fs/ocfs2/suballoc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* -*- mode: c; c-basic-offset: 8; -*-
   3  * vim: noexpandtab sw=8 ts=8 sts=0:
   4  *
   5  * suballoc.c
   6  *
   7  * metadata alloc and free
   8  * Inspired by ext3 block groups.
   9  *
  10  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  11  */
  12
  13 #include <linux/fs.h>
  14 #include <linux/types.h>
  15 #include <linux/slab.h>
  16 #include <linux/highmem.h>
  17
  18 #include <cluster/masklog.h>
  19
  20 #include "ocfs2.h"
  21
  22 #include "alloc.h"
  23 #include "blockcheck.h"
  24 #include "dlmglue.h"
  25 #include "inode.h"
  26 #include "journal.h"
  27 #include "localalloc.h"
  28 #include "suballoc.h"
  29 #include "super.h"
  30 #include "sysfile.h"
  31 #include "uptodate.h"
  32 #include "ocfs2_trace.h"
  33
  34 #include "buffer_head_io.h"
  35
  36 #define NOT_ALLOC_NEW_GROUP             0
  37 #define ALLOC_NEW_GROUP                 0x1
  38 #define ALLOC_GROUPS_FROM_GLOBAL        0x2
  39
  40 #define OCFS2_MAX_TO_STEAL              1024
  41
  42 struct ocfs2_suballoc_result {
  43         u64             sr_bg_blkno;    /* The bg we allocated from.  Set
  44                                            to 0 when a block group is
  45                                            contiguous. */
  46         u64             sr_bg_stable_blkno; /*
  47                                              * Doesn't change, always
  48                                              * set to target block
  49                                              * group descriptor
  50                                              * block.
  51                                              */
  52         u64             sr_blkno;       /* The first allocated block */
  53         unsigned int    sr_bit_offset;  /* The bit in the bg */
  54         unsigned int    sr_bits;        /* How many bits we claimed */
  55 };
  56
  57 static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
  58 {
  59         if (res->sr_blkno == 0)
  60                 return 0;
  61
  62         if (res->sr_bg_blkno)
  63                 return res->sr_bg_blkno;
  64
  65         return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
  66 }
  67
  68 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  69 static int ocfs2_block_group_fill(handle_t *handle,
  70                                   struct inode *alloc_inode,
  71                                   struct buffer_head *bg_bh,
  72                                   u64 group_blkno,
  73                                   unsigned int group_clusters,
  74                                   u16 my_chain,
  75                                   struct ocfs2_chain_list *cl);
  76 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  77                                    struct inode *alloc_inode,
  78                                    struct buffer_head *bh,
  79                                    u64 max_block,
  80                                    u64 *last_alloc_group,
  81                                    int flags);
  82
  83 static int ocfs2_cluster_group_search(struct inode *inode,
  84                                       struct buffer_head *group_bh,
  85                                       u32 bits_wanted, u32 min_bits,
  86                                       u64 max_block,
  87                                       struct ocfs2_suballoc_result *res);
  88 static int ocfs2_block_group_search(struct inode *inode,
  89                                     struct buffer_head *group_bh,
  90                                     u32 bits_wanted, u32 min_bits,
  91                                     u64 max_block,
  92                                     struct ocfs2_suballoc_result *res);
  93 static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
  94                                      handle_t *handle,
  95                                      u32 bits_wanted,
  96                                      u32 min_bits,
  97                                      struct ocfs2_suballoc_result *res);
  98 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  99                                          int nr);
 100 static int ocfs2_relink_block_group(handle_t *handle,
 101                                     struct inode *alloc_inode,
 102                                     struct buffer_head *fe_bh,
 103                                     struct buffer_head *bg_bh,
 104                                     struct buffer_head *prev_bg_bh,
 105                                     u16 chain);
 106 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 107                                                      u32 wanted);
 108 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 109                                                    u64 bg_blkno,
 110                                                    u16 bg_bit_off);
 111 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 112                                                 u64 data_blkno,
 113                                                 u64 *bg_blkno,
 114                                                 u16 *bg_bit_off);
 115 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 116                                              u32 bits_wanted, u64 max_block,
 117                                              int flags,
 118                                              struct ocfs2_alloc_context **ac);
 119
 120 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 121 {
 122         struct inode *inode = ac->ac_inode;
 123
 124         if (inode) {
 125                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 126                         ocfs2_inode_unlock(inode, 1);
 127
 128                 inode_unlock(inode);
 129
 130                 iput(inode);
 131                 ac->ac_inode = NULL;
 132         }
 133         brelse(ac->ac_bh);
 134         ac->ac_bh = NULL;
 135         ac->ac_resv = NULL;
 136         kfree(ac->ac_find_loc_priv);
 137         ac->ac_find_loc_priv = NULL;
 138 }
 139
 140 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 141 {
 142         ocfs2_free_ac_resource(ac);
 143         kfree(ac);
 144 }
 145
 146 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 147 {
 148         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 149 }
 150
 151 #define do_error(fmt, ...)                                              \
 152 do {                                                                    \
 153         if (resize)                                                     \
 154                 mlog(ML_ERROR, fmt, ##__VA_ARGS__);                     \
 155         else                                                            \
 156                 return ocfs2_error(sb, fmt, ##__VA_ARGS__);             \
 157 } while (0)
 158
 159 static int ocfs2_validate_gd_self(struct super_block *sb,
 160                                   struct buffer_head *bh,
 161                                   int resize)
 162 {
 163         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 164
 165         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 166                 do_error("Group descriptor #%llu has bad signature %.*s\n",
 167                          (unsigned long long)bh->b_blocknr, 7,
 168                          gd->bg_signature);
 169         }
 170
 171         if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 172                 do_error("Group descriptor #%llu has an invalid bg_blkno of %llu\n",
 173                          (unsigned long long)bh->b_blocknr,
 174                          (unsigned long long)le64_to_cpu(gd->bg_blkno));
 175         }
 176
 177         if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 178                 do_error("Group descriptor #%llu has an invalid fs_generation of #%u\n",
 179                          (unsigned long long)bh->b_blocknr,
 180                          le32_to_cpu(gd->bg_generation));
 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 claims that %u are free\n",
 185                          (unsigned long long)bh->b_blocknr,
 186                          le16_to_cpu(gd->bg_bits),
 187                          le16_to_cpu(gd->bg_free_bits_count));
 188         }
 189
 190         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 191                 do_error("Group descriptor #%llu has bit count %u but max bitmap bits of %u\n",
 192                          (unsigned long long)bh->b_blocknr,
 193                          le16_to_cpu(gd->bg_bits),
 194                          8 * le16_to_cpu(gd->bg_size));
 195         }
 196
 197         return 0;
 198 }
 199
 200 static int ocfs2_validate_gd_parent(struct super_block *sb,
 201                                     struct ocfs2_dinode *di,
 202                                     struct buffer_head *bh,
 203                                     int resize)
 204 {
 205         unsigned int max_bits;
 206         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 207
 208         if (di->i_blkno != gd->bg_parent_dinode) {
 209                 do_error("Group descriptor #%llu has bad parent pointer (%llu, expected %llu)\n",
 210                          (unsigned long long)bh->b_blocknr,
 211                          (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 212                          (unsigned long long)le64_to_cpu(di->i_blkno));
 213         }
 214
 215         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 216         if (le16_to_cpu(gd->bg_bits) > max_bits) {
 217                 do_error("Group descriptor #%llu has bit count of %u\n",
 218                          (unsigned long long)bh->b_blocknr,
 219                          le16_to_cpu(gd->bg_bits));
 220         }
 221
 222         /* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 223         if ((le16_to_cpu(gd->bg_chain) >
 224              le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 225             ((le16_to_cpu(gd->bg_chain) ==
 226              le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 227                 do_error("Group descriptor #%llu has bad chain %u\n",
 228                          (unsigned long long)bh->b_blocknr,
 229                          le16_to_cpu(gd->bg_chain));
 230         }
 231
 232         return 0;
 233 }
 234
 235 #undef do_error
 236
 237 /*
 238  * This version only prints errors.  It does not fail the filesystem, and
 239  * exists only for resize.
 240  */
 241 int ocfs2_check_group_descriptor(struct super_block *sb,
 242                                  struct ocfs2_dinode *di,
 243                                  struct buffer_head *bh)
 244 {
 245         int rc;
 246         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 247
 248         BUG_ON(!buffer_uptodate(bh));
 249
 250         /*
 251          * If the ecc fails, we return the error but otherwise
 252          * leave the filesystem running.  We know any error is
 253          * local to this block.
 254          */
 255         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 256         if (rc) {
 257                 mlog(ML_ERROR,
 258                      "Checksum failed for group descriptor %llu\n",
 259                      (unsigned long long)bh->b_blocknr);
 260         } else
 261                 rc = ocfs2_validate_gd_self(sb, bh, 1);
 262         if (!rc)
 263                 rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 264
 265         return rc;
 266 }
 267
 268 static int ocfs2_validate_group_descriptor(struct super_block *sb,
 269                                            struct buffer_head *bh)
 270 {
 271         int rc;
 272         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 273
 274         trace_ocfs2_validate_group_descriptor(
 275                                         (unsigned long long)bh->b_blocknr);
 276
 277         BUG_ON(!buffer_uptodate(bh));
 278
 279         /*
 280          * If the ecc fails, we return the error but otherwise
 281          * leave the filesystem running.  We know any error is
 282          * local to this block.
 283          */
 284         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 285         if (rc)
 286                 return rc;
 287
 288         /*
 289          * Errors after here are fatal.
 290          */
 291
 292         return ocfs2_validate_gd_self(sb, bh, 0);
 293 }
 294
 295 int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 296                                 u64 gd_blkno, struct buffer_head **bh)
 297 {
 298         int rc;
 299         struct buffer_head *tmp = *bh;
 300
 301         rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 302                               ocfs2_validate_group_descriptor);
 303         if (rc)
 304                 goto out;
 305
 306         rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 307         if (rc) {
 308                 brelse(tmp);
 309                 goto out;
 310         }
 311
 312         /* If ocfs2_read_block() got us a new bh, pass it up. */
 313         if (!*bh)
 314                 *bh = tmp;
 315
 316 out:
 317         return rc;
 318 }
 319
 320 static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 321                                           struct ocfs2_group_desc *bg,
 322                                           struct ocfs2_chain_list *cl,
 323                                           u64 p_blkno, unsigned int clusters)
 324 {
 325         struct ocfs2_extent_list *el = &bg->bg_list;
 326         struct ocfs2_extent_rec *rec;
 327
 328         BUG_ON(!ocfs2_supports_discontig_bg(osb));
 329         if (!el->l_next_free_rec)
 330                 el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 331         rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 332         rec->e_blkno = cpu_to_le64(p_blkno);
 333         rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 334                                   le16_to_cpu(cl->cl_bpc));
 335         rec->e_leaf_clusters = cpu_to_le16(clusters);
 336         le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 337         le16_add_cpu(&bg->bg_free_bits_count,
 338                      clusters * le16_to_cpu(cl->cl_bpc));
 339         le16_add_cpu(&el->l_next_free_rec, 1);
 340 }
 341
 342 static int ocfs2_block_group_fill(handle_t *handle,
 343                                   struct inode *alloc_inode,
 344                                   struct buffer_head *bg_bh,
 345                                   u64 group_blkno,
 346                                   unsigned int group_clusters,
 347                                   u16 my_chain,
 348                                   struct ocfs2_chain_list *cl)
 349 {
 350         int status = 0;
 351         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 352         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 353         struct super_block * sb = alloc_inode->i_sb;
 354
 355         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 356                 status = ocfs2_error(alloc_inode->i_sb,
 357                                      "group block (%llu) != b_blocknr (%llu)\n",
 358                                      (unsigned long long)group_blkno,
 359                                      (unsigned long long) bg_bh->b_blocknr);
 360                 goto bail;
 361         }
 362
 363         status = ocfs2_journal_access_gd(handle,
 364                                          INODE_CACHE(alloc_inode),
 365                                          bg_bh,
 366                                          OCFS2_JOURNAL_ACCESS_CREATE);
 367         if (status < 0) {
 368                 mlog_errno(status);
 369                 goto bail;
 370         }
 371
 372         memset(bg, 0, sb->s_blocksize);
 373         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 374         bg->bg_generation = cpu_to_le32(osb->fs_generation);
 375         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 376                                                 osb->s_feature_incompat));
 377         bg->bg_chain = cpu_to_le16(my_chain);
 378         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 379         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 380         bg->bg_blkno = cpu_to_le64(group_blkno);
 381         if (group_clusters == le16_to_cpu(cl->cl_cpg))
 382                 bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 383         else
 384                 ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 385                                               group_clusters);
 386
 387         /* set the 1st bit in the bitmap to account for the descriptor block */
 388         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 389         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 390
 391         ocfs2_journal_dirty(handle, bg_bh);
 392
 393         /* There is no need to zero out or otherwise initialize the
 394          * other blocks in a group - All valid FS metadata in a block
 395          * group stores the superblock fs_generation value at
 396          * allocation time. */
 397
 398 bail:
 399         if (status)
 400                 mlog_errno(status);
 401         return status;
 402 }
 403
 404 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 405 {
 406         u16 curr, best;
 407
 408         best = curr = 0;
 409         while (curr < le16_to_cpu(cl->cl_count)) {
 410                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 411                     le32_to_cpu(cl->cl_recs[curr].c_total))
 412                         best = curr;
 413                 curr++;
 414         }
 415         return best;
 416 }
 417
 418 static struct buffer_head *
 419 ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 420                                struct inode *alloc_inode,
 421                                struct ocfs2_alloc_context *ac,
 422                                struct ocfs2_chain_list *cl)
 423 {
 424         int status;
 425         u32 bit_off, num_bits;
 426         u64 bg_blkno;
 427         struct buffer_head *bg_bh;
 428         unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 429
 430         status = ocfs2_claim_clusters(handle, ac,
 431                                       le16_to_cpu(cl->cl_cpg), &bit_off,
 432                                       &num_bits);
 433         if (status < 0) {
 434                 if (status != -ENOSPC)
 435                         mlog_errno(status);
 436                 goto bail;
 437         }
 438
 439         /* setup the group */
 440         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 441         trace_ocfs2_block_group_alloc_contig(
 442              (unsigned long long)bg_blkno, alloc_rec);
 443
 444         bg_bh = sb_getblk(osb->sb, bg_blkno);
 445         if (!bg_bh) {
 446                 status = -ENOMEM;
 447                 mlog_errno(status);
 448                 goto bail;
 449         }
 450         ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 451
 452         status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 453                                         bg_blkno, num_bits, alloc_rec, cl);
 454         if (status < 0) {
 455                 brelse(bg_bh);
 456                 mlog_errno(status);
 457         }
 458
 459 bail:
 460         return status ? ERR_PTR(status) : bg_bh;
 461 }
 462
 463 static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 464                                         handle_t *handle,
 465                                         struct ocfs2_alloc_context *ac,
 466                                         unsigned int min_bits,
 467                                         u32 *bit_off, u32 *num_bits)
 468 {
 469         int status = 0;
 470
 471         while (min_bits) {
 472                 status = ocfs2_claim_clusters(handle, ac, min_bits,
 473                                               bit_off, num_bits);
 474                 if (status != -ENOSPC)
 475                         break;
 476
 477                 min_bits >>= 1;
 478         }
 479
 480         return status;
 481 }
 482
 483 static int ocfs2_block_group_grow_discontig(handle_t *handle,
 484                                             struct inode *alloc_inode,
 485                                             struct buffer_head *bg_bh,
 486                                             struct ocfs2_alloc_context *ac,
 487                                             struct ocfs2_chain_list *cl,
 488                                             unsigned int min_bits)
 489 {
 490         int status;
 491         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 492         struct ocfs2_group_desc *bg =
 493                 (struct ocfs2_group_desc *)bg_bh->b_data;
 494         unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 495                          le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 496         u32 p_cpos, clusters;
 497         u64 p_blkno;
 498         struct ocfs2_extent_list *el = &bg->bg_list;
 499
 500         status = ocfs2_journal_access_gd(handle,
 501                                          INODE_CACHE(alloc_inode),
 502                                          bg_bh,
 503                                          OCFS2_JOURNAL_ACCESS_CREATE);
 504         if (status < 0) {
 505                 mlog_errno(status);
 506                 goto bail;
 507         }
 508
 509         while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 510                                 le16_to_cpu(el->l_count))) {
 511                 if (min_bits > needed)
 512                         min_bits = needed;
 513                 status = ocfs2_block_group_claim_bits(osb, handle, ac,
 514                                                       min_bits, &p_cpos,
 515                                                       &clusters);
 516                 if (status < 0) {
 517                         if (status != -ENOSPC)
 518                                 mlog_errno(status);
 519                         goto bail;
 520                 }
 521                 p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 522                 ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 523                                               clusters);
 524
 525                 min_bits = clusters;
 526                 needed = le16_to_cpu(cl->cl_cpg) -
 527                          le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 528         }
 529
 530         if (needed > 0) {
 531                 /*
 532                  * We have used up all the extent rec but can't fill up
 533                  * the cpg. So bail out.
 534                  */
 535                 status = -ENOSPC;
 536                 goto bail;
 537         }
 538
 539         ocfs2_journal_dirty(handle, bg_bh);
 540
 541 bail:
 542         return status;
 543 }
 544
 545 static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 546                                    struct ocfs2_alloc_context *cluster_ac,
 547                                    struct inode *alloc_inode,
 548                                    struct buffer_head *bg_bh)
 549 {
 550         int i, ret;
 551         struct ocfs2_group_desc *bg;
 552         struct ocfs2_extent_list *el;
 553         struct ocfs2_extent_rec *rec;
 554
 555         if (!bg_bh)
 556                 return;
 557
 558         bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 559         el = &bg->bg_list;
 560         for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 561                 rec = &el->l_recs[i];
 562                 ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 563                                           cluster_ac->ac_bh,
 564                                           le64_to_cpu(rec->e_blkno),
 565                                           le16_to_cpu(rec->e_leaf_clusters));
 566                 if (ret)
 567                         mlog_errno(ret);
 568                 /* Try all the clusters to free */
 569         }
 570
 571         ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 572         brelse(bg_bh);
 573 }
 574
 575 static struct buffer_head *
 576 ocfs2_block_group_alloc_discontig(handle_t *handle,
 577                                   struct inode *alloc_inode,
 578                                   struct ocfs2_alloc_context *ac,
 579                                   struct ocfs2_chain_list *cl)
 580 {
 581         int status;
 582         u32 bit_off, num_bits;
 583         u64 bg_blkno;
 584         unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 585         struct buffer_head *bg_bh = NULL;
 586         unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 587         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 588
 589         if (!ocfs2_supports_discontig_bg(osb)) {
 590                 status = -ENOSPC;
 591                 goto bail;
 592         }
 593
 594         status = ocfs2_extend_trans(handle,
 595                                     ocfs2_calc_bg_discontig_credits(osb->sb));
 596         if (status) {
 597                 mlog_errno(status);
 598                 goto bail;
 599         }
 600
 601         /*
 602          * We're going to be grabbing from multiple cluster groups.
 603          * We don't have enough credits to relink them all, and the
 604          * cluster groups will be staying in cache for the duration of
 605          * this operation.
 606          */
 607         ac->ac_disable_chain_relink = 1;
 608
 609         /* Claim the first region */
 610         status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 611                                               &bit_off, &num_bits);
 612         if (status < 0) {
 613                 if (status != -ENOSPC)
 614                         mlog_errno(status);
 615                 goto bail;
 616         }
 617         min_bits = num_bits;
 618
 619         /* setup the group */
 620         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 621         trace_ocfs2_block_group_alloc_discontig(
 622                                 (unsigned long long)bg_blkno, alloc_rec);
 623
 624         bg_bh = sb_getblk(osb->sb, bg_blkno);
 625         if (!bg_bh) {
 626                 status = -ENOMEM;
 627                 mlog_errno(status);
 628                 goto bail;
 629         }
 630         ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 631
 632         status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 633                                         bg_blkno, num_bits, alloc_rec, cl);
 634         if (status < 0) {
 635                 mlog_errno(status);
 636                 goto bail;
 637         }
 638
 639         status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 640                                                   bg_bh, ac, cl, min_bits);
 641         if (status)
 642                 mlog_errno(status);
 643
 644 bail:
 645         if (status)
 646                 ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 647         return status ? ERR_PTR(status) : bg_bh;
 648 }
 649
 650 /*
 651  * We expect the block group allocator to already be locked.
 652  */
 653 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 654                                    struct inode *alloc_inode,
 655                                    struct buffer_head *bh,
 656                                    u64 max_block,
 657                                    u64 *last_alloc_group,
 658                                    int flags)
 659 {
 660         int status, credits;
 661         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 662         struct ocfs2_chain_list *cl;
 663         struct ocfs2_alloc_context *ac = NULL;
 664         handle_t *handle = NULL;
 665         u16 alloc_rec;
 666         struct buffer_head *bg_bh = NULL;
 667         struct ocfs2_group_desc *bg;
 668
 669         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 670
 671         cl = &fe->id2.i_chain;
 672         status = ocfs2_reserve_clusters_with_limit(osb,
 673                                                    le16_to_cpu(cl->cl_cpg),
 674                                                    max_block, flags, &ac);
 675         if (status < 0) {
 676                 if (status != -ENOSPC)
 677                         mlog_errno(status);
 678                 goto bail;
 679         }
 680
 681         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 682                                                  le16_to_cpu(cl->cl_cpg));
 683         handle = ocfs2_start_trans(osb, credits);
 684         if (IS_ERR(handle)) {
 685                 status = PTR_ERR(handle);
 686                 handle = NULL;
 687                 mlog_errno(status);
 688                 goto bail;
 689         }
 690
 691         if (last_alloc_group && *last_alloc_group != 0) {
 692                 trace_ocfs2_block_group_alloc(
 693                                 (unsigned long long)*last_alloc_group);
 694                 ac->ac_last_group = *last_alloc_group;
 695         }
 696
 697         bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 698                                                ac, cl);
 699         if (PTR_ERR(bg_bh) == -ENOSPC)
 700                 bg_bh = ocfs2_block_group_alloc_discontig(handle,
 701                                                           alloc_inode,
 702                                                           ac, cl);
 703         if (IS_ERR(bg_bh)) {
 704                 status = PTR_ERR(bg_bh);
 705                 bg_bh = NULL;
 706                 if (status != -ENOSPC)
 707                         mlog_errno(status);
 708                 goto bail;
 709         }
 710         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 711
 712         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 713                                          bh, OCFS2_JOURNAL_ACCESS_WRITE);
 714         if (status < 0) {
 715                 mlog_errno(status);
 716                 goto bail;
 717         }
 718
 719         alloc_rec = le16_to_cpu(bg->bg_chain);
 720         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 721                      le16_to_cpu(bg->bg_free_bits_count));
 722         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 723                      le16_to_cpu(bg->bg_bits));
 724         cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 725         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 726                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 727
 728         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 729                                         le16_to_cpu(bg->bg_free_bits_count));
 730         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 731         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 732
 733         ocfs2_journal_dirty(handle, bh);
 734
 735         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 736         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 737         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 738                                              le32_to_cpu(fe->i_clusters)));
 739         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 740         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 741         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 742         ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
 743
 744         status = 0;
 745
 746         /* save the new last alloc group so that the caller can cache it. */
 747         if (last_alloc_group)
 748                 *last_alloc_group = ac->ac_last_group;
 749
 750 bail:
 751         if (handle)
 752                 ocfs2_commit_trans(osb, handle);
 753
 754         if (ac)
 755                 ocfs2_free_alloc_context(ac);
 756
 757         brelse(bg_bh);
 758
 759         if (status)
 760                 mlog_errno(status);
 761         return status;
 762 }
 763
 764 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 765                                        struct ocfs2_alloc_context *ac,
 766                                        int type,
 767                                        u32 slot,
 768                                        u64 *last_alloc_group,
 769                                        int flags)
 770 {
 771         int status;
 772         u32 bits_wanted = ac->ac_bits_wanted;
 773         struct inode *alloc_inode;
 774         struct buffer_head *bh = NULL;
 775         struct ocfs2_dinode *fe;
 776         u32 free_bits;
 777
 778         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 779         if (!alloc_inode) {
 780                 mlog_errno(-EINVAL);
 781                 return -EINVAL;
 782         }
 783
 784         inode_lock(alloc_inode);
 785
 786         status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 787         if (status < 0) {
 788                 inode_unlock(alloc_inode);
 789                 iput(alloc_inode);
 790
 791                 mlog_errno(status);
 792                 return status;
 793         }
 794
 795         ac->ac_inode = alloc_inode;
 796         ac->ac_alloc_slot = slot;
 797
 798         fe = (struct ocfs2_dinode *) bh->b_data;
 799
 800         /* The bh was validated by the inode read inside
 801          * ocfs2_inode_lock().  Any corruption is a code bug. */
 802         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 803
 804         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 805                 status = ocfs2_error(alloc_inode->i_sb,
 806                                      "Invalid chain allocator %llu\n",
 807                                      (unsigned long long)le64_to_cpu(fe->i_blkno));
 808                 goto bail;
 809         }
 810
 811         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 812                 le32_to_cpu(fe->id1.bitmap1.i_used);
 813
 814         if (bits_wanted > free_bits) {
 815                 /* cluster bitmap never grows */
 816                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 817                         trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 818                                                                 free_bits);
 819                         status = -ENOSPC;
 820                         goto bail;
 821                 }
 822
 823                 if (!(flags & ALLOC_NEW_GROUP)) {
 824                         trace_ocfs2_reserve_suballoc_bits_no_new_group(
 825                                                 slot, bits_wanted, free_bits);
 826                         status = -ENOSPC;
 827                         goto bail;
 828                 }
 829
 830                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 831                                                  ac->ac_max_block,
 832                                                  last_alloc_group, flags);
 833                 if (status < 0) {
 834                         if (status != -ENOSPC)
 835                                 mlog_errno(status);
 836                         goto bail;
 837                 }
 838                 atomic_inc(&osb->alloc_stats.bg_extends);
 839
 840                 /* You should never ask for this much metadata */
 841                 BUG_ON(bits_wanted >
 842                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 843                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 844         }
 845
 846         get_bh(bh);
 847         ac->ac_bh = bh;
 848 bail:
 849         brelse(bh);
 850
 851         if (status)
 852                 mlog_errno(status);
 853         return status;
 854 }
 855
 856 static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 857 {
 858         spin_lock(&osb->osb_lock);
 859         osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 860         spin_unlock(&osb->osb_lock);
 861         atomic_set(&osb->s_num_inodes_stolen, 0);
 862 }
 863
 864 static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 865 {
 866         spin_lock(&osb->osb_lock);
 867         osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 868         spin_unlock(&osb->osb_lock);
 869         atomic_set(&osb->s_num_meta_stolen, 0);
 870 }
 871
 872 void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 873 {
 874         ocfs2_init_inode_steal_slot(osb);
 875         ocfs2_init_meta_steal_slot(osb);
 876 }
 877
 878 static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 879 {
 880         spin_lock(&osb->osb_lock);
 881         if (type == INODE_ALLOC_SYSTEM_INODE)
 882                 osb->s_inode_steal_slot = (u16)slot;
 883         else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 884                 osb->s_meta_steal_slot = (u16)slot;
 885         spin_unlock(&osb->osb_lock);
 886 }
 887
 888 static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 889 {
 890         int slot = OCFS2_INVALID_SLOT;
 891
 892         spin_lock(&osb->osb_lock);
 893         if (type == INODE_ALLOC_SYSTEM_INODE)
 894                 slot = osb->s_inode_steal_slot;
 895         else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 896                 slot = osb->s_meta_steal_slot;
 897         spin_unlock(&osb->osb_lock);
 898
 899         return slot;
 900 }
 901
 902 static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 903 {
 904         return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 905 }
 906
 907 static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 908 {
 909         return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 910 }
 911
 912 static int ocfs2_steal_resource(struct ocfs2_super *osb,
 913                                 struct ocfs2_alloc_context *ac,
 914                                 int type)
 915 {
 916         int i, status = -ENOSPC;
 917         int slot = __ocfs2_get_steal_slot(osb, type);
 918
 919         /* Start to steal resource from the first slot after ours. */
 920         if (slot == OCFS2_INVALID_SLOT)
 921                 slot = osb->slot_num + 1;
 922
 923         for (i = 0; i < osb->max_slots; i++, slot++) {
 924                 if (slot == osb->max_slots)
 925                         slot = 0;
 926
 927                 if (slot == osb->slot_num)
 928                         continue;
 929
 930                 status = ocfs2_reserve_suballoc_bits(osb, ac,
 931                                                      type,
 932                                                      (u32)slot, NULL,
 933                                                      NOT_ALLOC_NEW_GROUP);
 934                 if (status >= 0) {
 935                         __ocfs2_set_steal_slot(osb, slot, type);
 936                         break;
 937                 }
 938
 939                 ocfs2_free_ac_resource(ac);
 940         }
 941
 942         return status;
 943 }
 944
 945 static int ocfs2_steal_inode(struct ocfs2_super *osb,
 946                              struct ocfs2_alloc_context *ac)
 947 {
 948         return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 949 }
 950
 951 static int ocfs2_steal_meta(struct ocfs2_super *osb,
 952                             struct ocfs2_alloc_context *ac)
 953 {
 954         return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 955 }
 956
 957 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 958                                       int blocks,
 959                                       struct ocfs2_alloc_context **ac)
 960 {
 961         int status;
 962         int slot = ocfs2_get_meta_steal_slot(osb);
 963
 964         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 965         if (!(*ac)) {
 966                 status = -ENOMEM;
 967                 mlog_errno(status);
 968                 goto bail;
 969         }
 970
 971         (*ac)->ac_bits_wanted = blocks;
 972         (*ac)->ac_which = OCFS2_AC_USE_META;
 973         (*ac)->ac_group_search = ocfs2_block_group_search;
 974
 975         if (slot != OCFS2_INVALID_SLOT &&
 976                 atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
 977                 goto extent_steal;
 978
 979         atomic_set(&osb->s_num_meta_stolen, 0);
 980         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 981                                              EXTENT_ALLOC_SYSTEM_INODE,
 982                                              (u32)osb->slot_num, NULL,
 983                                              ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
 984
 985
 986         if (status >= 0) {
 987                 status = 0;
 988                 if (slot != OCFS2_INVALID_SLOT)
 989                         ocfs2_init_meta_steal_slot(osb);
 990                 goto bail;
 991         } else if (status < 0 && status != -ENOSPC) {
 992                 mlog_errno(status);
 993                 goto bail;
 994         }
 995
 996         ocfs2_free_ac_resource(*ac);
 997
 998 extent_steal:
 999         status = ocfs2_steal_meta(osb, *ac);
1000         atomic_inc(&osb->s_num_meta_stolen);
1001         if (status < 0) {
1002                 if (status != -ENOSPC)
1003                         mlog_errno(status);
1004                 goto bail;
1005         }
1006
1007         status = 0;
1008 bail:
1009         if ((status < 0) && *ac) {
1010                 ocfs2_free_alloc_context(*ac);
1011                 *ac = NULL;
1012         }
1013
1014         if (status)
1015                 mlog_errno(status);
1016         return status;
1017 }
1018
1019 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1020                                struct ocfs2_extent_list *root_el,
1021                                struct ocfs2_alloc_context **ac)
1022 {
1023         return ocfs2_reserve_new_metadata_blocks(osb,
1024                                         ocfs2_extend_meta_needed(root_el),
1025                                         ac);
1026 }
1027
1028 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1029                             struct ocfs2_alloc_context **ac)
1030 {
1031         int status;
1032         int slot = ocfs2_get_inode_steal_slot(osb);
1033         u64 alloc_group;
1034
1035         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1036         if (!(*ac)) {
1037                 status = -ENOMEM;
1038                 mlog_errno(status);
1039                 goto bail;
1040         }
1041
1042         (*ac)->ac_bits_wanted = 1;
1043         (*ac)->ac_which = OCFS2_AC_USE_INODE;
1044
1045         (*ac)->ac_group_search = ocfs2_block_group_search;
1046
1047         /*
1048          * stat(2) can't handle i_ino > 32bits, so we tell the
1049          * lower levels not to allocate us a block group past that
1050          * limit.  The 'inode64' mount option avoids this behavior.
1051          */
1052         if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1053                 (*ac)->ac_max_block = (u32)~0U;
1054
1055         /*
1056          * slot is set when we successfully steal inode from other nodes.
1057          * It is reset in 3 places:
1058          * 1. when we flush the truncate log
1059          * 2. when we complete local alloc recovery.
1060          * 3. when we successfully allocate from our own slot.
1061          * After it is set, we will go on stealing inodes until we find the
1062          * need to check our slots to see whether there is some space for us.
1063          */
1064         if (slot != OCFS2_INVALID_SLOT &&
1065             atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1066                 goto inode_steal;
1067
1068         atomic_set(&osb->s_num_inodes_stolen, 0);
1069         alloc_group = osb->osb_inode_alloc_group;
1070         status = ocfs2_reserve_suballoc_bits(osb, *ac,
1071                                              INODE_ALLOC_SYSTEM_INODE,
1072                                              (u32)osb->slot_num,
1073                                              &alloc_group,
1074                                              ALLOC_NEW_GROUP |
1075                                              ALLOC_GROUPS_FROM_GLOBAL);
1076         if (status >= 0) {
1077                 status = 0;
1078
1079                 spin_lock(&osb->osb_lock);
1080                 osb->osb_inode_alloc_group = alloc_group;
1081                 spin_unlock(&osb->osb_lock);
1082                 trace_ocfs2_reserve_new_inode_new_group(
1083                         (unsigned long long)alloc_group);
1084
1085                 /*
1086                  * Some inodes must be freed by us, so try to allocate
1087                  * from our own next time.
1088                  */
1089                 if (slot != OCFS2_INVALID_SLOT)
1090                         ocfs2_init_inode_steal_slot(osb);
1091                 goto bail;
1092         } else if (status < 0 && status != -ENOSPC) {
1093                 mlog_errno(status);
1094                 goto bail;
1095         }
1096
1097         ocfs2_free_ac_resource(*ac);
1098
1099 inode_steal:
1100         status = ocfs2_steal_inode(osb, *ac);
1101         atomic_inc(&osb->s_num_inodes_stolen);
1102         if (status < 0) {
1103                 if (status != -ENOSPC)
1104                         mlog_errno(status);
1105                 goto bail;
1106         }
1107
1108         status = 0;
1109 bail:
1110         if ((status < 0) && *ac) {
1111                 ocfs2_free_alloc_context(*ac);
1112                 *ac = NULL;
1113         }
1114
1115         if (status)
1116                 mlog_errno(status);
1117         return status;
1118 }
1119
1120 /* local alloc code has to do the same thing, so rather than do this
1121  * twice.. */
1122 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1123                                       struct ocfs2_alloc_context *ac)
1124 {
1125         int status;
1126
1127         ac->ac_which = OCFS2_AC_USE_MAIN;
1128         ac->ac_group_search = ocfs2_cluster_group_search;
1129
1130         status = ocfs2_reserve_suballoc_bits(osb, ac,
1131                                              GLOBAL_BITMAP_SYSTEM_INODE,
1132                                              OCFS2_INVALID_SLOT, NULL,
1133                                              ALLOC_NEW_GROUP);
1134         if (status < 0 && status != -ENOSPC)
1135                 mlog_errno(status);
1136
1137         return status;
1138 }
1139
1140 /* Callers don't need to care which bitmap (local alloc or main) to
1141  * use so we figure it out for them, but unfortunately this clutters
1142  * things a bit. */
1143 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1144                                              u32 bits_wanted, u64 max_block,
1145                                              int flags,
1146                                              struct ocfs2_alloc_context **ac)
1147 {
1148         int status, ret = 0;
1149         int retried = 0;
1150
1151         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1152         if (!(*ac)) {
1153                 status = -ENOMEM;
1154                 mlog_errno(status);
1155                 goto bail;
1156         }
1157
1158         (*ac)->ac_bits_wanted = bits_wanted;
1159         (*ac)->ac_max_block = max_block;
1160
1161         status = -ENOSPC;
1162         if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1163             ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1164                 status = ocfs2_reserve_local_alloc_bits(osb,
1165                                                         bits_wanted,
1166                                                         *ac);
1167                 if ((status < 0) && (status != -ENOSPC)) {
1168                         mlog_errno(status);
1169                         goto bail;
1170                 }
1171         }
1172
1173         if (status == -ENOSPC) {
1174 retry:
1175                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1176                 /* Retry if there is sufficient space cached in truncate log */
1177                 if (status == -ENOSPC && !retried) {
1178                         retried = 1;
1179                         ocfs2_inode_unlock((*ac)->ac_inode, 1);
1180                         inode_unlock((*ac)->ac_inode);
1181
1182                         ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
1183                         if (ret == 1) {
1184                                 iput((*ac)->ac_inode);
1185                                 (*ac)->ac_inode = NULL;
1186                                 goto retry;
1187                         }
1188
1189                         if (ret < 0)
1190                                 mlog_errno(ret);
1191
1192                         inode_lock((*ac)->ac_inode);
1193                         ret = ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
1194                         if (ret < 0) {
1195                                 mlog_errno(ret);
1196                                 inode_unlock((*ac)->ac_inode);
1197                                 iput((*ac)->ac_inode);
1198                                 (*ac)->ac_inode = NULL;
1199                                 goto bail;
1200                         }
1201                 }
1202                 if (status < 0) {
1203                         if (status != -ENOSPC)
1204                                 mlog_errno(status);
1205                         goto bail;
1206                 }
1207         }
1208
1209         status = 0;
1210 bail:
1211         if ((status < 0) && *ac) {
1212                 ocfs2_free_alloc_context(*ac);
1213                 *ac = NULL;
1214         }
1215
1216         if (status)
1217                 mlog_errno(status);
1218         return status;
1219 }
1220
1221 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1222                            u32 bits_wanted,
1223                            struct ocfs2_alloc_context **ac)
1224 {
1225         return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1226                                                  ALLOC_NEW_GROUP, ac);
1227 }
1228
1229 /*
1230  * More or less lifted from ext3. I'll leave their description below:
1231  *
1232  * "For ext3 allocations, we must not reuse any blocks which are
1233  * allocated in the bitmap buffer's "last committed data" copy.  This
1234  * prevents deletes from freeing up the page for reuse until we have
1235  * committed the delete transaction.
1236  *
1237  * If we didn't do this, then deleting something and reallocating it as
1238  * data would allow the old block to be overwritten before the
1239  * transaction committed (because we force data to disk before commit).
1240  * This would lead to corruption if we crashed between overwriting the
1241  * data and committing the delete.
1242  *
1243  * @@@ We may want to make this allocation behaviour conditional on
1244  * data-writes at some point, and disable it for metadata allocations or
1245  * sync-data inodes."
1246  *
1247  * Note: OCFS2 already does this differently for metadata vs data
1248  * allocations, as those bitmaps are separate and undo access is never
1249  * called on a metadata group descriptor.
1250  */
1251 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1252                                          int nr)
1253 {
1254         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1255         struct journal_head *jh;
1256         int ret;
1257
1258         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1259                 return 0;
1260
1261         if (!buffer_jbd(bg_bh))
1262                 return 1;
1263
1264         jh = bh2jh(bg_bh);
1265         spin_lock(&jh->b_state_lock);
1266         bg = (struct ocfs2_group_desc *) jh->b_committed_data;
1267         if (bg)
1268                 ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1269         else
1270                 ret = 1;
1271         spin_unlock(&jh->b_state_lock);
1272
1273         return ret;
1274 }
1275
1276 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1277                                              struct buffer_head *bg_bh,
1278                                              unsigned int bits_wanted,
1279                                              unsigned int total_bits,
1280                                              struct ocfs2_suballoc_result *res)
1281 {
1282         void *bitmap;
1283         u16 best_offset, best_size;
1284         int offset, start, found, status = 0;
1285         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1286
1287         /* Callers got this descriptor from
1288          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1289         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1290
1291         found = start = best_offset = best_size = 0;
1292         bitmap = bg->bg_bitmap;
1293
1294         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1295                 if (offset == total_bits)
1296                         break;
1297
1298                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1299                         /* We found a zero, but we can't use it as it
1300                          * hasn't been put to disk yet! */
1301                         found = 0;
1302                         start = offset + 1;
1303                 } else if (offset == start) {
1304                         /* we found a zero */
1305                         found++;
1306                         /* move start to the next bit to test */
1307                         start++;
1308                 } else {
1309                         /* got a zero after some ones */
1310                         found = 1;
1311                         start = offset + 1;
1312                 }
1313                 if (found > best_size) {
1314                         best_size = found;
1315                         best_offset = start - found;
1316                 }
1317                 /* we got everything we needed */
1318                 if (found == bits_wanted) {
1319                         /* mlog(0, "Found it all!\n"); */
1320                         break;
1321                 }
1322         }
1323
1324         if (best_size) {
1325                 res->sr_bit_offset = best_offset;
1326                 res->sr_bits = best_size;
1327         } else {
1328                 status = -ENOSPC;
1329                 /* No error log here -- see the comment above
1330                  * ocfs2_test_bg_bit_allocatable */
1331         }
1332
1333         return status;
1334 }
1335
1336 int ocfs2_block_group_set_bits(handle_t *handle,
1337                                              struct inode *alloc_inode,
1338                                              struct ocfs2_group_desc *bg,
1339                                              struct buffer_head *group_bh,
1340                                              unsigned int bit_off,
1341                                              unsigned int num_bits)
1342 {
1343         int status;
1344         void *bitmap = bg->bg_bitmap;
1345         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1346
1347         /* All callers get the descriptor via
1348          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1349         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1350         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1351
1352         trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1353
1354         if (ocfs2_is_cluster_bitmap(alloc_inode))
1355                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1356
1357         status = ocfs2_journal_access_gd(handle,
1358                                          INODE_CACHE(alloc_inode),
1359                                          group_bh,
1360                                          journal_type);
1361         if (status < 0) {
1362                 mlog_errno(status);
1363                 goto bail;
1364         }
1365
1366         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1367         if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1368                 return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1369                                    (unsigned long long)le64_to_cpu(bg->bg_blkno),
1370                                    le16_to_cpu(bg->bg_bits),
1371                                    le16_to_cpu(bg->bg_free_bits_count),
1372                                    num_bits);
1373         }
1374         while(num_bits--)
1375                 ocfs2_set_bit(bit_off++, bitmap);
1376
1377         ocfs2_journal_dirty(handle, group_bh);
1378
1379 bail:
1380         return status;
1381 }
1382
1383 /* find the one with the most empty bits */
1384 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1385 {
1386         u16 curr, best;
1387
1388         BUG_ON(!cl->cl_next_free_rec);
1389
1390         best = curr = 0;
1391         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1392                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1393                     le32_to_cpu(cl->cl_recs[best].c_free))
1394                         best = curr;
1395                 curr++;
1396         }
1397
1398         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1399         return best;
1400 }
1401
1402 static int ocfs2_relink_block_group(handle_t *handle,
1403                                     struct inode *alloc_inode,
1404                                     struct buffer_head *fe_bh,
1405                                     struct buffer_head *bg_bh,
1406                                     struct buffer_head *prev_bg_bh,
1407                                     u16 chain)
1408 {
1409         int status;
1410         /* there is a really tiny chance the journal calls could fail,
1411          * but we wouldn't want inconsistent blocks in *any* case. */
1412         u64 bg_ptr, prev_bg_ptr;
1413         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1414         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1415         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1416
1417         /* The caller got these descriptors from
1418          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1419         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1420         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1421
1422         trace_ocfs2_relink_block_group(
1423                 (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1424                 (unsigned long long)le64_to_cpu(bg->bg_blkno),
1425                 (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1426
1427         bg_ptr = le64_to_cpu(bg->bg_next_group);
1428         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1429
1430         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1431                                          prev_bg_bh,
1432                                          OCFS2_JOURNAL_ACCESS_WRITE);
1433         if (status < 0)
1434                 goto out;
1435
1436         prev_bg->bg_next_group = bg->bg_next_group;
1437         ocfs2_journal_dirty(handle, prev_bg_bh);
1438
1439         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1440                                          bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1441         if (status < 0)
1442                 goto out_rollback_prev_bg;
1443
1444         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1445         ocfs2_journal_dirty(handle, bg_bh);
1446
1447         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1448                                          fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1449         if (status < 0)
1450                 goto out_rollback_bg;
1451
1452         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1453         ocfs2_journal_dirty(handle, fe_bh);
1454
1455 out:
1456         if (status < 0)
1457                 mlog_errno(status);
1458         return status;
1459
1460 out_rollback_bg:
1461         bg->bg_next_group = cpu_to_le64(bg_ptr);
1462 out_rollback_prev_bg:
1463         prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1464         goto out;
1465 }
1466
1467 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1468                                                      u32 wanted)
1469 {
1470         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1471 }
1472
1473 /* return 0 on success, -ENOSPC to keep searching and any other < 0
1474  * value on error. */
1475 static int ocfs2_cluster_group_search(struct inode *inode,
1476                                       struct buffer_head *group_bh,
1477                                       u32 bits_wanted, u32 min_bits,
1478                                       u64 max_block,
1479                                       struct ocfs2_suballoc_result *res)
1480 {
1481         int search = -ENOSPC;
1482         int ret;
1483         u64 blkoff;
1484         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1485         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1486         unsigned int max_bits, gd_cluster_off;
1487
1488         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1489
1490         if (gd->bg_free_bits_count) {
1491                 max_bits = le16_to_cpu(gd->bg_bits);
1492
1493                 /* Tail groups in cluster bitmaps which aren't cpg
1494                  * aligned are prone to partial extension by a failed
1495                  * fs resize. If the file system resize never got to
1496                  * update the dinode cluster count, then we don't want
1497                  * to trust any clusters past it, regardless of what
1498                  * the group descriptor says. */
1499                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1500                                                           le64_to_cpu(gd->bg_blkno));
1501                 if ((gd_cluster_off + max_bits) >
1502                     OCFS2_I(inode)->ip_clusters) {
1503                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1504                         trace_ocfs2_cluster_group_search_wrong_max_bits(
1505                                 (unsigned long long)le64_to_cpu(gd->bg_blkno),
1506                                 le16_to_cpu(gd->bg_bits),
1507                                 OCFS2_I(inode)->ip_clusters, max_bits);
1508                 }
1509
1510                 ret = ocfs2_block_group_find_clear_bits(osb,
1511                                                         group_bh, bits_wanted,
1512                                                         max_bits, res);
1513                 if (ret)
1514                         return ret;
1515
1516                 if (max_block) {
1517                         blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1518                                                           gd_cluster_off +
1519                                                           res->sr_bit_offset +
1520                                                           res->sr_bits);
1521                         trace_ocfs2_cluster_group_search_max_block(
1522                                 (unsigned long long)blkoff,
1523                                 (unsigned long long)max_block);
1524                         if (blkoff > max_block)
1525                                 return -ENOSPC;
1526                 }
1527
1528                 /* ocfs2_block_group_find_clear_bits() might
1529                  * return success, but we still want to return
1530                  * -ENOSPC unless it found the minimum number
1531                  * of bits. */
1532                 if (min_bits <= res->sr_bits)
1533                         search = 0; /* success */
1534                 else if (res->sr_bits) {
1535                         /*
1536                          * Don't show bits which we'll be returning
1537                          * for allocation to the local alloc bitmap.
1538                          */
1539                         ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1540                 }
1541         }
1542
1543         return search;
1544 }
1545
1546 static int ocfs2_block_group_search(struct inode *inode,
1547                                     struct buffer_head *group_bh,
1548                                     u32 bits_wanted, u32 min_bits,
1549                                     u64 max_block,
1550                                     struct ocfs2_suballoc_result *res)
1551 {
1552         int ret = -ENOSPC;
1553         u64 blkoff;
1554         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1555
1556         BUG_ON(min_bits != 1);
1557         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1558
1559         if (bg->bg_free_bits_count) {
1560                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1561                                                         group_bh, bits_wanted,
1562                                                         le16_to_cpu(bg->bg_bits),
1563                                                         res);
1564                 if (!ret && max_block) {
1565                         blkoff = le64_to_cpu(bg->bg_blkno) +
1566                                 res->sr_bit_offset + res->sr_bits;
1567                         trace_ocfs2_block_group_search_max_block(
1568                                 (unsigned long long)blkoff,
1569                                 (unsigned long long)max_block);
1570                         if (blkoff > max_block)
1571                                 ret = -ENOSPC;
1572                 }
1573         }
1574
1575         return ret;
1576 }
1577
1578 int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1579                                        handle_t *handle,
1580                                        struct buffer_head *di_bh,
1581                                        u32 num_bits,
1582                                        u16 chain)
1583 {
1584         int ret;
1585         u32 tmp_used;
1586         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1587         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1588
1589         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1590                                       OCFS2_JOURNAL_ACCESS_WRITE);
1591         if (ret < 0) {
1592                 mlog_errno(ret);
1593                 goto out;
1594         }
1595
1596         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1597         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1598         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1599         ocfs2_journal_dirty(handle, di_bh);
1600
1601 out:
1602         return ret;
1603 }
1604
1605 void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1606                                        struct buffer_head *di_bh,
1607                                        u32 num_bits,
1608                                        u16 chain)
1609 {
1610         u32 tmp_used;
1611         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1612         struct ocfs2_chain_list *cl;
1613
1614         cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1615         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1616         di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1617         le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1618 }
1619
1620 static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1621                                          struct ocfs2_extent_rec *rec,
1622                                          struct ocfs2_chain_list *cl)
1623 {
1624         unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1625         unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1626         unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1627
1628         if (res->sr_bit_offset < bitoff)
1629                 return 0;
1630         if (res->sr_bit_offset >= (bitoff + bitcount))
1631                 return 0;
1632         res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1633                 (res->sr_bit_offset - bitoff);
1634         if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1635                 res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1636         return 1;
1637 }
1638
1639 static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1640                                           struct ocfs2_group_desc *bg,
1641                                           struct ocfs2_suballoc_result *res)
1642 {
1643         int i;
1644         u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1645         struct ocfs2_extent_rec *rec;
1646         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1647         struct ocfs2_chain_list *cl = &di->id2.i_chain;
1648
1649         if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1650                 res->sr_blkno = 0;
1651                 return;
1652         }
1653
1654         res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1655         res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1656         if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1657             !bg->bg_list.l_next_free_rec)
1658                 return;
1659
1660         for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1661                 rec = &bg->bg_list.l_recs[i];
1662                 if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1663                         res->sr_bg_blkno = bg_blkno;  /* Restore */
1664                         break;
1665                 }
1666         }
1667 }
1668
1669 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1670                                   handle_t *handle,
1671                                   u32 bits_wanted,
1672                                   u32 min_bits,
1673                                   struct ocfs2_suballoc_result *res,
1674                                   u16 *bits_left)
1675 {
1676         int ret;
1677         struct buffer_head *group_bh = NULL;
1678         struct ocfs2_group_desc *gd;
1679         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1680         struct inode *alloc_inode = ac->ac_inode;
1681
1682         ret = ocfs2_read_group_descriptor(alloc_inode, di,
1683                                           res->sr_bg_blkno, &group_bh);
1684         if (ret < 0) {
1685                 mlog_errno(ret);
1686                 return ret;
1687         }
1688
1689         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1690         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1691                                   ac->ac_max_block, res);
1692         if (ret < 0) {
1693                 if (ret != -ENOSPC)
1694                         mlog_errno(ret);
1695                 goto out;
1696         }
1697
1698         if (!ret)
1699                 ocfs2_bg_discontig_fix_result(ac, gd, res);
1700
1701         /*
1702          * sr_bg_blkno might have been changed by
1703          * ocfs2_bg_discontig_fix_result
1704          */
1705         res->sr_bg_stable_blkno = group_bh->b_blocknr;
1706
1707         if (ac->ac_find_loc_only)
1708                 goto out_loc_only;
1709
1710         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1711                                                res->sr_bits,
1712                                                le16_to_cpu(gd->bg_chain));
1713         if (ret < 0) {
1714                 mlog_errno(ret);
1715                 goto out;
1716         }
1717
1718         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1719                                          res->sr_bit_offset, res->sr_bits);
1720         if (ret < 0) {
1721                 ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1722                                                res->sr_bits,
1723                                                le16_to_cpu(gd->bg_chain));
1724                 mlog_errno(ret);
1725         }
1726
1727 out_loc_only:
1728         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1729
1730 out:
1731         brelse(group_bh);
1732
1733         return ret;
1734 }
1735
1736 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1737                               handle_t *handle,
1738                               u32 bits_wanted,
1739                               u32 min_bits,
1740                               struct ocfs2_suballoc_result *res,
1741                               u16 *bits_left)
1742 {
1743         int status;
1744         u16 chain;
1745         u64 next_group;
1746         struct inode *alloc_inode = ac->ac_inode;
1747         struct buffer_head *group_bh = NULL;
1748         struct buffer_head *prev_group_bh = NULL;
1749         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1750         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1751         struct ocfs2_group_desc *bg;
1752
1753         chain = ac->ac_chain;
1754         trace_ocfs2_search_chain_begin(
1755                 (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1756                 bits_wanted, chain);
1757
1758         status = ocfs2_read_group_descriptor(alloc_inode, fe,
1759                                              le64_to_cpu(cl->cl_recs[chain].c_blkno),
1760                                              &group_bh);
1761         if (status < 0) {
1762                 mlog_errno(status);
1763                 goto bail;
1764         }
1765         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1766
1767         status = -ENOSPC;
1768         /* for now, the chain search is a bit simplistic. We just use
1769          * the 1st group with any empty bits. */
1770         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1771                                              bits_wanted, min_bits,
1772                                              ac->ac_max_block,
1773                                              res)) == -ENOSPC) {
1774                 if (!bg->bg_next_group)
1775                         break;
1776
1777                 brelse(prev_group_bh);
1778                 prev_group_bh = NULL;
1779
1780                 next_group = le64_to_cpu(bg->bg_next_group);
1781                 prev_group_bh = group_bh;
1782                 group_bh = NULL;
1783                 status = ocfs2_read_group_descriptor(alloc_inode, fe,
1784                                                      next_group, &group_bh);
1785                 if (status < 0) {
1786                         mlog_errno(status);
1787                         goto bail;
1788                 }
1789                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1790         }
1791         if (status < 0) {
1792                 if (status != -ENOSPC)
1793                         mlog_errno(status);
1794                 goto bail;
1795         }
1796
1797         trace_ocfs2_search_chain_succ(
1798                 (unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1799
1800         res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1801
1802         BUG_ON(res->sr_bits == 0);
1803         if (!status)
1804                 ocfs2_bg_discontig_fix_result(ac, bg, res);
1805
1806         /*
1807          * sr_bg_blkno might have been changed by
1808          * ocfs2_bg_discontig_fix_result
1809          */
1810         res->sr_bg_stable_blkno = group_bh->b_blocknr;
1811
1812         /*
1813          * Keep track of previous block descriptor read. When
1814          * we find a target, if we have read more than X
1815          * number of descriptors, and the target is reasonably
1816          * empty, relink him to top of his chain.
1817          *
1818          * We've read 0 extra blocks and only send one more to
1819          * the transaction, yet the next guy to search has a
1820          * much easier time.
1821          *
1822          * Do this *after* figuring out how many bits we're taking out
1823          * of our target group.
1824          */
1825         if (!ac->ac_disable_chain_relink &&
1826             (prev_group_bh) &&
1827             (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1828                 status = ocfs2_relink_block_group(handle, alloc_inode,
1829                                                   ac->ac_bh, group_bh,
1830                                                   prev_group_bh, chain);
1831                 if (status < 0) {
1832                         mlog_errno(status);
1833                         goto bail;
1834                 }
1835         }
1836
1837         if (ac->ac_find_loc_only)
1838                 goto out_loc_only;
1839
1840         status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1841                                                   ac->ac_bh, res->sr_bits,
1842                                                   chain);
1843         if (status) {
1844                 mlog_errno(status);
1845                 goto bail;
1846         }
1847
1848         status = ocfs2_block_group_set_bits(handle,
1849                                             alloc_inode,
1850                                             bg,
1851                                             group_bh,
1852                                             res->sr_bit_offset,
1853                                             res->sr_bits);
1854         if (status < 0) {
1855                 ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1856                                         ac->ac_bh, res->sr_bits, chain);
1857                 mlog_errno(status);
1858                 goto bail;
1859         }
1860
1861         trace_ocfs2_search_chain_end(
1862                         (unsigned long long)le64_to_cpu(fe->i_blkno),
1863                         res->sr_bits);
1864
1865 out_loc_only:
1866         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1867 bail:
1868         brelse(group_bh);
1869         brelse(prev_group_bh);
1870
1871         if (status)
1872                 mlog_errno(status);
1873         return status;
1874 }
1875
1876 /* will give out up to bits_wanted contiguous bits. */
1877 static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1878                                      handle_t *handle,
1879                                      u32 bits_wanted,
1880                                      u32 min_bits,
1881                                      struct ocfs2_suballoc_result *res)
1882 {
1883         int status;
1884         u16 victim, i;
1885         u16 bits_left = 0;
1886         u64 hint = ac->ac_last_group;
1887         struct ocfs2_chain_list *cl;
1888         struct ocfs2_dinode *fe;
1889
1890         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1891         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1892         BUG_ON(!ac->ac_bh);
1893
1894         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1895
1896         /* The bh was validated by the inode read during
1897          * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1898         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1899
1900         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1901             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1902                 status = ocfs2_error(ac->ac_inode->i_sb,
1903                                      "Chain allocator dinode %llu has %u used bits but only %u total\n",
1904                                      (unsigned long long)le64_to_cpu(fe->i_blkno),
1905                                      le32_to_cpu(fe->id1.bitmap1.i_used),
1906                                      le32_to_cpu(fe->id1.bitmap1.i_total));
1907                 goto bail;
1908         }
1909
1910         res->sr_bg_blkno = hint;
1911         if (res->sr_bg_blkno) {
1912                 /* Attempt to short-circuit the usual search mechanism
1913                  * by jumping straight to the most recently used
1914                  * allocation group. This helps us maintain some
1915                  * contiguousness across allocations. */
1916                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1917                                                 min_bits, res, &bits_left);
1918                 if (!status)
1919                         goto set_hint;
1920                 if (status < 0 && status != -ENOSPC) {
1921                         mlog_errno(status);
1922                         goto bail;
1923                 }
1924         }
1925
1926         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1927
1928         victim = ocfs2_find_victim_chain(cl);
1929         ac->ac_chain = victim;
1930
1931         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1932                                     res, &bits_left);
1933         if (!status) {
1934                 if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1935                         hint = res->sr_bg_blkno;
1936                 else
1937                         hint = ocfs2_group_from_res(res);
1938                 goto set_hint;
1939         }
1940         if (status < 0 && status != -ENOSPC) {
1941                 mlog_errno(status);
1942                 goto bail;
1943         }
1944
1945         trace_ocfs2_claim_suballoc_bits(victim);
1946
1947         /* If we didn't pick a good victim, then just default to
1948          * searching each chain in order. Don't allow chain relinking
1949          * because we only calculate enough journal credits for one
1950          * relink per alloc. */
1951         ac->ac_disable_chain_relink = 1;
1952         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1953                 if (i == victim)
1954                         continue;
1955                 if (!cl->cl_recs[i].c_free)
1956                         continue;
1957
1958                 ac->ac_chain = i;
1959                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1960                                             res, &bits_left);
1961                 if (!status) {
1962                         hint = ocfs2_group_from_res(res);
1963                         break;
1964                 }
1965                 if (status < 0 && status != -ENOSPC) {
1966                         mlog_errno(status);
1967                         goto bail;
1968                 }
1969         }
1970
1971 set_hint:
1972         if (status != -ENOSPC) {
1973                 /* If the next search of this group is not likely to
1974                  * yield a suitable extent, then we reset the last
1975                  * group hint so as to not waste a disk read */
1976                 if (bits_left < min_bits)
1977                         ac->ac_last_group = 0;
1978                 else
1979                         ac->ac_last_group = hint;
1980         }
1981
1982 bail:
1983         if (status)
1984                 mlog_errno(status);
1985         return status;
1986 }
1987
1988 int ocfs2_claim_metadata(handle_t *handle,
1989                          struct ocfs2_alloc_context *ac,
1990                          u32 bits_wanted,
1991                          u64 *suballoc_loc,
1992                          u16 *suballoc_bit_start,
1993                          unsigned int *num_bits,
1994                          u64 *blkno_start)
1995 {
1996         int status;
1997         struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
1998
1999         BUG_ON(!ac);
2000         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2001         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2002
2003         status = ocfs2_claim_suballoc_bits(ac,
2004                                            handle,
2005                                            bits_wanted,
2006                                            1,
2007                                            &res);
2008         if (status < 0) {
2009                 mlog_errno(status);
2010                 goto bail;
2011         }
2012         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2013
2014         *suballoc_loc = res.sr_bg_blkno;
2015         *suballoc_bit_start = res.sr_bit_offset;
2016         *blkno_start = res.sr_blkno;
2017         ac->ac_bits_given += res.sr_bits;
2018         *num_bits = res.sr_bits;
2019         status = 0;
2020 bail:
2021         if (status)
2022                 mlog_errno(status);
2023         return status;
2024 }
2025
2026 static void ocfs2_init_inode_ac_group(struct inode *dir,
2027                                       struct buffer_head *parent_di_bh,
2028                                       struct ocfs2_alloc_context *ac)
2029 {
2030         struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2031         /*
2032          * Try to allocate inodes from some specific group.
2033          *
2034          * If the parent dir has recorded the last group used in allocation,
2035          * cool, use it. Otherwise if we try to allocate new inode from the
2036          * same slot the parent dir belongs to, use the same chunk.
2037          *
2038          * We are very careful here to avoid the mistake of setting
2039          * ac_last_group to a group descriptor from a different (unlocked) slot.
2040          */
2041         if (OCFS2_I(dir)->ip_last_used_group &&
2042             OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2043                 ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2044         else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2045                 if (di->i_suballoc_loc)
2046                         ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2047                 else
2048                         ac->ac_last_group = ocfs2_which_suballoc_group(
2049                                         le64_to_cpu(di->i_blkno),
2050                                         le16_to_cpu(di->i_suballoc_bit));
2051         }
2052 }
2053
2054 static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2055                                              struct ocfs2_alloc_context *ac)
2056 {
2057         OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2058         OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2059 }
2060
2061 int ocfs2_find_new_inode_loc(struct inode *dir,
2062                              struct buffer_head *parent_fe_bh,
2063                              struct ocfs2_alloc_context *ac,
2064                              u64 *fe_blkno)
2065 {
2066         int ret;
2067         handle_t *handle = NULL;
2068         struct ocfs2_suballoc_result *res;
2069
2070         BUG_ON(!ac);
2071         BUG_ON(ac->ac_bits_given != 0);
2072         BUG_ON(ac->ac_bits_wanted != 1);
2073         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2074
2075         res = kzalloc(sizeof(*res), GFP_NOFS);
2076         if (res == NULL) {
2077                 ret = -ENOMEM;
2078                 mlog_errno(ret);
2079                 goto out;
2080         }
2081
2082         ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2083
2084         /*
2085          * The handle started here is for chain relink. Alternatively,
2086          * we could just disable relink for these calls.
2087          */
2088         handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2089         if (IS_ERR(handle)) {
2090                 ret = PTR_ERR(handle);
2091                 handle = NULL;
2092                 mlog_errno(ret);
2093                 goto out;
2094         }
2095
2096         /*
2097          * This will instruct ocfs2_claim_suballoc_bits and
2098          * ocfs2_search_one_group to search but save actual allocation
2099          * for later.
2100          */
2101         ac->ac_find_loc_only = 1;
2102
2103         ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2104         if (ret < 0) {
2105                 mlog_errno(ret);
2106                 goto out;
2107         }
2108
2109         ac->ac_find_loc_priv = res;
2110         *fe_blkno = res->sr_blkno;
2111         ocfs2_update_inode_fsync_trans(handle, dir, 0);
2112 out:
2113         if (handle)
2114                 ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2115
2116         if (ret)
2117                 kfree(res);
2118
2119         return ret;
2120 }
2121
2122 int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2123                                  struct inode *dir,
2124                                  struct ocfs2_alloc_context *ac,
2125                                  u64 *suballoc_loc,
2126                                  u16 *suballoc_bit,
2127                                  u64 di_blkno)
2128 {
2129         int ret;
2130         u16 chain;
2131         struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2132         struct buffer_head *bg_bh = NULL;
2133         struct ocfs2_group_desc *bg;
2134         struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2135
2136         /*
2137          * Since di_blkno is being passed back in, we check for any
2138          * inconsistencies which may have happened between
2139          * calls. These are code bugs as di_blkno is not expected to
2140          * change once returned from ocfs2_find_new_inode_loc()
2141          */
2142         BUG_ON(res->sr_blkno != di_blkno);
2143
2144         ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2145                                           res->sr_bg_stable_blkno, &bg_bh);
2146         if (ret) {
2147                 mlog_errno(ret);
2148                 goto out;
2149         }
2150
2151         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2152         chain = le16_to_cpu(bg->bg_chain);
2153
2154         ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2155                                                ac->ac_bh, res->sr_bits,
2156                                                chain);
2157         if (ret) {
2158                 mlog_errno(ret);
2159                 goto out;
2160         }
2161
2162         ret = ocfs2_block_group_set_bits(handle,
2163                                          ac->ac_inode,
2164                                          bg,
2165                                          bg_bh,
2166                                          res->sr_bit_offset,
2167                                          res->sr_bits);
2168         if (ret < 0) {
2169                 ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2170                                                ac->ac_bh, res->sr_bits, chain);
2171                 mlog_errno(ret);
2172                 goto out;
2173         }
2174
2175         trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2176                                            res->sr_bits);
2177
2178         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2179
2180         BUG_ON(res->sr_bits != 1);
2181
2182         *suballoc_loc = res->sr_bg_blkno;
2183         *suballoc_bit = res->sr_bit_offset;
2184         ac->ac_bits_given++;
2185         ocfs2_save_inode_ac_group(dir, ac);
2186
2187 out:
2188         brelse(bg_bh);
2189
2190         return ret;
2191 }
2192
2193 int ocfs2_claim_new_inode(handle_t *handle,
2194                           struct inode *dir,
2195                           struct buffer_head *parent_fe_bh,
2196                           struct ocfs2_alloc_context *ac,
2197                           u64 *suballoc_loc,
2198                           u16 *suballoc_bit,
2199                           u64 *fe_blkno)
2200 {
2201         int status;
2202         struct ocfs2_suballoc_result res;
2203
2204         BUG_ON(!ac);
2205         BUG_ON(ac->ac_bits_given != 0);
2206         BUG_ON(ac->ac_bits_wanted != 1);
2207         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2208
2209         ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2210
2211         status = ocfs2_claim_suballoc_bits(ac,
2212                                            handle,
2213                                            1,
2214                                            1,
2215                                            &res);
2216         if (status < 0) {
2217                 mlog_errno(status);
2218                 goto bail;
2219         }
2220         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2221
2222         BUG_ON(res.sr_bits != 1);
2223
2224         *suballoc_loc = res.sr_bg_blkno;
2225         *suballoc_bit = res.sr_bit_offset;
2226         *fe_blkno = res.sr_blkno;
2227         ac->ac_bits_given++;
2228         ocfs2_save_inode_ac_group(dir, ac);
2229         status = 0;
2230 bail:
2231         if (status)
2232                 mlog_errno(status);
2233         return status;
2234 }
2235
2236 /* translate a group desc. blkno and it's bitmap offset into
2237  * disk cluster offset. */
2238 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2239                                                    u64 bg_blkno,
2240                                                    u16 bg_bit_off)
2241 {
2242         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2243         u32 cluster = 0;
2244
2245         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2246
2247         if (bg_blkno != osb->first_cluster_group_blkno)
2248                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2249         cluster += (u32) bg_bit_off;
2250         return cluster;
2251 }
2252
2253 /* given a cluster offset, calculate which block group it belongs to
2254  * and return that block offset. */
2255 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2256 {
2257         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2258         u32 group_no;
2259
2260         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2261
2262         group_no = cluster / osb->bitmap_cpg;
2263         if (!group_no)
2264                 return osb->first_cluster_group_blkno;
2265         return ocfs2_clusters_to_blocks(inode->i_sb,
2266                                         group_no * osb->bitmap_cpg);
2267 }
2268
2269 /* given the block number of a cluster start, calculate which cluster
2270  * group and descriptor bitmap offset that corresponds to. */
2271 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2272                                                 u64 data_blkno,
2273                                                 u64 *bg_blkno,
2274                                                 u16 *bg_bit_off)
2275 {
2276         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2277         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2278
2279         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2280
2281         *bg_blkno = ocfs2_which_cluster_group(inode,
2282                                               data_cluster);
2283
2284         if (*bg_blkno == osb->first_cluster_group_blkno)
2285                 *bg_bit_off = (u16) data_cluster;
2286         else
2287                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2288                                                              data_blkno - *bg_blkno);
2289 }
2290
2291 /*
2292  * min_bits - minimum contiguous chunk from this total allocation we
2293  * can handle. set to what we asked for originally for a full
2294  * contig. allocation, set to '1' to indicate we can deal with extents
2295  * of any size.
2296  */
2297 int __ocfs2_claim_clusters(handle_t *handle,
2298                            struct ocfs2_alloc_context *ac,
2299                            u32 min_clusters,
2300                            u32 max_clusters,
2301                            u32 *cluster_start,
2302                            u32 *num_clusters)
2303 {
2304         int status;
2305         unsigned int bits_wanted = max_clusters;
2306         struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2307         struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2308
2309         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2310
2311         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2312                && ac->ac_which != OCFS2_AC_USE_MAIN);
2313
2314         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2315                 WARN_ON(min_clusters > 1);
2316
2317                 status = ocfs2_claim_local_alloc_bits(osb,
2318                                                       handle,
2319                                                       ac,
2320                                                       bits_wanted,
2321                                                       cluster_start,
2322                                                       num_clusters);
2323                 if (!status)
2324                         atomic_inc(&osb->alloc_stats.local_data);
2325         } else {
2326                 if (min_clusters > (osb->bitmap_cpg - 1)) {
2327                         /* The only paths asking for contiguousness
2328                          * should know about this already. */
2329                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2330                              "group bitmap size %u!\n", min_clusters,
2331                              osb->bitmap_cpg);
2332                         status = -ENOSPC;
2333                         goto bail;
2334                 }
2335                 /* clamp the current request down to a realistic size. */
2336                 if (bits_wanted > (osb->bitmap_cpg - 1))
2337                         bits_wanted = osb->bitmap_cpg - 1;
2338
2339                 status = ocfs2_claim_suballoc_bits(ac,
2340                                                    handle,
2341                                                    bits_wanted,
2342                                                    min_clusters,
2343                                                    &res);
2344                 if (!status) {
2345                         BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2346                         *cluster_start =
2347                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2348                                                                  res.sr_bg_blkno,
2349                                                                  res.sr_bit_offset);
2350                         atomic_inc(&osb->alloc_stats.bitmap_data);
2351                         *num_clusters = res.sr_bits;
2352                 }
2353         }
2354         if (status < 0) {
2355                 if (status != -ENOSPC)
2356                         mlog_errno(status);
2357                 goto bail;
2358         }
2359
2360         ac->ac_bits_given += *num_clusters;
2361
2362 bail:
2363         if (status)
2364                 mlog_errno(status);
2365         return status;
2366 }
2367
2368 int ocfs2_claim_clusters(handle_t *handle,
2369                          struct ocfs2_alloc_context *ac,
2370                          u32 min_clusters,
2371                          u32 *cluster_start,
2372                          u32 *num_clusters)
2373 {
2374         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2375
2376         return __ocfs2_claim_clusters(handle, ac, min_clusters,
2377                                       bits_wanted, cluster_start, num_clusters);
2378 }
2379
2380 static int ocfs2_block_group_clear_bits(handle_t *handle,
2381                                         struct inode *alloc_inode,
2382                                         struct ocfs2_group_desc *bg,
2383                                         struct buffer_head *group_bh,
2384                                         unsigned int bit_off,
2385                                         unsigned int num_bits,
2386                                         void (*undo_fn)(unsigned int bit,
2387                                                         unsigned long *bmap))
2388 {
2389         int status;
2390         unsigned int tmp;
2391         struct ocfs2_group_desc *undo_bg = NULL;
2392         struct journal_head *jh;
2393
2394         /* The caller got this descriptor from
2395          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2396         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2397
2398         trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2399
2400         BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2401         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2402                                          group_bh,
2403                                          undo_fn ?
2404                                          OCFS2_JOURNAL_ACCESS_UNDO :
2405                                          OCFS2_JOURNAL_ACCESS_WRITE);
2406         if (status < 0) {
2407                 mlog_errno(status);
2408                 goto bail;
2409         }
2410
2411         jh = bh2jh(group_bh);
2412         if (undo_fn) {
2413                 spin_lock(&jh->b_state_lock);
2414                 undo_bg = (struct ocfs2_group_desc *) jh->b_committed_data;
2415                 BUG_ON(!undo_bg);
2416         }
2417
2418         tmp = num_bits;
2419         while(tmp--) {
2420                 ocfs2_clear_bit((bit_off + tmp),
2421                                 (unsigned long *) bg->bg_bitmap);
2422                 if (undo_fn)
2423                         undo_fn(bit_off + tmp,
2424                                 (unsigned long *) undo_bg->bg_bitmap);
2425         }
2426         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2427         if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2428                 if (undo_fn)
2429                         spin_unlock(&jh->b_state_lock);
2430                 return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
2431                                    (unsigned long long)le64_to_cpu(bg->bg_blkno),
2432                                    le16_to_cpu(bg->bg_bits),
2433                                    le16_to_cpu(bg->bg_free_bits_count),
2434                                    num_bits);
2435         }
2436
2437         if (undo_fn)
2438                 spin_unlock(&jh->b_state_lock);
2439
2440         ocfs2_journal_dirty(handle, group_bh);
2441 bail:
2442         return status;
2443 }
2444
2445 /*
2446  * expects the suballoc inode to already be locked.
2447  */
2448 static int _ocfs2_free_suballoc_bits(handle_t *handle,
2449                                      struct inode *alloc_inode,
2450                                      struct buffer_head *alloc_bh,
2451                                      unsigned int start_bit,
2452                                      u64 bg_blkno,
2453                                      unsigned int count,
2454                                      void (*undo_fn)(unsigned int bit,
2455                                                      unsigned long *bitmap))
2456 {
2457         int status = 0;
2458         u32 tmp_used;
2459         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2460         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2461         struct buffer_head *group_bh = NULL;
2462         struct ocfs2_group_desc *group;
2463
2464         /* The alloc_bh comes from ocfs2_free_dinode() or
2465          * ocfs2_free_clusters().  The callers have all locked the
2466          * allocator and gotten alloc_bh from the lock call.  This
2467          * validates the dinode buffer.  Any corruption that has happened
2468          * is a code bug. */
2469         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2470         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2471
2472         trace_ocfs2_free_suballoc_bits(
2473                 (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2474                 (unsigned long long)bg_blkno,
2475                 start_bit, count);
2476
2477         status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2478                                              &group_bh);
2479         if (status < 0) {
2480                 mlog_errno(status);
2481                 goto bail;
2482         }
2483         group = (struct ocfs2_group_desc *) group_bh->b_data;
2484
2485         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2486
2487         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2488                                               group, group_bh,
2489                                               start_bit, count, undo_fn);
2490         if (status < 0) {
2491                 mlog_errno(status);
2492                 goto bail;
2493         }
2494
2495         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2496                                          alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2497         if (status < 0) {
2498                 mlog_errno(status);
2499                 ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2500                                 start_bit, count);
2501                 goto bail;
2502         }
2503
2504         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2505                      count);
2506         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2507         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2508         ocfs2_journal_dirty(handle, alloc_bh);
2509
2510 bail:
2511         brelse(group_bh);
2512         return status;
2513 }
2514
2515 int ocfs2_free_suballoc_bits(handle_t *handle,
2516                              struct inode *alloc_inode,
2517                              struct buffer_head *alloc_bh,
2518                              unsigned int start_bit,
2519                              u64 bg_blkno,
2520                              unsigned int count)
2521 {
2522         return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2523                                          start_bit, bg_blkno, count, NULL);
2524 }
2525
2526 int ocfs2_free_dinode(handle_t *handle,
2527                       struct inode *inode_alloc_inode,
2528                       struct buffer_head *inode_alloc_bh,
2529                       struct ocfs2_dinode *di)
2530 {
2531         u64 blk = le64_to_cpu(di->i_blkno);
2532         u16 bit = le16_to_cpu(di->i_suballoc_bit);
2533         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2534
2535         if (di->i_suballoc_loc)
2536                 bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2537         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2538                                         inode_alloc_bh, bit, bg_blkno, 1);
2539 }
2540
2541 static int _ocfs2_free_clusters(handle_t *handle,
2542                                 struct inode *bitmap_inode,
2543                                 struct buffer_head *bitmap_bh,
2544                                 u64 start_blk,
2545                                 unsigned int num_clusters,
2546                                 void (*undo_fn)(unsigned int bit,
2547                                                 unsigned long *bitmap))
2548 {
2549         int status;
2550         u16 bg_start_bit;
2551         u64 bg_blkno;
2552
2553         /* You can't ever have a contiguous set of clusters
2554          * bigger than a block group bitmap so we never have to worry
2555          * about looping on them.
2556          * This is expensive. We can safely remove once this stuff has
2557          * gotten tested really well. */
2558         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb,
2559                                 ocfs2_blocks_to_clusters(bitmap_inode->i_sb,
2560                                                          start_blk)));
2561
2562
2563         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2564                                      &bg_start_bit);
2565
2566         trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2567                         (unsigned long long)start_blk,
2568                         bg_start_bit, num_clusters);
2569
2570         status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2571                                            bg_start_bit, bg_blkno,
2572                                            num_clusters, undo_fn);
2573         if (status < 0) {
2574                 mlog_errno(status);
2575                 goto out;
2576         }
2577
2578         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2579                                          num_clusters);
2580
2581 out:
2582         return status;
2583 }
2584
2585 int ocfs2_free_clusters(handle_t *handle,
2586                         struct inode *bitmap_inode,
2587                         struct buffer_head *bitmap_bh,
2588                         u64 start_blk,
2589                         unsigned int num_clusters)
2590 {
2591         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2592                                     start_blk, num_clusters,
2593                                     _ocfs2_set_bit);
2594 }
2595
2596 /*
2597  * Give never-used clusters back to the global bitmap.  We don't need
2598  * to protect these bits in the undo buffer.
2599  */
2600 int ocfs2_release_clusters(handle_t *handle,
2601                            struct inode *bitmap_inode,
2602                            struct buffer_head *bitmap_bh,
2603                            u64 start_blk,
2604                            unsigned int num_clusters)
2605 {
2606         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2607                                     start_blk, num_clusters,
2608                                     _ocfs2_clear_bit);
2609 }
2610
2611 /*
2612  * For a given allocation, determine which allocators will need to be
2613  * accessed, and lock them, reserving the appropriate number of bits.
2614  *
2615  * Sparse file systems call this from ocfs2_write_begin_nolock()
2616  * and ocfs2_allocate_unwritten_extents().
2617  *
2618  * File systems which don't support holes call this from
2619  * ocfs2_extend_allocation().
2620  */
2621 int ocfs2_lock_allocators(struct inode *inode,
2622                           struct ocfs2_extent_tree *et,
2623                           u32 clusters_to_add, u32 extents_to_split,
2624                           struct ocfs2_alloc_context **data_ac,
2625                           struct ocfs2_alloc_context **meta_ac)
2626 {
2627         int ret = 0, num_free_extents;
2628         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2629         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2630
2631         *meta_ac = NULL;
2632         if (data_ac)
2633                 *data_ac = NULL;
2634
2635         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2636
2637         num_free_extents = ocfs2_num_free_extents(et);
2638         if (num_free_extents < 0) {
2639                 ret = num_free_extents;
2640                 mlog_errno(ret);
2641                 goto out;
2642         }
2643
2644         /*
2645          * Sparse allocation file systems need to be more conservative
2646          * with reserving room for expansion - the actual allocation
2647          * happens while we've got a journal handle open so re-taking
2648          * a cluster lock (because we ran out of room for another
2649          * extent) will violate ordering rules.
2650          *
2651          * Most of the time we'll only be seeing this 1 cluster at a time
2652          * anyway.
2653          *
2654          * Always lock for any unwritten extents - we might want to
2655          * add blocks during a split.
2656          */
2657         if (!num_free_extents ||
2658             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2659                 ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2660                 if (ret < 0) {
2661                         if (ret != -ENOSPC)
2662                                 mlog_errno(ret);
2663                         goto out;
2664                 }
2665         }
2666
2667         if (clusters_to_add == 0)
2668                 goto out;
2669
2670         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2671         if (ret < 0) {
2672                 if (ret != -ENOSPC)
2673                         mlog_errno(ret);
2674                 goto out;
2675         }
2676
2677 out:
2678         if (ret) {
2679                 if (*meta_ac) {
2680                         ocfs2_free_alloc_context(*meta_ac);
2681                         *meta_ac = NULL;
2682                 }
2683
2684                 /*
2685                  * We cannot have an error and a non null *data_ac.
2686                  */
2687         }
2688
2689         return ret;
2690 }
2691
2692 /*
2693  * Read the inode specified by blkno to get suballoc_slot and
2694  * suballoc_bit.
2695  */
2696 static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2697                                        u16 *suballoc_slot, u64 *group_blkno,
2698                                        u16 *suballoc_bit)
2699 {
2700         int status;
2701         struct buffer_head *inode_bh = NULL;
2702         struct ocfs2_dinode *inode_fe;
2703
2704         trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2705
2706         /* dirty read disk */
2707         status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2708         if (status < 0) {
2709                 mlog(ML_ERROR, "read block %llu failed %d\n",
2710                      (unsigned long long)blkno, status);
2711                 goto bail;
2712         }
2713
2714         inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2715         if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2716                 mlog(ML_ERROR, "invalid inode %llu requested\n",
2717                      (unsigned long long)blkno);
2718                 status = -EINVAL;
2719                 goto bail;
2720         }
2721
2722         if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2723             (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2724                 mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2725                      (unsigned long long)blkno,
2726                      (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2727                 status = -EINVAL;
2728                 goto bail;
2729         }
2730
2731         if (suballoc_slot)
2732                 *suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2733         if (suballoc_bit)
2734                 *suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2735         if (group_blkno)
2736                 *group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2737
2738 bail:
2739         brelse(inode_bh);
2740
2741         if (status)
2742                 mlog_errno(status);
2743         return status;
2744 }
2745
2746 /*
2747  * test whether bit is SET in allocator bitmap or not.  on success, 0
2748  * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2749  * is returned and *res is meaningless.  Call this after you have
2750  * cluster locked against suballoc, or you may get a result based on
2751  * non-up2date contents
2752  */
2753 static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2754                                    struct inode *suballoc,
2755                                    struct buffer_head *alloc_bh,
2756                                    u64 group_blkno, u64 blkno,
2757                                    u16 bit, int *res)
2758 {
2759         struct ocfs2_dinode *alloc_di;
2760         struct ocfs2_group_desc *group;
2761         struct buffer_head *group_bh = NULL;
2762         u64 bg_blkno;
2763         int status;
2764
2765         trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2766                                       (unsigned int)bit);
2767
2768         alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2769         if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2770                 mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2771                      (unsigned int)bit,
2772                      ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2773                 status = -EINVAL;
2774                 goto bail;
2775         }
2776
2777         bg_blkno = group_blkno ? group_blkno :
2778                    ocfs2_which_suballoc_group(blkno, bit);
2779         status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2780                                              &group_bh);
2781         if (status < 0) {
2782                 mlog(ML_ERROR, "read group %llu failed %d\n",
2783                      (unsigned long long)bg_blkno, status);
2784                 goto bail;
2785         }
2786
2787         group = (struct ocfs2_group_desc *) group_bh->b_data;
2788         *res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2789
2790 bail:
2791         brelse(group_bh);
2792
2793         if (status)
2794                 mlog_errno(status);
2795         return status;
2796 }
2797
2798 /*
2799  * Test if the bit representing this inode (blkno) is set in the
2800  * suballocator.
2801  *
2802  * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2803  *
2804  * In the event of failure, a negative value is returned and *res is
2805  * meaningless.
2806  *
2807  * Callers must make sure to hold nfs_sync_lock to prevent
2808  * ocfs2_delete_inode() on another node from accessing the same
2809  * suballocator concurrently.
2810  */
2811 int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2812 {
2813         int status;
2814         u64 group_blkno = 0;
2815         u16 suballoc_bit = 0, suballoc_slot = 0;
2816         struct inode *inode_alloc_inode;
2817         struct buffer_head *alloc_bh = NULL;
2818
2819         trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2820
2821         status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2822                                              &group_blkno, &suballoc_bit);
2823         if (status < 0) {
2824                 mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2825                 goto bail;
2826         }
2827
2828         if (suballoc_slot == (u16)OCFS2_INVALID_SLOT)
2829                 inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2830                         GLOBAL_INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2831         else
2832                 inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2833                         INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2834         if (!inode_alloc_inode) {
2835                 /* the error code could be inaccurate, but we are not able to
2836                  * get the correct one. */
2837                 status = -EINVAL;
2838                 mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2839                      (u32)suballoc_slot);
2840                 goto bail;
2841         }
2842
2843         inode_lock(inode_alloc_inode);
2844         status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2845         if (status < 0) {
2846                 inode_unlock(inode_alloc_inode);
2847                 iput(inode_alloc_inode);
2848                 mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2849                      (u32)suballoc_slot, status);
2850                 goto bail;
2851         }
2852
2853         status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2854                                          group_blkno, blkno, suballoc_bit, res);
2855         if (status < 0)
2856                 mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2857
2858         ocfs2_inode_unlock(inode_alloc_inode, 0);
2859         inode_unlock(inode_alloc_inode);
2860
2861         iput(inode_alloc_inode);
2862         brelse(alloc_bh);
2863 bail:
2864         if (status)
2865                 mlog_errno(status);
2866         return status;
2867 }