Pileus Git - ~andy/linux/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 "blockcheck.h"
  39 #include "dlmglue.h"
  40 #include "inode.h"
  41 #include "journal.h"
  42 #include "localalloc.h"
  43 #include "suballoc.h"
  44 #include "super.h"
  45 #include "sysfile.h"
  46 #include "uptodate.h"
  47
  48 #include "buffer_head_io.h"
  49
  50 #define NOT_ALLOC_NEW_GROUP             0
  51 #define ALLOC_NEW_GROUP                 1
  52
  53 #define OCFS2_MAX_INODES_TO_STEAL       1024
  54
  55 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
  56 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
  57 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  58 static int ocfs2_block_group_fill(handle_t *handle,
  59                                   struct inode *alloc_inode,
  60                                   struct buffer_head *bg_bh,
  61                                   u64 group_blkno,
  62                                   u16 my_chain,
  63                                   struct ocfs2_chain_list *cl);
  64 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  65                                    struct inode *alloc_inode,
  66                                    struct buffer_head *bh,
  67                                    u64 max_block);
  68
  69 static int ocfs2_cluster_group_search(struct inode *inode,
  70                                       struct buffer_head *group_bh,
  71                                       u32 bits_wanted, u32 min_bits,
  72                                       u64 max_block,
  73                                       u16 *bit_off, u16 *bits_found);
  74 static int ocfs2_block_group_search(struct inode *inode,
  75                                     struct buffer_head *group_bh,
  76                                     u32 bits_wanted, u32 min_bits,
  77                                     u64 max_block,
  78                                     u16 *bit_off, u16 *bits_found);
  79 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
  80                                      struct ocfs2_alloc_context *ac,
  81                                      handle_t *handle,
  82                                      u32 bits_wanted,
  83                                      u32 min_bits,
  84                                      u16 *bit_off,
  85                                      unsigned int *num_bits,
  86                                      u64 *bg_blkno);
  87 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  88                                          int nr);
  89 static inline int ocfs2_block_group_set_bits(handle_t *handle,
  90                                              struct inode *alloc_inode,
  91                                              struct ocfs2_group_desc *bg,
  92                                              struct buffer_head *group_bh,
  93                                              unsigned int bit_off,
  94                                              unsigned int num_bits);
  95 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
  96                                                struct inode *alloc_inode,
  97                                                struct ocfs2_group_desc *bg,
  98                                                struct buffer_head *group_bh,
  99                                                unsigned int bit_off,
 100                                                unsigned int num_bits);
 101
 102 static int ocfs2_relink_block_group(handle_t *handle,
 103                                     struct inode *alloc_inode,
 104                                     struct buffer_head *fe_bh,
 105                                     struct buffer_head *bg_bh,
 106                                     struct buffer_head *prev_bg_bh,
 107                                     u16 chain);
 108 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 109                                                      u32 wanted);
 110 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 111                                                    u64 bg_blkno,
 112                                                    u16 bg_bit_off);
 113 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 114                                                 u64 data_blkno,
 115                                                 u64 *bg_blkno,
 116                                                 u16 *bg_bit_off);
 117 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 118                                              u32 bits_wanted, u64 max_block,
 119                                              struct ocfs2_alloc_context **ac);
 120
 121 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 122 {
 123         struct inode *inode = ac->ac_inode;
 124
 125         if (inode) {
 126                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 127                         ocfs2_inode_unlock(inode, 1);
 128
 129                 mutex_unlock(&inode->i_mutex);
 130
 131                 iput(inode);
 132                 ac->ac_inode = NULL;
 133         }
 134         brelse(ac->ac_bh);
 135         ac->ac_bh = NULL;
 136 }
 137
 138 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 139 {
 140         ocfs2_free_ac_resource(ac);
 141         kfree(ac);
 142 }
 143
 144 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 145 {
 146         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 147 }
 148
 149 #define do_error(fmt, ...)                                              \
 150         do{                                                             \
 151                 if (clean_error)                                        \
 152                         mlog(ML_ERROR, fmt "\n", ##__VA_ARGS__);        \
 153                 else                                                    \
 154                         ocfs2_error(sb, fmt, ##__VA_ARGS__);            \
 155         } while (0)
 156
 157 static int ocfs2_validate_gd_self(struct super_block *sb,
 158                                   struct buffer_head *bh,
 159                                   int clean_error)
 160 {
 161         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 162
 163         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 164                 do_error("Group descriptor #%llu has bad signature %.*s",
 165                          (unsigned long long)bh->b_blocknr, 7,
 166                          gd->bg_signature);
 167                 return -EINVAL;
 168         }
 169
 170         if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 171                 do_error("Group descriptor #%llu has an invalid bg_blkno "
 172                          "of %llu",
 173                          (unsigned long long)bh->b_blocknr,
 174                          (unsigned long long)le64_to_cpu(gd->bg_blkno));
 175                 return -EINVAL;
 176         }
 177
 178         if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 179                 do_error("Group descriptor #%llu has an invalid "
 180                          "fs_generation of #%u",
 181                          (unsigned long long)bh->b_blocknr,
 182                          le32_to_cpu(gd->bg_generation));
 183                 return -EINVAL;
 184         }
 185
 186         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 187                 do_error("Group descriptor #%llu has bit count %u but "
 188                          "claims that %u are free",
 189                          (unsigned long long)bh->b_blocknr,
 190                          le16_to_cpu(gd->bg_bits),
 191                          le16_to_cpu(gd->bg_free_bits_count));
 192                 return -EINVAL;
 193         }
 194
 195         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 196                 do_error("Group descriptor #%llu has bit count %u but "
 197                          "max bitmap bits of %u",
 198                          (unsigned long long)bh->b_blocknr,
 199                          le16_to_cpu(gd->bg_bits),
 200                          8 * le16_to_cpu(gd->bg_size));
 201                 return -EINVAL;
 202         }
 203
 204         return 0;
 205 }
 206
 207 static int ocfs2_validate_gd_parent(struct super_block *sb,
 208                                     struct ocfs2_dinode *di,
 209                                     struct buffer_head *bh,
 210                                     int clean_error)
 211 {
 212         unsigned int max_bits;
 213         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 214
 215         if (di->i_blkno != gd->bg_parent_dinode) {
 216                 do_error("Group descriptor #%llu has bad parent "
 217                          "pointer (%llu, expected %llu)",
 218                          (unsigned long long)bh->b_blocknr,
 219                          (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 220                          (unsigned long long)le64_to_cpu(di->i_blkno));
 221                 return -EINVAL;
 222         }
 223
 224         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 225         if (le16_to_cpu(gd->bg_bits) > max_bits) {
 226                 do_error("Group descriptor #%llu has bit count of %u",
 227                          (unsigned long long)bh->b_blocknr,
 228                          le16_to_cpu(gd->bg_bits));
 229                 return -EINVAL;
 230         }
 231
 232         if (le16_to_cpu(gd->bg_chain) >=
 233             le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) {
 234                 do_error("Group descriptor #%llu has bad chain %u",
 235                          (unsigned long long)bh->b_blocknr,
 236                          le16_to_cpu(gd->bg_chain));
 237                 return -EINVAL;
 238         }
 239
 240         return 0;
 241 }
 242
 243 #undef do_error
 244
 245 /*
 246  * This version only prints errors.  It does not fail the filesystem, and
 247  * exists only for resize.
 248  */
 249 int ocfs2_check_group_descriptor(struct super_block *sb,
 250                                  struct ocfs2_dinode *di,
 251                                  struct buffer_head *bh)
 252 {
 253         int rc;
 254         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 255
 256         BUG_ON(!buffer_uptodate(bh));
 257
 258         /*
 259          * If the ecc fails, we return the error but otherwise
 260          * leave the filesystem running.  We know any error is
 261          * local to this block.
 262          */
 263         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 264         if (!rc)
 265                 rc = ocfs2_validate_gd_self(sb, bh, 1);
 266         if (!rc)
 267                 rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 268
 269         return rc;
 270 }
 271
 272 static int ocfs2_validate_group_descriptor(struct super_block *sb,
 273                                            struct buffer_head *bh)
 274 {
 275         int rc;
 276         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 277
 278         mlog(0, "Validating group descriptor %llu\n",
 279              (unsigned long long)bh->b_blocknr);
 280
 281         BUG_ON(!buffer_uptodate(bh));
 282
 283         /*
 284          * If the ecc fails, we return the error but otherwise
 285          * leave the filesystem running.  We know any error is
 286          * local to this block.
 287          */
 288         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 289         if (rc)
 290                 return rc;
 291
 292         /*
 293          * Errors after here are fatal.
 294          */
 295
 296         return ocfs2_validate_gd_self(sb, bh, 0);
 297 }
 298
 299 int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 300                                 u64 gd_blkno, struct buffer_head **bh)
 301 {
 302         int rc;
 303         struct buffer_head *tmp = *bh;
 304
 305         rc = ocfs2_read_block(inode, gd_blkno, &tmp,
 306                               ocfs2_validate_group_descriptor);
 307         if (rc)
 308                 goto out;
 309
 310         rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 311         if (rc) {
 312                 brelse(tmp);
 313                 goto out;
 314         }
 315
 316         /* If ocfs2_read_block() got us a new bh, pass it up. */
 317         if (!*bh)
 318                 *bh = tmp;
 319
 320 out:
 321         return rc;
 322 }
 323
 324 static int ocfs2_block_group_fill(handle_t *handle,
 325                                   struct inode *alloc_inode,
 326                                   struct buffer_head *bg_bh,
 327                                   u64 group_blkno,
 328                                   u16 my_chain,
 329                                   struct ocfs2_chain_list *cl)
 330 {
 331         int status = 0;
 332         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 333         struct super_block * sb = alloc_inode->i_sb;
 334
 335         mlog_entry_void();
 336
 337         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 338                 ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
 339                             "b_blocknr (%llu)",
 340                             (unsigned long long)group_blkno,
 341                             (unsigned long long) bg_bh->b_blocknr);
 342                 status = -EIO;
 343                 goto bail;
 344         }
 345
 346         status = ocfs2_journal_access(handle,
 347                                       alloc_inode,
 348                                       bg_bh,
 349                                       OCFS2_JOURNAL_ACCESS_CREATE);
 350         if (status < 0) {
 351                 mlog_errno(status);
 352                 goto bail;
 353         }
 354
 355         memset(bg, 0, sb->s_blocksize);
 356         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 357         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 358         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
 359         bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 360         bg->bg_chain = cpu_to_le16(my_chain);
 361         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 362         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 363         bg->bg_blkno = cpu_to_le64(group_blkno);
 364         /* set the 1st bit in the bitmap to account for the descriptor block */
 365         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 366         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 367
 368         status = ocfs2_journal_dirty(handle, bg_bh);
 369         if (status < 0)
 370                 mlog_errno(status);
 371
 372         /* There is no need to zero out or otherwise initialize the
 373          * other blocks in a group - All valid FS metadata in a block
 374          * group stores the superblock fs_generation value at
 375          * allocation time. */
 376
 377 bail:
 378         mlog_exit(status);
 379         return status;
 380 }
 381
 382 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 383 {
 384         u16 curr, best;
 385
 386         best = curr = 0;
 387         while (curr < le16_to_cpu(cl->cl_count)) {
 388                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 389                     le32_to_cpu(cl->cl_recs[curr].c_total))
 390                         best = curr;
 391                 curr++;
 392         }
 393         return best;
 394 }
 395
 396 /*
 397  * We expect the block group allocator to already be locked.
 398  */
 399 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 400                                    struct inode *alloc_inode,
 401                                    struct buffer_head *bh,
 402                                    u64 max_block)
 403 {
 404         int status, credits;
 405         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 406         struct ocfs2_chain_list *cl;
 407         struct ocfs2_alloc_context *ac = NULL;
 408         handle_t *handle = NULL;
 409         u32 bit_off, num_bits;
 410         u16 alloc_rec;
 411         u64 bg_blkno;
 412         struct buffer_head *bg_bh = NULL;
 413         struct ocfs2_group_desc *bg;
 414
 415         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 416
 417         mlog_entry_void();
 418
 419         cl = &fe->id2.i_chain;
 420         status = ocfs2_reserve_clusters_with_limit(osb,
 421                                                    le16_to_cpu(cl->cl_cpg),
 422                                                    max_block, &ac);
 423         if (status < 0) {
 424                 if (status != -ENOSPC)
 425                         mlog_errno(status);
 426                 goto bail;
 427         }
 428
 429         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 430                                                  le16_to_cpu(cl->cl_cpg));
 431         handle = ocfs2_start_trans(osb, credits);
 432         if (IS_ERR(handle)) {
 433                 status = PTR_ERR(handle);
 434                 handle = NULL;
 435                 mlog_errno(status);
 436                 goto bail;
 437         }
 438
 439         status = ocfs2_claim_clusters(osb,
 440                                       handle,
 441                                       ac,
 442                                       le16_to_cpu(cl->cl_cpg),
 443                                       &bit_off,
 444                                       &num_bits);
 445         if (status < 0) {
 446                 if (status != -ENOSPC)
 447                         mlog_errno(status);
 448                 goto bail;
 449         }
 450
 451         alloc_rec = ocfs2_find_smallest_chain(cl);
 452
 453         /* setup the group */
 454         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 455         mlog(0, "new descriptor, record %u, at block %llu\n",
 456              alloc_rec, (unsigned long long)bg_blkno);
 457
 458         bg_bh = sb_getblk(osb->sb, bg_blkno);
 459         if (!bg_bh) {
 460                 status = -EIO;
 461                 mlog_errno(status);
 462                 goto bail;
 463         }
 464         ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);
 465
 466         status = ocfs2_block_group_fill(handle,
 467                                         alloc_inode,
 468                                         bg_bh,
 469                                         bg_blkno,
 470                                         alloc_rec,
 471                                         cl);
 472         if (status < 0) {
 473                 mlog_errno(status);
 474                 goto bail;
 475         }
 476
 477         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 478
 479         status = ocfs2_journal_access(handle, alloc_inode,
 480                                       bh, OCFS2_JOURNAL_ACCESS_WRITE);
 481         if (status < 0) {
 482                 mlog_errno(status);
 483                 goto bail;
 484         }
 485
 486         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 487                      le16_to_cpu(bg->bg_free_bits_count));
 488         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
 489         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
 490         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 491                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 492
 493         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 494                                         le16_to_cpu(bg->bg_free_bits_count));
 495         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 496         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 497
 498         status = ocfs2_journal_dirty(handle, bh);
 499         if (status < 0) {
 500                 mlog_errno(status);
 501                 goto bail;
 502         }
 503
 504         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 505         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 506         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 507                                              le32_to_cpu(fe->i_clusters)));
 508         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 509         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 510         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 511
 512         status = 0;
 513 bail:
 514         if (handle)
 515                 ocfs2_commit_trans(osb, handle);
 516
 517         if (ac)
 518                 ocfs2_free_alloc_context(ac);
 519
 520         brelse(bg_bh);
 521
 522         mlog_exit(status);
 523         return status;
 524 }
 525
 526 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 527                                        struct ocfs2_alloc_context *ac,
 528                                        int type,
 529                                        u32 slot,
 530                                        int alloc_new_group)
 531 {
 532         int status;
 533         u32 bits_wanted = ac->ac_bits_wanted;
 534         struct inode *alloc_inode;
 535         struct buffer_head *bh = NULL;
 536         struct ocfs2_dinode *fe;
 537         u32 free_bits;
 538
 539         mlog_entry_void();
 540
 541         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 542         if (!alloc_inode) {
 543                 mlog_errno(-EINVAL);
 544                 return -EINVAL;
 545         }
 546
 547         mutex_lock(&alloc_inode->i_mutex);
 548
 549         status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 550         if (status < 0) {
 551                 mutex_unlock(&alloc_inode->i_mutex);
 552                 iput(alloc_inode);
 553
 554                 mlog_errno(status);
 555                 return status;
 556         }
 557
 558         ac->ac_inode = alloc_inode;
 559         ac->ac_alloc_slot = slot;
 560
 561         fe = (struct ocfs2_dinode *) bh->b_data;
 562
 563         /* The bh was validated by the inode read inside
 564          * ocfs2_inode_lock().  Any corruption is a code bug. */
 565         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 566
 567         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 568                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 569                             (unsigned long long)le64_to_cpu(fe->i_blkno));
 570                 status = -EIO;
 571                 goto bail;
 572         }
 573
 574         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 575                 le32_to_cpu(fe->id1.bitmap1.i_used);
 576
 577         if (bits_wanted > free_bits) {
 578                 /* cluster bitmap never grows */
 579                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 580                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
 581                              bits_wanted, free_bits);
 582                         status = -ENOSPC;
 583                         goto bail;
 584                 }
 585
 586                 if (alloc_new_group != ALLOC_NEW_GROUP) {
 587                         mlog(0, "Alloc File %u Full: wanted=%u, free_bits=%u, "
 588                              "and we don't alloc a new group for it.\n",
 589                              slot, bits_wanted, free_bits);
 590                         status = -ENOSPC;
 591                         goto bail;
 592                 }
 593
 594                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 595                                                  ac->ac_max_block);
 596                 if (status < 0) {
 597                         if (status != -ENOSPC)
 598                                 mlog_errno(status);
 599                         goto bail;
 600                 }
 601                 atomic_inc(&osb->alloc_stats.bg_extends);
 602
 603                 /* You should never ask for this much metadata */
 604                 BUG_ON(bits_wanted >
 605                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 606                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 607         }
 608
 609         get_bh(bh);
 610         ac->ac_bh = bh;
 611 bail:
 612         brelse(bh);
 613
 614         mlog_exit(status);
 615         return status;
 616 }
 617
 618 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 619                                       int blocks,
 620                                       struct ocfs2_alloc_context **ac)
 621 {
 622         int status;
 623         u32 slot;
 624
 625         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 626         if (!(*ac)) {
 627                 status = -ENOMEM;
 628                 mlog_errno(status);
 629                 goto bail;
 630         }
 631
 632         (*ac)->ac_bits_wanted = blocks;
 633         (*ac)->ac_which = OCFS2_AC_USE_META;
 634         slot = osb->slot_num;
 635         (*ac)->ac_group_search = ocfs2_block_group_search;
 636
 637         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 638                                              EXTENT_ALLOC_SYSTEM_INODE,
 639                                              slot, ALLOC_NEW_GROUP);
 640         if (status < 0) {
 641                 if (status != -ENOSPC)
 642                         mlog_errno(status);
 643                 goto bail;
 644         }
 645
 646         status = 0;
 647 bail:
 648         if ((status < 0) && *ac) {
 649                 ocfs2_free_alloc_context(*ac);
 650                 *ac = NULL;
 651         }
 652
 653         mlog_exit(status);
 654         return status;
 655 }
 656
 657 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
 658                                struct ocfs2_extent_list *root_el,
 659                                struct ocfs2_alloc_context **ac)
 660 {
 661         return ocfs2_reserve_new_metadata_blocks(osb,
 662                                         ocfs2_extend_meta_needed(root_el),
 663                                         ac);
 664 }
 665
 666 static int ocfs2_steal_inode_from_other_nodes(struct ocfs2_super *osb,
 667                                               struct ocfs2_alloc_context *ac)
 668 {
 669         int i, status = -ENOSPC;
 670         s16 slot = ocfs2_get_inode_steal_slot(osb);
 671
 672         /* Start to steal inodes from the first slot after ours. */
 673         if (slot == OCFS2_INVALID_SLOT)
 674                 slot = osb->slot_num + 1;
 675
 676         for (i = 0; i < osb->max_slots; i++, slot++) {
 677                 if (slot == osb->max_slots)
 678                         slot = 0;
 679
 680                 if (slot == osb->slot_num)
 681                         continue;
 682
 683                 status = ocfs2_reserve_suballoc_bits(osb, ac,
 684                                                      INODE_ALLOC_SYSTEM_INODE,
 685                                                      slot, NOT_ALLOC_NEW_GROUP);
 686                 if (status >= 0) {
 687                         ocfs2_set_inode_steal_slot(osb, slot);
 688                         break;
 689                 }
 690
 691                 ocfs2_free_ac_resource(ac);
 692         }
 693
 694         return status;
 695 }
 696
 697 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 698                             struct ocfs2_alloc_context **ac)
 699 {
 700         int status;
 701         s16 slot = ocfs2_get_inode_steal_slot(osb);
 702
 703         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 704         if (!(*ac)) {
 705                 status = -ENOMEM;
 706                 mlog_errno(status);
 707                 goto bail;
 708         }
 709
 710         (*ac)->ac_bits_wanted = 1;
 711         (*ac)->ac_which = OCFS2_AC_USE_INODE;
 712
 713         (*ac)->ac_group_search = ocfs2_block_group_search;
 714
 715         /*
 716          * stat(2) can't handle i_ino > 32bits, so we tell the
 717          * lower levels not to allocate us a block group past that
 718          * limit.  The 'inode64' mount option avoids this behavior.
 719          */
 720         if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
 721                 (*ac)->ac_max_block = (u32)~0U;
 722
 723         /*
 724          * slot is set when we successfully steal inode from other nodes.
 725          * It is reset in 3 places:
 726          * 1. when we flush the truncate log
 727          * 2. when we complete local alloc recovery.
 728          * 3. when we successfully allocate from our own slot.
 729          * After it is set, we will go on stealing inodes until we find the
 730          * need to check our slots to see whether there is some space for us.
 731          */
 732         if (slot != OCFS2_INVALID_SLOT &&
 733             atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_INODES_TO_STEAL)
 734                 goto inode_steal;
 735
 736         atomic_set(&osb->s_num_inodes_stolen, 0);
 737         status = ocfs2_reserve_suballoc_bits(osb, *ac,
 738                                              INODE_ALLOC_SYSTEM_INODE,
 739                                              osb->slot_num, ALLOC_NEW_GROUP);
 740         if (status >= 0) {
 741                 status = 0;
 742
 743                 /*
 744                  * Some inodes must be freed by us, so try to allocate
 745                  * from our own next time.
 746                  */
 747                 if (slot != OCFS2_INVALID_SLOT)
 748                         ocfs2_init_inode_steal_slot(osb);
 749                 goto bail;
 750         } else if (status < 0 && status != -ENOSPC) {
 751                 mlog_errno(status);
 752                 goto bail;
 753         }
 754
 755         ocfs2_free_ac_resource(*ac);
 756
 757 inode_steal:
 758         status = ocfs2_steal_inode_from_other_nodes(osb, *ac);
 759         atomic_inc(&osb->s_num_inodes_stolen);
 760         if (status < 0) {
 761                 if (status != -ENOSPC)
 762                         mlog_errno(status);
 763                 goto bail;
 764         }
 765
 766         status = 0;
 767 bail:
 768         if ((status < 0) && *ac) {
 769                 ocfs2_free_alloc_context(*ac);
 770                 *ac = NULL;
 771         }
 772
 773         mlog_exit(status);
 774         return status;
 775 }
 776
 777 /* local alloc code has to do the same thing, so rather than do this
 778  * twice.. */
 779 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
 780                                       struct ocfs2_alloc_context *ac)
 781 {
 782         int status;
 783
 784         ac->ac_which = OCFS2_AC_USE_MAIN;
 785         ac->ac_group_search = ocfs2_cluster_group_search;
 786
 787         status = ocfs2_reserve_suballoc_bits(osb, ac,
 788                                              GLOBAL_BITMAP_SYSTEM_INODE,
 789                                              OCFS2_INVALID_SLOT,
 790                                              ALLOC_NEW_GROUP);
 791         if (status < 0 && status != -ENOSPC) {
 792                 mlog_errno(status);
 793                 goto bail;
 794         }
 795
 796 bail:
 797         return status;
 798 }
 799
 800 /* Callers don't need to care which bitmap (local alloc or main) to
 801  * use so we figure it out for them, but unfortunately this clutters
 802  * things a bit. */
 803 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 804                                              u32 bits_wanted, u64 max_block,
 805                                              struct ocfs2_alloc_context **ac)
 806 {
 807         int status;
 808
 809         mlog_entry_void();
 810
 811         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 812         if (!(*ac)) {
 813                 status = -ENOMEM;
 814                 mlog_errno(status);
 815                 goto bail;
 816         }
 817
 818         (*ac)->ac_bits_wanted = bits_wanted;
 819         (*ac)->ac_max_block = max_block;
 820
 821         status = -ENOSPC;
 822         if (ocfs2_alloc_should_use_local(osb, bits_wanted)) {
 823                 status = ocfs2_reserve_local_alloc_bits(osb,
 824                                                         bits_wanted,
 825                                                         *ac);
 826                 if (status == -EFBIG) {
 827                         /* The local alloc window is outside ac_max_block.
 828                          * use the main bitmap. */
 829                         status = -ENOSPC;
 830                 } else if ((status < 0) && (status != -ENOSPC)) {
 831                         mlog_errno(status);
 832                         goto bail;
 833                 }
 834         }
 835
 836         if (status == -ENOSPC) {
 837                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 838                 if (status < 0) {
 839                         if (status != -ENOSPC)
 840                                 mlog_errno(status);
 841                         goto bail;
 842                 }
 843         }
 844
 845         status = 0;
 846 bail:
 847         if ((status < 0) && *ac) {
 848                 ocfs2_free_alloc_context(*ac);
 849                 *ac = NULL;
 850         }
 851
 852         mlog_exit(status);
 853         return status;
 854 }
 855
 856 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
 857                            u32 bits_wanted,
 858                            struct ocfs2_alloc_context **ac)
 859 {
 860         return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0, ac);
 861 }
 862
 863 /*
 864  * More or less lifted from ext3. I'll leave their description below:
 865  *
 866  * "For ext3 allocations, we must not reuse any blocks which are
 867  * allocated in the bitmap buffer's "last committed data" copy.  This
 868  * prevents deletes from freeing up the page for reuse until we have
 869  * committed the delete transaction.
 870  *
 871  * If we didn't do this, then deleting something and reallocating it as
 872  * data would allow the old block to be overwritten before the
 873  * transaction committed (because we force data to disk before commit).
 874  * This would lead to corruption if we crashed between overwriting the
 875  * data and committing the delete.
 876  *
 877  * @@@ We may want to make this allocation behaviour conditional on
 878  * data-writes at some point, and disable it for metadata allocations or
 879  * sync-data inodes."
 880  *
 881  * Note: OCFS2 already does this differently for metadata vs data
 882  * allocations, as those bitmaps are separate and undo access is never
 883  * called on a metadata group descriptor.
 884  */
 885 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 886                                          int nr)
 887 {
 888         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 889
 890         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
 891                 return 0;
 892         if (!buffer_jbd(bg_bh) || !bh2jh(bg_bh)->b_committed_data)
 893                 return 1;
 894
 895         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
 896         return !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
 897 }
 898
 899 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
 900                                              struct buffer_head *bg_bh,
 901                                              unsigned int bits_wanted,
 902                                              unsigned int total_bits,
 903                                              u16 *bit_off,
 904                                              u16 *bits_found)
 905 {
 906         void *bitmap;
 907         u16 best_offset, best_size;
 908         int offset, start, found, status = 0;
 909         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 910
 911         /* Callers got this descriptor from
 912          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
 913         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
 914
 915         found = start = best_offset = best_size = 0;
 916         bitmap = bg->bg_bitmap;
 917
 918         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
 919                 if (offset == total_bits)
 920                         break;
 921
 922                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
 923                         /* We found a zero, but we can't use it as it
 924                          * hasn't been put to disk yet! */
 925                         found = 0;
 926                         start = offset + 1;
 927                 } else if (offset == start) {
 928                         /* we found a zero */
 929                         found++;
 930                         /* move start to the next bit to test */
 931                         start++;
 932                 } else {
 933                         /* got a zero after some ones */
 934                         found = 1;
 935                         start = offset + 1;
 936                 }
 937                 if (found > best_size) {
 938                         best_size = found;
 939                         best_offset = start - found;
 940                 }
 941                 /* we got everything we needed */
 942                 if (found == bits_wanted) {
 943                         /* mlog(0, "Found it all!\n"); */
 944                         break;
 945                 }
 946         }
 947
 948         /* XXX: I think the first clause is equivalent to the second
 949          *      - jlbec */
 950         if (found == bits_wanted) {
 951                 *bit_off = start - found;
 952                 *bits_found = found;
 953         } else if (best_size) {
 954                 *bit_off = best_offset;
 955                 *bits_found = best_size;
 956         } else {
 957                 status = -ENOSPC;
 958                 /* No error log here -- see the comment above
 959                  * ocfs2_test_bg_bit_allocatable */
 960         }
 961
 962         return status;
 963 }
 964
 965 static inline int ocfs2_block_group_set_bits(handle_t *handle,
 966                                              struct inode *alloc_inode,
 967                                              struct ocfs2_group_desc *bg,
 968                                              struct buffer_head *group_bh,
 969                                              unsigned int bit_off,
 970                                              unsigned int num_bits)
 971 {
 972         int status;
 973         void *bitmap = bg->bg_bitmap;
 974         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
 975
 976         mlog_entry_void();
 977
 978         /* All callers get the descriptor via
 979          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
 980         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
 981         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
 982
 983         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
 984              num_bits);
 985
 986         if (ocfs2_is_cluster_bitmap(alloc_inode))
 987                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
 988
 989         status = ocfs2_journal_access(handle,
 990                                       alloc_inode,
 991                                       group_bh,
 992                                       journal_type);
 993         if (status < 0) {
 994                 mlog_errno(status);
 995                 goto bail;
 996         }
 997
 998         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
 999
1000         while(num_bits--)
1001                 ocfs2_set_bit(bit_off++, bitmap);
1002
1003         status = ocfs2_journal_dirty(handle,
1004                                      group_bh);
1005         if (status < 0) {
1006                 mlog_errno(status);
1007                 goto bail;
1008         }
1009
1010 bail:
1011         mlog_exit(status);
1012         return status;
1013 }
1014
1015 /* find the one with the most empty bits */
1016 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1017 {
1018         u16 curr, best;
1019
1020         BUG_ON(!cl->cl_next_free_rec);
1021
1022         best = curr = 0;
1023         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1024                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1025                     le32_to_cpu(cl->cl_recs[best].c_free))
1026                         best = curr;
1027                 curr++;
1028         }
1029
1030         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1031         return best;
1032 }
1033
1034 static int ocfs2_relink_block_group(handle_t *handle,
1035                                     struct inode *alloc_inode,
1036                                     struct buffer_head *fe_bh,
1037                                     struct buffer_head *bg_bh,
1038                                     struct buffer_head *prev_bg_bh,
1039                                     u16 chain)
1040 {
1041         int status;
1042         /* there is a really tiny chance the journal calls could fail,
1043          * but we wouldn't want inconsistent blocks in *any* case. */
1044         u64 fe_ptr, bg_ptr, prev_bg_ptr;
1045         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1046         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1047         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1048
1049         /* The caller got these descriptors from
1050          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1051         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1052         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1053
1054         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
1055              (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1056              (unsigned long long)le64_to_cpu(bg->bg_blkno),
1057              (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1058
1059         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
1060         bg_ptr = le64_to_cpu(bg->bg_next_group);
1061         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1062
1063         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
1064                                       OCFS2_JOURNAL_ACCESS_WRITE);
1065         if (status < 0) {
1066                 mlog_errno(status);
1067                 goto out_rollback;
1068         }
1069
1070         prev_bg->bg_next_group = bg->bg_next_group;
1071
1072         status = ocfs2_journal_dirty(handle, prev_bg_bh);
1073         if (status < 0) {
1074                 mlog_errno(status);
1075                 goto out_rollback;
1076         }
1077
1078         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
1079                                       OCFS2_JOURNAL_ACCESS_WRITE);
1080         if (status < 0) {
1081                 mlog_errno(status);
1082                 goto out_rollback;
1083         }
1084
1085         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1086
1087         status = ocfs2_journal_dirty(handle, bg_bh);
1088         if (status < 0) {
1089                 mlog_errno(status);
1090                 goto out_rollback;
1091         }
1092
1093         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
1094                                       OCFS2_JOURNAL_ACCESS_WRITE);
1095         if (status < 0) {
1096                 mlog_errno(status);
1097                 goto out_rollback;
1098         }
1099
1100         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1101
1102         status = ocfs2_journal_dirty(handle, fe_bh);
1103         if (status < 0) {
1104                 mlog_errno(status);
1105                 goto out_rollback;
1106         }
1107
1108         status = 0;
1109 out_rollback:
1110         if (status < 0) {
1111                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
1112                 bg->bg_next_group = cpu_to_le64(bg_ptr);
1113                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1114         }
1115
1116         mlog_exit(status);
1117         return status;
1118 }
1119
1120 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1121                                                      u32 wanted)
1122 {
1123         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1124 }
1125
1126 /* return 0 on success, -ENOSPC to keep searching and any other < 0
1127  * value on error. */
1128 static int ocfs2_cluster_group_search(struct inode *inode,
1129                                       struct buffer_head *group_bh,
1130                                       u32 bits_wanted, u32 min_bits,
1131                                       u64 max_block,
1132                                       u16 *bit_off, u16 *bits_found)
1133 {
1134         int search = -ENOSPC;
1135         int ret;
1136         u64 blkoff;
1137         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1138         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1139         u16 tmp_off, tmp_found;
1140         unsigned int max_bits, gd_cluster_off;
1141
1142         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1143
1144         if (gd->bg_free_bits_count) {
1145                 max_bits = le16_to_cpu(gd->bg_bits);
1146
1147                 /* Tail groups in cluster bitmaps which aren't cpg
1148                  * aligned are prone to partial extention by a failed
1149                  * fs resize. If the file system resize never got to
1150                  * update the dinode cluster count, then we don't want
1151                  * to trust any clusters past it, regardless of what
1152                  * the group descriptor says. */
1153                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1154                                                           le64_to_cpu(gd->bg_blkno));
1155                 if ((gd_cluster_off + max_bits) >
1156                     OCFS2_I(inode)->ip_clusters) {
1157                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1158                         mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
1159                              (unsigned long long)le64_to_cpu(gd->bg_blkno),
1160                              le16_to_cpu(gd->bg_bits),
1161                              OCFS2_I(inode)->ip_clusters, max_bits);
1162                 }
1163
1164                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1165                                                         group_bh, bits_wanted,
1166                                                         max_bits,
1167                                                         &tmp_off, &tmp_found);
1168                 if (ret)
1169                         return ret;
1170
1171                 if (max_block) {
1172                         blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1173                                                           gd_cluster_off +
1174                                                           tmp_off + tmp_found);
1175                         mlog(0, "Checking %llu against %llu\n",
1176                              (unsigned long long)blkoff,
1177                              (unsigned long long)max_block);
1178                         if (blkoff > max_block)
1179                                 return -ENOSPC;
1180                 }
1181
1182                 /* ocfs2_block_group_find_clear_bits() might
1183                  * return success, but we still want to return
1184                  * -ENOSPC unless it found the minimum number
1185                  * of bits. */
1186                 if (min_bits <= tmp_found) {
1187                         *bit_off = tmp_off;
1188                         *bits_found = tmp_found;
1189                         search = 0; /* success */
1190                 } else if (tmp_found) {
1191                         /*
1192                          * Don't show bits which we'll be returning
1193                          * for allocation to the local alloc bitmap.
1194                          */
1195                         ocfs2_local_alloc_seen_free_bits(osb, tmp_found);
1196                 }
1197         }
1198
1199         return search;
1200 }
1201
1202 static int ocfs2_block_group_search(struct inode *inode,
1203                                     struct buffer_head *group_bh,
1204                                     u32 bits_wanted, u32 min_bits,
1205                                     u64 max_block,
1206                                     u16 *bit_off, u16 *bits_found)
1207 {
1208         int ret = -ENOSPC;
1209         u64 blkoff;
1210         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1211
1212         BUG_ON(min_bits != 1);
1213         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1214
1215         if (bg->bg_free_bits_count) {
1216                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1217                                                         group_bh, bits_wanted,
1218                                                         le16_to_cpu(bg->bg_bits),
1219                                                         bit_off, bits_found);
1220                 if (!ret && max_block) {
1221                         blkoff = le64_to_cpu(bg->bg_blkno) + *bit_off +
1222                                 *bits_found;
1223                         mlog(0, "Checking %llu against %llu\n",
1224                              (unsigned long long)blkoff,
1225                              (unsigned long long)max_block);
1226                         if (blkoff > max_block)
1227                                 ret = -ENOSPC;
1228                 }
1229         }
1230
1231         return ret;
1232 }
1233
1234 static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1235                                        handle_t *handle,
1236                                        struct buffer_head *di_bh,
1237                                        u32 num_bits,
1238                                        u16 chain)
1239 {
1240         int ret;
1241         u32 tmp_used;
1242         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1243         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1244
1245         ret = ocfs2_journal_access(handle, inode, di_bh,
1246                                    OCFS2_JOURNAL_ACCESS_WRITE);
1247         if (ret < 0) {
1248                 mlog_errno(ret);
1249                 goto out;
1250         }
1251
1252         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1253         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1254         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1255
1256         ret = ocfs2_journal_dirty(handle, di_bh);
1257         if (ret < 0)
1258                 mlog_errno(ret);
1259
1260 out:
1261         return ret;
1262 }
1263
1264 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1265                                   handle_t *handle,
1266                                   u32 bits_wanted,
1267                                   u32 min_bits,
1268                                   u16 *bit_off,
1269                                   unsigned int *num_bits,
1270                                   u64 gd_blkno,
1271                                   u16 *bits_left)
1272 {
1273         int ret;
1274         u16 found;
1275         struct buffer_head *group_bh = NULL;
1276         struct ocfs2_group_desc *gd;
1277         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1278         struct inode *alloc_inode = ac->ac_inode;
1279
1280         ret = ocfs2_read_group_descriptor(alloc_inode, di, gd_blkno,
1281                                           &group_bh);
1282         if (ret < 0) {
1283                 mlog_errno(ret);
1284                 return ret;
1285         }
1286
1287         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1288         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1289                                   ac->ac_max_block, bit_off, &found);
1290         if (ret < 0) {
1291                 if (ret != -ENOSPC)
1292                         mlog_errno(ret);
1293                 goto out;
1294         }
1295
1296         *num_bits = found;
1297
1298         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1299                                                *num_bits,
1300                                                le16_to_cpu(gd->bg_chain));
1301         if (ret < 0) {
1302                 mlog_errno(ret);
1303                 goto out;
1304         }
1305
1306         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1307                                          *bit_off, *num_bits);
1308         if (ret < 0)
1309                 mlog_errno(ret);
1310
1311         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1312
1313 out:
1314         brelse(group_bh);
1315
1316         return ret;
1317 }
1318
1319 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1320                               handle_t *handle,
1321                               u32 bits_wanted,
1322                               u32 min_bits,
1323                               u16 *bit_off,
1324                               unsigned int *num_bits,
1325                               u64 *bg_blkno,
1326                               u16 *bits_left)
1327 {
1328         int status;
1329         u16 chain, tmp_bits;
1330         u32 tmp_used;
1331         u64 next_group;
1332         struct inode *alloc_inode = ac->ac_inode;
1333         struct buffer_head *group_bh = NULL;
1334         struct buffer_head *prev_group_bh = NULL;
1335         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1336         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1337         struct ocfs2_group_desc *bg;
1338
1339         chain = ac->ac_chain;
1340         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
1341              bits_wanted, chain,
1342              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
1343
1344         status = ocfs2_read_group_descriptor(alloc_inode, fe,
1345                                              le64_to_cpu(cl->cl_recs[chain].c_blkno),
1346                                              &group_bh);
1347         if (status < 0) {
1348                 mlog_errno(status);
1349                 goto bail;
1350         }
1351         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1352
1353         status = -ENOSPC;
1354         /* for now, the chain search is a bit simplistic. We just use
1355          * the 1st group with any empty bits. */
1356         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1357                                              bits_wanted, min_bits,
1358                                              ac->ac_max_block, bit_off,
1359                                              &tmp_bits)) == -ENOSPC) {
1360                 if (!bg->bg_next_group)
1361                         break;
1362
1363                 brelse(prev_group_bh);
1364                 prev_group_bh = NULL;
1365
1366                 next_group = le64_to_cpu(bg->bg_next_group);
1367                 prev_group_bh = group_bh;
1368                 group_bh = NULL;
1369                 status = ocfs2_read_group_descriptor(alloc_inode, fe,
1370                                                      next_group, &group_bh);
1371                 if (status < 0) {
1372                         mlog_errno(status);
1373                         goto bail;
1374                 }
1375                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1376         }
1377         if (status < 0) {
1378                 if (status != -ENOSPC)
1379                         mlog_errno(status);
1380                 goto bail;
1381         }
1382
1383         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1384              tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
1385
1386         *num_bits = tmp_bits;
1387
1388         BUG_ON(*num_bits == 0);
1389
1390         /*
1391          * Keep track of previous block descriptor read. When
1392          * we find a target, if we have read more than X
1393          * number of descriptors, and the target is reasonably
1394          * empty, relink him to top of his chain.
1395          *
1396          * We've read 0 extra blocks and only send one more to
1397          * the transaction, yet the next guy to search has a
1398          * much easier time.
1399          *
1400          * Do this *after* figuring out how many bits we're taking out
1401          * of our target group.
1402          */
1403         if (ac->ac_allow_chain_relink &&
1404             (prev_group_bh) &&
1405             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1406                 status = ocfs2_relink_block_group(handle, alloc_inode,
1407                                                   ac->ac_bh, group_bh,
1408                                                   prev_group_bh, chain);
1409                 if (status < 0) {
1410                         mlog_errno(status);
1411                         goto bail;
1412                 }
1413         }
1414
1415         /* Ok, claim our bits now: set the info on dinode, chainlist
1416          * and then the group */
1417         status = ocfs2_journal_access(handle,
1418                                       alloc_inode,
1419                                       ac->ac_bh,
1420                                       OCFS2_JOURNAL_ACCESS_WRITE);
1421         if (status < 0) {
1422                 mlog_errno(status);
1423                 goto bail;
1424         }
1425
1426         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1427         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1428         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1429
1430         status = ocfs2_journal_dirty(handle,
1431                                      ac->ac_bh);
1432         if (status < 0) {
1433                 mlog_errno(status);
1434                 goto bail;
1435         }
1436
1437         status = ocfs2_block_group_set_bits(handle,
1438                                             alloc_inode,
1439                                             bg,
1440                                             group_bh,
1441                                             *bit_off,
1442                                             *num_bits);
1443         if (status < 0) {
1444                 mlog_errno(status);
1445                 goto bail;
1446         }
1447
1448         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1449              (unsigned long long)le64_to_cpu(fe->i_blkno));
1450
1451         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1452         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1453 bail:
1454         brelse(group_bh);
1455         brelse(prev_group_bh);
1456
1457         mlog_exit(status);
1458         return status;
1459 }
1460
1461 /* will give out up to bits_wanted contiguous bits. */
1462 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1463                                      struct ocfs2_alloc_context *ac,
1464                                      handle_t *handle,
1465                                      u32 bits_wanted,
1466                                      u32 min_bits,
1467                                      u16 *bit_off,
1468                                      unsigned int *num_bits,
1469                                      u64 *bg_blkno)
1470 {
1471         int status;
1472         u16 victim, i;
1473         u16 bits_left = 0;
1474         u64 hint_blkno = ac->ac_last_group;
1475         struct ocfs2_chain_list *cl;
1476         struct ocfs2_dinode *fe;
1477
1478         mlog_entry_void();
1479
1480         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1481         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1482         BUG_ON(!ac->ac_bh);
1483
1484         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1485
1486         /* The bh was validated by the inode read during
1487          * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1488         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1489
1490         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1491             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1492                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1493                             "bits but only %u total.",
1494                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1495                             le32_to_cpu(fe->id1.bitmap1.i_used),
1496                             le32_to_cpu(fe->id1.bitmap1.i_total));
1497                 status = -EIO;
1498                 goto bail;
1499         }
1500
1501         if (hint_blkno) {
1502                 /* Attempt to short-circuit the usual search mechanism
1503                  * by jumping straight to the most recently used
1504                  * allocation group. This helps us mantain some
1505                  * contiguousness across allocations. */
1506                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1507                                                 min_bits, bit_off, num_bits,
1508                                                 hint_blkno, &bits_left);
1509                 if (!status) {
1510                         /* Be careful to update *bg_blkno here as the
1511                          * caller is expecting it to be filled in, and
1512                          * ocfs2_search_one_group() won't do that for
1513                          * us. */
1514                         *bg_blkno = hint_blkno;
1515                         goto set_hint;
1516                 }
1517                 if (status < 0 && status != -ENOSPC) {
1518                         mlog_errno(status);
1519                         goto bail;
1520                 }
1521         }
1522
1523         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1524
1525         victim = ocfs2_find_victim_chain(cl);
1526         ac->ac_chain = victim;
1527         ac->ac_allow_chain_relink = 1;
1528
1529         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, bit_off,
1530                                     num_bits, bg_blkno, &bits_left);
1531         if (!status)
1532                 goto set_hint;
1533         if (status < 0 && status != -ENOSPC) {
1534                 mlog_errno(status);
1535                 goto bail;
1536         }
1537
1538         mlog(0, "Search of victim chain %u came up with nothing, "
1539              "trying all chains now.\n", victim);
1540
1541         /* If we didn't pick a good victim, then just default to
1542          * searching each chain in order. Don't allow chain relinking
1543          * because we only calculate enough journal credits for one
1544          * relink per alloc. */
1545         ac->ac_allow_chain_relink = 0;
1546         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1547                 if (i == victim)
1548                         continue;
1549                 if (!cl->cl_recs[i].c_free)
1550                         continue;
1551
1552                 ac->ac_chain = i;
1553                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1554                                             bit_off, num_bits, bg_blkno,
1555                                             &bits_left);
1556                 if (!status)
1557                         break;
1558                 if (status < 0 && status != -ENOSPC) {
1559                         mlog_errno(status);
1560                         goto bail;
1561                 }
1562         }
1563
1564 set_hint:
1565         if (status != -ENOSPC) {
1566                 /* If the next search of this group is not likely to
1567                  * yield a suitable extent, then we reset the last
1568                  * group hint so as to not waste a disk read */
1569                 if (bits_left < min_bits)
1570                         ac->ac_last_group = 0;
1571                 else
1572                         ac->ac_last_group = *bg_blkno;
1573         }
1574
1575 bail:
1576         mlog_exit(status);
1577         return status;
1578 }
1579
1580 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1581                          handle_t *handle,
1582                          struct ocfs2_alloc_context *ac,
1583                          u32 bits_wanted,
1584                          u16 *suballoc_bit_start,
1585                          unsigned int *num_bits,
1586                          u64 *blkno_start)
1587 {
1588         int status;
1589         u64 bg_blkno;
1590
1591         BUG_ON(!ac);
1592         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1593         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1594
1595         status = ocfs2_claim_suballoc_bits(osb,
1596                                            ac,
1597                                            handle,
1598                                            bits_wanted,
1599                                            1,
1600                                            suballoc_bit_start,
1601                                            num_bits,
1602                                            &bg_blkno);
1603         if (status < 0) {
1604                 mlog_errno(status);
1605                 goto bail;
1606         }
1607         atomic_inc(&osb->alloc_stats.bg_allocs);
1608
1609         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1610         ac->ac_bits_given += (*num_bits);
1611         status = 0;
1612 bail:
1613         mlog_exit(status);
1614         return status;
1615 }
1616
1617 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1618                           handle_t *handle,
1619                           struct ocfs2_alloc_context *ac,
1620                           u16 *suballoc_bit,
1621                           u64 *fe_blkno)
1622 {
1623         int status;
1624         unsigned int num_bits;
1625         u64 bg_blkno;
1626
1627         mlog_entry_void();
1628
1629         BUG_ON(!ac);
1630         BUG_ON(ac->ac_bits_given != 0);
1631         BUG_ON(ac->ac_bits_wanted != 1);
1632         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1633
1634         status = ocfs2_claim_suballoc_bits(osb,
1635                                            ac,
1636                                            handle,
1637                                            1,
1638                                            1,
1639                                            suballoc_bit,
1640                                            &num_bits,
1641                                            &bg_blkno);
1642         if (status < 0) {
1643                 mlog_errno(status);
1644                 goto bail;
1645         }
1646         atomic_inc(&osb->alloc_stats.bg_allocs);
1647
1648         BUG_ON(num_bits != 1);
1649
1650         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1651         ac->ac_bits_given++;
1652         status = 0;
1653 bail:
1654         mlog_exit(status);
1655         return status;
1656 }
1657
1658 /* translate a group desc. blkno and it's bitmap offset into
1659  * disk cluster offset. */
1660 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1661                                                    u64 bg_blkno,
1662                                                    u16 bg_bit_off)
1663 {
1664         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1665         u32 cluster = 0;
1666
1667         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1668
1669         if (bg_blkno != osb->first_cluster_group_blkno)
1670                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1671         cluster += (u32) bg_bit_off;
1672         return cluster;
1673 }
1674
1675 /* given a cluster offset, calculate which block group it belongs to
1676  * and return that block offset. */
1677 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
1678 {
1679         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1680         u32 group_no;
1681
1682         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1683
1684         group_no = cluster / osb->bitmap_cpg;
1685         if (!group_no)
1686                 return osb->first_cluster_group_blkno;
1687         return ocfs2_clusters_to_blocks(inode->i_sb,
1688                                         group_no * osb->bitmap_cpg);
1689 }
1690
1691 /* given the block number of a cluster start, calculate which cluster
1692  * group and descriptor bitmap offset that corresponds to. */
1693 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1694                                                 u64 data_blkno,
1695                                                 u64 *bg_blkno,
1696                                                 u16 *bg_bit_off)
1697 {
1698         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1699         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1700
1701         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1702
1703         *bg_blkno = ocfs2_which_cluster_group(inode,
1704                                               data_cluster);
1705
1706         if (*bg_blkno == osb->first_cluster_group_blkno)
1707                 *bg_bit_off = (u16) data_cluster;
1708         else
1709                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1710                                                              data_blkno - *bg_blkno);
1711 }
1712
1713 /*
1714  * min_bits - minimum contiguous chunk from this total allocation we
1715  * can handle. set to what we asked for originally for a full
1716  * contig. allocation, set to '1' to indicate we can deal with extents
1717  * of any size.
1718  */
1719 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
1720                            handle_t *handle,
1721                            struct ocfs2_alloc_context *ac,
1722                            u32 min_clusters,
1723                            u32 max_clusters,
1724                            u32 *cluster_start,
1725                            u32 *num_clusters)
1726 {
1727         int status;
1728         unsigned int bits_wanted = max_clusters;
1729         u64 bg_blkno = 0;
1730         u16 bg_bit_off;
1731
1732         mlog_entry_void();
1733
1734         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1735
1736         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1737                && ac->ac_which != OCFS2_AC_USE_MAIN);
1738
1739         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1740                 status = ocfs2_claim_local_alloc_bits(osb,
1741                                                       handle,
1742                                                       ac,
1743                                                       bits_wanted,
1744                                                       cluster_start,
1745                                                       num_clusters);
1746                 if (!status)
1747                         atomic_inc(&osb->alloc_stats.local_data);
1748         } else {
1749                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1750                         /* The only paths asking for contiguousness
1751                          * should know about this already. */
1752                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
1753                              "group bitmap size %u!\n", min_clusters,
1754                              osb->bitmap_cpg);
1755                         status = -ENOSPC;
1756                         goto bail;
1757                 }
1758                 /* clamp the current request down to a realistic size. */
1759                 if (bits_wanted > (osb->bitmap_cpg - 1))
1760                         bits_wanted = osb->bitmap_cpg - 1;
1761
1762                 status = ocfs2_claim_suballoc_bits(osb,
1763                                                    ac,
1764                                                    handle,
1765                                                    bits_wanted,
1766                                                    min_clusters,
1767                                                    &bg_bit_off,
1768                                                    num_clusters,
1769                                                    &bg_blkno);
1770                 if (!status) {
1771                         *cluster_start =
1772                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1773                                                                  bg_blkno,
1774                                                                  bg_bit_off);
1775                         atomic_inc(&osb->alloc_stats.bitmap_data);
1776                 }
1777         }
1778         if (status < 0) {
1779                 if (status != -ENOSPC)
1780                         mlog_errno(status);
1781                 goto bail;
1782         }
1783
1784         ac->ac_bits_given += *num_clusters;
1785
1786 bail:
1787         mlog_exit(status);
1788         return status;
1789 }
1790
1791 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1792                          handle_t *handle,
1793                          struct ocfs2_alloc_context *ac,
1794                          u32 min_clusters,
1795                          u32 *cluster_start,
1796                          u32 *num_clusters)
1797 {
1798         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1799
1800         return __ocfs2_claim_clusters(osb, handle, ac, min_clusters,
1801                                       bits_wanted, cluster_start, num_clusters);
1802 }
1803
1804 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
1805                                                struct inode *alloc_inode,
1806                                                struct ocfs2_group_desc *bg,
1807                                                struct buffer_head *group_bh,
1808                                                unsigned int bit_off,
1809                                                unsigned int num_bits)
1810 {
1811         int status;
1812         unsigned int tmp;
1813         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1814         struct ocfs2_group_desc *undo_bg = NULL;
1815
1816         mlog_entry_void();
1817
1818         /* The caller got this descriptor from
1819          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1820         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1821
1822         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1823
1824         if (ocfs2_is_cluster_bitmap(alloc_inode))
1825                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1826
1827         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1828                                       journal_type);
1829         if (status < 0) {
1830                 mlog_errno(status);
1831                 goto bail;
1832         }
1833
1834         if (ocfs2_is_cluster_bitmap(alloc_inode))
1835                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1836
1837         tmp = num_bits;
1838         while(tmp--) {
1839                 ocfs2_clear_bit((bit_off + tmp),
1840                                 (unsigned long *) bg->bg_bitmap);
1841                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1842                         ocfs2_set_bit(bit_off + tmp,
1843                                       (unsigned long *) undo_bg->bg_bitmap);
1844         }
1845         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1846
1847         status = ocfs2_journal_dirty(handle, group_bh);
1848         if (status < 0)
1849                 mlog_errno(status);
1850 bail:
1851         return status;
1852 }
1853
1854 /*
1855  * expects the suballoc inode to already be locked.
1856  */
1857 int ocfs2_free_suballoc_bits(handle_t *handle,
1858                              struct inode *alloc_inode,
1859                              struct buffer_head *alloc_bh,
1860                              unsigned int start_bit,
1861                              u64 bg_blkno,
1862                              unsigned int count)
1863 {
1864         int status = 0;
1865         u32 tmp_used;
1866         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1867         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1868         struct buffer_head *group_bh = NULL;
1869         struct ocfs2_group_desc *group;
1870
1871         mlog_entry_void();
1872
1873         /* The alloc_bh comes from ocfs2_free_dinode() or
1874          * ocfs2_free_clusters().  The callers have all locked the
1875          * allocator and gotten alloc_bh from the lock call.  This
1876          * validates the dinode buffer.  Any corruption that has happended
1877          * is a code bug. */
1878         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1879         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1880
1881         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1882              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1883              (unsigned long long)bg_blkno, start_bit);
1884
1885         status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
1886                                              &group_bh);
1887         if (status < 0) {
1888                 mlog_errno(status);
1889                 goto bail;
1890         }
1891         group = (struct ocfs2_group_desc *) group_bh->b_data;
1892
1893         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1894
1895         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1896                                               group, group_bh,
1897                                               start_bit, count);
1898         if (status < 0) {
1899                 mlog_errno(status);
1900                 goto bail;
1901         }
1902
1903         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1904                                       OCFS2_JOURNAL_ACCESS_WRITE);
1905         if (status < 0) {
1906                 mlog_errno(status);
1907                 goto bail;
1908         }
1909
1910         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1911                      count);
1912         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1913         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1914
1915         status = ocfs2_journal_dirty(handle, alloc_bh);
1916         if (status < 0) {
1917                 mlog_errno(status);
1918                 goto bail;
1919         }
1920
1921 bail:
1922         brelse(group_bh);
1923
1924         mlog_exit(status);
1925         return status;
1926 }
1927
1928 int ocfs2_free_dinode(handle_t *handle,
1929                       struct inode *inode_alloc_inode,
1930                       struct buffer_head *inode_alloc_bh,
1931                       struct ocfs2_dinode *di)
1932 {
1933         u64 blk = le64_to_cpu(di->i_blkno);
1934         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1935         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1936
1937         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1938                                         inode_alloc_bh, bit, bg_blkno, 1);
1939 }
1940
1941 int ocfs2_free_clusters(handle_t *handle,
1942                        struct inode *bitmap_inode,
1943                        struct buffer_head *bitmap_bh,
1944                        u64 start_blk,
1945                        unsigned int num_clusters)
1946 {
1947         int status;
1948         u16 bg_start_bit;
1949         u64 bg_blkno;
1950         struct ocfs2_dinode *fe;
1951
1952         /* You can't ever have a contiguous set of clusters
1953          * bigger than a block group bitmap so we never have to worry
1954          * about looping on them. */
1955
1956         mlog_entry_void();
1957
1958         /* This is expensive. We can safely remove once this stuff has
1959          * gotten tested really well. */
1960         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1961
1962         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1963
1964         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1965                                      &bg_start_bit);
1966
1967         mlog(0, "want to free %u clusters starting at block %llu\n",
1968              num_clusters, (unsigned long long)start_blk);
1969         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1970              (unsigned long long)bg_blkno, bg_start_bit);
1971
1972         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1973                                           bg_start_bit, bg_blkno,
1974                                           num_clusters);
1975         if (status < 0) {
1976                 mlog_errno(status);
1977                 goto out;
1978         }
1979
1980         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
1981                                          num_clusters);
1982
1983 out:
1984         mlog_exit(status);
1985         return status;
1986 }
1987
1988 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1989 {
1990         printk("Block Group:\n");
1991         printk("bg_signature:       %s\n", bg->bg_signature);
1992         printk("bg_size:            %u\n", bg->bg_size);
1993         printk("bg_bits:            %u\n", bg->bg_bits);
1994         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1995         printk("bg_chain:           %u\n", bg->bg_chain);
1996         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1997         printk("bg_next_group:      %llu\n",
1998                (unsigned long long)bg->bg_next_group);
1999         printk("bg_parent_dinode:   %llu\n",
2000                (unsigned long long)bg->bg_parent_dinode);
2001         printk("bg_blkno:           %llu\n",
2002                (unsigned long long)bg->bg_blkno);
2003 }
2004
2005 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
2006 {
2007         int i;
2008
2009         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
2010         printk("i_signature:                  %s\n", fe->i_signature);
2011         printk("i_size:                       %llu\n",
2012                (unsigned long long)fe->i_size);
2013         printk("i_clusters:                   %u\n", fe->i_clusters);
2014         printk("i_generation:                 %u\n",
2015                le32_to_cpu(fe->i_generation));
2016         printk("id1.bitmap1.i_used:           %u\n",
2017                le32_to_cpu(fe->id1.bitmap1.i_used));
2018         printk("id1.bitmap1.i_total:          %u\n",
2019                le32_to_cpu(fe->id1.bitmap1.i_total));
2020         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
2021         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
2022         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
2023         printk("id2.i_chain.cl_next_free_rec: %u\n",
2024                fe->id2.i_chain.cl_next_free_rec);
2025         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
2026                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
2027                        fe->id2.i_chain.cl_recs[i].c_free);
2028                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
2029                        fe->id2.i_chain.cl_recs[i].c_total);
2030                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
2031                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
2032         }
2033 }
2034
2035 /*
2036  * For a given allocation, determine which allocators will need to be
2037  * accessed, and lock them, reserving the appropriate number of bits.
2038  *
2039  * Sparse file systems call this from ocfs2_write_begin_nolock()
2040  * and ocfs2_allocate_unwritten_extents().
2041  *
2042  * File systems which don't support holes call this from
2043  * ocfs2_extend_allocation().
2044  */
2045 int ocfs2_lock_allocators(struct inode *inode,
2046                           struct ocfs2_extent_tree *et,
2047                           u32 clusters_to_add, u32 extents_to_split,
2048                           struct ocfs2_alloc_context **data_ac,
2049                           struct ocfs2_alloc_context **meta_ac)
2050 {
2051         int ret = 0, num_free_extents;
2052         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2053         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2054
2055         *meta_ac = NULL;
2056         if (data_ac)
2057                 *data_ac = NULL;
2058
2059         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2060
2061         num_free_extents = ocfs2_num_free_extents(osb, inode, et);
2062         if (num_free_extents < 0) {
2063                 ret = num_free_extents;
2064                 mlog_errno(ret);
2065                 goto out;
2066         }
2067
2068         /*
2069          * Sparse allocation file systems need to be more conservative
2070          * with reserving room for expansion - the actual allocation
2071          * happens while we've got a journal handle open so re-taking
2072          * a cluster lock (because we ran out of room for another
2073          * extent) will violate ordering rules.
2074          *
2075          * Most of the time we'll only be seeing this 1 cluster at a time
2076          * anyway.
2077          *
2078          * Always lock for any unwritten extents - we might want to
2079          * add blocks during a split.
2080          */
2081         if (!num_free_extents ||
2082             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2083                 ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2084                 if (ret < 0) {
2085                         if (ret != -ENOSPC)
2086                                 mlog_errno(ret);
2087                         goto out;
2088                 }
2089         }
2090
2091         if (clusters_to_add == 0)
2092                 goto out;
2093
2094         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2095         if (ret < 0) {
2096                 if (ret != -ENOSPC)
2097                         mlog_errno(ret);
2098                 goto out;
2099         }
2100
2101 out:
2102         if (ret) {
2103                 if (*meta_ac) {
2104                         ocfs2_free_alloc_context(*meta_ac);
2105                         *meta_ac = NULL;
2106                 }
2107
2108                 /*
2109                  * We cannot have an error and a non null *data_ac.
2110                  */
2111         }
2112
2113         return ret;
2114 }