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(struct ocfs2_journal_handle *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_reserve_suballoc_bits(struct ocfs2_super *osb,
  63                                        struct ocfs2_alloc_context *ac);
  64
  65 static int ocfs2_cluster_group_search(struct inode *inode,
  66                                       struct buffer_head *group_bh,
  67                                       u32 bits_wanted, u32 min_bits,
  68                                       u16 *bit_off, u16 *bits_found);
  69 static int ocfs2_block_group_search(struct inode *inode,
  70                                     struct buffer_head *group_bh,
  71                                     u32 bits_wanted, u32 min_bits,
  72                                     u16 *bit_off, u16 *bits_found);
  73 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
  74                               u32 bits_wanted,
  75                               u32 min_bits,
  76                               u16 *bit_off,
  77                               unsigned int *num_bits,
  78                               u64 *bg_blkno);
  79 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
  80                                      struct ocfs2_alloc_context *ac,
  81                                      u32 bits_wanted,
  82                                      u32 min_bits,
  83                                      u16 *bit_off,
  84                                      unsigned int *num_bits,
  85                                      u64 *bg_blkno);
  86 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  87                                          int nr);
  88 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
  89                                              struct buffer_head *bg_bh,
  90                                              unsigned int bits_wanted,
  91                                              u16 *bit_off,
  92                                              u16 *bits_found);
  93 static inline int ocfs2_block_group_set_bits(struct ocfs2_journal_handle *handle,
  94                                              struct inode *alloc_inode,
  95                                              struct ocfs2_group_desc *bg,
  96                                              struct buffer_head *group_bh,
  97                                              unsigned int bit_off,
  98                                              unsigned int num_bits);
  99 static inline int ocfs2_block_group_clear_bits(struct ocfs2_journal_handle *handle,
 100                                                struct inode *alloc_inode,
 101                                                struct ocfs2_group_desc *bg,
 102                                                struct buffer_head *group_bh,
 103                                                unsigned int bit_off,
 104                                                unsigned int num_bits);
 105
 106 static int ocfs2_relink_block_group(struct ocfs2_journal_handle *handle,
 107                                     struct inode *alloc_inode,
 108                                     struct buffer_head *fe_bh,
 109                                     struct buffer_head *bg_bh,
 110                                     struct buffer_head *prev_bg_bh,
 111                                     u16 chain);
 112 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 113                                                      u32 wanted);
 114 static int ocfs2_free_suballoc_bits(struct ocfs2_journal_handle *handle,
 115                                     struct inode *alloc_inode,
 116                                     struct buffer_head *alloc_bh,
 117                                     unsigned int start_bit,
 118                                     u64 bg_blkno,
 119                                     unsigned int count);
 120 static inline u64 ocfs2_which_suballoc_group(u64 block,
 121                                              unsigned int bit);
 122 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 123                                                    u64 bg_blkno,
 124                                                    u16 bg_bit_off);
 125 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
 126                                             u32 cluster);
 127 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 128                                                 u64 data_blkno,
 129                                                 u64 *bg_blkno,
 130                                                 u16 *bg_bit_off);
 131
 132 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 133 {
 134         if (ac->ac_inode)
 135                 iput(ac->ac_inode);
 136         if (ac->ac_bh)
 137                 brelse(ac->ac_bh);
 138         kfree(ac);
 139 }
 140
 141 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 142 {
 143         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 144 }
 145
 146 static int ocfs2_block_group_fill(struct ocfs2_journal_handle *handle,
 147                                   struct inode *alloc_inode,
 148                                   struct buffer_head *bg_bh,
 149                                   u64 group_blkno,
 150                                   u16 my_chain,
 151                                   struct ocfs2_chain_list *cl)
 152 {
 153         int status = 0;
 154         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 155         struct super_block * sb = alloc_inode->i_sb;
 156
 157         mlog_entry_void();
 158
 159         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 160                 ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
 161                             "b_blocknr (%llu)",
 162                             (unsigned long long)group_blkno,
 163                             (unsigned long long) bg_bh->b_blocknr);
 164                 status = -EIO;
 165                 goto bail;
 166         }
 167
 168         status = ocfs2_journal_access(handle,
 169                                       alloc_inode,
 170                                       bg_bh,
 171                                       OCFS2_JOURNAL_ACCESS_CREATE);
 172         if (status < 0) {
 173                 mlog_errno(status);
 174                 goto bail;
 175         }
 176
 177         memset(bg, 0, sb->s_blocksize);
 178         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 179         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 180         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
 181         bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 182         bg->bg_chain = cpu_to_le16(my_chain);
 183         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 184         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 185         bg->bg_blkno = cpu_to_le64(group_blkno);
 186         /* set the 1st bit in the bitmap to account for the descriptor block */
 187         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 188         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 189
 190         status = ocfs2_journal_dirty(handle, bg_bh);
 191         if (status < 0)
 192                 mlog_errno(status);
 193
 194         /* There is no need to zero out or otherwise initialize the
 195          * other blocks in a group - All valid FS metadata in a block
 196          * group stores the superblock fs_generation value at
 197          * allocation time. */
 198
 199 bail:
 200         mlog_exit(status);
 201         return status;
 202 }
 203
 204 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 205 {
 206         u16 curr, best;
 207
 208         best = curr = 0;
 209         while (curr < le16_to_cpu(cl->cl_count)) {
 210                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 211                     le32_to_cpu(cl->cl_recs[curr].c_total))
 212                         best = curr;
 213                 curr++;
 214         }
 215         return best;
 216 }
 217
 218 /*
 219  * We expect the block group allocator to already be locked.
 220  */
 221 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 222                                    struct inode *alloc_inode,
 223                                    struct buffer_head *bh)
 224 {
 225         int status, credits;
 226         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 227         struct ocfs2_chain_list *cl;
 228         struct ocfs2_alloc_context *ac = NULL;
 229         struct ocfs2_journal_handle *handle = NULL;
 230         u32 bit_off, num_bits;
 231         u16 alloc_rec;
 232         u64 bg_blkno;
 233         struct buffer_head *bg_bh = NULL;
 234         struct ocfs2_group_desc *bg;
 235
 236         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 237
 238         mlog_entry_void();
 239
 240         handle = ocfs2_alloc_handle(osb);
 241         if (!handle) {
 242                 status = -ENOMEM;
 243                 mlog_errno(status);
 244                 goto bail;
 245         }
 246
 247         cl = &fe->id2.i_chain;
 248         status = ocfs2_reserve_clusters(osb,
 249                                         handle,
 250                                         le16_to_cpu(cl->cl_cpg),
 251                                         &ac);
 252         if (status < 0) {
 253                 if (status != -ENOSPC)
 254                         mlog_errno(status);
 255                 goto bail;
 256         }
 257
 258         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 259                                                  le16_to_cpu(cl->cl_cpg));
 260         handle = ocfs2_start_trans(osb, handle, credits);
 261         if (IS_ERR(handle)) {
 262                 status = PTR_ERR(handle);
 263                 handle = NULL;
 264                 mlog_errno(status);
 265                 goto bail;
 266         }
 267
 268         status = ocfs2_claim_clusters(osb,
 269                                       handle,
 270                                       ac,
 271                                       le16_to_cpu(cl->cl_cpg),
 272                                       &bit_off,
 273                                       &num_bits);
 274         if (status < 0) {
 275                 if (status != -ENOSPC)
 276                         mlog_errno(status);
 277                 goto bail;
 278         }
 279
 280         alloc_rec = ocfs2_find_smallest_chain(cl);
 281
 282         /* setup the group */
 283         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 284         mlog(0, "new descriptor, record %u, at block %llu\n",
 285              alloc_rec, (unsigned long long)bg_blkno);
 286
 287         bg_bh = sb_getblk(osb->sb, bg_blkno);
 288         if (!bg_bh) {
 289                 status = -EIO;
 290                 mlog_errno(status);
 291                 goto bail;
 292         }
 293         ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);
 294
 295         status = ocfs2_block_group_fill(handle,
 296                                         alloc_inode,
 297                                         bg_bh,
 298                                         bg_blkno,
 299                                         alloc_rec,
 300                                         cl);
 301         if (status < 0) {
 302                 mlog_errno(status);
 303                 goto bail;
 304         }
 305
 306         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 307
 308         status = ocfs2_journal_access(handle, alloc_inode,
 309                                       bh, OCFS2_JOURNAL_ACCESS_WRITE);
 310         if (status < 0) {
 311                 mlog_errno(status);
 312                 goto bail;
 313         }
 314
 315         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 316                      le16_to_cpu(bg->bg_free_bits_count));
 317         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
 318         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
 319         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 320                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 321
 322         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 323                                         le16_to_cpu(bg->bg_free_bits_count));
 324         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 325         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 326
 327         status = ocfs2_journal_dirty(handle, bh);
 328         if (status < 0) {
 329                 mlog_errno(status);
 330                 goto bail;
 331         }
 332
 333         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 334         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 335         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 336                                              le32_to_cpu(fe->i_clusters)));
 337         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 338         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 339         alloc_inode->i_blocks =
 340                 ocfs2_align_bytes_to_sectors(i_size_read(alloc_inode));
 341
 342         status = 0;
 343 bail:
 344         if (handle)
 345                 ocfs2_commit_trans(handle);
 346
 347         if (ac)
 348                 ocfs2_free_alloc_context(ac);
 349
 350         if (bg_bh)
 351                 brelse(bg_bh);
 352
 353         mlog_exit(status);
 354         return status;
 355 }
 356
 357 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 358                                        struct ocfs2_alloc_context *ac)
 359 {
 360         int status;
 361         u32 bits_wanted = ac->ac_bits_wanted;
 362         struct inode *alloc_inode = ac->ac_inode;
 363         struct buffer_head *bh = NULL;
 364         struct ocfs2_journal_handle *handle = ac->ac_handle;
 365         struct ocfs2_dinode *fe;
 366         u32 free_bits;
 367
 368         mlog_entry_void();
 369
 370         BUG_ON(handle->flags & OCFS2_HANDLE_STARTED);
 371
 372         ocfs2_handle_add_inode(handle, alloc_inode);
 373         status = ocfs2_meta_lock(alloc_inode, handle, &bh, 1);
 374         if (status < 0) {
 375                 mlog_errno(status);
 376                 goto bail;
 377         }
 378
 379         fe = (struct ocfs2_dinode *) bh->b_data;
 380         if (!OCFS2_IS_VALID_DINODE(fe)) {
 381                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 382                 status = -EIO;
 383                 goto bail;
 384         }
 385         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 386                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 387                             (unsigned long long)le64_to_cpu(fe->i_blkno));
 388                 status = -EIO;
 389                 goto bail;
 390         }
 391
 392         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 393                 le32_to_cpu(fe->id1.bitmap1.i_used);
 394
 395         if (bits_wanted > free_bits) {
 396                 /* cluster bitmap never grows */
 397                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 398                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
 399                              bits_wanted, free_bits);
 400                         status = -ENOSPC;
 401                         goto bail;
 402                 }
 403
 404                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh);
 405                 if (status < 0) {
 406                         if (status != -ENOSPC)
 407                                 mlog_errno(status);
 408                         goto bail;
 409                 }
 410                 atomic_inc(&osb->alloc_stats.bg_extends);
 411
 412                 /* You should never ask for this much metadata */
 413                 BUG_ON(bits_wanted >
 414                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 415                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 416         }
 417
 418         get_bh(bh);
 419         ac->ac_bh = bh;
 420 bail:
 421         if (bh)
 422                 brelse(bh);
 423
 424         mlog_exit(status);
 425         return status;
 426 }
 427
 428 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
 429                                struct ocfs2_journal_handle *handle,
 430                                struct ocfs2_dinode *fe,
 431                                struct ocfs2_alloc_context **ac)
 432 {
 433         int status;
 434         struct inode *alloc_inode = NULL;
 435
 436         *ac = kcalloc(1, sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 437         if (!(*ac)) {
 438                 status = -ENOMEM;
 439                 mlog_errno(status);
 440                 goto bail;
 441         }
 442
 443         (*ac)->ac_bits_wanted = ocfs2_extend_meta_needed(fe);
 444         (*ac)->ac_handle = handle;
 445         (*ac)->ac_which = OCFS2_AC_USE_META;
 446
 447 #ifndef OCFS2_USE_ALL_METADATA_SUBALLOCATORS
 448         alloc_inode = ocfs2_get_system_file_inode(osb,
 449                                                   EXTENT_ALLOC_SYSTEM_INODE,
 450                                                   0);
 451 #else
 452         alloc_inode = ocfs2_get_system_file_inode(osb,
 453                                                   EXTENT_ALLOC_SYSTEM_INODE,
 454                                                   osb->slot_num);
 455 #endif
 456         if (!alloc_inode) {
 457                 status = -ENOMEM;
 458                 mlog_errno(status);
 459                 goto bail;
 460         }
 461
 462         (*ac)->ac_inode = igrab(alloc_inode);
 463         (*ac)->ac_group_search = ocfs2_block_group_search;
 464
 465         status = ocfs2_reserve_suballoc_bits(osb, (*ac));
 466         if (status < 0) {
 467                 if (status != -ENOSPC)
 468                         mlog_errno(status);
 469                 goto bail;
 470         }
 471
 472         status = 0;
 473 bail:
 474         if ((status < 0) && *ac) {
 475                 ocfs2_free_alloc_context(*ac);
 476                 *ac = NULL;
 477         }
 478
 479         if (alloc_inode)
 480                 iput(alloc_inode);
 481
 482         mlog_exit(status);
 483         return status;
 484 }
 485
 486 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 487                             struct ocfs2_journal_handle *handle,
 488                             struct ocfs2_alloc_context **ac)
 489 {
 490         int status;
 491         struct inode *alloc_inode = NULL;
 492
 493         *ac = kcalloc(1, sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 494         if (!(*ac)) {
 495                 status = -ENOMEM;
 496                 mlog_errno(status);
 497                 goto bail;
 498         }
 499
 500         (*ac)->ac_bits_wanted = 1;
 501         (*ac)->ac_handle = handle;
 502         (*ac)->ac_which = OCFS2_AC_USE_INODE;
 503
 504         alloc_inode = ocfs2_get_system_file_inode(osb,
 505                                                   INODE_ALLOC_SYSTEM_INODE,
 506                                                   osb->slot_num);
 507         if (!alloc_inode) {
 508                 status = -ENOMEM;
 509                 mlog_errno(status);
 510                 goto bail;
 511         }
 512
 513         (*ac)->ac_inode = igrab(alloc_inode);
 514         (*ac)->ac_group_search = ocfs2_block_group_search;
 515
 516         status = ocfs2_reserve_suballoc_bits(osb, *ac);
 517         if (status < 0) {
 518                 if (status != -ENOSPC)
 519                         mlog_errno(status);
 520                 goto bail;
 521         }
 522
 523         status = 0;
 524 bail:
 525         if ((status < 0) && *ac) {
 526                 ocfs2_free_alloc_context(*ac);
 527                 *ac = NULL;
 528         }
 529
 530         if (alloc_inode)
 531                 iput(alloc_inode);
 532
 533         mlog_exit(status);
 534         return status;
 535 }
 536
 537 /* local alloc code has to do the same thing, so rather than do this
 538  * twice.. */
 539 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
 540                                       struct ocfs2_alloc_context *ac)
 541 {
 542         int status;
 543
 544         ac->ac_inode = ocfs2_get_system_file_inode(osb,
 545                                                    GLOBAL_BITMAP_SYSTEM_INODE,
 546                                                    OCFS2_INVALID_SLOT);
 547         if (!ac->ac_inode) {
 548                 status = -EINVAL;
 549                 mlog(ML_ERROR, "Could not get bitmap inode!\n");
 550                 goto bail;
 551         }
 552         ac->ac_which = OCFS2_AC_USE_MAIN;
 553         ac->ac_group_search = ocfs2_cluster_group_search;
 554
 555         status = ocfs2_reserve_suballoc_bits(osb, ac);
 556         if (status < 0 && status != -ENOSPC)
 557                 mlog_errno(status);
 558 bail:
 559         return status;
 560 }
 561
 562 /* Callers don't need to care which bitmap (local alloc or main) to
 563  * use so we figure it out for them, but unfortunately this clutters
 564  * things a bit. */
 565 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
 566                            struct ocfs2_journal_handle *handle,
 567                            u32 bits_wanted,
 568                            struct ocfs2_alloc_context **ac)
 569 {
 570         int status;
 571
 572         mlog_entry_void();
 573
 574         BUG_ON(!handle);
 575
 576         *ac = kcalloc(1, sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 577         if (!(*ac)) {
 578                 status = -ENOMEM;
 579                 mlog_errno(status);
 580                 goto bail;
 581         }
 582
 583         (*ac)->ac_bits_wanted = bits_wanted;
 584         (*ac)->ac_handle = handle;
 585
 586         status = -ENOSPC;
 587         if (ocfs2_alloc_should_use_local(osb, bits_wanted)) {
 588                 status = ocfs2_reserve_local_alloc_bits(osb,
 589                                                         handle,
 590                                                         bits_wanted,
 591                                                         *ac);
 592                 if ((status < 0) && (status != -ENOSPC)) {
 593                         mlog_errno(status);
 594                         goto bail;
 595                 } else if (status == -ENOSPC) {
 596                         /* reserve_local_bits will return enospc with
 597                          * the local alloc inode still locked, so we
 598                          * can change this safely here. */
 599                         mlog(0, "Disabling local alloc\n");
 600                         /* We set to OCFS2_LA_DISABLED so that umount
 601                          * can clean up what's left of the local
 602                          * allocation */
 603                         osb->local_alloc_state = OCFS2_LA_DISABLED;
 604                 }
 605         }
 606
 607         if (status == -ENOSPC) {
 608                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 609                 if (status < 0) {
 610                         if (status != -ENOSPC)
 611                                 mlog_errno(status);
 612                         goto bail;
 613                 }
 614         }
 615
 616         status = 0;
 617 bail:
 618         if ((status < 0) && *ac) {
 619                 ocfs2_free_alloc_context(*ac);
 620                 *ac = NULL;
 621         }
 622
 623         mlog_exit(status);
 624         return status;
 625 }
 626
 627 /*
 628  * More or less lifted from ext3. I'll leave their description below:
 629  *
 630  * "For ext3 allocations, we must not reuse any blocks which are
 631  * allocated in the bitmap buffer's "last committed data" copy.  This
 632  * prevents deletes from freeing up the page for reuse until we have
 633  * committed the delete transaction.
 634  *
 635  * If we didn't do this, then deleting something and reallocating it as
 636  * data would allow the old block to be overwritten before the
 637  * transaction committed (because we force data to disk before commit).
 638  * This would lead to corruption if we crashed between overwriting the
 639  * data and committing the delete.
 640  *
 641  * @@@ We may want to make this allocation behaviour conditional on
 642  * data-writes at some point, and disable it for metadata allocations or
 643  * sync-data inodes."
 644  *
 645  * Note: OCFS2 already does this differently for metadata vs data
 646  * allocations, as those bitmaps are seperate and undo access is never
 647  * called on a metadata group descriptor.
 648  */
 649 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 650                                          int nr)
 651 {
 652         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 653
 654         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
 655                 return 0;
 656         if (!buffer_jbd(bg_bh) || !bh2jh(bg_bh)->b_committed_data)
 657                 return 1;
 658
 659         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
 660         return !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
 661 }
 662
 663 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
 664                                              struct buffer_head *bg_bh,
 665                                              unsigned int bits_wanted,
 666                                              u16 *bit_off,
 667                                              u16 *bits_found)
 668 {
 669         void *bitmap;
 670         u16 best_offset, best_size;
 671         int offset, start, found, status = 0;
 672         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 673
 674         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 675                 OCFS2_RO_ON_INVALID_GROUP_DESC(osb->sb, bg);
 676                 return -EIO;
 677         }
 678
 679         found = start = best_offset = best_size = 0;
 680         bitmap = bg->bg_bitmap;
 681
 682         while((offset = ocfs2_find_next_zero_bit(bitmap,
 683                                                  le16_to_cpu(bg->bg_bits),
 684                                                  start)) != -1) {
 685                 if (offset == le16_to_cpu(bg->bg_bits))
 686                         break;
 687
 688                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
 689                         /* We found a zero, but we can't use it as it
 690                          * hasn't been put to disk yet! */
 691                         found = 0;
 692                         start = offset + 1;
 693                 } else if (offset == start) {
 694                         /* we found a zero */
 695                         found++;
 696                         /* move start to the next bit to test */
 697                         start++;
 698                 } else {
 699                         /* got a zero after some ones */
 700                         found = 1;
 701                         start = offset + 1;
 702                 }
 703                 if (found > best_size) {
 704                         best_size = found;
 705                         best_offset = start - found;
 706                 }
 707                 /* we got everything we needed */
 708                 if (found == bits_wanted) {
 709                         /* mlog(0, "Found it all!\n"); */
 710                         break;
 711                 }
 712         }
 713
 714         /* XXX: I think the first clause is equivalent to the second
 715          *      - jlbec */
 716         if (found == bits_wanted) {
 717                 *bit_off = start - found;
 718                 *bits_found = found;
 719         } else if (best_size) {
 720                 *bit_off = best_offset;
 721                 *bits_found = best_size;
 722         } else {
 723                 status = -ENOSPC;
 724                 /* No error log here -- see the comment above
 725                  * ocfs2_test_bg_bit_allocatable */
 726         }
 727
 728         return status;
 729 }
 730
 731 static inline int ocfs2_block_group_set_bits(struct ocfs2_journal_handle *handle,
 732                                              struct inode *alloc_inode,
 733                                              struct ocfs2_group_desc *bg,
 734                                              struct buffer_head *group_bh,
 735                                              unsigned int bit_off,
 736                                              unsigned int num_bits)
 737 {
 738         int status;
 739         void *bitmap = bg->bg_bitmap;
 740         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
 741
 742         mlog_entry_void();
 743
 744         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 745                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 746                 status = -EIO;
 747                 goto bail;
 748         }
 749         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
 750
 751         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
 752              num_bits);
 753
 754         if (ocfs2_is_cluster_bitmap(alloc_inode))
 755                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
 756
 757         status = ocfs2_journal_access(handle,
 758                                       alloc_inode,
 759                                       group_bh,
 760                                       journal_type);
 761         if (status < 0) {
 762                 mlog_errno(status);
 763                 goto bail;
 764         }
 765
 766         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
 767
 768         while(num_bits--)
 769                 ocfs2_set_bit(bit_off++, bitmap);
 770
 771         status = ocfs2_journal_dirty(handle,
 772                                      group_bh);
 773         if (status < 0) {
 774                 mlog_errno(status);
 775                 goto bail;
 776         }
 777
 778 bail:
 779         mlog_exit(status);
 780         return status;
 781 }
 782
 783 /* find the one with the most empty bits */
 784 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
 785 {
 786         u16 curr, best;
 787
 788         BUG_ON(!cl->cl_next_free_rec);
 789
 790         best = curr = 0;
 791         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
 792                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
 793                     le32_to_cpu(cl->cl_recs[best].c_free))
 794                         best = curr;
 795                 curr++;
 796         }
 797
 798         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
 799         return best;
 800 }
 801
 802 static int ocfs2_relink_block_group(struct ocfs2_journal_handle *handle,
 803                                     struct inode *alloc_inode,
 804                                     struct buffer_head *fe_bh,
 805                                     struct buffer_head *bg_bh,
 806                                     struct buffer_head *prev_bg_bh,
 807                                     u16 chain)
 808 {
 809         int status;
 810         /* there is a really tiny chance the journal calls could fail,
 811          * but we wouldn't want inconsistent blocks in *any* case. */
 812         u64 fe_ptr, bg_ptr, prev_bg_ptr;
 813         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
 814         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 815         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
 816
 817         if (!OCFS2_IS_VALID_DINODE(fe)) {
 818                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 819                 status = -EIO;
 820                 goto out;
 821         }
 822         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 823                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 824                 status = -EIO;
 825                 goto out;
 826         }
 827         if (!OCFS2_IS_VALID_GROUP_DESC(prev_bg)) {
 828                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, prev_bg);
 829                 status = -EIO;
 830                 goto out;
 831         }
 832
 833         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
 834              (unsigned long long)fe->i_blkno, chain,
 835              (unsigned long long)bg->bg_blkno,
 836              (unsigned long long)prev_bg->bg_blkno);
 837
 838         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
 839         bg_ptr = le64_to_cpu(bg->bg_next_group);
 840         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
 841
 842         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
 843                                       OCFS2_JOURNAL_ACCESS_WRITE);
 844         if (status < 0) {
 845                 mlog_errno(status);
 846                 goto out_rollback;
 847         }
 848
 849         prev_bg->bg_next_group = bg->bg_next_group;
 850
 851         status = ocfs2_journal_dirty(handle, prev_bg_bh);
 852         if (status < 0) {
 853                 mlog_errno(status);
 854                 goto out_rollback;
 855         }
 856
 857         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
 858                                       OCFS2_JOURNAL_ACCESS_WRITE);
 859         if (status < 0) {
 860                 mlog_errno(status);
 861                 goto out_rollback;
 862         }
 863
 864         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
 865
 866         status = ocfs2_journal_dirty(handle, bg_bh);
 867         if (status < 0) {
 868                 mlog_errno(status);
 869                 goto out_rollback;
 870         }
 871
 872         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
 873                                       OCFS2_JOURNAL_ACCESS_WRITE);
 874         if (status < 0) {
 875                 mlog_errno(status);
 876                 goto out_rollback;
 877         }
 878
 879         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
 880
 881         status = ocfs2_journal_dirty(handle, fe_bh);
 882         if (status < 0) {
 883                 mlog_errno(status);
 884                 goto out_rollback;
 885         }
 886
 887         status = 0;
 888 out_rollback:
 889         if (status < 0) {
 890                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
 891                 bg->bg_next_group = cpu_to_le64(bg_ptr);
 892                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
 893         }
 894 out:
 895         mlog_exit(status);
 896         return status;
 897 }
 898
 899 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 900                                                      u32 wanted)
 901 {
 902         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
 903 }
 904
 905 /* return 0 on success, -ENOSPC to keep searching and any other < 0
 906  * value on error. */
 907 static int ocfs2_cluster_group_search(struct inode *inode,
 908                                       struct buffer_head *group_bh,
 909                                       u32 bits_wanted, u32 min_bits,
 910                                       u16 *bit_off, u16 *bits_found)
 911 {
 912         int search = -ENOSPC;
 913         int ret;
 914         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
 915         u16 tmp_off, tmp_found;
 916
 917         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
 918
 919         if (bg->bg_free_bits_count) {
 920                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
 921                                                         group_bh, bits_wanted,
 922                                                         &tmp_off, &tmp_found);
 923                 if (ret)
 924                         return ret;
 925
 926                 /* ocfs2_block_group_find_clear_bits() might
 927                  * return success, but we still want to return
 928                  * -ENOSPC unless it found the minimum number
 929                  * of bits. */
 930                 if (min_bits <= tmp_found) {
 931                         *bit_off = tmp_off;
 932                         *bits_found = tmp_found;
 933                         search = 0; /* success */
 934                 }
 935         }
 936
 937         return search;
 938 }
 939
 940 static int ocfs2_block_group_search(struct inode *inode,
 941                                     struct buffer_head *group_bh,
 942                                     u32 bits_wanted, u32 min_bits,
 943                                     u16 *bit_off, u16 *bits_found)
 944 {
 945         int ret = -ENOSPC;
 946         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
 947
 948         BUG_ON(min_bits != 1);
 949         BUG_ON(ocfs2_is_cluster_bitmap(inode));
 950
 951         if (bg->bg_free_bits_count)
 952                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
 953                                                         group_bh, bits_wanted,
 954                                                         bit_off, bits_found);
 955
 956         return ret;
 957 }
 958
 959 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
 960                               u32 bits_wanted,
 961                               u32 min_bits,
 962                               u16 *bit_off,
 963                               unsigned int *num_bits,
 964                               u64 *bg_blkno)
 965 {
 966         int status;
 967         u16 chain, tmp_bits;
 968         u32 tmp_used;
 969         u64 next_group;
 970         struct ocfs2_journal_handle *handle = ac->ac_handle;
 971         struct inode *alloc_inode = ac->ac_inode;
 972         struct buffer_head *group_bh = NULL;
 973         struct buffer_head *prev_group_bh = NULL;
 974         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
 975         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
 976         struct ocfs2_group_desc *bg;
 977
 978         chain = ac->ac_chain;
 979         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
 980              bits_wanted, chain,
 981              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
 982
 983         status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
 984                                   le64_to_cpu(cl->cl_recs[chain].c_blkno),
 985                                   &group_bh, OCFS2_BH_CACHED, alloc_inode);
 986         if (status < 0) {
 987                 mlog_errno(status);
 988                 goto bail;
 989         }
 990         bg = (struct ocfs2_group_desc *) group_bh->b_data;
 991         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 992                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 993                 status = -EIO;
 994                 goto bail;
 995         }
 996
 997         status = -ENOSPC;
 998         /* for now, the chain search is a bit simplistic. We just use
 999          * the 1st group with any empty bits. */
1000         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1001                                              bits_wanted, min_bits, bit_off,
1002                                              &tmp_bits)) == -ENOSPC) {
1003                 if (!bg->bg_next_group)
1004                         break;
1005
1006                 if (prev_group_bh) {
1007                         brelse(prev_group_bh);
1008                         prev_group_bh = NULL;
1009                 }
1010                 next_group = le64_to_cpu(bg->bg_next_group);
1011                 prev_group_bh = group_bh;
1012                 group_bh = NULL;
1013                 status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1014                                           next_group, &group_bh,
1015                                           OCFS2_BH_CACHED, alloc_inode);
1016                 if (status < 0) {
1017                         mlog_errno(status);
1018                         goto bail;
1019                 }
1020                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1021                 if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1022                         OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1023                         status = -EIO;
1024                         goto bail;
1025                 }
1026         }
1027         if (status < 0) {
1028                 if (status != -ENOSPC)
1029                         mlog_errno(status);
1030                 goto bail;
1031         }
1032
1033         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1034              tmp_bits, (unsigned long long)bg->bg_blkno);
1035
1036         *num_bits = tmp_bits;
1037
1038         BUG_ON(*num_bits == 0);
1039
1040         /*
1041          * Keep track of previous block descriptor read. When
1042          * we find a target, if we have read more than X
1043          * number of descriptors, and the target is reasonably
1044          * empty, relink him to top of his chain.
1045          *
1046          * We've read 0 extra blocks and only send one more to
1047          * the transaction, yet the next guy to search has a
1048          * much easier time.
1049          *
1050          * Do this *after* figuring out how many bits we're taking out
1051          * of our target group.
1052          */
1053         if (ac->ac_allow_chain_relink &&
1054             (prev_group_bh) &&
1055             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1056                 status = ocfs2_relink_block_group(handle, alloc_inode,
1057                                                   ac->ac_bh, group_bh,
1058                                                   prev_group_bh, chain);
1059                 if (status < 0) {
1060                         mlog_errno(status);
1061                         goto bail;
1062                 }
1063         }
1064
1065         /* Ok, claim our bits now: set the info on dinode, chainlist
1066          * and then the group */
1067         status = ocfs2_journal_access(handle,
1068                                       alloc_inode,
1069                                       ac->ac_bh,
1070                                       OCFS2_JOURNAL_ACCESS_WRITE);
1071         if (status < 0) {
1072                 mlog_errno(status);
1073                 goto bail;
1074         }
1075
1076         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1077         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1078         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1079
1080         status = ocfs2_journal_dirty(handle,
1081                                      ac->ac_bh);
1082         if (status < 0) {
1083                 mlog_errno(status);
1084                 goto bail;
1085         }
1086
1087         status = ocfs2_block_group_set_bits(handle,
1088                                             alloc_inode,
1089                                             bg,
1090                                             group_bh,
1091                                             *bit_off,
1092                                             *num_bits);
1093         if (status < 0) {
1094                 mlog_errno(status);
1095                 goto bail;
1096         }
1097
1098         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1099              (unsigned long long)fe->i_blkno);
1100
1101         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1102 bail:
1103         if (group_bh)
1104                 brelse(group_bh);
1105         if (prev_group_bh)
1106                 brelse(prev_group_bh);
1107
1108         mlog_exit(status);
1109         return status;
1110 }
1111
1112 /* will give out up to bits_wanted contiguous bits. */
1113 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1114                                      struct ocfs2_alloc_context *ac,
1115                                      u32 bits_wanted,
1116                                      u32 min_bits,
1117                                      u16 *bit_off,
1118                                      unsigned int *num_bits,
1119                                      u64 *bg_blkno)
1120 {
1121         int status;
1122         u16 victim, i;
1123         struct ocfs2_chain_list *cl;
1124         struct ocfs2_dinode *fe;
1125
1126         mlog_entry_void();
1127
1128         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1129         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1130         BUG_ON(!ac->ac_bh);
1131
1132         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1133         if (!OCFS2_IS_VALID_DINODE(fe)) {
1134                 OCFS2_RO_ON_INVALID_DINODE(osb->sb, fe);
1135                 status = -EIO;
1136                 goto bail;
1137         }
1138         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1139             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1140                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1141                             "bits but only %u total.",
1142                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1143                             le32_to_cpu(fe->id1.bitmap1.i_used),
1144                             le32_to_cpu(fe->id1.bitmap1.i_total));
1145                 status = -EIO;
1146                 goto bail;
1147         }
1148
1149         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1150
1151         victim = ocfs2_find_victim_chain(cl);
1152         ac->ac_chain = victim;
1153         ac->ac_allow_chain_relink = 1;
1154
1155         status = ocfs2_search_chain(ac, bits_wanted, min_bits, bit_off,
1156                                     num_bits, bg_blkno);
1157         if (!status)
1158                 goto bail;
1159         if (status < 0 && status != -ENOSPC) {
1160                 mlog_errno(status);
1161                 goto bail;
1162         }
1163
1164         mlog(0, "Search of victim chain %u came up with nothing, "
1165              "trying all chains now.\n", victim);
1166
1167         /* If we didn't pick a good victim, then just default to
1168          * searching each chain in order. Don't allow chain relinking
1169          * because we only calculate enough journal credits for one
1170          * relink per alloc. */
1171         ac->ac_allow_chain_relink = 0;
1172         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1173                 if (i == victim)
1174                         continue;
1175                 if (!cl->cl_recs[i].c_free)
1176                         continue;
1177
1178                 ac->ac_chain = i;
1179                 status = ocfs2_search_chain(ac, bits_wanted, min_bits,
1180                                             bit_off, num_bits,
1181                                             bg_blkno);
1182                 if (!status)
1183                         break;
1184                 if (status < 0 && status != -ENOSPC) {
1185                         mlog_errno(status);
1186                         goto bail;
1187                 }
1188         }
1189 bail:
1190
1191         mlog_exit(status);
1192         return status;
1193 }
1194
1195 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1196                          struct ocfs2_journal_handle *handle,
1197                          struct ocfs2_alloc_context *ac,
1198                          u32 bits_wanted,
1199                          u16 *suballoc_bit_start,
1200                          unsigned int *num_bits,
1201                          u64 *blkno_start)
1202 {
1203         int status;
1204         u64 bg_blkno;
1205
1206         BUG_ON(!ac);
1207         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1208         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1209         BUG_ON(ac->ac_handle != handle);
1210
1211         status = ocfs2_claim_suballoc_bits(osb,
1212                                            ac,
1213                                            bits_wanted,
1214                                            1,
1215                                            suballoc_bit_start,
1216                                            num_bits,
1217                                            &bg_blkno);
1218         if (status < 0) {
1219                 mlog_errno(status);
1220                 goto bail;
1221         }
1222         atomic_inc(&osb->alloc_stats.bg_allocs);
1223
1224         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1225         ac->ac_bits_given += (*num_bits);
1226         status = 0;
1227 bail:
1228         mlog_exit(status);
1229         return status;
1230 }
1231
1232 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1233                           struct ocfs2_journal_handle *handle,
1234                           struct ocfs2_alloc_context *ac,
1235                           u16 *suballoc_bit,
1236                           u64 *fe_blkno)
1237 {
1238         int status;
1239         unsigned int num_bits;
1240         u64 bg_blkno;
1241
1242         mlog_entry_void();
1243
1244         BUG_ON(!ac);
1245         BUG_ON(ac->ac_bits_given != 0);
1246         BUG_ON(ac->ac_bits_wanted != 1);
1247         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1248         BUG_ON(ac->ac_handle != handle);
1249
1250         status = ocfs2_claim_suballoc_bits(osb,
1251                                            ac,
1252                                            1,
1253                                            1,
1254                                            suballoc_bit,
1255                                            &num_bits,
1256                                            &bg_blkno);
1257         if (status < 0) {
1258                 mlog_errno(status);
1259                 goto bail;
1260         }
1261         atomic_inc(&osb->alloc_stats.bg_allocs);
1262
1263         BUG_ON(num_bits != 1);
1264
1265         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1266         ac->ac_bits_given++;
1267         status = 0;
1268 bail:
1269         mlog_exit(status);
1270         return status;
1271 }
1272
1273 /* translate a group desc. blkno and it's bitmap offset into
1274  * disk cluster offset. */
1275 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1276                                                    u64 bg_blkno,
1277                                                    u16 bg_bit_off)
1278 {
1279         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1280         u32 cluster = 0;
1281
1282         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1283
1284         if (bg_blkno != osb->first_cluster_group_blkno)
1285                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1286         cluster += (u32) bg_bit_off;
1287         return cluster;
1288 }
1289
1290 /* given a cluster offset, calculate which block group it belongs to
1291  * and return that block offset. */
1292 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
1293                                             u32 cluster)
1294 {
1295         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1296         u32 group_no;
1297
1298         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1299
1300         group_no = cluster / osb->bitmap_cpg;
1301         if (!group_no)
1302                 return osb->first_cluster_group_blkno;
1303         return ocfs2_clusters_to_blocks(inode->i_sb,
1304                                         group_no * osb->bitmap_cpg);
1305 }
1306
1307 /* given the block number of a cluster start, calculate which cluster
1308  * group and descriptor bitmap offset that corresponds to. */
1309 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1310                                                 u64 data_blkno,
1311                                                 u64 *bg_blkno,
1312                                                 u16 *bg_bit_off)
1313 {
1314         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1315         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1316
1317         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1318
1319         *bg_blkno = ocfs2_which_cluster_group(inode,
1320                                               data_cluster);
1321
1322         if (*bg_blkno == osb->first_cluster_group_blkno)
1323                 *bg_bit_off = (u16) data_cluster;
1324         else
1325                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1326                                                              data_blkno - *bg_blkno);
1327 }
1328
1329 /*
1330  * min_bits - minimum contiguous chunk from this total allocation we
1331  * can handle. set to what we asked for originally for a full
1332  * contig. allocation, set to '1' to indicate we can deal with extents
1333  * of any size.
1334  */
1335 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1336                          struct ocfs2_journal_handle *handle,
1337                          struct ocfs2_alloc_context *ac,
1338                          u32 min_clusters,
1339                          u32 *cluster_start,
1340                          u32 *num_clusters)
1341 {
1342         int status;
1343         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1344         u64 bg_blkno;
1345         u16 bg_bit_off;
1346
1347         mlog_entry_void();
1348
1349         BUG_ON(!ac);
1350         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1351
1352         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1353                && ac->ac_which != OCFS2_AC_USE_MAIN);
1354         BUG_ON(ac->ac_handle != handle);
1355
1356         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1357                 status = ocfs2_claim_local_alloc_bits(osb,
1358                                                       handle,
1359                                                       ac,
1360                                                       bits_wanted,
1361                                                       cluster_start,
1362                                                       num_clusters);
1363                 if (!status)
1364                         atomic_inc(&osb->alloc_stats.local_data);
1365         } else {
1366                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1367                         /* The only paths asking for contiguousness
1368                          * should know about this already. */
1369                         mlog(ML_ERROR, "minimum allocation requested exceeds "
1370                                        "group bitmap size!");
1371                         status = -ENOSPC;
1372                         goto bail;
1373                 }
1374                 /* clamp the current request down to a realistic size. */
1375                 if (bits_wanted > (osb->bitmap_cpg - 1))
1376                         bits_wanted = osb->bitmap_cpg - 1;
1377
1378                 status = ocfs2_claim_suballoc_bits(osb,
1379                                                    ac,
1380                                                    bits_wanted,
1381                                                    min_clusters,
1382                                                    &bg_bit_off,
1383                                                    num_clusters,
1384                                                    &bg_blkno);
1385                 if (!status) {
1386                         *cluster_start =
1387                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1388                                                                  bg_blkno,
1389                                                                  bg_bit_off);
1390                         atomic_inc(&osb->alloc_stats.bitmap_data);
1391                 }
1392         }
1393         if (status < 0) {
1394                 if (status != -ENOSPC)
1395                         mlog_errno(status);
1396                 goto bail;
1397         }
1398
1399         ac->ac_bits_given += *num_clusters;
1400
1401 bail:
1402         mlog_exit(status);
1403         return status;
1404 }
1405
1406 static inline int ocfs2_block_group_clear_bits(struct ocfs2_journal_handle *handle,
1407                                                struct inode *alloc_inode,
1408                                                struct ocfs2_group_desc *bg,
1409                                                struct buffer_head *group_bh,
1410                                                unsigned int bit_off,
1411                                                unsigned int num_bits)
1412 {
1413         int status;
1414         unsigned int tmp;
1415         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1416         struct ocfs2_group_desc *undo_bg = NULL;
1417
1418         mlog_entry_void();
1419
1420         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1421                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1422                 status = -EIO;
1423                 goto bail;
1424         }
1425
1426         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1427
1428         if (ocfs2_is_cluster_bitmap(alloc_inode))
1429                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1430
1431         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1432                                       journal_type);
1433         if (status < 0) {
1434                 mlog_errno(status);
1435                 goto bail;
1436         }
1437
1438         if (ocfs2_is_cluster_bitmap(alloc_inode))
1439                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1440
1441         tmp = num_bits;
1442         while(tmp--) {
1443                 ocfs2_clear_bit((bit_off + tmp),
1444                                 (unsigned long *) bg->bg_bitmap);
1445                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1446                         ocfs2_set_bit(bit_off + tmp,
1447                                       (unsigned long *) undo_bg->bg_bitmap);
1448         }
1449         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1450
1451         status = ocfs2_journal_dirty(handle, group_bh);
1452         if (status < 0)
1453                 mlog_errno(status);
1454 bail:
1455         return status;
1456 }
1457
1458 /*
1459  * expects the suballoc inode to already be locked.
1460  */
1461 static int ocfs2_free_suballoc_bits(struct ocfs2_journal_handle *handle,
1462                                     struct inode *alloc_inode,
1463                                     struct buffer_head *alloc_bh,
1464                                     unsigned int start_bit,
1465                                     u64 bg_blkno,
1466                                     unsigned int count)
1467 {
1468         int status = 0;
1469         u32 tmp_used;
1470         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
1471         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1472         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1473         struct buffer_head *group_bh = NULL;
1474         struct ocfs2_group_desc *group;
1475
1476         mlog_entry_void();
1477
1478         if (!OCFS2_IS_VALID_DINODE(fe)) {
1479                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
1480                 status = -EIO;
1481                 goto bail;
1482         }
1483         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1484
1485         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1486              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1487              (unsigned long long)bg_blkno, start_bit);
1488
1489         status = ocfs2_read_block(osb, bg_blkno, &group_bh, OCFS2_BH_CACHED,
1490                                   alloc_inode);
1491         if (status < 0) {
1492                 mlog_errno(status);
1493                 goto bail;
1494         }
1495
1496         group = (struct ocfs2_group_desc *) group_bh->b_data;
1497         if (!OCFS2_IS_VALID_GROUP_DESC(group)) {
1498                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, group);
1499                 status = -EIO;
1500                 goto bail;
1501         }
1502         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1503
1504         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1505                                               group, group_bh,
1506                                               start_bit, count);
1507         if (status < 0) {
1508                 mlog_errno(status);
1509                 goto bail;
1510         }
1511
1512         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1513                                       OCFS2_JOURNAL_ACCESS_WRITE);
1514         if (status < 0) {
1515                 mlog_errno(status);
1516                 goto bail;
1517         }
1518
1519         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1520                      count);
1521         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1522         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1523
1524         status = ocfs2_journal_dirty(handle, alloc_bh);
1525         if (status < 0) {
1526                 mlog_errno(status);
1527                 goto bail;
1528         }
1529
1530 bail:
1531         if (group_bh)
1532                 brelse(group_bh);
1533
1534         mlog_exit(status);
1535         return status;
1536 }
1537
1538 static inline u64 ocfs2_which_suballoc_group(u64 block, unsigned int bit)
1539 {
1540         u64 group = block - (u64) bit;
1541
1542         return group;
1543 }
1544
1545 int ocfs2_free_dinode(struct ocfs2_journal_handle *handle,
1546                       struct inode *inode_alloc_inode,
1547                       struct buffer_head *inode_alloc_bh,
1548                       struct ocfs2_dinode *di)
1549 {
1550         u64 blk = le64_to_cpu(di->i_blkno);
1551         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1552         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1553
1554         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1555                                         inode_alloc_bh, bit, bg_blkno, 1);
1556 }
1557
1558 int ocfs2_free_extent_block(struct ocfs2_journal_handle *handle,
1559                             struct inode *eb_alloc_inode,
1560                             struct buffer_head *eb_alloc_bh,
1561                             struct ocfs2_extent_block *eb)
1562 {
1563         u64 blk = le64_to_cpu(eb->h_blkno);
1564         u16 bit = le16_to_cpu(eb->h_suballoc_bit);
1565         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1566
1567         return ocfs2_free_suballoc_bits(handle, eb_alloc_inode, eb_alloc_bh,
1568                                         bit, bg_blkno, 1);
1569 }
1570
1571 int ocfs2_free_clusters(struct ocfs2_journal_handle *handle,
1572                        struct inode *bitmap_inode,
1573                        struct buffer_head *bitmap_bh,
1574                        u64 start_blk,
1575                        unsigned int num_clusters)
1576 {
1577         int status;
1578         u16 bg_start_bit;
1579         u64 bg_blkno;
1580         struct ocfs2_dinode *fe;
1581
1582         /* You can't ever have a contiguous set of clusters
1583          * bigger than a block group bitmap so we never have to worry
1584          * about looping on them. */
1585
1586         mlog_entry_void();
1587
1588         /* This is expensive. We can safely remove once this stuff has
1589          * gotten tested really well. */
1590         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1591
1592         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1593
1594         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1595                                      &bg_start_bit);
1596
1597         mlog(0, "want to free %u clusters starting at block %llu\n",
1598              num_clusters, (unsigned long long)start_blk);
1599         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1600              (unsigned long long)bg_blkno, bg_start_bit);
1601
1602         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1603                                           bg_start_bit, bg_blkno,
1604                                           num_clusters);
1605         if (status < 0)
1606                 mlog_errno(status);
1607
1608         mlog_exit(status);
1609         return status;
1610 }
1611
1612 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1613 {
1614         printk("Block Group:\n");
1615         printk("bg_signature:       %s\n", bg->bg_signature);
1616         printk("bg_size:            %u\n", bg->bg_size);
1617         printk("bg_bits:            %u\n", bg->bg_bits);
1618         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1619         printk("bg_chain:           %u\n", bg->bg_chain);
1620         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1621         printk("bg_next_group:      %llu\n",
1622                (unsigned long long)bg->bg_next_group);
1623         printk("bg_parent_dinode:   %llu\n",
1624                (unsigned long long)bg->bg_parent_dinode);
1625         printk("bg_blkno:           %llu\n",
1626                (unsigned long long)bg->bg_blkno);
1627 }
1628
1629 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
1630 {
1631         int i;
1632
1633         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
1634         printk("i_signature:                  %s\n", fe->i_signature);
1635         printk("i_size:                       %llu\n",
1636                (unsigned long long)fe->i_size);
1637         printk("i_clusters:                   %u\n", fe->i_clusters);
1638         printk("i_generation:                 %u\n",
1639                le32_to_cpu(fe->i_generation));
1640         printk("id1.bitmap1.i_used:           %u\n",
1641                le32_to_cpu(fe->id1.bitmap1.i_used));
1642         printk("id1.bitmap1.i_total:          %u\n",
1643                le32_to_cpu(fe->id1.bitmap1.i_total));
1644         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
1645         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
1646         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
1647         printk("id2.i_chain.cl_next_free_rec: %u\n",
1648                fe->id2.i_chain.cl_next_free_rec);
1649         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
1650                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
1651                        fe->id2.i_chain.cl_recs[i].c_free);
1652                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
1653                        fe->id2.i_chain.cl_recs[i].c_total);
1654                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
1655                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
1656         }
1657 }