fs/ocfs2/suballoc.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * suballoc.c
   5  *
   6  * metadata alloc and free
   7  * Inspired by ext3 block groups.
   8  *
   9  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public
  13  * License as published by the Free Software Foundation; either
  14  * version 2 of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public
  22  * License along with this program; if not, write to the
  23  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24  * Boston, MA 021110-1307, USA.
  25  */
  26
  27 #include <linux/fs.h>
  28 #include <linux/types.h>
  29 #include <linux/slab.h>
  30 #include <linux/highmem.h>
  31
  32 #include <cluster/masklog.h>
  33
  34 #include "ocfs2.h"
  35
  36 #include "alloc.h"
  37 #include "blockcheck.h"
  38 #include "dlmglue.h"
  39 #include "inode.h"
  40 #include "journal.h"
  41 #include "localalloc.h"
  42 #include "suballoc.h"
  43 #include "super.h"
  44 #include "sysfile.h"
  45 #include "uptodate.h"
  46 #include "ocfs2_trace.h"
  47
  48 #include "buffer_head_io.h"
  49
  50 #define NOT_ALLOC_NEW_GROUP             0
  51 #define ALLOC_NEW_GROUP                 0x1
  52 #define ALLOC_GROUPS_FROM_GLOBAL        0x2
  53
  54 #define OCFS2_MAX_TO_STEAL              1024
  55
  56 struct ocfs2_suballoc_result {
  57         u64             sr_bg_blkno;    /* The bg we allocated from.  Set
  58                                            to 0 when a block group is
  59                                            contiguous. */
  60         u64             sr_bg_stable_blkno; /*
  61                                              * Doesn't change, always
  62                                              * set to target block
  63                                              * group descriptor
  64                                              * block.
  65                                              */
  66         u64             sr_blkno;       /* The first allocated block */
  67         unsigned int    sr_bit_offset;  /* The bit in the bg */
  68         unsigned int    sr_bits;        /* How many bits we claimed */
  69 };
  70
  71 static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
  72 {
  73         if (res->sr_blkno == 0)
  74                 return 0;
  75
  76         if (res->sr_bg_blkno)
  77                 return res->sr_bg_blkno;
  78
  79         return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
  80 }
  81
  82 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
  83 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
  84 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  85 static int ocfs2_block_group_fill(handle_t *handle,
  86                                   struct inode *alloc_inode,
  87                                   struct buffer_head *bg_bh,
  88                                   u64 group_blkno,
  89                                   unsigned int group_clusters,
  90                                   u16 my_chain,
  91                                   struct ocfs2_chain_list *cl);
  92 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  93                                    struct inode *alloc_inode,
  94                                    struct buffer_head *bh,
  95                                    u64 max_block,
  96                                    u64 *last_alloc_group,
  97                                    int flags);
  98
  99 static int ocfs2_cluster_group_search(struct inode *inode,
 100                                       struct buffer_head *group_bh,
 101                                       u32 bits_wanted, u32 min_bits,
 102                                       u64 max_block,
 103                                       struct ocfs2_suballoc_result *res);
 104 static int ocfs2_block_group_search(struct inode *inode,
 105                                     struct buffer_head *group_bh,
 106                                     u32 bits_wanted, u32 min_bits,
 107                                     u64 max_block,
 108                                     struct ocfs2_suballoc_result *res);
 109 static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 110                                      handle_t *handle,
 111                                      u32 bits_wanted,
 112                                      u32 min_bits,
 113                                      struct ocfs2_suballoc_result *res);
 114 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 115                                          int nr);
 116 static int ocfs2_relink_block_group(handle_t *handle,
 117                                     struct inode *alloc_inode,
 118                                     struct buffer_head *fe_bh,
 119                                     struct buffer_head *bg_bh,
 120                                     struct buffer_head *prev_bg_bh,
 121                                     u16 chain);
 122 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 123                                                      u32 wanted);
 124 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 125                                                    u64 bg_blkno,
 126                                                    u16 bg_bit_off);
 127 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 128                                                 u64 data_blkno,
 129                                                 u64 *bg_blkno,
 130                                                 u16 *bg_bit_off);
 131 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 132                                              u32 bits_wanted, u64 max_block,
 133                                              int flags,
 134                                              struct ocfs2_alloc_context **ac);
 135
 136 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 137 {
 138         struct inode *inode = ac->ac_inode;
 139
 140         if (inode) {
 141                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 142                         ocfs2_inode_unlock(inode, 1);
 143
 144                 inode_unlock(inode);
 145
 146                 iput(inode);
 147                 ac->ac_inode = NULL;
 148         }
 149         brelse(ac->ac_bh);
 150         ac->ac_bh = NULL;
 151         ac->ac_resv = NULL;
 152         kfree(ac->ac_find_loc_priv);
 153         ac->ac_find_loc_priv = NULL;
 154 }
 155
 156 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 157 {
 158         ocfs2_free_ac_resource(ac);
 159         kfree(ac);
 160 }
 161
 162 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 163 {
 164         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 165 }
 166
 167 #define do_error(fmt, ...)                                              \
 168 do {                                                                    \
 169         if (resize)                                                     \
 170                 mlog(ML_ERROR, fmt, ##__VA_ARGS__);                     \
 171         else                                                            \
 172                 return ocfs2_error(sb, fmt, ##__VA_ARGS__);             \
 173 } while (0)
 174
 175 static int ocfs2_validate_gd_self(struct super_block *sb,
 176                                   struct buffer_head *bh,
 177                                   int resize)
 178 {
 179         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 180
 181         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 182                 do_error("Group descriptor #%llu has bad signature %.*s\n",
 183                          (unsigned long long)bh->b_blocknr, 7,
 184                          gd->bg_signature);
 185         }
 186
 187         if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 188                 do_error("Group descriptor #%llu has an invalid bg_blkno of %llu\n",
 189                          (unsigned long long)bh->b_blocknr,
 190                          (unsigned long long)le64_to_cpu(gd->bg_blkno));
 191         }
 192
 193         if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 194                 do_error("Group descriptor #%llu has an invalid fs_generation of #%u\n",
 195                          (unsigned long long)bh->b_blocknr,
 196                          le32_to_cpu(gd->bg_generation));
 197         }
 198
 199         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 200                 do_error("Group descriptor #%llu has bit count %u but claims that %u are free\n",
 201                          (unsigned long long)bh->b_blocknr,
 202                          le16_to_cpu(gd->bg_bits),
 203                          le16_to_cpu(gd->bg_free_bits_count));
 204         }
 205
 206         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 207                 do_error("Group descriptor #%llu has bit count %u but max bitmap bits of %u\n",
 208                          (unsigned long long)bh->b_blocknr,
 209                          le16_to_cpu(gd->bg_bits),
 210                          8 * le16_to_cpu(gd->bg_size));
 211         }
 212
 213         return 0;
 214 }
 215
 216 static int ocfs2_validate_gd_parent(struct super_block *sb,
 217                                     struct ocfs2_dinode *di,
 218                                     struct buffer_head *bh,
 219                                     int resize)
 220 {
 221         unsigned int max_bits;
 222         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 223
 224         if (di->i_blkno != gd->bg_parent_dinode) {
 225                 do_error("Group descriptor #%llu has bad parent pointer (%llu, expected %llu)\n",
 226                          (unsigned long long)bh->b_blocknr,
 227                          (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 228                          (unsigned long long)le64_to_cpu(di->i_blkno));
 229         }
 230
 231         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 232         if (le16_to_cpu(gd->bg_bits) > max_bits) {
 233                 do_error("Group descriptor #%llu has bit count of %u\n",
 234                          (unsigned long long)bh->b_blocknr,
 235                          le16_to_cpu(gd->bg_bits));
 236         }
 237
 238         /* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 239         if ((le16_to_cpu(gd->bg_chain) >
 240              le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 241             ((le16_to_cpu(gd->bg_chain) ==
 242              le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 243                 do_error("Group descriptor #%llu has bad chain %u\n",
 244                          (unsigned long long)bh->b_blocknr,
 245                          le16_to_cpu(gd->bg_chain));
 246         }
 247
 248         return 0;
 249 }
 250
 251 #undef do_error
 252
 253 /*
 254  * This version only prints errors.  It does not fail the filesystem, and
 255  * exists only for resize.
 256  */
 257 int ocfs2_check_group_descriptor(struct super_block *sb,
 258                                  struct ocfs2_dinode *di,
 259                                  struct buffer_head *bh)
 260 {
 261         int rc;
 262         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 263
 264         BUG_ON(!buffer_uptodate(bh));
 265
 266         /*
 267          * If the ecc fails, we return the error but otherwise
 268          * leave the filesystem running.  We know any error is
 269          * local to this block.
 270          */
 271         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 272         if (rc) {
 273                 mlog(ML_ERROR,
 274                      "Checksum failed for group descriptor %llu\n",
 275                      (unsigned long long)bh->b_blocknr);
 276         } else
 277                 rc = ocfs2_validate_gd_self(sb, bh, 1);
 278         if (!rc)
 279                 rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 280
 281         return rc;
 282 }
 283
 284 static int ocfs2_validate_group_descriptor(struct super_block *sb,
 285                                            struct buffer_head *bh)
 286 {
 287         int rc;
 288         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 289
 290         trace_ocfs2_validate_group_descriptor(
 291                                         (unsigned long long)bh->b_blocknr);
 292
 293         BUG_ON(!buffer_uptodate(bh));
 294
 295         /*
 296          * If the ecc fails, we return the error but otherwise
 297          * leave the filesystem running.  We know any error is
 298          * local to this block.
 299          */
 300         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 301         if (rc)
 302                 return rc;
 303
 304         /*
 305          * Errors after here are fatal.
 306          */
 307
 308         return ocfs2_validate_gd_self(sb, bh, 0);
 309 }
 310
 311 int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 312                                 u64 gd_blkno, struct buffer_head **bh)
 313 {
 314         int rc;
 315         struct buffer_head *tmp = *bh;
 316
 317         rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 318                               ocfs2_validate_group_descriptor);
 319         if (rc)
 320                 goto out;
 321
 322         rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 323         if (rc) {
 324                 brelse(tmp);
 325                 goto out;
 326         }
 327
 328         /* If ocfs2_read_block() got us a new bh, pass it up. */
 329         if (!*bh)
 330                 *bh = tmp;
 331
 332 out:
 333         return rc;
 334 }
 335
 336 static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 337                                           struct ocfs2_group_desc *bg,
 338                                           struct ocfs2_chain_list *cl,
 339                                           u64 p_blkno, unsigned int clusters)
 340 {
 341         struct ocfs2_extent_list *el = &bg->bg_list;
 342         struct ocfs2_extent_rec *rec;
 343
 344         BUG_ON(!ocfs2_supports_discontig_bg(osb));
 345         if (!el->l_next_free_rec)
 346                 el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 347         rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 348         rec->e_blkno = cpu_to_le64(p_blkno);
 349         rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 350                                   le16_to_cpu(cl->cl_bpc));
 351         rec->e_leaf_clusters = cpu_to_le16(clusters);
 352         le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 353         le16_add_cpu(&bg->bg_free_bits_count,
 354                      clusters * le16_to_cpu(cl->cl_bpc));
 355         le16_add_cpu(&el->l_next_free_rec, 1);
 356 }
 357
 358 static int ocfs2_block_group_fill(handle_t *handle,
 359                                   struct inode *alloc_inode,
 360                                   struct buffer_head *bg_bh,
 361                                   u64 group_blkno,
 362                                   unsigned int group_clusters,
 363                                   u16 my_chain,
 364                                   struct ocfs2_chain_list *cl)
 365 {
 366         int status = 0;
 367         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 368         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 369         struct super_block * sb = alloc_inode->i_sb;
 370
 371         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 372                 status = ocfs2_error(alloc_inode->i_sb,
 373                                      "group block (%llu) != b_blocknr (%llu)\n",
 374                                      (unsigned long long)group_blkno,
 375                                      (unsigned long long) bg_bh->b_blocknr);
 376                 goto bail;
 377         }
 378
 379         status = ocfs2_journal_access_gd(handle,
 380                                          INODE_CACHE(alloc_inode),
 381                                          bg_bh,
 382                                          OCFS2_JOURNAL_ACCESS_CREATE);
 383         if (status < 0) {
 384                 mlog_errno(status);
 385                 goto bail;
 386         }
 387
 388         memset(bg, 0, sb->s_blocksize);
 389         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 390         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 391         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 392                                                 osb->s_feature_incompat));
 393         bg->bg_chain = cpu_to_le16(my_chain);
 394         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 395         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 396         bg->bg_blkno = cpu_to_le64(group_blkno);
 397         if (group_clusters == le16_to_cpu(cl->cl_cpg))
 398                 bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 399         else
 400                 ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 401                                               group_clusters);
 402
 403         /* set the 1st bit in the bitmap to account for the descriptor block */
 404         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 405         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 406
 407         ocfs2_journal_dirty(handle, bg_bh);
 408
 409         /* There is no need to zero out or otherwise initialize the
 410          * other blocks in a group - All valid FS metadata in a block
 411          * group stores the superblock fs_generation value at
 412          * allocation time. */
 413
 414 bail:
 415         if (status)
 416                 mlog_errno(status);
 417         return status;
 418 }
 419
 420 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 421 {
 422         u16 curr, best;
 423
 424         best = curr = 0;
 425         while (curr < le16_to_cpu(cl->cl_count)) {
 426                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 427                     le32_to_cpu(cl->cl_recs[curr].c_total))
 428                         best = curr;
 429                 curr++;
 430         }
 431         return best;
 432 }
 433
 434 static struct buffer_head *
 435 ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 436                                struct inode *alloc_inode,
 437                                struct ocfs2_alloc_context *ac,
 438                                struct ocfs2_chain_list *cl)
 439 {
 440         int status;
 441         u32 bit_off, num_bits;
 442         u64 bg_blkno;
 443         struct buffer_head *bg_bh;
 444         unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 445
 446         status = ocfs2_claim_clusters(handle, ac,
 447                                       le16_to_cpu(cl->cl_cpg), &bit_off,
 448                                       &num_bits);
 449         if (status < 0) {
 450                 if (status != -ENOSPC)
 451                         mlog_errno(status);
 452                 goto bail;
 453         }
 454
 455         /* setup the group */
 456         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 457         trace_ocfs2_block_group_alloc_contig(
 458              (unsigned long long)bg_blkno, alloc_rec);
 459
 460         bg_bh = sb_getblk(osb->sb, bg_blkno);
 461         if (!bg_bh) {
 462                 status = -ENOMEM;
 463                 mlog_errno(status);
 464                 goto bail;
 465         }
 466         ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 467
 468         status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 469                                         bg_blkno, num_bits, alloc_rec, cl);
 470         if (status < 0) {
 471                 brelse(bg_bh);
 472                 mlog_errno(status);
 473         }
 474
 475 bail:
 476         return status ? ERR_PTR(status) : bg_bh;
 477 }
 478
 479 static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 480                                         handle_t *handle,
 481                                         struct ocfs2_alloc_context *ac,
 482                                         unsigned int min_bits,
 483                                         u32 *bit_off, u32 *num_bits)
 484 {
 485         int status = 0;
 486
 487         while (min_bits) {
 488                 status = ocfs2_claim_clusters(handle, ac, min_bits,
 489                                               bit_off, num_bits);
 490                 if (status != -ENOSPC)
 491                         break;
 492
 493                 min_bits >>= 1;
 494         }
 495
 496         return status;
 497 }
 498
 499 static int ocfs2_block_group_grow_discontig(handle_t *handle,
 500                                             struct inode *alloc_inode,
 501                                             struct buffer_head *bg_bh,
 502                                             struct ocfs2_alloc_context *ac,
 503                                             struct ocfs2_chain_list *cl,
 504                                             unsigned int min_bits)
 505 {
 506         int status;
 507         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 508         struct ocfs2_group_desc *bg =
 509                 (struct ocfs2_group_desc *)bg_bh->b_data;
 510         unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 511                          le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 512         u32 p_cpos, clusters;
 513         u64 p_blkno;
 514         struct ocfs2_extent_list *el = &bg->bg_list;
 515
 516         status = ocfs2_journal_access_gd(handle,
 517                                          INODE_CACHE(alloc_inode),
 518                                          bg_bh,
 519                                          OCFS2_JOURNAL_ACCESS_CREATE);
 520         if (status < 0) {
 521                 mlog_errno(status);
 522                 goto bail;
 523         }
 524
 525         while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 526                                 le16_to_cpu(el->l_count))) {
 527                 if (min_bits > needed)
 528                         min_bits = needed;
 529                 status = ocfs2_block_group_claim_bits(osb, handle, ac,
 530                                                       min_bits, &p_cpos,
 531                                                       &clusters);
 532                 if (status < 0) {
 533                         if (status != -ENOSPC)
 534                                 mlog_errno(status);
 535                         goto bail;
 536                 }
 537                 p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 538                 ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 539                                               clusters);
 540
 541                 min_bits = clusters;
 542                 needed = le16_to_cpu(cl->cl_cpg) -
 543                          le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 544         }
 545
 546         if (needed > 0) {
 547                 /*
 548                  * We have used up all the extent rec but can't fill up
 549                  * the cpg. So bail out.
 550                  */
 551                 status = -ENOSPC;
 552                 goto bail;
 553         }
 554
 555         ocfs2_journal_dirty(handle, bg_bh);
 556
 557 bail:
 558         return status;
 559 }
 560
 561 static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 562                                    struct ocfs2_alloc_context *cluster_ac,
 563                                    struct inode *alloc_inode,
 564                                    struct buffer_head *bg_bh)
 565 {
 566         int i, ret;
 567         struct ocfs2_group_desc *bg;
 568         struct ocfs2_extent_list *el;
 569         struct ocfs2_extent_rec *rec;
 570
 571         if (!bg_bh)
 572                 return;
 573
 574         bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 575         el = &bg->bg_list;
 576         for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 577                 rec = &el->l_recs[i];
 578                 ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 579                                           cluster_ac->ac_bh,
 580                                           le64_to_cpu(rec->e_blkno),
 581                                           le16_to_cpu(rec->e_leaf_clusters));
 582                 if (ret)
 583                         mlog_errno(ret);
 584                 /* Try all the clusters to free */
 585         }
 586
 587         ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 588         brelse(bg_bh);
 589 }
 590
 591 static struct buffer_head *
 592 ocfs2_block_group_alloc_discontig(handle_t *handle,
 593                                   struct inode *alloc_inode,
 594                                   struct ocfs2_alloc_context *ac,
 595                                   struct ocfs2_chain_list *cl)
 596 {
 597         int status;
 598         u32 bit_off, num_bits;
 599         u64 bg_blkno;
 600         unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 601         struct buffer_head *bg_bh = NULL;
 602         unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 603         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 604
 605         if (!ocfs2_supports_discontig_bg(osb)) {
 606                 status = -ENOSPC;
 607                 goto bail;
 608         }
 609
 610         status = ocfs2_extend_trans(handle,
 611                                     ocfs2_calc_bg_discontig_credits(osb->sb));
 612         if (status) {
 613                 mlog_errno(status);
 614                 goto bail;
 615         }
 616
 617         /*
 618          * We're going to be grabbing from multiple cluster groups.
 619          * We don't have enough credits to relink them all, and the
 620          * cluster groups will be staying in cache for the duration of
 621          * this operation.
 622          */
 623         ac->ac_disable_chain_relink = 1;
 624
 625         /* Claim the first region */
 626         status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 627                                               &bit_off, &num_bits);
 628         if (status < 0) {
 629                 if (status != -ENOSPC)
 630                         mlog_errno(status);
 631                 goto bail;
 632         }
 633         min_bits = num_bits;
 634
 635         /* setup the group */
 636         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 637         trace_ocfs2_block_group_alloc_discontig(
 638                                 (unsigned long long)bg_blkno, alloc_rec);
 639
 640         bg_bh = sb_getblk(osb->sb, bg_blkno);
 641         if (!bg_bh) {
 642                 status = -ENOMEM;
 643                 mlog_errno(status);
 644                 goto bail;
 645         }
 646         ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 647
 648         status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 649                                         bg_blkno, num_bits, alloc_rec, cl);
 650         if (status < 0) {
 651                 mlog_errno(status);
 652                 goto bail;
 653         }
 654
 655         status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 656                                                   bg_bh, ac, cl, min_bits);
 657         if (status)
 658                 mlog_errno(status);
 659
 660 bail:
 661         if (status)
 662                 ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 663         return status ? ERR_PTR(status) : bg_bh;
 664 }
 665
 666 /*
 667  * We expect the block group allocator to already be locked.
 668  */
 669 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 670                                    struct inode *alloc_inode,
 671                                    struct buffer_head *bh,
 672                                    u64 max_block,
 673                                    u64 *last_alloc_group,
 674                                    int flags)
 675 {
 676         int status, credits;
 677         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 678         struct ocfs2_chain_list *cl;
 679         struct ocfs2_alloc_context *ac = NULL;
 680         handle_t *handle = NULL;
 681         u16 alloc_rec;
 682         struct buffer_head *bg_bh = NULL;
 683         struct ocfs2_group_desc *bg;
 684
 685         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 686
 687         cl = &fe->id2.i_chain;
 688         status = ocfs2_reserve_clusters_with_limit(osb,
 689                                                    le16_to_cpu(cl->cl_cpg),
 690                                                    max_block, flags, &ac);
 691         if (status < 0) {
 692                 if (status != -ENOSPC)
 693                         mlog_errno(status);
 694                 goto bail;
 695         }
 696
 697         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 698                                                  le16_to_cpu(cl->cl_cpg));
 699         handle = ocfs2_start_trans(osb, credits);
 700         if (IS_ERR(handle)) {
 701                 status = PTR_ERR(handle);
 702                 handle = NULL;
 703                 mlog_errno(status);
 704                 goto bail;
 705         }
 706
 707         if (last_alloc_group && *last_alloc_group != 0) {
 708                 trace_ocfs2_block_group_alloc(
 709                                 (unsigned long long)*last_alloc_group);
 710                 ac->ac_last_group = *last_alloc_group;
 711         }
 712
 713         bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 714                                                ac, cl);
 715         if (IS_ERR(bg_bh) && (PTR_ERR(bg_bh) == -ENOSPC))
 716                 bg_bh = ocfs2_block_group_alloc_discontig(handle,
 717                                                           alloc_inode,
 718                                                           ac, cl);
 719         if (IS_ERR(bg_bh)) {
 720                 status = PTR_ERR(bg_bh);
 721                 bg_bh = NULL;
 722                 if (status != -ENOSPC)
 723                         mlog_errno(status);
 724                 goto bail;
 725         }
 726         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 727
 728         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 729                                          bh, OCFS2_JOURNAL_ACCESS_WRITE);
 730         if (status < 0) {
 731                 mlog_errno(status);
 732                 goto bail;
 733         }
 734
 735         alloc_rec = le16_to_cpu(bg->bg_chain);
 736         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 737                      le16_to_cpu(bg->bg_free_bits_count));
 738         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 739                      le16_to_cpu(bg->bg_bits));
 740         cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 741         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 742                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 743
 744         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 745                                         le16_to_cpu(bg->bg_free_bits_count));
 746         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 747         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 748
 749         ocfs2_journal_dirty(handle, bh);
 750
 751         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 752         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 753         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 754                                              le32_to_cpu(fe->i_clusters)));
 755         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 756         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 757         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 758         ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
 759
 760         status = 0;
 761
 762         /* save the new last alloc group so that the caller can cache it. */
 763         if (last_alloc_group)
 764                 *last_alloc_group = ac->ac_last_group;
 765
 766 bail:
 767         if (handle)
 768                 ocfs2_commit_trans(osb, handle);
 769
 770         if (ac)
 771                 ocfs2_free_alloc_context(ac);
 772
 773         brelse(bg_bh);
 774
 775         if (status)
 776                 mlog_errno(status);
 777         return status;
 778 }
 779
 780 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 781                                        struct ocfs2_alloc_context *ac,
 782                                        int type,
 783                                        u32 slot,
 784                                        u64 *last_alloc_group,
 785                                        int flags)
 786 {
 787         int status;
 788         u32 bits_wanted = ac->ac_bits_wanted;
 789         struct inode *alloc_inode;
 790         struct buffer_head *bh = NULL;
 791         struct ocfs2_dinode *fe;
 792         u32 free_bits;
 793
 794         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 795         if (!alloc_inode) {
 796                 mlog_errno(-EINVAL);
 797                 return -EINVAL;
 798         }
 799
 800         inode_lock(alloc_inode);
 801
 802         status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 803         if (status < 0) {
 804                 inode_unlock(alloc_inode);
 805                 iput(alloc_inode);
 806
 807                 mlog_errno(status);
 808                 return status;
 809         }
 810
 811         ac->ac_inode = alloc_inode;
 812         ac->ac_alloc_slot = slot;
 813
 814         fe = (struct ocfs2_dinode *) bh->b_data;
 815
 816         /* The bh was validated by the inode read inside
 817          * ocfs2_inode_lock().  Any corruption is a code bug. */
 818         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 819
 820         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 821                 status = ocfs2_error(alloc_inode->i_sb,
 822                                      "Invalid chain allocator %llu\n",
 823                                      (unsigned long long)le64_to_cpu(fe->i_blkno));
 824                 goto bail;
 825         }
 826
 827         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 828                 le32_to_cpu(fe->id1.bitmap1.i_used);
 829
 830         if (bits_wanted > free_bits) {
 831                 /* cluster bitmap never grows */
 832                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 833                         trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 834                                                                 free_bits);
 835                         status = -ENOSPC;
 836                         goto bail;
 837                 }
 838
 839                 if (!(flags & ALLOC_NEW_GROUP)) {
 840                         trace_ocfs2_reserve_suballoc_bits_no_new_group(
 841                                                 slot, bits_wanted, free_bits);
 842                         status = -ENOSPC;
 843                         goto bail;
 844                 }
 845
 846                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 847                                                  ac->ac_max_block,
 848                                                  last_alloc_group, flags);
 849                 if (status < 0) {
 850                         if (status != -ENOSPC)
 851                                 mlog_errno(status);
 852                         goto bail;
 853                 }
 854                 atomic_inc(&osb->alloc_stats.bg_extends);
 855
 856                 /* You should never ask for this much metadata */
 857                 BUG_ON(bits_wanted >
 858                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 859                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 860         }
 861
 862         get_bh(bh);
 863         ac->ac_bh = bh;
 864 bail:
 865         brelse(bh);
 866
 867         if (status)
 868                 mlog_errno(status);
 869         return status;
 870 }
 871
 872 static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 873 {
 874         spin_lock(&osb->osb_lock);
 875         osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 876         spin_unlock(&osb->osb_lock);
 877         atomic_set(&osb->s_num_inodes_stolen, 0);
 878 }
 879
 880 static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 881 {
 882         spin_lock(&osb->osb_lock);
 883         osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 884         spin_unlock(&osb->osb_lock);
 885         atomic_set(&osb->s_num_meta_stolen, 0);
 886 }
 887
 888 void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 889 {
 890         ocfs2_init_inode_steal_slot(osb);
 891         ocfs2_init_meta_steal_slot(osb);
 892 }
 893
 894 static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 895 {
 896         spin_lock(&osb->osb_lock);
 897         if (type == INODE_ALLOC_SYSTEM_INODE)
 898                 osb->s_inode_steal_slot = slot;
 899         else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 900                 osb->s_meta_steal_slot = slot;
 901         spin_unlock(&osb->osb_lock);
 902 }
 903
 904 static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 905 {
 906         int slot = OCFS2_INVALID_SLOT;
 907
 908         spin_lock(&osb->osb_lock);
 909         if (type == INODE_ALLOC_SYSTEM_INODE)
 910                 slot = osb->s_inode_steal_slot;
 911         else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 912                 slot = osb->s_meta_steal_slot;
 913         spin_unlock(&osb->osb_lock);
 914
 915         return slot;
 916 }
 917
 918 static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 919 {
 920         return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 921 }
 922
 923 static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 924 {
 925         return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 926 }
 927
 928 static int ocfs2_steal_resource(struct ocfs2_super *osb,
 929                                 struct ocfs2_alloc_context *ac,
 930                                 int type)
 931 {
 932         int i, status = -ENOSPC;
 933         int slot = __ocfs2_get_steal_slot(osb, type);
 934
 935         /* Start to steal resource from the first slot after ours. */
 936         if (slot == OCFS2_INVALID_SLOT)
 937                 slot = osb->slot_num + 1;
 938
 939         for (i = 0; i < osb->max_slots; i++, slot++) {
 940                 if (slot == osb->max_slots)
 941                         slot = 0;
 942
 943                 if (slot == osb->slot_num)
 944                         continue;
 945
 946                 status = ocfs2_reserve_suballoc_bits(osb, ac,
 947                                                      type,
 948                                                      (u32)slot, NULL,
 949                                                      NOT_ALLOC_NEW_GROUP);
 950                 if (status >= 0) {
 951                         __ocfs2_set_steal_slot(osb, slot, type);
 952                         break;
 953                 }
 954
 955                 ocfs2_free_ac_resource(ac);
 956         }
 957
 958         return status;
 959 }
 960
 961 static int ocfs2_steal_inode(struct ocfs2_super *osb,
 962                              struct ocfs2_alloc_context *ac)
 963 {
 964         return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 965 }
 966
 967 static int ocfs2_steal_meta(struct ocfs2_super *osb,
 968                             struct ocfs2_alloc_context *ac)
 969 {
 970         return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 971 }
 972
 973 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 974                                       int blocks,
 975                                       struct ocfs2_alloc_context **ac)
 976 {
 977         int status;
 978         int slot = ocfs2_get_meta_steal_slot(osb);
 979
 980         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 981         if (!(*ac)) {
 982                 status = -ENOMEM;
 983                 mlog_errno(status);
 984                 goto bail;
 985         }
 986
 987         (*ac)->ac_bits_wanted = blocks;
 988         (*ac)->ac_which = OCFS2_AC_USE_META;
 989         (*ac)->ac_group_search = ocfs2_block_group_search;
 990
 991         if (slot != OCFS2_INVALID_SLOT &&
 992                 atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
 993                 goto extent_steal;
 994
 995         atomic_set(&osb->s_num_meta_stolen, 0);
 996         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 997                                              EXTENT_ALLOC_SYSTEM_INODE,
 998                                              (u32)osb->slot_num, NULL,
 999                                              ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
1000
1001
1002         if (status >= 0) {
1003                 status = 0;
1004                 if (slot != OCFS2_INVALID_SLOT)
1005                         ocfs2_init_meta_steal_slot(osb);
1006                 goto bail;
1007         } else if (status < 0 && status != -ENOSPC) {
1008                 mlog_errno(status);
1009                 goto bail;
1010         }
1011
1012         ocfs2_free_ac_resource(*ac);
1013
1014 extent_steal:
1015         status = ocfs2_steal_meta(osb, *ac);
1016         atomic_inc(&osb->s_num_meta_stolen);
1017         if (status < 0) {
1018                 if (status != -ENOSPC)
1019                         mlog_errno(status);
1020                 goto bail;
1021         }
1022
1023         status = 0;
1024 bail:
1025         if ((status < 0) && *ac) {
1026                 ocfs2_free_alloc_context(*ac);
1027                 *ac = NULL;
1028         }
1029
1030         if (status)
1031                 mlog_errno(status);
1032         return status;
1033 }
1034
1035 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1036                                struct ocfs2_extent_list *root_el,
1037                                struct ocfs2_alloc_context **ac)
1038 {
1039         return ocfs2_reserve_new_metadata_blocks(osb,
1040                                         ocfs2_extend_meta_needed(root_el),
1041                                         ac);
1042 }
1043
1044 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1045                             struct ocfs2_alloc_context **ac)
1046 {
1047         int status;
1048         int slot = ocfs2_get_inode_steal_slot(osb);
1049         u64 alloc_group;
1050
1051         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1052         if (!(*ac)) {
1053                 status = -ENOMEM;
1054                 mlog_errno(status);
1055                 goto bail;
1056         }
1057
1058         (*ac)->ac_bits_wanted = 1;
1059         (*ac)->ac_which = OCFS2_AC_USE_INODE;
1060
1061         (*ac)->ac_group_search = ocfs2_block_group_search;
1062
1063         /*
1064          * stat(2) can't handle i_ino > 32bits, so we tell the
1065          * lower levels not to allocate us a block group past that
1066          * limit.  The 'inode64' mount option avoids this behavior.
1067          */
1068         if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1069                 (*ac)->ac_max_block = (u32)~0U;
1070
1071         /*
1072          * slot is set when we successfully steal inode from other nodes.
1073          * It is reset in 3 places:
1074          * 1. when we flush the truncate log
1075          * 2. when we complete local alloc recovery.
1076          * 3. when we successfully allocate from our own slot.
1077          * After it is set, we will go on stealing inodes until we find the
1078          * need to check our slots to see whether there is some space for us.
1079          */
1080         if (slot != OCFS2_INVALID_SLOT &&
1081             atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1082                 goto inode_steal;
1083
1084         atomic_set(&osb->s_num_inodes_stolen, 0);
1085         alloc_group = osb->osb_inode_alloc_group;
1086         status = ocfs2_reserve_suballoc_bits(osb, *ac,
1087                                              INODE_ALLOC_SYSTEM_INODE,
1088                                              (u32)osb->slot_num,
1089                                              &alloc_group,
1090                                              ALLOC_NEW_GROUP |
1091                                              ALLOC_GROUPS_FROM_GLOBAL);
1092         if (status >= 0) {
1093                 status = 0;
1094
1095                 spin_lock(&osb->osb_lock);
1096                 osb->osb_inode_alloc_group = alloc_group;
1097                 spin_unlock(&osb->osb_lock);
1098                 trace_ocfs2_reserve_new_inode_new_group(
1099                         (unsigned long long)alloc_group);
1100
1101                 /*
1102                  * Some inodes must be freed by us, so try to allocate
1103                  * from our own next time.
1104                  */
1105                 if (slot != OCFS2_INVALID_SLOT)
1106                         ocfs2_init_inode_steal_slot(osb);
1107                 goto bail;
1108         } else if (status < 0 && status != -ENOSPC) {
1109                 mlog_errno(status);
1110                 goto bail;
1111         }
1112
1113         ocfs2_free_ac_resource(*ac);
1114
1115 inode_steal:
1116         status = ocfs2_steal_inode(osb, *ac);
1117         atomic_inc(&osb->s_num_inodes_stolen);
1118         if (status < 0) {
1119                 if (status != -ENOSPC)
1120                         mlog_errno(status);
1121                 goto bail;
1122         }
1123
1124         status = 0;
1125 bail:
1126         if ((status < 0) && *ac) {
1127                 ocfs2_free_alloc_context(*ac);
1128                 *ac = NULL;
1129         }
1130
1131         if (status)
1132                 mlog_errno(status);
1133         return status;
1134 }
1135
1136 /* local alloc code has to do the same thing, so rather than do this
1137  * twice.. */
1138 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1139                                       struct ocfs2_alloc_context *ac)
1140 {
1141         int status;
1142
1143         ac->ac_which = OCFS2_AC_USE_MAIN;
1144         ac->ac_group_search = ocfs2_cluster_group_search;
1145
1146         status = ocfs2_reserve_suballoc_bits(osb, ac,
1147                                              GLOBAL_BITMAP_SYSTEM_INODE,
1148                                              OCFS2_INVALID_SLOT, NULL,
1149                                              ALLOC_NEW_GROUP);
1150         if (status < 0 && status != -ENOSPC) {
1151                 mlog_errno(status);
1152                 goto bail;
1153         }
1154
1155 bail:
1156         return status;
1157 }
1158
1159 /* Callers don't need to care which bitmap (local alloc or main) to
1160  * use so we figure it out for them, but unfortunately this clutters
1161  * things a bit. */
1162 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1163                                              u32 bits_wanted, u64 max_block,
1164                                              int flags,
1165                                              struct ocfs2_alloc_context **ac)
1166 {
1167         int status, ret = 0;
1168         int retried = 0;
1169
1170         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1171         if (!(*ac)) {
1172                 status = -ENOMEM;
1173                 mlog_errno(status);
1174                 goto bail;
1175         }
1176
1177         (*ac)->ac_bits_wanted = bits_wanted;
1178         (*ac)->ac_max_block = max_block;
1179
1180         status = -ENOSPC;
1181         if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1182             ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1183                 status = ocfs2_reserve_local_alloc_bits(osb,
1184                                                         bits_wanted,
1185                                                         *ac);
1186                 if ((status < 0) && (status != -ENOSPC)) {
1187                         mlog_errno(status);
1188                         goto bail;
1189                 }
1190         }
1191
1192         if (status == -ENOSPC) {
1193 retry:
1194                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1195                 /* Retry if there is sufficient space cached in truncate log */
1196                 if (status == -ENOSPC && !retried) {
1197                         retried = 1;
1198                         ocfs2_inode_unlock((*ac)->ac_inode, 1);
1199                         inode_unlock((*ac)->ac_inode);
1200
1201                         ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
1202                         if (ret == 1)
1203                                 goto retry;
1204
1205                         if (ret < 0)
1206                                 mlog_errno(ret);
1207
1208                         inode_lock((*ac)->ac_inode);
1209                         ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
1210                 }
1211                 if (status < 0) {
1212                         if (status != -ENOSPC)
1213                                 mlog_errno(status);
1214                         goto bail;
1215                 }
1216         }
1217
1218         status = 0;
1219 bail:
1220         if ((status < 0) && *ac) {
1221                 ocfs2_free_alloc_context(*ac);
1222                 *ac = NULL;
1223         }
1224
1225         if (status)
1226                 mlog_errno(status);
1227         return status;
1228 }
1229
1230 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1231                            u32 bits_wanted,
1232                            struct ocfs2_alloc_context **ac)
1233 {
1234         return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1235                                                  ALLOC_NEW_GROUP, ac);
1236 }
1237
1238 /*
1239  * More or less lifted from ext3. I'll leave their description below:
1240  *
1241  * "For ext3 allocations, we must not reuse any blocks which are
1242  * allocated in the bitmap buffer's "last committed data" copy.  This
1243  * prevents deletes from freeing up the page for reuse until we have
1244  * committed the delete transaction.
1245  *
1246  * If we didn't do this, then deleting something and reallocating it as
1247  * data would allow the old block to be overwritten before the
1248  * transaction committed (because we force data to disk before commit).
1249  * This would lead to corruption if we crashed between overwriting the
1250  * data and committing the delete.
1251  *
1252  * @@@ We may want to make this allocation behaviour conditional on
1253  * data-writes at some point, and disable it for metadata allocations or
1254  * sync-data inodes."
1255  *
1256  * Note: OCFS2 already does this differently for metadata vs data
1257  * allocations, as those bitmaps are separate and undo access is never
1258  * called on a metadata group descriptor.
1259  */
1260 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1261                                          int nr)
1262 {
1263         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1264         int ret;
1265
1266         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1267                 return 0;
1268
1269         if (!buffer_jbd(bg_bh))
1270                 return 1;
1271
1272         jbd_lock_bh_state(bg_bh);
1273         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
1274         if (bg)
1275                 ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1276         else
1277                 ret = 1;
1278         jbd_unlock_bh_state(bg_bh);
1279
1280         return ret;
1281 }
1282
1283 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1284                                              struct buffer_head *bg_bh,
1285                                              unsigned int bits_wanted,
1286                                              unsigned int total_bits,
1287                                              struct ocfs2_suballoc_result *res)
1288 {
1289         void *bitmap;
1290         u16 best_offset, best_size;
1291         int offset, start, found, status = 0;
1292         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1293
1294         /* Callers got this descriptor from
1295          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1296         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1297
1298         found = start = best_offset = best_size = 0;
1299         bitmap = bg->bg_bitmap;
1300
1301         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1302                 if (offset == total_bits)
1303                         break;
1304
1305                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1306                         /* We found a zero, but we can't use it as it
1307                          * hasn't been put to disk yet! */
1308                         found = 0;
1309                         start = offset + 1;
1310                 } else if (offset == start) {
1311                         /* we found a zero */
1312                         found++;
1313                         /* move start to the next bit to test */
1314                         start++;
1315                 } else {
1316                         /* got a zero after some ones */
1317                         found = 1;
1318                         start = offset + 1;
1319                 }
1320                 if (found > best_size) {
1321                         best_size = found;
1322                         best_offset = start - found;
1323                 }
1324                 /* we got everything we needed */
1325                 if (found == bits_wanted) {
1326                         /* mlog(0, "Found it all!\n"); */
1327                         break;
1328                 }
1329         }
1330
1331         if (best_size) {
1332                 res->sr_bit_offset = best_offset;
1333                 res->sr_bits = best_size;
1334         } else {
1335                 status = -ENOSPC;
1336                 /* No error log here -- see the comment above
1337                  * ocfs2_test_bg_bit_allocatable */
1338         }
1339
1340         return status;
1341 }
1342
1343 int ocfs2_block_group_set_bits(handle_t *handle,
1344                                              struct inode *alloc_inode,
1345                                              struct ocfs2_group_desc *bg,
1346                                              struct buffer_head *group_bh,
1347                                              unsigned int bit_off,
1348                                              unsigned int num_bits)
1349 {
1350         int status;
1351         void *bitmap = bg->bg_bitmap;
1352         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1353
1354         /* All callers get the descriptor via
1355          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1356         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1357         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1358
1359         trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1360
1361         if (ocfs2_is_cluster_bitmap(alloc_inode))
1362                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1363
1364         status = ocfs2_journal_access_gd(handle,
1365                                          INODE_CACHE(alloc_inode),
1366                                          group_bh,
1367                                          journal_type);
1368         if (status < 0) {
1369                 mlog_errno(status);
1370                 goto bail;
1371         }
1372
1373         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1374         if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1375                 return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1376                                    (unsigned long long)le64_to_cpu(bg->bg_blkno),
1377                                    le16_to_cpu(bg->bg_bits),
1378                                    le16_to_cpu(bg->bg_free_bits_count),
1379                                    num_bits);
1380         }
1381         while(num_bits--)
1382                 ocfs2_set_bit(bit_off++, bitmap);
1383
1384         ocfs2_journal_dirty(handle, group_bh);
1385
1386 bail:
1387         return status;
1388 }
1389
1390 /* find the one with the most empty bits */
1391 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1392 {
1393         u16 curr, best;
1394
1395         BUG_ON(!cl->cl_next_free_rec);
1396
1397         best = curr = 0;
1398         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1399                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1400                     le32_to_cpu(cl->cl_recs[best].c_free))
1401                         best = curr;
1402                 curr++;
1403         }
1404
1405         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1406         return best;
1407 }
1408
1409 static int ocfs2_relink_block_group(handle_t *handle,
1410                                     struct inode *alloc_inode,
1411                                     struct buffer_head *fe_bh,
1412                                     struct buffer_head *bg_bh,
1413                                     struct buffer_head *prev_bg_bh,
1414                                     u16 chain)
1415 {
1416         int status;
1417         /* there is a really tiny chance the journal calls could fail,
1418          * but we wouldn't want inconsistent blocks in *any* case. */
1419         u64 bg_ptr, prev_bg_ptr;
1420         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1421         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1422         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1423
1424         /* The caller got these descriptors from
1425          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1426         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1427         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1428
1429         trace_ocfs2_relink_block_group(
1430                 (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1431                 (unsigned long long)le64_to_cpu(bg->bg_blkno),
1432                 (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1433
1434         bg_ptr = le64_to_cpu(bg->bg_next_group);
1435         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1436
1437         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1438                                          prev_bg_bh,
1439                                          OCFS2_JOURNAL_ACCESS_WRITE);
1440         if (status < 0)
1441                 goto out;
1442
1443         prev_bg->bg_next_group = bg->bg_next_group;
1444         ocfs2_journal_dirty(handle, prev_bg_bh);
1445
1446         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1447                                          bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1448         if (status < 0)
1449                 goto out_rollback_prev_bg;
1450
1451         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1452         ocfs2_journal_dirty(handle, bg_bh);
1453
1454         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1455                                          fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1456         if (status < 0)
1457                 goto out_rollback_bg;
1458
1459         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1460         ocfs2_journal_dirty(handle, fe_bh);
1461
1462 out:
1463         if (status < 0)
1464                 mlog_errno(status);
1465         return status;
1466
1467 out_rollback_bg:
1468         bg->bg_next_group = cpu_to_le64(bg_ptr);
1469 out_rollback_prev_bg:
1470         prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1471         goto out;
1472 }
1473
1474 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1475                                                      u32 wanted)
1476 {
1477         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1478 }
1479
1480 /* return 0 on success, -ENOSPC to keep searching and any other < 0
1481  * value on error. */
1482 static int ocfs2_cluster_group_search(struct inode *inode,
1483                                       struct buffer_head *group_bh,
1484                                       u32 bits_wanted, u32 min_bits,
1485                                       u64 max_block,
1486                                       struct ocfs2_suballoc_result *res)
1487 {
1488         int search = -ENOSPC;
1489         int ret;
1490         u64 blkoff;
1491         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1492         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1493         unsigned int max_bits, gd_cluster_off;
1494
1495         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1496
1497         if (gd->bg_free_bits_count) {
1498                 max_bits = le16_to_cpu(gd->bg_bits);
1499
1500                 /* Tail groups in cluster bitmaps which aren't cpg
1501                  * aligned are prone to partial extension by a failed
1502                  * fs resize. If the file system resize never got to
1503                  * update the dinode cluster count, then we don't want
1504                  * to trust any clusters past it, regardless of what
1505                  * the group descriptor says. */
1506                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1507                                                           le64_to_cpu(gd->bg_blkno));
1508                 if ((gd_cluster_off + max_bits) >
1509                     OCFS2_I(inode)->ip_clusters) {
1510                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1511                         trace_ocfs2_cluster_group_search_wrong_max_bits(
1512                                 (unsigned long long)le64_to_cpu(gd->bg_blkno),
1513                                 le16_to_cpu(gd->bg_bits),
1514                                 OCFS2_I(inode)->ip_clusters, max_bits);
1515                 }
1516
1517                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1518                                                         group_bh, bits_wanted,
1519                                                         max_bits, res);
1520                 if (ret)
1521                         return ret;
1522
1523                 if (max_block) {
1524                         blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1525                                                           gd_cluster_off +
1526                                                           res->sr_bit_offset +
1527                                                           res->sr_bits);
1528                         trace_ocfs2_cluster_group_search_max_block(
1529                                 (unsigned long long)blkoff,
1530                                 (unsigned long long)max_block);
1531                         if (blkoff > max_block)
1532                                 return -ENOSPC;
1533                 }
1534
1535                 /* ocfs2_block_group_find_clear_bits() might
1536                  * return success, but we still want to return
1537                  * -ENOSPC unless it found the minimum number
1538                  * of bits. */
1539                 if (min_bits <= res->sr_bits)
1540                         search = 0; /* success */
1541                 else if (res->sr_bits) {
1542                         /*
1543                          * Don't show bits which we'll be returning
1544                          * for allocation to the local alloc bitmap.
1545                          */
1546                         ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1547                 }
1548         }
1549
1550         return search;
1551 }
1552
1553 static int ocfs2_block_group_search(struct inode *inode,
1554                                     struct buffer_head *group_bh,
1555                                     u32 bits_wanted, u32 min_bits,
1556                                     u64 max_block,
1557                                     struct ocfs2_suballoc_result *res)
1558 {
1559         int ret = -ENOSPC;
1560         u64 blkoff;
1561         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1562
1563         BUG_ON(min_bits != 1);
1564         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1565
1566         if (bg->bg_free_bits_count) {
1567                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1568                                                         group_bh, bits_wanted,
1569                                                         le16_to_cpu(bg->bg_bits),
1570                                                         res);
1571                 if (!ret && max_block) {
1572                         blkoff = le64_to_cpu(bg->bg_blkno) +
1573                                 res->sr_bit_offset + res->sr_bits;
1574                         trace_ocfs2_block_group_search_max_block(
1575                                 (unsigned long long)blkoff,
1576                                 (unsigned long long)max_block);
1577                         if (blkoff > max_block)
1578                                 ret = -ENOSPC;
1579                 }
1580         }
1581
1582         return ret;
1583 }
1584
1585 int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1586                                        handle_t *handle,
1587                                        struct buffer_head *di_bh,
1588                                        u32 num_bits,
1589                                        u16 chain)
1590 {
1591         int ret;
1592         u32 tmp_used;
1593         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1594         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1595
1596         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1597                                       OCFS2_JOURNAL_ACCESS_WRITE);
1598         if (ret < 0) {
1599                 mlog_errno(ret);
1600                 goto out;
1601         }
1602
1603         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1604         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1605         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1606         ocfs2_journal_dirty(handle, di_bh);
1607
1608 out:
1609         return ret;
1610 }
1611
1612 void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1613                                        struct buffer_head *di_bh,
1614                                        u32 num_bits,
1615                                        u16 chain)
1616 {
1617         u32 tmp_used;
1618         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1619         struct ocfs2_chain_list *cl;
1620
1621         cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1622         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1623         di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1624         le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1625 }
1626
1627 static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1628                                          struct ocfs2_extent_rec *rec,
1629                                          struct ocfs2_chain_list *cl)
1630 {
1631         unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1632         unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1633         unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1634
1635         if (res->sr_bit_offset < bitoff)
1636                 return 0;
1637         if (res->sr_bit_offset >= (bitoff + bitcount))
1638                 return 0;
1639         res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1640                 (res->sr_bit_offset - bitoff);
1641         if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1642                 res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1643         return 1;
1644 }
1645
1646 static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1647                                           struct ocfs2_group_desc *bg,
1648                                           struct ocfs2_suballoc_result *res)
1649 {
1650         int i;
1651         u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1652         struct ocfs2_extent_rec *rec;
1653         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1654         struct ocfs2_chain_list *cl = &di->id2.i_chain;
1655
1656         if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1657                 res->sr_blkno = 0;
1658                 return;
1659         }
1660
1661         res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1662         res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1663         if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1664             !bg->bg_list.l_next_free_rec)
1665                 return;
1666
1667         for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1668                 rec = &bg->bg_list.l_recs[i];
1669                 if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1670                         res->sr_bg_blkno = bg_blkno;  /* Restore */
1671                         break;
1672                 }
1673         }
1674 }
1675
1676 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1677                                   handle_t *handle,
1678                                   u32 bits_wanted,
1679                                   u32 min_bits,
1680                                   struct ocfs2_suballoc_result *res,
1681                                   u16 *bits_left)
1682 {
1683         int ret;
1684         struct buffer_head *group_bh = NULL;
1685         struct ocfs2_group_desc *gd;
1686         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1687         struct inode *alloc_inode = ac->ac_inode;
1688
1689         ret = ocfs2_read_group_descriptor(alloc_inode, di,
1690                                           res->sr_bg_blkno, &group_bh);
1691         if (ret < 0) {
1692                 mlog_errno(ret);
1693                 return ret;
1694         }
1695
1696         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1697         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1698                                   ac->ac_max_block, res);
1699         if (ret < 0) {
1700                 if (ret != -ENOSPC)
1701                         mlog_errno(ret);
1702                 goto out;
1703         }
1704
1705         if (!ret)
1706                 ocfs2_bg_discontig_fix_result(ac, gd, res);
1707
1708         /*
1709          * sr_bg_blkno might have been changed by
1710          * ocfs2_bg_discontig_fix_result
1711          */
1712         res->sr_bg_stable_blkno = group_bh->b_blocknr;
1713
1714         if (ac->ac_find_loc_only)
1715                 goto out_loc_only;
1716
1717         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1718                                                res->sr_bits,
1719                                                le16_to_cpu(gd->bg_chain));
1720         if (ret < 0) {
1721                 mlog_errno(ret);
1722                 goto out;
1723         }
1724
1725         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1726                                          res->sr_bit_offset, res->sr_bits);
1727         if (ret < 0) {
1728                 ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1729                                                res->sr_bits,
1730                                                le16_to_cpu(gd->bg_chain));
1731                 mlog_errno(ret);
1732         }
1733
1734 out_loc_only:
1735         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1736
1737 out:
1738         brelse(group_bh);
1739
1740         return ret;
1741 }
1742
1743 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1744                               handle_t *handle,
1745                               u32 bits_wanted,
1746                               u32 min_bits,
1747                               struct ocfs2_suballoc_result *res,
1748                               u16 *bits_left)
1749 {
1750         int status;
1751         u16 chain;
1752         u64 next_group;
1753         struct inode *alloc_inode = ac->ac_inode;
1754         struct buffer_head *group_bh = NULL;
1755         struct buffer_head *prev_group_bh = NULL;
1756         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1757         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1758         struct ocfs2_group_desc *bg;
1759
1760         chain = ac->ac_chain;
1761         trace_ocfs2_search_chain_begin(
1762                 (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1763                 bits_wanted, chain);
1764
1765         status = ocfs2_read_group_descriptor(alloc_inode, fe,
1766                                              le64_to_cpu(cl->cl_recs[chain].c_blkno),
1767                                              &group_bh);
1768         if (status < 0) {
1769                 mlog_errno(status);
1770                 goto bail;
1771         }
1772         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1773
1774         status = -ENOSPC;
1775         /* for now, the chain search is a bit simplistic. We just use
1776          * the 1st group with any empty bits. */
1777         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1778                                              bits_wanted, min_bits,
1779                                              ac->ac_max_block,
1780                                              res)) == -ENOSPC) {
1781                 if (!bg->bg_next_group)
1782                         break;
1783
1784                 brelse(prev_group_bh);
1785                 prev_group_bh = NULL;
1786
1787                 next_group = le64_to_cpu(bg->bg_next_group);
1788                 prev_group_bh = group_bh;
1789                 group_bh = NULL;
1790                 status = ocfs2_read_group_descriptor(alloc_inode, fe,
1791                                                      next_group, &group_bh);
1792                 if (status < 0) {
1793                         mlog_errno(status);
1794                         goto bail;
1795                 }
1796                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1797         }
1798         if (status < 0) {
1799                 if (status != -ENOSPC)
1800                         mlog_errno(status);
1801                 goto bail;
1802         }
1803
1804         trace_ocfs2_search_chain_succ(
1805                 (unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1806
1807         res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1808
1809         BUG_ON(res->sr_bits == 0);
1810         if (!status)
1811                 ocfs2_bg_discontig_fix_result(ac, bg, res);
1812
1813         /*
1814          * sr_bg_blkno might have been changed by
1815          * ocfs2_bg_discontig_fix_result
1816          */
1817         res->sr_bg_stable_blkno = group_bh->b_blocknr;
1818
1819         /*
1820          * Keep track of previous block descriptor read. When
1821          * we find a target, if we have read more than X
1822          * number of descriptors, and the target is reasonably
1823          * empty, relink him to top of his chain.
1824          *
1825          * We've read 0 extra blocks and only send one more to
1826          * the transaction, yet the next guy to search has a
1827          * much easier time.
1828          *
1829          * Do this *after* figuring out how many bits we're taking out
1830          * of our target group.
1831          */
1832         if (!ac->ac_disable_chain_relink &&
1833             (prev_group_bh) &&
1834             (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1835                 status = ocfs2_relink_block_group(handle, alloc_inode,
1836                                                   ac->ac_bh, group_bh,
1837                                                   prev_group_bh, chain);
1838                 if (status < 0) {
1839                         mlog_errno(status);
1840                         goto bail;
1841                 }
1842         }
1843
1844         if (ac->ac_find_loc_only)
1845                 goto out_loc_only;
1846
1847         status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1848                                                   ac->ac_bh, res->sr_bits,
1849                                                   chain);
1850         if (status) {
1851                 mlog_errno(status);
1852                 goto bail;
1853         }
1854
1855         status = ocfs2_block_group_set_bits(handle,
1856                                             alloc_inode,
1857                                             bg,
1858                                             group_bh,
1859                                             res->sr_bit_offset,
1860                                             res->sr_bits);
1861         if (status < 0) {
1862                 ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1863                                         ac->ac_bh, res->sr_bits, chain);
1864                 mlog_errno(status);
1865                 goto bail;
1866         }
1867
1868         trace_ocfs2_search_chain_end(
1869                         (unsigned long long)le64_to_cpu(fe->i_blkno),
1870                         res->sr_bits);
1871
1872 out_loc_only:
1873         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1874 bail:
1875         brelse(group_bh);
1876         brelse(prev_group_bh);
1877
1878         if (status)
1879                 mlog_errno(status);
1880         return status;
1881 }
1882
1883 /* will give out up to bits_wanted contiguous bits. */
1884 static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1885                                      handle_t *handle,
1886                                      u32 bits_wanted,
1887                                      u32 min_bits,
1888                                      struct ocfs2_suballoc_result *res)
1889 {
1890         int status;
1891         u16 victim, i;
1892         u16 bits_left = 0;
1893         u64 hint = ac->ac_last_group;
1894         struct ocfs2_chain_list *cl;
1895         struct ocfs2_dinode *fe;
1896
1897         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1898         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1899         BUG_ON(!ac->ac_bh);
1900
1901         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1902
1903         /* The bh was validated by the inode read during
1904          * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1905         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1906
1907         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1908             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1909                 status = ocfs2_error(ac->ac_inode->i_sb,
1910                                      "Chain allocator dinode %llu has %u used bits but only %u total\n",
1911                                      (unsigned long long)le64_to_cpu(fe->i_blkno),
1912                                      le32_to_cpu(fe->id1.bitmap1.i_used),
1913                                      le32_to_cpu(fe->id1.bitmap1.i_total));
1914                 goto bail;
1915         }
1916
1917         res->sr_bg_blkno = hint;
1918         if (res->sr_bg_blkno) {
1919                 /* Attempt to short-circuit the usual search mechanism
1920                  * by jumping straight to the most recently used
1921                  * allocation group. This helps us maintain some
1922                  * contiguousness across allocations. */
1923                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1924                                                 min_bits, res, &bits_left);
1925                 if (!status)
1926                         goto set_hint;
1927                 if (status < 0 && status != -ENOSPC) {
1928                         mlog_errno(status);
1929                         goto bail;
1930                 }
1931         }
1932
1933         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1934
1935         victim = ocfs2_find_victim_chain(cl);
1936         ac->ac_chain = victim;
1937
1938         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1939                                     res, &bits_left);
1940         if (!status) {
1941                 if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1942                         hint = res->sr_bg_blkno;
1943                 else
1944                         hint = ocfs2_group_from_res(res);
1945                 goto set_hint;
1946         }
1947         if (status < 0 && status != -ENOSPC) {
1948                 mlog_errno(status);
1949                 goto bail;
1950         }
1951
1952         trace_ocfs2_claim_suballoc_bits(victim);
1953
1954         /* If we didn't pick a good victim, then just default to
1955          * searching each chain in order. Don't allow chain relinking
1956          * because we only calculate enough journal credits for one
1957          * relink per alloc. */
1958         ac->ac_disable_chain_relink = 1;
1959         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1960                 if (i == victim)
1961                         continue;
1962                 if (!cl->cl_recs[i].c_free)
1963                         continue;
1964
1965                 ac->ac_chain = i;
1966                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1967                                             res, &bits_left);
1968                 if (!status) {
1969                         hint = ocfs2_group_from_res(res);
1970                         break;
1971                 }
1972                 if (status < 0 && status != -ENOSPC) {
1973                         mlog_errno(status);
1974                         goto bail;
1975                 }
1976         }
1977
1978 set_hint:
1979         if (status != -ENOSPC) {
1980                 /* If the next search of this group is not likely to
1981                  * yield a suitable extent, then we reset the last
1982                  * group hint so as to not waste a disk read */
1983                 if (bits_left < min_bits)
1984                         ac->ac_last_group = 0;
1985                 else
1986                         ac->ac_last_group = hint;
1987         }
1988
1989 bail:
1990         if (status)
1991                 mlog_errno(status);
1992         return status;
1993 }
1994
1995 int ocfs2_claim_metadata(handle_t *handle,
1996                          struct ocfs2_alloc_context *ac,
1997                          u32 bits_wanted,
1998                          u64 *suballoc_loc,
1999                          u16 *suballoc_bit_start,
2000                          unsigned int *num_bits,
2001                          u64 *blkno_start)
2002 {
2003         int status;
2004         struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2005
2006         BUG_ON(!ac);
2007         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2008         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2009
2010         status = ocfs2_claim_suballoc_bits(ac,
2011                                            handle,
2012                                            bits_wanted,
2013                                            1,
2014                                            &res);
2015         if (status < 0) {
2016                 mlog_errno(status);
2017                 goto bail;
2018         }
2019         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2020
2021         *suballoc_loc = res.sr_bg_blkno;
2022         *suballoc_bit_start = res.sr_bit_offset;
2023         *blkno_start = res.sr_blkno;
2024         ac->ac_bits_given += res.sr_bits;
2025         *num_bits = res.sr_bits;
2026         status = 0;
2027 bail:
2028         if (status)
2029                 mlog_errno(status);
2030         return status;
2031 }
2032
2033 static void ocfs2_init_inode_ac_group(struct inode *dir,
2034                                       struct buffer_head *parent_di_bh,
2035                                       struct ocfs2_alloc_context *ac)
2036 {
2037         struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2038         /*
2039          * Try to allocate inodes from some specific group.
2040          *
2041          * If the parent dir has recorded the last group used in allocation,
2042          * cool, use it. Otherwise if we try to allocate new inode from the
2043          * same slot the parent dir belongs to, use the same chunk.
2044          *
2045          * We are very careful here to avoid the mistake of setting
2046          * ac_last_group to a group descriptor from a different (unlocked) slot.
2047          */
2048         if (OCFS2_I(dir)->ip_last_used_group &&
2049             OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2050                 ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2051         else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2052                 if (di->i_suballoc_loc)
2053                         ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2054                 else
2055                         ac->ac_last_group = ocfs2_which_suballoc_group(
2056                                         le64_to_cpu(di->i_blkno),
2057                                         le16_to_cpu(di->i_suballoc_bit));
2058         }
2059 }
2060
2061 static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2062                                              struct ocfs2_alloc_context *ac)
2063 {
2064         OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2065         OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2066 }
2067
2068 int ocfs2_find_new_inode_loc(struct inode *dir,
2069                              struct buffer_head *parent_fe_bh,
2070                              struct ocfs2_alloc_context *ac,
2071                              u64 *fe_blkno)
2072 {
2073         int ret;
2074         handle_t *handle = NULL;
2075         struct ocfs2_suballoc_result *res;
2076
2077         BUG_ON(!ac);
2078         BUG_ON(ac->ac_bits_given != 0);
2079         BUG_ON(ac->ac_bits_wanted != 1);
2080         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2081
2082         res = kzalloc(sizeof(*res), GFP_NOFS);
2083         if (res == NULL) {
2084                 ret = -ENOMEM;
2085                 mlog_errno(ret);
2086                 goto out;
2087         }
2088
2089         ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2090
2091         /*
2092          * The handle started here is for chain relink. Alternatively,
2093          * we could just disable relink for these calls.
2094          */
2095         handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2096         if (IS_ERR(handle)) {
2097                 ret = PTR_ERR(handle);
2098                 handle = NULL;
2099                 mlog_errno(ret);
2100                 goto out;
2101         }
2102
2103         /*
2104          * This will instruct ocfs2_claim_suballoc_bits and
2105          * ocfs2_search_one_group to search but save actual allocation
2106          * for later.
2107          */
2108         ac->ac_find_loc_only = 1;
2109
2110         ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2111         if (ret < 0) {
2112                 mlog_errno(ret);
2113                 goto out;
2114         }
2115
2116         ac->ac_find_loc_priv = res;
2117         *fe_blkno = res->sr_blkno;
2118         ocfs2_update_inode_fsync_trans(handle, dir, 0);
2119 out:
2120         if (handle)
2121                 ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2122
2123         if (ret)
2124                 kfree(res);
2125
2126         return ret;
2127 }
2128
2129 int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2130                                  struct inode *dir,
2131                                  struct ocfs2_alloc_context *ac,
2132                                  u64 *suballoc_loc,
2133                                  u16 *suballoc_bit,
2134                                  u64 di_blkno)
2135 {
2136         int ret;
2137         u16 chain;
2138         struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2139         struct buffer_head *bg_bh = NULL;
2140         struct ocfs2_group_desc *bg;
2141         struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2142
2143         /*
2144          * Since di_blkno is being passed back in, we check for any
2145          * inconsistencies which may have happened between
2146          * calls. These are code bugs as di_blkno is not expected to
2147          * change once returned from ocfs2_find_new_inode_loc()
2148          */
2149         BUG_ON(res->sr_blkno != di_blkno);
2150
2151         ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2152                                           res->sr_bg_stable_blkno, &bg_bh);
2153         if (ret) {
2154                 mlog_errno(ret);
2155                 goto out;
2156         }
2157
2158         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2159         chain = le16_to_cpu(bg->bg_chain);
2160
2161         ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2162                                                ac->ac_bh, res->sr_bits,
2163                                                chain);
2164         if (ret) {
2165                 mlog_errno(ret);
2166                 goto out;
2167         }
2168
2169         ret = ocfs2_block_group_set_bits(handle,
2170                                          ac->ac_inode,
2171                                          bg,
2172                                          bg_bh,
2173                                          res->sr_bit_offset,
2174                                          res->sr_bits);
2175         if (ret < 0) {
2176                 ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2177                                                ac->ac_bh, res->sr_bits, chain);
2178                 mlog_errno(ret);
2179                 goto out;
2180         }
2181
2182         trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2183                                            res->sr_bits);
2184
2185         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2186
2187         BUG_ON(res->sr_bits != 1);
2188
2189         *suballoc_loc = res->sr_bg_blkno;
2190         *suballoc_bit = res->sr_bit_offset;
2191         ac->ac_bits_given++;
2192         ocfs2_save_inode_ac_group(dir, ac);
2193
2194 out:
2195         brelse(bg_bh);
2196
2197         return ret;
2198 }
2199
2200 int ocfs2_claim_new_inode(handle_t *handle,
2201                           struct inode *dir,
2202                           struct buffer_head *parent_fe_bh,
2203                           struct ocfs2_alloc_context *ac,
2204                           u64 *suballoc_loc,
2205                           u16 *suballoc_bit,
2206                           u64 *fe_blkno)
2207 {
2208         int status;
2209         struct ocfs2_suballoc_result res;
2210
2211         BUG_ON(!ac);
2212         BUG_ON(ac->ac_bits_given != 0);
2213         BUG_ON(ac->ac_bits_wanted != 1);
2214         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2215
2216         ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2217
2218         status = ocfs2_claim_suballoc_bits(ac,
2219                                            handle,
2220                                            1,
2221                                            1,
2222                                            &res);
2223         if (status < 0) {
2224                 mlog_errno(status);
2225                 goto bail;
2226         }
2227         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2228
2229         BUG_ON(res.sr_bits != 1);
2230
2231         *suballoc_loc = res.sr_bg_blkno;
2232         *suballoc_bit = res.sr_bit_offset;
2233         *fe_blkno = res.sr_blkno;
2234         ac->ac_bits_given++;
2235         ocfs2_save_inode_ac_group(dir, ac);
2236         status = 0;
2237 bail:
2238         if (status)
2239                 mlog_errno(status);
2240         return status;
2241 }
2242
2243 /* translate a group desc. blkno and it's bitmap offset into
2244  * disk cluster offset. */
2245 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2246                                                    u64 bg_blkno,
2247                                                    u16 bg_bit_off)
2248 {
2249         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2250         u32 cluster = 0;
2251
2252         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2253
2254         if (bg_blkno != osb->first_cluster_group_blkno)
2255                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2256         cluster += (u32) bg_bit_off;
2257         return cluster;
2258 }
2259
2260 /* given a cluster offset, calculate which block group it belongs to
2261  * and return that block offset. */
2262 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2263 {
2264         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2265         u32 group_no;
2266
2267         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2268
2269         group_no = cluster / osb->bitmap_cpg;
2270         if (!group_no)
2271                 return osb->first_cluster_group_blkno;
2272         return ocfs2_clusters_to_blocks(inode->i_sb,
2273                                         group_no * osb->bitmap_cpg);
2274 }
2275
2276 /* given the block number of a cluster start, calculate which cluster
2277  * group and descriptor bitmap offset that corresponds to. */
2278 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2279                                                 u64 data_blkno,
2280                                                 u64 *bg_blkno,
2281                                                 u16 *bg_bit_off)
2282 {
2283         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2284         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2285
2286         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2287
2288         *bg_blkno = ocfs2_which_cluster_group(inode,
2289                                               data_cluster);
2290
2291         if (*bg_blkno == osb->first_cluster_group_blkno)
2292                 *bg_bit_off = (u16) data_cluster;
2293         else
2294                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2295                                                              data_blkno - *bg_blkno);
2296 }
2297
2298 /*
2299  * min_bits - minimum contiguous chunk from this total allocation we
2300  * can handle. set to what we asked for originally for a full
2301  * contig. allocation, set to '1' to indicate we can deal with extents
2302  * of any size.
2303  */
2304 int __ocfs2_claim_clusters(handle_t *handle,
2305                            struct ocfs2_alloc_context *ac,
2306                            u32 min_clusters,
2307                            u32 max_clusters,
2308                            u32 *cluster_start,
2309                            u32 *num_clusters)
2310 {
2311         int status;
2312         unsigned int bits_wanted = max_clusters;
2313         struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2314         struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2315
2316         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2317
2318         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2319                && ac->ac_which != OCFS2_AC_USE_MAIN);
2320
2321         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2322                 WARN_ON(min_clusters > 1);
2323
2324                 status = ocfs2_claim_local_alloc_bits(osb,
2325                                                       handle,
2326                                                       ac,
2327                                                       bits_wanted,
2328                                                       cluster_start,
2329                                                       num_clusters);
2330                 if (!status)
2331                         atomic_inc(&osb->alloc_stats.local_data);
2332         } else {
2333                 if (min_clusters > (osb->bitmap_cpg - 1)) {
2334                         /* The only paths asking for contiguousness
2335                          * should know about this already. */
2336                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2337                              "group bitmap size %u!\n", min_clusters,
2338                              osb->bitmap_cpg);
2339                         status = -ENOSPC;
2340                         goto bail;
2341                 }
2342                 /* clamp the current request down to a realistic size. */
2343                 if (bits_wanted > (osb->bitmap_cpg - 1))
2344                         bits_wanted = osb->bitmap_cpg - 1;
2345
2346                 status = ocfs2_claim_suballoc_bits(ac,
2347                                                    handle,
2348                                                    bits_wanted,
2349                                                    min_clusters,
2350                                                    &res);
2351                 if (!status) {
2352                         BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2353                         *cluster_start =
2354                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2355                                                                  res.sr_bg_blkno,
2356                                                                  res.sr_bit_offset);
2357                         atomic_inc(&osb->alloc_stats.bitmap_data);
2358                         *num_clusters = res.sr_bits;
2359                 }
2360         }
2361         if (status < 0) {
2362                 if (status != -ENOSPC)
2363                         mlog_errno(status);
2364                 goto bail;
2365         }
2366
2367         ac->ac_bits_given += *num_clusters;
2368
2369 bail:
2370         if (status)
2371                 mlog_errno(status);
2372         return status;
2373 }
2374
2375 int ocfs2_claim_clusters(handle_t *handle,
2376                          struct ocfs2_alloc_context *ac,
2377                          u32 min_clusters,
2378                          u32 *cluster_start,
2379                          u32 *num_clusters)
2380 {
2381         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2382
2383         return __ocfs2_claim_clusters(handle, ac, min_clusters,
2384                                       bits_wanted, cluster_start, num_clusters);
2385 }
2386
2387 static int ocfs2_block_group_clear_bits(handle_t *handle,
2388                                         struct inode *alloc_inode,
2389                                         struct ocfs2_group_desc *bg,
2390                                         struct buffer_head *group_bh,
2391                                         unsigned int bit_off,
2392                                         unsigned int num_bits,
2393                                         void (*undo_fn)(unsigned int bit,
2394                                                         unsigned long *bmap))
2395 {
2396         int status;
2397         unsigned int tmp;
2398         struct ocfs2_group_desc *undo_bg = NULL;
2399
2400         /* The caller got this descriptor from
2401          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2402         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2403
2404         trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2405
2406         BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2407         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2408                                          group_bh,
2409                                          undo_fn ?
2410                                          OCFS2_JOURNAL_ACCESS_UNDO :
2411                                          OCFS2_JOURNAL_ACCESS_WRITE);
2412         if (status < 0) {
2413                 mlog_errno(status);
2414                 goto bail;
2415         }
2416
2417         if (undo_fn) {
2418                 jbd_lock_bh_state(group_bh);
2419                 undo_bg = (struct ocfs2_group_desc *)
2420                                         bh2jh(group_bh)->b_committed_data;
2421                 BUG_ON(!undo_bg);
2422         }
2423
2424         tmp = num_bits;
2425         while(tmp--) {
2426                 ocfs2_clear_bit((bit_off + tmp),
2427                                 (unsigned long *) bg->bg_bitmap);
2428                 if (undo_fn)
2429                         undo_fn(bit_off + tmp,
2430                                 (unsigned long *) undo_bg->bg_bitmap);
2431         }
2432         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2433         if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2434                 return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
2435                                    (unsigned long long)le64_to_cpu(bg->bg_blkno),
2436                                    le16_to_cpu(bg->bg_bits),
2437                                    le16_to_cpu(bg->bg_free_bits_count),
2438                                    num_bits);
2439         }
2440
2441         if (undo_fn)
2442                 jbd_unlock_bh_state(group_bh);
2443
2444         ocfs2_journal_dirty(handle, group_bh);
2445 bail:
2446         return status;
2447 }
2448
2449 /*
2450  * expects the suballoc inode to already be locked.
2451  */
2452 static int _ocfs2_free_suballoc_bits(handle_t *handle,
2453                                      struct inode *alloc_inode,
2454                                      struct buffer_head *alloc_bh,
2455                                      unsigned int start_bit,
2456                                      u64 bg_blkno,
2457                                      unsigned int count,
2458                                      void (*undo_fn)(unsigned int bit,
2459                                                      unsigned long *bitmap))
2460 {
2461         int status = 0;
2462         u32 tmp_used;
2463         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2464         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2465         struct buffer_head *group_bh = NULL;
2466         struct ocfs2_group_desc *group;
2467
2468         /* The alloc_bh comes from ocfs2_free_dinode() or
2469          * ocfs2_free_clusters().  The callers have all locked the
2470          * allocator and gotten alloc_bh from the lock call.  This
2471          * validates the dinode buffer.  Any corruption that has happened
2472          * is a code bug. */
2473         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2474         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2475
2476         trace_ocfs2_free_suballoc_bits(
2477                 (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2478                 (unsigned long long)bg_blkno,
2479                 start_bit, count);
2480
2481         status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2482                                              &group_bh);
2483         if (status < 0) {
2484                 mlog_errno(status);
2485                 goto bail;
2486         }
2487         group = (struct ocfs2_group_desc *) group_bh->b_data;
2488
2489         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2490
2491         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2492                                               group, group_bh,
2493                                               start_bit, count, undo_fn);
2494         if (status < 0) {
2495                 mlog_errno(status);
2496                 goto bail;
2497         }
2498
2499         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2500                                          alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2501         if (status < 0) {
2502                 mlog_errno(status);
2503                 ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2504                                 start_bit, count);
2505                 goto bail;
2506         }
2507
2508         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2509                      count);
2510         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2511         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2512         ocfs2_journal_dirty(handle, alloc_bh);
2513
2514 bail:
2515         brelse(group_bh);
2516
2517         if (status)
2518                 mlog_errno(status);
2519         return status;
2520 }
2521
2522 int ocfs2_free_suballoc_bits(handle_t *handle,
2523                              struct inode *alloc_inode,
2524                              struct buffer_head *alloc_bh,
2525                              unsigned int start_bit,
2526                              u64 bg_blkno,
2527                              unsigned int count)
2528 {
2529         return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2530                                          start_bit, bg_blkno, count, NULL);
2531 }
2532
2533 int ocfs2_free_dinode(handle_t *handle,
2534                       struct inode *inode_alloc_inode,
2535                       struct buffer_head *inode_alloc_bh,
2536                       struct ocfs2_dinode *di)
2537 {
2538         u64 blk = le64_to_cpu(di->i_blkno);
2539         u16 bit = le16_to_cpu(di->i_suballoc_bit);
2540         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2541
2542         if (di->i_suballoc_loc)
2543                 bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2544         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2545                                         inode_alloc_bh, bit, bg_blkno, 1);
2546 }
2547
2548 static int _ocfs2_free_clusters(handle_t *handle,
2549                                 struct inode *bitmap_inode,
2550                                 struct buffer_head *bitmap_bh,
2551                                 u64 start_blk,
2552                                 unsigned int num_clusters,
2553                                 void (*undo_fn)(unsigned int bit,
2554                                                 unsigned long *bitmap))
2555 {
2556         int status;
2557         u16 bg_start_bit;
2558         u64 bg_blkno;
2559         struct ocfs2_dinode *fe;
2560
2561         /* You can't ever have a contiguous set of clusters
2562          * bigger than a block group bitmap so we never have to worry
2563          * about looping on them.
2564          * This is expensive. We can safely remove once this stuff has
2565          * gotten tested really well. */
2566         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
2567
2568         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
2569
2570         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2571                                      &bg_start_bit);
2572
2573         trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2574                         (unsigned long long)start_blk,
2575                         bg_start_bit, num_clusters);
2576
2577         status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2578                                            bg_start_bit, bg_blkno,
2579                                            num_clusters, undo_fn);
2580         if (status < 0) {
2581                 mlog_errno(status);
2582                 goto out;
2583         }
2584
2585         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2586                                          num_clusters);
2587
2588 out:
2589         if (status)
2590                 mlog_errno(status);
2591         return status;
2592 }
2593
2594 int ocfs2_free_clusters(handle_t *handle,
2595                         struct inode *bitmap_inode,
2596                         struct buffer_head *bitmap_bh,
2597                         u64 start_blk,
2598                         unsigned int num_clusters)
2599 {
2600         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2601                                     start_blk, num_clusters,
2602                                     _ocfs2_set_bit);
2603 }
2604
2605 /*
2606  * Give never-used clusters back to the global bitmap.  We don't need
2607  * to protect these bits in the undo buffer.
2608  */
2609 int ocfs2_release_clusters(handle_t *handle,
2610                            struct inode *bitmap_inode,
2611                            struct buffer_head *bitmap_bh,
2612                            u64 start_blk,
2613                            unsigned int num_clusters)
2614 {
2615         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2616                                     start_blk, num_clusters,
2617                                     _ocfs2_clear_bit);
2618 }
2619
2620 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
2621 {
2622         printk("Block Group:\n");
2623         printk("bg_signature:       %s\n", bg->bg_signature);
2624         printk("bg_size:            %u\n", bg->bg_size);
2625         printk("bg_bits:            %u\n", bg->bg_bits);
2626         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
2627         printk("bg_chain:           %u\n", bg->bg_chain);
2628         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
2629         printk("bg_next_group:      %llu\n",
2630                (unsigned long long)bg->bg_next_group);
2631         printk("bg_parent_dinode:   %llu\n",
2632                (unsigned long long)bg->bg_parent_dinode);
2633         printk("bg_blkno:           %llu\n",
2634                (unsigned long long)bg->bg_blkno);
2635 }
2636
2637 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
2638 {
2639         int i;
2640
2641         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
2642         printk("i_signature:                  %s\n", fe->i_signature);
2643         printk("i_size:                       %llu\n",
2644                (unsigned long long)fe->i_size);
2645         printk("i_clusters:                   %u\n", fe->i_clusters);
2646         printk("i_generation:                 %u\n",
2647                le32_to_cpu(fe->i_generation));
2648         printk("id1.bitmap1.i_used:           %u\n",
2649                le32_to_cpu(fe->id1.bitmap1.i_used));
2650         printk("id1.bitmap1.i_total:          %u\n",
2651                le32_to_cpu(fe->id1.bitmap1.i_total));
2652         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
2653         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
2654         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
2655         printk("id2.i_chain.cl_next_free_rec: %u\n",
2656                fe->id2.i_chain.cl_next_free_rec);
2657         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
2658                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
2659                        fe->id2.i_chain.cl_recs[i].c_free);
2660                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
2661                        fe->id2.i_chain.cl_recs[i].c_total);
2662                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
2663                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
2664         }
2665 }
2666
2667 /*
2668  * For a given allocation, determine which allocators will need to be
2669  * accessed, and lock them, reserving the appropriate number of bits.
2670  *
2671  * Sparse file systems call this from ocfs2_write_begin_nolock()
2672  * and ocfs2_allocate_unwritten_extents().
2673  *
2674  * File systems which don't support holes call this from
2675  * ocfs2_extend_allocation().
2676  */
2677 int ocfs2_lock_allocators(struct inode *inode,
2678                           struct ocfs2_extent_tree *et,
2679                           u32 clusters_to_add, u32 extents_to_split,
2680                           struct ocfs2_alloc_context **data_ac,
2681                           struct ocfs2_alloc_context **meta_ac)
2682 {
2683         int ret = 0, num_free_extents;
2684         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2685         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2686
2687         *meta_ac = NULL;
2688         if (data_ac)
2689                 *data_ac = NULL;
2690
2691         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2692
2693         num_free_extents = ocfs2_num_free_extents(osb, et);
2694         if (num_free_extents < 0) {
2695                 ret = num_free_extents;
2696                 mlog_errno(ret);
2697                 goto out;
2698         }
2699
2700         /*
2701          * Sparse allocation file systems need to be more conservative
2702          * with reserving room for expansion - the actual allocation
2703          * happens while we've got a journal handle open so re-taking
2704          * a cluster lock (because we ran out of room for another
2705          * extent) will violate ordering rules.
2706          *
2707          * Most of the time we'll only be seeing this 1 cluster at a time
2708          * anyway.
2709          *
2710          * Always lock for any unwritten extents - we might want to
2711          * add blocks during a split.
2712          */
2713         if (!num_free_extents ||
2714             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2715                 ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2716                 if (ret < 0) {
2717                         if (ret != -ENOSPC)
2718                                 mlog_errno(ret);
2719                         goto out;
2720                 }
2721         }
2722
2723         if (clusters_to_add == 0)
2724                 goto out;
2725
2726         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2727         if (ret < 0) {
2728                 if (ret != -ENOSPC)
2729                         mlog_errno(ret);
2730                 goto out;
2731         }
2732
2733 out:
2734         if (ret) {
2735                 if (*meta_ac) {
2736                         ocfs2_free_alloc_context(*meta_ac);
2737                         *meta_ac = NULL;
2738                 }
2739
2740                 /*
2741                  * We cannot have an error and a non null *data_ac.
2742                  */
2743         }
2744
2745         return ret;
2746 }
2747
2748 /*
2749  * Read the inode specified by blkno to get suballoc_slot and
2750  * suballoc_bit.
2751  */
2752 static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2753                                        u16 *suballoc_slot, u64 *group_blkno,
2754                                        u16 *suballoc_bit)
2755 {
2756         int status;
2757         struct buffer_head *inode_bh = NULL;
2758         struct ocfs2_dinode *inode_fe;
2759
2760         trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2761
2762         /* dirty read disk */
2763         status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2764         if (status < 0) {
2765                 mlog(ML_ERROR, "read block %llu failed %d\n",
2766                      (unsigned long long)blkno, status);
2767                 goto bail;
2768         }
2769
2770         inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2771         if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2772                 mlog(ML_ERROR, "invalid inode %llu requested\n",
2773                      (unsigned long long)blkno);
2774                 status = -EINVAL;
2775                 goto bail;
2776         }
2777
2778         if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2779             (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2780                 mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2781                      (unsigned long long)blkno,
2782                      (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2783                 status = -EINVAL;
2784                 goto bail;
2785         }
2786
2787         if (suballoc_slot)
2788                 *suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2789         if (suballoc_bit)
2790                 *suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2791         if (group_blkno)
2792                 *group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2793
2794 bail:
2795         brelse(inode_bh);
2796
2797         if (status)
2798                 mlog_errno(status);
2799         return status;
2800 }
2801
2802 /*
2803  * test whether bit is SET in allocator bitmap or not.  on success, 0
2804  * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2805  * is returned and *res is meaningless.  Call this after you have
2806  * cluster locked against suballoc, or you may get a result based on
2807  * non-up2date contents
2808  */
2809 static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2810                                    struct inode *suballoc,
2811                                    struct buffer_head *alloc_bh,
2812                                    u64 group_blkno, u64 blkno,
2813                                    u16 bit, int *res)
2814 {
2815         struct ocfs2_dinode *alloc_di;
2816         struct ocfs2_group_desc *group;
2817         struct buffer_head *group_bh = NULL;
2818         u64 bg_blkno;
2819         int status;
2820
2821         trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2822                                       (unsigned int)bit);
2823
2824         alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2825         if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2826                 mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2827                      (unsigned int)bit,
2828                      ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2829                 status = -EINVAL;
2830                 goto bail;
2831         }
2832
2833         bg_blkno = group_blkno ? group_blkno :
2834                    ocfs2_which_suballoc_group(blkno, bit);
2835         status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2836                                              &group_bh);
2837         if (status < 0) {
2838                 mlog(ML_ERROR, "read group %llu failed %d\n",
2839                      (unsigned long long)bg_blkno, status);
2840                 goto bail;
2841         }
2842
2843         group = (struct ocfs2_group_desc *) group_bh->b_data;
2844         *res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2845
2846 bail:
2847         brelse(group_bh);
2848
2849         if (status)
2850                 mlog_errno(status);
2851         return status;
2852 }
2853
2854 /*
2855  * Test if the bit representing this inode (blkno) is set in the
2856  * suballocator.
2857  *
2858  * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2859  *
2860  * In the event of failure, a negative value is returned and *res is
2861  * meaningless.
2862  *
2863  * Callers must make sure to hold nfs_sync_lock to prevent
2864  * ocfs2_delete_inode() on another node from accessing the same
2865  * suballocator concurrently.
2866  */
2867 int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2868 {
2869         int status;
2870         u64 group_blkno = 0;
2871         u16 suballoc_bit = 0, suballoc_slot = 0;
2872         struct inode *inode_alloc_inode;
2873         struct buffer_head *alloc_bh = NULL;
2874
2875         trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2876
2877         status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2878                                              &group_blkno, &suballoc_bit);
2879         if (status < 0) {
2880                 mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2881                 goto bail;
2882         }
2883
2884         inode_alloc_inode =
2885                 ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
2886                                             suballoc_slot);
2887         if (!inode_alloc_inode) {
2888                 /* the error code could be inaccurate, but we are not able to
2889                  * get the correct one. */
2890                 status = -EINVAL;
2891                 mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2892                      (u32)suballoc_slot);
2893                 goto bail;
2894         }
2895
2896         inode_lock(inode_alloc_inode);
2897         status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2898         if (status < 0) {
2899                 inode_unlock(inode_alloc_inode);
2900                 iput(inode_alloc_inode);
2901                 mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2902                      (u32)suballoc_slot, status);
2903                 goto bail;
2904         }
2905
2906         status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2907                                          group_blkno, blkno, suballoc_bit, res);
2908         if (status < 0)
2909                 mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2910
2911         ocfs2_inode_unlock(inode_alloc_inode, 0);
2912         inode_unlock(inode_alloc_inode);
2913
2914         iput(inode_alloc_inode);
2915         brelse(alloc_bh);
2916 bail:
2917         if (status)
2918                 mlog_errno(status);
2919         return status;
2920 }