fs/ocfs2/suballoc.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * suballoc.c
   5  *
   6  * metadata alloc and free
   7  * Inspired by ext3 block groups.
   8  *
   9  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public
  13  * License as published by the Free Software Foundation; either
  14  * version 2 of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public
  22  * License along with this program; if not, write to the
  23  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24  * Boston, MA 021110-1307, USA.
  25  */
  26
  27 #include <linux/fs.h>
  28 #include <linux/types.h>
  29 #include <linux/slab.h>
  30 #include <linux/highmem.h>
  31
  32 #define MLOG_MASK_PREFIX ML_DISK_ALLOC
  33 #include <cluster/masklog.h>
  34
  35 #include "ocfs2.h"
  36
  37 #include "alloc.h"
  38 #include "blockcheck.h"
  39 #include "dlmglue.h"
  40 #include "inode.h"
  41 #include "journal.h"
  42 #include "localalloc.h"
  43 #include "suballoc.h"
  44 #include "super.h"
  45 #include "sysfile.h"
  46 #include "uptodate.h"
  47
  48 #include "buffer_head_io.h"
  49
  50 #define NOT_ALLOC_NEW_GROUP             0
  51 #define ALLOC_NEW_GROUP                 0x1
  52 #define ALLOC_GROUPS_FROM_GLOBAL        0x2
  53
  54 #define OCFS2_MAX_TO_STEAL              1024
  55
  56 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
  57 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
  58 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  59 static int ocfs2_block_group_fill(handle_t *handle,
  60                                   struct inode *alloc_inode,
  61                                   struct buffer_head *bg_bh,
  62                                   u64 group_blkno,
  63                                   u16 my_chain,
  64                                   struct ocfs2_chain_list *cl);
  65 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  66                                    struct inode *alloc_inode,
  67                                    struct buffer_head *bh,
  68                                    u64 max_block,
  69                                    u64 *last_alloc_group,
  70                                    int flags);
  71
  72 static int ocfs2_cluster_group_search(struct inode *inode,
  73                                       struct buffer_head *group_bh,
  74                                       u32 bits_wanted, u32 min_bits,
  75                                       u64 max_block,
  76                                       u16 *bit_off, u16 *bits_found);
  77 static int ocfs2_block_group_search(struct inode *inode,
  78                                     struct buffer_head *group_bh,
  79                                     u32 bits_wanted, u32 min_bits,
  80                                     u64 max_block,
  81                                     u16 *bit_off, u16 *bits_found);
  82 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
  83                                      struct ocfs2_alloc_context *ac,
  84                                      handle_t *handle,
  85                                      u32 bits_wanted,
  86                                      u32 min_bits,
  87                                      u16 *bit_off,
  88                                      unsigned int *num_bits,
  89                                      u64 *bg_blkno);
  90 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  91                                          int nr);
  92 static inline int ocfs2_block_group_set_bits(handle_t *handle,
  93                                              struct inode *alloc_inode,
  94                                              struct ocfs2_group_desc *bg,
  95                                              struct buffer_head *group_bh,
  96                                              unsigned int bit_off,
  97                                              unsigned int num_bits);
  98 static int ocfs2_relink_block_group(handle_t *handle,
  99                                     struct inode *alloc_inode,
 100                                     struct buffer_head *fe_bh,
 101                                     struct buffer_head *bg_bh,
 102                                     struct buffer_head *prev_bg_bh,
 103                                     u16 chain);
 104 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 105                                                      u32 wanted);
 106 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 107                                                    u64 bg_blkno,
 108                                                    u16 bg_bit_off);
 109 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 110                                                 u64 data_blkno,
 111                                                 u64 *bg_blkno,
 112                                                 u16 *bg_bit_off);
 113 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 114                                              u32 bits_wanted, u64 max_block,
 115                                              int flags,
 116                                              struct ocfs2_alloc_context **ac);
 117
 118 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 119 {
 120         struct inode *inode = ac->ac_inode;
 121
 122         if (inode) {
 123                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 124                         ocfs2_inode_unlock(inode, 1);
 125
 126                 mutex_unlock(&inode->i_mutex);
 127
 128                 iput(inode);
 129                 ac->ac_inode = NULL;
 130         }
 131         brelse(ac->ac_bh);
 132         ac->ac_bh = NULL;
 133 }
 134
 135 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 136 {
 137         ocfs2_free_ac_resource(ac);
 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 #define do_error(fmt, ...)                                              \
 147         do{                                                             \
 148                 if (resize)                                     \
 149                         mlog(ML_ERROR, fmt "\n", ##__VA_ARGS__);        \
 150                 else                                                    \
 151                         ocfs2_error(sb, fmt, ##__VA_ARGS__);            \
 152         } while (0)
 153
 154 static int ocfs2_validate_gd_self(struct super_block *sb,
 155                                   struct buffer_head *bh,
 156                                   int resize)
 157 {
 158         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 159
 160         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 161                 do_error("Group descriptor #%llu has bad signature %.*s",
 162                          (unsigned long long)bh->b_blocknr, 7,
 163                          gd->bg_signature);
 164                 return -EINVAL;
 165         }
 166
 167         if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 168                 do_error("Group descriptor #%llu has an invalid bg_blkno "
 169                          "of %llu",
 170                          (unsigned long long)bh->b_blocknr,
 171                          (unsigned long long)le64_to_cpu(gd->bg_blkno));
 172                 return -EINVAL;
 173         }
 174
 175         if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 176                 do_error("Group descriptor #%llu has an invalid "
 177                          "fs_generation of #%u",
 178                          (unsigned long long)bh->b_blocknr,
 179                          le32_to_cpu(gd->bg_generation));
 180                 return -EINVAL;
 181         }
 182
 183         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 184                 do_error("Group descriptor #%llu has bit count %u but "
 185                          "claims that %u are free",
 186                          (unsigned long long)bh->b_blocknr,
 187                          le16_to_cpu(gd->bg_bits),
 188                          le16_to_cpu(gd->bg_free_bits_count));
 189                 return -EINVAL;
 190         }
 191
 192         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 193                 do_error("Group descriptor #%llu has bit count %u but "
 194                          "max bitmap bits of %u",
 195                          (unsigned long long)bh->b_blocknr,
 196                          le16_to_cpu(gd->bg_bits),
 197                          8 * le16_to_cpu(gd->bg_size));
 198                 return -EINVAL;
 199         }
 200
 201         return 0;
 202 }
 203
 204 static int ocfs2_validate_gd_parent(struct super_block *sb,
 205                                     struct ocfs2_dinode *di,
 206                                     struct buffer_head *bh,
 207                                     int resize)
 208 {
 209         unsigned int max_bits;
 210         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 211
 212         if (di->i_blkno != gd->bg_parent_dinode) {
 213                 do_error("Group descriptor #%llu has bad parent "
 214                          "pointer (%llu, expected %llu)",
 215                          (unsigned long long)bh->b_blocknr,
 216                          (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 217                          (unsigned long long)le64_to_cpu(di->i_blkno));
 218                 return -EINVAL;
 219         }
 220
 221         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 222         if (le16_to_cpu(gd->bg_bits) > max_bits) {
 223                 do_error("Group descriptor #%llu has bit count of %u",
 224                          (unsigned long long)bh->b_blocknr,
 225                          le16_to_cpu(gd->bg_bits));
 226                 return -EINVAL;
 227         }
 228
 229         /* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 230         if ((le16_to_cpu(gd->bg_chain) >
 231              le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 232             ((le16_to_cpu(gd->bg_chain) ==
 233              le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 234                 do_error("Group descriptor #%llu has bad chain %u",
 235                          (unsigned long long)bh->b_blocknr,
 236                          le16_to_cpu(gd->bg_chain));
 237                 return -EINVAL;
 238         }
 239
 240         return 0;
 241 }
 242
 243 #undef do_error
 244
 245 /*
 246  * This version only prints errors.  It does not fail the filesystem, and
 247  * exists only for resize.
 248  */
 249 int ocfs2_check_group_descriptor(struct super_block *sb,
 250                                  struct ocfs2_dinode *di,
 251                                  struct buffer_head *bh)
 252 {
 253         int rc;
 254         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 255
 256         BUG_ON(!buffer_uptodate(bh));
 257
 258         /*
 259          * If the ecc fails, we return the error but otherwise
 260          * leave the filesystem running.  We know any error is
 261          * local to this block.
 262          */
 263         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 264         if (rc) {
 265                 mlog(ML_ERROR,
 266                      "Checksum failed for group descriptor %llu\n",
 267                      (unsigned long long)bh->b_blocknr);
 268         } else
 269                 rc = ocfs2_validate_gd_self(sb, bh, 1);
 270         if (!rc)
 271                 rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 272
 273         return rc;
 274 }
 275
 276 static int ocfs2_validate_group_descriptor(struct super_block *sb,
 277                                            struct buffer_head *bh)
 278 {
 279         int rc;
 280         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 281
 282         mlog(0, "Validating group descriptor %llu\n",
 283              (unsigned long long)bh->b_blocknr);
 284
 285         BUG_ON(!buffer_uptodate(bh));
 286
 287         /*
 288          * If the ecc fails, we return the error but otherwise
 289          * leave the filesystem running.  We know any error is
 290          * local to this block.
 291          */
 292         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 293         if (rc)
 294                 return rc;
 295
 296         /*
 297          * Errors after here are fatal.
 298          */
 299
 300         return ocfs2_validate_gd_self(sb, bh, 0);
 301 }
 302
 303 int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 304                                 u64 gd_blkno, struct buffer_head **bh)
 305 {
 306         int rc;
 307         struct buffer_head *tmp = *bh;
 308
 309         rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 310                               ocfs2_validate_group_descriptor);
 311         if (rc)
 312                 goto out;
 313
 314         rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 315         if (rc) {
 316                 brelse(tmp);
 317                 goto out;
 318         }
 319
 320         /* If ocfs2_read_block() got us a new bh, pass it up. */
 321         if (!*bh)
 322                 *bh = tmp;
 323
 324 out:
 325         return rc;
 326 }
 327
 328 static int ocfs2_block_group_fill(handle_t *handle,
 329                                   struct inode *alloc_inode,
 330                                   struct buffer_head *bg_bh,
 331                                   u64 group_blkno,
 332                                   u16 my_chain,
 333                                   struct ocfs2_chain_list *cl)
 334 {
 335         int status = 0;
 336         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 337         struct super_block * sb = alloc_inode->i_sb;
 338
 339         mlog_entry_void();
 340
 341         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 342                 ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
 343                             "b_blocknr (%llu)",
 344                             (unsigned long long)group_blkno,
 345                             (unsigned long long) bg_bh->b_blocknr);
 346                 status = -EIO;
 347                 goto bail;
 348         }
 349
 350         status = ocfs2_journal_access_gd(handle,
 351                                          INODE_CACHE(alloc_inode),
 352                                          bg_bh,
 353                                          OCFS2_JOURNAL_ACCESS_CREATE);
 354         if (status < 0) {
 355                 mlog_errno(status);
 356                 goto bail;
 357         }
 358
 359         memset(bg, 0, sb->s_blocksize);
 360         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 361         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 362         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
 363         bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 364         bg->bg_chain = cpu_to_le16(my_chain);
 365         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 366         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 367         bg->bg_blkno = cpu_to_le64(group_blkno);
 368         /* set the 1st bit in the bitmap to account for the descriptor block */
 369         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 370         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 371
 372         status = ocfs2_journal_dirty(handle, bg_bh);
 373         if (status < 0)
 374                 mlog_errno(status);
 375
 376         /* There is no need to zero out or otherwise initialize the
 377          * other blocks in a group - All valid FS metadata in a block
 378          * group stores the superblock fs_generation value at
 379          * allocation time. */
 380
 381 bail:
 382         mlog_exit(status);
 383         return status;
 384 }
 385
 386 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 387 {
 388         u16 curr, best;
 389
 390         best = curr = 0;
 391         while (curr < le16_to_cpu(cl->cl_count)) {
 392                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 393                     le32_to_cpu(cl->cl_recs[curr].c_total))
 394                         best = curr;
 395                 curr++;
 396         }
 397         return best;
 398 }
 399
 400 /*
 401  * We expect the block group allocator to already be locked.
 402  */
 403 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 404                                    struct inode *alloc_inode,
 405                                    struct buffer_head *bh,
 406                                    u64 max_block,
 407                                    u64 *last_alloc_group,
 408                                    int flags)
 409 {
 410         int status, credits;
 411         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 412         struct ocfs2_chain_list *cl;
 413         struct ocfs2_alloc_context *ac = NULL;
 414         handle_t *handle = NULL;
 415         u32 bit_off, num_bits;
 416         u16 alloc_rec;
 417         u64 bg_blkno;
 418         struct buffer_head *bg_bh = NULL;
 419         struct ocfs2_group_desc *bg;
 420
 421         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 422
 423         mlog_entry_void();
 424
 425         cl = &fe->id2.i_chain;
 426         status = ocfs2_reserve_clusters_with_limit(osb,
 427                                                    le16_to_cpu(cl->cl_cpg),
 428                                                    max_block, flags, &ac);
 429         if (status < 0) {
 430                 if (status != -ENOSPC)
 431                         mlog_errno(status);
 432                 goto bail;
 433         }
 434
 435         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 436                                                  le16_to_cpu(cl->cl_cpg));
 437         handle = ocfs2_start_trans(osb, credits);
 438         if (IS_ERR(handle)) {
 439                 status = PTR_ERR(handle);
 440                 handle = NULL;
 441                 mlog_errno(status);
 442                 goto bail;
 443         }
 444
 445         if (last_alloc_group && *last_alloc_group != 0) {
 446                 mlog(0, "use old allocation group %llu for block group alloc\n",
 447                      (unsigned long long)*last_alloc_group);
 448                 ac->ac_last_group = *last_alloc_group;
 449         }
 450         status = ocfs2_claim_clusters(osb,
 451                                       handle,
 452                                       ac,
 453                                       le16_to_cpu(cl->cl_cpg),
 454                                       &bit_off,
 455                                       &num_bits);
 456         if (status < 0) {
 457                 if (status != -ENOSPC)
 458                         mlog_errno(status);
 459                 goto bail;
 460         }
 461
 462         alloc_rec = ocfs2_find_smallest_chain(cl);
 463
 464         /* setup the group */
 465         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 466         mlog(0, "new descriptor, record %u, at block %llu\n",
 467              alloc_rec, (unsigned long long)bg_blkno);
 468
 469         bg_bh = sb_getblk(osb->sb, bg_blkno);
 470         if (!bg_bh) {
 471                 status = -EIO;
 472                 mlog_errno(status);
 473                 goto bail;
 474         }
 475         ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 476
 477         status = ocfs2_block_group_fill(handle,
 478                                         alloc_inode,
 479                                         bg_bh,
 480                                         bg_blkno,
 481                                         alloc_rec,
 482                                         cl);
 483         if (status < 0) {
 484                 mlog_errno(status);
 485                 goto bail;
 486         }
 487
 488         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 489
 490         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 491                                          bh, OCFS2_JOURNAL_ACCESS_WRITE);
 492         if (status < 0) {
 493                 mlog_errno(status);
 494                 goto bail;
 495         }
 496
 497         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 498                      le16_to_cpu(bg->bg_free_bits_count));
 499         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
 500         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
 501         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 502                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 503
 504         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 505                                         le16_to_cpu(bg->bg_free_bits_count));
 506         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 507         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 508
 509         status = ocfs2_journal_dirty(handle, bh);
 510         if (status < 0) {
 511                 mlog_errno(status);
 512                 goto bail;
 513         }
 514
 515         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 516         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 517         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 518                                              le32_to_cpu(fe->i_clusters)));
 519         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 520         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 521         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 522
 523         status = 0;
 524
 525         /* save the new last alloc group so that the caller can cache it. */
 526         if (last_alloc_group)
 527                 *last_alloc_group = ac->ac_last_group;
 528
 529 bail:
 530         if (handle)
 531                 ocfs2_commit_trans(osb, handle);
 532
 533         if (ac)
 534                 ocfs2_free_alloc_context(ac);
 535
 536         brelse(bg_bh);
 537
 538         mlog_exit(status);
 539         return status;
 540 }
 541
 542 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 543                                        struct ocfs2_alloc_context *ac,
 544                                        int type,
 545                                        u32 slot,
 546                                        u64 *last_alloc_group,
 547                                        int flags)
 548 {
 549         int status;
 550         u32 bits_wanted = ac->ac_bits_wanted;
 551         struct inode *alloc_inode;
 552         struct buffer_head *bh = NULL;
 553         struct ocfs2_dinode *fe;
 554         u32 free_bits;
 555
 556         mlog_entry_void();
 557
 558         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 559         if (!alloc_inode) {
 560                 mlog_errno(-EINVAL);
 561                 return -EINVAL;
 562         }
 563
 564         mutex_lock(&alloc_inode->i_mutex);
 565
 566         status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 567         if (status < 0) {
 568                 mutex_unlock(&alloc_inode->i_mutex);
 569                 iput(alloc_inode);
 570
 571                 mlog_errno(status);
 572                 return status;
 573         }
 574
 575         ac->ac_inode = alloc_inode;
 576         ac->ac_alloc_slot = slot;
 577
 578         fe = (struct ocfs2_dinode *) bh->b_data;
 579
 580         /* The bh was validated by the inode read inside
 581          * ocfs2_inode_lock().  Any corruption is a code bug. */
 582         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 583
 584         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 585                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 586                             (unsigned long long)le64_to_cpu(fe->i_blkno));
 587                 status = -EIO;
 588                 goto bail;
 589         }
 590
 591         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 592                 le32_to_cpu(fe->id1.bitmap1.i_used);
 593
 594         if (bits_wanted > free_bits) {
 595                 /* cluster bitmap never grows */
 596                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 597                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
 598                              bits_wanted, free_bits);
 599                         status = -ENOSPC;
 600                         goto bail;
 601                 }
 602
 603                 if (!(flags & ALLOC_NEW_GROUP)) {
 604                         mlog(0, "Alloc File %u Full: wanted=%u, free_bits=%u, "
 605                              "and we don't alloc a new group for it.\n",
 606                              slot, bits_wanted, free_bits);
 607                         status = -ENOSPC;
 608                         goto bail;
 609                 }
 610
 611                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 612                                                  ac->ac_max_block,
 613                                                  last_alloc_group, flags);
 614                 if (status < 0) {
 615                         if (status != -ENOSPC)
 616                                 mlog_errno(status);
 617                         goto bail;
 618                 }
 619                 atomic_inc(&osb->alloc_stats.bg_extends);
 620
 621                 /* You should never ask for this much metadata */
 622                 BUG_ON(bits_wanted >
 623                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 624                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 625         }
 626
 627         get_bh(bh);
 628         ac->ac_bh = bh;
 629 bail:
 630         brelse(bh);
 631
 632         mlog_exit(status);
 633         return status;
 634 }
 635
 636 static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 637 {
 638         spin_lock(&osb->osb_lock);
 639         osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 640         spin_unlock(&osb->osb_lock);
 641         atomic_set(&osb->s_num_inodes_stolen, 0);
 642 }
 643
 644 static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 645 {
 646         spin_lock(&osb->osb_lock);
 647         osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 648         spin_unlock(&osb->osb_lock);
 649         atomic_set(&osb->s_num_meta_stolen, 0);
 650 }
 651
 652 void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 653 {
 654         ocfs2_init_inode_steal_slot(osb);
 655         ocfs2_init_meta_steal_slot(osb);
 656 }
 657
 658 static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 659 {
 660         spin_lock(&osb->osb_lock);
 661         if (type == INODE_ALLOC_SYSTEM_INODE)
 662                 osb->s_inode_steal_slot = slot;
 663         else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 664                 osb->s_meta_steal_slot = slot;
 665         spin_unlock(&osb->osb_lock);
 666 }
 667
 668 static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 669 {
 670         int slot = OCFS2_INVALID_SLOT;
 671
 672         spin_lock(&osb->osb_lock);
 673         if (type == INODE_ALLOC_SYSTEM_INODE)
 674                 slot = osb->s_inode_steal_slot;
 675         else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 676                 slot = osb->s_meta_steal_slot;
 677         spin_unlock(&osb->osb_lock);
 678
 679         return slot;
 680 }
 681
 682 static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 683 {
 684         return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 685 }
 686
 687 static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 688 {
 689         return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 690 }
 691
 692 static int ocfs2_steal_resource(struct ocfs2_super *osb,
 693                                 struct ocfs2_alloc_context *ac,
 694                                 int type)
 695 {
 696         int i, status = -ENOSPC;
 697         int slot = __ocfs2_get_steal_slot(osb, type);
 698
 699         /* Start to steal resource from the first slot after ours. */
 700         if (slot == OCFS2_INVALID_SLOT)
 701                 slot = osb->slot_num + 1;
 702
 703         for (i = 0; i < osb->max_slots; i++, slot++) {
 704                 if (slot == osb->max_slots)
 705                         slot = 0;
 706
 707                 if (slot == osb->slot_num)
 708                         continue;
 709
 710                 status = ocfs2_reserve_suballoc_bits(osb, ac,
 711                                                      type,
 712                                                      (u32)slot, NULL,
 713                                                      NOT_ALLOC_NEW_GROUP);
 714                 if (status >= 0) {
 715                         __ocfs2_set_steal_slot(osb, slot, type);
 716                         break;
 717                 }
 718
 719                 ocfs2_free_ac_resource(ac);
 720         }
 721
 722         return status;
 723 }
 724
 725 static int ocfs2_steal_inode(struct ocfs2_super *osb,
 726                              struct ocfs2_alloc_context *ac)
 727 {
 728         return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 729 }
 730
 731 static int ocfs2_steal_meta(struct ocfs2_super *osb,
 732                             struct ocfs2_alloc_context *ac)
 733 {
 734         return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 735 }
 736
 737 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 738                                       int blocks,
 739                                       struct ocfs2_alloc_context **ac)
 740 {
 741         int status;
 742         int slot = ocfs2_get_meta_steal_slot(osb);
 743
 744         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 745         if (!(*ac)) {
 746                 status = -ENOMEM;
 747                 mlog_errno(status);
 748                 goto bail;
 749         }
 750
 751         (*ac)->ac_bits_wanted = blocks;
 752         (*ac)->ac_which = OCFS2_AC_USE_META;
 753         (*ac)->ac_group_search = ocfs2_block_group_search;
 754
 755         if (slot != OCFS2_INVALID_SLOT &&
 756                 atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
 757                 goto extent_steal;
 758
 759         atomic_set(&osb->s_num_meta_stolen, 0);
 760         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 761                                              EXTENT_ALLOC_SYSTEM_INODE,
 762                                              (u32)osb->slot_num, NULL,
 763                                              ALLOC_NEW_GROUP);
 764
 765
 766         if (status >= 0) {
 767                 status = 0;
 768                 if (slot != OCFS2_INVALID_SLOT)
 769                         ocfs2_init_meta_steal_slot(osb);
 770                 goto bail;
 771         } else if (status < 0 && status != -ENOSPC) {
 772                 mlog_errno(status);
 773                 goto bail;
 774         }
 775
 776         ocfs2_free_ac_resource(*ac);
 777
 778 extent_steal:
 779         status = ocfs2_steal_meta(osb, *ac);
 780         atomic_inc(&osb->s_num_meta_stolen);
 781         if (status < 0) {
 782                 if (status != -ENOSPC)
 783                         mlog_errno(status);
 784                 goto bail;
 785         }
 786
 787         status = 0;
 788 bail:
 789         if ((status < 0) && *ac) {
 790                 ocfs2_free_alloc_context(*ac);
 791                 *ac = NULL;
 792         }
 793
 794         mlog_exit(status);
 795         return status;
 796 }
 797
 798 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
 799                                struct ocfs2_extent_list *root_el,
 800                                struct ocfs2_alloc_context **ac)
 801 {
 802         return ocfs2_reserve_new_metadata_blocks(osb,
 803                                         ocfs2_extend_meta_needed(root_el),
 804                                         ac);
 805 }
 806
 807 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 808                             struct ocfs2_alloc_context **ac)
 809 {
 810         int status;
 811         int slot = ocfs2_get_inode_steal_slot(osb);
 812         u64 alloc_group;
 813
 814         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 815         if (!(*ac)) {
 816                 status = -ENOMEM;
 817                 mlog_errno(status);
 818                 goto bail;
 819         }
 820
 821         (*ac)->ac_bits_wanted = 1;
 822         (*ac)->ac_which = OCFS2_AC_USE_INODE;
 823
 824         (*ac)->ac_group_search = ocfs2_block_group_search;
 825
 826         /*
 827          * stat(2) can't handle i_ino > 32bits, so we tell the
 828          * lower levels not to allocate us a block group past that
 829          * limit.  The 'inode64' mount option avoids this behavior.
 830          */
 831         if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
 832                 (*ac)->ac_max_block = (u32)~0U;
 833
 834         /*
 835          * slot is set when we successfully steal inode from other nodes.
 836          * It is reset in 3 places:
 837          * 1. when we flush the truncate log
 838          * 2. when we complete local alloc recovery.
 839          * 3. when we successfully allocate from our own slot.
 840          * After it is set, we will go on stealing inodes until we find the
 841          * need to check our slots to see whether there is some space for us.
 842          */
 843         if (slot != OCFS2_INVALID_SLOT &&
 844             atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
 845                 goto inode_steal;
 846
 847         atomic_set(&osb->s_num_inodes_stolen, 0);
 848         alloc_group = osb->osb_inode_alloc_group;
 849         status = ocfs2_reserve_suballoc_bits(osb, *ac,
 850                                              INODE_ALLOC_SYSTEM_INODE,
 851                                              (u32)osb->slot_num,
 852                                              &alloc_group,
 853                                              ALLOC_NEW_GROUP |
 854                                              ALLOC_GROUPS_FROM_GLOBAL);
 855         if (status >= 0) {
 856                 status = 0;
 857
 858                 spin_lock(&osb->osb_lock);
 859                 osb->osb_inode_alloc_group = alloc_group;
 860                 spin_unlock(&osb->osb_lock);
 861                 mlog(0, "after reservation, new allocation group is "
 862                      "%llu\n", (unsigned long long)alloc_group);
 863
 864                 /*
 865                  * Some inodes must be freed by us, so try to allocate
 866                  * from our own next time.
 867                  */
 868                 if (slot != OCFS2_INVALID_SLOT)
 869                         ocfs2_init_inode_steal_slot(osb);
 870                 goto bail;
 871         } else if (status < 0 && status != -ENOSPC) {
 872                 mlog_errno(status);
 873                 goto bail;
 874         }
 875
 876         ocfs2_free_ac_resource(*ac);
 877
 878 inode_steal:
 879         status = ocfs2_steal_inode(osb, *ac);
 880         atomic_inc(&osb->s_num_inodes_stolen);
 881         if (status < 0) {
 882                 if (status != -ENOSPC)
 883                         mlog_errno(status);
 884                 goto bail;
 885         }
 886
 887         status = 0;
 888 bail:
 889         if ((status < 0) && *ac) {
 890                 ocfs2_free_alloc_context(*ac);
 891                 *ac = NULL;
 892         }
 893
 894         mlog_exit(status);
 895         return status;
 896 }
 897
 898 /* local alloc code has to do the same thing, so rather than do this
 899  * twice.. */
 900 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
 901                                       struct ocfs2_alloc_context *ac)
 902 {
 903         int status;
 904
 905         ac->ac_which = OCFS2_AC_USE_MAIN;
 906         ac->ac_group_search = ocfs2_cluster_group_search;
 907
 908         status = ocfs2_reserve_suballoc_bits(osb, ac,
 909                                              GLOBAL_BITMAP_SYSTEM_INODE,
 910                                              OCFS2_INVALID_SLOT, NULL,
 911                                              ALLOC_NEW_GROUP);
 912         if (status < 0 && status != -ENOSPC) {
 913                 mlog_errno(status);
 914                 goto bail;
 915         }
 916
 917 bail:
 918         return status;
 919 }
 920
 921 /* Callers don't need to care which bitmap (local alloc or main) to
 922  * use so we figure it out for them, but unfortunately this clutters
 923  * things a bit. */
 924 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 925                                              u32 bits_wanted, u64 max_block,
 926                                              int flags,
 927                                              struct ocfs2_alloc_context **ac)
 928 {
 929         int status;
 930
 931         mlog_entry_void();
 932
 933         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 934         if (!(*ac)) {
 935                 status = -ENOMEM;
 936                 mlog_errno(status);
 937                 goto bail;
 938         }
 939
 940         (*ac)->ac_bits_wanted = bits_wanted;
 941         (*ac)->ac_max_block = max_block;
 942
 943         status = -ENOSPC;
 944         if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
 945             ocfs2_alloc_should_use_local(osb, bits_wanted)) {
 946                 status = ocfs2_reserve_local_alloc_bits(osb,
 947                                                         bits_wanted,
 948                                                         *ac);
 949                 if (status == -EFBIG) {
 950                         /* The local alloc window is outside ac_max_block.
 951                          * use the main bitmap. */
 952                         status = -ENOSPC;
 953                 } else if ((status < 0) && (status != -ENOSPC)) {
 954                         mlog_errno(status);
 955                         goto bail;
 956                 }
 957         }
 958
 959         if (status == -ENOSPC) {
 960                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 961                 if (status < 0) {
 962                         if (status != -ENOSPC)
 963                                 mlog_errno(status);
 964                         goto bail;
 965                 }
 966         }
 967
 968         status = 0;
 969 bail:
 970         if ((status < 0) && *ac) {
 971                 ocfs2_free_alloc_context(*ac);
 972                 *ac = NULL;
 973         }
 974
 975         mlog_exit(status);
 976         return status;
 977 }
 978
 979 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
 980                            u32 bits_wanted,
 981                            struct ocfs2_alloc_context **ac)
 982 {
 983         return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
 984                                                  ALLOC_NEW_GROUP, ac);
 985 }
 986
 987 /*
 988  * More or less lifted from ext3. I'll leave their description below:
 989  *
 990  * "For ext3 allocations, we must not reuse any blocks which are
 991  * allocated in the bitmap buffer's "last committed data" copy.  This
 992  * prevents deletes from freeing up the page for reuse until we have
 993  * committed the delete transaction.
 994  *
 995  * If we didn't do this, then deleting something and reallocating it as
 996  * data would allow the old block to be overwritten before the
 997  * transaction committed (because we force data to disk before commit).
 998  * This would lead to corruption if we crashed between overwriting the
 999  * data and committing the delete.
1000  *
1001  * @@@ We may want to make this allocation behaviour conditional on
1002  * data-writes at some point, and disable it for metadata allocations or
1003  * sync-data inodes."
1004  *
1005  * Note: OCFS2 already does this differently for metadata vs data
1006  * allocations, as those bitmaps are separate and undo access is never
1007  * called on a metadata group descriptor.
1008  */
1009 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1010                                          int nr)
1011 {
1012         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1013         int ret;
1014
1015         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1016                 return 0;
1017
1018         if (!buffer_jbd(bg_bh))
1019                 return 1;
1020
1021         jbd_lock_bh_state(bg_bh);
1022         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
1023         if (bg)
1024                 ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1025         else
1026                 ret = 1;
1027         jbd_unlock_bh_state(bg_bh);
1028
1029         return ret;
1030 }
1031
1032 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1033                                              struct buffer_head *bg_bh,
1034                                              unsigned int bits_wanted,
1035                                              unsigned int total_bits,
1036                                              u16 *bit_off,
1037                                              u16 *bits_found)
1038 {
1039         void *bitmap;
1040         u16 best_offset, best_size;
1041         int offset, start, found, status = 0;
1042         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1043
1044         /* Callers got this descriptor from
1045          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1046         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1047
1048         found = start = best_offset = best_size = 0;
1049         bitmap = bg->bg_bitmap;
1050
1051         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1052                 if (offset == total_bits)
1053                         break;
1054
1055                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1056                         /* We found a zero, but we can't use it as it
1057                          * hasn't been put to disk yet! */
1058                         found = 0;
1059                         start = offset + 1;
1060                 } else if (offset == start) {
1061                         /* we found a zero */
1062                         found++;
1063                         /* move start to the next bit to test */
1064                         start++;
1065                 } else {
1066                         /* got a zero after some ones */
1067                         found = 1;
1068                         start = offset + 1;
1069                 }
1070                 if (found > best_size) {
1071                         best_size = found;
1072                         best_offset = start - found;
1073                 }
1074                 /* we got everything we needed */
1075                 if (found == bits_wanted) {
1076                         /* mlog(0, "Found it all!\n"); */
1077                         break;
1078                 }
1079         }
1080
1081         /* XXX: I think the first clause is equivalent to the second
1082          *      - jlbec */
1083         if (found == bits_wanted) {
1084                 *bit_off = start - found;
1085                 *bits_found = found;
1086         } else if (best_size) {
1087                 *bit_off = best_offset;
1088                 *bits_found = best_size;
1089         } else {
1090                 status = -ENOSPC;
1091                 /* No error log here -- see the comment above
1092                  * ocfs2_test_bg_bit_allocatable */
1093         }
1094
1095         return status;
1096 }
1097
1098 static inline int ocfs2_block_group_set_bits(handle_t *handle,
1099                                              struct inode *alloc_inode,
1100                                              struct ocfs2_group_desc *bg,
1101                                              struct buffer_head *group_bh,
1102                                              unsigned int bit_off,
1103                                              unsigned int num_bits)
1104 {
1105         int status;
1106         void *bitmap = bg->bg_bitmap;
1107         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1108
1109         mlog_entry_void();
1110
1111         /* All callers get the descriptor via
1112          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1113         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1114         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1115
1116         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
1117              num_bits);
1118
1119         if (ocfs2_is_cluster_bitmap(alloc_inode))
1120                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1121
1122         status = ocfs2_journal_access_gd(handle,
1123                                          INODE_CACHE(alloc_inode),
1124                                          group_bh,
1125                                          journal_type);
1126         if (status < 0) {
1127                 mlog_errno(status);
1128                 goto bail;
1129         }
1130
1131         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1132
1133         while(num_bits--)
1134                 ocfs2_set_bit(bit_off++, bitmap);
1135
1136         status = ocfs2_journal_dirty(handle,
1137                                      group_bh);
1138         if (status < 0) {
1139                 mlog_errno(status);
1140                 goto bail;
1141         }
1142
1143 bail:
1144         mlog_exit(status);
1145         return status;
1146 }
1147
1148 /* find the one with the most empty bits */
1149 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1150 {
1151         u16 curr, best;
1152
1153         BUG_ON(!cl->cl_next_free_rec);
1154
1155         best = curr = 0;
1156         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1157                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1158                     le32_to_cpu(cl->cl_recs[best].c_free))
1159                         best = curr;
1160                 curr++;
1161         }
1162
1163         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1164         return best;
1165 }
1166
1167 static int ocfs2_relink_block_group(handle_t *handle,
1168                                     struct inode *alloc_inode,
1169                                     struct buffer_head *fe_bh,
1170                                     struct buffer_head *bg_bh,
1171                                     struct buffer_head *prev_bg_bh,
1172                                     u16 chain)
1173 {
1174         int status;
1175         /* there is a really tiny chance the journal calls could fail,
1176          * but we wouldn't want inconsistent blocks in *any* case. */
1177         u64 fe_ptr, bg_ptr, prev_bg_ptr;
1178         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1179         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1180         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1181
1182         /* The caller got these descriptors from
1183          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1184         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1185         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1186
1187         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
1188              (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1189              (unsigned long long)le64_to_cpu(bg->bg_blkno),
1190              (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1191
1192         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
1193         bg_ptr = le64_to_cpu(bg->bg_next_group);
1194         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1195
1196         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1197                                          prev_bg_bh,
1198                                          OCFS2_JOURNAL_ACCESS_WRITE);
1199         if (status < 0) {
1200                 mlog_errno(status);
1201                 goto out_rollback;
1202         }
1203
1204         prev_bg->bg_next_group = bg->bg_next_group;
1205
1206         status = ocfs2_journal_dirty(handle, prev_bg_bh);
1207         if (status < 0) {
1208                 mlog_errno(status);
1209                 goto out_rollback;
1210         }
1211
1212         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1213                                          bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1214         if (status < 0) {
1215                 mlog_errno(status);
1216                 goto out_rollback;
1217         }
1218
1219         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1220
1221         status = ocfs2_journal_dirty(handle, bg_bh);
1222         if (status < 0) {
1223                 mlog_errno(status);
1224                 goto out_rollback;
1225         }
1226
1227         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1228                                          fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1229         if (status < 0) {
1230                 mlog_errno(status);
1231                 goto out_rollback;
1232         }
1233
1234         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1235
1236         status = ocfs2_journal_dirty(handle, fe_bh);
1237         if (status < 0) {
1238                 mlog_errno(status);
1239                 goto out_rollback;
1240         }
1241
1242         status = 0;
1243 out_rollback:
1244         if (status < 0) {
1245                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
1246                 bg->bg_next_group = cpu_to_le64(bg_ptr);
1247                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1248         }
1249
1250         mlog_exit(status);
1251         return status;
1252 }
1253
1254 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1255                                                      u32 wanted)
1256 {
1257         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1258 }
1259
1260 /* return 0 on success, -ENOSPC to keep searching and any other < 0
1261  * value on error. */
1262 static int ocfs2_cluster_group_search(struct inode *inode,
1263                                       struct buffer_head *group_bh,
1264                                       u32 bits_wanted, u32 min_bits,
1265                                       u64 max_block,
1266                                       u16 *bit_off, u16 *bits_found)
1267 {
1268         int search = -ENOSPC;
1269         int ret;
1270         u64 blkoff;
1271         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1272         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1273         u16 tmp_off, tmp_found;
1274         unsigned int max_bits, gd_cluster_off;
1275
1276         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1277
1278         if (gd->bg_free_bits_count) {
1279                 max_bits = le16_to_cpu(gd->bg_bits);
1280
1281                 /* Tail groups in cluster bitmaps which aren't cpg
1282                  * aligned are prone to partial extention by a failed
1283                  * fs resize. If the file system resize never got to
1284                  * update the dinode cluster count, then we don't want
1285                  * to trust any clusters past it, regardless of what
1286                  * the group descriptor says. */
1287                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1288                                                           le64_to_cpu(gd->bg_blkno));
1289                 if ((gd_cluster_off + max_bits) >
1290                     OCFS2_I(inode)->ip_clusters) {
1291                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1292                         mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
1293                              (unsigned long long)le64_to_cpu(gd->bg_blkno),
1294                              le16_to_cpu(gd->bg_bits),
1295                              OCFS2_I(inode)->ip_clusters, max_bits);
1296                 }
1297
1298                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1299                                                         group_bh, bits_wanted,
1300                                                         max_bits,
1301                                                         &tmp_off, &tmp_found);
1302                 if (ret)
1303                         return ret;
1304
1305                 if (max_block) {
1306                         blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1307                                                           gd_cluster_off +
1308                                                           tmp_off + tmp_found);
1309                         mlog(0, "Checking %llu against %llu\n",
1310                              (unsigned long long)blkoff,
1311                              (unsigned long long)max_block);
1312                         if (blkoff > max_block)
1313                                 return -ENOSPC;
1314                 }
1315
1316                 /* ocfs2_block_group_find_clear_bits() might
1317                  * return success, but we still want to return
1318                  * -ENOSPC unless it found the minimum number
1319                  * of bits. */
1320                 if (min_bits <= tmp_found) {
1321                         *bit_off = tmp_off;
1322                         *bits_found = tmp_found;
1323                         search = 0; /* success */
1324                 } else if (tmp_found) {
1325                         /*
1326                          * Don't show bits which we'll be returning
1327                          * for allocation to the local alloc bitmap.
1328                          */
1329                         ocfs2_local_alloc_seen_free_bits(osb, tmp_found);
1330                 }
1331         }
1332
1333         return search;
1334 }
1335
1336 static int ocfs2_block_group_search(struct inode *inode,
1337                                     struct buffer_head *group_bh,
1338                                     u32 bits_wanted, u32 min_bits,
1339                                     u64 max_block,
1340                                     u16 *bit_off, u16 *bits_found)
1341 {
1342         int ret = -ENOSPC;
1343         u64 blkoff;
1344         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1345
1346         BUG_ON(min_bits != 1);
1347         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1348
1349         if (bg->bg_free_bits_count) {
1350                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1351                                                         group_bh, bits_wanted,
1352                                                         le16_to_cpu(bg->bg_bits),
1353                                                         bit_off, bits_found);
1354                 if (!ret && max_block) {
1355                         blkoff = le64_to_cpu(bg->bg_blkno) + *bit_off +
1356                                 *bits_found;
1357                         mlog(0, "Checking %llu against %llu\n",
1358                              (unsigned long long)blkoff,
1359                              (unsigned long long)max_block);
1360                         if (blkoff > max_block)
1361                                 ret = -ENOSPC;
1362                 }
1363         }
1364
1365         return ret;
1366 }
1367
1368 static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1369                                        handle_t *handle,
1370                                        struct buffer_head *di_bh,
1371                                        u32 num_bits,
1372                                        u16 chain)
1373 {
1374         int ret;
1375         u32 tmp_used;
1376         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1377         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1378
1379         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1380                                       OCFS2_JOURNAL_ACCESS_WRITE);
1381         if (ret < 0) {
1382                 mlog_errno(ret);
1383                 goto out;
1384         }
1385
1386         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1387         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1388         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1389
1390         ret = ocfs2_journal_dirty(handle, di_bh);
1391         if (ret < 0)
1392                 mlog_errno(ret);
1393
1394 out:
1395         return ret;
1396 }
1397
1398 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1399                                   handle_t *handle,
1400                                   u32 bits_wanted,
1401                                   u32 min_bits,
1402                                   u16 *bit_off,
1403                                   unsigned int *num_bits,
1404                                   u64 gd_blkno,
1405                                   u16 *bits_left)
1406 {
1407         int ret;
1408         u16 found;
1409         struct buffer_head *group_bh = NULL;
1410         struct ocfs2_group_desc *gd;
1411         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1412         struct inode *alloc_inode = ac->ac_inode;
1413
1414         ret = ocfs2_read_group_descriptor(alloc_inode, di, gd_blkno,
1415                                           &group_bh);
1416         if (ret < 0) {
1417                 mlog_errno(ret);
1418                 return ret;
1419         }
1420
1421         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1422         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1423                                   ac->ac_max_block, bit_off, &found);
1424         if (ret < 0) {
1425                 if (ret != -ENOSPC)
1426                         mlog_errno(ret);
1427                 goto out;
1428         }
1429
1430         *num_bits = found;
1431
1432         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1433                                                *num_bits,
1434                                                le16_to_cpu(gd->bg_chain));
1435         if (ret < 0) {
1436                 mlog_errno(ret);
1437                 goto out;
1438         }
1439
1440         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1441                                          *bit_off, *num_bits);
1442         if (ret < 0)
1443                 mlog_errno(ret);
1444
1445         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1446
1447 out:
1448         brelse(group_bh);
1449
1450         return ret;
1451 }
1452
1453 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1454                               handle_t *handle,
1455                               u32 bits_wanted,
1456                               u32 min_bits,
1457                               u16 *bit_off,
1458                               unsigned int *num_bits,
1459                               u64 *bg_blkno,
1460                               u16 *bits_left)
1461 {
1462         int status;
1463         u16 chain, tmp_bits;
1464         u32 tmp_used;
1465         u64 next_group;
1466         struct inode *alloc_inode = ac->ac_inode;
1467         struct buffer_head *group_bh = NULL;
1468         struct buffer_head *prev_group_bh = NULL;
1469         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1470         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1471         struct ocfs2_group_desc *bg;
1472
1473         chain = ac->ac_chain;
1474         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
1475              bits_wanted, chain,
1476              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
1477
1478         status = ocfs2_read_group_descriptor(alloc_inode, fe,
1479                                              le64_to_cpu(cl->cl_recs[chain].c_blkno),
1480                                              &group_bh);
1481         if (status < 0) {
1482                 mlog_errno(status);
1483                 goto bail;
1484         }
1485         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1486
1487         status = -ENOSPC;
1488         /* for now, the chain search is a bit simplistic. We just use
1489          * the 1st group with any empty bits. */
1490         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1491                                              bits_wanted, min_bits,
1492                                              ac->ac_max_block, bit_off,
1493                                              &tmp_bits)) == -ENOSPC) {
1494                 if (!bg->bg_next_group)
1495                         break;
1496
1497                 brelse(prev_group_bh);
1498                 prev_group_bh = NULL;
1499
1500                 next_group = le64_to_cpu(bg->bg_next_group);
1501                 prev_group_bh = group_bh;
1502                 group_bh = NULL;
1503                 status = ocfs2_read_group_descriptor(alloc_inode, fe,
1504                                                      next_group, &group_bh);
1505                 if (status < 0) {
1506                         mlog_errno(status);
1507                         goto bail;
1508                 }
1509                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1510         }
1511         if (status < 0) {
1512                 if (status != -ENOSPC)
1513                         mlog_errno(status);
1514                 goto bail;
1515         }
1516
1517         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1518              tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
1519
1520         *num_bits = tmp_bits;
1521
1522         BUG_ON(*num_bits == 0);
1523
1524         /*
1525          * Keep track of previous block descriptor read. When
1526          * we find a target, if we have read more than X
1527          * number of descriptors, and the target is reasonably
1528          * empty, relink him to top of his chain.
1529          *
1530          * We've read 0 extra blocks and only send one more to
1531          * the transaction, yet the next guy to search has a
1532          * much easier time.
1533          *
1534          * Do this *after* figuring out how many bits we're taking out
1535          * of our target group.
1536          */
1537         if (ac->ac_allow_chain_relink &&
1538             (prev_group_bh) &&
1539             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1540                 status = ocfs2_relink_block_group(handle, alloc_inode,
1541                                                   ac->ac_bh, group_bh,
1542                                                   prev_group_bh, chain);
1543                 if (status < 0) {
1544                         mlog_errno(status);
1545                         goto bail;
1546                 }
1547         }
1548
1549         /* Ok, claim our bits now: set the info on dinode, chainlist
1550          * and then the group */
1551         status = ocfs2_journal_access_di(handle,
1552                                          INODE_CACHE(alloc_inode),
1553                                          ac->ac_bh,
1554                                          OCFS2_JOURNAL_ACCESS_WRITE);
1555         if (status < 0) {
1556                 mlog_errno(status);
1557                 goto bail;
1558         }
1559
1560         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1561         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1562         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1563
1564         status = ocfs2_journal_dirty(handle,
1565                                      ac->ac_bh);
1566         if (status < 0) {
1567                 mlog_errno(status);
1568                 goto bail;
1569         }
1570
1571         status = ocfs2_block_group_set_bits(handle,
1572                                             alloc_inode,
1573                                             bg,
1574                                             group_bh,
1575                                             *bit_off,
1576                                             *num_bits);
1577         if (status < 0) {
1578                 mlog_errno(status);
1579                 goto bail;
1580         }
1581
1582         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1583              (unsigned long long)le64_to_cpu(fe->i_blkno));
1584
1585         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1586         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1587 bail:
1588         brelse(group_bh);
1589         brelse(prev_group_bh);
1590
1591         mlog_exit(status);
1592         return status;
1593 }
1594
1595 /* will give out up to bits_wanted contiguous bits. */
1596 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1597                                      struct ocfs2_alloc_context *ac,
1598                                      handle_t *handle,
1599                                      u32 bits_wanted,
1600                                      u32 min_bits,
1601                                      u16 *bit_off,
1602                                      unsigned int *num_bits,
1603                                      u64 *bg_blkno)
1604 {
1605         int status;
1606         u16 victim, i;
1607         u16 bits_left = 0;
1608         u64 hint_blkno = ac->ac_last_group;
1609         struct ocfs2_chain_list *cl;
1610         struct ocfs2_dinode *fe;
1611
1612         mlog_entry_void();
1613
1614         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1615         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1616         BUG_ON(!ac->ac_bh);
1617
1618         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1619
1620         /* The bh was validated by the inode read during
1621          * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1622         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1623
1624         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1625             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1626                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1627                             "bits but only %u total.",
1628                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1629                             le32_to_cpu(fe->id1.bitmap1.i_used),
1630                             le32_to_cpu(fe->id1.bitmap1.i_total));
1631                 status = -EIO;
1632                 goto bail;
1633         }
1634
1635         if (hint_blkno) {
1636                 /* Attempt to short-circuit the usual search mechanism
1637                  * by jumping straight to the most recently used
1638                  * allocation group. This helps us mantain some
1639                  * contiguousness across allocations. */
1640                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1641                                                 min_bits, bit_off, num_bits,
1642                                                 hint_blkno, &bits_left);
1643                 if (!status) {
1644                         /* Be careful to update *bg_blkno here as the
1645                          * caller is expecting it to be filled in, and
1646                          * ocfs2_search_one_group() won't do that for
1647                          * us. */
1648                         *bg_blkno = hint_blkno;
1649                         goto set_hint;
1650                 }
1651                 if (status < 0 && status != -ENOSPC) {
1652                         mlog_errno(status);
1653                         goto bail;
1654                 }
1655         }
1656
1657         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1658
1659         victim = ocfs2_find_victim_chain(cl);
1660         ac->ac_chain = victim;
1661         ac->ac_allow_chain_relink = 1;
1662
1663         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, bit_off,
1664                                     num_bits, bg_blkno, &bits_left);
1665         if (!status)
1666                 goto set_hint;
1667         if (status < 0 && status != -ENOSPC) {
1668                 mlog_errno(status);
1669                 goto bail;
1670         }
1671
1672         mlog(0, "Search of victim chain %u came up with nothing, "
1673              "trying all chains now.\n", victim);
1674
1675         /* If we didn't pick a good victim, then just default to
1676          * searching each chain in order. Don't allow chain relinking
1677          * because we only calculate enough journal credits for one
1678          * relink per alloc. */
1679         ac->ac_allow_chain_relink = 0;
1680         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1681                 if (i == victim)
1682                         continue;
1683                 if (!cl->cl_recs[i].c_free)
1684                         continue;
1685
1686                 ac->ac_chain = i;
1687                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1688                                             bit_off, num_bits, bg_blkno,
1689                                             &bits_left);
1690                 if (!status)
1691                         break;
1692                 if (status < 0 && status != -ENOSPC) {
1693                         mlog_errno(status);
1694                         goto bail;
1695                 }
1696         }
1697
1698 set_hint:
1699         if (status != -ENOSPC) {
1700                 /* If the next search of this group is not likely to
1701                  * yield a suitable extent, then we reset the last
1702                  * group hint so as to not waste a disk read */
1703                 if (bits_left < min_bits)
1704                         ac->ac_last_group = 0;
1705                 else
1706                         ac->ac_last_group = *bg_blkno;
1707         }
1708
1709 bail:
1710         mlog_exit(status);
1711         return status;
1712 }
1713
1714 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1715                          handle_t *handle,
1716                          struct ocfs2_alloc_context *ac,
1717                          u32 bits_wanted,
1718                          u16 *suballoc_bit_start,
1719                          unsigned int *num_bits,
1720                          u64 *blkno_start)
1721 {
1722         int status;
1723         u64 bg_blkno;
1724
1725         BUG_ON(!ac);
1726         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1727         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1728
1729         status = ocfs2_claim_suballoc_bits(osb,
1730                                            ac,
1731                                            handle,
1732                                            bits_wanted,
1733                                            1,
1734                                            suballoc_bit_start,
1735                                            num_bits,
1736                                            &bg_blkno);
1737         if (status < 0) {
1738                 mlog_errno(status);
1739                 goto bail;
1740         }
1741         atomic_inc(&osb->alloc_stats.bg_allocs);
1742
1743         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1744         ac->ac_bits_given += (*num_bits);
1745         status = 0;
1746 bail:
1747         mlog_exit(status);
1748         return status;
1749 }
1750
1751 static void ocfs2_init_inode_ac_group(struct inode *dir,
1752                                       struct buffer_head *parent_fe_bh,
1753                                       struct ocfs2_alloc_context *ac)
1754 {
1755         struct ocfs2_dinode *fe = (struct ocfs2_dinode *)parent_fe_bh->b_data;
1756         /*
1757          * Try to allocate inodes from some specific group.
1758          *
1759          * If the parent dir has recorded the last group used in allocation,
1760          * cool, use it. Otherwise if we try to allocate new inode from the
1761          * same slot the parent dir belongs to, use the same chunk.
1762          *
1763          * We are very careful here to avoid the mistake of setting
1764          * ac_last_group to a group descriptor from a different (unlocked) slot.
1765          */
1766         if (OCFS2_I(dir)->ip_last_used_group &&
1767             OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
1768                 ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
1769         else if (le16_to_cpu(fe->i_suballoc_slot) == ac->ac_alloc_slot)
1770                 ac->ac_last_group = ocfs2_which_suballoc_group(
1771                                         le64_to_cpu(fe->i_blkno),
1772                                         le16_to_cpu(fe->i_suballoc_bit));
1773 }
1774
1775 static inline void ocfs2_save_inode_ac_group(struct inode *dir,
1776                                              struct ocfs2_alloc_context *ac)
1777 {
1778         OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
1779         OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
1780 }
1781
1782 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1783                           handle_t *handle,
1784                           struct inode *dir,
1785                           struct buffer_head *parent_fe_bh,
1786                           struct ocfs2_alloc_context *ac,
1787                           u16 *suballoc_bit,
1788                           u64 *fe_blkno)
1789 {
1790         int status;
1791         unsigned int num_bits;
1792         u64 bg_blkno;
1793
1794         mlog_entry_void();
1795
1796         BUG_ON(!ac);
1797         BUG_ON(ac->ac_bits_given != 0);
1798         BUG_ON(ac->ac_bits_wanted != 1);
1799         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1800
1801         ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
1802
1803         status = ocfs2_claim_suballoc_bits(osb,
1804                                            ac,
1805                                            handle,
1806                                            1,
1807                                            1,
1808                                            suballoc_bit,
1809                                            &num_bits,
1810                                            &bg_blkno);
1811         if (status < 0) {
1812                 mlog_errno(status);
1813                 goto bail;
1814         }
1815         atomic_inc(&osb->alloc_stats.bg_allocs);
1816
1817         BUG_ON(num_bits != 1);
1818
1819         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1820         ac->ac_bits_given++;
1821         ocfs2_save_inode_ac_group(dir, ac);
1822         status = 0;
1823 bail:
1824         mlog_exit(status);
1825         return status;
1826 }
1827
1828 /* translate a group desc. blkno and it's bitmap offset into
1829  * disk cluster offset. */
1830 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1831                                                    u64 bg_blkno,
1832                                                    u16 bg_bit_off)
1833 {
1834         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1835         u32 cluster = 0;
1836
1837         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1838
1839         if (bg_blkno != osb->first_cluster_group_blkno)
1840                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1841         cluster += (u32) bg_bit_off;
1842         return cluster;
1843 }
1844
1845 /* given a cluster offset, calculate which block group it belongs to
1846  * and return that block offset. */
1847 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
1848 {
1849         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1850         u32 group_no;
1851
1852         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1853
1854         group_no = cluster / osb->bitmap_cpg;
1855         if (!group_no)
1856                 return osb->first_cluster_group_blkno;
1857         return ocfs2_clusters_to_blocks(inode->i_sb,
1858                                         group_no * osb->bitmap_cpg);
1859 }
1860
1861 /* given the block number of a cluster start, calculate which cluster
1862  * group and descriptor bitmap offset that corresponds to. */
1863 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1864                                                 u64 data_blkno,
1865                                                 u64 *bg_blkno,
1866                                                 u16 *bg_bit_off)
1867 {
1868         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1869         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1870
1871         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1872
1873         *bg_blkno = ocfs2_which_cluster_group(inode,
1874                                               data_cluster);
1875
1876         if (*bg_blkno == osb->first_cluster_group_blkno)
1877                 *bg_bit_off = (u16) data_cluster;
1878         else
1879                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1880                                                              data_blkno - *bg_blkno);
1881 }
1882
1883 /*
1884  * min_bits - minimum contiguous chunk from this total allocation we
1885  * can handle. set to what we asked for originally for a full
1886  * contig. allocation, set to '1' to indicate we can deal with extents
1887  * of any size.
1888  */
1889 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
1890                            handle_t *handle,
1891                            struct ocfs2_alloc_context *ac,
1892                            u32 min_clusters,
1893                            u32 max_clusters,
1894                            u32 *cluster_start,
1895                            u32 *num_clusters)
1896 {
1897         int status;
1898         unsigned int bits_wanted = max_clusters;
1899         u64 bg_blkno = 0;
1900         u16 bg_bit_off;
1901
1902         mlog_entry_void();
1903
1904         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1905
1906         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1907                && ac->ac_which != OCFS2_AC_USE_MAIN);
1908
1909         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1910                 status = ocfs2_claim_local_alloc_bits(osb,
1911                                                       handle,
1912                                                       ac,
1913                                                       bits_wanted,
1914                                                       cluster_start,
1915                                                       num_clusters);
1916                 if (!status)
1917                         atomic_inc(&osb->alloc_stats.local_data);
1918         } else {
1919                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1920                         /* The only paths asking for contiguousness
1921                          * should know about this already. */
1922                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
1923                              "group bitmap size %u!\n", min_clusters,
1924                              osb->bitmap_cpg);
1925                         status = -ENOSPC;
1926                         goto bail;
1927                 }
1928                 /* clamp the current request down to a realistic size. */
1929                 if (bits_wanted > (osb->bitmap_cpg - 1))
1930                         bits_wanted = osb->bitmap_cpg - 1;
1931
1932                 status = ocfs2_claim_suballoc_bits(osb,
1933                                                    ac,
1934                                                    handle,
1935                                                    bits_wanted,
1936                                                    min_clusters,
1937                                                    &bg_bit_off,
1938                                                    num_clusters,
1939                                                    &bg_blkno);
1940                 if (!status) {
1941                         *cluster_start =
1942                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1943                                                                  bg_blkno,
1944                                                                  bg_bit_off);
1945                         atomic_inc(&osb->alloc_stats.bitmap_data);
1946                 }
1947         }
1948         if (status < 0) {
1949                 if (status != -ENOSPC)
1950                         mlog_errno(status);
1951                 goto bail;
1952         }
1953
1954         ac->ac_bits_given += *num_clusters;
1955
1956 bail:
1957         mlog_exit(status);
1958         return status;
1959 }
1960
1961 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1962                          handle_t *handle,
1963                          struct ocfs2_alloc_context *ac,
1964                          u32 min_clusters,
1965                          u32 *cluster_start,
1966                          u32 *num_clusters)
1967 {
1968         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1969
1970         return __ocfs2_claim_clusters(osb, handle, ac, min_clusters,
1971                                       bits_wanted, cluster_start, num_clusters);
1972 }
1973
1974 static int ocfs2_block_group_clear_bits(handle_t *handle,
1975                                         struct inode *alloc_inode,
1976                                         struct ocfs2_group_desc *bg,
1977                                         struct buffer_head *group_bh,
1978                                         unsigned int bit_off,
1979                                         unsigned int num_bits,
1980                                         void (*undo_fn)(unsigned int bit,
1981                                                         unsigned long *bmap))
1982 {
1983         int status;
1984         unsigned int tmp;
1985         struct ocfs2_group_desc *undo_bg = NULL;
1986
1987         mlog_entry_void();
1988
1989         /* The caller got this descriptor from
1990          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1991         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1992
1993         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1994
1995         BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
1996         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1997                                          group_bh,
1998                                          undo_fn ?
1999                                          OCFS2_JOURNAL_ACCESS_UNDO :
2000                                          OCFS2_JOURNAL_ACCESS_WRITE);
2001         if (status < 0) {
2002                 mlog_errno(status);
2003                 goto bail;
2004         }
2005
2006         if (undo_fn) {
2007                 jbd_lock_bh_state(group_bh);
2008                 undo_bg = (struct ocfs2_group_desc *)
2009                                         bh2jh(group_bh)->b_committed_data;
2010                 BUG_ON(!undo_bg);
2011         }
2012
2013         tmp = num_bits;
2014         while(tmp--) {
2015                 ocfs2_clear_bit((bit_off + tmp),
2016                                 (unsigned long *) bg->bg_bitmap);
2017                 if (undo_fn)
2018                         undo_fn(bit_off + tmp,
2019                                 (unsigned long *) undo_bg->bg_bitmap);
2020         }
2021         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2022
2023         if (undo_fn)
2024                 jbd_unlock_bh_state(group_bh);
2025
2026         status = ocfs2_journal_dirty(handle, group_bh);
2027         if (status < 0)
2028                 mlog_errno(status);
2029 bail:
2030         return status;
2031 }
2032
2033 /*
2034  * expects the suballoc inode to already be locked.
2035  */
2036 static int _ocfs2_free_suballoc_bits(handle_t *handle,
2037                                      struct inode *alloc_inode,
2038                                      struct buffer_head *alloc_bh,
2039                                      unsigned int start_bit,
2040                                      u64 bg_blkno,
2041                                      unsigned int count,
2042                                      void (*undo_fn)(unsigned int bit,
2043                                                      unsigned long *bitmap))
2044 {
2045         int status = 0;
2046         u32 tmp_used;
2047         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2048         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2049         struct buffer_head *group_bh = NULL;
2050         struct ocfs2_group_desc *group;
2051
2052         mlog_entry_void();
2053
2054         /* The alloc_bh comes from ocfs2_free_dinode() or
2055          * ocfs2_free_clusters().  The callers have all locked the
2056          * allocator and gotten alloc_bh from the lock call.  This
2057          * validates the dinode buffer.  Any corruption that has happended
2058          * is a code bug. */
2059         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2060         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2061
2062         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
2063              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
2064              (unsigned long long)bg_blkno, start_bit);
2065
2066         status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2067                                              &group_bh);
2068         if (status < 0) {
2069                 mlog_errno(status);
2070                 goto bail;
2071         }
2072         group = (struct ocfs2_group_desc *) group_bh->b_data;
2073
2074         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2075
2076         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2077                                               group, group_bh,
2078                                               start_bit, count, undo_fn);
2079         if (status < 0) {
2080                 mlog_errno(status);
2081                 goto bail;
2082         }
2083
2084         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2085                                          alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2086         if (status < 0) {
2087                 mlog_errno(status);
2088                 goto bail;
2089         }
2090
2091         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2092                      count);
2093         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2094         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2095
2096         status = ocfs2_journal_dirty(handle, alloc_bh);
2097         if (status < 0) {
2098                 mlog_errno(status);
2099                 goto bail;
2100         }
2101
2102 bail:
2103         brelse(group_bh);
2104
2105         mlog_exit(status);
2106         return status;
2107 }
2108
2109 int ocfs2_free_suballoc_bits(handle_t *handle,
2110                              struct inode *alloc_inode,
2111                              struct buffer_head *alloc_bh,
2112                              unsigned int start_bit,
2113                              u64 bg_blkno,
2114                              unsigned int count)
2115 {
2116         return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2117                                          start_bit, bg_blkno, count, NULL);
2118 }
2119
2120 int ocfs2_free_dinode(handle_t *handle,
2121                       struct inode *inode_alloc_inode,
2122                       struct buffer_head *inode_alloc_bh,
2123                       struct ocfs2_dinode *di)
2124 {
2125         u64 blk = le64_to_cpu(di->i_blkno);
2126         u16 bit = le16_to_cpu(di->i_suballoc_bit);
2127         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2128
2129         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2130                                         inode_alloc_bh, bit, bg_blkno, 1);
2131 }
2132
2133 static int _ocfs2_free_clusters(handle_t *handle,
2134                                 struct inode *bitmap_inode,
2135                                 struct buffer_head *bitmap_bh,
2136                                 u64 start_blk,
2137                                 unsigned int num_clusters,
2138                                 void (*undo_fn)(unsigned int bit,
2139                                                 unsigned long *bitmap))
2140 {
2141         int status;
2142         u16 bg_start_bit;
2143         u64 bg_blkno;
2144         struct ocfs2_dinode *fe;
2145
2146         /* You can't ever have a contiguous set of clusters
2147          * bigger than a block group bitmap so we never have to worry
2148          * about looping on them. */
2149
2150         mlog_entry_void();
2151
2152         /* This is expensive. We can safely remove once this stuff has
2153          * gotten tested really well. */
2154         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
2155
2156         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
2157
2158         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2159                                      &bg_start_bit);
2160
2161         mlog(0, "want to free %u clusters starting at block %llu\n",
2162              num_clusters, (unsigned long long)start_blk);
2163         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
2164              (unsigned long long)bg_blkno, bg_start_bit);
2165
2166         status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2167                                            bg_start_bit, bg_blkno,
2168                                            num_clusters, undo_fn);
2169         if (status < 0) {
2170                 mlog_errno(status);
2171                 goto out;
2172         }
2173
2174         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2175                                          num_clusters);
2176
2177 out:
2178         mlog_exit(status);
2179         return status;
2180 }
2181
2182 int ocfs2_free_clusters(handle_t *handle,
2183                         struct inode *bitmap_inode,
2184                         struct buffer_head *bitmap_bh,
2185                         u64 start_blk,
2186                         unsigned int num_clusters)
2187 {
2188         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2189                                     start_blk, num_clusters,
2190                                     _ocfs2_set_bit);
2191 }
2192
2193 /*
2194  * Give never-used clusters back to the global bitmap.  We don't need
2195  * to protect these bits in the undo buffer.
2196  */
2197 int ocfs2_release_clusters(handle_t *handle,
2198                            struct inode *bitmap_inode,
2199                            struct buffer_head *bitmap_bh,
2200                            u64 start_blk,
2201                            unsigned int num_clusters)
2202 {
2203         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2204                                     start_blk, num_clusters,
2205                                     _ocfs2_clear_bit);
2206 }
2207
2208 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
2209 {
2210         printk("Block Group:\n");
2211         printk("bg_signature:       %s\n", bg->bg_signature);
2212         printk("bg_size:            %u\n", bg->bg_size);
2213         printk("bg_bits:            %u\n", bg->bg_bits);
2214         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
2215         printk("bg_chain:           %u\n", bg->bg_chain);
2216         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
2217         printk("bg_next_group:      %llu\n",
2218                (unsigned long long)bg->bg_next_group);
2219         printk("bg_parent_dinode:   %llu\n",
2220                (unsigned long long)bg->bg_parent_dinode);
2221         printk("bg_blkno:           %llu\n",
2222                (unsigned long long)bg->bg_blkno);
2223 }
2224
2225 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
2226 {
2227         int i;
2228
2229         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
2230         printk("i_signature:                  %s\n", fe->i_signature);
2231         printk("i_size:                       %llu\n",
2232                (unsigned long long)fe->i_size);
2233         printk("i_clusters:                   %u\n", fe->i_clusters);
2234         printk("i_generation:                 %u\n",
2235                le32_to_cpu(fe->i_generation));
2236         printk("id1.bitmap1.i_used:           %u\n",
2237                le32_to_cpu(fe->id1.bitmap1.i_used));
2238         printk("id1.bitmap1.i_total:          %u\n",
2239                le32_to_cpu(fe->id1.bitmap1.i_total));
2240         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
2241         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
2242         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
2243         printk("id2.i_chain.cl_next_free_rec: %u\n",
2244                fe->id2.i_chain.cl_next_free_rec);
2245         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
2246                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
2247                        fe->id2.i_chain.cl_recs[i].c_free);
2248                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
2249                        fe->id2.i_chain.cl_recs[i].c_total);
2250                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
2251                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
2252         }
2253 }
2254
2255 /*
2256  * For a given allocation, determine which allocators will need to be
2257  * accessed, and lock them, reserving the appropriate number of bits.
2258  *
2259  * Sparse file systems call this from ocfs2_write_begin_nolock()
2260  * and ocfs2_allocate_unwritten_extents().
2261  *
2262  * File systems which don't support holes call this from
2263  * ocfs2_extend_allocation().
2264  */
2265 int ocfs2_lock_allocators(struct inode *inode,
2266                           struct ocfs2_extent_tree *et,
2267                           u32 clusters_to_add, u32 extents_to_split,
2268                           struct ocfs2_alloc_context **data_ac,
2269                           struct ocfs2_alloc_context **meta_ac)
2270 {
2271         int ret = 0, num_free_extents;
2272         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2273         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2274
2275         *meta_ac = NULL;
2276         if (data_ac)
2277                 *data_ac = NULL;
2278
2279         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2280
2281         num_free_extents = ocfs2_num_free_extents(osb, et);
2282         if (num_free_extents < 0) {
2283                 ret = num_free_extents;
2284                 mlog_errno(ret);
2285                 goto out;
2286         }
2287
2288         /*
2289          * Sparse allocation file systems need to be more conservative
2290          * with reserving room for expansion - the actual allocation
2291          * happens while we've got a journal handle open so re-taking
2292          * a cluster lock (because we ran out of room for another
2293          * extent) will violate ordering rules.
2294          *
2295          * Most of the time we'll only be seeing this 1 cluster at a time
2296          * anyway.
2297          *
2298          * Always lock for any unwritten extents - we might want to
2299          * add blocks during a split.
2300          */
2301         if (!num_free_extents ||
2302             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2303                 ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2304                 if (ret < 0) {
2305                         if (ret != -ENOSPC)
2306                                 mlog_errno(ret);
2307                         goto out;
2308                 }
2309         }
2310
2311         if (clusters_to_add == 0)
2312                 goto out;
2313
2314         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2315         if (ret < 0) {
2316                 if (ret != -ENOSPC)
2317                         mlog_errno(ret);
2318                 goto out;
2319         }
2320
2321 out:
2322         if (ret) {
2323                 if (*meta_ac) {
2324                         ocfs2_free_alloc_context(*meta_ac);
2325                         *meta_ac = NULL;
2326                 }
2327
2328                 /*
2329                  * We cannot have an error and a non null *data_ac.
2330                  */
2331         }
2332
2333         return ret;
2334 }
2335
2336 /*
2337  * Read the inode specified by blkno to get suballoc_slot and
2338  * suballoc_bit.
2339  */
2340 static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2341                                        u16 *suballoc_slot, u16 *suballoc_bit)
2342 {
2343         int status;
2344         struct buffer_head *inode_bh = NULL;
2345         struct ocfs2_dinode *inode_fe;
2346
2347         mlog_entry("blkno: %llu\n", (unsigned long long)blkno);
2348
2349         /* dirty read disk */
2350         status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2351         if (status < 0) {
2352                 mlog(ML_ERROR, "read block %llu failed %d\n",
2353                      (unsigned long long)blkno, status);
2354                 goto bail;
2355         }
2356
2357         inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2358         if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2359                 mlog(ML_ERROR, "invalid inode %llu requested\n",
2360                      (unsigned long long)blkno);
2361                 status = -EINVAL;
2362                 goto bail;
2363         }
2364
2365         if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2366             (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2367                 mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2368                      (unsigned long long)blkno,
2369                      (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2370                 status = -EINVAL;
2371                 goto bail;
2372         }
2373
2374         if (suballoc_slot)
2375                 *suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2376         if (suballoc_bit)
2377                 *suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2378
2379 bail:
2380         brelse(inode_bh);
2381
2382         mlog_exit(status);
2383         return status;
2384 }
2385
2386 /*
2387  * test whether bit is SET in allocator bitmap or not.  on success, 0
2388  * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2389  * is returned and *res is meaningless.  Call this after you have
2390  * cluster locked against suballoc, or you may get a result based on
2391  * non-up2date contents
2392  */
2393 static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2394                                    struct inode *suballoc,
2395                                    struct buffer_head *alloc_bh, u64 blkno,
2396                                    u16 bit, int *res)
2397 {
2398         struct ocfs2_dinode *alloc_fe;
2399         struct ocfs2_group_desc *group;
2400         struct buffer_head *group_bh = NULL;
2401         u64 bg_blkno;
2402         int status;
2403
2404         mlog_entry("blkno: %llu bit: %u\n", (unsigned long long)blkno,
2405                    (unsigned int)bit);
2406
2407         alloc_fe = (struct ocfs2_dinode *)alloc_bh->b_data;
2408         if ((bit + 1) > ocfs2_bits_per_group(&alloc_fe->id2.i_chain)) {
2409                 mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2410                      (unsigned int)bit,
2411                      ocfs2_bits_per_group(&alloc_fe->id2.i_chain));
2412                 status = -EINVAL;
2413                 goto bail;
2414         }
2415
2416         bg_blkno = ocfs2_which_suballoc_group(blkno, bit);
2417         status = ocfs2_read_group_descriptor(suballoc, alloc_fe, bg_blkno,
2418                                              &group_bh);
2419         if (status < 0) {
2420                 mlog(ML_ERROR, "read group %llu failed %d\n",
2421                      (unsigned long long)bg_blkno, status);
2422                 goto bail;
2423         }
2424
2425         group = (struct ocfs2_group_desc *) group_bh->b_data;
2426         *res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2427
2428 bail:
2429         brelse(group_bh);
2430
2431         mlog_exit(status);
2432         return status;
2433 }
2434
2435 /*
2436  * Test if the bit representing this inode (blkno) is set in the
2437  * suballocator.
2438  *
2439  * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2440  *
2441  * In the event of failure, a negative value is returned and *res is
2442  * meaningless.
2443  *
2444  * Callers must make sure to hold nfs_sync_lock to prevent
2445  * ocfs2_delete_inode() on another node from accessing the same
2446  * suballocator concurrently.
2447  */
2448 int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2449 {
2450         int status;
2451         u16 suballoc_bit = 0, suballoc_slot = 0;
2452         struct inode *inode_alloc_inode;
2453         struct buffer_head *alloc_bh = NULL;
2454
2455         mlog_entry("blkno: %llu", (unsigned long long)blkno);
2456
2457         status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2458                                              &suballoc_bit);
2459         if (status < 0) {
2460                 mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2461                 goto bail;
2462         }
2463
2464         inode_alloc_inode =
2465                 ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
2466                                             suballoc_slot);
2467         if (!inode_alloc_inode) {
2468                 /* the error code could be inaccurate, but we are not able to
2469                  * get the correct one. */
2470                 status = -EINVAL;
2471                 mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2472                      (u32)suballoc_slot);
2473                 goto bail;
2474         }
2475
2476         mutex_lock(&inode_alloc_inode->i_mutex);
2477         status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2478         if (status < 0) {
2479                 mutex_unlock(&inode_alloc_inode->i_mutex);
2480                 mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2481                      (u32)suballoc_slot, status);
2482                 goto bail;
2483         }
2484
2485         status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2486                                          blkno, suballoc_bit, res);
2487         if (status < 0)
2488                 mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2489
2490         ocfs2_inode_unlock(inode_alloc_inode, 0);
2491         mutex_unlock(&inode_alloc_inode->i_mutex);
2492
2493         iput(inode_alloc_inode);
2494         brelse(alloc_bh);
2495 bail:
2496         mlog_exit(status);
2497         return status;
2498 }