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 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
  50 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
  51 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  52 static int ocfs2_block_group_fill(handle_t *handle,
  53                                   struct inode *alloc_inode,
  54                                   struct buffer_head *bg_bh,
  55                                   u64 group_blkno,
  56                                   u16 my_chain,
  57                                   struct ocfs2_chain_list *cl);
  58 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  59                                    struct inode *alloc_inode,
  60                                    struct buffer_head *bh);
  61
  62 static int ocfs2_cluster_group_search(struct inode *inode,
  63                                       struct buffer_head *group_bh,
  64                                       u32 bits_wanted, u32 min_bits,
  65                                       u16 *bit_off, u16 *bits_found);
  66 static int ocfs2_block_group_search(struct inode *inode,
  67                                     struct buffer_head *group_bh,
  68                                     u32 bits_wanted, u32 min_bits,
  69                                     u16 *bit_off, u16 *bits_found);
  70 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
  71                                      struct ocfs2_alloc_context *ac,
  72                                      handle_t *handle,
  73                                      u32 bits_wanted,
  74                                      u32 min_bits,
  75                                      u16 *bit_off,
  76                                      unsigned int *num_bits,
  77                                      u64 *bg_blkno);
  78 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  79                                          int nr);
  80 static inline int ocfs2_block_group_set_bits(handle_t *handle,
  81                                              struct inode *alloc_inode,
  82                                              struct ocfs2_group_desc *bg,
  83                                              struct buffer_head *group_bh,
  84                                              unsigned int bit_off,
  85                                              unsigned int num_bits);
  86 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
  87                                                struct inode *alloc_inode,
  88                                                struct ocfs2_group_desc *bg,
  89                                                struct buffer_head *group_bh,
  90                                                unsigned int bit_off,
  91                                                unsigned int num_bits);
  92
  93 static int ocfs2_relink_block_group(handle_t *handle,
  94                                     struct inode *alloc_inode,
  95                                     struct buffer_head *fe_bh,
  96                                     struct buffer_head *bg_bh,
  97                                     struct buffer_head *prev_bg_bh,
  98                                     u16 chain);
  99 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 100                                                      u32 wanted);
 101 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 102                                                    u64 bg_blkno,
 103                                                    u16 bg_bit_off);
 104 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
 105                                             u32 cluster);
 106 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 107                                                 u64 data_blkno,
 108                                                 u64 *bg_blkno,
 109                                                 u16 *bg_bit_off);
 110
 111 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 112 {
 113         struct inode *inode = ac->ac_inode;
 114
 115         if (inode) {
 116                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 117                         ocfs2_meta_unlock(inode, 1);
 118
 119                 mutex_unlock(&inode->i_mutex);
 120
 121                 iput(inode);
 122         }
 123         if (ac->ac_bh)
 124                 brelse(ac->ac_bh);
 125         kfree(ac);
 126 }
 127
 128 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 129 {
 130         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 131 }
 132
 133 /* somewhat more expensive than our other checks, so use sparingly. */
 134 static int ocfs2_check_group_descriptor(struct super_block *sb,
 135                                         struct ocfs2_dinode *di,
 136                                         struct ocfs2_group_desc *gd)
 137 {
 138         unsigned int max_bits;
 139
 140         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 141                 OCFS2_RO_ON_INVALID_GROUP_DESC(sb, gd);
 142                 return -EIO;
 143         }
 144
 145         if (di->i_blkno != gd->bg_parent_dinode) {
 146                 ocfs2_error(sb, "Group descriptor # %llu has bad parent "
 147                             "pointer (%llu, expected %llu)",
 148                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 149                             (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 150                             (unsigned long long)le64_to_cpu(di->i_blkno));
 151                 return -EIO;
 152         }
 153
 154         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 155         if (le16_to_cpu(gd->bg_bits) > max_bits) {
 156                 ocfs2_error(sb, "Group descriptor # %llu has bit count of %u",
 157                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 158                             le16_to_cpu(gd->bg_bits));
 159                 return -EIO;
 160         }
 161
 162         if (le16_to_cpu(gd->bg_chain) >=
 163             le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) {
 164                 ocfs2_error(sb, "Group descriptor # %llu has bad chain %u",
 165                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 166                             le16_to_cpu(gd->bg_chain));
 167                 return -EIO;
 168         }
 169
 170         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 171                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 172                             "claims that %u are free",
 173                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 174                             le16_to_cpu(gd->bg_bits),
 175                             le16_to_cpu(gd->bg_free_bits_count));
 176                 return -EIO;
 177         }
 178
 179         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 180                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 181                             "max bitmap bits of %u",
 182                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 183                             le16_to_cpu(gd->bg_bits),
 184                             8 * le16_to_cpu(gd->bg_size));
 185                 return -EIO;
 186         }
 187
 188         return 0;
 189 }
 190
 191 static int ocfs2_block_group_fill(handle_t *handle,
 192                                   struct inode *alloc_inode,
 193                                   struct buffer_head *bg_bh,
 194                                   u64 group_blkno,
 195                                   u16 my_chain,
 196                                   struct ocfs2_chain_list *cl)
 197 {
 198         int status = 0;
 199         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 200         struct super_block * sb = alloc_inode->i_sb;
 201
 202         mlog_entry_void();
 203
 204         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 205                 ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
 206                             "b_blocknr (%llu)",
 207                             (unsigned long long)group_blkno,
 208                             (unsigned long long) bg_bh->b_blocknr);
 209                 status = -EIO;
 210                 goto bail;
 211         }
 212
 213         status = ocfs2_journal_access(handle,
 214                                       alloc_inode,
 215                                       bg_bh,
 216                                       OCFS2_JOURNAL_ACCESS_CREATE);
 217         if (status < 0) {
 218                 mlog_errno(status);
 219                 goto bail;
 220         }
 221
 222         memset(bg, 0, sb->s_blocksize);
 223         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 224         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 225         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
 226         bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 227         bg->bg_chain = cpu_to_le16(my_chain);
 228         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 229         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 230         bg->bg_blkno = cpu_to_le64(group_blkno);
 231         /* set the 1st bit in the bitmap to account for the descriptor block */
 232         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 233         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 234
 235         status = ocfs2_journal_dirty(handle, bg_bh);
 236         if (status < 0)
 237                 mlog_errno(status);
 238
 239         /* There is no need to zero out or otherwise initialize the
 240          * other blocks in a group - All valid FS metadata in a block
 241          * group stores the superblock fs_generation value at
 242          * allocation time. */
 243
 244 bail:
 245         mlog_exit(status);
 246         return status;
 247 }
 248
 249 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 250 {
 251         u16 curr, best;
 252
 253         best = curr = 0;
 254         while (curr < le16_to_cpu(cl->cl_count)) {
 255                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 256                     le32_to_cpu(cl->cl_recs[curr].c_total))
 257                         best = curr;
 258                 curr++;
 259         }
 260         return best;
 261 }
 262
 263 /*
 264  * We expect the block group allocator to already be locked.
 265  */
 266 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 267                                    struct inode *alloc_inode,
 268                                    struct buffer_head *bh)
 269 {
 270         int status, credits;
 271         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 272         struct ocfs2_chain_list *cl;
 273         struct ocfs2_alloc_context *ac = NULL;
 274         handle_t *handle = NULL;
 275         u32 bit_off, num_bits;
 276         u16 alloc_rec;
 277         u64 bg_blkno;
 278         struct buffer_head *bg_bh = NULL;
 279         struct ocfs2_group_desc *bg;
 280
 281         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 282
 283         mlog_entry_void();
 284
 285         cl = &fe->id2.i_chain;
 286         status = ocfs2_reserve_clusters(osb,
 287                                         le16_to_cpu(cl->cl_cpg),
 288                                         &ac);
 289         if (status < 0) {
 290                 if (status != -ENOSPC)
 291                         mlog_errno(status);
 292                 goto bail;
 293         }
 294
 295         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 296                                                  le16_to_cpu(cl->cl_cpg));
 297         handle = ocfs2_start_trans(osb, credits);
 298         if (IS_ERR(handle)) {
 299                 status = PTR_ERR(handle);
 300                 handle = NULL;
 301                 mlog_errno(status);
 302                 goto bail;
 303         }
 304
 305         status = ocfs2_claim_clusters(osb,
 306                                       handle,
 307                                       ac,
 308                                       le16_to_cpu(cl->cl_cpg),
 309                                       &bit_off,
 310                                       &num_bits);
 311         if (status < 0) {
 312                 if (status != -ENOSPC)
 313                         mlog_errno(status);
 314                 goto bail;
 315         }
 316
 317         alloc_rec = ocfs2_find_smallest_chain(cl);
 318
 319         /* setup the group */
 320         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 321         mlog(0, "new descriptor, record %u, at block %llu\n",
 322              alloc_rec, (unsigned long long)bg_blkno);
 323
 324         bg_bh = sb_getblk(osb->sb, bg_blkno);
 325         if (!bg_bh) {
 326                 status = -EIO;
 327                 mlog_errno(status);
 328                 goto bail;
 329         }
 330         ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);
 331
 332         status = ocfs2_block_group_fill(handle,
 333                                         alloc_inode,
 334                                         bg_bh,
 335                                         bg_blkno,
 336                                         alloc_rec,
 337                                         cl);
 338         if (status < 0) {
 339                 mlog_errno(status);
 340                 goto bail;
 341         }
 342
 343         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 344
 345         status = ocfs2_journal_access(handle, alloc_inode,
 346                                       bh, OCFS2_JOURNAL_ACCESS_WRITE);
 347         if (status < 0) {
 348                 mlog_errno(status);
 349                 goto bail;
 350         }
 351
 352         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 353                      le16_to_cpu(bg->bg_free_bits_count));
 354         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
 355         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
 356         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 357                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 358
 359         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 360                                         le16_to_cpu(bg->bg_free_bits_count));
 361         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 362         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 363
 364         status = ocfs2_journal_dirty(handle, bh);
 365         if (status < 0) {
 366                 mlog_errno(status);
 367                 goto bail;
 368         }
 369
 370         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 371         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 372         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 373                                              le32_to_cpu(fe->i_clusters)));
 374         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 375         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 376         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 377
 378         status = 0;
 379 bail:
 380         if (handle)
 381                 ocfs2_commit_trans(osb, handle);
 382
 383         if (ac)
 384                 ocfs2_free_alloc_context(ac);
 385
 386         if (bg_bh)
 387                 brelse(bg_bh);
 388
 389         mlog_exit(status);
 390         return status;
 391 }
 392
 393 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 394                                        struct ocfs2_alloc_context *ac,
 395                                        int type,
 396                                        u32 slot)
 397 {
 398         int status;
 399         u32 bits_wanted = ac->ac_bits_wanted;
 400         struct inode *alloc_inode;
 401         struct buffer_head *bh = NULL;
 402         struct ocfs2_dinode *fe;
 403         u32 free_bits;
 404
 405         mlog_entry_void();
 406
 407         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 408         if (!alloc_inode) {
 409                 mlog_errno(-EINVAL);
 410                 return -EINVAL;
 411         }
 412
 413         mutex_lock(&alloc_inode->i_mutex);
 414
 415         status = ocfs2_meta_lock(alloc_inode, &bh, 1);
 416         if (status < 0) {
 417                 mutex_unlock(&alloc_inode->i_mutex);
 418                 iput(alloc_inode);
 419
 420                 mlog_errno(status);
 421                 return status;
 422         }
 423
 424         ac->ac_inode = alloc_inode;
 425
 426         fe = (struct ocfs2_dinode *) bh->b_data;
 427         if (!OCFS2_IS_VALID_DINODE(fe)) {
 428                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 429                 status = -EIO;
 430                 goto bail;
 431         }
 432         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 433                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 434                             (unsigned long long)le64_to_cpu(fe->i_blkno));
 435                 status = -EIO;
 436                 goto bail;
 437         }
 438
 439         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 440                 le32_to_cpu(fe->id1.bitmap1.i_used);
 441
 442         if (bits_wanted > free_bits) {
 443                 /* cluster bitmap never grows */
 444                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 445                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
 446                              bits_wanted, free_bits);
 447                         status = -ENOSPC;
 448                         goto bail;
 449                 }
 450
 451                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh);
 452                 if (status < 0) {
 453                         if (status != -ENOSPC)
 454                                 mlog_errno(status);
 455                         goto bail;
 456                 }
 457                 atomic_inc(&osb->alloc_stats.bg_extends);
 458
 459                 /* You should never ask for this much metadata */
 460                 BUG_ON(bits_wanted >
 461                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 462                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 463         }
 464
 465         get_bh(bh);
 466         ac->ac_bh = bh;
 467 bail:
 468         if (bh)
 469                 brelse(bh);
 470
 471         mlog_exit(status);
 472         return status;
 473 }
 474
 475 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
 476                                struct ocfs2_dinode *fe,
 477                                struct ocfs2_alloc_context **ac)
 478 {
 479         int status;
 480         u32 slot;
 481
 482         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 483         if (!(*ac)) {
 484                 status = -ENOMEM;
 485                 mlog_errno(status);
 486                 goto bail;
 487         }
 488
 489         (*ac)->ac_bits_wanted = ocfs2_extend_meta_needed(fe);
 490         (*ac)->ac_which = OCFS2_AC_USE_META;
 491         slot = osb->slot_num;
 492         (*ac)->ac_group_search = ocfs2_block_group_search;
 493
 494         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 495                                              EXTENT_ALLOC_SYSTEM_INODE, slot);
 496         if (status < 0) {
 497                 if (status != -ENOSPC)
 498                         mlog_errno(status);
 499                 goto bail;
 500         }
 501
 502         status = 0;
 503 bail:
 504         if ((status < 0) && *ac) {
 505                 ocfs2_free_alloc_context(*ac);
 506                 *ac = NULL;
 507         }
 508
 509         mlog_exit(status);
 510         return status;
 511 }
 512
 513 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 514                             struct ocfs2_alloc_context **ac)
 515 {
 516         int status;
 517
 518         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 519         if (!(*ac)) {
 520                 status = -ENOMEM;
 521                 mlog_errno(status);
 522                 goto bail;
 523         }
 524
 525         (*ac)->ac_bits_wanted = 1;
 526         (*ac)->ac_which = OCFS2_AC_USE_INODE;
 527
 528         (*ac)->ac_group_search = ocfs2_block_group_search;
 529
 530         status = ocfs2_reserve_suballoc_bits(osb, *ac,
 531                                              INODE_ALLOC_SYSTEM_INODE,
 532                                              osb->slot_num);
 533         if (status < 0) {
 534                 if (status != -ENOSPC)
 535                         mlog_errno(status);
 536                 goto bail;
 537         }
 538
 539         status = 0;
 540 bail:
 541         if ((status < 0) && *ac) {
 542                 ocfs2_free_alloc_context(*ac);
 543                 *ac = NULL;
 544         }
 545
 546         mlog_exit(status);
 547         return status;
 548 }
 549
 550 /* local alloc code has to do the same thing, so rather than do this
 551  * twice.. */
 552 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
 553                                       struct ocfs2_alloc_context *ac)
 554 {
 555         int status;
 556
 557         ac->ac_which = OCFS2_AC_USE_MAIN;
 558         ac->ac_group_search = ocfs2_cluster_group_search;
 559
 560         status = ocfs2_reserve_suballoc_bits(osb, ac,
 561                                              GLOBAL_BITMAP_SYSTEM_INODE,
 562                                              OCFS2_INVALID_SLOT);
 563         if (status < 0 && status != -ENOSPC) {
 564                 mlog_errno(status);
 565                 goto bail;
 566         }
 567
 568 bail:
 569         return status;
 570 }
 571
 572 /* Callers don't need to care which bitmap (local alloc or main) to
 573  * use so we figure it out for them, but unfortunately this clutters
 574  * things a bit. */
 575 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
 576                            u32 bits_wanted,
 577                            struct ocfs2_alloc_context **ac)
 578 {
 579         int status;
 580
 581         mlog_entry_void();
 582
 583         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 584         if (!(*ac)) {
 585                 status = -ENOMEM;
 586                 mlog_errno(status);
 587                 goto bail;
 588         }
 589
 590         (*ac)->ac_bits_wanted = bits_wanted;
 591
 592         status = -ENOSPC;
 593         if (ocfs2_alloc_should_use_local(osb, bits_wanted)) {
 594                 status = ocfs2_reserve_local_alloc_bits(osb,
 595                                                         bits_wanted,
 596                                                         *ac);
 597                 if ((status < 0) && (status != -ENOSPC)) {
 598                         mlog_errno(status);
 599                         goto bail;
 600                 } else if (status == -ENOSPC) {
 601                         /* reserve_local_bits will return enospc with
 602                          * the local alloc inode still locked, so we
 603                          * can change this safely here. */
 604                         mlog(0, "Disabling local alloc\n");
 605                         /* We set to OCFS2_LA_DISABLED so that umount
 606                          * can clean up what's left of the local
 607                          * allocation */
 608                         osb->local_alloc_state = OCFS2_LA_DISABLED;
 609                 }
 610         }
 611
 612         if (status == -ENOSPC) {
 613                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 614                 if (status < 0) {
 615                         if (status != -ENOSPC)
 616                                 mlog_errno(status);
 617                         goto bail;
 618                 }
 619         }
 620
 621         status = 0;
 622 bail:
 623         if ((status < 0) && *ac) {
 624                 ocfs2_free_alloc_context(*ac);
 625                 *ac = NULL;
 626         }
 627
 628         mlog_exit(status);
 629         return status;
 630 }
 631
 632 /*
 633  * More or less lifted from ext3. I'll leave their description below:
 634  *
 635  * "For ext3 allocations, we must not reuse any blocks which are
 636  * allocated in the bitmap buffer's "last committed data" copy.  This
 637  * prevents deletes from freeing up the page for reuse until we have
 638  * committed the delete transaction.
 639  *
 640  * If we didn't do this, then deleting something and reallocating it as
 641  * data would allow the old block to be overwritten before the
 642  * transaction committed (because we force data to disk before commit).
 643  * This would lead to corruption if we crashed between overwriting the
 644  * data and committing the delete.
 645  *
 646  * @@@ We may want to make this allocation behaviour conditional on
 647  * data-writes at some point, and disable it for metadata allocations or
 648  * sync-data inodes."
 649  *
 650  * Note: OCFS2 already does this differently for metadata vs data
 651  * allocations, as those bitmaps are seperate and undo access is never
 652  * called on a metadata group descriptor.
 653  */
 654 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 655                                          int nr)
 656 {
 657         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 658
 659         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
 660                 return 0;
 661         if (!buffer_jbd(bg_bh) || !bh2jh(bg_bh)->b_committed_data)
 662                 return 1;
 663
 664         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
 665         return !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
 666 }
 667
 668 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
 669                                              struct buffer_head *bg_bh,
 670                                              unsigned int bits_wanted,
 671                                              unsigned int total_bits,
 672                                              u16 *bit_off,
 673                                              u16 *bits_found)
 674 {
 675         void *bitmap;
 676         u16 best_offset, best_size;
 677         int offset, start, found, status = 0;
 678         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 679
 680         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 681                 OCFS2_RO_ON_INVALID_GROUP_DESC(osb->sb, bg);
 682                 return -EIO;
 683         }
 684
 685         found = start = best_offset = best_size = 0;
 686         bitmap = bg->bg_bitmap;
 687
 688         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
 689                 if (offset == total_bits)
 690                         break;
 691
 692                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
 693                         /* We found a zero, but we can't use it as it
 694                          * hasn't been put to disk yet! */
 695                         found = 0;
 696                         start = offset + 1;
 697                 } else if (offset == start) {
 698                         /* we found a zero */
 699                         found++;
 700                         /* move start to the next bit to test */
 701                         start++;
 702                 } else {
 703                         /* got a zero after some ones */
 704                         found = 1;
 705                         start = offset + 1;
 706                 }
 707                 if (found > best_size) {
 708                         best_size = found;
 709                         best_offset = start - found;
 710                 }
 711                 /* we got everything we needed */
 712                 if (found == bits_wanted) {
 713                         /* mlog(0, "Found it all!\n"); */
 714                         break;
 715                 }
 716         }
 717
 718         /* XXX: I think the first clause is equivalent to the second
 719          *      - jlbec */
 720         if (found == bits_wanted) {
 721                 *bit_off = start - found;
 722                 *bits_found = found;
 723         } else if (best_size) {
 724                 *bit_off = best_offset;
 725                 *bits_found = best_size;
 726         } else {
 727                 status = -ENOSPC;
 728                 /* No error log here -- see the comment above
 729                  * ocfs2_test_bg_bit_allocatable */
 730         }
 731
 732         return status;
 733 }
 734
 735 static inline int ocfs2_block_group_set_bits(handle_t *handle,
 736                                              struct inode *alloc_inode,
 737                                              struct ocfs2_group_desc *bg,
 738                                              struct buffer_head *group_bh,
 739                                              unsigned int bit_off,
 740                                              unsigned int num_bits)
 741 {
 742         int status;
 743         void *bitmap = bg->bg_bitmap;
 744         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
 745
 746         mlog_entry_void();
 747
 748         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 749                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 750                 status = -EIO;
 751                 goto bail;
 752         }
 753         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
 754
 755         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
 756              num_bits);
 757
 758         if (ocfs2_is_cluster_bitmap(alloc_inode))
 759                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
 760
 761         status = ocfs2_journal_access(handle,
 762                                       alloc_inode,
 763                                       group_bh,
 764                                       journal_type);
 765         if (status < 0) {
 766                 mlog_errno(status);
 767                 goto bail;
 768         }
 769
 770         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
 771
 772         while(num_bits--)
 773                 ocfs2_set_bit(bit_off++, bitmap);
 774
 775         status = ocfs2_journal_dirty(handle,
 776                                      group_bh);
 777         if (status < 0) {
 778                 mlog_errno(status);
 779                 goto bail;
 780         }
 781
 782 bail:
 783         mlog_exit(status);
 784         return status;
 785 }
 786
 787 /* find the one with the most empty bits */
 788 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
 789 {
 790         u16 curr, best;
 791
 792         BUG_ON(!cl->cl_next_free_rec);
 793
 794         best = curr = 0;
 795         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
 796                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
 797                     le32_to_cpu(cl->cl_recs[best].c_free))
 798                         best = curr;
 799                 curr++;
 800         }
 801
 802         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
 803         return best;
 804 }
 805
 806 static int ocfs2_relink_block_group(handle_t *handle,
 807                                     struct inode *alloc_inode,
 808                                     struct buffer_head *fe_bh,
 809                                     struct buffer_head *bg_bh,
 810                                     struct buffer_head *prev_bg_bh,
 811                                     u16 chain)
 812 {
 813         int status;
 814         /* there is a really tiny chance the journal calls could fail,
 815          * but we wouldn't want inconsistent blocks in *any* case. */
 816         u64 fe_ptr, bg_ptr, prev_bg_ptr;
 817         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
 818         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 819         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
 820
 821         if (!OCFS2_IS_VALID_DINODE(fe)) {
 822                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 823                 status = -EIO;
 824                 goto out;
 825         }
 826         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 827                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 828                 status = -EIO;
 829                 goto out;
 830         }
 831         if (!OCFS2_IS_VALID_GROUP_DESC(prev_bg)) {
 832                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, prev_bg);
 833                 status = -EIO;
 834                 goto out;
 835         }
 836
 837         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
 838              (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
 839              (unsigned long long)le64_to_cpu(bg->bg_blkno),
 840              (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
 841
 842         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
 843         bg_ptr = le64_to_cpu(bg->bg_next_group);
 844         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
 845
 846         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
 847                                       OCFS2_JOURNAL_ACCESS_WRITE);
 848         if (status < 0) {
 849                 mlog_errno(status);
 850                 goto out_rollback;
 851         }
 852
 853         prev_bg->bg_next_group = bg->bg_next_group;
 854
 855         status = ocfs2_journal_dirty(handle, prev_bg_bh);
 856         if (status < 0) {
 857                 mlog_errno(status);
 858                 goto out_rollback;
 859         }
 860
 861         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
 862                                       OCFS2_JOURNAL_ACCESS_WRITE);
 863         if (status < 0) {
 864                 mlog_errno(status);
 865                 goto out_rollback;
 866         }
 867
 868         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
 869
 870         status = ocfs2_journal_dirty(handle, bg_bh);
 871         if (status < 0) {
 872                 mlog_errno(status);
 873                 goto out_rollback;
 874         }
 875
 876         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
 877                                       OCFS2_JOURNAL_ACCESS_WRITE);
 878         if (status < 0) {
 879                 mlog_errno(status);
 880                 goto out_rollback;
 881         }
 882
 883         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
 884
 885         status = ocfs2_journal_dirty(handle, fe_bh);
 886         if (status < 0) {
 887                 mlog_errno(status);
 888                 goto out_rollback;
 889         }
 890
 891         status = 0;
 892 out_rollback:
 893         if (status < 0) {
 894                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
 895                 bg->bg_next_group = cpu_to_le64(bg_ptr);
 896                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
 897         }
 898 out:
 899         mlog_exit(status);
 900         return status;
 901 }
 902
 903 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 904                                                      u32 wanted)
 905 {
 906         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
 907 }
 908
 909 /* return 0 on success, -ENOSPC to keep searching and any other < 0
 910  * value on error. */
 911 static int ocfs2_cluster_group_search(struct inode *inode,
 912                                       struct buffer_head *group_bh,
 913                                       u32 bits_wanted, u32 min_bits,
 914                                       u16 *bit_off, u16 *bits_found)
 915 {
 916         int search = -ENOSPC;
 917         int ret;
 918         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
 919         u16 tmp_off, tmp_found;
 920         unsigned int max_bits, gd_cluster_off;
 921
 922         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
 923
 924         if (gd->bg_free_bits_count) {
 925                 max_bits = le16_to_cpu(gd->bg_bits);
 926
 927                 /* Tail groups in cluster bitmaps which aren't cpg
 928                  * aligned are prone to partial extention by a failed
 929                  * fs resize. If the file system resize never got to
 930                  * update the dinode cluster count, then we don't want
 931                  * to trust any clusters past it, regardless of what
 932                  * the group descriptor says. */
 933                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
 934                                                           le64_to_cpu(gd->bg_blkno));
 935                 if ((gd_cluster_off + max_bits) >
 936                     OCFS2_I(inode)->ip_clusters) {
 937                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
 938                         mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
 939                              (unsigned long long)le64_to_cpu(gd->bg_blkno),
 940                              le16_to_cpu(gd->bg_bits),
 941                              OCFS2_I(inode)->ip_clusters, max_bits);
 942                 }
 943
 944                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
 945                                                         group_bh, bits_wanted,
 946                                                         max_bits,
 947                                                         &tmp_off, &tmp_found);
 948                 if (ret)
 949                         return ret;
 950
 951                 /* ocfs2_block_group_find_clear_bits() might
 952                  * return success, but we still want to return
 953                  * -ENOSPC unless it found the minimum number
 954                  * of bits. */
 955                 if (min_bits <= tmp_found) {
 956                         *bit_off = tmp_off;
 957                         *bits_found = tmp_found;
 958                         search = 0; /* success */
 959                 }
 960         }
 961
 962         return search;
 963 }
 964
 965 static int ocfs2_block_group_search(struct inode *inode,
 966                                     struct buffer_head *group_bh,
 967                                     u32 bits_wanted, u32 min_bits,
 968                                     u16 *bit_off, u16 *bits_found)
 969 {
 970         int ret = -ENOSPC;
 971         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
 972
 973         BUG_ON(min_bits != 1);
 974         BUG_ON(ocfs2_is_cluster_bitmap(inode));
 975
 976         if (bg->bg_free_bits_count)
 977                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
 978                                                         group_bh, bits_wanted,
 979                                                         le16_to_cpu(bg->bg_bits),
 980                                                         bit_off, bits_found);
 981
 982         return ret;
 983 }
 984
 985 static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
 986                                        handle_t *handle,
 987                                        struct buffer_head *di_bh,
 988                                        u32 num_bits,
 989                                        u16 chain)
 990 {
 991         int ret;
 992         u32 tmp_used;
 993         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
 994         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
 995
 996         ret = ocfs2_journal_access(handle, inode, di_bh,
 997                                    OCFS2_JOURNAL_ACCESS_WRITE);
 998         if (ret < 0) {
 999                 mlog_errno(ret);
1000                 goto out;
1001         }
1002
1003         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1004         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1005         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1006
1007         ret = ocfs2_journal_dirty(handle, di_bh);
1008         if (ret < 0)
1009                 mlog_errno(ret);
1010
1011 out:
1012         return ret;
1013 }
1014
1015 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1016                                   handle_t *handle,
1017                                   u32 bits_wanted,
1018                                   u32 min_bits,
1019                                   u16 *bit_off,
1020                                   unsigned int *num_bits,
1021                                   u64 gd_blkno,
1022                                   u16 *bits_left)
1023 {
1024         int ret;
1025         u16 found;
1026         struct buffer_head *group_bh = NULL;
1027         struct ocfs2_group_desc *gd;
1028         struct inode *alloc_inode = ac->ac_inode;
1029
1030         ret = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb), gd_blkno,
1031                                &group_bh, OCFS2_BH_CACHED, alloc_inode);
1032         if (ret < 0) {
1033                 mlog_errno(ret);
1034                 return ret;
1035         }
1036
1037         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1038         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
1039                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, gd);
1040                 ret = -EIO;
1041                 goto out;
1042         }
1043
1044         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1045                                   bit_off, &found);
1046         if (ret < 0) {
1047                 if (ret != -ENOSPC)
1048                         mlog_errno(ret);
1049                 goto out;
1050         }
1051
1052         *num_bits = found;
1053
1054         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1055                                                *num_bits,
1056                                                le16_to_cpu(gd->bg_chain));
1057         if (ret < 0) {
1058                 mlog_errno(ret);
1059                 goto out;
1060         }
1061
1062         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1063                                          *bit_off, *num_bits);
1064         if (ret < 0)
1065                 mlog_errno(ret);
1066
1067         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1068
1069 out:
1070         brelse(group_bh);
1071
1072         return ret;
1073 }
1074
1075 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1076                               handle_t *handle,
1077                               u32 bits_wanted,
1078                               u32 min_bits,
1079                               u16 *bit_off,
1080                               unsigned int *num_bits,
1081                               u64 *bg_blkno,
1082                               u16 *bits_left)
1083 {
1084         int status;
1085         u16 chain, tmp_bits;
1086         u32 tmp_used;
1087         u64 next_group;
1088         struct inode *alloc_inode = ac->ac_inode;
1089         struct buffer_head *group_bh = NULL;
1090         struct buffer_head *prev_group_bh = NULL;
1091         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1092         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1093         struct ocfs2_group_desc *bg;
1094
1095         chain = ac->ac_chain;
1096         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
1097              bits_wanted, chain,
1098              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
1099
1100         status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1101                                   le64_to_cpu(cl->cl_recs[chain].c_blkno),
1102                                   &group_bh, OCFS2_BH_CACHED, alloc_inode);
1103         if (status < 0) {
1104                 mlog_errno(status);
1105                 goto bail;
1106         }
1107         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1108         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1109         if (status) {
1110                 mlog_errno(status);
1111                 goto bail;
1112         }
1113
1114         status = -ENOSPC;
1115         /* for now, the chain search is a bit simplistic. We just use
1116          * the 1st group with any empty bits. */
1117         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1118                                              bits_wanted, min_bits, bit_off,
1119                                              &tmp_bits)) == -ENOSPC) {
1120                 if (!bg->bg_next_group)
1121                         break;
1122
1123                 if (prev_group_bh) {
1124                         brelse(prev_group_bh);
1125                         prev_group_bh = NULL;
1126                 }
1127                 next_group = le64_to_cpu(bg->bg_next_group);
1128                 prev_group_bh = group_bh;
1129                 group_bh = NULL;
1130                 status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1131                                           next_group, &group_bh,
1132                                           OCFS2_BH_CACHED, alloc_inode);
1133                 if (status < 0) {
1134                         mlog_errno(status);
1135                         goto bail;
1136                 }
1137                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1138                 status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1139                 if (status) {
1140                         mlog_errno(status);
1141                         goto bail;
1142                 }
1143         }
1144         if (status < 0) {
1145                 if (status != -ENOSPC)
1146                         mlog_errno(status);
1147                 goto bail;
1148         }
1149
1150         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1151              tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
1152
1153         *num_bits = tmp_bits;
1154
1155         BUG_ON(*num_bits == 0);
1156
1157         /*
1158          * Keep track of previous block descriptor read. When
1159          * we find a target, if we have read more than X
1160          * number of descriptors, and the target is reasonably
1161          * empty, relink him to top of his chain.
1162          *
1163          * We've read 0 extra blocks and only send one more to
1164          * the transaction, yet the next guy to search has a
1165          * much easier time.
1166          *
1167          * Do this *after* figuring out how many bits we're taking out
1168          * of our target group.
1169          */
1170         if (ac->ac_allow_chain_relink &&
1171             (prev_group_bh) &&
1172             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1173                 status = ocfs2_relink_block_group(handle, alloc_inode,
1174                                                   ac->ac_bh, group_bh,
1175                                                   prev_group_bh, chain);
1176                 if (status < 0) {
1177                         mlog_errno(status);
1178                         goto bail;
1179                 }
1180         }
1181
1182         /* Ok, claim our bits now: set the info on dinode, chainlist
1183          * and then the group */
1184         status = ocfs2_journal_access(handle,
1185                                       alloc_inode,
1186                                       ac->ac_bh,
1187                                       OCFS2_JOURNAL_ACCESS_WRITE);
1188         if (status < 0) {
1189                 mlog_errno(status);
1190                 goto bail;
1191         }
1192
1193         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1194         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1195         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1196
1197         status = ocfs2_journal_dirty(handle,
1198                                      ac->ac_bh);
1199         if (status < 0) {
1200                 mlog_errno(status);
1201                 goto bail;
1202         }
1203
1204         status = ocfs2_block_group_set_bits(handle,
1205                                             alloc_inode,
1206                                             bg,
1207                                             group_bh,
1208                                             *bit_off,
1209                                             *num_bits);
1210         if (status < 0) {
1211                 mlog_errno(status);
1212                 goto bail;
1213         }
1214
1215         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1216              (unsigned long long)le64_to_cpu(fe->i_blkno));
1217
1218         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1219         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1220 bail:
1221         if (group_bh)
1222                 brelse(group_bh);
1223         if (prev_group_bh)
1224                 brelse(prev_group_bh);
1225
1226         mlog_exit(status);
1227         return status;
1228 }
1229
1230 /* will give out up to bits_wanted contiguous bits. */
1231 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1232                                      struct ocfs2_alloc_context *ac,
1233                                      handle_t *handle,
1234                                      u32 bits_wanted,
1235                                      u32 min_bits,
1236                                      u16 *bit_off,
1237                                      unsigned int *num_bits,
1238                                      u64 *bg_blkno)
1239 {
1240         int status;
1241         u16 victim, i;
1242         u16 bits_left = 0;
1243         u64 hint_blkno = ac->ac_last_group;
1244         struct ocfs2_chain_list *cl;
1245         struct ocfs2_dinode *fe;
1246
1247         mlog_entry_void();
1248
1249         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1250         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1251         BUG_ON(!ac->ac_bh);
1252
1253         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1254         if (!OCFS2_IS_VALID_DINODE(fe)) {
1255                 OCFS2_RO_ON_INVALID_DINODE(osb->sb, fe);
1256                 status = -EIO;
1257                 goto bail;
1258         }
1259         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1260             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1261                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1262                             "bits but only %u total.",
1263                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1264                             le32_to_cpu(fe->id1.bitmap1.i_used),
1265                             le32_to_cpu(fe->id1.bitmap1.i_total));
1266                 status = -EIO;
1267                 goto bail;
1268         }
1269
1270         if (hint_blkno) {
1271                 /* Attempt to short-circuit the usual search mechanism
1272                  * by jumping straight to the most recently used
1273                  * allocation group. This helps us mantain some
1274                  * contiguousness across allocations. */
1275                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1276                                                 min_bits, bit_off, num_bits,
1277                                                 hint_blkno, &bits_left);
1278                 if (!status) {
1279                         /* Be careful to update *bg_blkno here as the
1280                          * caller is expecting it to be filled in, and
1281                          * ocfs2_search_one_group() won't do that for
1282                          * us. */
1283                         *bg_blkno = hint_blkno;
1284                         goto set_hint;
1285                 }
1286                 if (status < 0 && status != -ENOSPC) {
1287                         mlog_errno(status);
1288                         goto bail;
1289                 }
1290         }
1291
1292         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1293
1294         victim = ocfs2_find_victim_chain(cl);
1295         ac->ac_chain = victim;
1296         ac->ac_allow_chain_relink = 1;
1297
1298         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, bit_off,
1299                                     num_bits, bg_blkno, &bits_left);
1300         if (!status)
1301                 goto set_hint;
1302         if (status < 0 && status != -ENOSPC) {
1303                 mlog_errno(status);
1304                 goto bail;
1305         }
1306
1307         mlog(0, "Search of victim chain %u came up with nothing, "
1308              "trying all chains now.\n", victim);
1309
1310         /* If we didn't pick a good victim, then just default to
1311          * searching each chain in order. Don't allow chain relinking
1312          * because we only calculate enough journal credits for one
1313          * relink per alloc. */
1314         ac->ac_allow_chain_relink = 0;
1315         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1316                 if (i == victim)
1317                         continue;
1318                 if (!cl->cl_recs[i].c_free)
1319                         continue;
1320
1321                 ac->ac_chain = i;
1322                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1323                                             bit_off, num_bits, bg_blkno,
1324                                             &bits_left);
1325                 if (!status)
1326                         break;
1327                 if (status < 0 && status != -ENOSPC) {
1328                         mlog_errno(status);
1329                         goto bail;
1330                 }
1331         }
1332
1333 set_hint:
1334         if (status != -ENOSPC) {
1335                 /* If the next search of this group is not likely to
1336                  * yield a suitable extent, then we reset the last
1337                  * group hint so as to not waste a disk read */
1338                 if (bits_left < min_bits)
1339                         ac->ac_last_group = 0;
1340                 else
1341                         ac->ac_last_group = *bg_blkno;
1342         }
1343
1344 bail:
1345         mlog_exit(status);
1346         return status;
1347 }
1348
1349 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1350                          handle_t *handle,
1351                          struct ocfs2_alloc_context *ac,
1352                          u32 bits_wanted,
1353                          u16 *suballoc_bit_start,
1354                          unsigned int *num_bits,
1355                          u64 *blkno_start)
1356 {
1357         int status;
1358         u64 bg_blkno;
1359
1360         BUG_ON(!ac);
1361         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1362         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1363
1364         status = ocfs2_claim_suballoc_bits(osb,
1365                                            ac,
1366                                            handle,
1367                                            bits_wanted,
1368                                            1,
1369                                            suballoc_bit_start,
1370                                            num_bits,
1371                                            &bg_blkno);
1372         if (status < 0) {
1373                 mlog_errno(status);
1374                 goto bail;
1375         }
1376         atomic_inc(&osb->alloc_stats.bg_allocs);
1377
1378         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1379         ac->ac_bits_given += (*num_bits);
1380         status = 0;
1381 bail:
1382         mlog_exit(status);
1383         return status;
1384 }
1385
1386 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1387                           handle_t *handle,
1388                           struct ocfs2_alloc_context *ac,
1389                           u16 *suballoc_bit,
1390                           u64 *fe_blkno)
1391 {
1392         int status;
1393         unsigned int num_bits;
1394         u64 bg_blkno;
1395
1396         mlog_entry_void();
1397
1398         BUG_ON(!ac);
1399         BUG_ON(ac->ac_bits_given != 0);
1400         BUG_ON(ac->ac_bits_wanted != 1);
1401         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1402
1403         status = ocfs2_claim_suballoc_bits(osb,
1404                                            ac,
1405                                            handle,
1406                                            1,
1407                                            1,
1408                                            suballoc_bit,
1409                                            &num_bits,
1410                                            &bg_blkno);
1411         if (status < 0) {
1412                 mlog_errno(status);
1413                 goto bail;
1414         }
1415         atomic_inc(&osb->alloc_stats.bg_allocs);
1416
1417         BUG_ON(num_bits != 1);
1418
1419         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1420         ac->ac_bits_given++;
1421         status = 0;
1422 bail:
1423         mlog_exit(status);
1424         return status;
1425 }
1426
1427 /* translate a group desc. blkno and it's bitmap offset into
1428  * disk cluster offset. */
1429 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1430                                                    u64 bg_blkno,
1431                                                    u16 bg_bit_off)
1432 {
1433         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1434         u32 cluster = 0;
1435
1436         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1437
1438         if (bg_blkno != osb->first_cluster_group_blkno)
1439                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1440         cluster += (u32) bg_bit_off;
1441         return cluster;
1442 }
1443
1444 /* given a cluster offset, calculate which block group it belongs to
1445  * and return that block offset. */
1446 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
1447                                             u32 cluster)
1448 {
1449         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1450         u32 group_no;
1451
1452         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1453
1454         group_no = cluster / osb->bitmap_cpg;
1455         if (!group_no)
1456                 return osb->first_cluster_group_blkno;
1457         return ocfs2_clusters_to_blocks(inode->i_sb,
1458                                         group_no * osb->bitmap_cpg);
1459 }
1460
1461 /* given the block number of a cluster start, calculate which cluster
1462  * group and descriptor bitmap offset that corresponds to. */
1463 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1464                                                 u64 data_blkno,
1465                                                 u64 *bg_blkno,
1466                                                 u16 *bg_bit_off)
1467 {
1468         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1469         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1470
1471         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1472
1473         *bg_blkno = ocfs2_which_cluster_group(inode,
1474                                               data_cluster);
1475
1476         if (*bg_blkno == osb->first_cluster_group_blkno)
1477                 *bg_bit_off = (u16) data_cluster;
1478         else
1479                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1480                                                              data_blkno - *bg_blkno);
1481 }
1482
1483 /*
1484  * min_bits - minimum contiguous chunk from this total allocation we
1485  * can handle. set to what we asked for originally for a full
1486  * contig. allocation, set to '1' to indicate we can deal with extents
1487  * of any size.
1488  */
1489 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
1490                            handle_t *handle,
1491                            struct ocfs2_alloc_context *ac,
1492                            u32 min_clusters,
1493                            u32 max_clusters,
1494                            u32 *cluster_start,
1495                            u32 *num_clusters)
1496 {
1497         int status;
1498         unsigned int bits_wanted = max_clusters;
1499         u64 bg_blkno = 0;
1500         u16 bg_bit_off;
1501
1502         mlog_entry_void();
1503
1504         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1505
1506         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1507                && ac->ac_which != OCFS2_AC_USE_MAIN);
1508
1509         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1510                 status = ocfs2_claim_local_alloc_bits(osb,
1511                                                       handle,
1512                                                       ac,
1513                                                       bits_wanted,
1514                                                       cluster_start,
1515                                                       num_clusters);
1516                 if (!status)
1517                         atomic_inc(&osb->alloc_stats.local_data);
1518         } else {
1519                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1520                         /* The only paths asking for contiguousness
1521                          * should know about this already. */
1522                         mlog(ML_ERROR, "minimum allocation requested exceeds "
1523                                        "group bitmap size!");
1524                         status = -ENOSPC;
1525                         goto bail;
1526                 }
1527                 /* clamp the current request down to a realistic size. */
1528                 if (bits_wanted > (osb->bitmap_cpg - 1))
1529                         bits_wanted = osb->bitmap_cpg - 1;
1530
1531                 status = ocfs2_claim_suballoc_bits(osb,
1532                                                    ac,
1533                                                    handle,
1534                                                    bits_wanted,
1535                                                    min_clusters,
1536                                                    &bg_bit_off,
1537                                                    num_clusters,
1538                                                    &bg_blkno);
1539                 if (!status) {
1540                         *cluster_start =
1541                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1542                                                                  bg_blkno,
1543                                                                  bg_bit_off);
1544                         atomic_inc(&osb->alloc_stats.bitmap_data);
1545                 }
1546         }
1547         if (status < 0) {
1548                 if (status != -ENOSPC)
1549                         mlog_errno(status);
1550                 goto bail;
1551         }
1552
1553         ac->ac_bits_given += *num_clusters;
1554
1555 bail:
1556         mlog_exit(status);
1557         return status;
1558 }
1559
1560 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1561                          handle_t *handle,
1562                          struct ocfs2_alloc_context *ac,
1563                          u32 min_clusters,
1564                          u32 *cluster_start,
1565                          u32 *num_clusters)
1566 {
1567         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1568
1569         return __ocfs2_claim_clusters(osb, handle, ac, min_clusters,
1570                                       bits_wanted, cluster_start, num_clusters);
1571 }
1572
1573 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
1574                                                struct inode *alloc_inode,
1575                                                struct ocfs2_group_desc *bg,
1576                                                struct buffer_head *group_bh,
1577                                                unsigned int bit_off,
1578                                                unsigned int num_bits)
1579 {
1580         int status;
1581         unsigned int tmp;
1582         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1583         struct ocfs2_group_desc *undo_bg = NULL;
1584
1585         mlog_entry_void();
1586
1587         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1588                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1589                 status = -EIO;
1590                 goto bail;
1591         }
1592
1593         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1594
1595         if (ocfs2_is_cluster_bitmap(alloc_inode))
1596                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1597
1598         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1599                                       journal_type);
1600         if (status < 0) {
1601                 mlog_errno(status);
1602                 goto bail;
1603         }
1604
1605         if (ocfs2_is_cluster_bitmap(alloc_inode))
1606                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1607
1608         tmp = num_bits;
1609         while(tmp--) {
1610                 ocfs2_clear_bit((bit_off + tmp),
1611                                 (unsigned long *) bg->bg_bitmap);
1612                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1613                         ocfs2_set_bit(bit_off + tmp,
1614                                       (unsigned long *) undo_bg->bg_bitmap);
1615         }
1616         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1617
1618         status = ocfs2_journal_dirty(handle, group_bh);
1619         if (status < 0)
1620                 mlog_errno(status);
1621 bail:
1622         return status;
1623 }
1624
1625 /*
1626  * expects the suballoc inode to already be locked.
1627  */
1628 int ocfs2_free_suballoc_bits(handle_t *handle,
1629                              struct inode *alloc_inode,
1630                              struct buffer_head *alloc_bh,
1631                              unsigned int start_bit,
1632                              u64 bg_blkno,
1633                              unsigned int count)
1634 {
1635         int status = 0;
1636         u32 tmp_used;
1637         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
1638         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1639         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1640         struct buffer_head *group_bh = NULL;
1641         struct ocfs2_group_desc *group;
1642
1643         mlog_entry_void();
1644
1645         if (!OCFS2_IS_VALID_DINODE(fe)) {
1646                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
1647                 status = -EIO;
1648                 goto bail;
1649         }
1650         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1651
1652         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1653              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1654              (unsigned long long)bg_blkno, start_bit);
1655
1656         status = ocfs2_read_block(osb, bg_blkno, &group_bh, OCFS2_BH_CACHED,
1657                                   alloc_inode);
1658         if (status < 0) {
1659                 mlog_errno(status);
1660                 goto bail;
1661         }
1662
1663         group = (struct ocfs2_group_desc *) group_bh->b_data;
1664         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, group);
1665         if (status) {
1666                 mlog_errno(status);
1667                 goto bail;
1668         }
1669         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1670
1671         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1672                                               group, group_bh,
1673                                               start_bit, count);
1674         if (status < 0) {
1675                 mlog_errno(status);
1676                 goto bail;
1677         }
1678
1679         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1680                                       OCFS2_JOURNAL_ACCESS_WRITE);
1681         if (status < 0) {
1682                 mlog_errno(status);
1683                 goto bail;
1684         }
1685
1686         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1687                      count);
1688         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1689         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1690
1691         status = ocfs2_journal_dirty(handle, alloc_bh);
1692         if (status < 0) {
1693                 mlog_errno(status);
1694                 goto bail;
1695         }
1696
1697 bail:
1698         if (group_bh)
1699                 brelse(group_bh);
1700
1701         mlog_exit(status);
1702         return status;
1703 }
1704
1705 int ocfs2_free_dinode(handle_t *handle,
1706                       struct inode *inode_alloc_inode,
1707                       struct buffer_head *inode_alloc_bh,
1708                       struct ocfs2_dinode *di)
1709 {
1710         u64 blk = le64_to_cpu(di->i_blkno);
1711         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1712         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1713
1714         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1715                                         inode_alloc_bh, bit, bg_blkno, 1);
1716 }
1717
1718 int ocfs2_free_clusters(handle_t *handle,
1719                        struct inode *bitmap_inode,
1720                        struct buffer_head *bitmap_bh,
1721                        u64 start_blk,
1722                        unsigned int num_clusters)
1723 {
1724         int status;
1725         u16 bg_start_bit;
1726         u64 bg_blkno;
1727         struct ocfs2_dinode *fe;
1728
1729         /* You can't ever have a contiguous set of clusters
1730          * bigger than a block group bitmap so we never have to worry
1731          * about looping on them. */
1732
1733         mlog_entry_void();
1734
1735         /* This is expensive. We can safely remove once this stuff has
1736          * gotten tested really well. */
1737         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1738
1739         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1740
1741         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1742                                      &bg_start_bit);
1743
1744         mlog(0, "want to free %u clusters starting at block %llu\n",
1745              num_clusters, (unsigned long long)start_blk);
1746         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1747              (unsigned long long)bg_blkno, bg_start_bit);
1748
1749         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1750                                           bg_start_bit, bg_blkno,
1751                                           num_clusters);
1752         if (status < 0)
1753                 mlog_errno(status);
1754
1755         mlog_exit(status);
1756         return status;
1757 }
1758
1759 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1760 {
1761         printk("Block Group:\n");
1762         printk("bg_signature:       %s\n", bg->bg_signature);
1763         printk("bg_size:            %u\n", bg->bg_size);
1764         printk("bg_bits:            %u\n", bg->bg_bits);
1765         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1766         printk("bg_chain:           %u\n", bg->bg_chain);
1767         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1768         printk("bg_next_group:      %llu\n",
1769                (unsigned long long)bg->bg_next_group);
1770         printk("bg_parent_dinode:   %llu\n",
1771                (unsigned long long)bg->bg_parent_dinode);
1772         printk("bg_blkno:           %llu\n",
1773                (unsigned long long)bg->bg_blkno);
1774 }
1775
1776 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
1777 {
1778         int i;
1779
1780         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
1781         printk("i_signature:                  %s\n", fe->i_signature);
1782         printk("i_size:                       %llu\n",
1783                (unsigned long long)fe->i_size);
1784         printk("i_clusters:                   %u\n", fe->i_clusters);
1785         printk("i_generation:                 %u\n",
1786                le32_to_cpu(fe->i_generation));
1787         printk("id1.bitmap1.i_used:           %u\n",
1788                le32_to_cpu(fe->id1.bitmap1.i_used));
1789         printk("id1.bitmap1.i_total:          %u\n",
1790                le32_to_cpu(fe->id1.bitmap1.i_total));
1791         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
1792         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
1793         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
1794         printk("id2.i_chain.cl_next_free_rec: %u\n",
1795                fe->id2.i_chain.cl_next_free_rec);
1796         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
1797                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
1798                        fe->id2.i_chain.cl_recs[i].c_free);
1799                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
1800                        fe->id2.i_chain.cl_recs[i].c_total);
1801                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
1802                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
1803         }
1804 }