fs/ocfs2/suballoc.c

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