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         unsigned int    sr_max_contig_bits; /* The length for contiguous
  54                                              * free bits, only available
  55                                              * for cluster group
  56                                              */
  57 };
  58
  59 static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
  60 {
  61         if (res->sr_blkno == 0)
  62                 return 0;
  63
  64         if (res->sr_bg_blkno)
  65                 return res->sr_bg_blkno;
  66
  67         return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
  68 }
  69
  70 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  71 static int ocfs2_block_group_fill(handle_t *handle,
  72                                   struct inode *alloc_inode,
  73                                   struct buffer_head *bg_bh,
  74                                   u64 group_blkno,
  75                                   unsigned int group_clusters,
  76                                   u16 my_chain,
  77                                   struct ocfs2_chain_list *cl);
  78 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  79                                    struct inode *alloc_inode,
  80                                    struct buffer_head *bh,
  81                                    u64 max_block,
  82                                    u64 *last_alloc_group,
  83                                    int flags);
  84
  85 static int ocfs2_cluster_group_search(struct inode *inode,
  86                                       struct buffer_head *group_bh,
  87                                       u32 bits_wanted, u32 min_bits,
  88                                       u64 max_block,
  89                                       struct ocfs2_suballoc_result *res);
  90 static int ocfs2_block_group_search(struct inode *inode,
  91                                     struct buffer_head *group_bh,
  92                                     u32 bits_wanted, u32 min_bits,
  93                                     u64 max_block,
  94                                     struct ocfs2_suballoc_result *res);
  95 static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
  96                                      handle_t *handle,
  97                                      u32 bits_wanted,
  98                                      u32 min_bits,
  99                                      struct ocfs2_suballoc_result *res);
 100 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 101                                          int nr);
 102 static int ocfs2_relink_block_group(handle_t *handle,
 103                                     struct inode *alloc_inode,
 104                                     struct buffer_head *fe_bh,
 105                                     struct buffer_head *bg_bh,
 106                                     struct buffer_head *prev_bg_bh,
 107                                     u16 chain);
 108 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 109                                                      u32 wanted);
 110 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 111                                                    u64 bg_blkno,
 112                                                    u16 bg_bit_off);
 113 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 114                                                 u64 data_blkno,
 115                                                 u64 *bg_blkno,
 116                                                 u16 *bg_bit_off);
 117 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 118                                              u32 bits_wanted, u64 max_block,
 119                                              int flags,
 120                                              struct ocfs2_alloc_context **ac);
 121
 122 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 123 {
 124         struct inode *inode = ac->ac_inode;
 125
 126         if (inode) {
 127                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 128                         ocfs2_inode_unlock(inode, 1);
 129
 130                 inode_unlock(inode);
 131
 132                 iput(inode);
 133                 ac->ac_inode = NULL;
 134         }
 135         brelse(ac->ac_bh);
 136         ac->ac_bh = NULL;
 137         ac->ac_resv = NULL;
 138         kfree(ac->ac_find_loc_priv);
 139         ac->ac_find_loc_priv = NULL;
 140 }
 141
 142 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 143 {
 144         ocfs2_free_ac_resource(ac);
 145         kfree(ac);
 146 }
 147
 148 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 149 {
 150         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 151 }
 152
 153 #define do_error(fmt, ...)                                              \
 154 do {                                                                    \
 155         if (resize)                                                     \
 156                 mlog(ML_ERROR, fmt, ##__VA_ARGS__);                     \
 157         else                                                            \
 158                 return ocfs2_error(sb, fmt, ##__VA_ARGS__);             \
 159 } while (0)
 160
 161 static int ocfs2_validate_gd_self(struct super_block *sb,
 162                                   struct buffer_head *bh,
 163                                   int resize)
 164 {
 165         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 166
 167         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 168                 do_error("Group descriptor #%llu has bad signature %.*s\n",
 169                          (unsigned long long)bh->b_blocknr, 7,
 170                          gd->bg_signature);
 171         }
 172
 173         if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 174                 do_error("Group descriptor #%llu has an invalid bg_blkno of %llu\n",
 175                          (unsigned long long)bh->b_blocknr,
 176                          (unsigned long long)le64_to_cpu(gd->bg_blkno));
 177         }
 178
 179         if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 180                 do_error("Group descriptor #%llu has an invalid fs_generation of #%u\n",
 181                          (unsigned long long)bh->b_blocknr,
 182                          le32_to_cpu(gd->bg_generation));
 183         }
 184
 185         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 186                 do_error("Group descriptor #%llu has bit count %u but claims that %u are free\n",
 187                          (unsigned long long)bh->b_blocknr,
 188                          le16_to_cpu(gd->bg_bits),
 189                          le16_to_cpu(gd->bg_free_bits_count));
 190         }
 191
 192         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 193                 do_error("Group descriptor #%llu has bit count %u but max bitmap bits of %u\n",
 194                          (unsigned long long)bh->b_blocknr,
 195                          le16_to_cpu(gd->bg_bits),
 196                          8 * le16_to_cpu(gd->bg_size));
 197         }
 198
 199         return 0;
 200 }
 201
 202 static int ocfs2_validate_gd_parent(struct super_block *sb,
 203                                     struct ocfs2_dinode *di,
 204                                     struct buffer_head *bh,
 205                                     int resize)
 206 {
 207         unsigned int max_bits;
 208         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 209
 210         if (di->i_blkno != gd->bg_parent_dinode) {
 211                 do_error("Group descriptor #%llu has bad parent pointer (%llu, expected %llu)\n",
 212                          (unsigned long long)bh->b_blocknr,
 213                          (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 214                          (unsigned long long)le64_to_cpu(di->i_blkno));
 215         }
 216
 217         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 218         if (le16_to_cpu(gd->bg_bits) > max_bits) {
 219                 do_error("Group descriptor #%llu has bit count of %u\n",
 220                          (unsigned long long)bh->b_blocknr,
 221                          le16_to_cpu(gd->bg_bits));
 222         }
 223
 224         /* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 225         if ((le16_to_cpu(gd->bg_chain) >
 226              le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 227             ((le16_to_cpu(gd->bg_chain) ==
 228              le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 229                 do_error("Group descriptor #%llu has bad chain %u\n",
 230                          (unsigned long long)bh->b_blocknr,
 231                          le16_to_cpu(gd->bg_chain));
 232         }
 233
 234         return 0;
 235 }
 236
 237 #undef do_error
 238
 239 /*
 240  * This version only prints errors.  It does not fail the filesystem, and
 241  * exists only for resize.
 242  */
 243 int ocfs2_check_group_descriptor(struct super_block *sb,
 244                                  struct ocfs2_dinode *di,
 245                                  struct buffer_head *bh)
 246 {
 247         int rc;
 248         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 249
 250         BUG_ON(!buffer_uptodate(bh));
 251
 252         /*
 253          * If the ecc fails, we return the error but otherwise
 254          * leave the filesystem running.  We know any error is
 255          * local to this block.
 256          */
 257         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 258         if (rc) {
 259                 mlog(ML_ERROR,
 260                      "Checksum failed for group descriptor %llu\n",
 261                      (unsigned long long)bh->b_blocknr);
 262         } else
 263                 rc = ocfs2_validate_gd_self(sb, bh, 1);
 264         if (!rc)
 265                 rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 266
 267         return rc;
 268 }
 269
 270 static int ocfs2_validate_group_descriptor(struct super_block *sb,
 271                                            struct buffer_head *bh)
 272 {
 273         int rc;
 274         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 275
 276         trace_ocfs2_validate_group_descriptor(
 277                                         (unsigned long long)bh->b_blocknr);
 278
 279         BUG_ON(!buffer_uptodate(bh));
 280
 281         /*
 282          * If the ecc fails, we return the error but otherwise
 283          * leave the filesystem running.  We know any error is
 284          * local to this block.
 285          */
 286         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 287         if (rc)
 288                 return rc;
 289
 290         /*
 291          * Errors after here are fatal.
 292          */
 293
 294         return ocfs2_validate_gd_self(sb, bh, 0);
 295 }
 296
 297 int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 298                                 u64 gd_blkno, struct buffer_head **bh)
 299 {
 300         int rc;
 301         struct buffer_head *tmp = *bh;
 302
 303         rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 304                               ocfs2_validate_group_descriptor);
 305         if (rc)
 306                 goto out;
 307
 308         rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 309         if (rc) {
 310                 brelse(tmp);
 311                 goto out;
 312         }
 313
 314         /* If ocfs2_read_block() got us a new bh, pass it up. */
 315         if (!*bh)
 316                 *bh = tmp;
 317
 318 out:
 319         return rc;
 320 }
 321
 322 static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 323                                           struct ocfs2_group_desc *bg,
 324                                           struct ocfs2_chain_list *cl,
 325                                           u64 p_blkno, unsigned int clusters)
 326 {
 327         struct ocfs2_extent_list *el = &bg->bg_list;
 328         struct ocfs2_extent_rec *rec;
 329
 330         BUG_ON(!ocfs2_supports_discontig_bg(osb));
 331         if (!el->l_next_free_rec)
 332                 el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 333         rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 334         rec->e_blkno = cpu_to_le64(p_blkno);
 335         rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 336                                   le16_to_cpu(cl->cl_bpc));
 337         rec->e_leaf_clusters = cpu_to_le16(clusters);
 338         le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 339         le16_add_cpu(&bg->bg_free_bits_count,
 340                      clusters * le16_to_cpu(cl->cl_bpc));
 341         le16_add_cpu(&el->l_next_free_rec, 1);
 342 }
 343
 344 static int ocfs2_block_group_fill(handle_t *handle,
 345                                   struct inode *alloc_inode,
 346                                   struct buffer_head *bg_bh,
 347                                   u64 group_blkno,
 348                                   unsigned int group_clusters,
 349                                   u16 my_chain,
 350                                   struct ocfs2_chain_list *cl)
 351 {
 352         int status = 0;
 353         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 354         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 355         struct super_block * sb = alloc_inode->i_sb;
 356
 357         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 358                 status = ocfs2_error(alloc_inode->i_sb,
 359                                      "group block (%llu) != b_blocknr (%llu)\n",
 360                                      (unsigned long long)group_blkno,
 361                                      (unsigned long long) bg_bh->b_blocknr);
 362                 goto bail;
 363         }
 364
 365         status = ocfs2_journal_access_gd(handle,
 366                                          INODE_CACHE(alloc_inode),
 367                                          bg_bh,
 368                                          OCFS2_JOURNAL_ACCESS_CREATE);
 369         if (status < 0) {
 370                 mlog_errno(status);
 371                 goto bail;
 372         }
 373
 374         memset(bg, 0, sb->s_blocksize);
 375         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 376         bg->bg_generation = cpu_to_le32(osb->fs_generation);
 377         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 378                                                 osb->s_feature_incompat));
 379         bg->bg_chain = cpu_to_le16(my_chain);
 380         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 381         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 382         bg->bg_blkno = cpu_to_le64(group_blkno);
 383         if (group_clusters == le16_to_cpu(cl->cl_cpg))
 384                 bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 385         else
 386                 ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 387                                               group_clusters);
 388
 389         /* set the 1st bit in the bitmap to account for the descriptor block */
 390         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 391         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 392
 393         ocfs2_journal_dirty(handle, bg_bh);
 394
 395         /* There is no need to zero out or otherwise initialize the
 396          * other blocks in a group - All valid FS metadata in a block
 397          * group stores the superblock fs_generation value at
 398          * allocation time. */
 399
 400 bail:
 401         if (status)
 402                 mlog_errno(status);
 403         return status;
 404 }
 405
 406 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 407 {
 408         u16 curr, best;
 409
 410         best = curr = 0;
 411         while (curr < le16_to_cpu(cl->cl_count)) {
 412                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 413                     le32_to_cpu(cl->cl_recs[curr].c_total))
 414                         best = curr;
 415                 curr++;
 416         }
 417         return best;
 418 }
 419
 420 static struct buffer_head *
 421 ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 422                                struct inode *alloc_inode,
 423                                struct ocfs2_alloc_context *ac,
 424                                struct ocfs2_chain_list *cl)
 425 {
 426         int status;
 427         u32 bit_off, num_bits;
 428         u64 bg_blkno;
 429         struct buffer_head *bg_bh;
 430         unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 431
 432         status = ocfs2_claim_clusters(handle, ac,
 433                                       le16_to_cpu(cl->cl_cpg), &bit_off,
 434                                       &num_bits);
 435         if (status < 0) {
 436                 if (status != -ENOSPC)
 437                         mlog_errno(status);
 438                 goto bail;
 439         }
 440
 441         /* setup the group */
 442         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 443         trace_ocfs2_block_group_alloc_contig(
 444              (unsigned long long)bg_blkno, alloc_rec);
 445
 446         bg_bh = sb_getblk(osb->sb, bg_blkno);
 447         if (!bg_bh) {
 448                 status = -ENOMEM;
 449                 mlog_errno(status);
 450                 goto bail;
 451         }
 452         ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 453
 454         status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 455                                         bg_blkno, num_bits, alloc_rec, cl);
 456         if (status < 0) {
 457                 brelse(bg_bh);
 458                 mlog_errno(status);
 459         }
 460
 461 bail:
 462         return status ? ERR_PTR(status) : bg_bh;
 463 }
 464
 465 static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 466                                         handle_t *handle,
 467                                         struct ocfs2_alloc_context *ac,
 468                                         unsigned int min_bits,
 469                                         u32 *bit_off, u32 *num_bits)
 470 {
 471         int status = 0;
 472
 473         while (min_bits) {
 474                 status = ocfs2_claim_clusters(handle, ac, min_bits,
 475                                               bit_off, num_bits);
 476                 if (status != -ENOSPC)
 477                         break;
 478
 479                 min_bits >>= 1;
 480         }
 481
 482         return status;
 483 }
 484
 485 static int ocfs2_block_group_grow_discontig(handle_t *handle,
 486                                             struct inode *alloc_inode,
 487                                             struct buffer_head *bg_bh,
 488                                             struct ocfs2_alloc_context *ac,
 489                                             struct ocfs2_chain_list *cl,
 490                                             unsigned int min_bits)
 491 {
 492         int status;
 493         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 494         struct ocfs2_group_desc *bg =
 495                 (struct ocfs2_group_desc *)bg_bh->b_data;
 496         unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 497                          le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 498         u32 p_cpos, clusters;
 499         u64 p_blkno;
 500         struct ocfs2_extent_list *el = &bg->bg_list;
 501
 502         status = ocfs2_journal_access_gd(handle,
 503                                          INODE_CACHE(alloc_inode),
 504                                          bg_bh,
 505                                          OCFS2_JOURNAL_ACCESS_CREATE);
 506         if (status < 0) {
 507                 mlog_errno(status);
 508                 goto bail;
 509         }
 510
 511         while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 512                                 le16_to_cpu(el->l_count))) {
 513                 if (min_bits > needed)
 514                         min_bits = needed;
 515                 status = ocfs2_block_group_claim_bits(osb, handle, ac,
 516                                                       min_bits, &p_cpos,
 517                                                       &clusters);
 518                 if (status < 0) {
 519                         if (status != -ENOSPC)
 520                                 mlog_errno(status);
 521                         goto bail;
 522                 }
 523                 p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 524                 ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 525                                               clusters);
 526
 527                 min_bits = clusters;
 528                 needed = le16_to_cpu(cl->cl_cpg) -
 529                          le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 530         }
 531
 532         if (needed > 0) {
 533                 /*
 534                  * We have used up all the extent rec but can't fill up
 535                  * the cpg. So bail out.
 536                  */
 537                 status = -ENOSPC;
 538                 goto bail;
 539         }
 540
 541         ocfs2_journal_dirty(handle, bg_bh);
 542
 543 bail:
 544         return status;
 545 }
 546
 547 static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 548                                    struct ocfs2_alloc_context *cluster_ac,
 549                                    struct inode *alloc_inode,
 550                                    struct buffer_head *bg_bh)
 551 {
 552         int i, ret;
 553         struct ocfs2_group_desc *bg;
 554         struct ocfs2_extent_list *el;
 555         struct ocfs2_extent_rec *rec;
 556
 557         if (!bg_bh)
 558                 return;
 559
 560         bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 561         el = &bg->bg_list;
 562         for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 563                 rec = &el->l_recs[i];
 564                 ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 565                                           cluster_ac->ac_bh,
 566                                           le64_to_cpu(rec->e_blkno),
 567                                           le16_to_cpu(rec->e_leaf_clusters));
 568                 if (ret)
 569                         mlog_errno(ret);
 570                 /* Try all the clusters to free */
 571         }
 572
 573         ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 574         brelse(bg_bh);
 575 }
 576
 577 static struct buffer_head *
 578 ocfs2_block_group_alloc_discontig(handle_t *handle,
 579                                   struct inode *alloc_inode,
 580                                   struct ocfs2_alloc_context *ac,
 581                                   struct ocfs2_chain_list *cl)
 582 {
 583         int status;
 584         u32 bit_off, num_bits;
 585         u64 bg_blkno;
 586         unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 587         struct buffer_head *bg_bh = NULL;
 588         unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 589         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 590
 591         if (!ocfs2_supports_discontig_bg(osb)) {
 592                 status = -ENOSPC;
 593                 goto bail;
 594         }
 595
 596         status = ocfs2_extend_trans(handle,
 597                                     ocfs2_calc_bg_discontig_credits(osb->sb));
 598         if (status) {
 599                 mlog_errno(status);
 600                 goto bail;
 601         }
 602
 603         /*
 604          * We're going to be grabbing from multiple cluster groups.
 605          * We don't have enough credits to relink them all, and the
 606          * cluster groups will be staying in cache for the duration of
 607          * this operation.
 608          */
 609         ac->ac_disable_chain_relink = 1;
 610
 611         /* Claim the first region */
 612         status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 613                                               &bit_off, &num_bits);
 614         if (status < 0) {
 615                 if (status != -ENOSPC)
 616                         mlog_errno(status);
 617                 goto bail;
 618         }
 619         min_bits = num_bits;
 620
 621         /* setup the group */
 622         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 623         trace_ocfs2_block_group_alloc_discontig(
 624                                 (unsigned long long)bg_blkno, alloc_rec);
 625
 626         bg_bh = sb_getblk(osb->sb, bg_blkno);
 627         if (!bg_bh) {
 628                 status = -ENOMEM;
 629                 mlog_errno(status);
 630                 goto bail;
 631         }
 632         ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 633
 634         status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 635                                         bg_blkno, num_bits, alloc_rec, cl);
 636         if (status < 0) {
 637                 mlog_errno(status);
 638                 goto bail;
 639         }
 640
 641         status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 642                                                   bg_bh, ac, cl, min_bits);
 643         if (status)
 644                 mlog_errno(status);
 645
 646 bail:
 647         if (status)
 648                 ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 649         return status ? ERR_PTR(status) : bg_bh;
 650 }
 651
 652 /*
 653  * We expect the block group allocator to already be locked.
 654  */
 655 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 656                                    struct inode *alloc_inode,
 657                                    struct buffer_head *bh,
 658                                    u64 max_block,
 659                                    u64 *last_alloc_group,
 660                                    int flags)
 661 {
 662         int status, credits;
 663         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 664         struct ocfs2_chain_list *cl;
 665         struct ocfs2_alloc_context *ac = NULL;
 666         handle_t *handle = NULL;
 667         u16 alloc_rec;
 668         struct buffer_head *bg_bh = NULL;
 669         struct ocfs2_group_desc *bg;
 670
 671         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 672
 673         cl = &fe->id2.i_chain;
 674         status = ocfs2_reserve_clusters_with_limit(osb,
 675                                                    le16_to_cpu(cl->cl_cpg),
 676                                                    max_block, flags, &ac);
 677         if (status < 0) {
 678                 if (status != -ENOSPC)
 679                         mlog_errno(status);
 680                 goto bail;
 681         }
 682
 683         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 684                                                  le16_to_cpu(cl->cl_cpg));
 685         handle = ocfs2_start_trans(osb, credits);
 686         if (IS_ERR(handle)) {
 687                 status = PTR_ERR(handle);
 688                 handle = NULL;
 689                 mlog_errno(status);
 690                 goto bail;
 691         }
 692
 693         if (last_alloc_group && *last_alloc_group != 0) {
 694                 trace_ocfs2_block_group_alloc(
 695                                 (unsigned long long)*last_alloc_group);
 696                 ac->ac_last_group = *last_alloc_group;
 697         }
 698
 699         bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 700                                                ac, cl);
 701         if (PTR_ERR(bg_bh) == -ENOSPC)
 702                 bg_bh = ocfs2_block_group_alloc_discontig(handle,
 703                                                           alloc_inode,
 704                                                           ac, cl);
 705         if (IS_ERR(bg_bh)) {
 706                 status = PTR_ERR(bg_bh);
 707                 bg_bh = NULL;
 708                 if (status != -ENOSPC)
 709                         mlog_errno(status);
 710                 goto bail;
 711         }
 712         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 713
 714         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 715                                          bh, OCFS2_JOURNAL_ACCESS_WRITE);
 716         if (status < 0) {
 717                 mlog_errno(status);
 718                 goto bail;
 719         }
 720
 721         alloc_rec = le16_to_cpu(bg->bg_chain);
 722         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 723                      le16_to_cpu(bg->bg_free_bits_count));
 724         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 725                      le16_to_cpu(bg->bg_bits));
 726         cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 727         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 728                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 729
 730         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 731                                         le16_to_cpu(bg->bg_free_bits_count));
 732         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 733         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 734
 735         ocfs2_journal_dirty(handle, bh);
 736
 737         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 738         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 739         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 740                                              le32_to_cpu(fe->i_clusters)));
 741         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 742         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 743         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 744         ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
 745
 746         status = 0;
 747
 748         /* save the new last alloc group so that the caller can cache it. */
 749         if (last_alloc_group)
 750                 *last_alloc_group = ac->ac_last_group;
 751
 752 bail:
 753         if (handle)
 754                 ocfs2_commit_trans(osb, handle);
 755
 756         if (ac)
 757                 ocfs2_free_alloc_context(ac);
 758
 759         brelse(bg_bh);
 760
 761         if (status)
 762                 mlog_errno(status);
 763         return status;
 764 }
 765
 766 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 767                                        struct ocfs2_alloc_context *ac,
 768                                        int type,
 769                                        u32 slot,
 770                                        u64 *last_alloc_group,
 771                                        int flags)
 772 {
 773         int status;
 774         u32 bits_wanted = ac->ac_bits_wanted;
 775         struct inode *alloc_inode;
 776         struct buffer_head *bh = NULL;
 777         struct ocfs2_dinode *fe;
 778         u32 free_bits;
 779
 780         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 781         if (!alloc_inode) {
 782                 mlog_errno(-EINVAL);
 783                 return -EINVAL;
 784         }
 785
 786         inode_lock(alloc_inode);
 787
 788         status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 789         if (status < 0) {
 790                 inode_unlock(alloc_inode);
 791                 iput(alloc_inode);
 792
 793                 mlog_errno(status);
 794                 return status;
 795         }
 796
 797         ac->ac_inode = alloc_inode;
 798         ac->ac_alloc_slot = slot;
 799
 800         fe = (struct ocfs2_dinode *) bh->b_data;
 801
 802         /* The bh was validated by the inode read inside
 803          * ocfs2_inode_lock().  Any corruption is a code bug. */
 804         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 805
 806         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 807                 status = ocfs2_error(alloc_inode->i_sb,
 808                                      "Invalid chain allocator %llu\n",
 809                                      (unsigned long long)le64_to_cpu(fe->i_blkno));
 810                 goto bail;
 811         }
 812
 813         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 814                 le32_to_cpu(fe->id1.bitmap1.i_used);
 815
 816         if (bits_wanted > free_bits) {
 817                 /* cluster bitmap never grows */
 818                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 819                         trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 820                                                                 free_bits);
 821                         status = -ENOSPC;
 822                         goto bail;
 823                 }
 824
 825                 if (!(flags & ALLOC_NEW_GROUP)) {
 826                         trace_ocfs2_reserve_suballoc_bits_no_new_group(
 827                                                 slot, bits_wanted, free_bits);
 828                         status = -ENOSPC;
 829                         goto bail;
 830                 }
 831
 832                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 833                                                  ac->ac_max_block,
 834                                                  last_alloc_group, flags);
 835                 if (status < 0) {
 836                         if (status != -ENOSPC)
 837                                 mlog_errno(status);
 838                         goto bail;
 839                 }
 840                 atomic_inc(&osb->alloc_stats.bg_extends);
 841
 842                 /* You should never ask for this much metadata */
 843                 BUG_ON(bits_wanted >
 844                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 845                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 846         }
 847
 848         get_bh(bh);
 849         ac->ac_bh = bh;
 850 bail:
 851         brelse(bh);
 852
 853         if (status)
 854                 mlog_errno(status);
 855         return status;
 856 }
 857
 858 static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 859 {
 860         spin_lock(&osb->osb_lock);
 861         osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 862         spin_unlock(&osb->osb_lock);
 863         atomic_set(&osb->s_num_inodes_stolen, 0);
 864 }
 865
 866 static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 867 {
 868         spin_lock(&osb->osb_lock);
 869         osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 870         spin_unlock(&osb->osb_lock);
 871         atomic_set(&osb->s_num_meta_stolen, 0);
 872 }
 873
 874 void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 875 {
 876         ocfs2_init_inode_steal_slot(osb);
 877         ocfs2_init_meta_steal_slot(osb);
 878 }
 879
 880 static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 881 {
 882         spin_lock(&osb->osb_lock);
 883         if (type == INODE_ALLOC_SYSTEM_INODE)
 884                 osb->s_inode_steal_slot = (u16)slot;
 885         else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 886                 osb->s_meta_steal_slot = (u16)slot;
 887         spin_unlock(&osb->osb_lock);
 888 }
 889
 890 static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 891 {
 892         int slot = OCFS2_INVALID_SLOT;
 893
 894         spin_lock(&osb->osb_lock);
 895         if (type == INODE_ALLOC_SYSTEM_INODE)
 896                 slot = osb->s_inode_steal_slot;
 897         else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 898                 slot = osb->s_meta_steal_slot;
 899         spin_unlock(&osb->osb_lock);
 900
 901         return slot;
 902 }
 903
 904 static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 905 {
 906         return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 907 }
 908
 909 static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 910 {
 911         return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 912 }
 913
 914 static int ocfs2_steal_resource(struct ocfs2_super *osb,
 915                                 struct ocfs2_alloc_context *ac,
 916                                 int type)
 917 {
 918         int i, status = -ENOSPC;
 919         int slot = __ocfs2_get_steal_slot(osb, type);
 920
 921         /* Start to steal resource from the first slot after ours. */
 922         if (slot == OCFS2_INVALID_SLOT)
 923                 slot = osb->slot_num + 1;
 924
 925         for (i = 0; i < osb->max_slots; i++, slot++) {
 926                 if (slot == osb->max_slots)
 927                         slot = 0;
 928
 929                 if (slot == osb->slot_num)
 930                         continue;
 931
 932                 status = ocfs2_reserve_suballoc_bits(osb, ac,
 933                                                      type,
 934                                                      (u32)slot, NULL,
 935                                                      NOT_ALLOC_NEW_GROUP);
 936                 if (status >= 0) {
 937                         __ocfs2_set_steal_slot(osb, slot, type);
 938                         break;
 939                 }
 940
 941                 ocfs2_free_ac_resource(ac);
 942         }
 943
 944         return status;
 945 }
 946
 947 static int ocfs2_steal_inode(struct ocfs2_super *osb,
 948                              struct ocfs2_alloc_context *ac)
 949 {
 950         return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 951 }
 952
 953 static int ocfs2_steal_meta(struct ocfs2_super *osb,
 954                             struct ocfs2_alloc_context *ac)
 955 {
 956         return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 957 }
 958
 959 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 960                                       int blocks,
 961                                       struct ocfs2_alloc_context **ac)
 962 {
 963         int status;
 964         int slot = ocfs2_get_meta_steal_slot(osb);
 965
 966         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 967         if (!(*ac)) {
 968                 status = -ENOMEM;
 969                 mlog_errno(status);
 970                 goto bail;
 971         }
 972
 973         (*ac)->ac_bits_wanted = blocks;
 974         (*ac)->ac_which = OCFS2_AC_USE_META;
 975         (*ac)->ac_group_search = ocfs2_block_group_search;
 976
 977         if (slot != OCFS2_INVALID_SLOT &&
 978                 atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
 979                 goto extent_steal;
 980
 981         atomic_set(&osb->s_num_meta_stolen, 0);
 982         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 983                                              EXTENT_ALLOC_SYSTEM_INODE,
 984                                              (u32)osb->slot_num, NULL,
 985                                              ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
 986
 987
 988         if (status >= 0) {
 989                 status = 0;
 990                 if (slot != OCFS2_INVALID_SLOT)
 991                         ocfs2_init_meta_steal_slot(osb);
 992                 goto bail;
 993         } else if (status < 0 && status != -ENOSPC) {
 994                 mlog_errno(status);
 995                 goto bail;
 996         }
 997
 998         ocfs2_free_ac_resource(*ac);
 999
1000 extent_steal:
1001         status = ocfs2_steal_meta(osb, *ac);
1002         atomic_inc(&osb->s_num_meta_stolen);
1003         if (status < 0) {
1004                 if (status != -ENOSPC)
1005                         mlog_errno(status);
1006                 goto bail;
1007         }
1008
1009         status = 0;
1010 bail:
1011         if ((status < 0) && *ac) {
1012                 ocfs2_free_alloc_context(*ac);
1013                 *ac = NULL;
1014         }
1015
1016         if (status)
1017                 mlog_errno(status);
1018         return status;
1019 }
1020
1021 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1022                                struct ocfs2_extent_list *root_el,
1023                                struct ocfs2_alloc_context **ac)
1024 {
1025         return ocfs2_reserve_new_metadata_blocks(osb,
1026                                         ocfs2_extend_meta_needed(root_el),
1027                                         ac);
1028 }
1029
1030 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1031                             struct ocfs2_alloc_context **ac)
1032 {
1033         int status;
1034         int slot = ocfs2_get_inode_steal_slot(osb);
1035         u64 alloc_group;
1036
1037         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1038         if (!(*ac)) {
1039                 status = -ENOMEM;
1040                 mlog_errno(status);
1041                 goto bail;
1042         }
1043
1044         (*ac)->ac_bits_wanted = 1;
1045         (*ac)->ac_which = OCFS2_AC_USE_INODE;
1046
1047         (*ac)->ac_group_search = ocfs2_block_group_search;
1048
1049         /*
1050          * stat(2) can't handle i_ino > 32bits, so we tell the
1051          * lower levels not to allocate us a block group past that
1052          * limit.  The 'inode64' mount option avoids this behavior.
1053          */
1054         if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1055                 (*ac)->ac_max_block = (u32)~0U;
1056
1057         /*
1058          * slot is set when we successfully steal inode from other nodes.
1059          * It is reset in 3 places:
1060          * 1. when we flush the truncate log
1061          * 2. when we complete local alloc recovery.
1062          * 3. when we successfully allocate from our own slot.
1063          * After it is set, we will go on stealing inodes until we find the
1064          * need to check our slots to see whether there is some space for us.
1065          */
1066         if (slot != OCFS2_INVALID_SLOT &&
1067             atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1068                 goto inode_steal;
1069
1070         atomic_set(&osb->s_num_inodes_stolen, 0);
1071         alloc_group = osb->osb_inode_alloc_group;
1072         status = ocfs2_reserve_suballoc_bits(osb, *ac,
1073                                              INODE_ALLOC_SYSTEM_INODE,
1074                                              (u32)osb->slot_num,
1075                                              &alloc_group,
1076                                              ALLOC_NEW_GROUP |
1077                                              ALLOC_GROUPS_FROM_GLOBAL);
1078         if (status >= 0) {
1079                 status = 0;
1080
1081                 spin_lock(&osb->osb_lock);
1082                 osb->osb_inode_alloc_group = alloc_group;
1083                 spin_unlock(&osb->osb_lock);
1084                 trace_ocfs2_reserve_new_inode_new_group(
1085                         (unsigned long long)alloc_group);
1086
1087                 /*
1088                  * Some inodes must be freed by us, so try to allocate
1089                  * from our own next time.
1090                  */
1091                 if (slot != OCFS2_INVALID_SLOT)
1092                         ocfs2_init_inode_steal_slot(osb);
1093                 goto bail;
1094         } else if (status < 0 && status != -ENOSPC) {
1095                 mlog_errno(status);
1096                 goto bail;
1097         }
1098
1099         ocfs2_free_ac_resource(*ac);
1100
1101 inode_steal:
1102         status = ocfs2_steal_inode(osb, *ac);
1103         atomic_inc(&osb->s_num_inodes_stolen);
1104         if (status < 0) {
1105                 if (status != -ENOSPC)
1106                         mlog_errno(status);
1107                 goto bail;
1108         }
1109
1110         status = 0;
1111 bail:
1112         if ((status < 0) && *ac) {
1113                 ocfs2_free_alloc_context(*ac);
1114                 *ac = NULL;
1115         }
1116
1117         if (status)
1118                 mlog_errno(status);
1119         return status;
1120 }
1121
1122 /* local alloc code has to do the same thing, so rather than do this
1123  * twice.. */
1124 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1125                                       struct ocfs2_alloc_context *ac)
1126 {
1127         int status;
1128
1129         ac->ac_which = OCFS2_AC_USE_MAIN;
1130         ac->ac_group_search = ocfs2_cluster_group_search;
1131
1132         status = ocfs2_reserve_suballoc_bits(osb, ac,
1133                                              GLOBAL_BITMAP_SYSTEM_INODE,
1134                                              OCFS2_INVALID_SLOT, NULL,
1135                                              ALLOC_NEW_GROUP);
1136         if (status < 0 && status != -ENOSPC)
1137                 mlog_errno(status);
1138
1139         return status;
1140 }
1141
1142 /* Callers don't need to care which bitmap (local alloc or main) to
1143  * use so we figure it out for them, but unfortunately this clutters
1144  * things a bit. */
1145 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1146                                              u32 bits_wanted, u64 max_block,
1147                                              int flags,
1148                                              struct ocfs2_alloc_context **ac)
1149 {
1150         int status, ret = 0;
1151         int retried = 0;
1152
1153         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1154         if (!(*ac)) {
1155                 status = -ENOMEM;
1156                 mlog_errno(status);
1157                 goto bail;
1158         }
1159
1160         (*ac)->ac_bits_wanted = bits_wanted;
1161         (*ac)->ac_max_block = max_block;
1162
1163         status = -ENOSPC;
1164         if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1165             ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1166                 status = ocfs2_reserve_local_alloc_bits(osb,
1167                                                         bits_wanted,
1168                                                         *ac);
1169                 if ((status < 0) && (status != -ENOSPC)) {
1170                         mlog_errno(status);
1171                         goto bail;
1172                 }
1173         }
1174
1175         if (status == -ENOSPC) {
1176 retry:
1177                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1178                 /* Retry if there is sufficient space cached in truncate log */
1179                 if (status == -ENOSPC && !retried) {
1180                         retried = 1;
1181                         ocfs2_inode_unlock((*ac)->ac_inode, 1);
1182                         inode_unlock((*ac)->ac_inode);
1183
1184                         ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
1185                         if (ret == 1) {
1186                                 iput((*ac)->ac_inode);
1187                                 (*ac)->ac_inode = NULL;
1188                                 goto retry;
1189                         }
1190
1191                         if (ret < 0)
1192                                 mlog_errno(ret);
1193
1194                         inode_lock((*ac)->ac_inode);
1195                         ret = ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
1196                         if (ret < 0) {
1197                                 mlog_errno(ret);
1198                                 inode_unlock((*ac)->ac_inode);
1199                                 iput((*ac)->ac_inode);
1200                                 (*ac)->ac_inode = NULL;
1201                                 goto bail;
1202                         }
1203                 }
1204                 if (status < 0) {
1205                         if (status != -ENOSPC)
1206                                 mlog_errno(status);
1207                         goto bail;
1208                 }
1209         }
1210
1211         status = 0;
1212 bail:
1213         if ((status < 0) && *ac) {
1214                 ocfs2_free_alloc_context(*ac);
1215                 *ac = NULL;
1216         }
1217
1218         if (status)
1219                 mlog_errno(status);
1220         return status;
1221 }
1222
1223 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1224                            u32 bits_wanted,
1225                            struct ocfs2_alloc_context **ac)
1226 {
1227         return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1228                                                  ALLOC_NEW_GROUP, ac);
1229 }
1230
1231 /*
1232  * More or less lifted from ext3. I'll leave their description below:
1233  *
1234  * "For ext3 allocations, we must not reuse any blocks which are
1235  * allocated in the bitmap buffer's "last committed data" copy.  This
1236  * prevents deletes from freeing up the page for reuse until we have
1237  * committed the delete transaction.
1238  *
1239  * If we didn't do this, then deleting something and reallocating it as
1240  * data would allow the old block to be overwritten before the
1241  * transaction committed (because we force data to disk before commit).
1242  * This would lead to corruption if we crashed between overwriting the
1243  * data and committing the delete.
1244  *
1245  * @@@ We may want to make this allocation behaviour conditional on
1246  * data-writes at some point, and disable it for metadata allocations or
1247  * sync-data inodes."
1248  *
1249  * Note: OCFS2 already does this differently for metadata vs data
1250  * allocations, as those bitmaps are separate and undo access is never
1251  * called on a metadata group descriptor.
1252  */
1253 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1254                                          int nr)
1255 {
1256         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1257         struct journal_head *jh;
1258         int ret;
1259
1260         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1261                 return 0;
1262
1263         jh = jbd2_journal_grab_journal_head(bg_bh);
1264         if (!jh)
1265                 return 1;
1266
1267         spin_lock(&jh->b_state_lock);
1268         bg = (struct ocfs2_group_desc *) jh->b_committed_data;
1269         if (bg)
1270                 ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1271         else
1272                 ret = 1;
1273         spin_unlock(&jh->b_state_lock);
1274         jbd2_journal_put_journal_head(jh);
1275
1276         return ret;
1277 }
1278
1279 u16 ocfs2_find_max_contig_free_bits(void *bitmap,
1280                          u16 total_bits, u16 start)
1281 {
1282         u16 offset, free_bits;
1283         u16 contig_bits = 0;
1284
1285         while (start < total_bits) {
1286                 offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start);
1287                 if (offset == total_bits)
1288                         break;
1289
1290                 start = ocfs2_find_next_bit(bitmap, total_bits, offset);
1291                 free_bits = start - offset;
1292                 if (contig_bits < free_bits)
1293                         contig_bits = free_bits;
1294         }
1295
1296         return contig_bits;
1297 }
1298
1299 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1300                                              struct buffer_head *bg_bh,
1301                                              unsigned int bits_wanted,
1302                                              unsigned int total_bits,
1303                                              struct ocfs2_suballoc_result *res)
1304 {
1305         void *bitmap;
1306         u16 best_offset, best_size;
1307         u16 prev_best_size = 0;
1308         int offset, start, found, status = 0;
1309         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1310
1311         /* Callers got this descriptor from
1312          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1313         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1314
1315         found = start = best_offset = best_size = 0;
1316         bitmap = bg->bg_bitmap;
1317
1318         while ((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) <
1319                total_bits) {
1320                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1321                         /* We found a zero, but we can't use it as it
1322                          * hasn't been put to disk yet! */
1323                         found = 0;
1324                         start = offset + 1;
1325                 } else if (offset == start) {
1326                         /* we found a zero */
1327                         found++;
1328                         /* move start to the next bit to test */
1329                         start++;
1330                 } else {
1331                         /* got a zero after some ones */
1332                         found = 1;
1333                         start = offset + 1;
1334                         prev_best_size = best_size;
1335                 }
1336                 if (found > best_size) {
1337                         best_size = found;
1338                         best_offset = start - found;
1339                 }
1340                 /* we got everything we needed */
1341                 if (found == bits_wanted) {
1342                         /* mlog(0, "Found it all!\n"); */
1343                         break;
1344                 }
1345         }
1346
1347         /* best_size will be allocated, we save prev_best_size */
1348         res->sr_max_contig_bits = prev_best_size;
1349         if (best_size) {
1350                 res->sr_bit_offset = best_offset;
1351                 res->sr_bits = best_size;
1352         } else {
1353                 status = -ENOSPC;
1354                 /* No error log here -- see the comment above
1355                  * ocfs2_test_bg_bit_allocatable */
1356         }
1357
1358         return status;
1359 }
1360
1361 int ocfs2_block_group_set_bits(handle_t *handle,
1362                                              struct inode *alloc_inode,
1363                                              struct ocfs2_group_desc *bg,
1364                                              struct buffer_head *group_bh,
1365                                              unsigned int bit_off,
1366                                              unsigned int num_bits,
1367                                              unsigned int max_contig_bits,
1368                                              int fastpath)
1369 {
1370         int status;
1371         void *bitmap = bg->bg_bitmap;
1372         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1373         unsigned int start = bit_off + num_bits;
1374         u16 contig_bits;
1375         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
1376
1377         /* All callers get the descriptor via
1378          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1379         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1380         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1381
1382         trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1383
1384         if (ocfs2_is_cluster_bitmap(alloc_inode))
1385                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1386
1387         status = ocfs2_journal_access_gd(handle,
1388                                          INODE_CACHE(alloc_inode),
1389                                          group_bh,
1390                                          journal_type);
1391         if (status < 0) {
1392                 mlog_errno(status);
1393                 goto bail;
1394         }
1395
1396         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1397         if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1398                 return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1399                                    (unsigned long long)le64_to_cpu(bg->bg_blkno),
1400                                    le16_to_cpu(bg->bg_bits),
1401                                    le16_to_cpu(bg->bg_free_bits_count),
1402                                    num_bits);
1403         }
1404         while(num_bits--)
1405                 ocfs2_set_bit(bit_off++, bitmap);
1406
1407         /*
1408          * this is optimize path, caller set old contig value
1409          * in max_contig_bits to bypass finding action.
1410          */
1411         if (fastpath) {
1412                 bg->bg_contig_free_bits = cpu_to_le16(max_contig_bits);
1413         } else if (ocfs2_is_cluster_bitmap(alloc_inode)) {
1414                 /*
1415                  * Usually, the block group bitmap allocates only 1 bit
1416                  * at a time, while the cluster group allocates n bits
1417                  * each time. Therefore, we only save the contig bits for
1418                  * the cluster group.
1419                  */
1420                 contig_bits = ocfs2_find_max_contig_free_bits(bitmap,
1421                                     le16_to_cpu(bg->bg_bits), start);
1422                 if (contig_bits > max_contig_bits)
1423                         max_contig_bits = contig_bits;
1424                 bg->bg_contig_free_bits = cpu_to_le16(max_contig_bits);
1425                 ocfs2_local_alloc_seen_free_bits(osb, max_contig_bits);
1426         } else {
1427                 bg->bg_contig_free_bits = 0;
1428         }
1429
1430         ocfs2_journal_dirty(handle, group_bh);
1431
1432 bail:
1433         return status;
1434 }
1435
1436 /* find the one with the most empty bits */
1437 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1438 {
1439         u16 curr, best;
1440
1441         BUG_ON(!cl->cl_next_free_rec);
1442
1443         best = curr = 0;
1444         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1445                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1446                     le32_to_cpu(cl->cl_recs[best].c_free))
1447                         best = curr;
1448                 curr++;
1449         }
1450
1451         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1452         return best;
1453 }
1454
1455 static int ocfs2_relink_block_group(handle_t *handle,
1456                                     struct inode *alloc_inode,
1457                                     struct buffer_head *fe_bh,
1458                                     struct buffer_head *bg_bh,
1459                                     struct buffer_head *prev_bg_bh,
1460                                     u16 chain)
1461 {
1462         int status;
1463         /* there is a really tiny chance the journal calls could fail,
1464          * but we wouldn't want inconsistent blocks in *any* case. */
1465         u64 bg_ptr, prev_bg_ptr;
1466         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1467         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1468         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1469
1470         /* The caller got these descriptors from
1471          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1472         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1473         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1474
1475         trace_ocfs2_relink_block_group(
1476                 (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1477                 (unsigned long long)le64_to_cpu(bg->bg_blkno),
1478                 (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1479
1480         bg_ptr = le64_to_cpu(bg->bg_next_group);
1481         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1482
1483         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1484                                          prev_bg_bh,
1485                                          OCFS2_JOURNAL_ACCESS_WRITE);
1486         if (status < 0)
1487                 goto out;
1488
1489         prev_bg->bg_next_group = bg->bg_next_group;
1490         ocfs2_journal_dirty(handle, prev_bg_bh);
1491
1492         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1493                                          bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1494         if (status < 0)
1495                 goto out_rollback_prev_bg;
1496
1497         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1498         ocfs2_journal_dirty(handle, bg_bh);
1499
1500         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1501                                          fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1502         if (status < 0)
1503                 goto out_rollback_bg;
1504
1505         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1506         ocfs2_journal_dirty(handle, fe_bh);
1507
1508 out:
1509         if (status < 0)
1510                 mlog_errno(status);
1511         return status;
1512
1513 out_rollback_bg:
1514         bg->bg_next_group = cpu_to_le64(bg_ptr);
1515 out_rollback_prev_bg:
1516         prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1517         goto out;
1518 }
1519
1520 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1521                                                      u32 wanted)
1522 {
1523         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1524 }
1525
1526 /* return 0 on success, -ENOSPC to keep searching and any other < 0
1527  * value on error. */
1528 static int ocfs2_cluster_group_search(struct inode *inode,
1529                                       struct buffer_head *group_bh,
1530                                       u32 bits_wanted, u32 min_bits,
1531                                       u64 max_block,
1532                                       struct ocfs2_suballoc_result *res)
1533 {
1534         int search = -ENOSPC;
1535         int ret;
1536         u64 blkoff;
1537         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1538         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1539         unsigned int max_bits, gd_cluster_off;
1540
1541         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1542
1543         if (le16_to_cpu(gd->bg_contig_free_bits) &&
1544             le16_to_cpu(gd->bg_contig_free_bits) < bits_wanted)
1545                 return -ENOSPC;
1546
1547         /* ->bg_contig_free_bits may un-initialized, so compare again */
1548         if (le16_to_cpu(gd->bg_free_bits_count) >= bits_wanted) {
1549                 max_bits = le16_to_cpu(gd->bg_bits);
1550
1551                 /* Tail groups in cluster bitmaps which aren't cpg
1552                  * aligned are prone to partial extension by a failed
1553                  * fs resize. If the file system resize never got to
1554                  * update the dinode cluster count, then we don't want
1555                  * to trust any clusters past it, regardless of what
1556                  * the group descriptor says. */
1557                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1558                                                           le64_to_cpu(gd->bg_blkno));
1559                 if ((gd_cluster_off + max_bits) >
1560                     OCFS2_I(inode)->ip_clusters) {
1561                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1562                         trace_ocfs2_cluster_group_search_wrong_max_bits(
1563                                 (unsigned long long)le64_to_cpu(gd->bg_blkno),
1564                                 le16_to_cpu(gd->bg_bits),
1565                                 OCFS2_I(inode)->ip_clusters, max_bits);
1566                 }
1567
1568                 ret = ocfs2_block_group_find_clear_bits(osb,
1569                                                         group_bh, bits_wanted,
1570                                                         max_bits, res);
1571                 if (ret)
1572                         return ret;
1573
1574                 if (max_block) {
1575                         blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1576                                                           gd_cluster_off +
1577                                                           res->sr_bit_offset +
1578                                                           res->sr_bits);
1579                         trace_ocfs2_cluster_group_search_max_block(
1580                                 (unsigned long long)blkoff,
1581                                 (unsigned long long)max_block);
1582                         if (blkoff > max_block)
1583                                 return -ENOSPC;
1584                 }
1585
1586                 /* ocfs2_block_group_find_clear_bits() might
1587                  * return success, but we still want to return
1588                  * -ENOSPC unless it found the minimum number
1589                  * of bits. */
1590                 if (min_bits <= res->sr_bits)
1591                         search = 0; /* success */
1592         }
1593
1594         return search;
1595 }
1596
1597 static int ocfs2_block_group_search(struct inode *inode,
1598                                     struct buffer_head *group_bh,
1599                                     u32 bits_wanted, u32 min_bits,
1600                                     u64 max_block,
1601                                     struct ocfs2_suballoc_result *res)
1602 {
1603         int ret = -ENOSPC;
1604         u64 blkoff;
1605         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1606
1607         BUG_ON(min_bits != 1);
1608         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1609
1610         if (le16_to_cpu(bg->bg_free_bits_count) >= bits_wanted) {
1611                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1612                                                         group_bh, bits_wanted,
1613                                                         le16_to_cpu(bg->bg_bits),
1614                                                         res);
1615                 if (!ret && max_block) {
1616                         blkoff = le64_to_cpu(bg->bg_blkno) +
1617                                 res->sr_bit_offset + res->sr_bits;
1618                         trace_ocfs2_block_group_search_max_block(
1619                                 (unsigned long long)blkoff,
1620                                 (unsigned long long)max_block);
1621                         if (blkoff > max_block)
1622                                 ret = -ENOSPC;
1623                 }
1624         }
1625
1626         return ret;
1627 }
1628
1629 int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1630                                        handle_t *handle,
1631                                        struct buffer_head *di_bh,
1632                                        u32 num_bits,
1633                                        u16 chain)
1634 {
1635         int ret;
1636         u32 tmp_used;
1637         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1638         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1639
1640         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1641                                       OCFS2_JOURNAL_ACCESS_WRITE);
1642         if (ret < 0) {
1643                 mlog_errno(ret);
1644                 goto out;
1645         }
1646
1647         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1648         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1649         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1650         ocfs2_journal_dirty(handle, di_bh);
1651
1652 out:
1653         return ret;
1654 }
1655
1656 void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1657                                        struct buffer_head *di_bh,
1658                                        u32 num_bits,
1659                                        u16 chain)
1660 {
1661         u32 tmp_used;
1662         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1663         struct ocfs2_chain_list *cl;
1664
1665         cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1666         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1667         di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1668         le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1669 }
1670
1671 static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1672                                          struct ocfs2_extent_rec *rec,
1673                                          struct ocfs2_chain_list *cl)
1674 {
1675         unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1676         unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1677         unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1678
1679         if (res->sr_bit_offset < bitoff)
1680                 return 0;
1681         if (res->sr_bit_offset >= (bitoff + bitcount))
1682                 return 0;
1683         res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1684                 (res->sr_bit_offset - bitoff);
1685         if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1686                 res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1687         return 1;
1688 }
1689
1690 static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1691                                           struct ocfs2_group_desc *bg,
1692                                           struct ocfs2_suballoc_result *res)
1693 {
1694         int i;
1695         u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1696         struct ocfs2_extent_rec *rec;
1697         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1698         struct ocfs2_chain_list *cl = &di->id2.i_chain;
1699
1700         if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1701                 res->sr_blkno = 0;
1702                 return;
1703         }
1704
1705         res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1706         res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1707         if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1708             !bg->bg_list.l_next_free_rec)
1709                 return;
1710
1711         for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1712                 rec = &bg->bg_list.l_recs[i];
1713                 if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1714                         res->sr_bg_blkno = bg_blkno;  /* Restore */
1715                         break;
1716                 }
1717         }
1718 }
1719
1720 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1721                                   handle_t *handle,
1722                                   u32 bits_wanted,
1723                                   u32 min_bits,
1724                                   struct ocfs2_suballoc_result *res,
1725                                   u16 *bits_left)
1726 {
1727         int ret;
1728         struct buffer_head *group_bh = NULL;
1729         struct ocfs2_group_desc *gd;
1730         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1731         struct inode *alloc_inode = ac->ac_inode;
1732
1733         ret = ocfs2_read_group_descriptor(alloc_inode, di,
1734                                           res->sr_bg_blkno, &group_bh);
1735         if (ret < 0) {
1736                 mlog_errno(ret);
1737                 return ret;
1738         }
1739
1740         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1741         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1742                                   ac->ac_max_block, res);
1743         if (ret < 0) {
1744                 if (ret != -ENOSPC)
1745                         mlog_errno(ret);
1746                 goto out;
1747         }
1748
1749         if (!ret)
1750                 ocfs2_bg_discontig_fix_result(ac, gd, res);
1751
1752         /*
1753          * sr_bg_blkno might have been changed by
1754          * ocfs2_bg_discontig_fix_result
1755          */
1756         res->sr_bg_stable_blkno = group_bh->b_blocknr;
1757
1758         if (ac->ac_find_loc_only)
1759                 goto out_loc_only;
1760
1761         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1762                                                res->sr_bits,
1763                                                le16_to_cpu(gd->bg_chain));
1764         if (ret < 0) {
1765                 mlog_errno(ret);
1766                 goto out;
1767         }
1768
1769         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1770                                          res->sr_bit_offset, res->sr_bits,
1771                                          res->sr_max_contig_bits, 0);
1772         if (ret < 0) {
1773                 ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1774                                                res->sr_bits,
1775                                                le16_to_cpu(gd->bg_chain));
1776                 mlog_errno(ret);
1777         }
1778
1779 out_loc_only:
1780         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1781
1782 out:
1783         brelse(group_bh);
1784
1785         return ret;
1786 }
1787
1788 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1789                               handle_t *handle,
1790                               u32 bits_wanted,
1791                               u32 min_bits,
1792                               struct ocfs2_suballoc_result *res,
1793                               u16 *bits_left)
1794 {
1795         int status;
1796         u16 chain;
1797         u64 next_group;
1798         struct inode *alloc_inode = ac->ac_inode;
1799         struct buffer_head *group_bh = NULL;
1800         struct buffer_head *prev_group_bh = NULL;
1801         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1802         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1803         struct ocfs2_group_desc *bg;
1804
1805         chain = ac->ac_chain;
1806         trace_ocfs2_search_chain_begin(
1807                 (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1808                 bits_wanted, chain);
1809
1810         status = ocfs2_read_group_descriptor(alloc_inode, fe,
1811                                              le64_to_cpu(cl->cl_recs[chain].c_blkno),
1812                                              &group_bh);
1813         if (status < 0) {
1814                 mlog_errno(status);
1815                 goto bail;
1816         }
1817         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1818
1819         status = -ENOSPC;
1820         /* for now, the chain search is a bit simplistic. We just use
1821          * the 1st group with any empty bits. */
1822         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1823                                              bits_wanted, min_bits,
1824                                              ac->ac_max_block,
1825                                              res)) == -ENOSPC) {
1826                 if (!bg->bg_next_group)
1827                         break;
1828
1829                 brelse(prev_group_bh);
1830                 prev_group_bh = NULL;
1831
1832                 next_group = le64_to_cpu(bg->bg_next_group);
1833                 prev_group_bh = group_bh;
1834                 group_bh = NULL;
1835                 status = ocfs2_read_group_descriptor(alloc_inode, fe,
1836                                                      next_group, &group_bh);
1837                 if (status < 0) {
1838                         mlog_errno(status);
1839                         goto bail;
1840                 }
1841                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1842         }
1843         if (status < 0) {
1844                 if (status != -ENOSPC)
1845                         mlog_errno(status);
1846                 goto bail;
1847         }
1848
1849         trace_ocfs2_search_chain_succ(
1850                 (unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1851
1852         res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1853
1854         BUG_ON(res->sr_bits == 0);
1855         if (!status)
1856                 ocfs2_bg_discontig_fix_result(ac, bg, res);
1857
1858         /*
1859          * sr_bg_blkno might have been changed by
1860          * ocfs2_bg_discontig_fix_result
1861          */
1862         res->sr_bg_stable_blkno = group_bh->b_blocknr;
1863
1864         /*
1865          * Keep track of previous block descriptor read. When
1866          * we find a target, if we have read more than X
1867          * number of descriptors, and the target is reasonably
1868          * empty, relink him to top of his chain.
1869          *
1870          * We've read 0 extra blocks and only send one more to
1871          * the transaction, yet the next guy to search has a
1872          * much easier time.
1873          *
1874          * Do this *after* figuring out how many bits we're taking out
1875          * of our target group.
1876          */
1877         if (!ac->ac_disable_chain_relink &&
1878             (prev_group_bh) &&
1879             (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1880                 status = ocfs2_relink_block_group(handle, alloc_inode,
1881                                                   ac->ac_bh, group_bh,
1882                                                   prev_group_bh, chain);
1883                 if (status < 0) {
1884                         mlog_errno(status);
1885                         goto bail;
1886                 }
1887         }
1888
1889         if (ac->ac_find_loc_only)
1890                 goto out_loc_only;
1891
1892         status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1893                                                   ac->ac_bh, res->sr_bits,
1894                                                   chain);
1895         if (status) {
1896                 mlog_errno(status);
1897                 goto bail;
1898         }
1899
1900         status = ocfs2_block_group_set_bits(handle,
1901                                             alloc_inode,
1902                                             bg,
1903                                             group_bh,
1904                                             res->sr_bit_offset,
1905                                             res->sr_bits,
1906                                             res->sr_max_contig_bits,
1907                                             0);
1908         if (status < 0) {
1909                 ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1910                                         ac->ac_bh, res->sr_bits, chain);
1911                 mlog_errno(status);
1912                 goto bail;
1913         }
1914
1915         trace_ocfs2_search_chain_end(
1916                         (unsigned long long)le64_to_cpu(fe->i_blkno),
1917                         res->sr_bits);
1918
1919 out_loc_only:
1920         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1921 bail:
1922         brelse(group_bh);
1923         brelse(prev_group_bh);
1924
1925         if (status)
1926                 mlog_errno(status);
1927         return status;
1928 }
1929
1930 /* will give out up to bits_wanted contiguous bits. */
1931 static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1932                                      handle_t *handle,
1933                                      u32 bits_wanted,
1934                                      u32 min_bits,
1935                                      struct ocfs2_suballoc_result *res)
1936 {
1937         int status;
1938         u16 victim, i;
1939         u16 bits_left = 0;
1940         u64 hint = ac->ac_last_group;
1941         struct ocfs2_chain_list *cl;
1942         struct ocfs2_dinode *fe;
1943
1944         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1945         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1946         BUG_ON(!ac->ac_bh);
1947
1948         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1949
1950         /* The bh was validated by the inode read during
1951          * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1952         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1953
1954         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1955             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1956                 status = ocfs2_error(ac->ac_inode->i_sb,
1957                                      "Chain allocator dinode %llu has %u used bits but only %u total\n",
1958                                      (unsigned long long)le64_to_cpu(fe->i_blkno),
1959                                      le32_to_cpu(fe->id1.bitmap1.i_used),
1960                                      le32_to_cpu(fe->id1.bitmap1.i_total));
1961                 goto bail;
1962         }
1963
1964         res->sr_bg_blkno = hint;
1965         if (res->sr_bg_blkno) {
1966                 /* Attempt to short-circuit the usual search mechanism
1967                  * by jumping straight to the most recently used
1968                  * allocation group. This helps us maintain some
1969                  * contiguousness across allocations. */
1970                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1971                                                 min_bits, res, &bits_left);
1972                 if (!status)
1973                         goto set_hint;
1974                 if (status < 0 && status != -ENOSPC) {
1975                         mlog_errno(status);
1976                         goto bail;
1977                 }
1978         }
1979
1980         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1981
1982         victim = ocfs2_find_victim_chain(cl);
1983         ac->ac_chain = victim;
1984
1985         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1986                                     res, &bits_left);
1987         if (!status) {
1988                 if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1989                         hint = res->sr_bg_blkno;
1990                 else
1991                         hint = ocfs2_group_from_res(res);
1992                 goto set_hint;
1993         }
1994         if (status < 0 && status != -ENOSPC) {
1995                 mlog_errno(status);
1996                 goto bail;
1997         }
1998
1999         trace_ocfs2_claim_suballoc_bits(victim);
2000
2001         /* If we didn't pick a good victim, then just default to
2002          * searching each chain in order. Don't allow chain relinking
2003          * because we only calculate enough journal credits for one
2004          * relink per alloc. */
2005         ac->ac_disable_chain_relink = 1;
2006         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
2007                 if (i == victim)
2008                         continue;
2009                 if (le32_to_cpu(cl->cl_recs[i].c_free) < bits_wanted)
2010                         continue;
2011
2012                 ac->ac_chain = i;
2013                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
2014                                             res, &bits_left);
2015                 if (!status) {
2016                         hint = ocfs2_group_from_res(res);
2017                         break;
2018                 }
2019                 if (status < 0 && status != -ENOSPC) {
2020                         mlog_errno(status);
2021                         goto bail;
2022                 }
2023         }
2024
2025 set_hint:
2026         if (status != -ENOSPC) {
2027                 /* If the next search of this group is not likely to
2028                  * yield a suitable extent, then we reset the last
2029                  * group hint so as to not waste a disk read */
2030                 if (bits_left < min_bits)
2031                         ac->ac_last_group = 0;
2032                 else
2033                         ac->ac_last_group = hint;
2034         }
2035
2036 bail:
2037         if (status)
2038                 mlog_errno(status);
2039         return status;
2040 }
2041
2042 int ocfs2_claim_metadata(handle_t *handle,
2043                          struct ocfs2_alloc_context *ac,
2044                          u32 bits_wanted,
2045                          u64 *suballoc_loc,
2046                          u16 *suballoc_bit_start,
2047                          unsigned int *num_bits,
2048                          u64 *blkno_start)
2049 {
2050         int status;
2051         struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2052
2053         BUG_ON(!ac);
2054         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2055         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2056
2057         status = ocfs2_claim_suballoc_bits(ac,
2058                                            handle,
2059                                            bits_wanted,
2060                                            1,
2061                                            &res);
2062         if (status < 0) {
2063                 mlog_errno(status);
2064                 goto bail;
2065         }
2066         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2067
2068         *suballoc_loc = res.sr_bg_blkno;
2069         *suballoc_bit_start = res.sr_bit_offset;
2070         *blkno_start = res.sr_blkno;
2071         ac->ac_bits_given += res.sr_bits;
2072         *num_bits = res.sr_bits;
2073         status = 0;
2074 bail:
2075         if (status)
2076                 mlog_errno(status);
2077         return status;
2078 }
2079
2080 static void ocfs2_init_inode_ac_group(struct inode *dir,
2081                                       struct buffer_head *parent_di_bh,
2082                                       struct ocfs2_alloc_context *ac)
2083 {
2084         struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2085         /*
2086          * Try to allocate inodes from some specific group.
2087          *
2088          * If the parent dir has recorded the last group used in allocation,
2089          * cool, use it. Otherwise if we try to allocate new inode from the
2090          * same slot the parent dir belongs to, use the same chunk.
2091          *
2092          * We are very careful here to avoid the mistake of setting
2093          * ac_last_group to a group descriptor from a different (unlocked) slot.
2094          */
2095         if (OCFS2_I(dir)->ip_last_used_group &&
2096             OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2097                 ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2098         else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2099                 if (di->i_suballoc_loc)
2100                         ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2101                 else
2102                         ac->ac_last_group = ocfs2_which_suballoc_group(
2103                                         le64_to_cpu(di->i_blkno),
2104                                         le16_to_cpu(di->i_suballoc_bit));
2105         }
2106 }
2107
2108 static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2109                                              struct ocfs2_alloc_context *ac)
2110 {
2111         OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2112         OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2113 }
2114
2115 int ocfs2_find_new_inode_loc(struct inode *dir,
2116                              struct buffer_head *parent_fe_bh,
2117                              struct ocfs2_alloc_context *ac,
2118                              u64 *fe_blkno)
2119 {
2120         int ret;
2121         handle_t *handle = NULL;
2122         struct ocfs2_suballoc_result *res;
2123
2124         BUG_ON(!ac);
2125         BUG_ON(ac->ac_bits_given != 0);
2126         BUG_ON(ac->ac_bits_wanted != 1);
2127         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2128
2129         res = kzalloc(sizeof(*res), GFP_NOFS);
2130         if (res == NULL) {
2131                 ret = -ENOMEM;
2132                 mlog_errno(ret);
2133                 goto out;
2134         }
2135
2136         ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2137
2138         /*
2139          * The handle started here is for chain relink. Alternatively,
2140          * we could just disable relink for these calls.
2141          */
2142         handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2143         if (IS_ERR(handle)) {
2144                 ret = PTR_ERR(handle);
2145                 handle = NULL;
2146                 mlog_errno(ret);
2147                 goto out;
2148         }
2149
2150         /*
2151          * This will instruct ocfs2_claim_suballoc_bits and
2152          * ocfs2_search_one_group to search but save actual allocation
2153          * for later.
2154          */
2155         ac->ac_find_loc_only = 1;
2156
2157         ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2158         if (ret < 0) {
2159                 mlog_errno(ret);
2160                 goto out;
2161         }
2162
2163         ac->ac_find_loc_priv = res;
2164         *fe_blkno = res->sr_blkno;
2165         ocfs2_update_inode_fsync_trans(handle, dir, 0);
2166 out:
2167         if (handle)
2168                 ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2169
2170         if (ret)
2171                 kfree(res);
2172
2173         return ret;
2174 }
2175
2176 int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2177                                  struct inode *dir,
2178                                  struct ocfs2_alloc_context *ac,
2179                                  u64 *suballoc_loc,
2180                                  u16 *suballoc_bit,
2181                                  u64 di_blkno)
2182 {
2183         int ret;
2184         u16 chain;
2185         struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2186         struct buffer_head *bg_bh = NULL;
2187         struct ocfs2_group_desc *bg;
2188         struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2189
2190         /*
2191          * Since di_blkno is being passed back in, we check for any
2192          * inconsistencies which may have happened between
2193          * calls. These are code bugs as di_blkno is not expected to
2194          * change once returned from ocfs2_find_new_inode_loc()
2195          */
2196         BUG_ON(res->sr_blkno != di_blkno);
2197
2198         ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2199                                           res->sr_bg_stable_blkno, &bg_bh);
2200         if (ret) {
2201                 mlog_errno(ret);
2202                 goto out;
2203         }
2204
2205         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2206         chain = le16_to_cpu(bg->bg_chain);
2207
2208         ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2209                                                ac->ac_bh, res->sr_bits,
2210                                                chain);
2211         if (ret) {
2212                 mlog_errno(ret);
2213                 goto out;
2214         }
2215
2216         ret = ocfs2_block_group_set_bits(handle,
2217                                          ac->ac_inode,
2218                                          bg,
2219                                          bg_bh,
2220                                          res->sr_bit_offset,
2221                                          res->sr_bits,
2222                                          res->sr_max_contig_bits,
2223                                          0);
2224         if (ret < 0) {
2225                 ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2226                                                ac->ac_bh, res->sr_bits, chain);
2227                 mlog_errno(ret);
2228                 goto out;
2229         }
2230
2231         trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2232                                            res->sr_bits);
2233
2234         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2235
2236         BUG_ON(res->sr_bits != 1);
2237
2238         *suballoc_loc = res->sr_bg_blkno;
2239         *suballoc_bit = res->sr_bit_offset;
2240         ac->ac_bits_given++;
2241         ocfs2_save_inode_ac_group(dir, ac);
2242
2243 out:
2244         brelse(bg_bh);
2245
2246         return ret;
2247 }
2248
2249 int ocfs2_claim_new_inode(handle_t *handle,
2250                           struct inode *dir,
2251                           struct buffer_head *parent_fe_bh,
2252                           struct ocfs2_alloc_context *ac,
2253                           u64 *suballoc_loc,
2254                           u16 *suballoc_bit,
2255                           u64 *fe_blkno)
2256 {
2257         int status;
2258         struct ocfs2_suballoc_result res;
2259
2260         BUG_ON(!ac);
2261         BUG_ON(ac->ac_bits_given != 0);
2262         BUG_ON(ac->ac_bits_wanted != 1);
2263         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2264
2265         ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2266
2267         status = ocfs2_claim_suballoc_bits(ac,
2268                                            handle,
2269                                            1,
2270                                            1,
2271                                            &res);
2272         if (status < 0) {
2273                 mlog_errno(status);
2274                 goto bail;
2275         }
2276         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2277
2278         BUG_ON(res.sr_bits != 1);
2279
2280         *suballoc_loc = res.sr_bg_blkno;
2281         *suballoc_bit = res.sr_bit_offset;
2282         *fe_blkno = res.sr_blkno;
2283         ac->ac_bits_given++;
2284         ocfs2_save_inode_ac_group(dir, ac);
2285         status = 0;
2286 bail:
2287         if (status)
2288                 mlog_errno(status);
2289         return status;
2290 }
2291
2292 /* translate a group desc. blkno and it's bitmap offset into
2293  * disk cluster offset. */
2294 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2295                                                    u64 bg_blkno,
2296                                                    u16 bg_bit_off)
2297 {
2298         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2299         u32 cluster = 0;
2300
2301         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2302
2303         if (bg_blkno != osb->first_cluster_group_blkno)
2304                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2305         cluster += (u32) bg_bit_off;
2306         return cluster;
2307 }
2308
2309 /* given a cluster offset, calculate which block group it belongs to
2310  * and return that block offset. */
2311 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2312 {
2313         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2314         u32 group_no;
2315
2316         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2317
2318         group_no = cluster / osb->bitmap_cpg;
2319         if (!group_no)
2320                 return osb->first_cluster_group_blkno;
2321         return ocfs2_clusters_to_blocks(inode->i_sb,
2322                                         group_no * osb->bitmap_cpg);
2323 }
2324
2325 /* given the block number of a cluster start, calculate which cluster
2326  * group and descriptor bitmap offset that corresponds to. */
2327 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2328                                                 u64 data_blkno,
2329                                                 u64 *bg_blkno,
2330                                                 u16 *bg_bit_off)
2331 {
2332         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2333         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2334
2335         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2336
2337         *bg_blkno = ocfs2_which_cluster_group(inode,
2338                                               data_cluster);
2339
2340         if (*bg_blkno == osb->first_cluster_group_blkno)
2341                 *bg_bit_off = (u16) data_cluster;
2342         else
2343                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2344                                                              data_blkno - *bg_blkno);
2345 }
2346
2347 /*
2348  * min_bits - minimum contiguous chunk from this total allocation we
2349  * can handle. set to what we asked for originally for a full
2350  * contig. allocation, set to '1' to indicate we can deal with extents
2351  * of any size.
2352  */
2353 int __ocfs2_claim_clusters(handle_t *handle,
2354                            struct ocfs2_alloc_context *ac,
2355                            u32 min_clusters,
2356                            u32 max_clusters,
2357                            u32 *cluster_start,
2358                            u32 *num_clusters)
2359 {
2360         int status;
2361         unsigned int bits_wanted = max_clusters;
2362         struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2363         struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2364
2365         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2366
2367         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2368                && ac->ac_which != OCFS2_AC_USE_MAIN);
2369
2370         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2371                 WARN_ON(min_clusters > 1);
2372
2373                 status = ocfs2_claim_local_alloc_bits(osb,
2374                                                       handle,
2375                                                       ac,
2376                                                       bits_wanted,
2377                                                       cluster_start,
2378                                                       num_clusters);
2379                 if (!status)
2380                         atomic_inc(&osb->alloc_stats.local_data);
2381         } else {
2382                 if (min_clusters > (osb->bitmap_cpg - 1)) {
2383                         /* The only paths asking for contiguousness
2384                          * should know about this already. */
2385                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2386                              "group bitmap size %u!\n", min_clusters,
2387                              osb->bitmap_cpg);
2388                         status = -ENOSPC;
2389                         goto bail;
2390                 }
2391                 /* clamp the current request down to a realistic size. */
2392                 if (bits_wanted > (osb->bitmap_cpg - 1))
2393                         bits_wanted = osb->bitmap_cpg - 1;
2394
2395                 status = ocfs2_claim_suballoc_bits(ac,
2396                                                    handle,
2397                                                    bits_wanted,
2398                                                    min_clusters,
2399                                                    &res);
2400                 if (!status) {
2401                         BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2402                         *cluster_start =
2403                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2404                                                                  res.sr_bg_blkno,
2405                                                                  res.sr_bit_offset);
2406                         atomic_inc(&osb->alloc_stats.bitmap_data);
2407                         *num_clusters = res.sr_bits;
2408                 }
2409         }
2410         if (status < 0) {
2411                 if (status != -ENOSPC)
2412                         mlog_errno(status);
2413                 goto bail;
2414         }
2415
2416         ac->ac_bits_given += *num_clusters;
2417
2418 bail:
2419         if (status)
2420                 mlog_errno(status);
2421         return status;
2422 }
2423
2424 int ocfs2_claim_clusters(handle_t *handle,
2425                          struct ocfs2_alloc_context *ac,
2426                          u32 min_clusters,
2427                          u32 *cluster_start,
2428                          u32 *num_clusters)
2429 {
2430         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2431
2432         return __ocfs2_claim_clusters(handle, ac, min_clusters,
2433                                       bits_wanted, cluster_start, num_clusters);
2434 }
2435
2436 static int ocfs2_block_group_clear_bits(handle_t *handle,
2437                                         struct inode *alloc_inode,
2438                                         struct ocfs2_group_desc *bg,
2439                                         struct buffer_head *group_bh,
2440                                         unsigned int bit_off,
2441                                         unsigned int num_bits,
2442                                         unsigned int max_contig_bits,
2443                                         void (*undo_fn)(unsigned int bit,
2444                                                         unsigned long *bmap))
2445 {
2446         int status;
2447         unsigned int tmp;
2448         u16 contig_bits;
2449         struct ocfs2_group_desc *undo_bg = NULL;
2450         struct journal_head *jh;
2451
2452         /* The caller got this descriptor from
2453          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2454         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2455
2456         trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2457
2458         BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2459         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2460                                          group_bh,
2461                                          undo_fn ?
2462                                          OCFS2_JOURNAL_ACCESS_UNDO :
2463                                          OCFS2_JOURNAL_ACCESS_WRITE);
2464         if (status < 0) {
2465                 mlog_errno(status);
2466                 goto bail;
2467         }
2468
2469         jh = bh2jh(group_bh);
2470         if (undo_fn) {
2471                 spin_lock(&jh->b_state_lock);
2472                 undo_bg = (struct ocfs2_group_desc *) jh->b_committed_data;
2473                 BUG_ON(!undo_bg);
2474         }
2475
2476         tmp = num_bits;
2477         while(tmp--) {
2478                 ocfs2_clear_bit((bit_off + tmp),
2479                                 (unsigned long *) bg->bg_bitmap);
2480                 if (undo_fn)
2481                         undo_fn(bit_off + tmp,
2482                                 (unsigned long *) undo_bg->bg_bitmap);
2483         }
2484         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2485         if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2486                 if (undo_fn)
2487                         spin_unlock(&jh->b_state_lock);
2488                 return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
2489                                    (unsigned long long)le64_to_cpu(bg->bg_blkno),
2490                                    le16_to_cpu(bg->bg_bits),
2491                                    le16_to_cpu(bg->bg_free_bits_count),
2492                                    num_bits);
2493         }
2494
2495         /*
2496          * TODO: even 'num_bits == 1' (the worst case, release 1 cluster),
2497          * we still need to rescan whole bitmap.
2498          */
2499         if (ocfs2_is_cluster_bitmap(alloc_inode)) {
2500                 contig_bits = ocfs2_find_max_contig_free_bits(bg->bg_bitmap,
2501                                     le16_to_cpu(bg->bg_bits), 0);
2502                 if (contig_bits > max_contig_bits)
2503                         max_contig_bits = contig_bits;
2504                 bg->bg_contig_free_bits = cpu_to_le16(max_contig_bits);
2505         } else {
2506                 bg->bg_contig_free_bits = 0;
2507         }
2508
2509         if (undo_fn)
2510                 spin_unlock(&jh->b_state_lock);
2511
2512         ocfs2_journal_dirty(handle, group_bh);
2513 bail:
2514         return status;
2515 }
2516
2517 /*
2518  * expects the suballoc inode to already be locked.
2519  */
2520 static int _ocfs2_free_suballoc_bits(handle_t *handle,
2521                                      struct inode *alloc_inode,
2522                                      struct buffer_head *alloc_bh,
2523                                      unsigned int start_bit,
2524                                      u64 bg_blkno,
2525                                      unsigned int count,
2526                                      void (*undo_fn)(unsigned int bit,
2527                                                      unsigned long *bitmap))
2528 {
2529         int status = 0;
2530         u32 tmp_used;
2531         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2532         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2533         struct buffer_head *group_bh = NULL;
2534         struct ocfs2_group_desc *group;
2535         __le16 old_bg_contig_free_bits = 0;
2536
2537         /* The alloc_bh comes from ocfs2_free_dinode() or
2538          * ocfs2_free_clusters().  The callers have all locked the
2539          * allocator and gotten alloc_bh from the lock call.  This
2540          * validates the dinode buffer.  Any corruption that has happened
2541          * is a code bug. */
2542         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2543         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2544
2545         trace_ocfs2_free_suballoc_bits(
2546                 (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2547                 (unsigned long long)bg_blkno,
2548                 start_bit, count);
2549
2550         status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2551                                              &group_bh);
2552         if (status < 0) {
2553                 mlog_errno(status);
2554                 goto bail;
2555         }
2556         group = (struct ocfs2_group_desc *) group_bh->b_data;
2557
2558         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2559
2560         if (ocfs2_is_cluster_bitmap(alloc_inode))
2561                 old_bg_contig_free_bits = group->bg_contig_free_bits;
2562         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2563                                               group, group_bh,
2564                                               start_bit, count, 0, undo_fn);
2565         if (status < 0) {
2566                 mlog_errno(status);
2567                 goto bail;
2568         }
2569
2570         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2571                                          alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2572         if (status < 0) {
2573                 mlog_errno(status);
2574                 ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2575                                 start_bit, count,
2576                                 le16_to_cpu(old_bg_contig_free_bits), 1);
2577                 goto bail;
2578         }
2579
2580         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2581                      count);
2582         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2583         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2584         ocfs2_journal_dirty(handle, alloc_bh);
2585
2586 bail:
2587         brelse(group_bh);
2588         return status;
2589 }
2590
2591 int ocfs2_free_suballoc_bits(handle_t *handle,
2592                              struct inode *alloc_inode,
2593                              struct buffer_head *alloc_bh,
2594                              unsigned int start_bit,
2595                              u64 bg_blkno,
2596                              unsigned int count)
2597 {
2598         return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2599                                          start_bit, bg_blkno, count, NULL);
2600 }
2601
2602 int ocfs2_free_dinode(handle_t *handle,
2603                       struct inode *inode_alloc_inode,
2604                       struct buffer_head *inode_alloc_bh,
2605                       struct ocfs2_dinode *di)
2606 {
2607         u64 blk = le64_to_cpu(di->i_blkno);
2608         u16 bit = le16_to_cpu(di->i_suballoc_bit);
2609         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2610
2611         if (di->i_suballoc_loc)
2612                 bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2613         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2614                                         inode_alloc_bh, bit, bg_blkno, 1);
2615 }
2616
2617 static int _ocfs2_free_clusters(handle_t *handle,
2618                                 struct inode *bitmap_inode,
2619                                 struct buffer_head *bitmap_bh,
2620                                 u64 start_blk,
2621                                 unsigned int num_clusters,
2622                                 void (*undo_fn)(unsigned int bit,
2623                                                 unsigned long *bitmap))
2624 {
2625         int status;
2626         u16 bg_start_bit;
2627         u64 bg_blkno;
2628
2629         /* You can't ever have a contiguous set of clusters
2630          * bigger than a block group bitmap so we never have to worry
2631          * about looping on them.
2632          * This is expensive. We can safely remove once this stuff has
2633          * gotten tested really well. */
2634         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb,
2635                                 ocfs2_blocks_to_clusters(bitmap_inode->i_sb,
2636                                                          start_blk)));
2637
2638
2639         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2640                                      &bg_start_bit);
2641
2642         trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2643                         (unsigned long long)start_blk,
2644                         bg_start_bit, num_clusters);
2645
2646         status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2647                                            bg_start_bit, bg_blkno,
2648                                            num_clusters, undo_fn);
2649         if (status < 0) {
2650                 mlog_errno(status);
2651                 goto out;
2652         }
2653
2654         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2655                                          num_clusters);
2656
2657 out:
2658         return status;
2659 }
2660
2661 int ocfs2_free_clusters(handle_t *handle,
2662                         struct inode *bitmap_inode,
2663                         struct buffer_head *bitmap_bh,
2664                         u64 start_blk,
2665                         unsigned int num_clusters)
2666 {
2667         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2668                                     start_blk, num_clusters,
2669                                     _ocfs2_set_bit);
2670 }
2671
2672 /*
2673  * Give never-used clusters back to the global bitmap.  We don't need
2674  * to protect these bits in the undo buffer.
2675  */
2676 int ocfs2_release_clusters(handle_t *handle,
2677                            struct inode *bitmap_inode,
2678                            struct buffer_head *bitmap_bh,
2679                            u64 start_blk,
2680                            unsigned int num_clusters)
2681 {
2682         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2683                                     start_blk, num_clusters,
2684                                     _ocfs2_clear_bit);
2685 }
2686
2687 /*
2688  * For a given allocation, determine which allocators will need to be
2689  * accessed, and lock them, reserving the appropriate number of bits.
2690  *
2691  * Sparse file systems call this from ocfs2_write_begin_nolock()
2692  * and ocfs2_allocate_unwritten_extents().
2693  *
2694  * File systems which don't support holes call this from
2695  * ocfs2_extend_allocation().
2696  */
2697 int ocfs2_lock_allocators(struct inode *inode,
2698                           struct ocfs2_extent_tree *et,
2699                           u32 clusters_to_add, u32 extents_to_split,
2700                           struct ocfs2_alloc_context **data_ac,
2701                           struct ocfs2_alloc_context **meta_ac)
2702 {
2703         int ret = 0, num_free_extents;
2704         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2705         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2706
2707         *meta_ac = NULL;
2708         if (data_ac)
2709                 *data_ac = NULL;
2710
2711         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2712
2713         num_free_extents = ocfs2_num_free_extents(et);
2714         if (num_free_extents < 0) {
2715                 ret = num_free_extents;
2716                 mlog_errno(ret);
2717                 goto out;
2718         }
2719
2720         /*
2721          * Sparse allocation file systems need to be more conservative
2722          * with reserving room for expansion - the actual allocation
2723          * happens while we've got a journal handle open so re-taking
2724          * a cluster lock (because we ran out of room for another
2725          * extent) will violate ordering rules.
2726          *
2727          * Most of the time we'll only be seeing this 1 cluster at a time
2728          * anyway.
2729          *
2730          * Always lock for any unwritten extents - we might want to
2731          * add blocks during a split.
2732          */
2733         if (!num_free_extents ||
2734             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2735                 ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2736                 if (ret < 0) {
2737                         if (ret != -ENOSPC)
2738                                 mlog_errno(ret);
2739                         goto out;
2740                 }
2741         }
2742
2743         if (clusters_to_add == 0)
2744                 goto out;
2745
2746         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2747         if (ret < 0) {
2748                 if (ret != -ENOSPC)
2749                         mlog_errno(ret);
2750                 goto out;
2751         }
2752
2753 out:
2754         if (ret) {
2755                 if (*meta_ac) {
2756                         ocfs2_free_alloc_context(*meta_ac);
2757                         *meta_ac = NULL;
2758                 }
2759
2760                 /*
2761                  * We cannot have an error and a non null *data_ac.
2762                  */
2763         }
2764
2765         return ret;
2766 }
2767
2768 /*
2769  * Read the inode specified by blkno to get suballoc_slot and
2770  * suballoc_bit.
2771  */
2772 static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2773                                        u16 *suballoc_slot, u64 *group_blkno,
2774                                        u16 *suballoc_bit)
2775 {
2776         int status;
2777         struct buffer_head *inode_bh = NULL;
2778         struct ocfs2_dinode *inode_fe;
2779
2780         trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2781
2782         /* dirty read disk */
2783         status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2784         if (status < 0) {
2785                 mlog(ML_ERROR, "read block %llu failed %d\n",
2786                      (unsigned long long)blkno, status);
2787                 goto bail;
2788         }
2789
2790         inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2791         if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2792                 mlog(ML_ERROR, "invalid inode %llu requested\n",
2793                      (unsigned long long)blkno);
2794                 status = -EINVAL;
2795                 goto bail;
2796         }
2797
2798         if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2799             (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2800                 mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2801                      (unsigned long long)blkno,
2802                      (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2803                 status = -EINVAL;
2804                 goto bail;
2805         }
2806
2807         if (suballoc_slot)
2808                 *suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2809         if (suballoc_bit)
2810                 *suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2811         if (group_blkno)
2812                 *group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2813
2814 bail:
2815         brelse(inode_bh);
2816
2817         if (status)
2818                 mlog_errno(status);
2819         return status;
2820 }
2821
2822 /*
2823  * test whether bit is SET in allocator bitmap or not.  on success, 0
2824  * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2825  * is returned and *res is meaningless.  Call this after you have
2826  * cluster locked against suballoc, or you may get a result based on
2827  * non-up2date contents
2828  */
2829 static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2830                                    struct inode *suballoc,
2831                                    struct buffer_head *alloc_bh,
2832                                    u64 group_blkno, u64 blkno,
2833                                    u16 bit, int *res)
2834 {
2835         struct ocfs2_dinode *alloc_di;
2836         struct ocfs2_group_desc *group;
2837         struct buffer_head *group_bh = NULL;
2838         u64 bg_blkno;
2839         int status;
2840
2841         trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2842                                       (unsigned int)bit);
2843
2844         alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2845         if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2846                 mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2847                      (unsigned int)bit,
2848                      ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2849                 status = -EINVAL;
2850                 goto bail;
2851         }
2852
2853         bg_blkno = group_blkno ? group_blkno :
2854                    ocfs2_which_suballoc_group(blkno, bit);
2855         status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2856                                              &group_bh);
2857         if (status < 0) {
2858                 mlog(ML_ERROR, "read group %llu failed %d\n",
2859                      (unsigned long long)bg_blkno, status);
2860                 goto bail;
2861         }
2862
2863         group = (struct ocfs2_group_desc *) group_bh->b_data;
2864         *res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2865
2866 bail:
2867         brelse(group_bh);
2868
2869         if (status)
2870                 mlog_errno(status);
2871         return status;
2872 }
2873
2874 /*
2875  * Test if the bit representing this inode (blkno) is set in the
2876  * suballocator.
2877  *
2878  * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2879  *
2880  * In the event of failure, a negative value is returned and *res is
2881  * meaningless.
2882  *
2883  * Callers must make sure to hold nfs_sync_lock to prevent
2884  * ocfs2_delete_inode() on another node from accessing the same
2885  * suballocator concurrently.
2886  */
2887 int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2888 {
2889         int status;
2890         u64 group_blkno = 0;
2891         u16 suballoc_bit = 0, suballoc_slot = 0;
2892         struct inode *inode_alloc_inode;
2893         struct buffer_head *alloc_bh = NULL;
2894
2895         trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2896
2897         status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2898                                              &group_blkno, &suballoc_bit);
2899         if (status < 0) {
2900                 mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2901                 goto bail;
2902         }
2903
2904         if (suballoc_slot == (u16)OCFS2_INVALID_SLOT)
2905                 inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2906                         GLOBAL_INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2907         else
2908                 inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2909                         INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2910         if (!inode_alloc_inode) {
2911                 /* the error code could be inaccurate, but we are not able to
2912                  * get the correct one. */
2913                 status = -EINVAL;
2914                 mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2915                      (u32)suballoc_slot);
2916                 goto bail;
2917         }
2918
2919         inode_lock(inode_alloc_inode);
2920         status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2921         if (status < 0) {
2922                 inode_unlock(inode_alloc_inode);
2923                 iput(inode_alloc_inode);
2924                 mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2925                      (u32)suballoc_slot, status);
2926                 goto bail;
2927         }
2928
2929         status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2930                                          group_blkno, blkno, suballoc_bit, res);
2931         if (status < 0)
2932                 mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2933
2934         ocfs2_inode_unlock(inode_alloc_inode, 0);
2935         inode_unlock(inode_alloc_inode);
2936
2937         iput(inode_alloc_inode);
2938         brelse(alloc_bh);
2939 bail:
2940         if (status)
2941                 mlog_errno(status);
2942         return status;
2943 }