u16 bits_left = 0;
1392         u64 hint_blkno = ac->ac_last_group;
1393         struct ocfs2_chain_list *cl;
1394         struct ocfs2_dinode *fe;
1395
1396         mlog_entry_void();
1397
1398         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1399         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1400         BUG_ON(!ac->ac_bh);
1401
1402         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1403         if (!OCFS2_IS_VALID_DINODE(fe)) {
1404                 OCFS2_RO_ON_INVALID_DINODE(osb->sb, fe);
1405                 status = -EIO;
1406                 goto bail;
1407         }
1408         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1409             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1410                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1411                             "bits but only %u total.",
1412                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1413                             le32_to_cpu(fe->id1.bitmap1.i_used),
1414                             le32_to_cpu(fe->id1.bitmap1.i_total));
1415                 status = -EIO;
1416                 goto bail;
1417         }
1418
1419         if (hint_blkno) {
1420                 /* Attempt to short-circuit the usual search mechanism
1421                  * by jumping straight to the most recently used
1422                  * allocation group. This helps us mantain some
1423                  * contiguousness across allocations. */
1424                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1425                                                 min_bits, bit_off, num_bits,
1426                                                 hint_blkno, &bits_left);
1427                 if (!status) {
1428                         /* Be careful to update *bg_blkno here as the
1429                          * caller is expecting it to be filled in, and
1430                          * ocfs2_search_one_group() won't do that for
1431                          * us. */
1432                         *bg_blkno = hint_blkno;
1433                         goto set_hint;
1434                 }
1435                 if (status < 0 && status != -ENOSPC) {
1436                         mlog_errno(status);
1437                         goto bail;
1438                 }
1439         }
1440
1441         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1442
1443         victim = ocfs2_find_victim_chain(cl);
1444         ac->ac_chain = victim;
1445         ac->ac_allow_chain_relink = 1;
1446
1447         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, bit_off,
1448                                     num_bits, bg_blkno, &bits_left);
1449         if (!status)
1450                 goto set_hint;
1451         if (status < 0 && status != -ENOSPC) {
1452                 mlog_errno(status);
1453                 goto bail;
1454         }
1455
1456         mlog(0, "Search of victim chain %u came up with nothing, "
1457              "trying all chains now.\n", victim);
1458
1459         /* If we didn't pick a good victim, then just default to
1460          * searching each chain in order. Don't allow chain relinking
1461          * because we only calculate enough journal credits for one
1462          * relink per alloc. */
1463         ac->ac_allow_chain_relink = 0;
1464         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1465                 if (i == victim)
1466                         continue;
1467                 if (!cl->cl_recs[i].c_free)
1468                         continue;
1469
1470                 ac->ac_chain = i;
1471                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1472                                             bit_off, num_bits, bg_blkno,
1473                                             &bits_left);
1474                 if (!status)
1475                         break;
1476                 if (status < 0 && status != -ENOSPC) {
1477                         mlog_errno(status);
1478                         goto bail;
1479                 }
1480         }
1481
1482 set_hint:
1483         if (status != -ENOSPC) {
1484                 /* If the next search of this group is not likely to
1485                  * yield a suitable extent, then we reset the last
1486                  * group hint so as to not waste a disk read */
1487                 if (bits_left < min_bits)
1488                         ac->ac_last_group = 0;
1489                 else
1490                         ac->ac_last_group = *bg_blkno;
1491         }
1492
1493 bail:
1494         mlog_exit(status);
1495         return status;
1496 }
1497
1498 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1499                          handle_t *handle,
1500                          struct ocfs2_alloc_context *ac,
1501                          u32 bits_wanted,
1502                          u16 *suballoc_bit_start,
1503                          unsigned int *num_bits,
1504                          u64 *blkno_start)
1505 {
1506         int status;
1507         u64 bg_blkno;
1508
1509         BUG_ON(!ac);
1510         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1511         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1512
1513         status = ocfs2_claim_suballoc_bits(osb,
1514                                            ac,
1515                                            handle,
1516                                            bits_wanted,
1517                                            1,
1518                                            suballoc_bit_start,
1519                                            num_bits,
1520                                            &bg_blkno);
1521         if (status < 0) {
1522                 mlog_errno(status);
1523                 goto bail;
1524         }
1525         atomic_inc(&osb->alloc_stats.bg_allocs);
1526
1527         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1528         ac->ac_bits_given += (*num_bits);
1529         status = 0;
1530 bail:
1531         mlog_exit(status);
1532         return status;
1533 }
1534
1535 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1536                           handle_t *handle,
1537                           struct ocfs2_alloc_context *ac,
1538                           u16 *suballoc_bit,
1539                           u64 *fe_blkno)
1540 {
1541         int status;
1542         unsigned int num_bits;
1543         u64 bg_blkno;
1544
1545         mlog_entry_void();
1546
1547         BUG_ON(!ac);
1548         BUG_ON(ac->ac_bits_given != 0);
1549         BUG_ON(ac->ac_bits_wanted != 1);
1550         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1551
1552         status = ocfs2_claim_suballoc_bits(osb,
1553                                            ac,
1554                                            handle,
1555                                            1,
1556                                            1,
1557                                            suballoc_bit,
1558                                            &num_bits,
1559                                            &bg_blkno);
1560         if (status < 0) {
1561                 mlog_errno(status);
1562                 goto bail;
1563         }
1564         atomic_inc(&osb->alloc_stats.bg_allocs);
1565
1566         BUG_ON(num_bits != 1);
1567
1568         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1569         ac->ac_bits_given++;
1570         status = 0;
1571 bail:
1572         mlog_exit(status);
1573         return status;
1574 }
1575
1576 /* translate a group desc. blkno and it's bitmap offset into
1577  * disk cluster offset. */
1578 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1579                                                    u64 bg_blkno,
1580                                                    u16 bg_bit_off)
1581 {
1582         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1583         u32 cluster = 0;
1584
1585         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1586
1587         if (bg_blkno != osb->first_cluster_group_blkno)
1588                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1589         cluster += (u32) bg_bit_off;
1590         return cluster;
1591 }
1592
1593 /* given a cluster offset, calculate which block group it belongs to
1594  * and return that block offset. */
1595 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
1596 {
1597         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1598         u32 group_no;
1599
1600         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1601
1602         group_no = cluster / osb->bitmap_cpg;
1603         if (!group_no)
1604                 return osb->first_cluster_group_blkno;
1605         return ocfs2_clusters_to_blocks(inode->i_sb,
1606                                         group_no * osb->bitmap_cpg);
1607 }
1608
1609 /* given the block number of a cluster start, calculate which cluster
1610  * group and descriptor bitmap offset that corresponds to. */
1611 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1612                                                 u64 data_blkno,
1613                                                 u64 *bg_blkno,
1614                                                 u16 *bg_bit_off)
1615 {
1616         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1617         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1618
1619         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1620
1621         *bg_blkno = ocfs2_which_cluster_group(inode,
1622                                               data_cluster);
1623
1624         if (*bg_blkno == osb->first_cluster_group_blkno)
1625                 *bg_bit_off = (u16) data_cluster;
1626         else
1627                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1628                                                              data_blkno - *bg_blkno);
1629 }
1630
1631 /*
1632  * min_bits - minimum contiguous chunk from this total allocation we
1633  * can handle. set to what we asked for originally for a full
1634  * contig. allocation, set to '1' to indicate we can deal with extents
1635  * of any size.
1636  */
1637 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
1638                            handle_t *handle,
1639                            struct ocfs2_alloc_context *ac,
1640                            u32 min_clusters,
1641                            u32 max_clusters,
1642                            u32 *cluster_start,
1643                            u32 *num_clusters)
1644 {
1645         int status;
1646         unsigned int bits_wanted = max_clusters;
1647         u64 bg_blkno = 0;
1648         u16 bg_bit_off;
1649
1650         mlog_entry_void();
1651
1652         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1653
1654         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1655                && ac->ac_which != OCFS2_AC_USE_MAIN);
1656
1657         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1658                 status = ocfs2_claim_local_alloc_bits(osb,
1659                                                       handle,
1660                                                       ac,
1661                                                       bits_wanted,
1662                                                       cluster_start,
1663                                                       num_clusters);
1664                 if (!status)
1665                         atomic_inc(&osb->alloc_stats.local_data);
1666         } else {
1667                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1668                         /* The only paths asking for contiguousness
1669                          * should know about this already. */
1670                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
1671                              "group bitmap size %u!\n", min_clusters,
1672                              osb->bitmap_cpg);
1673                         status = -ENOSPC;
1674                         goto bail;
1675                 }
1676                 /* clamp the current request down to a realistic size. */
1677                 if (bits_wanted > (osb->bitmap_cpg - 1))
1678                         bits_wanted = osb->bitmap_cpg - 1;
1679
1680                 status = ocfs2_claim_suballoc_bits(osb,
1681                                                    ac,
1682                                                    handle,
1683                                                    bits_wanted,
1684                                                    min_clusters,
1685                                                    &bg_bit_off,
1686                                                    num_clusters,
1687                                                    &bg_blkno);
1688                 if (!status) {
1689                         *cluster_start =
1690                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1691                                                                  bg_blkno,
1692                                                                  bg_bit_off);
1693                         atomic_inc(&osb->alloc_stats.bitmap_data);
1694                 }
1695         }
1696         if (status < 0) {
1697                 if (status != -ENOSPC)
1698                         mlog_errno(status);
1699                 goto bail;
1700         }
1701
1702         ac->ac_bits_given += *num_clusters;
1703
1704 bail:
1705         mlog_exit(status);
1706         return status;
1707 }
1708
1709 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1710                          handle_t *handle,
1711                          struct ocfs2_alloc_context *ac,
1712                          u32 min_clusters,
1713                          u32 *cluster_start,
1714                          u32 *num_clusters)
1715 {
1716         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1717
1718         return __ocfs2_claim_clusters(osb, handle, ac, min_clusters,
1719                                       bits_wanted, cluster_start, num_clusters);
1720 }
1721
1722 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
1723                                                struct inode *alloc_inode,
1724                                                struct ocfs2_group_desc *bg,
1725                                                struct buffer_head *group_bh,
1726                                                unsigned int bit_off,
1727                                                unsigned int num_bits)
1728 {
1729         int status;
1730         unsigned int tmp;
1731         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1732         struct ocfs2_group_desc *undo_bg = NULL;
1733
1734         mlog_entry_void();
1735
1736         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1737                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1738                 status = -EIO;
1739                 goto bail;
1740         }
1741
1742         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1743
1744         if (ocfs2_is_cluster_bitmap(alloc_inode))
1745                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1746
1747         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1748                                       journal_type);
1749         if (status < 0) {
1750                 mlog_errno(status);
1751                 goto bail;
1752         }
1753
1754         if (ocfs2_is_cluster_bitmap(alloc_inode))
1755                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1756
1757         tmp = num_bits;
1758         while(tmp--) {
1759                 ocfs2_clear_bit((bit_off + tmp),
1760                                 (unsigned long *) bg->bg_bitmap);
1761                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1762                         ocfs2_set_bit(bit_off + tmp,
1763                                       (unsigned long *) undo_bg->bg_bitmap);
1764         }
1765         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1766
1767         status = ocfs2_journal_dirty(handle, group_bh);
1768         if (status < 0)
1769                 mlog_errno(status);
1770 bail:
1771         return status;
1772 }
1773
1774 /*
1775  * expects the suballoc inode to already be locked.
1776  */
1777 int ocfs2_free_suballoc_bits(handle_t *handle,
1778                              struct inode *alloc_inode,
1779                              struct buffer_head *alloc_bh,
1780                              unsigned int start_bit,
1781                              u64 bg_blkno,
1782                              unsigned int count)
1783 {
1784         int status = 0;
1785         u32 tmp_used;
1786         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
1787         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1788         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1789         struct buffer_head *group_bh = NULL;
1790         struct ocfs2_group_desc *group;
1791
1792         mlog_entry_void();
1793
1794         if (!OCFS2_IS_VALID_DINODE(fe)) {
1795                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
1796                 status = -EIO;
1797                 goto bail;
1798         }
1799         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1800
1801         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1802              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1803              (unsigned long long)bg_blkno, start_bit);
1804
1805         status = ocfs2_read_block(osb, bg_blkno, &group_bh, OCFS2_BH_CACHED,
1806                                   alloc_inode);
1807         if (status < 0) {
1808                 mlog_errno(status);
1809                 goto bail;
1810         }
1811
1812         group = (struct ocfs2_group_desc *) group_bh->b_data;
1813         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, group);
1814         if (status) {
1815                 mlog_errno(status);
1816                 goto bail;
1817         }
1818         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1819
1820         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1821                                               group, group_bh,
1822                                               start_bit, count);
1823         if (status < 0) {
1824                 mlog_errno(status);
1825                 goto bail;
1826         }
1827
1828         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1829                                       OCFS2_JOURNAL_ACCESS_WRITE);
1830         if (status < 0) {
1831                 mlog_errno(status);
1832                 goto bail;
1833         }
1834
1835         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1836                      count);
1837         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1838         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1839
1840         status = ocfs2_journal_dirty(handle, alloc_bh);
1841         if (status < 0) {
1842                 mlog_errno(status);
1843                 goto bail;
1844         }
1845
1846 bail:
1847         if (group_bh)
1848                 brelse(group_bh);
1849
1850         mlog_exit(status);
1851         return status;
1852 }
1853
1854 int ocfs2_free_dinode(handle_t *handle,
1855                       struct inode *inode_alloc_inode,
1856                       struct buffer_head *inode_alloc_bh,
1857                       struct ocfs2_dinode *di)
1858 {
1859         u64 blk = le64_to_cpu(di->i_blkno);
1860         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1861         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1862
1863         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1864                                         inode_alloc_bh, bit, bg_blkno, 1);
1865 }
1866
1867 int ocfs2_free_clusters(handle_t *handle,
1868                        struct inode *bitmap_inode,
1869                        struct buffer_head *bitmap_bh,
1870                        u64 start_blk,
1871                        unsigned int num_clusters)
1872 {
1873         int status;
1874         u16 bg_start_bit;
1875         u64 bg_blkno;
1876         struct ocfs2_dinode *fe;
1877
1878         /* You can't ever have a contiguous set of clusters
1879          * bigger than a block group bitmap so we never have to worry
1880          * about looping on them. */
1881
1882         mlog_entry_void();
1883
1884         /* This is expensive. We can safely remove once this stuff has
1885          * gotten tested really well. */
1886         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1887
1888         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1889
1890         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1891                                      &bg_start_bit);
1892
1893         mlog(0, "want to free %u clusters starting at block %llu\n",
1894              num_clusters, (unsigned long long)start_blk);
1895         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1896              (unsigned long long)bg_blkno, bg_start_bit);
1897
1898         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1899                                           bg_start_bit, bg_blkno,
1900                                           num_clusters);
1901         if (status < 0) {
1902                 mlog_errno(status);
1903                 goto out;
1904         }
1905
1906         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
1907                                          num_clusters);
1908
1909 out:
1910         mlog_exit(status);
1911         return status;
1912 }
1913
1914 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1915 {
1916         printk("Block Group:\n");
1917         printk("bg_signature:       %s\n", bg->bg_signature);
1918         printk("bg_size:            %u\n", bg->bg_size);
1919         printk("bg_bits:            %u\n", bg->bg_bits);
1920         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1921         printk("bg_chain:           %u\n", bg->bg_chain);
1922         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1923         printk("bg_next_group:      %llu\n",
1924                (unsigned long long)bg->bg_next_group);
1925         printk("bg_parent_dinode:   %llu\n",
1926                (unsigned long long)bg->bg_parent_dinode);
1927         printk("bg_blkno:           %llu\n",
1928                (unsigned long long)bg->bg_blkno);
1929 }
1930
1931 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
1932 {
1933         int i;
1934
1935         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
1936         printk("i_signature:                  %s\n", fe->i_signature);
1937         printk("i_size:                       %llu\n",
1938                (unsigned long long)fe->i_size);
1939         printk("i_clusters:                   %u\n", fe->i_clusters);
1940         printk("i_generation:                 %u\n",
1941                le32_to_cpu(fe->i_generation));
1942         printk("id1.bitmap1.i_used:           %u\n",
1943                le32_to_cpu(fe->id1.bitmap1.i_used));
1944         printk("id1.bitmap1.i_total:          %u\n",
1945                le32_to_cpu(fe->id1.bitmap1.i_total));
1946         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
1947         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
1948         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
1949         printk("id2.i_chain.cl_next_free_rec: %u\n",
1950                fe->id2.i_chain.cl_next_free_rec);
1951         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
1952                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
1953                        fe->id2.i_chain.cl_recs[i].c_free);
1954                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
1955                        fe->id2.i_chain.cl_recs[i].c_total);
1956                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
1957                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
1958         }
1959 }
1960
1961 /*
1962  * For a given allocation, determine which allocators will need to be
1963  * accessed, and lock them, reserving the appropriate number of bits.
1964  *
1965  * Sparse file systems call this from ocfs2_write_begin_nolock()
1966  * and ocfs2_allocate_unwritten_extents().
1967  *
1968  * File systems which don't support holes call this from
1969  * ocfs2_extend_allocation().
1970  */
1971 int ocfs2_lock_allocators(struct inode *inode,
1972                           struct ocfs2_extent_tree *et,
1973                           u32 clusters_to_add, u32 extents_to_split,
1974                           struct ocfs2_alloc_context **data_ac,
1975                           struct ocfs2_alloc_context **meta_ac)
1976 {
1977         int ret = 0, num_free_extents;
1978         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
1979         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1980
1981         *meta_ac = NULL;
1982         if (data_ac)
1983                 *data_ac = NULL;
1984
1985         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
1986
1987         num_free_extents = ocfs2_num_free_extents(osb, inode, et);
1988         if (num_free_extents < 0) {
1989                 ret = num_free_extents;
1990                 mlog_errno(ret);
1991                 goto out;
1992         }
1993
1994         /*
1995          * Sparse allocation file systems need to be more conservative
1996          * with reserving room for expansion - the actual allocation
1997          * happens while we've got a journal handle open so re-taking
1998          * a cluster lock (because we ran out of room for another
1999          * extent) will violate ordering rules.
2000          *
2001          * Most of the time we'll only be seeing this 1 cluster at a time
2002          * anyway.
2003          *
2004          * Always lock for any unwritten extents - we might want to
2005          * add blocks during a split.
2006          */
2007         if (!num_free_extents ||
2008             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2009                 ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2010                 if (ret < 0) {
2011                         if (ret != -ENOSPC)
2012                                 mlog_errno(ret);
2013                         goto out;
2014                 }
2015         }
2016
2017         if (clusters_to_add == 0)
2018                 goto out;
2019
2020         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2021         if (ret < 0) {
2022                 if (ret != -ENOSPC)
2023                         mlog_errno(ret);
2024                 goto out;
2025         }
2026
2027 out:
2028         if (ret) {
2029                 if (*meta_ac) {
2030                         ocfs2_free_alloc_context(*meta_ac);
2031                         *meta_ac = NULL;
2032                 }
2033
2034                 /*
2035                  * We cannot have an error and a non null *data_ac.
2036                  */
2037         }
2038
2039         return ret;
2040 }